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. 02, 2019
Filed:
Sep. 18, 2017
Canon Kabushiki Kaisha, Tokyo, JP;
Shunji Iwamoto, Utsunomiya, JP;
Shinichiro Saito, Utsunomiya, JP;
Satoshi Maetaki, Utsonomiya, JP;
Takahiro Hatada, Utsunomiya, JP;
Suguru Inoue, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An optical system includes an optical element. When the optical element is disposed on a magnification side with respect to an intersection point between an optical axis and a chief paraxial ray, the optical element is a positive lens. When the optical element is disposed on a reduction side with respect to the intersection point, the optical element is a negative lens. The optical element satisfies all of the following conditional expressions:30≤ν≤401.225≤[−(14.387/ν)]≤1.2760.4300≤[θ−(2.9795/ν)]≤0.5010where νd is Abbe number of the optical element, θgF is a partial dispersion ratio of the optical element for g-line and F-line, and nd is a refractive index of the optical element for d-line.