Touch Circuit, Touch Display Driver Circuit, Touch Display Device, and Method of Driving the Same

• US 20170168644A1
• Filed: 02/27/2017
• Published: 06/15/2017
• Est. Priority Date: 10/12/2015
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: KIM, SungChul, KANG, Seongkyu
• Granted Patent: US 9,946,399 B2
• Time in Patent Office: Days
• 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 2300/0413 Details of dummy pixels or dummy lines in flat panels
• CPC Class Codes: G09G 2310/0245 Clearing or presetting the whole screen independently of waveforms, e.g. on power-on G09G2310/063 takes precedence
• CPC Class Codes: G09G 2310/0275 Details of drivers for data electrodes, other than drivers for liquid crystal, plasma or OLED displays, not related to handling digital grey scale data or to communication of data to the pixels by means of a current
• 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 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 5/006 Details of the interface to the display terminal specific for a display terminal using a CRT G09G1/167; using a flat panel G09G3/2096; circuits for interfacing with colour displays G09G5/04

Abstract

A touch circuit, a display driver circuit, a touch display device, and a method of driving the same. After display driving is ended and before touch driving begins to be performed, touch driving and touch sensing are accurately performed through pre-setting driving without the influence of display driving that was ended already. An accurate touch sensing result without touch sensing noise is obtained.

Claims

1. A touch sensitive display device comprising:

a display panel including a plurality of electrodes; and

circuitry to drive the electrodes during at least a display mode and a touch mode, wherein;

during the touch mode, the circuitry provides a touch driving signal to at least one first electrode of the electrodes;

during the display mode, the circuitry provides a common voltage to the electrodes; and

during a post-setting period after the circuitry provides the touch driving signal to the at least one first electrode and before the circuitry provides the common voltage to the electrodes, the circuitry provides a post-setting signal of a predetermined voltage to the electrodes.

2. The touch sensitive display device of claim 1, wherein the predetermined voltage of the post-setting signal is a DC voltage.

3. The touch sensitive display device of claim 1, wherein the predetermined voltage of the post-setting signal is the common voltage.

4. The touch sensitive display device of claim 1, further comprising:

a timing controller to generate a touch synchronization signal having a first state during the touch mode and a second state during the display mode, wherein the post-setting period is during the touch mode when the synchronization signal is in the first state.

5. The touch sensitive display device of claim 1, wherein display driving for image display is not performed during the post-setting period.

6. The touch sensitive display device of claim 1,

wherein during an initial display mode prior to the touch mode, the circuitry provides the common voltage to the electrodes,

wherein during a pre-setting period after the common voltage is provided to the electrodes in the initial display mode and before the touch driving signal is provided to the at least one first electrode, the circuitry provides a pre-setting dummy pulse signal to the at least one first electrode, the pre-setting dummy pulse signal having a same phase as the touch driving signal.

7. The touch sensitive display device of claim 6, wherein the display panel comprises:

a plurality of data lines; and

a plurality of gate lines,

wherein the circuitry provides a pre-setting load free driving (LFD) signal to at least one of the gate lines or data lines while the pre-setting dummy pulse signal is provided to the at least one first electrode, and

wherein the pre-setting LFD signal has a same phase as the pre-setting dummy pulse signal.

8. A driver circuit for a touch sensitive display panel that includes a plurality of electrodes, the driver circuit comprising:

circuitry to drive the electrodes during at least a display mode and a touch mode, the circuitry to;

during the touch mode, provide a touch driving signal to at least one first electrode of the electrodes;

during the display mode, provide a common voltage to the electrodes; and

during a post-setting period after the circuitry provides the touch driving signal to the at least one first electrode and before the circuitry provides the common voltage to the electrodes, provide a post-setting signal of a predetermined voltage to the electrodes.

9. The driver circuit of claim 8, wherein the predetermined voltage of the post-setting signal is a DC voltage.

10. The driver circuit of claim 8, wherein the predetermined voltage of the post-setting signal is the common voltage.

11. The driver circuit of claim 8, wherein a touch synchronization signal has a first state during the touch mode and a second state during the display mode, wherein the post-setting period is during the touch mode when the synchronization signal is in the first state.

12. The driver circuit of claim 8, wherein display driving for image display is not performed during the post-setting period.

13. The driver circuit of claim 8,

wherein during an initial display mode prior to the touch mode, the circuitry provides the common voltage to the electrodes,

wherein during a pre-setting period after the common voltage is provided to the electrodes in the initial display mode and before the touch driving signal is provided to the at least one first electrode, the circuitry provides a pre-setting dummy pulse signal to the at least one first electrode, the pre-setting dummy pulse signal having a same phase as the touch driving signal.

14. The driver circuit of claim 13, wherein the circuitry provides a pre-setting load free driving (LFD) signal to at least one of gate lines or data lines of the display panel while the pre-setting dummy pulse signal is provided to the at least one first electrode, and

wherein the pre-setting LFD signal has a same phase as the pre-setting dummy pulse signal.

15. A method for operating a touch sensitive display device that comprises a display panel including a plurality of electrodes, the method comprising:

during a touch sensing mode, providing a touch driving signal to at least one first electrode of the electrodes;

during a display mode, providing a common voltage to the electrodes; and

during a post-setting period after the touch driving signal is provided to the at least one first electrode and before the common voltage is provided to the electrodes, providing a post-setting signal of a predetermined voltage to the electrodes.

16. The method of claim 15, wherein the predetermined voltage of the post-setting signal is a DC voltage.

17. The method of claim 15, wherein the predetermined voltage of the post-setting signal is the common voltage.

18. The method of claim 15, wherein a touch synchronization signal has a first state during the touch mode and a second state during the display mode, wherein the post-setting period is during the touch mode when the synchronization signal is in the first state.

19. The method of claim 15, wherein display driving for image display is not performed during the post-setting period.

20. The method of claim 15, further comprising:

during an initial display mode prior to the touch mode, providing the common voltage to the electrodes; and

during a pre-setting period after the common voltage is provided to the electrodes in the initial display mode and before the touch driving signal is provided to the at least one first electrode, providing a pre-setting dummy pulse signal to the at least one first electrode, the pre-setting dummy pulse signal having a same phase as the touch driving signal.