Capacitance imaging system using electro-optics
US5170127A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 19, 1991 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Feb 19, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/312
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An unassembled simple matrix liquid crystal display (LCD) panel, with strips of highly-conductive material, is tested by extracting a two-dimensional image of the capacitance distribution across the surface of the panel under test (PUT) through illumination of a modulator placed adjacent the surface, such as an NCAP modulator or other liquid dispersed polymer-based device. The light modulator is disposed to allow longitudinal probing geometries such that a measurement of capacitance is developed across a gap between the surface of the panel under test and the opposing face of the modulator which causes a power modulation in the optical energy which can be observed through an area optical sensor (such as a camera) for use in directly produce a two-dimensional spatially-dependent power modulation image directly representative of the spatially corresponding capacitance state on the surface of the panel under test.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.