Touch display device and touch driving circuit

Patent metadata

Field	Value
Publication number	US-11768559-B2
Application number	US-202217842250-A
Country	US
Kind code	B2
Filing date	Jun 16, 2022
Priority date	Jun 30, 2021
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A touch display device and a touch driving circuit are configured to drive at least one of the plurality of first touch electrode lines disposed in a first area with a first touch driving signal having a first touch driving frequency, and drive at least one of the plurality of second touch electrode lines disposed in a second area with a second touch driving signal having a second touch driving frequency that is different from the first touch driving frequency. Each of the first touch driving frequency and the second touch driving frequency is different from a display driving frequency related to display driving. to the touch display device reduces the influence of noise, increases the signal-to-noise ratio, and reduces the influence of driving the display, thereby improving the touch sensitivity.

First claim

What is claimed is:

1. A touch display device comprising:
a display panel including a plurality of data lines, a plurality of gate lines, and a touch sensor, wherein the touch sensor includes a plurality of first touch electrode lines and a plurality of second touch electrode lines;
a data driving circuit configured to drive the plurality of data lines;
a gate driving circuit configured to drive the plurality of gate lines; and
a touch driving circuit configured to drive at least one of the plurality of first touch electrode lines with a first touch driving signal having a first touch driving frequency, and drive at least one of the plurality of second touch electrode lines with a second touch driving signal having a second touch driving frequency that is different from the first touch driving frequency,
wherein the data driving circuit is configured to output data voltages to the plurality of data lines according to driving timings controlled by a display driving control signal,
wherein the gate driving circuit is configured to output gate signals to the plurality of gate lines according to driving timings controlled by the display driving control signal, and
wherein each of the first touch driving frequency and the second touch driving frequency is different from a display driving frequency of the display driving control signal related to display driving to display an image on the touch display device.

2. The touch display device according to claim 1 , wherein the plurality of first touch electrode lines are disposed in a first area of the touch display device and the plurality of second touch electrode lines are disposed in a second area of the touch display device that is different from the first area.

3. The touch display device according to claim 1 ,
wherein while the image is displayed, the touch driving circuit is configured to output at least one of the first touch driving signal and the second touch driving signal.

4. The touch display device according to claim 1 , wherein the display driving control signal includes at least one of a horizontal synchronization signal or a gate clock signal, and
wherein each of the first touch driving frequency and the second touch driving frequency is different from a frequency of the horizontal synchronization signal or a frequency of the gate clock signal.

5. The touch display device according to claim 2 , wherein the touch sensor further includes a plurality of third touch electrode lines disposed over the first area and the second area,
wherein each of the plurality of third touch electrode lines crosses the plurality of first touch electrode lines in the first area and crosses the plurality of second touch electrode lines in the second area,
wherein the touch driving circuit includes a receiving circuit configured to sense the plurality of third touch electrode lines, wherein the receiving circuit includes a plurality of analog front ends connected to the plurality of third touch electrode lines, each of the plurality of analog front ends comprising:
a first mixer configured to output a first mixed output signal by mixing a signal detected through a third touch electrode line of the plurality of third touch electrode lines and a first mixed signal, the first mixed signal having a same frequency as the first touch driving frequency of the first touch driving signal;
a second mixer configured to output a second mixed output signal by mixing the signal detected through the third touch electrode line of the plurality of third touch electrode lines and a second mixed signal, the second mixed signal having a same frequency as the second touch driving frequency of the second touch driving signal;
a first filter configured to apply a first filtering process on the first mixed output signal and output a first sensing signal having the first touch driving frequency based on the first filtering process; and
a second filter configured to apply a second filtering process on the second mixed output signal and output a second sensing signal having the second touch driving frequency based on the second filtering process.

6. The touch display device according to claim 5 , wherein responsive to the second touch driving frequency being greater than the first touch driving frequency, the first filter includes a low-pass filter that outputs a signal having a frequency less than or equal to a first cut-off frequency in the first mixed output signal as the first sensing signal, or the first filter includes a band-pass filter that outputs a signal having a frequency between a first low cut-off frequency and a first high cutoff frequency in the first mixed output signal as the first sensing signal,
wherein the first cut-off frequency is greater than the first touch driving frequency and less than the second touch driving frequency, the first high cut-off frequency is greater than the first touch driving frequency and less than the second touch driving frequency, and the first low cut-off frequency is less than the first touch driving frequency,
wherein the second filter is a high-pass filter that outputs a signal having a frequency equal to or greater than a second cut-off frequency in the second mixed output signal as the second sensing signal, or the second filter is a band-pass filter that outputs a signal having a frequency between a second low cut-off frequency and a second high cut-off frequency in the second mixed output signal as the second sensing signal, and
wherein the second cut-off frequency is greater than the first touch driving frequency and less than the second touch driving frequency, the second high cut-off frequency is greater than the second touch driving frequency, and the second low cut-off frequency is greater than the first touch driving frequency and less than the second touch driving frequency.

7. The touch display device according to claim 1 , further comprising a display panel including the touch sensor, wherein the display panel further includes:
a light emitting device including a cathode electrode;
an encapsulation layer on the light emitting device, and
wherein the plurality of first touch electrode lines and the plurality of second touch electrode lines are disposed on the encapsulation layer.

8. The touch display device according to claim 7 , wherein the display driving frequency is a frequency of voltage fluctuations in an electrode or signal line related to display driving, the electrode or the signal line overlapping the cathode electrode of the light emitting device.

9. The touch display device according to claim 7 , wherein the display panel further comprises:
a touch pad unit that is electrically connected to the touch driving circuit;
at least one dam located at an end of a slope of the encapsulation layer;
a plurality of first touch routing wires connected to the plurality of first touch electrode lines and the touch pad unit, the plurality of first touch routing wires extending along the slope of the encapsulation layer and overlapping an upper portion of the at least one dam; and
a plurality of second touch routing wires connected to the plurality of second touch electrode lines and the touch pad unit, the plurality of second touch routing wires extending along the slope of the encapsulation layer and passing over the upper portion of the at least one dam.

10. The touch display device according to claim 1 , wherein the touch driving circuit is configured to sequentially drive the plurality of first touch electrode lines using the first touch driving signal, and configured to sequentially drive the plurality of second touch electrode lines using the second touch driving signal, and
wherein the first touch driving signal suppl

Assignees

• Lg Display Co Ltd

Inventors

• Shin Seungrok
• Kim Sangkyu
• Lee Deuksu

Classifications

• G06F2203/04112

  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 title

• G06F2203/04111

  Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate · CPC title

• G06F2203/04108

  Touchless 2D- digitiser, i.e. digitiser detecting the X/Y position of the input means, finger or stylus, also when it does not touch, but is proximate to the digitiser's interaction surface without distance measurement in the Z direction · CPC title

• G06F3/0446 Primary

  using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes · CPC title

• G06F3/0445

  using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer · CPC title