Amicus Curiae Brief — DeForest Radio Co. v. General Elec. Co.

Pe Fo ae aes =

othe Radiological Sotiety 0 North ‘Américi*i is an asso-_

| ciation: of users of “X-ray: app ratus and the like, in con

2 edicine, . It has been active

.- in attempts. to improve ‘the. present X-ray tube trade con-

ditions and to secure relief from the present burdensome

- monopolies on apparatusand supplies useful in the prac-

‘tice of medicine. It is composed of upwards of thirteen”,

hundred leading mémbers of tize medical and teaching Se

| ~ professions, users of X-ray and radiological appliances,

~ each pf whom will, under the decision ‘and decree of the _

Court below in the instant ‘case, be subject. -to an exten-

5 sion of ‘the urden of a monopoly already too heavy for

8 the medical profession, and the public served thereby,, to“

bedr. It is a fact appearing in this record that the General See

Electric Company has already been enjoying patent.pro-.

tection on X-ray tubes since 1916, under the Coolidge ©

es ‘X-ray tube patent (Deft’s. Ex. 67, Rec., Vol. VI, pp. 1021--.

>, 1029), which protection will be extended for nearly ten &

years under the Langmuir patent, if the decree below is - :

permitted to stand fRec., Vol. I, p. 1281; this brief, pp.

87, 38). It will be apparent that each member of the pub- : #

_ lic treated by any appliances involving high vacuum tube

ee wit be subject‘to, the burden of this monopoly, although oF a.

“the General Electric Company has already reaped all the .

oo rds to which it is entitled by virtue of any invention

_ involved under the Coolidge patent. It is algo to be noted

- that it appears in this record that the Coolidge irivention —

. was — more e than. t coablgs Bax. of the — vacuum .

. refegved 4o above, and is. engaged: in research directed

toward obtaining relief from the‘ monopoly ofsthe Gen- “

eral Electric Company in this field. The effect 6f the a

decree below ‘is to.permit the blanketing of all this work as

, Sy a patent. issued more than twelve years after the stated —

date of conception’ of the alleged invention.

_ In addition to the effect of the decree, below upon 5 the : a

: X-ray field, it has a: ‘Serious and far-réaching effect upon ae

the field of radio communication and the’ public served

thereby, as will appear from the following: _ is

This Court (Westinghouse v. DeForést, 278 U. S. 562)

has held the DeForest patents, Nos. 1,507,016 and 1,507,017,

to cover basic inventions of DeForest, and has thus made 2

ownership of rights undér these patents a necessary. pre-

requisite to the manufacture of vacuum tube transmitting ;

apparatus, which is essential in modern commercial radio. - ;

transmission. It is impossible to compete commercially

in the field. of radio communication witiont operating ;

> rights unler these patents. o. a

‘« The only person outside of the so-called Radio Cacia :

ration group (which includes the General. Electric Com-

_° pany among others) and the petitidner herein that owns © es 3

. rights under the DeForest patents is the Federal Tele-

- graph Company. In fact, the rights owned by the Federal

| Telegraph Company under these DéForest patents are

.|* broader in scope than those held by any individual mem-

“ber of the Radio Corporation group and even broader

‘than those held by the DeForest Company, the petitioner 3 4

herein, The Radio‘ Corporation: ‘and the Federal Com- .

_ "pany are the only two persons holding rights under the

eS, _ DeForest patents in the field’ of Tadio er com~- : - |

_ Miunication for tolls. See

It is, therefore, upon, the F. ederal Telegraph Cinna oS

so tet es ee of the _— for a oo mes

wv. 3 . i? eo ae

3

$

7

:

ahs ,

_ radio comimunication rests and, in. fact, it is due. to the —

a _ Federal Telegraph Company, and the rights that it holds.

- under these DeForest patents, that the Radio Corporation

is now subject to the competition of such a system. The °

' rights of the F ederal Telegraph Company are being exer- _

/-- __ ¢ised by it in the manufacture and sale of tommunication =

: material and by. the purchaser of such material,’ The ae

Mackay Radio and Telegraph: Company, a controlled com: | re

pany of the International Telephone & Telegraph Corpo- :

- Fation,;in the operation of, its radio system. The. public

eee thus gravely interested in the perpetuation of the @x-

_ - . isting competitive conditions and therefore in. the con-

tinued operation of the Heciern} eres and its cus- ee

tomers. . She

The decree of the Court heen. would have the effect’ ae

of. depriving the Federal Company and the users of its —

_. @pparatus of the right to compete with, and of putting a

: monopoly on radio communication into the hands‘of the

owners of righis under the Langmuir patent—that is,into os

| the. hands.of the General Electric Company and of,its as-

ae iated Companies, particolarty 1 The Radio Pei badass 3s

ms ae : It is soneedediy. impossible to carry on nibdern. dio’

_. communication without high vacuum. ‘tubes, dnd bin

the invention attributed to Langmuir by the Third os

_ Court of Appeals upon the p-hearing is held to be|this.

__: precise thing without limitation, the entire art will *

the mercy of Langmuir’s assignee. The effect of such

action upon the Federal Telegraph Company and users —

of its communication apparatus is clear, also the ©

ee effect upon the other parties to this: brief Sea the

ape each of them serves. :

3 _ Aside from its effect upon each of th parties to ‘thls

Danae coe

es

*

oe would. be far-reaching. Not gra would all posi

hands of the Radio Corporation and its associates a com- :

upon the rehearing in the Circuit Court of Appeals and °

ae adopted by Judge Burrincton, speaking for: the majority

Of ramet Court, is as follows (44 Fed. 2nd, si at p. (87): t

‘mercial radio telegraphic communication be delivered ,

into the hands of the Radio Corporation and the entire

X-ray tube art be delivered into the hands of the General

_ Electric Company, but in addition to this, and as spat ted ;

below, darge numbers of persons not directly affected by ne

these considerations would feel the result of this decision. a

The patent is held by’ the decree below to cover the a

- so-called vacuum: tube used in every radio broadcasting eee

receiving set and in every apparatus for radio communi-

cation. The result of this decree would be to put into. the |

_ plete monopoly over the vital part of all of such radio

- apparatus and permit it to exact tribute from almost.

every family in-the United States. :

‘Except upen the ‘payment of burdensome rveltion: no

manufacturer could build tubes especially suited to his.

product, and. all communication systems, such as those

used on airplanes, ships and elsewhere, including those of

-the army and Navy, would be: subject to ca —

Counsel signing this briet, appearing on behalf oa

parties named above, have, therefore, asked leave to sub-

mit this brief, presenting their. argument int support of

"the prayer of the petitiwner that the decree of the Court

below be. gata e and ae decree of the Trial Count. ~— :

"SUMMARY OF ARGUMENT. : a

The definition of the inyention suggested by respondent .

e ; “But a vacuum, or, indeed, change of vacuum, =

isolated and staliding by itself, isnot the Langmuir

invention, but it is a -working tube.in which all the |

-. elements, cathode, plate, vacuum, so co-ordinate __

me and inter-work that current flow is not * * **- =

Bictee.,

< objectionably affected by gas. Jus

of vacuum shall be is ént on several eléments ~

rigueoae nnot be exactly stated. In that re- _

Ee gare nese says: “The evacuation of

the device should be preferably carried to a pres-

sure as low as-a few hundredths of a micron, or

even wee 8S Fo ‘

Counsel, in. this brief, ‘contend:

a

a . The invention, so defined, ESE ernie

(A) the definition lacks invention over the prior art Be:

fe acknowledged i in the patent, and (B) it differs neu Ses

in degree therefrom. © :

A. The patent in suit ichnasdabaoes the Fleming tube ye

- and the DeForest tube. - Like the Langmuir tube, both a are

hot cathode, electron discharge tubes. -— >

Fleming operates below ionization <ciiaiien sad hence”,

me ae without oaselt fompantton effects. and a a Purely, electron ee

cee flow. : ee

Ss * ~ DeForest, pe: ahve Siiinaticls ‘voltages. The o

act indication taking place in his tube affects the current flow,

in some respects objectionably. By the theory. of ioniza-—

_ tion, it was understood that. ionization could be reduced:

el redu: nes the. a ‘content Sebi the vacuum) in the nt

a se ‘the vacuum (reduce the gas content) when it was

es een to > reduce the ionization, and to ) make t ‘ace com-

a ipeusaling: hanes in current t andjog voltage to © secure

S Rare “ desired result. Se See

ei = s » BR Furthermore the tube of the patties differs from an”

€ ' Fleming and the DeForest tubes merely in the degree cele

3 vacuum, — &

‘This was admitted by reationden before the Coutt | =

Appeals. poo

And the result of ak diffe erence in atone was unk new. =

" To the man skilled in the art it was the to-be-expected -_

“result. According: to, Hogan, respondent's expert, there i is

‘no sudden beginning. or sudden stoppage of ionization —

with changes in the gas pressure. The ionization changes

_ gradually with the gas pressure. The discharge changes

correspondingly from one materially affected by ioniza-

; tion to one not objectionably. so affected, i. e., a pure o

: electron discharge according: to Langmuir’s terminology. « :

> Henve there is no new result in the reduction of ionization - ~ iS

-. with reduction of gas _hy raising of vacuum. The alleged =

invention of the definition i is a mere difference in degree,

~and there: being no new tora. — is n0_ at es

‘subject-matter, :

: SE each other and of Langmuir, pear eens

attained by Langmuir, as the thing sbvious t to one De

Mae skilled in the art. “‘Thibir ets lie art :

eee of invention; | Bee

“DeForest, in July and. early. ca 1912 ‘hee in yey aS

employ of Federal Telegraph Company), ‘when confronted _ 3

| by the necessity of avoiding excessive pales oar

_ the further evacuation of his tubes and succeeded

_ securing satisfactory operation; without objectionable

ee

he Sits o >

Aus +

Fee Oy

eae

4

3 3

ienieation effects at einen within the range specifjed by ue :

" the patent (materially above ionization voltages). oe

.. Arnold, ea November 1, 1912, did exactly the’ same

We PO end with an entire apeerrietion, of the scientific

principle involved.

Since these two men were able to sonal airs

result by the application of the skill of their calling, their

“acts lie athwart a finding of invention, as Judge Morris

‘ichos it. Aol °

ae 3. intatias the definition of the invention adopted

__ by. the Court below,’ we ® find that exact thing in the

prior art. |

Three workers in 1 the art did the exact thing prior to

ame weancl

ee ft) J.E. Lilienfeld i in his 1910. paper : iekactds to

anor ~ by Judge Morris and Judge Woottey) described’

ce Saas a ‘tube and a process, wherein and whereby he at-

ee tained the invention of the definition with substan-

Pee sg - tial ideatity. Such identity is: admitted by Lang-

a muir. The date is fixed by the publication and soe

2) 6 ices in his 1912 tirbe, referted to under

Point 2 of this brief, did the exact thing of the

be patent.

Gis a he iaasibity ie Weukeds beth es s accepted: by the

itd District Court and by Judge Woo.tey in the Court :

of Appeals; and is not mentioned by ec Bur-

~ Thealate i is fixed by the eles. :

(3) Arnold also did the exact thing as ss ie

; ee Point 2. The identity is practically admitted,

cree accepted by ne panes Morris and Ie aA

af “The date is k Fontedted, but, we submit, i is Proven.

ig:

Hise: ie Aisi these: instances of prior xniuléigs is

_andyor use where the identity is clearly shown, and the se

dates admitted or established by controlling evidence.

Each instance isa complete statutory bar to the pales:

ofa patent, éyen acimiitting patentability -en we do :

“* not. ee ne ae ere:

4. ‘The alleged invention is nothing more ek a iii

ment of the physical principle of pure electron dis-

_ charge and therefore ‘not patentable, Ree e

Claim 9 is broad Seay to cover a modern X-ray tube, Baie

- such as the Lilienfeld tube or ‘the Coolidge tube. The me

Lilienfeld. tube is admittedly the same as the Coolidge a

RS MEA

tube within the purview of this patent.

' The Coolidge X-ray tube is or covered) by the

- patent in suit.

But-in the Loolidge hie there i is edmittely 9 no space eee

charge effect. eras:

Nor does the 3/2 power law hold. -

Nor is the straight line logarithmic plot obtained d by ui

‘plotting the discharge of the Coolidge tube. -

All these phenomena are set-out in the patent as s tests : L

for the presence of the invention. |

But they are not present in the X-ray ee claimed to”

ae ” be covered by the invéntion.

_ Hence, the so-called “earmarks”. do not. ‘dels the

_ invention as applied to such a tube. They are, Ceneteey,

| not of the essence of the invention. Re

There is nothing left of the invention but a tbe |

evacuated so as to operate with a pure. electron ahaa

_acegrding to the circumstance of its use, without other —

ee : ‘ _ limitation than that the voltages. applied shall be above |

| voltages. This limitation. merely differentiates —

= 2 pd — — and is not patentable,

¥

. : from Fleming. The alleged invention is a mere ee

; x *

‘ : ’ 3

ye yy * + -

bed — ‘6, i 12

\ » 4 ~ ri ‘ ’ .

. 5) i A ;

o* * eee)

ne oo 5. -Langmuir’s only practical application of the prin- ie

Ne ie ciple of pure electron discharge was to the De-

ae x Forest tube.: This. application was anticipated by os

_ *\+ both DeForest and Arnold, Hence claims directed

1 to this use are void.” -— |

- Langmuir did not conceive this spplicitiole of the prin-

- ciple ‘until March-21, 1913. This is shown by his note book.

, Both DeForest and Arnold had made this application i in 58

1912 i ~ a

Even if this SS Sas were eee (which ii is) ee

* not), it was barred to Langmuir by the earlier neenienes ee

and/or use of DeForest and Arnold.

oA: ‘The invention, as defined ane the Cieek bulow. ee.

a e is unpatentable, because (A) the definition lacks .,

invention over the prior art acknowledged i in the

| ee ot it differs only in degree therefrom. :

= (A) The deGnition lacks invention over the prior art a

* acknowledged in the patent. aXe ‘ coe

The atent ih suit (PIff’s. Ex. 1, Rec., ‘Vol. IV, pp. 4: @

to 10) States (p. 1, Il. 16-16) that in the tube of the patent

_ the. electric current is carried: by electrons. emanating

from t ‘cathode, _independently of gaseous iGnization,

and | rentiates thereby from the prior art tubes. a

‘The iibeiney of ionization is set forth (p. 1. 34: to 75) oo

ees which it-appears that when a definite amount of gas. foe

sent in a tube, qvoltage of, say, 25 volts \ cause .

molecules to be split up into ions per | eetrons,

iF hrough “the action and shieractibe 3 f the .

ons” conduction of current across the t

| Nee 1 3

~

.

a : Fleming tube (valve) arid the DeForest tube {audion),

ue Both were hot: cathode electron discharge tubes. The

: = | patentee says (p. 4 .. re hae VAR Ae : |

coe ~ “Another ischarge device seevlonie. ue to igh

. some extent -was the Fleming valve. .:This was a’.

1 “two-electrode tube which, so far as. I’ am aware,

ce -. was always used at ‘voltages well below the volt- :

— ° ages at which positive ionization by: collision oc- ~~

wie curs. It was not evacuated in such a manner as to

permit it to be used at voltages materially above

these ionization voltages: without “is BE ‘sub-

stantial Positive ionization effects.” ag

@

4

ie The sadn ¢ of DeForest is described in the patent 0. ithe

_ 1,1677-92): Seer is ea

ae hee “The phenomena above deacribied + Vita Cian 3

acteristic of devices involving gas ionization are .

taken advantage of in an incandescent cathode de-

_ vice with three electrodes known as the ‘Audion’ —

‘This device has been used as a receiver for radio-

telegraphy and depends in its operation. upon the

rapid change of the discharge current when gas.

... fonization begins. This point depends upon vari-

-. ous accidental conditions which cause such irregu-

larities in the operation of various devices’ appar-

| ently identical that sometimes only one of a con-

+ siderable number can be used. Ordinarily the gas

jonization in the audion begins to be = 7

| — between 20 and ge volts.” i s

iS

od ba the ionization. voltages and thus without aid

. He could-have had ng such aid since no =

puld have occurred.. He was operating with —__

thode from which the electrons emanated and

°

The patent recognizes the prior existence of both the

neces

4

‘were drawn over to the anode by the voltage applied at as

_ the anode. ‘This was‘then purely an electronic flow, but. ibs

“helow the ionization voltages rather than materially’

_ higher as claimed by Langmuir. |

“That it was withip thé®knowledge of the art that Flem-

ing had a purely electronic flow, is shown by Fleming’s

article in the Scientific American, publighed in 19067 in —

which itis said (Rec., Vol. V, pp. 168, 170, 171):

oe “© -«* * * high vacuum may be a very good con-

‘/ ductor, provided that the negative electrode is.ren-

dered incandescent. This shows that the obstruc-

es i

oe e

a tion which a high vacuum offers to the passage of

ee __ , electricity is not due to the mere reduction of the

rd matter in the space (that is, to the_rarefaction of = >

the gas), but is, in some way or other, largely de-

pendent upon the temperature of the electrodes;

the resistance to the passage of electricity through

>... "vacuum can be rendered very small by intensely

BRB oc 2 pore the negative electrode.

If we take measurements of the current passing

.» through the vacuum when the negative electrode is

an incandescent carbon filament and the other & ‘

* cold metal plate, and, at thie same time, measure =)

‘difference of potential between the electrodes, we

_. find that the conductivity, as measured by the ratio

_- of current to voltage, is not constant, but varies . A

renee — the electromotive force. mere

eA * - * . * *

Re Mi de sha cine Ser Ea mass when |

- + gold, because if they did they would leave it posi- —

Be tively, electrified. If, on the other hand, we elec-

rit + the mass negatively to a high potential and

se it to a high temperature, electrons can escape _

eely from it. In every mass of matter there is |

at we may call a certain ‘electronic —

=

0-

15.

SS \

‘ \

2 \

hence, it follows that the resistance which a high

- vacuum offers to the passagevf el

it is, in fact, the resistance which is offered to the te ae

ejection or drawing out of electroné’ fix : the Co

' face of the electrodes? RTA Bivins é

re

Since Fleming shows a pure electronglischarge passing

_ from the hot cathode to the anode when operated below id

ionization voltages, and DeForest shows objectionable

effects of ionization, in substantially

tube, when operated above ionizating- volt "s it is the fe

contention of this brief that the

ionization i in the DeForest tube while still operating above AS

the ionization voltages, by reducing the ga3-content (rais-.

ing the vacuum) of the tube. He knew “haw to raise the’ a

vacuum before Langmuir (Petitioner's Brief, pp. 21-25).

So it was within the skill of the calling to avoid the ob-

jectionable effects of gas by raising the vacuum. Tile,

we contend, is abundantly shown by ‘the record. .. ee

‘Respondent’s expert, Mr. Hogan, testified that the «;

vacuum in the Fleming valve and in the DeForest audion _

is of the same order—about 1 to 10 microns for the

. ‘Fleming tube and-5 to 10 microns for the DeForest tube

_(Rec., Vol. III,*pp. 1660, 1677, 1682). . a

In the extract from the patent quoted asinine Lengrcate! ate

describes the operation of the DeForest audion as due to

“the rapid change of the discharge current when. gas ioni- ;

gation begins.” This‘ls an error. The operation is in fact .

due.to the rapid change of the discharge current when

the voltage epplied to the tube is changed, exactly as in |

_ the Langmuir tube. “However, the discharge current in| _

- the early DeForest tube, to which Langmuir is"here re-

___ ferring, is admittedly increased by the effect of ioniza nate oa

and this ie eaciaation oe causes # irregularities ,

oe

cea}

t

oes eee Te

ie sede RS

ye operation of the tube and: limits its usefulness. For the. A

-@. _. purposes. of this section .of the brief, therefore, we shall =~

~~ accept Langmuir’s description of the operation of the oe: ee

Se - Forest’ tube as substantix!'y eorrech. oe ee

. When in the DeForest tube the voltage apulied s was,

say, 25 volts, the gas in the tube, according to the theory, © | __

« was ionized ‘(Langmuir, Rec., Vol. II, p. 1246), and the*

3. +. fons resulting therefrom, by their interaction therewith, —

caused additional electrons to flow to. the anade: This |.

resulted, in greater current (Langmuir, Reg., Vol. TL p.. |

1242), ‘which’ “was taken’ advantage. of in a manner de-. = -

pendent ‘upon ‘the uses to which. the tube was to be put.

, For our porpoers here, we may disregard. the pervceise ee

/ use of the tube. ae oe

> + .So-long as the amount of, ioniaation remained ‘within aS

5 definite limits, the tube functioned satisfactorily. But if.

too much ionization took place, iit began to, affect the use-.

, » fulness of the tube (Langmuir, Rec., Vol. Il, p. 1242). |

From the theory of ionization: expressed in. the patent a ae 4

(p 1, ll. 40-56; Rec,, Vol: IV, p. 2), it is clear that too much ie

ionization could and would be cured by reducing the “ .

amount of gas in the tube (raising the vacuum), other . —

things remaining constant (Langmuir, Rec., Vol. II, p.

& . 1243). Oe RoR :

~s. With the Ss cehiibae that a pure electronic discharge

would flow with asdefinite voltage and current (as in the

. Flemirig valve), and the further knowledge that the

_— amount of ionization at a higher voltage could be reduced

_ ‘by reducing the amount df gas present in the tube, was it

‘not within the skill of the calling, the necessity oa

_-Sarose, to conclude that a pure ‘discharge with-°

out objectionable ionizatiop effects could be secuted at

r ‘voltages {above the normal ionization voltages) by —

rivin, : the retition of the: gas to the point where. no |

“S

3 7 ae

: harmful canon of ionization under oe conditions of €:

operation took place? ae

Let us see what the man skilled in the art saat have

- done if he had been handed a DeForest tube, with the

a ee

‘request to eliminate its erratic characteristics ware at, :

the same time increasing its power output. FP figer :

Such'a person would have observed at once, upon op- _ G,

_erating the DeForest tube, that its erratic operation was

dug to ionization of the gas in the tube (Langmuir, Rec, §§

Vol. Ii, p. 1242; Arnold, Rec., Vol. I, p. 559). From his ogee

e work with the Fleming tube, he would know that joniza- ne

. tion is not necessary to permit a current to flow ina .

vacuum from a hot cathode to an anode. vor his knowl-

e edge of the electron theory, he would know that the flow a5

‘of current in both the Fleming and the DeForest tubes

is made up. of electrons, emitted from the hot cathode .

and passing to’ the anode’ under the attractive infl

of the voltage applied to the anode. - He would sheets ota

ve no hesitation in removing: the ionization,’ on the

of stopping the electron flow. Further; he would

oe that the amount of ionization, other conditions be- _

ing equal, depends upon the amount of gas present, and

that the amount of ionization can be reduced by reducing’ -

the gas content. His first thought would therefore have ®.

, been further to evacuate the tube and thus to reduce the

' ionization in the DeForest tube4o the point where e if.was ae

not harmful. - . .

He would then consider the effect on the power output

__ of the tube caused by reducing the amount of ionization.

_ The power.output is the product of the current flowing si

cope sheiprttinae Asami! ~

\ pileodbeaect anode.. . He would know that the current -

—— the DeForest tube, ordinarily, was in--

send Gerth wing In th ace tn)

: by reason of the presence of the positive ions in the tube

-. proving the. operation of the DeForest tube and also in- -

creasing its power output, he would know that he must

apply higher yoltages to the anode in order to draw more

v

rent at or above its former value—<since he had reduced:

the. current for a given. voltage when he removed r

Se aS : 18

between the cathode and the anode. He would know,

he would also reduce the current, assuming other condi-

tions to remain the same. As his problem called for im-

- therefore, that as he reduced the ionization in the tube, a

electrons over to the anode, and thus maintain the cur- |

effect of ionization.

ae The power output being the pidoddnct of the voltage aaa

- the current, as stated above, it will be apparent that if

the voltage be increased sufficiently to bring the current

up to the value it ‘had before the increase ‘ip-the vacuum,

the power output of the tube will have been increased.

‘And any further increase in the voltage, with the conse- a

quent increase in current, will result in a corresponding :

ri increase in power output. :

. But it may be queried: Will not the iacvelnane voltage

and current again incPease the amount of iqnization and

put the tube back in the former condition of harmful

_*donization effect? In order to answer this, we must con-. *

sider Lric“ty, the causes: governing the amount of ioniza- |

_ tion.“ ionization js due to-collisions between electrons

‘and gas molecules; so anything that tends to decrease the _

_ probability of such collisions will tend to decrease the ©

"amount of ionizaticn, and vice versa. For the purpdses _

a we this. case, we may disregard the minor influences of _

-

tic | of the.electrons and of the gas molecules, S

consider merely the effect of thé number of electrons

and. of gas molecules: present in the space between the:

19

_ number of electrons will tend te increase the nun- —

ber of collisions, and‘a decrease in the number of’ gas

‘molecules will tend to decrease the number of colli-

sions. Hence the ionizing effect: of any increase in the

number of electrons (i. e., an incréase. in the -¢urrent __

flowing) due to an increase in the applied voltage, . may

be overeame by a suitable reduction in the number of -

gas molecules (i. e., an increase in the degree. of vacuum).

Thus we see that a worker skilled in the art would appre-

ciate that he would. merely have to increase his vacuum

sufficiently to keep the amount of ionization below the »

harmful limits for the desired conditions of operation, —

By way of illustration, let us assume that the current

| flowing in ‘the DeForest tube, which was the starting

‘point of our skilled worker, .was ample for the purposes

desired (as indeed it would be for many uses of the mod-

. ern high vacuum tubes even today). x then we increase

the vacuum, resulting in. a dccreasé @ ionization. and,

thus, in current; and, fterwards increase the voltage to

_ bring the current up pnly to its former. value; there will

have been no. ne¢ increase in the number of electrons.

There will, however, have been a decrease in the num-

ber of gas molecules, and, therefore, a decrease in the

amount of ionization over that obtaining originally in

'. the tube. Furthermore, there will have been an increase __

in the power output of the tube, sincef though. there has. 2

been ho net change in the current, there has been an in- we : |

_ Pease in the voltage, and hence in their product. We oe

_ ‘see, therefore, how simply a man skilled i in the art could _ §

- imerease the power output of a DeForest tube and at te |

_ same time eliminate its erratic characteristics by reduc- e :

be ing the amount of ionization. |

‘There is no invention here over the prior art. The :

= skilled = has ccaaalenss oe known ee

Mi: : - 2. ; on : i

on (By The definition dikers only in. ares from the

oe prior art, acknowledged in the patent. 3

ae Furthermore the ‘tube of the ‘patent. differs fei the

ae Fleming: -and the Deforest tubes merely in the degree of

‘. Vacuum obtaining in the tube. It was categorically ad-—

' ‘mitted by respondent that the oniy difference between.

___ the DeForest tube and the Langmuir tube was that in the

‘ . latter the gas had béen reduced to a pressure of a few.

thousandths of a micron. This admission appears in its i

brief before the Court of ‘Aepe at the. first hearing, ee

° ae

ae as s follows (p. 30): :

“On the other hand, the invention ass be at

. - ized by ‘producing and maintaining’ , as the Dis-

“trict Court put it, a pressure of a few thousandths :

-of a micron in a DeForest audioh.” "

ve There is no hie here to siraciure.: or: geometry, 7

because all of this is admittedly preent in the mies De-

: Forest tube. cate eo

A mere difference in Sdegtes is not patenteble, : unless oe

é “soni new and unexpected result is obtained. As we un- .

_dersiand respondent's position, it, contends that Lang- _

muir obtained, by reason of this increase of vacuum, a —

ir ectron flow substan unaffected by ionization

| | othe ionizing voltages, ne :

ee a RE (ps B tg pe

_ siastnguace sabsaalactsce me

pure electron discharge. The'mere statement of this,

that there is no Aifference in kind. It is a mere difference

: : charge—it is always an electronic discharge—it “differs _

* only in the degree to which it is affected by the beet

. zation changing with changing vacuum.

Mo new or tnexpected result was secured, there is no

Ee. —— ssc necihomgare! present and the — is void.

_- pure ‘electron flow as s bbtained sak defined by”

- (this brief, pp. 24-25). As, Mr. Hogan, respondent's

testified on direct examination (Rec., Vol. TH, P. 1722) ;

; “if we leave the ‘voltage the same ’and: the elec-

tron current the same, and gradually increase the

pre sure, the gas pressure in the tube, the ioniza-

tion in the tube will gradually increase. As we

se hae all recognized, there is some measurable ioni-

“' gation, even below points at which ionization

.harmfully affects the space charge. There is no - _

sudden beginning or sudden Da tine of eolenes. foe

as a — fact.”

Cciieacts. as ‘the gas pressure in a DeForest. tube is.

gradually reduced (vacuum gradually increased), the .

amount of ionization will be gradually reduced until fin-

ally and inevitably we reach a point where. the current _

flow is no longer objectionably affected by ionization. At

this point we have a Langmuir tube operating with a

gradual change in cause and effect shows conclusively

in degree of vacuum, and the same thing is equally true es ; :

as to the discharge. There is no difference in kind of dis-

Since the alleged invention differs only in degiet ant:

22

2: DeForest and Arnold, working independently ©

. of each other and of Langmuir, arrived at the result)

_? attained by Langmuir, as the thing obvious to one

skilled in the art.. ae. acts lie athwart a ean Bai

of invention.

_*" DeForest in 1912 was employed by the Federal Tele-

graph Company, which .at that time was operating a

commercial radio telegraph service on the Pacific Coast _

_ » (Rec., Vol. I, p, 1050). Its service-demanded ‘the best —

- available apparatus, and DeForest, Among others, was: °

_. employed to perfect this service (Rec: ‘Vol. II, p. 1045).°

_. Federal Telegraph Company in 1912-was employing De-

Forest tubes in amplifiers used in connection with high

| speed recording apparatus. in its commercial work (Rec., —

-Val.-Il, pp. 1045, 1046, 1051).

In 1912, DeForest was confronted with a situation in

which he found his tubes, in commercial ‘operation,

_ showing the effects of too much ionization. He knew at

once that he needed to reduce the amount. of gas present.

‘So he ordered these tubes evacuated to a higher degree

. (Rec., Vol. I, pp. 1052, 1059). As a result of such further

_*. evacuation, he was able to apply a higher. ‘voltage and =

secured a result substantially iree from | ton 3

ionization effects. . f me.

_: . The record contains contemp rary ‘writles evidetine of ae

cn DeForest’s desire for a higher vacuum in his tubes and —

__ of the improved results obtained thereby.- Under date

© Of July 26, 1912, DeForest wrote to the McCandless Com-

pany (which was then: manufacturing DeForest tubes

for the Federal Telegraph Company) as follows: — 2 =

ae “Out of the last lot of 24 audion bulbs which you”

eC en oe thee are gly 6 at eee

: a

to proper sensitiveness test. @ ppaiity the

vacuum in the other bulbs is too low, because in

these latter bulbs we notice that the blue are or

cathode beant starts suddenly at 15 or 20 volts, a

“under which condition the bulb is not sensitive” ee

(Deft’s. Ex. 79-A, Rec. Vol. Bele p. 1061). Reena

ours.)

- Shortly thereafter, on Agen 4 14, 1912, DeForest wrote ie

abate. to the McCandless Company. saying:

“We took two of the poorest of the dincantea 20 ie me

a San Francisco glass-blower, unknown to fame,

~—and-had him exhaust same to as high a vacuum as)”

- his pumps would take, These reexhausted bulbs ie

. how show a sensitiveness.equal to. those ef the

first four, which proves. conclusively that our ‘con-

_ tention is correct. For the work which we demand —

from these bulbs they are not sufficiently sensitive—.

‘and we would be glad therefore if you will reex-

_ haust them. You.certainly should be able to put — a

them: in as good condition as the aforesaid San *

|, Francisco glass-blower” (Deft's, Ex. 70-8, Rec, a

Ree Bh 3 Vi, P- 1062). easier ours.) - ,

: The wtiitence is clear that’ these tubes, re-evacuated z =

> by the San Francisco glass-blower (Lamont by name), 6

= used by the Federal Telegraph Company in its com-

mercial ‘operations at voltages running up to 54 volts § a

- (Tuel, Rec., Vol. II, p. 1052). There is also testimony that

an amateur named Hewlett used similar tubes, evacuated . oe

by Lamont, at voltages: in excess tod 60 volts: (Hewlett, os

; - Ree., Vol. I, p. 1008).

Naturally. enough, no evidence: was avalinble as is the Sieg |

aes so-called “earmarks” or characteristics of the discharges _ - |

: in these Lamont ‘tubes. These workers were not hunting : is

for material.to put in patent applications. They knew ee

there was ee eneoeeys here. Lamont and bdo

oe however, testified in detail (Lamont; Rec,, Vol Il, p. 1027,

et seq.) as to the thoroughness of their evacuation, which

os :

24

followed in large part the procedure subsequently recom- -

ee mended by Langmuir (Lamont, Rec; Vol. If, pp.. 1029,

ii 1030). It:was undoubtedly proven (Tuel, Rec., Vol. II, p.

1053; Watkins, Rec., Vol. Il, p. 1055). that “the tubes. oper-

:' ated satisfactorily at the voltages mentioned. These

: voltages are not Ohly “materially. above ionization volt-

ages” but are considerably above the lower limit of 40

volts set by Langmuir for his invention in claim 26 of :

his patent. |

“It is clear from. the secavd ‘that since eens ‘tubes op-

erated. satisfactorily at these high voltages, they must. |

have operated without. harmfui ionization (Langmuir, ©

Rec., Vol. II, p. 1263; Hogan, Rec., Vol. I, p. 97, Vol. Il, .

pp. 1713, 1714). As. satisfactory operation is the only

- essential test of. the presence of the Langmuir invention

(Langmuir, Rec., Vol. II, Q200, particularly pp. 1239-1240),

. these tubes had the ‘discharge of the Langmuir tube. - Dr:

) Langmuir defined) a pure electron discharge, the presence

. of which respondent contends evidences a lange tube,

as ic forws Rec. Vol. IL, p-. 1350) :

“Of course, the word. pure is always a relative

term which denotes a comparison between one

thing and another. When I talk of pure electron”

3 discharge I have usually meant a discharge in which :

_ the effects of ionization do not materially influence __

the usefulness or characteristics of the device as

"+ Gt-is to be used. That is what I — we os .

mean by cmaee

Re Pe aoe ‘ + a 2.

“As I understand the eed pure it means. free

from harmful. ingredients or harmful effects and

ae | of course that necessarily implies that the very —

; gauss -usaaesb means harmful ‘for some ss

eo

é

ie

’ bs s .

25 ee

A ‘ é %

oe crs Sinise occurs in all enbies at volo

- materi ly above the ionizing voltage. So to some >

extent no electron discharge can be absolutely pure.

_ There will always be some ionization. So that by —

the word pure we necessarily mean free from ioni-_

zation to an extent that is such that the. ionization

bring about no ‘ul or deleterious ation.”

“DeForest in his 1912 tube; $ secured | a vacuum such that

the ionization present brought about no harmful or dele-

- terious action, and may, therefore, properly be said 80:

~ have arrived at the same oy se did Langmuir in the

alleged invention. of the patent. Se

It certainly did not amount to invention for. Ledgonie

subsequently to discover. and set down the “earmarks” Of

_ characteristics of that tube. This is a. -mere matter of =

_ scientific observation. | piss INE eee ee

aes

Arxold. 3

On November 1,. 1912, Arnold did exactly the hing that

~ DeForest had done earlier in the same year. He was

shown a DeForest audion that amplified weak telephone

_ currents beautifully at low voltages, and functioned at

those. low voltages, without harmful ionization - (Arnold, |.

: = Vol. I, pp. 855, 556, 567); but the currents were distorted < aig

“and the tube failed to function i ina suitable manner when ©

~ higher voltages (higher Power outputs) were attempted |

. (Arnold, Rec., Vol. I, p. 560)“: He was asked how the

tube could be made to ‘operate properly as a telephone,‘ ‘

“ amplifier at the higher powers’ necessary in telephone — f ’

| ~ work, Although he had never before seen an audion, he |

ae a was acquainted with it from the literature (Arnold, Rec, |

- Voi: I, p. 556), and. he at once responded that: the ‘diffi- - . |

oe ‘culties experienced were due to ionization of the residual _ . |

f as, and that the difficulties could be eliminated and the | =

A Ne *

q

:

he vacuum, (Arnold, Rec., Vol. I, p. 559). He also made

(hvala, Bec, Vol. I, p. 557). : Ct, os

_ Arnold was the representative’“man skilled in the art”,

3 ‘ot whom we have spoken heretofore, and his reasoning __

‘and his conduct were exactly those that we described

oe fit brief, ‘pp. 17 to 19) as to be expected of

about this idea. As stated by Judge Monnis in the Dis-

a aS

| ee een rae 1, 1912, and saw it in at

QP

reduced until it was biaomléed by. increasing

E arcttns, principally directéd - to airy the

It did not occur to, him that he had made.

or that there was anything patentably new

Cy

“Moreover, the fact that falls but little short of

a demonstration that the employment of the known. .

pure electron discharge above ionization facie

in tubes of the DeForest type was but the avail-

‘ment of those skilled in, the:art of the store of

-knowledge that had been accumulated and: lay

. ready at hand is that when Arnold, who had had

_ Jong experience with electrical. discharges in high —

- vacuum,, ‘was shown a DeForest audion for the first —

+s

Like DeForest, pate appreciated ie once ‘that t6. 1S€

higher voltages and thus obtain increased power, he must

employ a higher vacuum. Arnold probably knéw more

than DeForest about the underlying principles of opera-

- tion of the tube, since the latter was more of an experi-

menter.and perhaps not as highly a trained sas

‘Arnold. But both men reached identically the same |

aa, and both considered the increase in the vac-

* uum as merely a manufacturing expedient t fit the tube ©

to the desired use. Both knew that the higher the voltage

“tobe applied, the higher the vacuum ‘should be, ’ Very

S tiheely’ DeForest had no full realization of. the: extent to.

which the improvement in vacuum and the correspond- _

ing improvement of the tube could be carried, but he ©

. Revertheless guicceeded in obtaining a tube of the pee

“that was satisfactory for his then purpose. Arnold, .on

the other hand, fully appreciated the electrical hentiie

ena involved, and was able forthwith t6 carry the thought ;

‘to its logical conclusion of substantial oe be ion-

ization. sees ai

. On the strength of his recommendation, oe ; = els =e |

: i “once authorized by his superiors to

be é

oe ae

re wee .

.

¥ | The inreaed vacuunt, was obtained at by ‘athe ee

tube and repumping it, but simply by using the phenom- .

ena of “clean-up,” already familiar from’ imcandeseent

”‘Jamp practice (Arnold, Rec., Vol. 1, pp. 596, 597, 602).

hea tube completely demonstt yted ‘the carrectness ot’

Arnold’s conclusions, and left him free to. proceed with.

.., the problems of i improving the mechanical design and life

” pf the tube’and fitting it into the existing telephone net- .

work, It also makes» ‘it unnecessary for us to consider

his later work, since we are interested: only in showing

_ that he did a thing obvious to one skilled in the art, and

hence unpatentable. Since what Arnold did, in the exer-,

cisé of the skill of his calling, was exactly the sum total _

of Langmuir’s accomplishmext, it follows thet the Lang- j,

muir patent.is void for want of invention: -

asec

“the use obthe term hgos conduction” has ne lai the

discussion of this point <

. any material extent, . We shall pass, for the prsasricee

: _ question whether the differences between the Langmuir

tube and the early DeForest tube amount to inventions -

and we look to the prior art for that which has the sub-

stantial identity of the claimed invention, according to.

the Court’s definition We have no difficulty in finding

three prior workers in’ this art who have each done the

same thing in substantial, or‘exact, identity. :

= EheEignt one was:-.. s

os E Lilienfeld.

- When’ we rea th admissions of Langmuir in a |

record (quoted by Judge Wootey in his dissenting opin-

don and reproduced by petitioner in its: brief, pp. 31, 32) -

_ We wonder what there is left to:be: said, boneetly, about .

the claimed invention in this re a ee Bes

-Ferexample: . . roe sg

a is the admission by. Langmuir that th ce ee

“Lilienfeld probably succeeded in obtaining’a dis-

oe a Pi = Charge in high vacuum substantially free from m

. . effects of positive ionization in the devies ~

| ace described in his 1910 pepe” ee a

: No importance is H placed by 2 ath, on ‘the “word

= cma

®

. 2f.

x

— experiments, realized a condition Charlot the dowering .

of the (gas) pressure (was brought): to such a point that

@ further lowering brings about no further: change.” It ?

was the same order of vacuum as Langmuir’s. And as.

Langmuir again.admitted, “the effects ‘he (Lilienfeld)

‘ measured were not dependent upon gas ionization.” .

. We cansot seriously consider as controlling the words -

“working tube,” in the definition adopted by. the Court.

below. The Court below based its finding of invention —

on cominercial use.: But the fact of commercial-use is. . -

only helpful in case: of serious doubt. If there is substan-.

. tial identity in a prior knowledge, it is immaterial whether

there was commercial usé of the prior knowledge. This

point was settled in this Court in the case of Corona’ Co. 8

_ v. Dovan Corp., 276 U. S. 358. Of course, the prior art —

~ device must have functioned in order that it be complete.

But for the purposes of this case, the knowledge of the.

invention of the definition is complete when there is pres- :

enta tube of substantially the constriction. of the broadest

claims and in which there is an electron discharge free® .

from objectionable effects of gas, working aboye ioniza- <

- tion voltages.

What have we in the Lilienfeld disclosure? We uaee a

tube used as an implement of research, but answering to.

_ the terms. of the claims of the patent, and consequently ee

he anticipating them. While the device was experimental,

a me adaptation of the device to any- commercial purpose | a

- _ contemplated. by ‘the patent, was obvious. In the sense _

~ that it produced Se — of reproducible character, 2

it. was a “working tube.” It had a hot cathode and an.

anode: Its vacuum was higher than required “by the

patent. Certainly it was higher than a few hundredths —

re ofa micron. And the coordination. of ‘the cathode and :

© ages anode and of the acum under appropriate voltage (fat

“a

“St.

ably, if at all,. affected by gas.

“It is difficult to understand how the ree hese oe

ean face tlie disclosure of. J. E. Lilienfeld and: persia in higee

the claims of invention.

: - It will not do for the ccaphealiet i pate fo ‘the work ¢ : x

TOF Lilienfeld as mere laboratory experiments. In the

Corona case (276 U. 'S. 358), this Court has‘ made clear:

the law with respect to prior knowledge as evidenced by

te laboratory work. If the : substantial identity of the earlier.

- work is established, it is a complete bar to a patent for og

re the later invention, provided it has worked on any scale.

And moreover, if Langmuir’s laboratory tubes and ex-

x : * the equivalent ‘work of Lilienfeld is an equally justifiable

Ne basis for establishing anticipation. Langmuir is subse-

a quent to Lilienfeld in the essence of his invention: So-the 2

patent is invalid.

~ Examiner in the Patent ‘Office not in discovering. or pro-

ducing anything new, but in perceiving the practicability _

of scientific facts. known in the laboratory and in making

mee practical ‘useful devices embodying the scientific laws

be a # known i in the laboratory. (See. opinion of Commissioner

2 OF Patents i in the Interference, blue pamphlet, pp. 10, 11)...

a oae ‘ elt-is true that there may be inventive subject-mattet in

ee such practical application of a principle. But if a ‘tul be :

oo is shown, as'by Lilienfeld, in which the principle of pire: =

ge is clearly disclosed, can. the subsequent a

“inventor foreclose ‘the prior discoverer of the right ‘to.

: tnake such use of his discovery : as he sees fit? Of course,

Selsnieesl use inde of the ir =~ ‘be mondpo

2 : awe ee cabling voltages~Hogan,” ec Vol. mm -

eae 1703) was such that the current flow was not sje ee

a periments may be the basis of his claim for a patent hére, |

It would seem that patentability. was PRR by the, pet a

AERP SC ORIEL ONE

ventor cannot ERS usurp all ipotiouonn of the prin :

ae e ciple, even ‘though the first discoverer had failed to put

- into force any practical application of his invention to 5

i = The sole ‘question ee is whether what Lilienfeld. wa

‘the useful art. As a matter of fact, Lilienfeld did subse- —

quently make such an application of his discovery to. the

_ X-ray art, and of this, werwill treat | in a a later portion of

this brief (pp. 38-40)... |

However, no such following up in any way affects the

force or effect of theslaboratory work as an anticipation. :

As was said by Chief Justice Tarr in the Gorona case sr ee

. U. S. 358, at p. 384):

“Tt is ‘ sit iot to assume that reduction touse -

must necessarily be a commercial use. ‘If Kratz dis-

- covered and completed, as we are convinced that

- he did, the first use of D.P.G. as an accelerator in - ae

making vulcanized rubber, he does not lose his right’

to use this discovery when he chooses to do so, for —

scientific purposes or purposes of publication or be- - eS

‘ ’ cause he does not subsequently sell the rubber thus —

vulcanized, or use his discovery in trade, or does . a :

’ not apply for a pétent for it. It is not an abandoned

‘experiment because he confines his use of the yub-

ber thus produced to-his laboratory or to his lec-

ture room. It is doubtless true that Kratz, by his a

course in: respect to his discovery as to the use of ie

-_. ).P.G3 has abandoned any claini as against the

eri “public. for a patent, but that is a very different thing

from saying that it was abandoned as — a sub- 5

oquent discoverer. or patentee.”

eG — = tera oe op a ‘com et

| . age e |

ee ‘thing, no one can, by subsequent act, exclude him from the

eee use of that completed. thing except by, and to the extent -

ae of, adding a further novel thing, in- patentable coaction, oe:

"to the thing completed by Lilienfeld. Therefore, we say re

) that,'if Lilienfeld has produced a tube. with elements, the

equivalent of Langmuir’s elements, no amount of subse- -

; quent. commercial’ application of substantially that thing. —

ean detract in any way from the exact quality. of Lilien-— se

© feld’s act.’ Whatever may have been the law before the

Corona case, thereafter the statement by the Law Exami- a

_ ner is not the law as applied to this case. Ae

In a subsequent sectiori of this brief we will pee ae

Langmuir’s claims in connection with the X-ray tubes of — aq

‘Lilienfeld. But at this point, it is ‘sufficient to point out a

- that Claim 11 is broad enough to cover any tube in which —— -

the elements are the same as in the Lilienfeld experi-

_ Mental tube; and wherein the vacuum and the voltages

- are of the same order and relation. All that is stated, as

- the result, is that.a pure electronic discharge shall be ob- a =

-tained free from appreciable, effects of gas. That is the - oa

admitted result of the Lilienfeld tube. And unless there

.- ~~ js added to the elements and vacuum and voltage of the

_ Lilienfeld tube something novel and useful, and in inven-

tive coaction with them, then’ no. subsequent act of Lang-

- muir can affect the quality or effect of Lilienfeld’s act. It

_ makes patenting of that thing to Langinuir ——

- donors demiae to de 1 teens Seong ae, Bes

oe We have, heretofore in this brief ‘Op 2 to > 25) te

scribed the DeForest work in 1912. For the purpose of

this point we need only call attention to the fact that the

a precise tube-of the patent was ‘evacuated in such a way as

= Sopa electron: ——— to, be srg ubst

S alls hoes feels ssiitaiih cottnek: een ef-

>. fects from gas: Hf the facts are accepted, as they were by —

“the District Court, then there can be no question that the

re invention of the definition adopted by. the Circuit Court -

| st 1912 abe inten-

“ “It is solely a question of fact, and’ ae voles line to-our

ee ‘discussion on pages 22 to 25 of this brief, and to the =~

- discussion of the same facts in the opinion of the District

Court (Rec., Vol. Ill, pp. 1965, 1966). We are able to find

~ ___ but one conclusion on this issue of fact. The invention —

‘of the definition was present in the DeForest work in 1912 :

= and prior to Langmuir. ; :

= And the third worker, knowingly and d intentionally, 4 do-

_- the identical ane was o

pe oe : S32 Arncld.

_ “On pages 25 to 28 of this brief, we have attempted ‘to s

show that in November, 1912, Arnold,:too, completely de-

veloped the. invention of the definition. He produced eee

._. tube of the exact construction of the tube of the patent and =

a 2 - obtained, an electron discharge substantially above ioni-.

gation voltages. without objectionable effects of gas. _

Gee If-the facts of the existence of the tube and its operation

- a are accepted, then there remains no problem—except that.

: of date—for here, as in the DeForest use, the identity of -

7 the thing is complete. -Moreover, it was intentionally and

: isely created, and the ie eines of its omens were A

oa

sworn Sechadaurs wl steteniedi 3 in the literterencs. ) of

“ing in the Patent Office. However, the Arnoid work was

s subsequent to the August, 1912, conception daté, later ad-

SS * vanced: by Langmuir. It is, therefore, necessary to con-—

sider for a, moment Langmuir’s August, 1912, work, which — <

was the only work by Langmuir on the invention con-.

uae. -. tended by respondent to have preceded the latter part of

-_. November, 1912, specifically November 19th, 1912

_. In the August work, Langmuir had a vacuum ‘tube con-

_ structed like an incandescent lamp with two filaments, one

of which he heated in the ordinary way, ent or Peep

~ of which he kept cold (Langmuir, Ree., Vol. If, p. 1116). oe

Nitrogen was introduced info the tube, and a discharge

caused to pass between the hot filament as a cathode and

the cold filament as an ‘anode by applying a potential of

about 250 volts therebetween (Langmuir, Rec., Vol. Il,

pp. 1122, 1124). Langmuir was then interested only in —

_ studying the rate at which the nitrogen was “cleaned up”

or caused to disappear by the discharge between the cath-

ode and the anode (Langinuir, -Rec., Vol. Il, pp. 1116,

1122). When the nitrogen pressure reached a value of

“. . about 0.4 of a-micron, the discharge current fell toalow

‘value (Langmuir, Rec., Vol. Il, pp. 1125, 1126). The tube —

_. was then refilled with the nitrogen gas for further experi-

: ments (Langmuir, Rec., Vol. Tip. HOD) eS

Respondent now contends that Langmuir had a pure Se

fe electron discharge unaffected. by ionization. when the —

es nitrogen. pressure was reduced to its lowest value of 04

on micron as described (Langmuir, Rec., Vol. Ii, Pp. 1128,

_ 1302). But ‘Langmuir admits that he was not then con-_

scious of this alleged fact. He testified in this case eon that

gate as follows (Rec., Vol. Il, _p. 1328) : aan

a 49380. You did not know at the. dasa or a

: B not auepone at the time’ that you wert a pure ise

= ‘tron | dackiacee substantially unaffected by positive

- ionization, did you?- ~ :

“A. No, I did not draw. that Ticinsiog at that

time. I know now but I did not, know it then.”

' it is so tea as to require no ‘souks that there- oe

ae eo no conception of an invention without perception of it.

“© (Robinson on Patents, Vol. I, Sec. 79, p. 121). a

a It should be noted that, in these August experiments, Sie

Langmuir merely reached the pint, even if’his conten-- —

‘tions be granted; where pure électron discharge com- -

‘menced. This condition he was not then interested in, so ~

he introduced more’ nitrogen gas and retraced his steps.

Instead of exploring the new field of pure electron dis-

o charge contended to have been opened to him, he closed

‘the door on that field by the introduction of gas, and con- —

tinued his study of gas clean-up effects. _ ee

_. It follows that Langmuir can be awarded no. date earlier: fe

than the November 1, 1912, date of Arnold. | . Bee

. We conclude that in view of the work of. Lilienfeld,

DeForest and Arnold, there i is no room for the invention.

: of the definition. Even the fact of commercial use im-

sd. in the words “working fube” can avail tht patentee |

ig, for there i is no room for doubt; arf it is only in”

f grave oubt as to invention accoriianied by no ‘

_. direct evidence of prior use, that the factor of'commercial —

use rani be considered. As Judge Morris points out (Rec.,:

Vol. IH, p. 1964) the radio art was young in 1912, Fleming

7

9 es

had ‘no need for this og invention. The DeForest

statement of the physical principle of pure el elect:

& The Aefcdittens of the invention ‘adopied Se ‘the Coma 7

below and the claims. of the patent are broad enough to-

include modern X-ray tubes. Indeed, respondent con-

tends in this case that the epasescck anced dominates

the Coolidge X-ray tube.

“Claim 9 is scanaage of a group of claims of such breadth.

= Iti is as follows:

9. A oe tube hsiding a. cethode staging

to emit electrons, an anode adapted to receive elec- .°

trons and tube walls’ fashioned, or shaped, so as to

= permit the free passage of a useful proportion of

_ said electrons from cathode to anode, the gas con-

eaters tent or residue of said tube and the relation of the

rot eae parts of the tube being sich that the tube is capa-—

._, . ble of- operation with stable and reproducible re-

sults substantially. unaffected by positive ioniza-_

tion, with currents of at least 5 milliamperes. and

with voltages of at: least 200 volts. a3

aa

: _ Analyzing this claim we find:

(i) A discharge tube _ ee

-.. (2) Cathode adapted to emit deta a oe

ae (3) Anode adapted to receive electrons — | |

oe CS (4) Free pease for electrons. from cathode he °

; anode : “

o Vacutrn sch: os to permit operation with be

oe -producible results ste ee

. O Substantially unaffected by ionization -

Mm With currents of at least 5 milliamperes

® ‘With Nei of at lesist 200 volts

As

4 oF

«

. x

a,

|

fy

‘The cbletraction of the tube eA We are

oo aide to have a free passage for electron8fgom a: hot

eathode to an anode, The vacuum is simply sa e such ©

a is necessary ‘(whatever that may be} to secure Stable ©

: ip and reproducible results,” by avoiding ionization under

_.. the conditions of operation. These conditions are that —

_ the current strength shall be at'/east 5 milliamperes; and =

_.. that the voltagé shall be at least 200 volts. It will be seen

- that there is no upper limit on 1 either the current strength % ee

~ or the voltage. S net Lae RR “ 2

- This claim completely covers the Coolidge Kay tube.

and the Lilienfeld. perfected X-ray tube, both of which ad-

- mittedly operate with a pure electron discharge, at cur--. | —

rents greatly in excess of 5, milliamperes and with voltages.

‘running to thany thousands of volts, ;

The period between the publication of Lilienfeld’s 1910

‘article describing his experimental discharge tube (dis- e

cussed above in this brief, 29 to 33) and the per- '

‘fection of the Lilienfeld X-ray ftibe referred to above, was

ie occupied with the usual p of development from the

ape 1910 experimental tube ie tee ‘commercial Lilien-

» -feld X-ray tube, | *

Respondent's ad mission with respect by the Sounaiiin ol

; » ent Lilienfeld X-ray tube is contained in a foot-

E Seoncesbiesgact gegen design

- use at all, resembles ‘the Coolidge tube singh ee 2

closély than it does the tube described in the Lilien-_

_ feld-Rosenthal paper. Instead of Coolidge or Lang-

muir learning something from Lilienfeld, it -was

Lilienfeld’ who learned from Coolidge and Lang- |

muir.” ;

. ra

_ Further Sens nya, ‘commencing on page 100 of

the same brief; . — ; :

- “If Lilienfeld’s. publications: plus all the we 2 ey ote

which Lilienfeld did, did not teach Lilienfeld to .~

7 -- -huild a hot-eathode, pure electron discharge tube—

* ._ and they did -not—that fact alone ‘would outweigh

. _. a thousand pages of expert testimony to the effect

ey oe. that they ought - -to have taught him, and anybody —__

oe ~ else skilled in the art, how to do it (Schmertz Wire

Glass Co. y. Pittsburgh Plate Glass Co., 168° Fed. ha | "

s a). ” (Italics rig. menaredis: | aaa

Se glee ekcchaaik is entirely unwarranted in concluding that tae

' the Lilienfeld perfected tube, referred to, owed any part ._

of its being to contributions from either Langmuir.or

Coolidge. The portions of the recerd (Vol. Ill, pp. 1698- ay

1700) cited’ by respondent, refer to various publications

Sas deséribing the improved Lilienfeld tube, but nowhere is

_ it stated that these were the firs publications of that kind.

Indeed, it is a fact within the available knowledge of coun- st

sel who wrote that brief, that this tube was invented by

© Dr. Liliefgld before November, 1913, the date of the ap-

plication in Germany for the Lilienfeld’ patent covering

that. ure electronic. discharge X-ray tube. That he could

- not have been assisted by either Coolidge or Langmuir -

‘in this developnient, is shown by the fact that the first

publication of their work occurred in December, 1913

ls Ex. 66, Vol. “4 P. 919; Plff’s. Ex. 21, Interf. Beas

‘Thus ‘it appears that. Lilienfeld’s publications and. his. es

work did teach him how to buiiu a practical, hot cathode,

pure” electron~dischatge X-ray “tube, and that Lilienfeld '

diligently: followed up the ‘transformation of_his fabora- ur

tory’ work into successful commercial produdts,

‘spondent so. aptly says, these facts speak lauder than a a

thousand pages- of expert testimony.” ;

We ‘see from the foregoing that the idtergretation : of.

"the patent contehded for by respondent and made by:the |

. Court below, gives it a.scope covering the appfication ’ of. |

the principle of pure electron discharge to practical de- | «~

‘vices in an art to which Langmuir made no real eontribus .

tion.. In other words,, although Lilienfeld disclosed the :

principle prior to Langmujr, he is, according-to respond-

. ent’s argument, to be. preGerited from applying that prin- ~~ ~

_. . ciple to the practical X-ray art, because, forsooth, Lang- © ‘

'.. muir preceded him.in the practical application of the prin-

oo ciple to quite another art. We submit that this would be __

a manifestly unjust result, based upon’ an untenable

*.. proposition of law entirely contra to the Corona case and -

- to the accepted principles underlying our patent. structure.

‘The same result may be_ reached | aah a somewhat

|. different aspect. mee name

- In the Coolic : tebe adhinithedly. ‘donslenial by ‘the 373)

Nie, Langmuir patent, the voltages employed are so high “that, , bs

ue practically all’of the’ electrons-emitted by the hot cathode - __

are drawn over to. the anode (Coolidge, Rec., Vol. Il, p.

. 1556). This is referred to im the patent in suit as oper-

ation in the saturation range (p. 2, 1. 77 t6 95). But this

ppnuar a ange effect of claims 1 and 10, for

- ) :

| ages are high, in the situation range, ‘the discharge aces:

: “not follow the so-called 3/2 power law of claims:such as

elaim 6. Nor is the straight line logarithmic plot of claim

. g obtained by plotting the discharge of the Coolidge tube.

: These’ are stated by respondent to be “earmarks” of ings

Langmuir invention, Geog

- What this means, in simple intaiiaks is. that ‘none of |

these complicat&d phenomena can be accepted as suifi-

cient tests for the presence- of. the invention, since the

"invention is claimed to exist in a tube lacking all of them,

It follows, therefore, that such things are not of the |

essence of the invention. But when we'look behind them _

: to find the essence of the invention, nothing. is‘ left but a

vacuum tube having a pure electron discharge; without.

limitation as to its construction, operation or application

to use,-other than: that the voltages applied shall be above

the ionizing’ voltages. This Tanitation. has. no other force.

than to differentiate from Fleming, who" has-a pure elec-

‘tron discharge below ionizing voltages, and, therefore, — eis

; without ionization effects, objectionable or otherwise.

We have, then, a situation where. what ‘actually is”

_ claimed i8 the physical principle of P ectron dis- >

charge, quite aside from its. practical ap lication to any |

perticular art. We have shown above that this principle, .

Dy ’ this type of discharge, was not new with Langfhuir. But

_ ° wholly apart from, this, it is inherently. unplatentitie, ”

mee. re tn Ne, es aes

.

“ee

As: L's : pe ee...

. ° Rage 2

¥ a } ? eae

é : t ee Ae &

. ° : ts

Si ehy ba

5. Langmuir’s chy pieetton eabbssiilia of the

principle of pure electron discharge was-to the De-*

Forest. tube. “This application was anticipated by

both DeForest and Arnold. Hence cleims directed =".

‘to this use are void. eis iY

If we accept the proposition that divans invention ae

uy in this case must be limita to the appligation of thie prin- |

_ ciple of pure electron discharge ‘to a particular practical

.- use, the only such applicatior by Langmuir was to. the _

three electrode DeForest. audion. But this application .

was not-evert conceived by him until March 21,,1913, Jong

after the same- practical use had been | made by both De-

:- Foregt and Arnold. (This invention is claimed only in -~

claims 10, 12, 18, 19; 21 and 22 of the patent.) &

It is true’ that respondent does contend to have devel:

‘oped, as coming within the alleged Langmuir invention,

the’ Coolidge X-ray tube, and the Kenotron high ‘voltage _

alfernating current rectifier, as well as the, high:vacuum

_” three electrode tube corresponding structurally: to the De- ©

Forest audion, _But we assert that ‘this contention ie

_ unfounded, aes

oe Coolidge X-ray tube is the developeannt: of Dr. Nae

) Coolidge, and respondent is estopped. to deny that it is ‘

-_.Coolidge’s. invention by having taken out the, Coolidge . -

_ patent thereon (Deft’s, Ex. 67, Rec., Vol. VI, p. 941).

_ "The Goolidge X-ray tube, as pointed out wbove (this

*. brief, p. 40), is a high voltage tube. . It is not disputed

that it is inherently a rectifier, and that the Kenotroft

___-reetifier is an outgrowth of the “Coolidge tube” (Rec. Vol: eae

ae 1m, pp. 1528, 1520).. The Kenotron rectifier is in fa a

. essentially a Coolidge tube arranged in the high voltage

_‘eireuit in such a way that the X-rays generated are of

ae —- a and do not get mee? the —

a

e

ee. a

$e . . : | eas 3

ee | 43 | ak

- (Coolidge, Rec., Vol. IH, pp. 1529, 1530).! There is nothing

’ jn-this record to indicate that Langmuir had anythi 7

do with its development, and from-the logic of the Five

ation; it is clear that he played no such part. .

The low voltage rectifiers, say, of the order of a few:

. hundred volts, in commercial use today, such as the Tun-

ae gf rectifier of respondent, are admittedly gaseous ‘tubes, , ”

-and-are in fact. merely structurally improved oesrage 8

valevs. It is admitted in "thigsrecord (Langmuir, Vol. Il,

pp. 1351, 1352) that. such tubes operate better witli gas,

“ and that they are outside of Langniuir’s alleged invention,

. This leaves us only the ‘high vacuum DeForest tube.

Langmuir testified that he fifst, saw a DeForest tube in Eri

y* February, 1913 (Rec., Vol, II, p. 1182), Shortly thereafter”

whe built several such tubes and experimented with them.

While there: is some contention by respondent that these fa

. tubes were high vacuum tubeg¢ operating with a pure.elec-

/ =. tpen discharge, we believe it is clear from the record that

_ this was not the case. The best evidence of this ig: to me

~ found jin ee. i s own notebook under: date of sspshorine

| _ 21, 1918 8:

“Now what I isha to do is to videos an aud Bias

don which will operate entirely and exclusively on:

the electron discharge. I shall attempt to get ee:

vacuum so good that ‘positive ions are present in —

BU) amounts.” Pleas ‘Ex. 131, P. in Interf.

7 0) aie ; . ;

eETPORRS A LA6

a ee “Dhis te a perfectly

Lae ~ only, possible invention here in issue, but it is, Patience

, a much too late to be-of any avail to Langmuir since this =

had been done in 1912 by both DeForest and Aaa a

, ind PP: 2 to : ta tases RE ae

fares t cs | | “4.

. a

It is for this reason that we hear so much in this record . §- >

e of Langmuir’s earlier expériments during August andNo- =

| vember, 1912. But it seems to us that Judge Morris’ has

properly characterized the earlier experiments, when hé,

‘said sc accurately in his dpinion (Rec. Vol. IIL, p, 196i) :

“Dangmuir made many experiments over a-long

\. period of time. Those. that were first made were,

~ however, for the purpose of discovering abstract

principles and not for the purpose of arriving at |

practical results. He made discoveries but he did

‘not immediately, or for soine time, perceive that

they had any practical use. Moreover, the discov-

es to ‘which his experiments led him, so far as

' we are here concerned, were those already made

by Lilienfeld’ and others, * * But the disclos-

‘ ures of the prior art reveal that Langmuir, great

* and ren@wned physicist that/he is justly conceded

to be, was, in this ins traveling, all usknowa

to him, over a field already well explored, ”

Ie We siibmit that not indy was Langmuir, in his earlier phi

| Pisiaibible traveling, ajl unknwn to him, over already EB:

} . ___well-explored fields, but, in his only practical application — Boe ti,

_.\ of the principle of pure eleogronic discharge as well,he =

ies sanenetely: aliticlpated by these other ersinthe ~ .§

oe os cannot, patent the principle and he is anticipated es

; is. only practical application: of that principle, evén,

it such a were not otherwise —: |

. ns

; a - Ny

| CONCLUSION. Lee

Misses tecieong, we contend that the decree of y .

; Solow should be reversed and the: Bil gf; Bee

7. Respectfully submitted, ah ee pO a

ad eae Ea ens Jon F. Neany, pee we

. “Reanay Hoover, | iets Caled sea

TaN «Of Counsel Pies ee care

Dae: Chemical Foundation; ag R tea ae

Bey ee URN - Radiological Society of North A

JAN’ 8

& alt a z ‘ "] nmsies taupni

“» , ) ; ae

cae ae .

«

IN THE

a _ SPE cc OF THE UNITED STATE

Ocroser TERM, 1930

No. 630 : |

DeFOREST RADIO COMPANY

A : . Petitioner

~ & v.

GENERAL ELECTRIC COMPANY

, : Respondent

OPINIONS OF. JUDGE. MORRIS AND

ae ‘JUDGE WOOLLEY te, Nid

Tuomas G. Haicur .

SAMUEL E, Darsy, JR. .

Counsel gd Petitioner

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PAGE

"The Opinion of Judge Morris (District Court of Dela-

3 ;

The Opinion of J udge Woolley (dissenting from pres-

[© ent majority decision of the Third Cirduit Court.

I of’ Appeals) pao a an ne wna aoer as 30° ”

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ar

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FOR THE, DISTRICT OF. ‘DELAWARE, pap

es

Genta esas Conceany,. . ob ig Re

7 Pie hig i oe

o ., 7 anid 508, oe .

_Deonsst Ranio ‘Company, sis * mae,

by eee 56 Dente.

v ; oe :

" The Ogliion of Judge Manvia.* Bes

: ae ; (23 Fed. [2nd] 698) . ec eae

o These two: suits of General Fiectric Company agin

‘DeForest Radio Company were tried together. In the first

suit all the claims of patent No. 1,558,436, granted to Irv-2

_”- “ing Langmuir, assignor to the plaintiff, October. 20, 1925,

for “electrical discharge apparatus and pfocess of prepar- —

+ ing and using the same” upon an application filed October.

‘©’ 16, 1913,.and renewed March 14, 1916, are in issue, It is’.

ae known’ as the high vacuum (abe-patent. Infringement. is o .

- conceded -if the claims are valid. Validity is denied for _

__ want of inventio#ind novelty and because of prior knowl

Pes ‘¢fige and use, for double patenting and upon nes es

< So srearapneeny — nee Re ae

.*

“”

ee !

xs it is someWhat difficult to isolate and ae separate from

the principles of physics involyed Langmuir’s conception

‘and peer of means. Yet an analysis of the Langmuirdevice

‘and cot MN mnt discloses that, apart from its function-

| rea‘ i= nothing more nor less.than a Fleming

; ie or th) fcudion, for « ample, in which a higher ©

— WACUAD, «Hh Awable durin. operation, exists. How

| mueh hi, - 1. é vacuum mu:: be to bring the tube within ¢

‘the paleu, is not definitely fixed ‘in terms of pressure.

The specification. states merely that “thé evacuation of © ~

the device ‘should be preferably carried to a pressure as a

low as a few hundredths of a micron; or even lower, but 3

"no definite limits can be assigned.” -A micron is a pres-

_ gure equal to a millionth of a meter or a ‘thousandth, of a

* + millimeter of mercury. , It corresponds to.a barometer

ne reading of that value. The normal barometer reading i in

. the open air is about 760 millimeters. The justification

.. for the failure to assign delinite pressure limits is that- =~

_ the invention. “comprises devices in w h the électrical

- €urrent is’ carried by. negative. charges ‘called electrons, _

. emanating from the cathode, independently. of gaseous —

ionigation”—-a device in which the residual gases play no oa

part in the operation. The résults desired to be obtained. ae

are stability and reproducibility of operation and increase

of power. The production of these results bf the specified

_ ~ manner of functioning is dependent not on. the degree

__-* - of vacuum: alone, but upon four coordinating variables— _

hay geometry or relation of parts of the tube, temperature of —

ee ae earl a aiet seats and degree of vacuum. This =

Se fact eS it. r ubavoidable ~ ies alee va ie

| caye the thing. Walker on Patents $165. Cai

enn deativ “gegen ey gs 7 ere ae

“ oO .

a \ * ; ?

\ - ‘ ws 5 ee,

“A disdlienge ebb oun a oi off ene.

*..yelape and electrodes. therein, the envelope bene:

* __— \._ shaped and the electrodes located so’that.the energy e :

of the discharge is delivered mainly upon one or, -

more of the electrodes, the inner wall-of the envel- uy

ope and electrodes being 80 free from occluded gas

and the pressure in the Aube. being sufficiently low, .

with respect to the spacing of the electrodes. and the

energy of-the discharge, so that the device is capable. -

‘of passing a sustained discharge of one tenth of a

milliampere at forty volts, without developing any

_ Substantial positive. ionization effects.”

PA] io

‘

The Fleming and DeForest. tubes are “discharge were x Sy

comprising a sealed off: envelope and electrodes therein,

‘the envelope being shaped and the electrodes located so’

that the energy of the discharge is delivered mainly upon

~,on€ or more of the electrodes.” : The next clat.se of the

~ laim-—“the inner wall of the envelope and elect esbe- <

ing t so free from occluded gas and the pressure in the tube

being sufficiently low, with respect to the spacing of the.

electrodes arid the energy of the discharge”—has to do’

| - ‘with the ‘manner ‘and degree of evacuation. Underlying — ee

| - this clause are these facts: “The glass wall, and” the de ° 8.

*: trodes harbour large volumes of occluded ‘Heatis-

necessary to expel these gases so they. may ‘eee i

“by. the pump. If, not ‘removed before the ‘tube is sealed’ -

off the heat ‘occurring during the operation of the tube’

expels: them, oe in large degree the vacuum: 6 soap OS

oan of the geome

N t Tht i rox! mit} pet

Fong mgt tech eet ye

ron ane weet: ee isc poe

; may be ices in terms of power which is the pods .

tet of the current values and the voltage. The unit ee

current flow is the ampere or the current which flows ata

pressure of one: volt through .a closed circiiit having a re-.

-sistence of one ‘ohm, The power of a circuit having a |

pressure of one wolt sie tt of one ampere is one

watt. The power output oP the device of claim 26 is 004

' of a watt or 4 milliwatts. And increase of energy means >

’.. gam increase in the number and velocity of tite electrons a

‘ passing from cathode to anode and consequently an in-.

’ crease in the number and effect of “ ollisions of electréns

with gas molecules. It follows, of course, that if the maxi- —

mum voltage at which a given tube will function %jthout

ionization is increased ionization will océur and the tube

fail to. function in the manfier specified in- the patent. .

Ae “Ionization,” by which is' meant the conversion of atoms

\ or molecules into ions, is explained by the “Electron The-

ory.” By this all atoms known to chemistry are deemed:

_to.be made up of a nucleus endowed with a permanent |

ys

"positive electrical charge aroutid which one-or more ele |

__- trons;-each of which has mass or weight‘and carries, or is, a

_ anatural unit of electricity, revolve at inconceivably | great.

speeds in, regular orbits in. somewhat the same manner

as that in which the planets of our solar system revolve’. — |

_ about the sun. According to this hypothesis the chief dif- .

: ference between the. chemical atoms lies ixj,the number =

s _ and arrangemerit of their electrons. ‘Under normal condi-_

- tions the electrons are maintained within their atoms and

eit ty Dn sean rons Ns mus

ss eabeeeicwierencbensilh heii’ “The posts

tively. charged nucleus predominates and ‘exhibits a unit

positive charge. In thermionic tubes. ions are created by

the impact upon the: gas atoms ‘or molecules of some of.

‘the myriads of electrons constituting the current flowing . -

from: the hot cathode to the cold anode—the Edison Ef- —

fect. See Westinghouse Elec. & Mfg.Co. v. DeForest Radio.

Tek. & Tel. Co., 21 Fed, (2d) 918. “To dislodge an electron

- rom its atom ‘the colliding’ eléctron must have sufficient

| momentum: The velocity required for this momentum: .»

ig given to. the electrons mainly by the pull or attractive

prt of the positively charged ‘anode. The strength ofthe

+” pull increases, other conditions being ‘stable, with the:

_ anode voltage. . For ‘the gases with which we here’ x

concerned 15 to % or 30 volts neers the’ naming volt |

_* ages. ° |

When substantial inablie of atoms or -gnolecuies are

being converted into to positive ions-by the-electron wreak

: he “ionization € effects” f forbidden by claim 26 occur. One’ whe

«+ effect of ionization is an increase in the current across’.

the tube over the value it would have ‘at the same voltage

7 in the particular tube were the vacuum sufficiently high’

to prevent iotiization. Such increase is due to two factsi>

ee First, the electrons, being riegative charges of electricity,’ a

tend in the absence of a countervailing force; violently” Ce

a to repel one another and ‘thus to diminish the number, © ree

-and so, ‘the value, of the current, Passing ‘to the: ‘anode.

ees sinaont farce" ‘to the cathode, the ene < aaa: :

v°

increase the supply of electrons and consequently-the cur-

< Pent passing to the anode. This bombardment is so severe

_ that, if continued, it destroys the filamentary cathode.

Another effect to. which substantial ionization vsually

gives rise ‘is a blue glow in the tube, This,'as I under- °

_stand it,-is accounted for upon the hypothesis that as the

electrons are shifted in the atom, by impact of the elec-

trons, from one orbit to another at prodigious speeds they

produce waves or vibrations in the ether which constitute

light... The ultimate effect or ‘result of ionization is an —

unstable, tidh-reproducible and, in a méasure, non-¢c0-

trollable current. As it is necessary, in order to prevent .

the destruction of the cathode and obtain a stable current,

. to operate gassy tubes below ionization,, their power out-

put—the product of current and voltage—was limited.

_ These constitute obvious defects. : ,

These defects are not present in the tube of the patent. ’

"It operates. without substantial ionization. When. there

_ is no substantial ionization the current increases and de-

_ creases in a fixed relation to the voltage of the anode un-

_ less and until the anode voltage is made sufficiently high —

to draw to the anode alll the electrons emitted at the cath-- ee

_ éde. The electronic emissivity of a given. -cathode in-

eee Searsbaaptenqaa ses .

Ee ite ® 7

and below: saturation respectively. if a tubs is: operating

below saturation an increase of the electron supply by an

_ increase of cathode temperate, but with no increase‘in

voltage, produces ao marked change in the current. . De-

creasing the electcons emitted by the cathode by: decreas: |

ing the cathode temperature is likewise, without effect

upon-the current, provided, of course, that the decregse

in the supply of électrons is limited to the electrons emit:

ted in excess of those pulled across the tube by the given’ -

voltage. The fact that if the anode voltage remains‘stable

‘the current can not be increased by aa incréase’ of The

cathode temperature, beyond that required to supply the

alpbirsnn chai of heing pied serves 100 SMAI

given@pltage is illdStrated by the “flat top: ss

gatry’ on tne lloeeing ammo SU eee nism me

4 > . . , ‘i % -

aha us - - P % 4 ee

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f% Tes apes 28 3 2 ‘ 22. an Pe an eae

4 $ ” . . Li

. Whe reason that the current does not increase beyond a

certain point dependent upon anode voltage. with the: in-

crease of the tertiperature of the cathode is that the elec-

trons, all being negatively charged, exert powerful repel-

ling forces on one another. ;When this force of repulsion

pene the pull or effect of the voltage on the anode,

anode is without power ‘to draw to itself a great

Gas ase electrons. The current-limiting effect of the

é field of the electrons on one another is known’as

the “space charge effect.” It is space charge which pro- .

the flat top of the temperature emission curve: in |

he foregoing graph. )

When the tem.perature of a cathode is. fixed and con-

vy, stant and the voltage is increased the limitation - ‘upon

ce the electrons limits the current. This is illustrated by.

he the following graph whereby it appears that the last few

| increases iu voltage make no increase in current—there

SR ee ere Ge Coe Oe ee

i 7 i . x a8 Wes v La]

S i : s Fe x *

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iy, setae arate Setied rt

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‘he curve of thin graph, tether paren var togue

_ mic paper. appears, up to the point approaching satura:

; ope tion, as a straight line, discloses a relation existing be--

teen. current “and voltage. That relation: is’ or

ctype AR aSOR thuss ys =

“In most devices of simple fact tt Ss which,

embody. my invention, the discharge current pass-

ing through a given space with the cathode ‘as a

> sufficiently high temperature with respect to the

"+ voltages employed, : varies directly with the $/2

- » power [square root of the hal of the one

voltages.”

€ zi

: “4 to “D” of the curve on the current-voltage’ chart, in

which ‘the temperature is constant, is the space charge.

part or that in which the current is limited by anode volt-

age and follows the’ 3/2 power law. The flat top repre-

“sents the saturation part or that in whick the current is

Jimited’ by the cathode and its temperature. The cn

_-yerse is true in the first or current-temperature, chart in

ue which the. voltage is constant. In that the rising part is

. ,the’part limited by cathode temperature hile the flat

top is the part limited by space charge. dh 3

“Another charac riley

PIS AD

i nated ta the specifigation, is that" the device is “

is legs than thet réquired for a given voltage in a given

tube it may be increased up to the pressure immediately

; below that. at which substantial ienization would occur

' at the given voltage without affecting the discharge. The

| discharge, however, is ih no sense indepéndent of the

pressure if the maximum voltage at which a given tube

will function without ionization is increased, for ioniza-

tion woulil instantly occur and the tube fail to function in

the manner specified in the patent. In such instance a

degrease in pressure simultanepusly with the increase in

voltage would be necessary to avoid ionization. In its.

ick begets tale kc soon, af atacns, 02 aD et 8

_- sionigation is to be avoided above ionization voltages co

ry lisions must be avoided between electrons and gas mole- |

cules and that the number of collisions in a given tube,

upon the relative. density of the two,

" \greabed, the preavure being stable, by en increase

number of eléctrons pulled to-the anode Sy the increased |

_, voltage.

Bee oe, These scientiilc explanations, arising mainly out of the-

© ¢lectron theory, of the functioning of the high vacuum.

tube change not at! all the fact that it differs structurally

ye

from the, Fleming alve and DeForest audion only in the —

_ +, fitineiples in accordance with whieh the device functions

11

disclosure of its solution in’ his ‘patent, siocaibectl ‘he

~ would be entitled to a patent for his disclosed:method

and device as a. rewdrd quite apart from his knowledge -

or lack of it with respect to scientific principles or Jaws‘5-/

of ph explaining the functioning brought ahout by ae .

the vacuum. Moreover, independently: of whether

or not invention was necessary to create a vacuum of the

_ tequired degree, Langmuir would be entitled, I take it,

to a patent for his device regardless of his ability or ins .

ability to explain its functiéning in,principles, lof physics,

if he was the first to appreciate that a high vacunm:main-'

“ tdinable during operation in a Fleming or DeForest struc-

- tufe, for example, would constitute means whereby the

- pesults produced by the high vacuum tube could. be ac

~.. complished, ided, of course, he reduced to practice:

- with reasonable Gas the device of his mind. .

- . Upon the question whether the claims for the p

of. making the high vacuum tube or those for the tube.

itself, which because of its stability, reproducibility and.

» power has. made possible radio broadcasting, mocern

radio reception and long - distance . telephony, involve

novelty and inventiofi the parties diffef widely. The

" plaintiff adsetts, witkp apparent confidence, that the*patent

is for invention of a high order—equal to or greater than

that of DeForest for the three.electrode tube... The de-

fendant, with equal confidence, finds not only all that

- Langmuir-did but all thatTie discloses with tespect to the

spread upon the records of the prior art. Site the

Spee reine set Sn Veloce iy oa ed

’

ne

a ont 32, directed to sales process: of eeihingt tubes having a ay

2

: vacuum of the required degree are valid. Claim 31 is:

“In the process of producing a hot ‘cathtile dua <a

. charge devicé, treating the interior surface of the .

envelope and the operating parts to liberate there.

from occluded gas, and ‘removing from the envel- s

_... ope gas liberated by said treatment and,free gas =

* originally contained therein, continuing these op- «= ~

“* erations intl the occluiled and original free gasis =.

so thoroughly removed as to enable the’finished

' sealed-off device to dperate helow saturation in a- . |

-. stable and reproducible manner at a voltage above

fifty volts and with a current greater than one ‘mil- ee

liampere and with the energy of the discharge d--

livered mainly at. one or more anodes.” HPS z

*

I find wherein Atell this anid the other process efaiuns

beyond the discoveries and ideas of others, béyond ~

tn oo use of wise judgment in selecting and combining those

discoveries and ideas, or beyond mechanical skill in ap-

: . plying them. to practical results, the specification and the

prior art must be examined. The specification states:

3 a: “For the eyacuation of the device the glass walls ., ieee

. of the tube are ; y heated to as high atem- - |

"perature as" we | stand without horas

( Nonted in pageants pei tsor Pine Mapai s

a fo agg ve guereor spe py

during the ‘evacuation the anodes may be heated,

. especial en the nen: are to be run at —

13 aes oo

| | | i je

Ph spigieinilbeaeieite bisttttect tiicainbenetiial ‘nthe

; case,of the structure shown in Fig. 1,-the heating —

may take place by passing au electrical current

-"o through’ the wire 12. The heating, éspecially of

oe “ ““golid anodes suth as shown in Figure 2, may, take .

. . place in a suitable vacuum furnace, the Galiierataty

preferably being taised to 2,500°:C. or even higher. es

Bones »rdment is‘a very effective means of — fe

~“@oceluded gas from aniudes.” BSS:

: The steps ane siebaetGanis stile to successfully Saar |

ate by. bombardment ar@ themdescribed afters which the

specification WAGGA cy -

‘ater the oases thas ian freed: rae ectbuded

piu reabsorption of gas will-not readily take place

ea even though it is exposed to the air or ‘other’ gases.’

For example, anodes thus treated may be removed _ .

- to other apparatus which then may be évacuated: °

-owith ‘Jess electron bombardment of the anode or

ahodés. * * * It is also true that when the anode’

| : her Dep carefully freed rom gas rl fee gat, :

: _, _ even if present in a sufficient amount to cause some

aon ae does little harm, as itis quickly removed by the gas

aoe 5 inde ae eaten ati Success as

| muita abacus Maal alta y

| | ~ onig before the earliest date claimed for Langmuir it was b

ee proc engage ATM IEE CO NE

: _ in the glass walls and electrodes of an alectrical dis- ©

oe neti shots and that. unless removed before or during» aaa

| [a ne ae ig Pee ne ae

“American Electrician” published an | article by Thomas ue

Duncan ini which he said: | ‘

met Fe incandescent lamp be exhausted untilno =

air can be seen escaping through the valves of the =~

_ pump, and the filament then incandesced, consider- |

- able tities of air will be expelled at each, opera-

... tien of the. pump, thereby showing that this air has

"_. been ‘occluded in the pores of the carbon filament, _

and could not have been gotten rid of wifhout heat-

_ ing the filament and ‘driving the air out into the ~

‘vacuous space surrounding it. . 7

ee. “This hesting also assists in drawing off the air

which clings or adheres against the glass tipon the .

inside of the bulb.. If the “electrodes are made from,

ae aluminum or other porous metal, the secondary

sie terminals from a spark coil can be applied to them,

‘and set ii operation in. a similar manner to that

_ in which the tube is to be used afterwards. This

-ean not help but be a ready and satisfactory means

of shen. the air occluded . Ve mm elec-

aes haces Hlectric Lamp Exhausting by foo

es he eee erm ont ee Be

yg ern es

“The exhausting. of incandescent electric lana mes

ws

the: lighted vane furnished: allthe weeidton iene Ae

euehe ~The lamps could be heated hot enough to cause the =.

bulb. to collapse if the hoods were»made too thick, = __

_. The filaments were - leo, heated: —, se the Bee oe

= currents: as fe ‘

Duta: in his patent No: 596,694, patted Paes 4 1808, “4

for a process of producing high vacuums in incandescent ae

electric lamps « or similar HR py. ‘during their ‘manun oe

facture recites ‘that in the past such lamps have’ been ex. |

: hausted by. mechdnical. pumps, “b emical processes in- :

; volving the displacement or absorption of. the gases con-,

tained 'in' the lamp, or by combinations of these processes.”

He says that a partial vacuum is ‘readily obtained by a

good mechanical or mercurial pump but *that’ complete ee

ee by this. means alone is not possible, He then. es

et ae “Go-carey. the wuitey: laden’ it healed

_. common practice to heat the lamp-bulb by angen ede

_. an external source of heat, such as a ga ne, or

by an electric current passed through the. lam} d :

filament, or by both of these means combined, so a

it to Gapand the gases Bi the temas, ‘and also to. riv

oe more particularly the joint between the. eading-in'

._ -.wires and the filament, which joint is usually made _ Se

oe behest lip tetbalinagit font? are komme oak

: iat therein, while continuing the Lpcem co op ration.

Bo, uae th Site’ yatent No. 859,021 of July’ 21907; for aa f

Se te lh se ee :

seared vacuum, declares:.

_ “nthe production’ of high ‘vacua riot ‘nly huis

5 a Pe peg pter alls ea jhe ases occluded

cattiinn dedicate an vntdaiaaa ey

condensed. ‘are given up slowly after-exhaus- -

tion and if not removed during the exhaustion S

cause the vacuum to deteriorate. * * |

“The heating and expelling of thi coiniibinlied: oid

occluded gases may be effected in any usual, or

- suitable, manner of expelling condensed and oc-

*. eluded gases from-the walls and contents of vessels. ae

_ being exhausted. The usual mann fecting

: ; , € vessel while it and

cio tte its contents are subjected to the same treatment as eh

_. ““they-are subjected to in after use. In incandescent

-. ‘electric lamps for example an electric current is

passed through the-filament, and in X-ray bulbs an. -

_. electric discharge is passed between the electrodes

during the continuation of the Shee: ELS

ie Siiiny Otsaei helenae diectote’ the bdking of the walla of

the envelope of a discharge device, the heating of the

electrodes, the filament and electron bom-

bardment of metallic ectrodes to expel occluded gases. ©

‘The gas clean-up effect was likewise old at the time Lang-.

oe " miuir began his operations. One instance of its disclosure ag

isin itent to Thatcher No. 1,028,636, granted June 4,1912,

- “‘applicatio: \ for which was filed March 30, 1910, for method

of seiennetiegs veenelen ey whch: thio tal nga

bec eel cte gas fond and torsepientio.

: jennings Sheets stick 0; Che gig wenn» ford wee amity

These steps ot the prior art are the identical. pte ae

- closed by Langmuir. Nor are his s disclosures with, respect. . 4

to how these steps-are. to be “employed. any more , au i tae ee

or complete. with the possible exception of heating | Be

bombardment... But bombardment has no saving. power

= for the claims are not restricted, to heang by, bomba ee

* mem. They are broad enough to include, any method < es

“treating the interio vi ‘surface of the eavelope.. and. ae

operating . parts to li erate . therefrom. occluded gas, and and

removing from the envelope gas liberated by said. in i

ment and free gas originally contained therein,” The ae

plaintiff, however, places some reliance upon. the clause. es

in the claims directing continuance of the steps until the Cone

desired vacuum is attained. and cites ‘Badische. v. Kalle, aa

“404 Fed. 802, But in that case those skilled in the art’) e

were ‘of the opinion that a more prolonged or intense ap- ue

| plication of the old steps would not accomplish the de-

. sired result, Sach is not the evidence here as i under ed

stand it, over er, the tools’ a the, sreeniie art Lies fe

is constantly ‘improving. Tn 7 incan--

- descent lamp art ue CS used the Aalages J umy ae

_ to Sbtain their vacua. It gave way to the Geissler pump

_ which, - in its turn was superseded or supplen é ;

, chemical evacuating processes. It is, I think, x

: that these old pumps and at least some of the

ss processes left in the tube mercury or other v

: 2 bese Jee, Biot fox the. be, of fhe 2

ees

t near s to ‘avoid that result it is by

yn) ed Gaede ‘molecular ‘Pump, a

| 8

gas-cr vapor that will ‘prevent the functioning of ‘a ther. ae

_ mionic’ tube above ionization voltages ‘without substan- =

. tial ionization. But Langmuir is entitled to no credit for: 3

that. 1 think the ‘process claims: are invalid. *

“his conclusion carries with it as a necessary. corollary

that the devic: itself, apart from its functioning and use, |

is lacking in patentable novelty. The inventive quality of

the device claims, if any they have, must consequently

reside in the discovery of a new principle that thermionic

discharges above ionization. voltages can be produced. 4

without substantial ionization if the vacuum be sufficiently

“high and the disclosure that the device of the claims con- __

stitutes suitable means for putting the principle into prac-

" tice to obtain useful results, or, in the application of that

principle, if known, to a useful purpose—in the realization.

that the instability, non-reproducibility and lower power.

output of the gassy tube was due to inadequate vacuum

is and the conception of a tube with a higher vacuum ~

a @ means.whereby stability, reproducibility and high _

= power output in thermionic devices might be had. That

Langmuir was not the first to discover that a pure eles

| tren discharge, a discharge without ‘substantial ioniza- =.

°° ‘tion, can be produced in a thermionic device if the

oa vacuum is sufficiently high was indicated by Richardson’s ae os ee

__. Law, evolved and formulated about 1903. If, perchance,

«that law was not universally accepted by physicists asbe-

3 ing operative in high vacua, as was suggested by Soddy, es

st Pring, Parker and some others, the publications of Lilien-

-feld in 1910 were clear, complete and specific upon this

pte point. In fact, Langmuir admits (I. B., p. 1378) that Lili- re

enfeld hed ermionic ‘discharges above ionization volt-

. stantidlly free from the effects of positive ioniza-

ed _ Moreover, if a thermionic discharge is unaccom-- _

ea by substantial ionization - the” asserted “ear

19

«

eee or’ cinbirhotettitin’ of tatu’: cevice:: are. pres =o 8

“ent for they are but incidents flowing from a sufficiently ’

high vacuum for the voltages. employed,-or, otherwise x=

_ pressed, from an absence of ionization. These character+ . _

istics are, -orinclude, (1). regularity ‘and. reproducibility ney

of operation, (2) 3/2 power felation of current to voltage;

re) no blue. glow or other visible evidence ‘of’ discharge,

(4),cathode not heated:by the discharge, (5) current lim Eey

‘ited by space-charge effect and (6) discharge-indep ent

‘of: pressure:in vacuum below certain’ pressure in the sense:

hereinbefore stated. As.I understand ‘the evidence ‘these ce

“earmarks” are likewise characteristics of the Fleming _

valve and original DeForest audion when operated at non=

ionizing voltages. It thus seems obvious that the’merit of-

the invention, if any, must lie inthe realization that the!

_ ktiown pur¢ electron discharge to be. had ina high vaeunr

‘would: overcome «the ‘special difficulties and limita

of thermionic discharge devices. ‘Whether this*re

- tion and the increase of vacuum instructurés of the Fleti

ing and DeForest type was a probable natural develoy

‘|.ment of the art or one requiring inventive skill is; Ike! Se

_ the question ‘of the presence or absence ‘ot easement a

other cases; not without some’ difficulty. - vs goat wc

One class of evidence’ which often initpiion: ‘di enn

‘is: the necessity for a series of experiments: ‘before the re-!

sult can be arrived at. Such evidence raises a strong in-'

ference that the result, was not obvious and ‘constitutes’! —

. Peal addition: to public knowledge. « But for such experi-’

ments to be ‘of much value the patentee must have started

his experiments with knowledge of the state of the art‘or ea |

his experiments. may have succeeded in: ‘enabling hiin ‘to

redisclose only what was already-known. Langmuir made: .

_ many experinients over long petiod of time.’ ‘Those that” .

| ae fat made were, however, for the: ‘purpose oP eae ‘

¥

\ r

ee

& *

N

We ae

"were those already made by Lilienfeld and others, Great

ae istics or incidents of a discharge in-a high vacuum with: .

; \ explored. Fleming, the inventor of the Fleming valve,

_ published in the “Scientific Américan Supplement” ‘for

a On

o

‘ covering abstract principles-and not for the purpose of

arriving at practical results: He made discoveriés ‘but he

« did not immediately, or for some time, perceive that they -

\ Sidlanh sbleiticliivant:: Moréover, the discoveries to which

his experiments led him, 'so far as we are here concerned,

\ evedit; bearing upon the ‘issue of invention, is claimed by -

the plaintiff for Langmuir for discovering from his experi-.

"ments that:electrons will boil out of a hot cathode in a :

high vacuum, that in a high vacuum: the current varies

with the 8/2 power of the voltage and other. character-

out substantial ionization. But disclosures of the prior

that he is justly conceded to’ be, was,-in this instance,

s _ travelling, all unknown to. him, over a field already well

January 20, 1906, an: article on, the electric conductivity’

_ offavacuum, disclosing not only that electrons are emitted : 2

by:ahot cathode in a high vacuum but.also “that ‘a high

| -Yacuum may. be a very good , provided that’

, the negative: electrode ‘is. Sincitcndlecitiy This

-shéws tliat the obstruction which a high vacuuin offers'to

_ the passage of electricity is not due tothe mere reduction —

of the matter in the space (that is, to thé rarefaction of

the: gas); but is, in some way or other, largely dependent’

‘upon the temperature of the electrodes; the resistance —

| des ipias be ah. cemtciehiy:shenigheceutin eusatek

_ ndeed Sin pean aa emai

art reveal that Langmuir, great and renowned physicist _ a

S06 ; ;

ee ae ae eg Oe ee PL eh a

Seer hay

= ht at.

ue tmceandesoeht corte filament and the othe a cold mein’

plate, and, at the ee ae oe difference of

aA potential between the electrodes, we find that the -con-

© ductivity, as measured. by the ratio of current to yoltage,

4g nof constant, but varies with the electromotive force.”

. Burthermore, that Fleming,knew the difference between’

_.. g-high’and low ‘vacuum ‘made manifest by his state-

ment: “The vacuum is Said to be low when the original

-normal air pressure in’ it is reduced to one-thousandth

atmosphere, or it may be only to one three-hundredth.,

It.is said to be high when it is reduced to one. hundred

millionth of an atmosphere.” It is true, as shown by’ the!

"Fleming curve sheet, that Fleming: did not employ i in caagh

valve ‘a high vacuum but it.is also true that Langmuir,’

Q212, conceded “There is no advantage in the device of”

the character the: Fleming. valve ‘to go to: pressures. oo

: less than £ | microns.” Both C. D. Child, in an article’

ae the “Physical Review,” ‘Vol, 82 (1912), and Lilienfeld):

in, an. article entitled. “Conduction. of

treme Vacuum,” published in “Annalen der. Physik,” Vol,

3 32 are disclosed that with the aid of ee ttain simplify-

‘+ ing ptior s, such as the ignoring of the: nitial velocity’

lich the ¢ s are boiled ont of the catho

e dische g> corrent varies in sopotdence with thethies®!

Ss half power ofthe voltage. This is conclusive evidence, as’

under tand it, that in a high vacuum the currents under '

, stable and reproducible and, since high oltages.

Noyed, that high power levels” may” ‘be attained

) joyment of a high vacuum. “Space chadge’ .

I zai e, but a rediscovery. ae eee,

Be ao icas aN Ml, it is: not exclusively hins:saloboecses

| apd emi from the exide cathode which, as was often —

tH ed, determined the discharge in high vacua,

eg but that the discharge depends essentially on a sec-

- ond factor. T‘pointed out more specifically in my

, second paper this view, that in consequence of the

'\. absence of the last traces of gas the. nimber ©

Se e density) of the negative electrons supply- _

current becomes great in comparison with

the. number of gas molecules per unit volume, so ,

ea therefore the tendency exists for ft formation

-of the greatest possible negative space charge—

which opposes the current transport by the hegative

: : “The higher the vacuum, the greater the curren?

‘ih rein ne seers. prowainent thie, new deine of die

; _ charge becomes * het me

“ a i eaacabaie ‘ei isan pebioncatty

independent of the pressure when the pressure is below .

a certain value was discovered by Langmuir after Lilien-

fold hed made the dieclosate th his article of 1010, where.

By be sald’ '

wee from a certain maximum value of the

os ee ie

; peer ere by

}

A

ew of hn peatn ema ome ha the oly

periments tint tivet they-constitate évidence of invention

but is rather that Langmuir was’ pot abreast of ‘the de- Ve 9

_'velopments Soweto Aas

periments. ae RTS AN

Other evidence bearing upon the istue of ‘invent

the great utility of the high vacuum tube. | ‘Bét\in 1912

the radio art was young Flemilig:did not need tor his

purposes, as Langmuir testified, a higher vaciun? than

that employed by him. The DeForest audién ‘wos not in

wide use. Langmuir did not see one until 1913. Under

such circumstances it would be difficult to

high vacuum tube satisfied a long felt wan

results long sought or that the evidence Pally wee

indicative of anything more than groper natural de- -

velopment of the art. Moreover, the fact that:falls but .

little short of a. demonstration that the employment of the a

known pure electron discharge above ionization voltages a

in tubes of the DeForest type was but the availment of © :

those skilled in the art of the store of knowledge that had :

been accumulated and lay ready at hand’ is that y i

Arnold, who had had long experience with electrical dis-

charges in high vacuum, was shown’ @ DeForest audion ce

for the first time on November 1, 1912, and saw it in

operation he.immediately realized 4 and | in effect, that :

by increasing the vacuum the would, be suffi- ,

ciently stable and at ddequate. fat toale be poutine

tube to be employed as a relay device in trans-continental .

- telephony, While not unmindfal that invention may . _

sometimes be the result of /an instantaneous happy :

thought, yet the state of the is strongly confirmative |

of Arnold’s own view at the time that the improvement |

by hint was obvious to one skilled in the art.

| The act of Arnold turn the seale #0 overwhelmingly that 8

a Se ee

The patent is Maewian invalid, in. my opinion, iodine :

of a knowledge and use by DeForest. The specifica-—

“tion states: “Ordinarily the gas ionization in the. audion 9

begins to be important somewhere between 20 and 30 —

~ volts.” That, as I understand it, means that at this voltage

‘ the current becomes affected by . positive iohization and

the tube ceases to function ‘a: « pure electron discharge

~~ device. . Yet, prior to August, 1912, the Federal Telegraph

Company of California, by’ which DeForest was then em-

“ployed, used a B battery of 36 cells, another of 45 cells,

or 54 and 6744 volts respectively, with the audion. ;Witen -

‘used as an amplifier the amplification increases, ~with the

se voltage. The testimony of Langmuir, XQs761-767, as-I

understand. it, makes it clear that this voltage was em-’

ployed for amplifying purposes and so with a discharge

ae — substantially unaffected by ionization. That De-

ee Forest, though not skilled in the art of evacuating his de- ce

. vice, knew. the effect thereon of an increased vacuum,

though he was very probably unaware of the extent to

which it could be carried, is disclosed by his letters of

\ July 26, 1912, and August 14, 1912, to the McCandless

Company, the manufacturer of audions for thé Federal

‘, Telegraph Compaay. ‘The first letter is: ie 3

; 4. “Out of the last lot of 24 audion buibs -which

+ pebtemnnntaatared for to there ere only 4 that come

~ red : * : 2 3 @ >N

7: ° as . Fe = " ‘ + u eee LY <

4 7 ‘; a < 2 € ji ¢

ae ; Le Sap ee * ae 8

= ¢ eis 2. aX s : ® © ~” ~ : ?

. aie? ‘

iu abe andthe fia exhaust same to as ‘high’ a saute 8

_. +. his pumps would take. These re-exhausted ‘bulbs ©

“now show a:sensitiveness equal to those of the first .

ee four which eee exclusively that; -our éontention

_/° "is correct. For the work which we demand from

“2° “these bulbs they are not sufficiently ‘sensitive and —

:" we would be glad therefore if you will re-exhaust

| | “them. You certainly should be ‘able to putthem in’

‘- as good condition as the. aforesaid San Francisco a

ae ages glass-blower.” : Lak

‘The Qe ee discloses that the glass-blower. pelea to

heated ghe tubes under an asbestos hodd almost to the

collapsing point of the tube while. they were being ex:

“hausted. The references of the prior art which. reveal that

a lamp may be made to. collapse by heating under an

asbestos hood leave no room to ‘doubt. this testimony. |

: . 2Such heat was sufficient to heat to a certain degree the.

_ metal electrodes. as well as the walls of the tube, thereby.

: driving off from the electrodes as well as the walls some.

of the gases occluded therein, The energy of the dis-,

. charge of the DeForest tube was low. The bombardment ‘g

- was probably not adequate to heat the anode to a t@n-.

peraturepeven approximating that to which it was raised.

by the Bunsen burner under the asbestos hood. Conse-

‘quently, little, if any, occluded gas would escape from the

anode and the gas cleanup effect probably tended to im-

ve

*

. for reasons conflicting with Mihie of the Santis of. In: -

terferences.. . The Commissioner of Patents: awardea |

_ priority to Arnold. The Court of Appeals of the District -

_of Columbia decided in favor. of Langmuir for. the rea- ©

sons stated by the Examiner of Interferences and the

Board of Examiners-in-Chief. «I am in accord with neither

of the divergent views expressed by the Examiner of In-

- terferences and-the Board of Examiners-in-Chief but,

"generally, with the reasoning and conclusion of the Com- - =

_ missioner of Patents. The defendant asserts that Arnold

_ is entitled to the date of November 1, 1912. ‘Upon that

date Arnold, who because of his training and experience

in the matter of electrical discharges in vacuum and

’ upon the recommendation of Dr. Robert A. Millikan, hiady

been theretofore employed by Western Electric Company’ |

_ to aid in making possible trans-conti ental telephone ser-

vice at.the opening of the San Francisco Exposition, was

shown by Doctors Jewett and Colpitts a DeForest tube

that had been brought by DeForest to the Western Elec-

tric Company a day or so before. Arnold examined the

audion and tested its performance as a repeater of speech

currents. It functioned well with weak currents but —

' choked, distorted the speech and ‘blue hazed when in-

et creased plate voltage or loud speech currents were ap-

plied. “Though Arnold had been engaged in perfecting

different device of his own to be employed for telephone _ a

po=s4 purposes, he instantly saw that the performance of -

its existing sore

ois ae wie thewpeed one effect and that it tech kee

me

= The tubessused: © _

Forest tube does not’ negative its being a tube of ‘the pat®

mr -

high plate picts to. obtain’ the desined sinctrsin. ote

_ from cathode to anode. Corroboration of the oral testi+

mony of Arnold, Colpitts and Jewett, if needed, is to be

- found in the fact that every act of the Telephone Come -

. pany from. that time on is consistent only with the in-"

tended use of the audion made more rugged and with-a :

. higher vacuum in its trans-continental service. Arnold’s

conception of the invention, consisting in ‘the ‘full per-

- formance of the mental part of the inventive act, was _

complete. Nothing remained to be done but to give the ~

device practical embodiment with reasonable diligence. ee

- If, in view of the fact that those skilled in the evacuating =

_ art knew how to reduce to physical form Arnold’s mental

-* gonception, a physical reduction of his conception: to prac-

tice was necessary, and I think it was not, McCormick:

Harvester Mach. Co. v. Minneapolis Harvester Works; 42 _

' Fed. 152, 155. Otto v. Linford, 46 L. T. (N. $.) 35, this:

requirement was performed by ‘Arnold. with reasonable —

- diligence, thus giving to him an effective date of Novem- -

ber 1, 1912. - He obtained, knowingly, inf@fat month with

_audion 7-A a current of 3 milliamper +s at 80 volts without

substantial ionization. Again, Arnold met the require;

ments of reduction to practice in April and May of 1913. |

In the tubes of these experim::nts 250 volts were impressed

oe ‘

in Philadelphia in the fall of 1913 functioned. well for

‘maity hours, one as long as 267 hours as commercial

repeaters. The fact that the output energy. of one $: aes

"these tubes was less than that of the usudl, oi ‘De -

eat, for the output ‘energy of claim 26 is likewise lest :

- than. the’ output energy of the usual, old DeForest tube. -

: Ssapaisond it seems to me that other claims of the patent,

- for example il, — was an | original claim, differs bestest joe

. 5 : a Senta:

a ; ' : sett

S% ; ¥ é 28. ¢

; oes : ea :

&

%

Biss

~ $6-is the:same way and only in the same way that claim

26 differs from the original DeForest device. a

, Langmuir began his experiments in August of 1912. He —

- now asserts and the defendant denies that he then ob-

tained a pure electron discharge substantially unaffected =

by positive ionization but concedes, XQ380, that though ©

che now knows that he did then obtain such a: discharge 3 sf

: he did not know, it then. This lack of contemporaneous ==

| knowledge denies to his August’work any effective value

>. upon the issue of priority. Robinson on Patents, Sec. 79, -

5 pie. 121. In November Langmuir made other experiments |

-” but these he concedes were for the purpose of ascertain-

- ing the accuracy and existence of certain laws of physics.

‘. ] find no evidence. that he then thought of applying the —

scientific principles in which he was interested to-any

- practical result in the useful arts. Consequently, there is. -

* no satisfactory evidence that Langmuir had a conception -

- of the device of the ‘patent before the end of November. |

. “It-is not while the creative energies are at work shaping §

«and sharpening the idea of means that the conception of

’ the invention becomes. perfect. It is when these energies

have ceased to act; when the idea stands before the mental =~

__* vision of the inventor as clearly asa concrete invention =

before | the eyes of an observer, that the conception is

comple and the work of reduction is ready to begin.” ae

Rok nsdn on Patents, Sec. 379. Tested by this rule even _

ES es

ale athedy and achat on the electron dia --

shall attempt to get the vacuum so good that positive.

jons are present in negligible. amounts.” It is not neces-

sary. to inquire when ‘the conception became complete

and his idea reduced to practice for Arnold had had the —

conception long before and had gree —_->

‘reduce it to practice. ~

The bill of complaint in this case ‘must be dismissed.

' lee : nee “Hoon M. Mons, J

Jaruary 3, 1928. a et , Tags

_ The Opinion a Woolley.

aa ae ae

UNITED > STATES CIRCUIT ‘COURT OF APPEALS, -

‘FOR THE ‘THIRD. CIRCUIT, © :

GENERAL ELectaic CoMPANy, ~

eres: Appellant, | \arch Panis

DeForest Rapio Company, es ee Le

; _ Appellee.

Woo Cireuit Judge, diencating:

“Tam: constrained to dissent from the judgment of the

> court: holding the Langmuir patent ‘No. 1,558,436 valid. .

Ss have the same trouble that other tribunals have aPyy

- throughout the twelve years of the patent prosecution ©

and five: years of the patent’s life in finding precisely

hat Langmuir. invented. My trouble, like that of others, .

has been increased by the difficulty which attorneys for —

pater i had in defining the invention and by the

»

ee

*

. The siet-sanale two related arts—is that of wire ong

‘chaeis telephony, the latter: commonly called radio. ©

The invention relates. generally to. an electron discharge

device comprising the familiar vacuum tube in: which

. . the customar'y electric current is carried by negative

charges called electrons from the cathode to the anode, »

gometiines. associated with a grid, and relates particu-

‘larly to a vacuum space so free from gases as to avoid

ionization. If the parts and principles of the mechanical —

construction were new and the gas evacuation’ old, there

might be invention; and also if the structure and its prin-

ciples were old and the gas evacuation—high vacuum—

were new, still: there might be invention. But the essen--

tial parts. and principles’ of the mechanism, comprising —

a tube, cathode, anode and grid, were old, and high

vacuutn.in the tube also was’ old. So the inventor was_

_ forced.to admit the presence of these’ old elements, yet,

still insisting he had created something new, he was”

compelled. to avoid the common art terms applicable

to these elements and particularly that. of “high vacuum”

in disclosing his invention and use technical terms which,

as I understand them, mean the same old things. - With —

this necessarily general preface to a highly: complicated —

situation arising out.of a difficult ~~ I come #40 the mati

ters. in hand. cae

In an effort to find what iataganie teveuted i wines

‘to begin at the beginning. I shall therefore turn to his:

application for a patent, for in that instrument must -

appear the substance of the invention as the basis f et F

ale —— amendments and for’ the _— as _ even"

i pallGeh dd te dnlectel Howat a Sateen 4 we

cae in chet tat es Sa PP

ugh the Patent Office is dreary reading yet, in this

“wan far: from: ‘certain. what he had invented. Naturally

> Lchesitate to say this: about Irving Langmuir, a great —

ae _ physicist, yet, saying it with entire respect, 1am: con-

_. -vineed that the history of the application establishes that

-. factand therefore is pertinent. tothe ‘ever "present in:

quiry: What did Langmuir invent?» ! =

| {Fhe patent issued on October 20, 1925. ‘The dietetic

ie tion was filed on. October 16, 1913; renewed March 14,

1916... These are critical dates. The original’ application’

contained five claims; two for'process:of removing ioni-)

gable gas from vacuum electron discharge devices, that:

7 Maclealaln words, tewcbtaiting 9 Ulf variienyent trey

. for methods of preparing such devices, and no claims

for discharge devices themselves. The specification con-:

- formed:to these claims, referred to the. art, stated the

_. problem, disclosed) construction adapted to the Operative: be

- principle of. such tubes and showed how they can be

' “evacuated” of gases by heating the glass walls, heating. ee

e and. bombarding the metal parts thereby expelling oc-

oe cluded gases, and drawing off both free gases and ex-'

Paid denne by naliablo nvnconting meres for engages:

ESS a €aede molécular pump.” Pe EE eee

et lows: or 1918; eight in 1914; one in 1915; ‘ve in 1016: ae

is u7jthiee in 1919 and abe dertin - Been’ = : ney

were fled ia additions enna ane

if made as follows: four in’ 1913;

Kg fifteen in 1914; twenty: in 1916; five in 1917; nine in'd919;

five in 1921 and forty-two in’ 1925, the -year of the patent.

. Analyzing these: amendments, it appears that the’ five’

original claims (which ‘were for process and method)

were at different ‘times wholly cancelled. Late in’ the

year 1913 Langmuir first madé:claim to invention of a

structure or Wevice, that is, fo inyention of a tdbe. “This

he did by four claims. The first was. amended four times’

and cancelled ini 1925. The second also was amended

four times and cancelled in 1925. The third wap amended

four ties and was not cancelled. ‘The fourth was’

amended once and: cancelled in 1925, Of the thirty-two —

dims allowed in the ‘issued patent, four are\for method

_ and process, being amplifications of the original method © ey

and process claims cancelled; twenty-eight are fora —

_- > device. Of chese device claims one was filed by amend-

ment in: 1913; one.in 1917; nine in’1919; three’in 1921'

" and fourteen in 1926, the year the patent issued. Beat

_,. ing on the question ‘whether Langmuir knew and diss

eos dosed in: 1913, or indeed in succeeding years, w! what he aed

had invented, it is significant to note that during twelve’

_' years, and mainly in the latter part of that period when

? a few had grown and reached a high stature, he re" ba

- wrote, by six ven “amendments, the major part of his’ oe

sto menine ee ae a ee rome |

ie in he mater at But deve

certain. devices of: the the prior art of which two

wii Ath es3

Toone eg

Amvantcen,:hepegiet into a very feeble art a

; ys

35 fe

AY

as ar amplifying telephone relay, thus making possible

the first transmission of vocal words from coast to coast

by wire. In 1917 the DeForest Radio Telephone Com-

pany, assignee of the DeForest patent, granted (with cer~ —

tain rights reserved) a license to. the Western Electric

- Company to mmke, use and sell the invention for cer+

tain purposes with the right to grant sub-licenses. In

. 1920 the General Electric Company, the plaintiff in this

“quit and: the assignee of the Langmuir patent in suit,

acquired through mesne conveyances a sub-license to

make, use and sell the DeForest audion, DeForest Radio

T.-& T. Co. v. Radio Corporation of America, :2) Fed.

(2d) 598, 599, 600, which (probably with a

rowing Seaplane seat pe =

2 ee nee a

” twelve’ years of ‘travail. in the Patent: Office; issued to

Langmuir, assignor to the General Electric Company; for

"an elediron discharge tube including the essential parts

and now universally accepted principles of the Fleming- -

_ DeForest tube.” The Langmuir patent now completely

» overs the field previously occupied by the audion, of the

% a

fh eheiclnhineidinandcinin: mcenatbiieetcaa

the best electrical result—and in the fact that, as I read

the record, ihese ‘three elements, separately and it com- sat

bination, operate on the same principle in which they =

operated in the art. Describing their iain > the

art then knew it. Laiigmuir said : : 5

. “The passage of an electric current across. a ‘tube :

& ordinerily involves “the movement of negative, ~

' charges called electrons which; under the influence.

of the impressed voltage, pass from the cathode

: to the anode through the vacuous space. - If these

‘electrons. when moving above a coktatin velocity

collide with gas molecules they tend to ionize the

. molecules, splitting them up- info electrons and

“larger and more slowly moving ions. Under these

circumstances the phenomena of conduction across

the tubes are ‘the result of the action and inter-

action of electrons and the ions;\* * : The.

cathode under these conditions is-disintegrated; .

*..* %, which causes its. rapid destruction. * *.*

The bombardment of the cafhode by positive ions

- ‘also causes heating of the cathode. The ionization

of gases at low pressures by collision -with

_ trons occurs at definitely determinable vol

these: voltages being known as the’:

"* * ™. {It should, for later use, be/ noted

that Langmuir said nothing about Es

| posed medium for conducting electrons from

ating: has: to, the other.) . :

ae “If for a given cathode seniperdiu the voliage: 5 eee

3 = motte nak ees -

op liberated atthe cathode to be drawn away, then * : site

east Sage neapaporpamitaerge pom iat ee

ain enh the carvet cab

a 37

#.

"He more ay designated merely a saturation oo

_If for a given cathode temperature the voltage is.

3 ~ not high ehough to cause-all of the electrons which —

--are emitted or liberated at the cathode tobe drawn — -

| * . @way, the. operation occurs in a range below the

saturation range. Operation in this range esd se

bce of as-operation below saturation: °

*

" deadinl Evite elbedsten dothittinie it inhedinlall

saturation Langmuir by claim 2, which has been treated

i GHEE Ree SEE Se ae ee

as tion is: :

eo . “A discharge. tube having a. oauiadla adapted to.

emit électrons and an anode adapted to receive

said emitted electrons, the tube walls being fash- -

parte shaped to permit the direct. passage of.

ul proportion of said electrons.from cathode

ode, the gas content or residue of said tube ~ —

ap age i cages ager gy age te gern

a Such that the tube is capable of being so operated

zs ‘in a range; below saturation and materially above

°°" jonization voltages that the space current is gov-

erned or limited by the electric field of said elec-

trons substantially unaffected by. pane joniza-

oon"

s

elie ue hsentt hij ‘cinigly dines “tags Wallan we Se

a tube properiy fashioned and shaped by skilled 2

and highly (thoroughly), evacuated of. gases—free and. ———

| aaeret range Oaneecth2 with a, two, electren. gremy -—

_ or with a group of two electrons, and # grid produce these’

+ Tesults; both groups, then and now, being in common

as oe cae nota grants mt pails Sos ae

ot -

os yn, high vacuum Ngee sana shoes a ook

| Gey aa bye nae en © gh acum

tube means a non-gaseous tube. . If the language of ‘the

_dlaims means high vacuum, it is prior art, for the art

was entirely familiar with the fact and effect:of sucha

' ‘vacuum; and if prier art, Langmuir invented nothing. Toe

“When the patent came into litigation in this case in.

the District Court of-the United States for the District.

of Delaware the learned trial judge, having trouble with...

the claims, endeavored to get from the plaintiff a defi-

nition of the- invention, asking time and again, as. did

this couri on 2ppeal: If not high vacuum, what is the

invention? An answer to this question seemingly had

_ its difficulties. The plaintiff, of course, could not say that

the invention was high vacuum alone, or high vacuum

in combination with Fleming and DeForest alone,

for that would be ap admission of old and would

' imstantly avoid the patent. It was f to admit that’)

the Langmuir device included all these old @lements but

claimed it included “something else.” So, eventually, in

- . order to show this something ¢else—something nev--it

produced, under the insistence of the trial-court, this care-

*. fully. constructed definition of Langmuir’s invention, on

: which the case was tried below and on which it was first

argued-and deded in: this court on appeal: Be

“The Langmuir invention is a coordination of oe

= __ elements having a-new functional relationmhetween

| SS ee Feoult foals Se

ssa’.

sh ¢

Phi kc ance piper l y

& Gece ponigiaths AudprapesmiMnti gr y-S ha

NS FEAT Pe >

AM BP - i

is £47 a ere" REA Gs ote

Phe fe an Py eeu e Coit

0 EA BRT e : R

O9 PA

Py

‘ rye

shat; Uurining;'sooubd beni toad pate alien! : Beers ©

ever, as it was intended to describe the invention more —

_ ‘early and moré definitely than Langmuir had dieconed

it in the patent claims I shall take it as it is written and

try to find what it means. I discern in its generalization =

_. three factors: (1) gas pressure in the tube; (2) “shape, -

size and space relation or geometry of the parts ‘of: the ss

tube”; and (3) the: relation of one to ‘the other.) = :

The first factor of gas pressure, or, more ‘properly, the

lack of it, if it means anything, must mean a minimum

of gas. This in turn means high vacuum. If it does not

. mean high vacuum there is no new vacuum factor ‘of

invention in the device, for low. vacuum ‘yas old and.

that isan end to the case. If-it does mean high vacuum

‘then again it is not new, for high vacua, their uses and

effect and how to produce them, were —_ meetin: ‘end:

practiced in the art. . |

Phe second factor, or ‘ “geometry,” of the physical Sine?

‘eleihents is not, so far as the claims reveal, involved in

the invention. The physical elements themselves: were‘

old, This the plaintiff admits. Though differing in shape -

_ ffom some-others, they are not claimed to be inventively —

wOvel in themselves, Indeed, each claim describes the — a

: ' iivention not so muclrby its parts as by its characteristics ~

of operation and results—tharacteristics inherent in any

@lectron discharge tube possessing a high vacuum. Nor

‘was this an inadvertence for when the Examiner, on

: 0 ao ean diab eer ben

said: sali ih ee ——

=

. Bebe 3 applicant's device is an ‘jeeeiveeil over

-... the ‘reference he should define -the differen: = by

structural: limitations,” the ‘applicant he ges. comieie

_ replied by saying:

= “The ‘structural limitations? in this case ‘are 1

" be —— in the ee bl vacuum.” ~~

ee

,

OD ERO

. So, thus far, the invention, with old parts and a high —

vacuum, gets back to: the: question whether there was

ee invention in the “difference” between low vacuum and

ae high peconny.t difference existing in 1 and known to the ae e

; The. third i the oidathend of dans rire cin of

‘gas pressure and physical parts, appears. nowhere in the.

claim unless it be implicit in the words “the gas content

or residue of said tube and the relation of the parts of es

the tube being such” as to’produce a certain result. (Gas

_. pressure is scarcely a part of a tube.).. If it isso implied; ©

- Langmuir cannot claim*invention by implication. :The Se

claim therefore is void for inadequate disclosure. If it

is not so implied, there is no claim for thé third factor. ;

=o _ Whether I am right or wrong in this analysis of the |

plaintiff's statement of Langmuir’s invention or in.my =

_ disposition.of its. elements is not importani for the validity ae

of the patent depends not on the plaintiff's. conception es

se and efinifios of the invention. but on the claims of mes =

pene ; peers

ro aa 5 nang hack to the claims of the Laiageaelt vanes ae

= to find. -Langmuir’s invention. But before doing thatol. eS.

-arrested by. still anotHer entirely néw definition of =

uir’s invention, this time made by the court in its’ —

pines (id net sont san: eet ene :

___ tube ‘is evidenced by its earnest and repeated

‘he tentelioni bat as the invention wo defined was old *

‘cannot avvee to hold a patent for it valid. ees

“It now appears, and I say this with entire respect, that

in interpreting “and sustaining ‘the patent broadly for . =

Tapas tube the court has given the plaintiff more

than it ever dared to claim. © ‘A high vacuum or non-

| gaseous tube being ‘old, the plaintiff knew that an ad- .

‘mission that the invention was a non-gaseous tube and

nothing else would defeat the patent. Langmuir also

"must have known that a non-gaseous tube was old for’

otherwise, if he had believed he was the first to concdive

and make one, he could, and doubtless would, have —

. daimed it in a half dozen words: “A non-gaseous dis- =

charge tube,” or “an electrica] discharge device with a

high vacuum tube,” whereas in his original application _

for a patent he made’no claim for a tube of that kind -

or, indeed, for a tube of any kind, the inevitable inference

being that at that time he thought all he had invented”

was a new method or process of gas evacuation, that is;

anew way-to produce an old thing. But that the plain-

‘tiff realized the necessity of claiming for the invention

something more than a high vacuum tube or non-gaseous af

a that Langmuir’s invention, while. including a non-ga! ee

tube—high vacuum—admittedly old, included “

else,” that something else being. disclosed by the re

- | mainder of the long claims and interpreted in its quoted oe

-. definition. The plaintiff nowhere and at no time has

--. claimed that ‘Langmuir’ invented ‘a nor-gaseous tube’

: oe Seaoan Aad ~— so, ‘for it well knew ssa while not : a _ |

Wein a AS

the artsin 1943 would effect, and that was.substantially

ee __ Above the ionization point, which is the crux of this case ;

, Returning to the’ patent claims and using claim 2 for :

| eleacidilant: & Allee Md Shininnestind tacaecslecliog i"

discharge tub’: which is capable of: being operated below soe

‘saturation and above ionization voltages. Langmuir called’

this a “pure electron discharge device”—“pure” because ©

unaffected by. gas. ionization which . either eee:

- - -gbsent:or negligible. 5S |

> .. Electricity is an elusive subject. Saccitess I shall, fon

the immediate purpose, restate in —— ve, if I can,

_-the theory. of ionization. — :

a fonization is an. effect iened by passing an Sleabdla

=. aisha Givenig hs liek outdid -reiapiiand,-dni x Sntteanin:tols

_ whien it has not been thoroughly evacuated. The myriads |

. of electrons, when: passing from cathode to anode above.

*. “a certain velocity, collide with and break up the mole- -

: cules of gas present and charge the resultant broken parts. :

~ or ions with positive charges of electricity. Thus elec-

tric reaction, is inevitable. The ions (with theit positive ;

charges of electricity) fight against the electrons (with -_

- their negative charges) in the normal flow of the latter =

- from cathode to anode resulting, at high voltages, in a :

en Oe nstion et bed orton a S88

‘to be avoided. The central point of. this. statement: is

nization “occurs at certain voltages in an electron

> ™ * vi! 2 5

aie ona Renin tin eaten oes eee ake

» é ¥ 7

o- eas

on the electric discharge itself; and from err

ee t-cathode by ‘the héat of an électric current

© ait old; and after this; that both, the expelled gas and

= "free gas should be pumped out of the tube during the »

-. heating process (old) by “a suitable evacuating means — :

(eld) for example, a Gaéde molecular. pemee! then anew

German: invention.

: - Thil the: capital Sdaheniidet if ast: thi nets tone

‘ment, of Langmuir’s claimed invention, is as nearly as .

possible to: withdraw from the tube all gas, free and —

— in other words, to obtain as high a vacuum _

le. “When that is done ionization is avoidedand =

a opie: electron discharge — Was grantee ishend Se

Tilapia. was met in the Patent Office with the Law

Extininer s statement that: |

- "Tt is apparent after a review of the record that

| ‘there is no single element which is broadly novel

in the assemblage of elements making up an elec-

tron discharge device of the character defined in’,

the issue. An evacuated tube having therein oS

. incandescent electron emitting: cathode and an ©

, anode was old prior to the filing of Largmutr’s ap- —

_ plication, and methods of attaining high vacua, vacua,

_ gufficient to give a relatively pure electron dis-

charge in a properly designed tube were also well

a Fae — and available to — skilled in the eek ay -

ie | Was-that. statement. of the Law. Examines piss he “ a |

SS Ades. it was..Just here occurs my.sharpest. departure. —— =

from the: opinion of the court which is based, as Ihave

a Ship c0-gbas: Lam consimningt: to believe is an &§

were gaseous 0 and that Langmuir invention

~~ first to. conceive it and reduce it to: practice. ‘That

the. Examiner was right in saying that high vacua in.

” electron discharge tubes were old before Langmuir and

that a pure electron. discharge—the inevitable result in,

@ high vaccum non-gaseous tube and an impossible re-

‘sult in a gaseous low, ‘vacuum tube—also wasrold:is: sus-

| tained by many prior publications and “patents: The.

: “

(ALMA tlic tlanty erent

same prior publications and patents contradict, 1 think,

the court's holding that Langmuir was first to male and —

‘invent a non-gaseous tube. They. are so numerous that

it would not be permissible to quote“them in an opinion.

[shall therefore do nothing more than citeafewofthem,

“ranging from 1881 to 1912, found in the record and to

be used hy anyone who: should desire teacne rane eR us

‘statement or who may be charged with the- duty of:.re-

_., trying the issue. They are: ‘Lilienfeld, Fleming, Doase, ee

VorBaeyer, Bissel & Hagen, Malignani, Edison, Dwyer,

Duncan, Leonard, Soddy, Thatcher, Ghild; illumined by _ :

the testimony of Waterman: and Chaffee.

dui teeed velereicen I athens: ‘and on them I would hold #

"the patent invalid for want of invention. °

Passing from the erature and patents of the prior

“ Lap cgualbbmog wimanty Sapir

temo fli hie 7s

‘oscillation detector or audion then normally having @

gas content. It was,a “gassy” tube. But desiring to use

oe not as a detector but as an amplifier, as later it was

_. glmost. universally used and indeed’ as made, for that

: use by the plaintiff itself under license and: by the West-

Electric & Manufacturing : -Company, its ‘sub-

“5 - ficensee, he had the audion exhausted of gas as far as

it was possible in that day. That is, he sought and ob-

tained as high a vacuum in-the tube as existing means

would produce. When the vacua were too low and the ~

amplications poor he gomplained to the manufacturer

and had the tubes re-exhausted. During that period

~ (1910, 1911-and 1912) the Federal Telegraph ‘Company

used DeForest’s amplifying audion at 54-and 6714 volts.

This was possible ouly because he had exhausted the tubes |

of gas, which otherwise would produce ionization at 20

~ to 30 volts, and thereby heightened the vacuum above -

that danger. line. This was “high vacut vacuum” within the

| definition of vacuum ebove-the point of ionization and

: was therefore high. vacuum within: the sense of those —

| words as used in ‘this case. It was not.so high as that

later attained by more ‘modern means, for’ instance the

“Gaede molecular pump, which had just come’ into the

ee art at. the time of the patent: application, referred to by

noe Langmuir in his application and. invented not. by him

but by Gaede. I agree with the court that DeForestidid

BE _not then understand the change in operative principle

_- for-in-later years ‘he expressed views contrary to those’

- addvanced’both.before and after that time. “But DeForest

ee ce

tion from detectors to.amplifiers. Whether he knew the -

winciple of the change is of no consequence. ‘The fact

h aves And:he did it before Langmuir. And by

y ‘; rely “i phy 4% my <x

Pos 31 ; ‘ pi aa re ¥ ght.

Ra i key ie! RE Oe ly Sey ;

i i + Sad d ot 7 Fit

pike b

j Ae | ry

. i ;

Bee -

: o

:

1 magi d omceisreeennen peace

three years before Langmuir, the very: Sechaties

of Langmuir’s.claimed-invention. come ges

; sii hadi hein sath aliens: Ae dated italian plies.

"equally. to the method.and. process claims. pattie Vaso :

_-On the subject of validity.as involving invention. I shall on

saiatelins, thin. sien of the. discussion by referring very: rs

briefly to the claimed advance made in the art by Lang-

muir’s. invention, matter.with which the plaintiff very _

earnestly began and ended. discussion in its brief and at |

the argument and matter by which the court: was imy ‘a

pressed.. Admittedly, when invention is in doubt—yet i

| only when it is in doubt—favorable reception by the art

- mney be placed in the scale. As the four judges who

git heard this case have divided evenly on the question of |

: invention, I shall, for that reason only,‘assume there is

doubt as to. invention. The plaintiff says that today

_treryhody. tases, “the Langmaic tub.” s: name: given dt |

oa the seioiidinenn lamp art. Auettioe sinciaanl

tthe incandescent p art and transferred to. tem

grt was: that of the Just ‘and Hanaman unstable qui

fungaten filament displacing Edison’s bamboo ‘ilar

- gtill-another was Coolidge’s method for obtaining af

| ment of pure tungsten, strong and stable. ‘tegelaneee

the radio art itself. came from many inventors, At ‘one

time there were seven thousand applications for patents’

pending in the radio section of the Patent Office. To

mention only one or ‘two inventions, they include dis-

- gharge devices of. the Fleming two electrode type and the

‘DeForest trpe. with a grid added to Fleming, the feed-

| back circuit invented at different times by DeForest, —

Armstrong, Langmuir and Meissner. There; are’ many

more, without any one of which it-has always been said

+ ~ by the particular inventor that the art would have gotten

| ‘nowhere. And now the plaintiff here says the same of

- Langmuir. Important and indeed great ds some of these ~

~ inventions. were, no one of them js entitled to all credit

‘for what has been accomplished in this great art, for

_ the art has been impelled. forward by hundreds of in-

‘ventors and- thousands of skilled workers; What: Lang-

- muir claims to have done—procured pure electron dis- -

qharge abo¥e ionization voltages in tubes of the DeForest.

ee type—appears to me to be the natural growth of the art, —

) begun by others before Langmuir and by them reduced —

Sak to practice with means then available, and developed to

"._ their later perfection during the twelve years of his patent

~~ prosecution through the Patent Office.

ces » TL thought affé? the argument, and still, think, the Lang-

we muir patent invalid because of lack of invention and. .

wior use. If I am wrong aid-the patent really:inyolves.

~

we

mn, then, again, I think it invalid for, as I read.

> 6

’

,

inventor, On this point, to avoid repetition, I refer and: 2

' subseribe to the opinion of Judge Morris holding on évi-

dence substantially greater than the eviderice in the inter

. ference. proceeding that, if invention, Arnold. was fhe fret

: * and original inventor, © ;

‘And so this court, one judge deciding attrnned, the .

decree_.of the District Court, on its, opinion, holding the \e

Langmuir patent invalid. Ton \

In due course the plaintifr fled a petition for, rehearing

based on this proposition; ~~ , se)

~“In-simple language, ‘Langmuir’s invention con- — -

“ited in taking out the conductor (gas) which was .

- in the Fleming valve and the DeForest audion and

_. putting nothing in, its place; he dispensed with’

‘-’ what was regarded ds an essentialeelement in the ~ -

_. , operation of the tube (gas). and by doing sc made

oe . tube which worked infinitely better,”

The petition was allowed and the reargumenit was based

on this entirely new statement of Langmuir’s invention

'. . miadé for the first time four. years after suit was Yrought, :

e five years after the patent was issued and seventeen years

_ after. the: me tion was filed. Of course if the*facts =

asserted were f established by the. evidence there - e o

would be no bt about what Langmuir did and’no

-_- doubt that it was invention and, cee res no doubt he? ae

was entitled fo a patent. = |

‘The plaintiff rests its proposition upon its ‘own state- sina

. ‘ment'that “Both Fleming and DeForest depended upon

Sas the: conductivity of gas as. ‘the fundamental basis of the: Bar Me

ere A f 5 ? ® os . f

: > Y Y re “49° a aN

ls: Wee u: ‘ *

* ‘

gor the theory of electron Yhovement in electron discharge

ee’ "tubes, some of whom based it on conduction by’ rarified |

gases or air, some on conduction -by ionized gases, ‘and

_ some not on cdnduction at all but-on free passage “of _

** ‘electrons through space in a high vacuum, that is, in the

absence of gas of air. And in’ addition. the plaintiffto

4h support its statement poirits to an adverse criticism by

|, DeForest in-2915 of Langmuir’s “extremely. high vacuum”

“quoted in the. court’s opinion. The plaintiff ignored all

} the testimony on the subjects of prior art high vacua and a

7 pute electron discharge, which means absence of gas as -

+ @ conductor, their advantages and uses, » which I have

prev iously alluded with citations. 25

Bin i course, if the belief and practice of the. art were’

* that gas conducts, the. electrons, that gas therefore is

> tea necessary to. conduction, and Langmuir. disgovered it to’ |

_ be wrong, that in fact-gas_is' an enemy to conduction,

ie and. omitted gas as an élement in his tube yet obtained

_ 2 the same of a better result, ‘clearly he made an inven-

* tion, . These are the things which new the plaintiff and 3

, also the court say he did. But Lenugmuir did not,say _

2 Cet If that was his invention he should five disclosed _ ae

_ itin his claims for we are called upon to judge the patent

i on’Langmuir’s disclosures, not on the plaintiff's: defini-

a tions of his inyention. To be ‘sure, he did refér in his

‘ ‘specification to. several tubes—the Geisler tubc and the

aoe ‘ Roentgen X-ray tube—“whose operation depends upon

~oocarneigsiellmied gee Beret

-on gas content. Buf he nowhere val tt his

ia a ag sc

| ef (gas ionization.” ‘He might, more or less correctly, have ae

"added to. the list detectors with gas content, thenand —

a ee me

t

a

| . in part based its judgment. = = *.

~~

4 9%

Pap ‘ . NS se

ee ; \

>. on ars Soh S at e.

_ to reproduce sounds. fone of the purposes a the De- Re

Forest audion and the thing we are dealing with in this: +

case) depended én low. vacuum or that the art regarded,

as an essential element of such a- device,.gas as a-con-

ductor, for 1e probably knew the contrary was ‘rue. To

. show that tl plaintiff’s last definition of Langmuir’s fine ae

' vention is without founda on in the évidence I refer to,”

but shail not. repeat, what have Said about: prior. knowl- ;

_edge and prior use of high vacuum tubes. I shall’ en-

deavor, very briefly, to show that Langmuir by his own ~

words contradicts the plai.atif’s last definition of his in. oA

- yention: and .refutes the theory on which the court has

6

In Larigmuir’s original specification he stated that when ;

there was: enough gas in the tube to become ionized by

the discharge of. electrons “The positive ions -(gas mole.

‘- cules) fake part in the conduction of cirrent, giving at

first erratic. readings on measuring instruments connected *

tinuing, he said, that the audion, the DeForest. tube, was,

__a deyice that took advantage of that ‘phenomenon. . “But

% Pak ot

an

'. >) Se

. ’ J Se

: he cancelled the quoted statement before the patcnt issued.

_ At the trial he was examined with: respect to that states

ment in, his patent. application and was asked whether

the sentence would be true if it read; “The positive ions ~

in. the conduction of current by, acting as

tor’ was left in for it is inconceivable |

in circuit,” which is what the plaintiff now says. Cone Ree 4

ah or carriers ‘of current.” He answered:. Te aw

\ Dtet eaten panne nna ;

>)

Pact eon

- With this cancellation and: ‘explanation Langonute

rested. Neither by amendment nor in ‘his testimonly did

. he again advert.to a prior art theory. of gas doniducfon, ae

which the plaintiff now says. “was regarded ‘by the art) “3

~ gs an essential element of the operati

= respect to the early work of. Lilienfeld, ‘as follows:

~ “Lilienfeld proved beyond ques ion, I think, that

he obtained: discharg ‘in some Cases at least, in.

_ which the effects that Ke measured were nof de- -

.

pendent upon gas ionization *. *

'. “Lilienfeld probably succeeded . in obtaining a

scribed in-his 1910 paper * *

walls of the vessel, he reduces. the gas pressure to

¥ we 2 — his electrodes by a _bombard-

: en e gre

. “Heating of glasi and olentrodie: i soheuatiaa

to low pressure, are elements which were used by

arti 2 * *

' “Wactor No. 1 which I gave in answer to XQ84, he

‘viz., that the bulb should be fieated during exhaust =»

“In the interference proceeding Lanigmulr. testified with »)

+ discharge ‘high vacung substantially free from.

_- : | effects of. positive ionization in the device he de- .

he “Lilienfeld in his experiments of 1910 heated the.

a low. value, and in seme of his iexperiments. he

Lilienfeld and were; Snowe prier, | a Litientelit's Pa |

st)

_ / ~~, to a’temperature materially higher than the operat--

con Jee temperature, ‘was used by Lilienfeld ‘in much - : x .

“yh “Pactor No. 4, ih is that which I gave inthe

“oat aa Ped casing nnd aba refers to the lower-

brings about no further change.’ In‘:

ce td iy 12 at i Te

tok Liliénfeld’s sot coaieaennniae this condition - :

* 4. 3

ae 7 wai <

;

i ORs ‘

hase oe " 3 ‘-) 3°

eee Aone,

vacuum to avoid the influence of jonization.” Langmuty

admitted that “Wehnelt eiaimed that * * * currents

of the order of 10 milliamperes could be obtained even

Sy: Lerelasapnenhconigrmel aa

_ Referring to an interview with Richardson in 1912

"Langmuir seid:

int ‘Atcharison - mS expressed himeelf as con:

" fident that even in the highest vacuum thermionic

currents could still be obtained.”

admitted in the iselorenae proceeding that

“prior to 1 1: (the yeat before his application) there ee

were some mano ge who “took Lop renencentiy tore |

Sropemetmrmmecoaias

.

Beene fore - .

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Aug. 17, 1923.

In ‘THR

“United States Patent Office

. | 4

' Anwovp v. Laxowur,

po :

Patent INTERFERENCE No. 40,380.

APPRAL FROM ‘Bxamnvens-1¥-Curer,

6

of

| Bunorn, Descteanns Arpanatos AND THE ‘Procuas OF.

- Priparina THE Same. ot

—_

<r n of Harold De Forest Arnold filed November 2,

me 69,210, _ Seats

ss of Irving Langmair filed March 14 ihe, a.

Wy far renewal of eppliontion fled: Ontober, 1%

soe

pap 8

x tthe AG Be

$e8. aS a talopbiie'é rite less detector or ampli- —

fier, # rectifier of stieroastag aibcke and possibly a genera =

- . = for of X-rays. Iti is the device of. defeddant in Hewitt», .

o peor f: and T. Co.,. 272 Fed. Rep., 194, and 272 Fed: .

ee) < eps 392. The invention is exemplified by a strac {re such

as the well known De Forest audion or Fleming Val 6 (200

wh sf Marconi Co. v. De Forest Co., 236 Fed. Rep., 942), mddified

- ff so thai there. is present during operation too little gas to.

cs or affect the pure electron discharge from the ¢ ~ " 2

: The applications were, filed in 1913 (renewed in 1916

| 1915. After the inte sug ch Eyer ‘Arnold:

=

a 2 . : 5 . ; :

* one of whieh is ‘adapted to emit electrons, the Lote

“+, eontent. or residue of said tube and the relation of —

=) the parts of the tube Being «ich that the tube is capa: ,

"ble of being so operated in a range below saturation

- .. > and-materiajly above ionization voltages that in that |

/ .° 4 pange the space current is governed by the combiged —

<4 potentials applied to said electrodes, the governing

‘> or limiting of the ‘current being substantially un-

Cane affected by positive ionization and ty —e eles...

Pp toh Smee emission rome the walls of the tube. « t

. € oat ae discharge device comprising a she and elec-

... trodes therein one of which is adapted. to. emit elec-

trogs, the degree of evacuation and the relation of

_ ‘the parts te the device being such that the device is.’

. + « > ogapable of being so operated, when voltages mate- .

pabinck ridlly hig&er than ionization voltages are impressed _

ener -on electrodes of the device and when the electron

L emission has any. value such that the space. current

se - .. ig below the saturation region at, such voltages, that

ce ‘the line obtained by plotting the logarithms of any

ee values of said current below the saturation region

mo me as ordinates against the logarithms .of the corres- .

Pee aes ponding values of said .impressed voltages as a.

oes scismas is straight and continuous...

. 9. garde deve umprising a abe and de

_ trodes themgin one of which is an electron emitting

ea: : the degree of evacuation of device and

: ein per dre elng SU

df being so operated,

bi “ah calackatners ‘alin; nvinat whackeoden ‘st aie

effect of the electric field of said clectrons and the ~~

o

-

4

n. A denies tube hearted a esithode cilapiol “ae

emit electrons, an anode adapted to receive elec- ae

.trons and tube walls fashioned or shaped 80 as'to ->.

_ ‘permit the free passage of a useful proportion of

_° gaid electrons from cathode to anode, the gas con-

- - tent or residud of said tube and the relation of the

parts of the tube being such that the tube is capable

of operation with stable and reproducible results

substantially unaffected by positive ionization, with .

currents of at Jeast 5 milliamperes and with en

of at least 200 volts:

18. The method of controlling an electric current

*. in one cireuit by an electromotive force in another —

; circuit which consists in causing said current at volt-.

ages materially above ionization voltages to pass as

_ a discharge across a vacuous space between an elec- -

tron emitting cathode azid an’ anode, maintaining a

high vacuum in said space, governing or limiting the

current by a space charge effect in said space sub-

stantially ‘unaffected by positive ionization, and --

superimposing the effect of ‘said electromotive force =

_ on said space charge effect to control said current in’ ~

a stable and cies, Seay ‘Manner, : :

- the counts are- ably and clearly: analyzed by the ons

aminers-in-chief thus: ! Chae Petes

mids A thermionic tube witch operates solely by: glass i.

” <tron discharges‘ or currents has certain disiizdtive:

7 bresire pe gourd Ago swent ib gedaan dg bene

invention may be d, and the counts have ~ ©

7 cite mes Sons tack Eas out oie or more of

2 Mens thn | gone es sgn is evacuated to such a ve

f= - 2

ae, roi

y

cas ; ag eer tis» 2, PERRIS TEAR

* S : rg ae . i 4 “ by a ee aa hg ys ie e . 5 4 ee

pA UGOY | Mantes Ray ey inet carat Pica rahe iit Bone Nr ares paren ES ats

FD ft SE CES GE TS Ree EAS

| while the device is bperating at or above a certai

ag os SENN * as ae ear be de Ponte: 3 fosy ve ‘ ‘ o

: ¥ " fie v.

ui . »

‘degree ‘that count 1 calls for and, at an. impressed .

voltage of about 30, ionization occurs. Count 5.

specifies that the relation of the parts of the tube —

and the“degree of evagnation are such that, when

fe ie voltage. The audion is por evacuated | ie the high:

operated in a range below saturation a materially fe

above ionization voltages, #4he space current is gov-- -

-‘erned by the combined effect of the ales tric field of —

the electrons and the potentials applied to the elec-

_ trodes, the governing or limiting of the current str

io substantially unaffected by secondary electron.emis-

age sion: from the walls of the tube. ~

When a thermionié tubo is operating by a pure

_electronig discharge-at.a voltage substantially. below

saturation, the current varies.in substantial accord-

ance with the 3/2 power of the impressed aon ge. If ©

. ‘." sthe voltages be plotted as abscissas and :

| as ordinates, the result is a-curve that peasants

and turns toward the left—the curve of the 372 >

a

* ,

‘power. This obtains while there are plenty of elec-

3 <i . $P0ns emitted from the cathode, at the temperature

me es ih which it. is heated, to make ap the increasing

. ‘eurrent, But the number of electrons e emitted varies

with the temperature ofthe cathode pe that tem-

perature is, generally maintained constant. Cohse-

- quently, a voltage will be reached’ w is capable —

- of

ats

- of forcing the electrons across the space more rapidly _

>» than they van be emitted. The result is the flat-

at See topped curve showing saturation. The tubes of the

. . issue are operated at voltages above that of ioniza-:

S™ +‘ tion and below that of saturation, and the voltage

“... gurrent eurve follows the 3/2 power law. This is one”

of the charactéristics of the tubes; and a tube that —

peel ny Se Somapery meet seery of oh |

Se a :

’

a Oe soe ae

* tthe dldctioden na walls act like sponges, ‘thing ts up

- the gas when cola pao again giving it off :when heated >

~ during operation. A-tube which bar gas either in. ©

- @ normalfree st te or occluded in the. electrodes or . &

walls is subject ti ionization; and ionization takss =f .

rises sufficiently to produce.

“About 15 volts is sufficient to give this: result.

oe a tube which operates by ionizing-#. gas‘ does not

Tespond to the 3/2 power law. and is %ot a tube of 3

the issue. Excessive ionization is usually accom- °

ie panied by a blne glow or haze; but such a ‘glow #9 not

a reliable test, as both parties admit; since a tube

that does not show blue glow may produce ignization

to such a degree as to cause it to ore from the 3/2 .

power characteristic. = a)

| | Any tube which gives the 3/2 power voltage- 3 4

+. --@nrrent eurve must also give the straight-line when

- the volts and current are plotted on logarithmic

paper. These’two curves are plotted from the same ~

‘Gate and their differences are due simply fo the @.-

ee ae

| be plot.

pa | :

“~~ fed on! one kind of paper and the result ows a pure

electron | there can be no doubt what the

other kind of ‘paper would show.. Certain counts, as_

6 enc, call for the straight-line, while count § catls

refer othe elated of th ee

eurrent cee

a

“~<

» 7 | i

. Py ‘

‘

~ geross the field to it, tens satisicee nial That

‘is whatyhappen s in-the tubes of the issue. The elec-

trons are generated ted or emitted by the heated cathode; —

“and if there is’ no way. of neutralizing them they

- simply fill the space, charge it negatively, and react .

on one another.. But if the anode ‘be charged posi-

tively, the electrons fly across the field to it and be-

come neutralized. — This flow of electrons is a current;

and, assuming a sufficient emission of electrons, the’ —

strength of the current is dependent on the potential

"difference between the cathode and anode, If this

“difference is small, . comparatively few electrons get

through and the others continue to react on one an-.

other. If ne gas be present in the tube, either free’

or: oceluded, the current is astral by thaelectric {

- field of the electrons and the potential applied to the ©

"electrodes. If gas is sprain fot tne

These positively charged molecnles or ions remain in.

See acs J apporne OW

Py 2 , : .

4 \" ‘ ; R . bd

” . ‘ j ¥ . ee «

e

passage for the electrons is aes, narrow or crooked;

the electrons strike the walls of the tube ‘and adhere |

- thereto. This is exemplified by the Behe Ape -r ex- —

- ‘periments in which a long, crooked,'capillary-like

vA tube was employed. - Only a very minute current was,

eta, obtained although thousands of volts were employed. ©

L7ON: Furthermore, it-is not possible to remove all the gas, —-

a ene, when the passage for the electrons is restricted, .

ioniza n takes place even in avery high vacuam. .

Such as 5, 8 and 9 call for such a **pelation +

-¥ parts” as render the tube capable of producing

-eurrent governed by the combined effect of the py

. trie field of the electrons and the potentia applied

to the electrodes. Count 9 further states that the

current is substantially unaffected by secondary elec-

tron emission from the walls of the tube. Whenthe

_ walls are long, crooked or narrowly gpaced, thé elec- *

trons adhere to them, as stated, until they areknocked =.

loose by the electrons of the/primary discharge. <—

~ When thus Set free, they constitute a secondary elec. +

tron emission. . The count: further states that the

: current is substantially independent ‘gf the cathode e

. According to Richardson’s Law, which Sg

is extensively discussed in the records, the electra a

‘dhidales tenactae ats onsen ote tie ah s

~ perature of the latter. ‘But the number passing to

Soca anode, in a tube of the issue, bee ied Prscct

era}

9 : ; i) Deny

\

is no ‘idan this control is coven end the varia-

tions in the current foljow proportionately andina = -

_._, peproducible manner the variations of the electromo-

atte ie: tive feree applied to the grid.

} -. The invention in issue is, therefore, a thermionic.

tube that operates with a pure primary end substan- ye

tially no, secdidary discharge at voltages above jion- ..

- jzation and below saturation; and such 4 tube is to -

be recognized by its response to the characteristics

expressed ir. the several counts, The “tubes of counts ©

12 and 13 have three electrodes, while those of counts

1 to 11 may have two or more, these counts, ee

generic,

tTi@record 0 on the ih, and the ncncuneietne ex-

hibits were stipulated, i in for use. on priority, and during ¢

1921 and i929, upwards: of. 300 additional pages of testi-

mony were taken. Appeals were promptly taken in what ue

geome to be an honest effort of the parties to hasten a final

es [en We ee. Shiba Sait ne

: - The invention’ and. their devalewment have. téken place :

in the laboratories and shops of the Western Electric Com- |

?p ie Gegeral Electric Company. The parties

08a. al unlimited i bth personal and be

tothe decisions tow, bat beth atiempt

0, 80 “hat this decision may follow

if’ thene is patentability, it nist be as set out_j

of the law examiner bn the motion, and:l fo

y

rstand either party to attack that Suidides hevk: ;

— thst when he made the cyphesent a thought <

Lae a This in why he filed vo labe

I do not find it ti

This text is long and has been trimmed here. Open the source document for the complete record.