| 摘要 |
PURPOSE:To improve the tracking performance with respect to fluctuation of a focus point by controlling the turning speed of a focus ring into an optimum state based on the result of detection of a luminance component in an image pickup signal. CONSTITUTION:In the case of detecting a maximum value of a luminance component, in order to discriminate an increasing direction of the luminance component from a start point, after a focus ring 1a of an image pickup lens 1 is turned at a low speed for a prescribed time, the focus ring 1a is driven at a high speed till the luminance component exceeds a prescribed level. Then the focus ring 1a is driven at a low speed at a level over the prescribed level. Thus, a focus control circuit is obtained, in which the fast response is obtained for the automatic focusing and the the motion of the focus ring 1a is smooth. |
