Patent attributes
An optical disc apparatus comprises an optical pickup with a thread load, a thread motor for moving the optical pickup, and an inner circumferential switch. When the optical pickup is moved to an innermost circumference of an optical disc to turn on the switch, the pickup is stopped, and the moving direction of the pickup is changed to the outer circumferential side. A driving voltage applied to the motor is gradually increased. The driving voltage, at which the pickup moving to the outer circumferential side causes the switch to be turned off, is set as an automatically adjusted value of the driving voltage applied to the motor. Thereafter, this automatically adjusted value, which corresponds to the thread load, is used to drive the motor. This makes it possible to absorb variations of thread loads and reduce variation in rezero operation, achieving cost reduction, without using a thread sensor.
