GB432017A - Improvements in and relating to television and the like systems - Google Patents

Abstract

432,017. Television. WALTON, G. W., 2, Dean Street, Soho, London. Oct. 19, 1933, No. 29001. [Class 40 (iii)] A plurality of simultaneously operative scanning-apertures A .. K co-operate with a less number of transmittihg-channels. A one-dimensional equivalent of an object 11 produced by an apparatus 10, as described in Specification 328,286, [Class 40 (iii)], is swept at a regular speed over the apertures by a rotating mirror drum 12. A photo-electric cell A1 .. K1 behind each aperture is connected to a corresponding coil A2 .. K2 on a stationary distributer. The signal from each cell comprises a fundamental frequency, which is the frequency of scanning, together with harmonics. Most of these produce rotating fields in the distributer, which are picked up by secondary windings 4, 5, 6 and transmitted over separate channels or a three-phase channel, Fig. 10 (not shown). A converse arrangement is used at a receiver. Two or more distributers may be used in series, Fig. 11 (not shown). Some harmonics produce stationary or oscillating fields which cannot be properly picked up by the secondary coils. To overcome this difficulty, three distributers are used in parallel with their windings differently arranged, Figs. 12 and 13 (not shown). The two-phase output may be combined in a single phase by a Wheatstone bridge arrangement, Fig. 16 (not shown). Electrostatic distributers may be used, Figs. 14 and 15 (not shown). Specifications 379,303 and 403,395 also are referred to.