KR20180078051A - Backlight unit and liquid crystal display device having the same - Google Patents

Abstract

The present invention relates to a backlight unit and a liquid crystal display apparatus having the same. According to the present invention, a light guide plate is provided with a recessed part due to a difference in length between first and second portions, and a light source is disposed in the recessed part. Further, the second portion facing the light source is formed into a symmetric wedge structure. Accordingly, light efficiency is improved through the symmetric wedge structure, and at the same time, a side spot output from the light source is incident on the light guide plate through the first portion, thereby effectively improving a hot spot. In addition, even when a parting line is formed according to a process error, an image with the improved hot spot can be stably maintained.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and a liquid crystal display device having the same, and more particularly, to a backlight unit that improves light efficiency and effectively improves a hot spot and a liquid crystal display having the same.

As the information society has developed, the demand for the display field has been increasing in various forms. In response to this demand, various flat panel display devices having characteristics such as thinning, light weight, and low power consumption have been developed. For example, A liquid crystal display device, a plasma display panel device, and an organic light emitting diode display device have been studied.

Among these, a liquid crystal display device is one of the most widely used flat panel display devices, and includes two substrates on which pixel electrodes and common electrodes are formed, and a liquid crystal layer between two substrates.

Such a liquid crystal display device determines the orientation of liquid crystal molecules in the liquid crystal layer according to the electric field generated by the voltage applied to the two electrodes, and controls the polarization of the incident light to display an image.

In recent years, in manufacturing a liquid crystal display device, a display area of a liquid crystal display device is required to be maximized and a non-display area (bezel part) to be as small as possible.

Hereinafter, a hot spot generated when a bezel portion is reduced in a conventional liquid crystal display device will be described with reference to the drawings.

1 and 2 are views for explaining a hot spot according to a width change of a bezel in a conventional liquid crystal display device.

1, a conventional liquid crystal display device may include a light guide plate 44, a plurality of light sources 45, a guide panel 60, a cover bottom 70, and the like.

The plurality of light sources 45 may be mounted on a printed circuit board (not shown) with a predetermined distance therebetween.

A plurality of grooves may be formed in the guide panel 60, and a light source 45 may be disposed in each of the grooves.

For example, the light source 45 may emit light having red (R), green (G), and blue (B) colors toward the light incoming portion of the light guide plate 44, It is possible to realize white light by color mixing.

On the other hand, since most of the light emitted from the light source 45 advances forward and the light exiting toward the side direction is relatively small, light emitted from the light source 45 is uniformly supplied to the light incoming portion of the light guide plate 44, There is a problem that a hot spot is generated in the vicinity

Accordingly, in the conventional liquid crystal display device, the light emitted from the light source 45 enters the light guide plate 44, and the area where the light is sufficiently mixed is defined as the optical distance, ) Is set.

That is, the optical distance defined by the distance from the light incident surface of the light guide plate 44 to the display area AA is maintained to be 'L1' so that hot spots do not occur in the display area AA.

However, according to recent narrow bezel implementation of the liquid crystal display device, the optical distance from the light-incoming portion of the light guide plate 44 to the display area AA is gradually narrowing.

As shown in FIG. 2, if the optical distance from the light entering portion to the display area AA of the light guide plate 44 is 'L2', a hot spot is generated in the display area AA.

Therefore, in the conventional liquid crystal display device, since it is necessary to maintain a certain distance from the light-incoming portion to the display area AA of the light guide plate 44 in order to prevent hot spots from occurring in the display area AA, There arises a problem of generation of hot spots in accordance with the above-described method.

Disclosure of the Invention Problems to be Solved by the Invention The present invention provides a backlight unit capable of improving light efficiency and effectively improving hot spots and a liquid crystal display device having the same.

According to an aspect of the present invention, there is provided a light guide plate including a light guide plate including a first region and a second region, and a light source disposed on one side of the light guide plate, And a non-pattern portion disposed between the first region and the second region, wherein the second region has a first portion extending in the first region and having the same thickness in the direction of the light source, and a second portion extending in the first region toward the light source Wherein the first portion provides a backlight unit that is longer in length than the second portion

The second portion includes a first inclined surface disposed on the upper surface of the light guide plate, a second inclined surface opposite to the first inclined surface, and a vertical surface connecting the first inclined surface and the second inclined surface, One inclined surface and the second inclined surface may be symmetrical.

In addition, a lenticular pattern including a plurality of hemispheres extending in a first axis may be disposed on the upper surface of the pattern unit.

A dot pattern may be disposed on the back surface of the pattern unit.

The plurality of hemispheres may be spaced apart from each other by a second axis perpendicular to the first axis.

Here, a plurality of the first portion and the second portion may be arranged alternately.

A light source may be disposed corresponding to each of the vertical surfaces of the first portion.

Here, the light source may be an LED assembly formed by mounting a plurality of LEDs on a printed circuit board.

According to another aspect of the present invention, there is provided a liquid crystal display device including a backlight unit, a guide panel surrounding a side surface of the light guide plate, and a liquid crystal panel disposed on the backlight unit.

According to the present invention, the light guide plate is provided with the recessed portion by the difference in length between the first and second portions, and the light source is disposed in the recessed portion. Further, the second portion facing the light source is formed as a symmetric wedge structure.

 Accordingly, the light efficiency is improved through the symmetric wedge structure, and at the same time, the side spot output from the light source is incident on the light guide plate through the first portion, thereby effectively improving the hot spot.

In addition, even when a parting line is formed according to a process error, an image with improved hot spot can be stably maintained

1 and 2 are views for explaining a hot spot according to a width change of a bezel in a conventional liquid crystal display device.
3 is an exploded perspective view schematically showing a liquid crystal display device according to a first embodiment of the present invention.
4 is a cross-sectional view schematically illustrating a light-incident portion of a liquid crystal display device according to a first embodiment of the present invention.
5A and 5B are views schematically showing a light guide plate according to a first embodiment of the present invention.
6A and 6B are views schematically showing an optical path of a liquid crystal display according to a first embodiment of the present invention.
7A is a schematic view of a parting line formed in the manufacturing process of the light guide plate.
FIG. 7B is a view schematically showing a path of light along a parting line. FIG.
8A is a view schematically showing the shape of the light guide plate when the alignment between the second mold core and the third mold core is shifted.
8B is a view schematically showing a crack in the light guide plate due to an external force.
9A is a schematic view of a parting line formed in a manufacturing process of a light guide plate according to a second embodiment of the present invention.
FIG. 9B is a view schematically showing the path of light according to the parting line of the second embodiment of the present invention. FIG.
10A is a photograph of a hot spot of a conventional liquid crystal display device.
10B is a photograph of a hot spot improved in a liquid crystal display according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

≪ Embodiment 1 >

FIG. 3 is an exploded perspective view schematically illustrating a liquid crystal display device according to a first embodiment of the present invention, FIG. 4 is a cross-sectional view schematically illustrating a light-incident portion of a liquid crystal display device according to a first embodiment of the present invention, 5A and 5B are views schematically showing a light guide plate according to a first embodiment of the present invention.

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The liquid crystal display 100 according to the first embodiment of the present invention supports the liquid crystal panel 110, the backlight unit 120, the liquid crystal panel 110, and the backlight unit 120, A cover panel 130, and a cover bottom 150. The cover panel 150 includes a cover panel 150,

Here, the backlight unit 120 of the liquid crystal display device 100 according to the first embodiment of the present invention may be composed of the edge type backlight unit 120.

For convenience of explanation, the display surface direction of the liquid crystal panel 110 is referred to as forward or upward (or upward), and the opposite direction is referred to as rearward or downward (or downward).

The liquid crystal panel 110 includes a first and second substrates 112 and 114 bonded to each other and a liquid crystal layer (not shown) interposed between the first and second substrates 112 and 114 .

Although not shown in detail, on the inner surface of the first substrate 112 called a lower substrate or an array substrate, a plurality of gate wirings and data wirings cross each other to define pixels, and each pixel is connected to a corresponding one of the gate wirings and the data wirings, And a pixel electrode connected to the thin film transistor may be formed.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate as a counter substrate facing the lower substrate, a color filter pattern corresponding to each pixel and a gate electrode, a data wiring, A black matrix covering a non-display element such as a transistor can be formed.

At this time, as the liquid crystal panel 110, all kinds of liquid crystal panels can be used. For example, all types of liquid crystal panels such as an IPS system, an FFS system, a TN system, a VA system, and an ECB system can be used. In the case where the IPS system is an FFS system, a common electrode for forming a transverse electric field together with a pixel electrode may be formed on the first substrate 112.

An orientation film for determining the initial molecular orientation direction of the liquid crystal may be formed on the interface between the first and second substrates 112 and 114 and the liquid crystal layer and a liquid crystal layer filled between the first and second substrates 112 and 114 A seal pattern may be formed along the edges of the two substrates 112, 114 to prevent leakage.

Polarizing plates 119a and 119b may be attached to the outer surfaces of the first and second substrates 112 and 114 to selectively transmit specific polarized light.

The printed circuit board 116 is connected to at least one edge of the liquid crystal panel 110 via a connection member such as a flexible circuit board or a tape carrier package so that the printed circuit board 116 is bent toward the backside of the cover bottom 150 Lt; / RTI >

A backlight unit 120 is disposed behind the liquid crystal panel 110 configured as described above.

The backlight unit 120 includes an LED assembly 129, a white or silver reflective plate 125, a light guide plate 123 mounted on the reflection plate 125, and an optical sheet 127 on the light guide plate 123 .

The LED assembly 129 includes a plurality of LEDs 129a that function as a light source of the backlight unit 120 and face one side of the light guide plate 123 and a plurality of LEDs 129a, 129b.

The light guide plate 123 to which the light emitted from the plurality of LEDs 129a is incident is formed such that the light incident from the LED 129a travels in the light guide plate 123 by total reflection several times, So that the liquid crystal panel 110 can be provided with a uniform surface light.

The reflection plate 125 is positioned behind the light guide plate 123 and reflects the light that has passed through the back surface of the light guide plate 123 toward the liquid crystal panel 110 to improve the brightness of light.

The structure of the light guide plate 123 will be described in detail later.

The optical sheet 127 may be disposed on the light guide plate 123. For example, the optical sheet 127 includes a diffusion sheet and a light condensing sheet, and diffuses and condenses the light emitted from the light guide plate 123 so that a more uniform surface light processed into a high-quality image is incident on the liquid crystal panel 110. [ Lt; / RTI >

Here, the cover bottom 150 of the liquid crystal display device 100 according to the first embodiment of the present invention may have a plate shape.

Here, the cover bottom 150 has a first horizontal surface 152 disposed in the liquid crystal panel direction, a second horizontal surface 154 opposite to the first horizontal surface 152, and a first horizontal surface 152 and a second horizontal surface 154, (Not shown).

The guide panel 130 of the liquid crystal display device 100 according to the first embodiment of the present invention may include a body 132, a horizontal portion 136, and a vertical portion 134.

The main body 132 includes an upper surface 132a on which the liquid crystal panel 110 is attached and an inner surface 132b on which the LED assembly 129 is attached, . ≪ / RTI >

The back surface of the horizontal portion 136 may face the first horizontal surface 152 of the cover bottom 150

In addition, the inner surface of the vertical portion 134 may face the side surface 156 of the cover bottom 150.

Here, the guide panel 130 may have a rectangular frame shape surrounding the backlight unit 120.

That is, since the cover bottom 150 is disposed inside the guide panel 130, the thin liquid crystal display device 100 can be effectively implemented.

A shielding tape (not shown) may be disposed between the horizontal portion 136 of the guide panel 130 and the first horizontal surface 152 of the cover bottom 150. That is, it is possible to fix the guide panel 130 and the cover bottom 150 through the light shielding tape having adhesive force on both sides, and to prevent light leakage between the guide panel 130 and the cover bottom 150.

The liquid crystal display device 100 according to the first embodiment of the present invention can directly attach the liquid crystal panel 110 to the guide panel 130 through the adhesive member so that the liquid crystal display device 100 can be mounted on the liquid crystal panel 110, And a case top surrounding the front edge may not be separately provided.

When the liquid crystal panel 110 is directly exposed to the outside without the case top, the liquid crystal display device 100 can have a beautiful appearance and can be recognized by the user in a larger area do..

As described above, the liquid crystal panel 110 and the backlight unit 120 can be modularized using the guide panel 130 and the cover bottom 150.

Meanwhile, the light guide plate 123 of the liquid crystal display 100 according to the first embodiment of the present invention may include a first area A1 and a second area A2.

Here, the first region A1 may include a pattern portion PA and a non-pattern portion NPA.

A lenticular pattern P1 may be disposed on the upper surface of the pattern unit PA.

Here, the lenticular pattern P1 may include a plurality of hemispheres extending in a first axis X connecting the light-incident portion where the light source is disposed and the light-receiving portion opposite to the light-incident portion. That is, the lenticular pattern P1 may be formed in the longitudinal direction parallel to the direction in which the light is incident.

Here, the plurality of hemispheres may be disposed apart from the second axis Y perpendicular to the first axis X. [

The lenticular pattern P1 as described above can not only light out the light traveling in the light guide plate 123 to the liquid crystal panel 110 but also have a light converging effect.

The dot pattern P2 may be disposed on the back surface of the pattern unit PA. However, the present invention is not limited thereto.

That is, the light guide plate 123 may be an embossed pattern having a specific shape for allowing the light incident into the light guide plate 123 to enter the liquid crystal panel 110 through the light incident portion of the light guide plate 123 from the back surface of the light guide plate 123. For example, an elliptical pattern, a polygon pattern, a hologram pattern, and the like.

The non-pattern portion NPA is disposed between the pattern portion PA of the first region A1 and the second region A2. That is, it can be defined as an area in which no pattern is formed between the pattern part PA and the second area A2 in the first area

The light emitted from the LED 129a as the light source is incident into the light guide plate 123 by the non-patterned portion NPA, thereby preventing hot spots generated in the light incident portion.

Further, the second region A2 may include a first portion A21 and a second portion A22.

Here, the first portion A21 may extend with the same thickness d1 in the direction in which the light sources are arranged in the first region A1. That is, it may be a bar extending in the light source direction from the non-pattern portion NPA of the first region A1.

 In addition, the thickness d2 of the second portion A22 may increase in the direction in which the light source is arranged in the first region A1. That is, the shape may be such that the thickness d2 increases as the light source extends in the non-pattern portion NPA of the first region A1.

Here, the second portion A22 includes a first inclined surface S1 disposed on the upper surface, a second inclined surface S2 disposed on the back surface opposite to the first inclined surface S1, a first inclined surface S1, And a vertical surface V connecting the two inclined surfaces S2 on the side where the light sources are disposed.

 That is, the first inclined surface S1 and the second inclined surface S2 may be symmetric wedge structures.

 Further, the first portion A21 may be formed longer than the second portion A22.

The first portion A21 and the second portion A22 may be arranged in a plurality alternatingly. Although two pieces of the first part A21 and the second part A22 are shown on the drawing, this is an example, and may be variously arranged according to the size of the light guide plate 123. [

  In this manner, the recessed portion can be formed due to the difference in length between the first portion A21 and the second portion A22, and the light source can be disposed at the recessed portion. That is, the second portion A22 may be disposed between the first portions A21 to form the recessed portion, and the LED assembly 129, which is a light source, may be disposed in each recessed portion.

Therefore, the light output from the LED assembly 129, which is a light source disposed at the concave portion, can be incident into the light guide plate 123 through the vertical plane V of the second portion A22.

Here, the light guide plate 123 is made of a plastic material such as polymethylmethacrylate (PMMA) or polycarbonate (PC), which is an acrylic transparent resin, which is one of the transparent materials capable of transmitting light, But is not limited thereto.

6A and 6B are views schematically showing an optical path of a liquid crystal display according to a first embodiment of the present invention.

The light guide plate 123 includes a first area A1 and a second area A2 and the first area A1 includes a pattern part PA and a non-pattern part NPA, The second region A2 includes a first portion (A21 in Fig. 3) and a second portion (A22 in Fig. 3), and an LED assembly 129 are disposed.

6), the light that has not been incident on the light guide plate 123 from the light source (45 in FIG. 2) is divided into the first inclined plane S1 and the second inclined plane S1 2 incidence plane S2 to the inside of the light guide plate 123. That is, since the second portion (A22 in Fig. 3) of the light guide plate 123 has a symmetric wedge structure in which the thickness thereof increases toward the light source, the light leaked upward and downward from the conventional light guide plate (44 in Fig. 2) So that the light efficiency can be effectively improved.

6B, since the LED assembly 129, which is a light source, is disposed facing the second portion A22 between the first portions A21, the path of the light output from the side surface of the light source is referred to as a first portion A21, The hot spot generated in the display area can be effectively improved according to the implementation of the narrow bezel.

FIG. 7A is a schematic view of a parting line formed in the manufacturing process of the light guide plate, and FIG. 7B is a view schematically showing a path of light along a parting line.

As shown in the figure, the light guide plate 123 may be manufactured by an injection process. That is, the movable mold can be manufactured by a movable mold which can move in a direction approaching or away from the stationary mold.

Here, a fixed mold core is fixed to the inner side surface of the stationary mold facing the movable mold, and a movable mold core can be fixed to the inner side surface of the movable mold facing the stationary mold core.

The light guide plate 123 can be manufactured by injecting molten material into the cavity formed when the fixed mold core and the movable mold core are closely contacted.

6A) of the back surface of the light guide plate 123 and the first mold core C1 for forming the lenticular pattern (P1 of FIG. 6A) on the upper surface of the light guide plate 123, The light guide plate 123 can be manufactured through the second mold core C2 for forming the first inclined plane S2 and the third mold core C3 for forming the second inclined plane S2 on the back surface of the light guide plate 123. [

Here, the first mold core C1 is a fixed mold core, and the second and third mold cores C2 and C3 are movable mold cores.

The inner surface of the third mold core C3 may have a slant surface C31 and a horizontal surface C32.

Therefore, the second and third mold cores C2 and C3 are required to form the back surface of the light guide plate 123, and the extra and the second mold cores C2, The material may leak and a parting line (PL), which is a fine linear mark, may occur.

7B, the parting line PL formed on the back surface of the light guide plate 123 causes light traveling inside the light guide plate 123 to be emitted to the display area AA, which causes hot spot.

The distance T between the vertical plane V and the parting line PL as the light incidence surface may be 1.2 mm and the height h of the parting line PL may be 3 um.

FIG. 8A is a view schematically showing the shape of the light guide plate when the second mold core and the third mold core are misaligned, and FIG. 8B is a view schematically showing a state where cracks are generated in the light guide plate by an external force.

As shown in FIG. 8A, the back surface of the light guide plate 123 is formed through the second mold core C2 and the third mold core C3.

Accordingly, when the alignment of the second mold core C2 and the third mold core C3 is shifted according to a process error, a step K is generated on the back surface of the first region A1 .

     Therefore, when pressure EP is externally applied, a crack CR is generated in the first region A1 as shown in FIG. 8B. The crack CR generated in the first area A1 affects the path of the light inputted through the light incident surface of the light guide plate 123 and causes a deterioration of the image quality of the liquid crystal display device.

 The liquid crystal display 100 according to the first embodiment of the present invention has a symmetrical wedge structure in which the thickness of the second portion A2 of the light guide plate 123 increases toward the light source, The light leaking to the upper and lower sides of the light guide plate (44 in FIG. 2) can be incident into the light guide plate 123, thereby effectively improving the light efficiency.

In addition, by changing the path of the light output from the side surface of the light source to the area where the dark portion is generated through the first portion A2, hot spots generated in the display region AA can be effectively .

However, hot spots (hot spots by parting lines) and image quality deterioration may be accompanied by an error in the manufacturing process of the light guide plate.

≪ Embodiment 2 >

Hereinafter, a detailed description of a similar configuration to the first embodiment may be omitted.

FIG. 9A is a schematic view of a parting line formed in a manufacturing process of a light guide plate according to a second embodiment of the present invention, and FIG. 9B is a view schematically showing a path of light according to the parting line of the second embodiment of the present invention.

As shown in the figure, the light guide plate 223 can be manufactured by an injection process. That is, the movable mold is made of a movable mold which can move in a direction approaching or away from the stationary mold.

Here, a fixed mold core is fixed to the inner surface of the stationary mold facing the movable mold, and a movable mold core is fixed to the inner surface of the movable mold facing the stationary mold core.

The molten material is injected into the cavity formed when the fixed mold core and the movable mold core are closely contacted to produce the light guide plate 223. [

6A) of the back surface of the light guide plate 223 and the first mold core C1 for forming the lenticular pattern (P1 of FIG. 6A) on the upper surface of the light guide plate 223, And the third mold core C3 for forming the second inclined plane S2 on the back surface of the light guide plate 223. The light guide plate 223 is made of the same material as that of the light guide plate 223.

The light guide plate 223 according to the second embodiment of the present invention is configured such that the second and third mold cores C2 and C3 for forming the back surface of the light guide plate 223 are disposed on the upper side and the upper surface of the light guide plate 223 is formed The first mold core C1 is disposed at the lower portion.

The first mold core C1 is a movable mold core, and the second and third mold cores C2 and C3 are fixed mold cores.

The inner surface of the third mold core (C3) may be made of the inclined surface (C31). 7A) and the horizontal plane (C32 in FIG. 7A). However, the inner mold of the third mold core (C3 of FIG. 7A) 3 The inner surface of the mold core (C3) can be made only of the inclined surface (C31).

Therefore, even if a parting line, which is a fine linear mark, is generated due to leakage of extra material from the alignment marks of the second and third dies (C2, C3) due to a process error, the vertical surface (V) And the distance T between the parting lines PL can be minimized.

Here, the distance T between the vertical plane V as the light incidence surface and the parting line PL can be minimized to 0.7 mm or less.

In addition, the size of the parting line PL can be minimized by disposing the second mold core C2 and the third mold core C3, which form the back surface of the light guide plate 223, on the upper part.

Here, the height of the parting line PL can be minimized to 0.1 μm or less.

9B, a parting line PL formed on the back surface of the light guide plate 223 of the liquid crystal display (100 of FIG. 4) according to the second embodiment of the present invention is formed in the light guide plate 223 It is possible to prevent the occurrence of hot spots due to the progressive light being emitted to the non-display area.

That is, even if the parting line PL is formed according to the error in the process, it is possible to prevent the occurrence of the hot spot in advance.

In addition, the second and third mold cores C2 and C3 are disposed at the upper portion, so that the problem of the alignment of the second and third molds C2 and C3 can be prevented.

8B) does not occur in the first region (A1 in FIG. 8B), and the cracks (FIG. 8B) in the first region (A1 in FIG. 8B) It is possible to prevent the image quality degradation problem caused by the crack (CR in FIG. 8B) in advance.

FIG. 10A is a photograph of a hot spot of a conventional liquid crystal display, and FIG. 10B is a photograph of a hot spot of the liquid crystal display according to the second embodiment of the present invention.

As shown in the figure, the liquid crystal display according to the second embodiment of the present invention is improved in hot spot as compared with the conventional liquid crystal display. In addition, even when the parting line PL is formed according to a process error, it is possible to stably maintain an image with an improved hot spot.

The liquid crystal display according to the second embodiment of the present invention has a symmetric wedge structure in which the thickness of the second portion A2 of the light guide plate 223 increases toward the light source, The light leaking to the upper side and the lower side of the light guide plate 44 can be incident into the light guide plate 223, thereby effectively improving the light efficiency.

In addition, it is possible to effectively change the hot spot generated in the display area AA according to the narrow bezel implementation by changing the path of the light output from the side of the light source to the area where the dark part is generated through the first part A1 do.

Furthermore, even if a process error occurs, the possibility of hot spot and image quality deterioration can be prevented in advance.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

100: liquid crystal display device 110: liquid crystal panel
112: first substrate 114: second substrate
116: printed circuit board 120: backlight unit
123: light guide plate 125: reflector
127: optical sheet 129: LED assembly
129a: LED 129b: PCB
130: guide panel 150: cover bulge
152: first horizontal plane 154: second horizontal plane
156: side A1: first region
A2: second area PA: pattern part
NPA: non-patterned portion A21: first portion
A22: second part P1: lenticular pattern
P2: dot pattern d1: thickness of the first portion
d2: thickness of the second part

Claims (9)

A light guide plate including a first area and a second area;
A light source disposed on one side of the light guide plate,
/ RTI >
Wherein the first region includes a pattern portion, and a non-pattern portion disposed between the pattern portion and the second region,
Wherein the second region includes a first portion extending in the first region and having the same thickness in the direction of the light source and a second portion increasing in thickness toward the light source in the first region, Is longer than the second portion.
The method according to claim 1,
Wherein the second portion comprises:
A second inclined surface opposed to the first inclined surface; and a vertical surface connecting the first inclined surface and the second inclined surface, wherein the first inclined surface, the second inclined surface,
Wherein the first inclined surface and the second inclined surface are symmetrical.
3. The method of claim 2,
And a lenticular pattern including a plurality of hemispheres extending in a first axis is disposed on an upper surface of the pattern unit.
The method of claim 3,
And a dot pattern is disposed on a back surface of the pattern unit.
5. The method of claim 4,
Wherein the plurality of hemispheres are spaced apart from each other by a second axis perpendicular to the first axis.
6. The method of claim 5,
Wherein the first portion and the second portion are arranged alternately in plural numbers.
The method according to claim 6,
And the light source is disposed corresponding to each of the vertical surfaces of the first portion.
8. The method of claim 7,
Wherein the light source is an LED assembly formed by mounting a plurality of LEDs on a printed circuit board.
9. A backlight unit comprising: a backlight unit according to any one of claims 1 to 8;
A guide panel surrounding a side surface of the light guide panel;
And a liquid crystal panel disposed above the backlight unit.

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