Color temperature correction circuit

Abstract

Abstract PURPOSE:To avoid the white part from being yellow due to the saturation of blue color, by slightly shifting a focus voltage for the blue color from a specified value, at the white peak of a video signal. CONSTITUTION:When a level of a video signal is low, an output of a detection circuit 4 goes to H and a transistor (TR) 63 turns on. Then, since a resistor 69 is shortened, one end of a variable resister 5B is grounded the same as variable resister 5R and 5G. The variable resister 5R, 5G and 5B are adjusted to obtain an optimum focus in this state. When a whie level signal of high amplitude is detected at the detection circuit 4, an output of the circuit 4 goes to L, a TR63 turned off and the shortening of the resistor 69 is released. Thus, the resistor 69 is connected in series with the variable resister 5B, the focus voltage of blue color can slightly be shifted from the adjusted value.

Inventors

• 👤 Katsuyuki Akimoto
• 👤 秋元　克幸

Bibliographic Details