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:
Oct. 25, 2011
Filed:
Sep. 09, 2009
Kenji Shinohara, Utsunomiya, JP;
Kenji Shinohara, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes a first lens unit with a negative refractive power, a second lens unit with a positive refractive power, and a third lens unit with a positive refractive power in order from the object side to the image side. The first lens unit includes a negative lens and a positive lens. When the curvature radius of the object side surface and that of the image side surface of the negative lens are respectively defined as Rand Rand the curvature radius of the object side surface and that of the image side surface of the positive lens are respectively defined as Rand R, the following conditional expression is satisfied: −5.6<(R+R)/(R−R)<−4.7 and 1.5<(R+R)/(R−R)<2.3.