In-cell capacitive touch panel
US8441459B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2009 |
| Grant date | May 14, 2013 |
| Priority date | — |
| Expiry date | Aug 13, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F3/044
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An in-cell capacitive touch panel is disclosed. The present invention utilizes a sensing unit that comprises a sensing liquid crystal capacitor and three transistors to detect touch events. A first transistor is connected to a first gate line and the sensing liquid crystal capacitor and controlled by the first gate line to charge the sensing liquid crystal capacitor. A second transistor together with a third transistor functions as a capacitance-current converter. The second transistor generates an output current according to the voltage of a first electrode of the sensing liquid crystal capacitor. A second gate line controls the third transistor to transfer the output current through a readout line to a readout unit that determines the touch positions. Thus, the in-cell capacitive touch panel of the present invention can use a simple-structure readout circuit to achieve superior readout accuracy and is adaptive to various sizes of touch panels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.