Patent ID: 7671556

Claim:
An image sensing apparatus including a stepping motor of a constant-voltage driving type, the stepping motor having a motor coil to which a constant voltage is applied via a switching device that is turned on or off by receiving a pulse signal, the image sensing apparatus comprising: a PWM waveform generation section to generate the pulse signal to be fed to the switching device; a correction gain calculation section to calculate a correction gain by multiplying an initial correction value stored internally beforehand by a predetermined factor determined according to a specified rotation speed of the stepping motor; and a duty ratio range determination section to: specify, according to specified output torque of the stepping motor, a duty ratio range, which is a range between a minimum and a maximum duty ratio of the pulse signal, correct the duty ratio range according to the correction gain fed from the correction gain calculation section, and feed a corrected duty ratio range to the PWM waveform generation section, wherein the predetermined factor increases as the rotation speed increases.