Improvements in and relating to photo-multiplier circuits

摘要

919,035. Television. SYLVANIA-THORN COLOUR TELEVISION LABORATORIES Ltd. Oct. 14, 1959 [Oct. 17, 1958], No. 34856/59. Divided out of 919,034. Class 40 (3). In a colour television receiver two separate sets of indexing signals of different frequency corresponding to the scanning of two differently-spaced sets of index stripes on the screen of a colour picture tube are derived from two tuned circuits L1, L2 resonant at the respective different frequencies and connected to different electrodes of a photo-multiplier tube 10 on which radiation (which may be in the ultra-violet region of the spectrum) from the screen of the colour picture tube impinges.