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:
May. 12, 2015
Filed:
Aug. 23, 2010
Miwako Yoshida, Yokohama, JP;
Akiko Miyakawa, Sagamihara, JP;
Miwako Yoshida, Yokohama, JP;
Akiko Miyakawa, Sagamihara, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An objective lens OL comprises: a first lens group Gdisposed on an object side, having positive refractive power as a whole and having a positive lens (plano-convex lens L) which is disposed closest to the object and of which lens surface closest to the object is a plane or a surface having a low curvature, and at least one cemented lens (cemented lens CLor the like); a second lens group Gdisposed on an image side, having negative refractive power as a whole, and having a concave surface facing the image and a concave surface facing the object, which face each other; and a diffractive optical element GD in which two diffractive element constituents made from different optical materials are cemented, which has a diffractive optical surface D formed with diffraction grating grooves on the cemented surface, and which is disposed closer to the object than a position where a principal ray crosses the optical axis.