Patent ID: 7136339

Claim:
A positioning control apparatus for controlling a moving member to trace the position of a target member, said target member almost-equally repeating position shift at a predetermined period, said positioning control apparatus comprising: a position detector which detects a relative position error between said moving member and a target position of said target member; a first adding unit which adds a delay signal and a position error signal which is outputted by said position detector, wherein the output of said first adding unit is a first sum; a signal delay unit which outputs said delay signal which is obtained by filtering by a first filter and delaying a first sum output of said first adding unit at a period corresponding to the position shift of said target member; a second filter having predetermined frequency characteristics, which receives the output of the signal delay unit as an input; an additional adding unit which adds said position error signal, said delay signal, and said second filter output; a drive unit for driving said moving member by a signal based on an output of said additional adding unit; and a delay-amount setting unit for setting the amount of delay of a signal which is delayed by said signal delay unit.