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. 19, 2021
Filed:
Nov. 15, 2018
Canon Kabushiki Kaisha, Tokyo, JP;
Shinichiro Saito, Utsunomiya, JP;
Makoto Nakahara, Utsunomiya, JP;
Suguru Inoue, Utsunomiya, JP;
Akira Mizuma, Utsunomiya, JP;
Masakazu Yamagishi, Saitama, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
An optical system includes a first lens unit having positive refractive power, a second lens unit, and a third lens unit having negative refractive power arranged in order from an object side to an image side. The second lens unit moves in focusing, thereby changing a distance between adjacent lens units. The first lens unit includes a positive lens, and the third lens unit includes a negative lens. A focal length of the positive lens, a focal length of the negative lens, a focal length of the third lens unit, and a back focus of the optical system are appropriately set.