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. 31, 2015
Filed:
Aug. 05, 2013
Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;
Fumitomo Yamasaki, Nara, JP;
Yoshiaki Komma, Osaka, JP;
Abstract
An objective lens () is configured to converge laser light of a first wavelength λ(390 [nm]≦λ≦430 [nm]), laser light of a second wavelength λ(630 [nm]≦λ≦680 [nm]), and laser light of a third wavelength λ(750 [nm]≦λ≦810 [nm]) on an information recording surface of a first information recording medium, an information recording surface of a second information recording medium, and an information recording surface of a third information recording medium, and is configured such that the distance from a convergent point of normal diffracted order light, to a virtual collecting point formed by virtual diffracted order light between the convergent point of normal diffracted order light and a collecting point of unwanted diffracted order light is twice or more of the pull-in range of a focus error signal to be obtained in recording or reproducing information with respect to the third information recording medium.