Touch detection method and touch detection apparatus having built up linearity
US9448664B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 27, 2013 |
| Grant date | Sep 20, 2016 |
| Priority date | — |
| Expiry date | Feb 27, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/04164
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A touch detection apparatus includes a sensor pad to output a signal based on a touch state in response to an alternating voltage in a floating state after being charged, an operational amplifier including a first input connected to an output of the sensor pad and a second input to receive the alternating voltage, a level shift detection unit to detect a touch signal based on a difference between a voltage variation at an output end of the operational amplifier caused by the alternating voltage and a voltage variation at the output end of the operational amplifier caused by occurrence of a touch, and a switching unit including a first switch to control an electric potential between a first input and the output end of the operational amplifier and a second switch to connect or not the sensor pad and the first input of the operational amplifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.