KR20090055770A - Liquid crystal dispaly device - Google Patents

Abstract

A liquid crystal display is provided to avoid a hot spot and a bright line generated by light emitted from a support main. A liquid crystal display comprises as follows. A light crystal panel displays an image by controlling transmittance of light. A backlight unit irradiates the light on the liquid crystal panel. A support main(110) forms a projected portion at the edge of a light guide plate of the backlight unit. The support main comprises as follows. The liquid crystal panel is settled on a panel settling portion. A light guide plate guiding portion covers a side of the light guide plate. The projected portion is projected between the panel settling portion and the light guide plate guiding portion.

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 capable of preventing hot spots and bright lines.

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 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.

In this case, the liquid crystal panel of the liquid crystal display device is a light-receiving element that displays 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, the liquid crystal display includes 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 covering the 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, the light emitted from the light source passes through the light guide plate to irradiate the inner surface of the support main 10 opposite to the light source. At this time, the light irradiated to the inner surface of the support main 10 is concentrated at the end of the top cover 20 which is a boundary between the area A of the liquid crystal panel 24, that is, the display area of the liquid crystal panel 24 and the non-display area. .

Therefore, a hot spot phenomenon occurs in the LED backlight unit that is a point light source, and a bright line occurs in the lamp backlight unit that is a linear light source.

In order to solve the above problems, the present invention is to provide a liquid crystal display that can prevent hot spots and bright lines caused by the light reflected from the support main.

A liquid crystal display device according to the present invention comprises: a liquid crystal panel which displays an image by adjusting a transmittance of a liquid crystal; A backlight unit radiating light onto the liquid crystal panel; It includes a support main formed with a protrusion at the edge of the light guide plate of 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 projecting between the panel seating portion and the light guide plate guide portion.

The protrusion may have an inclined surface inclined from an edge of the light guide plate to the light guide plate guide.

The inclined surface of the protrusion 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.

The light guide plate is characterized in that the chamfered surface is cut off to correspond to the inclined surface of the protrusion.

In the backlight unit and the liquid crystal display according to the present invention, projections are formed between the panel seating portion of the support main and the light guide plate guide portion, and the light reflected from the light guide plate guide portion of the support main is formed by filling the edges of the corresponding light guide plate. By blocking the direct irradiation on the liquid crystal panel it is possible to prevent hot spots and bright lines generated by the light source.

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

2 is a diagram illustrating a liquid crystal display according to a first embodiment of the present invention.

Referring to FIG. 2, a liquid crystal panel 100 displaying an image by adjusting a transmittance of liquid crystal, a backlight unit 150 radiating light to the liquid crystal panel 100, and an edge of the light guide plate 106 of the backlight unit 150. In the protrusion 126 is formed, including the support main 110 is formed.

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 upper substrate 116 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 supplied with a common voltage, and the like. Here, the common electrode may be formed on the lower substrate 114 according to the mode of the liquid crystal.

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 the image signal from the data line to the liquid crystal cell in response to the gate pulse from the gate line.

The liquid crystal cell (not shown) may be equivalently represented as a liquid crystal capacitor because the liquid crystal cell includes a common electrode facing each other with a liquid crystal layer interposed therebetween and a pixel electrode connected to the thin film transistor TFT. The liquid crystal cell also includes a storage capacitor (not shown) for maintaining the image signal charged in the liquid crystal capacitor until the next image signal is charged.

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 200 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 200 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 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 is formed by filling the inclined surface 122a at the corner corresponding to the inclined surface 124 inclined to the protrusion 126 of the support main 110. The light guide plate 106 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 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 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.

4 is a diagram illustrating a support main according to an embodiment of the present invention.

The support main 110 is seated on the bottom cover 102 to fix the backlight unit 150. In this case, as shown in FIG. 4, the support main 110 includes a side wall frame 130 forming an outer shape of the support main 110 and a seating groove in which the support main 110 may be mounted on the bottom cover 102. 132; The panel seating portion 132 on which the liquid crystal panel 100 is seated, the light guide plate guide portion 128 surrounding the outside of the light guide plate 106, and a protrusion projecting between the panel seating portion 132 and the light guide plate guide portion 128. 126).

The side wall frame 130 is formed in a rectangular strip shape, and the coupling grooves 132 to which the inner wall of the bottom cover 102 is coupled are formed at the bottom of each outer surface. At this time, 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.

The panel seating portion 134 is formed to allow the rear edge of the liquid crystal panel 100 to be seated. In this case, an adhesive pad (not shown) for fixing the liquid crystal panel 100 may be formed on the panel seating part 134.

The light guide plate guide portion 128 is formed to surround the outer edge of the light guide plate 106. Here, the light guide plate guide 128 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, the protrusion 126 has an inclined surface 124 inclined toward the panel guide 130. In addition, a reflective material for reflecting light of the light guide plate 106 may be formed on the inclined surface of the protrusion 126. In this case, the reflective material is formed by mixing any one of Cr, Ag, and Br.

Therefore, the liquid crystal display according to the first exemplary embodiment of the present invention forms a protrusion between the panel seating portion of the support main part and the light guide plate guide part, and fills the edge of the light guide plate corresponding to the guide part of the support main part. It is possible to prevent the reflected light from being directly irradiated to the liquid crystal panel to prevent hot spots and bright lines generated by the light source.

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

First, since the liquid crystal display according to the second embodiment of the present invention has the same configuration as the first embodiment of the present invention except for the support main, the description of the same configuration will be replaced with the above description. .

In the support main 210 according to the second embodiment of the present invention, the liquid crystal panel 100 covers the protrusion 226 of the support main 210 by the top cover 220 without deforming the conventional light guide plate 206. The light reflected from the light guide plate guide portion 224 of the support main 210 may be prevented from being directed toward the non-display area of the support main 210 to the liquid crystal panel 100.

Accordingly, the liquid crystal display according to the second exemplary embodiment of the present invention prevents light reflected from the light guide plate guide of the support main from being directly irradiated onto the liquid crystal panel by forming a protrusion in the support main without deforming the conventional light guide plate. Hot spots and bright lines generated according to the light source can be prevented.

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 illustrates a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a cross-sectional view taken along line II ′ of the liquid crystal display according to the first embodiment of the present invention.

4 is a view showing a support main according to a first embodiment of the present invention;

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

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

100: liquid crystal panel 102: bottom cover

104: reflective sheet 106: light guide plate

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 124: inclined surface

126: protrusion 128: light guide plate guide

130: side frame 132: coupling groove

134: Panel Guide

Claims (6)

A liquid crystal panel which displays an image by adjusting light transmittance; A backlight unit radiating light onto the liquid crystal panel; And a support main having a protrusion formed at an edge of the light guide plate of the backlight unit. The method of claim 1, The support main, A panel seating part on which the genital liquid crystal panel is mounted; A light guide plate guide part surrounding a side surface of the light guide plate; And a protrusion protruding between the panel seating portion and the light guide plate guide portion. The method of claim 2, Wherein the protrusion has an inclined surface inclined from an edge of the light guide plate to the light guide plate guide. The method of claim 3, wherein And a reflective material is plated, coated or painted on the inclined surface of the protrusion. The method of claim 4, wherein The reflective material is any one of Cr, Ag, and Br or formed by mixing them. The method of claim 3, wherein The light guide plate is a liquid crystal display, characterized in that the chamfered surface is formed so as to correspond to the inclined surface of the protrusion.

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