Contact imaging device
US5907627A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 1995 |
| Grant date | May 25, 1999 |
| Priority date | — |
| Expiry date | Nov 6, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2224/48465
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A fingerprint sensing device and recognition system includes an array of closely spaced apart semiconductor dies bonded to a substrate. The dies are spaced with a minimal space that will ensure that adjacent edges of the dies do not wipe against one another when a finger is pressed upon them. Each die includes an row/column array of sense elements that are coupled to a drive circuit and a sense circuit by sets of row and column conductors, respectively. The sense elements are actively addressable by the drive circuit. Capacitances resulting from individual finger surface portions in combination with sense electrodes are sensed by the sense circuit by applying a potential to the sense electrodes and measuring charging characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.