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:
Oct. 12, 2010
Filed:
Jul. 17, 2008
Applicants:
Tsutomu Ishikawa, Yamanashi, JP;
Toyotoshi Machida, Yamanashi, JP;
Hirokazu Tanaka, Yamanashi, JP;
Inventors:
Assignee:
Eudyna Devices Inc., Yamanashi, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01R 23/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
An optical device includes an optical element, a detector and a controller. The optical element has an optical waveguide. Refractive index of the optical waveguide is controlled by a heater. A temperature of the optical element is controlled by a temperature control device. The detector detects a current flowing in the heater and/or a voltage applied to the heater. The controller controls an electrical power provided to the heater so as to be kept constant according to the detection result of the detector.