Circuit for detecting touch point location on a touch panel, touch panel and display device

Patent metadata

Field	Value
Publication number	US-9542900-B2
Application number	US-201314351699-A
Country	US
Kind code	B2
Filing date	May 7, 2013
Priority date	Mar 4, 2013
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

A circuit for detecting a touch point location on a touch panel, a touch panel and a display device for improving the precision of touch point location on the touch panel are disclosed. The circuit for detecting a touch point location on a touch panel comprises: a sensing sub-circuit, an amplification sub-circuit connected to the sensing sub-circuit, an output sub-circuit connected to the amplification sub-circuit, a detection sub-circuit connected to the output sub-circuit, and a first touch drive electrode line. The sensing sub-circuit comprising a fixed capacitor, a variable capacitor, and a first switch transistor, wherein a gate terminal and a source terminal of the first switch transistor are connected to the first touch drive electrode line, a drain terminal of the first switch transistor is connected to a terminal of the fixed capacitor, a terminal of the variable capacitor is connected to the other terminal of the fixed capacitor, the other terminal of the variable capacitor is connected to a reference voltage, and the amplification sub-circuit is connected to the terminal of the fixed capacitor that is connected to the variable capacitor.

First claim

What is claimed is:

1. A circuit for detecting a touch point location on a touch panel, comprising: a sensing sub-circuit, an amplification sub-circuit connected to the sensing sub-circuit, an output sub-circuit connected to the amplification sub-circuit, a detection sub-circuit connected to the output sub-circuit, and a first touch drive electrode line,
wherein the sensing sub-circuit comprises a fixed capacitor, a variable capacitor, and a first switch transistor; and
wherein a gate terminal and a source terminal of the first switch transistor are connected to the first touch drive electrode line, a drain terminal of the first switch transistor is connected to a terminal of the fixed capacitor, a terminal of the variable capacitor is connected to the other terminal of the fixed capacitor, the other terminal of the variable capacitor is connected to a reference voltage, and the amplification sub-circuit is connected to the terminal of the fixed capacitor that is connected to the variable capacitor,
wherein the amplification sub-circuit comprises a second switch transistor, a third switch transistor, and a amplification transistor, a gate terminal of the second switch transistor being connected to the terminal of the fixed capacitor that is connected to the first switch transistor, a gate terminal of the third switch transistor being connected to the terminal of the fixed capacitor that is connected to the variable capacitor, a drain terminal of the second switch transistor being connected to a source terminal of the third switch transistor, a source terminal of the second switch transistor being connected to a high level voltage source, a drain terminal of the third switch transistor being connected to a low level voltage source, a gate terminal of the amplification transistor being connected to the drain terminal of the second switch terminal, a drain terminal of the amplification transistor being connected to the output sub-circuit, and a source terminal of the amplification transistor being connected to the high level voltage source.

2. The circuit of claim 1 , wherein the amplification sub-circuit comprises an amplification transistor, a gate terminal of the amplification transistor being connected to the terminal of the fixed capacitor that is connected to the variable capacitor, a drain terminal of the amplification transistor being connected to the output sub-circuit, and a source terminal of the amplification transistor being connected to the high level voltage source.

3. The circuit of claim 2 , further comprising a second touch drive electrode line, wherein the output sub-circuit comprises a fourth switch transistor, a gate terminal of the fourth switch transistor being connected to the second touch drive electrode line, a source terminal of the fourth switch transistor being connected to the drain terminal of the amplification transistor, and a drain terminal of the fourth switch transistor being connected to the detection sub-circuit.

4. The circuit of claim 3 , wherein the detection sub-circuit comprises an amplifier, a capacitor spanning across an inverse input terminal and an output terminal of the amplifier, and a switch spanning across the inverse input terminal and the output terminal of the amplifier.

5. The circuit of claim 2 , wherein the detection sub-circuit comprises an amplifier, a capacitor spanning across an inverse input terminal and an output terminal of the amplifier, and a switch spanning across the inverse input terminal and the output terminal of the amplifier.

6. The circuit of claim 1 , further comprising a second touch drive electrode line, wherein the output sub-circuit comprises a fourth switch transistor, a gate terminal of the fourth switch transistor being connected to the second touch drive electrode line, a source terminal of the fourth switch transistor being connected to the drain terminal of the amplification transistor, and a drain terminal of the fourth switch transistor being connected to the detection sub-circuit.

7. The circuit of claim 6 , wherein the detection sub-circuit comprises an amplifier, a capacitor spanning across an inverse input terminal and an output terminal of the amplifier, and a switch spanning across the inverse input terminal and the output terminal of the amplifier.

8. The circuit of claim 6 , wherein the first touch drive electrode line and the second touch electrode line are gate lines.

9. The circuit of claim 6 , wherein the first switch transistor, the second switch transistor, the third switch transistor, the fourth switch transistor and the amplification transistor are N-type transistors.

10. The circuit of claim 1 , wherein the detection sub-circuit comprises an amplifier, a capacitor spanning across an inverse input terminal and an output terminal of the amplifier, and a switch spanning across the inverse input terminal and the output terminal of the amplifier.

11. The circuit of claim 10 , wherein the first touch drive electrode line and the second touch electrode line are gate lines.

12. The circuit of claim 10 , wherein the first switch transistor, the second switch transistor, the third switch transistor, the fourth switch transistor and the amplification transistor are N-type transistors.

13. The circuit of claim 1 , wherein the detection sub-circuit comprises an amplifier, a capacitor spanning across an inverse input terminal and an output terminal of the amplifier, and a switch spanning across the inverse input terminal and the output terminal of the amplifier.

14. A touch panel comprising a circuit for detecting a touch point location on a touch panel, the circuit comprising: a sensing sub-circuit, an amplification sub-circuit connected to the sensing sub-circuit, an output sub-circuit connected to the amplification sub-circuit, a detection sub-circuit connected to the output sub-circuit, and a first touch drive electrode line,
wherein the sensing sub-circuit comprises a fixed capacitor, a variable capacitor, and a first switch transistor; and
wherein a gate terminal and a source terminal of the first switch transistor are connected to the first touch drive electrode line, a drain terminal of the first switch transistor is connected to a terminal of the fixed capacitor, a terminal of the variable capacitor is connected to the other terminal of the fixed capacitor, the other terminal of the variable capacitor is connected to a reference voltage, and the amplification sub-circuit is connected to the terminal of the fixed capacitor that is connected to the variable capacitor,
wherein the amplification sub-circuit comprises a second switch transistor, a third switch transistor, and a amplification transistor, a gate terminal of the second switch transistor being connected to the terminal of the fixed capacitor that is connected to the first switch transistor, a gate terminal of the third switch transistor being connected to the terminal of the fixed capacitor that is connected to the variable capacitor, a drain terminal of the second switch transistor being connected to a source terminal of the third switch transistor, a source terminal of the second switch transistor being connected to a high level voltage source, a drain terminal of the third switch transistor being connected to a low level voltage source, a gate terminal of the amplification transistor being connected to the drain terminal of the second switch terminal, a drain terminal of the amplification transistor being connected to the output sub-circuit, and a source terminal of the amplification transistor being connected to the high level voltage source.

15. The touch panel of claim 14 , w

Assignees

• Boe Technology Group Co Ltd
• Hefei Boe Optoelectronics Tech

Inventors

• Hu Zuquan
• Wang Guolei
• Gu Xiaofang
• Hu Ming

Classifications

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title

• G09G3/3648 Primary

  using an active matrix (G09G3/367 - G09G3/3696 take precedence) · CPC title

• G09G2310/0289

  Details of voltage level shifters arranged for use in a driving circuit · CPC title

• G09G2310/0202

  Addressing of scan or signal lines · CPC title

• G09G2310/0272

  Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current · CPC title