Back to results
US 8,896,565 B2Granted
In-cell touch sensing panel
AssigneeAu Optronics Corporation
InventorTzu-Wei Liu
Life of this patent
Estimating the term…
Abstract
The present invention in one aspect relates to an in-cell touch panel. In one embodiment, the in-cell touch panel includes at least one touch sensing device configured such that when a touch occurs, it responsively generates a first sensing signal and a second sensing signal that is different from the first sensing signal, and at least one reverse amplification circuit electrically coupled to the at least one touch sensing device for amplifying the difference between the first and second sensing signals.
Claims8
An in-cell touch panel, comprising:
- (a) a plurality of pixels spatially arranged in a matrix;
- (b) a plurality of scanning lines, each scanning line electrically coupled to a corresponding pixel row of the pixel matrix;
- (c) at least one touch sensing device electrically coupled between two neighboring scanning lines and associated with a pixel therebetween;
- and
- (d) at least one reverse amplification circuit comprising:
- (i) a first thin-film transistor (TFT) having a gate electrically coupled to the at least one touch sensing device, a source and a drain configured to receive a first bias voltage, Vdh;
- (ii) a second TFT having a gate electrically coupled to the at least one touch sensing device, a source configured to receive a second bias voltage, Vdl, and a drain electrically coupled to the source of the first TFT;
- (iii) an amplification TFT having a gate electrically coupled to both the source of the first TFT and the drain of the second TFT, a source and a drain configured to receive a power supply voltage, VDD;
- and
- (iv) a selection TFT having a gate electrically coupled to one of the two neighboring scanning lines, a source electrically coupled to a signal readout line and a drain electrically coupled to the source of the amplification TFT,
- wherein the at least one touch sensing device is configured such that when a touch occurs, it causes a gate voltage level of one of the first TFT and the second TFT to increase and the gate voltage level of the other to decrease;
- and wherein Vdh>Vdl, and wherein the at least one touch sensing device is characterized with a first charge sharing circuit and a second charge sharing circuit, each charge sharing circuit comprising:
- a first transistor, T1, having a gate electrically coupled to the first one of the two neighboring scanning lines, a source configured to receive one of the first and second bias voltages Vdh and Vdl, and a drain electrically coupled to a first node, respectively;
- a second transistor, T2, having a gate electrically coupled to the second one of the two neighboring scanning lines, a source electrically coupled to the first node, and a drain electrically coupled to a second node, respectively;
- a third transistor, T3, having a gate electrically coupled to the first one of the two neighboring scanning lines, a source electrically coupled to the second node, and a drain configured to receive the other of the first and second bias voltages Vdh and Vdl, respectively;
- a touch sensing capacitor, Clc, electrically coupled between the first node and a common voltage, Vcom;
- and
- a reference capacitor Cref electrically coupled between the second node and a reference voltage, VSS.
15 more elements
Dependencies are inferred from the claim text.