Patent ID: 6762983
Filing Date: 2004-07-13
Classification: G11B

Abstract:
An optical disc drive, comprising:a spindle motor having a rotation speed for rotating an optical disc wherein the rotation speed of the spindle motor is adapted to change in multiple steps given by integral multiples of one to change a data reproducing rate; an optical pick-up which can move at least in a radial direction of the optical disc; a sensor for detecting the rotation of the spindle motor; rotation speed control means for controlling the rotation speed of the spindle motor wherein the rotation speed control means has a first rotation speed control means for controlling the rotation speed of the spindle motor based on information obtained from the optical disc and a second rotation speed control means for controlling the rotation speed of the spindle motor based on signals from the sensor; and switching means for switching the rotation speed control given by said rotation speed control means between the first rotation speed control means and the second rotation speed control means during the operation of the optical disc drive, wherein said switching means being operated at least at a time when the rotation speed of the spindle motor is to be changed between the multiple steps to change the first rotation speed control means to the second rotation speed control means and wherein the switching means is operated to change the second rotation speed control means to the first rotation speed control means at a time when the rotation speed of the spindle motor reaches a predetermined rotation speed at a changed level of the multiple steps.