| 摘要 |
PURPOSE:To reproduce a picture without deterioration the picture quality even at the input of an RGB signal by providing an emitter follower transistor (TR) and a diode to the input section of a velocity modulation circuit. CONSTITUTION:A video signal is inputted to an emitter follower TR 1 from an input terminal 7 and a common mode signal is outputted from the emitter output. At the operation as a color television receiver, a switching signal fed to an input terminal 6 is at a low level, a diode 3 is turned off, a video signal is inputted to the velocity modulation circuit 5 to apply velocity modulation. In case of the RGB display, the input terminal 6 goes to a high level, the diode 3 is turned on and the emitter potential of the emitter follower TR 1 is increased, the emitter follower TR 1 is cut off and no video signal is inputted to the velocity modulation circuit 5. Thus, the velocity modulation is stopped. Then even at a general reception and RGB display, a picture with excellent picture quality is displayed.
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