Apparatus and method for measuring charge density distribution
US8798947B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 2011 |
| Grant date | Aug 5, 2014 |
| Priority date | — |
| Expiry date | Feb 25, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1306
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention provides a method and apparatus for the detection of charge density distribution at the surface of a material sample. The apparatus comprises an electric potential sensor for measuring surface charge on a material sample, wherein the electrical potential sensor includes a probe for capacitively coupling the electric potential sensor to the surface of the material sample, an amplifier for generating a measurement output, the probe being connected to an input of the amplifier and the measurement output being supplied at an output of the amplifier, and a feedback arrangement driven from the output of the amplifier for enhancing the input impedance of the amplifier. A positioning system mounts the probe of the electric potential sensor above the material sample and moves the probe at a constant height over a surface of the said sample, and a processing system receives and processes the measurement output of the electric potential sensor for generating a digital record of the charge density distribution at the surface of the material sample.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.