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:
Jan. 11, 2000
Filed:
Nov. 20, 1998
Applicant:
Inventors:
Morihiko Uchida, Tokyo, JP;
Takahiro Sugiyama, Saitama, JP;
Assignee:
Clarion Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359719 ; 359718 ; 359708 ;
Abstract
An objective lens for an optical disc includes a positive single lens, disposed between a light source and the optical disc. The objective lens has a first surface directed to the light source and a second surface directed to the optical disc. The first surface has a convex shape and both the first surface and the second surface are aspheric. The objective lens satisfies the following condition: 1.0<.vertline.R2/R1.vertline.<1.2, where R1 is the paraxial radius of curvature on the light source side surface and R2 is the paraxial radius of curvature on the optical disc side surface.