| 摘要 |
PROBLEM TO BE SOLVED: To prevent gradation to be displayed from being reduced even when a vertical scan frequency is high with respect to a plasma display device compli ant to the change of the vertical scan frequency of a video signal. SOLUTION: Whether or not movement exists in a video is detected by a movement detection part 52, and when a displaying vertical synchronizing signal generation part 13 generates a displaying vertical synchronizing signal, when the matter that the movement doesn't exist in the video is detected the frequency of the displaying vertical synchronizing signal to be generated is lowered to be outputted, and when a sub-field is generated by a sub-field generation part 14, when a low frequency displaying vertical synchronizing signal is outputted by the displaying vertical synchronizing signal generation part 13, the number of sub-fields is increased. |
