Signal processing circuit for electrostatic capacitor type touch sensor
US8619057B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jun 4, 2010 |
| Grant date | Dec 31, 2013 |
| Priority date | — |
| Expiry date | Mar 25, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0446
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention realizes certainly detecting two or more positions on a touch panel that are touched at the same time. A drive circuit selects one from X lines, and supplies an alternating drive voltage to the selected line. A multiplexer selects a first sense line and a second sense line from Y lines that extend to cross the X lines. A charge amplifier outputs an output voltage corresponding to a difference between a first capacitance between the first sense line and the X line selected by the drive circuit and a second capacitance between the second sense line and the X line selected by the drive circuit. A touch position is then detected based on the output voltage of the charge amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.