Voltage imaging system using electro-optics
US4983911A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 15, 1990 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Feb 15, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/309
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A two-dimensional image of the voltage distribution across a surface at a large plurality voltage test points of a panel under test is extracted by illuminating the surface with an expanded, collimated beam of optical energy of a known polarization state through an electro-optic modulator crystal, such as KDP, wherin the crystal is disposed to allow longitudinal probing geometries such that a voltage on the surface of the panel under test causes a phase shift in the optical energy (the electro-optic effect) which can be observed through an area polarization sensor (a polarizing lens) for use to directly produce a two-dimensional spatially-dependent power modulation image directly representative of the spatially corresponding voltage state on the surface of the panel under test. Surface cross-talk is minimized by placing the face of the crystal closer to the panel under test than the spacing of voltage sites in the panel under test. The device may operate in a pass-through mode or in a reflective mode. An etalon may be used to enhance sensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.