Device and method for determining touch position on sensing area of capacitive touch panel
US7808490B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 29, 2007 |
| Grant date | Oct 5, 2010 |
| Priority date | — |
| Expiry date | May 7, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0444
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Described is a device and a method for determining a touch position on a sensing area of a capacitive touch panel. In the device and method, an alternating current (AC) scan signal having a frequency and a current value is supplied to each of four corners of the capacitive touch panel. Next, the frequencies of the AC scan signals are each rapidly switched among a group of specific frequencies. The current values of the AC scan signals detected. In response, a group of selected frequencies is selected according to a noise filtering procedure from the group of specific frequencies based on the current values. Final current values are obtained by calculating the current values of the AC scan signals of the group of selected frequencies. Finally, the touch position on the capacitive touch panel is determined based on the final current values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.