Patent ID: 7654756

Claim:
An actuator drive circuit comprising: a counter arranged to start counting of a frequency-divided clock obtained by dividing a frequency of a reference clock in response to an activation signal; a D/A converter arranged to provide a converted voltage gradually increasing or decreasing in a stepwise fashion in response to an output of said counter; a coil current control amplifier arranged to compare a coil current detection voltage corresponding to a value of a coil current of an actuator with the converted voltage of said D/A converter immediately after activation, arranged to compare said coil current detection voltage with a coil current limitation reference voltage corresponding to an upper limit value of the coil current after the converted voltage of said D/A converter matches with said coil current limitation reference voltage, and arranged to provide an amplified output voltage by amplifying a difference between the compared voltages; and a drive current output circuit arranged to provide a drive current of the actuator according to the amplified output voltage of said coil current control amplifier.