Liquid crystal display device having touch panel

• US 8,937,690 B2
• Filed: 11/29/2012
• Issued: 01/20/2015
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Nam, Seunghee, Shin, Woosup, Yoo, Soonsung, Kim, Namkook
• Primary Examiner(s): Kim, Dennis Y
• Application Number:
  US13/689,448
• Publication Number:
  US 20130135540A1
• Time in Patent Office: 782 Days
• Field of Search: 349/12
• US Class Current: 349/12
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer

Abstract

A liquid crystal display device including a touch panel having a simple structure and minimized thickness is provided. The liquid crystal display (LCD) device according to an embodiment includes a liquid crystal panel and a touch panel structure. The liquid crystal panel includes a thin film transistor (TFT) array substrate, a color filter substrate having a black matrix therein, and a liquid crystal layer disposed between the TFT array substrate and the color filter substrate. The touch panel structure includes at least one touch sensor. Each touch sensor includes a first electrode disposed within the liquid crystal panel, and a second electrode disposed outside the liquid crystal panel.

Claims

1. A liquid crystal display (LCD) device comprising:

first and second base substrates;

gate lines and data lines formed on the first base substrate and defining a plurality of pixels;

thin film transistors (TFTs) formed in respective pixels;

a common electrode formed on the first base substrate;

a pixel electrode formed on the first base substrate and alternating with the common electrode so as to form an in-plane electric field parallel to a surface of the first base substrate;

a liquid crystal layer formed on the common electrode and formed under the second base substrate;

a black matrix and a color filter layer both formed between the second base substrate and the liquid crystal layer;

a first electrode formed below the black matrix and formed on a top surface of the liquid crystal layer, a width of the first electrode being less than that of the black matrix so that the first electrode is totally covered with the black matrix; and

a second electrode formed on the second base substrate to form a capacitance with the first electrode, wherein a variation of the capacitance is used to detect a touch input to the LCD device.

2. The liquid crystal display device of claim 1, wherein the first electrode is made of a metal, and the second electrode is made of indium tin oxide (ITO) or indium zinc oxide (IZO).

3. The liquid crystal display device of claim 1, wherein the first electrode is disposed directly under the black matrix and directly above the at least one of the gate lines and data lines.

4. The liquid crystal display device of claim 1, wherein the first electrode is arranged along the black matrix and substantially aligned with at least one gate line and at least one data line of at least one column or row of pixels to form a touch sensor.

5. The liquid crystal display device of claim 1, wherein the first electrode has a matrix shape.

6. The liquid crystal display device of claim 1, wherein one first electrode forming a single touch sensor is spaced apart by a certain interval from another adjacent first electrode forming a different touch sensor.

7. The liquid crystal display device of claim 6, wherein an interval between the touch sensors corresponds to a plurality of columns of pixels or a plurality of rows of pixels.

8. The liquid crystal display device of claim 1, wherein the second electrode is arranged in a stripe shape having a certain width.

9. The liquid crystal display device of claim 1, wherein at least a portion of the second electrode is arranged to cross or overlap the first electrode to form a single touch sensor.

10. The liquid crystal display device of claim 1, further comprising:

an overcoat layer formed between the black matrix and the first electrode, and being in contact with the liquid crystal layer.

11. The liquid crystal display device of claim 1, wherein the second electrode functions as an electrode for removing static electricity.

12. A liquid crystal display (LCD) device comprising:

a liquid crystal panel including;

a thin film transistor (TFT) array substrate,

a color filter substrate having a black matrix therein,

a liquid crystal layer disposed between the TFT array substrate and the color filter substrate, and

a common electrode formed under the liquid crystal layer; and

a touch panel structure including at least one touch sensor, each touch sensor including;

a first electrode disposed on the liquid crystal panel and disposed below the black matrix, a width of the first electrode being less than that of the black matrix so that the first electrode is totally covered with the black matrix, and

a second electrode disposed outside the liquid crystal panel and formed on the color filter substrate,

wherein the first electrode is not in contact with the common electrode.

13. The LCD device of claim 12, wherein the first electrode is in a shape of a matrix, and is disposed below the black matrix so as to be substantially aligned with at least a part of a pattern of the black matrix.

14. The LCD device of claim 12, wherein a width of the first electrode is less than a width of the black matrix.

15. The LCD device of claim 12, wherein the first electrode is in direct contact with the liquid crystal layer, and the first electrode is disposed directly under the black matrix and directly above at least one of gate lines and data lines provided in the TFT array substrate.

16. The LCD device of claim 12, wherein the first electrode is made of a metal, and the second electrode is made of indium tin oxide (ITO) or indium zinc oxide (IZO).

17. The LCD device of claim 12, wherein the LCD device is an in-plane switching mode LCD device.

18. The LCD device of claim 12, wherein the second electrode functions as an electrode for removing static electricity.