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. 11, 2014
Filed:
Oct. 22, 2012
Canon Kabushiki Kaisha, Tokyo, JP;
Tomoyuki Nakamura, Utsunomiya, JP;
Shoichi Takemoto, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A zoom lens including, in order from object side to image side: a first positive lens unit which does not move for zooming; a second negative lens unit which moves during zooming; a third positive lens unit which moves during zooming; a fourth lens unit which moves during zooming; and a fifth positive lens unit which does not move for zooming. The second unit passes through a point at which magnification of the second unit becomes −1 during zooming from wide-angle end to telephoto end, and −1<β34<−0.3, and 4.0<|m2/m3|<15 are satisfied where β34 represents a magnification of a combined unit including the third and fourth units at a zoom position fz at which the magnification of the second unit becomes −1, and m2 and m3 respectively represent displacements of the second and third units on optical axis at the zoom position fz with reference to the wide-angle end.