KR100862871B1 - In-Plane Switching mode Liquid Crystal Display Device - Google Patents

Abstract

A transverse electric field liquid crystal display device according to the present invention includes an upper substrate and a lower substrate; A plurality of gate lines and a common line formed on the lower substrate, a plurality of data lines crossing the gate line to define a plurality of pixel regions, a thin film transistor positioned at an intersection of the gate line and the data line, A plurality of common electrodes vertically branched from a common line on the pixel region, and a plurality of pixel electrodes alternately arranged with the common electrode; A black matrix formed on the upper substrate and extending over an edge of the outermost pixel region of the lower substrate; Characterized in that the liquid crystal layer interposed between the upper substrate and the lower substrate is included.

According to the present invention, in the display area of the transverse electric field type liquid crystal display device array substrate, the last block of the outermost line is slightly enlarged to cover the black matrix area of the upper substrate, thereby eliminating light leakage, thereby improving productivity. There is an advantage to improve.

Description

Transverse electric field type liquid crystal display device {In-Plane Switching mode Liquid Crystal Display Device}

1 is a view schematically showing a general liquid crystal panel.

2 is a schematic cross-sectional view of a portion of a conventional IPS mode liquid crystal display device;

3 is a plan view showing a part of an outer portion of a conventional array substrate for an IPS mode liquid crystal display device.

4 is a view briefly showing a liquid crystal panel of a transverse electric field type liquid crystal display device according to the present invention;

5 is a cross-sectional view showing a part of an outer portion of a liquid crystal panel of a transverse electric field type liquid crystal display device according to the present invention;

<Explanation of symbols for the main parts of the drawings>

100: upper substrate 110: black matrix

120: sub color filter 200: lower substrate

220: block 220 ': outermost block

230: gate line 240: data line

250: display area 260: non-display area

270 dummy data line 300 pixel region                 

310: gate electrode 320: source electrode

330: drain electrode 340: common electrode

350: pixel electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device operating in an in-plane switching (hereinafter referred to as IPS mode), and more particularly to a structure for removing light leakage defects occurring at the outermost portion of the IPS mode liquid crystal panel display area. It is about.

In general, the driving principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. Since the liquid crystal is thin and long in structure, the liquid crystal has directivity in the arrangement of molecules and can be artificially applied to the liquid crystal to control the direction of the molecular arrangement.

Currently, an active matrix liquid crystal display device in which thin film transistors (TFTs) and pixel electrodes connected to the thin film transistors are arranged in a matrix manner has attracted the most attention due to its excellent resolution and ability to implement video.

1 is a view schematically showing a general liquid crystal panel.

Referring to FIG. 1, the structure of a liquid crystal panel which is a basic component of a general liquid crystal display device will be described.

The liquid crystal display has a color filter 7 including a black matrix 6 and a sub color filter 8 R, G, and B, and a transparent common electrode 18 formed on the color filter. And a lower substrate 22 having an array wiring including a substrate 5, a pixel region P, a pixel electrode 17 formed on the pixel region, and a thin film transistor as a switching element T. The upper substrate ( The liquid crystal 14 is filled between 5) and the lower substrate 22.

The lower substrate 22 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is disposed in a matrix form, and a gate line 13 and a data line 15 passing through the plurality of thin film transistors are formed.

The pixel region P is a region where the gate line 13 and the data line 15 cross each other. The pixel electrode 17 formed on the pixel region P uses a transparent conductive metal having a relatively high transmittance of light, such as indium-tin oxide (ITO).

Referring to the operation of the liquid crystal panel, a voltage is applied between the common electrode 18 formed on the upper substrate 5 and the pixel electrode 17 formed on the lower substrate 22, thereby providing a voltage between the two substrates. The image is displayed by changing the amount of light transmitted according to the arrangement of the liquid crystals 14 to be filled.

As described above, the liquid crystal display device having the structure in which the common electrode 18 is perpendicular to the pixel electrode 17 drives the liquid crystal by an electric field applied up and down, and has excellent characteristics such as transmittance and aperture ratio. The common electrode of the substrate serves as a ground to prevent destruction of the liquid crystal cell due to static electricity.

However, the liquid crystal drive by the electric field applied up and down has a disadvantage in that the viewing angle characteristic is not excellent, and thus a new technique for overcoming the above disadvantage has been proposed, and the transverse electric field type liquid crystal described below is proposed. The display device can overcome the disadvantage of the viewing angle characteristic.

2 is a cross-sectional view schematically illustrating a part of a conventional IPS mode liquid crystal display device.

Referring to FIG. 2, in the conventional IPS mode liquid crystal display, the pixel electrode 34 and the common electrode 36 are formed on the same plane on the substrate 30. That is, the liquid crystal 10 is operated by the horizontal electric field of the pixel electrode 34 and the common electrode 36 on the same substrate 30.

In addition, a color filter substrate 32, that is, an upper substrate, is formed on the liquid crystal layer 10. Thus, in the IPS mode liquid crystal display device, since both the pixel electrode and the common electrode exist on the same plane, the transverse electric field is used. There is a feature that uses.

An overcoat layer 44 is formed on the upper substrate 32 to protect the color resin 42. The sealant 40 for bonding the upper substrate 32 and the lower substrate 30 to the upper substrate 32 is formed. And along the edge of the lower substrate 30.

In addition, a black matrix (not shown) is formed on the upper substrate 32. Since the IPS mode liquid crystal display drives a liquid crystal in a transverse electric field, the black matrix is formed of metal to prevent distortion of the electric field. Use organic materials (resins).

3 is a plan view showing a portion of an outer portion of a conventional array substrate for an IPS mode liquid crystal display device.

In general, an array substrate of a liquid crystal display device may be divided into a display area which is an area where an optical beam is transmitted and displays an image, and a non-display area where the light beam is blocked by a black matrix so that an image is not displayed. The portion shown in the drawing is a pixel area at the boundary between the display area and the non-display area.

Referring to FIG. 3, the array substrate in the display area is formed in parallel with the gate line 50 and the common line 54 in the horizontal direction, and the data line 60 is the gate line in the vertical direction. It is formed perpendicular to the 50 and the common line 54.

In addition, a gate electrode 52 is formed on one side of the gate line 50, and a source electrode 62 is formed on the data line 60 near the gate electrode 52. The overlapping area is formed, and the drain electrode 64 is formed at a position corresponding to the gap between the source electrode 62 and the gap.

In addition, the common line 54 is formed with a plurality of common electrodes 54a branched from the common line 54. A lead wire 66 is connected to the drain electrode 64. Reference numeral 66 denotes a plurality of pixel electrodes 66a branched from the lead wire 66.

In this configuration, the common electrode 54a and the pixel electrode 66a are alternately arranged, and the common electrode configured in the pixel region is always in a state where a common voltage input from the common line is applied.

In addition, various levels of image signals are applied to the pixel electrode through the data line according to the level of the gate voltage applied to the gate electrode. Accordingly, in the pixel region, the lateral electric field is distributed by voltages applied to the pixel electrode and the common electrode, and the degree of alignment of the liquid crystal varies according to the intensity of the electric field.

In this way, a region in which a transverse electric field is distributed by the pixel electrode and the common electrode to display an image is called a block, and a plurality of blocks may be formed in each pixel region, and generally four blocks in one pixel region. This existing four-block form is used a lot.

Further, in the non-display area, although the light beam is blocked by a black matrix (not shown) formed on the upper substrate, in the non-display area, pixels and dummy data lines 61 formed in the display area in a predetermined portion are also provided. Is formed.

This is to perform the rubbing from the non-display area in the rubbing process so as to have a uniform effect on the rubbing in the display area.

In the non-display area, a separate dummy line connected to the antistatic circuit and the antistatic circuit and to which the same signal as the signal flowing through the common electrode is applied is formed.

However, in the conventional IPS mode liquid crystal display device, in the outermost block formed by the rightmost outer pixel of the display area, that is, the outermost common electrode and the pixel electrode among the pixels of the blue line, the non-display area dummy. The undesired electric field is affected by the data line, which causes light leakage to appear brighter than the central display area of the liquid crystal display.

 The present invention provides a transverse electric field type liquid crystal display device which prevents light leakage by covering the last block of the outermost line in the display area of the transverse electric field type liquid crystal display device array substrate by slightly enlarging the black matrix area of the upper substrate. Has its purpose.

A horizontal electric field liquid crystal display device according to the present invention for achieving the above object,

An upper substrate and a lower substrate;

A plurality of gate lines and a common line formed on the lower substrate, a plurality of data lines crossing the gate line to define a plurality of pixel regions, a thin film transistor positioned at an intersection of the gate line and the data line, A plurality of common electrodes vertically branched from a common line on the pixel region, and a plurality of pixel electrodes alternately arranged with the common electrode;

A black matrix formed on the upper substrate and extending over an edge of the outermost pixel region of the lower substrate;

Characterized in that the liquid crystal layer interposed between the upper substrate and the lower substrate is included.

The lower substrate may be divided into a display area and a non-display area.

In addition, the outermost pixel area of the lower substrate may be a pixel area line formed in the outermost part of the display area of the lower substrate.                     

In addition, the pixel region line is a pixel region line subjected to an unwanted electric field by the data line formed in the non-display region, and the pixel region line is a blue line.

In addition, the data line formed in the non-display area is always grounded to maintain 0V.

According to the present invention, in the display area of the transverse electric field type liquid crystal display device array substrate, the last block of the outermost line is slightly enlarged to cover the black matrix area of the upper substrate, thereby eliminating light leakage, thereby improving productivity. There is an advantage to improve.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a view briefly showing a liquid crystal panel of a transverse electric field type liquid crystal display device according to the present invention.

Referring to FIG. 4, the transverse electric field type liquid crystal panel according to the present invention includes an upper substrate 100 including a black matrix 110 (BM) and a sub color filter 120 (R, G, B). ), And a lower substrate 200 in which an array wiring including a pixel electrode (not shown) and a common electrode (not shown) alternately formed on the pixel region P and the pixel region and a thin film transistor T as a switching element are formed. The liquid crystal (not shown) is filled between the upper substrate 100 and the lower substrate 200.

Here, the lower substrate 200 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is positioned in a matrix form, and the plurality of thin film transistors are formed at the intersection of the gate line 230 and the data line 240. Is formed.

The pixel area P is an area defined by the gate line 230 and the data line 240 crossing each other, and a pixel electrode (not shown) and a common electrode (not shown) are formed in the pixel area. That is, the liquid crystal is operated by a horizontal electric field of the pixel electrode (not shown) and the common electrode (not shown) on the same substrate.

In this way, a region in which the lateral electric field is distributed by the pixel electrode (not shown) and the common electrode (not shown) to display an image is called a block 220, and a plurality of blocks 220 are formed in each pixel area. In general, a four-block type in which four blocks 220 exist in one pixel area is commonly used.

In addition, the lower substrate 200 is entirely blocked by the display area 250, which is an area where light beams are transmitted to display an image, and a black matrix 110 formed on the upper substrate 100 so that the image is blocked. The non-display area 260 may not be displayed, and the non-display area 260 is formed at an outer portion of the lower substrate.

Also, in the non-display area 260, although the light beam is blocked by the black matrix 110 formed on the upper substrate 100, the pixel formed in the display area in a portion of the non-display area 260 is also blocked. And dummy data lines 270 are formed.

This is to perform the rubbing from the non-display area in the rubbing process so as to have a uniform effect on the rubbing in the display area.

In addition, a color filter substrate, that is, an upper substrate 100 is formed on the liquid crystal layer, and an overcoat (not shown) layer is formed on the upper substrate 100 to protect the color resin. A sealant (not shown) for bonding the substrate is formed along the edges of the upper substrate 100 and the lower substrate 200.

In addition, a black matrix 110 is formed on the upper substrate 100, which is generally the non-display area 260, that is, the outer portion of the upper substrate 100 so that an image is not displayed because the light beam is not transmitted. On the whole.

Here, in the present invention, the black matrix 110 is formed to be enlarged to a part of the display area 250, that is, a part of the area where the light beam is transmitted and the image is displayed, so that the display area ( In order to improve the productivity, the light leakage phenomenon is eliminated by covering the last outermost block 220 'line of the outermost line at 250 in a somewhat enlarged manner.

In FIG. 5, the black matrix area enlarged on the last outermost block 220 ′ line of the outermost line in the display area 250 is displayed as a dark area.

5 is a cross-sectional view showing a part of the outer portion of the liquid crystal panel of the transverse electric field type liquid crystal display device according to the present invention.

5 is a cross-sectional view of a specific portion A-A 'shown in FIG. 4.

Referring to Fig. 5, the liquid crystal display of the transverse electric field system according to the present invention will be described.

An array substrate of a general liquid crystal display device includes a display area 250 which is an area where light beams are actually transmitted to display an image, and a non-display area 260 where the light beam is blocked by the black matrix 110 so that an image is not displayed. In FIG. 5, the portion shown in FIG. 5 is the pixel area 300 at the boundary between the display area 250 and the non-display area 260 and the upper substrate 100 thereon.

The array substrate in the display area 250 is formed by forming a parallel gate line (230 of FIG. 4) and a common line (not shown) in a horizontal direction, and a data line (240 of FIG. 4) in the vertical direction. It is formed perpendicular to the gate line and the common line.

In addition, a gate electrode 310 is formed at one side of the gate line, and a source electrode 320 is formed to overlap a predetermined area with the gate electrode 310 in the data line near the gate electrode 310. The drain electrode 330 is formed at a position corresponding to the source electrode 320 with a gap therebetween.

In addition, the common line includes a plurality of common electrodes 340 branched from the common line, and a drain line is connected to the drain electrode 330, and the plurality of pixels branched from the draw line. The electrode 350 is formed.

In this configuration, the common electrode 340 and the pixel electrode 350 are alternately arranged, and the common electrode 340 configured in the pixel region is in a state where a common voltage input from the common line is always applied.                     

In addition, various levels of image signals are applied to the pixel electrode 350 based on the level of the gate voltage applied to the gate electrode 310. Accordingly, the lateral electric field is distributed by the voltages applied to the pixel electrode 350 and the common electrode 340 in the pixel region, and the degree of alignment of the liquid crystals varies according to the intensity of the electric field.

The pixel electrode 350 and the common electrode 340 may be formed on the same layer as the gate electrode 310 or the source / drain electrodes 320 and 330, and the gate insulating layer 311 or the protective layer 312 may be formed on the same layer. It is also possible to form in different layers in between, and it is applicable to any structure irrespective of the said structure.

In addition, although the light beam is blocked by the black matrix 110 formed on the upper substrate 100 in the outer portion of the non-display area 260, that is, the liquid crystal panel, a portion of the non-display area 260 is also fixed. In the display panel, pixels and dummy data lines 270 formed in the display area 250 are formed.

This is to perform the rubbing from the non-display area 260 in the rubbing process to have a uniform effect on the rubbing in the display area, and the dummy data line 270 is always grounded to maintain 0V.

Here, the upper substrate 100 is formed to include a black matrix 110 and the sub color filter 120.

In the non-display area 260, a separate dummy line (not shown) connected to the antistatic circuit (not shown) and the antistatic circuit and to which the same signal as the signal flowing through the common electrode is applied is formed. .                     

However, in an array substrate having such a structure, the pixel area 300 at the boundary between the display area 250 and the non-display area 260, that is, the rightmost pixel area 300 of the display area, is Undesired by the dummy data line 270 of the non-display area 260 in the outermost block 220 'formed by the outermost common electrode 340 and the pixel electrode 350 among the pixels of the blue line. It is not possible to eliminate the occurrence of the light leakage phenomenon that is affected by the electric field and becomes brighter than the central display area of the liquid crystal display.

Accordingly, the transverse electric field type liquid crystal display device according to the present invention includes a black matrix 110 formed on the upper substrate 100 only for the non-display area 260 of the related art in order to remove the same. As described above, the display area 250 is formed to be enlarged to the last block 220 'of the outermost line, thereby essentially eliminating the line light leakage phenomenon.

This does not add a separate process to the conventional manufacturing process of the liquid crystal display, and also enlarges the black matrix 110 only for the last block 220 'of the edge of the outermost pixel line of the display area. There is an advantage that the light leakage phenomenon can be suppressed with little effect on the aperture ratio of.

As described above, according to the transverse electric field type liquid crystal display device according to the present invention, the last block of the outermost line in the display area of the transverse electric field type liquid crystal display device array substrate is somewhat enlarged to cover the black matrix area of the upper substrate. As a result, the light leakage phenomenon is eliminated, thereby improving productivity.

Claims (6)

Upper substrate; A lower substrate divided into a display area for displaying an image and a non-display area for not displaying an image; A plurality of gate lines and a common line formed on the lower substrate, a plurality of data lines crossing the gate line to define a plurality of pixel regions, a thin film transistor positioned at an intersection of the gate line and the data line, A plurality of common electrodes vertically branched from a common line on the pixel region, and a plurality of pixel electrodes alternately arranged with the common electrode; A plurality of blocks included in the pixel area for displaying an image in which a transverse electric field is distributed by the pixel electrode and the common electrode; A black matrix formed on the upper substrate so as to correspond to the non-display area of the lower substrate and extending to the last block of the outermost line of the display area of the lower substrate; And A transverse electric field type liquid crystal display device comprising a liquid crystal layer interposed between the upper substrate and the lower substrate. delete delete The method of claim 1, And the last block of the outermost line of the display area is subjected to an unwanted electric field by a data line formed in the non-display area. The method of claim 4, wherein And the last block of the outermost line of the display area includes pixels of a blue line. The method of claim 1, And a data line formed in the non-display area is always grounded to maintain 0V.

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