Patent ID: 7760609
Filing Date: 2010-07-20
Classification: G11B

Abstract:
1. An optical disc apparatus comprising: an optical pickup unit for irradiating a laser beam onto an optical disc to record/reproduce data on/from the optical disc, the optical pickup unit having a thread load; a thread motor for moving the optical pickup unit in one direction directed to an inner circumferential side or outer circumferential side of the optical disc; and a control unit for controlling the entire optical disc apparatus, wherein the optical disc apparatus further comprises a circumferential switch to be turned on when the optical pickup unit is moved to arrive at an inner or outer circumference of the optical disc, wherein when a power supply to the optical disc apparatus is turned on, the control unit applies a driving voltage to the thread motor to drive the thread motor so as to move the optical pickup unit in a direction directed to the inner circumferential side or outer circumferential side of the optical disc, and then stops driving the thread motor when the circumferential switch is turned on, wherein the control unit then changes the moving direction to an opposite direction to the one direction, and gradually increases the driving voltage applied to the thread motor to start moving the optical pickup unit in the opposite direction, thereby causing the circumferential switch to be turned off after the optical pickup starts moving in the opposite direction, wherein the driving voltage applied to the thread motor, when the circumferential switch is turned off after the optical pickup starts moving in the opposite direction, is set by the control unit as an automatically adjusted value of the driving voltage of the thread motor which value corresponds to the thread load, and wherein thereafter the control unit uses the automatically adjusted value to drive the thread motor for moving the optical pickup unit without using a thread sensor.