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:
May. 03, 2011
Filed:
Jul. 24, 2007
James Joseph Anthony Mccormack, Eindhoven, NL;
Alberto Martin-consuegra Granados, Eindhoven, NL;
James Joseph Anthony McCormack, Eindhoven, NL;
Alberto Martin-Consuegra Granados, Eindhoven, NL;
Koninklijke Philips Electronics N.V., Eindhoven, NL;
Abstract
Spherical aberration correction is provided for CD writing in a double (CD+DVD), triple (CD+DVD+BD) or quadruple (CD+DVD+BD+HD-DVD) writer, which use the same light path for CD and DVD. In an optical drive that uses numerous laser wavelengths combined into one light path each wavelength having a different numerical apertures a correction for spherical aberration is made to correct for effective numerical apertures of the light path that becomes shifted up from the original value to higher values. The correction in spherical aberration removes that effect of the higher effective NA and defects, particularly in writing, are corrected.