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:
Sep. 20, 2011
Filed:
Apr. 12, 2009
Applicant:
Saburo Masugi, Kawasaki, JP;
Inventor:
Saburo Masugi, Kawasaki, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 15/14 (2006.01); G02B 13/18 (2006.01); G02B 3/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
A lens system includes, in order from an object: a first lens group having negative refractive power; and a second lens group having positive refractive power, the first lens group including, in order from the object, a lens having a negative refractive power, a plastic aspherical lens, and a lens having a positive refractive power, and the following conditional expression |fp/f|>4.0 being satisfied, where fp denotes a focal length of the plastic aspherical lens, and fdenotes a focal length of the first lens group.