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:
Apr. 20, 2021
Filed:
Feb. 22, 2019
Canon Kabushiki Kaisha, Tokyo, JP;
Satoshi Maetaki, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical system according to the present invention is an optical system consisting of a front lens group having a positive or negative refractive power, an aperture stop, and a rear lens group having a positive or negative refractive power that are placed in order from an object side to an image side. In the optical system, relationships between a distance on an optical axis between a negative lens having the strongest refractive power in the rear lens group and a positive lens placed on the image side of the negative lens, an opening angle of the positive lens, a back focus of the optical system, and a focal length of the optical system are appropriately determined.