TOUCH PANEL AND DISPLAY DEVICE WITH DIFFERENTIAL DATA INPUT

• US 20130050130A1
• Filed: 08/22/2011
• Published: 02/28/2013
• Est. Priority Date: 08/22/2011
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: BROWN, Christopher James
• Application Number:
  US13/214,346
• Publication Number:
  US 20130050130A1
• Time in Patent Office: Days
• US Class Current: 345/174
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A touch panel and display device is provided which includes a projected capacitance type touch panel; and a display, the display including a plurality of pixels each including a pixel circuit having differential data inputs.

Claims

1. A touch panel and display device, comprising:

a projected capacitance type touch panel; and

a display, the display including a plurality of pixels each including a pixel circuit having differential data inputs.

2. The touch panel and display device according to claim 1, wherein the display includes a data driver circuit configured to provide pairs of differential voltage signals to the differential data inputs of each of the pixel circuits.

3. The touch panel and display device according to claim 2, wherein the differential voltage signals in each pair have a sum which is a constant value and a difference representative of image data to be presented by the pixel circuit which receives the pair of differential voltage signals.

4. The touch panel and display device according to claim 2, wherein a polarity of the pairs of differential voltage signals provided to the pixel circuits is periodically reversed.

5. The touch panel and display device according to claim 1, wherein the touch panel includes:

a touch panel electrode array including an array of drive electrodes and an array of sense electrodes;

a drive circuit which supplies a voltage excitation signal to the drive electrodes; and

a sense circuit configured to sense coupling capacitance between the sense electrodes and the drive electrodes based on the voltage excitation signal.

6. The touch panel and display device according to claim 5, wherein the plurality of pixels are arranged in a matrix spatially aligned with the touch panel electrode array.

7. The touch panel and display device according to claim 1, wherein each pixel circuit is arranged so as to have a first half and a second half which are symmetrical and which each include a corresponding one of the differential data inputs.

8. The touch panel and display device according to claim 1,

wherein each pixel circuit includes:

a first switch transistor;

a second switch transistor;

a first storage capacitor;

a second storage capacitor;

a first capacitive liquid crystal element; and

a second capacitive liquid crystal element;

wherein a drain terminal of the first switch transistor is connected to a first terminal of the first storage capacitor and a first terminal of the first liquid crystal element;

a drain terminal of the second switch transistor is connected to a first terminal of the second storage capacitor and a first terminal of the second liquid crystal element;

a second terminal of the first liquid crystal element and a second terminal of the second liquid crystal element are connected together;

wherein a gate addressing line is connected to gate terminals of both the first switch transistor and second switch transistor;

a first source addressing line is connected to a source terminal of the first switch transistor and a second source addressing line is connected to a source terminal of the second switch transistor; and

the second terminal of the first storage capacitor and the second terminal of the second storage capacitor are connected to a common electrode line; and

wherein the first terminal of the first liquid crystal element and the first terminal of the second liquid crystal element respectively represent the differential data inputs of the pixel circuit.

9. The touch panel and display device according to claim 5, wherein the touch panel electrode array is formed on substrate and the plurality of pixels are formed on a different substrate.

10. The touch panel and display device according to claim 1, wherein the plurality of pixels include in-plane switching type liquid crystal materials.

11. The touch panel and display device according to claim 10, wherein each pixel circuit includes differential data inputs represented by inter-digitated first and second electrodes.

12. The touch panel and display device according to claim 5, wherein the touch panel electrode array is formed on a top surface of a counter substrate included in the display.

13. The touch panel and display device according to claim 1,

wherein each pixel circuit includes:

a first switch transistor;

a second switch transistor;

a first capacitive liquid crystal element;

a second capacitive liquid crystal element; and

a storage capacitor;

wherein a drain terminal of the first switch transistor is connected to a first terminal of the first liquid crystal element and a first terminal of the storage capacitor;

a drain terminal of the second switch transistor is connected to a first terminal of the second liquid crystal element and a second terminal of the storage capacitor;

a second terminal of the first liquid crystal element and a second terminal of the second liquid crystal element are connected together such that a series combination of the first and second liquid crystal elements is in parallel with the storage capacitor;

wherein a gate addressing line is connected to gate terminals of both the first switch transistor and second switch transistor;

a first source addressing line is connected to a source terminal of the first switch transistor and a second source addressing line is connected to a source terminal of the second switch transistor; and

wherein the first terminal of the first liquid crystal element and the first terminal of the second liquid crystal element respectively represent the differential data inputs of the pixel circuit.

14. The touch panel and display device according to claim 1, wherein the plurality of pixels are arranged in a matrix, adjacent pixels within a given row of the matrix share a source line, and two gate lines are provided for each row of pixels in the display.

15. The touch panel and display device according to claim 1, comprising:

a first substrate on which display electronic layers are formed, the display electronic layers including thin film transistors which are part of the pixel circuits; and

a second substrate on which touch panel electronic layers are formed, the touch panel electronic layers including a touch panel electrode array having sense electrodes and drive electrodes which are part of the projected capacitance type touch panel,

wherein the first substrate and the second substrate are arranged opposite each other with the display electronic layers and the touch panel electronic layers facing one another and separated by a layer of liquid crystal material.

16. The touch panel and display device according to claim 15, wherein the sense electrodes and drive electrodes function both as part of the touch panel, and as part of the display as counter electrodes.

17. The touch panel and display device according to claim 16, wherein the sense electrodes and the drive electrodes are patterned in a single layer.

18. The touch panel and display device according to claim 15, wherein the sense electrodes and the drive electrodes are aligned with the plurality of pixels.

19. The touch panel and display device according to claim 15, wherein the sense electrodes and drive electrodes in the touch panel electronic layers are formed by groups of pixel counter electrode segments serving as pixel counter electrodes in relation to the display electronic layers formed on the first substrate.

20. The touch panel and display device according to claim 19, wherein the pixel counter electrode segments in a given group are patterned as individual segments.

21. The touch panel and display device according to claim 19, wherein the pixel counter electrode segments in a given group are patterned to form one continuous area.

22. The touch panel and display device according to claim 15, wherein electrical connections to the touch panel electrode array are made to the first substrate, and the pixel circuits include switch transistors operative in a sensing function in combination with the touch panel electrode array.

23. The touch panel and display device according to claim 22, wherein a source line operative in the display to provide image data to a pixel circuit during a display period is operative to provide sensor data from the touch panel electrode array during a sensing period.

24. The touch panel and display device according to claim 22, wherein each pixel circuit includes:

a first switch transistor;

a second switch transistor;

a first capacitive liquid crystal element;

a second capacitive liquid crystal element;

a first storage capacitor;

a second storage capacitor; and

a sensor switch transistor;

wherein a drain terminal of the first switch transistor is connected to a first terminal of the first liquid crystal element and a first terminal of the first storage capacitor;

a drain terminal of the second switch transistor is connected to a first terminal of the second liquid crystal element and a first terminal of the second storage capacitor;

a second terminal of the first liquid crystal element and a second terminal of the second liquid crystal element are connected together at a pixel common electrode node; and

a second terminal of the first storage capacitor and a second terminal of the second storage capacitor are connected together at a sensing node; and

wherein the sensing node is connected to a drain terminal of the sensor switch transistor, a source terminal of which is connected to either of two source addressing lines and a gate terminal of which is connected to a sensor select addressing line.

25. The touch panel and display device according to claim 22, wherein each pixel circuit includes:

a first switch transistor;

a second switch transistor;

a first capacitive liquid crystal element;

a second capacitive liquid crystal element;

a first storage capacitor;

a second storage capacitor;

a sensor amplifier transistor; and

a sensor select transistor;

wherein a drain terminal of the first switch transistor is connected to a first terminal of the first liquid crystal element and a first terminal of the first storage capacitor;

a drain terminal of the second switch transistor is connected to a first terminal of the second liquid crystal element and a first terminal of the second storage capacitor;

a second terminal of the first liquid crystal element and a second terminal of the second liquid crystal element are connected together at a pixel common electrode node; and

a second terminal of the first storage capacitor and a second terminal of the second storage capacitor are connected together at a sensing node;

wherein the sensing node is connected to a gate terminal of the sensor amplifier transistor, a source terminal of which is connected to a drain terminal of the sensor select transistor, and a drain terminal of which is connected to a sensor select addressing line; and

wherein a gate terminal of the sensor select transistor is connected to the sensor select addressing line and a source terminal of the sensor select transistor is connected to either of two source addressing lines.