Patent ID: 6130418
Filing Date: 2000-10-10
Classification: G11B

Abstract:
An optical scanning device for scanning an information track of an optically readable record carrier, which scanning device includes a radiation source, a radiation-sensitive detection system, and an optical scanning unit for focusing a scanning beam produced by the radiation source to a scanning spot on the record carrier and for imaging the scanning spot on the detection system, the scanning unit including a lens system having an optical axis, which lens system comprises a first lens unit having a main lens and a second lens unit having an auxiliary lens, which scanning device further includes a first detection means involved in detection of the main lens with respect to the record carrier, and a second detection means involved in detection of the auxiliary lens, the scanning unit further including a first electrical drive unit for moving the first lens unit in dependence upon a signal supplied by the first detection means, and a second electrical drive unit for moving the second lens unit with respect to the main lens in dependence upon a signal supplied by the second detection means, the second drive unit comprising a first part and a second part which cooperates with the first part via an air gap, the first part being secured to the first lens unit and the second part being secured to the second lens unit, characterized in that the second detection means includes a position and orientation detector system for detecting a position and orientation of the auxiliary lens with respect to the record carrier during scanning.