GB337477A - Improvements in light-sensitive devices - Google Patents

Abstract

337,477. Compagnie des Lampes. April 10, [Convention date]. Copying -telegraphs. - Electric oscillations, which can be controlled by light, are set up in a neon tube or the like L by connecting it in series with a resistance R across a potential AB with a condenser C in parallel with the resistance or neon tube. Changes of frequency and intensity of the oscillation, produced by variation of the light falling on the neon tube; are detected by a telephone receiver T or a galvanometer G, and may be used directly or after amplification to control a copying- telegraph or television transmitter. The oscillation may be modulated by applying alternating- current or by interrupting the light incident on the tube. The colour-sensitivity of the tube depends on the pressure and nature of the gaseous filling, which may be neon or argon. According to modifications the telephones and galvanometer are in parallel (Fig. 5, not shown) or in series with the tube (Figs. 6, 7 and 8, not shown); two independent oscillators act on the same telephones and galvanometers, Fig. 6a (not shown); an intermediate, polarized electrode provides amplified current for the telephones and galvanometer (Figs. 9 and 10, not shown) ; two additional electrodes are used so that the circuit of the telephone and galvanometer is separate from the feeding circuit, Figs. 11 and 12 (not shown). Specification 313,143, [Class 38 (ii)], Electric currents, Converting &c.], is referred to.