Touch sensing method and apparatus
US5920309A · kind A · utility
387Cited by
13References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1996 |
| Grant date | Jul 6, 1999 |
| Priority date | — |
| Expiry date | Jan 4, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0441
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for sensing the simultaneous proximity of one or more fingers or other appropriate objects to a capacitive touch sensor. A modulator/demodulator pair drive and sense either a single trace or a pair of traces. In a dual trace embodiment, differentially sensed signals are then peak detected converted from voltage to current. The output signal is then calibrated to adjust for trace variations, followed by appropriate gain and level shifting, and analog-to-digital conversion for use as the input to a microcontroller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.