Method and apparatus for improving dynamic range of a touchscreen controller
US8830207B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 2013 |
| Grant date | Sep 9, 2014 |
| Priority date | — |
| Expiry date | Nov 4, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/96062
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touchscreen system for increasing the dynamic range of the system comprising a touchscreen coupled to an offset cancellation element and a capacitance measuring element. The offset cancellation element is configured to be dynamically changed in capacitance such that it offsets parasitic and sensor capacitances of the touchscreen sensors thereby leaving only touch event capacitance to be measured by the measuring element. The offset cancellation element is able to adjust to the initial unwanted capacitances of each sensor as well as dynamically adjust to changes in the unwanted capacitance due to the environment. In some embodiments, the offset cancellation element is a capacitance digital-to-analog converter that is controlled by a controller for offsetting the unwanted capacitance. As a result, the touchscreen system is able to utilize a small integrating capacitor thereby lowering cost and improving the dynamic range of the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.