TW202026726A - Backlight unit and display device including the same - Google Patents

Abstract

In an embodiment, a backlight unit includes a light-emitting device and a lower reflector on a substrate. The lower reflector has a hole that accommodates and exposes the light-emitting device. The lower reflector may have a height greater than a height of the light-emitting device. The backlight unit may include a color resin in the hole and on the light-emitting device. The backlight unit may include a light path modulator above the light emitting device and on the color resin. The light path modulator may have a different refractive index than a refractive index of the color resin to reflect the emitted light at a boundary of the light path modulator and the color resin towards the lower reflector.

Description

Backlight unit and display device containing the backlight unit

The embodiments disclosed herein relate to a backlight unit and a display device including the backlight unit.

A liquid crystal display (LCD) is a type of flat panel display used to display images using liquid crystal. LCD is widely used in the entire industry due to its advantages of thin thickness, light weight, and low power consumption. The LCD can display images by adjusting the transmittance of light emitted from the backlight unit according to its characteristics, which is to control the transmittance by changing the arrangement of the liquid crystal. Such LCD uses light-emitting diode (LED), cold cathode fluorescent lamp (CCFL), hot cathode fluorescent lamp (HCLF), etc. as the light source of the backlight unit . In recent years, light emitting diodes with excellent light efficiency and high color reproducibility have been widely used as light sources for backlight units.

According to the arrangement of the light source and the light transmission form, the backlight unit can be divided into edge-type or direct-type. In the direct type backlight unit, a light source such as an LED may be provided on the rear side of the display device.

The light source device used in such a direct type backlight unit may include a light-emitting diode and a substrate on which the light-emitting diode is mounted, and the substrate includes circuit elements for driving the light-emitting diode and the like. In addition, a phosphor film containing an expensive phosphor may be provided on the light emitting diode so that the light emitted from the light emitting device is excited to display a color. However, since a large amount of phosphors are used in the phosphor film, the manufacturing cost of the backlight unit may increase. In addition, when the light emitted from the light emitting device is not sufficiently excited, the color reproducibility deteriorates.

Embodiments of the present invention provide a backlight unit with high color reproducibility and a display device including the backlight unit.

In addition, embodiments of the present invention provide a backlight unit capable of reducing manufacturing costs and a display device including the backlight unit.

According to the embodiments of the present invention, a backlight unit with high color reproducibility and a display device including the backlight unit can be provided.

According to the embodiments of the present invention, a backlight unit capable of reducing manufacturing costs and a display device including the backlight unit can be provided.

In various embodiments, a backlight unit includes: a substrate; a light emitting device located on the substrate; a lower reflector located on the substrate, the lower reflector having a hole for receiving and exposing the light emitting device, and the lower portion The height of the reflector is greater than the height of the light-emitting device and is configured to reflect the light emitted from the light-emitting device; a colored resin is located in the hole and on the light-emitting device, and its height is lower than the height of the lower reflector; And an optical path adjuster located above the light emitting device and on the colored resin, the optical path adjuster has a refractive index different from that of the colored resin, so as to reduce the emission at the boundary between the optical path adjuster and the colored resin The light is reflected toward the lower reflector.

In one embodiment, the colored resin includes a plurality of phosphors having at least two different colors. In one embodiment, an upper surface of the colored resin is concave or convex.

In an embodiment, the optical path regulator includes air.

In an embodiment, the backlight unit further includes a distributed Bragg reflector (distributed Bragg reflector) on the light-emitting device, the distributed Bragg reflector is located in the hole, and is located between the substrate and the optical path adjuster between.

In one embodiment, the backlight unit further includes an adhesive film on the lower reflector and the light path adjuster; and a light modification sheet on the adhesive film, the light modification sheet including at least partially and a plurality of A plurality of light-modifying patterns partially overlapped by a light-emitting device, the plurality of light-modifying patterns having one or more layers including a top layer on a surface of the light-modifying sheet facing the substrate, and the one or more layers are bonded to the There is an air gap between the membranes.

In one embodiment, the one or more layers further include an intermediate layer located on a surface of the top layer facing the substrate, and the size of the top layer is larger than the size of the intermediate layer.

In one embodiment, the one or more layers further include a bottom layer located on a surface of the substrate of the middle layer, and the size of the bottom layer is smaller than the size of the middle layer.

In an embodiment, the backlight unit further includes: a phosphor film on the light modification sheet; a diffusion plate on the phosphor film; and an optical sheet on the diffusion plate.

In various embodiments, a backlight unit includes: a substrate including a groove having a side wall coated with a reflective material and having a first height; a light emitting device located in the groove and having a low At a second height of the first height; a colored resin located in the groove and on the light emitting device, the colored resin having a third height lower than the first height; and a light path adjuster located at the In the groove and on the colored resin, the refractive index of the optical path adjuster is different from the refractive index of the colored resin to direct the light emitted from the light emitting device at the boundary of the optical path adjuster and the colored resin toward the groove的 These side walls reflect.

In various embodiments, a method for manufacturing a backlight unit includes: disposing a plurality of light emitting devices in an area of a substrate; disposing a lower reflector on the substrate, and a hole of the lower reflector receives and exposes the plurality of light emitting devices. The light-emitting device, the depth of the holes is greater than the height of the plurality of light-emitting devices; curing a colored resin in the holes, the height of the cured resin is lower than the depth; and disposing an optical path regulator in the holes By neutralizing the colored resin, the optical path regulator has a refractive index different from that of the colored resin.

In one embodiment, the method further includes disposing a reflector on the plurality of light emitting devices, and coating the substrate with a reflective material.

In one embodiment, the method further includes: disposing an adhesive film on the lower reflector and the light path modifier; and disposing a light modification sheet on the bonding film, the light modification sheet including at least partially A plurality of light-modifying patterns overlapped with a plurality of light-emitting devices, the plurality of light-modifying patterns having one or more layers including a top layer on a surface of the light-modifying sheet facing the substrate, and the one or more layers and the There is an air gap between the adhesive films.

In an embodiment, the method further includes: printing the top layer on the surface of the light modification sheet.

In one embodiment, the method further comprises: printing an intermediate layer on the top layer of the one or more layers, the area of the top layer is larger than the area of the intermediate layer, wherein the light modification sheet is disposed on the adhesive film Previously, the light modifying sheet with the top layer and the middle layer printed was reversed.

In one embodiment, the method further includes: printing a bottom layer of the one or more layers on the intermediate layer, the area of the bottom layer is smaller than the area of the intermediate layer.

In various embodiments, a backlight unit includes: a light emitting device having a flip-chip structure; a first reflector arranged to surround a first area including the light emitting device and the periphery of the light emitting device; and a coloring A resin arranged in the first region; an adhesive film arranged above the colored resin to be spaced apart from the colored resin by a predetermined distance; and a light modifying sheet arranged on the adhesive film, the light modifying sheet including the arrangement The pattern is modified with a light corresponding to the position of the light-emitting device.

In one embodiment, the backlight unit further includes a material disposed between the adhesive film and the colored resin, and has a refractive index different from that of the colored resin.

In an embodiment, the height of the first reflector is higher than the height of the colored resin.

In one embodiment, the backlight unit further includes a substrate including a groove corresponding to the first area, and wherein a reflective film is applied to the substrate.

In one embodiment, the backlight unit further includes a phosphor film disposed above the light modification sheet and including a phosphor having a color different from that of the colored resin.

In one embodiment, the colored resin includes two phosphors with different colors.

In an embodiment, the backlight unit further includes a second reflector disposed on an upper surface of the light emitting device.

In various embodiments, a display device includes: a display panel; and a backlight unit disposed under the display panel and configured to radiate light to the display panel. The backlight unit includes: a light emitting device having a flip chip structure; a first reflector arranged to surround a first area including the light emitting device and the periphery of the light emitting device; and a colored resin arranged on the first area In a region; an adhesive film arranged above the colored resin to be spaced apart from the colored resin by a predetermined distance; and a light-modifying sheet arranged on the adhesive film and including settings to correspond to the position of the light emitting device A light modification pattern.

10: Display device

100: display panel

1AR: first area

200, 200a, 200b, 200c: backlight unit

205: Light source protection unit

210: substrate

210a: Adhesive tape

211: Light-emitting device

211a: Light-emitting part

211b: Electrode part

212, 212a: reflector

213: Colored resin

214: Optical Path Adjuster

215: Adhesive film

216: Light Modified Film

216p: light modification pattern

216pa, 216pb, 216pc, 216pd, 216pe, 216pf, 216pg: light modification pattern

217: Phosphor film

218: diffuser

219: optical sheet

300: bottom cover

400: Light guide plate

500: foam pad

A: The first group

B: The second group

C: third group

CA: Groove

d1: predetermined distance

D1, D2, D3, D4: interval

h1, h2: height

S1, S2: size

T1, T2: thickness

W1, W2: area

θ 1: Angle

The above and other aspects, features, and advantages of the present invention will be more apparent from the following detailed description in conjunction with the accompanying drawings, among which:

FIG. 1 is a structural diagram illustrating a display device according to an embodiment of the invention.

FIG. 2 is a view illustrating the structure of a backlight unit included in a display device according to an embodiment of the present invention.

3A to 3E are views respectively illustrating examples of the specific structure of the backlight unit shown in FIG. 2.

4 is a view illustrating the structure of a backlight unit according to an embodiment of the present invention.

5A and 5B are views illustrating an example of a structure of modifying the position of a pattern according to the light included in the backlight unit shown in FIG. 4.

Fig. 6 is a structural diagram illustrating an embodiment of the backlight unit shown in Fig. 1.

Fig. 7 is a perspective view illustrating a reflector used in the backlight unit shown in Fig. 1.

Fig. 8 is a conceptual diagram illustrating the path of light emitted from the light emitting device.

9A to 9F are conceptual diagrams illustrating the manufacturing process of the backlight unit shown in FIG. 6.

Fig. 10 is a structural diagram illustrating an embodiment of the backlight unit shown in Fig. 1.

Fig. 11 is a structural diagram illustrating an embodiment of the backlight unit shown in Fig. 1.

With reference to the accompanying drawings, by referring to the embodiments of the present invention described in detail below, the advantages and features of the present invention and the method for implementing the present invention will become apparent. However, the present invention is not limited to the embodiments set forth below, but can be implemented in various different forms. The following embodiments are provided only to fully disclose the present invention and to inform those skilled in the art of the scope of the present invention, and the present invention is only limited by the scope of the appended claims.

The shapes, sizes, ratios, angles, numbers, etc. shown in the drawings for explaining the embodiments of the present invention are exemplary, and therefore, the present invention is not limited to the content shown. Throughout the specification, the same or similar element numbers indicate the same or similar elements. In addition, in the description of the present invention, when it is determined that the detailed description of the related well-known technology unnecessarily makes the subject of the present invention unclear, the detailed description will be omitted. When using sentences such as "include", "have", "include", etc. mentioned here, you can add any other part, unless you use the sentence "only". When an element is expressed in a singular form, the element may encompass the plural form unless the element is clearly indicated.

In addition, when explaining the elements in the embodiments of the present invention, even if no clear instructions are otherwise given, they should be interpreted as covering the tolerance range.

In addition, when describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used herein. Each of these terms is not used to define the nature, order, or order of the corresponding components, but is only used to distinguish the corresponding components from other components. In the case of describing a particular structural element being "connected to" another structural element, "coupled to" another structural element, or "contacting" another structural element, it should be interpreted as that another structural element can be "connected to" a structure Element, "coupled to" a structural element, or "contact" a structural element, and the specific structural element directly The ground is connected to or in direct contact with another structural element. When using, for example, "on", "above", "below", "beside", etc. to describe the positional relationship between two parts, unless you use something like " Only" or "direct" terms, otherwise more than one other part can be located between the two parts.

In addition, the components in the embodiments of the present invention are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, when the constituent element is referred to as the first constituent element below, it may be the second constituent element within the technical idea of the present invention.

In addition, the features (components) in the embodiments of the present invention may be partially or completely coupled or combined with each other or partially or completely separated from each other, may be interlocked and separated technically, and the various embodiments may be mutually It can be implemented independently or in combination with each other.

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

FIG. 1 is a structural diagram illustrating a display device according to an embodiment of the invention.

1, the display device 10 may include a display panel 100: and a backlight unit 200 configured to radiate light to the display panel 100.

The display panel 100 may be a liquid crystal panel. The liquid crystal panel may include: a liquid crystal layer capable of generating a difference in transmittance according to the arrangement of liquid crystal molecules; pixel electrodes configured to selectively apply voltage to the liquid crystal layer; and common electrodes configured to apply a common voltage to the liquid crystal layer ( common voltage) to correspond to the pixel electrode. The liquid crystal layer may be disposed between the pixel electrode and the common electrode, and the arrangement of the liquid crystal molecules may be determined based on the voltage applied between the pixel electrode and the common electrode. In addition, the display panel 100 may include a color filter. In addition, the display panel 100 may further include: a pixel circuit configured to selectively apply a voltage to the pixel electrode; and a driving circuit configured to apply a signal and voltage to the pixel circuit.

The backlight unit 200 is disposed under the display panel 100, and may uniformly radiate light to at least a part or the entire surface of the display panel 100 from under the display panel 100. The backlight unit 200 may generate and radiate light using a light emitting diode. The backlight unit 200 may be spaced apart from the display panel 100 by a predetermined distance d1.

FIG. 2 is a view illustrating the structure of a backlight unit included in a display device according to an embodiment of the present invention.

2, the display device 10 according to an embodiment of the present invention may include a display panel 100; and a backlight unit 200 disposed under the display panel 100 and configured to supply light to the display panel 100.

Various structures may be provided between the backlight unit 200 and the display panel 100. For example, the display panel 100 may be fixed to the backlight unit 200 via a light guide plate 400, a foam pad 500, etc., but the present invention is not limited thereto.

The backlight unit 200 may include a bottom cover 300 configured to accommodate optical elements and the like constituting the backlight unit 200.

The substrate 210 may be disposed on the cover bottom 300, and a plurality of light emitting devices 211 may be disposed on the substrate 210. The light emitting device 211 may be, for example, a light emitting diode (LED), or may be a small LED or a micro LED. In addition, the light emitting device 211 may be provided in a form in which the wafer type light emitting device 211 is mounted on the substrate 210, so that the thickness of the backlight unit 200 may be reduced, and a light source with a wide radiation angle and high optical efficiency may also be provided. The light emitting device 211 configured to be mounted on the substrate 210 may be referred to as a light emitting device 211 having a flip chip structure.

The light emitting device 211 may emit light in a white wavelength band, or in some cases, may emit light in a specific wavelength band (for example, a blue wavelength band). The substrate 210 may be a printed circuit board, and the reflector 212 may be provided on at least a part of an area where the light emitting device 211 is not provided on the substrate 210. The light source protection unit 205 may be provided on a plurality of light emitting devices 211 and reflectors 212. The light source protection unit 205 can protect a plurality of light emitting devices 211 and can provide a function of diffusing light emitted from the light emitting devices 211. The light source protection unit 205 may be a resin layer containing resin.

The light modification sheet 216 may be provided on the light source protection unit 205. The light modification sheet 216 may include a plurality of light modification patterns 216p provided on the face facing the light emitting device 211. Here, a plurality of light modification patterns 216p may be disposed at positions corresponding to the plurality of light emitting devices 211 on the lower surface of the light modification sheet 216. The light modification pattern 216p may transmit a part of the light emitted from the light emitting device 211. The light modification sheet 216 may be a light control sheet capable of transmitting a part of light. The light modification sheet can diffuse, reflect, diffract, or transmit light emitted from the light emitting device 211, thereby improving the image quality of the backlight unit 200.

That is, by arranging the light modification pattern 216p in the region where the intensity of the light emitted from the light emitting device 211 is the highest, it is possible to reduce the gap between the region where the light emitting device 211 is provided (the region with a larger amount of light) and the light emitting device 211. The brightness deviation between regions (regions with a small amount of light).

The light modifying sheet 216 may contain a light modifying material. In addition, the light modification pattern 216p may include titanium dioxide (TiO ₂ ). In addition, the light modifying material may be white. However, it is not limited to this.

A diffusion plate 218 configured to diffuse light incident from below may be provided on the light modification sheet 216. In addition, the phosphor film 217 or one or more optical sheets 219 may be provided on the diffusion plate 218. When the light incident on the phosphor film 217 is blue light, the light passing through the phosphor film 217 may be converted into white light.

3A to 3E are views respectively illustrating examples of the specific structure of the backlight unit shown in FIG. 2.

3A, a plurality of light emitting devices 211 may be disposed on the substrate 210. A reflective film coated on the substrate 210 may be provided. The coated reflective film may be formed of white pigment. That is, a white pigment may be applied to the substrate 210.

Referring to FIG. 3B, the reflector 212 may be disposed on at least a part of an area other than the area where the light emitting device 211 is disposed on the substrate 210.

The reflector 212 may be provided in a shape in which an area corresponding to the light emitting device 211 is open, and may be provided on the substrate 210. The reflector 212 can reflect the light emitted from the light emitting device 211 to the front surface of the backlight unit (facing the display panel 100), thereby improving the optical efficiency of the backlight unit.

Here, when the light emitting device 211 is provided in the form of a wafer, since the size of the light emitting device 211 is small, the height of the reflector 212 may be greater than the height of the light emitting device 211.

Therefore, the light emitted in the lateral direction of the light emitting device 211 can be reflected by the side of the opening in the reflector 212 and can be emitted to the front surface of the backlight unit 200, thus further improving the optical efficiency of the backlight unit 200.

Referring to FIG. 3C, the light source protection unit 205 may be provided on a plurality of light emitting devices 211 and reflectors 212. The light source protection unit 205 may contain, for example, resin. When the light source protection unit 205 contains resin, the light source protection unit 205 can be installed by arranging a partition wall on the outside of the substrate 210 or the area where the plurality of light emitting elements 211 are provided, and coating the resin on the inside of the partition wall. . The light source protection unit 205 functions to protect a plurality of light emitting devices 211 disposed on the substrate 210, and can provide the function of a light guide plate by diffusing the light emitted from the light emitting devices 211. The light emitted from the light emitting device 211 may be more uniformly spread to the upper surface of the light source protection unit 205 by the light source protection unit 205. At this time, even if the reflector 212 changes or adjusts the direction in which light is spread by the light source protection unit 205 or the like, the intensity of the light emitted in the vertical direction of the light emitting device 211 may be high, and thus the uniformity of the image may be deteriorated.

According to the embodiment of the present invention, by providing a light modification pattern 216p having optical characteristics such as scattering, reflection, diffraction, and transmission at a position corresponding to the light emitting device 211 on the light source protection unit 205, the backlight can be reduced. The thickness of the unit 200 improves the uniformity of the image.

3D, the light modification sheet 216 may be disposed on the light source protection unit 205, and a plurality of light modification patterns 216p may be disposed on the lower surface of the light modification sheet 216. However, the present invention is not limited to this, and a plurality of light modification patterns 216p may be provided on the upper surface of the light modification sheet 216. Then, the light modification sheet 216 may be adhered to the light source protection unit 205 through a sheet of adhesive film 215. The adhesive film 215 may be an OCA (Optical Clear Adhesive, optical adhesive) film. The light modification sheet 216 may be made of, for example, PET or the like, but is not limited thereto. Each of the plurality of light modification patterns 216 p provided on the lower surface or the upper surface of the light modification sheet 216 may be arranged to correspond to one of the plurality of light emitting devices 211 provided on the substrate 210. For example, in consideration of the diffusion characteristics of light, the light modification pattern 216p may be set to at least partially overlap the light emitting device 211, and may be set to overlap the area including the area where the light emitting device 211 is provided. The light modification pattern 216p may scatter, reflect, diffract, or transmit light emitted from the light emitting device 211. For example, the light modification pattern 216p may scatter the light emitted from the light emitting device 211 to allow the light to be emitted from the light modification sheet 216. In addition, the light modification pattern 216p may reflect the light emitted from the light emitting device 211 in the vertical direction, and may cause the light to be reflected by the reflector 212 again, and therefore, the light is emitted between the light emitting devices 211 or between the light modification patterns 216p. area.

As described above, the light emitted from the light emitting device 211 may be scattered, reflected, diffracted, or transmitted by the light modification pattern 216p, and the image quality of the backlight unit 200 may be improved.

3E, the diffusion plate 218 may be provided on the light modification sheet 216, and a phosphor film 217 may be provided on the diffusion plate 218. Then, at least one optical sheet 219 may be disposed on the phosphor film 217. Here, the arrangement positions of the diffusion plate 218 and the phosphor film 217 may be exchanged with each other. The diffusion plate 218 may diffuse the light emitted through the light modification sheet 216.

The phosphor film 217 may include a phosphor having a specific color, and may excite incident light to emit light in a specific wavelength band. Therefore, the light passing through the phosphor film 217 may have a specific color contained in the phosphor film 217 or a color mixed with the specific color. For example, in a case where the light emitting device 211 emits light in the first wavelength band (for example, blue light), the phosphor film 217 may emit light in the second wavelength band (for example, green light) and light in the third wavelength band (for example, , Red light) in response to the light incident on it.

In some cases, the phosphor film 217 may be provided in a partial area on the diffusion plate 218. For example, when the light emitting device 211 emits light in the blue wavelength band, the phosphor film 217 may only be provided in the In the area other than the area corresponding to the area where the blue sub-pixels are arranged in the display panel 100. That is, light that has not passed through the phosphor film 217 can reach the blue sub-pixels of the display panel 100. In addition, the phosphor film 217 may not be provided in the backlight unit 200. For example, when the light emitting device 211 emits light in the white wavelength band or is coated with a color conversion film on its emission surface, and the color conversion film emits light in the green wavelength band and the red wavelength band, the phosphor film 217 may not be provided. .

As described above, these embodiments can reduce the thickness of the backlight unit while improving the backlight by providing the light modifying sheet 216 including the light modifying patterns 216p provided at positions corresponding to the light emitting device 211 and various optical elements. The image quality of the unit.

Hereinafter, the embodiment will be described using a specific example of the light modification pattern 216p provided on the light modification sheet 216.

4 is a view illustrating the structure of a backlight unit according to an embodiment of the present invention.

4, the substrate 210 may be disposed on the cover bottom 300, and the substrate 210 may be bonded to the cover bottom 300 through an adhesive tape 210a disposed between the cover bottom 300 and the substrate 210.

A plurality of light emitting devices 211 may be provided on the substrate 210, and the reflector 212 may be provided on at least a part of an area other than the area where the light emitting device 211 is provided on the substrate 210.

Here, each of the light emitting devices 211 may be, for example, an LED, and may include: a light emitting portion 211a including an n-type semiconductor layer, an active layer, and a p-type semiconductor layer; and an electrode portion 211b. The light source protection unit 205 is provided on a plurality of light emitting devices 211 and reflectors 212. The light modification sheet 216 may be disposed on the light source protection unit 205, and the light modification sheet 216 is provided with a light modification pattern 216p at a position corresponding to the light emitting device 211. Then, the diffusion plate 218, the phosphor film 217, the optical sheet 219, and the like may be disposed on the light modification sheet 216.

The light modification pattern 216p provided on the lower surface of the light modification sheet 216 can be realized by printing a substance having a light modification property on the light modification sheet 216. For example, the light modification pattern 216p can be set by a method of printing ink containing titanium dioxide (TiO ₂ ) on the light modification sheet 216. In addition, the light modification patterns 216p provided on the lower surface of the light modification sheet 216 may be arranged in one layer, or may be arranged in a multilayer structure. That is, as shown in FIG. 4, the light modification pattern 216p provided on the lower surface of the light modification sheet 216 may be configured in three layers. The light-modifying pattern 216p can be realized by printing the light-modifying substance three times on the light-modifying sheet 216, and the area of the light-modifying substance to be printed can be gradually narrowed. Then, the light modification pattern 216p can be set on the light emitting device 211 by reversing and setting the light modification sheet 216 on the light source protection unit 205 with the light modification pattern 216p disposed thereon.

Therefore, in a direction away from the bottom of the light modification sheet 216, the area of the light modification patterns 216p may gradually narrow, and the thickness of each light modification pattern 216p may be greater in its central portion than its outer (peripheral) portion.

That is, since the intensity of light emitted in the vertical direction from the light emitting device 211 is greater than the intensity of light emitted in the oblique or lateral direction, the central part of the light modification pattern 216p may be configured to be thinner than other parts. However, the embodiment is not limited to this.

By providing the light-modifying pattern 216p on the light-emitting device 211 as described above, it is possible to prevent or reduce the occurrence of hot spots by scattering, reflecting, diffracting, or blocking at least a part of the light emitted from the light-emitting device 211 in the vertical direction. In the area of the light emitting device 211. The light modification sheet 216 on which the light modification pattern 216p is provided may be adhered to the light source protection unit 205 via an adhesive film 215. At this time, the adhesive film 215 may be disposed in at least a part of an area other than the area where the light modification pattern 216p is disposed on the lower surface of the light modification sheet 216.

Therefore, the adhesive film 215 may not be disposed in the area where the light modification pattern 216p is disposed, and there may be an air gap between the light modification pattern 216p and the light source protection unit 205. In addition, the side portion of the light modification pattern 216p and the adhesive film 215 may be spaced apart from each other. Since there is an air gap between the light modification pattern 216p and the light source protection unit 205, light emitted in the lateral direction of the modification pattern 216p may be reflected by the air gap through the light modification sheet 216 and toward the display panel 100. That is, the light emitted in the lateral direction of the light modification pattern 216p may be emitted by an air layer having a low refractive index at a large refraction angle, or may be reflected by the air layer. Since the light reflected by the air layer is emitted after being reflected again by the reflector 212, it is possible to improve optical efficiency while assisting the light modification function of the light modification pattern 216p.

As described above, through the structure in which the light modification pattern 216p and the air gap are arranged at the position corresponding to the light emitting device 211, the optical efficiency of the backlight unit can be improved while preventing or reducing hot spots. In addition, the dimming patterns 216p provided on the lower surface of the light modification sheet 216 may be arranged in different structures according to where they are provided.

5A and 5B are views illustrating an example of the structure according to the position of the light modification pattern included in the backlight unit shown in FIG. 4.

5A, there is shown an example of the brightness that appears through the backlight unit according to the structure of the light modification pattern 216p, where EX1 shows an example of the brightness measured when the light modification pattern 216p is arranged in a fixed structure, and EX2 represents when An example of the measured brightness when the light modification pattern 216p is arranged in a different structure according to its position.

As shown in EX1 in FIG. 5A, when the structure of the light modification pattern 216pa arranged in the outer area of the backlight unit 200 and the structure of the light modification pattern 216pc, 216pd arranged in the central area are the same (for example, the same thickness or size ), the brightness of the outer (peripheral) area of the backlight unit may be lower than the brightness of the central area of the backlight unit.

That is, since in the outer area of the backlight unit, when the light modification patterns 216p having the same degree of light modification characteristics are provided, the number of light emitting devices 211 that supply light to the corresponding area is relatively small compared to the central area, Therefore, the brightness may be reduced compared to the central area of the backlight unit.

Therefore, as shown in EX2 in FIG. 5A, by arranging the light modification pattern 216pa provided in the outer area of the backlight unit 200 and the light modification pattern 216pd provided in the central area of the backlight unit 200 to have different structures, The brightness of the outer area of the unit 200 can be prevented from deteriorating, and the overall brightness can be made more uniform.

As an example, the light modification pattern 216p may be arranged such that the thickness T1 of the light modification pattern 216pa provided in the outer region of the backlight unit 200 is smaller than the thickness T2 of the light modification pattern 216pd provided in the central region.

Alternatively, the light modification pattern 216p may be arranged so that the area W1 of the thickest part of the light modification pattern 216pb disposed adjacent to the outer region of the backlight unit is smaller than the area W2 of the thickest part of the light modification pattern 216pd. That is, in the light modification patterns 216pa and 216pb provided in the outer area of the backlight unit 200 or in the area adjacent to the outer area, the area of the portion having the higher blocking characteristic is reduced.

In addition, the light modification pattern 216p may be arranged such that the thickness of the light modification pattern 216p gradually decreases from the central area of the backlight unit 200 toward the outer area, or the area of the thickest part of the light modification pattern 216p is gradually decreased. That is, the light modification patterns 216pd and 216pb provided in or adjacent to the outer area of the backlight unit 200, the area of the portion having the high blocking characteristic is reduced.

In addition, the thickness of the light modification pattern 216p gradually decreases from the central area to the outer area of the backlight unit 200, or the area of the thickest part of the light modification pattern 216p gradually decreases.

In addition, in some cases, the light modification pattern 216p may be arranged in a different manner so that the number or interval of the light emitting devices 211 is different between the central area and the outer area of the backlight unit 200.

5B, another example of the structure in which the light modification pattern 216p is provided on the lower surface of the light modification sheet 216 is shown.

Here, the distance between the light emitting devices 211 provided in the outer area of the backlight unit 200 may be smaller than the distance between the light emitting devices 211 provided in the central area of the backlight unit 200. That is, the light emitting devices 211 may be arranged in a structure in which the light emitting devices 211 are more densely arranged in the outer area of the backlight unit 200 so that the brightness becomes uniform in the central area and the outer area of the backlight unit 200.

In addition, since the light modification patterns 216p disposed on the lower surface of the light modification sheet 216 are disposed to correspond to the light emitting device 211, the interval between the light modification patterns 216p disposed in the outer area of the backlight unit 200 may be different from those disposed in the center. The light in the area modifies the spacing between patterns 216p.

As an example, the interval D1 in the first direction of the light modification patterns 216p disposed in the outer area of the backlight unit 200 may be smaller than the interval D2 in the first direction of the light modification patterns 216p disposed in the central area. In addition, the interval D3 in the second direction of the light modification patterns 216p disposed in the outer area of the backlight unit 200 may be smaller than the interval D4 in the second direction of the light modification patterns 216p disposed in the central area.

The size, thickness, etc. of the light modification pattern 216p provided in the outer region of the backlight unit may be different from the size, thickness, etc. of the light modification pattern 216p provided in the central region of the backlight unit.

For example, as shown in FIG. 5B, the size S1 of the light modification patterns 216pe and 216pf provided in the outer area of the backlight unit 200 may be smaller than the size S2 of the light modification pattern 216pg provided in the central area of the backlight unit 200.

Alternatively, the light modification pattern 216p may have a multilayer structure as described above. In this case, the thickness of the light modification patterns 216pe and 216pf or the area of the portion having the largest thickness of the light modification patterns 216pe and 216pf provided in the outer area of the backlight unit may be smaller than that provided in the central area of the backlight unit 200 The thickness of the light modification pattern 216pg or the region of the portion having the largest thickness in the light modification pattern 216pg.

That is, by reducing the size of the light modification patterns 216pe and 216pf provided in the outer area of the backlight unit, the light modification patterns 216pe and 216pf can be set to correspond to the light emitting devices 211 arranged at small intervals. Therefore, it is possible to prevent or alleviate the occurrence of hot spots at a position corresponding to the light emitting device 211 in the outer area of the backlight unit 200.

In addition, by reducing the degree to which the light emitted from the light emitting device 211 is scattered, reflected, diffracted, or blocked in the outer area of the backlight unit 200, the amount of emitted light is increased and the backlight unit is improved. The brightness of the outer area of the element 200. Therefore, the entire area of the backlight unit 200 can exhibit more uniform brightness.

As described above, by arranging the light modification pattern 216p in the backlight unit 200 to have a different structure in each area, the decrease in brightness in the outer area of the backlight unit 200 can be prevented or reduced, and the uniformity of brightness can be improved.

In addition, the hot spot of the backlight unit 200 can be prevented or reduced and the uniformity of brightness can be improved through the structure in which the above-mentioned modified pattern 216p is provided.

The embodiment can also provide a method for improving the image quality of the backlight unit 200 and improving the optical efficiency of the backlight unit by diffracting the light emitted in the vertical direction of the light emitting device 216p.

6 is a structural diagram illustrating an embodiment of the backlight unit shown in FIG. 1; and FIG. 7 is a perspective view illustrating a reflector used in the backlight unit shown in FIG. 1.

6 and 7, the backlight unit 200a may include: a substrate 210; a light-emitting device 211 disposed on the substrate 210 having a flip-chip structure; a reflector 212 disposed to surround the light-emitting device 211 and the periphery of the light-emitting device A region 1AR; the colored resin 213 is provided in the first region 1AR; an adhesive film 215 is provided above the colored resin 213 to be spaced apart from the colored resin 213 by a predetermined distance; and a light modification sheet 216 is provided on the adhesive film 215 and There is a light modification pattern 216p arranged to correspond to the position of the light emitting device 211.

The light emitting device 211 may have a flip chip structure. The light emitting device 211 may emit blue light. However, the color of the light emitted by the light emitting device 211 is not limited to this. The light emitting device 211 may be disposed in the center of the first area 1AR on the substrate 210.

The reflector 212 may reflect the light emitted from the light emitting device 211. The reflector 212 may be provided on the substrate 210. The reflector 212 may include a hole corresponding to the first area 1AR, as shown in FIG. 7. When the reflector 212 is disposed on the substrate 210, the first area 1AR on the substrate 210 may be exposed to correspond to the hole. In addition, the substrate 210 may reflect light. The substrate 210 may include a reflective material. The substrate 210 and the reflector 212 may be coated with a white pigment to reflect light. The white pigment may include a photo solder resist (PSR). However, the present invention is not limited to this. Here, the shape of the hole corresponding to the first region 1AR is shown as a circle, but is not limited thereto.

The colored resin 213 may be disposed in the first area 1AR. Due to the hole, the colored resin 213 may be provided only in the first region 1AR. The colored resin 213 can be cured by ultraviolet rays. Will be colored After the resin 213 is disposed in the first region 1AR, ultraviolet rays may be used to cure the colored resin 213. The colored resin 213 may include a red phosphor. The light passing through the colored resin 213 may be purple. However, the present invention is not limited to this. Since the colored resin 213 is provided only in the first region 1AR, the amount of phosphor used can be reduced, thereby reducing manufacturing costs.

The adhesive film 215 may be provided on the colored resin 213. The adhesive film 215 may contain resin. The refractive index of the adhesive film 215 may be the same as or similar to the refractive index of the colored resin 213. However, the present invention is not limited to this. The adhesive film 215 may be disposed to be spaced apart from the coloring resin 213 by a predetermined distance. That is, the optical path regulator 214 having a refractive index different from that of the coloring resin 213 may be provided between the adhesive film 215 and the coloring resin 213. The light path adjuster 214 and the colored resin 213 may be in contact with each other so that light may undergo total internal reflection at the boundary between the light path adjuster 214 and the colored resin 213. The angle at which the light is totally reflected may correspond to the refractive index difference between the optical path adjuster 214 and the coloring resin 213. The optical path adjuster 214 may be a material having a refractive index in the range of 1 to 1.46. The light path regulator 214 may be air. However, the present invention is not limited to this.

The light modification sheet 216 may contain a light modification pattern 216p. The light modification sheet 216 may be disposed on the adhesive film 215 such that the light modification pattern 216p is disposed at a position corresponding to the light emitting device 211. The light modification pattern 216p can prevent the light emitted from the light emitting device in the vertical direction from being scattered, reflected, diffracted, or blocked from hot spots. The light modification pattern 216p may reflect incident light.

The phosphor film 217 may be provided on the light modification sheet 216. The color of the phosphor included in the phosphor film 217 may be different from the color of the phosphor included in the colored resin 213. The diffusion plate 218 may be provided on the phosphor film 217 and the optical sheet 219 may be provided on the diffusion plate 218. The number of optical sheets 219 is shown as one, but is not limited to this.

In an embodiment, the reflector 212a may be further disposed above the light emitting device 211. The reflector 212a provided above the light emitting device 211 may be a distributed Bragg reflector. However, the present invention is not limited to this. The light emitted from the light emitting device 211 and having a path in the vertical direction or in a direction close to the vertical direction may be reflected by the reflector 212a.

Fig. 8 is a conceptual diagram illustrating the path of light emitted from the light emitting device.

Referring to FIG. 8, the light emitting device 211 may be provided in the colored resin 213. Therefore, when the light emitted from the light emitting device 211 passes through the colored resin 213, the light emitted from the light emitting device 211 may be excited to have energy corresponding to the color mixed with the color of the phosphor contained in the colored resin 213. For example, when the light emitting device 211 emits blue light and the colored resin 213 contains a red phosphor, it passes through the colored tree The light of the grease 213 may have a purple color. However, depending on the light path, the degree of color mixing may vary. For example, since the thickness of the coloring resin 213 through which the light beam of the first group A passes among the light beams emitted from the light emitting device 211 is small, the colors cannot be mixed sufficiently. However, among the light beams emitted from the light emitting device 211, the light beams corresponding to the second group B pass through the colored resin 213 and are reflected by the reflector 212. Then, the light beam passes through the colored resin 213 again, and then proceeds to the display panel 100. Therefore, the light beams of the first group A and the light beams of the second group B may be different in color reproducibility. In addition, there is a problem that the color reproducibility of the backlight unit 200a is deteriorated by the light beam of the first group A.

In order to solve the above-mentioned problem, when at least some of the light beams of the first group A undergo total internal reflection at the boundary of the colored resin 213 and their path is changed, the light beams emitted from the light emitting device 211 may be included in the third group C in. The light beams of the third group C are reflected at the upper boundary of the colored resin 213, and then directed toward the colored resin 213 toward the reflector 212 (or substrate 210), and then reflected by the reflector 212 (or substrate 210) to radiate toward the display panel 100. This can enhance the color reproducibility of the backlight unit 200a.

In order to cause total internal reflection to occur at the boundary of the colored resin 213, a material having a refractive index different from that of the colored resin 213 (for example, the optical path regulator 214 shown in FIG. 6) may be provided on the colored resin 213. In addition, by setting a larger refractive index difference between the colored resin 213 and the material provided on the colored resin 213, the angle θ 1 at which total internal reflection occurs at the boundary of the colored resin 213 can also be increased, which makes it possible The amount of light undergoing total internal reflection at the boundary of the colored resin 213 is increased.

9A to 9F are conceptual diagrams illustrating the manufacturing process of the backlight unit shown in FIG. 6.

As shown in FIG. 9A, in the backlight unit 200a, the light emitting device 211 may be disposed on the substrate 210. Each light emitting device 211 may have a flip chip structure directly connected to the substrate 210. The light emitting device 211 may be arranged to correspond to the first area 1AR on the substrate 210. Each light emitting device 211 may be disposed in the center of one of the first regions 1AR. Here, although the number of light emitting devices 211 provided on the substrate 210 is shown as three, the present invention is not limited thereto. The substrate 210 may include a reflective material to reflect light. In addition, the substrate 210 may be coated with white pigment. In addition, each light-emitting device 211 may be further provided with a reflector 212a, as shown in FIG. 6. The reflector 212a provided on the light emitting device 211 may be a distributed Bragg reflector.

As shown in FIG. 9B, the reflector 212 may be provided on the substrate 210. The reflector 212 may include holes having a predetermined diameter, and these holes may correspond to the first area 1AR. Therefore, the first area 1AR on the substrate 210 may not be covered by the reflector 212.

In addition, as shown in FIG. 9C, the colored resin 213 is placed in the first area 1AR corresponding to the holes of the reflector 212, and cured by ultraviolet rays. The upper surface of the colored resin 213 may be disposed below the upper surface of the reflector 212. That is, the height h2 of the reflector 212 may be higher than the height h1 of the colored resin 213. Here, although the upper surface of the colored resin 213 is shown to be parallel to the horizontal surface, the present invention is not limited to this, and the upper surface of the colored resin 213 may be concave or convex. However, the highest point of the upper surface of the colored resin 213 is lower than the height of the reflector 212.

Then, as shown in FIG. 9D, the adhesive film 215 may be disposed above the substrate 210 on which the reflector 212 is disposed. Since the height of the reflector 212 is higher than the height of the colored resin 213, the adhesive film 215 may be provided so that the adhesive film 215 is disposed above the colored resin 213 to form a predetermined gap above the colored resin 213. The optical path adjuster 214 may be provided in the predetermined gap. The light path regulator 214 may be air. However, the optical path adjuster 214 is not limited to this, and may be any material as long as the material has a refractive index different from that of the coloring resin 213. The adhesive film 215 may be a light-transmitting material.

In addition, as shown in FIG. 9E, the light modification sheet 216 may be provided on the adhesive film 215. The light modification sheet 216 may include a light modification pattern 216p, and the light modification pattern 216p may be disposed at a position corresponding to a position where the light emitting device 211 is disposed. The light modification pattern 216p included in the light modification sheet 216 can reflect, scatter, diffract, or block light emitted from the light emitting device 211 in the vertical direction or at an angle close to the vertical direction, thereby preventing or reducing the A hot spot generated in the backlight unit 200.

In addition, as shown in FIG. 9F, a phosphor film 217 may be provided on the light modification sheet 216. The phosphor film 217 may include a phosphor having a color different from that of the coloring resin. The diffusion plate 218 may be provided on the phosphor film 217 and the optical sheet 219 may be provided on the diffusion plate 218.

Fig. 10 is a structural diagram illustrating an embodiment of the backlight unit shown in Fig. 1.

10, the backlight unit 200b may include: a substrate 210; a light emitting device 211 provided on the substrate 210 having a flip chip structure; a reflector 212 provided to surround the light emitting device 211 and a first area 1AR including the periphery of the light emitting device Colored resin 213, disposed in the first area 1AR; Adhesive film 215, disposed to be spaced apart from the coloring resin 213 by a predetermined distance; and Light modification sheet 216, disposed on the Adhesive film 215 and has a setting corresponding to the light emitting device 211 The position of the light modifies the pattern 216p.

The light emitting device 211 may emit blue light. However, the present invention is not limited to this. The light emitting device 211 may be disposed in the center of the first area 1AR on the substrate 210.

The reflector 212 may reflect the light emitted from the light emitting device 211. The reflector 212 may be provided on the substrate 210. The reflector 212 may be the same as the reflector 212 shown in FIG. 7 and may include A hole corresponding to the first area 1AR. When the reflector 212 is disposed on the substrate 210, the first area 1AR on the substrate 210 may be exposed to correspond to the hole. The reflector 212 may be coated with white pigment to reflect light. The white pigment may include a photo solder resist (PSR). However, the present invention is not limited to this. Here, the shape of the hole corresponding to the first region 1AR is shown as a circle, but is not limited thereto.

The colored resin 213 may be disposed in the first area 1AR. Due to the hole, the colored resin 213 may be provided only in the first area 1AR (and in other areas exposed by other holes formed by the reflector 212). The colored resin 213 can be cured by ultraviolet rays. After the colored resin 213 is disposed in the first region 1AR, the colored resin 213 may be cured using ultraviolet rays. The colored resin 213 may include a yellow phosphor. In addition, the colored resin 213 may include a red phosphor and a green phosphor. The light passing through the colored resin 213 may be purple. However, the present invention is not limited to this. Since the colored resin 213 is provided only in the first area 1AR (not in a larger area on the substrate 210), the amount of phosphor used can be reduced, thereby reducing manufacturing costs.

The adhesive film 215 may be provided on the colored resin 213. The adhesive film 215 may contain resin. The refractive index of the adhesive film 215 may be the same as or similar to the refractive index of the colored resin 213. However, the present invention is not limited to this. The adhesive film 215 may be an OCA film. The adhesive film 215 may be disposed to be spaced apart from the coloring resin 213 by a predetermined distance. That is, the optical path regulator 214 having a refractive index different from that of the coloring resin 213 may be provided between the adhesive film 215 and the coloring resin 213. The light path adjuster 214 and the colored resin 213 may be in contact with each other so that light may undergo total internal reflection at the boundary between the light path adjuster 214 and the colored resin 213. The angle at which the light undergoes total internal reflection may correspond to the refractive index difference between the light path adjuster 214 and the coloring resin 213. The light path regulator 214 may be air. However, the present invention is not limited to this.

The light modification sheet 216 may contain a light modification pattern 216p. The light modification sheet 21 may be disposed on the adhesive film 215 so that the light modification pattern 216p is disposed at a position corresponding to the light emitting device 211. The light modification pattern 216p can prevent or alleviate hot spots generated in the backlight unit 200b due to reflection, scattering, diffraction, or blocking of light emitted from the light emitting device and having a path in the vertical direction or a path close to the vertical direction. The light modification pattern 216p may have the same shape as the light modification pattern shown in FIG. 4.

The diffusion plate 218 may be provided on the light modification sheet 216 and the optical sheet 219 may be provided on the diffusion plate 218. The number of optical sheets 219 is shown as one, but is not limited to this.

Therefore, the colored resin 213 may contain two phosphors having different colors, or may contain phosphors having two colors, so that unlike the backlight unit shown in FIG. The phosphor film 217 above the light modification sheet is not included. This can reduce the amount of phosphor used in the backlight unit 200b, thereby reducing manufacturing costs.

Fig. 11 is a structural diagram illustrating an embodiment of the backlight unit shown in Fig. 1.

11, the backlight unit 200c may include: a substrate 210; a light emitting device 211 provided on the substrate 210 having a flip chip structure; a reflector provided to surround the light emitting device 211 and the first area 1AR including the periphery of the light emitting device; The colored resin 213 is disposed in the first area 1AR; the adhesive film 215 is disposed above the colored resin 213 to be spaced apart from the colored resin 213 by a predetermined distance; and the light modification sheet 216 is disposed on the adhesive film 215 and has a setting to correspond The light modification pattern 216p at the position of the light emitting device 211.

The light emitting device 211 may have a flip chip structure. In the flip chip structure, the light emitting device 211 is directly disposed on the substrate 210 instead of being installed in the package, so that a light source with a light weight and a large radiation angle can be manufactured. The light emitting device 211 may emit blue light. However, the present invention is not limited to this. The light emitting device 211 may be disposed in the center of the first area 1AR on the substrate 210.

The groove CA corresponding to the first area 1AR may be provided in the substrate 210. The light emitting device 211 may be disposed in the groove CA. The outer wall of the groove CA can be used as a reflector. In order for the outer wall of the groove CA to function as a reflector, a white pigment may be applied to the substrate 210. That is, the reflector may include the substrate 210 and the white pigment applied to the substrate. The white pigment may include a photo solder resist (PSR). However, the present invention is not limited to this. Here, the shape of the groove CA corresponding to the first area 1AR may be circular, but is not limited thereto.

The colored resin 213 may be disposed in the first area 1AR. Due to the groove CA, the colored resin 213 may be provided only in the first area 1AR (and in other areas exposed by other grooves of the substrate 210). The colored resin 213 can be cured by ultraviolet rays. After the colored resin 213 is disposed in the first region 1AR, the colored resin 213 may be cured using ultraviolet rays. The colored resin 213 may include a red phosphor. However, the colored resin 213 is not limited thereto, and may include a yellow phosphor. In addition, the colored resin 213 may include a red phosphor and a green phosphor. The light passing through the colored resin 213 may be purple. However, the present invention is not limited to this. Since the colored resin 213 is provided only in the first region 1AR, the amount of phosphor used can be reduced.

The adhesive film 215 may be provided on the colored resin 213. The adhesive film 215 may contain resin. The refractive index of the adhesive film 215 may be the same as or similar to the refractive index of the colored resin 213. However, the present invention is not limited to this. The adhesive film 215 may be an OCA film. The adhesive film 215 can be set with the coloring resin 213 Be separated by a predetermined distance. That is, the optical path regulator 214 having a refractive index different from that of the coloring resin 213 may be provided between the adhesive film 215 and the coloring resin 213. The light path adjuster 214 and the colored resin 213 may be in contact with each other so that light may undergo total internal reflection at the boundary between the light path adjuster 214 and the colored resin 213. The angle at which the light undergoes total internal reflection may correspond to the refractive index difference between the light path adjuster 214 and the coloring resin 213. The optical path adjuster 214 may be a material having a refractive index in the range of 1 to 1.46. The light path regulator can be air. However, the present invention is not limited to this.

The light modification sheet 216 may contain a light modification pattern 216p. The light modification sheet 216 may be disposed on the adhesive film 215 such that the light modification pattern 216p is disposed at a position corresponding to the light emitting device 211. The light modification pattern 216p can prevent or alleviate the hot spots generated in the backlight unit 200c due to reflection, scattering, diffraction, or blocking of light emitted from the light emitting device and having a path in the vertical direction or a path close to the vertical direction. . The light modification pattern 216p may have the same shape as the light modification pattern shown in FIG. 4. However, the present invention is not limited to this.

The phosphor film 217 may be provided on the light modification sheet 216. The phosphor film 217 may include a green phosphor. However, the present invention is not limited to this. In addition, when the colored resin 213 contains yellow phosphors or red phosphors and green phosphors, the phosphor film 217 may not be provided on the light modification sheet 216.

The diffusion plate 218 may be provided on the light modification sheet 216 or the phosphor film 217, and the optical sheet 219 may be provided on the diffusion plate 218. The number of optical sheets 219 is shown as one, but is not limited to this.

The above description and accompanying drawings provide examples of the technical idea of the present invention for illustrative purposes only. Those with ordinary knowledge in the technical field of the present invention will understand that various modifications and changes in form can be made without departing from the basic characteristics of the present invention, such as combination, separation, replacement, and configuration changes. Therefore, the embodiments disclosed in the present invention are intended to illustrate the scope of the technical idea of the present invention, and the scope of the present invention is not limited by the embodiments. The scope of the present invention should be interpreted on the basis of the appended claims, so that all technical ideas included in the scope equivalent to the claims belong to the present invention.

This application claims priority from Korean Patent Application No. 10-2018-0159467 filed on December 11, 2018, which is incorporated herein by reference for all purposes, as if it were fully described here.

1AR: first area

200a: backlight unit

210: substrate

211: Light-emitting device

212: reflector

212a: reflector

213: Colored resin

214: Optical Path Adjuster

215: Adhesive film

216: Light Modified Film

216p: light modification pattern

217: Phosphor film

218: diffuser

219: optical sheet

Claims (34)

A backlight unit includes: A substrate; A light emitting device located on the substrate; The lower reflector is located on the substrate, the lower reflector has a hole for accommodating and exposing the light emitting device, the height of the lower reflector is greater than the height of the light emitting device, and is configured to reflect the light emitted from the light emitting device ； A colored resin located in the hole and on the light emitting device, and the height of which is lower than the height of the lower reflector; and An optical path adjuster is located above the light-emitting device and on the colored resin, the optical path adjuster has a refractive index different from that of the colored resin to adjust the emitted light at the boundary between the optical path adjuster and the colored resin Reflect to the lower reflector. The backlight unit according to claim 1, wherein the colored resin includes a plurality of phosphors having at least two different colors. The backlight unit according to claim 1, wherein an upper surface of the colored resin is concave or convex. The backlight unit according to claim 1, wherein the light path regulator includes air. The backlight unit according to claim 1, further comprising: A distributed Bragg reflector located on the light-emitting device, the distributed Bragg reflector is located in the hole and between the substrate and the optical path adjuster. The backlight unit according to claim 1, further comprising: An adhesive film on the lower reflector and the optical path adjuster; and A light-modifying sheet is located on the adhesive film, the light-modifying sheet includes a plurality of light-modifying patterns at least partially overlapping with a plurality of light-emitting devices, and the plurality of light-modifying patterns has One or more layers of a top layer on a surface of the substrate, and there is an air gap between the one or more layers and the adhesive film. The backlight unit according to claim 6, wherein the one or more layers further comprise: An intermediate layer is located on a surface of the top layer facing the substrate, and the size of the top layer is larger than the size of the intermediate layer. The backlight unit according to claim 7, wherein the one or more layers further include: A bottom layer is located on a surface of the substrate of the middle layer, and the size of the bottom layer is smaller than the size of the middle layer. The backlight unit according to claim 6, further comprising: A phosphor film on the light modification sheet; A diffusion plate located on the phosphor film; and An optical sheet is located on the diffusion plate. A backlight unit includes: A substrate including a groove having a side wall coated with a reflective material and having a first height; A light emitting device located in the groove and having a second height lower than the first height; A colored resin located in the groove and on the light-emitting device, the colored resin having a third height lower than the first height; and An optical path adjuster is located in the groove and on the colored resin, the optical path adjuster has a refractive index different from that of the colored resin, so that the light emitted from the boundary between the optical path adjuster and the colored resin The light emitted by the device is reflected toward the side walls of the groove. The backlight unit according to claim 10, wherein the colored resin includes a plurality of phosphors having at least two different colors. The backlight unit according to claim 10, wherein an upper surface of the colored resin is concave or convex. The backlight unit according to claim 10, wherein the light path regulator includes air. The backlight unit according to claim 10, further comprising: A distributed Bragg reflector is located on the light-emitting device, and the distributed Bragg reflector is located in the groove and between the substrate and the optical path adjuster. A method for manufacturing a backlight unit, the method comprising: A plurality of light emitting devices are arranged in an area of a substrate; A lower reflector is arranged on the substrate, the lower reflector has holes for accommodating and exposing the plurality of light-emitting devices, and the depth of the holes is greater than the height of the plurality of light-emitting devices; Curing a colored resin in the holes, the height of the cured resin is lower than the depth; and An optical path adjuster is arranged in the holes and on the colored resin, and the optical path adjuster has a refractive index different from that of the colored resin. The method according to claim 15, further comprising: Arranging reflectors on the plurality of light emitting devices; and Coating the substrate with a reflective material. The method according to claim 15, further comprising: Placing an adhesive film on the lower reflector and the optical path adjuster; and A light-modifying sheet is disposed on the adhesive film, the light-modifying sheet includes a plurality of light-modifying patterns at least partially overlapping the plurality of light-emitting devices, and the plurality of light-modifying patterns has the light-modifying sheet facing the One or more layers of a top layer on a surface of the substrate have an air gap between the one or more layers and the adhesive film. The method according to claim 17, further comprising: The top layer is printed on the surface of the light modification sheet. The method according to claim 18, further comprising: Print an intermediate layer of the one or more layers on the top layer, the area of the top layer is larger than the area of the intermediate layer, wherein, before the light modification sheet is placed on the adhesive film, there will be printing of the top layer and the intermediate layer The light modifier is reversed. The method according to claim 19, further comprising: A bottom layer of the one or more layers is printed on the middle layer, and the area of the bottom layer is smaller than the area of the middle layer. A backlight unit includes: A light emitting device with a flip chip structure; A first reflector arranged to surround a first area including the light emitting device and the periphery of the light emitting device; A colored resin is arranged in the first area; An adhesive film arranged above the colored resin to be spaced apart from the colored resin by a predetermined distance; and A light modification sheet is arranged on the adhesive film, and the light modification sheet includes a light modification pattern arranged to correspond to the position of the light-emitting device. The backlight unit according to claim 21, further comprising: A material is arranged between the adhesive film and the colored resin and has a refractive index different from that of the colored resin. The backlight unit according to claim 21, wherein the height of the first reflector is higher than the height of the colored resin. The backlight unit according to claim 21, further comprising: a substrate including a groove corresponding to the first region, and wherein a reflective film is applied to the substrate. The backlight unit according to claim 21, further comprising: A phosphor film is disposed above the light modification sheet and includes a phosphor having a color different from that of the colored resin. The backlight unit according to claim 21, wherein the colored resin includes two phosphors having different colors. The backlight unit according to claim 21, further comprising: A second reflector is arranged on an upper surface of the light emitting device. A display device includes: A display panel; A backlight unit arranged under the display panel and configured to radiate light to the display panel; Wherein, the backlight unit includes: A light emitting device with a flip chip structure; A first reflector arranged to surround a first area including the light emitting device and the periphery of the light emitting device; A colored resin is arranged in the first area; An adhesive film arranged above the colored resin to be spaced apart from the colored resin by a predetermined distance; and A light modification sheet is arranged on the adhesive film, and the light modification sheet includes a light modification pattern arranged to correspond to the position of the light-emitting device. The display device according to claim 28, further comprising: A material is arranged between the adhesive film and the colored resin and has a refractive index different from that of the colored resin. The display device according to claim 28, wherein the height of the first reflector is higher than the height of the colored resin. The display device according to claim 28, wherein the backlight unit further includes a substrate including a groove corresponding to the first region, and wherein a reflective film is applied to the substrate. The display device according to claim 28, further comprising: A phosphor film is disposed above the light modification sheet and includes a phosphor having a color different from that of the colored resin. The display device according to claim 28, wherein the colored resin includes two phosphors having different colors. The display device according to claim 28, further comprising: A second reflector is arranged on an upper surface of the light emitting device.

Images