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. 04, 1998
Filed:
Apr. 20, 1995
Chiaki Terasawa, Kanagawa-ken, JP;
Jun Hosoya, Kanagawa-ken, JP;
Yasuhiro Izumi, Kanagawa-ken, JP;
Yasuyuki Tomita, Kanagawa-ken, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom lens is disclosed comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a flare cut stop for cutting a lower marginal ray of an off-axial bundle of rays for a maximum image height, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power, wherein the second and third lens units move axially to effect zooming, while either varying the aperture diameter of the flare cut stop or axially moving the flare cut stop to thereby cut the harmful rays for good optical performance.