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:
Apr. 07, 2015
Filed:
May. 05, 2014
Fujifilm Corporation, Tokyo, JP;
Nobuaki Toyama, Saitama-ken, JP;
Michio Cho, Saitama-ken, JP;
FUJIFILM Corporation, Tokyo, JP;
Abstract
A zoom lens includes first, second, third, and fourth lens groups respectively having positive, negative, negative, and positive powers. The first lens group includes a first lens subgroup having a negative power, which is fixed while focusing, a second lens subgroup having a positive power, which moves while focusing, and a third lens subgroup having a positive power, which is fixed while focusing. The second lens subgroup includes a positive lens having a surface having a radius of curvature with a smaller absolute value toward the image side; and a cemented lens constituted by a negative lens toward the object side and a positive lens toward the image side, cemented together at a joint surface having a convex surface toward the object side. The focal distance f12 of the second lens subgroup and the focal length fw of the entire system at the wide angle end satisfy the relationship: 3.0<f12/fw<20.0.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile