| 摘要 |
PURPOSE:To stop a lens group at an appropriate position in the vicinity of a focusing point and to effectively prevent a malfunction by using a self- scanning typed solid stage image pickup element of an area type and providing a means to move the lens group by one step for a prescribed distance and a control means having a focusing function and a focusing process restart function. CONSTITUTION:A lens group 10A is moved by a moving mechanism 12 by setting DELTAx as one step. By the moving, a focus detecting signal for neighboring three positions shifted by DELTAx with each other is obtained and based upon the size, the moving volume and the moving direction of the lens group is decided by a focus detecting means 16 and the necessary displacement of the lens group is performed and the lens group is located to a position where the focus detecting signal becomes maximum. Furthermore, after the lens group is located at the maximum position of the focus detecting signal by the above, the focus detecting signal is generated from the detecting means 16 and when the fluctua tion of the focus detecting signal is exceded over a regulated value, the above stated focusing function is started again. |
