Display device and driving method thereof

• US 9,542,026 B2
• Filed: 10/08/2014
• Issued: 01/10/2017
• Est. Priority Date: 12/30/2013
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Young Joon
• Primary Examiner(s): Spar, Ilana
• Assistant Examiner(s): Rayan, Mihir K
• Application Number:
  US14/509,838
• Publication Number:
  US 20150185937A1
• Time in Patent Office: 825 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 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2310/0297 Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns
• CPC Class Codes: G09G 2320/0223 Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/2092 Details of a display terminals using a flat panel, the details relating to the control arrangement of the display terminal and to the interfaces thereto suitable for both CRT and flat panel G09G5/003; specific for a CRT G09G1/165
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3688 suitable for active matrices only

Abstract

Disclosed is a display device. The display device includes a panel into which a touch panel including a plurality of driving electrodes and a plurality of receiving electrodes is built, a touch sensing unit configured to supply a plurality of sensing pulses to the plurality of driving electrodes during a touch sensing period, a driver configured to drive the panel to allow the panel to display an image during an image display period, and a data line controller configured to connect a plurality of data lines to ground in a sensing pulse non-output period where the plurality of the sensing pulses are not supplied to the plurality of driving electrodes during the touch sensing period.

Claims

1. A method of driving a display device, the method comprising:

connecting a plurality of data lines, formed in a panel, to ground during a touch preparation period after a touch sensing period arrives until a plurality of sensing pulses are supplied to a plurality of driving electrodes, the plurality of sensing pulses including at least a first set of sensing pulses to be applied to a first driving electrode of the plurality of driving electrodes during a first portion of the touch sensing period, and a second set of sensing pulses to be supplied to a second driving electrode of the plurality of driving electrodes during a second portion of the touch sensing period;

floating the plurality of data lines while the first set of sensing pulses are supplied to the first of driving electrode after the touch preparation period;

connecting the plurality of data lines to ground while no sensing pulse is supplied to the plurality of driving electrodes, after the first set of sensing pulses have been supplied to the first driving electrode, but before the second set of sensing pulses are supplied to the second driving electrode; and

floating the plurality of data lines while the second set of sensing pulses are supplied to the second of driving electrode.

2. The method of claim 1, wherein the floating of the data lines comprises repeatedly performing an operation that floats the plurality of data lines in a sensing pulse output period where the plurality of sensing pulses are supplied to the plurality of driving electrodes during the touch sensing period, and connects the plurality of data lines to ground in a sensing pulse non-output period where the plurality of sensing pulses are not supplied to the plurality of driving electrodes during the touch sensing period.

3. A display device comprising:

a panel into which a touch panel including a plurality of driving electrodes and a plurality of receiving electrodes is built;

a touch sensing unit configured to supply a plurality of sensing pulses to the plurality of driving electrodes during a touch sensing period, the plurality of sensing pulses including at least a first set of sensing pulses to be applied to a first driving electrode of the plurality of driving electrodes during a first portion of the touch sensing period, and a second set of sensing pulses to be supplied to a second driving electrode of the plurality of driving electrodes during a second portion of the touch sensing period;

a driver configured to drive the panel to allow the panel to display an image during an image display period; and

a data line controller configured to;

float a plurality of data lines while the first set of sensing pulses are supplied to the first of driving electrode;

connect the plurality of data lines to ground while no sensing pulse is supplied to the plurality of driving electrodes, after the first set of sensing pulses have been supplied to the first driving electrode, but before the second set of sensing pulses are supplied to the second driving electrode; and

float the plurality of data lines while the second set of sensing pulses are supplied to the second of driving electrode.

4. The display device of claim 3, wherein,

during a touch preparation period after the touch sensing period arrives until the plurality of sensing pulses are supplied to the plurality of driving electrodes, the data line controller connects the plurality of data lines, formed in the panel, to ground.

5. The display device of claim 3, wherein the data line controller repeatedly performs an operation that floats the plurality of data lines in a sensing pulse output period where the plurality of sensing pulses are supplied to the plurality of driving electrodes during the touch sensing period, and connects the plurality of data lines to ground during the sensing pulse non-output period in the touch sensing period.

6. The display device of claim 3, wherein the data line controller connects the data lines to ground or floats the data lines according to a data line sync signal received from the driver.

7. The display device of claim 3, wherein,

the driver comprises a data driver configured to respectively supply a plurality of data voltages to the plurality of data lines formed in the panel, and

the data line controller is connected to the data driver.

8. The display device of claim 7, wherein,

the data line controller comprises a plurality of switches corresponding to a number of the data lines, and

each of the plurality of switches comprises a first terminal connected to ground, a second terminal connected to the data driver, a third terminal connected to a corresponding data line, and a fourth terminal which is floated.

9. The display device of claim 8, wherein,

each of the plurality of switches connects the first terminal to the third terminal according to a data line sync signal received from the driver, in the sensing pulse non-output period where the plurality of sensing pulses are not supplied to the plurality of driving electrodes during the touch sensing period, and

each of the plurality of switches connects the fourth terminal to the third terminal according to the data line sync signal, in a sensing pulse output period where the plurality of sensing pulses are supplied to the plurality of driving electrodes during the touch sensing period.

10. The display device of claim 7, wherein the data line controller is provided as one body with the data driver.

11. A method for driving a display device, the method comprising:

connecting a plurality of data lines of the display panel to a data driver to drive a display portion of the display device during a display period of a frame; and

driving a touch sensor portion of the display device during a sense period of the frame, wherein driving the touch sensor comprises;

connecting the plurality of data lines to ground during a preparation portion of the sense period;

sequentially supplying a plurality of sensing pulses to a plurality of driving electrodes during a sensing portion of the sense period, the plurality of sensing pulses including at least a first set of sensing pulses to be applied to a first driving electrode of the plurality of driving electrodes during a first portion of the sense period, and a second set of sensing pulses to be supplied to a second driving electrode of the plurality of driving electrodes during a second portion of the sense period;

floating one or more of the plurality of data lines during the sensing portion of the sense period while the first set of sensing pulses are being supplied to at least one of the plurality of driving electrodes;

connecting the plurality of data lines to ground while no sensing pulse is supplied to the plurality of driving electrodes, after the first set of sensing pulses have been supplied to the first driving electrode, but before a second set of sensing pulses are supplied to the second driving electrode; and

floating the plurality of data lines while the second set of sensing pulses are supplied to the second driving electrode.

12. A display device comprising:

a display panel including a display portion and a touch portion, the display portion including a plurality of data lines, and the touch portion including a plurality of driving electrodes and a plurality of receiving electrodes;

a data driver configured to drive the display portion of the display panel;

a plurality of switches each of which is coupled to a corresponding one of the plurality of data lines; and

a controller configured to control operation of the plurality of switches, wherein the controller controls the switches to;

connect the plurality of data lines to the data driver during a display period of a frame;

connect the plurality of data lines to ground during a preparation portion of a sense period of the frame, until a plurality of sensing pulses are supplied to the plurality of driving electrodes, the plurality of sensing pulses including at least a first set of sensing pulses to be applied to a first driving electrode of the plurality of driving electrodes during a first portion of the sense period, and a second set of sensing pulses to be supplied to a second driving electrode of the plurality of driving electrodes during a second portion of the sense period; and

float one or more of the plurality of data lines during a sensing portion of the sense period while the first set of sensing pulses are supplied to the first driving electrode;

connect the plurality of data lines to ground while no sensing pulse is supplied to the plurality of driving electrodes, after the first set of sensing pulses have been supplied to the first driving electrode, but before the second set of sensing pulses are supplied to the second driving electrode; and

float the plurality of data lines while the second set of sensing pulses are supplied to the second driving electrode.

13. The display device of claim 12, wherein the controller further controls the switches to connect the plurality of data lines to ground, subsequent to floating one or more of the plurality of data lines, during the sensing portion of the sense period while sensing pulses are not supplied to any of the plurality of driving electrodes.

14. The display device of claim 12, wherein each of the plurality of switches comprises a triple-throw switch, the triple-throw switch including:

a first terminal for connection to ground;

a second terminal for connection to the data driver;

a third terminal for connection to a data line of the plurality of data lines; and

a fourth terminal, the fourth terminal being floated.