| 摘要 |
PURPOSE:To automatically control the image display mode to the desired one and to eliminate the troublesomeness of the control by providing a video signal detection means and an image area detection means which detects an image area based on the output of the video signal detection means and controlling the image display mode shown on a screen in response to the output of the image area detection means. CONSTITUTION:A selection switch 12 selects an optional signal out of those input signals by the selection signal received from a main CPU 30 and outputs the luminance and color signals. The composite video signal inputted to the switch 12 is supplied to a Y/C separator circuit 22 and separated into a luminance signal and a color signal in response to the output of the switch 12. Meanwhile the luminance and color signals received from the switch 12 are supplied to a video chroma processing circuit 24, and the horizontal and vertical synchronizing signals are separated from each other and outputted and also converted into the R, G and B signals. These R, G and a signals are supplied to a CRT drive circuit 26 and drive a CRT 28. |
