DISPLAY DEVICE WITH INTEGRATED TOUCH SCREEN AND METHOD FOR DRIVING THE SAME

• US 20130215075A1
• Filed: 04/16/2012
• Published: 08/22/2013
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Sungchul Kim
• Inventors: LEE, JungHan, Kim, HongChul, Kim, SungChul, Lee, JeongSeop, Pyo, SeungEun
• Granted Patent: US 9,377,906 B2
• Time in Patent Office: Days
• US Class Current: 345/174
• 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 display device with integrated touch screen, comprising:

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.

2. The display device of claim 1, wherein when the display driver applies the touch scan signal to the one or more of the m electrodes, the display driver applies the touch scan signal sequentially to each of the n number of electrode groups.

3. The display device of claim 1, wherein,

when the driving mode is in a display driving mode, each of the m electrodes operates as a common electrode for displaying images on the display panel, and

when the driving mode is in a touch driving mode, each of the m electrodes operates as a touch electrode for sensing a touch input to the touch screen.

4. The display device of claim 1, wherein the number of electrodes present in each of the electrode groups is m/n.

5. The display device of claim 1, wherein the n electrode groups have block configurations.

6. The display device of claim 1, wherein the m electrodes are formed into the n electrode groups by dividing the m electrodes along a shorter side direction of the touch screen.

7. The display device of claim 1, wherein the display driver includes:

a common voltage generator configured to generate the common voltage;

a sync signal generator configured to generate a sync signal indicating the driving mode;

a switching control signal generator configured to generate a control signal which allows the m electrodes to be simultaneously connected to the common voltage generator or allows the m electrodes to be connected to the touch driver sequentially for each of the electrode groups, according to the sync signal; and

a switching unit configured to operate according to the sync signal and the control signal.

8. The display device of claim 7, wherein the switching unit includes:

a plurality of first switching units directly connected to the common voltage generator and the touch driver, and

a plurality of second switching units connected to the first switching units and the electrode groups.

9. The display device of claim 8, wherein each of the second switching units includes a plurality of CMOS transistors, and controls respective gates of the CMOS transistors to simultaneously connect the first switching units and the electrode groups or sequentially connect the first switching units and each of the electrode groups.

10. The display device of claim 8, wherein when the sync signal is a first sync signal indicating the display driving mode, the first switching units electrically connect the common voltage generator to the second switching units, and

when the sync signal is a second sync signal indicating the touch driving mode, the first switching units electrically connect the touch driver to the second switching units.

11. The display device of claim 10, wherein when the control signal is a first control signal corresponding to the first sync signal indicating the display driving mode, the second switching units electrically connect the m electrodes to the first switching units, and

when the control signal is a second control signal corresponding to the second sync signal indicating the touch driving mode, the second switching units sequentially and electrically connect the respective electrodes to the first switching units for the electrode groups, one electrode group at a time.

12. The display device of claim 11, wherein the second control signal includes n number of group selection signals corresponding to respectively to the electrode groups, the n group selection signals allowing the first switching units to be respectively and electrically connected to the electrodes for each of the electrode groups.

13. The display device of claim 8, wherein the number of the second switching units is m/n.

14. The display device of claim 1, wherein the number of touch signal channels present in the touch driver is m/n.

15. A method of operating a display device, the display device including a display panel including a plurality of pixel electrodes and 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, the display device further including a touch driver and a display driver, the method comprising:

dividing the m electrodes into n number of electrode groups;

generating, by the touch driver, a touch scan signal; and

applying, by the display driver, a common voltage or the generated touch scan signal to one or more of the m electrodes depending on a driving mode of the display device,

wherein when the generated touch scan signal is applied to the one or more of the m electrodes, the touch scan signal is selectively applied to each of the electrode groups.

16. The method of claim 15, wherein in the dividing step, the number of electrodes present in each of the electrode groups is m/n.

17. The method of claim 15, wherein the n electrode groups have block configurations.

18. The method of claim 15, wherein the dividing step divides the m electrodes into the n electrode groups along a shorter side direction of the touch screen.

19. The method of claim 15, wherein the display driver includes a common voltage generator, a sync signal generator, and a switching control signal generator, and a switching unit, and

wherein the applying step includes:

generating, by the common voltage generator, the common voltage,

generating, by the sync signal generator, a sync signal indicating the driving mode,

generating, by switching control signal generator, a control signal which allows the m electrodes to be simultaneously connected to the common voltage generator or allows the m electrodes to be connected to the touch driver sequentially for each of the electrode groups, according to the generated sync signal, and

operating the switching unit according to the sync signal and the control signal, such that the common voltage or the touch scan signal is selectively applied to the one or more m electrodes according to the operation of the switching unit.

20. The method of claim 19, wherein in the operating step, the switching unit includes:

a plurality of first switching units directly connected to the common voltage generator and the touch driver, and

a plurality of second switching units connected to the first switching units and the electrode groups.

21. The method of claim 20, wherein when the sync signal is a first sync signal indicating a display driving mode, the operating step electrically connects the common voltage generator to the second switching units using the first switching units, and

when the sync signal is a second sync signal indicating a touch driving mode, the operating step electrically connects the touch driver to the second switching units using the first switching units.

22. The method of claim 21, wherein when the control signal is a first control signal corresponding to the first sync signal indicating the display driving mode, the operating step electrically connects the m electrodes to the first switching units using the second switching units, and

when the control signal is a second control signal corresponding to the second sync signal indicating the touch driving mode, the operating step sequentially and electrically connects using the second switching units the respective electrodes to the first switching units for the electrode groups, one electrode group at a time.