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:
Jul. 24, 2018
Filed:
Aug. 27, 2015
Canon Kabushiki Kaisha, Tokyo, JP;
Ken Wada, Sakura, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
Provided is a compact zoom lens having a high aperture ratio and high optical performance over an entire zoom range. The zoom lens includes, in order from object side to image side: first, second, and third lens units respectively having positive, negative, and positive refractive powers; an aperture stop; a middle lens group; and a final lens unit. An interval between adjacent lens units is changed during zooming. The third lens unit includes at least two positive lenses and at least one negative lens. A combined focal length (f) of first lens unit and second lens unit at telephoto end, a focal length (fn) of a lens unit (N) having a largest absolute value of the negative refractive power of the lens unit forming middle lens group, a focal length (f) of third lens unit, and a focal length (ft) of zoom lens at telephoto end are appropriately set.