Paintbrush stylus for capacitive touch sensor pad
US5488204A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 1994 |
| Grant date | Jan 30, 1996 |
| Priority date | — |
| Expiry date | Oct 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/20
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A proximity sensor system includes a touch-sensor pad with a sensor matrix array having a characteristic capacitance on horizontal and vertical conductors connected to sensor pads. The capacitance changes as a function of the proximity of an object or objects to the sensor matrix. The change in capacitance of each node in both the X and Y directions of the matrix due to the approach of an object is converted to a set of voltages in the X and Y directions. These voltages are processed by circuitry to develop electrical signals representative of the centroid of the profile of the object, i.e, its position in the X and Y dimensions. Noise reduction and background level setting techniques inherently available in the architecture are employed. A conductive paintbrush-type stylus is used to produce paint-like strokes on a display associated with the touch-sensor pad.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.