In-cell touch type liquid crystal display device and method for driving the same

• US 10,429,967 B2
• Filed: 12/27/2012
• Issued: 10/01/2019
• Est. Priority Date: 05/24/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Cho, SeongHo, Shin, CheonKee, Kim, KyungSeok
• Primary Examiner(s): Xie, Kwin
• Application Number:
  US13/727,780
• Publication Number:
  US 20130314343A1
• Time in Patent Office: 2,469 Days
• Field of Search: 345173-174
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• 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 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• CPC Class Codes: G09G 2310/0205 Simultaneous scanning of several lines in flat panels
• CPC Class Codes: G09G 2354/00 Aspects of interface with display user
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence

Abstract

The present disclosure relates to a liquid crystal display (LCD) device, and particularly, to an in-cell touch type LCD device, and a method for driving capable of preventing deterioration of picture quality and enhancing touch sensitivity, by dividing a touch block in a spatial manner, not in a time manner.

The in-cell touch type liquid crystal display (LCD) device, includes: an LCD panel including a first touch block and a second touch block having a plurality of gate lines and common lines; a gate driver for applying high-potential gate driving signals to the gate lines of the first touch block; a common voltage generator for supplying common voltages (Vcom) of first and second waveforms, to the common lines of the first and second touch blocks, respectively; and a touch detection circuit for detecting a touched position on the LCD panel through the second waveform common voltages.

Claims

1. An in-cell touch type liquid crystal display (LCD) device, comprising:

an LCD panel including;

a first touch block including;

a first set of gate lines; and

a first set of common lines; and

a second touch block including;

a second set of gate lines; and

a second set of common lines;

a gate driver for sequentially applying a high-potential gate driving signal to the first set of gate lines of the first touch block and the second set of gate lines of the second touch block for a single horizontal time period;

a common voltage generator for concurrently supplying common voltages (Vcom) of;

a first waveform to all the first set of common lines and the second set of common lines for a display time period during which an image is displayed by the LCD panel; and

a second waveform to the second set of common lines of the second touch block rather than the first touch block to which the high-potential gate driving signal is being currently applied through the first set of gate lines for detecting a touch input for a touch time period less than the single horizontal time period; and

a touch detection circuit for detecting a touched position on the liquid crystal (LC) panel through the second waveform common voltages,

wherein the first waveform common voltage is a direct current (DC) common voltage corresponding to a pixel voltage of a pixel provided at the LC panel,

wherein the second waveform common voltage is an alternating current (AC) common voltage including multiple repetitive square waveforms within the touch time period,

wherein, within the single horizontal period, the high-potential gate driving signal partially overlaps and precedes the second waveform common voltage, and

wherein the second waveform common voltage swings at constant intervals.

2. The in-cell touch type LCD device of claim 1, wherein the high-potential gate driving signal and the second waveform common voltage overlap with each other for a time period of at least 70% of the single horizontal time period (1H).

3. The in-cell touch type LCD device of claim 1, wherein:

the high-potential gate driving signal has a time period more than 2 horizontal time periods (2H); and

an n^th high-potential gate driving signal and an n+1^th high-potential gate driving signal overlap each other for the single horizontal time period (1H).

7. The in-cell touch type LCD device of claim 1, wherein the first waveform is also applied to the first touch block while the second waveform is applied to the second touch block.

4. A method for driving an in-cell touch type liquid crystal display (LCD) device including an LCD panel including a first touch block, including a first set of gate lines and a first set of common lines, and a second touch block, including a second set of gate lines and a second set of common lines, the method comprising:

sequentially applying a high-potential gate driving signal to the first set of gate lines of the first touch block and the second set of gate lines of the second touch block for a single horizontal time period; and

concurrently applying common voltages (Vcom) of;

a first waveform to all the first set of common lines and the second set of common lines for a display time period during which an image is displayed by the LCD panel; and

a second waveform to the second set of common lines of the second touch block, rather than the first touch block to which the high-potential gate driving signal is being currently applied through the first set of gate lines for detecting a touch input for a touch time period less than the single horizontal time period,

wherein the first waveform common voltage is a direct current (DC) common voltage corresponding to a pixel voltage of a pixel provided at the liquid crystal (LC) panel,

wherein the second waveform common voltage is an alternating current (AC) common voltage including multiple repetitive square waveforms within the touch time period, and

wherein, within the single horizontal time period, the high-potential gate driving signal partially overlaps and precedes the second waveform common voltage.

5. The method of claim 4, wherein the high-potential gate driving signal and the second waveform common voltage overlap with each other for a time period of at least 70% of the single horizontal time period (1H).

6. The method of claim 4, wherein:

the high-potential gate driving signal has a time period more than 2 horizontal time periods (2H); and

an n^th high-potential gate driving signal and an n+1^th high-potential gate driving signal overlap each other for the single horizontal time period (1H).

8. The method of claim 4, wherein the first waveform is also applied to the first touch block while the second waveform is applied to the second touch block.