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:
Dec. 03, 2013
Filed:
Feb. 14, 2012
Takahiro Yoshimi, Utsunomiya, JP;
Takahiro Yoshimi, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes a first lens unit with positive refraction that is stationary for zooming, a second unit with negative refraction that moves during zooming, a third unit that moves on the optical axis along with movement of the second unit, and a fourth unit with positive refraction that is stationary during zooming, arranged in order from the object to image planes. The first unit includes a negative meniscus element Gconvex towards the object plane, a positive element G, a positive element G, and a positive meniscus element Gconvex towards the object plane, arranged in order from the object to image planes. The respective curvature radii GR, GR, GR, and GRof surfaces of the elements Gand Gand the respective focal lengths fG, fG, and fof the elements Gand Gand the first unit are set appropriately.