| 摘要 |
PURPOSE:To speedily and accurately focus and control an image pickup optical system with respect to an object by calculating defocus quantity from deviation from the position of a picture element when it is focused and controlling a driving means according to the defocus quantity so that the image pickup optical system is driven to a focal point on its optical axis. CONSTITUTION:A sensor means 32 nondestructively outputs a pair of analog electrical signals corresponding to the luminosity distribution of a pair of optical images at prescribed intervals by shifting the output timing on a picture element basis. A comparing means 78 compares the magnification of correlation values outputted from an analog arithmetic means 74, and based on the result, a control means 86 calculates the deviation from the position of a picture element of the sensor means 32 when the correlation values are minimized. The defocus quantity is calculated from the deviation, and the driving means is controlled such that the image pickup optical system is driven by the defocus quantity in the direction in which said system can be focused. Thus, the image pickup optical system can be speedily and precisely focused and controlled with respect to an object by the simple expedient. |
