| 摘要 |
<p>A multipurpose interface circuit through which the control current for operating an electromagnetically driven shutter actuator (12) for a still camera may be precisely defined throughout a shutter actuation sequence (open, hold and close) has a clock signal counter unit, which contains a set of counter circuits associated with respective components of the shutter actuator drive current waveform. The counter circuits are sequentially enabled to count clock signals generated by a clock signal generator. The counter circuits produce output signals in accordance with a set of relationships among the numbers of clock signals counted and a set of camera shutter control codes representative of desired shutter aperture size and shutter speed. A control circuit is coupled to the clock signal counter unit for controlling the generation of the respective components of the actuator drive current in accordance with output signals produced by the clock signal counter circuit.</p> |
