KR20180046467A - Back light unit and liquid crystal display device using the same - Google Patents

Abstract

The present invention provides a backlight unit which is thinned and can prevent image quality from being degraded, and a liquid crystal display device. The backlight unit comprises: a light source connected to a circuit board; a light shielding pattern facing the light source; and an optical member located on the light shielding pattern, and having an optical pattern. An encapsulating resin and an air layer are arranged between the light source and the optical member.

Description

BACKLIT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE USING THE SAME [0002]

The present invention relates to a backlight unit and a liquid crystal display including the same.

An active matrix type liquid crystal display device displays a moving image by using a thin film transistor (Thin Film Transistor) as a switching element. This liquid crystal display device is widely used in portable information equipment, office equipment, computers, and televisions. Since such a liquid crystal display device is not a self-luminous device, a backlight unit is provided under the liquid crystal panel to display an image using the light emitted from the backlight unit.

The backlight unit can be divided into a side edge type and a direct light type according to a method of arranging the light sources.

In the side-type backlight unit, a light source is disposed on a side surface of a light guide plate provided below a liquid crystal panel, and light emitted from a light source through a light guide plate is converted into planar light and irradiated onto the liquid crystal panel.

However, the side-type backlight unit has a problem that the local dimming effect is greatly reduced because it is difficult to realize a large number of local dimming divisions for dividing the backlight into a plurality of regions because the light source is on the side. Local dimming, which refers to screen division driving, divides the backlight into a plurality of areas, and the area corresponding to the dark part of the image in conjunction with the image signal turns off the backlight or reduces the light, Thereby significantly improving the contrast ratio and power consumption.

It is a direct-type backlight unit that solves the problem of such a side-type backlight unit.

A direct-type backlight unit is a system in which a plurality of light sources are disposed at a lower portion of a liquid crystal panel to directly irradiate light to the entire surface of the liquid crystal panel, thereby improving the uniformity and brightness of light irradiated to the liquid crystal panel, It is possible to perform local dimming, thereby improving the contrast ratio and reducing power consumption.

However, in the direct-type backlight unit, since the light source is disposed under the liquid crystal panel and directly irradiates light to the front surface of the liquid crystal panel, a light source and a liquid crystal It is necessary to maintain a light diffusion distance (optical gap) between the display panels, thereby limiting the thickness of the liquid crystal display device. Also, in the conventional direct-type backlight unit, a halo phenomenon may occur due to light over a local dimming zone due to a wide light diffusion distance, and image quality may be deteriorated.

SUMMARY OF THE INVENTION It is a general object of the present invention to provide a backlight unit and a liquid crystal display device which are thinned and can prevent image quality from deteriorating.

According to an aspect of the present invention, there is provided a light emitting device including a light source connected to a circuit board, a light shielding pattern facing the light source, and an optical member disposed on the light shielding pattern and having an optical pattern, And a backlight unit provided with an air layer.

The backlight unit according to an exemplary embodiment of the present invention is a direct-type backlight unit, and local dimming can be performed with high brightness, thereby improving the contrast ratio and reducing power consumption.

In addition, the backlight unit according to an embodiment of the present invention diffuses light without maintaining a wide optical diffusion distance (optical gap) as in the conventional manner by the optical member having the encapsulating resin, the first and second air layers, The backlight unit and the liquid crystal display device can be made thin.

Therefore, the backlight unit and the liquid crystal display device according to an embodiment of the present invention can prevent the halo phenomenon because the light emitted from the light source does not exceed the local dimming zone due to the narrow light diffusion distance, Can be prevented.

The effects obtained in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description .

1 is a perspective view of a liquid crystal display device according to an exemplary embodiment of the present invention.
2 is an exploded perspective view for explaining a liquid crystal display device according to an exemplary embodiment of the present invention.
Fig. 3 is a cross-sectional view taken along line II in Fig. 2, and is a cross-sectional view of a liquid crystal display device according to an example of the present invention.
4 shows a light-shielding pattern of a liquid crystal display according to an example of the present invention.
FIG. 5 is a diagram illustrating a correlation of structures of a liquid crystal display device according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 6 is a cross-sectional view taken along line II-II of FIG. 2, and is a cross-sectional view of a liquid crystal display device according to an example of the present invention.
Fig. 7 is a cross-sectional view taken along line II in Fig. 2, and is a cross-sectional view of a liquid crystal display device according to another example of the present invention.
Fig. 8 is a cross-sectional view taken along line II in Fig. 2, and is a cross-sectional view of a liquid crystal display device according to another example of the present invention.

The meaning of the terms described herein should be understood as follows.

The word " first, "" second," and the like, used to distinguish one element from another, are to be understood to include plural representations unless the context clearly dictates otherwise. The scope of the right should not be limited by these terms. It should be understood that the terms "comprises" or "having" does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. It should be understood that the term "at least one" includes all possible combinations from one or more related items. For example, the meaning of "at least one of the first item, the second item and the third item" means not only the first item, the second item or the third item, but also the second item and the second item among the first item, Means any combination of items that can be presented from more than one. The term "on" means not only when a configuration is formed directly on top of another configuration, but also when a third configuration is interposed between these configurations.

Hereinafter, preferred embodiments of a backlight unit and a liquid crystal display including the same according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals are used to denote like elements throughout the drawings, even if they are shown on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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

FIG. 1 is a perspective view of a liquid crystal display device according to an exemplary embodiment of the present invention, and FIG. 2 is an exploded perspective view illustrating a liquid crystal display device according to an exemplary embodiment of the present invention.

1 and 2, a liquid crystal display device according to an exemplary embodiment of the present invention includes a rear external appearance substrate 100, a backlight unit 200, a liquid crystal panel 300, a panel driving unit 310, (400), and a lower case (410).

The rear external appearance substrate 100 supports the backlight unit 200 and also provides a rear view of the liquid crystal display device.

The circuit board 210 is disposed on the rear faceted substrate 100. The circuit board 210 mounts a plurality of light sources 220.

The light source 220 is mounted on the circuit board 210, and emits light by emitting a light source driving signal supplied from a backlight driver (not shown). At least one light source 220 is mounted on the circuit board 210. The plurality of light sources 220 are covered by the sealing resin 230. The encapsulation resin 230 serves to diffuse light.

The optical member 250 is disposed on the light source 220 to diffuse light incident from the light source 220. The optical member 250 is formed in the form of a flat plate (or wedge) so as to have a light incidence surface on the bottom surface thereof, and advances the light incident from the light source 220 through the light incidence surface toward the liquid crystal panel 300. The optical member 250 according to an example of the present invention is provided with an optical pattern on the upper surface of the member at an oblique angle. According to such an optical pattern, the backlight unit 200 of the present invention has improved light uniformity and can be thinned. A detailed description of the optical member 250 according to an exemplary embodiment of the present invention will be described later with reference to FIGS. 3 to 8. FIG.

The liquid crystal panel 300 displays images by adjusting the light transmittance of the liquid crystal layer. The liquid crystal panel 300 includes a lower substrate 301, an upper substrate 302, and a lower polarizing member (not shown) 303, and an upper polarizing member 304. The liquid crystal panel 300 displays a predetermined color image according to the light transmittance of the liquid crystal layer by driving the liquid crystal layer according to the electric field formed for each pixel by the data voltage and the common voltage applied to each pixel.

The panel driving unit 310 is connected to a pad unit provided on the lower substrate 301 and displays a predetermined color image on the liquid crystal panel 300 by driving each pixel of the liquid crystal panel 300. The panel driver 310 according to an exemplary embodiment includes a plurality of circuit films 311 connected to the pad portion of the liquid crystal panel 300, a data driving integrated circuit 313 mounted on each of the plurality of circuit films 311, A display printed circuit board 312 coupled to each of the films 311 and a timing control unit 314 mounted on the printed circuit board 312 for display.

Each of the circuit films 311 is attached between the pad portion of the lower substrate 301 and the printed circuit board 312 for display by a film attaching process and is formed of a tape carrier package (TCP) or a chip on flexible board Chip On Film). Each of the plurality of circuit films 311 may be bent to one side of the liquid crystal panel 300, that is, the lower side thereof, and disposed in the lower case 410.

The data driving integrated circuit 313 is mounted on each of the plurality of circuit films 311 and connected to the pad portion through the circuit film 311. [ The data driving integrated circuit 313 receives the pixel data and the data control signal for each pixel supplied from the timing control unit 314 and converts the pixel data for each pixel into an analog data signal in accordance with the data control signal, And supplies it to the corresponding data line.

The printed circuit board 312 for display is connected to a plurality of circuit films 311. The printed circuit board 312 for display functions to provide a signal necessary for displaying an image to each pixel of the liquid crystal panel 300 to the data driving IC 313 and the gate driving circuit. To this end, various signal lines, various power supply circuits (not shown), memory devices (not shown), and the like are mounted on the printed circuit board 312 for display.

The timing controller 314 is mounted on the display printed circuit board 312 and outputs digital image data input from the driving system in response to a timing synchronizing signal supplied from an external driving system (not shown) to the liquid crystal panel 300 Generates pixel data for each pixel by arranging the pixel data in accordance with the pixel arrangement structure, and provides the generated pixel data to the data driving IC 313. The timing control unit 314 generates a data control signal and a gate control signal based on the timing synchronization signal, and controls the driving timing of each of the data driving integrated circuit 313 and the gate driving circuit.

In addition, the timing controller 314 may control the brightness of each region of the liquid crystal panel 300 individually by controlling the backlight unit 200 through the edge-type local dimming technique.

The side faceting member 400 is disposed to surround the side surface of the backlight unit. The side faceting member 400 may be disposed on the liquid crystal panel 300 except the side on which the panel driving unit 310 is disposed, but this is not necessarily the case.

The lower case 410 houses the panel driving unit 310, which is bent and protruded from the liquid crystal panel 300. The lower case 410 hides the panel driving unit 310. The lower case 410 may serve as a support for inserting and supporting the backlight unit 200 and the liquid crystal display panel.

As described above, the backlight unit 200 according to an embodiment of the present invention is a direct-type backlight unit, and highly accurate local dimming is possible, thereby improving the contrast ratio and reducing power consumption. In addition, the backlight unit 200 according to an exemplary embodiment of the present invention diffuses light without the need to maintain a wide optical diffusion gap (optical gap) as in the prior art by the encapsulation resin 230 and the optical member 250 having the engraved pattern. The backlight unit 200 and the liquid crystal display device can be made thin. Therefore, the backlight unit 200 and the liquid crystal display according to the exemplary embodiment of the present invention can prevent a halo phenomenon because the light emitted from the light source 220 does not pass through the local dimming zone due to a narrow light diffusion distance .

Fig. 3 is a cross-sectional view taken along line I-I of Fig. 2, and is a cross-sectional view of a liquid crystal display device according to an example of the present invention. FIG. 4 is a photograph showing a light-shielding pattern of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 5 is a diagram illustrating a correlation of structures of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 3, a liquid crystal display according to an exemplary embodiment of the present invention includes a rear external appearance substrate 100, a backlight unit 200, a liquid crystal panel 300, and a side external appearance member 400.

The rear external appearance substrate 100 supports the backlight unit 200 and also provides a rear view of the liquid crystal display device. The back-side external appearance substrate 100 of the present invention eliminates the same structure as the cover bottom included in the conventional backlight unit, so that the backlight unit 200 and the liquid crystal display device can be made thin. A rear-faced substrate 100 according to this example includes a cover glass 101, an outer-facing pattern 102, and a base substrate 103.

The cover glass 101 protects the backlight unit 200 and the liquid crystal display device from the outside with the rear exposed substrate 100 exposed to the outside. The cover glass 101 keeps the rear-faced substrate 100 in a planar state. The cover glass 101 according to an exemplary embodiment may be made of a glass material or a plastic material.

The external appearance pattern 102 is disposed on the cover glass 101. The outer appearance pattern 102 may be disposed between the cover glass 101 and the base substrate 103 in the form of a film. In addition, the external appearance pattern 102 can be printed on the inner surface of the cover glass 101 where the cover glass 101 is not exposed to the outside. Since the external appearance pattern 102 is provided inside the transparent cover glass 101, the pattern is not damaged and the external appearance design is easy.

The base substrate 103 is disposed on the cover glass 101 with the external appearance pattern 102 interposed therebetween. The base substrate 103 may comprise a plastic material or a glass material. The base substrate 103 according to one example may be made of a flexible plastic material, for example, an opaque or colored PI (polyimide) material. The base substrate 103 may be formed by curing a polyimage resin coated on a top surface of a release layer provided on a relatively thick carrier substrate to a predetermined thickness. Here, the carrier substrate is separated from the base substrate 103 by the release of the release layer using a laser-releasing process.

The backlight unit 200 is disposed on the rear faceted substrate 100. A backlight unit 200 according to an embodiment of the present invention includes a circuit board 210, a light source 220, a sealing resin 230, a light shielding pattern 240, and an optical member 250.

The circuit board 210 is disposed on the rear faceted substrate 100. The circuit board 210 includes a plurality of light sources 220 mounted thereon and a plurality of light sources 220 electrically connected to each other. More specifically, the circuit board 210 includes a driving power supply line supplied with external driving power, and supplies driving power supplied from the outside through the driving power supply line to each of the plurality of light sources 220, (220). In this case, the circuit for electrically connecting the plurality of light sources 220 is made of a reflective material such as a metal so as to reflect the light emitted from the light source 220 upward.

Each of the plurality of light sources 220 is arranged on the circuit board 210 so as to be spaced apart from each other and connected to a light source driving signal line. The plurality of light sources 220 emits light to the bottom surface of the optical member 250. Each of the plurality of light sources 220 emits light simultaneously or individually according to a light source driving signal supplied from the light source driving signal. Each of the plurality of light sources 220 may individually emit light in accordance with a local dimming method for partially controlling the brightness.

Each of the plurality of light sources 220 according to an exemplary embodiment of the present invention includes a chip-scale package and is directly mounted on a top surface of the circuit board 210. Accordingly, . Accordingly, the size of the light source 220 according to an exemplary embodiment of the present invention is similar to the size of the light emitting chip incorporated in the conventional light source module. The backlight unit 200 and the liquid crystal display device according to an exemplary embodiment of the present invention may be thin and aesthetically pleasing by applying the light source 220 formed of a chip scale package.

In addition, the light source 220 according to an exemplary embodiment of the present invention emits the first color light according to the light source driving signal. For example, the light source 220 may be a light emitting diode chip that emits white light. The light source 220 may have a structure such as a lateral chip structure, a flip chip structure, a vertical chip structure, and a chip scale package.

The encapsulation resin 230 covers a plurality of light sources 220 and is disposed between the circuit board 210 and the optical member 250. The encapsulation resin 230 protects the plurality of light sources 220 and fixes the plurality of light sources 220 to the circuit board 210. In addition, the encapsulation resin 230 may serve as a medium for diffusing light emitted from the light source 220. The encapsulation resin 230 according to an exemplary embodiment may be formed of a resin such as Si, UV resin, PC, PMMA, or a combination of these materials, but is not limited thereto.

The light shielding pattern 240 is disposed on the lower surface 250a of the optical member 250 so as to face the light source 220. [ The light shielding pattern 240 is disposed on the first air layer 235 between the bottom surface 250a of the optical member and the sealing resin 230. [ The light shielding pattern 240 is disposed to face the light source 220 to prevent strong light emitted from the light source 220 from directly entering the optical member 250. Accordingly, the backlight unit 200 according to an exemplary embodiment of the present invention can prevent the occurrence of a mosaic like a hot-spot.

Referring to FIG. 4, the light-shielding pattern 240 according to an exemplary embodiment of the present invention has at least one hole. The light blocking pattern 240 according to an exemplary embodiment of the present invention blocks a part of the light incident from the opposing light source 220 while a part of the light is incident on the optical member 250 so that the backlight unit 200 and the liquid crystal display Thereby preventing the brightness from lowering and preventing hot spots.

The optical member 250 is formed in a flat plate shape having a predetermined thickness and is disposed on the light source 220 so as to cover the front surface of the light source 220. The optical member 250 diffuses the light emitted from each of the plurality of light sources 220 and advances the light toward the liquid crystal panel 300.

The optical member 250 may be supported and fixed by a first adhesive resin RS1 disposed on the encapsulation resin 230. [ The first adhesive resin RS1 surrounds the edge of the encapsulation resin 230 and has a constant thickness. The first air layer 235 is provided between the encapsulation resin 230 and the optical member 250 and the light shielding pattern 240 is disposed on the first air layer 235. The backlight unit 200 according to an embodiment of the present invention includes the encapsulation resin 230 and the first air layer 235 between the light source 220 and the optical member 250 so that the light emitted from the light source 220 Is firstly diffused by the encapsulation resin (230). The light diffused by the encapsulation resin 230 is refracted and diffused by the light due to the refractive index difference with the first air layer 235.

The optical member 250 according to an exemplary embodiment may include, but is not limited to, PMMA, PC, PS, Si, COC, MS, UV Resin, The optical member 250 according to an exemplary embodiment of the present invention includes a light incidence surface 250a and an optical pattern 250b on the upper surface of the member.

The light-incident surface 250a has a light-shielding pattern 240 disposed on a surface facing the light source 220. The light-

The optical pattern 250b is provided on the upper surface of the optical member 250 at an obtuse angle. The optical pattern 250b according to an exemplary embodiment has a shape of a cone or a polygonal pyramid with its corner pointing toward the light source 220 and its bottom facing the liquid crystal panel 300. A second air layer 255 is provided in the interior of the optical pattern 250b provided at a negative angle, that is, between the optical pattern 250b and the liquid crystal panel 300. [ Light incident from the light source 220 into the optical pattern 250b is refracted by diffracting light due to the refractive index difference with the second air layer 255. [

5, the height of the light source 220 of the liquid crystal display according to an embodiment of the present invention is t1, the width is c, the height of the encapsulation resin 230 is t2, the width of the light shielding pattern 240 is d, The radius of the light source 250b may be defined as r, and the refractive index of the light source 220 may be defined as n2. At this time, the radius r of the optical pattern of the liquid crystal display according to an exemplary embodiment of the present invention is smaller than 0.3 times the width c of the light source.

Further, the width d of the shielding pattern can be calculated by Equation (2).

The optical member 250 according to an exemplary embodiment of the present invention may be formed by spreading and diffusing light by the optical pattern 250b so that the light incident from the light source 220 is not directly irradiated to the liquid crystal panel 300, ) And a hot spot of a liquid crystal display device can be prevented. In addition, the optical member 250 according to an exemplary embodiment of the present invention can uniformly diffuse the light without maintaining the optical diffusion distance (optical gap) by the optical pattern 250b, and the backlight unit 200 and the liquid crystal display It is possible to make the apparatus thinner while improving image quality with high luminance. Therefore, the backlight unit 200 and the liquid crystal display according to the exemplary embodiment of the present invention can prevent the halo from being caused by light emitted from the light source 220 due to a narrow light diffusion distance, have.

The liquid crystal panel 300 is disposed on the optical member 250. A second adhesive resin RS2 is further disposed between the liquid crystal panel 300 and the optical member 250, that is, between the liquid crystal panel 300 and the backlight unit 200. [ The backlight unit 200 and the liquid crystal panel 300 are bonded together by the second adhesive resin RS2. Therefore, the backlight unit 200 and the liquid crystal display of the present invention can be thinned by eliminating the same structure as the guide panel included in the conventional backlight unit. The second adhesive resin RS2 surrounds the edge of the optical member 250 and has a constant thickness. Accordingly, a second air layer 255 is provided between the liquid crystal panel 300 and the optical member 250 to prevent the occurrence of egg mura.

The side surface externalizing member 400 is disposed so as to surround the backlight unit 200 and the side surface of the liquid crystal display device and integrates them. The side faceting member 400 fixes the backlight unit 200 and the liquid crystal display device, and simultaneously makes the appearance. The side faceting member 400 may be disposed on the liquid crystal panel 300 except the side on which the panel driving unit 310 is disposed, but this is not necessarily the case. When the side surface externalizing member 400 is disposed except the side surface on which the panel driving unit 310 is disposed, the surface on which the lower case 410 is exposed can be concealed. The side faceting member 400 according to one example may be a resin, a film tape, a thermosetting adhesive, a photocurable adhesive, or the like.

As described above, the backlight unit 200 according to an embodiment of the present invention is a direct-type backlight unit, and highly accurate local dimming is possible, thereby improving the contrast ratio and reducing power consumption. The backlight unit 200 according to an exemplary embodiment of the present invention may be constructed as a conventional wide-angle optical system by the encapsulation resin 230, the first and second air layers 235 and 255, The light can be diffused without maintaining the optical diffusion distance (optical gap), so that the backlight unit 200 and the liquid crystal display device can be made thin. Therefore, the backlight unit 200 and the liquid crystal display according to the exemplary embodiment of the present invention can prevent a halo phenomenon because the light emitted from the light source 220 does not pass through the local dimming zone due to a narrow light diffusion distance , It is possible to prevent the image quality from deteriorating.

FIG. 6 is a cross-sectional view taken along line II-II of FIG. 2, and is a cross-sectional view of a liquid crystal display device according to an example of the present invention. The liquid crystal display device shown in FIG. 6 is substantially the same as that described in FIGS. 1 to 3 except that the panel driving part 310 is disposed at the edge of the liquid crystal panel 300. Therefore, only the liquid crystal panel 300 and the panel driving unit 310 will be described and repeated explanation will be omitted.

The liquid crystal panel 300 includes a lower substrate 301 and an upper substrate 302 bonded to each other with a liquid crystal layer (not shown) interposed therebetween, a lower polarizing film 303 attached to the rear surface of the lower substrate 301, And an upper polarizing film 304 attached to the front surface of the substrate 302.

Although not shown in the figure, pixels are formed on the lower substrate 301 for each intersection region of the gate lines and the data lines. The pixel includes a thin film transistor (TFT), a common electrode, and a pixel electrode.

The thin film transistors serve as switching for transferring and controlling an electrical signal to each pixel. A common voltage for driving the liquid crystal is applied to the common electrode. The pixel electrode is disposed on a protective film covering the common electrode, and is connected to the thin film transistor.

The lower substrate 301 controls the light transmittance of the liquid crystal layer by forming an electric field corresponding to a difference voltage between a data voltage and a common voltage applied to each pixel. A pad portion including a signal applying pad connected to a plurality of data lines is disposed at an edge of the lower substrate 301.

The upper substrate 302 includes a black matrix (BM) and a color filter. In the color filter, R (Red), G (Green), and B (Blue) patterns are formed. The black matrix is disposed between the R, G, and B patterns of the color filter, respectively. A column spacer (CS) for maintaining a cell gap between the upper substrate 302 and the lower substrate 301 may be disposed on the upper substrate 302.

The upper substrate 302 is formed to have a size smaller than the size of the lower substrate 301 to open a pad portion of the lower substrate 301 with a liquid crystal layer (not shown) therebetween, Respectively.

The panel driving unit 310 is connected to the opened pad unit and drives each pixel of the liquid crystal panel 300 to display a predetermined color image on the liquid crystal panel 300. The panel driver 310 according to an exemplary embodiment includes a plurality of circuit films 311 connected to the pad portion of the liquid crystal panel 300, a data driving integrated circuit 313 mounted on each of the plurality of circuit films 311, A film 311, and a printed circuit board 312 for display combined with each other. The panel driving unit 310 is bent toward the front surface of the liquid crystal panel 300 and housed in the lower case 410.

The detailed configuration of the lower substrate 301 and the upper substrate 302 may be a driving mode of the liquid crystal layer, for example, a TN (Twisted Nematic) mode, VA (Vertical Alignment) And a Fringe field switching (FFS) mode.

The lower polarizing film 303 is attached to a lower surface of the lower substrate 301 to polarize light incident on the lower substrate 301.

The upper polarizing film 304 is attached to the front surface of the upper substrate 302 to polarize the light transmitted through the upper substrate 302 and emitted to the outside.

Each of the lower polarizing film 303 and the upper polarizing film 304 has different polarizing functions through a stretching process in directions opposite to each other and has contraction forces in directions opposite to each other in accordance with stretching. Each of the lower polarizing film 303 and the upper polarizing film 304 is attached to the lower substrate 301 and the upper substrate 302 so that the contracting forces of the lower polarizing film 303 and the upper polarizing film 304, So that the liquid crystal panel 300 does not bend upward or downward, but is in a planar state.

Fig. 7 is a cross-sectional view taken along line I-I of Fig. 2, and is a cross-sectional view of a liquid crystal display device according to another example of the present invention. The liquid crystal display device shown in Fig. 7 is the same as the liquid crystal display device shown in Figs. 1 to 7 except that the third and fourth adhesive resins RS3 and RS4, the phosphor sheet 260, and the third air layer 265 are further included. 3 < / RTI > Therefore, only the added third and fourth adhesive resins RS3 and RS4, the phosphor sheet 260, and the third air layer 265 will be described and repeated descriptions will be omitted.

Referring to FIG. 7, the third and fourth adhesive resins RS3 and RS4 are disposed with the phosphor sheet 260 therebetween. More specifically, the third adhesive resin RS3 is disposed between the optical member 250 and the phosphor sheet 260, and the fourth adhesive resin RS4 is disposed between the phosphor sheet 260 and the liquid crystal panel 300 do. The third adhesive resin RS3 has a predetermined thickness with the bottom edge of the phosphor sheet 260 disposed therebetween to provide a second air layer 255 between the optical member 250 and the phosphor sheet 260. The fourth adhesive resin RS4 has a predetermined thickness on the upper surface of the phosphor sheet 260 to provide a third air layer 265 between the phosphor sheet 260 and the liquid crystal panel 300.

The phosphor sheet 260 is disposed on the optical member 250. The phosphor sheet 260 includes at least one phosphor. The phosphor is a plurality of fluorescent materials that emit at least one color contained in the phosphor sheet 260. The fluorescent material may be a yellow fluorescent material, but is not limited thereto and may be one or more color fluorescent materials for generating white light in accordance with the color light emitted from the light source 220. The phosphor according to one example may emit yellow light by absorbing a part of blue light emitted from the light source 220.

At this time, the light source 220 according to an exemplary embodiment of the present invention emits the first color light according to the light source driving signal. For example, the light source 220 may be a blue light emitting diode chip emitting blue light. The light source 220 may have a structure such as a lateral chip structure, a flip chip structure, a vertical chip structure, and a chip scale package.

The backlight unit 200 and the liquid crystal display according to another example of the present invention may generate white light by mixing the blue light emitted from the light source 220 and the yellow light emitted by the phosphor and may be emitted to the outside.

As described above, the backlight unit 200 according to an embodiment of the present invention is a direct-type backlight unit, and highly accurate local dimming is possible, thereby improving the contrast ratio and reducing power consumption. The backlight unit 200 according to an exemplary embodiment of the present invention may be constructed as a conventional wide-angle optical system by the encapsulation resin 230, the first and second air layers 235 and 255, The light can be diffused without maintaining the optical diffusion distance (optical gap), so that the backlight unit 200 and the liquid crystal display device can be made thin. Therefore, the backlight unit 200 and the liquid crystal display according to the exemplary embodiment of the present invention can prevent a halo phenomenon because the light emitted from the light source 220 does not pass through the local dimming zone due to a narrow light diffusion distance , It is possible to prevent the image quality from deteriorating.

8 is a cross-sectional view taken along line I-I of FIG. 2, and is a cross-sectional view of a liquid crystal display device according to another example of the present invention. The liquid crystal display device shown in Fig. 8 is substantially the same as that described in Figs. 1 to 3 described above, except for the light-shielding pattern 240 and the optical pattern 250b of the optical member 250. [ Therefore, only the modified light-shielding pattern 240 and the optical pattern 250b of the optical member 250 will be described and repeated description will be omitted.

Referring to FIG. 8, the light shielding pattern 240 is disposed on the encapsulation resin 230 so as to face the light source 220. The light shielding pattern 240 is disposed on the first air layer 235 between the bottom surface 250a of the optical member and the sealing resin 230. [ The light shielding pattern 240 is disposed to face the light source 220 to prevent strong light emitted from the light source 220 from directly entering the optical member 250. Accordingly, the backlight unit 200 according to an exemplary embodiment of the present invention can prevent the occurrence of a mosaic like a hot-spot.

The optical member 250 includes a light incidence surface 250a and an optical pattern 250b on an absent surface.

An optical pattern 250b is disposed on a surface of the light incidence surface 250a facing the light source 220. [

The optical pattern 250b is provided on the light incidence surface 250a of the optical member 250 at an obtuse angle. The optical pattern 250b according to an example has the shape of a cone or a polygonal pyramid whose bottom surface faces the light source 220, A first air layer 235 is provided in the interior of the optical pattern 250b provided at a negative angle, that is, between the optical pattern 250b and the light shielding pattern 240. [ Light incident from the light source 220 into the optical pattern 250b is refracted by diffracting light due to the refractive index difference with the first air layer 235. [

On the other hand, the optical pattern 250b may be disposed on both the upper surface and the lower surface of the optical member 250, and may be a double-sided engraved pattern. Also, the optical pattern 250b may be a relief pattern having a cone shape or a polygonal shape.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of protection of the present invention should be construed according to the claims, and all technical ideas within the scope of equivalents should be interpreted as being included in the scope of the present invention.

100: rear faceted substrate 200: backlight unit
210: circuit board 220: light source
230: encapsulation resin 240: shielding pattern
250: optical member 260: phosphor sheet
300: liquid crystal panel 400: outer tubular member
410: Lower case

Claims (10)

A light source connected to the circuit board;
A light-shielding pattern facing the light source; And
And an optical member disposed on the shielding pattern and having an optical pattern,
And a sealing resin and an air layer are provided between the light source and the optical member. The method according to claim 1,
Wherein the optical member includes a member lower surface facing the light source and a member upper surface opposite to the member lower surface,
Wherein the upper surface of the member is provided with the optical pattern in the form of a cone or polygonal pyramid. 3. The method of claim 2,
Wherein the light shielding pattern is disposed on the absent surface, and the light shielding pattern is disposed on the air layer. The method of claim 3,
Wherein the shielding pattern has at least one hole. The method according to claim 1,
Wherein the circuit board is disposed on a back faceted substrate,
Cover glass;
An outer appearance pattern disposed on the cover glass; And
And a base substrate disposed on the external appearance pattern. The method according to claim 1,
An adhesive resin is further disposed between the encapsulation resin and the optical member, and the adhesive resin covers an edge of the encapsulation resin. The method according to claim 1,
And a phosphor sheet is further provided on the optical member. 8. The method of claim 7,
An adhesive resin and an air layer are further disposed between the optical member and the phosphor sheet, and the adhesive resin covers an edge of the optical member. 9. A backlight unit according to any one of claims 1 to 8; And
And a liquid crystal panel disposed on the backlight unit,
And an adhesive resin is included between the backlight unit and the liquid crystal panel. 10. The method of claim 9,
And a side surface externalizing member surrounding the side surface of the liquid crystal display device.

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