Method and system for suppressing unwanted reflections in an optical system
US6028671A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 1996 |
| Grant date | Feb 22, 2000 |
| Priority date | — |
| Expiry date | Jan 31, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/95623
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and system are provided for suppressing or filtering multiple reflections which corrupt photometric (grey scale or color) or height measurements within optical systems such as imaging systems. The reflections may originate within the instrument (i.e. back reflections) or may be inter-reflections between one or more surfaces in a scene. In one embodiment, a beam of electromagnetic energy generated by a source is polarized in a first rotational sense, is transmitted to a point of interest (i.e., scene) of an object, is reflected and received by a receiver having a polarizer which passes reflected electromagnetic energy having a second rotational sense opposite the first rotational sense. In this way, unwanted reflections from the point of interest having the first rotational sense are suppressed and back-reflections to the source of electromagnetic energy are substantially eliminated. In another embodiment, a detector which normally back-reflects a portion of electromagnetic energy it receives along a first axis, has a surface normal which is maintained in a fixed, non-colinear relation to the first axis and back-reflected electromagnetic energy is prevented from reaching th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.