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:
Jun. 17, 2025
Filed:
Aug. 30, 2022
Seiko Epson Corporation, Tokyo, JP;
Kohei Yamada, Shiojiri, JP;
SEIKO EPSON CORPORATION, , JP;
Abstract
A laser interferometer includes a laser light source, a collimator generating collimated light, an optical modulator modulating the collimated light into reference light having a different frequency, and a light receiving element receiving object light and the reference light and outputting a light receiving signal. An optical axis of the collimated light is a first optical axis. When return light is generated, an optical axis of the return light is a second optical axis. A position at which the collimated light is generated is a reference position. The first and second optical axes at the reference position has a shift width Δy. The collimator has an effective diameter κ. The collimated light has a light diameter R. The reference position is away from the optical modulator by a distance L. The collimated light has a wavelength λ. These properties satisfy a specific equation (A).