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:
Mar. 24, 2015
Filed:
Jan. 09, 2012
Makoto Fujimoto, Tokyo, JP;
Makoto Fujimoto, Tokyo, JP;
Nikon Corporation, Tokyo, JP;
Abstract
A telephoto lens TL having, in order from an object, a plurality of lenses L, L, . . . and a diffractive optical element DOE which has a diffraction grating having a rotationally symmetric shape with respect to the optical axis, wherein the diffractive optical element DOE is disposed on any one of lens surfaces of the plurality of lenses L, L, . . . , and conditional expression 0.50<fa/Rd<0.90 or 1.10<fa/Rd<2.00 is satisfied, where fa denotes a combined focal length of each lens from the lens L, which is closest to the object, of the plurality of lenses L, L, . . . to the lens L, on which the diffractive optical element DOE is disposed, and Rd is a radius of curvature of the lens surface on which the diffractive optical element DOE is disposed.