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:
Oct. 24, 2006
Filed:
Sep. 08, 2005
Manabu Hakko, Utsunomiya, JP;
Koshi Hatakeyama, Tokyo, JP;
Manabu Hakko, Utsunomiya, JP;
Koshi Hatakeyama, Tokyo, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom optical system provided, in order from a reduction side toward a magnification side, with: a first lens unit having positive optical power; a second lens unit having positive optical power; a third lens unit having positive optical power; and a fourth lens unit having negative optical power; wherein the interval between adjacent ones of the first, second, third and fourth lens units is varied during zooming, and in an entire zooming range, a magnification side conjugate position relative to a reduction side conjugate position, and the position of the pupil of the zoom optical system relative to the reduction side conjugate position are substantially immovable.