KR20140065213A - Backlight unit - Google Patents

Abstract

A backlight unit according to an embodiment of the present invention comprises: a light emitting element module which includes a printed circuit board and a plurality of light emitting element packages disposed on the printed circuit board; and a light guide plate which is disposed to face the light emitting element module and contains a plurality of projections spaced apart with a predetermined distance on an opposite side of the light emitting element module. The printed circuit board includes a plurality of concave portions in correspondence to the plurality of projections. The plurality of light emitting element packages is disposed between the plurality of concave portions. A part of the plurality of projections is located inside of the plurality of concave portions. A height of the plurality of projections is higher than a height of the plurality of light emitting element packages.

Description

BACKLIGHT UNIT}

An embodiment relates to a backlight device.

The display device includes a CRT (Cathode Ray Tube), a liquid crystal display (LCD) using an electric field effect, a plasma display panel (PDP) using a gas discharge, and an EL display device (ELD: Electro Luminescence Display), among which liquid crystal display devices are being actively studied.

Since a liquid crystal display device is a light-receiving device that displays an image by adjusting the amount of light coming from the outside, a separate light source for illuminating the LCD panel, that is, a backlight unit, is required.

The backlight device to which the light emitting diode is applied can be used for a liquid crystal display device and a display device as described above, and can also be used for a lighting device in a wide variety of fields. BACKGROUND ART A backlight device generally used includes a light emitting device package including a light emitting diode, a light guide plate for diffusing light of the light emitting device package, and an optical sheet functioning to diffuse or condense light emitted from the light guide plate.

A light emitting diode (LED) included in a light emitting device package of a backlight device can perform high efficiency and low voltage driving. The light emitting diode is a two-terminal diode element including compound semiconductors such as gallium arsenide (GaAs), gallium nitride (GaN), and indium gallium nitride (InGaN). When power is applied to the cathode terminal and the anode terminal of the light emitting diode, the light emitting diode emits visible light as light energy generated when electrons and holes are combined.

Korean Patent Registration No. 10-1044193 discloses a flat illuminating device including a light guide substrate having a hemispherical lens pattern formed on a surface thereof and having an excellent illuminance characteristic compared with the conventional one.

In the case of configuring the backlight device to which the light emitting device package is applied, it is necessary to minimize the amount of light generated from the light emitting device package without being incident on the light guiding plate. For this purpose, it is important that the light guiding plate and the light emitting device package are accurately arranged .

Embodiments provide a backlight device capable of improving the accuracy of a light emitting device package and a light guide plate arrangement, minimizing loss of light emitted from the light emitting device package, improving the amount of light, and reducing a defective ratio.

A backlight device according to an embodiment of the present invention includes a light emitting device module including a printed circuit board and a plurality of light emitting device packages disposed on the printed circuit board and a light emitting device module disposed facing the light emitting module, And a light guide plate having a plurality of protrusions spaced apart from each other by a predetermined distance, the printed circuit board including a plurality of recesses corresponding to the plurality of protrusions, wherein the plurality of light emitting device packages are disposed between the plurality of recesses And the plurality of projections are positioned in the plurality of concave internal areas, and the height of the plurality of projections is greater than the height of the light emitting device package.

The backlight device according to the embodiment includes a printed circuit board including a light guide plate including a plurality of protrusions and a plurality of recesses corresponding to the plurality of protrusions to increase the accuracy of the arrangement of the light emitting device package and the light guide plate, It is possible to minimize the loss of the light generated from the light source and improve the light amount.

Further, the backlight device according to the embodiment can reduce the defect rate.

1 is an exploded perspective view showing a backlight device according to an embodiment.
2 is an exploded perspective view illustrating a light emitting device module according to an embodiment.
3 is a cross-sectional view illustrating a light emitting device package according to an embodiment.
4 is a perspective view showing the arrangement structure of the light emitting device module and the light guide plate of FIG.
5 is a cross-sectional view taken along the line A-A 'in Fig.
6 is an enlarged view of an enlarged portion B in Fig.
7 is a cross-sectional view illustrating an arrangement structure of a light emitting device module and a light guide plate according to another embodiment.
FIG. 8 is an exploded perspective view of a liquid crystal display device including a backlight device according to an embodiment, and FIG. 9 is an assembled perspective view illustrating the liquid crystal display device of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size and area of each component do not entirely reflect actual size or area.

Further, the angle and direction mentioned in the description of the structure of the light emitting device in the embodiment are based on those shown in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

1 is an exploded perspective view showing a backlight device according to an embodiment.

1, the backlight device 100 includes a light emitting device module 120 including a printed circuit board 122 and a light emitting device package 124, a light guide plate 130, an optical sheet 160, and a reflective sheet 150 ).

The light guide plate 130 may convert the light emitted from the light emitting device package 124 into plane light and provide the light to the optical sheet 160.

That is, the light guide plate 130 may be formed of PMMA (polymethylmethacrylate) or transparent acrylic resin in a flat type or a wedge type and may be formed of a glass material, I never do that.

The above-mentioned transparent acrylic resin has a high strength, is less deformed, is light, and has high transmittance of visible light. In the edge-light type, the light emitting device package 124 is located on the outer surface of the backlight device 100, so that the edge of the backlight device 100 may be brighter than other parts.

The light guide plate 130 has a high transmittance of the visible light and can prevent the light from being uniformly transmitted through the entire area of the backlight device 100 and brighter edges.

The optical sheet 160 may be disposed on the light guide plate 130. The optical sheet 160 may include light diffusing particles such as beads and the like to be incident on the light guide plate 130, A prism sheet 164 on which a prism pattern is formed to concentrate the light on the top of the diffusion sheet 166 and a prism sheet 164 on the top surface of the prism sheet 164 to protect the prism sheet 164, And may include a protective sheet 162 to be laminated.

The optical sheet 160 can diffuse and condense the light emitted from the light emitting device package 124 and guided by the light guide plate 130 to secure the brightness and viewing angle.

The diffusion sheet 166 can scatter light and condense the light from the light emitting device package 124 and the prism sheet 164 to make the brightness uniform.

The diffusion sheet 166 may have a thin sheet shape and may be formed of a transparent resin. For example, the diffusion sheet 166 may be formed by coating a film made of polycarbonate or polyester with a resin for light scattering and a light condensing resin.

The prism sheet 164 condenses the light output from the diffusion sheet 166 by forming a prism pattern vertically or horizontally on the surface of the sheet.

The prism pattern of the prism sheet 164 may be formed to have a triangular cross-section to increase the light-condensing efficiency, and the best luminance can be obtained when the vertex angle is 90 ° using a right angle prism.

The protective sheet 162 may be laminated on the top surface of the prism sheet 164 to protect the prism sheet 164.

The reflective sheet 150 may be formed on the lower surface of the light guide plate 130, but is not limited thereto. The reflective sheet 150 may reflect the light generated from the light emitting device package 124 in the direction of the top surface of the light guide plate 130 to increase the light transmission efficiency.

The reflection sheet 150 may be formed by stacking a polyester film having a high reflectivity on the base of a polyethylene resin (PET) base, for example, a white polyester film. Or a reflective material having excellent reflectance including aluminum (Al) and silver (Ag).

The reflective sheet 150 may cover the entire lower surface of the light guide plate 130 and may extend to a region where the light emitting device module 120 is disposed.

The backlight device 100 may further include a light guide plate 130 and a bottom cover 170 for supporting the light emitting device module 120.

 The bottom cover 170 may include a reflective material on a surface facing the light guide plate 130 so as to reflect the light generated from the light emitting device package 124 to the light guide plate 130. [ For example, at least one of aluminum (Al), silver (Ag), gold (Au), platinum (Pt), copper (Cu), and palladium (Pd). In the case where the bottom cover 170 includes the reflective material as described above, the reflective sheet 150 may be omitted.

The light emitting device module 120 will be described in detail below with reference to FIGS. 2 and 3. FIG.

FIG. 2 is an exploded perspective view illustrating the light emitting device module of FIG. 1, and FIG. 3 is a cross-sectional view illustrating the light emitting device package of FIG.

Referring to FIG. 2, the light emitting device module 120 includes a printed circuit board 122 and a light emitting device package 124.

The printed circuit board 122 may be a printed circuit board (PCB), a printed circuit board (PCB), or a printed circuit board (PCB) And does not limit it.

A circuit pattern (not shown) for supplying power to the light emitting element may be formed on the surface of the printed circuit board 122. At this time, the circuit pattern is made of a conductive material, and may be made of copper (Cu), for example.

Referring again to FIG. 2, the light emitting device module 120 may further include a power control module 210 and a connector 230.

The power supply control module 210 shown in FIG. 2 shows a power supply, that is, a power supply for supplying external power, but is not limited thereto.

The power supply control module 210 generates power consumed in the light emitting device package 124 mounted on the printed circuit board 122 and controls the operation of the power supply 212 and the power supply 212 214 and a connector connection portion 216 to which one side of the connector 230 is connected.

At this time, the power supply 212 operates under the control of the control unit 214 and generates the power consumed in the light emitting device package 122.

The control unit 214 can control the operation of the power supply 212 according to an externally input command.

In this case, the command input from the outside may be a command to be output from an input device (not shown) directly connected to the remote controller and the light emitting device module 120, which commands the operation of the device including the light emitting device module 120 , But does not limit it.

The connector connection part 116 is connected to one side of the connector 130 and can supply the power supplied from the power supply 212 to the connector 230.

In addition, the printed circuit board 122 may include a connector terminal 129 to which the other side of the connector 230 is connected.

At this time, the connector terminal 129 may be electrically connected to the connector connection portion 216 through the connector 230.

The plurality of light emitting device packages 124 may be divided into a plurality of groups (not shown), and the light emitting device packages 124 disposed in the plurality of groups may be connected in series.

At this time, the number of the light emitting device packages 124 included in the plurality of groups is not limited.

At least two or more light emitting device packages 124 having different colors may be alternately mounted on the plurality of light emitting device packages 124. The light emitting device packages 124 may be mounted in groups according to the package size, And may be mounted in a light emitting device package. Further, the present invention is not limited thereto.

For example, when the light emitting device module 120 emits white light, the plurality of light emitting device packages 124 may include a light emitting device package that emits green light, a light emitting device package that emits red light, Emitting device package. Accordingly, the light emitting device package that emits green light, red light, and blue light may be alternately mounted, and may be formed of red light, blue light, and green light.

3, the light emitting device package 124 may include a body 341 formed with a cavity C, a lead frame 342, a light emitting device 343, a wire 345, and a resin material 346 have.

The body 341 serves as a housing and has a first lead frame 347 and a second lead frame 348. [ The body 341 may be made of a resin material such as polyphthalamide (PPA), silicon (Si), aluminum (Al), aluminum nitride (AlN), liquid crystal polymer (PSG), polyamide 9T And may be formed of at least one of silicon nitride, silicon carbide, silicon carbide, silicon carbide, silicon carbide, silicon carbide, silicon carbide, But is not limited to this.

The body 341 may be provided with a cavity C having an open top so as to expose the light emitting device 343 to the outside so that the light emitting device 343 may be positioned within the cavity C. In addition, the inside of the body 341 may be inclined so that the angle of reflection of light emitted from the light emitting device 343 may be different depending on the angle of the inclined surface.

As the directional angle of light decreases, the concentration of light emitted to the outside from the light emitting device 343 increases. On the contrary, as the directional angle of the light increases, the light emitted from the light emitting device 343 to the outside The concentration of emitted light is reduced.

The shape of the cavity C formed on the body 341 may be circular, square, polygonal, elliptical, or the like, and may be curved, but the present invention is not limited thereto.

At this time, a reflection coating film (not shown) may be formed on the side surface and the bottom surface of the cavity C forming the inner wall of the cavity C. Here, the surface of the body 341 on which the reflection coating film (not shown) is formed may be smooth or have a predetermined roughness, and may be formed of silver (Ag), aluminum (Al), or the like.

The lead frame 342 may be made of a metal material such as titanium, copper, nickel, gold, chromium, tantalum, platinum, tin, (Al), indium (In), palladium (Pd), cobalt (Co), silicon (Si), germanium (Ge), hafnium (Hf), ruthenium (Ru), and iron (Fe). Further, the lead frame 342 may be formed to have a single layer or a multi-layer structure, but is not limited thereto.

Further, the lead frame 342 may be composed of a first lead frame 347 and a second lead frame 348 to apply different power sources. The light emitting device 343 may be disposed on the second lead frame 348 and the second lead frame 348 may be spaced apart from the first lead frame 347 by a predetermined distance.

The light emitting device 343 is a semiconductor device mounted on the second lead frame 348 and emitting light of a predetermined wavelength by a power source applied from the outside, and is made of GaN (gallium nitride), AlN (aluminum nitride), InN (Indium nitride), GaAs (gallium arsenide), and the like. For example, the light emitting device 343 may be a light emitting diode.

The light emitting diode may be, for example, a colored light emitting diode that emits light such as red, green, blue, or white, or a UV (Ultra Violet) light emitting diode that emits ultraviolet light. In the embodiment, a single light emitting diode is illustrated as being provided at the central portion, but the present invention is not limited thereto, and it is also possible to include a plurality of light emitting diodes.

In addition, the light emitting device 343 may be a horizontal type in which all the electric terminals are formed on the upper surface, a flip type formed in the lower surface of the light emitting element 343, or a vertical type ). ≪ / RTI >

The light emitting device 343 is electrically connected to the first lead frame 347 and the second lead frame 348 via the wire 345 to receive external power. In this case, the horizontal type light emitting device uses a wire bonding method using two wires, and the vertical type light emitting device uses a wire bonding method using one wire.

The resin material 346 may be filled in the cavity C to seal the light emitting element 343 and the wire 345. At this time, the resin material 346 may be formed of a light-transmissive resin material such as silicone or epoxy, and the material may be filled in the cavity and then formed by ultraviolet ray or thermal curing.

The surface of the resin material 346 may be formed in a concave lens shape, a convex lens shape, a flat shape, or the like, and the orientation angle of the light emitted from the light emitting element 343 may be changed according to the shape of the resin material 346 have.

In addition, resin materials having different lens shapes may be formed or adhered on the resin material 346, but the present invention is not limited thereto.

The resin material 346 may include a phosphor. Here, the phosphor may be selected according to the wavelength of the light emitted from the light emitting device 343, so that the light emitting device package 340 may emit white light.

That is, the phosphor can be excited by the light having the first light emitted from the light emitting element 343 to generate the second light. For example, when the light emitting element 343 is a blue light emitting diode and the phosphor is a yellow phosphor The yellow phosphor is excited by the blue light to emit yellow light and the blue light generated from the blue light emitting diode and the yellow light generated by the excitation by the blue light are mixed and the light emitting device package 340 emits white light Can be provided.

Similarly, when the light emitting element 343 is a green light emitting diode, the magenta phosphor or the blue and red phosphors are mixed, and when the light emitting element 343 is a red light emitting diode, the cyan phosphors or the blue and green phosphors are mixed For example.

Such a fluorescent material may be a known fluorescent material such as a YAG, TAG, sulfide, silicate, aluminate, nitride, carbide, nitridosilicate, borate, fluoride or phosphate.

FIG. 4 is a perspective view showing the arrangement structure of the light emitting device module and the light guide plate of FIG. 1, FIG. 5 is a sectional view taken along line A-A 'of FIG. 4, and FIG. 6 is an enlarged view of a portion B of FIG.

4 to 6, the backlight device 100 according to the embodiment may be arranged such that the light guide plate 130 and the light emitting device module 120 face each other, and the light guide plate 130 is disposed between the light emitting device module 120 And a plurality of protrusions 135 spaced apart from each other by a predetermined distance.

The plurality of protrusions 135 may be formed by forming a predetermined structure on a region of the light guide plate 130, arranging predetermined members, or applying pressure to protrude one region of the light guide plate 130, The forming method may be a predetermined bonding method, a coating method, a pressing method, or the like, but is not limited thereto.

In addition, the plurality of protrusions 135 may be formed spaced apart at regular intervals.

The light emitting device module 120 includes a printed circuit board 122 and a light emitting device package 124 disposed on the printed circuit board 122 as described above. The printed circuit board 122 may include a plurality of recesses 125 corresponding to the plurality of protrusions 135.

For example, the plurality of recesses 125 may be formed by removing one region of the printed circuit board 122, or by applying pressure so that one region of the printed circuit board 122 is recessed, An etching method, or a pressing method may be used, but the present invention is not limited thereto. In addition, the plurality of recesses 125 may be formed spaced apart at regular intervals.

The light emitting device package 124 may be disposed between the plurality of recesses 125.

Further, a part of the plurality of projections 135 may be arranged to be located in the plurality of recessed inner regions. For example, as shown in FIG. 5, a part of the protrusion 135 may be arranged to be partially inserted into the recess 125. The width d1 of the plurality of projections 135 is preferably smaller than the width d2 of the plurality of recesses 125. [

The width d2 of the plurality of recesses 125 may be determined according to the distance between the light emitting device packages 124, for example, 50 mu m. The width of the plurality of protrusions 135 may be formed to be about 10 to 15 占 퐉 smaller than the width d2 of the plurality of recesses 125 in view of process errors and the like.

When the backlight device 100 is operated, the light guide plate 130 may be expanded by the heat generated in the light emitting device package 124, so that the plurality of protrusions 135 may be formed inside the plurality of recesses 125 The plurality of projections 135 and the plurality of recesses 125 may be spaced apart from each other so as not to be in contact with each other.

When the plurality of protrusions 135 expand due to the heat generated in the light emitting device as described above, a space is formed between the plurality of protrusions 135 and the plurality of recesses 125, And the light emitting device package 124 can be prevented from being damaged.

The height h2 of the plurality of protrusions 135 may be 110% to 130% of the height h1 of the light emitting device package 124.

When the height h2 of the plurality of protrusions is less than 110% of the height h1 of the light emitting device package, the light guide plate 130 is not expanded enough due to the expansion of the concave portion of the printed circuit board, Stress may be applied to the printed circuit board 130 and the printed circuit board 122 to cause deformation.

On the other hand, when the height h2 of the protrusion is greater than 130% of the height h1 of the light emitting device package, the distance between the light guiding plate 130 and the light emitting device package 124 is large, .

As described above, there is a risk of damage to the light emitting device package 124 or the light guide plate 130. When the distance between the light emitting device package 124 and the light guide plate 130 is increased, The generated light can not be efficiently transmitted to the light guide plate 130.

The height h2 of the plurality of protrusions may be 50 to 200 mu m. If the height h2 of the plurality of protrusions is less than 50 占 퐉, the light guide plate 130 can not be expanded due to the height of the concave portion of the printed circuit board due to the expansion of the light guide plate 130, Stress may be applied to the printed circuit board 122 to cause deformation.

On the other hand, when the height h2 of the plurality of protruding parts 135 is larger than 200 mu m, the distance between the light guide plate 130 and the light emitting device package 124 is large, so that a lot of light may be transmitted to the light guide plate.

As described above, there is a risk of damage to the light emitting device package 124 or the light guide plate 130. When the distance between the light emitting device package 124 and the light guide plate 130 is increased, The generated light can not be efficiently transmitted to the light guide plate 130.

The cross-sectional shape of the protrusion 135 may be at least one of a circular shape, an elliptical shape, and a polygonal shape, but is not limited thereto. In addition, the cross-sectional shape of the concave portion may be at least one of a circle, an ellipse, and a polygon, but is not limited thereto.

The shape of the protrusion 135 may also be a polygonal pyramid, a cone, a polygonal column, a hemispherical shape, or the like, but is not limited thereto.

The side surface of the protrusion 135 may include a reflective layer 137. The reflective layer 137 may include at least one of aluminum (Al), silver (Ag), gold (Au), platinum (Pt), copper (Cu), and palladium (Pd).

When the reflective layer 137 is included in the side surface of the protrusion 135 as described above and the light generated from the light emitting device package is directed to the side surface of the protrusion 135, . Thus, loss of light generated from the light emitting device package 124 can be reduced.

7 is a cross-sectional view illustrating an arrangement structure of a light emitting device module and a light guide plate according to another embodiment.

Referring to FIG. 7, the protrusions 135 and the recesses 125 may have different shapes. For example, the projection 135 may be a rotating body of a predetermined shape, and the corresponding recess 125 may have a rectangular parallelepiped shape. Although not shown, the protrusion 135 may have a square pillar shape, and the concave portion 125 may have a circular column shape, but is not limited thereto. The width d1 of the protrusion 135 should be smaller than the width d2 of the recess 125 even when the shapes of the protrusion 135 and the recess 125 are different from each other, The width of the concave portion 125 may be smaller than the width of the concave portion 125 by 10 to 15 占 퐉.

FIG. 8 is an exploded perspective view of a liquid crystal display device including a backlight device according to an embodiment, and FIG. 9 is an assembled perspective view illustrating the liquid crystal display device of FIG.

8 and 9, the liquid crystal display device 200 of the embodiment may include a liquid crystal display panel 220 for displaying an image and a backlight device 100 for supplying light to the liquid crystal display panel 220 .

Here, the configuration of the backlight device 100 may be configured as described above with reference to FIG.

The liquid crystal display panel 220 can display an image using light provided from the backlight device 100. The liquid crystal display panel 220 may include a color filter substrate 222 and a thin film transistor substrate 224 facing each other with a liquid crystal therebetween.

The color filter substrate 222 can realize the color of the image to be displayed through the liquid crystal display panel 220.

The thin film transistor substrate 224 is electrically connected to a printed circuit board 228 on which a plurality of circuit components are mounted via a driving film 227. The thin film transistor substrate 224 may apply a driving voltage provided from the printed circuit board 228 to the liquid crystal in response to a driving signal provided from the printed circuit board 228.

The thin film transistor substrate 224 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate of a transparent material such as glass or plastic.

The liquid crystal display panel 220 may further include a top cover 230.

The top cover 230 may be engaged with the outer surface of the bottom cover 170. However, the present invention is not limited thereto, and the top cover 230 may be combined with the inner surface of the bottom cover 170. [

The top cover 230 and the bottom cover 170 may be coupled by any one of the bolt connection, adhesive bonding, and interference fit methods. However, the present invention is not limited thereto.

Accordingly, the liquid crystal display device 220 can be made thinner.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

100: backlight device 120: light emitting device module
122: printed circuit board 124: light emitting device package
125: concave portion 130: light guide plate
135: protrusion 150: reflective sheet
160: Optical sheet

Claims (11)

A light emitting device module including a printed circuit board and a plurality of light emitting device packages disposed on the printed circuit board; And
And a light guide plate disposed to face the light emitting element module and having a plurality of protrusions spaced apart from each other by a predetermined distance on a surface facing the light emitting element module,
Wherein the printed circuit board includes a plurality of recesses corresponding to the plurality of protrusions, the plurality of light emitting device packages are disposed between the plurality of recesses, and a part of the plurality of protrusions is arranged in the plurality of recessed- Located,
Wherein a height of the plurality of protrusions is greater than a height of the light emitting device package. The method according to claim 1,
And the plurality of projections and the plurality of recesses are spaced apart from each other. The method according to claim 1,
Wherein a height of the plurality of protrusions is 110% to 130% of a height of the light emitting device package. The method according to claim 1,
And the height of the plurality of protrusions is 50 to 200 占 퐉. The method according to claim 1,
Wherein a width of the plurality of projections is smaller than a width of the plurality of recesses. The method according to claim 1,
Wherein the cross-sectional shape of at least one of the plurality of protrusions and the recesses is at least one of a polygonal shape, a circular shape, and an elliptical shape. The method according to claim 1,
Wherein the side surfaces of the plurality of protrusions include a reflective layer. The method according to claim 1,
And an optical sheet positioned above the light guide plate. 9. The method of claim 8,
Wherein the optical sheet includes at least one of a diffusion sheet, a prism sheet, and a protective sheet. The method according to claim 1,
And a reflective sheet positioned under the light guide plate. A liquid crystal display device comprising the backlight device according to any one of claims 1 to 10.

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