Method and apparatus for detecting a touch on a device
US9639225B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2015 |
| Grant date | May 2, 2017 |
| Priority date | — |
| Expiry date | Dec 29, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04108
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and circuitry for detecting a touch on a device is provided herein. Touch-sensing circuitry comprises two antennas coupled to two voltage-controlled oscillators (VCOs). A phase locked loop (PLL) is provided coupled to the VCOs. The PLL compares a VCO output with a frequency source (temperature controlled crystal oscillator (TCXO)), and outputs a tuning voltage (steering voltage) for the VCO that is based on the difference between the VCO frequency and the TCXO frequency. The steering voltages for each VCO are compared, and a decision is made as to whether or not a touch has been made to the antennas. If the antennas have been touched, a location of the touch is determined based on a difference in the steering voltages of the two VCOs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.