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:
Sep. 16, 2025
Filed:
Feb. 23, 2023
Seiko Epson Corporation, Tokyo, JP;
Kohei Yamada, Shiojiri, JP;
Takeshi Shimizu, Chino, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
A laser interferometer includes a laser light source that emits laser light, an optical modulator which superimposes a modulation signal on the laser light using a vibrator driven by a drive signal, a photodetector that receives the laser light including a sample signal and the laser light including the modulation signal, and outputs a light receiving signal, an oscillator that generates a reference signal, an amplifier that outputs the drive signal from the reference signal, and a processor that extracts a frequency modulation component from the light receiving signal and the reference signal, outputs a preprocessing signal including the frequency modulation component, demodulates the sample signal from the preprocessing signal and the reference signal, outputs a correction signal based on an output signal depending on driving of the vibrator, and corrects the drive signal and the reference signal based on the correction signal.