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

• US 9,377,906 B2
• Filed: 04/16/2012
• Issued: 06/28/2016
• 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): Patel, Kumar
• Assistant Examiner(s): Ahn, Sejoon
• Application Number:
  US13/448,021
• Publication Number:
  US 20130215075A1
• Time in Patent Office: 1,534 Days
• Field of Search: 345173-174, 345/103, 345/104
• 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 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

a display driver comprising;

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

first switching units and second switching units configured to operate according to the sync signal and the control signal, the first switching units connected to the common voltage generator and to the touch driver, and the second switching units connected to the first switching units and the n electrode groups, the first switching units and the second switching units configured to apply the common voltage to the m electrodes or to apply the touch scan signal sequentially to the n electrode groups, depending on a driving mode of the display device.

2. 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.

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

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

5. 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.

6. The display device of claim 1, 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.

7. The display device of claim 1, 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.

8. The display device of claim 7, 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.

9. The display device of claim 8, wherein the second control signal includes n number of group selection signals, each group selection signal corresponding to a respective one of 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.

10. The display device of claim 1, wherein the number of the second switching units is m/n.

17. The display device of claim 1, wherein the m number of electrodes are arranged in a grid including a plurality of rows and a plurality of columns, and

wherein each row of the plurality of rows includes a plurality of electrodes and each column of the plurality of columns includes a plurality of electrodes.

19. The display device of claim 1, wherein the n number of electrode groups includes a first electrode group, which includes a first portion of the m number of electrodes, and a second electrode group, which includes a second portion of the m number of electrodes.

11. A method of operating a display device including a touch driver, a display driver, and a display panel, which includes a plurality of pixel electrodes and a touch screen including m number of electrodes 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, wherein the m electrodes are divided into n number of electrode groups, and the display driver includes a common voltage generator, a sync signal generator, a switching control signal generator, first switching units and second switching units, the method comprising:

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

generating, by the common voltage generator, a common voltage;

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

generating, by the 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 sync signal, and

operating the first switching units and the second switching units according to the sync signal and the control signal, such that the common voltage or the touch scan signal is selectively applied to the m electrodes according to the operation of the first switching units and the second switching units, wherein operating the first switching units and the second switching units includes;

providing, by the first switching units of the display driver to the second switching units of the display driver, the common voltage from the common voltage generator during a display driving mode or the touch scan signal from the touch driver during a touch driving mode; and

applying, by the second switching units of the display driver, the common voltage to the m electrodes during the display driving mode or the touch scan signal sequentially to the n electrode groups during the touch driving mode.

12. The method of claim 11, wherein the touch scan signal is sequentially applied to the number of electrodes present in each of the electrode groups comprising m/n number of electrodes during the touch driving mode.

13. The method of claim 11, wherein the touch scan signal is applied to the n electrode groups having block configurations during the touch driving mode.

14. The method of claim 11, wherein the m electrodes are divided into the n electrode groups along a shorter side direction of the touch screen.

15. The method of claim 11, wherein operating the first switching units and the second switching units comprises when the sync signal is a first sync signal indicating the display driving mode, electrically connecting 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 the touch driving mode, electrically connecting the touch driver to the second switching units using the first switching units.

16. The method of claim 15, wherein when the control signal is a first control signal corresponding to the first sync signal indicating the display driving mode, the m electrodes are electrically connected 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 second switching units electrically connect the respective electrodes to the first switching units for the electrode groups, one electrode group at a time.

18. The method of claim 11, wherein the m number of electrodes are arranged in a grid including a plurality of rows and a plurality of columns, and

wherein each row of the plurality of rows includes a plurality of electrodes and each column of the plurality of columns includes a plurality of electrodes.

20. The method of claim 11, wherein a first portion of the m number of electrodes in a first electrode group of the n number of electrode groups is applied with the touch scan signal at a first time during a touch driving mode, and a second portion of the m number of electrodes in a second electrode group of the n number of electrode groups is applied with the touch scan signal at a second time during the touch driving mode.