Two-dimensional position encoder
US10921718B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2018 |
| Grant date | Feb 16, 2021 |
| Priority date | — |
| Expiry date | Dec 14, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70516
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A position encoder for monitoring relative movement between a first object and a second object includes a grating that is coupled to the first object, and an image sensor assembly that is coupled to the second object. The image sensor includes a first image sensor; a second image sensor that is spaced apart from the first image sensor; an optical element that includes a first optical surface and a second optical surface that is spaced apart from the first optical surface; and an illumination system. The illumination system directs an illumination beam at the optical element to create (i) a first reference beam that is reflected by the first optical surface and directed at the first image sensor, (ii) a second reference beam that is reflected by the second optical surface and directed at the second image sensor, and (iii) a transmitted beam that is transmitted through the optical element and is directed at and impinges on the grating to create a first measurement beam that is diffracted by the grating and directed at the first image sensor, and a second measurement beam that is diffracted by the grating and directed at the second image sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.