Ultrasonic water-agnostic touch detection sensor
US11422113B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2020 |
| Grant date | Aug 23, 2022 |
| Priority date | — |
| Expiry date | Dec 8, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/106
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic touch sensing system that uses both compressional and shear waves for touch and water detection is disclosed. When no touch or water is present, less shear and compressional wave energy is absorbed, so both shear and compressional wave reflections do not have significant amplitude decreases. When a finger is in contact with the sensing plate, both shear and compressional wave energy is absorbed, so both shear and compressional wave reflections have significant amplitude decreases. When water is in contact with the sensing plate, compressional energy is absorbed but little or no shear wave energy is absorbed, so while compressional wave reflections have significant amplitude decreases, shear wave reflections do not. From these amplitudes, a determination can be made as to whether no touch is present on the sensing plate, whether a touch is present on the sensing plate, or whether water is present on the sensing plate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.