TOUCH DISPLAY AND METHOD FOR DRIVING A PLURALITY OF TOUCH DRIVING ELECTRODES OF TOUCH DISPLAY

• US 20140071360A1
• Filed: 11/15/2013
• Published: 03/13/2014
• Est. Priority Date: 03/19/2008
• Status: Active Grant

• Current Assignee: eGalax_eMPIA Technology Inc.
• Original Assignee: eGalax_eMPIA Technology Inc.
• Inventors: CHANG, CHIN-FU, YEH, SHANG-TAI
• Granted Patent: US 9,645,431 B2
• Time in Patent Office: Days
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/136218 Shield electrodes
• CPC Class Codes: G06F 2203/04104 Multi-touch detection in digitiser, i.e. details about the simultaneous detection of a plurality of touching locations, e.g. multiple fingers or pen and finger
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0416 Control or interface arrangements specially adapted for digitisers
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

A touch display provided by the present invention includes a control unit and a display. The control unit outputs driving signals to a plurality of touch driving electrodes and receives sensing signals from a plurality of touch sensing electrodes so as to detect touch or proximity of at least one external object based on the capacitive coupling between the driving and sensing electrodes. The display includes a liquid crystal layer, a pixel electrode and a common electrode, wherein the liquid crystal layer is driven by the pixel electrode and the common electrode. The common electrode includes the touch driving electrodes, and the common electrode except the touch driving electrodes are electrically coupled to a DC potential to form a shielded region.

Claims

1. A display, comprising:

a pixel electrode;

a common electrode, comprising a plurality of touch driving electrodes of a touch device, wherein the common electrode except the plurality of touch driving electrodes is coupled with a DC potential to form a shielding region; and

a liquid crystal layer, placed between the pixel electrode and the common electrode and driven by the pixel electrode and the common electrode.

2. The display of claim 1, wherein the area of the shielding region is larger than the area of the plurality of touch driving electrodes.

3. The display of claim 1, wherein the pixel electrode is integrated into a TFT (thin film transistor) layer, and the plurality of touch driving electrodes are configured horizontally and parallels a plurality of horizontal pixel lines updated by the TFT layer, wherein the driving direction of the plurality of touch driving electrodes is opposite to the updating direction of the TFT layer, wherein when at least one touch driving electrode which be driven will influence the horizontal pixel line updated by the TFT layer, driving signals of the at least one touch driving electrode is suspended until the horizontal pixel line updated by the TFT layer leaves the effect range of the at least one touch driving electrode.

4. The display of claim 1, further comprising a TFT (thin film transistor) layer, wherein the shielding region is placed between the TFT layer and a plurality of touch sensing electrodes so as to reduce EMI (ElectroMagnetic Interference) caused by the updating TFT layer, wherein the plurality of touch driving electrodes are provided with driving signals, and sensing signals are received from the plurality of the touch sensing electrodes such that touch or proximity of at least one external object is detected based on the capacitive coupling between the plurality of touch driving electrodes and the plurality of touch sensing electrodes.

5. The display of claim 1, wherein the common electrode comprises a plurality of sub electrodes which are arranged in parallel, wherein the plurality of touch driving electrodes are continuously or discretely integrated into the plurality of sub electrodes, and parallel the plurality of sub electrodes.

6. The display of claim 1, further comprising a plurality of touch sensing electrodes of the touch device, wherein each touch sensing electrode comprises a plurality of extensions, and each extension parallels the plurality of touch driving electrodes so as to enhance capacitive coupling between the touch sensing electrode and the plurality of touch driving electrodes.

7. The display of claim 1, further comprising a first polarizing layer, a black matrix layer and a first substrate on the plurality of touch driving electrodes, wherein the plurality of touch sensing electrodes are placed between two of the layers on the plurality of touch driving electrodes, or are integrated into the layers on the plurality of touch driving electrodes.

8. A touch device, comprising:

a plurality of touch driving electrodes, integrated into a common electrode of a liquid crystal layer, wherein the common electrode except the plurality of touch driving electrodes is coupled with a DC potential to form a shielding region;

a plurality of touch sensing electrodes; and

a control unit, detecting capacitive coupling between the plurality of touch driving electrodes and the plurality of touch sensing electrodes so as to execute operations of at least one external object.

9. The touch device of claim 8, wherein the area of the shielding region is larger than the area of the plurality of touch driving electrodes.

10. The touch device of claim 8, wherein each touch sensing electrode comprises a plurality of extensions, and each extension parallels the plurality of touch driving electrodes so as to enhance capacitive coupling between the touch sensing electrode and the plurality of touch driving electrodes.

11. The touch device of claim 8, wherein the plurality of touch driving electrodes are configured horizontally and parallels a plurality of horizontal pixel lines updated by a TFT (thin film transistor) layer, wherein the driving direction of the plurality of touch driving electrodes is opposite to the updating direction of the TFT layer, wherein when at least one touch driving electrode which be driven will influence the horizontal pixel line updated by the TFT layer, driving signals of the at least one touch driving electrode is suspended until the horizontal pixel line updated by the TFT layer leaves the effect range of the at least one touch driving electrode, wherein the TFT layer comprises a pixel electrode, and the pixel electrode and the common electrode drive the liquid crystal layer.

12. The touch device of claim 8, wherein the shielding region is placed between a TFT (thin film transistor) layer and the plurality of touch sensing electrodes so as to reduce EMI (ElectroMagnetic Interference) caused by the updating TFT layer.

13. The touch device of claim 8, wherein the common electrode comprises a plurality of sub electrodes which are arranged in parallel, wherein the plurality of touch driving electrodes are continuously or discretely integrated into the plurality of sub electrodes, and parallel the plurality of sub electrodes.

14. A touch display, comprising:

a control unit, providing driving signals to a plurality of touch driving electrodes and receiving sensing signals from a plurality of touch sensing electrodes so as to detect touch or proximity of at least one external object based on capacitive coupling between the plurality of touch driving electrodes and the plurality of touch sensing electrodes; and

a display, comprising a liquid crystal layer; and

a pixel electrode and a common electrode which both drive the liquid crystal layer, wherein the common electrode comprises the plurality of touch driving electrodes, and the common electrode except the plurality of touch driving electrodes is coupled with a DC potential to form a shielding region.

15. The touch display of claim 14, wherein the area of the shielding region is larger than the area of the plurality of touch driving electrodes.

16. The touch display of claim 14, wherein the pixel electrode is integrated into a TFT (thin film transistor) layer, and the plurality of touch driving electrodes are configured horizontally and parallels a plurality of horizontal pixel lines updated by the TFT layer, wherein the driving direction of the plurality of touch driving electrodes is opposite to the updating direction of the TFT layer, wherein when at least one touch driving electrode which be driven will influence the horizontal pixel line updated by the TFT layer, driving signals of the at least one touch driving electrode is suspended until the horizontal pixel line updated by the TFT layer leaves the effect range of the at least one touch driving electrode.

17. The touch display of claim 14, wherein the display further comprises a TFT (thin film transistor) layer, and the shielding region is placed between the TFT layer and a plurality of touch sensing electrodes so as to reduce EMI (ElectroMagnetic Interference) caused by the updating TFT layer

18. The touch display of claim 14, wherein the common electrode comprises a plurality of sub electrodes which are arranged in parallel, wherein the plurality of touch driving electrodes are continuously or discretely integrated into the plurality of sub electrodes, and parallel the plurality of sub electrodes.

19. The touch display of claim 14, wherein each touch sensing electrode comprises a plurality of extensions, and each extension parallels the plurality of touch driving electrodes so as to enhance capacitive coupling between the touch sensing electrode and the plurality of touch driving electrodes.

20. The touch display of claim 14, wherein the display further comprises a first polarizing layer, a black matrix layer and a first substrate on the plurality of touch driving electrodes, wherein the plurality of touch sensing electrodes are placed between two of the layers on the plurality of touch driving electrodes, or are integrated into the layers on the plurality of touch driving electrodes.

21. A common electrode, integrated into a display, and the common electrode and a pixel electrode both drive a liquid crystal layer, wherein the common electrode comprises:

a plurality of touch driving electrodes, wherein the common electrode except the plurality of touch driving electrodes is coupled with a DC potential to form a shielding region;

wherein the plurality of touch driving electrodes are provided with driving signals, and sensing signals are received from the plurality of the touch sensing electrodes such that touch or proximity of at least one external object is detected based on the capacitive coupling between the plurality of touch driving electrodes and the plurality of touch sensing electrodes.

22. A method for driving a plurality of touch driving electrodes of a touch display, comprising:

simultaneously providing driving signals to at least one touch driving electrode to detect mutual capacitances while the display updates one or more horizontal pixel lines.

23. The method of claim 22, wherein the driving direction of the plurality of touch driving electrodes is opposite to the updating direction of the horizontal pixel lines of the display.

24. The method of claim 22, further comprising:

determining if at least one horizontal pixel line, which is updating, is inside an effect range of at least one touch driving electrode, which is driven;

continuously driving the at least one touch driving electrode while the at least one horizontal pixel line, which is updating, is outside the effect range;

suspending driving signals of the at least one touch driving electrode while the at least one horizontal pixel line, which is updating, is inside the effect range; and

driving the at least one touch driving electrode while updating the at least one horizontal pixel line which is outside the effect range.