Display Device with Integrated Touch Screen and Method for Driving the Same

• US 20160098126A1
• Filed: 12/14/2015
• Published: 04/07/2016
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, HongChul, Kim, SungChul, Lee, JeongSeop, Pyo, SeungEun, Lee, JungHan
• Granted Patent: US 9,910,549 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 touch sensitive display device comprising a plurality of electrodes, the electrodes including at least a first group of electrodes and a second group of electrodes, the driver circuit comprising:

a first circuit to generate a touch scan signal; and

a second circuit to provide a common voltage to both the first group of electrodes and the second group of electrodes during a display drive period, and to provide the touch scan signal to the first group of electrodes during a first part of a touch drive period and to the second group of electrodes during a second part of the touch drive period, the second circuit providing the touch scan signal to all of the electrodes of the display device in said touch drive period.

2. The driver circuit of claim 1, wherein the second circuit provides the touch scan signal to all of the electrodes of the display device 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 electrodes and to the second group of electrodes sequentially.

4. The driver circuit of claim 1, wherein the 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 electrodes being divided into the first group of electrodes and the second group of electrodes along the second edge.

5. The driver circuit of claim 1, wherein:

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

during the touch drive period, each of the 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 electrodes to be simultaneously connected to the common voltage generator during the display drive period, or allows the first group of electrodes or the second group of 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 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 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 electrodes or the second group of electrodes to the first switches.

10. A touch sensitive display device comprising:

a plurality of electrodes, the electrodes including at least a first group of electrodes and a second group of electrodes; and

a driver circuit, including;

a first circuit to generate a touch scan signal; and

a second circuit to provide a common voltage to both the first group of electrodes and the second group of electrodes during a display drive period, and to provide the touch scan signal to the first group of electrodes during a first part of a touch drive period and to the second group of electrodes during a second part of the touch drive period, the second circuit providing the touch scan signal to all of the electrodes of the display device in said touch drive period.

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

13. The display device of claim 10, wherein the 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 electrodes being divided into the first group of electrodes and the second group of electrodes along the second edge.

14. The display device of claim 10, wherein:

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

during the touch drive period, each of the 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 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 electrodes to be simultaneously connected to the common voltage generator during the display drive period, or allows the first group of electrodes or the second group of 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 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 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 electrodes or the second group of electrodes to the first switches.

19. A method for driving a touch sensitive display device comprising a plurality of electrodes, the electrodes including at least a first group of electrodes and a second group of electrodes, the method comprising:

generating a touch scan signal; and

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

providing the touch scan signal to the first group of electrodes during a first part of a touch drive period and to the second group of electrodes during a second part of the touch drive period, the touch scan signal provided to all of the electrodes of the display device in said touch drive period.

20. The method of claim 19, wherein the touch scan signal is provided to all of the electrodes of the display device once in said touch drive period.

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

22. The method of claim 19, wherein the 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 electrodes being divided into the first group of electrodes and the second group of electrodes along the second edge.

23. The method of claim 19, wherein:

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

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