Electrostatic discharge protection of a capacitive type fingerprint sensing array
US7768273B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 2, 2009 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Mar 2, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04107
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A planar fingerprint pattern detecting array includes a large number of individual skin-distance sensing cells that are arranged in a row/column configuration. Each sensing cell includes a first capacitor plate placed vertically under the upper surface of a dielectric layer and a second capacitor plate that is placed vertically under the upper surface of the dielectric layer in close horizontal spatial relation to the first capacitor plate. Electrostatic discharge protection relative to electrostatic potential that may be carried by an ungrounded fingertip is provided by placing a number of grounded metal paths within the dielectric layer to spatially surround each of the first and second capacitor plates, this being done in a manner that does not disturb the ungrounded state of the fingertip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.