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:
Sep. 19, 1989

Filed:

Mar. 14, 1988
Applicant:
Inventors:

Kimihiko Nishioka, Tokyo, JP;

Kikumi Tojo, Kanagawa, JP;

Akira Yokota, Tokyo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350432 ;
Abstract

An objective lens system for an endoscope comprising a front lens unit, a stop, and a rear lens unit wherein the front lens unit comprises a lens component arranged that the surface on the object side thereof is formed as an aspherical surface having portions whose curvature is made gradually stronger as they are farther from the optical axis or a lens component arranged that the surface on the image side thereof is formed as an aspherical surface having portions whose curvature is made gradually weaker as they are farther from the optical axis, and the rear lens unit comprises a lens component arranged that the surface on the image side thereof is formed as an aspherical surface having portions whose curvature is made gradually stronger as they are farther from the optical axis or a lens component arranged that the surface on the object side thereof is formed as an aspherical surface having portions whose curvature is made gradually weaker as they are farther from the optical axis, the objective lens system for an endoscope being arranged that distortion and curvature of field are corrected favorably.


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