KR20120123888A - backlight unit and display apparatus using the same - Google Patents

Abstract

PURPOSE: A backlight unit and a display device using the same are provided to form a reflector for an air guide, thereby providing uniform brightness. CONSTITUTION: At least one light source is arranged between first and second reflectors(200,300). The second reflector includes a specular reflection area(300a) and a diffused reflection area(300b). The specular reflection area is 5 to 50% of the entire area of the second reflector. The specular reflection area is overlapped with the first reflector. The second reflector properly adjusts an area ratio of the specular reflection area to the diffused reflection area. Therefore, a backlight unit provides the entirely uniform brightness. [Reference numerals] (AA) Regular reflection area; (BB) Irregular reflection area

Description

Backlight unit and display apparatus using the same

An embodiment relates to a backlight unit and a display device using the same.

Typically, typical large-sized display devices include a liquid crystal display (LCD), a plasma display panel (PDP), and the like.

Unlike the self-luminous PDP, an LCD requires a separate backlight unit due to the absence of its own light emitting device.

The backlight unit used in LCD is classified into an edge type backlight unit and a direct type backlight unit according to the position of the light source. In the edge type, the light source is disposed on the left and right sides or the top and bottom sides of the LCD panel and the light guide plate is used. Since the light is evenly distributed on the front surface, the light is uniform and the panel thickness can be made ultra thin.

The direct-type method is generally used for a display of 20 inches or more, and since the light source is arranged at a lower portion of the panel, the light efficiency is higher than that of the edge method. Thus, it is mainly used for a large display requiring high brightness.

CCFL (Cold Cathode Fluorescent Lamp) was used as the light source of the existing edge type or direct type backlight unit.

However, since the CCFL-based backlight unit is always powered by the CCFL, a considerable amount of power is consumed, and the problems of environmental pollution due to the addition of about 70% color reproduction rate and mercury are pointed out as disadvantages.

As a substitute for solving the above problems, research on a backlight unit using an LED (Light Emitting Diode) has been actively conducted.

When the LED is used as a backlight unit, the LED array can be partially turned on and off, which can drastically reduce the power consumption. For the RGB LED, it exceeds 100% of the NTSC (National Television System Committee) color reproduction range specification. To provide consumers with more vivid picture quality.

In addition, the LED produced by the semiconductor process is characterized by harmless to the environment.

LCD products employing LEDs with the above advantages are being released one after another. However, since the driving mechanism is different from the existing CCFL light source, driving drivers and PCB substrates are expensive.

Therefore, the LED backlight unit is still applied only to expensive LCD products.

Embodiments provide a backlight unit having an air guide and a display device using the reflector having a specular reflection area and a diffuse reflection area.

An embodiment includes a first reflector, a second reflector, and at least one light source disposed between the first and second reflectors, the second reflector being a specular reflection area and It includes a scattered reflection area, the specular reflection area occupies 5-50% of the total area of the second reflector, the specular reflection area may overlap the first reflector.

Here, the second reflector may include at least one inclined surface and at least one flat surface, and the plane of the second reflector may be a surface parallel to the first reflector.

The second reflector may include at least two inclined surfaces having at least one inflection point, and the curvatures of the first and second inclined surfaces adjacent to the inflection point may be different from each other.

Meanwhile, as the specular reflection area of the second reflector moves away from the light source, the area ratio may decrease.

Also, the specular reflection area of the second reflector adjacent to the light source may be larger in area than the specular reflection area of the second reflector away from the light source.

Here, the specular reflection area of the second reflector may occupy 20-30% of the entire area of the second reflector, and the ratio of the area of the specular reflection area and the diffuse reflection area of the second reflector may be 1: 1-20.

The second reflector may be a single layer including a specular reflection area and a diffuse reflection area. The single layer may include a specular reflection layer and a diffuse reflection layer arranged on the same plane, and the specular reflection layer and the diffuse reflection layer may be the same. It may have a thickness.

Subsequently, the single layer is composed of a specular reflection layer and a diffuse reflection layer arranged on the same plane, the specular reflection layer and the diffuse reflection layer partially overlap each other, and the thickness of the specular reflection layer overlapping the diffuse reflection layer does not overlap with the diffuse reflection layer. It may be thinner than its thickness.

Here, in the overlapping region of the specular reflection layer and the diffuse reflection layer, a specular reflection layer may be formed on the diffuse reflection layer, and at least one hole may be formed in the specular reflection layer to expose a part of the diffuse reflection layer, and the specular reflection layer overlapping the diffuse reflection layer The thickness of may become thinner away from the light source.

The second reflector may include a double layer including a diffuse reflection layer and a specular reflection layer formed on the diffuse reflection layer to expose a portion of the diffuse reflection layer.

Here, in the specular reflection layer formed on the diffuse reflection layer, a plurality of holes may be formed to expose a part of the diffuse reflection layer, and the number of holes may increase as the hole formed in the specular reflection layer moves away from the light source.

Subsequently, the specular reflection layer may include a first area adjacent to the light source and a second area away from the light source, and the second area may have a smaller area than the first area.

Here, the planar shape of the second region may be at least one of hemispherical, triangular, rectangular, and polygonal, and the second region of the specular reflection layer may extend by a distance of 5 to 200 mm from the first region of the specular reflection layer.

In addition, the second region of the specular reflection layer may decrease in thickness as it moves away from the light source, or may decrease in thickness as it moves away from the light source.

Embodiments can form a reflector for an air guide to have a specular reflection area and a scattered reflection area, thereby providing light weight, low manufacturing cost, and uniform luminance.

Therefore, the economics and reliability of the backlight unit can be improved.

1A and 1B illustrate a backlight unit according to an embodiment.
2A and 2B show a first reflector overlapping a specular reflection area of a second reflector;
3a to 3c show a second reflector comprising an inclined surface and a plane
4A-4C show a second reflector comprising a plurality of slopes
5 is a cross-sectional view showing a second reflector of the single layer structure according to the first embodiment
6A to 6D are plan views illustrating various shapes of the second reflector in which the specular reflection area decreases away from the light source module.
7A to 7C are plan views illustrating various shapes of the second reflector having the specular reflection area having different areas depending on the distance from the light source module.
8 is a sectional view showing a second reflector of the single layer structure according to the second embodiment
9A to 9D are cross-sectional views illustrating various shapes of the overlapping region of FIG. 8.
10A to 10C are plan views illustrating various shapes of the specular reflection layer formed on the overlapping region of FIG. 8.
FIG. 11 is a cross-sectional view illustrating a hole of a specular reflection layer formed in an overlapping region of FIG. 8.
12A and 12B are plan views illustrating holes of a specular reflection layer formed in the overlapping region of FIG. 8.
13 is a cross-sectional view showing a second reflector of a double layer structure;
14A and 14B are cross-sectional views showing thicknesses of the specular reflection layer of FIG. 13.
15A and 15B are plan views showing holes formed in the specular reflection area;
16A to 16C are plan views showing various shapes of the second region of the specular reflection region.
17A to 17C and 18 are views for explaining the uniformity of luminance according to the shape of the specular reflection area of the second reflector.
19 shows a specular reflection area having a hole and a triangular shape;
20A and 20B show a specular reflection area having a stripe shape.
21 is a view showing a second reflector having a plurality of diffuse reflection regions having different light reflection characteristics.
FIG. 22 shows a second reflector of one edge type. FIG.
FIG. 23 shows a second reflector of a two edge type; FIG.
24 and 25 show a second reflector of the four edge type.
26 illustrates a backlight unit including an optical member.
27 shows an example of a shape of an optical member;
28 shows a reinforcing rib formed on the lower surface of the second reflector.
29 shows a support pin formed on the upper surface of the second reflector.
30 is a view showing a display module having a backlight unit according to an embodiment
31 and 32 illustrate a display device according to an embodiment.

Hereinafter, exemplary embodiments will be described with reference to the accompanying drawings.

In the description of the present embodiment, when described as being formed on the "on or under" of each element, the (top) or (bottom) ( on or under includes both that two elements are in direct contact with one another or one or more other elements are formed indirectly between the two elements.

In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

1A and 1B are diagrams for describing a backlight unit according to an embodiment. FIG. 1A is a cross-sectional view and FIG. 1B is a top perspective view.

As shown in FIGS. 1A and 1B, the backlight unit may include a light source module 100 including at least one light source 110, a first reflector 200, and a second reflector 300. have.

Here, the light source module 100 including the light source 110 is positioned between the first reflector 200 and the second reflector 300 and disposed adjacent to the first reflector 200 or the second reflector 300. Can be.

In some cases, the light source module 100 may be disposed away from the second reflector 300 at the same time as being in contact with the first reflector 200, or may be disposed in contact with the second reflector 300 and at the same time as the first reflector 300. 200 may be spaced apart from each other.

Alternatively, the light source module 100 may be disposed apart from the first reflector 200 and the second reflector 300 by a predetermined distance, or may be in contact with the first reflector 200 and the second reflector 300 at the same time. .

The light source module 100 may include a circuit board having an electrode pattern and a light emitting device for generating light.

In this case, at least one light emitting device may be mounted on the circuit board, and an adapter for supplying power and an electrode pattern for connecting the light emitting device may be formed.

For example, a carbon nanotube electrode pattern for connecting the light emitting device and the adapter may be formed on the upper surface of the circuit board.

The circuit board may be made of polyethylene terephthalate (PET), glass, polycarbonate (PC) or silicon (Si), and may be a printed circuit board (PCB) substrate on which a plurality of light sources 100 are mounted, and in the form of a film. Can be formed.

In addition, the substrate may selectively use a single layer PCB, a multilayer PCB, a ceramic substrate, a metal core PCB and the like.

Meanwhile, the light emitting device may be a light emitting diode chip, and the light emitting diode chip may include a blue LED chip or an ultraviolet LED chip, or a red LED chip, a green LED chip, a blue LED chip, and a yellow green LED. It may also be configured in a package form combining at least one or more of a chip, a white LED chip.

The white LED may be realized by combining a yellow phosphor on a blue LED or by simultaneously using a red phosphor and a green phosphor on a blue LED, (Yellow phosphor), Red phosphor (Phosphor) and Green phosphor (Phosphor).

Next, the first reflector 200 and the second reflector 300 may face each other at a predetermined interval so as to have an air guide in the empty space between the first reflector 200 and the second reflector 300. have.

In addition, the first reflector 200 may be formed of any one of a reflective coating film and a reflective coating material layer to reflect the light generated from the light source module 100 in the direction of the second reflector 300.

In addition, a serrated reflection pattern is formed on a surface of the first reflector 200 facing the light source module 100, and the surface of the reflection pattern may be flat or curved.

The reason for forming the reflective pattern on the surface of the first reflector 200 is to increase the luminance in the central region of the backlight unit by reflecting the light generated in the light source module to the central region of the second reflector 300.

Next, the second reflector 300 includes a specular reflection area 300a and a scattered reflection area 300b.

Here, the specular reflection area 300a may serve to specularly reflect the incident light, and the diffuse reflection area 300b may perform the specular reflection of the incident light, and the specular reflection area 300a and the diffuse reflection area 300b may be used as the specular reflection area 300a. The light reflectivity can be about 50-99.99%.

In addition, the specular reflection area 300a may occupy about 5-50% of the entire area of the second reflector 300.

In some cases, in the second reflector 300, the specular reflection area 300a may occupy about 20-30% of the entire area of the second reflector 300.

In addition, in the second reflector 300, an area ratio between the specular reflection area 300a and the diffuse reflection area 300b may be 1: 1-20.

As such, the reason for determining the area ratio between the specular reflection area 300a and the diffuse reflection area 300b of the second reflector 300 is to determine the difference in luminance between the area adjacent to the light source 110 and the area far from the light source 110. To reduce.

That is, the second reflector 300 may provide uniform luminance as a whole by appropriately adjusting the area ratio between the specular reflection area 300a and the diffuse reflection area 300b.

Here, the second reflector 300 may include a metal or a metal oxide having a high reflectance such as aluminum (Al), silver (Ag), gold (Au), titanium dioxide (TiO ₂ ), or the like. The reflector 300 may have different materials formed in the specular reflection area 300a and the diffuse reflection area 300b, and may have different surface roughnesses of the specular reflection area 300a and the diffuse reflection area 300b.

That is, in the second reflector 300, the specular reflection area 300a and the diffuse reflection area 300b may be formed of the same material and may have different surface roughnesses.

Alternatively, the second reflector 300 may be formed of different materials from the specular reflection area 300a and the diffuse reflection area 300b, and may have different surface roughnesses.

At least one of the light source 110 and the first reflector 200 may overlap the specular reflection area 300a.

That is, only part of the first reflector 200 may overlap the specular reflection area 300a of the second reflector 300 or may completely overlap.

The specular reflection area 300a of the second reflector 300 is positioned adjacent to the light source module 100, and reflects the light emitted from the light source 110 to the center area of the second reflector 300. The diffuse reflection area 300b of the second reflector 300 may be positioned in the center area of the second reflector 300 to diffuse the incident light.

In addition, the second reflector 300 may include at least one inclined surface and at least one flat surface.

Here, the inclined surface of the second reflector 300 may be a surface inclined at an angle with respect to the first reflector 200, and the plane of the second reflector 300 may be a surface parallel to the first reflector 200.

In addition, the inclined surface of the second reflector 300 may have a whole area as a specular reflection area, or only a partial area may be a specular reflection area, and at least one of the light source 110 and the first reflector 200. Can be nested with

2A and 2B illustrate a first reflector overlapping a specular reflection area of a second reflector, and FIG. 2A illustrates a first reflector partially overlapping a specular reflection area of a second reflector, and FIG. 2B illustrates a second reflector. 1 is a view showing a first reflector completely overlapping the specular reflection region of the?

As shown in FIG. 2A, only a part of the first reflector 200 may overlap the specular reflection area 300a of the second reflector 300.

Here, the light source 100 may partially or completely overlap the specular reflection area 300a of the second reflector 300.

As shown in FIG. 2B, the first reflector 200 may completely overlap the specular reflection area 300a of the second reflector 300.

Here, the light source 100 may partially or completely overlap the specular reflection area 300a of the second reflector 300.

3A to 3C show a second reflector comprising an inclined surface and a plane.

3A may have a flat surface and may be included in the specular reflection area 300a of the second reflector 300.

3B has a curved surface having a concave surface, and may be included in the specular reflection area 300a of the second reflector 300, and FIG. 2C has a curved surface having a convex surface convex and the specular reflection area 300a of the second reflector 300. ) May be included.

3A to 3C, the plane of the second reflector 300 parallel to the first reflector 200 may be included in the diffuse reflection area 300b of the second reflector 300.

The second reflector 300 may include at least two inclined surfaces having at least one inflection point, and the curvatures of the first and second inclined surfaces adjacent to the inflection point may be different from each other.

4A to 4C show a second reflector including a plurality of inclined surfaces.

4A shows that two inclined surfaces adjacent to each other have a flat surface, one inclined surface is included in the specular reflection area 300a of the second reflector 300, and the other inclined surface is in the diffuse reflection area 300b of the second reflector 300. May be included.

In some cases, the remaining inclined surface may be partially included in the specular reflection area 300a of the second reflector 300.

In addition, in FIG. 4B, two inclined surfaces adjacent to each other may have a concave curved surface, and the curvatures of the two inclined surfaces may be different from each other.

Here, one inclined surface may be included in the specular reflection area 300a of the second reflector 300, and the other inclined surface may be included in the diffuse reflection area 300b of the second reflector 300.

In some cases, the remaining inclined surface may be partially included in the specular reflection area 300a of the second reflector 300.

As such, the inclined surface of the second reflector 300 may be at least one of a concave surface, a convex surface, and a flat surface.

Meanwhile, the second reflector 300 may be a single layer or a double layer.

That is, the second reflector 300 may be a single layer including the specular reflection area 300a and the diffuse reflection area 300b, or may be formed on the diffuse reflection layer so that a part of the diffuse reflection layer and the diffuse reflection layer are exposed. It may also be a double layer comprising a layer.

5 is a cross-sectional view illustrating a second reflector having a single layer structure according to the first embodiment, and FIG. 5 is a structure in which the specular reflection area 300a and the diffuse reflection area 300b of the second reflector 300 do not overlap each other.

As illustrated in FIG. 5, the specular reflection layer 300a of the second reflector 300 may have a specular reflection layer, and the specular reflection layer 300b of the second reflector 300 may have a diffuse reflection layer.

Here, the specular reflection layer and the diffuse reflection layer may be arranged on the same plane, and the thickness t1 of the specular reflection layer and the thickness t2 of the diffuse reflection layer may be the same.

In addition, the specular reflection layer and the diffuse reflection layer may include a metal or a metal oxide having high reflectivity such as aluminum (Al), silver (Ag), gold (Au), titanium dioxide (TiO ₂ ), and the like. The materials of the diffuse reflection layer may be the same or different from each other, and their surface roughness may be different from each other.

In addition, the specular reflection layer and the diffuse reflection layer may have a structure in which a reflective film is attached to a mold body, or may be a mold body having a specular reflection surface or a diffuse reflection surface.

In some cases, the specular reflection layer and the diffuse reflection layer may be made of a polymer resin such as plastic to enable injection molding.

Here, the reflective film may include at least one of a metal or a metal oxide, and for example, a metal having high reflectance such as aluminum (Al), silver (Ag), gold (Au), or titanium dioxide (TiO ₂ ). Or a metal oxide.

In addition, an adhesive or a coupling member may be formed on an interface between the specular reflection area 300a formed of the specular reflection layer and the diffuse reflection area 300b made of the diffuse reflection layer, such that the specular reflection area 300a and the diffuse reflection area 300b may be connected to each other.

Subsequently, as the specular reflection area 300a of the second reflector 300 moves away from the light source module 100, the area ratio may decrease.

6A through 6D are plan views illustrating various shapes of the second reflector in which the specular reflection area decreases away from the light source module.

6A shows that the specular reflection area 300a of the second reflector 300 has a triangular shape, FIG. 6B shows that the specular reflection area 300a of the second reflector 300 has a hemispherical shape, and FIG. 6C shows the second reflector 300. ), The specular reflection area 300a may have a stepped shape, and FIG. 6D may have the slant line shape of the specular reflection area 300a of the second reflector 300.

 6A to 6D, the area of the specular reflection region 300 may gradually decrease as the specular reflection region 300a of the second reflector 300 moves away from the light source module 100.

On the other hand, as the diffuse reflection area 300b of the second reflector 300 moves away from the light source module 100, the area of the diffuse reflection area may gradually increase.

Here, the specular reflection area 300a of the second reflector 300 may occupy about 20-30% of the entire area of the second reflector 300.

In some cases, in the second reflector 300, an area ratio between the specular reflection area 300a and the diffuse reflection area 300b may be about 1: 1-20.

As such, the reason why the area ratio decreases as the specular reflection area 300a of the second reflector 300 moves away from the light source module 100 appears at the boundary between the specular reflection area 300a and the diffuse reflection area 300b. This is because the black line can be removed to provide uniform luminance.

In addition, as another embodiment, the specular reflection area 300a of the second reflector 300 may include a first area adjacent to the light source module 100 and a second area far from the light source module 100. The specular reflection area 300a of the second reflector 300 adjacent to the 100 may have a larger area than the specular reflection area 300a of the second reflector 300 far from the light source module 100.

7A to 7C are plan views illustrating various shapes of the second reflector having the specular reflection area having different areas depending on the distance from the light source module.

In FIG. 7A, the specular reflection region of the second region may have a triangular shape, in FIG. 7B, the specular reflection region of the second region may have a hemispherical shape, and in FIG. 7C, the specular reflection region of the second region may have a rectangular shape.

As shown in FIGS. 7A to 7C, the specular reflection area 300a of the second reflector 300 may include a first area adjacent to the light source module 100 and a second area far from the light source module 100. have.

Here, the specular reflection area 300a of the second area has a smaller area than the specular reflection area 300a of the first area, and may have various shapes such as a triangle, a hemisphere, a rectangle, and a polygon.

That is, as the specular reflection area 300a of the second area moves away from the light source module 100, the area of the specular reflection area may gradually decrease.

On the other hand, the area of the diffuse reflection area 300b of the second area may gradually increase as the distance from the light reflection module 100 increases.

Here, the specular reflection area 300a of the second reflector 300 may occupy about 20-30% of the entire area of the second reflector 300.

In some cases, in the second reflector 300, an area ratio between the specular reflection area 300a and the diffuse reflection area 300b may be about 1: 1-20.

In addition, in the specular reflection area 300a of the second reflector 300, an area ratio between the first area and the second area may be about 1-10: 0.4.

Next, the second area of the specular reflection area 300a may extend by a distance of about 5 to 200 mm from the first area of the specular reflection area 300a.

FIG. 8 is a cross-sectional view illustrating a second reflector having a single layer structure according to a second embodiment, and FIG. 8 is a structure in which the specular reflection area 300a and the diffuse reflection area 300b of the second reflector 300 overlap each other.

As shown in FIG. 8, the specular reflection layer 300a of the second reflector 300 has a specular reflection layer, and the specular reflection layer 300b of the second reflector 300 has a diffuse reflection layer, and a second reflector ( The overlap region of 300 may be formed by overlapping the specular reflection layer and the diffuse reflection layer.

Here, the overlapping region may have a structure in which a specular reflection layer is stacked on the diffuse reflection layer, and the overall thickness of the overlapping region may be substantially the same as the thickness of the specular reflection region 300a and the thickness of the diffuse reflection region 300b.

In some cases, the total thickness of the overlapping region may be different from at least one of the thickness of the specular reflection region 300a and the thickness of the diffuse reflection region 300b.

Although not shown, the overlapping region may have a structure in which a diffuse reflection layer is stacked on the specular reflection layer.

As such, the specular reflection layer and the diffuse reflection layer of the second reflector 300 may be arranged on the same plane, and a portion of the specular reflection layer and the diffuse reflection layer may overlap each other.

9A to 9D are cross-sectional views illustrating various shapes of the overlapping region of FIG. 8.

9A and 9D illustrate embodiments in which the thickness of the specular reflection layer in the overlapping region is constant, and FIGS. 9B and 9C illustrate embodiments in which the thickness of the specular reflection layer in the overlapping region gradually decreases.

As shown in FIGS. 9A to 9D, the overlapping region may be a layer in which the specular reflection layer and the diffuse reflection layer are stacked, and the thickness t11 of the specular reflection layer overlapping the diffuse reflection layer may be thinner than the thickness t1 of the specular reflection layer which does not overlap the diffuse reflection layer. .

In more detail, as shown in FIG. 9A, the thickness t11 of the specular reflection layer formed in the overlapping region is smaller than the thickness t1 of the specular reflection layer formed in the specular reflection region 300a and the thickness of the diffuse reflection layer formed in the overlapping region. The thickness t22 may be smaller than the thickness t2 of the diffuse reflection layer formed in the diffuse reflection area 300b.

The thickness t11 of the specular reflection layer formed in the overlapped region may be the same as the thickness t22 of the diffuse reflection layer formed in the overlapped region while maintaining a constant thickness in the overlapped region.

However, in some cases, the thickness t11 of the specular reflection layer formed in the overlapping region may be larger or smaller than the thickness t22 of the diffuse reflection layer formed in the overlapping region.

As shown in FIG. 9B, the thicknesses t11 and t12 of the specular reflection layer formed in the overlapping region may be smaller than the thickness t1 of the specular reflection layer formed in the specular reflection region 300a.

Here, the thicknesses t11 and t12 of the specular reflection layer formed in the overlapped area may be gradually reduced as the distance from the light source module is increased.

That is, the specular reflection layer formed in the overlapping region may gradually decrease from the thickness t11 of the region adjacent to the light source module to the thickness t12 of the region far from the light source module.

Subsequently, as illustrated in FIG. 9C, the thicknesses t11 and t12 of the specular reflection layer formed in the overlap region may be smaller than the thickness t1 of the specular reflection layer formed in the specular reflection region 300a.

Here, the thicknesses t11 and t12 of the specular reflection layer formed in the overlapping region may be gradually reduced as the distance from the light source module increases.

That is, the specular reflection layer formed in the overlapped region may be reduced from the thickness t11 of the region adjacent to the light source module to the thickness t12 of the region far from the light source module.

Next, as shown in FIG. 9D, the diffuse reflection layer formed in the overlap region is inserted between the specular reflection layers.

In the overlapping region, the thickness t11 of the specular reflection layer located above the diffuse reflection layer and the thickness t12 of the specular reflection layer located below the diffuse reflection layer are smaller than the thickness t1 of the specular reflection layer formed in the specular reflection area 300a, The thickness t22 of the diffuse reflection layer formed may be smaller than the thickness t2 of the diffuse reflection layer formed in the diffuse reflection area 300b.

In addition, the thicknesses t11 and t12 of the specular reflection layer formed in the overlapping region may be the same as the thickness t22 of the diffuse reflection layer formed in the overlapping region while maintaining a constant thickness in the overlapping region.

However, in some cases, the thicknesses t11 and t12 of the specular reflection layer formed in the overlapping region may be larger or smaller than the thickness t22 of the diffuse reflection layer formed in the overlapping region.

10A through 10C are plan views illustrating various shapes of the specular reflection layer formed in the overlapping region of FIG. 8.

In FIG. 10A, the specular reflection layer of the overlapping region may have a triangular shape, in FIG. 10B, the specular reflection layer of the overlapping region may have a hemispherical shape, and in FIG. 10C, the specular reflection layer of the overlapping region may have a rectangular shape.

As shown in FIGS. 10A to 10C, the second reflector 300 may include an overlapping area in which the specular reflection layer of the specular reflection area 300a and the diffuse reflection layer of the diffuse reflection area 300b overlap each other. The specular reflection layer has a smaller area than the specular reflection layer of the specular reflection area 300a and may have various shapes, such as a triangle, a hemisphere, a rectangle, and a polygon.

That is, as the specular reflection layer of the overlapping area moves away from the light source module 100, the area of the specular reflection layer may gradually decrease.

On the other hand, as the diffuse reflection layer of the overlapped area moves away from the light source module 100, the area of the diffuse reflection layer may gradually increase.

Here, the specular reflection area 300a of the second reflector 300 may occupy about 20-30% of the entire area of the second reflector 300.

In some cases, in the second reflector 300, an area ratio between the specular reflection area 300a and the diffuse reflection area 300b may be about 1: 1-20.

In addition, in the specular reflection area 300a of the second reflector 300, an area ratio between areas other than the overlap area and the overlap area may be about 1-10: 0.4.

Next, the overlapping area of the specular reflection area 300a may be extended by a distance of about 5-200 mm from the specular reflection area 300a.

In addition, in the specular reflection layer of the overlapped region, at least one hole may be formed in the specular reflection layer so that a part of the diffuse reflection layer is exposed.

FIG. 11 is a cross-sectional view illustrating holes of the specular reflection layer formed in the overlapped region of FIG. 8, and FIGS. 12A and 12B are plan views illustrating holes of the specular reflective layer formed in the overlapped region of FIG. 8.

As shown in FIG. 11, in the overlapping region, a plurality of holes may be formed in the specular reflection layer formed on the diffuse reflection layer so that a part of the diffuse reflection layer is exposed.

Here, the number of holes formed in the specular reflection layer may increase as the distance from the light source module increases.

The sizes of the holes formed in the specular reflection layer may be the same, but in some cases, they may be different.

As shown in FIG. 12A, the sizes of the holes formed in the overlapped areas may be the same, or as illustrated in FIG. 12B, the sizes of the holes formed in the overlapped areas may be different from each other.

When the sizes of the holes formed in the overlapping regions are different from each other, the size of the holes may increase as the distance from the light source module 100 increases.

And, the number of holes formed in the overlapping area may increase as the distance from the light source module 100 increases, regardless of the size.

As described above, the reason why the hole is formed in the overlapping region of the second reflector is that as the distance from the light source module 100 increases, the area ratio of the specular reflection region 300a can be reduced, thereby providing uniform luminance.

The specular reflection layer formed in the specular reflection area of the second reflector and the diffuse reflection layer formed in the diffuse reflection area of the second reflector may have a structure in which a reflective film is attached to a mold body, and has a specular reflection surface or a diffuse reflection surface. It may also be the mold body itself.

In some cases, the specular reflection layer and the diffuse reflection layer may be made of a polymer resin such as plastic to enable injection molding.

Here, the reflective film may include at least one of a metal or a metal oxide, and for example, a metal having high reflectance such as aluminum (Al), silver (Ag), gold (Au), or titanium dioxide (TiO ₂ ). Or a metal oxide.

In addition, an adhesive or a coupling member may be formed between the specular reflection area made of the specular reflection layer and the diffuse reflection area made of the diffuse reflection layer, so that the specular reflection area and the diffuse reflection area may be connected to each other.

13 is a cross-sectional view illustrating a second reflector of a double layer structure.

As shown in FIG. 13, the second reflector 300 has a structure in which the specular reflection area 300a and the diffuse reflection area 300b overlap each other.

The second reflector 300 may include a double layer including a diffuse reflection layer and a specular reflection layer formed on the diffuse reflection layer so that a portion of the diffuse reflection layer is exposed.

That is, the specular reflection area 300a of the second reflector 300 has a structure in which the specular reflection layer is formed on the diffuse reflection layer, and the diffuse reflection area 300b of the second reflector 300 is a structure in which the diffuse reflection layer is exposed.

In this case, the specular reflection area 300a of the second reflector 300 may occupy about 20-30% of the entire area of the second reflector 300. In some cases, in the second reflector 300, the specular reflection area ( The area ratio between 300a) and the diffuse reflection area 300b may be about 1: 1-20.

In addition, the specular reflection area 300a may include a first area adjacent to the light source module 100 and a second area far from the light source module 100. The second area may have a smaller area than the first area. .

Here, in the specular reflection area 300a of the second reflector 300, an area ratio between the first area and the second area may be about 1-10: 0.4.

In addition, in the specular reflection area 300a of the second reflector 300, the thickness of the specular reflection layer formed in the second area may be the same as that of the specular reflection layer formed in the first area, but may be different from each other.

14A and 14B are cross-sectional views illustrating thicknesses of the specular reflection layer of FIG. 13.

14A is an embodiment in which the thickness of the specular reflection layer formed in the second region gradually decreases away from the light source module (not shown). It is an embodiment in which the thickness is constant and gradually decreases as it goes further away.

As shown in FIG. 14A, the thicknesses t11 and t12 of the specular reflection layer formed in the second region of the specular reflection region 300a may be smaller than the thickness t1 of the specular reflection layer formed in the first region of the specular reflection region 300a. .

Here, the thicknesses t11 and t12 of the specular reflection layer formed in the second region may become smaller as the distance from the light source module increases.

That is, the specular reflection layer formed in the second region may gradually decrease from the thickness t11 of the region adjacent to the light source module to the thickness t12 of the region far from the light source module.

Subsequently, as illustrated in FIG. 14B, the thicknesses t11 and t12 of the specular reflection layer formed in the second region of the specular reflection region 300a are the same as the thickness t1 of the specular reflection layer formed in the first region of the specular reflection region 300a. It can be gradually decreased while maintaining.

That is, the specular reflection layer formed in the second region may be reduced from the thickness t11 of the region adjacent to the light source module to the thickness t12 of the region far from the light source module.

As described above, the reason for reducing the thickness of the specular reflection layer formed in the second region is to reduce the sudden brightness change in the boundary region between the specular reflection region 300a and the diffuse reflection region 300b.

In addition, in the specular reflection layer formed on the diffuse reflection layer, a plurality of holes may be formed so that a part of the diffuse reflection layer is exposed.

15A and 15B are plan views illustrating holes formed in the specular reflection area.

15A illustrates an example in which the number of holes formed in the specular reflection area 300a increases as the distance from the light source module 100 increases, and FIG. 15B illustrates the size of the holes formed in the specular reflection area 300a as the light source module 100. It is an embodiment showing the increase away from.

As shown in FIG. 15A, in the specular reflection area 300a, a plurality of holes may be formed in the specular reflection layer formed on the diffuse reflection layer so that a part of the diffuse reflection layer is exposed.

Here, the number of holes may increase as the holes formed in the specular reflection layer move away from the light source module 100.

The sizes of the holes formed in the specular reflection layer may be the same, but in some cases, they may be different.

That is, as the holes formed in the specular reflection layer move away from the light source module 100, the number of holes and the size of the holes may simultaneously increase.

As shown in FIG. 15B, in the specular reflection area 300a, a plurality of holes may be formed in the specular reflection layer formed on the diffuse reflection layer to expose a part of the diffuse reflection layer.

Here, the size of the hole may increase as the hole formed in the specular reflection layer moves away from the light source module 100.

The number of holes formed in the specular reflection layer may be the same, but in some cases, may be different.

That is, as the holes formed in the specular reflection layer move away from the light source module 100, the number of holes and the size of the holes may simultaneously increase.

As such, the reason for forming the hole in the specular reflection area 300a of the second reflector 300 is to provide uniform luminance by decreasing the area ratio of the specular reflection area 300a as it moves away from the light source module 100. Because it can.

In addition, the specular reflection area 300a may include a first area adjacent to the light source module 100 and a second area far from the light source module 100. The second area may have a smaller area than the first area. .

16A to 16C are plan views illustrating various shapes of the second region of the specular reflection region.

16A may have a triangular shape of the specular reflection area of the second area, FIG. 16B may have a hemispherical shape of the regular reflection area of the second area, and FIG. 16C may have a quadrangular shape of the regular reflection area of the second area.

As shown in FIGS. 16A to 16C, the specular reflection area 300a of the second reflector 300 may include a first area adjacent to the light source module 100 and a second area far from the light source module 100. have.

Here, the specular reflection area 300a of the second area has a smaller area than the specular reflection area 300a of the first area, and may have various shapes such as a triangle, a hemisphere, a rectangle, and a polygon.

That is, as the specular reflection area 300a of the second area moves away from the light source module 100, the area of the specular reflection area may gradually decrease.

On the other hand, the area of the diffuse reflection area 300b of the second area may gradually increase as the distance from the light reflection module 100 increases.

Here, the specular reflection area 300a of the second reflector 300 may occupy about 20-30% of the entire area of the second reflector 300.

In some cases, in the second reflector 300, an area ratio between the specular reflection area 300a and the diffuse reflection area 300b may be about 1: 1-20.

In addition, in the specular reflection area 300a of the second reflector 300, an area ratio between the first area and the second area may be about 1-10: 0.4.

Next, the second area of the specular reflection area 300a may extend by a distance of about 5 to 200 mm from the first area of the specular reflection area 300a.

In addition, the specular reflection layer formed in the specular reflection area 300a of the second reflector 300 and the diffuse reflection layer formed in the diffuse reflection area 300b of the second reflector 300 may include a reflective film attached to a mold body. It may be a structure, or may be a mold body itself having a specular or diffuse reflection surface.

In some cases, the specular reflection layer and the diffuse reflection layer may be made of a polymer resin such as plastic to enable injection molding.

Here, the reflective film may include at least one of a metal or a metal oxide, and for example, a metal having high reflectance such as aluminum (Al), silver (Ag), gold (Au), or titanium dioxide (TiO ₂ ). Or a metal oxide.

An adhesive or a coupling member may be formed between the specular reflection area 300a formed of the specular reflection layer and the diffuse reflection area 300b formed of the diffuse reflection layer, so that the specular reflection area 300a and the diffuse reflection area 300b may be connected to each other.

17A to 17C and FIG. 18 are diagrams for describing uniformity of luminance according to the shape of the specular reflection area of the second reflector.

17A is an embodiment in which the triangular shape is not at the end of the specular reflection area, and FIGS. 17B and 17C are embodiments in which the triangular shape is formed at the end of the specular reflection area, and FIG. It is a graph comparing uniformity.

First, although not shown, a second reflector having no specular reflection area but only a diffuse reflection area is Example A, and as shown in Fig. 17A, a second reflector having a specular reflection area 300a having a distance D1 at both ends is about 100 mm. 300 is Example B, and as shown in FIG. 17B, in the specular reflection area 300a in which the distance D1 at both ends is about 100 mm, the distance D2 at both ends (that is, the height of the triangular shape) is about 30 mm. A second reflector 300 having a triangular shape of which is the embodiment C, and as shown in Fig. 17C, in the specular reflection area 300a in which the distance D1 at both ends is about 100 mm, the distance D2 at both ends (that is, Embodiment D may be a second reflector 300 having a triangular shape having a triangular shape) of about 90 mm.

18 is a graph in which luminance according to a distance from a light source is measured and compared for each embodiment.

As shown in FIG. 18, in Example A without the specular reflection region, the luminance of the region adjacent to the light source is high and the luminance of the region far from the light source is low.

And in Example B where there is a specular reflection area, it turns out that the brightness | luminance of the area | region adjacent to a light source appears low, and the brightness | luminance of the area | region far from a light source appears high.

Further, in Examples C and D having a triangular shape in the specular reflection region, it can be seen that the luminance of the region adjacent to the light source and the luminance of the region far from the light source are almost uniform.

Here, it can be seen that Example D having a triangular height of about 90 mm is more uniform and more uniform than Example C having a triangular height of about 30 mm.

As such, the specular reflection region of the second reflector may include a first region adjacent to the light source and a second region far from the light source. When the second region of the specular reflection region has a shape that gradually decreases away from the light source, It can be seen that the luminance appears uniformly.

19 is a view showing a specular reflection area having a hole and a triangular shape.

As shown in FIG. 19, a specular reflection layer having a plurality of holes may be formed in the first region of the specular reflection region 300a, and a specular reflection layer having a triangular shape may be formed in the second region of the specular reflection region 300a. .

Here, the diffuse reflection layer positioned below the specular reflection layer may be exposed in the hole formed in the first region.

In the embodiment of FIG. 19, by appropriately adjusting the number of holes or the size of the holes of the specular reflection layer formed in the first region of the specular reflection region 300a, and the shape of the specular reflection layer formed in the second region of the specular reflection region 300a, It is possible to provide uniform brightness throughout.

20A and 20B show a specular reflection area having a stripe shape.

As shown in FIGS. 20A and 20B, a specular reflection layer may be formed in the first region of the specular reflection region 300a, and a specular reflection layer having a stripe shape may be formed in the second region of the specular reflection region 300a.

Here, the specular reflection layer formed in the second region of the specular reflection area 300a may be composed of a plurality of stripes, and the widths of the stripes adjacent to each other may be the same or different from each other.

20A illustrates an embodiment in which a plurality of stripes having the same width are arranged in the second region of the specular reflection region 300a, and FIG. 19B illustrates a plurality of stripes having a different width in the second region of the specular reflection region 300a. Example.

Among the stripes of FIG. 20B, the width w1 of the stripe adjacent to the light source module 100 may be wider than the width w3 of the stripe away from the light source module 100.

In some cases, the specular reflection layer formed in the first region of the specular reflection area 300a may have a plurality of holes, and the holes may be exposed to the diffuse reflection layer positioned below the specular reflection layer.

20A and 20B may provide uniform brightness as a whole by appropriately adjusting the number and width of stripes formed in the second area of the specular reflection area 300a.

21 is a view showing a second reflector having a plurality of diffuse reflection regions having different light reflection characteristics.

As shown in FIG. 21, the diffuse reflection region of the second reflector may be divided into a plurality of regions according to light reflection characteristics.

For example, a reflection sheet having specular reflection characteristics is disposed in the specular reflection region 300a of the second reflector 300, and a reflection in which specular reflection and diffuse reflection characteristics are mixed in the first diffuse reflection region 300b1 of the second reflector 300. A sheet may be disposed, and a reflective sheet having diffuse reflection characteristics may be disposed in the second diffuse reflection region 300b2 of the second reflector 300.

That is, a reflective sheet having a Lambertian surface may be disposed in the second diffuse reflection region 300b2 of the second reflector 300.

Here, the reflective sheet having a Lambertian surface may be a reflective sheet which may have a diffusion surface in which almost the same luminance appears in all directions.

In the first diffuse reflection region 300b1 of the second reflector 300, a reflective sheet having a lower density of a lambertian surface than the second diffuse reflection region 300b2 of the second reflector 300 may be disposed. have.

Subsequently, in the specular reflection area 300a of the second reflector 300, a reflective sheet having a lower density of the Lambertian surface than the first diffuse reflection area 300b1 of the second reflector 300 may be disposed, Or there may be little Lambertian surface.

Meanwhile, the second reflector having the specular reflection area and the diffuse reflection area may be manufactured in various shapes according to the arrangement of the light source module.

FIG. 22 is a view showing a second reflector of one edge type, FIG. 23 is a view showing a second reflector of a two edge type, and FIGS. 24 and 25 are four edge types ( 4 shows a second reflector of four edge types.

FIG. 22 is a plan view illustrating a second reflector of one edge type. As illustrated in FIG. 21, the light source module 100 is disposed on one side of the second reflector 300 of one edge type. The specular reflection area 300a may be disposed adjacent to the light source module 100, and the diffuse reflection area 300b may be disposed in an area far from the light source module 100.

23 is a plan view illustrating a second edger of a two-edge type. As illustrated in FIG. 23, the light source module 100 is disposed at both sides of the second edger 300 of the two-edge type, and the specular reflection region ( 300a may be disposed adjacent to the light source module 100, and the diffuse reflection area 300b may be disposed in an area far from the light source module 100.

Subsequently, FIG. 24 is a plan view illustrating a second reflector of a four edge type. As shown in FIG. 24, the second reflector 300 of the four edge type has a light source module 100 on four sides, respectively. In this case, the specular reflection area 300a may be disposed adjacent to the light source module 100, and the diffuse reflection area 300b may be disposed in an area far from the light source module 100.

Next, FIG. 25 is a plan view illustrating the second reflector of the four edge type. As shown in FIG. 25, the second reflector 300 of the four edge type has a light source module 100 at each of the four corner regions. ) Is disposed, the specular reflection area 300a may be disposed adjacent to the light source module 100, and the diffuse reflection area 300b may be disposed in an area far from the light source module 100.

In addition, the backlight unit according to the embodiment may further include an optical member disposed at a predetermined interval from the second reflector, the air guide may be formed in the space between the second reflector and the optical member. have.

FIG. 26 is a view illustrating a backlight unit including an optical member, and FIG. 27 is a diagram illustrating a shape of an optical member as an example.

As illustrated in FIG. 26, the optical member 600 may be disposed in an open area of the first reflector 200 and have an uneven pattern 620 on an upper surface thereof.

Here, the optical member 600 is to diffuse light emitted through the open region of the first reflector 200, and the concave-convex pattern 620 is formed on the upper surface of the diffusion sheet 600 to increase the diffusion effect. can do.

As shown in FIG. 27, the uneven pattern 620 may have a stripe shape disposed along the light source module 100.

At this time, the concave-convex pattern 620 has a protrusion on the surface of the optical member 600, the protrusion is composed of a first surface and a second surface facing each other, the angle between the first surface and the second surface is an obtuse or acute angle Can be.

In some cases, the optical member 600 may include at least one sheet, and may include a diffusion sheet, a prism sheet, a brightness enhancement sheet, and the like.

Here, the diffusion sheet diffuses the light emitted from the light source, and the prism sheet guides the diffused light to the light emitting area, and the brightness diffusion sheet strengthens the brightness.

As such, the backlight unit may form a plurality of patterns such that the concave lines and the convex lines are alternately arranged on the surface of the second reflector, thereby improving luminance and providing uniform luminance.

In the present embodiment, the light exit surface of the light source module may be arranged in various directions.

That is, the light source module may be a direct emitting type structure in which the light exit surface is disposed in the direction of the air guide between the optical member and the second reflector, and the light source module may include the first reflector and the first light reflector. It may also be an indirect emitting type structure which is arranged to face in one of two reflector and cover plate directions.

Here, in the indirect emission type light source module, the emitted light may be reflected by the first reflector, the second reflector, and the cover plate, and the reflected light may go back toward the air guide direction of the backlight unit.

As such, the reason for arranging the light source module in the indirect light emitting structure is that a hot spot phenomenon can be reduced.

In addition, a plurality of reinforcing ribs may be disposed on the lower surface of the second reflector.

FIG. 28 is a view illustrating reinforcing ribs formed on the lower surface of the second reflector. As shown in FIG. 28, a plurality of reinforcing ribs 350 may be disposed on the lower surface of the second reflector.

The reason is that since the second reflector has a reflective surface having a curved surface, it may be deformed by external environmental conditions, so that a reinforcing rib 350 may be installed to prevent this.

The reinforcing rib 350 may be disposed not only on the rear surface facing the inclined surface of the second reflector but also on the rear surface facing the side of the second reflector.

In addition, support pins for supporting the optical member may be formed on the upper surface of the second reflector.

FIG. 29 is a view illustrating a support pin formed on an upper surface of the second reflector. As illustrated in FIG. 29, support pins 360 for supporting an optical member may be formed on the upper surface of the second reflector 300. have.

The reason is that since the optical member is spaced apart from the second reflector 300 and an air guide is formed therebetween, the central region of the optical member may sag downward.

Here, the support pin 360 may be stable to form an area of the lower surface in contact with the second reflector 300 than the area of the upper surface.

Meanwhile, circuit devices for driving the light source module may be disposed under the inclined surface of the second reflector.

Since a predetermined space is formed between the inclined surfaces on the rear surface of the second reflector, by arranging circuit devices in the corresponding space, the empty space can be efficiently used.

30 is a view illustrating a display module having a backlight unit according to an embodiment.

As shown in FIG. 30, the display module 20 may include a display panel 800 and a backlight unit 700.

The display panel 800 includes a color filter substrate 810 and a TFT (Thin Film Transistor) substrate 820 bonded to each other to maintain a uniform cell gap, A liquid crystal layer (not shown) may be interposed.

The upper polarizer 830 and the lower polarizer 840 may be disposed on the upper and lower sides of the display panel 800 and more specifically the upper polarizer 830 may be disposed on the upper surface of the color filter substrate 810 And the lower polarizer 840 may be disposed on the lower surface of the TFT substrate 820.

Although not shown, a gate and a data driver for generating a driving signal for driving the panel 800 may be provided on a side of the display panel 800.

31 and 32 illustrate a display apparatus according to an embodiment.

Referring to FIG. 31, the display apparatus 1 includes a display module 20, a front cover 30 surrounding the display module 20, a back cover 35, and a driver 55 provided in the back cover 35. And a driving unit cover 40 surrounding the driving unit 55.

The front cover 30 may include a front panel (not shown) of a transparent material that transmits light, and the front panel protects the display module 20 at regular intervals, and the light emitted from the display module 20. The light is transmitted through the display module 20 so that the image displayed on the display module 20 can be seen from the outside.

The back cover 35 may be combined with the front cover 30 to protect the display module 20.

The driving unit 55 may be disposed on one surface of the back cover 35.

The driving unit 55 may include a driving control unit 55a, a main board 55b, and a power supply unit 55c.

The driving controller 55a may be a timing controller. The driving controller 55a may be a driver for controlling operation timing of each driver IC of the display module 20. The main board 55b may include a V sink, an H sink, and an R, G, The driving unit transmits a B resolution signal, and the power supply unit 55c is a driving unit that applies power to the display module 20.

The driving unit 55 may be provided in the back cover 35 and may be wrapped by the driving unit cover 40.

A plurality of holes may be provided in the back cover 35 to connect the display module 20 and the driving unit 55, and a stand 60 supporting the display device 1 may be provided.

On the other hand, as shown in FIG. 32, the driving control unit 55a of the driving unit 55 may be provided in the back cover 35, and the main board 55b and the power board 55c may be provided in the stand 60. have.

In addition, the driving unit cover 40 may wrap only the driving unit 55 provided in the back cover 35.

Although the main board 55b and the power board 55c are separately formed in the present embodiment, they may be formed as one integrated board, but are not limited thereto.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in each embodiment may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (21)

A first reflector;
A second reflector; And,
At least one light source disposed between the first and second reflectors,
The second reflector includes a specular reflection area and a scattered reflection area,
The specular reflection area occupies 5-50% of the total area of the second reflector,
The specular reflection area overlaps the first reflector. The backlight unit of claim 1, wherein the second reflector includes at least one inclined surface and at least one flat surface, and the plane of the second reflector is a plane parallel to the first reflector. The backlight unit of claim 1, wherein the second reflector includes at least two inclined surfaces having at least one inflection point, and the curvatures of the first and second inclined surfaces adjacent to the inflection point are different from each other. The method of claim 1,
And a optical member disposed at a predetermined interval from the second reflector, wherein an air guide is formed in the space between the second reflector and the optical member. The backlight unit of claim 1, wherein an area ratio of the second reflector decreases as the distance from the light source increases. The backlight unit of claim 1, wherein the specular reflection area of the second reflector adjacent to the light source is larger in area than the specular reflection area of the second reflector far from the light source. The backlight unit of claim 1, wherein the specular reflection area of the second reflector occupies 20-30% of the entire area of the second reflector. The backlight unit of claim 1, wherein an area ratio of the specular reflection area and the diffuse reflection area of the second reflector is 1: 1-20. The backlight unit of claim 1, wherein the second reflector is a single layer including the specular reflection area and the diffuse reflection area. The backlight unit of claim 9, wherein the single layer comprises a specular reflection layer and a diffuse reflection layer arranged on the same plane, and the specular reflection layer and the diffuse reflection layer have the same thickness. The method of claim 9, wherein the single layer is composed of a specular reflection layer and a diffuse reflection layer arranged on the same plane, the specular reflection layer and the diffuse reflection layer is partially overlapping each other, the thickness of the specular reflection layer overlapping the diffuse reflection layer is Backlight unit thinner than the thickness of the specular reflection layer that does not overlap the diffuse reflection layer. 12. The backlight of claim 11, wherein the overlapping region between the specular reflection layer and the diffuse reflection layer is formed with the specular reflection layer on the diffuse reflection layer, and at least one hole is formed in the specular reflection layer to expose a part of the diffuse reflection layer. unit. The backlight unit of claim 11, wherein a thickness of the specular reflection layer overlapping the diffuse reflection layer becomes thinner as it moves away from the light source. The backlight unit of claim 1, wherein the second reflector comprises a double layer including a diffuse reflection layer and a specular reflection layer formed on the diffuse reflection layer to expose a portion of the diffuse reflection layer. The backlight unit of claim 14, wherein the specular reflection layer formed on the diffuse reflection layer has a plurality of holes formed to expose a portion of the diffuse reflection layer. The backlight unit of claim 15, wherein the number of holes formed in the specular reflection layer increases as the distance from the light source increases. The backlight unit of claim 14, wherein the specular reflection layer comprises a first area adjacent to the light source and a second area away from the light source, the second area having a smaller area than the first area. The backlight unit of claim 17, wherein the plane shape of the second region is at least one of a hemispherical shape, a triangle shape, a rectangle shape, and a polygon shape. 18. The backlight unit of claim 17, wherein the second region of the specular reflection layer extends by a distance of 5-200 mm from the first region of the specular reflection layer. The backlight unit of claim 17, wherein the second region of the specular reflection layer decreases in thickness as it moves away from the light source, or decreases in thickness as it moves away from the light source. Display panel;
It includes a backlight unit for irradiating light to the display panel,
Display device using the backlight unit is any one of the backlight unit of claim 1 to claim 20, wherein the backlight unit.

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