Method and apparatus for determining contact areas within a touch sensing region
US8519980B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 2010 |
| Grant date | Aug 27, 2013 |
| Priority date | — |
| Expiry date | Aug 8, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04104
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The invention determines the location of multiple, simultaneous contact areas on a touch sensing region using a light source and several light detectors. The invention is robust against occlusion and many of the ambiguities that can arise with multiple, simultaneous contact areas. Generally, the light source is positioned such that light emanating the light source passes across the touch sensing region, and the light detector are positioned such that at least a portion of the light source is within the field of view of each light detector. The contact areas are determined by identifying positive fans corresponding to an angular sector of the field of view of a light detector in which the view of the light source is occluded and negative fans corresponding to an angular sector of the field of view of a light detector in which the view of the light source is not occluded. The positive fans and negative fans are then additively and subtractively combined, respectively, to determine the contact areas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.