| 摘要 |
PURPOSE:To prevent erroneous judjement due to a noise by vibrating a focus lens with a detected just-focus position as a center after the just-focus position is detected and confirming the position to be the correct just-focus position. CONSTITUTION:After a just-focus position P is once detected, a control circuit 3 vibrates a focus lens 1 with the detected just-focus position as the center by prescribed quantity and the value of a focus voltage E based on the output of a highpass filter 10 to be detected at such a time and the focus voltage in the just-focus position to be stored in the control circuit 3 are compared. As the result of the comparison, when difference is over a prescribed value, a focusing is started again and by continuously executing the focusing, a correct just-focus position P is detected. When the difference is in a prescribed range, the detected just-focus position is regarded as being correct and the focusing is finished. |
