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. 15, 2024
Filed:
Jan. 21, 2020
Yokogawa Electric Corporation, Tokyo, JP;
Hosei University, Tokyo, JP;
YOKOGAWA ELECTRIC CORPORATION, Tokyo, JP;
Hosei University, Tokyo, JP;
Abstract
An electric field sensor includes a light source; an electro-optical crystal, a first separator, a first wavelength plate, first and second light receivers, a differential amplifier, and a controller. The electro-optical crystal has light from the light source incident thereon and receives an electric field generated by an object. The first separator separates light emitted from the electro-optical crystal into a P wave and an S wave. The first wavelength plate changes a phase of light at a pre-stage of the first separator. The first and second light receivers receive the P wave and S-wave light respectively, and convert the received light into first and second electrical signals, respectively. The differential amplifier generates a differential signal between the first and second electrical signals. The controller adjusts a wavelength of the light source such that an output value of a direct-current component of the differential amplifier is within a value range.