CONSTRICTION DEVICE AND OPTICAL EQUIPMENT THEREWITH

摘要

PROBLEM TO BE SOLVED: To achieve a constriction device that is capable of energy-saving drive and accurate constriction control. SOLUTION: In a constriction device for driving a constriction member by applying a pulse signal to a step motor, a control means for performing pulse width modulation chopper control to the pulse signal is provided, and a chipper control duty ratio (3t4/4) of the final pulse signal from among of pulse signals that are applied to the step motor is allowed to differ from a chipper control duty ratio (t4/2) of the pulse signal other than the final pulse signal.