Optical scanning device

Abstract

An optical head for use in the scanning of a record carrier, the record carrier having data stored on data tracks therein on a plurality of information layers (3, 4) at a plurality of depths within the record carrier. The optical head comprises: a movable optical element (16) arranged in an optical path to act upon a first radiation beam (12) and a second radiation beam (14) to provide the beams with a different displacement perpendicular to the optical path; and a lens system for focusing said first beam (12) at a first focal point (A) on a first information layer (3) of the record carrier and the focusing of the second beam (14) at a second different focal point (B) on a second information layer (4), wherein a spacing, transverse to the data tracks, between said first and second focal points (A, B) is controllable by varying the configuration of the movable optical element.

Dependencies are inferred from the claim text.