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:
Sep. 13, 2005
Filed:
May. 05, 2004
Makoto Sekita, Kanagawa, JP;
Makoto Sekita, Kanagawa, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens system is disclosed which includes a first lens unit with negative optical power, a second lens element with positive optical power, and a third lens element with positive optical power, arranged in that order from an object side to an image side. The zoom lens system performs zooming by changing distances between the lens units. By configuring the first lens unit of a meniscus-shaped negative lens element whose convex surface faces the object side and a positive lens element, and by setting the refractive indices of the lens elements to appropriate values, a zoom lens system is realized, which has a small number of constituent lenses, which is compact and which has an excellent optical performance.