Touch sensing apparatus and method of operating the same
US8581884B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 2009 |
| Grant date | Nov 12, 2013 |
| Priority date | — |
| Expiry date | Dec 12, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04109
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch sensing apparatus is controlled to determine the position of one or more objects (7) that interact with a touch surface (1). The apparatus includes a group of emitters (2) arranged to emit light to illuminate at least part of the touch surface (1), a light detector (4) arranged to receive light from the group of emitters (2), and a processing element (7). Each emitter (2) is controlled to transmit a code by way of the emitted light such that the code identifies the respective emitter (2). The codes may at least partly be transmitted concurrently. The codes may be selected such that a value of an autocorrelation of each code is significantly higher than a value of a cross-correlation between any two codes of different emitters (2). The processing element processes an output signal from the light detector (4) to separate the light received from the individual emitters (2) based on the transmitted codes, and to determine the position of the object/objects (7) based on the light received from the individual emitters (2), e.g. using triangulation or image reconstruction such as an algorithm for transmission tomography.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.