KR20190062889A - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a backlight unit for a liquid crystal display device, which can prevent generation of non-uniform luminance in a liquid crystal display device with a narrow bezel. An air layer in a glass expansion plate, which is positioned in the upper part of an LED assembly of a backlight unit, is divided into a first region and a second region corresponding to the edge region and the central unit region of a liquid crystal panel to be defined wherein the air layer in the first region has a smaller density per unit area than the density per unit area of the air layer in the second region. Accordingly, the backlight unit for a liquid crystal display device can prevent generation of a light deviation in the edge region and the central unit region of a liquid crystal panel and thus, can prevent generation of a problem of reduction in display quality of the liquid crystal display device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit for a liquid crystal display,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit for a liquid crystal display, and more particularly, to a backlight unit for a liquid crystal display capable of eliminating unevenness in luminance of a liquid crystal display having a narrow bezel.

2. Description of the Related Art Recently, display devices capable of visually displaying information together with development of information technology and mobile communication technology have been developed, and display devices are classified into a self-luminous display having a luminescent characteristic and an image Emitting display that can be used as a display device.

An example of a non-light emitting type display device that does not have a self-luminous element is a liquid crystal display (LCD).

Accordingly, the LCD, which is a non-light emitting type display, requires a separate light source. A backlight unit having a light source on its back surface is provided to irradiate light toward the front surface of the LCD.

The backlight unit uses a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, and a light emitting diode (LED) as a light source.

In particular, LEDs are widely used as light sources for displays, having characteristics such as small size, low power consumption, and high reliability.

Meanwhile, a general backlight unit is divided into a side light type and a direct light type according to the arrangement structure of the lamp. In the sidelight type, one or a pair of lamps are disposed on one side of the light guide plate Or two or two pairs of lamps are disposed on both side portions of the light guide plate, and the direct light type lamp has a structure in which several lamps are disposed under the optical sheet.

In recent years, research on liquid crystal display devices that are large-sized according to the demand of consumers has been actively conducted, and the direct light type is more suitable for a large-screen liquid crystal display device than the sidelight type.

1 is a cross-sectional view of a direct light type liquid crystal display device using a general LED as a light source.

As shown in the figure, a typical liquid crystal display device is provided with a liquid crystal panel 10 composed of first and second substrates 12 and 14 and a backlight unit 20 behind the liquid crystal panel 10.

The backlight unit 20 includes a reflection plate 25 on which a plurality of LEDs 28 are arranged in parallel and on which a diffusion plate 24 and an optical sheet 26 are arranged, And is integrally modularized through the cover bottom 50, the guide panel 30, and the case top 40.

That is, the cover bottom 50 is positioned on the back side of the reflector 25, the guide panel 30 is positioned around the edge of the LED 28, and the case top 40 is positioned in front of the liquid crystal panel 10 And the case top 40 and the cover bottom 50 are coupled to each other through the guide panel 30 to be integrated.

In the direct light type liquid crystal display device, light emitted from two or three neighboring LEDs 28 are superimposed and mixed with each other to be provided to the liquid crystal panel 10. At this time, the edge of the liquid crystal panel 10 The LEDs 28 corresponding to the regions are provided with light having a brightness lower than that of the center portion in the edge region of the liquid crystal panel 10 as the number of the neighboring LEDs 28 decreases.

That is, a deviation of light supplied to the edge region and the central region of the liquid crystal panel 10 occurs.

2 is an experimental result showing the distribution of light provided to the liquid crystal panel including the direct-write type backlight unit of FIG.

In this case, the higher the red color of the image, the higher the brightness is provided by the relatively larger amount of light, and the lower the brightness of the red color of the image, the lower the brightness.

Therefore, as shown in the figure, it can be seen that the S region has less light reaching from the light source (= LED 28) than the surrounding region. When the image is displayed through the liquid crystal panel 10 in this state, Area is formed relatively dark compared with the area.

As described above, in the direct light type liquid crystal display device of the related art, there is a problem that a dark region is generated in the edge region of the liquid crystal panel 10 due to the supply of uneven light.

Particularly, in recent years, the importance of a narrow-bezel liquid crystal display device has been increasing. In the conventional liquid crystal display device, it is possible to cover all the edge regions provided with low-luminance light through the bezel. However, The edge regions of the liquid crystal panel 10 are not uniformly shaded, so that light irregularities are generated in the edge regions of the liquid crystal panel 10, so that shadows are formed and the user recognizes them as dark.

This causes a problem of lowering the display quality of the liquid crystal display device.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an image having uniform brightness over the entire area of a liquid crystal panel by eliminating light unevenness occurring in an edge region of a liquid crystal panel.

A second object of the present invention is to prevent the problem of deterioration of display quality due to unevenness of luminance of a liquid crystal display device.

A third object of the present invention is to provide a liquid crystal display device having a light weight, a thin shape, and a narrow bezel.

According to an aspect of the present invention, there is provided a light emitting diode (LED) comprising: an LED assembly including a plurality of LEDs and a PCB on which the plurality of LEDs are mounted; a reflector having a plurality of through holes through which the plurality of LEDs pass; And a glass diffusion plate disposed above the LED assembly and including a light collecting portion and a diffusion portion, wherein the glass diffusion plate has a first region defined along an edge region and a second region positioned inside the first region, Wherein the first region has a smaller density per unit area than the air layer of the diffusing portion of the second region in the air layer of the diffusing portion.

 At this time, light emitted from three neighboring LEDs among the plurality of LEDs is provided in a superimposed and mixed manner in the second region, and the first region is provided with light emitted from one or two LEDs of the plurality of LEDs The air layer in the second region has a density of 92 to 95%, and the density of the air layer in the first region is 90 to 91.7%.

The diffusion section includes first and second diffusion supporting layers and a light diffusion bonding layer sandwiched between the first and second diffusion supporting layers, the air layer being located between the light diffusion bonding layer and the second diffusion supporting layer, The adhesive force between the diffusion bonding layer and the second diffusion supporting layer is 4.1 to 4.3 N / inch.

At this time, a plurality of grooves constituting the air layer are formed on one surface of the second diffusion supporting layer contacting with the light diffusion bonding layer, and the grooves have a plurality of strip-like lenticular lens shapes in which recesses and crests are repeated.

At this time, the light diffusion adhesive layer includes a light diffusion bead, and a diffusion layer including beads is provided on the other surface of the second diffusion support layer.

The light diffusing plate may include a base substrate made of a glass material. The light converging unit may include a light-converging support layer and a lens layer having a prism mountain protruding from the top of the light-converging support layer along the longitudinal direction of the light- Wherein the light collecting portion is attached to one surface of the base substrate through a first adhesive layer, and a first diffusion supporting layer is attached through the base substrate and the second adhesive layer.

As described above, the air layer of the glass diffuser positioned above the LED assembly of the backlight unit according to the present invention is divided into first and second regions corresponding to the edge region and the central region of the liquid crystal panel, It is possible to prevent a light deviation from occurring in the edge region and the central region of the liquid crystal panel by forming the air layer of the region so as to have a smaller density per unit area than the air layer of the second region, There is an effect that it is possible to prevent the occurrence of the problem.

In addition, there is provided an advantage of being able to provide a liquid crystal display device having a lightweight, thin and narrow bezel.

1 is a sectional view of a direct light type liquid crystal display device using a general LED as a light source.
2 is an experimental result showing the distribution of light provided to the liquid crystal panel including the direct-write type backlight unit of FIG.
3 is an exploded perspective view illustrating a liquid crystal display device according to an embodiment of the present invention.
Fig. 4 is a cross-sectional view schematically showing the modular liquid crystal display of Fig. 3; Fig.
5 is a cross-sectional view schematically showing a glass diffuser plate according to an embodiment of the present invention.
6 is an experimental result schematically showing the adhesion surface of the light diffusion bonding layer and the second diffusion support layer.
7 is an experimental result showing a transmittance distribution diagram of light transmitted through a glass diffuser according to an embodiment of the present invention.
8 is an experimental result showing a distribution diagram of light provided to a liquid crystal panel of a liquid crystal display device according to an embodiment of the present invention.

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

3 is an exploded perspective view illustrating a liquid crystal display device according to an embodiment of the present invention.

As shown in the figure, the liquid crystal display device 100 includes a liquid crystal panel 110 and a backlight unit 120.

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 intersect with each other on the inner surface of the first substrate 112, which is usually referred to as a lower substrate or an array substrate, although not clearly shown in the figure, And a thin film transistor (TFT) is provided at each intersection point and is connected in a one-to-one correspondence with the transparent pixel electrode formed in each pixel.

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. In addition, a transparent common electrode covering these elements is provided.

The printed circuit boards 118a and 118b are connected to each other via a connecting member 116 such as a flexible circuit board along at least one edge of the liquid crystal panel 110 so that the side surfaces or the cover bottoms 150).

Although not clearly shown in the drawing, an upper and a lower alignment film (not shown) for determining the initial alignment direction of the liquid crystal are interposed between the two substrates 112 and 114 of the liquid crystal panel 110 and the liquid crystal layer A seal pattern is formed along the edges of both substrates 112 and 114 to prevent leakage of the liquid crystal layer filled therebetween.

At this time, the first and second polarizers 119a and 119b (see FIG. 4) are attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A backlight unit 120 for supplying light to the back surface of the liquid crystal panel 110 is provided so that a difference in transmittance represented by the liquid crystal panel 110 is externally manifested.

The backlight unit 120 includes an LED assembly 128 positioned on the back surface of the liquid crystal panel 110 and a reflective plate 125 disposed on an upper side of the LED assembly 128 and an LED assembly 128 and a guide support 127, A cover bottom 150 on which the reflective plate 125 and the LED assembly 128 are mounted and a guide panel 130 covering the edge of the LED assembly 128, .

The LED assembly 128 is a light source of the backlight unit 120 and includes a plate-shaped PCB 128b that is seated inside the lower surface 151 of the cover bottom 150, And a plurality of LEDs 128a mounted on the LEDs.

At this time, the PCB 128b may be divided into a plurality of bars.

The plurality of LEDs 128a use a blue LED 128a including a blue LED chip having excellent luminous efficiency and luminance for improving luminous efficiency and luminance and use a cerium-doped yttrium aluminum garnet (YAG: Ce ), That is, a blue LED 128a made of a yellow phosphor is used.

The blue light emitted from the LED 128a is mixed with the yellow light emitted by the phosphor through the phosphor, thereby emitting white light toward the glass diffuser plate 300. [

The reflector 125 has a plurality of through holes 125a through which the plurality of LEDs 128a can pass so that the PCB 128b excluding the plurality of LEDs 128a and the bottom surface 151b of the cover bottom 150 The light directed toward the back surface of the plurality of LEDs 128a is reflected toward the glass diffuser plate 300, thereby improving the brightness of the light.

A light diffusing lens 129 is provided on the plurality of LEDs 128a exposed through the through holes 125a of the reflection plate 125 to improve the directivity angle of the light emitted from the LEDs 128a.

A glass diffuser plate 300 for uniformity of brightness is disposed on an upper portion of the LED assembly 128 including the light diffusion lens 129.

The glass diffusing plate 300 is a returning optical sheet including a lower diffusion portion 320 of the base substrate 301 and an upper first light collecting portion 310. The glass diffusing plate 300 is a high- And provided to the liquid crystal panel 110.

Here, the glass diffuser plate 300 is supported through the guide support 127 to prevent sagging.

In this case, the liquid crystal display 100 according to the embodiment of the present invention includes the glass diffusion plate 300 of the backlight unit 120 and the air layer 330 (see FIG. 5) 5) are formed to have different densities with respect to the edge region A (see FIG. 4) and the central region B (see FIG. 4) of the liquid crystal panel 110. Let's take a closer look at this later.

The light emitted from the plurality of LEDs 128a of the LED assembly 128 is guided through the light diffusing lens 129 and is then processed into a uniform high quality surface light source in the process of passing through the glass diffuser plate 300 And is incident on the liquid crystal panel 110. By using this, the liquid crystal panel 110 displays the high luminance image to the outside.

At this time, as the directing angle of light emitted from the plurality of LEDs 128a is improved through the light diffusion lens 300, the color mixing space in the backlight unit 120 is increased, and the LED 128a It is possible to prevent the LED mura phenomenon from occurring even if the distance between the glass diffuser plate 300 and the LED 128a is minimized.

The liquid crystal panel 110 and the glass diffuser plate 300 as well as the LED assembly 128 and the reflector plate 125 are all modularly integrated through the guide panel 130 and the cover bottom 150.

The guide panel 130 has a rectangular shape and includes a vertical part 131 and a guide part 133 protruding from the inside of the vertical part 131 to have a predetermined inclination to change the path of light provided from the LED 128a .

The back edge of the glass diffuser plate 300 is adhered and fixed to the upper portion of the guide panel 130 through a first adhesive member 180a having a tackiness (refer to FIG. 4) so that the LED assembly 128 and the glass diffuser plate 300 (See FIG. 4) or an air gap between the optical fibers (not shown).

The rear edge of the liquid crystal panel 110 is attached and fixed to the glass diffuser plate 300 through a second adhesive member 180b (see FIG. 4) having adhesiveness.

The liquid crystal display 100 according to the embodiment of the present invention is configured to remove the case top (40 in FIG. 1) and mount the liquid crystal panel (not shown) through the guide bottom plate 130 and the cover bottom 150 in order to implement the narrow bezel The guide panel 130 supports the liquid crystal panel 110 and the glass diffuser plate 300 more stably by modularizing both the LED diffuser plate 110 and the glass diffuser plate 300 as well as the LED assembly 128 and the reflector plate 125. [ To be made of metal.

That is, in order to stably support the liquid crystal panel 110 and the glass diffuser plate 300, the guide panel 130 requires a predetermined strength to withstand the weight of the liquid crystal panel 110 and the glass diffuser plate 300 For this reason, the guide panel 130 may be formed of a metal material, for example, by extruding aluminum.

The guide panel 130 for stably mounting and fixing the liquid crystal panel 110 and the glass diffuser plate 300 receives the LED assembly 128 and the reflection plate 125 to cover the back surface of the reflection plate 125, The liquid crystal display device 100 according to the embodiment of the present invention is integrally modularized.

The cover bottom 150 that is a basis for assembling the entire instrument of the liquid crystal display 100 includes a plate-shaped lower surface 151 and a side surface 153 having a vertically bent edge at the lower surface 151 .

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

As described above, the liquid crystal display 100 of the present invention locates only the glass diffuser plate 300 on the upper portion of the LED assembly 128, 26 can be prevented from deteriorating in light efficiency.

In addition, compared to a configuration in which a plurality of optical sheets (24 and 26 in FIG. 1) are provided, the light weight and thinness of the liquid crystal display device 100 can be realized, and at the same time, the process of modularizing the liquid crystal display device 100 can be simplified, The manufacturing time can be shortened and the material cost can be reduced, thereby improving the efficiency of the process.

4) of the liquid crystal panel 110 and the air layer 330 (see FIG. 5) provided in the glass diffuser plate 300 and the edge region A (see FIG. 4) of the liquid crystal panel 110 are formed in the liquid crystal display device 100 according to the embodiment of the present invention. And the central region B (see FIG. 4) are formed to have different densities.

Accordingly, the liquid crystal display device 100 of the present invention can provide a high-quality surface light source over the entire area of the liquid crystal panel 110, so that even when the narrow bezel is implemented, the edge areas A and B of the liquid crystal panel 110 4) and the central area (B, see FIG. 4), thereby preventing the display quality of the liquid crystal display device 100 from deteriorating.

FIG. 4 is a cross-sectional view schematically showing the modular liquid crystal display of FIG. 3;

Here, for convenience of explanation, the outgoing light for each of the LEDs 128a is also displayed.

A plurality of LEDs 128a of the LED assembly 128 are mounted on a PCB 128b having a plate shape and a plurality of LEDs 128a mounted on the PCB 128b, The light diffusion lens 129 is positioned above the LED 128a exposed through the through hole 125a of the reflection plate 125 and the reflection plate 125 which exposes only the through hole 125a.

A glass diffuser plate 300 is stacked on the LED assembly 128 and a liquid crystal layer (not shown) is formed between the first and second substrates 112 and 114 on the glass diffuser plate 300 And the polarizing plates 119a and 119b for selectively transmitting only specific light are attached to the respective outer surfaces of the first and second substrates 112 and 114. [

The first substrate 112 and the second substrate 114 are formed in the same shape so that one end of the first substrate 112 and the other end of the second substrate 114 are aligned with each other, A pad (not shown) provided at an end of a plurality of wiring lines (not shown) provided on the first substrate 112 is exposed at a side surface between the first substrate 112 and the second substrate 114 .

A printed circuit board 117 is connected to one side of the liquid crystal panel 110 through a connection member 116. The connection member 116 is attached to a side surface of the liquid crystal panel 110 and connected thereto.

The glass diffuser plate 300, the LED assembly 128, and the reflector plate 125 are integrally modularized together with the liquid crystal panel 110 through the cover bottom 150 and the guide panel 130.

The LED assembly 128 is mounted on the lower surface 151 of the cover bottom 150 and the plurality of LED assemblies 128 are mounted on the upper portion of the LED assembly 128 through the through holes 125a. The reflector 125 is positioned to expose only the LED 128a.

At this time, the light diffusing lens 129 is positioned above the LED 129a, and the glass diffuser plate 300 is disposed at an upper portion of the LED assembly 128 including the light diffusion lens 129, The glass diffuser plate 300 is supported through a guide support 127.

The LED assembly 128 is surrounded by a guide panel 130. The guide panel 130 includes a vertical portion 131 and a guide bar 133 projecting from the inside of the vertical portion 131 .

The guide panel 130 has the side surface 153 of the cover bottom 150 interposed between the vertical portion 131 and the guide bar 133 so that the guide panel 130 and the cover bottom 150 are assembled and fastened to each other .

Here, the glass diffuser plate 300 is partly supported by the vertical portion 131 of the guide panel 130 to be positioned above the guide panel 130.

A first adhesive member 180a is interposed between the glass diffuser plate 300 and the vertical portions 131 of the guide panel 130 so that the glass diffuser plate 300 is attached and fixed to the guide panel 130 do.

As the back edge of the glass diffuser plate 300 is seated and supported on the guide panel 130, the glass diffuser plate 300 and the LEDs 128a of the LED assembly 128 are guided by the guide panel 130, (127), thereby maintaining the optical gap (G).

At this time, as the light diffusing lens 129 is positioned above the LED 128a, the light emitted from the LED 128a diffuses laterally by the light diffusion lens 129 and is emitted only from the LED 128a The directing angle of light is substantially increased as compared with the angle.

Accordingly, in order to reduce the weight and thickness of the LCD device 100, the optical proximity G, which is the distance between the LED 128a and the glass diffuser plate 300, is reduced, It is possible to prevent a hot spot from being generated and to prevent a dark portion between the LED 128a and the LED 128a adjacent thereto from occurring such that light emitted from the LED 128a does not overlap and mix with each other have.

This prevents LED mura phenomenon from occurring.

A part of the rear edge of the liquid crystal panel 110 is supported and positioned above the glass diffuser plate 300. A second adhesive member 180b is interposed between the glass diffuser plate 300 and the liquid crystal panel 110 , The glass diffuser plate 300 and the liquid crystal panel 110 are attached and fixed to each other.

Accordingly, the liquid crystal panel 110, the glass diffuser plate 300, the LED assembly 128, and the reflection plate 125 are both connected to the guide panel 130, the cover bottom 150 and the first and second adhesive members 180a and 180b ). ≪ / RTI >

That is, the glass diffusion plate 300 and the liquid crystal panel 110 are attached and fixed to the guide panel 130, and the LED assembly 128 and the reflection plate 125 are mounted on the cover bottom 150, The LCD panel 110, the glass diffuser plate 300, the LED assembly 128, and the reflection plate 125 are integrally modularized by assembling and fastening the guide plate 150 with the guide panel 130.

The width D1 of the first adhesive member 180a is wider than the width of the second adhesive member 180b that attaches and fixes the glass diffuser plate 300 and the liquid crystal panel 110, The plate 300 and the liquid crystal panel 110 can be attached and fixed with the guide panel 130 more stably.

The width D2 of the second adhesive member 180b for attaching and fixing the glass diffuser plate 300 and the liquid crystal panel 110 to each other is larger than the width D2 of the second adhesive member 180b for attaching and fixing the glass diffuser plate 300 and the liquid crystal panel 110 to the bezel region 100 of the liquid crystal display device 100 The Narrow bezel can be realized as the width D2 of the second adhesive member 180b is narrower.

However, when the width D2 of the second adhesive member 180b is too narrow, adhesion and fixing force between the glass diffuser plate 300 and the liquid crystal panel 110 are weakened. However, in the liquid crystal display device according to the embodiment of the present invention, The apparatus 100 is configured such that the glass diffuser plate 300 restricting the liquid crystal panel 110 through the second adhesive member 180b has a width D1 larger than the guide panel 130 and the second adhesive member 180b, The glass diffuser plate 300 and the liquid crystal panel 110 can be stably attached to each other even if the width D2 of the second adhesive member 180b is narrow, And fixed.

In other words, the liquid crystal display device 100 according to the embodiment of the present invention can realize more narrow bezel, and can be modularized more stably and integrally.

The first and second adhesive members 180a and 180b may be formed of a resilient resin. However, the present invention is not limited thereto. For example, a foam pad, an optical clear adhesive, OCA) or a double side tape or the like.

The liquid crystal display 100 according to the embodiment of the present invention may be configured such that light emitted from two or three neighboring LEDs 128a of the backlight unit 120 are overlapped and mixed with each other, And is supplied to the liquid crystal panel 110 as a high-quality surface light source.

The liquid crystal panel 110 includes a central region B in which light emitted from three or more neighboring LEDs 128a among the light emitted from the plurality of LEDs 128a of the backlight unit 120 are overlapped and mixed with each other, And an edge region A where only light emitted from one or two LEDs 128a is incident along the edge of the central region B. The edge region A may be defined by an edge region A of the backlight unit 120, Is an area corresponding to the outermost angle.

At the outermost edge of the backlight unit 120, as the number of adjacent LEDs 128a decreases, the edge area A of the liquid crystal panel 110 corresponding to the outermost edge of the backlight unit 120 has a central area A small amount of light is provided as compared with the case (B).

The path of light provided from the LED 128a located at the outermost position of the backlight unit 120 is changed through the guide portion 131 of the guide panel 130 so as to be guided toward the edge region A of the liquid crystal panel 110 A large amount of light is provided. However, there is still a variation in light amount in the edge region A of the liquid crystal panel 110 and the central region B corresponding to the central portion.

The liquid crystal display 100 according to the embodiment of the present invention includes the air diffusion layers 330 and 330 provided in the diffusion portion 320 of the glass diffusion plate 300 corresponding to the edge region A of the liquid crystal panel 110, 5) is formed to be smaller per unit area than the density of the air layer 330 (see FIG. 5) corresponding to the central region B of the liquid crystal panel 110.

As a result, the liquid crystal display 100 of the present invention can provide a high-quality surface light source over the entire area of the liquid crystal panel 110, so that even when the narrow bezel is implemented, It is possible to prevent a problem that a deviation in the light supplied to the central region B occurs and the display quality of the liquid crystal display device 100 deteriorates.

5 is a cross-sectional view schematically showing a glass diffuser according to an embodiment of the present invention.

As shown in the drawing, the glass diffuser plate 300 according to the embodiment of the present invention includes a diffuser (not shown) on the lower side of the base substrate 301 made of a transparent glass material, more precisely, 320 are located on the upper side of the base substrate 301 and the first light collecting part 310 is located on one side of the base substrate 301 that is more precisely facing the liquid crystal panel 110 in FIG.

The first condensing unit 310 includes a condensing support layer 311 and a lens layer 313 for condensing light on the upper surface of the condensing support layer 311. The condensing support layer 311 and the base substrate 301 Are attached to each other through the first adhesive layer 340 interposed therebetween.

At this time, the light-converging support layer 311 may be formed of a material such as a polycarbonate series, a poly sulfone series, a polyacrylate series, a polystyrene series, a polyvinyl chloride poly vinyl chloride series, poly vinyl alcohol series, poly norbornene series, and polyester series.

The lens layer 313 located above the light-converging support layer 311 is made of transparent acryl-based resin and is arranged adjacent to the light-converging support layer 311 along the longitudinal direction of the light-converging support layer 311, A plurality of prism mountains 315 of the plurality of prism mountains 315 are arranged so as to protrude from the light-converging support layer 311.

Due to the prism mountains 315, the glass diffuser plate 300 converges light to a liquid crystal panel (110 in FIG. 4) located on the glass diffuser plate 300, thereby realizing a brightness increasing effect.

The lens layer 313 may be formed of a prism having a polygonal cross section, a microlens pattern, a lenticular lens, an emboss pattern, or a combination thereof, in addition to the prism mountains 315.

The height of the prism mountains 315 may be different from each other. The height of the prism mountains 315 may be 10 占 퐉 to 40 占 퐉, specifically, 10 占 퐉 to 30 占 퐉, Lt; / RTI >

Also, the pitches of the prism mountains 315 may be different from each other, and the pitch corresponding to the bottom face of the prism mountains 315 may be 10 占 퐉 to 60 占 퐉, specifically, 20 占 퐉 to 60 占 퐉.

The vertex angle of the prism mountains 315 may be 80 DEG to 100 DEG, and in this range, there may be a brightness enhancement effect.

A diffusion portion 320 is disposed below the base substrate 301 having the first light collecting portion 310. The diffusion portion 320 includes first and second diffusion supporting layers 321 and 323, And a light diffusion bonding layer 325 between the second diffusion support layers 321 and 323 and a diffusion layer 327 below the second diffusion support layer 323. [

At this time, the first diffusion supporting layer 321 and the base substrate 301 are attached to each other through the second adhesive layer 350 interposed therebetween.

The first and second diffusion supporting layers 321 and 323 may also be formed of a material such as polycarbonate, polysulfone, polyacrylate, polystyrene, Polyvinyl chloride series, polyvinyl alcohol series, poly norbornene series, polyester series, and the like.

The first and second diffusion supporting layers 321 and 323 may be formed to have a thin thickness, for example, a thickness of 10 to 250 mu m in response to the thinning of the backlight unit 120 (FIG. 4) And the second diffusion supporting layers 321 and 323 have a thickness of 10 탆 or more, the backlight unit 120 (Fig. 4) can be made as thin as possible as long as the mechanical properties and heat resistance of the optical film are not deteriorated.

Further, by making the first and second diffusion supporting layers 321 and 323 have a thickness of 250 mu m or less, the thickness of the backlight unit (120 in Fig. 4) can be reduced and the mechanical properties and heat resistance of the optical film can be maximized .

The diffusion layer 327 may include a light diffusion component such as a bead 327b or may be formed by forming a fine pattern (not shown) on the lower surface of the diffusion layer 327 without including the bead 327b You may.

Accordingly, the diffusion layer 327 diffuses the light by refracting and scattering the incident light, and serves to emit the uneven light emitted from the LED assembly (128 in FIG. 4) as a uniform light.

At this time, the beads 327b are included in the binder resin 327a, and the beads 327b are characterized in that light can be partially prevented from being concentrated by dispersing the light incident on the diffusion layer 327. [

As the binder resin 327a, acrylic resin, urethane resin, epoxy resin, vinyl resin, polyester resin, polyamide resin and the like can be used as the binder resin 327a because of high transparency and excellent light transmittance and easy viscosity control.

The diffusion layer 327 not including the beads 327b is characterized in that the light scattering angle can be controlled according to the shape of a fine pattern (not shown). The fine pattern (not shown) may have an elliptical pattern, And a polygon pattern. By using a hologram pattern to refract light incident by an interference pattern in an asymmetrical direction, the condensed light is diffused at a more inclined angle .

The light diffusion adhesive layer 325 includes the light diffusion beads 325b in the base polymer 325a. The base polymer 325a contains the (meth) acrylic polymer (A). The (meth) acryl-based polymer (A) contains, as monomer units, an alkyl (meth) acrylate (a1) and an aromatic ring-containing (meth) acrylic monomer (a2) constituting the main skeleton of the (meth) Lt; / RTI >

As the aromatic ring-containing (meth) acrylic monomer (a2), for example, benzyl (meth) acrylate may be used. Since the (meth) acrylic monomer having an aromatic ring has a positive intrinsic birefringence, it can be used in combination with an alkyl (meth) acrylate and a (meth) acrylate monomer having a negative intrinsic birefringence.

At this time, when a specific amount of the aromatic ring-containing (meth) acrylic monomer is used together with the carboxyl group-containing monomer (a3) and the hydroxyl group-containing monomer (a4), a pressure sensitive adhesive having a desired refractive index can be obtained.

Such a base polymer 325a has a refractive index of 1.47 or more, and more preferably has a refractive index of 1.49.

The light diffusion beads 325b contained in the base polymer 325a are made of polymer fine particles. As the material of the polymer fine particles, for example, a silicone resin, a methacrylic resin, a polystyrene resin, a polyurethane resin, .

Since these resins have a good dispersibility to the base polymer 325a and an appropriate refractive index difference from the base polymer 325a, a light diffusion bonding layer 325 having excellent diffusion performance can be realized.

That is, the light diffusion beads 325b are preferably lower than the refractive index of the base polymer 325a. The refractive index of the light diffusion beads 325b is 1.30 to 1.70, and more preferably 1.45.

The absolute value of the difference in refractive index between the light diffusion beads 325b and the base polymer 325a is preferably more than 0 and not more than 0.2. It is preferable that the refractive index difference between 0 and 0.05 desirable.

It is preferred that the light diffusion beads 325b have a particle diameter of 4 to 7 um, an average particle diameter of 6 um on average, and a content of 2.6 to 3.5 percent in the base polymer 325a, It is possible to obtain the light diffusion bonding layer 325 having the performance.

The glass diffuser 300 according to the embodiment of the present invention forms a plurality of air layers 330 between the second diffusion support layer 323 of the diffusion section 320 and the optical diffusion bonding layer 325, A plurality of grooves 323a are provided on one surface of the second diffusion supporting layer 323 facing the diffusion bonding layer 325. [

The plurality of grooves 323a provided on one surface of the second diffusion supporting layer 323 are arranged adjacent to each other along the direction transverse to the longitudinal direction of the second diffusion supporting layer 323 to form a plurality of strip- And has a negative lenticular lens shape.

At this time, the lenticular lens-shaped acid of the groove 323a in the second diffusion supporting layer 323 is brought into contact with the light diffusion bonding layer 325, and the lenticular lens-shaped valley of the groove 323a forms the air layer 330 do.

The air layer 330 of the diffusion part 320 further improves the light diffusion function.

That is, the condition under which light diffuses must be refracted due to the difference in refractive index between the two media.

Here, the materials used for general optical films have a refractive index range of 1.5 to 1.7. In this case, if the second diffusion supporting layer 323 and the optical diffusion bonding layer 325 are directly bonded to each other, there is no difference in refractive index between the second diffusion supporting layer 323 and the optical diffusion bonding layer 325, do.

By providing a plurality of grooves 323a in the second diffusion support layer 323 as in the embodiment of the present invention, an air layer 330 is formed between the second diffusion support layer 323 and the light diffusion adhesion layer 325 do. The refractive index of the air layer 330 is 1.0.

The light incident from the second diffusion supporting layer 323 passes through the second diffusion supporting layer 323 and is incident on the light diffusion bonding layer 325. The refractive index of the second diffusion supporting layer 323 and the air layer 330 is The light is refracted at the interface between the second diffusion supporting layer 323 and the air layer 330, and the path is changed. As the path of the light changes, the light is condensed upward or diffused laterally.

Further, the light that has passed through the air layer 330 is refracted at the interface with the light diffusing adhesive layer 325 having a different refractive index, and is changed to a path that is condensed or diffused.

Therefore, the light passing through the diffusion portion 320 of the glass diffuser 300 according to the embodiment of the present invention becomes more diffused.

Here, the higher the density per unit area of the air layer 330, the higher the light diffusion function. The lower the density per unit area of the air layer 330, the lower the light diffusion function.

4) corresponding to the edge region (A in FIG. 4) of the liquid crystal panel (110 in FIG. 4) and the liquid crystal panel (FIG. 4 The first region A 'may be divided into a second region B' corresponding to the central region (B in FIG. 4) of the second region B ' Is formed to have a low density per unit area.

The adhesive strength between the light diffusion bonding layer 325 and the second diffusion support layer 323 is larger than that of the light diffusing adhesive layer 325. As shown in Table 1, This means that the density of the air layer 330 between the light diffusion bonding layer 325 and the second diffusion support layer 323 becomes smaller.

That is, the adhesion of the light diffusion bonding layer 325 and the density of the air layer 330 are in inverse proportion, and as the adhesion of the light diffusion bonding layer 325 increases, the density of the air layer 330 decreases. The transmittance is also lowered.

Adhesion (N / inch) Transmittance (%) 1.2 74.50% 4.3 60.90%

The light diffusion adhesive layer 325 is bonded to the surface of the groove 323a by the lenticular lens groove 323a of the second diffusion support layer 323 and is then attached to the adhesive surface E ). Therefore, the adhesive force of the light diffusion bonding layer 325 has a unit of N / inch.

In order to stably adhere the light diffusion bonding layer 325 and the second diffusion support layer 323 to each other, the light diffusion bonding layer 325 preferably has an adhesive strength of 4.3 N / inch or more, The transmittance of the diffusion portion 320 of the glass diffuser plate 300 may be lowered to 60% or less with reference to Table 1 above, At least 4.1 to 4.3 N / inch of adhesive strength is required to achieve the optimum design value to satisfy both adhesive strength and transmittance. Thus, when the adhesive force of the light diffusion bonding layer 325 is 4.1 to 4.3 N / inch, the density per unit area of the air layer 330 is 90 to 95%.

That is, the light diffusion bonding layer 325 and the second diffusion support layer 323 should be in contact with each other at a surface area of 4.1 to 4.3 N / inch So that they can stably come into contact with each other.

Therefore, the density of the air layer 330 can be set to 90 to 95% between the light diffusion bonding layer 325 and the second diffusion support layer 323. The center region of the liquid crystal panel 110 The second region B 'corresponding to B of the second diffusion supporting layer 323 has a density of the air layer 330 which can be maximally formed between the light diffusion bonding layer 325 and the second diffusion supporting layer 323 in order to further improve the light diffusion function Preferably 92 to 95%.

The first area A 'corresponding to the edge area (A in FIG. 4) of the liquid crystal panel 110 of FIG. 4 is formed to have a density per unit area of 90 to 91.7%, and the first area A' It is preferable to make the light diffusion less than the second region B '.

Therefore, a larger amount of light is condensed in the first area A 'of the glass diffuser plate 300 than in the second area B', so that the edge area of the liquid crystal panel 110 ).

4) can be prevented from being generated in the edge region (A in FIG. 4) and the central region (B in FIG. 4) of the liquid crystal panel (110 in FIG. 4) It is also possible to prevent the display quality of the display device from lowering.

7, the transmittance distribution diagram of the light transmitted through the glass diffuser plate 300 shows that the first region A 'is redder than the second region B'.

This means that the amount of light transmitted through the first region A 'of the glass diffuser plate 300 is relatively larger than the amount of light transmitted through the second region B' The first region A 'of the glass diffuser plate 300 is formed so that the air layer 330 of the first region A' is formed to have a density lower than that of the air layer 330 of the second region B ' It can be seen that a larger amount of light is condensed and transmitted than the second region B '.

Therefore, it is confirmed that the light is uniformly distributed over the entire area of the liquid crystal panel (110 in FIG. 4) as shown in FIG. 8, which is a liquid crystal display device (100 in FIG. 4) including such a glass diffuser plate 300 In particular, as compared with FIG. 2, it can be seen that a larger amount of light is provided to the S region.

As described above, the liquid crystal display (100 in FIG. 4) according to the embodiment of the present invention includes the glass diffuser plate 300 positioned above the LED assembly (128 in FIG. 4) of the backlight unit (120 in FIG. 4) The air layer 330 of the liquid crystal panel 330 is divided into first and second regions A 'and B' corresponding to the edge region (A in FIG. 4) and the central region (B in FIG. 4) The air layer 330 of the first area A 'is formed to have a smaller density per unit area than the air layer 330 of the second area B' (A in Fig. 4) and the central region (B in Fig. 4).

Therefore, it is also possible to prevent the display quality of the liquid crystal display (100 in Fig. 4) from being lowered finally.

Although the glass diffuser plate 300 has been illustrated and described as being attached to the upper portion of the guide panel 130 of FIG. 4 through the first adhesive member 180a (FIG. 4), the glass diffuser plate 300, May be directly adhered to the outside of the second polarizer (119b in Fig. 4) of the liquid crystal panel (110 in Fig. 4).

That is, by integrating the glass diffuser plate 300 with the second polarizing plate 119b (FIG. 4), it is possible to provide a liquid crystal display device (100 of FIG. 4) having a thinner thickness than the prior art.

The prism mount 315 of the first light collecting part 310 may be provided on the upper surface of the first light collecting part 310 of the glass diffuser plate 300, The prism mountains of the second light collecting unit (not shown) are arranged in a direction perpendicular to the longitudinal direction of the glass diffuser plate 300 along the second direction Y defined by the drawing (Not shown) arranged so as to be perpendicular to the prism mountains 315 located in the first light-condensing layer 310 and arranged so as to protrude in the transverse direction.

Alternatively, a reflective polarizing film (not shown) may be further provided on the glass diffuser plate 300. The brightness of the light can be further improved by regenerating light through a reflective polarizing film (not shown).

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.

300: glass diffuser plate
301: Base substrate
310: First collecting part
311: condensing supporting layer, 313: lens layer, 315: prism mountain
320:
321, 323: first and second diffusion supporting layers (323a: groove)
325: light diffusion bonding layer 325a: base polymer 325b: light diffusion bead 327: diffusion layer 327a: binder resin 327b: bead)
330: air layer
340, 350: first and second adhesive layers

Claims (11)

An LED assembly including a plurality of LEDs and a PCB on which the plurality of LEDs are mounted;
A reflector having a plurality of through holes through which the plurality of LEDs pass;
A glass diffuser plate disposed above the LED assembly and including a light collecting portion and a diffusing portion,
/ RTI >
Wherein the glass diffusion plate is divided into a first region defined along an edge region and a second region positioned inside the first region,
Wherein the first region has a smaller density per unit area than the air layer of the diffusion portion of the second region.
The method according to claim 1,
Wherein the second region is provided by overlapping and mixing light emitted from three neighboring LEDs among the plurality of LEDs, and only the light emitted from one or two LEDs of the plurality of LEDs A backlight unit for a liquid crystal display provided.
3. The method of claim 2,
Wherein the air layer of the second region has a density of 92 to 95%, and the density of the air layer of the first region is 90 to 91.7%.
The method of claim 3,
Wherein the diffusion portion includes first and second diffusion supporting layers and a light diffusion bonding layer interposed between the first and second diffusion supporting layers,
And the air layer is located between the light diffusion bonding layer and the second diffusion support layer.
5. The method of claim 4,
And an adhesive force between the light diffusion bonding layer and the second diffusion support layer is 4.1 to 4.3 N / inches.
6. The method of claim 5,
And a plurality of grooves constituting the air layer are provided on one surface of the second diffusion supporting layer in contact with the light diffusion bonding layer.
The method according to claim 6,
Wherein the grooves are in the form of a plurality of strip-like lenticular lenses in which obtuse-shaped mountains and valleys are repeated.
5. The method of claim 4,
Wherein the light diffusion adhesive layer comprises a light diffusion bead.
5. The method of claim 4,
And a diffusion layer including beads is provided on the other surface of the second diffusion supporting layer.
5. The method of claim 4,
Wherein the glass diffuser plate comprises a base substrate made of a glass material,
Wherein the light-converging portion includes a light-converging support layer and a lens layer protruding from the upper portion of the light-converging support layer, the prism mountains being repeatedly arranged along the longitudinal direction of the light-converging support layer.
11. The method of claim 10,
The light condensing unit is attached to one surface of the base substrate through a first adhesive layer,
Wherein the first diffusion supporting layer is attached through the base substrate and the second adhesive layer.

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