Fast multi-touch post processing
US9158411B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 1, 2013 |
| Grant date | Oct 13, 2015 |
| Priority date | — |
| Expiry date | Apr 9, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2203/04112
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a low-latency touch-sensitive device, post-processing is performed to convert a two-dimensional map of signal strengths into usable touch events. Four such post-processing procedures are disclosed: field flattening, touch point detection, interpolation and touch point matching between frames. The field flattening procedure subtracts an offset to remove crosstalk between rows and columns, and compensates for differences in amplitude between particular row/column combinations due to attenuation. The touch point detection procedure computes coarse touch points by finding local maxima in the flattened signal. The interpolation procedure computes fine touch points from the coarse touch points. In an embodiment, such interpolation is done by fitting the coarse touch points to a paraboloid. The frame matching procedure matches the calculated touch points to each other across frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.