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:
Feb. 18, 2011
Tomonori Kimura, Utsunomiya, JP;
Akihisa Horiuchi, Utsunomiya, JP;
Tomonori Kimura, Utsunomiya, JP;
Akihisa Horiuchi, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A zoom lens includes positive, negative, positive, and positive lens units, and the second lens unit includes negative, negative, negative and positive lenses. The first and third lens units are fixed and the second and fourth lens units are moved in zooming. 0.01<|f2/√(fw*ft)|<0.35 and 0.070<D2/TL<0.105 are satisfied. fw and ft are focal lengths of an overall system at wide angle and telephoto ends, f2 is a focal length of the second lens unit, TL is a distance on an optical axis from a lens surface closest to an object plane to an image plane when a distance from a lens surface closest to the image plane to the image plane is aerially converted, and D2 is a distance on the optical axis from a lens surface closest to the object plane in the second lens unit to the lens surface closest to the image plane in the second lens unit.