KR101717653B1 - Liquid crystal display panel - Google Patents

Abstract

The present invention discloses a liquid crystal display device. More particularly, the present invention relates to a liquid crystal display panel having a light blocking layer that effectively improves light leakage occurring in an edge region through structural modification of a liquid crystal display panel.
According to a preferred embodiment of the present invention, there is provided a liquid crystal display panel comprising a display region and a non-display region surrounding the display region, the lower substrate defining a plurality of pixel regions, A color filter for red (R), green (G), and blue (B) respectively corresponding to the regions of the lower substrate and a black matrix for separating the color filters by color, And a light blocking layer extending from the black matrix on the non-display area of the upper substrate is formed.
Accordingly, it is an object of the present invention to provide a liquid crystal display panel in which light leakage generated in a non-display area is prevented without using a separate light shielding member to improve image quality.

Description

[0001] LIQUID CRYSTAL DISPLAY PANEL [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (LCD), and more particularly, to a liquid crystal display (LCD) panel having a light blocking layer that effectively improves a light leakage phenomenon occurring in an edge region by changing a structure of the liquid crystal display panel.

2. Description of the Related Art [0002] With the development of information devices such as potable devices such as mobile phones and notebook computers and high-resolution and high-quality images such as HDTVs, flat panel displays Display Device) is increasing. As such flat panel display devices, a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and an organic light emitting diode (OLED) have been actively studied. However, And realization of a large area screen, a liquid crystal display (LCD) is in the spotlight at present.

The liquid crystal display device described above includes a liquid crystal display panel in which two opposing substrates are bonded together and an image is realized through the liquid crystal between the electric and optical characteristics of the liquid crystal therebetween, a driving circuit for controlling the liquid crystal display panel, And a backlight unit provided.

FIG. 1 is an exploded perspective view schematically showing a structure of a general liquid crystal display panel, and FIG. 2 is a cross-sectional view of an edge portion of the liquid crystal display panel of FIG.

As shown in the figure, the liquid crystal display panel comprises a lower substrate 2 and an upper substrate 3 bonded together to hold a uniform cell gap so as to face each other, and a liquid crystal layer interposed within the cell gap between the two substrates 2, And a liquid crystal layer (4).

The lower substrate 2 includes a plurality of gate lines 16 and data lines 17 arranged vertically and horizontally to define a plurality of pixel regions P and a plurality of gate lines 16 and data lines 17 extending in a crossing region of the gate lines 16 and the data lines 17 A thin film transistor T which is a switching element formed and a pixel electrode 18 formed on the pixel region P.

The upper substrate 3 is a color filter composed of a plurality of sub-color filters which realize the three primary colors of red (R), green (G) 6b and blue A black matrix 7 for separating the sub color filters from each other and shielding light transmitted through the liquid crystal layer 4 and a transparent common electrode 8 for applying a voltage to the liquid crystal layer 4 . Although not shown, an overcoat layer 9 for planarization is formed on the entire surface of the upper substrate 3.

The lower substrate 2 and the upper substrate 3 are held together by a spacer 11 by a sealant 14 formed along the outer periphery of each of the substrates 2 and 3 . The first and second polarizers 12 and 13 are attached to the outer surfaces of the substrates 2 and 3, respectively.

The liquid crystal display panel having such a structure is generally divided into a twisted nematic (TN) mode liquid crystal display panel and an in-plane switching (IPS) mode liquid crystal display panel. The TN mode liquid crystal display panel has the above- A pixel electrode 18 is formed on the lower substrate 2 for each unit pixel and a common electrode 8 is formed on the entire surface of the upper substrate 3. [ The liquid crystal layer 4 is driven by the electric field between the pixel electrode 18 formed on the lower substrate 2 and the common electrode 8 formed on the upper substrate 3. [

In the IPS mode liquid crystal display panel, the pixel electrode 18 and the common electrode 8 are formed with a constant spacing from the lower substrate 2. The liquid crystal layer 4 is driven by the horizontal electric field between the pixel electrode 18 formed on the lower substrate 2 and the common electrode 8. [

The liquid crystal display panel 1 is divided into a display area A / A in which an image is realized according to the electric field between the electrodes and a non-display area N / A surrounding the display area N / A The outer black matrix 7a formed in the non-display area N / A is formed in the inner black matrix 7b of the display area A / A in the inner display area A / A of the sealant 14, As shown in FIG. This is to prevent a light leakage from the light emitted from the light source into the bezel region of the light incident on the liquid crystal display panel 1.

However, the lower substrate 2 of the liquid crystal display panel 1 generally has a width larger than that of the upper substrate 3 for connection with the driving circuit. Therefore, as shown in Fig. 3, the non-display area N / A is formed to be wide including the area where the sealant 14 is formed outside the outer black matrix 7a in the non-display area N / A The light incident on this area causes light leakage, which causes the quality of the image to be realized by the liquid crystal display device to deteriorate.

Currently, a method of attaching a light shielding member to a bezel region of a liquid crystal display panel in order to solve a problem of image quality degradation due to a light leakage has been disclosed. However, this increases the cost of adding a light shielding member, There is a disadvantage in that the process time is extended.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above problems, and it is an object of the present invention to improve the quality of images realized by removing light leakage generated in a bezel region of a liquid crystal display panel without using a separate light- And to provide a liquid crystal display panel.

In order to achieve the above object, a liquid crystal display panel according to a preferred embodiment of the present invention is a liquid crystal display panel divided into a display area and a non-display area surrounding the display area, A lower substrate on which a plurality of signal lines and thin film transistors are formed to define a plurality of pixel regions; A red (R), green (G), and blue (B) color filters corresponding to the plurality of pixel regions, and a black matrix And the upper substrate is extended to coincide with a side surface of the lower substrate, and a light blocking layer is formed on the non-display region.

The light blocking layer is characterized in that the black matrix is formed to extend to a side surface of the upper substrate.

The light blocking layer is formed of any one of the red (R), green (G) and blue (B) color filters.

The light blocking layer is characterized in that two or more of the red (R), green (G) and blue (B) color filters are laminated.

Wherein the color filter further comprises a sub color filter made up of any one of white (W), yellow (Y) and magenta (M), and the light blocking layer comprises red (R), green (G) B) and the sub-color filter are stacked.

At least one of the upper substrate and the lower substrate includes a spacer, and the light blocking layer is formed of the same material as the spacer.

The black matrix is formed of the same material as the spacer.

The light blocking layer is formed by overlapping a sealant of the lower substrate.

In order to achieve the above object, a liquid crystal display panel according to a preferred embodiment of the present invention includes: a lower substrate having a plurality of signal lines and thin film transistors formed therein to define a plurality of pixel regions; And an upper substrate disposed to face the lower substrate and having red (R), green (G), and blue (B) color filters corresponding to the plurality of pixel regions, And a black matrix for dividing the color filter by color is formed of any one of the signal lines.

And one of the signal lines is a common wiring for applying a common voltage to the pixel region.

According to a preferred embodiment of the present invention, a light blocking layer is formed by aligning the widths of two substrates constituting the liquid crystal display panel and extending the black matrix to the end of the non-display area, It is possible to provide a liquid crystal display panel in which the light leakage generated in the region is prevented to improve the image quality.

In addition, the present invention is configured to form a black matrix on the display area using the same materials and processes as the column spacers, or to substitute the black matrix of the upper substrate by using any one of the signal electrodes and wires on the lower substrate, There is an effect that the manufacturing process can be omitted.

1 is an exploded perspective view schematically showing a structure of a general liquid crystal display panel.
Fig. 2 is a cross-sectional view of the edge portion of the liquid crystal display panel of Fig. 1; Fig.
3 is a plan view showing a display area and a non-display area of a conventional liquid crystal display panel, and a black matrix and a sealant formed thereon.
4 is a cross-sectional view showing a part of a liquid crystal display panel according to the first embodiment of the present invention.
5 is a plan view showing a preferred embodiment of the liquid crystal display panel according to the first embodiment of the present invention.
6 is a cross-sectional view showing a part of a liquid crystal display panel according to a second embodiment of the present invention.
7 is a cross-sectional view showing a part of a liquid crystal display panel according to a third embodiment of the present invention.
8 is a graph showing the transmittance (%) of each sub-color filter for each light wavelength band.
9 is a cross-sectional view showing a partial structure of a liquid crystal display panel according to a fourth embodiment of the present invention.

Hereinafter, a liquid crystal display panel according to a preferred embodiment of the present invention will be described with reference to the drawings. The drawings referred to in the following embodiments are not intended to limit the connection form and arrangement of the constituent elements to the illustrated form, and in particular, in order to facilitate understanding of the technical structure and the shape of the present invention, Exaggerated or reduced.

4 is a cross-sectional view showing a part of a liquid crystal display panel according to the first embodiment of the present invention.

As shown in the figure, the liquid crystal display panel 100 of the present invention includes a lower substrate 102 and an upper substrate 103 having side surfaces having the same width, which are aligned so as to face each other and maintain a uniform cell gap, And a liquid crystal layer 104 formed in the cell gap between the liquid crystal layer 104 and the liquid crystal layer 104.

The lower substrate 102 is an array substrate in which a gate line and a data line intersect to define a pixel region and a thin film transistor and a pixel electrode are formed. The upper substrate 103 includes red (R) 106a, green Green, and G) 106b and blue (B, B) 106c.

Particularly, the upper substrate 103 includes black matrices 107a and 107b for separating the sub-color filters 106a to 106c from each other and blocking light transmitted through the liquid crystal layer 104, and a color filter 106a to 106c and the overcoat layer 109 for planarizing the steps generated by the black matrices 107a, 107b. Here, the overcoat layer 109 is formed of an acrylic resin or a polyimide resin by a spin coating method. Such an overcoat layer 109 may be omitted in order to lower the manufacturing cost.

When the liquid crystal display panel is in the TN mode, a transparent common electrode for applying a voltage to the liquid crystal layer 104 is formed on the entire surface of the upper substrate 102. In the case of the IPS mode, 102, a common electrode is formed in parallel with the pixel electrode.

The lower substrate 102 and the upper substrate 103 described above are held together by a spacer 111 by a sealant 114 formed along the outer periphery of each of the substrates 102 and 103. The first and second polarizers 112 and 113 are attached to the outer surfaces of the substrates 102 and 103, respectively.

The liquid crystal display panel 100 includes a display area A / A for displaying an image and a non-display area N / A for surrounding the display area A / A driving circuit for providing a signal to the display area A / A is directly mounted on the non-display area N / A, or the driving circuit for driving the display area A / A gate and a data pad electrically connected to the printed circuit board (PCB) on which the semiconductor device is mounted.

In the liquid crystal display panel having such a structure, in particular, in the case of the active matrix driving method using the thin film transistor which is the switching element described above, a high light shielding property is required for each pixel, and as the light shielding film for the black matrix, The material may be formed on a substrate by vacuum deposition or the like, coated with a photosensitive resin, and then patterned and etched through photo lithography to form a lattice structure. The black matrix is advantageous in that it can be easily implemented in a thin film form and has high chemical resistance and high light shielding performance. However, since the black matrix has a high light reflectance characteristic, the display quality of an image is degraded and a separate processing step for total reflection is required There is a drawback.

In addition, according to the above-described method of manufacturing a black matrix using a metal material, since a vacuum deposition process such as sputtering is accompanied, manufacturing cost increases, and a waste liquid generated after the etching process may cause environmental pollution, It is preferable to apply a black matrix using a material.

The black matrix using such a resin material can be formed by a method including a dyeing method using a resin material, a printing method, a pigment dispersion method, an electrodeposition method, or the like between a sub-color filter of red (R), green (G) and blue Method. In particular, the black matrix of the liquid crystal display panel according to the first embodiment of the present invention can be manufactured by a pigment dispersion method.

In the first embodiment of the present invention, the lower substrate 102 and the upper substrate 103 are formed to have the same width and at least one side surface coincide with each other, and a black matrix (not shown) formed on the upper substrate 103 The black matrix 107a on the non-display area N / A is formed to extend to the side end of the upper substrate 103 to form a light blocking layer.

This black matrix 107a is simultaneously formed by patterning the same metal layer in the formation of the black matrix 107b on the display area A / A, and therefore, no additional process for forming the light blocking layer is required.

FIG. 5 shows a preferred embodiment of the liquid crystal display panel according to the first embodiment of the present invention. Referring to the drawing, upper and lower substrates are formed in the same width on three sides except for one side of the liquid crystal display panel 100, and a black matrix 107a in a region excluding the central display area A / And is formed throughout the entire non-display area N / A.

One surface of the upper and lower substrates that is not the same width is for securing a space for mounting the driving circuit, and a type in which a driving circuit is embedded on a substrate such as a GIP (Gate In Panel) or an SOP (System On Panel) The upper substrate and the lower substrate may be formed to have the same width on all sides of the liquid crystal display panel 100 of FIG.

According to this structure, the liquid crystal display panel according to the first embodiment of the present invention has the widths of the upper and lower substrates aligned with each other, and the black matrix is formed throughout the non-display region, The light leakage can be improved.

Hereinafter, a liquid crystal display panel according to a second embodiment of the present invention will be described with reference to the drawings.

6 is a cross-sectional view showing a part of a liquid crystal display panel according to a second embodiment of the present invention.

As shown in the drawing, in the second embodiment of the present invention, the lower substrate 202 and the upper substrate 203, which have the same lateral widths of the liquid crystal display panel 200, are bonded together so that a uniform cell gap is maintained , And the liquid crystal layer 204 is interposed in the cell gap between these two substrates 202 and 203.

Further, the lower substrate 202 is an array substrate, in which gate lines and data lines cross to define pixel regions, and thin film transistors and pixel electrodes are formed. The upper substrate 203 includes a plurality of sub color filters that implement the three primary colors of red (R) 206a, green (G) 206b, and blue (B) 206c as color filter substrates, 206a to 206c, a black matrix 207b for shielding light transmitted through the liquid crystal layer 204, and an overcoat layer 209 for planarization are formed. A common electrode is formed on the entire surface of the upper substrate 202 according to the driving mode of the liquid crystal display panel, or a common electrode is formed on the lower substrate 202 in parallel with the pixel electrode.

The lower substrate 202 and the upper substrate 203 described above are held together by spacers 211a by a spacer 211a and are bonded together by a sealant 214 formed along the outer periphery of each substrate 202 and 203. [ The first and second polarizers 212 and 213 are attached to the outer surfaces of the substrates 202 and 203 in the direction opposite to the liquid crystal layer 204, respectively.

Here, as the above-described spacer, a ball spacer scattered on the lower substrate 202, or a column spacer patterned on one of the lower substrate 202 and the upper substrate 203 at regular intervals may be applied, The first column spacer 211a is formed on the overcoat layer 209 of the display area A / A of the upper substrate 203 in the second embodiment. A light blocking layer 211b is formed in the non-display area N / A over the entire area at the same time in the same step as the column spacer 211a on the display area A / A.

The light blocking density (OD) of the light blocking layer 211b is defined as a logarithm of the amount of light incident on the material and the amount of light transmitted through the light blocking layer 211b, and the light blocking density of the second column spacer 211b OD) is proportional to its thickness. That is, the greater the thickness of the light blocking layer 211b, the smaller the amount of light transmitted through the light blocking layer 211b, and thus the light blocking effect in the non-display area N / A of the liquid crystal display panel 200 becomes greater. .

6, a normal black matrix 207b is formed on the upper substrate 203 of the display area A / A, but instead of this, a light blocking layer of the non-display area N / A is formed A separate manufacturing process for forming the black matrix 207b on the display area A / A may be omitted by forming the second column spacer 211b using the same material and process as those of the second column spacer 211b.

According to this structure, in the liquid crystal display panel according to the second embodiment of the present invention, a light blocking layer formed through the same material and process as the column spacer of the display area is formed throughout the non-display area, Thereby improving light leakage generated through the region.

Hereinafter, a liquid crystal display panel according to a third embodiment of the present invention will be described with reference to the drawings.

7 is a cross-sectional view showing a part of a liquid crystal display panel according to a third embodiment of the present invention. In the following description, an example of a color filter composed of three primary colors of red (R), green (G), and blue (B) has been described. However, Color filters such as red (R), green (G), and blue (Blue, B) may be constituted by sub-color filters such as yellow (Y), magenta Color filter including any one of white (W), yellow (Y, yellow), and magenta (M, Magenta).

The liquid crystal layer 304 is formed in the cell gap between the lower substrate 302 and the upper substrate 303 of the liquid crystal display panel 300 and the two substrates 302 and 303, Respectively. A plurality of sub-color filters 306a to 306c for realizing three primary colors and a sub-color filter 306a to 306c for separating the sub-color filters 306a to 306c are provided on the display area A / A of the upper substrate 303, And a light blocking layer 316 composed of at least one sub color filter 306a to 306c is formed on the non-display area N / A.

The black matrix 307 and the sub color filters 306a to 306c and the overcoat layer 309 made of an acrylic resin or a polyimide based resin are further formed on the light blocking layer 316 .

The light blocking layer 316 is formed in the same material and in the same process as the sub color filters 306a to 306c, and its lamination shape is determined so as to maximize the light blocking degree of the light blocking layer 316. [

That is, the color filters have different light transmissivities for respective light wavelength ranges. 8 is a graph showing the transmittance (%) of each sub-color filter for each light wavelength band.

As shown, the red (R) sub-color filter has a transmittance close to 0% at a wavelength of 380 nm to 580 nm, but gradually becomes higher than 580 nm and has a transmittance close to 100% at 630 nm. In addition, the green (G) sub-color filter has transmittance close to 0% in the wavelength range excluding 450 nm to 630 nm, and the blue (B) sub-color filter has a transmittance close to 0% in the wavelength range of 530 nm or more. Therefore, the red (R) and blue (B) sub-color filters have a low transmittance at a wavelength of visible light of 550 nm, which is suitable for a light blocking layer.

In addition, the light blocking layer 316 may have a different degree of light blocking depending on one or two or more combinations, so that the light blocking layer 316 may be formed of a single sub color filter or multiple laminated layers of two or more sub color filters.

Table 1 below shows the light shielding degree of each light blocking layer when a light blocking layer is implemented by a combination of sub color filters and two or more sub color filters.

Color filter R G B R + G R + B G + B R + G + B OD 2.3 0.095 0.64 2.9 3.9 0.75 4.1

As described above, according to the combination of the respective sub-color filters and the color filters, one blue (B) sub-color filter has the lowest light blocking density at the wavelength 550 nm of the visible light ray, and the light blocking density Is the highest.

Therefore, although the light blocking layer formed by combination of the three primary color filters is the most effective, it is preferable that the combination of the two sub-color filters of red (R) and blue (B) in consideration of the transmittance and the cell gap margin of the liquid crystal display panel A light blocking layer is preferred.

In the case of a liquid crystal display panel having four sub-color filters, the light blocking layer may include one sub-color filter of the three primary colors and white (W), yellow (Y), or magenta , Or magenta) may be stacked.

According to this structure, the liquid crystal display panel according to the third embodiment of the present invention can improve the light leakage generated through the bezel area of the liquid crystal display panel according to one or more combinations of the sub color filters formed in the first half of the non- have.

Here, in the above-described second and third embodiments, the black matrix formed on the upper substrate may be omitted through a structure capable of replacing the black matrix on the lower substrate in the display area A / A, Hereinafter, one embodiment of a liquid crystal display panel in which a black matrix is omitted on an upper substrate will be described with reference to the drawings.

9 is a cross-sectional view showing a partial structure of a liquid crystal display panel according to a fourth embodiment of the present invention. In the following description, only the display area A / A of the liquid crystal display panel is shown, and the non-display area N / A includes the extended black matrix, the second column spacer, and the second column spacer, as in the first to third embodiments described above. Or a combination of one or more color filters.

The liquid crystal layer 404 is formed in the cell gap between the lower substrate 402 and the upper substrate 403 of the liquid crystal display panel 400 and between the two substrates 402 and 403, Respectively. A plurality of sub-color filters 406a to 406c for realizing three primary colors are formed on the display area A / A of the upper substrate 403. The black matrix for distinguishing the sub-color filters 406a to 406c is omitted And an overcoat layer 409 made of an acrylic resin or a polyimide resin may be further formed on the sub color filters 406a to 406c.

The liquid crystal layer 404 is interposed between the upper substrate 403 and the first and second polarizers 412 and 440. The liquid crystal layer 404 is interposed between the upper substrate 403 and the upper substrate 403 by a spacer 411, And 413, respectively.

Although not shown, a plurality of thin film transistors (TFTs) for realizing an image and a plurality of gate wirings, data wirings, pixel electrodes, common electrodes, and common wirings for providing signals to the display region A / A of the upper substrate 403 The wiring and the electrode are formed in a lattice form. In the fourth embodiment of the present invention, the black matrix 407 is replaced with any one of the above-described plurality of wirings and electrodes. That is, as shown in Fig. 9, any one of various electrodes and wirings made of opaque metal is disposed on the lower substrate 402 at opposed positions between the sub color filters 406a to 406c, And serves as a black matrix 407. It is preferable that the black matrix 407 is formed as a common wiring for providing a common voltage to the common electrode in the signal wiring.

While a great many are described in the foregoing description, it should be construed as an example of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

A / A: display area N / A: non-display area
100: liquid crystal display panel 102: lower substrate
103: upper substrate 104: liquid crystal layer
106a, b, c: color filter 107a:
107b: black matrix 111: spacer
112, 113: first and second polarizers 114: sealant

Claims (10)

An upper substrate and a lower substrate including a display region and a non-display region;
A plurality of signal lines and thin film transistors arranged on a lower substrate of the display region;
A black matrix disposed on an upper substrate of the display region;
A color filter disposed on an upper substrate of the display area;
A spacer disposed on at least one of the upper substrate and the lower substrate;
And a light blocking layer disposed on the entire non-display area to block light from passing through the non-display area, the light blocking layer being made of the same material as the spacer. delete delete delete delete delete The method according to claim 1,
Wherein the black matrix is made of the same material as the spacer. The method according to claim 1,
Wherein the light blocking layer overlaps the sealant of the lower substrate. delete delete

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