White balance device

Abstract

Abstract PURPOSE:To adjust properly the white balance under iluminating light in flickering by executing the automatic control so as to transmit an appropriate signal to a chrominance signal circuit in accordance with the detected output from a color temperature detection means. CONSTITUTION:A reflected light 1 from a subject is converted into red (R) and blue (B) electrical signals by a red light receiving element 5 and blue light receiving element 6. Then both signals go to R/B signals in a divider 7, which are transmitted to an analog gate 10 and AC amplifier 8. The output of the AC amplifier 8 is compared with a voltage value Vi preset in a comparator 9. When said output exceeds the prescrbed value, the connection of the analog gate 10 is switched. Namely, when there is no flicker, an AC signal will not be detected; therefore the R/B signal added from a terminal 14 is transmitted to a white balance adjustment circuit through an LPF11. On the other hand, if there are flickers, a voltage set in accordance with the color and temperature of the illuminating light in flickering added to a terminal 13 is added to the white balance adjustment circuit.

Inventors

• 👤 Masaki Shimada
• 👤 雅樹 嶋田

Bibliographic Details