DISPLAY DEVICE INCLUDING INTEGRATED TOUCH PANEL AND METHOD OF DRIVING THE SAME

• US 20140132525A1
• Filed: 04/02/2013
• Published: 05/15/2014
• Est. Priority Date: 11/13/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: PYO, Seung-Eun, LEE, Jeong-Seop
• Granted Patent: US 9,317,152 B2
• Time in Patent Office: Days
• US Class Current: 345/173
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0418 for error correction or compensation, e.g. based on parallax, calibration or alignment
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

A method of driving a display device including an integrated touch panel, the method comprising: applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel; determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages; comparing the plurality of noise levels to a threshold level; and selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level; and applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

Claims

1. A method of driving a display device including an integrated touch panel, the method comprising:

applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel;

determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages;

comparing the plurality of noise levels to a threshold level; and

selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level; and

applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

2. The method of claim 1, wherein the plurality of sampling voltages are selected from a range of 0.01 VDDT_threshold to 1 VDDT_threshold, wherein VDDT_threshold is the threshold level to sense a touch of the display device.

3. The method of claim 1, wherein the plurality of noise levels are determined during a period of time from when the integrated touch panel is turned on.

4. The method of claim 3, wherein the period of time corresponds to two frames of the integrated touch panel from when the integrated touch panel is turned on.

5. The method of claim 1, wherein the plurality of noise levels are determined within a period of time from when the integrated touch panel is turned on to when a touch input is received.

6. The method of claim 1, wherein selecting the sampling voltage comprises:

determining that all the plurality of noise levels are greater than the threshold level;

determining a sampling voltage associated with a minimum noise level from amongst the plurality of noise levels; and

selecting the determined sampling voltage associated with the minimum noise level as the touch driving voltage.

7. The method of claim 1, wherein selecting the sampling voltage comprises:

determining one of the sampling voltages associated with a determined noise level that is less than the threshold level; and

selecting the determined sampling voltage as the touch driving voltage.

8. The method of claim 1, wherein applying the touch driving voltage comprises:

applying the touch driving voltage to the plurality of electrodes while the integrated touch panel is driven in a time sharing method during a touch driving mode, wherein during the time sharing method, the integrated touch panel is driven in both a display driving mode and the touch driving mode during a period of the integrated touch panel.

9. The method of claim 1, wherein the threshold level is within a range of ¼

of a touch threshold level to ¾

of the touch threshold level, the touch threshold level signifying whether a touch input is received at the integrated touch panel.

10. The method of claim 1, wherein the threshold level is ½

of a touch threshold level, the touch threshold level signifying whether a touch input is received at the integrated touch panel.

11. A method of driving a display device including an integrated touch panel, the method comprising:

applying a plurality of sampling voltages to a plurality of electrodes of the integrated touch panel;

determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages;

comparing the plurality of noise levels to a threshold level;

responsive to determining that all the plurality of noise levels are greater than the threshold level;

determining a sampling voltage associated with a minimum noise level from amongst the plurality of noise levels; and

selecting the determined sampling voltage associated with the minimum noise level as the touch driving voltage;

responsive to determining one of the sampling voltages that is associated with a determined noise level that is less than the threshold level;

selecting the determined sampling voltage as the touch driving voltage;

and

applying the selected sampling voltage as the touch driving voltage to the plurality of electrodes.

12. A display device comprising:

an integrated touch panel having a plurality of electrodes; and

a touch integrated circuit (IC), comprising;

a switching unit for applying a plurality of sampling voltages to the plurality of electrodes of the integrated touch panel;

a comparing unit for;

determining a plurality of noise levels each of which is associated with a corresponding one of the plurality of sampling voltages;

comparing the plurality of noise levels to a threshold level; and

selecting a sampling voltage from the plurality of sampling voltages to use as a touch driving voltage based on the comparison of the plurality of noise levels to the threshold level;

and

a touch sensing unit for applying the touch driving voltage to the plurality of electrodes.

13. The display device of claim 12, wherein the plurality of sampling voltages are selected from a range of 0.01 VDDT_threshold to 1 VDDT_threshold, wherein VDDT_threshold is the threshold level to sense a touch of the display device.

14. The display device of claim 12, wherein the comparing unit determines the plurality of noise levels during a period of time from when the integrated touch panel is turned on.

15. The display device of claim 14, wherein the period of time corresponds to two frames of the integrated touch panel from when the integrated touch panel is turned on.

16. The display device of claim 12, wherein the comparing unit determines the plurality of noise levels within a period of time from when the integrated touch panel is turned on to receiving a touch input.

17. The display device of claim 12, wherein the comparing unit selects the sampling voltage by:

determining that all the plurality of noise levels are greater than the threshold level;

determining a sampling voltage associated with a minimum noise level from amongst the plurality of noise levels; and

selecting the determined sampling voltage associated with the minimum noise level as the touch driving voltage.

18. The display device of claim 12, wherein the comparing unit selects the sampling voltage by:

determining one of the sampling voltages associated with a noise level that is less than the threshold level; and

selecting the determined sampling voltage as the touch driving voltage.

19. The display device of claim 12, wherein the touch sensing unit applies the touch driving voltage while the integrated touch panel is driven in a time sharing method during a touch driving mode, wherein during the time sharing method, the integrated touch panel is driven in both a display driving mode and the touch driving mode during a period of the integrated touch panel.

20. The display device of claim 12, wherein the threshold level is within a range of ¼

of a touch threshold level to ¾

of the touch threshold level or the threshold level is ½

of the touch threshold level, the touch threshold level signifying whether a user has touched the integrated touch panel.