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:
Nov. 13, 2007
Filed:
Sep. 06, 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, in order from a reduction side to a magnification side, includes a first lens unit having positive optical power, a second lens unit having the positive optical power, a third lens unit having negative optical power, and a fourth lens unit having the positive optical power, wherein respective intervals between the first, second, third and fourth lens units change during zooming, a conjugate position on the magnification side with respect to a conjugate position on the reduction side, and a position of a pupil of the zoom optical system with respect to the conjugate position on the reduction side, are substantially fixed over an entire zooming range, and during zooming from a wide angle end to a telephoto end, the fourth lens unit moves toward the magnification side, and an interval between the first lens unit and the fourth lens unit increases.