| 摘要 |
PROBLEM TO BE SOLVED: To provide a gradation correction circuit that can realize video correction with high accuracy without the need for increasing the circuit scale and for a memory storing a lookup table. SOLUTION: The gradation correction circuit is provided with arithmetic means (101-104, 106, 108-110) that calculate an output value corresponding to each polygonal point of a polygonal line for a vertical blanking period, a level detection circuit 107 that identifies a magnitude relation between each polygonal line point being an input value corresponding to each polygonal point for a video signal period and an input video signal and calculate a difference between the input video signal and the polygonal line point, and correction means (101, 102, 104, 107, 109-111) that select the gradation of the polygonal line on the basis of the identification result by the level detection circuit 107 and apply gradation correction to the input video signal on the basis of the gradation of the selected polygonal line, an output value calculated by the arithmetic operation, and the difference calculated by the level detection circuit, and the arithmetic means and the correction means use in common the prescribed circuits (102, 109, 110).
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