Method and apparatus for sensing
US7986153B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 2009 |
| Grant date | Jul 26, 2011 |
| Priority date | — |
| Expiry date | Dec 10, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/9622
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for sensing a change in capacitance of a sensing electrode to a system ground, such as that which may be used to form a touch sensor, with the sensing electrode forming touch sensitive surface is arranged to include a sleep mode of operation. The apparatus includes a sample capacitor having a first terminal coupled to the sensing electrode, and a second terminal coupled to a voltage measurement circuit. The voltage measurement circuit is arranged in operation to determine a voltage at the second terminal of the sample capacitor. A voltage biasing arrangement is arranged under the control of a controller to apply a biasing voltage or the system ground to the first terminal or the second terminal of the sample capacitor in accordance with a measurement cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.