Apparatus and method for roll invariant reflective position sensing
US6552802B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 3, 2000 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | May 3, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A position sensor having a wavefront compensator, a detector array and a grating in a diffractive configuration, and which incorporates a second wavefront compensator and a second detector array in parallel with the first wavefront compensator and detector array, to provide a second optical channel for measurement of an additional degree of freedom (roll), the effects of which can then be removed from or utilized in the main measurement channel; and in which the relative effects of grating roll and grating displacement are different in this second channel when compared to the first sensing channel; and in one embodiment of which this differentiation is created by having different ratios of the grating period to the detector fringe period in the two channels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.