US3046540A - Electro-optical translator - Google Patents

Description

July 24, 1962 Filed June 10. 1959 F. A. LlTZ ET AL ELECTRO-OPTICAL TRANSLATOR 5 Sheets-Sheet 1 IlIllIllIllllllIlIlIlllllIIll/lllIIlIllII/l/ L am;

BY MARCEL .1. VOGEL Madan/My.

'ATTORNEY July 24, 1962 F. A. LlTz TAL 3,046,540

ELECTRO-OPTICAL TRANsLA'roR 3 Sheets-Sheet 2 Filed June 10, 1959 July 24, 1962 F. A. LlTz ETAT. 3,046,540

, ELECTR0-0PTTCAL TRANsLAToR Filed June 1o, 1959 s sheets-sheet s f' ONDUCTNE y sTR|Rs ,l

RENT coNDuCTTvE TRANSPARENT MATERIAL CONDUCTA/E MA-Tf-RAL ELECTRoLuMlNEs-NT MATERIAL ELECTRO- LUMiNESCENT- PHOTOCONDUCT IVE TRANSLATOR FIG. 5

Y 3,046,540 t -Emscmo-forumcAIJ rnANsLATon FrankA; LitzA and Marcel J. Vogel, SanvJose, Calif., as-

`imsignorssto International-Business Machines Corpora- Ition, New York, NX., a corporation of New York Filed June 10, 1959, Ser; No. 819,401

y10 Claims. (Cl. 340-347) This invention relates in general to electro-opticalrtranslaters andrelates more particularly to such translators (utilizing lelt'ectroluminescent materials and photoconductive materials.

v The present invention contemplates a translating device in which'the infor-mationor data to be translated is convertedto variationsr in -the luminescence Yof discrete elee i. ments of an electroluminescent material, and these lumi-f nescent variations are sensed `by photoconductive elements through coded openings in `an opaquev coding element which is disposed between the'electroluminescent `material and the photoconductive material. The elements of electroluminescent material are preferably in the form of generally parallel stripswhich are selectively excitable under the control of the'in-fformation to bev ftranslated. Each off these strips is in registry with the corresponding series-lof coded openings in the vcoding element, so vthat the output from the coding element is an group of one or more lightl pulses from those openings which are'in-registrywith the luminescing strip or strips. These light 'pulses are the code representation of the' information being translated, and `are projected onto the photoconductive material.

The photoconductive material is preferably in the formfof generally parallel strips extending in a direction per# .f pendicular to the direction of extension'of the electroi` Y luminuescent strips `and in registry withthe coded openings. Those kphotoconductive strips which receive light.I pulses from the coded openings undergo a substantial" resistance change by virtue of'their photoconductive propf- -erties, and this resistance change is sensed to produce an Aoutput from the translator. The structure of the present invention is preferably-'of unitary 'formv with the -opaquef-f. Ycoding element interposed between the electroluminescentrr material and the'photoconductive material, and the en-i vftire structurernay lb'edisposed in an opaque enclosure.. 5v5 Y :45. ricatedfnin various fOr-ms, Such as. phtogranhic film,

The ytranslator of the'v present invention has a numiberI of vdifferent applications, such as ay decimahto-binary or :f1

-binarytodecimal converter, Ia read-only memory or a Vprogrammer lfor programming some type of apparatus in Y'response 'toJ-.aiprogram represented -by coded openings ink-Lef the coding element.

Y 4ltis th-ereforean'object of this invention to lprovides an improved electro-optical translator.

It is a further object of. the present invention to pro;L vide an improved electro-optical translator utilizing elec -i troluminescent materials.

of lan electrolumine'scent material and these variations are y sensed by photoconductive elements through coded open-,2

.ings inzan opaquecoding element.

. i Other `objects of thel mventionwrllj-be pointed out in- "the -following description and; clairnsrand, illustrated inV ffrthexaccompanying `drawings which disclose-by way of .f eXarnple', the ,principle of the invention;andthebest'mode' '.Igwhich hasibeen contemplated (if-.applyingv that principle..,

:1, In .the drawings:

FIG. l is an explodedperspectiveviewgillustrating the f f structure of atranslatorfin ,accordance-with the prese-nt l 70 same ydirection as .thetransparent ,conductive 'strips 26.

f invention;

i `FIG.12y is an elevationalyiew in cross section illustraty 3,046,540 Patented July 274,1962

r* rs ice lFIG.c 5 is a perspectivejview off an alternative embodiment of y"the present `invention'for programm-ingapparatus in'response to a program represented by'c'oded openings in a moving `coding element.

'Referring to FIG. liby character! reference, there is `shown'in exploded forma translatorll'of generally rectangular form.' The translator includes ya pair-lof plate vmembers 12 and 1310i glasslo other .transparent sub- 15' strate material, Ysuch as mic'a,liwhch -form the body of :the structure *on which the electrominescent and "photoconductive materials are supported. v'Member 12' is prog videdl on one surface with a layer 14 of transparent, electrically conductive 'material such as .stannie oxide. A layer 1-5' ofl electroluminescent material, suchsas ZnSCu, is-disposedonttransparent vconductive material 14, and electroluminescent material, 15 is 'overlaid with ispaced strips 16 of electrically conductive material such as silver or' aluminum. The elementsjlkl 15 and 16 form the meansr for converting-information into variations; in the Vlur'riinesce'nce of the,electroluminescentmaterial15. Al-

y though-the operation will-beidescribed in more detail below, ,itl-willbe clear at'this point ,thatbyqsupplying electrical..currents "to, selected o nespfl the Velectrically conductive strips 16, the portions ofwtheelectrolpmines- Lcent layenlSfnderlying these strips Awill luminesce and -flthis luminescence willfbe projected throughnthe trans- -parentzconductive layer 14 andthe transparent member 1.2. i i opaqueycoding elementy v21 is ,disposed between plates 12 and -13 andis providedwith a plurality kor coded `:openings 2 21tfor selectively passing-light produced by the Lluminescence of material 15- g through plate 13 to the photocondnctive elements. The loca-tions of coded open-A ings 22,1nfthe0naque' member 21 ,WilldPHF P011 the particulancode being used ini-theV conversion, land it lwill `4`beunderstoodthatjthe positions-of these yopenings may 1 It; is also understood-thaty this code-element. may :be 'fabpunched cards, hard' enameled transparent plastic forms f and the ,lilrefand may .Ibe fxed, movable or replaceable. kItiisjalsonunderstoodv-that,'the code element may be a tion., lPlate 13is.,backed by-=a plurality yof strips 26 of a suitable photoconductive material such as cadmium selenide-orvcadmiumsulfide. Member 13 ispprovided on 5,5v-of-,conductive Vstrip electrodes, ;26a,through 26m, which g extend acio'ss member 13 in audirection'perpendicular to the directionofpthe conductive stripsl. Conductive i method, such; las, by evaporation ,of platinum, jzinc or 6()` silver, or;` preferably/.by .forming separate tra,r'isparent SnOz' strips on the member 13'to providevthe electrical insulating vspaces,..7a,through27lcl1etveen these strips as l shown. Transparent conductivestrips26areybest,formed byrirst depositinga layer of tiarisparent'cbnductive mate- 65.,.rial. on the entire suraceof imember A13"and` n sandblasting.oracidA etch-ing.111,51?llllel4 grooves tofprm the insulating gaps Z7.r t V l .i

Conductive strips 2.61am overlaid'bystripslzahrough 28h. of. photocfonduct'ive'rnaterial which, extendX in the Asishown in FIG. 2 forthis embodiment, each o fphotoconductive strips 28l-vismpositioned psoasto, span'one of .fbevariedin accordanevwith the particular code utilized?V matrix offferroelectricvlight.gatessuch as lbariunntitanate 50 zto permit electronicjcontrol of the code element'conguraits surface opposite to .coding element 21 with appluralityA s'trips26 may be formed on :member 13 by anysuitable spaanse i tor strip.

All of the elements of the translator may be disposed closely adjacent each other as illustrated in FIG. 2, and the entire assembly may ybe enclosed in a suitable opaque enclosure 30. Enclosure 30` may be, `for example, an opaque plastic material in which the translator assembly is encapsulated after assembly of the components.

The electrical connections to the diiterent elements of the translator are best illustrated in FIG. 3, which is a perspective view, partly in section7 of the device of FIGS. 1 and 2, utilized as a decimal to binary converter. In FIG. 3, opaque enclosure 30 has been removed -for purposes of clarity, but it will be understood that in practice this enclosure would be provided to shield the device from ambient light. In the embodiment of FIG. 3 it is assumed that a decimal digit is to be converted to binary form utilizing a well known binary code employing the Y' code elements l, 2, 4, 8 and n2, The decimal digit to fbe converted is entered into the system by means shown schematically as switches 400 through 4tlg. Switches 40o-4tlg may be mechanical switches which are selectively closed to represent the particular decimal digit associated therewith, or these switches may be photocon* ductors or any other type of switching elements capable of being selectively energized in response to the desired decimal digit.

One terminal of each of the switches is connected to an associated one of the conductive strips 16 which are numbered 160 through 169 to show their association with the different digits. The other terminals of the switches are connected in common to one terminal of a current source 32. The other terminal of source 32 is connected to the transparent conductive layer 14 which underlies electroluminescent layer 15 and the conductive strips 16. It will be seen that when one of switches 40o-409 is closed, current will flow from source 32 through this closed switch to the associated one of the conductive strips 16, then through theV portion of the electroluminescent Inaterial 15 which is directly under this conductive strip to the transparent conductive layer 14 and back to the other terminal of source 32. The electroluminescent material "15 thus has current flow therethrough in the portion thereof directly underlying the conductive strip 16 through which current is flowing. Material 15 will thus luminesce only in the area immediately underlying the energized one of conductive strips 16, to produce a strip 0f luminescence corresponding to the configuration of the energized conductive strip 16. Y

Assume that switch 405 has been closed, representing the decimal digit 5, thus producing current flow through the conductive strip` 165 and producing a strip of electroluminescence in the portion of electroluminescent layer 15 immediately underlying conductive strip 165. This electroluminescence is projected through transparent conductive member 14 and member 12 to the column of coded openings 22 representing the digit 5 in the coding element 21.

The disposition of the openings 22 in the 5 column ofcoding element 2'1 will depend upon the particular code being utilized, but regardless of what code is employed, the light from the luminescing strip will be projected through these openings to produce one or more .discrete-light pulses representing the code for that par- Vticular digit. These coded light pulses pass through member 13 and transparent conductive material 26 to V`selectively fall upon the photoconductive strip or strips As shown in FIG. 3, the photoconductive strips 26 are connection with the above embodiment.

by the B+ terminal 51. This may be an A C. or `D.C. source and has no electrical coupling to the electroluminescent power source. Current from terminal 51 is supplied through four parallel paths 51h, 51e, 51h, 51k to the ends of four common photoconductor electrode strips 26h, 26e, 2611 26k. The 'other ends of the other eight conductive electrode strips 26a, 26C, 26d, 26f, 26g, 26 26j, 26m are connected to a series of external circuit con- yY ductors 52a, 52C, 52d, 52,4?, 52g, 52 52j, 52m. Each of conductors 52 is thus connected to a transparent conductive strip 26 at a point which is separatedfrom any point of input connection 51 by one of the insulating gaps 27. Thus, current can ow between conductors 51 and conductors 52 only through one of the photoconductive strips 2S. Current from each of conductors 52 goes through an associated load which is shown in this embodiment 4as resistors 53a, 53C, 53d, 53f, 53g, 531, 53j, 53m. This load :however could be an electroluminescent element, a transistor, a neon lamp or the grid of a vacuum tube. The other terminals of yresistors 53 are connected in common to a return for the B+ source 51. Resistors 53 represent one form of output device across which the binary coded output signals appear for subsequent utilization.

In the absence of lightpulses on the photoconductive strips, the full supply voltage appears across each of the photoconductor strips owing to their extremely high, dark impedance. When a photoconductor strip is illuminated, its impedance decreases and a voltage VL appears across the load according tothe Kformula signicant change in the resistance of the photoconductive strip to produce a large. voltage swing across the associated load resistor 53. sensed by the utilization apparatus such as neon indicator lamps or electroluminescent elements (not shown), to provide an indication of the binary representation of the particular decimal digit being converted. It is understood that the load may be the input to other optoelectronic devices.

FIG. 4 illustrates an alternative embodiment of the present invention in which the translator has a cylindrical shape. The device of FIG. 4 contains the same elements shown in the embodiment of FIGS. 1, 2 and 3, `and these elements function inthe same manner described in The device of FIG. 4 includes a plurality of strips 66 of a conductive material which are similar in function to the strips 16 in the above embodiment. The strips 66 are spaced apart from each other around the periphery of a cylinder and` each of the strips extends longitudinally of the axis of the cylinder. A layer of electroluminescent material is disposed under the conductive strips 66 and corresponds to the electroluminescent layer 15. Electroluminescent layer 65 is underlaid by a transparent conductive -layer`64 which rests on a transparent vglass or mica base 62.

The photoconductive portion of the apparatus ofV FIG.

4 includes a plurality of strips of photoconductive Vmaterial 78 disposed `around the inner'surface of the cylinder and extending in a direction perpendicular to. the di- These voltage swings are rection of extension of the conductive strips 66. Photoconductive strips 73 span insulating gaps between adjacent strips of a transparent conductive material 76 which in turn rests on a transparent glass or mica member 73. The insulating gaps. are similar to gaps 27 of FGS. l, 2 and 3 'and serve toprovide electrical insulation between adjacent strips of material 7 6.

The space between cylindrical members 62 and 73 is occupied by 4a cylindrical opaque coding element 71 which is similar in function to the coding element 21 ofthe abovedescribed embodiment. Coding element 71 is preferably freely insertable in and removable from the space between members 62 and 73 so as to facilitate the use of different coding elements 71 in the programmer.. Codn ing element 71 is provided with a plurality of coded openings' 72 which serve to encode the light produced by luminescent material 65 into light pulses for trans fission to the photocon'ductive strips 78. It will be understood that in practice the device will be enclosed in an opaque enclosure to provide shielding from ambient light.

When suitable electrical connections (not shown) are made to the device of FIG. 4 in a manner similarl to that shown in FIG. 3, the device may be utilized as adecimall'to-binary or binary-to-decimal converter as in the embodiment of FIGS. l, 2 and 3. Alternately, the device may serve as a read only memory with vthe memory stored in the openings 72 in coding element 71 and read out therefrom whenV the associated electrical circuits are energized or addressed. It will be understood that different coding elements 71 may be utilized to vary the memory stored in the device.

FIG. 5 illustrates an additional embodiment of the present invention utilized as a programming device. The translating device 11 of FIG. 5 is similar to'that shown in FlGS. 1, 2. and 3, except that the coding element in the embodiment of FIG. 5 is "in `the form of a movable member 81 which is movable through the space between members 12 and 13. Coding element 81 contains, ajplurality of separate programs, such as program C shown, each program comprising a plurality of coded openings which are in registry with the electroluminescent and photoconductive members when the program is positioned p in device 11. Coding element 81 may be advanced in steps -by suitable means (not shown), with each separate step presenting a different program to the translator.

6 tor strips correspond to specific register and control gates. To add A and B and store the results in C, the code mask in step l'would contain a code instruction to reset the accumulator C through a translator output photoconductor control gate; next, commutating to EL strip 2 would scan the data stored in the'code mask which would transfer the contents of A register to C register; stepping to EL strip 3 would result in the transfer of the contents of registerB to register (3, thus giving the results A and B in C as required. Step 4 might contain control instructions to transfer the contents Wit-h the appropriate electrical connections to the translator input electroluminescent strips, the output from the photoconductive strips may be utilized to control or program Vsome equipment as a function of the different programs represented by the different openings in element 81.

As an example, format control of a printer coupled to `an accounting machine may be effected 'by commutating through the electroluminescent strips which in this case would'correspond to different specific line positions on a given form. The coded mask would contain the information corresponding to the addresses of data stored in the accounting machine registers to be printed in specific fields or columns on the form. Accordingly, the translator photoconductor outputswould gate specific data registers and also operate on the printer horizontal and vertical tab controls to effect the printing of specificpdata, such las quantity or unit price, in appropriate fields or columns on the form. Changing forms would require a change in code mask. This is analogous to changing plug boards or plug board Wiring on some typical present accounting machines, and represent a major improvement over this technique. K

From this it becomes apparent that other plug board functions may be performed using this typical solid state translator technique. Other examples are computer subroutine programming or stored program computer plug board functions.

Computer subroutine programming may be illustrated by the following example: Let each electroluminescent strip correspond to a program step and the photoconducof' register C to an output printer, etc.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the deviceillus'trated and in itsV operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

'What is claimed is:

l. An electro-optical translator for converting a frstsignal to another signal in accordance with a' given conversion code comprising 'an electroluminescent member, a plurality of strip members overlying said member for producing electrofluminescence of selected strips of said electroluminescent member as a function of said first signal, an opaque coding element having openings therein corresponding to said conversion code disposed adjacent said electroluminescent member for modulating said selected electroluminescence in Vaccordance with said conversion code between said first signal and said second signal, and a photoconductive material having different areas thereof responsive to said modulated electroluminescence for producing an output signal representing said second signal.

2,. An electro-optical translator for converting a first signal lto another signal in accordance with a given conversion code comprising an electroluminescent member, a plurality of electrically conductive strip members overlying said member, means for selectively energizing said strips as a function of said first signal to produce electrol-uminescence of selected strips of said electroluminescent member, an opaque coding element having openingsw therein corresponding to said conversion code disposed adjacent said electroluminescent member for modulating said selected electroluminescence in accordance with said conversion code between said first signal and said second signal, and a photoconductive material having different areas thereof responsive to said modulated electroluminescence for producing an output signal represen-ting said second signal.

3. An electro-optical translator for converting a rst signal `to another signal in accordance with a given conversion code comprising an electroluminescent member, a plurality'of generally parallel electrically conductive strips overly-ing said member, means for selectively' energizing said strips as a function of 'saidrst signal to produce electroluminescence of selectedlportions of said yelectroluminescent member, yan opaquecoding element having openings therein corresponding to said conversion code disposed adjacent said electroluminescentv member for modulating said selected electroluminescence in accordance with said conversion code between said 4first signal and said second signal, and a plurality of parallel strips :of photoconductive material extending normal to said conductive strips and responsive to said modulated electroluminescence for producing an output signal representing said second signal.

4. An electro-optical translator for converting a first signal to another signal in accordance Awith a given conversion code comprising a cylindrical electroluminescent member, a plurality of electrically conductivemembers overlying said member, means for selectively energizing said strips as a function of said first signal to produce.

electroluminescence of selected strips of said electroluminescent member, an opaque coding element disposed adjacent said member and having openings for modulating said selected electroluminescence in accordance With said conversion code between said first signal and said second signal, and a plurality of strips of photoconductive material disposed adjacent said openings and responsive to, said modulated electroluminescence for producing an output signal'representing said second signal.

5. An electro-optical translator for converting a first signal to a second signal in accordance with a given code comprising an electroluminescent member, means for producing electroluminescence of selected areas of said electroluminescent member in response to said first signal, an opaque coding element disposed adjacent said'electroluminescent member and having coded openings therein in registry With different areas of said electroluminescent material for transmitting light from said electroluminescent material in accordance with said code, a photoconductive material disposed on the opposite side of said coding element from said eleetroluminescent material and having a plurality of separate photoconductive elements in registry with said openings for receiving said transmitted light, and means responsive to changes in the electrical characteristics of said photoconductive elements as a result of receipt of said transmitted light for producing `an indication of said second signal. l

6. An `eleetro-ptical translator for converting a first signal to another signal in accordance with a given code comprising a cylindrical electroluminescent member, means for producing electroluminescence of selected areas of said electroluminescent member in response to said first signal, a cylindrical opaque coding element disposed adjacent said electroluminescent member and having coded openings therein in registry With different areas of said electroluminescent member for transmitting light from said electroluminescent member in accordance with said code, a cylindrical photoconductive member disposed on vthe opposite side of said coding element from said electroluminescent member and having a plurality of separate photoconductive elements in registry with said openings for receiving said transmitted light, and means responsive kto changes in the electrical characteristics of said photo- .conductive elements as a result of receipt of said transinitted light for producing an indication of said second signal.

7. An electro-optical translator for converting a irst signal to another signal in accordance wtih a given code program for programming an output device comprising an electroluminescent member, means for producing electroluminescence ofselected areas to said electroluminescent member in response to said lirst signal, a movable coding element having a plurality of different programs thereon which are separately disposable adjacent said electroluminescent member, `each of said programs com- .prising a plurality of coded openings which are in registry terial disposed `on the opposite side of said coding ele-l ment from said electrolumineseent member and having a `plurality of separate photoconductive elements in registry With said openings for receiving said vtransrnittedlight, and means responsive to changes in the electrical characteristics of said photoconductive elements as a result of receipt of said transmitted light for producing an output signal.

8. An electro-optical translator for converting-a rst signal to another signal in accordance with `a given code comprising an electroluminescent member, a plurality of 'i parallel electrically conductive strips overlying said member, means for selectively energizing said strips as a function of said first signal to produce electroluminescence of selected areas of said electroluminescent member underlying said strips, a coding element disposed adjacent said electroluminescent member and having coded openings therein in registry with -diierent areas of said electroluminescent member for transmitting light from said electroluminescent member in accordance with said code, a plurality of strips of photoconductive material disposed on the opposite side of said coding element from said elec# troluminesccnt material and extending in a direction normal to said conductive strips, each of said photoconductive strips being in registry lwith some of said openings for receiving said transmitted light, and means responsive to changes in the electrical characteristics of said photoconductive elements as a result of receipt of said transmitted light for producing an indication of said second signal.

9. An electrooptical*translator for sequentially carrying out the instructions of a programcomprising an electroluminescent member, a plurality of generally parallel electrically conductive strips overlying said member and corresponding to the steps of said program, means for selectively energizing said strips as a function of said program to produce electroluminescence of selected portions of said electroluminescent member, an opaque coding element having openings therein corresponding to said program disposed adjacent said electroluminescent memberfoij modulating said selected electroluminescence in accordance With said program instructions, and a pluralit'y of parallel strips of photoconductive material eX- tending normal to said conductive strips and responsive to vsaid modulated electroluminescence for producing an output signal in accordance With said program.

10.?An electro-optical translator for converting a tirst signal to another signal in accordance With a given con# Version code comprising an electrolurninescent member, a plurality of strip members overlying said Vmember for producing electroluminescence of selected strips ofsaid electroluminescent member -as a function of said first signal, a plurality of terroelectric light gates for controllably modulating said selected electroluminescence in accordance with said conversion code between said first signal yand said second signal, and `a photoconductive material having different areas thereof responsive to said modulated electroluminescence for producing an output signal representing said second signal.

References Cited in the tile of this patent UNITED STATES PATENTSY Jay Apr. 12, 1960

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