| 摘要 |
PURPOSE:To shorten the time required to complete focus detection once by permitting the generation of a following shift pulse once the arithmetic processing of an image signal is copleted when the output of a monitor circuit drops below a specific level during the arithmetic processing. CONSTITUTION:A microcomputer 30 inputs transfer clock pulses phi1 and phi2 from a clock circuit CL1 to the CCD of a photoelectric conversion block 1 to generate a generation permission signal for a shift pulse at a terminal 19. A shift pulse, on the other hand, are inputted to a terminal 21 and also inputted to the CCD through T7, and an image signal is digitized through a circuit block 20 and inputted to the computer 30 to decide the focus state of a photographic lens. On the other hand, a shift pulse is inputted to the terminal 21 to clear the CCD and charge accumulation is restarted. A brightness decision circuit 40 decides the output of the monitor circuit of the block 1, and when the output drops below the specific level, the shift pulse permission signal appears at a terminal once the arithmetic processing is completed. |
