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. 11, 2000
Filed:
Jun. 15, 1999
Norikazu Arai, Hachioji, JP;
Masaya Kobayashi, Hachioji, JP;
Hiroyuki Yamazaki, Hachioji, JP;
Hiroshi Kibayashi, Hino, JP;
Konica Corporation, Tokyo, JP;
Abstract
An optical system for recording or reproducing of information to or from an optical information recording medium, includes a light source, a coupling lens for converting a diverging light emergent from the light source to a converging light, and an objective lens for further converging the converted converging light and for focusing on an information recording surface of the optical information recording medium. A lateral magnification M.sub.c of the coupling lens on an image side for a light source side and a numerical aperture NA.sub.o on the light source side of the coupling lens satisfy the following expressions respectively, -7.0.ltoreq.M.sub.c .ltoreq.-0.5 and 0.06.ltoreq.NA.sub.o .ltoreq.0.21.