Patent ID: 6295256
Filing Date: 2001-09-25
Classification: G11B

Abstract:
A focusing bias adjusting apparatus in an optical recording medium playing apparatus, comprising:an optical pickup having an optical system for irradiating a laser beam onto an optical recording medium and detecting light reflected from said optical recording medium by a split type photodetector;focusing servo control means for generating a focusing error signal on the basis of each output signal of said photodetector and moving an objective lens in said pickup in an optical axial direction of said laser beam in accordance with said focusing error signal;focusing bias adjusting means for making a focusing bias adjustment in order to remove an offset component in said focusing error signal;tilt servo control means for adjusting said optical system so as to maximize a read signal as a sum signal of each output signal of said photodetector in order to compensate a tilt angle which is defined by a normal at the irradiating position of said laser beam on a recording surface of said optical recording medium and the optical axial direction of said laser beam; andreadjustment control means for controlling said focusing bias adjusting means so as to execute said focusing bias adjustment again when the adjusting operation of said optical system is performed by said tilt servo control means after completion of said focusing bias adjustment by said focusing bias adjusting means.