A control method for optical scanners, optical scanners and laser machining apparatus

A control method for an optical scanner and optical scanners that can move a mirror at a high speed, irrespective of a pivoting angle, and laser processing apparatus for irradiating a printed circuit board with a laser beam using the optical scanner, to thereby pierce the printed circuit board. In order to operate an actuator Gleid for pivoting the mirror on the basis of a deviation of a present position from a target value, in correspondence with each pivot angle measured a change in the gain of the actuator in advance, and the manipulated variable of the actuator is corrected to eliminate the change in gain. Thus, the Einflus the change of a torque constant in accordance with the rotation angle can be suppressed, so that the response over an entire scanning area is uniformly and the positioning speed can be improved.