In-cell touch display device

• US 9,459,717 B2
• Filed: 12/23/2014
• Issued: 10/04/2016
• Est. Priority Date: 07/16/2014
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, KiJeong, Kwon, KeukSang, Park, SeungChul
• Primary Examiner(s): Li, Lin
• Application Number:
  US14/581,310
• Publication Number:
  US 20160018916A1
• Time in Patent Office: 651 Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04182 Filtering of noise external to the device and not generated by digitiser components
• 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 3/044 by capacitive means
• CPC Class Codes: G06F 3/0448 Details of the electrode shape, e.g. for enhancing the detection of touches, for generating specific electric field shapes, for enhancing display quality
• CPC Class Codes: G09G 2300/0876 Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes
• CPC Class Codes: G09G 2310/0208 using active addressing
• CPC Class Codes: G09G 2310/0213 controlling the sequence of the scanning lines with respect to the patterns to be displayed, e.g. to save power
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 2330/021 Power management, e.g. power saving
• 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 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: G09G 5/00 Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators image data processing or generation, in general G06T

Abstract

An in-cell touch display device. A panel has a plurality of data lines, a plurality of gate lines and a plurality of touch electrodes disposed thereon. A touch driving signal is applied to the plurality of touch electrodes when a driving mode is a touch mode. A data driver drives the plurality of data lines. A gate driver drives the plurality of gate lines. The gate driver sequentially outputs a scanning signal for driving the plurality of gate lines to the plurality of gate lines when the driving mode is a display mode, and outputs a load-free driving signal corresponding to the touch driving signal to at least one gate line when the driving mode is the touch mode. A level shifter generates the load-free driving signal. A multiplexer inputs a scanning voltage or the load-free driving signal to the gate driver depending on the driving mode.

Claims

1. An in-cell touch display device comprising:

a panel including a plurality of data lines, a plurality of gate lines, a plurality of pixels located at intersections of the gate lines and the data lines, and a plurality of touch electrodes disposed thereon, wherein a touch driving signal is applied to the plurality of touch electrodes when a driving mode is a touch mode;

a data driver configured to drive the plurality of data lines;

a gate driver configured to drive the plurality of gate lines, wherein the gate driver sequentially outputs a scanning signal to the plurality of gate lines when the driving mode is a display mode, and outputs a load-free driving signal having same phase as the touch driving signal to at least one gate line of the plurality of gate lines when the driving mode is the touch mode;

a level shifter configured to generate the load-free driving signal; and

a multiplexer configured to input a scanning voltage or the load-free driving signal to the gate driver depending on the driving mode.

2. The in-cell touch display device according to claim 1, wherein the plurality of touch electrodes are in shape of blocks separated from each other.

3. The in-cell touch display device according to claim 1, wherein the plurality of touch electrodes include a plurality of touch mode electrodes to which the touch driving signal is applied only in the touch mode, or a plurality of common mode electrodes to which a display driving signal is applied in the display mode and the touch driving signal is applied in the touch mode.

4. The in-cell touch display device according to claim 3, wherein, when the plurality of touch electrodes are the common mode electrodes, a plurality of common electrodes formed as blocks on the panel for displaying an image function as the plurality of touch electrodes,

wherein a common voltage is applied as the display driving signal to the plurality of touch electrodes corresponding to the plurality of common electrodes formed as the blocks on the panel when the driving mode is the display mode, and the touch driving signal is applied to at least one touch electrode of the plurality of touch electrodes when the driving mode is the touch mode.

5. The in-cell touch display device according to claim 4, wherein signal lines are disposed on the panel, each of the signal lines being connected to a corresponding touch electrode of the plurality of touch electrodes,

wherein the plurality of signal lines transfer the common voltage to the touch electrodes connected thereto in the display mode, and transfer the touch driving signal to the touch electrodes connected thereto in the touch mode.

6. The in-cell touch display device according to claim 1, wherein, in the touch mode, the gate driver outputs the load-free driving signal corresponding to the touch driving signal to all of the plurality of gate lines, or outputs the load-free driving signal corresponding to the touch driving signal to at least one gate line of the plurality of gate lines formed at a position in which the at least one gate line is to form parasitic capacitance with at least one touch electrode of the plurality of touch electrodes to which the touch driving signal.

7. The in-cell touch display device according to claim 1, wherein, in the touch mode, the data driver outputs the load-free driving signal corresponding to the touch driving signal to all of the plurality of data lines, or outputs the load-free driving signal corresponding to the touch driving signal to at least one data line of the plurality of data lines formed at a position in which the at least one data line is to form parasitic capacitance with at least one touch electrode of the plurality of touch electrodes to which the touch driving signal is applied.

8. The in-cell touch display device according to claim 1, wherein the level shifter generates the load-free driving signal corresponding to the touch driving signal by modulating the scanning voltage in synchronization with the touch driving signal based on an input timing signal.

9. The in-cell touch display device according to claim 8, further comprising a micro control unit configured to output the timing signal used for generation of the load-free driving signal to the level shifter.

10. The in-cell touch display device according to claim 9, wherein the micro control unit has a touch enable signal input thereto from a timing controller controlling the data driver and the gate driver, and outputs the input touch-enable signal to the multiplexer.

11. The in-cell touch display device according to claim 10, wherein the multiplexer selectively outputs one of the scanning voltage and the load-free driving signal to the gate driver based on the touch enable signal input from the timing controller or the micro control unit.

12. The in-cell touch display device according to claim 9, wherein the micro control unit is provided inside or outside the data driver.

13. The in-cell touch display device according to claim 1, further comprising a power management integrated circuit configured to output the scanning voltage to the multiplexer.

14. The in-cell touch display device according to claim 13, wherein the power management integrated circuit is provided inside or outside the data driver.

15. The in-cell touch display device according to claim 1, further comprising a timing controller configured to control the data driver and the gate driver, wherein the timing controller is provided inside or outside the data driver.

16. The in-cell touch display device according to claim 1, further comprising a touch sensing unit configured to measure a change in capacitance of at least one common electrode of the plurality of common electrodes to which the touch driving signal is applied, a touch and coordinates of a touched point being detected based on the change in capacitance.

17. The in-cell touch display device according to claim 16, wherein the touch sensing unit is provided inside or outside the data driver.