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. 12, 2011
Filed:
Oct. 29, 2007
Koichi Oshita, Tokyo, JP;
Koichi Oshita, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A diopter-adjustable eyepiece lens EL, comprising first through third lenses Lthrough L, satisfies the condition −0.9<S<−0.3, wherein first lens Lshape factor Sdenotes a shape factor of the first lens L, Redenotes the radius of curvature of a concave surface of the first lens Lon an eyepoint EP side and Rsdenotes the radius of curvature of a concave surface of the first lens Lon the object side. The diopter adjustment satisfies also the condition 0.4<d/Σd<0.6 wherein ddenotes an air gap along the optical axis between the first lens Land the second lens Lwhen diopter adjustment is carried out so that diopter becomes maximum on the negative side, and Ed denotes an air gap along the optical axis between a concave surface of the first lens Lon the eyepoint side and a concave surface of the third lens Lon the object side when diopter adjustment is carried out so that diopter becomes maximum on the negative side.