06586717 is referenced by 4 patents and cites 1 patents.

An optical head scans the information layer (

3

) of an optical record carrier (

1

) by means of a radiation beam (

13

). Optical aberrations in the beam such as coma and spherical aberration, caused by tilt and thickness variations in the optical disc respectively, are compensated by an aberration compensator (

27

) arranged in the radiation beam. The tilt or thickness variation is measured by a detector (

30

) and used to control the aberration compensator. The radiation beam is focused onto the information layer by an objective system (

11

). A displacement of the objective system in the transverse direction (

26

) as used for radial tracking of the optical beam, causes a mismatch between the wavefront to be compensated and the wavefront introduced by the aberration compensator (

27

). The mismatch is reduced by using a position detector (

33

) for measuring the transverse position of the objective system and using the position signal (

34

) as input for the control of the aberration compensator.

Title
Optical scanning head
Application Number
9/914007
Publication Number
6586717 (B2)
Application Date
August 21, 2001
Publication Date
July 1, 2003
Inventor
Sjoerd Stallinga
Eindhoven
US
Jeroen Wals
Eindhoven
US
Joris Jan Vrehen
Eindhoven
US
Agent
Michael E Belk
US
Assignee
Koninklijke Philips Electronics
US
IPC
G02B 27/40
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