US2112684A - Television process - Google Patents

Description

March 29, 1938.

TELEVIS ION PROCESS Filed Dec. 23, 1931 wil u M. voN ARDENNE /Wm MM,

Patented Mar. 29, 1938 UNITED STATES TELEVISION PROCESS Manfred von Ardenne, Berlin, Germany, assignor to Radioaktiengesellschaft D. S. Loewe, Berlin- Steglitz, Germany, a company of Germany Application December 23, 1931, Serial No. 582,737

In Germany December 22, 1930 1 Claim. (Cl. 178-7-7) the carrier wave, in cable transmission by the frequency dependency of the'cable, by the leakage, etc. For television receivers the fact is also particularly disturbing that the image appears to be divided into strips, the faultless assembly of which may only be obtained with considerable This impression of the image divided into strips arises, as known, from the fact that the scanning ray sweeps over the picture, line after line and the inevitable intervals between those lines are left. An avoidance of the formation of such intervals, by partly covering or overlapping one line and the next line of the picture elements, has already been proposed for certain purposes, but has the disadvantage that the pictures seem to be faded and unclear.

The subject matter of the present invention is a method, by means of which these difficulties are overcome.

For this purpose the image,upon the transmission, is divided into strips, which are not situated 30 permanently at the one point, but pass continuously over the image. For example, in the case of television processes employing Braun tubes the scanning cathode ray, which passes, for example, sinuously over the surface, or irradiates the 35 surface in relaxation oscillations (which have a straight-line wave form) is deflected, transversely or perpendicularly to its direction, by a frame frequency in respect of which the line frequency amounts to a non-integral multiple.

4 In the described type, for instance, in one,

frame the scanning control begins at the beginning of the first line,-whereas in the following employing amplifiers, which are incapable of transmitting low frequencies.

In the drawing Fig. 1 illustrates an arrangement in which the present invention can be adapted, and Fig. 2 shows, in diagrammatic fashion, the scanning of two successlveframes. In Fig. 1, i represents a Braun tube, containing the cathode 2, the Wehnelt-cylinder 3, the anode I, the deflecting plate-pairs 5 and 6 as well as the fluorescent screen I. The cathode 2 is heated by means of a battery 8. 9 designates an anode battery and I an initial potential battery for the Wehnelt-cylinder 3, which is supplied over a transformer I I with the voltages controlling the cathode ray-intensity. ,The relaxation (straight line wave form) oscillations produced by the generators l2 and I3 are conducted to the deflecting plate pairs and 6. The frequency of the linefrequency oscillation generator I! amounts according to the invention to a non-integral multiple of the frequency of the image frequency or frame frequency oscillation generator [3.

Fig. 2 shows diagrammatically the scanning of two successive frames, and in this view the scanning strips are indicated by hatching while the intervening gaps are unhatched. By comparing the diagram of one frame (marked I) with that of the other or second frame (marked 2), the shifting or displacement of the scanningstrlps from one frame to the next will be observed readily, particularly when comparing the position of the said strips at the upper and the lower edges of the two frame diagrams.

I claim:

The method of scanning a succession of related television picture frames in a definite frame frequency with the aid of an oscillating cathode ray,

which comprises causing such ray to scan first one of such frames along a series of lines exhibiting a to frame.

MANFRED von ARDENNE.

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