Fixed point detecting device using detection of light diffracted by holographic diffraction gratings
US5637868A · kind A · utility
10Cited by
6References
14Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 29, 1995 |
| Grant date | Jun 10, 1997 |
| Priority date | — |
| Expiry date | Mar 29, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fixed point detecting device comprises a light source, a hologram disposed therebelow and having two portions, and two light receivers for detecting lights diffracted by the two portions of the hologram, wherein an angle of diffraction of light diffracted by one of the two portions of the hologram and an angle of diffraction of light diffracted by another of the two portions of the hologram have opposite signs and the same absolute value and are constant along the axis of measurement, and a difference in luminous intensity is great between positive and negative homogeneous lights diffracted by the two portions of the hologram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.