| 摘要 |
Since A/D conversion circuits 30r, 30g and 30b to convert for output analog R, G and B signals to digital signals, a phase adjustment circuit 31 to output by delaying in the portion of 1 line output signals of these A/D conversion circuits 30r, 30g and 30b, a first signal generation circuit 35 to generate Y signals from output signals of A/D conversion circuits 30r, 30g and 30b, a second Y signal generation circuit 37 to generate a Y signal from an output signal of the phase adjustment circuit 31, a contour extracting circuit 39 to extract a vertical contour component and a horizontal contour component from Y signals generated by first and second Y signal generation circuits, and contour adders 34r, 34g and 34b to output signals contour-emphasized adding a vertical contour component and a horizontal contour component extracted by this contour extracting circuit 39 to output signals of the phase adjustment circuit are provided, and as it has been designed to output adding contour components after converting analog R, G and B signals to digital signals by A/D conversion circuits 30r, 30g and 30b, as the conventional example that A/D is converted after adding contour components to analog R, G and B signals, the contour emphasizing component does not surpass the dynamic range of A/D conversion circuit. For this reason, in case analog R, G and B signals to input in the contour emphasizing circuit of the present invention are large amplitude signals, or even in case the contour emphasizing quantity is "large", when the video is displayed to output signals to output from the contour emphasizing circuit of the present invention to the display device driven by digital video signals neither white crushing nor black crushing is produced. Further, since it has been designed that the contour extracting 39 extracts a vertical contour component and a horizontal contour component from Y signals generated by first and second Y signal generation circuits 35 and 37, provided the line memory necessary for the contour extracting circuit 39 is made as 1 piece, the power consumption can be made smaller, as well the cost can be lowered. <IMAGE> |
