| 摘要 |
PURPOSE:To widen the reproducing range of a gradation with scarcely deteriorating the picture quality by controlling the compression start point of a white compression according to the white peak level of a video signal. CONSTITUTION:According to the output of a differential amplifier circuit 7, the white compression start point is controlled and the output level of the differential amplifier circuit 7 is controlled by a control circuit 4. For instance, the output level of the differential amplifier circuit 7 is controlled so as not to have the compression start point below 80% of a standard signal level. In a white compression circuit 5, the output of the control circuit 4 applied to a control terminal 3, accordingly, the start point of the compression is changed correspondingly to the output of the differential amplifier circuit 7 to perform the white compression. Namely, when the white peak level is comparatively low, the compression start point is made high and when the white peak level is comparatively high, the compression start point is made low, thereby, the reproducing range of the gradation can be fully taken with hardly deteriarating the picture quality.
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