Camera shutter unit

A camera shutter unit comprising:

• a base plate having an exposure aperture;
• a diaphragm blade arranged to be capable of moving between a stopping-down position wherein the aperture is stopped down and an evacuating position wherein the aperture is opened;
• a shutter blade arranged to be capable of moving between an opening position wherein the aperture is opened and a closing position wherein the aperture is closed;
• and
• a drive-control mechanism for drive-controlling the shutter blade and the diaphragm blade, the drive-control mechanism including
• a single electromagnetic drive source capable of driving the shutter blade and the diaphragm blade to interlock the diaphragm blade with the shutter blade so that the opening position corresponds to the evacuating position and a travel of from a way position between the opening position and the closing position to the closing position corresponds to the stopping-down position,
• a restricting means 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 level drive force generated by the electromagnetic drive source, and
• a control means for controlling the electromagnetic drive source, the control means controlling to move the shutter blade up to a nearby position beyond a way position corresponding to the stopping-down position in advance and next move in reverse the shutter blade by a predetermined amount when moving to position the diaphragm blade in the stopping-down position.

A camera shutter unit comprising:

• a base plate having an exposure aperture;
• a diaphragm blade arranged to be capable of moving between a stopping-down position wherein the aperture is stopped down and an evacuating position wherein the aperture is opened;
• a shutter blade arranged to be capable of moving between an opening position wherein the aperture is opened and a closing position wherein the aperture is closed;
• and
• a drive-control mechanism for drive-controlling the shutter blade and the diaphragm blade, the drive-control mechanism including
• a single electromagnetic drive source capable of driving the shutter blade and the diaphragm blade to interlock the diaphragm blade with the shutter blade so that the opening position corresponds to the evacuating position and a travel of from a way position between the opening position and the closing position to the closing position corresponds to the stopping-down position,
• a restricting means 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 level drive force generated by the electromagnetic drive source, and
• a control means for controlling the electromagnetic drive source, the control means controlling to move the shutter blade gradually from the evacuating position to the stopping-down position when moving to position the diaphragm blade in the stopping-down position.