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. 10, 2007
Filed:
Jun. 05, 2006
Atsushi Shibayama, Tokyo, JP;
Keiko Mizuguchi, Kawasaki, JP;
Atsushi Shibayama, Tokyo, JP;
Keiko Mizuguchi, Kawasaki, JP;
Nikon Corporation, Tokyo, JP;
Abstract
Object is to provide an inner-focusing type zoom lens system carrying out focusing by moving a portion of a first lens group suitable for an auto-focus SLR camera. A zoom lens system includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a distance between the first and the second lens groups increases, and a distance between the second and the third lens groups decreases. The first lens group is composed of, in order from the object, a 1A lens group GA having positive refractive power, and a 1B lens group GB having positive refractive power. Focusing from infinity to a close-range object is carried out by moving only the 1B lens group GB to the object.