KR101824035B1 - backlight unit and display apparatus using the same - Google Patents

Abstract

The present invention relates to a backlight unit and a display device using the same and includes a first reflector, a second reflector, and at least one light source disposed between the first and second reflectors, A specular reflection area and a diffuse reflection area. The irregular reflection area reflects the incident light to at least one of a lambertian distribution and a gaussian distribution, the point of incidence of light incident on each point may be at least 55 degrees relative to the normal passing through each point.

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 a self-luminous PDP, a backlight unit is indispensable because of the absence of its own light emitting device.

The backlight unit used in the LCD is divided into an edge type backlight unit and a direct-type backlight unit according to the position of the light source. In the edge type, a light source is disposed on the right and left sides or upper and lower sides of the LCD panel, Since the light is uniformly distributed over the surface, uniformity of light is good and the thickness of the panel can be made very 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) is used as a light source of the backlight unit of the conventional edge method or direct-down type.

However, since the backlight unit using CCFL is always supplied with power to the CCFL, a considerable amount of power is consumed, and a color reproduction ratio of about 70% as compared with CRT and environmental pollution problems caused by the addition of mercury are pointed out as disadvantages.

BACKGROUND ART [0002] As a substitute product for solving the above problem, researches on a backlight unit using an LED (Light Emitting Diode) have been actively conducted.

When the LED is used as a backlight unit, it is possible to partially turn on / off the LED array, thereby drastically reducing the power consumption. In the case of the RGB LED, the color reproduction range specification exceeding 100% of the National Television System Committee (NTSC) So that a more vivid image quality can be provided to the consumer.

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

Currently, LCD products employing LEDs having the above advantages are being marketed extensively. However, since the conventional CCFL light source is different from the driving mechanism, driving drivers and PCB substrates are expensive.

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

The embodiment is intended to provide a backlight unit having an air guide and a display device using the same, by using a reflector having a regular reflection area and a diffusive reflection area.

An embodiment includes a first reflector, a second reflector, and at least one light source disposed between the first and second reflectors, wherein the second reflector includes a specular reflection area The diffuse reflection region reflects the incident light to at least one of a lambertian distribution and a gaussian distribution, and all the points of the diffuse reflection region are located at each point The incidence angle of incident light may be at least 55 degrees relative to the normal passing through each point.

Here, the diffuse reflection area may occupy 50 to 95% of the entire area of the second reflector.

Alternatively, the diffuse reflection area may occupy 70 to 80% of the entire area of the second reflector.

Then, the area ratio of the regular reflection area to the irregular reflection area of the second reflector may be 1: 1 - 20.

Next, the diffuse reflection region may include a first layer made of polyethylene terephthalate (PET) and a second layer formed on the first layer and made of at least one of TiO2 and SiO2.

The distance between the diffuse reflection region and the light source may be longer than the distance between the regular reflection region and the light source.

Further, the regular reflection area can be overlapped with the first reflector.

Then, 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 plane parallel to the first reflector.

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

Next, an air guide may be formed in a space between the second reflector and the optical member, and an optical member disposed at a predetermined distance from the second reflector.

Another embodiment includes a first reflector, a second reflector, and at least one light source disposed between the first and second reflectors, wherein the second reflector includes a specular reflection area And first and second diffuse reflection areas. The first and second diffusive reflection areas reflect incident light to at least one of a lambertian distribution and a gaussian distribution, 1 All points in the diffuse reflection region are at least 55 degrees with respect to the normal line passing through each point of light incident on each point and all points of the second diffraction reflection region are incident on each point The angle of incidence of light may be at least 60 degrees relative to the normal passing through each point.

Here, the first diffusely reflective region has a greater amount of light reflected by the Gaussian distribution than the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution, and the second diffusive region has a larger amount of light reflected by the Lambertian distribution and a Gaussian distribution The amount of light reflected by the Lambertian cyan distribution may be larger.

The area ratio of the first diffusive region and the second diffusive region may be 1: 1-5.

Then, the area ratio between the regular reflection area and the first diffusive area may be 1: 1-4.

Next, the area ratio of the specular reflection area to the second diffusive reflection area may be 1: 1 - 20.

In addition, the first irregular reflection region may be located between the specular reflection region and the second irregular reflection region.

The distance between the regular reflection region and the light source is closer to the distance between the first irregular reflection region and the light source, and the distance between the first diffusive reflection region and the light source may be closer to the distance between the second diffusive reflection region and the light source.

Next, the first and second diffuse reflection regions include a first layer made of polyethylene terephthalate (PET), a second layer formed on the first layer and made of at least one of TiO2 and SiO2, 1 The amount of particles included in the diffuse reflection region may be smaller than the amount of particles included in the second diffusive reflection region.

By forming the reflector for the air guide so as to have a specular reflection area and a diffuse reflection area, the embodiments are light in weight, low in manufacturing cost, and can provide uniform brightness.

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

1A and 1B are views for explaining a backlight unit according to the first embodiment;
2 is a diagram for explaining the regular reflection characteristic and the diffuse reflection characteristic of light;
3 is a view showing the distribution of light reflected in the irregular reflection region of FIG. 1A
4 is a cross-sectional view showing the configuration of a diffusive reflective area of the second reflector
5 is a graph showing the light reflection characteristic of the diffusive region
6A and 6B are views showing a first reflector superimposed on the regular reflection area of the second reflector
7A to 7C are views showing a second reflector including an inclined plane and a plane
8A to 8C are views showing a second reflector including a plurality of inclined surfaces
9 is a cross-sectional view showing a second reflector of a single-
10 is a cross-sectional view showing a second reflector of a double-
11A and 11B are views for explaining the backlight unit according to the second embodiment;
12A is a graph showing the light reflection characteristic of the first diffusive region
12B is a graph showing the light reflection characteristic of the second diffusive reflective area
13 is a view showing a second reflector of two edge type
Figs. 14 and 15 are views showing a second reflector of four edge type
16 is a view showing a backlight unit including an optical member
17 is a view showing an example of the shape of the optical member
18 is a view showing a reinforcing rib formed on the lower surface of the second reflector
19 is a view showing a support pin formed on the upper surface of the second reflector
20 is a view showing a display module having a backlight unit according to an embodiment
21 and 22 are views showing a display device according to an embodiment

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

In the description of the present embodiment, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) on or under includes both the two elements being directly in contact with each other or one or more other elements being indirectly formed between the two elements.

Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

1A and 1B are views for explaining a backlight unit according to the first embodiment, wherein FIG. 1A is a sectional view and FIG. 1B is a top perspective view.

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.

The light source module 100 including the light source 110 is disposed between the first reflector 200 and the second reflector 300 and disposed adjacent to the first reflector 200 or the second reflector 300 .

In some cases, the light source module 100 may be spaced apart from the second reflector 300 at the same time that the light source module 100 contacts the first reflector 200, or may be disposed at a distance from the first reflector 300 200 at regular intervals.

Alternatively, the light source module 100 may be spaced apart from the first reflector 200 and the second reflector 300, 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.

At this time, at least one light emitting element may be mounted on the circuit board, and an electrode pattern for connecting the adapter supplying the power and the light emitting element 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.

Such a circuit board may be a PCB (Printed Circuit Board) substrate made of polyethylene terephthalate (PET), glass, polycarbonate (PC), silicon (Si) or the like and mounted with a plurality of light sources 100, .

In addition, the substrate may be a single layer PCB, a multilayer PCB, a ceramic substrate, a metal core PCB, or the like.

The light emitting diode may be a blue LED chip or an ultraviolet LED chip or a red LED chip, a green LED chip, a blue LED chip, a yellow green LED, Chip, a white LED chip, and a UV 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).

The first reflector 200 and the second reflector 300 are arranged in a space between the first reflector 200 and the second reflector 300 so as to have an air guide without a light guide plate They can face each other apart.

The first reflector 200 may be formed of one of a reflective coating film and a reflective coating material layer to reflect light generated from the light source module 100 toward the second reflector 300.

In addition, a sawtooth-shaped reflection pattern may be formed on the 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 reflection pattern on the surface of the first reflector 200 is to increase the brightness in the central region of the backlight unit by reflecting the light generated by 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 diffuse reflection area 300b.

Here, the regular reflection area 300a serves to regularly reflect the incident light, and the irregular reflection area 300b can diffuse the incident light irregularly. The regular reflection area 300a and the irregular reflection area 300b The light reflectance may be about 50 - 99.99%.

The irregular reflection region 300b may reflect the incident light to at least one of a lambertian distribution and a gaussian distribution.

Here, all the points in the diffusive reflection region 300b are arranged such that when the incident angle of the light incident on each point is at least 55 degrees from the normal line passing through each point, the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution , The amount of light reflected by the Gaussian distribution may be larger, or the amount of light reflected by the Lambertian distribution may be larger.

For example, a reflection sheet having regular reflection characteristics may be disposed in the regular reflection area 300a of the second reflector 300, and a reflection sheet having diffuse reflection characteristics may be disposed in the irregular reflection area 300b of the second reflector 300 have.

That is, the reflective sheet having the diffuse reflection characteristics that reflects in the lambda cyan distribution and the Gaussian distribution can be disposed in the irregular reflection area 300b of the second reflector 300. [

Here, when the incident angle of the incident light is about 55 degrees or more from the normal, the amount of light reflected by the Gaussian distribution among the amounts of light reflected by the Lambertian distribution and the Gaussian distribution is smaller than the amount of light reflected by the Gaussian distribution It can have many diffuse reflection characteristics.

In some cases, the reflection sheet disposed in the diffusive reflection region 300b may reflect the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution when the incident angle of the incident light is about 60 degrees or more from the normal line May have more diffuse reflection characteristics.

2 is a view for explaining the regular reflection characteristic and the diffusive reflection characteristic of light.

As shown in FIG. 2, the light may be specular reflection and diffuse reflection depending on the surface characteristics of the reflector.

The diffuse reflection may include gaussian reflections, lambertian reflections, and mixed reflections.

Generally, a specular reflection means a reflection where the angle between the normal line passing through the point and the optical axis of the incident light and the angle between the normal line and the optical axis of the reflected light are the same when the light is incident on a point of the reflector.

The Gaussian reflection means a reflection in which the intensity of the reflected light along the angle of the surface of the reflector changes from the normal to the direction of the reflected light to a Gaussian function value.

Next, the reflection of the lambs cyan reflects the reflection of the reflected light according to the angle of the surface of the reflector, and the angle between the normal and the direction of the reflected light changes as a cosine function value.

Next, the mixed reflection means reflection in which at least one of the specular reflection, the Gaussian reflection, and the Lamberber reflection is mixed.

Therefore, in this embodiment, the reflection characteristic of the light can be controlled by adjusting the surface characteristics of the second reflector 300. [

FIG. 3 is a view showing a distribution of light reflected in the irregular reflection region of FIG. 1A.

3, in the specular reflection region 300a of the second reflector 300, when the incident light is incident on the first point, the angle? 1 between the optical axis of the incident light and the normal passing through the first point is the first point 2 between the optical axis of the reflected light reflected from the light source and the normal line.

When the incident light enters the second point in the irregular reflection region 300b of the second reflector 300, the reflected light reflected from the second point is reflected by the lambertian distribution and the gaussian distribution can do.

Here, when the angle? Between the optical axis of the incident light incident at the second point and the normal line passing through the second point is about 55 degrees or more, the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution are reflected by the Gaussian distribution The amount of light can be more.

The amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution when the angle &thetas; between the optical axis of the incident light incident on the second point and the normal passing through the second point is about 60 degrees or more, The amount of reflected light may be larger.

The reason why the second reflector 300 is fabricated to have the light reflection characteristic is to reduce the luminance difference between the region adjacent to the light source 110 and the region far from the light source 110.

That is, the regular reflection area 300a adjacent to the light source 110 serves to regularly reflect the light to the central area of the backlight having a weak luminance, and the diffusive reflection area 300b far from the light source 110 diffusely reflects light, The brightness can be compensated.

Therefore, the second reflector 300 can provide uniform overall brightness by appropriately adjusting the light reflection characteristics of the regular reflection area 300a and the irregular reflection area 300b.

The second reflector 300 may include a metal or metal oxide having a high reflectivity such as aluminum (Al), silver (Au), gold (Au), titanium dioxide (TiO ₂ ) The reflector 300 may have different materials formed in the regular reflection region 300a and the irregular reflection region 300b and may have different surface roughnesses in the regular reflection region 300a and the irregular reflection region 300b.

That is, in the second reflector 300, the regular reflection area 300a and the irregular reflection area 300b may be formed of the same material, and the surface roughness may be different from each other.

Alternatively, in the second reflector 300, the regular reflection area 300a and the irregular reflection area 300b may be formed of different materials, and the surface roughness may be different from each other.

For example, the irregular reflection region 300b of the second reflector 300 may include a first layer made of polyethylene terephthalate (PET), a second layer formed on the first layer and made of at least one of TiO2 and SiO2 .

4 is a cross-sectional view showing the configuration of a diffusely reflecting region of the second reflector.

As shown in FIG. 4, the irregular reflection region of the second reflector may be a structure in which the first layer 302 and the second layer 304 are laminated.

Here, the first layer 302 may be made of polyethylene terephthalate (PET), and the second layer 304 may be made of at least one of the particles 304a of TiO2 and SiO2.

The particles 304a of the second layer 304 may be of the same size or may have different sizes.

At this time, the particles 304a of the second layer 304 may occupy about 20-90% of the total area of the first layer 302.

Also, the size of the particles 304a may be about 5-50 um.

Further, a protective layer may be additionally formed on the second layer 304. [

Thus, the second reflector can control the light reflection characteristic of the irregular reflection region 300b by controlling the amount of particles contained in the second layer 304 in the irregular reflection region.

5 is a graph showing light reflection characteristics of a diffusely reflecting region.

As shown in FIG. 5, when the incident angle of the light incident on the diffuse reflection region is about 57.5 degrees from the normal, the ratio of the amount of light reflected by the Lambertian distribution to the amount of light reflected by the Gaussian distribution is 5: 5.

Here, when the amount of particles of at least one of TiO 2 and SiO 2 contained in the diffuse reflection region of the second reflector is about 50% of the total area of the diffusive reflection region, the amount of light reflected by the Lamberaian distribution according to the incident angle of light, The amount of light to be emitted is shown in Table 1 below.

Incidence angle (°) Lambertian distribution of light intensity (%) Gaussian distribution light intensity (%) 0 91 9 10 92 8 20 90 10 30 86 14 40 78 22 50 65 35 60 45 55 70 17 83

Accordingly, as shown in Table 1, the present embodiment controls the light reflection characteristic of the diffusely reflecting region so that the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Lambertian distribution It is possible to fabricate a diffusive region having a greater amount of light reflected by the Gaussian distribution or a diffusive region having a larger amount of light reflected by the Lamberian distribution than the amount of light reflected by the Gaussian distribution.

On the other hand, the irregular reflection region 300b of the second reflector 300 can occupy about 50-95% of the entire area of the second reflector 300. [

In some cases, the irregular reflection region 300b may occupy about 70 - 80% of the entire area of the second reflector 300.

The area ratio of the regular reflection area 300a to the irregular reflection area 300b of the second reflector 300 may be 1: 1 to 20.

The reason why the area ratio between the regular reflection area 300a and the irregular reflection area 300b of the second reflector 300 is determined is that the difference in luminance between the area adjacent to the light source 110 and the area far from the light source 110 To reduce it.

That is, the second reflector 300 can provide a uniform luminance as a whole by appropriately adjusting the area ratio between the regular reflection area 300a and the irregular reflection area 300b.

1A, the regular reflection area 300a may be disposed adjacent to the light source 110, and the irregular reflection area 300b may be disposed apart from the light source 110. [

That is, the distance between the irregular reflection region 300b and the light source 110 may be longer than the distance between the regular reflection region 300a and the light source 110. [

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

That is, the first reflector 200 may be partially overlapped with the regular reflection area 300a of the second reflector 300, or may be completely overlapped.

The regular reflection area 300a of the second reflector 300 is located adjacent to the light source module 100 and reflects the light emitted from the light source 110 to the central area of the second reflector 300 And the irregular reflection region 300b of the second reflector 300 is located in the central region of the second reflector 300 and can 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 inclined at an angle with respect to the first reflector 200, and the plane of the second reflector 300 may be parallel to the first reflector 200.

The inclined surface of the second reflector 300 may be a regular reflection area or only a part of the regular reflection area may be a regular reflection area and may include at least one of the light source 110 and the first reflector 200 Lt; / RTI >

6A is a view showing a first reflector partially overlapping a regular reflection area of a second reflector, and FIG. 6B is a view showing a first reflector superimposed on a regular reflection area of a second reflector, And the first reflector is completely overlapped with the regular reflection area of the first reflector.

6A, the first reflector 200 may be partially overlapped with the regular reflectance region 300a of the second reflector 300. As shown in FIG.

Here, the light source 100 may be partially overlapped or partially overlapped with the regular reflection area 300a of the second reflector 300. [

6B, the first reflector 200 may be completely overlapped with the regular reflection area 300a of the second reflector 300. In this case,

Here, the light source 100 may be partially overlapped or partially overlapped with the regular reflection area 300a of the second reflector 300. [

7A to 7C are views showing a second reflector including an inclined plane and a plane.

7A, the inclined surface has a flat surface and can be included in the regular reflection area 300a of the second reflector 300. [

7C shows a case where the inclined plane has a convex curved surface and the regular reflection area 300a of the second reflector 300 has a curved surface with a concave curved surface and can be included in the regular reflection area 300a of the second reflector 300. FIG. ).

7A to 7C, the plane of the second reflector 300 parallel to the first reflector 200 may be included in the diffusive reflection area 300b of the second reflector 300. [

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

8A to 8C are views showing a second reflector including a plurality of inclined surfaces.

8A shows a case where two adjacent inclined surfaces have a flat surface and one inclined surface is included in the regular reflection area 300a of the second reflector 300 and the remaining inclined surfaces are included in the diffuse reflection area 300b of the second reflector 300 .

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

8B shows two concave curved surfaces adjacent to each other having concave curved surfaces, and curvatures of two inclined surfaces may be different from each other. FIG. 8C shows that two adjacent inclined surfaces have convex curved surfaces, and curvatures of the two inclined surfaces may be different from each other.

Here, one inclined surface may be included in the regular reflection area 300a of the second reflector 300, and the remaining inclined surfaces may be included in the irregular reflection area 300b of the second reflector 300. [

In some cases, the remaining inclined surfaces may be partially included in the regular 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 regular reflection region 300a and the irregular reflection region 300b, and may include a diffusive layer and a regular reflection layer formed on the diffusive layer so that a part of the diffusive reflection layer is exposed. Or a double layer including a layer.

9 is a cross-sectional view showing a second reflector having a single layer structure, and FIG. 9 is a structure in which the regular reflection area 300a and the irregular reflection area 300b of the second reflector 300 are not overlapped with each other.

9, the regular reflection region 300a of the second reflector 300 is formed with a regular reflection layer, and the irregular reflection region 300b of the second reflector 300 is formed with a diffusive layer.

Here, the regular reflection layer and the diffusive reflection layer are arranged on the same plane, and the thickness t1 of the regular reflection layer and the thickness t2 of the diffusive reflection layer may be equal to each other.

The regular reflection layer and the diffusive reflection layer may include a metal or metal oxide having a high reflectance such as aluminum (Al), silver (Ag), gold (Au), titanium dioxide (TiO ₂ ) The materials of the diffusive 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 diffusive reflective layer may be a structure in which a reflective film is attached to a mold body or a metal body, or may be a mold body itself having a regular reflection surface or a diffusely reflecting surface.

In some cases, the regular reflection layer and the diffusive reflection layer may be made of a polymer resin such as a plastic or the like to enable injection molding.

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

An adhesive or bonding member may be formed on the interface between the regular reflection area 300a made of the regular reflection layer and the irregular reflection area 300b made of the diffusive layer so that the regular reflection area 300a and the irregular reflection area 300b can be connected to each other.

10 is a cross-sectional view showing a second reflector of a double-layer structure.

As shown in FIG. 10, the second reflector 300 has a structure in which the regular reflection area 300a and the irregular reflection area 300b are overlapped with each other.

Here, the second reflector 300 may be a double layer including a diffusive layer and a regular reflection layer formed on the diffusive layer so that a part of the diffusive layer is exposed.

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

At this time, the irregular reflection region 300b of the second reflector 300 may occupy about 70-80% of the entire area of the second reflector 300, and in some cases, the second reflector 300 may reflect the regular reflection region 300a and the irregular reflection region 300b may be about 1: 1 - 20.

11A and 11B are views for explaining the backlight unit according to the second embodiment, wherein FIG. 11A is a sectional view and FIG. 11B is a top perspective view.

11A and 11B, 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.

The second reflector 300 may include a specular reflection region 300a and a diffusive reflection region 300b and the diffusive reflection region 300b may include a first diffusive reflection region 300b1 and a second diffusive reflection region 300b2 .

Here, the regular reflection area 300a serves to regularly reflect the incident light, and the irregular reflection area 300b can diffuse the incident light irregularly. The regular reflection area 300a and the irregular reflection area 300b The light reflectance may be about 50 - 99.99%.

The first and second diffusely reflective regions 300b1 and 300b2 may reflect the incident light to at least one of a lambertian distribution and a gaussian distribution.

Here, all the points of the first diffusely reflecting region 300b1 are arranged such that when the incident angle of the light incident on each point is at least about 55 degrees or more from the normal line passing through each point, the amount of light reflected by the Lambertian distribution and the The amount of light reflected by the Gaussian distribution may be larger.

All points of the second diffusive reflective area 300b2 are arranged such that when the incident angle of the light incident on each point is at least about 60 degrees or more from the normal line passing through each point, the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution The amount of light reflected by the Gaussian distribution may be larger.

At this time, the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution may be larger in the first diffusely reflective region 300b1 than in the Gaussian distribution.

The amount of light reflected by the lambda cyan distribution and the amount of light reflected by the lambda cyan distribution among the amount of light reflected by the Gaussian distribution may be larger in the second diffusive reflective area 300b2.

For example, a reflection sheet having regular reflection characteristics may be disposed in the regular reflection area 300a of the second reflector 300, and a reflection sheet having diffuse reflection characteristics may be disposed in the irregular reflection area 300b of the second reflector 300 have.

That is, the reflective sheet having the diffuse reflection characteristics that reflects in the lambda cyan distribution and the Gaussian distribution can be disposed in the irregular reflection area 300b of the second reflector 300. [

Here, the reflective sheet disposed in the first diffusely reflecting region 300b1 has a light amount that is reflected by the Gaussian distribution among the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution when the incident angle of the incident light is about 55 degrees or more from the normal Can have more diffuse reflection characteristics.

When the incident angle of incident light is about 60 degrees or more from the normal, the reflective sheet disposed in the second diffusive reflective area 300b2 has a light quantity reflected by the Lambertian distribution and a light quantity reflected by the Gaussian distribution Can have more diffuse reflection characteristics.

At this time, the first irregular reflection region 300b1 may have more diffuse reflection characteristics than the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution, among the amount of light reflected by the Gaussian distribution.

The second diffusely reflective region 300b2 may have a more diffuse reflection characteristic than the Lambler cyan distribution and the Lambler cyan distribution among the amount of light reflected by the Gaussian distribution.

The reason why the second reflector 300 is fabricated so as to have the diffuse reflection characteristic is to reduce the luminance difference between the region adjacent to the light source 110 and the region far from the light source 110.

That is, the regular reflection region 300a adjacent to the light source 110 serves to regularly reflect light to the central region of the backlight having a weak luminance, and to reflect the first and second diffusely reflective regions 300b1 and 300b2 ) Can diffuse light to compensate for weak luminance.

Accordingly, the second reflector 300 can provide a uniform luminance as a whole by appropriately adjusting the light reflection characteristics of the regular reflection area 300a and the first and second irregular reflection areas 300b1 and 300b2.

Here, the second reflector 300 may include a metal or metal oxide having a high reflectance such as aluminum (Al), silver (Ag), gold (Au), titanium dioxide (TiO ₂ ) The reflector 300 may be formed of a material that differs from the regular reflection area 300a and the first and second irregular reflection areas 300b1 and 300b2 and may include a regular reflection area 300a and first and second diffusely reflective areas 300b1 and 300b2 ) May have different surface roughnesses.

That is, in the second reflector 300, the regular reflection area 300a and the first and second irregular reflection areas 300b1 and 300b2 may be formed of the same material and have different surface roughnesses.

Alternatively, in the second reflector 300, the regular reflection area 300a and the first and second irregular reflection areas 300b1 and 300b2 may be formed of different materials, and the surface roughness may be different from each other.

For example, the irregular reflection region 300b of the second reflector 300 may include a first layer made of polyethylene terephthalate (PET), a second layer formed on the first layer and made of at least one of TiO2 and SiO2 .

Here, the first and second irregular reflection regions 300b1 and 300b2 include the same material, and the amount of the material may be different from each other.

That is, the amount of the substance contained in the first diffusely reflecting region 300b1 may be smaller than the amount of the substance contained in the second diffusely reflecting region 300b2.

This is because the surface roughness of the first and second diffusely reflective regions 300b1 and 300b2 may vary depending on the amount of particles.

Here, the amount of the substance included in the first irregular reflection region 300b1 may account for about 20-90% of the total area of the first irregular reflection region 300b1.

The amount of the material contained in the second diffusive reflective area 300b2 may be about 20 to 90% of the total area of the second diffusive reflective area 300b2.

In addition, the first and second diffusely reflective regions 300b1 and 300b2 include the same materials in the same amount, and the particle sizes of the materials may be different from each other.

Here, the particle size of the substance included in the first diffusely reflective region 300b1 may be about 5 to 50 mu m.

As described above, the second reflector adjusts the light reflection characteristics of the first and second irregular reflection regions 300b1 and 300b2 by adjusting the particle amount or the particle size of the substance included in the first and second irregular reflection regions 300b1 and 300b2 Can be controlled.

On the other hand, the area of the first diffusive reflection area 300b1 may be equal to or smaller than the area of the second diffusive reflection area 300b2.

In some cases, the area ratio of the first diffusive reflection area 300b1 and the second diffusive reflection area 300b2 may be 1: 1-5.

The area of the regular reflection area 300a may be equal to or smaller than the area of the first irregular reflection area 300b1.

In some cases, the area ratio of the regular reflection area 300a to the first irregular reflection area 300b1 may be 1: 1-4.

Then, the area of the regular reflection area 300a may be equal to or smaller than the area of the second irregular reflection area 300b2.

In some cases, the area ratio of the regular reflection area 300a to the second diffusive reflection area 300b2 may be 1: 1 to 20.

In addition, the first irregular reflection region 300b1 may be positioned between the regular reflection region 300a and the second irregular reflection region 300b2.

The distance between the regular reflection region 300a and the light source 110 is closer to the distance between the first irregular reflection region 300b1 and the light source 110 and the distance between the first diffusive reflection region 300b1 and the light source 110 is 2 < / RTI > diffuse reflection region 300b2 and the light source 110, as shown in FIG.

FIG. 12A is a graph showing the light reflection characteristic of the first irregular reflection region, and FIG. 12B is a graph showing the light reflection characteristic of the second irregular reflection region.

As shown in FIG. 12A, when the incident angle of the light incident on the first diffusive region is about 57.5 degrees from the normal, the ratio of the amount of light reflected by the Lambertian distribution to the amount of light reflected by the Gaussian distribution is 5: 5 have.

Here, when the amount of particles of at least one of TiO2 and SiO2 contained in the first diffusely reflective region of the second reflector is about 50% of the total area of the first diffusive reflection region, the amount of light reflected by the Lamberaian distribution along the incident angle of light The amount of light reflected by the Gaussian distribution is shown in Table 2 below.

Incidence angle (°) Lambertian distribution of light intensity (%) Gaussian distribution light intensity (%) 0 91 9 10 92 8 20 90 10 30 86 14 40 78 22 50 65 35 60 45 55 70 17 83

12B, when the incident angle of the light incident on the second diffusive region is about 65.5 degrees from the normal, the ratio of the amount of light reflected by the Lambertian distribution to the amount of light reflected by the Gaussian distribution is 5: 5 Able to know.

Here, when the amount of particles of at least one of TiO 2 and SiO 2 contained in the second diffuse reflection region of the second reflector is about 70% of the total area of the diffusive region, the amount of light reflected by the Lamberaian distribution along the incident angle of light and the Gaussian distribution Is shown in Table 3 below.

Incidence angle (°) Lambertian distribution of light intensity (%) Gaussian distribution light intensity (%) 0 91 9 10 89 11 20 85 15 30 79 21 40 71 29 50 62 38 60 53 47 70 44 56

Therefore, as shown in Tables 2 and 3, the present embodiment controls the light reflection characteristic of the diffusely reflecting region so that the amount of light reflected by the lambda cyan distribution and the amount of light reflected by the Gaussian distribution, It is possible to fabricate a diffusive region having a greater amount of light reflected by the Gaussian distribution than the amount of light that is reflected by the Gaussian distribution or to produce a diffusely reflective region having a larger amount of light reflected by the Lamberian distribution than the amount of light reflected by the Gaussian distribution.

In addition, although the diffuse reflection region can be divided into two regions having different diffuse reflection characteristics, the diffuse reflection region can be divided into 3 to 10 regions having different diffuse reflection characteristics.

The irregularly reflecting regions of the second reflector can be designed to have optimum light reflection characteristics in accordance with the overall size and structure of the backlight unit.

On the other hand, the second reflector having the regular reflection area and the first and second diffusive reflection areas can be manufactured in various shapes according to the arrangement of the light source modules.

11A and 11B are views showing a second reflector of one edge type. As shown in FIGS. 11A and 11B, a first edge type second reflector 300 includes a light source module The regular reflection area 300a may be disposed adjacent to the light source module 100 and the first and second irregular reflection areas 300b1 and 300b2 may be disposed in a region distant from the light source module 100. [

FIG. 13 is a view showing a second reflector of a two edge type, and FIGS. 14 and 15 are views showing a second reflector of a four edge type.

13 is a plan view showing a second edge type second reflector. As shown in FIG. 13, a second edge type second reflector 300 includes a light source module 100 disposed on both sides thereof, a regular reflection area 300a, The first and second irregular reflection regions 300b1 and 300b2 may be disposed in a region distant from the light source module 100. [

14 is a plan view showing a fourth reflector of a four edge type. As shown in FIG. 14, a second reflector 300 of a four-edge type includes a light source module 100 on four sides, The regular reflection region 300a is disposed adjacent to the light source module 100 and the first and second irregular reflection regions 300b1 and 300b2 may be disposed in a region distant from the light source module 100. [

15 is a plan view showing a second reflector of four edge type. As shown in FIG. 15, the second edge of the second reflector 300 includes four light source modules 100 The regular reflection area 300a is disposed adjacent to the light source module 100 and the first and second irregular reflection areas 300b1 and 300b2 may be disposed in a region distant from the light source module 100. [

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

Fig. 16 is a view showing a backlight unit including an optical member, and Fig. 17 is a view showing an example of the shape of an optical member.

16, the optical member 600 may be disposed in an open region of the first reflector 200 and may be formed in a plurality of layers, and the concave-convex pattern 620 may be provided on the uppermost layer or on the surface of any one layer .

Optionally, the optical member 600 is made of at least one sheet, and may optionally 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 described above, the optical member 600 diffuses the light emitted through the open region of the first reflector 200 and has an irregular pattern 620 on the upper surface of the diffusion sheet 600 to increase the diffusion effect .

The concave-convex pattern 620 may have a strip shape arranged along the light source module 100, as shown in FIG.

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, and an angle between the first surface and the second surface is an obtuse angle or an acute angle .

Optionally, the optical member 600 is made of at least one sheet, and may optionally 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 described above, in the backlight unit, a plurality of patterns are formed so that the concave lines and the convex lines are alternately arranged on the surface of the second reflector, thereby improving the brightness and providing uniform brightness.

On the other hand, in this embodiment, the light exit surface of the light source module may be arranged in various directions.

That is, the light source module may have a direct emitting type structure in which the light exit surface is disposed so as to face the air guide direction between the optical member and the second reflector, and the light source module has a light exit surface, 2 reflector and the cover plate direction so as to face each other.

Here, in the indirect emission type light source module, the emitted light is reflected on the first reflector, the second reflector, and the cover plate, and the reflected light can again travel in the air guide direction of the backlight unit.

The reason why the light source module is disposed in the indirect output structure is that it can reduce the hot spot phenomenon.

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

Fig. 18 is a view showing a reinforcing rib formed on the lower surface of the second reflector. As shown in Fig. 18, a plurality of reinforcing ribs 350 may be disposed on the lower surface of the second reflector.

The reason is that the second reflector has a reflecting surface having a curved surface, so that it can be deformed by external environmental conditions, so that a reinforcing rib 350 can be provided 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 surface of the second reflector.

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

19 is a view showing a support pin formed on the upper surface of the second reflector. As shown in FIG. 19, support pins 360 for supporting the optical member may be formed on the upper surface of the second reflector 300 have.

This is because the optical member is separated from the second reflector 300 and the air guide is formed therebetween, so that the central region of the optical member can be lowered.

Here, it is stable that the area of the lower surface of the support pin 360 contacting the second reflector 300 is larger than the area of the upper surface.

On the other hand, circuit devices for driving the light source module may be disposed below 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, if the circuit devices are arranged in the space, the empty space can be efficiently used.

20 is a view showing a display module having a backlight unit according to an embodiment.

As shown in FIG. 20, 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.

21 and 22 are views showing a display device according to an embodiment.

21, the display device 1 includes a display module 20, a front cover 30 and a back cover 35 surrounding the display module 20, a driving unit 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) made of a transparent material transmitting light. The front panel may protect the display module 20 at regular intervals, and light emitted from the display module 20 So that an image displayed on the display module 20 is displayed from the outside.

The back cover 35 can be coupled with the front cover 30 to protect the display module 20.

A driving unit 55 may be disposed on one side 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 control unit 55a may be a timing controller and is a driving unit for adjusting the operation timing of each driver IC of the display module 20. The main board 55b may include a V-sync, an H- B resolution signal, and the power supply unit 55c is a driving unit for applying power to the display module 20. [

The driving part 55 may be provided on the back cover 35 and may be surrounded by the driving part cover 40.

The back cover 35 may include a plurality of holes to connect the display module 20 and the driving unit 55 and a stand 60 for supporting the display device 1.

22, the driving control unit 55a of the driving unit 55 is provided in the back cover 35, and the main board 55b and the power board 55c may be provided in the stand 60 have.

The driving unit cover 40 may cover only the driving unit 55 provided on 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.

The features, structures, effects and the like described in the 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 the embodiments can be combined and modified by other persons 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 (25)

A first reflector;
A second reflector; And
And at least one light source disposed between the first and second reflectors,
The second reflector includes a specular reflection area and a diffuse reflection area,
The irregular reflection region reflects incident light to at least one of a lambertian distribution and a gaussian distribution,
Wherein all the points of the diffusive reflection region are at least 55 degrees with respect to a normal line passing through each of the points,
The irregular reflection region may be formed,
A first layer made of polyethylene terephthalate (PET); And
And a second layer formed on the first layer and made of at least one of TiO ₂ and SiO ₂ ,
The amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution in a Gaussian distribution in the irregular reflection region are larger. delete The method according to claim 1,
Wherein the regular reflection area overlaps with the first reflector,
The irregular reflection area occupies 70 to 80% of the entire area of the second reflector,
The area ratio of the regular reflection area to the irregular reflection area of the second reflector is 1: 1 to 20,
Wherein the distance between the irregular reflection region of the second reflector and the light source is longer than the distance between the regular reflection region of the second reflector and the light source. delete delete delete delete The method according to claim 1 or 3,
Wherein the second reflector includes at least one flat surface and the plane of the second reflector is a plane parallel to the first reflector. The method according to claim 1 or 3,
Wherein the second reflector includes at least two inclined surfaces having at least one inflection point, and curvatures of the first and second inclined surfaces adjacent to each other around the inflection point are different from each other. The method according to claim 1,
Wherein an air guide is formed in a space between the second reflector and the optical member, wherein the air guide is formed in the space between the second reflector and the optical member. delete A first reflector;
A second reflector; And,
And at least one light source disposed between the first and second reflectors,
The second reflector includes a specular reflection area and first and second diffuse reflection areas,
The first and second diffusely reflective regions reflect incident light to at least one of a lambertian distribution and a gaussian distribution,
All the points of the first irregular reflection region are at least 55 degrees with respect to a normal line passing through each of the points,
Wherein all the points of the second diffusive region are at least 60 degrees with respect to a normal line passing through each of the points,
The first irregular reflection region has a greater amount of light reflected by the Gaussian distribution than the amount of light reflected by the Lambertian distribution and the amount of light reflected by the Gaussian distribution,
Wherein the second diffusive region has a greater amount of light reflected by the Lambertian distribution and a Lambertian distribution of the amount of light reflected by the Gaussian distribution. delete 13. The method of claim 12,
The area ratio of the first irregular reflection area to the second irregular reflection area is 1: 1 to 5,
Wherein the area ratio of the regular reflection area to the first irregular reflection area is 1: 1 to 4,
Wherein the area ratio of the regular reflection area to the second irregular reflection area is 1: 1 to 20. delete delete 13. The method of claim 12,
The first irregular reflection region is located between the regular reflection region and the second irregular reflection region,
Wherein the distance between the specular reflection region and the light source is closer to the distance between the first irregular reflection region and the light source and the distance between the first irregular reflection region and the light source is smaller than the distance between the second diffusive reflection region and the light source Device. delete 13. The method of claim 12,
The first and second diffusely reflective regions may be formed in the following order:
A first layer made of polyethylene terephthalate (PET)
And a second layer formed on the first layer and made of at least one of TiO ₂ and SiO ₂ ,
Wherein the amount of particles included in the first irregular reflection area is smaller than the amount of particles included in the second irregular reflection area. delete delete The method according to claim 1 or 3,
Wherein the second reflector includes an inclined surface having at least one inflection point, and along the inclined surface, the concave line and the convex line are alternately arranged. The method according to claim 1,
Wherein the second reflector is a single layer including the regular reflection region and the diffuse reflection region. The method according to claim 1,
Wherein the second reflector comprises a double layer including a diffusing layer and a regular reflection layer formed on the diffusing layer to expose a part of the diffusing layer.

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