| 摘要 |
PURPOSE:To enable a focal position to be detected quickly and highly accurately with an image signal having improved sensitivity and S/N ratio by setting a given cycle equal to the integer of multiplication of the half-cycle of an electric charge transfer clock as the reset cycle of an output section. CONSTITUTION:The output section 5 of a CCD image sensor 1 is reset at a given reset cycle equal to the integer of multiplication of an electric charge transfer clock, and the reset cycle so set becomes a sampling cycle for an image signal. As a result, the electric charge of a plurality of picture elements is accumulated in the output section 5, and the synthetic accumulated electric charge of the aforesaid plurality of picture elements is sampled by an image sampling means. According to the aforesaid construction, a dynamic range is expanded without extending the electric charge accumulation time of the CCD image sensor 1 for each picture element, and an image signal with improved sensitivity and S/N ratio can be obtained. At the same time, a focal position can be quickly detected, and detection accuracy can be made higher. |
