KR101718486B1 - Back Light Unit and Display Apparatus - Google Patents

Abstract

The present invention relates to a backlight unit and a display device.
A backlight unit according to the present invention includes a substrate, a light source disposed on the substrate, and a resin layer disposed on the substrate on which the light source is disposed, wherein the resin layer may include a depression recessed toward the substrate have.

Description

BACKLIGHT UNIT AND DISPLAY APPARATUS Technical Field [1]

The present invention relates to a backlight unit and a display device.

(PDP), Electro Luminescent Display (ELD), Vacuum Fluorescent Display (VFD), and the like have been developed in recent years in response to the demand for display devices. Display) have been studied and used. Among them, a liquid crystal panel of an LCD includes a TFT substrate and a color filter substrate which are opposed to each other with a liquid crystal layer and a liquid crystal layer interposed therebetween, and an image can be displayed using light provided from the backlight unit.

An object of the present invention is to provide a backlight unit and a display device that improve optical characteristics while improving structural stability.

A backlight unit according to the present invention includes a substrate, a light source disposed on the substrate, and a resin layer disposed on the substrate on which the light source is disposed, wherein the resin layer may include a depression recessed toward the substrate have.

In addition, the light source may include a light emitting diode.

In addition, the light source may be oriented in a direction in which the light emitting surface is perpendicular to the substrate.

In addition, the light source may face the light emitting surface in a direction parallel to the substrate.

In addition, the depression may be disposed between two adjacent light sources.

In addition, the minimum thickness of the resin layer in the depression may be thicker than the thickness of the resin layer in a position corresponding to the light source.

A reflective layer may be disposed between the resin layer and the substrate.

The minimum thickness of the resin layer in the depression may be greater than the height of the light source from the reflective layer.

In addition, the minimum thickness of the resin layer in the depression may be smaller than the height of the light source from the reflective layer.

A diffusion plate may be disposed on the resin layer.

An optical sheet may be disposed on the diffusion plate.

An adhesive layer may be disposed between the resin layer and the diffusion plate.

In addition, the thickness of the adhesive layer at a position corresponding to the depression may be thicker than the thickness of the adhesive layer at a position corresponding to the light source.

In addition, the adhesive layer may not be formed between the light source and the diffusion plate.

Further, an air layer may be formed between the diffusion plate and the depressed portion.

Another backlight unit according to the present invention includes a substrate, a light source disposed on the substrate, and a resin layer disposed on the substrate on which the light source is disposed, wherein the light source includes a first light source, And a third light source disposed adjacent to the second light source, wherein an interval between the first light source and the second light source is different from an interval between the second light source and the third light source , The minimum thickness of the resin layer between the first light source and the second light source may be different from the minimum thickness of the resin layer between the second light source and the third light source.

The distance between the first light source and the second light source is larger than the distance between the second light source and the third light source, and the minimum thickness of the resin layer between the first light source and the second light source And may be smaller than the minimum thickness of the resin layer between the two light sources and the third light source.

In addition, the light emitting surface of the first light source and the light emitting surface of the second light source are oriented in the same direction, and the light emitting surface of the second light source and the light emitting surface of the third light source may be directed in different directions.

The first light source and the second light source are disposed adjacent to each other in the direction parallel to the short side of the substrate, and the second light source and the third light source are disposed adjacent to each other in the direction crossing the short side of the substrate .

Further, the light emitting surfaces of the first, second, and third light sources may be oriented in a direction parallel to the substrate.

A display device according to the present invention includes a display panel and a backlight unit attached to the back surface of the display panel, wherein the backlight unit includes a substrate, a light source disposed on the substrate, and a resin layer And the resin layer may include a depression recessed in a direction toward the substrate.

Another display device according to the present invention includes a display panel and a backlight unit attached to a back surface of the display panel, wherein the backlight unit is disposed on a substrate, a light source disposed on the substrate, and a substrate on which the light source is disposed Wherein the light source includes a first light source, a second light source disposed adjacent to the first light source, and a third light source disposed adjacent to the second light source, wherein the first light source and the second light source, The distance between the second light sources is different from the distance between the second light source and the third light source and the minimum thickness of the resin layer between the first light source and the second light source is between the second light source and the third light source The minimum thickness of the resin layer may be different from the minimum thickness of the resin layer.

The backlight unit and the display device according to the present invention have the effect of improving the optical characteristics while improving the structural stability by forming depressions that are recessed toward the substrate in the resin layer formed on the substrate.

1 is an exploded perspective view showing a configuration of a display device;
2 is a schematic cross-sectional view of a display device according to an embodiment of the present invention;
3 is a cross-sectional view of the backlight unit;
4 is a cross-sectional view of another configuration of the backlight unit;
FIGS. 5 to 8 are diagrams for explaining the direct-type method; FIG.
9 to 18 are views for explaining the resin layer in more detail;
FIGS. 19 to 24 are views for explaining the case of including a diffusion plate; FIG. And
25 to 27 are views for explaining another example of the depressed portion.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood that the present invention is not intended to be limited to the specific embodiments but includes all changes, equivalents, and alternatives falling within the spirit and scope of the present invention.

In describing the present invention, the terms first, second, etc. may be used to describe various components, but the components may not be limited by the terms. The terms may only be used for the purpose of distinguishing one element from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The term " and / or " may include any combination of a plurality of related listed items or any of a plurality of related listed items.

When an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may be present in between Can be understood. On the other hand, when it is mentioned that an element is "directly connected" or "directly connected" to another element, it can be understood that no other element exists in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions may include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used interchangeably to designate one or more of the features, numbers, steps, operations, elements, components, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries can be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are, unless expressly defined in the present application, interpreted in an ideal or overly formal sense .

In addition, the following embodiments are provided to explain more fully to the average person skilled in the art. The shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

FIG. 1 is an exploded perspective view of the configuration of a display device. FIG.

1, the display device 1 may include a front cover 30, a rear cover 40, and a display module 20 disposed between the front cover 30 and the back cover 40 .

The front cover 30 may be disposed to surround the display module 20 and may include a front panel (not shown) of a substantially transparent material capable of transmitting light. Here, the front panel may be disposed on the front surface of the display module 20 at regular intervals to protect the display module 20 from an external impact.

2 is a cross-sectional view of a display device according to an embodiment of the present invention.

2, the display module 20 included in the display device may include a display panel 100 and a backlight unit 200. Referring to FIG.

The display panel 100 may include a color filter substrate 110 and a TFT (Thin Film Transistor) substrate 120 so as to be opposed to each other to maintain a uniform cell gap. In addition, a liquid crystal layer (not shown) may be disposed between the color filter substrate 110 and the TFT substrate 120.

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, and the present invention is not limited thereto.

The TFT substrate 120 can switch a pixel electrode (not shown) as a switching element.

The liquid crystal layer is made up of a plurality of liquid crystal molecules, and the liquid crystal molecules can change the arrangement in accordance with a voltage difference generated between a pixel electrode and a common electrode (not shown) The light can be incident on the color filter substrate 110 in accordance with the change in 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 and more specifically the upper polarizer 130 may be formed on the upper surface of the color filter substrate 110 And a lower flat plate 140 may be formed on the lower surface of the TFT substrate 120.

A gate and a data driver (not shown) may be provided on a side surface of the display panel 100 to generate a driving signal for driving the panel 100.

The structure and configuration of the display panel 100 are merely examples, and modifications, additions, and deletions of the embodiments are possible within the scope of the present invention.

2, the display device according to the embodiment of the present invention can be configured by closely attaching the backlight unit 200 to the display panel 100. For example, the backlight unit 200 may be attached to and fixed to the lower surface of the display panel 100, more specifically, to the lower polarizer 140. For this purpose, the backlight unit 200 may be fixed between the lower polarizer 140 and the backlight unit 200 An adhesive layer (not shown) may be formed.

By forming the backlight unit 200 in close contact with the display panel 100 as described above, the overall thickness of the display device can be reduced to improve the appearance, and the structure for fixing the backlight unit 200 can be removed, And the manufacturing process can be simplified. In addition, by reducing the space between the backlight unit 200 and the display panel 100, it is possible to prevent a malfunction of the display device due to the insertion of foreign substances into the space or deterioration of the image quality of the display image.

According to an exemplary embodiment of the present invention, the backlight unit 200 may include a plurality of functional layers stacked, and at least one of the plurality of functional layers may include a plurality of light sources (not shown) .

The backlight unit 200 and more specifically the plurality of layers constituting the backlight unit 200 may be disposed on the lower surface of the display panel 100 so that the backlight unit 200 is in contact with the lower surface of the display panel 100. [ It is preferable that they are made of a material having flexibility.

A bottom cover (not shown) on which the backlight unit 200 is mounted may be provided on the lower side of the backlight unit 200.

According to an embodiment of the present invention, the display panel 100 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 light source is adjusted, so that the brightness of the display panel 100 can be adjusted.

For this purpose, 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.

3 is a view showing a cross section of the backlight unit.

Referring to FIG. 3, the backlight unit 200 may include a substrate 210, a light source 220, a resin layer 230, and a reflective layer 240.

The plurality of light sources 220 may be formed on the substrate 210 and the resin layer 230 may be formed on the substrate 210 to surround the plurality of light sources 220.

An electrode pattern (not shown) for connecting the connector (not shown) and the light source 220 (not shown) may be formed on the substrate 210. For example, a carbon nanotube electrode pattern (not shown) for connecting the light source 220 and the connector may be formed on the upper surface of the substrate 210. The connector may be electrically connected to a power supply unit (not shown) that supplies power to the light source 220.

The substrate 210 may be a printed circuit board (PCB) including a material such as polyethylene terephthalate, glass, polycarbonate, and silicone. In addition, the substrate 210 may be a film substrate.

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 the present embodiment, a light emitting diode package is provided as the light source 220. FIG.

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. Also, 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 changed within the technical scope of the embodiment.

The resin layer 230 disposed on the upper side of the substrate 210 transmits and diffuses the light emitted from the light source 220 to uniformly transmit light emitted from the light source 220 to the display panel 100 . In addition, depressions may be formed in the resin layer 230 to be recessed toward the substrate 210. This will be described in detail with reference to FIG. 9, and depressions are not shown in FIGS. 4 to 8 for convenience of explanation.

A reflective layer 240 may be formed between the substrate 210 and the resin layer 230 or more specifically on the upper surface of the substrate 210 to reflect light emitted from the light source 220.

The reflective layer 240 may reflect the light totally reflected from the boundary of the resin layer 230 to diffuse the light emitted from the light source 220 more widely.

The reflective layer 240 may be formed by dispersing a white pigment such as titanium oxide in a synthetic resin sheet, a metal vapor-deposited film on a surface thereof, or a sheet made of a synthetic resin in which bubbles are dispersed in order to scatter light. , And silver (Ag) may be coated on the surface to increase the reflectance. Alternatively, the reflective layer 240 may be coated on the upper surface of the substrate 210.

The resin layer 230 may be composed of various resins having light transmittance. For example, the resin layer 230 may include any one material selected from the group consisting of polyethylene terephthalate, polycarbonate, polypropylene, polyethylene, polystyrene, and polyepoxy, silicone, acrylic, or at least two materials. Do.

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

The resin 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 resin layer 230 may be formed by applying a liquid or gel resin to the upper surface of the substrate 210 on which the plurality of light sources 220 and the reflective layer 240 are formed and then curing the resin, And may be separately formed and bonded to the upper surface of the substrate 210.

As the thickness a of the resin layer 230 increases, the light emitted from the light source 200 spreads more widely, and light of uniform luminance from the backlight unit 200 can be provided to the display panel 100. On the other hand, as the thickness a of the second layer 230 increases, the amount of light absorbed in the second layer 230 may increase, and thus the amount of light absorbed by the backlight unit 200, which is provided to the display panel 100 The brightness of the light can be reduced as a whole.

The thickness a of the resin layer 230 is 0.1 to 4.5 mm so as to provide uniform brightness without reducing the brightness of the light provided to the display panel 100 from the backlight unit 200 desirable.

4 is a cross-sectional view of another configuration of the backlight unit. Hereinafter, the description of the parts described in detail in FIG. 3 will be omitted.

4, a plurality of light sources 220 may be mounted on a substrate 210, and a resin layer 230 may be disposed on a substrate 210. Referring to FIG. Meanwhile, a reflective layer 240 may be formed between the substrate 210 and the resin layer 230.

The resin layer 230 may include a plurality of scattering particles 231. The scattering particles 231 scatter or refract incident light so that the light emitted from the light source 220 is diffused more widely. can do.

The scattering particles 231 are formed of a material having a refractive index different from that of the material constituting the resin layer 230 in order to scatter or refract light emitted from the light source 220, Or a material having a refractive index higher than that of the acrylic resin.

For example, the scattering particles 231 may be selected from the group consisting of polymethylmethacrylate / styrene copolymer (MS), polymethylmethacrylate (PMMA), polystyrene (PS), silicon, titanium dioxide (TiO2) ), And the like, and may be formed by combining the above materials.

The scattering particles 231 may be formed of a material having a refractive index lower than that of the material of the resin layer 230. For example, the scattering particles 231 may be formed by forming bubbles in the resin layer 230 .

In addition, the material constituting the scattering particles 231 is not limited to the above-described materials, and may be formed using various polymer materials or inorganic particles.

The resin layer 230 may be formed by mixing scattering particles 231 with a liquid or gel resin and then irradiating the substrate 210 on which the plurality of light sources 220 and the reflective layer 240 are formed ), And then curing it.

4, an optical sheet 250 may be disposed on the upper side of the resin layer 230. For example, the optical sheet 250 may include a prism sheet 251 and a diffusion sheet 252 . In this case, the plurality of sheets included in the optical sheet 250 are provided without being spaced apart from each other and adhered or adhered to each other, so that the thickness of the optical sheet 250 or the backlight unit 200 can be minimized.

The lower surface of the optical sheet 250 is in close contact with the resin layer 230 so that the upper surface of the optical sheet 250 is in contact with the lower surface of the display panel 100 and more specifically the lower polarizer 140 .

The diffusion sheet 252 diffuses the incident light to prevent the light from the resin layer 230 from being partially concentrated, thereby uniformizing the brightness of the light. The prism sheet 251 condenses the light emitted from the diffusion sheet 252 and allows light to be vertically incident on the display panel 100.

According to another embodiment of the present invention, at least one of the optical sheet 250 as described above, e.g., the prism sheet 251 and the diffusion sheet 252, may be removed, or the prism sheet 251 and / And may further include various functional layers other than the diffusion sheet 252. [

The LED package constituting the light source 220 in the direct-down type may be divided into a top view mode and a side view mode depending on the direction in which the light emitting surface is directed. The following is a look at this.

5 to 8 are diagrams for explaining the direct-down method.

FIG. 5 shows a top view method in the direct-down method.

5, the plurality of light sources 220 provided in the backlight unit 200 are arranged such that the light-emitting surfaces thereof are disposed on the upper surface thereof and are arranged in a direction perpendicular to the substrate 210 or the reflective layer 240 Light can be emitted.

FIG. 6 shows a side view method of the direct down method.

6, each of the plurality of light sources 220 provided in the backlight unit 200 has a light emitting surface disposed on a side surface thereof to emit light in a lateral direction, that is, in a direction parallel to the substrate 210 or the reflective layer 240. [ can do. For example, the plurality of light sources 220 may be configured using a side-view LED package, thereby reducing the problem that the light source 220 is viewed as a hot spot on the screen , The thickness (a) of the resin layer 230 can be reduced to realize the slimming of the backlight unit 200 and further the display device.

Referring to FIG. 6, the backlight unit 200 may include a plurality of resin layers 230 and 235.

The light emitted to the side from the light source 220 may travel through the first resin layer 230 to the region where the adjacent light source 225 is disposed.

Some of the light transmitted through the first resin layer 230 may be emitted toward the upper side of the display panel 100. For this, the first resin layer 230 may include a plurality of scattering particles 231 as described with reference to FIG. 4 to scatter or refract the direction of the traveling light upward.

Also, some of the light emitted from the light source 220 may be incident on the reflective layer 240, and the light incident on the reflective layer 240 may be reflected and diffused upward.

On the other hand, a large amount of light can be emitted from a region adjacent to the light source 220 due to a strong scattering phenomenon near the light source 220 or light emitted in a direction close to the image side from the light source 220, Light of brightness can be observed. As shown in FIG. 7, the first light shielding pattern 260 may be formed on the first resin layer 230 to reduce the brightness of light emitted from the light source 220. Accordingly, light of uniform luminance can be emitted from the backlight unit 200. For example, the first light-shielding pattern 260 may be formed on the first resin layer 230 to correspond to a position where the plurality of light sources 220 are disposed, and a part of the light incident from the light source 220 may be It is possible to reduce the brightness of the light emitted upward by blocking the remaining part.

The first light-shielding pattern 260 may be made of titanium dioxide (TiO 2). In this case, a part of the light incident from the light source 220 may be reflected downward and partially transmitted.

According to an embodiment of the present invention, a second resin layer 235 may be disposed on the first resin layer 230. The second resin layer 235 may be formed of the same or different material as the first resin layer 230 and may be formed by diffusing light emitted upward from the first resin layer 230, The uniformity of light luminance can be improved.

The second resin layer 235 may be made of a material having the same refractive index as the material of the first resin layer 230, or may be made of a material having a different refractive index.

For example, when the second resin layer 235 is composed of a material having a refractive index higher than that of the first resin layer 230, the light emitted from the first resin layer 230 can be diffused more widely.

On the contrary, when the second resin layer 235 is made of a material having a refractive index lower than that of the first resin layer 230, light emitted from the first resin layer 230 is reflected by the lower surface of the second resin layer 235 The light emitted from the light source 220 can be more easily propagated along the first resin layer 230.

The first resin layer 230 and the second resin layer 235 may each include a plurality of scattering particles. In this case, the density of the scattering particles included in the second resin layer 235 may be different from that of the first resin layer 235. [ May be higher than the density of the scattering particles contained in the scattering particles 230. When scattering particles are included in the second resin layer 235 with a higher density, the light emitted upward from the first resin layer 230 can be diffused more widely, and the light emitted from the backlight unit 200, It is possible to make the luminance of the light emitted from the light source more uniform.

The second light shielding pattern 265 is formed on the second resin layer 235 and the light emitted from the second resin layer 235 can be uniformed as shown in FIG. For example, when light emitted upward from the second resin layer 235 is concentrated on a specific portion and observed at a high luminance on the screen, a portion of the upper surface of the second resin layer 235 corresponding to the specific portion The second light-shielding pattern 265 can be formed on the backlight unit 200, thereby reducing the brightness of the light in the specific portion, thereby making the brightness of the light emitted from the backlight unit 200 uniform.

The second light-shielding pattern 265 may be made of titanium dioxide (TiO2). In this case, part of the light emitted from the second resin layer 235 may be reflected downward in the second light-shielding pattern 265, .

8, a pattern may be formed on the reflective layer 240 to facilitate the light emitted from the light source 220 to travel to the adjacent light source 225.

The pattern formed on the upper surface of the reflective layer 240 may include a plurality of protrusions 241. The light incident on the plurality of protrusions 241 after being emitted from the light source 220 may be scattered in the traveling direction It can be refracted.

8, the density of the protrusions 241 formed on the reflection layer 240 may increase as the distance from the light source 220, that is, toward the adjacent light source 225 is increased. Accordingly, it is possible to prevent the brightness of the light emitted upward from the region remote from the light source 220, that is, the region near the adjacent light source 225, to be reduced, thereby reducing the brightness of the light provided from the backlight unit 200 And can be kept uniform.

The protrusions 241 may be formed of the same material as the reflection layer 240. In this case, the protrusions 241 may be formed by processing the upper surface of the reflection layer 240. [

Alternatively, the protrusions 241 may be formed of a material different from the reflective layer 240, and may be formed by printing a pattern as shown in FIG. 8 on the upper surface of the reflective layer 240.

The shape of the protruding portions 241 is not limited to that shown in Fig. 8, and various shapes such as a prism, for example, may be possible.

9 to 17 are views for explaining the resin layer in more detail. Hereinafter, the description of the parts described in detail above will be omitted. For example, the description of the reflection pattern, the shielding pattern, and the like is omitted.

9, the resin layer 230 disposed on the substrate 210 on which the plurality of light sources 220 are disposed may include a depression 900 depressed in a direction toward the substrate 210. Here, the depression 900 may be disposed between two adjacent light sources 220. That is, the resin layer 230 between the two light sources 220 can be recessed. In other words, both ends P1 and P2 of the depression 900 may be spaced apart from the adjacent light sources 220 by a predetermined distance.

The light source 220 may be a top-view type in which the light emitting surface is oriented in a direction perpendicular to the substrate 210, or a side-view type in which the light emitting surface is oriented in a direction parallel to the substrate 210. [ (Side-View) type may be possible.

When the depression 900 is formed in the resin layer 230, the adhesion force can be improved by increasing the contact area between the resin layer 230 and another layer such as an optical sheet (not shown). Thus, it is possible to improve the structural stability of the backlight unit.

When the depression 900 is formed in the resin layer 230, the contact area between the resin layer 230 and the other layer is increased, so that even if a relatively small amount of adhesive material is used, The adhesive strength can be sufficiently strong, and accordingly, the thickness of the backlight unit can be reduced.

On the other hand, in order to reduce the total thickness of the backlight unit, it may be desirable to make the thickness of the resin layer 230 sufficiently thin. On the other hand, in order to protect the light source 220 by an external impact or the like, the resin layer 230 may be formed on the light source 220.

In order to protect the light source 220 while reducing the total thickness of the backlight unit, the resin layer 230 is formed on the light source 220 and the resin layer 230 on the light source 220, It may be preferable to make the thickness t2 of the thin film layer thinner. The minimum thickness t1 of the resin layer 230 in the depressed portion 900 may be thicker than the thickness t2 of the resin layer 230 at the position corresponding to the light source 220. [

In the case where the light source 220 is a side view type, optical characteristics may be improved if the depression 900 is formed in the resin layer 230. This is illustrated in FIG.

10, when the depression 900 is formed in the resin layer 230, light emitted to the light source 220 at an angle of approximately? 1 with the substrate 210 is incident on the depression 900 at an angle of? Can reach. Here, the light reaching the depression 900 can be reflected by the depression 900. Here, the light reflected by the oblique depression 900 may be incident on the reflective layer 240 at a relatively large angle, and may be reflected by the reflective layer 240 again. The light reflected by the reflective layer 240 can reach the surface of the resin layer 230 at a relatively large angle and can pass through the resin layer 230. If the depression 900 is formed in the resin layer 230, the light loss can be reduced to improve the light efficiency. That is, it is possible to improve the optical characteristics.

The minimum thickness of the depression 900 formed in the resin layer 230 can be variously adjusted. 11, the minimum thickness t1 of the resin layer 230 in the recessed portion 900, that is, the minimum thickness t1 of the depressed portion 900, is determined by the light source 220 H1 " of " H1 "

In this case, the process of forming the depressed portion 900 may be easy. That is, in the manufacturing process, it may be preferable that the minimum thickness t1 of the depressed portion 900 is larger than the height H1 of the light source 220 measured from the reflection layer 240.

In addition, the minimum thickness of the depression 900 can be set in consideration of the light emitting surface of the light source 220.

Referring to FIG. 12 (a), the light source 220 may include a light emitting surface 1300 for emitting light. In addition, the side view type light source 220 may have a length in the horizontal direction of the light emitting surface 1300 that is larger than a height in the vertical direction. Thus, it is possible to improve the brightness characteristic while reducing the thickness of the backlight unit.

Considering the light emitting surface 1300 of the light source 220, it is preferable that the lowest surface of the depression 900 is positioned higher than the uppermost surface of the light emitting surface 1300 as shown in FIG. 12 (b) . The minimum thickness t1 of the depression 900 measured from the reflective layer 240 is preferably larger than the height t2 of the light emitting surface 1300 of the light source 220 measured from the reflective layer 240 You can do it.

13, the minimum thickness t1 of the resin layer 230 in the depression 900 may be smaller than the height H1 of the light source 220 measured from the reflection layer 240 by DELTA H2.

In this case, the light emitted from the side surface of the side-view type light source 220 can be reflected by the depression portion 900 in the direction of the reflection layer 240, thereby improving the optical characteristics.

14, the minimum thickness t1 of the resin layer 230 in the depression 900 is smaller than the height H1 of the light source 220 measured from the reflection layer 240, The minimum thickness t1 of the resin layer 230 at the position corresponding to the light source 220 may be smaller than the thickness t2 of the resin layer 230 at the position corresponding to the light source 220. [ In this case, the light reflection by the depressed portion 900 is further increased, so that the optical characteristics can be further improved.

Alternatively, as shown in FIG. 15, a part of the depression 900 may overlap with the light source 220. For example, both ends P1 and P2 of the depression 900 may be located above the adjacent light sources 220. [ Even in this case, it is possible to further improve the optical characteristics.

A method of manufacturing the depression 900 will be described below.

The light source 220 may be mounted on the substrate 210 and then the reflective layer 240 may be formed on the substrate 210 as shown in FIG.

16 (b), a resin material in a liquid state or a gel state is coated on the substrate 210 on which the light source 220 and the reflective layer 240 are disposed to form a resin material layer 1500 can do. Alternatively, a method of laminating the resin material layer 1500 in the form of a sheet on a substrate 210 may be possible.

Thereafter, the resin material layer 1500 can be dried. Alternatively, the resin material layer 1500 can be dried by applying a weak heat to the resin material layer 1500. Then, as shown in FIG. 16C, the resin material layer 1500 is contracted, and the depression 900 can be formed.

As described above, in the method of forming the depression 900 by the drying method, it may be preferable to appropriately adjust the viscosity of the resin material layer 1500. For example, by adjusting the viscosity of the resin material layer 1500 within the critical range, the depression can be formed in the resin layer 230 while the resin material layer 1500 contracts.

Alternatively, after the resin material layer 1500 is formed on the substrate 210 as shown in FIG. 17A, a part of the resin material layer 1500 is formed by using the blade 1600 as shown in FIG. 17B A depression 900 may be formed.

When the depression 900 is formed in the resin material layer 1500 with the blade 1600, it may be preferable to carry out the process after drying the resin material layer 1500 first.

When the depression 900 is formed using the blade 1600, depressions 900 having various shapes can be formed. For example, it is possible to form depressions 900 of various shapes as shown in Figs. 18 (a), 18 (b) and 18 (c).

19 to 24 are views for explaining the case of including a diffusion plate. Hereinafter, the description of the parts described in detail above will be omitted.

Referring to FIG. 19, a diffusion plate 1800 may be disposed on an upper portion of the resin layer 230 on which the depression 900 is formed.

Since the diffusion plate 1800 has a plate shape, it can serve as a support for other functional layers and can diffuse the light incident from the light source 220.

The diffuser plate 1800 may include a plurality of beads (not shown), and scatter light incident using the beads to prevent light from concentrating on a specific portion.

The diffusion plate 1800 may include a material such as polycarbonate (PC), polymethylmethacrylate (PMMA), cyclic olefin copolymer (COC), or the like.

An air layer 1810 may be formed between the diffusion plate 1800 and the resin layer 230. That is, a depression 900 is formed in the resin layer 230, and a diffusion plate 1800 in the form of a hard plate is disposed on the resin layer 230, so that the resin layer 230 and the diffusion plate 1800 The air layer 1810 may be formed at a position corresponding to the depressed portion 900.

The air layer 1810 may have a substantially refractive index of 1 and may be different from the refractive index of the resin layer 230 and the refractive index of the diffuser plate 1800. Accordingly, the formation of the air layer 1810 may result in the formation of another layer, i.e., the air layer 1810, having a different refractive index between the resin layer 230 and the diffuser plate 1800, It is possible to more effectively diffuse the light diverged by the light source 220.

Alternatively, as shown in FIG. 20, the optical sheet 250 may be disposed on the diffusion plate 1800. This optical sheet 250 has been described in detail in FIG.

Alternatively, as shown in FIG. 21, an adhesive layer 2000 may be formed between the diffusion plate 1800 and the resin layer 230. In this case, it is possible to improve the adhesion between the diffusion plate 1800 and the resin layer 230, thereby improving the structural stability.

In order to obtain an effect similar to that of forming the air layer 1810 between the diffusion plate 1800 and the resin layer 230, it is preferable that the refractive index of the adhesive layer 2000 is smaller than the refractive index of the resin layer 230 .

The refractive index of the adhesive layer 2000 may be greater than the refractive index of the resin layer 230 in order to reflect light incident on the adhesive layer 2000 and to reflect the light incident on the adhesive layer 2000 again to facilitate diffusion of light. May be preferred.

In the case of FIG. 21, the adhesive layer 2000 is formed substantially only on the depression 900. Accordingly, the adhesive layer 2000 may not be formed between the light source 220 and the diffusion plate 1800.

Alternatively, an adhesive layer 2000 may be formed between the diffusion plate 1800 and the light source 220, as shown in FIG. The thickness t10 of the adhesive layer 2000 at a position corresponding to the depression 900 may be greater than the thickness t11 of the adhesive layer 2000 at a position corresponding to the light source 220. [

On the other hand, as shown in FIG. 23, a diffusion plate 1800 printed with a light shielding portion 260 may be disposed on the resin layer 230. For example, a light shielding portion 260 of a predetermined pattern may be printed on one surface of the diffusion plate 1800. Here, one surface of the diffusion plate 1800 on which the light-shielding portion 260 is printed may be disposed to face the resin layer 230.

Since the diffusion plate 1800 has a plate shape, it can serve as a support for other functional layers and can diffuse the light incident from the light source 220.

The light shielding part 260 may be formed at a position corresponding to the light source 220 in the diffusion plate 1800. The light-shielding portion 260 can prevent the light emitted from the light source 220 from being concentrated in a specific region.

The light shielding portion 260 allows a part of the light incident from the light source 220 to be transmitted, and a part of the light can be reflected. To this end, the light-shielding portion 260 may include a titanium dioxide (TiO ₂ ) material. In this case, the color of the light-shielding portion 260 may be substantially white, thereby allowing a part of the incident light to be transmitted while reflecting a part of the incident light more effectively.

When the light shield 260 is printed on the diffuser 1800, the light shield 260 is printed on the relatively hard diffuser 1800 and then the light shield 260 is printed on the diffuser 1800, Can be disposed above the resin layer 230, the manufacturing process of the backlight unit can be simplified, and the time required for the manufacturing process can be shortened.

The light shield 260 may be formed at a position corresponding to the light source 220 in the diffuser plate 1800 so that the substrate 210 is formed on the resin layer 230 between two adjacent light shields 260. [ A depression 900 may be formed.

Accordingly, the interval t20 between the resin layer 230 and the diffusion plate 1800 at the position where the depressed portion 900 is disposed can be sufficiently wide, and thus it is possible to further improve the optical characteristics.

24, a diffusion plate 1800 printed with a light shielding portion 260 is disposed on the upper portion of the resin layer 230. One surface of the diffusion plate 1800 on which the light shielding portion 260 is printed has a resin layer As shown in FIG. That is, assuming that the shielding part 260 is printed on one surface of the diffusion plate 1800, the other surface of the diffusion plate 1800 can contact the resin layer 230.

25 to 27 are views for explaining another example of the depressed portion. Hereinafter, the description of the parts described in detail above will be omitted.

25, a method in which the light emitting surface 1300 of the light source 220 is oriented parallel to the substrate 210, that is, the side view method in which the light source 220 emits light in one direction with the substrate 210 Is disclosed. 25, the light emitting surface 1300 of the plurality of light sources 220 emits light in a direction parallel to the X axis. However, the direction in which the light emitting surfaces 1300 of the plurality of light sources 220 face is limited to this It does not. For example, the light emitting surface 1300 of the plurality of light sources 220 may emit light in a direction parallel to the Y axis.

The depression 900 may be formed around the light source 220. Although the depression 900 has a mesh-like pattern in FIG. 25, the pattern of the depression 900 is not limited thereto.

25, a light source 220 adjacent to the first light source (1) in a direction parallel to the X axis is referred to as a second light source (2), and a plurality of light sources Let the first light source (1) and the adjacent light source 220 be a third light source (3).

In this case, the interval D2 between the first light source 1 and the second light source 2 may be different from the interval D1 between the first light source 1 and the third light source 3. The width and / or the height of the depression 900 formed between the first light source 1 and the second light source 2 may be set to a predetermined value by a depression formed between the first light source 1 and the third light source 3 900 may be different from the width and / or height. 25, the depressed portion 900 is indicated by a dotted line.

For example, as shown in FIG. 25, the interval D2 between the first light source (1) and the second light source (2) is longer than the interval D1 between the first light source (1) and the third light source Let's assume a small case. Of course the opposite is also possible.

In this case, the thickness t20 of the depression 900 formed between the first light source (1) and the second light source (2) in FIG. 26 (a) And the thickness t21 of the depression 900 formed between the third light source and the third light source.

The width W1 of the depression 900 formed between the first light source (1) and the second light source (2) in Figure 26 (a) corresponds to the width of the first light source (1) And the width W2 of the depression 900 formed between the third light source and the third light source.

Referring to FIG. 27, at least one light emitting surface 1300 of the plurality of light sources 220 disposed on the substrate 210 is capable of emitting light in a direction different from the rest. For example, at least one light emitting surface 1300 of the plurality of light sources 220 emits light in the + X axis direction, and at least one light emitting surface 1300 of the remaining light sources 220 emits light in the + It is possible to generate light in the -X-axis direction. The light emitting direction of the light emitting surface 1300 of the light source 220 is not limited to that shown in Fig.

The light source 220 in which the light emitting surface 1300 is disposed in the direction parallel to the + X axis and the light source 220 in which the light emitting surface 1300 is disposed in the direction parallel to the -X axis are adjacent to each other in the Y axis direction . That is, as shown in FIG. 27, the two light sources 220 in which the light emitting surfaces 1300 are arranged in different directions may be arranged to be adjacent to each other in the diagonal direction. In Fig. 27, the light emitting surface of the light source 220, that is, the direction in which the light emitting surface 1300 faces, is indicated by an arrow.

27, the plurality of light sources 220 may be arranged to form two or more rows, and two or more light sources 220 arranged in the same row may emit light in the same direction.

In this manner, by making the directions of the light emitting surfaces 1300 of the arbitrary two light sources 220 to be different from each other, the phenomenon that the brightness of light is concentrated or weakened in a specific region of the backlight unit is reduced, The luminance of the emitted light can be made uniform.

On the other hand, the interval D20 between the two light sources 220 arranged adjacent to each other and in which the light emitting surface 1300 is disposed in the mutually opposite directions is defined as a distance D20 between two light emitting surfaces 1300 arranged in the same direction, May be smaller than the interval D10 between the light sources 220. This is to prevent dark portions from being generated between the two light sources 220, which are arranged adjacent to each other and in which light emitting surfaces 1300 are arranged in directions opposite to each other.

In this case, the width and / or the thickness of the depressions 900 formed between the adjacent two light sources 220 in which the light emitting surfaces 1300 are disposed in the mutually opposite directions are arranged such that the light emitting surfaces 1300 are arranged in the same direction May be different from the width and / or thickness of the depression (900) formed between adjacent two light sources (220).

For example, the first light source (1) and the second light source (2) are arranged in the same direction with the light emitting surface 1300, and the third light source (3) And the light emitting surface 1300 is disposed in a direction opposite to the light emitting surface 1300. In this case, the interval D10 between the first light source 1 and the second light source 2 may be larger than the interval D20 between the second light source 2 and the third light source 3. The first light source 1 and the second light source 2 are disposed adjacent to each other in a direction parallel to the short side SS of the substrate 210 and the second light source 2 and the third light source 3 May be disposed adjacent to each other in a direction intersecting the short side SS of the substrate 210 (diagonal direction with respect to the short side SS of the substrate 210).

In this case, the thickness of the depression 900 formed between the first light source (1) and the second light source (2) is smaller than the thickness of the depression 900 formed between the second light source (2) and the third light source (3) Lt; / RTI >

The width of the depression 900 formed between the first light source 1 and the second light source 2 may be a width of the depression 900 formed between the second light source 2 and the third light source 3 Width. This can be substantially the same as the case of Fig.

As described above, it is to be understood that the technical structure of the present invention can be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention.

Therefore, it should be understood that the embodiments described above are intended to be illustrative and not limiting in any way, and that the scope of the present invention is defined by the appended claims rather than the foregoing description, And all changes or modifications derived from equivalents thereof should be construed as being included within the scope of the present invention.

Claims (22)

Board;
A light source disposed on the substrate;
A resin layer disposed on the substrate on which the light source is disposed; And
A reflective layer disposed between the resin layer and the substrate;
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Wherein the resin layer includes a depression recessed in a direction toward the substrate,
Wherein the minimum thickness of the resin layer in the depression is smaller than the height of the light source from the reflective layer. The method according to claim 1,
Wherein the light source includes a light emitting diode. The method according to claim 1,
Wherein the light source faces the direction in which the light emitting surface is perpendicular to the substrate. The method according to claim 1,
Wherein the light source faces the light emitting surface in a direction parallel to the substrate. The method according to claim 1,
Wherein the depression is disposed between two adjacent light sources. The method according to claim 1,
Wherein the minimum thickness of the resin layer in the depression is thicker than the thickness of the resin layer in a position corresponding to the light source. delete delete delete The method according to claim 1,
And a diffusion plate is disposed on the upper portion of the resin layer. 11. The method of claim 10,
And an optical sheet is disposed on an upper portion of the diffusion plate. 11. The method of claim 10,
And an adhesive layer is disposed between the resin layer and the diffusion plate. 13. The method of claim 12,
Wherein a thickness of the adhesive layer at a position corresponding to the depression is thicker than a thickness of the adhesive layer at a position corresponding to the light source. 13. The method of claim 12,
Wherein the adhesive layer is not formed between the light source and the diffusion plate. 11. The method of claim 10,
And an air layer is formed between the diffusion plate and the depression. delete delete delete delete delete A display panel; And
A backlight unit attached to a back surface of the display panel;
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The backlight unit
Board;
A light source disposed on the substrate;
A resin layer disposed on the substrate on which the light source is disposed; And
A reflective layer disposed between the resin layer and the substrate;
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Wherein the resin layer includes a depression recessed in a direction toward the substrate,
Wherein the minimum thickness of the resin layer in the depression is smaller than the height of the light source from the reflective layer. delete

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