Display Device with Integrated Touch Screen

• US 20130241868A1
• Filed: 09/10/2012
• Published: 09/19/2013
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Kim, HoonBae, Hwang, SangSoo
• Granted Patent: US 10,175,791 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/3685 Details of drivers for data electrodes

Abstract

Disclosed is a display device with an integrated touch screen, including a touch screen comprising a plurality of driving electrodes and sensing electrodes built in a panel; a display driver integrated circuit (IC) (i) converting a first driving pulse into a second driving pulse with a gate high voltage Vgh, wherein the second driving pulse is applied to the driving electrodes when the panel operates in a touch driving mode, (ii) receiving a plurality of sensing signals from the sensing electrodes when the panel operates in a touch driving mode, and (iii) applying a common voltage to the driving electrodes and the sensing electrodes when the panel operates in a display driving mode; and a touch IC generating the first driving pulse, wherein the first driving pulse is applied to the display driver IC, and receiving the sensing signals from the display driver IC to detect a touch.

Claims

1. A display device comprising:

a touch screen comprising a plurality of driving electrodes and sensing electrodes built in a panel;

a display driver integrated circuit (IC)

(i) converting a first driving pulse into a second driving pulse with a gate high voltage Vgh, wherein the second driving pulse is applied to the driving electrodes when the panel operates in a touch driving mode,

(ii) receiving a plurality of sensing signals from the sensing electrodes when the panel operates in a touch driving mode, and

(iii) applying a common voltage to the driving electrodes and the sensing electrodes when the panel operates in a display driving mode; and

a touch IC generating the first driving pulse, wherein the first driving pulse is applied to the display driver IC, and receiving the sensing signals from the display driver IC to detect a touch.

2. The display device according to claim 1, wherein the display driver IC comprises a voltage generator, a driving pulse converter, a sync signal generator, a first switching part, and a second switching part.

3. The display device according to claim 2, wherein the display driver IC further comprises a gate driver, a data driver, and a controller.

4. The display device according to claim 1, wherein the display driver IC comprises a voltage generator, and the voltage generator comprises a common voltage generator generating a common voltage Vcom, a gate high voltage generator generating a gate high voltage Vgh, and a touch sensing reference voltage generator generating a touch sensing reference voltage Vref.

5. The display device according to claim 4, wherein (i) the display driver IC outputs the common voltage Vcom in the display driving mode, and (ii) the display driver IC selectively outputs the gate high voltage Vgh and the touch sensing reference voltage Vref in the touch driving mode.

6. The display device according to claim 1, wherein the display driver IC comprises a driving pulse converter converting the first driving pulse into the second driving pulse.

7. The display device according to claim 6, wherein the driving pulse converter is configured to convert the first driving pulse into the second driving pulse with the gate high voltage Vgh as a maximum value and with the touch sensing reference voltage Vref as a minimum value.

8. The display device according to claim 1, wherein the display driver IC comprises a sync signal generator generating (i) a first sync signal indicating the touch driving mode when the panel operates in the touch driving mode, and (ii) a second sync signal indicating the display driving mode when the panel operates in the display driving mode.

9. The display device according to claim 2, wherein the display driver IC comprises a sync signal generator generating and outputting (i) a first sync signal indicating the touch driving mode to the first and second switching parts when the panel operates in the touch driving mode, and (ii) a second sync signal indicating the display driving mode to the first and second switching parts when the panel operates in the display driving mode.

10. The display device according to claim 8, wherein the first and second sync signals are transferred to the touch IC.

11. The display device according to claim 2, wherein the first switching part selectively connects the driving pulse converter or the common voltage generator to the driving electrodes according to an output of the sync signal generator, and the second switching part selectively connects the touch IC or the common voltage generator to the sensing electrodes according to the output of the sync signal generator.

12. The display device according to claim 11, wherein

when the panel operates in the touch driving mode, the first switching part is configured to connect the driving electrodes to the driving pulse converter, and the second switching part is configured to connect the sensing electrodes to the touch IC, and

when the panel operates in the display driving mode, the first switching part is configured to connect the driving electrodes to the common voltage generator, and the second switching part is configured to connect the sensing electrodes to the common voltage generator.

13. The display device according to claim 2, wherein the first switching part includes a plurality of switches respectively connected to the driving electrodes, and the second switching part includes a plurality of switches respectively connected to the sensing electrodes.

14. The display device according to claim 2, wherein each of the driving electrodes comprises sub driving electrodes, and the sub driving electrodes and the sensing electrodes are formed as one common electrode for a plurality of unit pixel groups.

15. The display device according to claim 1, wherein the touch IC comprises a driver and a sensing part connected to the display driver IC.

16. The display device according to claim 2, wherein the touch IC comprises (i) a driver connected to the driving pulse converter of the display driver IC, and (ii) a sensing part connected to the second switching part of the display driver IC.

17. The display device according to claim 1, wherein the touch IC is connected to the display driver IC through a Flexible Printed Circuit Board (FPCB).

18. A method of internally switching a common voltage in the display device of claim 1, comprising

outputing a common voltage Vcom by the display driver IC in the display driving mode, and

selectively outputing a gate high voltage Vgh and a touch sensing reference voltage Vref in the touch driving mode,

wherein the display driver IC comprises a voltage generator, and the voltage generator comprises a common voltage generator generating the common voltage Vcom, a gate high voltage generator generating the gate high voltage Vgh, and a touch sensing reference voltage generator generating the touch sensing reference voltage Vref.

19. The method of internally switching a common voltage according to claim 18, wherein the method further comprising sensing a change amount of a mutual capacitance between the driving electrodes and the sensing electrodes by the touch IC using the touch sensing reference voltage Vref.

20. The method of internally switching a common voltage according to claim 18,

generating and outputting by a sync signal generator (i) a first sync signal indicating the touch driving mode to first and second switching parts when the panel operates in the touch driving mode, and (ii) a second sync signal indicating the display driving mode to the first and second switching parts when the panel operates in the display driving mode,

wherein the display driver IC comprises the sync signal generator, the first switching part, and the second switching part.