KR20100000642A - Liquid crystal dispaly device - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to block light applied to a liquid crystal panel from a dummy cutting area of a light guide plate, thereby preventing a hot spot. CONSTITUTION: A liquid crystal panel(100) controls transmittance of light to display an image. A backlight unit(150) applies light on the liquid crystal panel. A bottom cover(102) receives the backlight unit. A top cover(120) protects a front edge of the liquid crystal panel and a side of the bottom cover. In a support main(110), a protrusion unit(126) preventing light leakage is formed in a cutting area of a light guide plate included in the backlight unit.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPALY DEVICE}

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device that can improve the display quality by preventing the hot spot phenomenon.

Recently, various flat panel display devices that can reduce weight and volume, which are disadvantages of cathode ray tubes, have emerged. Such a flat panel display includes a liquid crystal display, a field emission display, a plasma display panel, a light emitting device, and the like.

The liquid crystal display device displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display device includes a liquid crystal panel having a liquid crystal cell, a backlight unit for irradiating light to the liquid crystal panel, and a driving circuit for driving the liquid crystal cell.

At this time, the liquid crystal panel of the liquid crystal display device is a light-receiving element for displaying an image by adjusting the amount of light source coming from the outside, so a backlight unit, which is a separate light source for irradiating light to the liquid crystal panel, is required. The backlight unit is divided into an edge method and a direct method according to the installation position.

Here, the edge type backlight unit is formed on one side of the liquid crystal panel to guide the light generated from the lamp and the lamp toward the liquid crystal panel, the light guide plate formed on the lower liquid crystal panel, and the lamp housing formed on the side of the lamp to protect the lamp And optical sheets formed on the lamp housing and the light guide plate to uniformly transmit light toward the liquid crystal panel.

1 is a view showing a conventional liquid crystal display device.

Referring to FIG. 1, a liquid crystal display device covers a bottom cover 2, a backlight unit accommodated in the bottom cover, a liquid crystal panel stacked on the backlight unit, and side surfaces of the bottom cover 2, and covers a non-display area of the liquid crystal panel. It is configured to include a top cover 20 is formed to.

The bottom cover 2 is formed as a bottom case to accommodate the backlight unit.

The backlight unit includes a reflective sheet 4, a light guide plate 6, a plurality of optical sheets 8, and a support main 10.

The light guide plate 6 scatters the light irradiated from the light source and supplies it to the plurality of optical sheets 8. In this case, a reflective sheet 4 is formed below the light guide plate 6 to reflect the light totally reflected inside the light guide plate 6 to the liquid crystal panel 24.

The plurality of optical sheets 8 enhances the luminance and uniformity of the emitted light emitted from the light guide plate 6 and irradiates the liquid crystal panel 24. In this case, the plurality of optical sheets 8 includes a diffusion sheet and a prism sheet.

The support main 10 is formed to support the liquid crystal panel on the side of the light guide plate 6. At this time, the outside of the support main 10 is formed in white to reflect the light of the light source to improve the brightness.

The liquid crystal panel 24 is formed by opposing the upper substrate 16 and the lower substrate 14. In this case, the liquid crystal panel 24 includes a liquid crystal layer (not shown) between the upper substrate 16 and the lower substrate 14. In addition, upper and lower polarizing films 12 and 18 are attached to the outside of the upper and lower substrates 14 and 16 constituting the liquid crystal panel 24.

The top cover 20 surrounds the front edge of the liquid crystal panel 24 disposed on the support main 10 and the side of the bottom cover 2.

In the conventional liquid crystal display device configured as described above, the light guide plate becomes thinner and thinner as the liquid crystal display device becomes thinner according to the needs of consumers. In order to accurately cut the light guide plate having the reduced thickness to meet the requirements of the user, the thickness should be 0.8 mm or more, but the thickness thereof is reduced to 0.6 mm or less. Therefore, a problem arises in that the surface to be cut is not cut accurately when cutting the light guide plate having a reduced thickness to conform to the specification.

At this time, in the cutting region 6a of the light guide plate which is not accurately cut, the light is not reflected to the support main and supplied to the inside of the light guide plate again, but as shown in area A of FIG. 1 and FIG. The light spot is reflected to the inside of the display area so that light spots brighten at the interface between the display area and the top cover.

In order to solve the above problems, the present invention is to provide a liquid crystal display device that can improve the display quality by preventing the hot spot phenomenon.

According to an aspect of the present invention, there is provided a liquid crystal display, comprising: a liquid crystal panel which displays an image by controlling light transmittance; A backlight unit radiating light onto the liquid crystal panel; A bottom cover to accommodate the backlight unit; A top cover surrounding a front edge of the liquid crystal panel and a side of the bottom cover; And a support main formed with a protrusion to prevent light leakage in the cutting area of the light guide plate provided in the backlight unit.

The support main may include a panel seating portion on which the liquid crystal panel is mounted; A light guide plate guide part surrounding a side surface of the light guide plate; And a protrusion protruding inwardly of the light guide plate to prevent light leakage in the cutting area of at least one side of the light guide plate.

The support main to which the light of the light guide plate reaches is characterized in that the reflective material is formed by plating, coating or painting.

The reflective material is characterized in that it is formed by any one of Cr, Ag and Br or mixed.

In the liquid crystal display according to the present invention, a protrusion is formed in a support main corresponding to at least one side of the light guide plate dummy cutting area formed during cutting of the light guide plate, thereby blocking the light spot irradiated to the liquid crystal panel from the dummy cutting area of the light guide plate to prevent hot spot phenomenon. It can prevent and improve the display quality of liquid crystal panel.

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

3 is a diagram illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel 100 for displaying an image by adjusting light transmittance, a backlight unit 150 for irradiating light to the liquid crystal panel 100, Cutting of the light guide plate provided in the bottom cover 102 to accommodate the backlight unit 150, the top cover 120 surrounding the front edge of the liquid crystal panel 100 and the side of the bottom cover 102, and the backlight unit 150. It is configured to include a support main 110 formed with a protrusion 126 to prevent light leakage in the area.

The liquid crystal panel 100 includes a lower substrate 114 and an upper substrate 116 which are bonded to face each other. At this time, between the lower substrate 114 and the upper substrate 116 is configured to include a spacer (not shown) and a liquid crystal layer (not shown) to maintain a constant gap between the two substrates.

The lower substrate 114 includes a plurality of data lines and a plurality of gate lines formed to intersect each other, a thin film transistor (TFT) and a thin film transistor formed in each pixel cell region defined by crossing the data lines and the gate lines. And a pixel electrode connected to the TFT). The thin film transistor TFT supplies an image signal from the data line to the liquid crystal cell Clc in response to a gate pulse from the gate line.

The liquid crystal cell Clc may be equivalently represented as a liquid crystal capacitor because the liquid crystal cell Clc includes a common electrode Vcom facing the liquid crystal layer and a pixel electrode connected to the thin film transistor TFT. The liquid crystal cell also includes a storage capacitor Cst for maintaining the image signal charged in the liquid crystal capacitor until the next image signal is charged.

The upper substrate includes at least three color filters including red, green, and blue, a separation of each color filter, a black matrix defining a pixel cell, a common electrode Vcom supplied with a common voltage, and the like. Here, the common electrode is formed on the upper glass substrate in a vertical electric field driving method such as twisted nematic (TN) mode and vertical alignment (VA) mode, such as IPS (In Plane Switching) mode and FFS (Fringe Field Switching) mode. In the horizontal electric field driving method, the pixel electrode is formed on the lower glass substrate together with the pixel electrode. On the upper glass substrate and the lower glass substrate of the liquid crystal panel 102, a polarizing plate having an optical axis orthogonal to each other is attached, and an alignment film for setting the pretilt angle of the liquid crystal is formed on the inner surface in contact with the liquid crystal.

In addition, a lower polarizing film 112 facing the plurality of optical sheets 108 is attached to the rear surface of the lower substrate 114. The lower polarizing film 112 polarizes the light emitted from the plurality of optical sheets 108. At this time, the transmission axis of the lower polarizing film 112 is disposed at a predetermined angle to match the alignment direction of the liquid crystal layer.

The upper polarizing film 118 is attached to the upper substrate 116. The upper polarizing film 118 polarizes light passing through the liquid crystal layer and the color filter array substrate. In this case, the transmission axis of the upper polarizing film 118 is disposed to be perpendicular to the transmission axis of the lower polarizing film 112.

The top cover 120 surrounds the front edge of the liquid crystal panel 100 and the side of the bottom cover 102. To this end, the top cover 120 includes a non-display area except for the display area of the liquid crystal panel 100, that is, a flat part covering the edge and a side part bent vertically from the flat part to surround the side of the bottom cover 102. It is configured by.

The bottom cover 102 is formed to accommodate the backlight unit 150 and the support main 110. In this case, the bottom cover 102 may be formed of a material having high thermal conductivity so that heat generated from the backlight unit 150 may be discharged to the outside.

The backlight unit 150 includes at least one light source (not shown), a reflective sheet 104 stacked on the bottom cover 102, a light guide plate 106 disposed on the reflective sheet 104, and a light guide plate ( And a plurality of optical sheets 108 stacked on 106.

The light source is disposed at one edge portion of the bottom cover 102 to face the light incident portion of the light guide plate 106. In this case, the light source may be a fluorescent lamp or a light emitting diode. The at least one light source is driven by a light source voltage from the outside to generate light, and irradiates the light guide plate 106 with the generated light.

The light source housing is formed to protect at least one light source from one side of the light guide plate 106. In this case, the light source housing guides the light of the at least one light source to the light incident part of the light guide plate 106, and prevents the light guide plate 106 from penetrating into the light source housing to damage the at least one light source 112.

The reflective sheet 104 is disposed on the bottom surface of the bottom cover 102 to prevent light loss by reflecting the light traveling toward the rear surface of the light guide plate 106 toward the liquid crystal panel 100. In this case, the reflective sheet 104 is formed to be the same as or larger than the width of the light guide plate 106 to prevent light leakage of the light reflected from the light guide plate 106.

The light guide plate 106 is disposed on the bottom cover 102 to which the reflective sheet 104 is attached. In this case, the light guide plate 106 includes an area for supplying light to the liquid crystal panel 100 and a dummy cutting area 106a that is not cut at the time of cutting.

First, the light guide plate 106 in the region for supplying light to the liquid crystal panel 100 diffuses the light irradiated from the at least one light source through the light incident part and exits toward the liquid crystal panel 100. That is, the light guide plate 106 converts incident light incident from the light source into planar light and irradiates the plurality of optical sheets 108. In this case, the light guide plate 106 may be formed of a plastic, resin, or heat resistant glass material, such as PMA (FlatMethylMethacrylAte), in a flat type or a wedge type. On the other hand, the light guide plate 106 may be a prism light guide plate having an inclined rear surface and a prism-shaped exit surface having a hill and a valley formed in a linear or circular shape. That is, a plurality of prism patterns having peaks and valleys may be formed on the exit surface of the light guide plate 106.

The plurality of optical sheets 108 improve the luminance and uniformity of the emitted light emitted from the light guide plate 106 and irradiate the liquid crystal panel 100. To this end, the plurality of optical sheets 108 includes at least one diffusion sheet for diffusing the light emitted from the light guide plate 106 to the entire area, and at least one prism sheet for collecting the light diffused by the diffusion sheet. do. Here, the laminated structure of each of the at least one diffusion sheet and the prism sheet may be sequential, non-sequential or alternating to improve brightness and uniformity of the light.

The support main 110 is seated on the bottom cover 102 to fix the backlight unit 150. The support main 110 is formed in a rectangular band shape, and a coupling groove 132 to which an inner wall of the bottom cover 102 is coupled is formed at a lower portion of each outer surface. In addition, the coupling groove 132 prevents the outer wall of the bottom cover 102 from protruding to the outer surface of the side wall frame 130. In this case, the support main 110 includes a seating groove 132 in which the support main 110 may be seated on the bottom cover 102, a panel seating portion 128 in which the liquid crystal panel 100 is seated, and a light guide plate 106. It includes a light guide plate guide portion 124 surrounding the outer periphery) and a protrusion 126 to prevent light leakage in the dummy cutting area (106a) of the light guide plate 106.

The panel mounting portion 128 is formed so that the rear edge of the liquid crystal panel 100 can be seated. In this case, an adhesive pad (not shown) for fixing the liquid crystal panel 100 may be formed on the panel seating portion 128.

The light guide plate guide part 124 is formed to surround the outer edge of the light guide plate 106. Here, the light guide plate guide part 124 reflects the light irradiated from the light guide plate 106 back to the light guide plate 106.

The protrusion 126 is formed to protrude between the panel seating part 130 and the light guide plate guide 128. Here, the protrusion 126 prevents the light emitted from the light guide plate 106 from being reflected and irradiated onto the liquid crystal panel 100. In this case, a reflective material for reflecting light of the light guide plate 106 may be formed on the lower surface of the protrusion 126 and the light guide plate guide part 124. In this case, the reflective material is formed by mixing any one of Cr, Ag, and Br.

In this way, the liquid crystal display configured as described above forms a protrusion at a support main corresponding to at least one side of the light guide plate dummy cutting area formed during cutting of the light guide plate, thereby blocking the light spot irradiated to the liquid crystal panel from the dummy cutting area of the light guide plate to prevent hot spot phenomenon. It can prevent and improve the display quality of liquid crystal panel.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a view showing a conventional liquid crystal display device.

2 is a photograph showing a liquid crystal display device in which a conventional hot spot phenomenon occurs.

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

4 is a sectional view taken along the line II ′ of the liquid crystal display according to the exemplary embodiment of the present invention.

FIG. 5 is a view illustrating a liquid crystal display device having improved hot spot phenomenon according to an exemplary embodiment of the present invention. FIG.

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

100: liquid crystal panel 102: bottom cover

104: reflective sheet 106: light guide plate

106a: dummy cutting area 108: a plurality of optical sheets

110: support main 112: lower polarizing film

114: upper polarizing film 116: upper substrate

118: lower substrate 120: top cover

Claims (4)

A liquid crystal panel which displays an image by adjusting light transmittance; A backlight unit radiating light onto the liquid crystal panel; A bottom cover to accommodate the backlight unit; A top cover surrounding a front edge of the liquid crystal panel and a side of the bottom cover; And And a support main having a protrusion for preventing light leakage in a cutting area of the light guide plate of the backlight unit. The method of claim 1, The support main, A panel seating part on which the liquid crystal panel is mounted; A light guide plate guide part surrounding a side surface of the light guide plate; And a protrusion protruding inwardly of the light guide plate to prevent light leakage in the cutting area of at least one side of the light guide plate. The method of claim 2, And a reflective material is plated, coated or painted on the support main through which the light of the light guide plate reaches. The method of claim 3, wherein The reflective material is any one of Cr, Ag, and Br or formed by mixing them.

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