Acoustic touch position sensor using higher order horizontally polarized shear wave propagation
US5591945A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1995 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Apr 19, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S367/907
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An acoustic touch position sensor having a transducer which imparts a wave, propagating along a first axis. A reflective array disposed along the first axis which reflects the wave as a set of waves having a horizontally polarized component and a non-uniform volumetric energy density along an axis normal to said surface, traveling along a different axis into the touch surface region of the substrate. The waves are partially absorbed, attenuated or perturbed by an object touching the substrate, to create a modified waveform having characteristics indicative of the axial displacement and/or contact condition of the object with the substrate. The wave perturbation is detected by collecting the set of waves with a reflective array, which redirects the wave energy to a receiving transducer. The transducers preferably produce and are responsive to Rayleigh type waves, with the reflective arrays mode-converting acoustic wave energy between higher order horizontally polarized shear waves and Rayleigh type waves.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.