Combined capacitive and piezoelectric sensing in a human machine interface
US11775120B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 2021 |
| Grant date | Oct 3, 2023 |
| Priority date | — |
| Expiry date | Oct 20, 2041 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04106
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A human machine interface (HMI) system and method of operating. The system includes capacitive measurement circuitry coupled to one or more capacitive touch elements, and piezoelectric measurement circuit including interface circuitry coupled to one or more piezoelectric touch elements. The capacitive measurement circuitry includes a gain stage configured to amplify a signal corresponding to a capacitance at the one or more capacitor input terminals by a gain level for communication to processing circuitry. Gain control circuitry is configured to increase the gain level of the gain stage of the capacitive measurement circuitry responsive to the piezoelectric measurement circuitry receiving a user input from at least one of the piezoelectric touch elements. Implementations that further include piezoelectric drive circuitry for haptic output and clearing debris from the keypad are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.