Displacement detection apparatus
US9303973B2 · kind B2 · utility
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4References
5Claims
0Family size
Assignee
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Key dates
| Filing date | Jul 2, 2015 |
| Grant date | Apr 5, 2016 |
| Priority date | — |
| Expiry date | Jul 2, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A first light flux serving as object light is caused to enter a member to be measured, and reflected light thereof is caused to enter again the member to be measured after being diffracted by a first diffraction grating. Then, the second-time reflected light of the first light flux by the member to be measured is diffracted by a second diffraction grating. By diffracting the first light flux by the second diffraction grating, a change of the optical path length caused by tilting of the member to be measured is cancelled.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.