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:
Nov. 23, 2021
Filed:
Jun. 21, 2018
Canon Kabushiki Kaisha, Tokyo, JP;
Koichi Sakuma, Utsunomiya, JP;
CANON KABUSHIKI KAISHA, Tokyo, JP;
Abstract
Provided is a converter lens arranged between an interchangeable lens and an image pickup apparatus, wherein a distance from a most-object-side lens surface vertex to an object point of the converter lens, a distance L from the most-object-side lens surface vertex to a most-image-side lens surface vertex, and a most-image-side distance from the lens surface vertex to an image point of the converter lens are properly set, wherein, at least one negative lens included in a rear lens unit composed of lenses satisfying LN>0.5×L where LN is a most-object-side distance from the lens surface vertex to a surface vertex on the object side of the lenses, satisfies ΘgF>−0.00162×vd+0.654, where θgF is relative partial dispersion and vd is Abbe number in d-line, and an average focal length of the at least one negative lens, and a focal length of an entire system of the converter lens are properly set.