Self-capacitor sensing for capacitive touch panels
US11914831B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 2023 |
| Grant date | Feb 27, 2024 |
| Priority date | — |
| Expiry date | Feb 5, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/04166
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Techniques are described for discrete-time self-capacitor sensing in a touch panel. The self-capacitor manifests a detectably different capacitance based on presence or absence of a local touch event on the touch panel. In a first time phase, embodiments charge a self-capacitor and initialize a ramp bias generator. In a second time phase, embodiments discharge the self-capacitor with a ramp-controlled current source that is biased by the ramp bias generator to produce a discharge current that transitions from high at the beginning of the second time phase to low at the end of the second time phase. By the end of the second phase, the remaining charge in the self-capacitor depends on presence or absence of a local touch event. Some embodiments convert the remaining charge to an amplified sense output for readout.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.