Heterodyne two-dimensional grating measuring device and measuring method thereof
US12188793B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 31, 2022 |
| Grant date | Jan 7, 2025 |
| Priority date | — |
| Expiry date | Jan 6, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/285
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A heterodyne two-dimensional grating measuring device and measuring method thereof includes a light source, a reading head, a photoelectric receiving module, and a processor. The light source is configured to generate two beams of linearly polarized light having characteristics of overlapping, polarization orthogonal, and fixed frequency difference. The reading head is configured to receive the two beams of the linearly polarized light, the two beams of the linearly polarized light are respectively incident on a surface of a moving two-dimensional measuring grating to generate ±1-order diffracted lights of two dimensions, and the ±1-order diffracted lights are respectively incident to the photoelectric receiving module through the reading head. The photoelectric receiving module is configured to generate beat frequency signals, the processor is configured to perform differential calculation on the beat frequency signals to realize a displacement measurement of measuring grating for four-fold optical subdivision.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.