Capacitive sensing array device
US5952588A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Jul 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/044
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A capacitive sensing array device, such as a fingerprint sensing device, includes an array of individual sensing electrodes (14) covered by a layer of insulating material (40) defining a sensing surface on which a person's finger is placed, each sensing electrode, its overlying fingerprint portion and intervening insulating layer providing a capacitance in operation. The sensing electrodes are of chromium and the covering insulating material includes a thin layer of chromium oxide which offers excellent scratch resistance and can be formed conveniently by oxidation of a surface region of the sensing electrodes. In a row and column array, address lines (18) extending between rows of electrodes (14) may also include chromium and be covered by chromium oxide. Preferably, the sensing electrodes and address lines are defined from a common deposited chromium layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.