Touch sense using time domain reflectometry
US8599155B2 · kind B2 · utility
2Cited by
5References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2010 |
| Grant date | Dec 3, 2013 |
| Priority date | — |
| Expiry date | Jan 5, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/04166
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch panel or screen has a serpentine transmission line fabricated on a substrate, e.g., printed circuit board, LCD, plasma or LED screen, etc., and has a constant impedance. A touch to the touch panel will cause a change of impedance of the transmission line at the location of the touch. Time domain reflectometry (TDR) is used for determining the location of the change of impedance of the transmission line by accurately measuring the return pulse time at the source of the initial pulse, and then converting the return pulse time to X-Y coordinates of the touch panel or screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.