KR101327836B1 - Liquid Crystal Display Device - Google Patents

Abstract

The occurrence of optical leakage from the gap between the gate line and the common line is suppressed, thereby improving display quality.

A liquid crystal display device in which a gate line and a data line cross each other to define a pixel area, the liquid crystal display device being formed near an intersection of the gate line and the data line of the pixel area and connected to the gate line, and the data line. A transistor having a drain electrode connected to the gate electrode, a source electrode connected to the pixel ITO electrode formed at the pixel region, a common line formed at the pixel region, and formed between the gate line and the common line, and shielding backlight light. It is provided with a light shielding means.

Backlight, TFT, shielding means, gate line, data line, common line

Description

[0001] The present invention relates to a liquid crystal display device,

1 is a plan view showing the structure of a conventional liquid crystal display device.

2 is a cross-sectional view showing the configuration of a conventional liquid crystal display device.

3 is a plan view showing the configuration of a liquid crystal display device according to an embodiment of the present invention.

4 is a cross-sectional view showing the configuration of a liquid crystal display device according to an embodiment of the present invention.

5 is a plan view showing a configuration of a modification of the liquid crystal display device according to the embodiment of the rod invention.

6 is an explanatory diagram showing a manufacturing process of the liquid crystal display device according to the embodiment of the present invention.

7 is an explanatory diagram showing a manufacturing process of the liquid crystal display device according to the embodiment of the present invention.

8 is an explanatory diagram showing a manufacturing process of the liquid crystal display device according to the embodiment of the present invention.

9 is an explanatory diagram showing a manufacturing process of the liquid crystal display device according to the embodiment of the present invention.

DESCRIPTION OF THE DRAWINGS FIG.

1,101: gate line 2,102: data line

3,103 common line 4,104 pixel ITO electrode

5,105: pixel ITO common electrode 6,106: source electrode

7,107: drain electrode 8,108: load capacity

9A, 9B, 109A, 109B: Contact hole 10, 110: First glass substrate

11,111 insulating film 12,112 insulating film

13,113: alignment layer 15,115 liquid crystal

17,117: alignment layer 18,118: color filter layer

19,119: black matrix layer 20,120: second glass substrate

30,130: B / L light 40,41,50,51: shielding means

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to liquid crystal display devices, and more particularly to transmissive and transflective liquid crystal display devices.

1 is a view showing the configuration of a conventional liquid crystal display device.

In FIG. 1, 101 is a gate line, 102 is a data line, 103 is a common line, 104 is a pixel ITO electrode, 105 is a pixel ITO common electrode, and 106 and 107 are source electrodes constituting a thin film transistor (hereinafter referred to as TFT). And the drain electrode, 108 is a load capacitance, and 109A and 109B are contact holes.

In the detailed description, the drain electrode 107 is connected to the data line 102, and the source electrode 106 is connected to the pixel ITO electrode 105 formed in the pixel region.

In addition, the load capacitance 108 includes the hatched portion of FIG. 1, that is, the overlapped portion of the common line 103 and the source electrode 106 of the TFT, and the overlapped portion of the common line 103 and the pixel ITO electrode 104. It is an included portion (except for a portion of the source electrode 106 of the TFT).

2 is a cross-sectional view taken along line A-A 'in Fig.

As shown in FIG. 2, the conventional liquid crystal display device is composed of a color filter substrate (upper substrate in FIG. 2) and a TFT array substrate (lower substrate in FIG. 2) bonded via a liquid crystal 115. As shown in FIG.

In the TFT array substrate, as shown in FIG. 2, the gate line 101 and the common line 103 are formed on the first glass substrate 110 at regular intervals from each other.

In addition, an insulating layer 111 is formed on the entire surface of the first glass substrate 110 including the gate line 101 and the common line 103. The insulating film 111 is made of SiOx or SiNx, for example.

The source electrode 106 and the drain electrode 107 which are signal lines are formed on the insulating film 111. The source electrode 106, the drain electrode 107, and the gate electrode that is part of the gate line 101 constitute a TFT.

Signal lines, such as the source electrode 106 and the drain electrode 107, are formed in a multilayer structure as shown in FIG. On the insulating film 111 on the front surface including the signal lines such as the source electrode 106 and the drain electrode 107, an insulating film 112 is formed as a protective film made of SiNx or the like.

Further, the pixel ITO electrode 104 is formed in the region where the TFT is not formed. An alignment film 113 is formed on the insulating film 112 and the pixel ITO electrode 104.

As described above, the TFT array substrate includes a pixel region defined by the intersection of the gate line 101 and the data line 102 formed on the first glass substrate 110 with each other, and the gate line 101 and the data line for each pixel region. A TFT formed near the intersection of the 102 and the pixel ITO electrode 104 formed in the pixel region are provided.

The TFT temporarily stores the data signal from the data line 102 in the load capacitor 108 in accordance with the gate signal from the gate line 101. The data signal stored at this time becomes a voltage based on the common electrode applied to the common line 103. The pixel ITO electrode 104 made of a transparent conductive layer drives the liquid crystal 115 according to the voltage of the pixel ITO electrode 104 by the data signal so that an image is reflected in the pixel region.

As shown in FIG. 2, the color filter array substrate has a black matrix layer 119 formed on the second glass substrate 120, a color filter layer 118 formed thereon, and an alignment layer formed on the color filter layer 118. 117 is formed.

Thus, the color filter substrate is provided with the black matrix layer 119 and the color filter layer 118 which were formed in turn on the 2nd glass substrate 120. FIG. The black matrix constituting the black matrix layer 119 divides an area on the second glass substrate 120 into a plurality of cell areas in which the color filter layer 118 is formed, and prevents light interference and reflection of external light between adjacent cells. do.

The color filter layer 118 divides the cell region divided by the black matrix layer 119 into red (R), green (G), and blue (B), and transmits RGB color light, respectively.

The liquid crystal 115 having the dielectric anisotropy rotates according to the electric field formed by the data signal of the pixel ITO electrode 104 and the common voltage Vcom of the common electrode, and realizes gradation by adjusting the light transmittance.

The conventional liquid crystal display device is constructed as described above, and in the conventional array pattern, the backlight disposed below the TFT array substrate, i.e., the rear surface of the liquid crystal panel (B) from the gap between the gate line 101 and the common line 103, is described below. B / L light 130 from < RTI ID = 0.0 > / L < / RTI >

In a switching device using a semiconductor layer such as a TFT, when light is irradiated to a semiconductor, a carrier is generated and an off current increases, so that display mura, cross talk, contrast defect, etc. This occurs and the display material ages.

Conventionally, optical leakage has not been so much a problem, but in recent years, a video product or the like requires a surface luminance of 500 nits, and optical leakage has become a problem due to an increase in B / L luminance.

A liquid crystal display device having a structure for preventing optical leakage of the TFT portion is also proposed (see Patent Document 1, for example).

In the conventional liquid crystal display device described in Patent Literature 1, there is no light leak from the gap between the gate line 101 and the common line 103, and the light leak in the TFT portion is a problem.

The liquid crystal display device of Patent Literature 1 has a structure in which a black matrix layer is removed in order to reduce the cost. Therefore, the optical leakage of the TFT portion becomes a problem, so that a metal film or the like overlaps with the semiconductor layer of the TFT and the source electrode and drain electrode. The light shielding film which consists of these is formed.

Patent Document 1: Japanese Patent Application Laid-Open No. 10-20298

In the conventional liquid crystal display device shown in Figs. 1 and 2, the B / L light 130 from the B / L formed on the lower side of the TFT array substrate between the gate line 101 and the common line 103. This has caused a problem that aging of display quality occurs by reflecting from the opposing color filter substrate and irradiating the TFT to become a source of optical leakage.

Further, in the conventional liquid crystal display device described in Patent Document 1, even if the optical leakage of the TFT portion is prevented, there is no measure regarding the optical leakage from the gap between the gate line and the common line, so that optical leakage from the corresponding place occurs. There was a problem to say.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to obtain a liquid crystal display for improving the display material by suppressing the occurrence of optical leakage from the gap between the gate line and the common line.

The liquid crystal display according to the present invention for achieving the above object is a liquid crystal display device in which the gate line and the data line cross each other to define a pixel area, the liquid crystal display device in the vicinity of the intersection of the gate line and the data line of the pixel area A transistor having a gate electrode connected to the gate line, a drain electrode connected to the data line, a source electrode connected to a pixel ITO electrode formed on the pixel region, a common line formed on the pixel region, And light blocking means formed between the gate line and the common line and shielding backlight light.

3 is a diagram showing the configuration of a liquid crystal display device according to an embodiment of the present invention.

3, 1 is a gate line, 2 is a data line, 3 is a common line, 4 is a pixel ITO electrode, 5 is a pixel ITO common electrode, 6 and 7 are source and drain electrodes constituting a TFT, and 8 is a load capacitance. , 9A and 9B are contact holes.

The load capacitance 8 is the sum of the hatched portions of FIG. 3, that is, the overlapping portion of the common line 3 and the source electrode 6 of the TFT, and the overlapping portion of the common line 3 and the pixel ITO electrode 4. Part (except for the part of the source electrode 6 of the TFT).

4 is a cross-sectional view taken along line BB ′ of FIG. 3.

As shown in FIG. 4, the liquid crystal display device according to the embodiment of the present invention comprises a color filter substrate (upper substrate in FIG. 4) and a TFT array substrate (lower substrate in FIG. 4) bonded via a liquid crystal 15. As shown in FIG. do.

In the TFT array substrate, as shown in FIG. 4, the gate line 1 and the common line 3 are formed on the first glass substrate 10 at regular intervals from each other.

In addition, an insulating film 11 is formed on the entire surface of the first glass substrate 10 including the gate line 1 and the common line 3. The insulating film 11 is made of SiOx or SiNx, for example.

The source electrode 6 and the drain electrode 7 which are signal lines are formed on the insulating film 11, and shielding means 40 and 41 for blocking an optical leak are formed. The shielding means 40 and 41 are mentioned later.

The source electrode 6, the drain electrode 7, and the gate electrode that is part of the gate line 1 constitute a TFT.

As shown in Fig. 4, the source electrode 6, the drain electrode 7, and the shielding means 40, 41 are formed in a multilayer structure.

In the example of FIG. 4, it consists of three layers, a-Si (amorphous silicon), n +, and a signal metal. On the insulating film 11 on the front surface including the signal lines such as the source electrode 6 and the drain electrode 7 and the light blocking means 40, 41, an insulating film 12 is formed as a protective film made of SiNx or the like.

Further, the pixel ITO electrode 4 is formed in the region where the TFT is not formed. An alignment film 13 is formed on the insulating film 12 and the pixel ITO electrode 4.

In the color filter array substrate, as shown in FIG. 2, a black matrix layer 19 is formed on the second glass substrate 20, a color filter layer 18 is formed thereon, and an alignment layer is formed on the color filter layer 18. (17) is formed.

 The black matrix constituting the black matrix layer 19 is formed on the second glass substrate 20 in a matrix form.

Such a black matrix divides an area on the second glass substrate 20 into a plurality of cell areas in which the color filter layer 18 is formed, and prevents light interference and reflection of external light between adjacent cells.

The color filter layer 18 divides the cell region divided by the black matrix layer 19 into red (R), green (G), and blue (B), and transmits RGB color light, respectively.

As described above, in the present embodiment, as shown in FIGS. 3 and 4, shielding means 40 and 41 are formed to shield the optical leakage in the gap between the gate line 1 and the common line 3. It is.

The shielding means 40, 41 are made of the same material as the source electrode 6 and the drain electrode 7, and are formed simultaneously in the same mask process for forming them.

Other configurations and operations are basically the same as those shown in Figs. 1 and 2, and will be omitted here with reference to the description thereof.

As described above, in this embodiment, the B / L light 30 penetrating from the gap between the gate line 1 and the common line 3 is shielded by the shielding means 40, 41 formed from the floating signal line. , The B / L light irradiated to the TFT can be greatly reduced, and the optical leakage countermeasure can be taken.

5 is a cross-sectional view showing a modification of the embodiment. In this modified example, as shown in FIG. 5, shielding means 50 and 51 are formed instead of the shielding means 40 and 41 shown in FIG.

The shielding means 50 and 51 are disposed so that a portion of the shielding means 50 and 51 overlaps the gate line 1 and the common line 3 in the horizontal direction through the insulating film 11. That is, the shielding means 50 and 51 have a width larger than the gap between the gate line 1 and the common line 3 and overlap with the gate line 1 and the common line 3 in the horizontal direction. I have a place to do it.

The shielding means 50 and 51 are made of the same material as the source electrode 6 and the drain electrode 7 in the same manner as the shielding means 40 and 41, and are simultaneously formed in the same mask process for forming them. Other configurations are the same as those in FIGS. 3 and 4 described above.

As described above, in the modification of FIG. 5, the shielding means 50 and 51 are arranged to overlap the gate line 1 and the common line 3, so that a further light shielding effect can be obtained. Further, since the shielding means 50, 51 are constructed from floating signal lines, there is no electrical problem.

6 to 9 are views illustrating a manufacturing process of the TFT array substrate in the embodiment of the present invention.

The TFT array substrate according to this embodiment is formed using a plurality of mask processes.

One mask process includes a plurality of processes, such as a photoresist coating process, a mask fitting process, an exposure process, a developing process, an etching process, a photoresist removing process, and an inspection process. Since the mask process proceeds by a general conventional method, detailed description is omitted here.

First, as shown in FIG. 6, the gate line 1 and the common line 3 are formed on the 1st glass substrate 10 by a 1st mask process. And the thick part of FIG. 6 is a member formed by a 1st mask process, and what was shown with the thin line is not formed at this time, but is described with the solid line for reference.

7 to 8 are also the same, and the thick line part is formed by the mask process at that time, and the thin line part is a member formed by the pre mask process or the post mask process.

As shown in FIG. 7, the load is applied to the data line 2, the source electrode 6, the drain electrode 7, the shielding means 40, 41 and the common line 3 by the second mask process. The capacitance 8 is formed. The multilayers of the source electrode 6 and the drain electrode 7 are formed by halftone exposure.

Next, as shown in FIG. 8, contact hole 9A, 9B is formed by a 3rd mask process. The contact hole 9A is for electrically connecting the pixel ITO electrode 4 and the source electrode 6 of the TFT, and the contact hole 9B electrically connects the common line 3 and the pixel ITO common electrode 5. It is for connection.

9, the pixel ITO common electrode 5 and the pixel ITO electrode 4 are formed by a 4th mask process.

In this way, the TFT array substrate according to the present embodiment is formed using a plurality of mask processes.

As described above, in the liquid crystal display device according to the present embodiment, the gate line 1 is formed between the gate line 1 and the common line 3 by forming shielding means 40, 41 or 50, 51 composed of floating signal lines. It is possible to shield the B / L light 30 coming in between the gap between (1) and the common line 3, and it is possible to significantly reduce the light irradiated to the TFT.

As a result, the generation of display stains, crosstalk, and poor contrast can be suppressed and the display quality can be improved.

In addition, since the shielding means 40, 41 or 50, 51 is formed of the same material by the same mask process as the source electrode 6 and the drain electrode 7 which comprise a TFT, it does not require a special process, and it is easy and It can be formed inexpensively.

As shown in the modification of Fig. 5, the shielding means 50, 51 are arranged so as to slightly overlap the gate line 1 and the common line 3, so that further light leakage can be prevented. Can improve the quality.

As described above, the present invention is a liquid crystal display device in which a gate line and a data line cross each other to define a pixel area, and are formed in the vicinity of an intersection of the gate line and the data line of the pixel area and connected to the gate line. A transistor having a gate electrode, a drain electrode connected to the data line, a source electrode connected to a pixel ITO electrode formed in the pixel region, a common line formed in the pixel region, and between the gate line and the common line. Since the liquid crystal display device is formed and includes a light shielding means for shielding backlight light, the light shielding means can suppress the occurrence of light leakage from the gap between the gate line and the common line, thereby improving display quality.

Claims (3)

In a liquid crystal display device in which a gate line and a data line cross each other to define a pixel area, A gate electrode connected to the gate line, a drain electrode connected to the data line, and a pixel ITO electrode formed on the pixel region, which are formed near an intersection of the gate line and the data line of the pixel region. A transistor having a source electrode, A common line formed on the same layer as the gate line in the pixel region and spaced apart from the gate line; A light blocking means formed between the gate line and the common line and shielding backlight light; And the light blocking means is formed on the same layer as the drain electrode and the source electrode and is floated. The liquid crystal display device according to claim 1, wherein the light blocking means is made of the same material as the drain electrode and the source electrode. The light blocking means has a width larger than a gap between the gate line and the common line, and is disposed to overlap the gate line and the common line. LCD display device.

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