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:
Oct. 15, 2013
Filed:
Sep. 29, 2010
Satoshi Inoue, Saitama, JP;
Yuta Yoshida, Saitama, JP;
Naoto Hashimoto, Tochigi, JP;
Suguru Takishima, Tokyo, JP;
Satoshi Inoue, Saitama, JP;
Yuta Yoshida, Saitama, JP;
Naoto Hashimoto, Tochigi, JP;
Suguru Takishima, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
An optical information recording/reproducing optical system where resin material has Tg>115° C., first, second and third films are on an optical disc side of an objective lens and surfaces of an optical element, respectively, a light source side of the objective lens has a fourth film having four or more layers not containing Ti, each of the first, second and third films includes a non-high refractive index layer made of one of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride or a mixture of at least two of them, each of the first, second and third films is not made of one of Ti, Ta, Hf, Zr, Nb, Mo and Cr, a layer of the fourth film closest to a base material is the non-high refractive index layer. The fourth film satisfies 350<λ<420 and 600<λ<750, and reflectivity thereof decreases monotonously.