| 摘要 |
PURPOSE:To completely remove a luminance component due to a triangular wave in one horizontal scanning period by calculating a luminance fluctuation from the potential fluctuation of the tip end of a horizontal synchronizing signal, and correcting the video signal by a saw-tooth-wave generated with the calculated value as an amplitude. CONSTITUTION:A synchronizing separating part 1 generates a horizontal synchronizing pulse Ph whose frequency and phase are the same as the horizontal synchronizing signal of an input video signal S1 on which the triangular wave is superimposed. A video delay part 2 outputs a video signal S2 obtained by delaying the signal S1 only in one horizontal scanning period. Sample/hold parts 3 and 4 make sampling the top end potential of the horizontal synchronizing signal of the signals S1 and S2, and hold the potentials V1 and V2. A reference voltage generating part 5 generates a reference voltage V3 corresponding to a clamp potential. An error amplifier 6 outputs a difference between the potentials V1 and V2 as a difference voltage V4, and a saw-tooth-wave generating part 7 generates a saw-tooth-wave S3 using the difference voltage V4 as the amplitude, and synchronizing with one horizontal scanning period. An adding part 8 adds the signal S2 to the saw-tooth-wave S3, removes the luminance fluctuation component, and outputs a video signal S4.
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