Light-emitting/receiving combined unit and displacement sensors using the same
US6980303B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Feb 1, 2002 |
| Grant date | Dec 27, 2005 |
| Priority date | — |
| Expiry date | Jan 11, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a light emitting/receiving composite unit (1) for emitting and receiving lights, which includes a light source (3), an optical splitting unit (4) for splitting returning lights to the composite unit (1) into a plurality of lights, a polarizing unit (5) for increasing and decreasing quantity of lights transmitted therefrom corresponding to polarization state of the returning lights, and an optical receiving unit (6) which has a plurality of photo-detecting elements (6—1 to 6—4) for detecting the lights transmitted through the polarizing unit (5), which are unitedly integrated into one unit. Also, the present invention provides a displacement detection apparatus of grating interference type, which includes thus unitedly integrated composite unit (1), and an external optical system of an objective unit having a reflection type diffraction grating RG, a reflecting unit (R1a, R1b) for reflecting lights from the composite unit (1) to the reflection type diffraction grating RG, a polarizing unit (WP1a, WP1b) for changing polarization state of diffracted lights from the reflection type diffraction grating RG, and a reflecting unit (R2a, R2b) for reflecting li…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.