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:
Nov. 06, 2007
Filed:
Apr. 04, 2002
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 scanning device for scanning of a first, second and third type of optical record carrier with radiation of a first wavelength λ, a second wavelength λand a third wavelength λ, respectively, where the three wavelengths are substantially different. The device comprises: a radiation source for emitting a beam of said radiation, an objective system for converging the beam on a selected one of the optical record carriers, and a phase structure arranged in the path of the beam, the phase structure comprising a plurality of phase elements of different heights, forming a non-periodic stepped profile of optical paths in the beam, and is characterised in that the stepped profile substantially approximates a flat wavefront at the first wavelength λ, a spherical aberration wavefront at the second wavelength λ, and a flat or spherical aberration wavefront at the third wavelength λ.