Patent ID: 7301872
Filing Date: 2007-11-27
Classification: G11B

Abstract:
1. An optical pickup designed to record or reproduce data signals on or from two types of optical discs that differ in at least data recording density and thickness, by using the same objective lens, said optical pickup comprising: two light source sections for emitting laser beams having different wavelengths; and a lens-supporting mechanism for controlling a position of the objective lens in a radial direction of the optical discs and along an optical axis, wherein the lens-supporting mechanism has a lens-inclination adjusting mechanism capable of changing an angle at which the objective lens is inclined to the optical axis, substantially in proportion to a displacement of the optical disc of the first type, and the second light source section for recording or reproducing data signals on or from the optical disc of the second type is positioned with respect to the position of the first light source section for recording or reproducing data signals on or from the optical disc of the first type, so as to satisfy the following condition: where θ is an angle measured counterclockwise from the first light source section used to record or reproduce data signals on or from the optical disc of the first type to the second light source section used to record or reproduce data signals on or from the optical disc of the second type, along a straight line in which the optical pickup moves toward an outer circumference of the optical disc to record or reproduce data signals on or form the optical disc, wherein the lens-inclination adjusting mechanism is configured to change the angle at which the objective lens is inclined, to satisfy the following condition: where S is the inclination angle of the objective lens, δ is the displacement of the objective lens from a reference position, and R is the radius of the optical disc.