GB321104A - Improvements in or relating to picture and the like telegraph systems - Google Patents

Abstract

321,104. Carpmael, A., (Telefunken Ges. fiir Drahtlose Telegraphie). Dec. 22, 1928. Copying-telegraphs.-Apparatus for transmitting or receiving pictures, in which sections which are not adjacent are recorded successively, comprises successively operating pick-up or recording devices, or a single recording or pick-up device traversing consecutive sections of a band or strip picture. The pictures lines may be so arranged that when recorded, they overlap, forming a more definite picture. When the recording devices are light-sensitive cells, the frequency of operation of the light imposes a frequency on the cell which can be utilized in known fashion for controlling synchronization of transmitter with receiver. In Fig. 1, light sources 8, 9, 10 illuminate by lens 7 points 14, 15 16 on the picture 2 and the reflected light is gathered by an annular lightsensitive cell 6. A screen 13 consisting for example of a slotted disc, ensures that only one source is in operation for each rotation of the drum 1 carrying the picture. The drum 1 is moved forward after each rotation and each source in turn reproduces one picture line. The receiving arrangement shown in Fig. 2 has a photographic strip 18, moving over rollers 19 synchronously with a similar strip in the transmitter. The recording points of light 14, 15, 16 are brought successively into operation by means of a screen 17. The movements of the points of light at transmitter and receiver are synchronized in a known manner. Figs. 3, 4 illustrate arrangements where one pick-up or recording device only is used. In Fig. 3 the film moves over rollers as shown while the recording device moves across the sections of the film as indicated by the long arrow. In Fig. 4, the point of light moves round the axis of cylinder 22 on which the film 23 is wound in such a way that the point of light traverses the film obliquely, the reflected light being gathered by the light-sensitive cell 33. The film 23 is drawn over rollers 25 which displace it laterally so as to divide it intosections equivalent to those shown in Fig. 3. In all forms, a carrier frequency for the picture signal may be introduced by rotating a slotted wheel 12, Fig. 1, interrupting the light rapidly.