Color temperature automatic adjustment circuit

Abstract

Abstract PURPOSE:To improve coloring characteristic at the time when a power source is on by providing a circuit which lowers the gain of the amplifier for respective color channels when the power source is turned on and recovers the gain in a specific time constant in a feedback control sequence circuit controlling the characteristic of said amplifier in a color television receiver. CONSTITUTION:At the time when the power source is on, the cathode emission of a color picture tube 7 is near zero, but the gain of a gain control amplification circuit 5R is controlled to become high, as the cathode emission rises by means of heating. And when a cathode current IKR begins to be detected, a sample voltage ER corresponding to the detected cathode current IKR is impressed on a hold capacitor CS. Then after the time (t), the control voltage (the sample voltage ER) corresponding to the cathode current value detected by a comparator circuit 10R is supplied to the gain control amplification circuit 5R instead of the initial control voltage EC outputted from a control voltage generation circuit 15 and the coloring characteristic of the color picture tube 7 is controlled to be in the best condition.

Inventors

• 👤 Yoshiya Sengoku
• 👤 仙石　喜也

Bibliographic Details