Improvements in or relating to light beam signalling or the like systems

摘要

451,854. Photophones. CADZOW, R., Ardentinny, Argyllshire. Feb. 12, 1935, No. 4438. [Class 40 (v)] A transmitter has a source of light S, a polarizer P, a Kerr cell KC and a projecting lens LST, a receiver has an analyzer A and a photo-electric cell PC for deriving the signals, and the polarizer and analyzer are moved in synchronism. The polarizer and analyzer are crossed Nicol prisms.