Display device with integrated touch screen and method for driving the same

• US 9,910,549 B2
• Filed: 12/14/2015
• Issued: 03/06/2018
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, JungHan, Kim, HongChul, Kim, SungChul, Lee, JeongSeop, Pyo, SeungEun
• Primary Examiner(s): Ahn, Sejoon
• Application Number:
  US14/968,681
• Publication Number:
  US 20160098126A1
• Time in Patent Office: 813 Days
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04166 Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes

Abstract

Discussed are a display device with an integrated touch screen and a method of operating the same. The display device according to an embodiment includes a display panel including a plurality of pixel electrodes; a touch screen including m number of electrodes which are formed to overlap with the plurality of pixel electrodes, wherein m is a multiple of n, and n is an integer equal to or greater than two, and wherein the m electrodes are divided into n number of electrode groups; a touch driver configured to generate a touch scan signal and to supply the generated touch scan signal to a display driver; and the display driver configured to apply a common voltage or the touch scan signal to one or more of the m electrodes depending on a driving mode of the display device.

Claims

1. A driver circuit for driving a self-capacitive touch sensitive display device comprising a two dimensional array of touch electrodes that represent all touch electrodes of the display device used for determining touch with self-capacitive touch sensing, the touch electrodes including at least a first group of touch electrodes including two or more first touch electrodes and a second group of touch electrodes including two or more second touch electrodes different from the first touch electrodes, the driver circuit comprising:

a first circuit to generate a touch scan signal for self-capacitive touch sensing; and

a second circuit to;

provide a common voltage to both the first group of touch electrodes and the second group of touch electrodes during a display drive period via a plurality of lines,

provide the touch scan signal to the two or more first touch electrodes of the first group of touch electrodes simultaneously during a first part of a touch drive period for self-capacitive touch sensing; and

provide the touch scan signal to the two or more second touch electrodes of the second group of touch electrodes simultaneously during a second part of the touch drive period for self-capacitive touch sensing,

the second circuit providing the touch scan signal in said touch drive period to each of the touch electrodes that represent all touch electrodes of the display device used for determining touch with self-capacitive touch sensing, the second circuit providing the touch scan signal for self-capacitive touch sensing via the plurality of lines, and wherein each corresponding line is electrically connected to a single corresponding touch electrode.

2. The driver circuit of claim 1, wherein the second circuit provides the touch scan signal to each of the touch electrodes of the display device that are used for determining touch once in said touch drive period.

3. The driver circuit of claim 1, wherein the second circuit provides the touch scan signal to the first group of touch electrodes and to the second group of touch electrodes sequentially.

4. The driver circuit of claim 1, wherein the touch electrodes are arranged in a rectangular shape including at least a first edge and a second edge that is shorter than the first edge, the touch electrodes being divided into the first group of touch electrodes and the second group of touch electrodes along the second edge.

5. The driver circuit of claim 1, wherein:

during the display drive period, each of the touch electrodes operates as a common electrode for displaying images on the display device, and

during the touch drive period, each of the touch electrodes operates as a touch electrode to sense a touch input.

6. The driver circuit of claim 1, wherein the second circuit comprises:

a common voltage generator configured to generate the common voltage;

a sync signal generator configured to generate a sync signal indicating the display drive period and the touch drive period;

a switching control signal generator configured to generate a control signal which allows the touch electrodes to be simultaneously connected to the common voltage generator during the display drive period, or allows the first group of touch electrodes or the second group of touch electrodes to be connected to the first circuit during the touch drive period, according to the sync signal; and

a plurality of switches configured to operate according to the sync signal and the control signal.

7. The driver circuit of claim 6, wherein the switches include:

first switches connected to the common voltage generator and the first circuit, and

second switches connected to the first switches and the first and second groups of touch electrodes.

8. The driver circuit of claim 7, wherein:

when the sync signal is a first sync signal indicating the display drive period, the first switches electrically connect the common voltage generator to the second switches, and

when the sync signal is a second sync signal indicating the touch drive period, the first switches electrically connect the first circuit to the second switches.

9. The driver circuit of claim 8, wherein:

when the control signal is a first control signal corresponding to the first sync signal indicating the display drive period, the second switches electrically connect the touch electrodes to the first switches, and

when the control signal is a second control signal corresponding to the second sync signal indicating the touch drive period, the second switches electrically connect the first group of touch electrodes or the second group of touch electrodes to the first switches.

26. The driver circuit of claim 1, wherein the touch electrodes further comprise a third group of touch electrodes including two or more third touch electrodes,

wherein the second circuit provides the common voltage to the third group of touch electrodes during the display drive period, and provides the touch scan signal to the two or more third touch electrodes of the third group of touch electrodes simultaneously during a third part of the touch drive period.

10. A touch sensitive display device comprising:

a two dimensional array of touch electrodes that represent all touch electrodes of the display device used for determining touch with self-capacitive touch sensing, the touch electrodes including at least a first group of touch electrodes including two or more first touch electrodes and a second group of touch electrodes including two or more second touch electrodes different from the first touch electrodes; and

a driver circuit, including;

a first circuit to generate a touch scan signal for self-capacitive touch sensing; and

a second circuit to provide a common voltage to both the first group of touch electrodes and the second group of touch electrodes during a display drive period via a plurality of lines, to provide the touch scan signal to the two or more first touch electrodes of the first group of touch electrodes simultaneously during a first part of a touch drive period for self-capacitive touch sensing, and to provide the touch scan signal to the two or more second touch electrodes of the second group of touch electrodes simultaneously during a second part of the touch drive period for self-capacitive touch sensing,

the second circuit providing the touch scan signal in said touch drive period to each of the touch electrodes that represent all touch electrodes of the display device used for determining touch with self-capacitive touch sensing, the second circuit providing the touch scan signal for self-capacitive touch sensing via the plurality of lines, and wherein each corresponding line is electrically connected to a single corresponding touch electrode.

11. The display device of claim 10, wherein the second circuit provides the touch scan signal to each of the touch electrodes of the display device that are used for determining touch once in said touch drive period.

12. The display device of claim 10, wherein the second circuit provides the touch scan signal to the first group of touch electrodes and to the second group of touch electrodes sequentially.

13. The display device of claim 10, wherein the touch electrodes are arranged in a rectangular shape including at least a first edge and a second edge that is shorter than the first edge, the touch electrodes being divided into the first group of touch electrodes and the second group of touch electrodes along the second edge.

14. The display device of claim 10, wherein:

during the display drive period, each of the touch electrodes operates as a touch electrode for displaying images on the display device, and

during the touch drive period, each of the touch electrodes operates as a touch electrode to sense a touch input.

15. The display device of claim 10, wherein the second circuit comprises:

a common voltage generator configured to generate the touch voltage;

a sync signal generator configured to generate a sync signal indicating the display drive period and the touch drive period;

a switching control signal generator configured to generate a control signal which allows the touch electrodes to be simultaneously connected to the common voltage generator during the display drive period, or allows the first group of touch electrodes or the second group of touch electrodes to be connected to the first circuit during the touch drive period, according to the sync signal; and

a plurality of switches configured to operate according to the sync signal and the control signal.

16. The display device of claim 15, wherein the switches include:

first switches directly connected to the common voltage generator and the first circuit, and

second switches connected to the first switches and the first and second groups of touch electrodes.

17. The display device of claim 16, wherein:

when the sync signal is a first sync signal indicating the display drive period, the first switches electrically connect the common voltage generator to the second switches, and

when the sync signal is a second sync signal indicating the touch drive period, the first switches electrically connect the first circuit to the second switches.

18. The display device of claim 17, wherein:

when the control signal is a first control signal corresponding to the first sync signal indicating the display drive period, the second switches electrically connect the touch electrodes to the first switches, and

when the control signal is a second control signal corresponding to the second sync signal indicating the touch drive period, the second switches electrically connect the first group of touch electrodes or the second group of touch electrodes to the first switches.

25. The display device of claim 10, wherein the first group of touch electrodes is not overlapped with the second group of touch electrodes.

27. The display device of claim 10, wherein the touch electrodes further comprise a third group of touch electrodes including two or more third touch electrodes,

wherein the second circuit provides the common voltage to the third group of touch electrodes during the display drive period, and provides the touch scan signal to the two or more third touch electrodes of the third group of touch electrodes simultaneously during a third part of the touch drive period.

19. A method for driving a touch sensitive display device comprising a two dimensional array of touch electrodes that represent all touch electrodes of the display device used for determining touch with self-capacitive touch sensing, the touch electrodes including at least a first group of touch electrodes including two or more first touch electrodes and a second group of touch electrodes including two or more second touch electrodes different from the first touch electrodes, the method comprising:

generating a touch scan signal for self-capacitive touch sensing;

providing a common voltage to both the first group of touch electrodes and the second group of touch electrodes during a display drive period via a plurality of lines;

providing the touch scan signal to the two or more first touch electrodes of the first group of touch electrodes simultaneously during a first part of a touch drive period for self-capacitive touch sensing; and

providing the touch scan signal to the two or more second touch electrodes of the second group of electrodes simultaneously during a second part of the touch drive period for self-capacitive touch sensing,

the touch scan signal provided in said touch drive period to each of the touch electrodes that represent all touch electrodes of the display device used for determining touch in said touch drive period with self-capacitive touch sensing, the touch scan signal for self-capacitive touch sensing provided via the plurality of lines, wherein each corresponding line is electrically connected to a single corresponding touch electrode.

20. The method of claim 19, wherein the touch scan signal is provided to each of the touch electrodes of the display device that are used for determining touch once in said touch drive period.

21. The method of claim 19, wherein the touch scan signal is provided to the first group of touch electrodes and to the second group of touch electrodes sequentially.

22. The method of claim 19, wherein the touch electrodes are arranged in a rectangular shape including at least a first edge and a second edge that is shorter than the first edge, the touch electrodes being divided into the first group of touch electrodes and the second group of touch electrodes along the second edge.

23. The method of claim 19, wherein:

during the display drive period, each of the touch electrodes operates as a common electrode for displaying images on the display device, and

during the touch drive period, each of the touch electrodes operates as a touch electrode to sense a touch input.

24. The method of claim 19, further comprising:

generating a sync signal indicating the display drive period and the touch drive period; and

generating a control signal which allows the touch electrodes to be simultaneously connected to the common voltage during the display drive period, or allows the first group of touch electrodes or the second group of touch electrodes to be connected to the touch scan signal during the touch drive period, according to the sync signal.

28. The method of claim 19, wherein the touch electrodes further comprise a third group of touch electrodes including two or more third touch electrodes, and the method further comprises:

providing the common voltage to the third group of touch electrodes during the display drive period, and

providing the touch scan signal to the two or more third touch electrodes of the third group of touch electrodes simultaneously during a third part of the touch drive period.

29. A touch sensitive display device comprising:

a display panel comprising;

a plurality of touch electrodes, the plurality of touch electrodes including at least a first group of touch electrodes including a first touch electrode and a second touch electrode and a second group of touch electrodes including a third touch electrode and a fourth touch electrode, and a plurality of touch lines, the plurality of touch lines including at least a first touch line, a second touch line, a third touch line and a fourth touch line; and

a display driver Integrated Circuit (IC) comprising a plurality of touch channel outputs, the plurality of touch channel outputs including at least a first touch channel output, a second touch channel output, a third touch channel output and a forth touch channel output;

wherein the first touch electrode is not overlapped with the second touch electrode in the first touch electrode group of the touch electrodes, and the third touch electrode is not overlapped with the fourth touch electrode in the second touch electrode group of the touch electrodes, wherein the first touch electrode is connected to the first channel output via the first touch line, the second touch electrode is connected to the second channel output via the second touch line, the third touch electrode is connected to the third channel output via the third touch line, the forth touch electrode is connected to the fourth channel output via the fourth touch line, wherein the display driver IC is configured to supply a common voltage to the plurality of touch electrodes and drive a data line of the display panel during a display period, wherein the display driver IC is configured to supply a touch scan signal to the plurality of touch electrodes during a touch period, wherein the display driver IC is configured to supply the touch scan signal to the first touch electrode and the second touch electrode simultaneously during a first part of the touch period, and wherein the display driver IC is configured to supply the touch scan signal to the third touch electrode and the fourth touch electrode simultaneously during a second part of the touch period.