Patent ID: 6496452
Filing Date: 2002-12-17
Classification: G11B

Abstract:
An optical system for scanning an optical record carrier having an information layer, said optical system comprising:a radiation source for generating a radiation beam; an objective system for converging the radiation beam to a focus on the information layer; an actuator for displacing the objective system over a range of displacements in a direction transverse to an optical axis of the objective system; an aberration detector for detecting an amount of an optical aberration in the radiation beam; an aberration compensator arranged in the optical path between the radiation source and the objective system; and a control circuit connected to an output of the aberration detector for controlling the aberration compensator, wherein the control circuit is adapted to have the aberration compensator compensate the optical aberration to a degree of compensation that is less than a total amount of the optical aberration detected by the aberration detector, for substantially all displacements in the range of displacements.