Camera for producing colour television pictures - has device for automatic correction of colour channel sensitivity for correct colour reproduction

摘要

The colour reproduction of a television camera may be corrected for different colour temperatures of the lighting of the scene in a studio. The camera is fitted with two optical filters (5, 6), each of which passes a different wavelength; and the filters are each followed by a photoelectric sensor (1, 2) and there is a differential amplifier (7) which is used to form the ratio of signals from the sensors (1, 2). This ratio is then used as a control variable for the colour television camera. Light may be reflected into the two sensors (1, 2) by a mirror (4) which may tilt to and fro (8).