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:
Aug. 31, 2010
Filed:
Apr. 18, 2006
Koichiro Wakabayashi, Ibaraki, JP;
Mitsuhiro Miyauchi, Ibaraki, JP;
Yasuyuki Sugi, Ibaraki, JP;
Yutaka Makino, Ibaraki, JP;
Koichiro Wakabayashi, Ibaraki, JP;
Mitsuhiro Miyauchi, Ibaraki, JP;
Yasuyuki Sugi, Ibaraki, JP;
Yutaka Makino, Ibaraki, JP;
Hitachi Maxwell, Ltd., Ibaraki-shi, JP;
Abstract
An optical pickup lens focuses laser beams having different wavelengths λand λon at least three kinds of optical discs. At least one side of the optical pickup lens has a concentric loop zonal structure for compensating wavefront aberration occurring when recording or reproducing an optical disc having a substrate thickness tby the laser beam having the wavelength λand wavefront aberration occurring when recording or reproducing an optical disc having a substrate thickness tby the laser beam having the wavelength λ. When recording or reproducing an optical disc having a substrate thickness tby the laser beam having the wavelength λ, a phase difference given to the laser beam having the wavelength λdue to the concentric loop zonal structure is about 0.15λ or smaller.