GB653441A - Improvements in or relating to television systems - Google Patents

Abstract

653,441. Cathode-ray tubes. DU MONT LABORATORIES, Inc., A. B. Dec. 8, 1947, No. 32361. Convention date, Dec. 17, 1946. [Class 39 (i)] [Also in Group XL (b)] Picture and synchronizing signals from a television camera 1, Fig. 1, modulate at 2 the intensity of a beam of cathode-rays, the light from the fluorescent screen acting as the transmission medium and falling on a photo-cell 5 at the distant receiver to provide signals for reconstituting the picture. The signals supplied at 2 may be pre-amplified, Fig. 2, not shown, and speech may be similarly transmitted on a light beam of different wavelength, Fig. 3, not shown. The speech and signal carrying beams may be superposed and separated at the receiver by a half-silvered reflector and filters. Twoway television is envisaged, Fig. 6, not shown. Several transmitters operating on different wavelengths may be provided, selection being effected by filters. Colour television is contemplated, red, blue and green video-signals being sent on different channels. The cathoderay tube used as modulated light source may have its fluorescent screen of zinc oxide, which may be coated on to numerous cones, Figs. 11, 12, and activated by a plurality of beams, Figs. 9, 10. The different beams may be modulated with different signals and each act on a portion only of the screen, the different portions having different fluorescent properties. The screen may be rotated to prevent burning, Fig. 13, not shown. The screen may be formed with a number of flat triangular areas, Figs. 14, 15 and 16.