| 摘要 |
PURPOSE:To reduce the stability and power consumption of lens driving in focusing and to eliminate the delay of focusing-to-defocusing decision by expanding range finding intervals at specific intervals of time in a focusing state and continuously in a defocusing state according to a range-finding result of each time. CONSTITUTION:An electric signal corresponding to the quantity of light made incident on a sensor is processed by an amplifying circuit 5, a detecting circuit 6, and an integration circuit 7 to input information to a microcomputer 9 through a comparing circuit 8. The microcomputer 9 makes a focusing/ defocusing decision according to the input information and controls a motor driving circuit 10 to drive a motor 11, thereby adjusting the focus automatically. In this case, the focusing decision is made in focusing according to the range finding result after an averaging process as well as the range finding result of each time and the range finding operation is performed intermittently for every specific time. In defocusing, on the other hand, the range finding operation is carried on continuously without waiting for a specific time. Consequently, the stability and power consumption of the lens driving in the focusing are reducible and the delay of focusing-to-defocusing decision is eliminated. |
