GB907540A - Improvements relating to television - Google Patents

Abstract

907,540. Television. ELECTRIC & MUSICAL INDUSTRIES Ltd. May 1, 1958 [May 7, 1957], No. 14570/57. Class 40 (3). Television apparatus comprises a pick-up tube, means for scanning a strip of an image and means for causing the strip to alternate between two predetermined positions spaced relative to the tube in a direction transverse to the strip whereby a stereoscopic representation of an image moving in said direction relative to the tube may be formed in response to signals derived from the tube. In the Figure, a pick-up tube 1 is mounted in an aircraft moving in the direction of the arrow and a ground scene A 1 B 1 is focused on the tube; the frame scanning is produced by the movement of the aircraft, and the line scanning is performed at a frequency of double that necessary to scan the image exactly once each frame. A " frame " scanning is applied to the tube by coils to which is applied a square waveform of half the frequency of the line scanning so that one " line " of the scene is scanned at A 1 and a further " line " of the scene is scanned at B 1 ; thus when the tube is at the further position shown, an image of the scene line B 1 is again scanned but this time as a scene line A 2 so that the picture signals comprise alternate " lines " of information representing different portions of the image. At the receiver the alternate lines of the received picture signals may be separated by regenerating the square-wave from the linesynchronizing pulses and adding this regenerated waveform and its inverse to two separate picture signals before applying them to cathoderay tubes or other display.