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:
Nov. 20, 2012
Filed:
Sep. 15, 2011
Eijiroh Tada, Saitama, JP;
Eijiroh Tada, Saitama, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A variable power optical system, including a fixed negative first lens group, a second positive lens group and a third positive lens group, wherein the first lens group includes a deflecting element arranged to bend an optical path, and when ddenotes a distance between an image side principal point of the first lens group and an object side principal point of the second lens group at a short focal length end, ddenotes a distance between the image side principal point of the first lens group and the object side principal point of the second lens group at a long focal length end, fw denotes a focal length of the optical system at the short focal length end, ft denotes a focal length of the optical system at the long focal length end, and fdenotes a focal length of the first lens group, the optical system satisfies:2.5<(1212)/|√1|<4.0.