Optical inverse-square displacement sensor
This invention comprises an optical displacement sensor that uses the inverse-square attenuation of light reflected from a diffused surface to calculate the distance from the sensor to the reflecting surface. Light emerging from an optical fiber or the like is directed onto the surface whose distance is to be measured. The intensity I of reflected light is angle dependent, but within a sufficiently small solid angle it falls off as the inverse square of the distance from the surface. At least a pair of optical detectors are mounted to detect the reflected light within the small solid angle, their ends being at different distances R and R + [Delta]R from the surface. The distance R can then be found in terms of the ratio of the intensity measurements and the separation length as given in an equation. 10 figs.
- DOE Contract Number:
- FG03-85ER13393
- Assignee:
- Leland Stanford Junior Univ., Stanford, CA (United States)
- Patent Number(s):
- US 4865443; A
- Application Number:
- PPN: US 7-060766
- OSTI ID:
- 7067544
- Resource Relation:
- Patent File Date: 10 Jun 1987
- Country of Publication:
- United States
- Language:
- English
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