US2221091A

US2221091A - Television system

Info

Publication number: US2221091A
Application number: US245342A
Authority: US
Inventors: Alfred N Goldsmith
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-12-13
Filing date: 1938-12-13
Publication date: 1940-11-12
Anticipated expiration: 1957-11-12

Description

-Nov. 12, 1940. AMGOLDSWTH 2,221,091

TELEVISI-ON SYSTEM Filed Dec. 13, 1958 V I NV EN TOR. ALFRED N7G0LD5M/TH I ATTORNEY.

Patented Nov. 12, 1940 UNITED STATES PATENT, OFFICE This invention relates to an improvement in television systems and more particularly to studio technique and to the manner in which the various portions of a television program are assembled for transmission.

In present television systems, in order that the production of a television program may be continuous, it is necessary to use a plurality of television transmitting cameras since at least two cameras are desirable in the studio and since a certain percentage of each program is also generally derived from film. When this is the case and when-the film used comprises more than one reel, it is necessary to use at least two cameras in the film studio.

It is desirable to be able to use a single television camera insofar as film is concerned since the equipment necessary in the studio may be reduced thereby. Where two or more cameras are used, it is necessary not onlyto have a I separate transmitter tube and pre-amplifierfor each camera, but also separate deflection voltage generators are also conventionally used for each separate television camera, since all television transmitting tubes are not exactly identical insofar as their deflection response is concerned.

Aside from this, other apparatus must be duplicated for each additional television camera used.

Accordingly, it is one purpose of the present invention to provide an arrangement whereby a single television transmitting tube may be used to produce television signals from all picture film sources used during a television program.

It is still another purpose of the present invention to provide a means whereby the images from separate moving picture projectors or slide projectors may be so situated that they may readily and quickly be shifted into position so as to project their images in sequence on the single television transmitting tube.

Still another purpose of the present invention resides in the provision of means whereby superimposed images which are derived from two films or from one film and a slide projector may be simultaneously projected upon the light sensitive mosaic electrode of the single transmitting tube.

Still another purpose of the present invention resides in the provision of means whereby various dramatic and pictorial effects may be accomplished through the use of a single transmitting tube.

Still another purpose of the present invention resides in the provision of means whereby all of the film or slide material necessary in the presentation of a particular television program may be previously set up and conditioned for sequential operation with the result that a minimum of manual attention is necessary during the actual presentation of the program.

A still further purpose of the present invention resides in the provision of means whereby the images from two films or slides may be controlled so as to produce certain desirable effects in connection with certain Studio scenes.

Still other purposes of the present invention -will become more apparent to those skilled in the mosaic electrode may be scanned in a systematic manner in order to produce a series of video or television picture signals from the signal plate it. The signal energy derived from the signal plate l6 is'impressed across a-load resistance it, the signal energy being supplied to the control electrode of an amplifier tube by Way of a coupling condenser 22. The anode of the amplifier tube 20 may be coupled to Succeeding stages of amplificationand modulation (not I shown) whereby the television signals as derived from the signal plate l6 may be transmitted to outlying television receivers.

For projecting optical images on the light responsive electrode of the transmitter tube lo,

a plurality of projectors 24, 25, 2E and 2? are provided, the images wherefrom are projected on translucent screens such as 69. Alternatively, the screen [is may be omitted, and in that case, aerial images will be-formed at the same location. These projectors may boot the moving picture type wherein a picture film is used, or they may be of the lantern. slide type wherein still pictures are projected. These projectors are positioned on a common base member 33 which also carries a plurality of sources of

illumination

32, 33, 34 and 35. Each of these sources of illumination is provided with a reflector 38 and either a translucent or opalescent screen or a lens 38.

The base member 30 which supports the projectors and the sources of illuminationmay be rotated about a vertical axis to by a motor t2 operating through anappropriate gear reduction device. The projectors and the various sources of illumination are so positioned that they may successively project light or images on the mosaic electrode of a transmitter tube.

In addition to the projectors 24, 25, 26 and 21, still another source of optical images is provided, including the film 50. The film is adapted to be passed through a film gate 52 and two or more spur gears 54 are provided for transporting the film. Thesegears are rotated by means of a motor 56 operating through gear reduction devices 58. As the motor 56 rotates the gear reduction devices cause the film 50 to be transported in the direction indicated by the arrow in either a continuous or an intermittent manner. Means may be added.- whereby the gear 54 will stop only in positions such that a frame of film 50 is exactly framed in gate 52.

In order that the images from the projectors 24, 25, 26 and 21 may ultimately be projected on the light responsive electrode I2, a lens system 65 is provided for producing an image in the plane of the film gate 52. The image, after being projected therethrough, is again focused into an optical image in the plane of the mosaic electrode by a second lens system 62. These two lens systems are provided in order that images from the film 56 may be projected on the mosaic electrode of the transmitter tube through the lens system 62 and also in order that images from the projectors may be projected thereon. A further purpose in the provision of these two lens systems resides in the fact that images from both the film 50 and the projectors may be brought to focus on one and the same mosaic electrode.

When the projector 22, for instance, is in the position as shown in the drawing, images from this projector will be projected on the mosaic electrode l2. If, at the same time, the film 50 is transported through the film gate 52 and an image is present on the film, then a superimposed image of the subject matter on the film will also appear on the mosaic electrode. 'If only the image from the projector 241 is desired, then the film 50 may either be eliminated or may contain transparent or translucent portions upon which no film images are provided. For example, film gate 52 may be arranged to slide in its own plane 40 out of the path of the beam 10., If, on the other hand, the images from the film 50 alone are desired, the support member 30 may be rotated so as bring the source of light 32 in the position occupied by the projector 24 in order that only the image which appears on the film 50 will be projected on the light responsive electrode l2. It is possible, therefore, to create an aerial image at the plane of the film gate 52 from the subject matter contained on the film (or the slide) that is projected through the projectors 24, 25, 26 or 21.

Further means may be provided for controlling the absolute brightness of the illumination of film 50 in all parts of the field at the gate 52, over and above the illumination of film 5!] by means of either the image formed thereon by one of the projectors 24, 25, 26 or 21 or by means of one of the

light sources

32, 33, 34, or 35. The further means are the light sources 61 and 68 which are placed within the reflectors 65 and 66 which may be provided with any desired degree of diffusion of the emergent beam of light. The reflectors 65 and 66 are placed outside of the path of the image-forming beam 10 emerging from lens to fall on gate 52 so as to avoid intercepting any portion of such beam. The reflectors are directed toward the gate 52 in such fashion as to illuminate that portion of the film contained therein, and may be at any appropriate distance from such gate and at any suitable angle to the optical axis of lens 60 and 62 sothat the light passing through film 52 may be picked up by lens 62 from all parts of the field. A slightly diffusing sheet of ground glass or similar material may be placed in gate 52 on the side of film 50 toward lens 60.

In order to control the brightness of the illumination produced by 61 and 68, switches (not shown) may be provided whereby one or the other of these sources may be turned out, and rheostats (also not shown) may be placed in the supply circuits of these light sources so as to control their degree of incandescence.

It thus becomes readily possible to vary the relative brightness on the mosaic 12 of the images produced by the projectors 24, 25, 28 or 27 on the one hand and of the images of the film 50 on the other hand. Further, the brightness of the image of film 50 becomes relatively independent of the illumination from the projectors 24 25, 25, or 21 which is particularly desirable for those parts of the field which may not be illuminated momentarily by one of such projectors. In addition, the illumination of film 50 by means of sources 61 and 68 may be made additive to the illumination from one of the

sources

32, 33, 34 or 35.

An arrangement such as that described above lends itself very conveniently to various usages and may be further used in presenting titles to the various parts of a television studio program. For instance, the film 50 may comprise a loop of film upon which is present a series of moving picture frames typical of the general subject matter of the particular studio presentation to be given. Each of the projectors 24, 25, 25 and 2'! may be used to project the headings, titles or captions from slides so that at the television receiver an image will be presented showing a typical scene or theme of the studio presentation to be given, upon which are superimposed headings indicating the title of the presentation, the names of the actors, the locale, etc. As a still further example, the device described could be conveniently used to indicate the lapse of time. One film might indicate a stop at a certain location which would be immediately followed by the appearance of a series of wavy lines which could be procured from the film 50 when the support 30 is rotated so as to bring the lamp 32, for instance, into the path of-the optical system, or by lighting sources 61, 68. The representation of the wavy lines would indicate the lapse of time which would then be followed by another length of film in the projector 25 indicating another stop, etc.

Again, the apparatus could be used where certain lengths of film are necessary in order to show scenes which are not conveniently capable of reproduction in a studio. When that part of the play is reached in which the film is used, one of the projectors, for instance, 24, could be used to project that particular portion of the film upon the transmitting tube Ill. The studio presentation would then continue after the required length of film had been shown and if subsequently another length of film is necessary, this film could be obtained in projector 25 so that by moving the supporting base 30 into such a position as to place the projector 25 in the optical system of the device, this length of film could then be shown. It may seem, therefore, that in studio presentations Where lengths of film are necessary to show, at various places during the presentation, scenes which cannot be brought to the studio, these lengths of film may be positioned in the cameras 24, 25, 26 and 21 in the proper order so that they are in readiness for use w en desired.

Various. other effects, including montage effects as used in motion pictures, can thus be introduced.

In order that the projectors 24, 25, 26 and 21 may be controlled insofar as their operation is concerned, it is desirable to provide some form of a switching arrangement whereby the operation of these projectors and the movement of the film therethrough may be placed under the control of an operator. In order to conserve power, it is also desirable that the

lamps

32, 33, 34 and 35 be also controlled by an appropriate switching arrangement, and inasmuch as these lamps are in active use only when positioned in alignment with the optical system, the circuits to the lamps may be completed by a switching arrangement operated in conjunction with the rotation of the supporting base 30. Further switching means are desirable whereby the motor and lamp circuits of the projectors 24, 25, 26, 21 are open unless either the projector is in the operating position 24 or unless a special switch marked with-a caution in-'- dication is operated. Thus incorrect operation is avoided. Further, means can be provided whereby the light source 32 which is about to be used may be preheated to partial or full brightness on reaching the position shown in the drawing, thusavoiding delays in projection when 32 is moved into the operating position.

Likewise, since it will become necessary to control the movement of the film a proper switching arrangement may be included in the circuit of the motor 56, in order that the movement of the film 50 through the film gate 52 may be under the control of the operator.

If desired, the lens 60 and the translucent glass screen 69 may be omitted, and the objective lens H of the projector 24 so positioned that the projector will cast its image directly on the film in Y the film gate 52. When this is done it may become desirable to move the film gate 52 along the optical axis of lens 62 by a slight amount as the support 30 is rotated in order that proper focal conditions may be maintained.

Although a more or less specific form of the present invention is shown in the drawing, it is to be understood that various modifications and obvious ramifications of the system may be made without departing from the spirit and scope thereof, and it'is desired that any and all of these modifications shall be considered within the purview of the present invention, except as limited by the hereinafter appended claims.

I claim:

1. A television transmitting system including a. transmitting tube for translating light values into a series of electrical signals, a photo-sensitive electrode in said tube, means including an optical lens system-for focusing an image on said photosensitive electrode, an image projection device positioned in the optical axis of said lens system for producing an aerial image at a plane along the optical axis, an image bearing surface posi- .tioned in the aerial image plane, and independent means for illuminating said image bearing surface whereby an image from said projection device or from said surface, or both, may be projected on said photo-sensitive electrode.

2. A television transmitting system including a transmitting tube for translating light values into a series of electrical signals, a photo-sensitive electrode in said tube, means including a lens system for focusing an image on said photo-sensitive electrode, a motion picture projection "device positioned in the optical axis of said lens system, an image bearing surface positioned between said projection device and said lens system, and means for illuminating said surface by a predetermined degree independently of said projection device whereby an image may be selectively projected on said photo-sensitive electrode from said projection device or from said surface.

3. A television transmitting system including a transmitting tube for translating light values into a series of electrical signals, a light sensitive electrode in said tube, an optical lens system for focusing an image on said light-sensitive electrode, projection means positioned in alignment with the optical system, an image bearing surface positioned between said projection means and said lens system, means for transporting said image bearing surface, and selective means for illuminating said surface whereby different images may be selectively projected on said light sensitive electrode.

4. A television transmitting system including a transmitting tube for translating light values into a series of electrical signals, a light sensitive elecrtrode in said tube, an optical lens system for focusing an image on said light-sensitive electrode, projection device positioned in alignment with the optical system, an image bearing surface, means for positioning a portion of said image bearing surface between said device and said lens system, means for transporting said image bearing surface, and means including said projection device for illuminating said surface whereby different images may be selectively projected on said light sensitive electrode.

5. A television transmitting system including a transmitting tube for translating light values into a series of electrical signals, a photo-sensitive electrode in said tube, means including a lens system for focusing an image on said photo-sensitive electrode, a motion picture projection device positioned along the optical axis of the lens system for producing an aerial image in a plane normal to the optical axis, an image bearing surface positioned between said projection device and said lens system and coinciding with the aerial image plane, and means including said projection device for illuminating said surface whereby a composite image from said projection device and from said surface may be projected on the photo-sensitive electrode.

6. A television transmitting system including a transmitting tube for translating light values into a series of electrical signals, a photo-sensitive electrode in said tube upon which an optical im-' age is adapted to be projected along a. predetermined optical axis, an image projection device positioned in the optical axis of said transmitting tube, optical means for forming a real aerial image from the projection device in a plane normal [to the optical axis and along the axis, further optical means for refocusingthe aerial image on the photo-sensitive electrode, an image-bearing surface placed in the plane of the aerial image, and light projection means for directly and regulably illuminating said image bearing surface, whereby images on said surface may also be projected on said photo-sensitive electrode.

ALFRED N. GOLDSMITH.