| 摘要 |
The camera shutter unit of the present invention comprises a diaphragm blade arranged to be capable of moving between a stopping-down position wherein an aperture is stopped down, and an evacuating position wherein the aperture is opened. A shutter blade is arranged to be capable of moving between an opening position, wherein the aperture is opened, and a closing position, wherein the aperture is closed. A drive-control mechanism is provided for drive-controlling the shutter blade and the diaphragm blade. The drive-control mechanism has a single electromagnetic (drive source, a spring for restricting movement of the shutter blade toward the closing position when the diaphragm blade is positioned in the stopping-down position, and for releasing its restriction by a predetermined or more drive force generated by the electromagnetic drive source, and a control means for controlling the electromagnetic drive source. The control means, upon stopping-down, controls to move the shutter blade to the closing position in advance and next move in reverse the shutter blade by a predetermined amount, thereby positioning the diaphragm blade in the stopping-down position. Accordingly, the unit can be of a small size and low in cost, and the bouncing of diaphragm blade can be prevented.
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