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:
Feb. 02, 2021
Filed:
Apr. 06, 2018
Applicant:
Mitutoyo Corporation, Kanagawa, JP;
Inventors:
Assignee:
MITUTOYO CORPORATION, Kanagawa, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B 15/14 (2006.01); G02B 7/04 (2006.01); G02B 3/14 (2006.01); G02B 7/28 (2006.01); G02B 7/08 (2006.01); H04N 5/225 (2006.01);
U.S. Cl.
CPC ...
G02B 15/14 (2013.01); G02B 3/14 (2013.01); G02B 7/04 (2013.01); G02B 7/08 (2013.01); G02B 7/28 (2013.01); H04N 5/2254 (2013.01);
Abstract
A variable focal length lens device includes: a lens system whose refractive index changes in accordance with an inputted drive signal; and a resonance-lock controller that locks the drive signal to a resonance frequency of the lens system. The resonance-lock controller tunes a frequency of the drive signal to a peak position of a voltage-current phase difference between a voltage of the drive signal and a drive current of the lens system, and raises or lowers the frequency of the drive signal in accordance with the drive current when the voltage-current phase difference changes.