KR20110113906A - Back light unit and display apparatus - Google Patents

Abstract

The present invention relates to a backlight unit and a display device.
The backlight unit according to the present invention may include a substrate, a light source disposed on the substrate, and a resin layer disposed on an upper portion of the substrate on which the light source is disposed, and the resin layer may include a depression recessed in a direction toward the substrate. have.

Description

Back Light Unit and Display Apparatus

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

As the information society develops, the demand for display devices is increasing in various forms, and in recent years, liquid crystal display devices (LCDs), plasma display panels (PDPs), electro luminescent displays (ELDs), and vacuum fluorescents (VFDs) have been developed. Various display devices such as displays have been researched and used. Among them, the liquid crystal panel of the LCD includes a TFT substrate and a color filter substrate facing each other with the liquid crystal layer and the liquid crystal layer interposed therebetween, and can display an image using light provided from the backlight unit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight unit and a display device for improving optical stability while improving structural stability.

The backlight unit according to the present invention may include a substrate, a light source disposed on the substrate, and a resin layer disposed on an upper portion of the substrate on which the light source is disposed, and the resin layer may include a depression recessed in a direction toward the substrate. have.

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

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

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

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

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

In addition, a reflective layer may be disposed between the resin layer and the substrate.

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

In addition, a diffusion plate may be disposed on the resin layer.

In addition, an optical sheet may be disposed on the diffusion plate.

In addition, 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 recess 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.

In addition, an air layer may be formed between the diffusion plate and the depression.

Further, another backlight unit according to the present invention includes a substrate, a light source disposed on the substrate, and a resin layer disposed on an upper portion of the substrate on which the light source is disposed, wherein the light source is adjacent to the first light source and the first light source. A second light source disposed 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.

In addition, an interval between the first light source and the second light source is greater than an interval between the second light source and the third light source, and a minimum thickness of the resin layer is between the first light source and the second light source. It may be less than the minimum thickness of the resin layer between the second light source and the third light source.

The light emitting surface of the first light source and the light emitting surface of the second light source may face the same direction, and the light emitting surface of the second light source and the light emitting surface of the third light source may face different directions.

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

In addition, the light emitting surfaces of the first, second, and third light sources may face a direction parallel to the substrate.

The display apparatus according to the present invention includes a display panel and a backlight unit attached to a rear surface of the display panel, wherein the backlight unit is a resin layer disposed on a substrate, a light source disposed on the substrate, and a substrate on which the light source is disposed. It includes, and the resin layer may include a recessed portion recessed in the direction toward the substrate.

In addition, another display device according to the present invention includes a display panel and a backlight unit attached to a rear 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. And a resin layer, 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. The distance between the second light source 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. May be different from the lowest thickness of the resin layer.

The backlight unit and the display apparatus according to the present invention have an effect of improving optical stability while improving structural stability by forming a recessed portion recessed in the direction of the substrate in a resin layer formed on the substrate.

1 is an exploded perspective view showing the 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;
5 to 8 are views for explaining the direct method;
9 to 18 are views for explaining the resin layer in more detail;
19 to 24 are views for explaining the case including the diffusion plate; And
25 to 27 are views for explaining still another example of the depression.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. 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, terms such as first and second may be used to describe various components, but the components may not be limited by the terms. The terms may be used only for the purpose of distinguishing one component from another component. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The term and / or may include a combination of a plurality of related items or any item of a plurality of related 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 herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present 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.

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

Referring to 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 rear 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 external impact.

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

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

The display panel 100 may include a color filter substrate 110 and a thin film transistor (TFT) substrate 120 bonded to face 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 including red (R), green (G), and blue (B) sub-pixels, and generates an image corresponding to the color of red, green, or blue when light is applied. You can.

The pixels may include red, green, and blue subpixels, but the red, green, blue, and white (W) subpixels constitute one pixel, but are not necessarily limited thereto, and may be configured in various combinations.

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

The liquid crystal layer is composed of a plurality of liquid crystal molecules, and the liquid crystal molecules may change an arrangement corresponding to a voltage difference generated between a pixel electrode and a common electrode, which are not shown. Accordingly, the liquid crystal molecules may be provided from the backlight unit 200. Light may be incident on the color filter substrate 110 in response to a change in the molecular arrangement of the liquid crystal layer.

An upper polarizer 130 and a lower polarizer 140 may be disposed on upper and lower sides of the display panel 100, and more specifically, an upper polarizer 130 is formed on an upper surface of the color filter substrate 110. The lower flat plate 140 may be formed on the lower surface of the TFT substrate 120.

Side of the display panel 100 may be provided with a gate and a data driver (not shown) for generating a driving signal for driving the panel 100.

The structure and configuration of the display panel 100 as described above is merely an example, and the embodiments may be changed, added, or deleted within the scope of the spirit of the present invention.

As shown in FIG. 2, the display apparatus according to the exemplary embodiment of the present invention may be configured by closely placing the backlight unit 200 on the display panel 100. For example, the backlight unit 200 may be attached to and fixed to the lower side of the display panel 100, more specifically, the lower polarizer 140, and for this purpose, between the lower polarizer 140 and the backlight unit 200. An adhesive layer (not shown) may be formed on the substrate.

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

According to an exemplary embodiment of the present invention, the backlight unit 200 may be configured in a form of 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). Can be.

In addition, as described above, in order for the backlight unit 200 to be closely fixed to the lower surface of the display panel 100, the plurality of layers constituting the backlight unit 200, more specifically, the backlight unit 200 may be provided. It is preferable that it is comprised from the material which has ductility, respectively.

In addition, a bottom cover (not shown) on which the backlight unit 200 is seated may be provided below the backlight unit 200.

According to an exemplary embodiment of the present invention, the display panel 100 may be divided into a plurality of areas, and the display panel 100 may be divided from areas of the backlight unit 200 corresponding to gray peak values or color coordinate signals of each of the divided areas. The brightness of the emitted light, that is, the brightness of the corresponding light source, may be adjusted to adjust the brightness of the display panel 100.

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

3 is a cross-sectional view 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.

Although not illustrated, an electrode pattern (not shown) for connecting the connector (not shown) and the light source 220 may be formed on the substrate 210. For example, a carbon nanotube electrode pattern (not shown) may be formed on the upper surface of the substrate 210 to connect the light source 220 and the connector. 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 materials such as polyethylene terephthalate, glass, polycarbonate and silicon. 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 this embodiment, a light emitting diode package is provided as the light source 220.

The light source 220 may be a colored LED or a white LED emitting at least one of colors such as red, blue, and green. In addition, 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 the light emitting diode may be changed within the technical scope of the embodiment.

On the other hand, the resin layer 230 disposed on the upper side of the substrate 210 transmits and diffuses the light emitted from the light source 220, and the light emitted from the light source 220 is uniformly distributed to the display panel 100. Can be provided. In addition, the resin layer 230 may have a recessed portion recessed in the direction of the substrate 210. This will be described in detail with reference to FIG. 9, and the depressions are not shown in the following FIGS. 4 to 8 for convenience of description.

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

The reflective layer 240 may reflect the light totally reflected from the boundary of the resin layer 230 so that the light emitted from the light source 220 may be diffused more widely.

The reflective layer 240 may include a white pigment such as titanium oxide dispersed in a sheet of synthetic resin, a metal deposition film laminated on the surface, or a bubble dispersed to scatter light in a synthetic resin sheet. In order to increase the reflectance, silver (Ag) may be coated on the surface. Alternatively, the reflective layer 240 may be formed by coating the upper surface of the substrate 210.

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

In addition, in order for the light emitted from the light source 220 to be diffused so that the backlight unit 200 has uniform luminance, the refractive index of the resin layer 230 may be about 1.4 to 1.6.

The resin layer 230 may include a polymer resin having adhesiveness so as to be in close contact with the light source 220 and the reflective layer 240. For example, the second layer 230 may be unsaturated polyester, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, normal butyl methacrylate, normal butyl methyl methacrylate, acrylic acid, methacrylic acid, Hydroxy ethyl methacrylate, hydroxy propyl methacrylate, hydroxy ethyl acrylate, acrylamide, metyrol acrylamide, glycidyl methacrylate, ethyl acrylate, isobutyl acrylate, normal butyl acrylate, 2 -Acryl-based, urethane-based, epoxy-based, melamine-based, and the like, such as ethyl hexyl acrylate polymer or copolymer or terpolymer.

The resin layer 230 may be formed by applying a resin on a liquid or gel 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. It is also possible to be formed separately 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 may be spread more widely, and light of uniform brightness may be provided from the backlight unit 200 to the display panel 100. On the other hand, as the thickness a of the second layer 230 increases, the amount of light absorbed by the second layer 230 may increase, thereby providing the display panel 100 from the backlight unit 200. The brightness of the light may be reduced overall.

Therefore, in order to provide light of uniform brightness without greatly reducing the brightness of the light provided from the backlight unit 200 to the display panel 100, the thickness a of the resin layer 230 may be 0.1 to 4.5 mm. desirable.

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

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

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

The scattering particles 231 may be formed of a material having a refractive index different from that of the material of the resin layer 230, and more particularly of the silicon of the resin layer 230 in order to scatter or refract light emitted from the light source 220. Or it may be made of a material having a higher refractive index than the acrylic resin.

For example, the scattering particles 231 may be polymethyl methacrylate / styrene copolymer (MS), polymethyl methacrylate (PMMA), polystyrene (PS), silicon, titanium dioxide (TiO2), silicon dioxide (SiO2). ), Or a combination of the above materials.

On the other hand, the scattering particles 231 may be made of a material having a lower refractive index than the material constituting the resin layer 230, for example, may be formed by forming a bubble in the resin layer (230). .

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

According to the exemplary embodiment of the present invention, the resin layer 230 is a substrate 210 in which a plurality of light sources 220 and a reflective layer 240 are formed after mixing the scattering particles 231 in a liquid or gel resin. It may be formed by applying to the upper surface of the) and then curing.

Referring to FIG. 4, an optical sheet 250 may be disposed above the resin layer 230, and 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 may be provided in a state of being bonded or adhered to each other without being spaced apart from each other, thereby minimizing the thickness of the optical sheet 250 or the backlight unit 200.

On the other hand, the lower surface of the optical sheet 250 is in close contact with the resin layer 230, the upper surface of the optical sheet 250 is in close contact with the lower surface of the display panel 100, more specifically, the lower polarizing plate 140. Can be.

The diffusion sheet 252 diffuses the incident light to prevent the light emitted from the resin layer 230 from being partially concentrated, thereby making the brightness of the light uniform. In addition, the prism sheet 251 may collect light emitted from the diffusion sheet 252 to allow light to enter the display panel 100 vertically.

According to another embodiment of the present invention, the optical sheet 250 as described above, for example, at least one of the prism sheet 251 and the diffusion sheet 252 may be removed, or the prism sheet 251 and In addition to the diffusion sheet 252 may be configured to further include a variety of functional layers.

The LED package constituting the light source 220 in the direct method may be divided into a top view method and a side view method according to a direction in which the light emitting surface is directed. This is described below.

5 to 8 are views for explaining the direct method.

FIG. 5 is a view illustrating a top view method of the direct method.

Referring to FIG. 5, the light emitting surfaces of the plurality of light sources 220 provided in the backlight unit 200 are disposed on an upper surface thereof, respectively, in a direction perpendicular to the upper direction, for example, the substrate 210 or the reflective layer 240. It can emit light.

FIG. 6 illustrates a side view of the direct method.

Referring to FIG. 6, each of the light sources 220 provided in the backlight unit 200 has a light emitting surface disposed on a side thereof, and emits 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 observed as a hot spot on the screen. In addition, the thickness (a) of the resin layer 230 may be reduced to reduce the thickness 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.

Light emitted from the light source 220 to the side may pass through the first resin layer 230 and may proceed to an area where the adjacent light source 225 is disposed.

Some of the light that passes through the first resin layer 230 may be emitted to an upper side of the display panel 100. To this end, 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 advancing light in an upward direction.

In addition, 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 may be emitted in an area adjacent to the light source 220 due to a strong scattering phenomenon near the light source 220 or light emitted from the light source 220 in a direction closer to the upper side, and the like. Light of brightness can be observed. In order to prevent this, as shown in FIG. 7, the first light blocking pattern 260 may be formed on the first resin layer 230 to reduce the luminance of light emitted from the region adjacent to the light source 220. Accordingly, light of uniform brightness may be emitted from the backlight unit 200. For example, the first light blocking pattern 260 may be formed on the first resin layer 230 so as to correspond to the position where the plurality of light sources 220 are disposed, and a part of the light incident from the light source 220 may be formed. It can block and transmit the remaining part to reduce the brightness of the light emitted upwards.

The first light blocking pattern 260 may be formed of titanium dioxide (TiO 2), and in this case, a part of the light incident from the light source 220 may be reflected downward and transmit the remaining part.

According to an embodiment of the present invention, the second resin layer 235 may be disposed above the first resin layer 230. The second resin layer 235 may be made of the same or different material as that of the first resin layer 230, and diffuses light emitted from the first resin layer 230 in the upward direction of the backlight unit 200. The uniformity of optical brightness can be improved.

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

For example, when the second resin layer 235 is made of a material having a refractive index higher than that of the first resin layer 230, light emitted from the first resin layer 230 may 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, the light emitted from the first resin layer 230 is reflected on the bottom surface of the second resin layer 235. The reflectance may be improved, and thus, light emitted from the light source 220 may be made to travel along the first resin layer 230 more easily.

Meanwhile, 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 the first resin layer. It may be higher than the density of the scattering particles included in (230). As such, when the scattering particles are included in the second resin layer 235 at a higher density, the light emitted upward from the first resin layer 230 may be diffused more widely, and accordingly, the backlight unit 200 may be diffused. The luminance of the light emitted from the screen can be made more uniform.

As shown in FIG. 7, the second light blocking pattern 265 is formed on the upper side of the second resin layer 235 to make the luminance of the light emitted from the second resin layer 235 uniform. For example, when light emitted upward from the second resin layer 235 is concentrated at a specific portion and observed with high luminance on the screen, an area corresponding to the specific portion of the upper surface of the second resin layer 235 is observed. The second light blocking pattern 265 may be formed at the upper portion of the second light blocking pattern 265, thereby reducing the luminance of the light in the specific portion, thereby making the luminance of the light emitted from the backlight unit 200 uniform.

The second light blocking pattern 265 may be formed of titanium dioxide (TiO 2). In this case, part of the light emitted from the second resin layer 235 is reflected downward from the second light blocking pattern 265, and the other part Can be permeable.

Referring to FIG. 8, a pattern may be formed in the reflective layer 240 to facilitate the progress of light emitted from the light source 220 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, and the light incident on the plurality of protrusions 241 after being emitted from the light source 220 is scattered in the advancing direction. Can be refracted.

As illustrated in FIG. 8, the densities of the protrusions 241 formed in the reflective layer 240 may increase as they are spaced apart from the light source 220, that is, closer to the adjacent light source 225. Accordingly, it is possible to prevent the luminance of the light emitted upward from the region far from the light source 220, that is, the region close to the adjacent light source 225, to thereby reduce the luminance of the light provided from the backlight unit 200. It can be kept uniform.

In addition, the protrusions 241 may be formed of the same material as the reflective layer 240, and in this case, the protrusions 241 may be formed by processing an upper surface of the reflective layer 240.

Alternatively, the protrusions 241 may be formed of a material different from that of 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.

Shapes of the protrusions 241 are not limited to those shown in FIG. 8, and various shapes such as prisms 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, description of a reflection pattern, a light shielding pattern, etc. is abbreviate | omitted.

Referring to FIG. 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 recessed in a direction toward the substrate 210. Here, the recess 900 may be disposed between two adjacent light sources 220. That is, the resin layer 230 may be recessed in between the two light sources 220. In other words, both ends P1 and P2 of the recess 900 may be spaced apart from the adjacent light source 220 by a predetermined distance.

In this case, the light source 220 may be a top-view type in which the light emitting surface faces a direction perpendicular to the substrate 210, or the side view in which the light emitting surface faces the direction parallel to the substrate 210. (Side-View) type may also be possible.

As such, when the recess 900 is formed in the resin layer 230, the adhesive force may be improved by increasing the contact area between the resin layer 230 and another layer, for example, an optical sheet (not shown). Accordingly, it is possible to improve the structural stability of the backlight unit.

In addition, 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 adhesion can be sufficiently strong, and it is therefore possible to reduce the thickness of the backlight unit.

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 from an impact applied from the outside, the resin layer 230 may be formed on the upper portion of the light source 220.

In view of the above, 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 while the resin layer 230 is formed on the light source 220. It may be desirable to thin the thickness t2. Accordingly, the lowest thickness t1 of the resin layer 230 in the recess 900 may be thicker than the thickness t2 of the resin layer 230 at a position corresponding to the light source 220.

On the other hand, when the light source 220 is a side-view type, when the depression 900 is formed in the resin layer 230, the optical characteristics may be improved. This will be described with reference to FIG. 10.

Referring to FIG. 10, when the depression 900 is formed in the resin layer 230, the light emitted from the light source 220 at an angle of approximately θ1 with the substrate 210 is transferred to the depression 900 at an angle of 20. Can be reached. Here, the light reaching the depression 900 may 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. As such, the light reflected by the reflective layer 240 reaches the surface of the resin layer 230 at a relatively large angle to pass through the resin layer 230. As such, when the recess 900 is formed in the resin layer 230, light efficiency may be improved by reducing the light lost. That is, it is possible to improve optical characteristics.

The lowest thickness of the recess 900 formed in the resin layer 230 may be variously adjusted. For example, as shown in FIG. 11, the minimum thickness t1 of the resin layer 230 in the depression 900, that is, the minimum thickness t1 of the depression 900, is measured by the light source 220. ) May be larger by ΔH1 than the height H1.

In this case, the process of forming the depression 900 may be easy. That is, in terms of the manufacturing process, it may be preferable that the minimum thickness t1 of the recess 900 is greater than the height H1 of the light source 220 measured from the reflective layer 240.

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

Referring to FIG. 12A, 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 greater than a height in the vertical direction. Thereby, 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, as shown in FIG. 12B, the lowest surface of the recess 900 may be located higher than the uppermost side of the light emitting surface 1300. Can be. In other words, it is preferable that the minimum thickness t1 of the depression 900 measured from the reflective layer 240 is greater 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.

Alternatively, as shown in FIG. 13, the lowest thickness t1 of the resin layer 230 in the recess 900 may be smaller than ΔH2 than the height H1 of the light source 220 measured from the reflective layer 240.

In this case, the recess 900 may reflect the light emitted from the side of the side-view light source 220 in the direction of the reflective layer 240 to improve the optical characteristics.

Alternatively, as illustrated in FIG. 14, the lowest thickness t1 of the resin layer 230 in the recess 900 is smaller than the height H1 of the light source 220 measured from the reflective layer 240, but the recess 900 ), The lowest thickness t1 of the resin layer 230 may be smaller than the thickness t2 of the resin layer 230 at a position corresponding to the light source 220. In this case, the light reflection by the depression 900 is further increased to further improve the optical characteristics.

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

Looking at the manufacturing method of the depression 900 is as follows.

As illustrated in FIG. 16A, the light source 220 may be mounted on the substrate 210, and then the reflective layer 240 may be formed on the substrate 210.

Thereafter, as shown in FIG. 16B, the resin material layer 1500 is formed by coating a resin material in a liquid or gel state on the substrate 210 on which the light source 220 and the reflective layer 240 are disposed. can do. Alternatively, a method of laminating the resin material layer 1500 in a sheet state of the sheet to the substrate 210 may be possible.

Thereafter, the resin material layer 1500 may be dried. Alternatively, the resin material layer 1500 may be dried by applying weak heat to the resin material layer 1500. Then, as shown in FIG. 16C, the recess 900 may be formed while the resin material layer 1500 shrinks.

As such, in the method of forming the depression 900 by a drying method, it may be desirable to appropriately adjust the viscosity of the resin material layer 1500. For example, by adjusting the viscosity of the resin material layer 1500 within a critical range, a depression may be formed in the resin layer 230 while the resin material layer 1500 shrinks.

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

When the depression 900 is formed in the resin material layer 1500 using the blade 1600, it may be preferable to first dry the resin material layer 1500 and then proceed with the process.

As such, when the depression 900 is formed using the blade 1600, it is possible to form the depression 900 of various shapes. For example, it is possible to form the depression 900 of various forms such as (a), (b), (c) of FIG.

19 to 24 are diagrams for explaining the case of including the 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 in which the depression 900 is formed.

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

Although not shown, the diffusion plate 1800 may include a plurality of beads, and scatter the light incident by using the beads to prevent the light from being concentrated at a specific portion.

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

An air layer 1810 may be formed between the diffusion plate 1800 and the resin layer 230. That is, since the depression 900 is formed in the resin layer 230, and the diffusion plate 1800 in the form of a rigid plate is disposed on the resin layer 230, the resin layer 230 and the diffusion plate 1800 are formed. In between, the air layer 1810 may be formed at a position corresponding to the depression 900.

The air layer 1810 may have a refractive index of 1 substantially different from that of the resin layer 230 and that of the diffusion plate 1800. Accordingly, formation of the air layer 1810 may result in the formation of another layer having a different refractive index, that is, the air layer 1810, between the resin layer 230 and the diffusion plate 1800, and thus, the light source. The light emitted by 220 may be diffused more effectively.

Alternatively, as shown in FIG. 20, the optical sheet 250 may be disposed on the diffusion plate 1800. The optical sheet 250 has been described in detail with reference to FIG. 4.

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 structural stability by improving the adhesion between the diffusion plate 1800 and the resin layer 230.

In addition, 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, the refractive index of the adhesive layer 2000 may be smaller than that of the resin layer 230. Can be.

Alternatively, the refractive index of the adhesive layer 2000 is greater than the refractive index of the resin layer 230 in order to reflect the light incident on the adhesive layer 2000 and to reflect the light again by the reflective layer 240 to facilitate the diffusion of the light. It may be desirable.

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

Alternatively, as shown in FIG. 22, an adhesive layer 2000 may be formed between the diffusion plate 1800 and the light source 220. In this case, the thickness t10 of the adhesive layer 2000 at the position corresponding to the recess 900 may be thicker than the thickness t11 of the adhesive layer 2000 at the position corresponding to the light source 220.

Meanwhile, as shown in FIG. 23, a diffusion plate 1800 on which the light blocking portion 260 is printed may be disposed on the resin layer 230. For example, the light blocking part 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 rigid plate shape, the diffusion plate 1800 may serve as a support for other functional layers, and may diffuse light incident from the light source 220.

The light blocking unit 260 may be formed at a position corresponding to the light source 220 in the diffusion plate 1800. The light blocking unit 260 may prevent the light emitted from the light source 220 from being concentrated in a specific area.

The light blocking unit 260 may transmit a part of light incident from the light source 220 and reflect a part of the light. To this end, the light blocking portion 260 may include titanium dioxide (TiO ₂ ) material. In this case, the color of the light blocking part 260 may be substantially white, and thus may reflect a part of the incident light more effectively while transmitting a part of the incident light.

As such, when the light shield 260 is printed on the diffusion plate 1800, after the light shield 260 is printed on the relatively hard diffusion plate 1800, the light shield 260 is printed on the diffuser plate 1800. Since it can be disposed on the resin layer 230, the manufacturing process of the backlight unit can be simplified, and the time required for the manufacturing process can be reduced.

In addition, since the light blocking unit 260 may be formed at a position corresponding to the light source 220 in the diffusion plate 1800, the substrate 210 may be disposed on the resin layer 230 between two adjacent light blocking units 260. A depression 900 recessed in the direction may be formed.

Accordingly, the distance t20 between the resin layer 230 and the diffusion plate 1800 at the position where the recess 900 is disposed may be sufficiently wide, thereby further improving the optical characteristics.

Alternatively, as shown in FIG. 24, a diffusion plate 1800 on which the light blocking part 260 is printed is disposed on the resin layer 230, and one surface of the diffusion plate 1800 on which the light blocking part 260 is printed is a resin layer. It may be disposed to face in the opposite direction of 230. That is, assuming that the light blocking portion 260 is printed on one surface of the diffusion plate 1800, the other surface of the diffusion plate 1800 may contact the resin layer 230.

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

Referring to FIG. 25, a light emitting surface 1300 of the light source 220 faces in a direction parallel to the substrate 210, that is, a side-view method in which the light source 220 emits light in a direction parallel to the substrate 210. An example of this is disclosed. In FIG. 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 of the light emitting surface 1300 of the plurality of light sources 220 is limited thereto. It doesn't work. 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.

In addition, the depression 900 may be formed around the light source 220. In FIG. 25, the recess 900 has a square mesh pattern, but the pattern of the recess 900 is not limited thereto.

In FIG. 25, the light source 220 adjacent to the first light source ① in the direction parallel to the X axis among the plurality of light sources 220 disposed on the substrate 210 is called a second light source ② and is parallel to the Y axis. Therefore, let the light source 220 adjacent to the first light source ① be called the third light source ③.

In this case, the distance D2 between the first light source ① and the second light source ② may be different from the distance D1 between the first light source ① and the third light source ③. In addition, the width and / or height of the recess 900 formed between the first light source ① and the second light source ② is a recessed portion formed between the first light source ① and the third light source ③. 900 and width and / or height. In FIG. 25, the depression 900 is indicated by a dotted line.

For example, as shown in FIG. 25, the distance D2 between the first light source ① and the second light source ② is greater than the distance D1 between the first light source ① and the third light source ③. Let's assume a small case. Of course the opposite is also true.

In this case, the thickness t20 of the recess 900 formed between the first light source ① and the second light source ② of FIG. 26A is the first light source ① of FIG. 26B. ) And greater than the thickness t21 of the recess 900 formed between the third light source ③.

In addition, the width W1 of the recess 900 formed between the first light source ① and the second light source ② of FIG. 26A is the first light source ① of FIG. 26B. And a width W2 of the depression 900 formed between the third light source ③.

Referring to FIG. 27, at least one light emitting surface 1300 of the plurality of light sources 220 disposed on the substrate 210 may emit 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 may be formed on the substrate 210. It is possible to generate light in the -X axis direction. The light divergence direction of the light emitting surface 1300 of the light source 220 is not limited to FIG. 27.

In addition, 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. Can be arranged. That is, as shown in FIG. 27, the two light sources 220 in which the emission surfaces 1300 are disposed in different directions may be disposed to be adjacent to each other in a 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 as an arrow.

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

As such, when the light emitting surfaces 1300 of the two arbitrary light sources 220 face each other, the phenomenon in which the luminance of the light is concentrated or weakened in a specific region of the backlight unit is reduced, thereby reducing the phenomenon of the backlight unit 200. The luminance of the emitted light can be made uniform.

Meanwhile, the distance D20 between the two light sources 220 disposed adjacent to each other and the light emitting surfaces 1300 are disposed in the opposite direction to each other is the two light emitting surfaces 1300 disposed in the same direction adjacent to each other. It may be smaller than the distance D10 between the light sources 220. This is to prevent the dark portion from being generated adjacent to each other and the area between the two light sources 220 in which the light emitting surface 1300 is disposed in the opposite direction.

In this case, the width and / or thickness of the recess 900 formed between two adjacent light sources 220 in which the light emitting surfaces 1300 are disposed in opposite directions may be disposed in the same direction. The width and / or thickness of the recess 900 formed between two adjacent light sources 220 may be different.

For example, the light emitting surface 1300 is disposed in the same direction as the first light source ① and the second light source ②, and the third light source ③ is the first light source ① and the second light source ②. Assume that the light emitting surface 1300 is disposed in the opposite direction to the? In this case, the distance D10 between the first light source ① and the second light source ② may be greater than the distance D20 between the second light source ② and the third light source ③. In addition, 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 ② are disposed adjacent to each other. ) May be disposed adjacent to each other in a direction crossing the short side SS of the substrate 210 (a diagonal direction based on the short side SS of the substrate 210).

In this case, the thickness of the recess 900 formed between the first light source ① and the second light source ② is the recess 900 formed between the second light source ② and the third light source ③. It may be less than the thickness of.

In addition, the width of the recess 900 formed between the first light source ① and the second light source ② is the width of the recess 900 formed between the second light source ② and the third light source ③. It can be larger than the width. This may 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, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the foregoing description, and the meaning and scope of the claims are as follows. And all changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

Claims (22)

Board;
A light source disposed on the substrate; And
A resin layer disposed on the substrate on which the light source is disposed;
Including,
The resin layer includes a recessed portion recessed in the direction toward the substrate. The method of claim 1,
The light source includes a light emitting diode. The method of claim 1,
And the light source faces a direction in which the light emitting surface is perpendicular to the substrate. The method of claim 1,
The light source has a light emitting unit facing the direction parallel to the substrate. The method of claim 1,
The recessed unit is disposed between two adjacent light sources. The method of claim 1,
And a minimum thickness of the resin layer at the depression is thicker than the thickness of the resin layer at a position corresponding to the light source. The method of claim 1,
And a reflective layer disposed between the resin layer and the substrate. The method of claim 7, wherein
And a minimum thickness of the resin layer at the depression is greater than a height of the light source from the reflective layer. The method of claim 7, wherein
And a minimum thickness of the resin layer at the depression is smaller than a height of the light source from the reflective layer. The method of claim 1,
The backlight unit is a diffusion plate disposed on the resin layer. The method of claim 10,
And a back light unit on which the optical sheet is disposed. The method of claim 10,
And a bonding layer disposed between the resin layer and the diffusion plate. The method of claim 12,
And a thickness of the adhesive layer at a position corresponding to the recess is thicker than a thickness of the adhesive layer at a position corresponding to the light source. The method of claim 12,
And the adhesive layer is not formed between the light source and the diffusion plate. The method of claim 10,
And an air layer formed between the diffusion plate and the depression. Board;
A light source disposed on the substrate; And
A resin layer disposed on the substrate on which the light source is disposed;
Including,
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,
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 lowest thickness of the resin layer between the first light source and the second light source is different from the lowest thickness of the resin layer between the second light source and the third light source. 17. The method of claim 16,
An interval between the first light source and the second light source is greater than 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 is less than the minimum thickness of the resin layer between the second light source and the third light source. The method of claim 17,
And a light emitting surface of the first light source and a light emitting surface of the second light source face the same direction, and a light emitting surface of the second light source and the light emitting surface of the third light source face different directions. The method of claim 18,
The first light source and the second light source are disposed adjacent to each other in a 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 a direction crossing the short side of the substrate. The method of claim 19,
And a light emitting surface of the first, second and third light sources faces in a direction parallel to the substrate. Display panel; And
A backlight unit attached to a rear surface of the display panel;
Including,
The backlight unit
Board;
A light source disposed on the substrate; And
A resin layer disposed on the substrate on which the light source is disposed;
Including,
The resin layer includes a depression recessed in the direction toward the substrate. Display panel; And
A backlight unit attached to a rear surface of the display panel;
Including,
The backlight unit
Board;
A light source disposed on the substrate; And
A resin layer disposed on the substrate on which the light source is disposed;
Including,
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,
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 lowest thickness of the resin layer between the first light source and the second light source is different from the lowest thickness of the resin layer between the second light source and the third light source.

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