US2052298A

US2052298A - Electrooptical system

Info

Publication number: US2052298A
Application number: US440908A
Authority: US
Inventors: Herbert E Ives
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1930-04-02
Filing date: 1930-04-02
Publication date: 1936-08-25
Anticipated expiration: 1953-08-25
Also published as: FR713927A

Description

Aug. 25, 1936. 5 53 2,052,298

ELECTROOPTICAL SYSTEM Filed April 2, 1950 INVENTOP h; E lvzs A TTOPNEY Patented Aug. 25, 1936 UNITED ST T PATENT oFFicE This invention relates to electro-optica'l systerns and more particularly to arrangements-for monitoring. television reception It'has been proposed, as disclosed in U.-S.--Pat ent 1,717,782; June18, 1929 tolI-ves et alt,- taprovidea television system with an arrangement; for monitoringat thetransmi'tting station. the: patentedhsystem, acerta'in amountof theout going image current is diverted, amplified and used to control a light sourcewhich is viewed: through apertures inthe disc 'used to scan the scene or object to be transmitted;

In certain types oftelevision: receivers, the incoming picture currents are used to control the intensity of the light supplied by a local source,.whi'ch is viewed by an observer through apertures spiral1y arranged in: a continuously moving scanning member: operating in synchronismi with. a similarlyl apertured s'cannin'gmemher. at a cooperating transmitting station.-

One: object of the presentinvention-is to permit monitoring at a television receiving"station which operates: as described: in the preceding paragraph.

. Another object is: to' enable: the? reproducing; light source to be viewed by an observer and a monitoring. operator;

Inzoneembodimeritof theiinvention the monitoring; operator? views the light:- source, which is viewedlby theobserver tthrougli-ascanningzmemher; by means of. a mirror? placed; atv one side of the: source: at approximately45 to the plane of the scanning member and ofisetwith respecti-totheaobservers positionlens is: placed close a T to the scanningu member' and has aiocal length such-that the light source is imaged upon the: pupil of the eyeofthe monitorthrough the .aper-- tured portion of the member. corresponding to theoffset position or the'mirror.

A more detailed .description of the inventionfollows'andis illustrated in-the attacheddrawing.

Fig. lillustrates atelevision receiver including the invention and Fig. 2 is a front view of part of thescanning disc showing the frame.

557; A: system;foraccomplishing.theaobject ofthe invention comprises an observers booth- I-, a cabinet 2' enclosing the receiving apparatus, and amonitoring apparatuswhich may be used by the operator without entering the booth.

- Image currents received from a remote station are su plied through the circuit 3 to the amplifier 4 which may comprise any number of stages. The amplified image currents are impressed upon the light source, herein shown as a glow lamp 5.

Any suitable type of glow lamp, for example,

a lampof the design disclosed in- Ganadian Patent 326,606 of H. W. Weinhart, issued Oct. 11, 1 932, by Weinhart, may be used. As thereindisclosed; the lampincludes a cathode 6 having a large fiat surface which is substantially completelycovered by a negative glow, caused by the electric discharge from-its anode 7' through the gas.

The amplified image currents cause the brilliancy of the glow area of the lamp to vary in 2 accordance with changes in the amplitude ofthe' current.

The observer 0 views the glow area of the lamp through a row of apertures or perforations 8 spirally arranged near the periphery of the rotatmg disc 9 driven by a motor 20. At the same time, light reflected by the mirror It] is transmitted through a lens ll, perforations 8 of the disc 9 and the mirror I2 to the monitor M.

The mirror It is set at an angle of approxi- 3"0 mately 45 to the disc 9 and is offset with respectto the lamp 5, so that it is removed from the line of vision of the observer. The position of the mirror is such that it receives light radiated in the form of awedge having its apex in the form of: a thinline of light'correspondingto the edge of the: glowing layer within the lamp.

The'lens H is of such focal length that it forms an image of the light refi-ected'by the mirrors It upon thef-pupil of the monitors eye over a path including the mirror I2. While the mirror I2 is provided as'a means to determine one desirable monitoring position, it is not essential to the invention.

As is well known the disc 9 is controlled to rotate in synchronism with the scanning" disc at the transmitting station. A suitable system for this purpose is disclosed in U. S. Patent 1,763,909 of 'stollerand Morton issued June 17, 1930. Such apparatus is not a feature of the present invention and hence it hasnot been illustrated.

Disc 9 is operated at such a rate of speed that an image, produced upon the retina of the' observers eye, is repeated ator above the rate of persistence of vision, namely, about 16 to 20 times per second.

The frames I3 and [4, respectively, serve to determine the size of the image viewed by the observer and the monitor.

As the image viewed by the observer is produced by a spiral of apertures extending over 360, it is necessary to provide a spiral of apertures at 360 in order to produce the image to be viewed by the monitor. It is also essential that, at any given instant, a similarly numbered aperture of the spiral controlling the production of the images should simultaneously pass before the field of vision of the observer and monitor. This could be efiected by using two discs having two rows of spirals, one for the observer and one for the monitor.

However, as shown in Fig. 2, the disc 9 is provided with a spiral row of apertures which extend over 360 plus an angle corresponding to the ofiset position of the mirror in. For example, if the mirror is offset 90, the total angular length of the row of spirals is 450. The frames l3 and M are provided with openings which are of such size and are so displaced radially with respect to each other that they are respectively traversed by apertures extending over a total angle of only 360. The image seen by the monitor is identical with that viewed by the observer.

For the purpose of disclosing an operative apparatus for practicing the invention, specific devices and details have been described. However, it is to be understood that these specific features are merely typical and are not essential to the invention, for example, any suitable source of illumination may be used in place of the lamp 5 and any approved scanning member may be substituted for the disc 9.

What is claimed is:

l. A television receiving system comprising a light source, means for applying incoming image current to said source to thereby control the production of light rays varying as the tone values of a field of View scanned at a rate within the period of persistence of vision, an apertured member through the apertures of which rays from said source pass to set up an image, and means, utilizing other rays from said source and cooperating with the apertures of said member, for setting up a second image element by element simultaneously with the elements of said first image.

2. A television receiving system comprising a light source, means for applying incoming image current to said source to thereby control the production of light rays varying as the tone values of a field of view scanned at a rate within the period of persistence of vision, an apertured rotatable member through the apertures of which rays from said source pass to set up an image, and means, utilizing other rays from said source and cooperating with the apertures of said memher, for setting up a second image element by element simultaneously with the elements of said first image.

3. A television receiving system comprising a source of light controlled by an incoming image current corresponding to a field of View scanned within the period of persistence of vision, an apertured rotating scanning element through the apertures of which light from said source passes to set up an image, means for simultaneously producing a second image including means for directing light from said source through a differcut one of said apertures than the one utilized at any instant in forming the first image.

4. A television receiving system comprising a source of light controlled by incoming image current, an apertured rotating scanning member, and means, including light directing means, for causing light to pass through a plurality of said apertures to simultaneously control the production of duplicate images.

5. A television receiver comprising an observers booth, a source of light controlled by incoming image currents, an apertured scanning element outside said booth, and means for directing light from said source through a plurality of said apertures to simultaneously set up duplicate images, and means permitting one of said images to be viewed from a position outside said booth.

6. A television receiving system comprising a source of light controlled by incoming image current, an element for scanning light rays supplied by said source to set up an image, and means including said element for utilizing other light rays supplied by said source for setting up a second image simultaneously with said first image.

'7. A television receiving system comprising an observers booth, a source of light controlled by incoming image current, an element for scanning light from said source to set up an image observable within said booth, and light directing means cooperating with said source and said element to simultaneously set up a second image observable outside said booth.

8. A television image producer comprising an observers booth, a source of light controlled by incoming image current, and a scanning means comprising an element having apertures and light control means which cooperate with the light source for causing light to simultaneously pass through a plurality of said apertures for respectively producing an image observable within said booth and simultaneously therewith a second image observable outside said booth.

9. Television apparatus for simultaneously setting up spaced images of the same object for separate viewing, comprising at a receiving station scanning means, said means comprising a rotatable element for scanning image modulated radiations, and means associated therewith for directing radiations having identical image modulations to be scanned by said element whereby the latter operates to control the simultaneous building up, in phase with each other, of a plurality of images spaced apart.

10. Television apparatus for the simultaneous production of a plurality of duplicate images comprising means for setting up radiations modulated under control of incoming image currents to be utilized in the production of said duplicate images, and rotatable scanning means carrying a plurality of spirally arranged means and light control means cooperating with said spirally arranged means for simultaneously selectively directing different portions of said radiations to set up corresponding strips of said duplicate images respectively.

11. Television apparatus for the simultaneous production of a plurality of duplicate images comprising means for setting up radiations modulated under control of incoming image currents to be utilized in the production of said images, and rotatable scanning means carrying a plurality of spirally arranged means and light control means cooperating therewith for'simultaneously selectively directing different portions of said radiations to set upcorresponding strips of said images respectively, the number of said spirally arranged means being greater than the number of strips in each of said duplicate images.

12. A television apparatus including means for simultaneously producing a plurality of duplicate images comprising a source for producing radiations modulated in accordance with incoming image currents, means using certain of said image modulated radiations to set up an image field, and optical means, cooperating with said source and said first mentioned means, for utilizing other of said image modulated radiations radiated from a portion of said source which is restricted in area compared with that of an image field, to simultaneously set up at least one other image field, said optical means operating to direct said other radiations to said first mentioned means in the form of a beam of image field dimensions.

13. Television apparatus for the production of a plurality of images comprising means for producing radiations modulated under control of incoming image currents to be utilized in the production of said images, and rotatable scanning means having a plurality of spirally arranged means and light control means cooperating therewith for directing image modulated radiations to set up separate image fields respectively occupying different positions in the path of travel of said light directing means.

14. Television apparatus for the production of a plurality of images comprising means for producing radiations modulated under control of incoming image currents to be utilized in the production of said images, and rotatable scanning means having spirally arranged light apertures and light control means cooperating therewith for directing image modulated radiations to set up separate image fields respectively occupying different positions in the path of travel of said light apertures.

15. Television apparatus for the production of a plurality of images comprising means for producing radiations modulated under control of incoming image currents to be utilized in the production of said images, and rotatable scanning means having a plurality of spirally arranged means and light control means cooperating therewith for directing image modulated radiations to set up a plurality of image fields respectively observable by means of said light directing means travelling substantially vertically or by means of said light directing means travelling substantially horizontally.

16. Television apparatus for the production of a plurality of images comprising means for producing radiations modulated under control of incoming image currents to be utilized in the production of said images, and rotatable scanning means having a plurality of spirally arranged light apertures and light control means cooperating therewith for directing image modulated radiations to set up a plurality of image fields respectively observable through said light apertures travelling substantially vertically or through said light apertures travelling substantially horizontally.

HERBERT E. IVES.