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:
Jul. 02, 2002
Filed:
Aug. 15, 2000
Noboru Koizumi, Omiya, JP;
Fuji Photo Optical Co., Ltd., Saitama, JP;
Abstract
An eyepiece, consisting of two lens groups, is lighter in weight and more compact than known previously, yet has aberrations that are favorably corrected despite the eyepiece having a large exit pupil diameter. This is accomplished by including a predetermined diffraction optical element (DOE) surface on one of the optical elements in order to minimize the number of lens elements that are required, while simultaneously ensuring the image is of high quality. Thus, a high quality image may be observed even while walking, riding in a vehicle, or the like. In order from the eye side, the first lens group has positive refractive power with its surface nearest the eye side being convex and its surface farthest from the eye side being concave. The first lens group may be formed of a single lens element or a pair of lens elements that are cemented together. Among the two lens groups, the eyepiece includes at least one negative lens element and at least two positive lens elements. Preferably, specified conditions are satisfied to ensure that the eyepiece is compact, yet well-corrected for aberrations.