US2166247A - Electro-optical transmission system - Google Patents

Description

R. v. l.. HARTLEY Er AL, 2,166,247

ELECTRO-OPTICAL TRANSMISSION SYSTEM July 1s, 1939.

original Filed sept. 14, 1927 2 sheetsrsheet 1 @4LP/f L/L /afmfy NVE/VMS: HERBERT t". /vfs July 18, 1939. R. v. L. HARTLEY ET Al. 2,166,247

ELECTRO-OPTICAL TRANSMISSION SYSTEM Original Filed Sept. 14, 1927 2 Sheets-Sheet 2 Patented July 18, 1939 j UNITED STATES PATENT OFFlClE.

ELECTRO OPTICAL TRANSDHSSION SYSTElVI Application September 14, 1927, Serial No. 219,404 Renewed August 27, 1930 42 Claims.

This invention relates to electro-optical transmission and more particularly to television oi moving objects and also to combined television and sound reproduction.

The principal object of the invention is to increase the amount of illumination available in the television process soy that such process is applicable to the production of images of elds of large size, a part at least of which are at a considerable distance from the scanning mechamsm.

Heretofore in the practice of television it has not been possible to obtain a television image of sufficient brightness when the ield scanned is partly or wholly at a distance from the scanning mechanism, as is necessarily the case when the iield comprises a ball game or a street scene for example. In general, such scenes can not be illuminated by artiiicial light, natural lighting only being available.

In accordance with the present invention a method and means are provided for overcoming this difficulty. A motion picture or other record of the iield of view is taken, developed if necessary, and then scanned, all in one continuous process, so that the delay introduced by the record making becomes a negligible time factor.

An additional feature of the invention is the transmission of the sounds produced in the eld viewed in such manner that they are reproduced at the receiving point in proper synchronism with the image, This' is preferably effected by recording the sound and introducing a delay in the reproduction equal to that introduced in the image reproduction of the eld. For example, a photographic record of the sound may be made upon the picture nlm or upon a separate lm and the developing may the-n take place simultaneously with that of the picture.

The invention also contemplates increasing the brightness of the image by introducing the step of taking and developing the motion picture at the receiver rather than at the transmitter or at the receiver in addition to a similar step at the transmitter. In the former case the sound record or delaying action may be made at the receiving point or it may be made at the transmitting point if proper line synchronizing is provided.

If motion pictures are taken at both the transmitter and the receiver, the sound recording or delay, although preferably confined to one station, may be at both stations; if at one station only, the delay means introduces a double delay in the sound reproduction.

A more detailed description of the invention follows' and is illustrated in the accompanying drawings.

Fig. l is a general schematic arrangement of an embodiment of this invention diagrammatically showing the terminal apparatus of a trans- 5 mitting and a receiving station and the arrangement of the electrical interconnections.

Fig. 2 is a diagrammatic general assembly elevational View in section of the transmitting apparatus.

Fig. 3 is a general assembly elevational View in section of the receiving apparatus.

Fig. 4 is a diagrammatic drawing of an arrangement for recording and reproducing the sound by phonographic means.

In accordance with the speciiic embodiment of the invention herein chosen for purposes of illustration, apparatus is provided for making a photographic nlm record of both the picture and the sound to be transmitted, developing and fixing the film and then passing the picture record and the sound record which have been recorded upon the lm through beams of light directed upon photoelectric cells thereby causing the photoelectric cells to generate electric currents varying in accordance with the picture and the sound records. The sounds are picked up by microphone or microphones |90 (Fig. 1) which connectsI with the input element Il I of the sound recording apparatus. The various pieces of apparatus must be operated in proper relation to each other and they are driven by an electric motor through suitable gearing, not shown, or other suitable means. In addition arrangements are provided for synchronizing the receiving apparatus with the transmitting apparatus. The transmitting apparatus is mounted on a suitable base and properly housed, as is indicated by the rectangle mi), Fig. 1, and as sho-wn in detail in Fig. 2. Referring especially to Fig. l, picture current is generated by the photoelectric cell H50, sound current by the photoelectric cell lll and synchronizing current by synchronizing apparatus |51. From each of these sources' of current suitable circuits are provided connecting with the corresponding apparatus at the receiver Zilli. The picture current translating device terminating in the photoelectric cell It!! connects with the transmission circuit 3|!) through the terminal amplifying apparatus 3H and 312 at' the two ter- 50 minals of the transmission circuit, respectively, and through the switching connections 3I3 to the picture light generating apparatus 28! in the receiver. Similarly, the sound current translating device terminating in the photoelectric cell A llii connects with the transmission circuit 32D through the terminal amplifying apparatus 32| and 322 at the two terminals of the transmission circuit, respectively, and through the switch connections 323 to the sound light controlling apparatus 2li in the receiver. synchronizing current for maintaining the transmitting and receiving apparatus in synchronism and in phase are generated by the synchronizing apparatus |5| at the transmitting station and transmitted over the transmission line 33E and through the switching connections 333 to the synchronizing apparatus in the receiver. In the arrangement shown both the picture and the sound are photographically recorded at the transmitting station and again at the receiving station, the two photographic processes neutralizing the distortion due to a. single photographic process being non-linear. Further, by means of the lm record proper synchronism between the picture and the sound is lmaintainedl After the iilm record has been made at the receiver it is run through a standard projecting machine and the picture thrown on a screen 2&9, and the sound record portion passed through suitable apparatus 2li) which converts the sound portion into electric current which upon passing through any necessary amplifying apparatus 255| operates a loud speaker 229B.

It will sometimes be desirable to omit the photographic processes at the receiver while retaining those at the transmitter, or vice versa. Fig. l shows, in addition to the arrangement already described, an alternative receiving arrangement to be 'used when the receiving photographic processes are omitted. The receiver may consist of a large number of light sources uniformly positioned and so energized that they are lighted in accordance with the tone values of the object whose image is being transmitted, all in known manner. Such a lamp receiving arrangement iiiii is shown, in which a plurality of lamps 40| are positioned in checker-board formation. Each lamp represents an elemental area of the object whose image is being transmitted and only one lamp is energized at any instant. 'Ihe successive energization of these lamps is accomplished by means of the commutator distributor Mii which has a series of contacts 4H equalling the number of lamps in the screen. A rotating Contact arm M2 is operated by means ofthe synchronizing apparatus 42E) in synchronism with the scanning apparatus |50 at the transmitting station. The picture currents coming in over the transmission line pass from the switching apparatus 3|@ through the conductor 43|, the contact arm M2, one of the contacts di l, through an individual wire leading therefrom to one of the lamps iti through the common connection i3? and to the other side of the line at the switching apparatus EHS. The synchronizing apparatus i253 may comprise a high frequency synchronous rotating unit of usual construction. It is connected to the synchronizing channel through the switching apparatus 333. The sound reproducing apparatus i553 may be of any known form. It is connected through the switching apparatus 323 to the sound transmitting channel. The switching apparatus 3|3, 323 and 333 associated with the picture, sound and synchronizing channels may be of any suitable type such as plugs and jacks for connecting the different types of receiving apparatus as indicated in the drawings.

When photographic processes are employed at both the transmitting and the receiving stations two photographic steps are used, and while each step causes a non-linear translation the second step compensates for the non-linearity of the rst step. This applies to the sound record when it is photographic as well as to the picture record. When a single photographic process is used, as is the case when the picture and sound currents are Vcontrolled by negatives at the transmitting station and then applied directly to the electrical picture and sound reproducing apparatus at the receiver, the distortion which occurs can be corf:

rected by any suitable means giving an inverse or approximately inverse response such as a vacuum tube `repeater having a properly shaped characteristic.

The employment of a photographic process at the receiver permits light amplification at this point and the projecting of the picture on a large screen, while a lamp bank receiving arrangement to give fine grained image production which would compare favorably with the photographic production with respect to detail, might be difcult and costly to construct.

A general View of the transmitting apparatus comprising a moving picture recording camera, photographic sound recording apparatus, film photographic developing and xing apparatus, moving picture projecting apparatus for projecting the picture record vinto television transmitting scanning apparatus and the sound record into the sound translating apparatus for converting these records into varying electric currents for transmission and synchronizing apparatus is shown in Fig. 2. The various component elements of the transmitting apparatus are mounted within and upon the framework 50. s

The moving picture camera |lJ| may be any suitable standard moving picture camera. It is so associated with the other transmitting apparatus that the moving picture film 99 after being exposed for the picture record passes through the sound recording apparatus IIB and then to the photographic developing and xingapparatus |29. Any suitable photographic developing and fixing process may be used, though in the drawings only two steps are indicated by tanks |2| and |22 for the developing and fixing operations, respectively. Such other steps as provision for washing and drying may be incorporated in the apparatus. The iilrn after being iXed is passed without drying through the picture projecting apparatus i3!! and the sound translating apparatus HHB. An image of the picture Vis projected into the television scanning apparatus |50 which successively impresses the light from each elemental area of the image onto the photoelectric cell |613. The sound translating device also causes a beam of light to pass through the sound record and onto the photoelectric cell |70. The photoelectric cells |55] and |10 connect through suitable amplifying networks to the picture current and the sound current transmission channels. Synchronizing apparatus is arranged to transmit synchronizing current and it is also connected to a suitable transmission channel. The general arrangement of these connections has already been shown in Fig. 1. After the film has `passed through the transmitting apparatus, it may be wound upon a reel |80 or otherwise disposed of.

The picture and sound records may be made upon seperate strips of film or upon the same strip of film. In this description they are considered as being upon the same film. The two records when so made are permanently displaced by a few feet as is obvious from the fact that the picture and sound recording positions are at different points. In order to translate the two records into electric currents so that the picture and sound are in synchronism, a similar displacement between the point of translating the picture into electric current and of translating the sound record into electric current is maintained between the picture projecting apparatus |30 and the sound translating apparatus |40 as exists between camera and sound recorder H. This relationship while not always necessary permits the transmitting apparatus to directly control the receiving reproducing picture and sound apparatus.

The transmitting apparatus is positioned so that the moving picture camera |0| is directed upon the object or iield the image oi which is to be transmitted. Unexposed moving picture hlm 93 is placed in the magazine ID3 of the moving picture camera |0| and then threaded through the various apparatus units, as shown in the drawings, and finally to the storing reel IBD. Suitable guides and driving gearing control the movement of the iilm at various positions. The film in passing through the moving picture camera IQ! and the picture projecting apparatus |33 is intermittently driven, while in passing through the sound recording apparatus Ilii and the sound translating apparatus |40 it is driven at a uniform rate. rThe movement of the nlm at the different points is maintained in proper synchronism with the different apparatus elements by means of gearing, not shown in the drawings, interconnecting the various driving gears, and all connected with the synchronous driving motor which is of usual construction b-ut preferably of good size to overcome any tendency to change of speed with changing reactions from the apparatus driven thereby. Connection of this gearing with the motor may be made through any suitable arrangement such as the worm and gear connection 52 and |53. The movement of the film through the camera |D| is obtained by any well-known standard gearing arrangement H52 associated with the camera, and the uniform movement of the film through the sound recording apparatus H0 is obtained by means of the gearing H2 consisting of a set of sprockets driven at a uniform rate. In the projecting apparatus the film is fed in and out at a uniform rate by means of the sprocket gearing |3| and |32, while it is driven intermittently by the sprocket gearing |34 and |35, all of which are connected by well-known means to the driving gearing from the motor element 5|. The sprocket gearing |3| also moves the iilm through the developing and xing tanks |2| and |22. The film is next moved through the sound translating apparatus at a uniform rate by means of the sprocket gearing M2 and then stored on the reel |86 which is also mechanically driven.

The sound which is picked up by microphones operates a light valve lil or other suitable light controlling device in the sound recording apparatus. A source oi light H3 together with the necessary lens system H4 and H53 projects beam of light through the light valve i and onto the portion of the film 99 Where the sound record is recorded. The telephone transmitter so actuates the light valve that it causes photographic variations in the lm representing the sound.

The exposed iilm after being developed and fixed is passed to the projector |36 where it is passed through an intense beam oi' light from the projector lamp |36 and a lens system |31 and |38 which projects in accordance with standard practice an image of the picture upon the scanning disc |55y of the television scanning apparatus |50. The scanning disc contains a series of small apertures arranged in a spiral and so positioned that light from only one elemental area of the image can be transmitted at any instant. When this disc is rapidly rotated it permits light to successively pass from each element of the image to the photoelectric translating device or cell |60, wherein photoelectric current varying in accordance with the tone value of each elemental area of the image is generated. The film is next passed through the sound translating apparatus |40 wherein it is exposed to an intense beam of light. A light source 43 and a lens system |44 and an aperture in the sides of the channel through which the nlm passes direct the beam of light through the sound record on the lm and onto the photoelectric cell |10 wherein sound current is generated.

A general View of the receiving apparatus cornprising television receiving scanning apparatus, a moving picture recording camera, photographic sound recording apparatus, film photographic developing and iixing apparatus, moving picture projecting apparatus, and sound translating apparatus for converting the picture and the sound record into pictures and sounds, respectively, and synchronizing apparatus is shown in Fig. 3. The various component elements of the receiving apparatus, many of which are similar to corresponding elements in the transmitting apparatus, are mounted within and upon framework: 68. moving picture camera 29| may be any suitable standard moving picture camera. This receiving camera is positioned in front of the television receiving apparatus 286 in such relation thereto that the image produced by the television apparatus is focused upon the moving picture film |952. The television apparatus contains a light source 28| which varies in light intensity in accordance with the incoming pictiue signal. This light source is positioned behind a scanning disc L 232 in the television apparatus 259. The scanning disc contains a series of small apertures arranged in a spiral and positioned sufciently far apart so that light passes at any instant through only one aperture to the camera, the scanning disc being located between the receiving light source and the camera. The scanning disc 382 is similar to the scanning disc in the transmitting apparatus and it is operated by synchronous driving motor element 283, which may be of any well known form and preferably of good sise, in synchronism and in phase with the transmitting apparatus. As heretofore described, the transmitting scanning disc scans the photographic image of the picture to be transmitted in a series of parallel lines, thereby setting up varying picture current whose strength at any instant corresponds with the light intensity of the image on the transmitting film and this current causes a corresponding variation in the light intensity oi the light source 28|, which, in turn, is caused to successively illuminate the corresponding elemental areas of the receiving iilm at each instant with a light intensity similar to that of the image on the film at the transmitting station. A positive picture is thus recorded on the receiving film 59 which corresponds to the negative picture cn the transmitting lrn 99. 'I'he moving picture recording lm |99 after being exposed for the picture record passes through the sound recording The f! apparatus 2l@ and then to the photographic developing and fixing apparatus 22S. Photographic developing and xing tanks 22H and 222, respectively, are shown. However, as explained in connection with the transmitting apparatus any suitable process inay be used and such steps as washing and drying the lm may be incorporated. The lm after being fixed is passed without drying through the picture projecting apparatus 23B and the sound translating apparatus ZM. An image of the picture is projected in accordance with standard moving picture practice upon a suitable screen for viewing. The sound translating device passes a beam of lightthroughthe sound record film and onto the photoelectric cell 2id. The sound photoelectric cell connects through a suitable amplifier to a loud speaker which may preferably be associated with the viewing screen 29.9. The light source ii-i3 in the sound translatn ing apparatus is similar to the light source 2M in the television receiving scanning apparatus and it is controlled by the incoming sound current which is generated in the photoe'lectric cell il@ at the transmitting station. Light from this source is caused to pass through the sound record portion of the lm by means of a suitable lens system 2M and an aperture 245 in the sides of the channel through which the lm passes. After the lm is passed through both the picture and the sound projecting apparatus, it may be wound upon a reel 289 or otherwise disposed of. As pointed out in the description of the transmitting apparatus, the picture and sound records may be made upon separate strips of film or upon the same stripof film, but they are here considered as being upon the same lm. Here also as in the transmitting apparatus the two records when so made are permanently displaced by a few feet as is obvious from the fact that the picture and sound recording positions are at different points in the apparatus. In order to project the picture and the associated sound in synchronism a similar displacement between the point of projecting the picture and the translating of the sound record into sound is maintained between the picture projecting apparatus 239 and the sound translating apparatus 240.

The receiving apparatus is positioned so that the moving picture projecting apparatus projects the picture on a large screen 292 in front of the audience, and the loud. speaking apparatus may preferably be positioned near or behind the viewing screen.

UneXposed moving picture lm i539 is placed in the magasine 203 of the moving picture camera 20| and then threaded through the various apparatus units as shown in the drawings and finally to the storing reel 280, substantially the same as in the transmitting apparatus. Suitable guides and driving gearing control the movement of the lm at various positions. The film in passing through the moving picture camera 2M and the picture projecting apparatus 23!! is intermittently driven While in passing through the sound recording apparatus 2 lll and the sound translating apparatus 24!! is driven at a uniform rate. The movement of the film at the different points is maintained in proper synchronism with the different apparatus elements by means of gearing not shown in the drawings, interconnecting the various driving gears and all connected with the synchronous driving motor 283. Connection of this gearing with the motor may be made through the worm gear connection 284 and 285i. The movement of the lm through the camera` 23| is obtained by any well-known standard gearing arrangement 202 associated with the camera and the uniform movement of the iilm through the sound recording apparatus 2l!) is obtained by means of the gearing 2l2 consisting of a set of sprockets driven at a uniform rate. In the projecting apparatus 230 the film is fed in and out at a uniform rate by means of a sprocket gearing 23| and 232, While it is driven intermittently by the sprocket gearing 23d and 235, all of which are connected by well-known means to the driving gearing from the motor element 283. The sprocket gearing 23! also moves the film through the developing and fixing tanks 22E and 222. The film is next moved through the sound translating apparatus 24B at a uniform rate by means of the sprocket gearing 242 and thence stored on the reel 28E! which is also mechanically driven.

The incoming sound current operates a light valve 2|| of the sound recording apparatus. A source of light 2l3 together with the necessary lens system 2l@ and 2i5 projects a beam of light through the light valve 2H and on the portion of the film 199, where the sound record is recorded.

The exposed nlm after being developed and Xed is passed to the picture projector 230 where it is passed through an intense beam of light from the projector lamp 236 and a lens system 23T and 238 which projects in accordance with standard practice an image of the picture upon a large viewing screen 299.

When a photographic process is used in connection with picture television transmission it is necessary to store the associated or concurrent y sound for the period requiredV for the development of the photographic picture lm in order that the picture and the sound may be projected in synchronism. The storing of the sound may be accomplished by a phonographic process rather than a photographic one, if desired. Fig. 4 diagrammatically shows an arrangement of a phonographic record and recording and reproducing elements, suitable for this purpose, each of which would preferably be electrically operated, though the reproducing element might be of the ordinary mechanical type, provided this apparatus is located at the receiving station. The recording stylus 402 is attached to and actuated by an electromagnetic element 403 supported on a swinging arm MM which permits the stylus to follow a spiral over the surface of the record. This electromagnetic driving element 403 which actuates the recording stylus in accordance with the received sound current may, with th-e addition of suitable connections to the stylus, be similar to a powerful telephone receiver. The reproducer iii-5 may be quite similar to the electromagnetic recording device. It is caused to generate electric currents in accordance with the movement of its stylus 40? in contact with the record. A good microphone may also be used. The stylus of the recorder and the stylus of the reproducer are so positioned on the phonograph record that the delay between the incoming or recorded sound and the outgoing or reproduced sound is equal to the corresponding delay in the pictures and consequently by this arrangement the sound is stored by the phonograph record and subsequently reproduced in synchronism with the reproduction of the picture. When the phonograph` is located at the transmitting station, it must be arranged to generate electric current for transmission to the receiving station, while as above stated if it is located at the receiving station, it may mechanically reproduce the sound. Another arrangement available for storing sound is the telegraphone, by means of which.` the sound record is magnetically stored on a steel Wire or disc. The operation of this device to obtain the necessary delay would be analogous to that of the phonograph having a mechanical record, but the telegraphone would have the advantage in employing a steel wire in the form of an endless belt upon which the record is magnetically made and erased thus permitting its being used over and ovei Without renewal or any mechanical operations, such as required Where a Wax disc is used to put it in condition for using a second time.

What is claimed is:

l. A system for producing successive images of a eld in which the objects may be moving or changing comprising means for successively impressing views of the field upon a photographic record, means controlled by said record and operating simultaneously with said rst means for producing said images, means for scanning the elemental areas one at a time of each image, and means to maintain a xed motional relation between said recording means, said image producing means and said scanning means.

2. A system for producing successive images of a eld in which the objects may be moving or changing, comprising means for successively impressing views of the field upon a light sensitive record, means for scanning said record, one elemental area at a time, for producing an image current corresponding to the tone values of the successively scanned elemental areas of the successive light records, means for transmitting said image currents to a receiving station, means electrically controlled at said receiving station by said record, and operating simultaneously with said recording means for producing said images, and means to maintain a fixed motional relation between said recording and said image producing means.

3. Means for scanning a field to set up tele- Vision image currents comprising a record blank, means for impressing successive views of the field upon said blank, driving means therefor, means including a source of radiant energy for successively exploring the elemental areas of said blank, driving means therefor, means for moving the impressed portions of said blank from the point Where the impression is made to the exploring point, and means to maintain a fixed motional relation between all of said driving and said moving means.

4. Means for scanning a field to set up television image currents comprising a photographic film, means for impressing successive views of the eld upon said lm, driving means therefor, means for developing said film to form a negative, means including a source of light for exploring elemental areas in succession of said negative, driving means therefor, means for moving the impressed portions of said blank from the point Where the impression is made to the exploring point, means to maintain a fixed motional relation between all of said driving means, and means for compensating for the distortion introduced by the non-linear characteristic of the photographic process.

V5. A television system comprising means for exposing portions of a strip of light sensitized film to light from a eld of View in Which objects may be moving or changing, including means for moving said iilm, means for developing an exposed portion of said film While another portion is being exposed, means for scanning elemental areas in succession of a portion of the developed film While another portion is being exposed, means for maintaining a fixed motional relation between said lm moving means and said scanning means, and means for setting up image currents under control of said scanning means.

6. The method of television which comprises taking a series of motion pictures of a iield of View in Which objects may be moving or changing, immediately developing a portion of said series before the taking of said series is completed, scanning in succession all the elemental areas of an entire frame of the developed series, one at a time, and succeeding frames in sequence and in step With said taking and While said taking is in progress, and controlling the production of the image currents by said scanning.

7. A television system comprising means for scanning all portions of a eld of View in a period which is very short compared With the period of persistence of vision and for repeating said scanning at periods about the same as that of the persistence of vision, and means including a second scanning means for producing an image current during a period about the same as that of the period of persistence of vision under control of said scanning means, which current varies in accordance with the tone value of elemental c areas of said field of vievv taken in succession, and means for maintaining a fixed motional relation between said scanning means.

8. A television system comprising means for practically instantaneously scanning a eld of to View in its entirety and for repeating said scanning With a periodicity less than the period of persistence of vision, said means including means for producing a unitary lm record of all of said scannings, and means including a second scanning means for scanning succeeding portions of said record one at a time in elemental strips transversely of said record While the producing of said record is in progress, said second scanning means comprising a moving scanning beam and stationary means under control of said beam for setting up an image current.

9. A television system comprising means for practically instantaneously scanning a field of vieW in its entirety and for repeating said scanning at a rate Within the persistence of vision, means for producing an` optical record of said scannings, a light sensitive device, a second scanning means for directing light from elemental areas in succession of said optical record to said light sensitive device, and means for maintaining a fixed motional relation between said scanning means.

10. Television receiving apparatus comprising a source of relatively Weak light, means for causing incoming image currents to modulate light from said source, scanning means controlled by said modulated light, means for storing a strip of sensitized lm, means for causing said scanning means to repeatedly scan said film to produce successive records of successive aspects respectively of the distant field of view, including means for moving said film, a lm developing tank into which said lm is immediately fed after being exposed, a source of light of relatively great intensity, means for feeding said film from said tank past light from said source to modulate said light, and means for simultaneously driving said scanning means and said iilm moving and feeding means, whereby said incoming image currents control said source of light of great intensity through the intermediary of said light of small intensity and said lm.

1l. A television system comprising means for generating image current representative of the light tone values of the eld of view comprising scanning means for scanning said eld and for producing an optical miniature replica thereof, a source of relatively intense illumination, means for causing said replica to modulate the light from said source simultaneously with the operation of said scanning means, stationary light sensitive means controlled by said modulated light for generating said image current, means for amplifying said image current, and means for impressing said image current upon a transmission medium.

12. The method of broadcasting previously recorded visual and related acoustic actions from a nlm which includes analyzing and transmitting the recorded visual actions and separately and optically analyzing and transmitting the related acoustic actions coordinated with the said visual actions.

13. The method of broadcasting from a film record visual and accompanying acoustic actions from previously recorded visual records produced at uniformly spaced time intervals and accompanied by continuously produced related sound records from a nlm which comprises scanning the record of the visual actions, transmitting a current modulated in accordance with the light impulses obtained by said scanning, optically analyzing the record of acoustic actions, and transmitting a current modulated in accordance With said sound reproduction simultaneously with the visual actions.

14. Electro-optical apparatus for transmitting images and accompanying sound effects recorded on a sound motion picture film, comprising means including a light sensitive electric element for scanning the picture portions of the motion picture nlm for producing a current which varies in accordance with the tone values of successively scanned elemental areas of the picture, means including a second light sensitive electric element for scanning the sound track of said sound motion picture film separately from the scanning of said picture portions for producing a current which varies in accordance with the sounds recorded on the film, and means for transmitting the current variations set up by said light sensitive electric elements.

15. Electro-optical apparatus for transmitting images and accompanying sound effects recorded on a sound motion picture lm, comprising means including a light sensitive electric element for scanning the picture portions of the motion picture film for producing a current which varies in accordance with the tone values of successively scanned elemental areas of the pictures, sound pick-up means for scanning the sound track of said motion picture film separately from the scanning of said picture portions for producing a current Which Varies in accordance With the sounds recorded on the lm, and means for transmitting the current variations set up by said light sensitive electric element and said sound pick-up means.

16. The method of television transmission which comprises taking a series of motion pictures of a field of View by exposing in succession adjacent portions of a continuous motion picture lm as in ordinary motion picture photography, immediately developing a portion of said series before the taking of said series is completed, and scanning a portion of the developed series an elemental area at a time While said taking is in progress to control the production of image currents by said scanning.

17. The method of transmitting images and accompanying sound eiiects which comprises taking a series of motion pictures and simultaneousn ly recording accompanying sound effects upon a motion picture film, immediately developing a portion or" said film While said taking is in progress, scanning a portion of the developed iilm While said taking is in progress for converting the picture tone values and the sound record into electromagnetic Wave energy, transmitting and receiving said electromagnetic Wave energy, exposing a light sensitive moving picture film to light under control ci the received electromagnetic wave energy, immediately developing a portion oi' the film at the receiving station while another portion is being exposed, thereby producing a sound motion picture nlm like the film at the transmitting station and immediately projecting said motion picture film and converting the sound record into accompanying sound effects while exposure of lm is in progress.

i8. The method of electrically transmitting television images which comprises analyzing each image into corresponding image points, translating said image points into corresponding electric currents, forming a non-pictorial record of each image in turn under control of said currents, suitably modifying each record as it is completed to enable a transient image to be obtained therefrom, and producing in turn from each of said modified records a complete transient image all vat one time; all of said steps proceeding simultaneously.

19. A television image producing apparatus comprising a source of image current having Variations corresponding to the variations in tone value of the elemental areas of a negative of a eid oi view, images ci which are to be produced, a motion picture film, means under control of said image current for controlling the exposure of the elemental areas in succession of said motion picture nlm, each frame of said film being exposed Within the period of persistence of vision, means for developing the film, and means for successively projecting the images from the developed nlm, all portions of each complete image being projected simultaneously for a period materially greater than the period of exposure of an elemental area but not greater than the period o1" persistence of vision.

20. A television image producing apparatus comprising a source oi relatively Weak light, light from which is modulated by incoming image current produced as the result of scanning a negative image of a field of View, images of Which are to be produced, a motion picture film, means for exposing the eiemental areas in succession of said motion picture lm to said modulated light from said source, the elemental areas of each frame of the film being exposed within the period of persistence of vision, means for preparing said film for projection, a second source of light of constant intensity, said intensity being substantially greater than the maximum intensity of said iirst source, and means including said second source of light for projecting images from said motion picture film, each complete image being projected for a period many times greater than the period of exposure of an elemental area of the motion picture lm, thereby producing images of much greater brightness than could be obtained by means of said first light source directly.

21. A television image producing apparatus comprising a source of relatively weak light, light from which is modulated by incoming image current produced as the result of scanning a negative image of a eld of View, images of which are to be produced, a. motion picture film, scanning means for exposing the elemental areas in succession' of said motion picture film to said modulated light from said source, the elemental areas of each frame of the film being exposed within the period oi' persistence of vision, said scanning means including means for moving said lm, a film developing tank into which said film is immediately fed after being exposed, a second source of light of constant intensity, said intensity being substantially greater than the maximum intensity of said first source, means for feeding said film from said tank past light from said second source to modulate said light to cause images to be projected in succession from said motion picture lm, and means for simultaneously driving said scanning means and said lm feeding means, whereby each complete image is projected for a period many times greater than the period of exposure of an elemental area of the motion picture lm and brighter images are prouced than could be obtained by means of said first light source directly.

22. The method of producing television images of a field of view which comprises producing a current having variations representative oi tone value of elemental areas in succession of a negative of a` iield of view, producing under control of said current light the intensity of which varies in accordance with said current variations, exposing the elemental areas in succession of a motion picture lm under control of light from said source, all the elemental areas of each frame of the lm being exposed within the period of persistence of vision, preparing the exposed portions of the film for projection while other portions of the same film strip are being exposed, and directing light of much greater intensity than the light used for exposing the film 'through the prepared film a frame at a time, while other portions of the same iilm strip are being prepared for projection, for projecting motion pictures from the film.

23. In a system for transmitting scenic representations and accompanying sounds and reproducing them in proper time relation, the combination of means for receiving image impulses, means for utilizing said impulses to reproduce the scenic representations on a motion picture lm, means for receiving currents representing the sounds to accompany said scenes, a channel for continuously translating the last-mentioned currents into audible vibrations, said channel comprising means for delaying said translation between two points of said channel a predetermined interval after the time of reception of the sound impulses.

24. The combination of a television picture projector, a sound reproducing device and an electro-mechanical sound lagging device adapted to receive sound controlled impulses and reproduce such impulses in synchronism with the projected television pictures, said lagging device comprising means for delaying said reproduction of said sound a predetermined interval after the time of reception of the sound impulses.

25. Television transmission apparatus comprising means for exposing the frames of a motion picture film in succession to light from a field of View within the period of persistencev of vision, means for developing the exposed portions of the film While other portions of the same film strip are being exposed, and means for scanning the developed portions of the iilm, while other portions are being exposed and developed, to produce a television image current, said lastmentioned means comprising means for illuminating the lm by intense light and stationary light sensitive means for receiving light from said source directed through the lm.

26. Television transmission apparatus comprising means for exposing the frames of a motion picture film in succession to light from a field of View within the period of persistence of vision, means for developing the exposed portions of the film while other portions of the same film strip are being exposed, and means for scanning the L developed portions of the film, while other portions are being exposed and developed, to produce a television image current, said last-mentioned means comprising alight source and a light sensitive electric means in iixed position with respect to each other, and means for moving the lm into the light path between said light source and said light sensitive means.

27. Television transmission apparatus comprising means for exposing the frames of a motion picture film in succession to light from a field of view, means for developing the exposed portions of the film While other portions of the same film strip are being exposed, and means for scanning each developed portion of the film, while other portions are being exposed and developed, within the period of persistence of vision, all the elemental areas thereof being scanned in succession, to produce a television image current,

said last-mentioned means comprising means for I producing a moving scanning beam, electric means sensitive to light in. fixed position with respect to said last-mentioned means, means for moving the frames of the film in succession into the light path between said light source and said light sensitive means, and means for directing light from the illuminated elemental areas in succession of the motion picture film to said light sensitive means.

28. Television transmitting apparatus comprisy ing a motion picture camera, Iilm developing means, film scanning means comprising a light source and a light sensitive electric device in xed position with respect to said light source, and

means for moving and guiding a motion picture iilm strip through said camera, said developing means and said scanning means simultaneously so that different portions respectively of the lm may be exposed in the camera, developed and scanned simultaneously.

29. Apparatus for producing television images, comprising a source of image current produced as the result of scanning the successive elemental areas of a field of View, all the elemental areas of the iield being scanned within the period of persistence of vision, means controlled by current from said source for exposing elemental areas of a motion picture film in synchronism with the scanning of the elemental areas of the field of view, film developing means, a motion picture projector, and means for moving and guiding a motion picture film strip through said film exposing means, said developing means and said motion picture projector simultaneously so that different portions of. said. film, respectively,

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may be exposed, developed and projected simultaneously, each complete image being projected within the period of persistence of vision.

30. Apparatus for producing television images comprising a source of image current produced as the result of repeatedly scanning a field of view, each complete scanning taking place within the period of persistence of vision, a source of radiant energy, means for modulating energy from said source under control of said image current, a motion picture film, means for exposing a motion picture film to radiant energy from said source to produce latent images of the field of view upon said motion picture ilm, film developing means, a motion picture projector, and means for moving said motion picture lm simultaneously through said iilm exposing means, said developing means, and said motion picture projector so that different portions of the lm, respectively, may be exposed, developed and projected simultaneously, each complete image being projected within the period of persistence of vision.

31. Apparatus for producing television images comprising a source of image current produced as the result of repeatedly scanning a iield of View, each complete scanning taking place Within the period of persistence of vision, a source of light, means for modulating the light from said source under control of said image current, means for exposing the motion picture film to light from said source to produce latent images of successive aspects of the eld of View upon successive frames of the motion picture lm, film developing means, a second source of light of a constant intensity much greater than the maximum intensity of said rst light source, means for projecting light from said second source through the frames of the developed motion picture lm in succession to produce images of said eld of vievv of greater brightness than could be obtained directly by use of light from said rst source, and means for moving said motion picture nlm simultaneously through said nlm exposing means, said developing means ancl said motion picture projector so that different portions of the lm, respectively, may be exposed, developed, and projected simultaneously, the images being projected in succession at a rate Within the period of persistence of vision,

32. Apparatus for producing television images comprising a source of image current produced as the result of repeatedly scanning a field of view, each complete scanning taking place within the period of persistence of vision, a source of light, means for modulating light from said source under control of said image current, a motion picture film, means for exposing elemental areas in succession of said motion picture film to iight from said source to produce latent images of successive aspects of the iield of view upon successive frames of the motion picture lm, nlm developing means, a second source of light of constant intensity, means for projecting light from said second source through all the elemental areas of a frame of the developed motion picture film simultaneously for a period greater than the period of exposure of each elemental area to produce images of said field of view of greater apparent brightness than could be obtained directly by use of light from said first source, and means for moving said motion picture film simultaneously through said iilm exposing means, said developing means and said projecting means so that different portions of the film, respectively,

may be exposed, developed and projected simultaneously, each complete image being projected Within the period of persistence of vision.

33. Apparatus for producing television images comprising a source of image current produced as the result of repeatedly scanning a field of view, each complete scanning taking place within the period of persistence of vision, a source ci radiant energy, a motion picture film sensitized to energy from said source, means for modulating energy from said source under control of said image current, means for exposing elemental areas in succession of said motion picture film to radiant energy from said source to produce latent images of successive aspects of the field of view upon successive frames of the motion picture film, film developing means, a source of light of constant intensity, a screen, means for projecting light from said source upon said screen through all the elemental areas of a frame of the developed motion picture lm simultaneously for a period greater than the period of exposure of each elemental area, and means for moving said motion picture lm simultaneously through said lm exposing means, said developing means and said projecting means so that different portions of the lm, respectively, may be exposed, developed and projected simultaneously, each complete image being projected Within the period of persistence of vision.

34. Apparatus for producing television images and accompanying sound effects comprising a source of television image current produced as the result of repeatedly scanning a iield of View, each complete scanning taking place Within the period of persistence of vision, a source of current representative of the accompanying sound effects, a motion picture lm, means under control of said image current for exposing said motion picture lm to produce latent images of said eld of view thereon, film developing means, a motion picture projector, means for moving said motion picture nlm simultaneously through said lm exposing means, said developing means and said motion picture projector so that different portions of said nlm may be exposed, developed and projected simultaneously, each complete image being projected Within the period of persistence of vision, and means under control of the sound current for producing the accompanying sound in the correct time relationship with respect to said projected images,

35. Apparatus for producing television images and accompanying sound effects comprising a source of television image current produced as the result of repeatedly scanning a field of view, each complete scanning taking place Within the period of persistence of vision, a source of current representative of the accompanying sound effects, a source of radiant energy, means for modulating energy from said source under control of said image current, a motion picture film, means for exposing said motion picture film to nadiant energy from said source to produce latent images of said eld of View upon said motion picture film, iilm developing means, a motion picture projector, means for moving said motion picture lm simultaneously through said film exposing means, said developing means and said motion picture projector so that different portions of said lm may be exposed, developed and projected simultaneously, successive images being projected at a rate within the period of persistence of vision, and means under control of the sound current for producing the accompanying sound in the correct time relationship with respect to said projected images, said last-mentioned means comprising means for delaying the production of the sound to compensate for the delay in the image production occurring due to the time required for preparing the motion picture lm for projection.

36. Apparatus for producing television images and accompanying sound effects comprising a source of electric energy representative or the tone values of elemental areas of a eld of View which is repeatedly scanned at a rate Within the period of persistence of vision and of accompanying sound effects, a motion picture film, means for exposing said motion picture lm under control of said electric energy to produce thereon latent images of successive aspects of the field of View and a latent record of the accompanying sound eiects, film developing means, a motion picture projector, means for producing sound under control of said film, and means for moving said nlm simultaneously through said lm exposing means, said developing means, said projector, and said sound producing means to produce television images and accompanying sound effects in correct time relationship.

87. Electro-optical apparatus for transmitting television images and accompanying sound effects comprising a motion picture iilm, means for exposing the frames of the motion picture im in succession in accordance with the successive aspects of a eld of View, means for developing the motion picture lm, means for scanning the frames of the developed film in succession at a rate Within the period of persistence of vision to produce a television image current, means for moving said motion picture ilm simultaneously through said lm exposing means, said developing means and said scanning means, and means for producing a current representative of the accompanying sound eirects, said lastmentioned means including delay means for lcausing said television current and said sound current to be produced in correct time relationship.

38. Electro-optical apparatus for transmitting television images and accompanying sound effects comprising a motion picture lm, means for exposing the frames of the motion picture lm in succession in accordance with successive aspects of a field of view, means for exposing the motion picture lm in accordance with the accompanying sound, means for developing the motion picture lm, means for scanning the frames of the motion picture lm in succession at a rate Within the period of persistence of vision to produce a television image current and a current representative of the accompanying sound, and means for moving said motion picture film simultaneously through said exposing means, said developing means, and said scanning means so that diierent portions of the film, respectively, may be simultaneously exposed, developed and scanned.

39. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for recording upon a moving lm, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for independently receiving and amplifying impulses coming from a sound transmitter; and means for reproducing the sound in synchronism with the projected pictures, said last-mentioned means including means for delaying the reproduction of the sound.

40. A television and sound receiving and reproducing system embodying: means for receiving television impulses, means for producing a record luider control of said received television impulses; means for projecting pictures upon a screen under control of said record; means for receiving sound controlled impulses simultaneously With the reception of said television impulses; and means for reproducing the sound in synchronism With the projected pictures, the last-mentioned means including means for delaying the reproduction of the sound.

41. A television and sound receiving and reproducing system embodying: means for receiving and amplifying impulses coming from a television transmitter; means controlled by said television impulses for recording upon a moving lm, pictures corresponding with the transmitted images; means for projecting said pictures upon a screen; means for receiving impulses coming from a sound controlled transmitter; and means for reproducing the sound impulses in synchronism with the projected pictures; said last-mentioned means comprising a rst element adapted to receive impulses from said sound impulse receiving means, a second element, associated with a loud-speaker, and means interposed between said iirst and second elements for causing each impulse received by the former to control the latter to in turn control the production of a corresponding sound impulse by said loud-speaker with a delay sufficient to effect said synchronism.

42. A television and sound receiving and reproducing system embodying; means for receiving television impulses; a moving record strip and means under control of the received television impulses for producing television images upon said strip, means for projecting said images from said strip upon a screen; means for receiving sound controlled impulses simultaneously With the reception of television impulses; and means for reproducing sound from said sound impulses in synchronism with the projected images comprising means for causing a delay of the reproduction of the sound substantially equal to the delay between the time of recording each image on said strip and the time of projecting it from said strip on said screen.

RALPH V. L. HARTLEY. HERBERT E. IVES.

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