Tough control arrangement for graphics display apparatus
US4700176A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 5, 1985 |
| Grant date | Oct 13, 1987 |
| Priority date | — |
| Expiry date | Feb 5, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/0436
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A system for recognizing touch positions along a coordinate axis on a surface associated with a touch control apparatus comprises a substrate having a surface capable of propagating surface acoustic waves and is so characterized that a touch on that surface causes a partial absorption of energy of a surface wave passing through the region of touch. An input surface wave transducer coupled to the surface launches a burst of surface waves on the surface in a first direction parallel to the axis. An output surface wave transducer coupled to the surface receives the burst of surface waves. A first surface wave reflecting arrangement derives wave components from the launched wave and reflects them across the surface to a second wave reflecting arrangement that redirects the reflected components in a direction opposited the first direction. The reflecting arrangements collectively cause wave components to traverse the surface orthogonally to the coordinate axis along a progression of paths associated with different positions along that axis. Circuitry coupled to the input and output trnasducers initiate surface wave bursts across the substrate surface as well as dsetect touch-induced dam…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.