Signal processing circuit for a capacitive touch panel capable of switching between a differential-input sensor circuit and a single-input sensor circuit
US8441462B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Nov 17, 2010 |
| Grant date | May 14, 2013 |
| Priority date | — |
| Expiry date | Jul 9, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49105
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
This invention offers a signal processing circuit of an electrostatic capacity type touch panel which is capable of switching between a differential input mode and a single input mode and has an extended adjustable range of an offset in the single input mode. The signal processing circuit of this invention includes a first sensor circuit of a differential input type, a second sensor circuit of a single input type, a third and fourth electrostatic capacitors that are variable capacitors for calibration to adjust the offset in an output voltage of the first sensor circuit, and a switching control circuit to control so as to put in operation one of the first and second sensor circuits. The switching control circuit also controls so that the third and fourth electrostatic capacitors for calibration are connected in parallel to each other when the second sensor circuit is put in operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.