KR101784705B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device.
According to the present invention, when the light guide plate is moved by the light guide plate and the LED assembly being coupled with each other, the LED assembly also flows together, and the alignment position between the light guide plate and the LED assembly is maintained unchanged.
This makes it possible to prevent a hot spot phenomenon in which the liquid crystal display screen is stained.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of realizing a higher quality image.

A liquid crystal display device (LCD), which is advantageous for moving picture display and has a large contrast ratio and is actively used in TVs and monitors, exhibits optical anisotropy and polarization properties of a liquid crystal, And the like.

Such a liquid crystal display device has a liquid crystal panel in which a liquid crystal panel is interposed between two adjacent substrates through a liquid crystal layer as an essential component and changes the alignment direction of the liquid crystal molecules in an electric field in the liquid crystal panel to realize a difference in transmittance do.

However, since the liquid crystal panel does not have its own light emitting element, a separate light source is required to display the difference in transmittance as an image. To this end, a backlight unit having a light source is disposed on the back of the liquid crystal panel.

The backlight unit includes a light source and is divided into a direct type and an edge type according to the position of a light source. The direct-type backlight unit emits light from a light source by arranging a light source under the liquid crystal panel The backlight unit of the side-type type has a structure in which a light guide plate is disposed under the liquid crystal panel and a light source is disposed on at least one side surface of the light guide plate, And the emitted light is indirectly supplied to the liquid crystal panel.

In recent years, a light guide plate is also applied to a backlight unit of a direct-type type. By inserting the light guide plate into a space formed for light uniformity between a light source and a diffusion plate, a more uniform planar light source is supplied to the liquid crystal panel.

FIG. 1A is a cross-sectional view of a direct-type liquid crystal display module, and FIG. 1B is a view illustrating a light guide plate and a light source in the liquid crystal display module of FIG.

The liquid crystal display module includes a liquid crystal panel (not shown) composed of first and second substrates (not shown) and a backlight unit 20 behind the liquid crystal panel. The backlight unit 20 and the liquid crystal panel (not shown) Is modularized through a top cover (not shown), a support main (not shown) and a cover bottom 50.

The backlight unit 20 includes a plurality of LED assemblies 80, a reflection plate 21, a light guide plate 23 positioned above the reflection plate 21, a diffusion plate 24 positioned above the light guide plate 23, And a plurality of optical sheets (not shown).

Each of the plurality of LED assemblies 80 is formed by mounting a plurality of LEDs 82 as a light source to the LED printed circuit board 84.

Each of the plurality of LED assemblies 80 is fixedly adhered on the cover bottom 50 through a double-sided adhesive tape 60 positioned on the back side of the LED printed circuit board 84, The reflector 21 is positioned.

A plurality of LED grooves 23a for inserting a plurality of LEDs 82 of each of the plurality of LED assemblies 80 are formed on the lower surface of the light guide plate 23 as shown in FIG.

Accordingly, the light emitted from each of the plurality of LEDs 82 spreads through the plurality of LED grooves 23a and is reflected by the reflective plate 22, the diffuser plate 24, and a plurality of optical sheets (not shown) And is incident on a liquid crystal panel (not shown).

On the other hand, the light guide plate 23 can flow with thermal expansion or contraction according to changes in the external temperature.

For example, as shown in FIG. 1B, the light guide plate 23 may be thermally expanded or contracted and moved in the a direction, wherein each of the plurality of LED assemblies 80 is positioned on the back surface of the LED printed circuit board 84 Only the light guide plate 23 is moved in the direction a and the center of the LED 82 as the light source is 1 because the light guide plate 23 is fixed on the cover bottom 50 through the double- So that alignment positions between the light guide plate 23 and the light source are different from each other.

As a result, the brightness of light emitted from each of the plurality of LEDs 82 becomes uneven, resulting in a hot spot phenomenon in which the screen is stained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display device in which an alignment position between a light guide plate and an LED assembly is not changed irrespective of the surrounding environment by fastening and fixing the light guide plate and the LED assembly.

In order to achieve the above object, a liquid crystal display device according to the present invention includes: a liquid crystal panel; A plurality of LED assemblies including a plurality of LEDs mounted on a printed circuit board, a reflector positioned above the printed circuit board, a light guide plate provided on the reflector, and a plurality of optical sheets interposed on the light guide plate A backlight unit; And a cover bottom having a plurality of insertion grooves for receiving each of the plurality of LED assemblies on a front surface thereof. The light guide plate includes a plurality of light emitting diodes And a plurality of protrusions protruding in a direction toward the cover bottom along both edges of each of the plurality of LED grooves, wherein the printed circuit board is disposed at a position corresponding to each of the plurality of protrusions Each of the plurality of protrusions has a plurality of fixing holes for insertion.

Here, the plurality of protrusions are formed to be offset from each other along both edges of the plurality of LED grooves.

Alternatively, the plurality of projections are formed so as to be located on the same line along both edges of each of the plurality of insertion grooves.

The reflective plate may include a plurality of first through holes corresponding to the plurality of LEDs to allow the plurality of LEDs to pass therethrough, and a plurality of second through holes corresponding to the plurality of LEDs, respectively .

The printed circuit board may include a printed circuit board such as a Flame Retardant type-4 (FR-4), a ceramic printed circuit board, a flexible printed circuit board (FPCB), and a metal core printed circuit (Metal Core Printed Circuit Board).

The light guide plate is made of polymethyl methacrylate (PMMA) or polymethacrylic styrene (MS) resin in which polymethyl methacrylate (PMMA) and polystyrene (PS) are mixed do.

Meanwhile, a backlight unit according to the present invention includes: a plurality of LED assemblies having a plurality of LEDs mounted on a printed circuit board; A light guide plate having a plurality of LED recesses corresponding to the plurality of LED assemblies at a lower portion thereof and a plurality of protrusions protruding downward along both edges of each of the plurality of LED recesses; A plurality of first through-holes corresponding to the plurality of LEDs, and a plurality of second through-holes corresponding to the plurality of protrusions, and positioned between the printed circuit board and the light guide plate; And a plurality of optical sheets interposed on an upper portion of the light guide plate, wherein the printed circuit board has a plurality of fixing holes for inserting the plurality of projections at positions corresponding to the plurality of projections.

As described above, according to the present invention, the plurality of projections of the light guide plate are inserted and fixed to each of the plurality of fixing holes of the LED printed circuit board, so that the LED assembly flows together with the flow of the light guide plate.

Accordingly, even if the light guide plate is thermally expanded or contracted depending on the surrounding environment, the alignment position between the light guide plate and the LED assembly is not changed, thereby preventing a stain phenomenon that the screen of the liquid crystal display device is stained.

1A is a partial cross-sectional view of a liquid crystal display device module of a direct-type type.
FIG. 1B is a view showing a state in which the light guide plate and the light source are mutually different in the liquid crystal display module of FIG. 1A; FIG.
FIG. 2 is an exploded perspective view schematically showing a liquid crystal display module according to a preferred embodiment of the present invention. FIG.
3 is a view illustrating an LED printed circuit board according to a preferred embodiment of the present invention.
4 is a perspective view showing a rear surface of a light guide plate according to a preferred embodiment of the present invention.
FIG. 5 is a cross-sectional view of a liquid crystal display module according to a preferred embodiment of the present invention. FIG.
6 is a view illustrating a light guide plate and a light source when the light guide plate is moved in a liquid crystal display module according to a preferred embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

FIG. 2 is an exploded perspective view schematically showing a liquid crystal display module according to a preferred embodiment of the present invention, FIG. 3 is a view showing an LED printed circuit board according to a preferred embodiment of the present invention, FIG. FIG. 4 is a perspective view showing a rear surface of a light guide plate according to an embodiment. FIG.

2, the liquid crystal display module 100 includes a liquid crystal panel 110, a backlight unit 120, a support main body 130, a cover bottom 150, and a top cover 140 do.

First, the liquid crystal panel 110 plays a key role in image display and includes first and second substrates 112 and 114 which are bonded to each other with a liquid crystal layer interposed therebetween.

At this time, a plurality of gate lines and data lines cross each other on the inner surface of the first substrate 112, which is usually called a lower substrate or an array substrate, although not clearly shown in the figure, And a thin film transistor (TFT) is provided at each of the intersections, and is connected in one-to-one correspondence with the transparent pixel electrodes formed in the respective pixels.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, color filters of red (R), green (G), and blue (B) And a black matrix for covering non-display elements such as a gate line, a data line, and a thin film transistor.

First and second polarizing plates (not shown) may be attached to the outer surfaces of the first and second substrates 112 and 114 to selectively transmit only specific light.

A printed circuit board 118 is connected to at least one edge of the liquid crystal panel 110 via a flexible circuit board or a connection member 116 such as a tape carrier package To the side of the support main body 130 or to the back surface of the cover bottom 150, as shown in FIG.

When the thin film transistor selected for each gate line is turned on by the on / off signal of the gate driving circuit transmitted through the printed circuit board 118, the liquid crystal panel 110 having the above- The signal voltage is transmitted to the corresponding pixel electrode through the data line, and the alignment direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode.

On the rear surface of the liquid crystal panel 110, a backlight unit 120 is provided to supply light so that the difference in transmittance can be displayed as an image.

The backlight unit 120 includes a plurality of LED assemblies 180 corresponding to a light source, a reflection plate 121, a light guide plate 123 and a diffusion plate 124 positioned above the reflection plate 121, (126).

Each of the plurality of LED assemblies 180 is formed by mounting a plurality of LEDs 182 on a LED printed circuit board (PCB) 184 at a predetermined interval, And are arranged in a state of being spaced apart at regular intervals along the direction.

The LED printed circuit board 184 on which the plurality of LEDs 182 are mounted may be a Flame Retardant type-4 (FR-4) printed circuit board, a ceramic printed circuit board, or a flexible printed circuit board (FPCB) ).

Or a metal core printed circuit board having a heat dissipation function for dissipating heat generated from each of the plurality of LEDs 182 to the outside.

In this LED printed circuit board 184, a plurality of fixing holes 184a are formed along each of the first and second long edges 184-1 and 184-2 facing each other as shown in Fig. 3, And the arrays are formed so as to be offset from each other.

Here, each of the plurality of fixing holes 184a formed along the first long edge 184-1 may be formed such that the first long edge 184-1 is opened, and the second long edge 184- Each of the plurality of fixing holes 184a formed along the second long edge 184-2 may be formed with the second long edge 184-2 opened.

The shape of each of the plurality of fixing holes 184a may be variously changed depending on the shape of the plurality of protrusions 220 formed on the light guide plate 123, such as a rectangular shape or a circular shape.

The area of each of the plurality of fixing holes 184a is formed to have an area corresponding to the plurality of protrusions 220 formed on the light guide plate 123. Considering the characteristic of the light guide plate 123 that thermally expands or shrinks due to the surrounding environment An area larger than the area of each of the plurality of protrusions 220 can be formed.

A white or silver reflector 121 is positioned on top of the LED printed circuit board 184.

The reflection plate 121 reflects a part of the light emitted from each of the plurality of LEDs 182 toward the cover bottom 150 toward the liquid crystal panel 110.

To this end, the reflection plate 121 is provided with a plurality of first through holes 121a corresponding to each of the plurality of LEDs 182 through which the plurality of LEDs 182 can pass, and a plurality of first through holes 121b formed in the LED printed circuit board 184 And a plurality of second through holes 121b corresponding to each of the fixing holes 184a of the fixing hole 184a.

Accordingly, when the reflection plate 121 is seated on the LED printed circuit board 184, each of the plurality of LEDs 182 is exposed through each of the plurality of first through holes 121a.

A light guide plate 123 is positioned above the reflection plate 121 to realize light of each of the LEDs 182 of the LED assembly 180 as a high-quality surface light source.

4, a plurality of LED recesses 210 for inserting a plurality of LEDs 182 are formed on a lower surface of the light guide plate 123 and a plurality of LED recesses 210 for fastening between the light guide plate 123 and the LED assembly 180 A plurality of protrusions 220 are formed.

The plurality of LED recesses 210 correspond to the positions and the number of the LED assemblies 180 arranged on the cover bottom 150 and the plurality of protrusions 220 correspond to a plurality of second through holes Corresponding to the positions and the number of the plurality of fixing holes 184a formed in the LED printed circuit board 184 and the LED printed circuit board 184, respectively.

The width d1 of the LED groove 210 may be varied according to the size of the LED 182. More light is emitted from each of the plurality of LEDs 182 mounted on the LED printed circuit board 184, It is preferable that a clearance space is secured between the LED groove 210 and the LED 182 so as to allow the light to enter the LED 123.

The shape of the LED groove 210 may be various shapes such as a hemisphere shape, a polygonal shape, a rectangular shape, and a trapezoidal shape.

A plurality of protrusions 220 extending in a direction toward the cover bottom 150 along the both edges 212 and 214 of the plurality of LED recesses 210 are formed with a predetermined spacing.

Each of the plurality of protrusions 220 binds the LED printed circuit board 184 and the light guide plate 123. The length of the protrusion 220 is determined by the thickness of the reflector 121 and the thickness of the LED printed circuit board 184 And are formed in a combined length.

The plurality of protrusions 220 formed on the light guide plate 123 are inserted into the plurality of fixing holes 184a formed in the LED printed circuit board 184 so that the light guide plate 123 and the LED assembly 180 are coupled to each other And becomes fixed.

On the other hand, although not shown in the drawings, the light guide plate 123 may have a pattern formed on its upper surface, lower surface, or upper and lower surfaces.

First, when a top surface pattern (not shown) is formed on the upper surface of the light guide plate 123, the top surface pattern (not shown) serves to guide light emitted from each of the plurality of LEDs 182, The light emitted from each of the plurality of LEDs 182 is totally reflected so that the light is incident into the light guide plate 123.

Accordingly, a part of the light emitted from each of the plurality of LEDs 182 is reflected by a top surface pattern (not shown) formed on the upper surface of the light guide plate 123 and is incident into the light guide plate 123, (Not shown), and is emitted toward the liquid crystal panel 110. [0064]

When a back surface pattern (not shown) is formed on the lower surface of the light guide plate 123, the back surface pattern (not shown) And a plurality of protrusions 220 are formed.

The backside pattern (not shown) serves to guide light incident into the light guide plate 123, so that light incident into the light guide plate 123 is reflected toward the liquid crystal panel 110.

The top surface pattern (not shown) or the back surface pattern (not shown) may be formed in various shapes such as an elliptical pattern, a polygon pattern, a hologram pattern, The back surface pattern may be formed by a printing method or an injection method.

Accordingly, some of light emitted from each of the plurality of LEDs 182 is reflected by a top pattern (not shown) or a back pattern (not shown) formed on the light guide plate 123 and is incident into the light guide plate 123, The light is emitted to the surface light source, and a part of the light is transmitted through the light guide plate 123 and emitted toward the liquid crystal panel 110.

The light guide plate 123 may be formed by injection molding used for molding a specific shape and may be made of polymethyl methacrylate (PMMA) or polymethyl methacrylate (PMMA) and polystyrenes : PS) mixed with polymethacrylic styrene (MS) resin.

Meanwhile, the light guide plate 123 may be composed of a plurality of divided light guide plates arranged side by side on the same plane. In this case, one or more LED grooves 210 may be formed on the lower surface of one of the divided light guide plates, and the number of the LED grooves 210 is determined by the number of the divided light guide plates and the number of the LED assemblies 180 .

A diffusion plate 124 and a plurality of optical sheets 126 for uniformity of luminance are disposed on the light guide plate 123 as described above.

Here, the plurality of optical sheets 126 include a diffusion sheet, at least one light collecting sheet, and the like, and may include various functional sheets such as a reflective polarizing film called a dual brightness enhancement film (DBEF).

Accordingly, the light emitted from each of the plurality of LEDs 182 implements a uniform planar light source through the light guide plate 123, and the planar light source, which is implemented, transmits the light reflected by the reflection plate 121, And the plurality of optical sheets 126 in order, and then enters the liquid crystal panel 110. The liquid crystal panel 110 displays the high brightness image by using the light.

The liquid crystal panel 110 and the backlight unit 120 are modularized through a top cover 140, a support main 130 and a cover bottom 150. The top cover 140 is disposed on the upper surface and the side surface of the liquid crystal panel 110, And the top cover 140 is opened to display an image to be displayed on the liquid crystal panel 110. The liquid crystal panel 110 is a liquid crystal panel.

A plurality of insertion grooves 150a corresponding to the plurality of LED assemblies 180 are formed on the inner surface of the cover bottom 150. The plurality of insertion grooves 150a Each of the plurality of LED assemblies 180 is seated.

Each of the plurality of insertion grooves 150a protrudes from the front surface of the cover bottom 150 in the back direction to guide a position where each of the plurality of LED assemblies 180 is arranged.

The insertion groove 150a is formed at a depth corresponding to the thickness of the LED printed circuit board 184 so that the LED printed circuit board 184 of the LED assembly 180 does not protrude outside the insertion groove 150a.

In addition, the cover bottom 150 may form a predetermined space in which at least two edges of the cover bottom 150 are bent at an oblique angle so that the backlight unit 120 can be seated therein.

Alternatively, a pair of bar side supports (not shown) are coupled to opposite ends of the cover bottom 150, and the other two edges except the side supports (not shown) are connected to a side support So that it is possible to form a predetermined space in which the backlight unit 120 can be seated.

Here, the top cover 140 may be referred to as a case top or a top case, and the support main 130 may be referred to as a guide panel or a main support or a mold frame, and the cover bottom 150 may be referred to as a bottom cover.

The liquid crystal display module 100 according to the present invention may be divided into a plurality of LED assemblies 180 or a predetermined number of LEDs 182. The LED assemblies 180 or each LED 182 are sequentially turned on / off to implement a backlight division driving, so that a more vivid image can be displayed.

By performing the backlight division drive for each region through the plurality of LEDs 182, only the light emitted for each region is supplied to a specific region of the liquid crystal panel 110, thereby brightening the bright image in the image implemented by the liquid crystal panel 110 Or darker images can be made darker. Accordingly, the contrast ratio can be improved, and a live image can be realized.

In addition, brightness suitable for an image can be adjusted, and an image having a dark brightness can have light having a dark brightness, so that power consumption of the backlight unit 120 can be reduced.

Hereinafter, the relationship between the light guide plate and the LED assembly fastened and fixed together according to the present invention will be described in detail with reference to the drawings.

FIG. 5 is a cross-sectional view of a liquid crystal display module according to a preferred embodiment of the present invention. FIG. 6 is a plan view of a liquid crystal display module according to an exemplary embodiment of the present invention. Referring to Figs. 2 to 4, the drawings are shown.

5, a plurality of LED assemblies 180 are mounted on each of the plurality of insertion grooves 150a of the cover bottom 150 and the LED printed circuit board 184 of each of the plurality of LED assemblies 180 is mounted. A plurality of first through holes 121a and a plurality of second through holes 121b are formed on an upper portion of the first through holes 121a, And is exposed to the upper side of the reflection plate 121 through the reflection plate 121.

Here, the LED printed circuit board 184 of each of the plurality of LED assemblies 180 is provided with a plurality of fixing holes 184a which are offset from each other along both edges (184-1 and 184-2 in FIG. 3) .

The light guide plate 123 is positioned above the reflection plate 121. The light guide plate 123 includes a plurality of LED recesses 210 for receiving a plurality of LEDs 182 corresponding to the plurality of LED assemblies 180, And a plurality of protrusions 220 corresponding to each of a plurality of fixing holes 184a of the LED printed circuit board 184. Here, each of the plurality of protrusions 220 extends in a direction toward the cover bottom 150 along both edges (212 and 214 in FIG. 4) of each of the plurality of LED recesses 210.

The plurality of fixing holes 184a and the plurality of protrusions 220 corresponding to the fixing holes 184a are formed so as to be offset from each other along both edges of the fixing hole 184a, And corresponding protrusions 220 are shown.

The light guide plate 123 is seated on the upper surface of the reflection plate 121 and each of the plurality of protrusions 220 formed on the light guide plate 123 passes through each of the plurality of second through holes 121b, The light guide plate 123 and the LED assembly 180 are fixed to each other by being inserted into the plurality of fixing holes 184a formed in the light guide plate 123. [

Thereafter, the diffusion plate 124 which makes the luminance uniform is seated on the upper side of the light guide plate 123.

6, when the light guide plate 123 is thermally expanded or contracted due to external temperature change and is moved in the direction a as shown in FIG. 6, the light guide plate 123 is fastened to the LED assembly 180 The LED assembly 129 moves together in the direction a, so that the alignment position between the light guide plate 123 and the LED assembly 180 is kept unchanged, so that the uniformity of the liquid crystal display screen can be maintained.

7 is a cross-sectional view of a liquid crystal display module according to a second preferred embodiment of the present invention. Here, a plurality of protrusions formed on the light guide plate and a plurality of fixing holes formed on the LED printed circuit board are formed so as to face each other along both edges, referring to FIGS. 2 through 5, The same reference numerals are given.

7, a plurality of LED assemblies 180 are mounted on each of the plurality of insertion grooves 150a of the cover bottom 150 and the LED printed circuit board 184 of each of the plurality of LED assemblies 180 is mounted. A plurality of first through holes 121a and a plurality of second through holes 121b are formed on an upper portion of the first through holes 121a, And is exposed to the upper side of the reflection plate 121 through the reflection plate 121.

3, a plurality of fixing holes 184a are formed along both edges (184-1 and 184-2 in Fig. 3), respectively, in the LED printed circuit board 184 of each of the plurality of LED assemblies 180, Are provided so as to face each other. Accordingly, the plurality of fixing holes 184a formed along both edges (184-1 and 184-2 in Fig. 3) are symmetrical with respect to the center.

The light guide plate 123 is positioned above the reflection plate 121. The light guide plate 123 includes a plurality of LED recesses 210 for receiving a plurality of LEDs 182 corresponding to the plurality of LED assemblies 180, And a plurality of protrusions 220 corresponding to each of a plurality of fixing holes 184a of the LED printed circuit board 184. Here, each of the plurality of protrusions 220 extends in a direction toward the cover bottom 150 along both edges (212 and 214 in FIG. 4) of each of the plurality of LED recesses 210.

The plurality of fixing holes 184a and the plurality of protrusions 220 corresponding to the plurality of fixing holes 184a are formed so as to face each other on the same line along both edges, A fixing hole 184a and a corresponding protrusion 220 are shown.

The light guide plate 123 is seated on the upper surface of the reflection plate 121 and each of the plurality of protrusions 220 formed on the light guide plate 123 passes through each of the plurality of second through holes 121b, The light guide plate 123 and the LED assembly 180 are fixed to each other by being inserted into the plurality of fixing holes 184a formed in the light guide plate 123. [

Thereafter, the diffusion plate 124 which makes the luminance uniform is seated on the upper side of the light guide plate 123.

Even if the light guide plate 123 is thermally expanded or contracted due to external temperature change after the module is thus modulated, the LED assembly 180 flows together and the alignment position between the light guide plate 123 and the LED assembly 180 is changed So that the uniformity of the liquid crystal display screen can be maintained.

According to the present invention, a plurality of fixing holes are formed on an LED printed circuit board and a plurality of protrusions corresponding to the fixing holes are formed on the light guide plate, so that the light guide plate and the LED assembly are fixed to each other.

Accordingly, it is not necessary to adhesively fix the LED printed circuit board on the cover bottom with the double-sided adhesive tape as in the prior art, thereby reducing the cost and time for parts and assembling processes.

Particularly, when the light guide plate is thermally expanded or contracted due to the ambient environment and flows, the LED assembly also flows like the light guide plate, so that the center of the LED is maintained without being tilted so that the brightness in the screen of the liquid crystal display device is maintained uniformly.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

110: liquid crystal panel 120: backlight unit
121: reflector 121a: first through hole
121b: second through hole 123: light guide plate
210: LED groove 220: projection
124: diffuser plate 126: multiple optical sheets
150: cover bottom 150a: insertion groove
180: LED assembly 182: LED
184: LED printed circuit board 184a: fixing hole

Claims (11)

A liquid crystal panel;
A plurality of LEDs mounted on a printed circuit board, a reflective plate positioned above the printed circuit board, a light guide plate provided on the reflective plate, and a plurality of optical sheets interposed on the upper surface of the light guide plate, A backlight unit including:
A cover plate having a plurality of insertion grooves for seating each of the plurality of LED assemblies on a front surface thereof,
/ RTI >
The light guide plate is in the form of a plate having a thickness, and the upper surface on which the light is emitted is flat. On the lower surface provided on the opposite side of the upper surface,
A plurality of LED recesses corresponding to each of the plurality of LED assemblies and a plurality of protrusions protruding from the bottom surface toward the cover bottom along both edges of each of the plurality of LED recesses,
Wherein the printed circuit board has a plurality of fixing holes for inserting the plurality of protrusions at positions corresponding to the plurality of protrusions,
Wherein the plurality of insertion grooves have a depth corresponding to the thickness of the printed circuit board, and the LED groove is recessed from the lower surface.
The method according to claim 1,
The plurality of projections
And protruding or protruding from each other along both edges of the plurality of LED grooves or protruding from each other.
The method according to claim 1,
The plurality of projections
And a thickness of the reflector and the printed circuit board.
The method according to claim 1,
The reflector
A plurality of first through holes corresponding to the plurality of LEDs to allow the plurality of LEDs to pass therethrough, and a plurality of second through holes corresponding to each of the plurality of LEDs.
The method according to claim 1,
The printed circuit board
A printed circuit board (FR-4), a ceramic printed circuit board, a flexible printed circuit board (FPCB), and a metal core printed circuit board A liquid crystal display device, and a liquid crystal display device.
The method according to claim 1,
The light-
A liquid crystal display device comprising polymethyl methacrylate (PMMA) or polymethacrylic styrene (MS) resin mixed with polymethyl methacrylate (PMMA) and polystyrene (PS).
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