| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need for time and labor required for controlling the focusing of a display video and to enable a sharp image without out-of-focus to be displayed. SOLUTION: By photographing the video projected and displayed on a screen 15 by using a video camera 12, a video signal is obtained. By a focusing action control part 16, an evaluation value is obtained by extracting a high-frequency component from the video signal. Based on the change of the evaluation value between video frames, a projection lens part 3 is driven so as to control the focusing of the video displayed on the screen 15. Even while a video device is actuated, the sharpness of the video can be automatically excellently maintained. |
