Optical coupling in touch-sensing systems using diffusively transmitting element
US9857916B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 2013 |
| Grant date | Jan 2, 2018 |
| Priority date | — |
| Expiry date | Sep 30, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04109
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch-sensitive apparatus operates by light frustration and comprises a light transmissive panel with a front surface and a rear surface. Light emitters and light detectors optically face the rear surface along a perimeter of a touch-sensitive region on the panel. At least one non-imaging, diffusively transmitting optical element is arranged on the rear surface along the perimeter of the touch-sensitive region. The light emitters are arranged to emit a respective beam of light onto the non-imaging optical element so as to generate, by diffuse transmission, propagating light that propagates by total internal reflection inside the panel across the touch-sensitive region, and the light detectors are arranged to receive detection light generated, by diffuse transmission, as the propagating light impinges on the non-imaging optical element, so as to define a grid of propagation paths across the touch-sensitive region between pairs of light emitters and light detectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.