Display device, and device and method for driving the same

• US 9,477,345 B2
• Filed: 10/23/2015
• Issued: 10/25/2016
• Est. Priority Date: 01/30/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Moon, Suhwan
• Primary Examiner(s): Kumar, Srilakshmi K
• Assistant Examiner(s): Reed, Stephen T
• Application Number:
  US14/922,097
• Publication Number:
  US 20160224175A1
• Time in Patent Office: 368 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0272 Details of drivers for data electrodes, the drivers communicating data to the pixels by means of a current
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/20 for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
• CPC Class Codes: G09G 3/3677 suitable for active matrices only

Abstract

A display device and a device and method for driving the same are provided. The display device minimizes leakage of a stage in a standby state to hold a voltage of a Q node of the stage during touch operation.

Claims

1. A display device, comprising:

a display panel in which data lines and gate lines intersect and pixels are disposed in a matrix form, the display panel including touch sensors;

a touch driver circuit that drives the touch sensors;

a data driver circuit that supplies a data signal to the data lines;

a gate driving circuit that supplies gate pulses to the gate lines using a shift register; and

a timing controller that supplies data of an input image to the data driver circuit and that controls operation timing of the data driver circuit and the gate driving circuit,

wherein the timing controller generates a touch enable signal that defines a display time and a touch time, the touch enable signal at a low level voltage during the display time and a high level voltage during the touch time, and

the shift register comprises a stage in which the touch enable signal is input,

wherein the stage comprises;

a Q node that controls a pull-up transistor; and

a transistor comprising a drain directly connected to the Q node and a source directly connected to the touch enable signal, the high level voltage of the touch enable signal being applied to the source of the transistor during the touch time.

2. The display device of claim 1, wherein a voltage between a gate and the source of the transistor is lower than a threshold voltage of the transistor during the touch time, and

the voltage between the drain and the source of the transistor is substantially zero during the touch time.

3. The display device of claim 2, wherein the touch enable signal comprises a high level time that rises to the high level voltage from a time later by a time within 1 clock pulse width than the start of the touch time and that falls to the low level voltage at a time within 1 clock pulse width immediately after the touch time terminates to be enlarged further than the touch time, and

a lower level time of the touch enable signal is the display time, except for the high level time.

4. The display device of claim 2, wherein the touch enable signal comprises a high level time that rises to the high level voltage when the touch time starts and that falls to the low level voltage when the touch time terminates to have the same time as the touch time, and

a low level time of the touch enable signal corresponds to the display time.

5. A driving device of a display device comprising a gate driver circuit that time-divides one frame into a display time and a touch time and that supplies gate pulses to a gate line of the display device according to a voltage of a Q node, the driving device comprising:

a timing control circuit that generates a touch enable signal that defines the display time and the touch time, the touch enable signal at a low level voltage during the display time and a high level voltage during the touch time,

wherein the high level voltage of the touch enable signal is supplied to the gate driving circuit during the touch time, and

the gate driving circuit comprises a transistor comprising a drain directly connected to the Q node and a source directly connected to the touch enable signal, the high level voltage of the touch enable signal being applied to the source of the transistor during the touch time.

6. The driving device of claim 5, wherein a voltage between a gate and the source of the transistor is lower than a threshold voltage of the transistor for the touch time, and

a voltage between the drain and the source of the transistor is substantially zero during the touch time.

7. The driving device of claim 6, wherein the touch enable signal rises to the high level voltage from a time later by a time within 1 clock pulse width than the start of the touch time and falls to the low level voltage at a time within 1 clock pulse width immediately after the touch time terminates.

8. The driving device of claim 7, wherein the touch enable signal rises to the high level voltage when the touch time starts and falls to the low level voltage when the touch time terminates.

9. A method of driving a display device that divides one frame into a display time and a touch time to be time-division driven, the method comprising:

generating a touch enable signal that defines the display time and the touch time, the touch enable signal at a low level voltage during the display time and a high level voltage during the touch time; and

reducing a voltage between a drain and a source of a transistor connected to a discharge path of a Q node by supplying the high level voltage of the touch enable signal during the touch time to the source of the transistor in a gate driver circuit that supplies gate pulses to a gate line of the display device according to a voltage of the Q node, the drain of the transistor directly connected to the Q node and the source of the transistor directly connected to the touch enable signal.

10. The method of claim 9, wherein a voltage between a gate and the source of the transistor is lower than a threshold voltage of the transistor for the touch time, and

the voltage between the drain and the source of the transistor is substantially zero during the touch time.

11. A gate driver circuit that time-divides one frame into a display time and a touch time and in which a touch enable signal becomes a first level during the touch time or a second level during the display time, the gate driver circuit comprising:

a shift register,

wherein an N-th (N is a positive integer) stage of the shift register comprises;

a first transistor controlled by an output signal of a previous stage to supply the touch enable signal having the first level to a Q node, the first transistor directly connected to the Q node;

a second transistor controlled by an output signal of a next stage to supply the touch enable signal having the second level to the Q node, the second transistor directly connected to the Q node; and

a pull-up transistor controlled by a voltage of the Q node to output a first clock signal applied thereto to an N-th output terminal,

wherein the first level is a high level and the second level is a low level, when the first transistor, the second transistor, and the pull-up transistor are N-type transistors, and the first level is the low level and the second level is the high level, when the first transistor, the second transistor, and the pull-up transistor are P-type transistors.

12. The gate driver circuit of claim 11, wherein the N-th stage is a dummy stage, and the display time includes a first display time prior to the touch time and a second display time following the touch time,

wherein the Q node is charged during the first display time, a carry signal is output through the N-th output terminal during the touch time, and the Q node is discharged during the second display time.

13. The gate driver circuit of claim 11, wherein the display time includes a first display time prior to the touch time and a second display time following the touch time,

wherein the Q node is charged during the first display time, and gate pulses are output to the N-th output terminal for during the second display time.

14. The gate driver circuit of claim 12, wherein the N-th stage further includes a third transistor controlled by the voltage of the Q node to supply the touch enable signal to the Q node.

15. The gate driver circuit of claim 14, further comprising a pull-down transistor controlled by a voltage of a QB node to discharge the N-th output terminal.

16. A touchscreen integrated display device, comprising:

the gate driver circuit according to claim 11;

a panel displaying images; and

a touch driver circuit for sensing touch applied to the panel,

wherein the panel includes a plurality of pixels grouped into a plurality of pixel groups, a plurality of pattern electrodes one-to-one corresponding to the plurality of pixel groups, and sensing lines for respectively connecting the pattern electrodes to the touch driver circuit.

17. The touchscreen integrated display device of claim 16,

wherein the N-th stage is a dummy stage, and the display time includes a first display time prior to the touch time and a second display time following the touch time,

wherein the Q node is charged during the first display time, a carry signal is output to the N-th output terminal during the touch time, and the Q node is discharged during the second display time.

18. The touchscreen integrated display device of claim 16, wherein the display time includes a first display time prior to the touch time and a second display time following the touch time,

wherein the Q node is charged during the first display time, and gate pulses are output to the N-th output terminal during the second display time.

19. The touchscreen integrated display device of claim 17,

wherein the N-th stage further includes a third transistor controlled by a voltage of a QB node to supply the touch enable signal to the Q node.

20. The touchscreen integrated display device of claim 16, wherein the gate driver circuit further comprises a pull-down transistor controlled by the voltage of a QB node to supply a low-level voltage to the N-th output terminal.