Patent ID: 6771455
Filing Date: 2004-08-03
Classification: G11B

Abstract:
A control system for moving a data-reading object reading data from a recording medium, to a target position in accordance with a position data read by the data-reading object, said control system comprising:a first control section generating a first operation signal for moving the data-reading object; and an output section distributing the first operation signal to a plurality of signal lines, said output section comprising: a plurality of changing sections changing a gain and phase characteristics of the first operation signal generated by the first control section and generating second operation signals; and an adding section adding each of the second operation signals generated by said changing sections, thereby generating a third operation signal which has a gain-peak lower than that of the first operation signal, and outputting the third operation signal as a control signal controlling the data-reading object as a controlled object, wherein each of said changing sections includes: a gain-characteristic changing unit changing the gain characteristic of the first operation signal by multiplying the first operation signal by a specific coefficient; and a phase-characteristic changing unit changing the phase characteristic of the first operation signal by applying a delay time specific to one signal line, wherein the coefficient and delay time are set in accordance with a frequency band in which the first operation signal has a gain-peak; and a second control section changing the coefficient, thereby to determine how much the gain is to be reduced, and changing the delay time, thereby to set a frequency band in which a gain-peak is to be lowered, wherein said second control section sets a phase difference between the second operation signals of two of the signal lines, at about 180 degrees at the frequency band where the gain-peak should be lowered.