| 摘要 |
PURPOSE:To discriminate contrast between a character and a video in an on- screen time, and to eliminate a difference between them, by adjusting the gain of a video apparatus in an AV (Audiovisual) center. CONSTITUTION:A control line 26 in an AV center 2 is operated only when a character signal is generated from a character generator 24, and controls a gain control part 25. In other words, in a regular operation, the video is transmitted according to a regulated specification (for example, 1Vp-p in a video signal) to signal lines 31 and 21, however, when the character is generated from the character generator 24, an output to the signal line is reduced a little bit. The output of a synchronizing signal remains unchanged. Also, the peak to peak value of the output of the video signals in total on which the character signal is added, remains unchanged. In this way, the video signal from which the character signal is eliminated, becomes small with the function of the gain control part 25 in the generation time of the character signal, and the contrast of the video on a monitor screen is reduced in the generation time of the character.
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