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:
Apr. 10, 2012
Filed:
Aug. 26, 2008
Kunihiko Taka, Musashino, JP;
Kunihiko Taka, Musashino, JP;
Konica Minolta Opto, Inc., Tokyo, JP;
Abstract
Disclosed is an objective lens used for an optical pickup apparatus to perform writing and/or reading of an optical information recording medium, comprising an antireflective film on a surface of a light source side, wherein a light flux of wavelengths including a wavelength λ1 of 380 nm≦λ1≦420 nm and a wavelength λ2 of 630 nm≦λ2≦810 nm, is condensed on the medium, a numerical aperture on the light source side with respect to the wavelength λ1 is within a range of 0.8-0.9, and that with respect to the wavelength λ2 is 0.7 or less, and a band of the antireflective film is within a range of 700 nm-800 nm in a state where a reflectance of a light flux perpendicularly entering a central portion of the surface in a wavelength region from 400 nm to 1200 nm is 3.0% or less.