KR20080022244A - LCD panel - Google Patents

Abstract

A liquid crystal display panel capable of improving luminance is disclosed. The liquid crystal display panel faces an array substrate including an array layer formed in a pixel region formed by crossing gate lines and a source wiring, an array substrate including pixel electrodes formed on the array layer, and an array substrate, and a green color filter formed in the first pixel region. And a liquid crystal layer interposed between the opposite substrate and the array substrate and the opposite substrate including a red color filter formed in the second pixel region and a blue color filter formed in the third pixel region. The liquid crystal layer has a first cell gap, and the liquid crystal layer of the third pixel region has a second cell gap smaller than the first cell gap. Accordingly, the luminance of the entire display panel can be improved without changing color reproducibility by improving the transmittance of the first pixel region.

Description

Liquid Crystal Display Panel {LIQUID CRYSTAL DISPLAY PANEL}

1 is a plan view of a liquid crystal display panel according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal display panel according to the first exemplary embodiment of the present invention taken along the line II ′ of FIG. 1.

3 is a cross-sectional view of the liquid crystal display panel according to the second exemplary embodiment of the present invention taken along the line II-II ′ of FIG. 1.

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

500 and 502: first and second liquid crystal display panels 100 and 102: first and second array substrates

P1, P2, P3: first, second, third pixel areas

TFT1, TFT2, TFT3: first, second, third switching element

PE1, PE2, PE3: first, second and third pixel electrodes

200, 202: First and second opposing substrates BM: Light shielding pattern

BCF1, BCF2: first and second blue color filters CE: common electrode

GCF1, GCF2: First and second green color filters 300, 302: First and second liquid crystal layers

RCF1, RCF2: first and second red color filters 150, 152: first and second organic layers

D1, D2, D3: first, second, third cell gap

The present invention relates to a liquid crystal display panel, and more particularly, to a liquid crystal display panel with improved brightness.

In general, a liquid crystal display panel includes an array substrate on which switching elements are formed, an opposite substrate facing the array substrate and including a black matrix pattern and color filters, and a liquid crystal layer interposed between the array substrate and the opposite substrate.

The array substrate includes gate wirings forming a pixel region, source wirings, switching elements connected to each gate wiring and source wiring and formed in each pixel region, and pixel electrodes connected to the switching elements.

The opposing substrate includes a black matrix pattern formed to correspond to the gate lines, the source lines and the switching elements, and color filters formed to correspond to the pixel areas. The color filters include a red color filter, a green color filter, and a blue color filter, and the LCD displays the color by controlling a brightness by applying a signal corresponding to each color to each color filter. Transmittance, which is the most important characteristic of color filters, reflects the visual characteristics of the human eye, and thus increases in the order of blue, red, and green.

The liquid crystal display panel receives light from the backlight and displays an image by using a difference in transmittance of light generated by a change in the arrangement of liquid crystal molecules of the liquid crystal layer. The liquid crystal layer is classified into a horizontal, vertical, inclined, twisted array, and the like according to the initial arrangement of the liquid crystal molecules.

On the other hand, since each color has a property in which the dispersibility of a specific wavelength of light is different, the relationship between transmittance and color reproducibility of each color filter should be taken into consideration when manufacturing a liquid crystal display panel. However, if the color filter is thinned to improve the transmittance of the color filter, the color reproducibility is lowered. If the color filter is made thicker to improve the color reproducibility, the transmittance is decreased. In order to improve the color gamut, color reproducibility may be changed. Therefore, it is difficult to simultaneously optimize color reproducibility and luminance of the liquid crystal display panel.

Accordingly, the technical problem of the present invention was conceived in this respect, and an object of the present invention is to provide a liquid crystal display panel with improved luminance without variation in color reproducibility.

According to an aspect of the present invention, there is provided a liquid crystal display panel comprising: an array substrate including an array layer formed in a pixel region formed by crossing gate lines and a source line, and a pixel electrode formed on the array layer; An opposing substrate facing the array substrate, wherein the opposing substrate includes a green color filter formed in the first pixel region, a red color filter formed in the second pixel region, and a blue color filter formed in the third pixel region; And a liquid crystal layer interposed therebetween, wherein the liquid crystal layer of the first and second pixel regions has a first cell gap, and the liquid crystal layer of the third pixel region has a second cell gap smaller than the first cell gap. Characterized in having a.

According to the liquid crystal display panel, the luminance of the liquid crystal display panel can be improved without changing color reproducibility by improving the transmittance of the first pixel region.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention.

1 is a plan view of a liquid crystal display panel according to a first exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of the liquid crystal display panel according to the first exemplary embodiment of the present invention taken along the line II ′ of FIG. 1.

1 and 2, the first liquid crystal display panel 500 may include a first array substrate 100 including an array layer and a first opposing substrate including first color filters RCF1, GCF1, and BCF1. 200 and the first liquid crystal layer 300 interposed between the first array substrate 100 and the first opposing substrate 200.

The first array substrate 100 includes an array layer formed on the first base substrate 110, a first organic layer 150 formed on the array layer, and a pixel electrode PE formed on the first organic layer 150. It includes.

The array layer includes gate lines GL, source lines DL, and switching elements TFT1, TFT2, and TFT3. The gate lines GL and the source lines DL cross each other to form pixel regions P1, P2, and P3. In the pixel regions P1, P2, and P3, switching elements TFT1, TFT2, and TFT3 connected to the gate lines GL and source lines DL, and pixels connected to the switching elements TFT1, TFT2, and TFT3, respectively. Electrodes PE1, PE2, PE3 are formed.

For example, a first switching element TFT1 and a first pixel electrode PE1 electrically connected to the first switching element TFT1 are formed in the first pixel region P1. The first switching element TFT1 includes a first gate electrode G1, a first source electrode S1, and a first drain electrode D1, and includes a first drain electrode D1 and a first pixel electrode PE1. ) Is contacted at the contact portion CNT and electrically connected thereto. A second switching element TFT2 electrically connected to the second pixel electrode PE2 is formed in the second pixel region P2, and a third electrically connected to the third pixel electrode PE3 is formed in the third pixel region P3. Three switching elements TFT3 are formed.

The array layer may include a gate insulating layer 120 formed on the first, second and third gate electrodes G1, G2, and G3, and a semiconductor layer 132 sequentially stacked on the gate insulating layer 120. And an ohmic contact layer 134. The gate insulating layer 120 is made of, for example, silicon nitride (SiNx) or silicon oxide (SiOx). The semiconductor layer 132 is made of, for example, amorphous silicon (a-Si), and the ohmic contact layer 134 is made of, for example, heavily doped amorphous silicon (n + a-Si).

The array layer further includes a passivation layer 140 and a first organic layer 150 formed on the first, second and third switching elements TFT1, TFT2, and TFT3. The passivation layer 140 is made of, for example, silicon nitride (SiNx). The first organic layer 150 is formed on the entire surface of the first base substrate 110 to form the first array substrate 100 to a predetermined thickness.

The pixel electrodes PE1, PE2, and PE3 formed on the array layer are made of a transparent conductive material, for example, indium zinc oxide (IZO) or indium tin oxide (ITO).

The first opposing substrate 200 includes a light blocking pattern BM formed on the second base substrate 210 and a first color filter layer and a light blocking pattern BM including first color filters BCF1, GCF1, and RCF1. And an overcoat layer 220 formed on the color filter layer and a common electrode CE.

The light blocking pattern BM is formed on the second base substrate 210 corresponding to the gate lines GL, the source lines DL, and the switching elements TFT1, TFT2, and TFT3. The light blocking pattern BM partitions the pixel areas P1, P2, and P3 and blocks leakage light flowing into the switching element TFT. The light shielding pattern BM is formed of, for example, a chromium (Cr) metal film.

The first color filter layer includes first color filters RCF1, GCF1, and BCF1 formed on the pixel areas P1, P2, and P3 partitioned by the light blocking pattern BM. The first color filters RCF1, GCF1, and BCF1 may include a first green color filter GCF1 expressing a green color, a first red color filter RCF1 expressing a red color, and a first blue color filter expressing a blue color. (BCF1). The first color filters RCF1, GCF1, and BCF1 are repeatedly arranged in a predetermined pattern to represent various colors.

The first green color filter GCF1 is formed in the first pixel region P1 at a first thickness d1, and the first red color filter RCF1 is formed at the second pixel region P2 at a second thickness d2. The first blue color filter BCF1 is formed in the third pixel region P3 at a third thickness d3. Since the green, red, and blue colors have different dispersibility to specific wavelengths of light, the thicknesses of the first green, red, and blue color filters GCF1, RCF1, and BCF1 are adjusted to control light transmittance and color reproducibility.

An overcoat layer 220 is formed on the light blocking pattern BM and the second base substrate 210 including the first color filter layer. The overcoat layer 220 may be formed of a transparent photosensitive material, and the overcoat layer 220 may be omitted according to the characteristics of the first opposing substrate 200.

The common electrode CE is formed on the light blocking pattern BM and the second base substrate 210 including the first color filter layer. The common electrode CE is a transparent conductive material, and is formed of, for example, indium zinc oxide (IZO) or indium tin oxide (ITO).

The first liquid crystal layer 300 is interposed between the first array substrate 100 and the first opposing substrate 200, and includes a plurality of liquid crystal molecules. The arrangement of the liquid crystal molecules is changed by external light supplied from the lower portion of the first liquid crystal display panel 500, and the first liquid crystal display panel 500 is changed by using a difference in transmittance of light generated by the arrangement change of the liquid crystal molecules. To display an image. The first liquid crystal layer 300 is preferably in a vertical alignment mode (VA mode).

Hereinafter, when the distance between the first array substrate 100 and the first opposing substrate 200 is defined as a cell gap, the cell gap of the liquid crystal layer of the first pixel region P1 is defined as the first cell gap. (D1), the cell gap of the liquid crystal layer of the second pixel region P2 is referred to as the second cell gap D2 and the cell gap of the liquid crystal layer of the third pixel region P3 is referred to as the third cell gap D3. In detail, the first cell gap D1 is a distance between the first pixel electrode PE1 and the common electrode CE formed on the first green color filter GCF1, and the second cell gap D2 is the second pixel. The distance between the electrode PE2 and the common electrode CE formed on the first red color filter RCF1, and the third cell gap D3 is formed on the third pixel electrode PE3 and the first blue color filter BCF1. The distance between the common electrodes CE is formed.

Referring to FIG. 2, the array layer, the first organic layer 150, and the pixel electrodes PE1, PE2, and PE3 formed on the first array substrate 100 have the same thickness over the entire surface of the first base substrate 110. It is formed uniformly.

The first thickness d1 and the second thickness d2 of the first color filter layer of the first opposing substrate 200 have the same value, and the third thickness d3 is the first and second thicknesses d1 and d2. Has a value greater than As a result, the first cell gap D1 and the second cell gap D2 are formed in the same manner, and the third cell gap D3 is formed lower than the first and second cell gaps D1 and D2. It is preferable that the third cell gap D3 is approximately 0.2 μm to 0.3 μm lower than the first and second cell gaps D1 and D2.

For example, in the case where the first and second thicknesses d1 and d2 are formed at about 1.5 μm to 1.6 μm, the third thickness d3 is formed at about 1.8 μm so that the first and second cell gaps D1, D2) is set to approximately 4.0 mu m, and the third cell gap D3 is formed to approximately 3.8 mu m.

In general, the transmittance, which is the rate at which light passes through the color filter, varies according to the thickness and cell gap of the color filter, and the color reproducibility and luminance of the liquid crystal display panel vary according to the transmittance of the color filter. That is, the thinner the thickness of the color filter, the higher the transmittance. The larger the cell gap, the higher the transmittance, while the thicker the color filter, the smaller the transmittance, the smaller the cell gap, the transmittance decreases. However, as the thickness of the color filter increases, the purity of the color increases and the color reproducibility of the color filter increases. Therefore, it is most important to determine the thickness and the cell gap of the color filter that can simultaneously optimize the luminance and the color reproducibility.

In particular, in the VA mode, a multi-cell gap is formed to solve a problem in which color reproducibility is different due to different dispersibility of the same wavelength, but the color reproducibility and luminance of the liquid crystal display panel in At the same time, there is a limit to improvement. The multi-cell gap structure of the VA mode is, for example, each pixel region of the array substrate is the same structure, is formed with the same thickness, the thickness of each color filter of the opposite substrate is the thickness of the blue color filter, green color filter It has a thinly formed structure in the order of the thickness and the thickness of the red color filter.

According to the first embodiment of the present invention, the transmittance of the first pixel region may be improved by increasing the cell gap of the first pixel region by approximately 0.1 μm to 0.2 μm. Considering that the luminance ratio of the red, green, and blue colors to the white luminance is approximately 23:65:12, since the ratio of the green color is relatively high, the luminance of the entire display panel is improved by improving the transmittance of the first pixel region. You can.

While the luminance of the display panel may be improved by increasing the transmittance of the first pixel area, the color reproducibility of the green color may change, and thus the color reproducibility of the entire display panel may be changed. Since the influence of varying the color coordinates of the color is relatively smaller than that of the red and blue colors, the possibility of variation of the color reproducibility of the entire display panel is minimized so that display quality is not a problem.

3 is a cross-sectional view of the liquid crystal display panel according to the second exemplary embodiment of the present invention taken along the line II-II ′ of FIG. 1.

1 and 3, the second display panel 502 includes a second array substrate 102, a second opposing substrate 202, and a second liquid crystal layer 302.

The second array substrate 102 includes an array layer including gate lines GL, source lines DL, and switching elements TFT1, TFT2, and TFT3, and a second organic layer 152 formed on the array layer. And pixel electrodes PE1, PE2, and PE3 formed on the second organic layer 152. Since the array layer of the second display panel 502 is substantially the same as the array layer of the first display panel 500, description thereof will be omitted.

The second organic layer 152 is formed on the array layer of the pixel regions P1, P2, and P3 formed by the gate lines GL and the source lines DL. The thickness x of the second organic layer 152 on the first pixel region P1 corresponding to the second green color filter GCF2 may correspond to the second and second colors corresponding to the second red and blue color filters RCF2 and BCF2. The thicknesses of the second organic layers 152 on the three pixel areas P2 and P3 are lower than the thicknesses y and z. Preferably, the thicknesses y and z of the second organic layers 152 on the second and third pixel regions P2 and P3 corresponding to the second red and blue color filters RCF2 and BCF2 are the same.

The second opposing substrate 202 includes a second color filter layer including the second color filters GCF2, RCF2, and BCF2, a light blocking pattern BM, and a common electrode CE.

The light shielding pattern BM partitions the second base substrate 210 into the first, second and third pixel regions P1, P2, and P3, and the first, second and third pixel regions P1, P2, A second green color filter GCF2, a second red color filter RCF2, and a second blue color filter BCF2 are formed in each of P3). An overcoat layer 220 may be formed on the light blocking pattern BM and the second color filter layer, and a common electrode CE is formed on the overcoat layer 220.

The second green color filter GCF2 has a fourth thickness d4, the second red color filter RCF2 has a fifth thickness d5, and the second blue color filter BCF2 has a sixth thickness d6). The second blue, green, and red color filters (BCF2, GCF2, RCF2) are formed so as to become thinner. That is, the sixth thickness d6 is thicker than the fourth thickness d4, and the fourth thickness d4 is thicker than the fifth thickness d5. For example, when the sixth thickness d6 is formed to be approximately 1.8 μm, the fourth thickness d4 is formed to be approximately 1.7 μm, and the fifth thickness d5 is formed to be approximately 1.6 μm.

The second green, red, and blue color filters GCF2, RCF2, and BCF2 are formed by varying the fourth, fifth, and sixth thicknesses d4, d5, and d6, as in the conventional VA mode, and the second organic layer 152. ), That is, the thickness of the second organic layer 152 on the first pixel region P1 corresponding to the second green color filter GCF2 is determined by the second organic layer (2) on the second and third pixel regions P2 and P3. The first cell gap D1 and the second cell gap D2 are formed to be the same by forming lower than the thickness of 152, and the third cell gap D3 is smaller than the first and second cell gaps D1 and D2. Can be formed low. It is preferable that the third cell gap D3 is approximately 0.2 μm to 0.3 μm lower than the first and second cell gaps D1 and D2.

For example, when the fourth thickness d4 is about 1.7 μm and the fifth thickness d5 is about 1.6 μm, the sixth thickness d6 is about 1.8 μm, and the first and second cell gaps D1 and D2. ) Is approximately 4.0 mu m, and the third cell gap D3 is formed at approximately 3.8 mu m.

According to the second embodiment of the present invention, the thickness of the organic layer corresponding to the green color filter is approximately 0.1 μm to 0.2 μm thinner than before, thereby increasing the cell gap of the first pixel area, thereby improving the transmittance of the first pixel area. have.

As described above in detail, the first cell gap D1 of the first pixel region P1 having the green color filters GCF1 and GCF2 is formed in the second pixel region P2 having the red color filters RCF1 and RCF2. A third cell gap of the third pixel region P3 having the same color as that of the second cell gap D2, and the first and second cell gaps D1 and D2 having the blue color filters BCF1 and BCF2 formed therein. It is formed larger than (D3). By adjusting the thickness of the green color filter or by adjusting the thickness of the organic layer of the array substrate, the overall luminance of the liquid crystal display panel may be improved without changing color reproducibility by improving the transmittance of the first pixel region P1.

According to the liquid crystal display panel, the third cell gap of the first pixel region in which the green color filter is formed is formed to be the same as the second cell gap of the second pixel region in which the red color filter is formed, and the third in which the blue color filter is formed. The transmittance of the first pixel region may be improved by forming a third cell gap of the pixel region smaller than the first and second cell gaps. As the transmittance of the first pixel region is improved, the luminance of the entire liquid crystal display panel may be improved without changing color reproducibility.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (7)

An array substrate including an array layer formed in a pixel region where the gate wiring and the source wiring cross each other, and a pixel electrode formed on the array layer; An opposite substrate facing the array substrate and including a green color filter formed in a first pixel region, a red color filter formed in a second pixel region, and a blue color filter formed in a third pixel region; And It includes a liquid crystal layer interposed between the array substrate and the opposite substrate, The liquid crystal layer of the first and second pixel regions has a first cell gap, and the liquid crystal layer of the third pixel region has a second cell gap smaller than the first cell gap. . The method of claim 1, wherein the array layer Switching elements connected to the gate line and the source line; And And an organic layer formed on the switching elements. 3. The liquid crystal display panel of claim 2, wherein thicknesses of the array layers of the first, second, and third pixel areas are the same. The liquid crystal display panel of claim 3, wherein the green color filter and the red color filter have the same thickness, and the blue color filter has a thickness smaller than that of the green and red color filters. 3. The thickness of the organic layer of the second and third pixel regions is equal to each other, and the thickness of the organic layer of the first pixel region is thinner than the thickness of the organic layer of the second and third pixel regions. Liquid crystal display panel, characterized in that formed. The liquid crystal display panel of claim 5, wherein a thickness of the blue color filter is thicker than a thickness of the green color filter, and a thickness of the green color filter is thicker than a thickness of the red color filter. The method of claim 1, wherein the opposite substrate A light shielding pattern partitioning the pixel region corresponding to the gate wiring and the source wiring and formed to correspond to the switching elements; And And a common electrode formed on the light blocking pattern, the green, red, and blue color filters.

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