Touch sensing method, touch sensing circuit, and touch display device

Patent metadata

Field	Value
Publication number	US-10042470-B2
Application number	US-201615393125-A
Country	US
Kind code	B2
Filing date	Dec 28, 2016
Priority date	Apr 15, 2016
Publication date	Aug 7, 2018
Grant date	Aug 7, 2018

Abstract

A touch sensing method, a touch sensing circuit, and a touch display device perform multifrequency touch driving by varying the frequencies of touch driving signals when sensing a touch or a touched position by outputting pulse-type touch driving by which one or more touch electrodes among a number of touch electrodes disposed on a display panel are driven sequentially. Undesired parasitic capacitance that would otherwise be caused by touch driving signals is prevented from occurring, and EMI influence is reduced.

First claim

What is claimed is:

1. A driver circuit for driving a display device integrated with a touch screen, the display device comprising a display panel including a plurality of data lines, a plurality of gate lines, and a plurality of touch electrodes that are common electrodes and are disposed within the display panel, a plurality of pixels of the display device defined at intersections of the data lines and the gate lines, the driver circuit comprising:
a touch signal generator circuit to generate a touch driving signal having a plurality of pulses, the touch driving signal having varying frequencies among a plurality of frequencies including at least a first frequency and a second frequency different from the first frequency; and
a touch driver circuit to:
apply a common voltage to the touch electrodes to display an image on the pixels of the display device;
apply the touch driving signal having the pulses at the first frequency to a first one of the touch electrodes during a first unit touch time section and apply the touch driving signal having the pulses at the second frequency to a second one of the touch electrodes during a second unit touch time section different from the first unit touch time section, a frequency of the pulses of the touch driving signal being constant within a predetermined tolerance margin at the first frequency during the first unit touch time section and at the second frequency during the second unit touch time section.

2. The driver circuit of claim 1 , wherein the first touch electrode is same as the second touch electrode.

3. The driver circuit of claim 1 , wherein the first touch electrode is at a first position on the display panel and the second touch electrode is at a second position on the display panel different from the first position.

4. The driver circuit of claim 1 , wherein:
a first image is displayed on the entire display panel once during a first frame, and a second image is displayed on the entire display panel once during a second frame;
the first frame includes a single first display period and single first touch period, and the second frame includes a single second display period and single second touch period; and
the first unit touch time section is the first touch period, and the second unit touch time section is the second touch period.

5. The driver circuit of claim 1 , wherein:
an image is displayed on the entire display panel once during a frame;
the frame includes a first display period, a first touch period subsequent to the first display period, a second display period subsequent to the first touch period, and a second touch period subsequent to the second display period; and
the first unit touch time section is the first touch period, and the second unit touch time section is the second touch period.

6. The driver circuit of claim 1 , wherein:
the touch driver circuit applies a first load-free driving signal at the first frequency to a first data lines corresponding to the first one of the touch electrodes during the first unit touch time section, the first load-free driving signal identical to the first touch-driving signal; and
the touch driver circuit applies a second load-free driving signal at the second frequency to a second data lines corresponding to the second one of the touch electrodes during the second unit touch time section, the second load-free driving signal identical to the second touch-driving signal.

7. The driver circuit of claim 1 , wherein:
the touch driver circuit applies a first load-free driving signal at the first frequency to a first gate lines corresponding to the first one of the touch electrodes during the first unit touch time section, the first load-free driving signal identical to the first touch-driving signal; and
the touch driver circuit applies a second load-free driving signal at the second frequency to a second gate lines corresponding to the second one of the touch electrodes during the second unit touch time section, the second load-free driving signal identical to the second touch-driving signal.

8. The driver circuit of claim 1 , wherein:
the touch driver circuit applies a first load-free driving signal at the first frequency to a third one of the touch electrodes corresponding to the first one of the touch electrodes during the first unit touch time section, the first load-free driving signal identical to the first touch-driving signal; and
the touch driver circuit applies a second load-free driving signal at the second frequency to a fourth one of the touch electrodes corresponding to the second one of the touch electrodes during the second unit touch time section, the second load-free driving signal identical to the second touch-driving signal.

9. The driver circuit of claim 5 , wherein the first touch period includes a touch application period during which touch drive pulses are applied and a touch idle period during which touch drive pulses are not applied, the image being displayed on the pixels of the display device during the touch idle period.

10. The driver circuit of claim 5 , wherein:
the first touch period includes a touch application period during which touch drive pulses are applied and a touch idle period during which touch drive pulses are not applied;
the first one of the touch electrodes is farther in position from the touch driver circuit than the second one of the touch electrodes;
a first number of touch pulses of the touch driving signal are applied to the first one of the touch electrodes during the first touch period;
a second number of touch pulses of the touch driving signal are applied to the second one of the touch electrodes during the second touch period, the second number of touch pulses fewer than the first number of touch pulses by a third number; and
the third number of touch pulses are applied to the first one of the touch electrodes during the touch idle period of the first touch period.

11. The driver circuit of claim 1 , wherein the touch signal generator circuit selects the first frequency and the second frequency from a set of predetermined touch driving frequencies to generate the touch driving signal.

12. The driver circuit of claim 1 , wherein the touch signal generator circuit randomly determines the first frequency and the second frequency to generate the touch driving signal.

13. A driver circuit for driving a display device integrated with a touch screen, the display device comprising a display panel including a plurality of data lines, a plurality of gate lines, and a plurality of touch electrodes that are common electrodes and are disposed within the display panel, a plurality of pixels of the display device defined at intersections of the plurality of the data lines and the plurality of gate lines, the driver circuit comprising:
a touch signal generator circuit to generate a touch driving signal having a plurality of pulses, the touch driving signal having varying frequencies among a plurality of frequencies including at least a first frequency and a second frequency different from the first frequency;
a touch driver circuit to:
apply a common voltage to the touch electrodes to display an image on the pixels of the display device;
apply the touch driving signal having the pulses at the first frequency to a first one of the touch electrodes during a first period and apply the touch driving signal having the pulses at the second frequency to a second one of the touch electrodes during a second period different from the first period, the first one of the touch electrodes and the second one of the touch electrodes at different locations on the display panel.

14. A d

Assignees

• Lg Display Co Ltd

Inventors

• Shin Myungho
• Byun Sunguk
• Choi Yongwoo
• Hwang Minwoo
• Kim Kiyong
• Kwon Youngho
• Jang Kyungjin
• Park Jaekyu

Classifications

• G06F3/0418

  for error correction or compensation, e.g. based on parallax, calibration or alignment · CPC title

• G06F2203/04107

  Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds · CPC title

• G09G3/2092

  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 title

• G09G2330/06

  Handling electromagnetic interferences [EMI], covering emitted as well as received electromagnetic radiation · 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