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.

Date of Patent:
Jan. 09, 2007

Filed:

Apr. 04, 2005
Applicants:

Tatsuo Ohta, Otsuki, JP;

Takashi Nozaki, Hino, JP;

Inventors:

Tatsuo Ohta, Otsuki, JP;

Takashi Nozaki, Hino, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 13/24 (2006.01); G02B 1/10 (2006.01); G02B 13/14 (2006.01);
U.S. Cl.
CPC ...
Abstract

An objective lens for converging a monochromatic light flux having a specific wavelength in a range of 350 to 450 nm on an optical information recording medium while the objective lens is placed facing the optical information recording medium, the objective lens comprising: a lens body containing a polymer resin having an alicyclic structure; a first film having a refractive index of less than 1.7 for light having a wavelength of 405 nm; a second film having a refractive index of 1.7 or more for the light having the wavelength of 405 nm; and a third film having a refractive index of 1.55 or less for the light having the wavelength of 405 nm, wherein: the first film, the second film and the third film are provided on the lens body; the first film is provided between the lens body and the second film; the second film is provided between the first film and the third film; and a thickness of the first film is in a range of 50 to 15000 nm.


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