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:
Jan. 08, 2013
Filed:
Jul. 06, 2010
Hideki Sakai, Utsunomiya, JP;
Hideki Sakai, 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, and a third lens unit having a positive refractive power. The first lens unit, the second lens unit, and the third lens unit are arranged in order from an object side to an image side. Distances between the lens units change during zooming. The first lens unit consists of two lenses. Radii of curvature of a lens surface closest to the object side and a lens surface closest to the image side in the first lens unit, a focal length of the first lens unit, and a focal length of the entire zoom lens at a telephoto end are set appropriately.