Driving circuit, touch display apparatus, and method for driving touch display apparatus

• US 10,444,913 B2
• Filed: 04/05/2017
• Issued: 10/15/2019
• Est. Priority Date: 04/15/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Han, Sungsu, Park, YongChan, Kim, SungChul, Kim, Jinseong
• Primary Examiner(s): Soto Lopez, Jose R
• Application Number:
  US15/480,301
• Publication Number:
  US 20170300146A1
• Time in Patent Office: 923 Days
• CPC Class Codes: G06F 2203/04105 Pressure sensors for measuring the pressure or force exerted on the touch surface without providing the touch position
• CPC Class Codes: G06F 2203/04112 Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• 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 3/2092 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

Abstract

The present embodiments relate to a driving circuit and a touch display apparatus for sensing a user'"'"'s touch position and touch force with respect to a display panel, and further relate to a driving method thereof. The touch display apparatus may include a plurality of first electrodes that are configured to be embedded in a display panel, and a second electrode that is configured to be positioned outside the display panel. The touch display apparatus may read a force sensing signal from the second electrode through a signal detecting unit that is electrically connected to the second electrode. Therefore, it is possible to sense a touch force without separating a force sensing signal from a signal received from the first electrode, and to sense a user'"'"'s touch force through the driving of the second electrode regardless of the driving mode of the first electrode.

Claims

1. A touch display apparatus comprising:

a plurality of first electrodes configured to be embedded in a display panel;

one second electrode configured to be positioned outside the display panel, and configured to be spaced apart from the plurality of first electrodes; and

a driving circuit configured to output a first electrode driving signal to the plurality of first electrodes and to receive a touch sensing signal from the plurality of first electrodes in a touch sensing period, and configured to output a second electrode driving signal independent of the first electrode driving signal to the second electrode and at least one of a display driving voltage, the first electrode driving signal, and a first force sensing signal different from the second electrode driving signal to at least one of the plurality of first electrodes and to receive a second force sensing signal independent of the touch sensing signal from the second electrode in a force sensing period.

2. The touch display apparatus according to claim 1, wherein the driving circuit comprises a signal detecting unit configured to be electrically connected to the plurality of first electrodes and the second electrode, and configured to receive the touch sensing signal and the second force sensing signal, and

wherein the signal detecting unit is configured to receive the touch sensing signal through a first channel in the touch sensing period, and is configured to receive the second force sensing signal through a second channel that is different from the first channel in the force sensing period.

3. The touch display apparatus according to claim 1, wherein the driving circuit comprises:

a first signal detecting unit configured to be electrically connected to the plurality of first electrodes, and configured to receive the touch sensing signal from the plurality of first electrodes in the touch sensing period; and

a second signal detecting unit configured to be electrically connected to the second electrode, and configured to receive the second force sensing signal from the second electrode in the force sensing period.

4. The touch display apparatus according to claim 1, wherein the force sensing period coincides with at least a part of a display driving period that does not coincide with the touch sensing period.

5. The touch display apparatus according to claim 1, wherein the force sensing period coincides with at least a part of the touch sensing period.

6. The touch display apparatus according to claim 1, wherein the force sensing period coincides with at least a part of both (i) a display driving period that does not coincide with the touch sensing period and (ii) the touch sensing period.

7. The touch display apparatus according to claim 1, wherein the force sensing period does not coincide with the touch sensing period.

8. The touch display apparatus according to claim 1, wherein the first electrode driving signal is an AC signal, and the second electrode driving signal is a DC signal.

9. A method for driving a touch display apparatus that includes a plurality of first electrodes that are embedded in a display panel and one second electrode that is positioned outside the display panel, the method comprising:

outputting a first electrode driving signal to the plurality of first electrodes in a touch sensing period;

receiving a touch sensing signal from the plurality of first electrodes through a signal detecting unit, that is electrically connected to the plurality of first electrodes and the second electrode, in the touch sensing period;

outputting a second electrode driving signal independent of the first electrode driving signal to the second electrode and at least one of a display driving voltage, the first electrode driving signal, and a first force sensing signal different from the second electrode driving signal to at least one of the plurality of first electrodes in a force sensing period; and

receiving a second force sensing signal independent of the touch sensing signal from the second electrode through the signal detecting unit in the force sensing period.

10. The method according to claim 9, wherein the force sensing period coincides with at least a part of a display driving period that does not coincide with the touch sensing period.

11. The method according to claim 9, wherein the force sensing period coincides with at least a part of the touch sensing period.

12. The method according to claim 9, wherein the force sensing period coincides with at least a part of both (i) a display driving period that does not coincide with the touch sensing period and (ii) the touch sensing period.

13. The method according to claim 9, wherein the first electrode driving signal is an AC signal, and the second electrode driving signal is a DC signal.

14. A driving circuit comprising:

a signal generating unit configured to generate a first electrode driving signal that is applied to a plurality of first electrodes embedded in a display panel in a touch sensing period, and configured to generate a second electrode driving signal that is applied to a second electrode positioned outside the display panel in a force sensing period;

an electrode driving unit configured to output the first electrode driving signal to the plurality of first electrodes in the touch sensing period, and configured to output the second electrode driving signal independent of the first electrode driving signal to the second electrode and at least one of a display driving voltage, the first electrode driving signal, and a first force sensing signal different from the second electrode driving signal to at least one of the plurality of first electrodes in the force sensing period; and

a signal detecting unit configured to receive a touch sensing signal from the plurality of first electrodes in the touch sensing period, and configured to receive a second force sensing signal independent of the touch sensing signal from the second electrode in the force sensing period.

15. The driving circuit according to claim 14, wherein the signal detecting unit is configured to be electrically connected to the plurality of first electrodes and the second electrode, and is configured to receive the touch sensing signal from the plurality of first electrodes through a first channel in the touch sensing period and to receive the second force sensing signal from the second electrode through a second channel that is different from the first channel in the force sensing period.

16. The driving circuit according to claim 14, wherein the signal detecting unit comprises:

a first signal detecting unit configured to be electrically connected to the plurality of first electrodes, and configured to receive the touch sensing signal from the plurality of first electrodes in the touch sensing period; and

a second signal detecting unit configured to be electrically connected to the second electrode, and configured to receive the second force sensing signal from the second electrode in the force sensing period.

17. The driving circuit according to claim 14, wherein the signal detecting unit is configured to receive the second force sensing signal from the second electrode in the force sensing period that coincides with at least a part of a display driving period that does not coincide with the touch sensing period.

18. The driving circuit according to claim 14, wherein the signal detecting unit is configured to receive the second force sensing signal from the second electrode in the force sensing period that coincides with at least a part of the touch sensing period.

19. The driving circuit according to claim 14, wherein the signal detecting unit is configured to receive the second force sensing signal from the second electrode in the force sensing period that coincides with at least a part of both (i) a display driving period that does not coincide with the touch sensing period and (ii) the touch sensing period.

20. The driving circuit according to claim 14, wherein the signal generating unit generates an AC signal as the first electrode driving signal, and generates a DC signal as the second electrode driving signal.