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:
Feb. 08, 2011
Filed:
Mar. 17, 2010
Yu Inomoto, Tokyo, JP;
Shinichiro Yakita, Utsunomiya, JP;
Yu Inomoto, Tokyo, JP;
Shinichiro Yakita, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
A zoom lens system including, in order from an object side to an image side: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a negative refractive power; an aperture stop; and a fourth lens unit having a positive refractive power and including a front lens subunit and a rear lens subunit in which Abbe numbers of lenses in the rear lens subunit satisfy the following expression,0.400<ν/(ν)<0.630,where νm represents the Abbe number of the material of a first positive lens having the largest dispersion of the positive lenses included in the rear lens subunit, νrp represents the average Abbe number of materials of positive lenses other than the first positive lens in the rear lens subunit, and νrn represents the average Abbe number of materials of negative lenses in the rear lens subunit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile