OPTICAL SCANNING DEVICE

摘要

An optical scanning device for scanning an optical record carrier. A high numerical aperture objective lens system includes at least a first lens element (12) arranged to converge the beam to a certain extent and a second lens element (13) arranged to converge the beam to a greater extent. The device comprises a spherical aberration compensation optical subsystem including an electro-optical element for altering an optical path length in a spherical aberration generating region, which region is located in the optical path between the first lens element and the location of the record carrier in the device.