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:
Feb. 08, 2011
Filed:
Jun. 17, 2010
Miho Matsumoto, Tokyo, JP;
Miho Matsumoto, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An eyepiece system has a lens group Sin which a lens Lhaving a negative refractive index and refractive power and a lens Lhaving a positive refractive index and refractive power are joined, so that the lens group Sas a whole has a positive refractive index and refractive power; and a multi-layer (stacked) diffraction optical element PF. In an optical system positioned between an image surface I and an eye point EP, the position of a diffraction plane on the optical axis is between EF in FIG.. In FIG., EF is the range in which the value ra of the ratio between a distance (DH) between the diffraction plane (C) and a principal point (H) near the diffraction plane and a distance (DHH) between principal points is 0.5 or less in both directions from the principal points H, H