| 摘要 |
PURPOSE:To simplify and miniaturize the constitution of a drive control part by providing a position detector detecting the rotary position of an aperture adjusting ring and a differentiating circuit detecting the turning speed of the aperture adjusting ring from this output, to control the aperture speed from this output. CONSTITUTION:The position detector 20 detecting the rotary position of the aperture adjusting ring 14 and the differentiating circuit 24 detecting the turning speed of the aperture adjusting ring 14 from the output of the position detector20 are provided. The output of the differentiating circuit 24 is inputted to the 1st comparator circuit 8 as a signal for controlling the aperture speed. Further, an output of the position detector 20 and an output of the aperture setting means such as a potentiometer 27 and an exposure operating circuit or the like are compared by the 2nd comparator circuit 25 and a current is fed selectively to a driving coil in response to the difference of both the outputs to change over the still pickup and video pickup.
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