BSTJ 10: 2. April 1931: Some Optical Features in Two-Way Television. (Ives, Herbert E.)

4 MB·English

Some Optical Fealures in Two-Way Television”
Dy MURMERT 8. VE,

bse Sev he ena iti mln ae
Bidet nicingemes whereby he ae fie ntscue we peopel
Pare ae ein os Ys sahy ape Sr apc
Fane Cathet te nies eco Ses, ae te er
cakoterac may once thom hogy Wes

[ia imtesat str of he oo nay tevin sate thar ther
twee a continuously rou ie thedanage fe the distant
station, “Taebeorn searing onl ly wich a beast ight ewes
lover tae subjet's face enables the acanaing operon to In peered
va rninunn amet of Ket, Even ose he rea ey
Teo inlny ef the tlevision ings it fe mecesary Uo raduce the in
tenity ef the scanning bow hr every way pease, 1a the te way
spats an ft apetsted, adyantoge wi Laken a the [ac tha the
ler ie elle employed, which were of pouaiuen, were yinipaly
enstve to dive igae, “Ue acaaning bear derive! Foam igh pant
are lamp was actovdin'y yunsn’ Hnnugh deep Blue ttt, whic
Feeizoed the phleecsic eiccney of the Bent were el, hr Reese
file lava Lae viel vale of ie gh eleticly road the
Twighteees of the Begm Tiny’ fines. The urce ef the apgarauin si,
above she‘sermsing imvive, meray a mud blue spot of Ege, aie did
tht iceslene ili vison

2 dvculvanlge of te aoe of hue light, which was acticipated, and
founsl i prantine ta be quite zal. wes thet dark, Umm ur rudely
cunplevinns were seme 08 as alegstee too dare, fa compareon with
‘whites udm the vlnny Tinen ola Tho elect is poets that
‘:eeouateced in the earlier photographie poco lire aor arsine
Places and coloc Hers mere avila. Wile his leer ae ont
Irized by the wre of ailark laclgrevad, ard te some cxcent by chaps
(ve ighlights by elacueal weans, is was zcomrived a5 urdeeuabic

fisher ase, Jy 1
(ne recent mp-nvenentin dhe apparatus a change inthe nature of
Uhencning igh, wherthy, witout saving ee gezeral principe of
wing Vell inelicirat Tau phulilertrieally eleieat rlftion, Whe
proper habmoe nf one walis in the Fane i estore, This has heen
esr be ys In eer of he seasive potassium cell
S gen ef eal eile rau geile cell ant acaing by fauple
rete of ve Hight, 2hat #2. both eade of the wisble spectrum are
ve ia place of one end.

in making this chance, a number of uchere were involved, mst of
whieh resulted in seplifeatin oe Sepmovtimes One port
Essraton wes the sit tien forthe an asre previenny vie,
ft incandescent lamps of a type available from noon pieuuee projec
Sion petit wean in Fg. The ean ened Hf i ak
ter, four verse Aelia cal of sgt wie ed fs Fora with 3
Fellcror which ages the culs back on the iuerveuig spacte. As
fMficent condeoserseetem chrows a briliant eeceanerlar image oa the
Tracks of the scanning disc, which fs substaeriay uniform over the
whe ike Wil ths al Le sng ea aH eaves te pr
Jeetion lene bene engender an the heen as peace
fom the are. Chmsequenlly, Cur oenitie avase Crone the Teun
Frye of ie ie hl, che seanaing beam larg than before with,
somermalion Unwio hecangesl sbacpest daticition. Since, however
The woe af Une Lnu-wey appara x sated ins Hoel es, We baa Ae
‘opportunity t move far ou: of the plane ia which the dec hues are
ews, 20 thee this obiection is no serious. The setae uf this
bet tution wee Poofold. Tse won 2 great gain a simplicity of
Satins al pie ewane. Seon. the Lroadescext lamp, being. 2
heer enna eli cle elaively many tine a8 mel
se light oa doe che ate forte sare amount of blue, Consequently
tin an izcantsonae azap unie was fous which cave the emoun: of
Ie ig quizes tor the potasium cella the area exces of vod list
sade possi the nae ot cuatvely few crstum wile ell Sine
these arcintnkealyramehat rere anc shan aeons cll
the not reculs wae that vel signal compeccSle with the Blue algal
‘ould Lele by che stallion of ony tea cesium ells each ef ess
Tun lithe electese cea af che patassium eel

Te was found mast eoavenien: to meant che sw sion ce ells
lively infront of the abeecver, to ber side of the rierovheme, ad
above the opeaing ix the boosh through which the seanning, beam
fers a sigs Het the ining fae ae Ts amg
fmt foe Bigs 2. "Thon lesie s acing heel Us
ion is thas Usey anes muons inc dhe raion west selec
tions of the cule (ebich are wisi ght eure ae likly ve be seen
reece in croglasiee, Snoe, hums the hovel fs nocmaly rece
Somesrhat downer, vas palin these up borne Spaces are mot
rion eles in Li ee

“Two sles Tealives ei the bro-way eysteat which aeceed veviion
‘wen the cesium celle were adepred, were the vadable angle p-isms
sed 19 eigee the sczaning Sean upward or downxard, dependine on

the user's tight, ané the geneial illumination of the televisies:
here booth. Ast che variable angle prams, tee only charge called
foc was the stnitucion nf ashvematis prema, cocreted for eee ve
2d blue ight, ‘a caer ue prevent the ecannias beem from breaking
Tectivety feta too berms erga of lett. Ths pre
ever snr on of oe Ina 3 tsi He be
ot Fhe hice wall acct acer the potassium nor te exaiam cel
Tor this pspose. ¢ ioaoehramacie yrlleagrern ae une
bey euvering ll te kes with a combination of erage aad signa green
lesen. The poten el en thi et of Tigh ed
the crs ous were rewcernl a0 Ly placing ves chem, wisonce
Cover with sleep camete geacin, ‘This ehcine af Wanton ear
rade possible a salsmeiney general level of iumination of che hoot
sed |e airomeTngso the age withanticresducag sptsious igh

‘The traaniensa ol the pospe ites, the rsperse curve of the
otassium sd ouaium oxide cells, the radiacion curve of the ineandee-
Fret bie ae “che canning beam, and the tranemisioa curves of
the gliers sal mses tie Jape for gesezl iDumination, ale shown

1 £m ny esa tons wir ation fp ena i

in Fig. 4. Compatins thew ill: the response earve a ie exe, alo
Shown tke sere tre wil be evident hen she geneeal problem
“eating phot teri sigualbat marimun ecency without interfering
‘withthe general quality ofthe moe, or ceirale conditions of ue

ination, har bees scousee

Talore going. oa to desribe ue of che eptial ectuees ae re
ceiving rin, we may pase icin the improvements in che tle
ion sien! which have bern incroduesd Sy 2he evar jtalscuTbed
Tove enue, a sultant gait is che steadivesof eimage Cue

x0 BELL SISTEM TECUNSCEL JOUREAL

1 che climination of the are lamp, much of whose eetive radiation
wis fn the sre area whieh always wanders samen. Thee
chief gain, however. i in the tone quality ab the iauge of the face
The diferenee i very early show sf shu ers ey arrange 99 that
ither the potessirn ar the crn els omy Imes alecnatey,
fand can then be cil exponel together. Wish the potazeum elle
Tae salva vote, te tins seein yer tw al ed
trernidy compesiricshon sn-atued contrast wal ewes, Tih
Tights due to reflection on the sk are len ulseeve to be one of sale,
seth erst eller of wating of te ki. With Ue exc eis
‘esc the en Td le leds tnt ave geste a igh, and
faces ae ups Wo appear wtsy Ht, These etevenees weve aula,
bu: ethers not co obviously to be expected. have been observed. For
inseance, with the esa celle, the pupil ane iso che eye aze out
out with ates stating Hacknow, while with che pocesiut ctl
the cea! semua the exes ix be le The at aiaetory re
slecine lei ou steele ating, on ews ges the
Combination af the two ends of che apectrsm, gives, ik the case of the
face, ap fle: very Uke thet whic Ht rom: the middle of the vise
pcetrm would give, that i £9 "orthuchromatie" image, as it would
Feckeerihel iv phargeophy: wlile Ue defuctin af pena yates,
sc the je lie feo

Pasig now tothe receiving ead af tae cwo-way tial apparatus
tye va thai ce sparatin ts miginaly a2 up aa ei
Shue ine with vegeta holes vat used, immediately bela we
‘as a con ‘emp with a large Hac warercueltd cleecrede. On con
tinued opetscin, it wae found thas the hey carsene demanded ia
these lamps, in one to secre an image of sfhicertbrighenes,enueed
Seid sullering on Ue ciel clfecea glass wa! decesialig Tre=
‘quent ences af lamps A veny vadioalcheage isthe elise and aay
esi lta ees made by which ts undesirab'e eiation he Lew
remedied,

‘The change ithe disc con's in eubst-tuing forthe simp. Nipkow
dic, with its apiral ot hale. an slternativn form, stgeete also by
[plow in hich exch dike hole ae wean with condensing
ies, pained 0 0 Focus n craton wil fel lima
lego, al sage of the course on the dive hele, ‘Tie opti: arrange
sect is show i Eig. 4, and a photogceph ofthe die with lenses ad
fomp i: place in Fig. &. Refecing to Pig. , D reprecerts in section
the septs with pal of olen HF epese sal het Toes
Ten, fist in poison with respeet eo ft A dimause rel (Ste focal
leneh Z cepreonts a ined lens of diameter lange exch to cover the

tise fame ofthe picture and he Inve: P represcnt the glow fam
fecinade. A gient advantage of thin opieal arrangement is that the
tathode a che glow In ca ie made quite sal, and can be removed,
fs shown, to a eonlerabledintaace Lom the glass wal of the contain
ing tube,” To consequence ot ches charg in Loup espn, a very high
fharent dsasity ean be obtained for a rekitvely hie expenditure of
fnengy, with st the same tie along lem Bt.

"The ehadeasee lene die ie obser exneily asthe sple dse, by
the eye placed at 2. According tw Nipkow, when leer sre used 09
Ie is the Ties shina be covered wath difsing material. This
hot nasty in the present ees boven in the bina boot, the
fer ves hae very litle itd of don, aud acy neeesaey Use
his eye ie in the overlanpie cones of rays from ehe extreme hoes i
the fehl. By making the lenses of Large diameter vompared wit
thee focal Heng, he eid eale throush hich am image fe visible
inentiey adequate

‘The genecl characteristhn of i Tens antl ase showa ia Figs,
ang 5. The cathode is a heavy aig uf cope ato which a ballow
Slindvcal a unininmn eertrnle i sevewed, shielded rem the copper by
trict ani gle. Rersune of the lange mas of che copper, the waces-
Ceoling is no longer sustaacy. With lamps of thie ype, the amolier
{Sreus sed before males it possible tw nln niagen a” nue. grter
hulianey, whereby the controst evr the aug sad the seancing
light ie ei further inerensed beyond whac wea efare found eatie‘ae-
cexy. This rargin uf lrighlaese be so Laege that ic has bcos fou
posible to wee lps el with lin in lace of neon, giving a much
waiter image, more peasng ta ame people