Acoustic wave touch detection circuit and method
US7265746B2 · kind B2 · utility
32Cited by
20References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2003 |
| Grant date | Sep 4, 2007 |
| Priority date | — |
| Expiry date | Mar 11, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/96011
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit for an acoustic wave switch or sensor having a resonant acoustic wave cavity detects a touch or sensed event using a time domain approach. The circuit includes a controller that drives an acoustic wave transducer to generate a resonant acoustic wave in the acoustic wave cavity during a first portion of a sampling cycle. In a second portion of the sampling cycle, the controller monitors the time that it takes for the acoustic wave signal from the transducer to decay to a predetermined level. Based on the decay time, the controller detects a sensed event, such as a touch on the acoustic wave switch/sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.