KR101707574B1 - backlight unit having light blocking pattern and method for forming light blocking pattern of the same - Google Patents

Abstract

A backlight unit having a light-shielding pattern and a method of forming a light-shielding pattern, the light-source unit including a light-shielding layer having a light-shielding pattern positioned at at least one of an upper portion and a lower portion of the light source and having a higher light transmittance .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit having a light-shielding pattern and a method of forming a light-

The present invention relates to a backlight unit, and more particularly, to a backlight unit having a light-shielding pattern and a method of forming a light-shielding pattern thereof.

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 having a size of 20 inches or more. Since the light source is disposed at a lower portion of the panel, the light efficiency is higher than that of the edge type.

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 locally turn on / off the LED array, thereby dramatically reducing power consumption. In the case of the RGB LED, the LED is over 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 present invention provides a backlight unit having a light-shielding pattern capable of appropriately blocking light to uniformly adjust brightness of light and minimizing color change of transmitted light.

Further, the present invention provides a method of forming a light-shielding pattern of a backlight unit capable of appropriately shielding light to uniformly control brightness of light and at the same time to fabricate a light- do.

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Here, the light transmittance of the light shielding layer can be determined by the following equation.

Light transmittance _{T (x) = I 0 *} e -a (Lx) n

(Where I ₀ is the light intensity of the light source, L is the distance between adjacent light sources, x is the distance from the light emitting surface of the light source to the light transmittance measuring area, and a and n are the coefficients)

The light-shielding layer is composed of a first region corresponding to the position of the light source, a second region adjacent to the outer boundary surface of the first region, and a third region adjacent to the outer boundary surface of the second region, (Light transmittance of the first region) / (total area of the first region + (pattern area of the first region * pattern transmittance of the first region) / total area of the first region}, and the light transmittance of the second region is (The pattern area of the second area * the pattern transmittance of the second area) / the total area of the second area}, and the light transmittance of the third area is larger than the light transmittance of the third area (The pattern area of the third area * the pattern transmittance of the third area) / the total area of the third area}, and the light transmittance of the third area is equal to the total area of the first area and the second area And the light transmittance of the second region may be higher than the light transmittance of the first region.

Further, the light-shielding layer may be formed as a single layer or a plurality of layers having a thickness that decreases as the distance from the light source increases.

Here, the light-shielding layer includes at least one of a plurality of holes and / or grooves, and at least one of the holes and the grooves has a distance from the light source to the distance between adjacent holes or between adjacent grooves or between adjacent holes It can become narrower.

The light shielding layer may include at least one of a plurality of holes and grooves, and the width of the holes or grooves may become larger or larger as the distance from the light source increases.

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Further, the light-shielding layer may be formed of a plurality of layers having different light-shielding patterns.

Here, the respective layers of the light-shielding layer may be made of different materials or may have different thicknesses.

A method of forming a light-shielding pattern of a backlight unit according to the present invention includes the steps of preparing a light-transmitting substrate having first and second surfaces facing each other, forming a light-shielding layer on the first surface of the light- Forming a mask layer on the second surface and patterning to expose a second surface of the predetermined region; irradiating the first surface with a pulsed laser at a second surface of the exposed light-transmitting substrate; And removing the light shielding layer formed on the first surface area to form a light shielding pattern of the light shielding layer.

A method of forming a light-shielding pattern of a backlight unit according to the present invention includes the steps of preparing a light-transmitting substrate having first and second surfaces facing each other, forming a light-shielding layer on the first surface of the light- Forming a mask layer on the layer, exposing a light-shielding layer in a predetermined region by patterning the mask layer, irradiating a pulsed laser onto the first surface of the light-transmitting substrate, and exposing the exposed light- And forming a light-shielding pattern of the light-shielding layer.

By using a light-shielding layer having a light-shielding pattern with a higher light transmittance as the distance from the light source increases, the light transmittance in the region adjacent to the light source can be lowered and the color change in the transmitted light can be minimized.

In addition, since a large area such as a surface light source can be illuminated by using a partial luminescent light source such as an LED (Light Emitting Diode), the present invention can realize a thin thickness compared with a conventional illumination optical system.

Therefore, the present invention can provide an advantage of being able to constitute an optical system which is thin and has excellent light uniformity as a next generation backlight and illumination as compared with existing products.

In the meantime, the present invention can manufacture a light-shielding layer of a backlight unit by utilizing a thermal expansion phenomenon of a laser absorbing material using a pulsed laser.

 This method can form arbitrary complex patterns desired by the user on the reflective light shielding layer by selectively removing the reflective light shielding layer having a very high reflectance of the laser beam formed on the light transmitting substrate without using a photoresist.

Further, since the present invention does not require a complicated and non-complicated photolithography and etching process and does not require a process of forming a pattern in advance on a substrate, a pulse laser can be used even in forming a pattern of an absorption layer in advance, It is not only very simple, but also has advantages of rapid patterning since the particles are separated by a single pulse.

1A and 1B are views showing a backlight unit according to an embodiment of the present invention.
FIGS. 2A to 2C illustrate various embodiments of the present invention showing the position of the light-
3A and 3B are diagrams showing the light transmittance distribution of the light shielding layer according to the light source arrangement of the backlight unit
4 is a graph showing the light transmittance of the light-shielding layer according to the distance between adjacent light sources
5A and 5B are a plan view and a cross-sectional view showing a light transmittance according to a single-layer light-shielding layer
6A and 6B are a plan view and a cross-sectional view showing a light transmittance according to a light-shielding layer having a two-layer structure
7A and 7B are a plan view and a cross-sectional view showing the light transmittance according to the three-layered light-shielding layer
8 is a diagram for explaining the light transmittance according to the light shielding pattern of the light shielding layer by an equation
9A and 9B are views showing a light-shielding layer having a light-shielding pattern
10A to 10C are views showing a backlight unit having a light-shielding layer according to the first embodiment of the present invention
11A and 11B are views showing holes or grooves formed in the light-shielding layer of the first embodiment of the present invention
12 is a view showing a backlight unit having a light-shielding layer according to a second embodiment of the present invention
13A and 13B are views showing holes or grooves formed in the light-shielding layer of the second embodiment of the present invention
14A to 14C are views showing a backlight unit having a light-shielding layer according to a third embodiment of the present invention
15A to 15C are views showing a backlight unit having a light-shielding layer according to a fourth embodiment of the present invention
16A to 16C are views showing a backlight unit having a light-shielding layer according to a fifth embodiment of the present invention
17A and 17B are views showing a backlight unit having a light-shielding layer according to a sixth embodiment of the present invention
18A to 18C are process sectional views showing a method of manufacturing a light-shielding layer according to the first embodiment of the present invention
19A to 19C are process sectional views showing a method of manufacturing a light-shielding layer according to the second embodiment of the present invention
20A to 20C are process sectional views showing a method of manufacturing a light-shielding layer according to the third embodiment of the present invention
21 is a view showing a display module having a backlight unit of the present invention
22 and 23 are views showing a display device according to an embodiment of the present invention

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

1A and 1B are diagrams showing a backlight unit according to an embodiment of the present invention, wherein FIG. 1A is a backlight unit having an edge type optical system, and FIG. 1B is a diagram showing a backlight unit having a direct type optical system.

1A and 1B, the backlight unit 200 includes a first layer 210, a light source 220, a second layer 230, a reflective layer 240, and a light shield layer 250 .

A plurality of light sources 220 may be formed on the first layer 210 and a second layer 230 may be disposed on the first layer 210 to surround the plurality of light sources 220 .

The first layer 210 may be a substrate on which a plurality of light sources 220 are mounted and may include an electrode pattern (not shown) for connecting an adapter (not shown) .

For example, a carbon nanotube electrode pattern (not shown) for connecting the light source 220 and an adapter (not shown) may be formed on the upper surface of the substrate.

The first layer 210 may be a printed circuit board (PCB) on which a plurality of light sources 220 are mounted, such as polyethylene terephthalate (PET), glass, polycarbonate (PC) , Or in the form of a film.

The light source 220 may be one of a light emitting diode (LED) chip or a light emitting diode package having at least one light emitting diode chip.

In this embodiment, the light source 220 is a light emitting diode package.

The LED package constituting the light source 220 may be divided into a side view type and a top view type according to the direction in which the light emitting surface is directed. And the light source 220 of FIG. 1B is a top view type LED package in which a light emitting surface is formed toward the upper side.

The present invention can be configured using at least one of a light source of a side view system and a light source of a top view system.

In the embodiment of the present invention, in the case where the light source 220 is a side view type LED package, as shown in FIG. 1A, a plurality of light sources 220 are arranged in the lateral direction, The reflective layer 210 or the reflective layer 240 may emit light in the extended direction.

1B, the plurality of light sources 220 are arranged on the upper side of the light source 220, respectively, so that the upper surface of the second layer 230 and / Light can be emitted in the direction of the light shielding layer 250.

In addition, the light source 220 may be a colored LED or a white LED that emits at least one color among colors such as red, blue, green, and the like.

And, the colored LED may include at least one of a red LED, a blue LED, and a green LED, and the arrangement and emission light of such a light emitting diode may be variously changed and applied.

The second layer 220 disposed on the first layer 210 and surrounding the plurality of the light sources 220 transmits and diffuses the light emitted from the light source 220 to form a light source 220 So that the light emitted from the display panel 100 can be uniformly provided to the display panel 100.

A reflective layer 240 may be disposed on the first layer 210 to reflect light emitted from the light source 220.

The reflective layer 240 may be formed on the first layer 210 except the region where the light source 220 is formed.

The reflective layer 240 reflects the light emitted from the light source 220 and reflects the light totally reflected from the boundary of the second layer 230 to spread the light more widely.

The reflective layer 240 may include at least one of a metal or a metal oxide as a reflective material and may have a high reflectance such as aluminum (Al), silver (Ag), gold (Ag), or titanium dioxide (TiO ₂ ) Or a metal oxide.

In this case, the reflective layer 240 may be formed by depositing or coating a metal or a metal oxide on the first layer 210, or may be formed by printing metallic ink.

Here, as the deposition method, a vacuum deposition method such as a thermal deposition method, an evaporation method, or a sputtering method can be used. As the coating or printing method, a printing method, a gravure coating method, or a silk screen method can be used.

Meanwhile, the second layer 230 located on the first layer 210 may be made of a light-transmitting material, for example, silicon or an acrylic resin.

However, the second layer 230 is not limited to the above materials and may be made of various resins.

The second layer 230 may be formed of a resin having a refractive index of about 1.4 to 1.6 so that light emitted from the light source 220 is diffused and the backlight unit 200 has a uniform brightness.

For example, the second layer 230 may be formed of a material selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyepoxy And the like.

The second layer 230 may include a polymer resin having adhesion so as to firmly adhere to the light source 220 and the reflective layer 240.

For example, the second layer 230 may comprise at least one of an unsaturated polyester, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, n-butyl methacrylate, n-butyl methyl methacrylate, Hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxyethyl acrylate, acrylamide, methylol acrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, 2 -Ethylhexyl acrylate polymer, a copolymer or a terpolymer, and the like, acrylic, urethane, epoxy, melamine and the like.

The second layer 230 may be formed by applying a liquid or gel resin on the first layer 210 on which the plurality of light sources 220 and the reflective layer 240 are formed and curing the resin, It may be formed by applying a resin on the sheet and then partially curing it and adhering it on the first layer 210.

The second layer 230 may serve as a light guide plate for guiding light generated from the light source.

The light shielding layer 250 may reduce the brightness of light emitted from a region adjacent to the light source 220, thereby emitting light of a uniform brightness from the backlight unit 200.

The thickness of the backlight unit 200 is gradually becoming thinner and the uniformity of the light becomes worse as the thickness of the backlight unit 200 becomes thinner so that the role of the light shielding layer 250 is very important.

In the backlight unit 200, the light-shielding layer 250 of the present invention has the light intensity of the light in the region near the light-emitting surface of the light source 220 is the brightest and the light in the region farther from the light- As the distance from the light emitting surface of the light source 220 increases, the light transmittance can be increased.

That is, in the light-shielding layer 250 of the present invention, the entire area of the light-shielding layer 250 does not have the same light transmittance, but the light transmittance is low in a region near the light emitting surface of the light source 220, May have different light transmissivity for each region so that the light transmittance is high.

In addition, the material used for the light-shielding layer 250 may have a problem that the transmitted light is colored and the color uniformity is lowered because the characteristics of the transmission spectrum are not uniform. However, the color change of the transmitted light is minimized If the light transmittance of the light-shielding layer is increased, another problem that the light shielding ability of the light may be lowered may occur.

Therefore, when fabricating the light-shielding layer 250, the present invention may further form an appropriate light-shielding pattern in consideration of these problems.

The light-shielding layer 250 of the present invention may be a single layer having different light transmittance for each region, or may be a plurality of layers.

The light shielding layer 250 may have a light shielding pattern including at least one of a plurality of holes and grooves.

Here, the distance between at least one of the holes and the grooves may be narrower between adjacent holes, between adjacent grooves, or between adjacent holes and grooves, as the distance from the light emitting surface of the light source 220 is larger.

The width of the light shielding pattern of the light shielding layer 250 may be the same or smaller as the distance from the light emitting surface of the light source 220 is larger.

The thickness of the light shielding pattern of the light shielding layer 250 may be the same or smaller as the distance from the light emitting surface of the light source 220 is larger.

The light-shielding layer 250 may be formed of at least one of metal, TiO2, CaCO3, and ZnO.

FIGS. 2A to 2C show various embodiments showing the position of the light-shielding layer according to the present invention.

The light-shielding layer 250 of the present invention may be formed directly on or in contact with the second layer 230 of light-transmitting material, as shown in FIGS. 1A and 1B, As shown in FIG.

That is, the diffusion layer 260 may be provided on the light-shielding layer 250 to diffuse the light upward. At this time, the diffusion layer 260 may be directly bonded to the light-shielding layer 250, May be used.

Here, the diffusion layer 260 may diffuse the incident light to prevent the light from the light-shielding layer 250 from being partially concentrated, thereby making the brightness of the light more uniform.

2B, the light-shielding layer 250 may be formed with a predetermined space 270 filled with air or gas from the second layer 230 of a light-transmitting material, A predetermined buffer layer 280 may be further formed between the first layer 250 and the second layer 230.

Here, the buffer layer 280 may be a diffusion layer 260 of FIG. 2A or may be a material having a different refractive index from that of the second layer 230, and may be an adhesive for improving adhesion between the light-shielding layer 250 and the second layer, Or the heat absorbing layer that remains in fabricating the light shielding pattern of the light shielding layer 250.

3A and 3B are diagrams showing the light transmittance distribution of the light shielding layer according to the light source arrangement of the backlight unit. FIG. 3A is a view showing the arrangement structure of the light sources of the backlight unit, Layer light transmittance distribution.

As shown in FIG. 3A, a plurality of light sources 220 are disposed on the first layer 210, and adjacent light sources 220 may be arranged side by side on the same line, or may be arranged to be shifted from each other.

Here, the light emitting surfaces of the light sources 220 may be arranged to face the same direction.

In addition, the light sources 220 positioned on different lines adjacent to each other may be arranged side by side or may be arranged to be shifted from each other.

Here, the light sources 220 positioned on the same line may be disposed such that the light emitting surfaces face in the same direction, and the light sources 220 positioned on other lines adjacent to each other face the light emitting surface in the opposite direction.

When the light shielding layer 250 is formed on the plurality of light sources 220 arranged as above, the transmission distribution of the light is as shown in FIG. 3B,

An area closest to the light emitting surface of the light source 220 among the upper surface areas of the light shielding layer 250 is referred to as a first area 300a and an area closest to the light emitting surface of the light source 220 And a region located between the first region 300a and the third region 300c is referred to as a second region 300b and the light transmittance of the first region 300a is The light transmittance of the third region 300c is the highest and the light transmittance of the second region 300b is intermediate between the first region 300a and the third region 300c.

That is, the light-shielding layer 250 of the present invention has the lowest light transmittance in the region closest to the light emitting surface of the light source 220 and the highest light transmittance in the region farthest from the light emitting surface of the light source 220, The amount of light can be adjusted so as to have a uniform light transmittance.

4 is a graph showing the light transmittance of the light shielding layer according to the distance between adjacent light sources. As shown in FIG. 4, as the distance from the light emitting surface of the light source 220 increases, the light transmittance of the light shielding layer gradually increases .

That is, the present invention can produce a light-shielding layer having a light transmittance as shown in FIG.

Here, the light transmittance of the light shielding layer can be adjusted according to the following equation.

Light transmittance _{T (x) = I 0 *} e -a (Lx) n

(Where I ₀ is the light intensity of the light source, L is the distance between adjacent light sources, x is the distance from the light emitting surface of the light source to the light transmittance measuring area, and a and n are the coefficients)

As described above, the light-shielding layer of the present invention has different light transmittance for each region between the adjacent light sources 220. This is due to the optical design conditions such as the number of light sources, the reference brightness of the light source, It can change again.

Accordingly, the present invention is the light transmittance _{T (x) = I 0 *} e -a (Lx) via a formula such as ^n, each area of the light-shielding layer, and each setting a different light transmittance, to produce the light-shielding layer according to the set transmission have.

That is, in fabricating the light-shielding layer, the light transmittance setting procedure of the light-shielding layer is as follows.

First, the optical design conditions such as the number of light sources, the reference brightness of the light source, and the interval between the light sources are measured.

Next, using a formula such as the _{T (x) = I 0 *} e -a (Lx) n, and determines the light transmissivity of each area of the light-shielding layer.

Next, the light-shielding layer is formed in consideration of the thickness of the light-shielding layer, the material of the light-shielding layer, the shape of the light-shielding pattern of the light-shielding layer, etc., in accordance with the determined light transmittance.

5A and 5B are a plan view and a cross-sectional view showing a light transmittance according to a single-layer light-shielding layer, and FIGS. 6A and 6B are views showing light transmittance according to the thickness of the light- 7a and 7b are a plan view and a cross-sectional view showing a light transmittance according to a three-layered light-shielding layer, respectively.

As shown in FIGS. 5A and 5B, the light-shielding layer 250a of the one-layer structure has the highest light transmittance in the region closest to the light source 220, but as shown in FIGS. 6A and 6B, As shown in FIGS. 7A and 7B, the light-shielding layers 250a and 250b of the two-layer structure have a three-layer structure It can be seen that the light transmittance of the light shielding layers 250a, 250b and 250c is lower in the same region.

As described above, since the light transmittance varies depending on the thickness of the light shielding layer, an effective light transmittance distribution can be obtained by forming the light shielding pattern through adjustment of the thickness of the light shielding layer.

The light shielding layer requires a low light transmittance in the region near the light source and at the same time the color change rate of the transmitted light must be minimized while the region far from the light source requires a relatively high light transmittance.

In order to realize a light-shielding layer having such a light transmittance distribution, not only light-shielding pattern formation of a predetermined shape but also thickness adjustment of the light-shielding layer is an important factor.

Therefore, when fabricating the light shielding layer, the light transmittance can be adjusted by using the shape of the light shielding pattern as well as the thickness of the light shielding layer.

Here, each layer constituting the light-shielding layer may be made of a different material.

8, if the area between the light source 220 and the light source 220 is divided into ten areas as shown in FIG. 8, the light transmittance of the light shielding layer The region may be formed with light-shielding patterns of a predetermined shape according to the determined light transmittance.

If one of the 10 regions is called a pattern cell, the pattern cell will have an area of A.

The pattern cell of area A may be an _open area A _open with a hole formed therein and may be a pattern area A _patterned with a light shielding pattern.

Therefore, if the pattern cell of area A has no light shielding pattern, the light transmittance of the area is the total area (A _cell ) of the opening area (A _open ) / A of T (x) = A.

The pattern area A of the area A may be formed with an aperture area A _open with no light shielding pattern and a pattern area A _pattern with a light shielding pattern.

Here, the pattern area (A _pattern ) where the light-shielding pattern is formed may be located at the center or the edge of the area A.

When the pattern transmittance of the pattern area (A _pattern ) where the light-shielding pattern is formed is T _pattern , the light transmittance of the pattern cell of the area A having the light-shielding pattern is expressed by the total of the _open area (A _open ) / A (A _cell ) + {(A _closed area * pattern transmittance (T _pattern )) / total area of A (A _cell )}.

Accordingly, when forming a light shielding pattern in the light shielding layer, the light transmittance can be adjusted by using the above-described formula.

That is, when fabricating the light shielding pattern of the light shielding layer, the light transmittance setting procedure of the light shielding layer is as follows.

First, since the light transmittance according to each region of the light shielding layer is set in advance, the light transmittance of the region where the light shielding pattern is to be formed is searched and confirmed.

Then, the pattern area and the opening area of the area are determined by using the above formula according to a preset light transmittance.

Next, a light shielding pattern is formed on the light shielding layer according to the determined pattern area and opening area.

As described above, according to the present invention, the light transmittance of the light shielding layer is determined according to the design conditions of the backlight such as the light source, and the light shielding pattern of the light shielding layer is formed on the basis of the determined light transmittance, At the same time, a backlight unit having a light-shielding pattern capable of minimizing the color change of transmitted light can be manufactured.

9A and 9B are views showing a light-shielding layer having a light-shielding pattern. FIG. 9A is a view showing a light-shielding layer of a three-layer structure having a light-shielding pattern in the form of a hole, Shielding layer having a single-layer structure having a light-shielding pattern.

9A, the light-shielding layer having the hole-shaped light-shielding pattern has a structure in which the first light-shielding layer 250a, the second light-shielding layer 250b, and the third light-shielding layer 250c are laminated, Layer structure in which the first light-shielding layer 250a and the second light-shielding layer 250b are laminated. In some cases, the first light-shielding layer 250a and the second light-shielding layer 250b may be formed as a single layer only of the first light-shielding layer 250a.

In the three-layered light-shielding layer, the first light-shielding layer 250a is composed of a first region having no first light-shielding pattern and a second region adjacent to an outer boundary surface of the first region and having a first light-

The second light-shielding layer 250b is formed on the first region of the first light-shielding layer 250a and has a third region without the second light-shielding pattern and a third region adjacent to the outer boundary surface of the third region, As shown in FIG.

Then, the third light-shielding layer 250c may be formed on the third region of the second layer 250b and may include a fifth region having the third light-shielding pattern.

Here, the light source may be positioned to correspond to the fifth region of the third blocking layer 250c, the light-shielding layer of the region closest to the light source may have the thickest three-layer structure, and the light- It can be made of a thin one-layer structure.

9B is a view showing a light-shielding layer of a one-layer structure having a light-shielding pattern in the form of a groove, wherein the light-shielding layer is composed of a single layer and the thickness of the light- It may be formed so as to gradually become thinner.

9B is a method of forming a shielding pattern by transferring a pattern of the mold 800 to the light shielding layer 250 by using a mold 800 having a predetermined pattern.

In this case, a region close to the light source is thick, a groove-shaped light-shielding pattern is formed, a region far from the light source is thin, and a light-shielding pattern of a groove or a hole shape can be formed.

10A to 10C are views showing a backlight unit having a light-shielding layer according to the first embodiment of the present invention. FIG. 10A is a view showing a light-shielding layer of a single-layer structure having a light- FIG. 10C is a view showing a backlight unit to which a light-shielding layer having a light-shielding pattern with a different thickness is applied. FIG.

As shown in FIG. 10A, the single-layer light-shielding layer 250 may have different thicknesses depending on the light transmittance of each region.

That is, in the entire region of the light-shielding layer 250, the region corresponding to the light transmittance is formed to have the thickest thickness d1 so as to block the light most in the region through which the brightest light is transmitted, The thickness of the light-transmissive region is set to the thickness d3 corresponding to the light transmittance so that the light can be blocked at a minimum.

In addition, as shown in FIG. 10B, the light-shielding layer 250 of a multilayer structure in which a plurality of layers are stacked may be formed by laminating one or more layers depending on the light transmittance of each region.

That is, in the entire region of the light-shielding layer 250, the first, second, and third light-shielding layers 250a and 250b are formed to have the thickness corresponding to the corresponding light transmittance, , 250b, and 250c may be laminated on the first light-shielding layer 250a, and only the first light-shielding layer 250a may be formed to have a thickness corresponding to the corresponding light transmittance so that light can be least blocked in the least light-transmitting region.

The multi-layer structure of FIG. 10B may have the advantage of finer adjustment of the light transmittance than the single layer structure, since the material of each layer can be used differently and the thickness of each layer can be used differently.

The thickness of the light shielding layer 250 is thick in the region closest to the light source 220 and the thickness of the light shielding layer 250 in the region farther from the light source 220 is thin, Can be uniformly adjusted.

In some cases, the first embodiment of the present invention may form an opening region such as a hole or a groove in the light shielding layer 250.

Here, the width of the opening region may become gradually larger or may be the same as the distance from the light source.

11A and 11B are views showing holes or grooves formed in the light-shielding layer of the first embodiment of the present invention. As shown in FIGS. 11A and 11B, the depth of holes or grooves formed in the third light- The thicknesses of the first and second light-shielding layers 250a and 250b may be the same as the thickness of the third light-shielding layer 250c or the thicknesses of the second and third light-shielding layers 250b and 250c, , 250b, and 250c may be the same as the sum of the thicknesses.

The depth of the hole or groove formed in the second light shielding layer 250b is equal to the thickness of the second light shielding layer 250b or the thickness value of the first and second light shielding layers 250a and 250b . ≪ / RTI >

The depth of the holes or grooves formed in the first light-shielding layer 250a may be equal to or less than the thickness of the first light-shielding layer 250a.

12 shows a backlight unit having a light-shielding layer according to a second embodiment of the present invention. FIG. 12 shows a light-shielding pattern of the light-shielding layer 250 in an island shape.

As shown in Fig. 12, the light-shielding layer 250 of the second embodiment of the present invention has a shape in which the slopes of both sides are different from each other.

The thickness of the light shielding layer 250 is thick and the slope of the light shielding layer 250 is thinner than that of the light source 220, The light transmittance can be uniformly adjusted.

In some cases, the second embodiment of the present invention may form an opening region such as a hole or a groove in the light shielding layer 250.

Here, the width of the opening region may become gradually larger or may be the same as the distance from the light source.

FIGS. 13A and 13B are views showing holes or grooves formed in the light-shielding layer according to the second embodiment of the present invention. As shown in FIGS. 13A and 13B, the depths of holes or grooves may vary depending on the thickness of the light- .

14A to 14C are diagrams showing a backlight unit having a light-shielding layer according to the third embodiment of the present invention. FIG. 14A is a view showing a light-shielding layer having a different width of a hole width and a light- FIG. 14C is a view showing a backlight unit to which a light shielding layer having a hole width and a light shielding pattern width different from each other is applied.

14A to 14C, the third embodiment differs from the light source 220 in that the hole width w1 and the light-shielding pattern width w2 formed in the light-shielding layer 250 vary with distance from the light source 220 .

That is, the hole width w1 of the light shielding layer 250 gradually increases as the distance from the light source 220 increases, and the light shielding pattern width w2 of the light shielding layer 250 gradually decreases as the distance from the light source 220 increases.

In some cases, the light-shielding layer 250 may be a single layer in the third embodiment of the present invention, but it may be composed of a plurality of layers in which at least two layers are stacked.

15A to 15C are views showing a backlight unit having a light-shielding layer according to a fourth embodiment of the present invention, wherein FIG. 15A is a view showing a light-shielding layer having a constant light-shielding pattern width and a different hole width, FIG. 15C is a view showing a backlight unit to which a light-shielding layer having a constant light-shielding pattern width and a different hole width is applied. FIG.

15A to 15C, the hole width w1 formed in the light shielding layer 250 is changed as the distance from the light source 220 is increased, and the light shielding pattern width w2 is It is always constant.

That is, the hole width w1 of the light shielding layer 250 gradually increases as the distance from the light source 220 increases, and the light shielding pattern width w2 of the light shielding layer 250 is always constant even when it is away from the light source 220.

In some cases, the light-shielding layer 250 may be a single layer in the fourth embodiment of the present invention, but may be formed of a plurality of layers in which at least two layers are stacked.

16A is a view showing a backlight unit having a light-shielding layer according to a fifth embodiment of the present invention, FIG. 16A is a view showing a light-shielding layer having a constant hole width and a different light-shielding pattern width, FIG. 16C is a view showing a backlight unit to which a light-shielding layer having a constant hole width and a different light-shielding pattern width is applied. FIG.

16A to 16C, the light-shielding pattern width w2 formed in the light-shielding layer 250 is changed as the distance from the light source 220 is increased, and the hole width w1 is It is always constant.

That is, the light shielding pattern width w2 of the light shielding layer 250 gradually decreases as the light shielding layer 250 moves away from the light source 220, and the hole width w1 of the light shielding layer 250 is always constant even when it is away from the light source 220.

In some cases, the light-shielding layer 250 may be a single layer in the fifth embodiment of the present invention, but may be formed of a plurality of layers in which at least two layers are stacked.

17A and 17B are views showing a backlight unit having a light-shielding layer according to a sixth embodiment of the present invention. FIG. 17A is a view showing reflection characteristics of light reflected at the upper and lower portions of the light- And a backlight unit to which a light-shielding layer having different reflection characteristics of light with respect to the lower portion is applied.

As shown in FIGS. 17A and 17B, the light-shielding layer of the sixth embodiment of the present invention may further include a reflective film 400 on the light-shielding layer 250.

Here, the reflective film 400 is made of a material capable of irregularly reflecting incident light. For example, a white ink thin film may be used.

That is, the light-shielding layer 250 of FIG. 17A is composed of a metal thin film layer having a high reflectance and regularly reflects incident light, and the reflective film 400 formed on the light-shielding layer 250 can irregularly reflect incident light.

17B, the light emitted from the light source 220 is transmitted through the hole of the light shielding layer 250, and the light emitted from the light shielding layer 250 is transmitted through the light shielding layer 250. As described above, when the light shielding layer 250 formed with the reflective film 400 is applied to the backlight unit, Is reflected by the optical sheet 500 positioned in the reflective film 400 and is incident on the reflective film 400.

The light incident on the reflective film 400 is irregularly reflected by the reflective film 400 and can be uniformly propagated.

Therefore, the light shielding layer 250 formed with the reflective film 400 forms a point light source with a uniform planar light source, which is somewhat more advantageous than the light shielding layer 250 without the reflective film 400.

As described above, the light-shielding layer having various structures can also be manufactured by various manufacturing methods.

18A to 18C are process cross-sectional views illustrating a method of manufacturing a light-shielding layer according to the first embodiment of the present invention.

18A, a light shielding layer 250 is formed on a substrate 700, and a mask layer 600 is formed on the light shielding layer 250. Referring to FIG.

The light shielding layer 250 may be a metal layer and the mask layer 600 may be made of a material that does not react with an etchant of the light shielding layer 250. For example, If it is a metal, the mask layer 600 may be a white ink composed of organic and inorganic particles.

Then, a part of the light shielding layer 250 is exposed by patterning in accordance with a light shielding pattern to be formed on the mask layer 600.

18B, the exposed light shielding layer 250 is etched and removed using the patterned mask layer 600 as a mask.

Next, as shown in FIG. 18C, the remaining mask layer 600 may be removed to form the light-shielding layer 250 having a light-shielding pattern.

In some cases, the mask layer 600 may be left without being removed by not performing the process of Fig. 18C.

The reason for this is that when the mask layer 600 is made of a reflective film such as white ink and the mask layer 600 is left intact, the light incident on the mask layer 600 is diffusely reflected as in the sixth embodiment of the present invention Because it can serve as a reflective film.

As described above, the light-shielding layer manufacturing method of the first embodiment of the present invention is a method using a chemical etching process combined with a photoresist process.

19A to 19C are process sectional views showing a method of manufacturing a light-shielding layer according to a second embodiment of the present invention.

The second embodiment of the present invention is a method of patterning using a pulsed laser. The basic mechanism is that a light absorbing material absorbs a pulse laser, instantaneous thermal expansion occurs, and the light absorbing material is released from the substrate by rapid thermal expansion .

This process is a direct photoetching process that does not require a photoresist process and a chemical etch process. There must be sufficient interaction between the laser beam and the light absorbing material, and the phenomenon also occurs in a short time. .

19A, a light-shielding layer 250 and a mask layer 600 are sequentially formed on a transparent substrate 700, and a light-shielding layer 250 and a mask layer 600 are sequentially formed on the light- Patterning is performed to expose a part of the light shielding layer 250 according to the pattern.

Then, as shown in Fig. 19B, a pulse laser is irradiated toward the opposite surface of the transparent substrate 700 on which the light shielding layer 250 is formed.

Here, the light shielding layer 250 is made of a light absorbing material that absorbs the laser, and the laser transmitted through the transparent substrate 700 is absorbed by the light shielding layer 250.

The light shielding layer 250 instantaneously causes thermal expansion, and a relatively thin region, that is, a region exposed from the mask layer 600, is separated from the substrate 700. [

Next, as shown in FIG. 19C, the remaining mask layer 600 may be removed to form the light shielding layer 250 having a light shielding pattern.

In some cases, the mask layer 600 may be left without being removed by not performing the process of Fig. 19C.

The reason for this is that when the mask layer 600 is made of a reflective film such as white ink and the mask layer 600 is left intact, the light incident on the mask layer 600 is diffusely reflected as in the sixth embodiment of the present invention Because it can serve as a reflective film.

As described above, the light-shielding layer manufacturing method of the second embodiment of the present invention is a method using a physical etching process combined with a photoresist process and a pulse laser patterning process.

20A to 20C are process sectional views showing a method of manufacturing a light-shielding layer according to a third embodiment of the present invention.

20A, a light shielding layer 250 is formed on a transparent substrate 700 and a light shielding layer 250 is formed on the opposite side of the transparent substrate 700 on which the light shielding layer 250 is formed. (600).

Then, a part of the light shielding layer 250 is exposed by patterning in accordance with a light shielding pattern to be formed on the mask layer 600.

20B, using the mask layer 600 as a mask, a pulse laser is irradiated to the transparent substrate 700 having the mask layer 600 formed thereon.

Here, the light shielding layer 250 is made of a light absorbing material that absorbs the laser, and the laser transmitted through the transparent substrate 700 is absorbed by the light shielding layer 250.

A part of the light-shielding layer 250 in which the laser is absorbed instantaneously causes thermal expansion, and is separated from the substrate 700.

Next, as shown in FIG. 20C, the remaining mask layer 600 may be removed to form the light-shielding layer 250 having a light-shielding pattern.

In some cases, the mask layer 600 may be left without being removed by not performing the process of Fig. 20C.

As described above, the light-shielding layer manufacturing method of the third embodiment of the present invention is a method using a physical etching process combined with a photoresist process and a pulse laser patterning process.

21 is a view showing a display module having a backlight unit of the present invention.

As shown in FIG. 21, the display module 20 may include a display panel 100 and a backlight unit 200.

The display panel 100 includes a color filter substrate 110 and a TFT (Thin Film Transistor) substrate 120 bonded to each other so as to maintain a uniform cell gap, and between the two substrates 110 and 120 A liquid crystal layer (not shown) may be interposed.

The color filter substrate 110 includes a plurality of pixels composed of red (R), green (G), and blue (B) subpixels and generates an image corresponding to red, green, .

The pixels may be composed of red, green, and blue subpixels, but the red, green, blue, and white (W) subpixels constitute one pixel.

The TFT substrate 120 can switch pixel electrodes (not shown) as elements having switching elements formed thereon.

For example, the common electrode (not shown) and the pixel electrode can change the arrangement of molecules in the liquid crystal layer according to a predetermined voltage applied from outside.

The liquid crystal layer is composed of a plurality of liquid crystal molecules, and the liquid crystal molecules change their arrangement in accordance with the voltage difference generated between the pixel electrode and the common electrode.

Thus, the light provided from the backlight unit 200 can be incident on the color filter substrate 110 in accordance with the change in the molecular arrangement of the liquid crystal layer.

The upper polarizer 130 and the lower polarizer 140 may be disposed on the upper and lower sides of the display panel 100. More specifically, the upper polarizer 130 may be disposed on the upper surface of the color filter substrate 110 And the lower polarizer 140 may be disposed on the lower surface of the TFT substrate 120.

Although not shown, a gate and a data driver for generating a driving signal for driving the panel 100 may be provided on a side surface of the display panel 100.

As shown in FIG. 21, the display module according to an embodiment of the present invention can be configured by placing a backlight unit 200 in close contact with the display panel 100.

For example, the backlight unit 200 may be adhered and fixed to the lower surface of the display panel 100, more specifically, to the lower polarizer 140, and the lower polarizer 140 and the backlight unit 200 An adhesive layer (not shown) may be formed.

As described above, by forming the backlight unit 200 in close contact with the display panel 100, it is possible to improve the appearance by reducing the overall thickness of the display device, and the additional structure for fixing the backlight unit 200 can be removed So that the structure and manufacturing process of the display device can be simplified.

Also, by removing the space between the backlight unit 200 and the display panel 100, it is possible to prevent a malfunction of the display device or deterioration of the display quality of the display image due to the penetration of foreign matter into the space.

The backlight unit 200 according to an exemplary embodiment of the present invention may be configured as a stack of a plurality of functional layers, and at least one layer of the plurality of functional layers may include a plurality of light sources (not shown) have.

The plurality of functional layers constituting the backlight unit 200, more specifically, the backlight unit 200, are each flexible so that the backlight unit 200 is closely attached to the lower surface of the display panel 100 and fixed. ). ≪ / RTI >

The display panel 100 according to an exemplary embodiment of the present invention may be divided into a plurality of regions and may be divided into a plurality of regions corresponding to a gray peak value or a color coordinate signal of each of the divided regions from a corresponding region of the backlight unit 200 The brightness of the emitted light, that is, the brightness of the corresponding light source is adjusted, so that the brightness of the display panel 100 can be adjusted.

To this end, the backlight unit 200 may be divided into a plurality of divided driving regions corresponding to the respective divided regions of the display panel 100 and operated.

22 and 23 are views showing a display device according to an embodiment of the present invention.

22, a display device 1 according to an embodiment of the present invention includes a display module 20, a front cover 30 and a back cover 35 surrounding the display module 20, a back cover 35 And a driving unit cover 40 that surrounds 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.

Further, the front cover 30 can be made of a flat plate without the window 30a.

In this case, the front cover 30 is made of a transparent material that transmits light, for example, an injection-molded plastic.

Thus, if the front cover 30 is formed as a flat plate, the frame can be removed from the front cover 30. [

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.

23, 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.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (19)

A first layer;
A plurality of light sources emitting light and arranged on the first layer;
A second layer covering the plurality of light sources; And
And a light-shielding layer disposed on the second layer at a portion corresponding to the light source,
The light-
A first light shielding layer composed of a first region having no first light blocking pattern and a second region adjacent to an outer boundary surface of the first region and having a first light blocking pattern; And
A second light-shielding layer formed on the first region of the first light-shielding layer and including a third region having no second light-shielding pattern and a fourth region adjacent to an outer boundary surface of the third region and having a second light- Layer. ≪ Desc / Clms Page number 13 > The backlight unit according to claim 1, wherein the light transmittance of the light-shielding layer is determined by the following equation.
Light transmittance _{T (x) = I 0 *} e -a (Lx) n
(Where I ₀ is the light intensity of the light source, L is the distance between adjacent light sources, x is the distance from the light emitting surface of the light source to the light transmittance measuring area, and a and n are the coefficients) delete The method according to claim 1,
Wherein the light-shielding layer is held in contact with the second layer or is spaced apart from the second layer by a certain space. 5. The method of claim 4,
And a buffer layer is formed between the second layer and the light-shielding layer. The method according to claim 1,
Wherein a reflective film for reflecting the incident light is formed on the light blocking layer. The method according to claim 1,
Wherein the light-shielding layer has a thickness that decreases as the distance from the light source increases. 8. The method of claim 7,
Wherein the light-shielding layer includes at least one of a plurality of holes and grooves,
Wherein a distance between the adjacent holes or between the adjacent holes or between the adjacent holes and the groove is gradually narrowed as the distance from the light source is at least one of the hole and the groove. 8. The method of claim 7,
Wherein the light-shielding layer includes at least one of a plurality of holes and grooves,
Wherein the width of the hole or groove is larger or constant as the distance from the light source increases. delete The method according to claim 1,
Wherein the light-shielding layer includes a plurality of holes,
As the distance from the light source increases, the width between the adjacent holes decreases and the width of the hole increases, or the distance from the light source increases, the width between the adjacent holes becomes constant and the width of the hole increases, or Wherein a distance between the adjacent holes decreases and a width of the hole is constant as the distance from the light source increases. The method according to claim 1,
Wherein the light-shielding layer is made of at least one of metal, TiO2, CaCO3, and ZnO. delete delete The method according to claim 1,
A third light-shielding portion formed on the third region of the second light-shielding layer and including a fifth region having no third light-shielding pattern and a sixth region adjacent to the outer boundary surface of the fifth region and having the third light- Wherein the backlight unit further comprises a layer. 16. The method of claim 15,
And the light source is positioned to correspond to the fifth region of the third light shielding layer. The method according to claim 1,
Wherein each layer of the light-shielding layer is made of a different material or has a different thickness. delete delete

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