US2219149A - Television system - Google Patents

Description

A. N. GOLDSMITH TELEVISION SYSTEM Filed Feb. 6, 1957 Oct. 22, 1940.

Y16 Sheets-Sheet 1 INVENTOR ALFRED N. GOLDSMITH ATTORNEY Oct 22, 1,940l A. N. GoLDsMlTH 2,219,149

` TELEVlsIoN SYSTEM Filed Feb. e, 1957 1e sheets-sheet 2 6'/ AMP! /Fl MPl/F/ MPl/ ER mok MPL /F/ AMPLIFIER .s764441 m ff/54470K INVENTOR ALFRED N. OLDSMTH BY /W'U'f/l/ ATTORNEY 70 OUTPUT JCL 22. 1940. A, N GOLDSMn-H 2,219,149

TELEVISION SYSTEM Filed Feb. 6, 193'? Jaya 16 Sheets-Sheet 3 CONSTANT afl/'Mo VOLTAGE SOURCE ATTORNEY Oct. 22, 1940.

A. N. GOLDSMITH TELEVISION SYSTEM Filed Feb. 6, 1937 16 Sheets-SheetV 4 NE FRAU/@NAL SCAM/N6 UNE ERAcr/o/VAL scA/wv/NG Po@ r/o/v n/BE Pom/0N TUBE Vo-' 3o N -36f 0" 56 f 5-1 4'2 361 -2/ 57 ,2Enl/ zwlfsEAM oFF 42, 30 REru/a/v--BEAM OEE 57, 56 2 o -g 30 362 o -g 56 2 f-l 42 362 5 57 l @Era/2N" BEAM oFF 42, 30 RETURN BEAM OEE 57,56 3 0 30 Il' E :l 3 5 42 72o o 56 REvl'L/R/w- EEAMl 'af-' E 42,30 720 g 57 E l REr//R/v--BEAM 0EF 36o o 2f 30 ro .SEG/MNE 0E /vExr P/cn/R 36o g-f 42 L f o- 30 RETURN" BEAM oFF 42, 30 *l I/ 5- l 4.2

I I INVENTORI ALFRED N. GOLDSMITH ATTORNEY Oct 22, 1940. A. N. GoLDsMn-H 2,219,149v

TELEVISION SYSTEM Filed Feb. e, 193'/ 1e sheets-sheet s VOLTAGE INVENTOR ALFRED N. GOLDSMITH ATTORNEY Oct. 22, 1940 Y A. N. GoLDsMxTH 2,219,149

TELEVISION SYSTEM Filed Feb. e, 1937 1e sheets-sheet 7 INVENTOR ALFRED N. GOLDSM ITH ATTORNEY Ot. 22. 1940. A, N GQLDsMrn-l 2,219,149

TELEVISION SYSTEM Filed Feb. 6, 195'7 16 Sheets-Sheet 9 OC 22, 1940 A. N. GOLDSMITH TELEVISION SYSTEM Filed Feb. e, 1937 16 Sheets-Sheet 12 ALFRED' N. GOLD5M|TH- BY N ATTORNEY Oct. 22, 1940. A, N, GOLDSMn-H 2,219,149

TELEVISION SYSTEM A Filed Feb. e. 193" 1e sheets-sheet 1s ATTORNEY Oct. 22. 1.940. A. N. GoLDsMlTH 2,219,149

TELEVSION SYSTEM FiledFeb'. 6, 195'? 1e shee'ts-sheet 14 Oct. 22, 1940. A. N. VGoLDsMlTl-l 9 2,219,149

TELEVISION SYSTEM vFiled Feb. 6. 193'1 lssheetS-sheet 15 ALFRED N. GOLDSMITH ATTORNEY A Oct. 22, 1940. A, N, GOLDsMn-H 2,219,149

` TELEVISION SYSTEM Filed Feb. 6, 193'? 16 sheets-smet 16 VVV VVVVV INVENTOR ALFRED N. GOLDSMITH ATTORNEY Patented Oct. 22, 1940 UNITED y STATES PATENT Iol-l-icE 2,219,149 TELEVISION SYSTEM Alfred N. Goldsmith, New -York,.N. Y. f applicati@ February e, 1937, serial 30,124,434

c 59 claims.

The present invention relates to television systems and to both the transmitting and receiving portions thereof.

More particularly, the invention is concerned with ways and means and a method for producing at receiving stations images or pictures produced detail or quality substantially increased I over the detail producing qualities of any known and/or existing types of picture or image pro` ducing apparatus, irrespective of the character of such apparatus.

Further the invention is concerned with pro- 'viding a method and apparatus for increasing the definition of television pictures beyond that which can be obtained by any known and presently existing types of television transmitting apparatus.

In the present day types of television apparatus and for the purpose of this consideration, reference will be made substantially only to the so-called electrical types of transmitter and receiver apparatus since these are now capable of providing maximum detail and deiinition. Both the size of the image ultimately produced at the receiver point and the degree of definition is determined largely by the character of the visual pick-up transmitting tube and the spot size of the cathode ray beam which is utilized as a scanning instrumentality, asis alsov the casein the receiver. The size of theY image ultimately resulting at the receiver point is, according to the prior art systems, considered as a function of the size to which any practical electronic image reproducing tube may be built and the brightness of the spot formed by the cathode ray. y

In present day types of television apparatus, and considering for the time being the aforesaid electrical types, an image of the subject at the point of transmission is projected upon a light receiving surface which is suitably photosensitized.

In one of the commonly known forms of television electronic scanners for transmitting stations such asthat known by the trade name- Iconoscope, the image to be scanned is focussed upon a` mosaic structure which comprises a plurality or electrically isolated photoelectric par- (ci. 17a-6.8)

.ticles supported upon an insulating base, which base, in turn, is supported by a conducting support member or signal plate. The light falling upon the isolated photoelectrio particles causes photo-electrons to be. emitted therefrom with the result that a corresponding distribution of electrostatic' charges (a form of "electrical image") is accumulated upon the surface of the mosaic I structure, as has already been described in numerous publications. The mosaic surface upon which the charges have accumulated is then scanned by a focussed cathode ray beam of a cross-sectional diameter corresponding in size to individual elemental areas into which the subject is assumed to be divided for scansion and rebuilding. During scansion of the charge image, there is produced in an external circuit a wave train of energy representative of the subject whose image causes the electrostatic charges (of relatedl voltages) to build up or to be accumulatedl on the mosaic.

Tle signal transmitted may be developed either as aresult of the change in potential of the signal plate under the scanning action of the cathode ray on the mosaic or the signal may be determined by the secondary emission from the illuminated side of the mosaic when secondary electronsare released under beam impact upon each charged photoelectric particle.

Various methods of scanning in such a system may be used and need not be discussed herein ,in detail, but reference to this electronic form of' scanning may be found in the article published by Zworykin` in the Journal of the Franklin Institute for January, 1934, Vol. 217, No. 1. It should be understood-in connection with this type of system that the resultant image signals are due to the release of the charge accumulation on the mosaic structure during the time interval between successive traversals of each elemental section or area thereofbythe scanning cathode ray beam and may develop in either manner above suggested. In the scanning process, the scanning beam may trace a pattern along a series" of substantially adjacent lines, Yin'which case the beam moves at a relatively slow rate across the assumed lines'of the mosaic structure and returns at a relatively rapid rate to start the next line or path of scanning. In another form of l scanning the pattern may be the so-called interlaced pattern where the so-called odd linesot the mosaic are rst yscanned and the so-called even lines' are skipped during its scanning; during the next succeeding scanning the so-called lleven lines are scanned and the so-called oddl 2 lines are skipped while the scanning cathode ray traverses the' mosaic. If, for example, in this socalled "interlaced" pattern of scanning the resultantl image to be transmitted 'is assumed to be of 343 line detail for example. the first scanning will include the 171% odd lines with the nrst scanning starting, for example, at the upper lefthand corner of the mosaic and the last line terminating at the bottom of the mosaic midway between the lefthand and righthand edges thereof. The next succeeding scanning trace will then start at a point along the upper edge of the mosaic midway between the lefthand and righthandA edges thereof, but will terminate in the -lower righthand corner of the mosaic after the rst half line and the succeeding 171 additional lines are scanned. In this way, each' two scannedV groum of 17.1% lines portray, when pieced to-` gether, one complete scanned image., This formation of the image is known as the odd line interlacing method of scanning. However, a socalled even line" method of interlacing the scanning pattern may also be used. In such even 342 lines of scanning may be assumed, and, in this case, the mosaic electrode will then be traced yby the scanning beam along twoseries f scanning paths which each include 171 complete scanning lines with alternate lines being skipped between each traversal.

The method and system to be herein disclosed is also applicable to that type of electronic television scanning system wherein the light of the image falls upon alight sensitive surface which emits electrons which are accelerated toward an accelerating electrode whose central point is apertured. Behind the aperture of the accelerator electrode is located an electron collecting electrode. The collecting electrode is main- .tained at a highly positive potential relative to the photoelectric surface which is of the same general order as that of the accelerating electrode with respect to the photoelectric emitter surface. The collecting electrode may, where desired, be housed within a collecting target capable of emitting a great number of secondary electrons per primary electron to be collected by the target electrode. With a system of this type the entire bundle of photo-electrons moving from the photo-sensitive cathode toward the accelerating electrode is deflected electromagnetih cally or electrostatically in two mutually perpendicular directions so thatthe aperture in the accelerating electrode scans the elemental areas of the complete bundle of electrons.

Furthermore, the system to be herein described i'sapplicable tothose types of systems which are known as velocity modulation systems. In such systems, the rate of scanning the sub-` ject is assumed to be normally of some constant value for one predetermined condition of light and shadow on,the subject, but with changes in the intensity of light and shadow to be repre-l sented, the velocity of the scanning is changed to values above and below the assumed normal value or the change in velocity may take place only in one direction from the assumed normal velocity.

Referring now to the systems' for receiving scanned picture subjects, it is customary usually to provide (still assuming purely electronic types of image reproducing apparatus, although it is understood that 'mechanical forms may be used where desired) a cathode ray type device such, for example, as that known in the art under the trade name designation K inescope, wherein an electron beam is produced to initiate on the tube end wall the luminous trace. The electron beam developed within a cathode ray tube of this type is projected longitudinally of the tube and focussed 'by suitably developed electrical fields and by suitably designed electrodes into s. sharply devilned spot which implnges upon a luminescent screen structure supported upon the-inner sur-l face of the tube end'wall opposite' the source from which the electron stream or cathode ray beam is developed. The developed electron stream is suitably influenced by the sin;

nals resulting-from the transmitter to cause the resulting luminouseiiects upon the luminescent screen which portray the various intensities of light and shadow upon the original subject to vary as the beam is moved across the screen. 'Ihe deflection of the beam, asin the transmitting systems, may be accomplished by suitable electrostatic or electromagnetic beam deecting means or the combination of both, so that the beam or cathode ray traverses the entire luminescent screen according to the desired pattern of traversal, and vthis patternl may be the same as that described for the transmitting device.

'I'he resulting intensity of the luminous trace produced by the beam bombarding the luminescent screen is determined in various ways, and among thosecommonly used and to which this invention is intended to be .applicable are the so-called grid control, the varying area spot control, the velocity modulation, systems, and the like.

Such systems of the prior art while generally capable of producing televison images at receiver points of substantially satisfactory brilliance for small pictures to be viewed nearby in the home have not been found capable of producing large size images. Up to vthe present time, the maximum size of cathodey ray tube which could be to height of the ratio fi to 3 which would t within the 15" circle. The rectangular shaped subject is assumed in view of the current practice in the motion picture industry to provide rectangular shaped screen portrayals of actions, although it is obvious that a circular or a square formation of the resulting image could be realized. Such tubes as would produce an image of this size, which is not suiiiciently large to be viewed by large sized audiences are, nevertheless, both extremely difllcult to build and expensive to buy and, as well, are continually subject to possible breakage. Hence, Lfor the most part, present day television is restricted to that size of reproduced image which can be placed within the boundaries of the socalled 9" cathode ray beam. But, in this connection it should be understood that this is not a limitation in the theoretical capabilities of the system, but rather a limitation in the practicability and the economical development of known systems. Even -in cases where th'e so-called 12" tube is utilized with Hence, the maximum size of the resulting image pattern of the order of '1% x 10", the image or picture produced upon the luminescent screen is still not` su'mciently large for satisfactory large size demonstrations or sufficiently large to be viewed by large size audistantial commercial possibilities unless it be of the order of at least l5" by 20".

Therefore, according to the present invention it is proposed to provide a system wherein it is possible to increaseshe detail orr the definition obtainable in television pick-ups as well as to provide a system wherein the resultant image size may be substantially increased while providing even increased brightness and substantially little, if any, additional expense for the installation over that whichit is considered will be necessary for large sized tubes. Ac-

cording to the present invention' to beherein disclosed,'it should be understood that any large screen television system should ipreferably be of such a type that large size pictures of the character herein referred to shall be obtained Without any change in the general nature or characteristics of conventional television transmission. Further than this, large screen television should be capable of being carried out through the use of the now conventional types of cathode ray devices for reasons of economy, design, construction, shipping and usage.

In accordance with the present invention,

l however, it is proposed to provide a system wherein it is possible to increase the detail of definition obtainable in television pick-ups. object ofV this invention to provide a system which will not only increase the detail of deflnitionto some extent, but will make it possible to transmit pictures` for television purposes which have a detail which is substantially that of the currently produced motion pictures. It is further proposed in accordance with the present invention to accomplish the increased definition and detail with a single pick-up lens associated with the scanning instrumentality where the lens will be utilizcd so as to be without parallax or overlapping effects within 'the pick-up image.

Further, it is an object of the present Y/inven-v duced and simply operating system for obtain-I ing these effects by electronic scanning tube commutation where no mechanical moving parts are utilized and still obtain the increased detail and definition on an economically satisfactory basis.

It, of course, will be appreciated that with the approach of color television, that is, the television transmission of colored images on a commercial scale, it will be necessary to increase the effectiveness and detail of the picture severalfold since, in addition to the transmission ofintelllgence corresponding to the, position and luminosity of each picture element, it will be likewise necessary to transmit an exact index of the colors of each element of the subject, and if trichromatic vision be assumed, the amount of effective detail to be transmitted for color therefore will be of the order of three-fold thatrequired for black-and-White television.

A further object of this invention insofar as the transmitter end of-the system is concerned, is that of providing a simple, effective, and reliable method by which a plurality of scanning .tubes or other electronic scanning devices may It is also an operative to scan and produce from the scanning image signals representative of the subject, and in such connection it is an object of the invention to provide ways and means by which independent scanning devices select separated areas or sections of the subject for analyzing purposes, and at the same time tubes or scanning elements not instantaneously effective in the transmission of signals are so arranged and utilized Athat power consumption is reduced to a minimum.

With respect to the receiver end of the system,

the invention is intended to provide for the production of large television pictures in contrast to pictures of the sizes above noted; and in making reference to large television pictures, it is intended that the size of the picture shall be of the order of square feet through tens of square feet, and up to hundreds of square feet in contrast to the presently known size of pictures which are measured in the order of square inches, and still it is an object of the invention to provide these pictures of large dimensions vin forms which will be of normal brightness and conveniently useable for theatre or home viewingat comfortable viewing distances. F

A further object of this invention is to provide a television image reproducing system which will produce large and bright television pictures which shall also be of high detail and definition reaching, for example, from the present day types of pictures customarily considered of the order of between 300 and 400 lines per picture up to several times this amount of detail, for example, pictures having 700 to 800lines, or even more.

It is a further object of the present invention i to provide a system by which this increased size and detail in resulting picture can be produced While utilizing in the process only those present day types of tubes which are satisfactory for small size pictures and which can be constructed and sold cheaply, or to utilize tubes ofeven smaller size than those used at the present date, and still to provide a system whereinv these results are accomplished with equipment purely electrical in its nature requiring no moving parts and requiring a minimum amount of maintenance and attendance.

It is a further object of this invention to provide a system for reproducing large size pictures, for example, on translucent screens l(but not necessarily) in such a manner that if the. television receiver of the nature to be herein described is utilized in the home for deluxe home pictures, such a receiver can be viewed by the audience in any lposition without the interception of vprojected beams by members of the audience, and ln the case of use for theatre installations on the stage, no equipment need be placed in the usual motion picture projection room, the entire equipment being such that it can be placed readily upon the stage of the theatre.

A further object is to provide equipment for producing large size television pictures which can be assembled so as to be shallow in the direction perpendicular to the plane of the viewing screen, and .thus permitting its installation on shallow stages of theatres or any similar form for use in the home in reasonably compact exhibited, and yet to providea suitable arrangement for matching on the viewing screen the w different sectional portions of that-viewin such manner that there will bewno discernible distinctions between a view reconstructed in sequeng tially produced sectional' areas and a view of equal sizeproducedasaunit b A further object ofA the invention is to provide a system for securing large screen pictures which is entirely electrical and involves no mov- 1i) ing parts or mechanical complications and to provide optical arrangements for producing component pictures which are. of utmost simplicity in their nature and which can be manufactured and sold at a selling price little, if any, in advance 1s of television systems using but a single image reproducing tube. V

A still further object of the invention is to provide a television image producing system winch will use only conventionally and present day types of equipment with minor structural and/or operating alterations, and at the same time'to provide a resulting image which will. over its large area,. be of a brilliance at least equal to It is anc the types of large pictures, above referred to, which will operate with equal fidelity from the o present single scanning tube transmitter of the transmitter systems now generally known or which will operate to provide increased detail where receiving signals transmitted from a transmitting system of the character herein described. In this way, it becomes obvious that an important part of this invention is the feature of'providing a receiver with a multiplicity of image producing tubes which each produce a selected partial area of the' complete image but` which operate with complete control from the same signals which would control the complete image production on a single image producing tube.

Another object of the invention involves th use of a' multiplicity of image scanning tubes for scanning partial areas of a complete picture after the formation upon the light sensitive. scanning surface thereof 'of non-parallactic partial-images, which may result from an aerial image, for such consequent scanning.

Still a further object of the invention residesl in the use of a plurality of image scanning tubes as well as image reproducing tubes which may be controlled through the usewof suitable deflection biascontrols in both horizontal and vertical directions of scanning so that the sc'anning beams are suitably retarded or triggered and become active in any desired sequence so that the partial images are scanned and/or reproduced according to a pattern equivalent to the now conventional scanning patterns.

A further object of the invention is that of providing suitable inter-connections of the deectibn control systems of each image scanning or reproducing tube so that the sequence of opan object of the present invention to provide a receiver system capable of producing eration may. be autsbly remained u above An additional object of the invention is that of providing suitable .ways and means to produce large sin television .images through the -use of s partial-imagearea scannings at either or both I transmitter and receiver while providing masking areas of suitable coniiguration and rsecondary emission properties to produce the desired type of reproduced electro-optical image.

Btill a further, object of the invention is to provide suitable means for conserving both tube life and power consumption by rendering inactive any tube not at the moment utilized in the system for producing'or reproducing image or l5 video signals.

A still further object of the invention resides in providing suitable ways and means for reforming the partial-image areas produced as an electro-optical image in each of a plurality of 20 image producing tubes into a single large size electro-optical image capable of being produced upon a viewing screen with the partial-image areas in suitable relationship and accurate juxtaposition. 25 Another object of the invention is that of providing by means'of a series of suitably posi-` tioned partial-image producing tubes a means' to develop a large picture area from the several partial areas while providing suitable interlocks I0 between the partial area image producing tubes` to permit the sequential or selected operation of each to locate the several partial areas in proper space relationship in the complete area.

stm a further object of the invention is that of controlling the operation of the several partial-image producing tubes from the deilection control systems of each tube under the iniluence of a developed control deflection electrical means for controlling the electron beam deilec- 40 tion in each tube in sequence and at the same'. time providing flexibility of operation, which may function either at high or low bias values v on each tube deflection systemor which may function from a single phase or multi-phase de- .45 ection control electrical wave formation.

Still another object of the invention is that of l rendering tubes in the image producing system not at the moment effective in producing a partial area of the complete image area to be 50 .made inoperative soy as to decrease power consumption and increase tube life. v

A further object of the invention is that of providing a large size image producing system which will function equally well with electro- 55 static or electromagnetic beam deflecting systems or a combination of both and with all known types `of intensity control systems for varying the resultant luminous spot intensity.

A still further object of the invention is that g( of providing an array or system of separate partial-image producing tubes which may as a unit be assembled in or as a part of any known and existing type of electronic television receiver apparatus so that when signals of the character 5f transmittedfrom any of the aforementioned types of transmitter apparatus are received the produced image on the viewing screen will be many times the area of that of the usual and known receiver and will be formed from a series 7( of juxtaposed partial-image areas.

An additional object of the invention is that of providing a system of concatenated partialimage producing tubes and their associated and' controlling commutating circuits iny such fashion 7iv

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