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:
Dec. 20, 2016
Filed:
Feb. 17, 2015
Canon Kabushiki Kaisha, Tokyo, JP;
Takashi Ode, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A zoom optical system includes, in order from an enlargement conjugate side to a reduction conjugate side, a first optical group, and a second optical group having a zoom function. The second optical group includes, in order from the enlargement conjugate side to the reduction conjugate side, a lens unit Bwith positive refractive power, a lens unit Bwith positive refractive power, and a lens unit Bwith positive refractive power. The lens units Band Bmove with a distance therebetween changed at the time of zooming. A predetermined relationship between a focal length fR of the second optical group in a wide-angle end and a focal length fBof the lens unit Bis satisfied.