Displacement detection apparatus, displacement measurement apparatus and fixed point detection apparatus
US7933023B2 · kind B2 · utility
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4Claims
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Assignee
Inventor
Key dates
| Filing date | May 19, 2006 |
| Grant date | Apr 26, 2011 |
| Priority date | — |
| Expiry date | May 19, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/015
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A displacement detection apparatus includes a light source for emitting light and an extinction ratio conversion element which raises an extinction ratio of the light to 20 dB or more. A condenser lens condenses the light having the increased extinction ratio and a polarization maintaining type optical fiber transmits the condensed light which is subsequently transferred to a diffraction grating that is attached to an object to be measured. The displacement detection apparatus adjusts a polarization axis of the light having increased extinction ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.