KR20060109577A - Liquid crystal display panel - Google Patents

Abstract

An LCD is provided to compensate ununiformity of a backlight brightness by designing pixel sizes varying according locations thereof within a panel. An array substrate(110) includes a pixel unit(125). Gate lines(116) and data lines(117) are formed in the pixel unit of the array substrate, and intersect each other to define a plurality of pixels(170A~170E). A color filter substrate(105) is bonded with the array substrate in a mutually facing manner. The pixels have different sizes according to locations thereof. The pixels have different sizes according to the intensity of a lower backlight brightness. A pixel in a region where the backlight brightness is low is greater than a pixel in another region.

Description

Liquid Crystal Display Panel {LIQUID CRYSTAL DISPLAY PANEL}

1 is a plan view schematically illustrating a structure of a general liquid crystal display panel.

2 is a plan view schematically illustrating a structure of a liquid crystal display panel according to a first exemplary embodiment of the present invention.

3 is an exploded perspective view schematically illustrating a structure of a backlight unit used in the liquid crystal display panel illustrated in FIG. 2.

4 is a plan view illustrating a light guide plate and a lamp of the backlight unit illustrated in FIG. 3.

FIG. 5 is a plan view illustrating pixels having different sizes according to positions of the liquid crystal display panel shown in FIG. 2; FIG.

6 is a plan view schematically illustrating a structure of a liquid crystal display panel according to a second exemplary embodiment of the present invention.

** Description of symbols for the main parts of the drawing **

105,205: color filter substrate 110,210: array substrate

170A ~ 170E, 270A ~ 270E: Pixel 125,225: Pixel part

150,250: Backlight

The present invention relates to a liquid crystal display panel, and more particularly, to a liquid crystal display panel in which image quality is improved by compensating for non-uniformity of backlight brightness.

In general, a liquid crystal display device is a display device that displays a desired image by separately supplying data signals according to image information to pixels arranged in a matrix form, and adjusting light transmittance of the pixels.

To this end, the liquid crystal display includes a liquid crystal display panel in which pixels are arranged in a matrix and a driving unit for driving the pixels.

The liquid crystal display panel is bonded to an array substrate on which a thin film transistor array is formed and a color filter substrate on which a color filter is formed to maintain a uniform cell gap, and the array substrate and the color filter substrate. The liquid crystal layer is formed in the cell gap therebetween.

In this case, an alignment layer is formed on the surface of the array substrate and the color filter substrate facing each other, and rubbing is performed to arrange the liquid crystals of the liquid crystal layer in a predetermined direction.

In addition, the array substrate and the color filter substrate are bonded by a seal pattern formed along the outer edge of the pixel portion, and the polarized plate and the phase difference plate are provided on the outer surfaces of the bonded array substrate and the color filter substrate. By selectively configuring the elements, a liquid crystal display panel having high luminance and contrast characteristics is formed by changing the traveling state of the light or changing the refractive index.

Hereinafter, the liquid crystal display panel configured as described above will be described in detail with reference to the accompanying drawings.

1 is a plan view schematically illustrating a structure of a general liquid crystal display panel.

As shown in the figure, the liquid crystal display panel is largely arranged in a matrix form with pixels 70A to 70E connected to the pixel portion 25 displaying an image and the gate lines 16 of the pixel portion 25. The data pad unit 27 is connected to the gate pad unit 26 and the data lines 17.

In this case, the gate pad part 26 and the data pad part 27 are formed in an edge region of the array substrate 10 which does not overlap the color filter substrate 5, and the gate pad part 26 is a gate driver (not shown). The scan signal supplied from the C) to the gate lines 16 of the pixel unit 25, and the data pad unit 27 supplies the image information supplied from the data driver (not shown) to the data of the pixel unit 25. To the lines 17.

In addition, data lines 17 to which image information is applied and gate lines 16 to which a scan signal is applied are arranged on the array substrate 10 so that the data lines 17 and the gate line 16 are intersected with each other. Thin film transistors (not shown) and pixel electrodes (not shown) are respectively provided in regions partitioned by the plurality of pixels.

Although not shown in detail in the drawing, the color filter substrate 5 includes color filters partitioned by pixels 70A to 70E by a black matrix and pixels formed on the array substrate 10. A common electrode serving as a counter electrode of the electrode is provided.

Since the liquid crystal display device configured as described above does not emit light by itself and has a characteristic of displaying an image by adjusting the transmittance of light supplied from the outside, an additional means for irradiating light to the liquid crystal display panel, that is, a backlight unit is required. .

However, in a general liquid crystal display panel, the lower backlight unit does not form uniform luminance on the front surface of the panel, and as shown in FIG. 1, all pixels 70A to 70E are designed to have the same size in the entire panel. There arises a problem that the image quality of the liquid crystal display panel is lowered due to the difference in luminance.

That is, the sizes of the pixels 70A to 70E are designed to be the same at each position (1 to 5) of the liquid crystal display panel, wherein the pixels 70A to 70E are red, green, and blue sub-color filters. It consists of sub-pixels 71A to 71E, 72A to 72E, and 73A to 73E, and the sizes of the subpixels 71A to 71E, 72A to 72E, and 73A to 73E are also the same. However, the lower backlight unit does not form the same luminance at the sub-pixels 71A to 71E, 72A to 72E, and 73A to 73E at each position (1 to 5) of the liquid crystal display panel. Will be degraded.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and an object of the present invention is to provide a liquid crystal display panel that compensates for the unevenness of backlight brightness by designing different pixel sizes according to positions in the panel.

Other features and objects of the present invention will be described in detail in the configuration and claims of the invention below.

In order to achieve the above object, the liquid crystal display panel of the present invention includes an array substrate including a pixel portion; A gate line and a data line formed in a pixel portion of the array substrate and crossing each other to define a plurality of pixels; And a color filter substrate bonded to face the array substrate, wherein each pixel has a different size according to its position.

In addition, another liquid crystal display panel of the present invention is an array substrate including a pixel portion; A gate line and a data line formed in a pixel portion of the array substrate and crossing each other to define a plurality of pixels; And a color filter substrate bonded to face the array substrate, wherein each pixel has a different size according to the backlight brightness of the lower portion.

Hereinafter, exemplary embodiments of the liquid crystal display panel according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a plan view schematically illustrating a structure of a liquid crystal display panel according to a first exemplary embodiment of the present invention.

As shown in the figure, the liquid crystal display panel is largely arranged with the pixels 170A to 170E arranged in a matrix form and connected to the pixel portion 125 displaying the image and the gate lines 116 of the pixel portion 125. The data pad unit 127 is connected to the gate pad unit 126 and the data lines 117.

In this case, the gate pad part 126 and the data pad part 127 are formed in an edge region of the array substrate 110 that does not overlap the color filter substrate 105, and the gate pad part 126 is a gate driver (not shown). The scan signal supplied from the C) to the gate lines 116 of the pixel unit 125, and the data pad unit 127 supplies the image information supplied from the data driver (not shown) to the data of the pixel unit 125. To the lines 117.

In addition, the data lines 117 to which image information is applied and the gate lines 116 to which a scan signal is applied are arranged on the array substrate 110 so that the data lines 117 and the gate lines 116 intersect each other. Thin film transistors (not shown) and pixel electrodes (not shown) are respectively provided in the pixel regions 170A to 170E divided by the plurality of pixels.

Although not shown in detail in the drawing, the color filter substrate 105 includes a common electrode which is a relative electrode of color filters partitioned by the pixels 170A to 170E by the black matrix and pixel electrodes formed on the array substrate 110. Is provided.

The color filter substrate 105 and the array substrate 110 configured as described above have a constant cell gap maintained by spacers (not shown), and are bonded to each other by a seal pattern (not shown) formed along the periphery of the pixel portion 125. do.

 Since the liquid crystal display panel configured as described above does not emit light by itself and has a characteristic of displaying an image by adjusting the transmittance of light supplied from the outside, an additional means for irradiating light to the liquid crystal display panel, that is, a backlight unit is required. Do.

Although not shown in the drawings, the backlight unit includes a lamp assembly including a lamp for emitting light, a reflection sheet for reflecting light emitted from the lamp, and a light guide plate for guiding light. And a plurality of optical sheets installed on an upper surface of the light guide plate to diffuse and collect light transmitted from the light guide plate.

The lamp assembly is divided into a direct method in which the light source is disposed on the rear surface of the liquid crystal display panel, and an edge method in which the light source is disposed on one side or both sides of the liquid crystal display panel. The edge type liquid crystal display device is a light source for supplying light to the liquid crystal display panel, the lamp is formed on the side of the liquid crystal display panel.

3 is an exploded perspective view schematically illustrating a structure of a backlight unit used in the liquid crystal display panel illustrated in FIG. 2, and illustrates an edge lamp assembly in which a lamp is formed on a side of the liquid crystal display panel.

4 is a plan view illustrating a light guide plate and a lamp of the backlight unit illustrated in FIG. 3.

As shown in the drawing, a light guide plate 141 for guiding light to the liquid crystal display panel is installed under the liquid crystal display panel (not shown), and the light guide plate 141 has a predetermined thickness and is disposed on the liquid crystal display panel. It consists of a corresponding rectangle.

 A lamp assembly is positioned on one surface of four side surfaces of the light guide plate 141 as a light source for supplying light to the liquid crystal display panel. The lamp assembly includes a lamp 150 as a light source and a lamp housing 151 surrounding the lamp 150. The lamp 150 has a bar shape to correspond to the side surface of the light guide plate 141, and the lamp housing 151 may allow the light generated by the lamp 150 to travel only to the light guide plate 141. Wrapping 150 on three sides is composed of a bar shape.

In addition, the length of the bar-shaped lamp 150 is configured to be substantially the same as the length of the side of the corresponding light guide plate 141, the voltage is applied to the light emitting unit 150A and the lamp 150 is coated with a light emitting material It consists of the electrode part 150B. Therefore, the light emitting part 150A is shorter than the length of the side surface of the light guide plate 141.

In the liquid crystal display panel according to the exemplary embodiment of the present invention, the first prism sheet 142 is printed on the rear surface of the light guide plate 141 in order to increase the brightness. The first prism sheet 142 is integral with the light guide plate 141 and is composed of a plurality of parallel prism mountains. The prism acid is arranged in parallel with the traveling direction of the light generated from the backlight, that is, the lamp 150, and is configured to guide the backlight light to the uppermost surface. That is, the light propagating from the backlight is guided to the liquid crystal display panel while totally reflecting through the light guide plate 141, and the bottom surface is focused on the top plate by the mountains of the reflecting plate 143 and the first prism sheet 142.

In addition, a second prism sheet 144 and a diffusion sheet 145 are further disposed between the light guide plate 141 and the liquid crystal display panel to collect and diffuse backlight light.

However, the lamp 150 includes a light emitting unit 150A for generating light and an electrode unit 150B for applying a voltage to the lamp 150 as shown in FIG. 4, and the electrode unit 150B. Is positioned at edges A and A 'of the light guide plate 141. That is, some of the light generated from the light emitting unit 150A is perpendicular to the light guide plate 141 because the electrode unit 150B, which does not generate light, is positioned at the edge portions A and A 'of the light guide plate 141. It cannot be incident.

Therefore, the light emitted from the light emitting unit 150A of the lamp 150 is not properly incident on the light guide plate 141 at the edge of the light guide plate 141, so that the light guide plate (S) of the surface where the lamp 150 and the light guide plate 141 are in contact with each other. Dark areas appear at both edge portions A and A 'of 141.

In general, the edge type liquid crystal display panel tends to have the highest backlight luminance while the edge portion has the lowest backlight luminance. As described above, the edge portion of the light emitting unit 150A of the lamp 150 is shown. Since the length does not reach the length of the light guide plate 141, the side edge portions A and A ′ of the light guide plate 141 have a smaller amount of light incident from the lamp 150 than other portions, so that the lower portion of the light guide plate 141 is lower. The edge portion has a lower luminance than other regions.

The non-uniformity of the backlight brightness varies depending on the design of the backlight unit, the structure of the lamp assembly, and the like, but it may be a problem in all liquid crystal display panels.

Accordingly, as shown in FIG. 2, the liquid crystal display panel of the first exemplary embodiment of the present invention has different pixel sizes according to the brightness of the backlight for each position (① to ⑤) of the liquid crystal display panel. The nonuniformity of luminance is compensated for.

That is, the center portion ① of the liquid crystal display panel having a high backlight brightness has a smaller size than the pixels 170B to 170E at other positions, and the edges ② of the liquid crystal display panel having low backlight brightness are designed. 5) design the size of the pixels 170B to 170E large, and in particular, the lower edge portions 4 and 5 of the liquid crystal display panel have the largest size of the pixels 170D and 170E.

In this case, the red, green, and blue sub-color filters are applied to the pixels 170A to 170E according to the present embodiment, and three sub-pixels 171A to 171E, 172A to 172E, and 173A to 173E, respectively, represent red, green, and blue colors. ), But the present invention is not limited thereto, and a white sub color filter may be additionally configured in the three types of sub color filters of red, green, and blue.

The three types of sub-pixels 171A to 171E, 172A to 172E, and 173A to 173E are designed to have the same size in each of the positions ① to ⑤ of the liquid crystal display panel, but the present invention is not limited thereto. The three types of sub-pixels 171A to 171E, 172A to 172E, and 173A to 173E may be different from each other.

In addition, in the present exemplary embodiment, an area of the liquid crystal display panel having a non-uniform backlight brightness is divided into a central portion (①) and four edge portions (② to ⑤), and accordingly different sizes of pixels 170A to 170E are designed. For example, the present invention is not limited thereto, and in the present invention, when the luminance of the backlight is different according to the position of the liquid crystal display panel, the pixel size of the pixel is differently designed according to the position to compensate for this. May be applied in the case.

On the other hand, the control of the pixel size to compensate for the non-uniformity of the backlight brightness actually means the size control of the opening of the pixel through which the lower backlight light is emitted through the sub-color filter, which will be described in detail with reference to the drawings.

FIG. 5 is a plan view illustrating pixels having different sizes according to positions of the liquid crystal display panel illustrated in FIG. 2.

As shown in the figure, three pixels 170A, 170B and 170D arranged in a line through the opening 160 of the black matrix 106 are exposed to the outside.

The pixels 170A, 170B, and 170D refer to the pixels 170A, 170B, and 170D positioned in the center portion ①, the upper edge portion ②, and the lower edge portion ⑤ of the liquid crystal display panel in order from above.

The region of the black matrix 106 overlapping the pixel electrodes 118A, 118B, 118D of the pixels 170A, 170B, 170D is designed differently for each pixel 170A, 170B, 170D. That is, as illustrated, the pixels of 170A may be designed such that the pixels of D1, 170B, and the pixels of D2 and 170D have overlapping widths of D3, and the overlapping widths have a size relationship of D1 <D2 <D3.

That is, by controlling the size of the black matrix 106 overlapping the pixel electrodes 118A, 118B, and 118D, the size of the opening of the pixels 170A, 170B, and 170D is controlled, and thus the size of the pixels 170A, 170B, and 170D is controlled. The amount of backlight light emitted through the opening is controlled to compensate for the non-uniformity of backlight brightness over the entire liquid crystal display panel.

Meanwhile, in the first embodiment, a liquid crystal display panel in which a lamp is applied to an edge type lamp assembly positioned on one side of the light guide plate is described as an example. However, the present invention is not limited thereto. Applicable to the panel, it will be described in detail through the following second embodiment.

6 is a plan view schematically illustrating a structure of a liquid crystal display panel according to a second exemplary embodiment of the present invention.

As shown in the figure, the liquid crystal display panel of the second embodiment includes a pixel portion 225 in which pixels 270A to 270C are arranged in a matrix form to display an image, and a gate line 216 of the pixel portion 225. And a gate pad portion 226 connected to the data lines and a data pad portion 227 connected to the data lines 217.

In this case, the gate pad part 226 and the data pad part 227 are formed in an edge region of the array substrate 210 that does not overlap the color filter substrate 205, and the gate pad part 226 is a gate driver (not shown). The scan signal supplied from the C) to the gate lines 216 of the pixel unit 225, and the data pad unit 227 supplies the image information supplied from the data driver (not shown) to the data of the pixel unit 225. To the lines 217.

In addition, the data lines 217 to which image information is applied and the gate lines 216 to which a scan signal is applied are arranged on the array substrate 210 so that the data lines 217 and the gate lines 216 may cross each other. Thin film transistors (not shown) and pixel electrodes (not shown) are respectively provided in the pixel areas 270A to 270C divided by the plurality of pixels.

Although not shown in detail in the drawing, the color filter substrate 205 includes a common electrode which is a relative electrode of color filters partitioned by pixels 270A to 270C by a black matrix and pixel electrodes formed on the array substrate 210. Is provided.

The color filter substrate 205 and the array substrate 210 configured as described above have a constant cell gap maintained by spacers (not shown), and are bonded by a seal pattern (not shown) formed along the periphery of the pixel portion 225. do.

The liquid crystal display panel according to the present embodiment configured as described above employs a direct method in which the lamp 250 is positioned below the liquid crystal display panel. In this case, the liquid crystal display panel region (that is, the upper portion of the upper portion of the lamp 250) is generally used. In contrast, the first region ① has a high backlight brightness, whereas the upper liquid crystal display panel region (ie, the second region ②) between the lamps 250 has a low backlight brightness.

Accordingly, the liquid crystal display panel according to the second exemplary embodiment of the present invention is designed such that the size of the pixel 270A is smaller than the pixels 270B and 270C at other positions in the first region ① above the lamp 250 having high backlight brightness. In addition, the upper second area ② between the lamps 250 having low backlight brightness design a large size of the pixel 270B. In addition, since the third region ③ between the first region ① and the second region ② has an intermediate backlight luminance characteristic, the third region ③ is designed to have an intermediate pixel size 270C.

At this time, the pixel 270A to 270C of the present embodiment is applied to the red, green, and blue sub-color filters to represent the three types of sub-pixels 271A to 271C, 272A to 272C, and 273A to 273C that represent red, green, and blue colors, respectively. ), But the present invention is not limited thereto, and a white sub color filter may be further configured to the three types of sub color filters of red, green, and blue.

In addition, according to the present exemplary embodiment, the liquid crystal display panel is divided into the first region ① to the third region ③ according to the backlight luminance, and the pixels 270A to 270C have different sizes according to the respective regions ① to ③. However, the present invention is not limited thereto, and the pixel may be designed to divide the liquid crystal display panel into various regions according to the backlight brightness and have various sizes according to the respective regions.

In addition, as in the aforementioned first embodiment, both side portions of the liquid crystal display panel having a relatively low backlight brightness due to the electrode portion of the lamp may have a larger pixel size than other regions.

In addition, when the luminance of the backlight is different from the transmittance of the color filter of the color filter substrate corresponding to the pixel, the size of the pixel may be varied according to the transmittance.

The manufacturing method of the liquid crystal display panel according to the present embodiment configured as described above is largely an array process for forming an array substrate, a color filter process for forming a color filter substrate, and a unit liquid crystal display panel by combining the array substrate and the color filter substrate. It is made of a cell process to form a, looking at this in more detail as follows.

First, a thin film transistor which is a switching element which is arranged vertically and horizontally on a transparent insulating substrate such as glass to define a plurality of pixel regions and is connected to the gate line and the data line in each pixel region. To form. In addition, the pixel electrode is connected to the thin film transistor through the array process and drives the liquid crystal layer as a signal is applied through the thin film transistor. In the case of the in-plane switching (IPS) mode, the pixel electrode and the common electrode forming the horizontal electric field are formed together in the liquid crystal layer through the array process.

In addition, a color matrix is formed on the color filter substrate to form a black matrix that distinguishes between the color filter composed of a sub color filter that implements red, green, and blue colors and the sub color filter and blocks light transmitted through the liquid crystal layer. do.

The black matrix may be an organic film made of a resin material, for example, colored acrylic, epoxy, or polyimide resin including any one of carbon black and black pigment. Organic resin etc. can be applied.

At this time, the opening of the black matrix is designed to have a different size for each pixel as described above, wherein the pixels of the region having low backlight brightness increase the size of the opening and the pixels of the region of high backlight brightness are the size of the opening. Make small.

In the case of the transverse electric field mode, the common electrode is formed on the array substrate as described above, but indium tin oxide is formed on the back or top surface of the color filter substrate to prevent the influence of static electricity from the outside. The color filter process may be performed after forming a transparent electrode made of ITO.

Next, an overcoat layer made of a transparent insulating material is formed on the entire surface of the substrate.

The overcoat layer may be formed of a transparent resin having insulating properties to planarize the substrate on which the color filter is formed and to prevent elution of the pigment ions, and may be formed of an acrylic resin or an epoxy resin.

In this case, when the organic film made of a resin material is applied to the black matrix, the overcoat layer is formed to prevent driving failure of the liquid crystal layer due to the step difference in the region where the black matrix and the color filter overlap. However, the present invention is not limited thereto, and when the color filter corresponding to the pixels is formed so as not to overlap the black matrix, an additional overcoat layer for surface planarization is not required.

Next, a spacer is formed of an organic layer on the color filter substrate or the array substrate.

As the spacers are gradually enlarged in size, column spacers (or patterned spacers) of a type fixed to an array substrate or a color filter substrate are used.

Subsequently, an alignment layer is applied to the array substrate and the color filter substrate, respectively, and then the alignment layer is provided to provide alignment control force or surface fixation force (ie, pretilt angle and alignment direction) to the liquid crystal molecules of the liquid crystal layer formed between the two substrates. Orientation treatment. In this case, a rubbing or photoalignment method may be applied as the alignment treatment method.

Next, a predetermined seal pattern is formed on the color filter substrate with a sealant, and a liquid crystal layer is formed on the array substrate.

Thereafter, pressure is applied to the array substrate and the color filter substrate to form a unit liquid crystal display panel.

Meanwhile, in order to improve the yield in manufacturing the unit liquid crystal display panel as described above, a method of simultaneously forming a plurality of unit liquid crystal display panels on a large area mother substrate is generally applied. Accordingly, there is a need for a process of cutting and processing a mother substrate on which a plurality of liquid crystal display panels are manufactured to separate a unit liquid crystal display panel from a large area mother substrate.

Thereafter, the liquid crystal display panel is manufactured by inspecting the liquid crystal display panels.

Many details are set forth in the foregoing description but should be construed as illustrative of preferred embodiments rather than to limit the scope of the invention. Therefore, the invention should not be defined by the described embodiments, but should be defined by the claims and their equivalents.

As described above, the liquid crystal display panel according to the present invention can compensate for the unevenness of the backlight brightness by designing different pixel sizes according to the position in the panel, thereby providing an effect of improving the image quality of the liquid crystal display panel.

Claims (11)

An array substrate including a pixel portion; A gate line and a data line formed in a pixel portion of the array substrate and crossing each other to define a plurality of pixels; And And a color filter substrate bonded to the array substrate, wherein each pixel has a different size according to its position. The liquid crystal display panel of claim 1, wherein each pixel has a different size according to a size of a lower backlight brightness. 3. The liquid crystal display panel according to claim 2, wherein the pixels of the region having low backlight brightness are larger than other regions. 3. The liquid crystal display panel according to claim 2, wherein the pixels of the region having high backlight brightness are smaller in size than other regions. The liquid crystal display panel of claim 1, wherein the size of each pixel represents a size of an opening of a black matrix formed in a color filter substrate. 7. The liquid crystal display panel of claim 6, wherein the size of the opening of the black matrix is adjusted by adjusting an overlapping width between the black matrix and the pixel electrode formed in each pixel. The liquid crystal display panel according to claim 1, wherein when the lamp assembly of the direct type is adopted, the pixels located above the lamps have a smaller size and the pixels located between the lamps have a larger size. 2. The liquid crystal display panel according to claim 1, wherein when the edge lamp assembly is adopted, the pixel positioned at the center of the pixel portion is made smaller and the pixel positioned at the edge of the pixel portion is made larger. An array substrate including a pixel portion; A gate line and a data line formed in a pixel portion of the array substrate and crossing each other to define a plurality of pixels; And And a color filter substrate bonded to face the array substrate, wherein each pixel has a different size according to a backlight brightness of a lower portion. 10. The liquid crystal display panel of claim 9, wherein the pixel of the region having low backlight brightness is larger than that of other regions. 10. The liquid crystal display panel of claim 9, wherein the pixels of the region having high backlight brightness are smaller than other regions.

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