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:
Apr. 08, 2003
Filed:
May. 02, 2000
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens includes, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power for variation of magnification, a third lens unit for compensating for shift of an image plane caused by the variation of magnification, and a fixed fourth lens unit of positive refractive power, wherein the first lens unit comprises a first lens subunit of negative refractive power fixed during focusing, a second lens subunit having a focusing function, and a third lens subunit of positive refractive power fixed during focusing, and at least one of the first lens subunit and the second lens subunit and the third lens subunit respectively have aspheric lenses.