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:
Jun. 01, 2004
Filed:
Apr. 08, 2002
Kazuya Kitamura, Tenri, JP;
Yukio Kurata, Tenri, JP;
Takeshi Yamaguchi, Sakai, JP;
Tetsuo Iwaki, Yamatokoriyama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An objective lens is a single-lens objective lens both surfaces of which are aspherical. The objective lens has a numerical aperture not less than 0.75, and is made of glass satisfying 1.75<n, and 35<v, where n is a refractive index of the glass for at least one of used wavelengths, and v is an Abbe number for a d-lay. With this arrangement, it becomes possible to provide an objective lens which is downsized, has less aberration, and corrects the aberration easily, without a decline in light utilization efficiency; a method for correcting a manufacturing error thereof; and an optical pick-up device using the objective lens.