KR20120003082A - Backlight unit and display device including the same - Google Patents

Abstract

PURPOSE: A backlight unit equipped with a light emitting device and display device including the same are provided to increase the efficiency of a light emitting device package by including a heat radiation pin structure on a bracket. CONSTITUTION: An LED module comprises a printed circuit board(81) and a bracket(12). The printed circuit board includes a luminous element array. The bracket includes a fixing unit and a heat radiating unit. A heat radiating unit(12b) emits the heat of the printed circuit board. A first side of a heat radiating unit is welded to a printed circuit board. A surface structure is included in the first side.

Description

Backlight unit and display device including the same {Backlight unit and display device including the same}

Embodiments relate to a backlight having a light emitting device and a display device including the same.

Light emitting devices such as light emitting diodes or laser diodes using semiconductors of Group 3-5 or 2-6 compound semiconductor materials of semiconductors have various colors such as red, green, blue and ultraviolet rays due to the development of thin film growth technology and device materials. It is possible to realize efficient white light by using fluorescent materials or combining colors, and it has low power consumption, semi-permanent life, fast response speed, safety and environmental friendliness compared to conventional light sources such as fluorescent and incandescent lamps. Has an advantage.

Therefore, a white light emitting device that can replace a fluorescent light bulb or an incandescent bulb that replaces a Cold Cathode Fluorescence Lamp (CCFL) constituting a backlight of a transmission module of an optical communication means and a liquid crystal display (LCD) display device. Applications are expanding to diode lighting devices, automotive headlights and traffic lights.

The embodiment is intended to improve heat dissipation efficiency of a light emitting device package or the like.

Embodiments include a printed circuit board having a light emitting device array; And a bracket having a fixing part and a heat dissipating part for dissipating heat from the printed circuit board, wherein the heat dissipating part is bonded to the printed circuit board on a first surface thereof, and has a second direction opposite to the first surface. Provided is a light emitting device module having a fin structure on a surface thereof.

Another embodiment includes a printed circuit board having a light emitting device array, a fixing unit, and a bracket having a heat dissipating unit for dissipating heat from the printed circuit board, wherein the heat dissipating unit is formed on the first surface of the printed circuit board. A light emitting device module which is bonded and has a fin structure on a second surface opposite to the first surface; And a bottom cover accommodating the light emitting device module, the reflector, and the light guide plate.

Another embodiment includes a printed circuit board having a light emitting element array and a bracket having a fixing part and a heat dissipating part for dissipating heat from the printed circuit board, wherein the heat dissipating part is formed on the first surface of the printed circuit board. A backlight unit bonded to and including a light emitting device module having a fin structure on a second surface opposite to the first surface, a reflecting plate and a light guide plate; An optical member projecting the light projected from the backlight unit to a panel; A panel provided on the optical member to implement an image by projected light; A color filter provided on the front surface of the panel and selectively transmitting one of red, green, and blue light; And a top cover fastened to the bottom cover and the bracket with the optical member, the panel, and the color filter interposed therebetween.

The fixing part and the heat dissipating part may be perpendicular to each other.

The printed circuit board may be bonded to the bracket with column pads therebetween.

The bottom cover may be fastened to the bracket of the light emitting device module.

The backlight unit may further include a protrusion formed on the bottom cover, and the protrusion may be inserted into the bracket.

The backlight unit may further include a top cover facing the bottom cover and fastened to the bracket.

In addition, a groove is formed on the bracket, and the bottom cover and the bracket may be fastened with a screw.

The backlight according to the embodiment may improve the heat radiation efficiency of the light emitting device package.

1 is an exploded perspective view of an embodiment of a display device;
FIG. 2 is a front perspective view of the bottom cover of FIG. 1;
3 is a perspective view of a light emitting device module in an embodiment of the backlight unit;
4A to 5B are cross-sectional views of one embodiment of a backlight unit;
6 is a view showing an embodiment of a top cover in FIG.
7 is an exploded perspective view of another embodiment of a display device;
8a and 8b compare the heat radiation efficiency of the light emitting device module according to the embodiment with the prior art.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

In the description of the above embodiments, each layer (region), region, pattern or structures may be "on" or "under" the substrate, each layer (layer), region, pad or pattern. In the case of what is described as being formed, "on" and "under" include both being formed "directly" or "indirectly" through another layer. In addition, the criteria for the top or bottom of each layer will be described with reference to the drawings.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of description. In addition, the size of each component does not necessarily reflect the actual size.

1 is an exploded perspective view of an embodiment of a display device.

As shown, an embodiment of a display device includes a bottom cover 10, a light emitting device package module (not shown) provided at one side of the bottom cover, and a front surface of the bottom cover 10. A reflector 20 disposed in the light guide plate, a light guide plate 30 disposed in front of the reflector plate 20, and guiding light emitted from the light emitting module to the front of the display device, and an optical disposed in front of the light guide plate 30. The member 40, the liquid crystal display panel 60 disposed in front of the optical member 40, a top cover 70 provided in front of the liquid crystal display panel 60, and the bottom cover. Is disposed between the 10 and the top cover 70 may include a fixing member 50 for fixing the bottom cover 10 and the top cover 70 together.

The light guide plate 30 guides the light emitted from the light emitting module (not shown) to be emitted in the form of a surface light source, and the reflector 20 disposed behind the light guide plate 30 is the light emitting device package module. The light emitted from (not shown) is reflected in the light guide plate 30 to improve light efficiency.

However, the reflecting plate 20 may be provided as a separate component as shown in the figure, is provided in the form of a high reflectivity material is coated on the back of the light guide plate 30, or the front of the bottom cover 10. It is also possible.

Here, the reflective plate 20 may use a material having a high reflectance and that can be used in an ultra-thin shape, and may use polyethylene terephthalate (PET).

The light guide plate 30 scatters the light emitted from the light emitting device package module so that the light is uniformly distributed over the entire area of the screen of the liquid crystal display. Therefore, the light guide plate 30 is made of a material having a good refractive index and a high transmittance, and may be formed of polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene (PE), or the like.

The optical member 40 is provided on the light guide plate 30 to diffuse the light emitted from the light guide plate 30 at a predetermined angle. The optical member 40 allows the light guided by the light guide plate 30 to be uniformly irradiated in the direction of the liquid crystal display panel 60.

As the optical member 40, an optical sheet such as a diffusion sheet, a prism sheet or a protective sheet may be selectively laminated, or a micro lens array may be used. In this case, a plurality of optical sheets may be used, and the optical sheets may be made of a transparent resin such as acrylic resin, polyurethane resin, or silicone resin. The fluorescent sheet may be included in the above-described prism sheet as described above.

A liquid crystal display panel 60 may be provided on the front surface of the optical member 40. Here, it is obvious that other types of display devices requiring a light source besides the liquid crystal display panel 60 may be provided.

In the liquid crystal display panel 60, the liquid crystal is located between the glass substrates, and the polarizing plates are placed on both glass substrates in order to use the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

The liquid crystal display panel used in the display apparatus uses a transistor as a switch for regulating a voltage supplied to each pixel as an active matrix method.

Since the structure of a specific liquid crystal display panel is the same as that of the prior art, it abbreviate | omits.

In addition, a color filter (not shown) is provided on the front surface of the liquid crystal display panel 60 to transmit the light projected from the liquid crystal display panel 60 to transmit only the red, green, and blue light for each pixel. I can express it.

FIG. 2 is a front perspective view of the bottom cover of FIG. 1. FIG.

The bottom cover 10 may be formed in the form of a metal plate, and in order to reinforce its strength, the first forming part 10a and the first forming part 10a which extend in the lateral direction and are formed to be convex forward. It may include a second forming portion 10b is formed convexly perpendicular to the arrangement direction of 10a).

The first forming unit 10a and the second forming unit 10b may be formed by pressing the bottom cover 10. In addition, the front surface of the first forming unit 10a and the second forming unit 10b may have a constant flat surface, and the flat surfaces may be provided to have the same height.

This is for the reflector 20 to be disposed in the first forming portion 10a and the second forming portion 10b. The second forming unit 10b may be provided in plural to reinforce strength and spaced apart from each other.

In addition, a heat dissipation member 11 provided in the form of a heat pipe or a heat sink is installed between the second forming portions 10b, and the heat dissipation member 11 may also be provided in plural and spaced apart from each other.

The heat dissipation member 11 is provided to receive heat generated during the light emission operation of the light emitting device package module disposed on the bottom cover 10 to radiate heat to the outside. It may be disposed up and down within 10 by a predetermined length.

In addition, since the second forming part 10b is formed to protrude forward by a predetermined length, an inclined surface may be formed at a portion adjacent to the heat radiating member 11 to facilitate the installation thereof.

An edge wall 10c formed by bending forward is formed at the edge of the bottom cover 10 so that the light guide plate, the optical sheet, or the reflective sheet mounted inside the bottom cover 10 may not be separated to the outside. have.

In addition, grooves (not shown) formed at edges of the light guide plate 30, the reflector plate 20, and the optical member 40 are formed at a portion of the front portion of the bottom cover 10 adjacent to the left and right edge walls 10c. The support part for supporting the light guide plate, the reflecting plate, and the optical member may be provided.

Coupling holes 10f and 10g may be provided at the lower side of the bottom cover 10 to allow the fixing member 50 and the top cover 70 to be coupled through a coupling member such as a screw. In addition, the left and right edge walls 10c of the bottom cover 10 are provided with a coupling protrusion 10e through which the top cover 70 may be caught.

On the other hand, in order to compensate for the rigidity of the bottom cover 10, the bottom surface of the bottom cover 10 may be installed an H beam. The bottom cover 10 is provided with an installation member 13 for fixing the heat radiating member 11 to the bottom cover 10.

The installation member 13 includes a body portion 13a disposed in a left and right direction, an extension portion 13b extending toward the heat dissipation member 11 in a vertical direction from the body portion 13a, and the extension portion ( 13b) and a fastening hole 13c to which a fastening member to which the heat dissipation member 11 and the bottom cover 10 can be fastened is coupled.

Therefore, after the heat dissipation member 11 is placed on the bottom cover 10, the extension part 13b of the installation member 13 is placed on the front side of the heat dissipation member 11, and then the fastening member is attached to the fastening member. When inserted into the fastening hole 13c provided in the extension part 13b and fastened, the heat dissipation member 11 is closely contacted between the bottom cover 10 and the extension part 13b by the fastening force of the fastening member. And can be fixed in a placed state.

3 is a perspective view of a light emitting device module in an embodiment of the backlight unit.

As shown, the configuration of the light emitting device module 80 includes a printed circuit board 81, a plurality of light emitting device packages 82 disposed to be spaced apart from each other on the printed circuit board 81, and the printed circuit. The connector 81 is provided on the board 81 and connects the printed circuit board 81 to an external power supply device.

4A is a cross-sectional view of one embodiment of a backlight unit.

As shown in the drawing, the reflective plate 20 is placed on the bottom cover 10, and the light guide plate 30 is placed on the reflective plate 20. Thus, the reflector 20 may be in direct contact with the heat dissipation member 11.

The printed circuit board 81 to which each light emitting device package 82 is fixed may be bonded to the bracket 12. In addition, the bracket 12 may be divided into 12a and 12b which are provided in a 'b' type and are perpendicular to each other, as shown in the drawing. It is called (12b). Here, the fixing part 12a is supported by the bottom cover 10, and the heat dissipation part 12b may fix the printed circuit board 81 and perform heat dissipation as will be described later.

In addition, a fin structure is formed on the bracket 12 to easily discharge heat transferred from the light emitting device package 82 and the printed circuit board 81 to the outside, and the fin structure may be provided on the heat dissipation part 12b. Can be. That is, as shown, the fin structure 15 may be provided in the heat dissipating portion 12b of the bracket 12, specifically, a printed circuit on the first surface of the heat dissipating portion 12b of the bracket 12. The substrate 82 may be bonded to each other, and the fin structure 15 may be provided on the second surface parallel to the first surface.

Here, the first surface is toward the printed circuit board 81, the second surface is the same as the first surface is shown as the opposite direction. In FIG. 4A, the first surface is labeled 'A' and the second surface is labeled 'B', and the same is true in other embodiments.

In this case, in order for the heat generated from the light emitting device package 82 to be discharged to the outside of the bracket 12, the contact area between the bracket 12 and the atmosphere should be wide, so that the fin structure 15 may have a protrusion ( 15a) and the recessed portion 15b may be provided in sequence. In addition, although the fin structure 15 is provided in parallel with the light guide plate 30 and the like in FIG. 4, the fin structure 15 may be provided in a vertical direction or an inclined direction. In addition, the fin structure 15 may be formed in a shape in which the horizontal and vertical lines coexist together instead of the line type.

4B is a cross-sectional view of another embodiment of the backlight unit.

This embodiment is basically the same as the embodiment shown in FIG. 4A, but with a thermal pad 84. That is, the bracket 12 is made of a material having high thermal conductivity for heat dissipation in addition to the fixing of the light emitting device package 82, and a thermal pad 84 is provided between the bracket 12 and the light emitting device package 82. Heat transfer may be facilitated. FIG. 5A is a cross-sectional view of another embodiment of a backlight unit.

This embodiment is the same as the embodiment shown in FIG. 4A, but a groove is formed on the fixing part 12a of the bracket 12, and a protrusion 16 is formed on one side of the bottom cover 10 such that the bracket is formed. It can be inserted into the groove on the fixing portion 12a of the (12).

That is, when the pin structure 15 as shown in the bracket 12 is formed, the strength of the bracket may be weakened, so that the bonding force with the bottom cover 10 may be weakened, thereby forming the above-described fastening structure. In addition, when the bracket 12 is not a 'b' shape as shown, and the horizontal portion is omitted structure, the necessity of the above-described fastening structure is even greater.

5B is a cross-sectional view of another embodiment of a backlight unit.

This embodiment is basically the same as the embodiment shown in FIG. 5A, but with a thermal pad 84. That is, the bracket 12 is made of a material having high thermal conductivity for heat dissipation in addition to the fixing of the light emitting device package 82, and a thermal pad 84 is provided between the bracket 12 and the light emitting device package 82. Heat transfer can be facilitated.

6 is a view showing an embodiment of a top cover in FIG.

As shown, the top cover 70 is provided with a plurality of grooves 71, in particular can be formed only on the side of the horizontal direction. That is, the above-described fin type heat dissipation structure is provided in the light emitting device module provided on the horizontal side of the 1-edge type backlight or display device, and in particular, when the bracket is provided with the heat dissipation structure, the groove 71 is fixed to fix the bracket. ) Is needed more.

7 is an exploded perspective view of another embodiment of a display device.

This embodiment is basically the same as the embodiment shown in FIG. 1, except that a fin structure for heat dissipation is provided on a bracket of the light emitting device module, and a groove 71 is formed on the top cover 70. . And, as shown in the groove is also formed on the bracket, the screw 72 is fastened to the groove 71 of the top cover 70 is also fastened to the bracket. Further, as described above, since the protrusion on the batam cover may be fastened to the groove of the horizontal portion of the bracket, the fastening structure between the bracket and the batam cover / top cover may be more firm.

8a and 8b compare the heat radiation efficiency of the light emitting device module according to the embodiment with the prior art. In FIG. 8A, a heat dissipation fin structure is provided on the bracket, and it can be seen that the temperature of the backlight side of the rear surface of the light emitting device module is lower than that of the related art (FIG. 8B) due to the improvement of heat dissipation performance.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

In addition, the above description has been made with reference to the embodiment, which is merely an example, and is not intended to limit the present invention. Those skilled in the art to which the present invention pertains will be illustrated as above without departing from the essential characteristics of the present embodiment. It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

10: bottom cover 10a: first forming part
10b: second forming part 10c: edge wall
10e: engaging projection 10f, 10g: engaging hole
11: heat radiating member 12: bracket
12a: fixed part 12b: heat dissipation part
15: pin structure 20: reflector
30: light guide plate 40: optical member
50: fixing member 60: liquid crystal display panel
70: top cover 80: light emitting device package module
81: module substrate 82: light emitting device package
83: connector 84: thermal pad
A: first side B: second side

Claims (11)

A printed circuit board having a light emitting device array; And
A bracket having a fixing part and a heat dissipating part for dissipating heat from the printed circuit board,
The heat dissipating unit is a light emitting device module is bonded to the printed circuit board on the first surface, the fin structure is provided on the second surface in the opposite direction to the first surface. The method of claim 1,
The fixing part and the heat dissipating part are perpendicular to each other light emitting device module The method of claim 1,
The printed circuit board is bonded to the bracket with a thermal pad therebetween. A printed circuit board including a light emitting device array, a fixing unit, and a bracket including a heat dissipating unit for dissipating heat from the printed circuit board, wherein the heat dissipating unit is bonded to the first surface of the heat dissipating unit; A light emitting device module having a fin structure on a second surface opposite to the first surface; And
And a bottom cover accommodating the light emitting device module, the reflector, and the light guide plate. The method of claim 4, wherein
The fixing unit and the heat dissipating unit are perpendicular to each other light emitting device module. The method of claim 4, wherein
And the printed circuit board is bonded to the bracket with a thermal pad interposed therebetween. The method of claim 4, wherein
The bottom cover is a backlight unit fastened to the bracket of the light emitting device module. The method of claim 7, wherein
And a protrusion formed on the bottom cover, wherein the protrusion is inserted into the bracket. The method of claim 4, wherein
And a top cover facing the bottom cover and fastened to the bracket. The method of claim 9,
Grooves are formed on the bracket, and the bottom cover and the bracket are fastened with screws. A printed circuit board including a light emitting device array; and a bracket having a fixing unit and a heat dissipating unit for dissipating heat of the printed circuit board, wherein the heat dissipating unit is bonded to the printed circuit board on a first surface thereof. A backlight unit including a light emitting device module having a fin structure on a second surface opposite to one surface, a reflecting plate, and a bottom cover to accommodate the light guide plate;
An optical member projecting the light projected from the backlight unit to a panel;
A panel provided on the optical member to implement an image by projected light; And
And a top cover fastened to the bottom cover and the bracket with the optical member and the panel interposed therebetween.

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