US2050411A

US2050411A - Receiving apparatus for television

Info

Publication number: US2050411A
Application number: US581395A
Authority: US
Inventors: Barthelemy Rene
Original assignee: Compteurs Schlumberger SA
Current assignee: Compteurs Schlumberger SA
Priority date: 1930-12-20
Filing date: 1931-12-16
Publication date: 1936-08-11
Anticipated expiration: 1953-08-11
Also published as: FR724524A; BE384874A; GB394341A

Description

g 1 R. BAR'IHELEMY 2,050,411

RECEIVING APPARATUS FOR TELEVISION Filed Dec. 16, 1931 fien Bar H7 elem INVENTOR 4 ATTORNEY Aug. 11, 19361 RECEIVING srrsns'rns non TELEVISION Ren Barthelemy, Fontenay aux Roses, France, assignor to Compagnie pour la Fabrication des iJOm-pteurs et Materiel dUsines a Gas, Montrouge, France Application December 16, 193i, Serial'No. 581,395 In France'Deceinber 20, 193d 7 r V c fluorescent surface which forms the screen.

The present invention has for itsobiect to 'providean apparatus in which the moving lumi:

. nous source will be considerably more intense and in which a cathode ray oscillograph is used in order to cause the movable light source to traverse the screen on which the, image or scene produced is observed.

To this end, the beam of cathode rays in the oscillograph is used as a moving conductor to connect..at a great speed, an electric source to a number of points disposed on the interior; of the oscillograph, each of these points being electricalla connected with the cathode of a tube con- 7 taming a rare gas maintained at a low pressure.

In this manner the electric discharge set up successively between each one of the cathodes and the anode of the rarefied gas tube renders each of the cathodes successively luminous with an intensity proportional to that of the cathode ray beam, and by causing the intensity of the directing fields of the oscillograph to vary in synchronism with the transmission to be received, one can obtain the synthesis of the image or scene to be reproduced.

The system will thus comprise a cathode ray tube set up as an oscillograph and provided with means for modulating the cathode ray beam according to the variations of current produced in the receiveriiby the received transmissions; a tube of rarefied rare gas containing alarge number of cathodes having extremities or prolongations which project into the interior of a cathode ray tube and form a surface swept by the cathode ray beam, the anode of the said rarefied gas F d in such a manner that it does not obstruct the view of the cathodes, and the source producing the electric discharges between said anode and successive cathodes having such a voltage that the intensity and desired luminous eiiectsareob The attached drawing shows by way of example and not oi limitation, one embodiment of the system in which the rare gas tube is contiguous to the oscillograph.

Figurelisaplanviewand e 2 is an end view oi the arrangement. As shown in Figure l, I is the cathode ray tube,

(on. 17M) 2 is the rarefied gas tube juxtaposed to the oscillograph i. The oscillograph I comprises a cathode 3 and an anode 4. This anode is provided with an opening through which passes the oathode ray beam emitted by the cathode 3. The directing fields ofthe oscillograph are here shown as two rectangularly disposed electro-static fields produced by the two condensers 5 and 6 between which passes the cathode ray beam, which is thus deviated. This beam sweeps the surface I of 10 the wall 9 which separates the cathode ray tube i from the rarefied gas tube 2. Said wall 9 is constructed very thin and consists of electrically semi-conducting material. The surface I0 of the wall 9, which is disposed in the rarefied gas tube 2, represents the screen on which the reproduced scene or image will appear. Thus, a luminous spot will appear inside the tube 2 on the surface it of the wall 9 opposite the point of impact of the cathode ray beam on the surface i in tube I. This tube is also provided with an anode ll disposed peripherally with respect to the screen surface li! in order that it shall not obstruct the view of the surface (FigureZ).

The gas contained in the interior of the tube 2 may be, for example, helium or neon or a mixture of these gases. The pressure in the interior of the tube 2 depends upon the nature of the gas and is such that the discharge produces only luminosity of the cathodes. 3Q The electric discharge between the anode H and the various cathodes constituting the surface i0 is produced by an electric source ii the voltage of which is such that the desired luminosity of the said cathode is obtained. The source i2 is connected on one hand to the anode Ii and on the other hand to the cathode 3 of the cathode ray tube, the cathode .ray beam thereby serving as a moving conductor to connect the source l2 successively to the various cathodes oi the tube 2.

The brilliancy oi the luminous-spot covering the said cathodes depends upon the intensity of the discharge current. This intensity in turn depends upon the resistance to the passage of the current ofiered by the cathode ray beam, that is to say, on the intensity of the said beam. Thus, the variations of brllliancy of the cathodes of the tubes necessary for the synthesis of the images or scenes to bereproduced will be obtained by modulating the intensity of the cathode ray beam acac cording to the variations of the current produced at the receiver by the transmission to be received. In the example shown in Figure 1 this modulation is obtained by interposing in the circuit of the anode i the secondary of a transformer is,

tion.

the primary of which is traversed by the current setup at the receiver by the transmission to be received. There are thus produced voltage variations resulting in corresponding variations intlge intensity of the cathode ray beam.

The voltages applied to the terminals of the condensers 5 and 6 are such that the cathode ray beam sweeps the surface i in parallel juxtaposed bands. in synchronism with the transmitter. Magnetic fields could be employed equally well.

The embodiment shown in Figure 1 is not intended to be in any. way limitative of this inven- The two tubes 9 and 2 may be separated and the-cathodes of the tube 2 suitably'connected to the difierent points of the surface i in the tube 8.

What I claim is:

- I i. In an apparatus for reproducing images and scenes by television and telecinematosraphy formed by a cathode ray tube and a luminescent electric discharge tube forming a continuation of the first mentioned tube, a thin partition of semiconducting material separating said tubes, one

" face of said partition being impinged by the cathode rays and the other forming the cathodic surface of the luminescent tube and the screen on which the reproduced image is observed, a metallic piece withinthe int tube and constituting the anode thereof perpendicular to the mean direction or the cathode rays, said metaliic piece having an opening through which the entire cathodic surface may be observed, a source ofwires to said anode of the luminescent tube and to the cathode of the cathode ray tube, and a transformer'in the'primary of which flows the; received current, the secondary being connected in series in cathode-anode circuit of the cathode 5 ray tube.

2. In an apparatus as claimed in claim 1,- in which the said luminescent tube contains an inert gas.

3. In an apparatus for reproducing images and i0 scenes by television and telecinematography formed by a cathode ray tube and a luminescent electric discharge tube forming a continuation of the first mentioned tube, a thin partition of semiconducting material separating said tubes: one 15 said tubular anode being parallel with the mean t direction of the cathode rays, the-entire cathodic surface being observable through said tubular anode, a'source'oi. electric voltage directly conv nected by conductingwires to said tubular anode oi the luminescent tube and to the cathode of I the cathode ray tube, and a transformer in the primary of which flows the received current, the

secondary being connected in series in the oathode-anode circuit of the cathode ray' tube. r 1