Patent ID: 7164642

Claim:
An optical disk reproducing apparatus including: a spindle motor configured to rotate an optical disk; an optical pickup configured to emit a laser beam onto the optical disk and to receive light reflected from the optical disk for reproducing information recorded on the optical disk; and a spindle motor controller configured to control the spindle motor on the basis of a synchronization signal contained in a reproduction signal output from the optical pickup in a reproduction process, the apparatus comprising: a braking control circuit which comprises: a first frequency measuring section configured to measure a frequency of a read clock signal that is synchronized with an RF signal corresponding to the reproduction signal, as a first frequency in a process of braking the spindle motor; a first brake signal outputting section configured to output a brake signal for applying a brake to the spindle motor for a predetermined time, after the first frequency is measured; a second frequency measuring section configured to measure the frequency of the read clock signal after the brake is applied for the predetermined time, as a second frequency; a frequency difference determining section configured to determine whether or not a frequency difference obtained by subtracting the second frequency from the first frequency is equal to or larger than a first threshold and equal to or smaller than a second threshold; a braking time calculating section configured to calculate a braking time from an expression of {the first frequency/(the first frequency−the second frequency)}*(a measuring time from a timing when the first frequency is measured to a timing when the second frequency is measured), in a case where determined that the frequency difference is equal to or larger than the first threshold and equal to or smaller than the second threshold; a servo-off section configured to turn off a servo system of the spindle motor, after the braking time is calculated; a second brake signal outputting section configured to output a brake signal to the spindle motor for the calculated braking time, after the servo system is turned off; a first braking voltage setting section configured to set a braking voltage to a higher level and returns a control to a process of the first frequency measuring section, in a case where determined that the frequency difference is smaller than the first threshold; and a second braking voltage setting section configured to set the braking voltage to a lower level and returns the control to the process of the first frequency measuring section, in a case where determined that the frequency difference is larger than the second threshold.