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. 27, 2009
Filed:
May. 27, 2008
Rei Iwama, Utsunomiya, JP;
Rei Iwama, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power in that order from an object side to an image side. Zooming is performed by changing distances between the lens units. The first lens unit includes two or less lenses and the second lens unit consists of a negative lens and a positive lens in that order from the object side to the image side. The zoom lens satisfies the following condition:−1.3<1/√{square root over (())}<−0.8where fw and fT are focal lengths of the entire lens unit at wide-angle and telephoto ends, respectively, and mis an amount of movement of the first lens unit in an optical axis direction during zooming from the wide-angle end to the telephoto end.