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:
Aug. 21, 2012
Filed:
Jan. 10, 2011
Rei Ito, Utsunomiya, JP;
Rei Ito, 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. Each lens unit moves during zooming. The first lens unit consists of two lenses, the second lens unit consists of, in order from the object side to the image side, a positive lens, a positive lens, a negative lens, and a positive lens, and the third lens unit consists of one lens. A focal length of the entire zoom lens at a wide-angle end (fw), a focal length of the first lens unit (f), a focal length of the second lens unit (f), a focal length of the positive lens included in the second lens unit (fG), and amounts of movement (m, m) of the second lens unit and the third lens unit during zooming are appropriately set.