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. 17, 2019
Filed:
Dec. 04, 2017
Canon Kabushiki Kaisha, Tokyo, JP;
Shinji Yamasaki, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
Provided is an optical system according to the present invention, comprising a protection cover made of resin and a lens portion arranged in order from an object side to an image side, in which the protection cover includes an aspherical surface whose shape changes continuously from an optical axis to a peripheral portion, and where an effective diameter of the aspherical surface is represented as 2×ha, a distance sagin a direction of the optical axis between the aspherical surface and a reference spherical surface of the aspherical surface at a position where the height from the optical axis is ha, and a thickness tc of the protection cover on the optical axis are appropriately set.