The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 14, 2006
Filed:
Dec. 20, 2000
Bernardus Hendrikus Wilhelmus Hendriks, Eindhoven, NL;
Jorrit Ernst DE Vries, Eindhoven, NL;
Bernardus Hendrikus Wilhelmus Hendriks, Eindhoven, NL;
Jorrit Ernst De Vries, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
An optical head () for scanning optical record carriers () is provided with a compensator () for compensating spherical aberration of the objective system () or defocus of the collimator lens () caused by operation of the optical head at a temperature different from the design temperature. A surface of the compensator () comprises a phase structure in the form of annular areas (), the areas forming a non-periodic pattern of optical paths of different length. The optical paths change as a function of temperature and form a temperature-dependent wavefront deviation that compensates the spherical aberration and/or defocus.