Apparatus for sensing patterns of electrical field variations across a surface
US6304666A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 1998 |
| Grant date | Oct 16, 2001 |
| Priority date | — |
| Expiry date | Oct 7, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An array of nonvolatile field effect transistors used to sense electric potential variations. The transistors owe their nonvolatility to the movement of protons within the oxide layer that occurs only in response to an externally applied electric potential between the gate on one side of the oxide and the source/drain on the other side. The position of the protons within the oxide layer either creates or destroys a conducting channel in the adjacent source/channel/drain layer below it, the current in the channel being measured as the state of the nonvolatile memory. The protons can also be moved by potentials created by other instrumentalities, such as charges on fingerprints or styluses above the gates, pressure on a piezoelectric layer above the gates, light shining upon a photoconductive layer above the gates. The invention allows sensing of fingerprints, handwriting, and optical images, which are converted into digitized images thereof in a nonvolatile format.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.