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:
Jan. 29, 2002
Filed:
Oct. 10, 2000
Fumiaki Usui, Utsunomiya, JP;
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 arranged to move during variation of magnification, a third lens unit arranged to move during variation of magnification, and a fourth lens unit of positive refractive power. The first lens unit includes a first lens subunit arranged to be stationary during focusing, and a second lens subunit of positive refractive power arranged to move during focusing. The first lens subunit includes, in order from the object side to the image side, at least one first positive lens, at least one negative lens of bi-concave form, and at least one second positive lens.