| 摘要 |
PURPOSE:To make it possible that the user avoids hearing a loud noise suddenly when he puts an earphone on his ear, by indicating the proportion of increment and decrement of the sound volume level of a subscreen on the border of the subscreen in a two- screen TV receiver. CONSTITUTION:A signal processing circuit 1 processes a video signal for the subscreen to obtain red, green, and blue primary color signals, and digital signals obtained by subjecting these signals to A/D conversion by a circuit 2 are subjected to D/A conversion through switch circuits 6-11 by a circuit 13, and primary color signals for the main screen and contracted primary color signals for the subscreen are synthesized by a signal processing circuit 14. A signal (j) indicates the L potential of the vertical time for the display of the subscreen, and a signal (g) increase or decreases a voltage in accordance with increment or decrement of the sound volume level of the subscreen. A comparator 22 compares the signal (g) with an integral waveform signal (f) of the signal (J); and if the signal (g) is larger than the signal (f), the comparator 22 outputs an H-potential signal and sends it to an inverter 19. Thus, according as the level of the signal (g) is reduced, the time when a subscreen border signal in the display time of vertical direction of the subscreen is outputted becomes longer, and the time when the border is green becomes shorter. |
