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:
Oct. 09, 2012
Filed:
Mar. 08, 2011
Ayami Imamura, Hachioji, JP;
Ayami Imamura, Hachioji, JP;
Olympus Corporation, Tokyo, JP;
Abstract
A zoom optical system in which: a positive first lens group, a negative second lens group, a positive third lens group, and a positive fourth lens group are arranged in that order from the object side and magnification is changed by properly changing distances between these lens groups; the first lens group consists of only one lens element and the most object-side surface of the first lens group has a convex shape which faces toward the object side; the second lens group includes, in order from the object side, a negative single lens, a negative cemented lens, and a positive single lens; and the following condition (1) or (2) is satisfied:0.2≦Δ≦0.35  (1)=()/()>0  (2)where ΔDdenotes the variation in the distance between the first and second lens groups in changing from the wide angle end position to the position in which the focal length is ten times or more as large as that in the wide angle end position, Ldenotes the total length of the optical system in the telephoto end position, SFdenotes the shape factor of the fourth lens group, rdenotes the radius of curvature of the most object-side surface of the fourth lens group, and rdenotes the radius of curvature of the most image-side surface of the fourth lens group.