Liquid crystal device for calibration and testing of optical instruments
US5030005A · kind A · utility
6Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1989 |
| Grant date | Jul 9, 1991 |
| Priority date | — |
| Expiry date | Nov 29, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/278
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device and method for optical calibration of an optical instrument that measures optical characteristics along an optical path. A controllable shutter having electrically alterable optical characteristics is placed across the optical path of the instrument. An electrical control is connected to the shutter for selectively providing a variable voltage to the shutter to electrically alter optical characteristics of the shutter in a controlled manner so that the optical characteristics of the shutter correspond to selected optical characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.