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:
Sep. 08, 2009
Filed:
Oct. 19, 2005
Koichiro Wakabayashi, Ibaraki, JP;
Keiko Hirao, Ibaraki, JP;
Mitsuhiro Miyauchi, Ibaraki, JP;
Yutaka Makino, Ibaraki, JP;
Yasuyuki Sugi, Ibaraki, JP;
Yoshikazu Mitsui, Ibaraki, JP;
Koichiro Wakabayashi, Ibaraki, JP;
Keiko Hirao, Ibaraki, JP;
Mitsuhiro Miyauchi, Ibaraki, JP;
Yutaka Makino, Ibaraki, JP;
Yasuyuki Sugi, Ibaraki, JP;
Yoshikazu Mitsui, Ibaraki, JP;
Hitachi Maxell, Ltd., Ibaraki, JP;
Abstract
A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of twith a laser beam having a wavelength λand wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of twith a laser beam having a wavelength λ. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of twith a laser beam having a wavelength λ