| 摘要 |
PURPOSE:To control a focus voltage automatically, by outputting control variable with a prescribed step over the entire range of control with a microprocessor and detecting the aperture response for the time. CONSTITUTION:A pattern having a specific frequency is picked up with television cameras 1-3, each video signal at this time is rectified for the peak value, and the level (aperture response) is read in a microprocessor 8 with video signal input terminals R, G, and B. The microprocessor 7 outputs a control variable with a prescribed step over the entire range of control, the aperture response is detected for the time, the focus voltage control variable where the aperture response is the maximum is calculated, and the control voltage of the focus voltage for controlled channel is outputted. |
