Color temperature correction device

Abstract

Abstract PURPOSE: To simplify the correction for the color temperature change caused by the change of the illumination light source by giving the control to each output gain in accordance with the change of the output ratio between signals R and B. CONSTITUTION: The white balance of the camera output is secured when the color temperature of the light source is 3200°K to be used as the reference temperature. The gain is controlled for R and B signal amplifiers 505 and 506' against the change of the color temperature. To keep the white balance constant, the output ratio between the R and B signals is fixed through control of the gain. In terms of the characteristics due to the color temperatures of signals R and B, the correction to the Kelvin of the amplifier is attained by applying the reciprocal-fold gain of the output fluctuation ratio due to the temperature change to gain GR3200°K and GB3200°K each at 3200°K. The gain control voltage is generated from the single power source and via inverse amplifier 702 and nonlinear circuit 701 which satisfies the temperature characteristic curve. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Masaaki Nakayama
• 👤 Yoshinori Kitamura
• 👤 Shoji Nishikawa
• 👤 Tatsuki Ide

Bibliographic Details