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. 12, 2016
Filed:
Dec. 18, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Takayoshi Yokoyama, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An imaging optical system includes, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, and a third lens unit having a positive refractive power. The second lens unit moves toward the image side during focusing from a far object to a near object. The third lens unit includes, in order from the object side to the image side, two lenses having concave surfaces that face each other with a largest air gap in the third lens unit provided therebetween, and a positive lens. A focal length of the entire imaging optical system and a focal length of the second lens unit are appropriately set.