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. 19, 2022
Filed:
Jan. 14, 2021
Mitutoyo Corporation, Kanagawa, JP;
Koji Kubo, Tokyo, JP;
Yuko Shishido, Kanagawa, JP;
MITUTOYO CORPORATION, Kanagawa, JP;
Abstract
A variable focal length optical system includes: an imaging lens configured to condense a parallel beam of light from an objective lens to form an intermediate image; a relay system including, in sequence from an object side, a first relay lens and a second relay lens and configured to relay the intermediate image to infinity; and a lens system of a liquid resonant type which is located between the first relay lens and the second relay lens. A front principal point of the lens system is located to be conjugated with an exit pupil of the objective lens and an expression, 1.90≤f/f≤2.15, is satisfied. In the expression, fdenotes a focal length of the imaging lens and fdenote a focal length of the first relay lens.