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. 29, 2015
Filed:
Nov. 26, 2012
Canon Kabushiki Kaisha, Tokyo, JP;
Yoshihisa Tashiro, Nikko, JP;
Yasuaki Hagiwara, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes a first lens unit having a negative refractive power, a second lens unit having a positive refractive power, a third lens unit having a negative refractive power, and a fourth lens unit having a positive refractive power, disposed in order from an object side to an image side, and an aperture stop between a lens surface closest to the object side of the second lens unit and a lens surface closest to the object side of the third lens unit, the third lens unit is moved to the image side during a focusing operation from an infinite object to a short distance object, the first lens unit is configured by at most two negative lenses and one positive lens, the third lens unit is configured by a single lens or a cemented lens, and an appropriate conditional expression are met.