KR20120009557A - Backlight unit and display device including the same - Google Patents

Abstract

PURPOSE: A backlight unit and a display device including the same are provided to reduce the weight of a display device and to reduce material costs. CONSTITUTION: A backlight unit includes a first optical source module array(80), a second optical source module array, a reflective layer(R), and a reflective sheet(20). The first optical source module array is faced with the second optical source module array. The reflective layer projects light which is projected from the first optical source module array and the second optical source module array on the reflective sheet. The reflective sheet reflects light to the optical sheet.

Description

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

Embodiments relate to a backlight unit and a display device provided with light emitting devices.

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 reduce the weight of the backlight unit and the display device and to reduce the material cost.

Embodiments include a first light source module array and a second light source module array, each provided on a surface facing each other; A reflective layer for projecting light projected from the first light source module array and the second light source module array at an acute angle on the reflective sheet below; And a reflecting sheet reflecting light incident from the reflector to the optical sheet, wherein the reflecting sheet and the optical sheet are divided into a first region and a second region, and the light projected from the first light source module array is reflected. It provides a backlight unit that is reflected in the first area of the sheet and projected to the second area of the optical sheet.

In another embodiment, the first light source module array and the second light source module array and the light source projected from the first light source module array and the second light source module array, respectively provided on opposite surfaces, are acutely angled on the reflective sheet below. A reflective layer for projecting, and a reflective sheet for reflecting light incident from the reflector to an optical sheet, wherein the reflective sheet and the optical sheet are divided into a first region and a second region, and are projected from the first light source module array. A backlight unit in which light is reflected from the first area of the reflective sheet and projected to the second area of the optical sheet; An optical sheet for diffusing the light projected from the backlight unit; A panel provided on the optical sheet and implementing an image by projected light; And a bottom cover accommodating the backlight unit and the optical sheet.

The first light source module array and the second light source module array may project light in a direction perpendicular to the reflective sheet.

The reflective layer may be provided with a first surface parallel to the reflective sheet and a second surface perpendicular to the first surface.

In addition, the reflective layer may be coated with a reflective material on the bottom cover.

The reflective layer may be aspherical or parabolic.

The reflective layer may include a plurality of reflective sectors.

The light source module array may project light in an edge direction of the bottom cover.

In addition, the reflective layer may be a '' 'shape.

In the backlight unit and the display device according to the embodiment, the light guide plate is omitted, thereby reducing the weight ratio.

1 is an exploded perspective view of a display device according to an embodiment;
2 is a front perspective view of a bottom cover of a display device and a backlight unit according to an embodiment;
3 is a rear perspective view of a bottom cover of a display device and a backlight unit according to an embodiment;
FIG. 4 is a diagram illustrating a light source module having an inner side of a bottom cover in a display device and a backlight unit according to an exemplary embodiment.
5A to 5D are views illustrating the configuration and operation of the light source module array, the reflective layer, and the reflective sheet;
6A to 6D illustrate fastening of the bottom cover and the optical sheet of the display device and the backlight unit according to the embodiment;
7 is a view showing another embodiment of the fastening of the bar cover and the reflective sheet and the optical sheet disposed in the display device and the backlight unit according to the embodiment.

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 a display device according to an exemplary embodiment.

As shown, the display device according to the present exemplary embodiment includes a bottom cover 10, a light source module (not shown) provided on one side of the bottom cover, and a reflection disposed on the front surface of the bottom cover 10. An optical sheet 40 disposed in front of the sheet 20, the reflective sheet 20, and guiding light emitted from the light emitting module to the front of the display device, and a liquid crystal disposed in front of the optical sheet 40. The top cover 70 provided in front of the display panel 60, the liquid crystal display panel 60, the bottom cover 10 and the top cover 70, and disposed between the bottom cover 10 and the bottom cover 10. And fixing members 51, 52, 53, and 54 for fixing the top cover 70 together.

The reflective sheet 20 serves to enhance light efficiency by reflecting the light emitted from the light source module to be emitted in the form of a surface light source. Here, the reflective sheet 20 may be provided as a separate component, or may be provided in the form of a high reflectivity coating on the front of the bottom cover 10.

The optical sheet 40 disposed on the front surface of the reflective sheet 20 may improve luminance and light efficiency by allowing the light reflected from the reflective sheet 20 to be diffused and refracted. The optical sheet 40 may be composed of a plurality of components or may be one component.

That is, the optical sheet 40 may include a first diffusion sheet 41, a prism sheet 42, and a second diffusion sheet 43, and have a function of a diffusion sheet and a function of a prism sheet. It may be composed of an optical sheet of. The number and type of the optical sheets 40 may be variously selected according to the required luminance characteristics.

2 is a front perspective view of a bottom cover of a display device and a backlight unit according to an exemplary embodiment.

The bottom cover 10 may be formed in a plate shape of a metal material. The bottom cover 10 extends in a left and right direction and is convex forward to reinforce its strength, and the first forming part (not shown). It may include a second forming portion 10b is formed convexly perpendicular to the arrangement direction of 10a).

The first forming portion and the second forming portion 10b may be formed by pressing the bottom cover 10. In addition, the front surfaces of the first forming unit and the second forming unit 10b may have constant flat surfaces, and the flat surfaces may be provided to have the same height. This is to allow the reflective sheet 20 (see FIG. 1) to be disposed in the first forming portion 10a and the second forming portion 10b.

The second forming unit 10b is preferably provided in plural to reinforce strength and spaced apart from each other. The first 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 first heat dissipation member 11 may also be provided in plurality and spaced apart from each other.

The first heat dissipation member 11 is provided to radiate heat to the outside by receiving heat generated during the light emitting operation of the light source module (not shown) disposed on the bottom cover 10. To this end, the first heat dissipation member 11 may be disposed in the bottom cover 10 by a predetermined length up and down.

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 first 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 is not separated from the outside.

The lower side of the bottom cover 10 is provided with a coupling hole (10f, 10g) for allowing the fixing member (51, 52, 53, 54) and the top cover 70 can be coupled through a coupling member such as a screw do.

In addition, the left and right edge walls 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 may be provided with an installation member 13 for fixing the first heat dissipation 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 first heat dissipation member 11 in a vertical direction from the body portion 13a, and the extension. The fastening hole 13c provided in the portion 13b may be coupled to a fastening member to which the first heat dissipation member 11 and the bottom cover 10 may be coupled.

Therefore, after the first 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 first heat dissipation member 11, and then the When the fastening member is inserted into and fastened to the fastening hole 13c provided in the extension part 13b, the first heat dissipation member 11 is connected to the bottom cover 10 and the extension part by the fastening force of the fastening member. It is fixed in the state arranged in close contact between 13b.

3 is a rear perspective view of a bottom cover of a display device and a backlight unit according to an exemplary embodiment.

As shown, a plurality of fixing pins 14 are provided on the rear surface of the bottom cover 10, and a power supply or a printed circuit board disposed on the rear surface of the bottom cover 10 by the fixing pins 14. The back is fixed.

The fixing pin 14 is combined with a power supply or a printed circuit board to enhance the rigidity of the bottom cover 10.

4 is a view illustrating a light source module provided on an inner side of a bottom cover in a display device and a backlight unit according to an exemplary embodiment.

Here, the array of light source modules 80 may be formed of a light emitting diode package, but is not limited thereto, and may be configured of a lamp such as CCFL or an organic light emitting device such as OLED.

The light emitting device 82 is configured in a so-called "1-edge" shape disposed only on the upper portion of the display panel 60 and the bottom cover 10 or disposed only on the lower portion thereof, or on two sides facing each other. It may be configured in the form of "1-edge" to be disposed.

The number of light emitting devices 82 may vary depending on the size of the display panel 60, that is, the number of inches of the display panel 60, for uniform distribution of desired luminance and light. The light emitting devices 82 may be disposed at a number of 2,5 to 3.5 times the number of inches of the display panel 60. When the light emitting device 82 is less than 2.5 times the number of inches of the display panel 60 or more than 3,5 times the number of the light emitting elements 82, it is difficult to provide light having an appropriate brightness and uniform distribution.

For example, when the display panel 60 is 47 inches, 118 to 164 light emitting devices 82 may be installed. In the present embodiment, the display panel 60 is 47 inches, and the light emitting elements 82 may be installed at 138.

The support portions 10d are spaced apart from each other in a straight direction on the second forming portion 10b provided at the leftmost and rightmost portions of the bottom cover 10 of the second forming portions 10b.

5A to 5D are views illustrating the configuration and operation of the light source module array, the reflective layer, and the reflective sheet.

FIG. 5A is a cross-sectional view taken along the line AA ′ of FIG. 4, and a portion of the cross-section of the backlight unit of the “2-edge” type is shown.

The bottom cover 10 is provided with an array of light source modules 80 on surfaces facing each other. The light source module 80 is provided on the circuit board 81 and the light emitting device 82 spaced apart from each other on the circuit board 81, and the circuit board 81 is provided outside the circuit board 81. It may include a connector (not shown) for connecting to the power supply.

In addition, the light source module 80 is provided on the bracket 12, and the reflective sheet 20 is provided on one side of the bracket 12. In addition, a first heat dissipation member 11 is provided on the bottom cover 10, and the first heat dissipation member 11 is connected to the bracket 12 to directly transfer heat generated from the light source module 80 to the outside. Can be released. In addition, although the reflective sheet 20 and the first heat dissipation member 11 are shown to be in contact with each other in FIG. 5A, the reflective sheet 11 may be prevented from being deformed by heat by being spaced apart by a predetermined interval. .

Each of the light source module 80 arrays provided on the opposing surfaces may be referred to as a first light source module array and a second light source module array. In addition, the light emitting device 82 emits light in a direction opposite to the bracket 12, that is, in an upward direction in FIG. 5A. Considering the directivity of the light emitting device 82, the light emitting device 82 has a width of about 120 degrees. Is released.

In this case, a reflective layer R is formed on a surface of the bottom cover 10 facing the light emitting element 82 and a surface perpendicular to the edge of the bottom cover 10, such as silver (Ag), aluminum (Al), or the like having excellent reflectance. The material may be formed by a method such as coating. Therefore, the light emitted from the light emitting element 82 is reflected by the reflective layer R, and then proceeds to the reflective sheet 20. At this time, the light directed from the reflective layer R toward the reflective sheet 20 is incident on the reflective sheet 20 at an acute angle.

The light reflected from the reflective sheet 20 proceeds to the optical sheet 40 (see FIG. 1). In this case, as shown in FIG. 2, the reflective sheet 20 of the first region A is divided into two regions A and B according to an imaginary line C that divides the array of opposing light source modules 80 into two portions. The light reflected from is projected onto the optical sheet of the second region B, and the light reflected from the reflecting sheet 20 of the second region B is projected to the optical sheet of the first region A. Therefore, the light projected from the array of light source modules 80 facing each other may be uniformly projected to the entire area of the optical sheet through the above-described process to implement a surface light source.

In FIG. 5A, the edge of the bottom cover 10 having the reflective layer R reflecting the light emitted from the light emitting element 82 surrounds the light source module 80 in a 'c' shape.

5B and 5C, the bottom cover 10 has an edge in a round type. In the embodiment shown in FIG. 5B, the reflective layer R is provided as an aspherical or parabolic surface.

In addition, in the exemplary embodiment illustrated in FIG. 5C, the edge of the bottom cover 10 or the reflective layer R may include a plurality of reflective sectors. Here, the reflective sector means that a plurality of planar reflective surfaces are provided to form the reflective layer R. FIG.

5B and 5C, light may be uniformly projected on the entire area of the reflective sheet 20 as compared with a spherical reflective surface. 5B, 5C, and 5D described later, the light source module 80 disposed on one surface of the backlight of the " 2-edge " type is shown. As in the embodiment, the backlight is divided into two regions according to an imaginary line that bisects the array of opposing light source modules 80. The light reflected from the reflective sheet 20 of the first region is projected onto the optical sheet of the second region, and the light reflected from the reflective sheet 20 of the second region is projected to the optical sheet of the first region. same.

Another embodiment of the light source module is shown in FIG. 5D.

In the present embodiment, the light projected from the light emitting device 82 provided in the light source module 80 is projected in the edge direction of the backlight, and considering the directing angle of the light emitting device 82 within a range of about 120 degrees Light can be projected. In addition, the reflective layer R is provided on the bottom cover 10 in a 'c' shape to reflect the light projected from the light emitting device 82.

In the backlight unit according to the above-described embodiments, since the light projected from the light source module 80 array is reflected by the reflective sheet 20 and projected onto the optical sheet 40 in the form of a surface light source, the light guide plate may be omitted. Therefore, the cost and weight of the backlight and the display device are reduced. In addition, when the resin-based light guide plate is omitted, conventionally, the composition of the light guide plate is vulnerable to moisture and can be expected to solve the problem of thermal expansion caused by heat generated from the light source. In addition, the rigid structure for fixing the light guide plate to the bottom cover of the backlight may be omitted.

In this case, when the light guide plate is omitted, the optical sheet 40 is provided to be spaced apart from the reflective sheet 20 by a predetermined interval. In this case, the reflective sheet 20 may be fixed to the bottom cover 10, but may be a problem because the optical sheet 40 may be floating. That is, the optical sheet 41 is detachably fixed to the fixing member 10a on the bottom cover 10, and in a direction perpendicular to the bottom cover 10 on each side of the bottom cover 10. A rectangular fixing member 10a is provided.

In addition, a groove 40a is formed on an edge of the optical sheet 40, and at least one groove 41a is formed at each side, and the fixing member 10a on the bottom cover 10 is formed on the diffusion sheet. The bottom cover 10 and the optical sheet 40 may be coupled to the groove 40a at the edge of the 40.

Therefore, since the first diffusion sheet 41, the prism sheet 42, and the second diffusion sheet 43 are both engaged with the bottom cover 10 at the same portion, the same portions of the respective sheets 41, 42, 43 are located. Tension can be concentrated. In order to solve the above problems, the optical sheet has a fastening structure described below.

6A to 6D illustrate fastening of the bottom cover and the optical sheet of the display device and the backlight unit according to the embodiment.

Here, the first diffusion sheet 41 and the prism sheet 42 are provided in FIG. 6A, and the first diffusion sheet 41, the prism sheet 42, and the second diffusion sheet 43 are shown in FIGS. 6B and 6C. Although shown to be fastened, each sheet may be provided with three or more, and may be provided with a micro lens array sheet and a protective sheet in addition to the above-described sheet.

In this case, the number of fixing members 10a on the bottom cover 10 may be greater than the number of grooves 41a of the edges of the respective sheets. In addition, the size of the grooves 41a, 42a, 43a provided in each sheet may be larger than that of the fixing member 10a, in case the sheets 41, 42, 43 are expanded due to thermal expansion. .

In FIG. 6A, the first sheet 41 and the second sheet 42 are fastened to the bottom cover 10. In addition, a fixing member 10a may be provided on an edge of the bottom cover 10 to fasten the first optical sheet 41 and the second optical sheet 42.

In this case, the groove 41a provided in the first optical sheet 41 and the groove 42a provided in the second optical sheet 42 are provided at different positions. That is, the groove 41a provided in the first optical sheet 41 and the groove 42a provided in the second optical sheet 42 are fastened to the fixing member 10a at different positions.

At this time, among the grooves 41a provided in the first optical sheet 41 and the grooves 42a provided in the second optical sheet 42, the grooves provided on the upper and lower edges are provided at different positions. The grooves provided at the left and right edges may be provided at the same position. Here, the upper and lower parts are based on the direction in which the backlight unit or the display device including the same is placed, and the tension applied to each of the sheets 41 and 42 is mainly applied to the vertical direction, that is, the upper and lower parts. Because.

In FIG. 6B, the first sheet 41, the second sheet 42, and the third sheet 43 are fastened to the bottom cover 10. In addition, a fixing member 10a may be provided on an edge of the bottom cover 10 to fasten the first optical sheet 41, the second optical sheet 42, and the third sheet 43.

In this case, the groove 41a provided in the first optical sheet 41 and the groove 42a provided in the second optical sheet 42 are provided at different positions. That is, the groove 41a provided in the first optical sheet 41 and the groove 42a provided in the second optical sheet 42 are fastened to the fixing member 10a at different positions. In addition, the groove 42a provided in the second optical sheet 42 and the groove 43a provided in the third optical sheet 43 are provided at different positions. That is, the groove 42a provided in the second optical sheet 42 and the groove 43a provided in the third optical sheet 43 are fastened to the fixing member 10a at different positions.

On the other hand, the groove (41a) provided in the first optical sheet 41 and the groove (43a) provided in the third optical sheet 43 are provided at different positions, the first optical sheet 41 The groove 41a provided in the groove 43a and the groove 43a provided in the third optical sheet 43 are fastened to the fixing member 10a at the same position.

In the embodiment shown in FIG. 6C, similar to the embodiment shown in FIG. 6B, the first sheet 41, the second sheet 42, and the third sheet 43 are fastened to the bottom cover 10. However, the groove 41a provided in the first optical sheet 41 and the groove 42a provided in the second optical sheet 42 and the groove 43a provided in the third optical sheet are respectively different positions. It is provided in, and is fastened with the fixing member (10a) of different positions.

That is, when a part of the sheets is overlapped and fastened at the same position as in the embodiment shown in FIG. 6B, when the offset of the tension applied to the sheet cannot be expected, all the sheets are respectively different from the bottom cover 10. Tightening can be expected with the dispersion of tension. Here, since the tension applied to the left and right directions of the sheets is not large, the fastening sites are the same.

6A to 6C, the number of fixing members 10a provided in the bottom cover 10 is larger than the number of grooves provided in each sheet due to the fastening structure described above.

7 is a view showing another embodiment of the fastening of the bar cover and the reflective sheet and the optical sheet disposed in the display device and the backlight unit according to the embodiment.

FIG. 7 illustrates the fastening of the reflective sheet 20 and the optical sheet 40 on the left and right sides, and the second support member 52 disposed on the bottom cover 10 and the side of the bottom cover 10. ) And the reflective sheet 20 and the optical sheet 40 are disposed between the third supporting member 53 and the side edges of the reflective sheet 20 and the optical sheet 40. Supported grooves 20a and 40a may be provided.

 As described above, since the tension does not greatly act on the left and right sides of the optical sheet 40, a simple fastening structure may be provided as shown.

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: fixing member
11: first heat radiating member 20: reflective sheet
40: optical sheet
41, 42, 43: first optical sheet, second optical sheet, third optical sheet
41a, 42a, 43a: home
51, 52, 53, 54: support member
60: display panel 70: top cover
R: reflective layer

Claims (9)

A first light source module array and a second light source module array respectively provided on surfaces facing each other;
A reflective layer for projecting light projected from the first light source module array and the second light source module array at an acute angle on the reflective sheet below; And
It includes a reflection sheet for reflecting the light incident from the reflector to the optical sheet,
The reflective sheet and the optical sheet are divided into a first region and a second region, and the light projected from the first light source module array is reflected from the first region of the reflective sheet and is projected to the second region of the optical sheet. unit. The method of claim 1,
And a first light source module array and a second light source module array to project light in a direction perpendicular to the reflective sheet. The method of claim 1, wherein the reflective layer,
And a first surface parallel to the reflective sheet and a second surface perpendicular to the first surface. The method of claim 1, wherein the reflective layer,
Back light unit with reflective material coated on the bottom cover. The method of claim 1, wherein the reflective layer,
Aspherical or parabolic backlight unit. The method of claim 1, wherein the reflective layer,
A backlight unit comprising a plurality of reflective sectors. The method of claim 1,
The light source module array is a backlight unit for projecting light in the direction of the edge of the bottom cover. The method of claim 7, wherein the reflective layer,
A back-light unit shaped like 'ㄷ'. A backlight unit according to any one of claims 1 to 8;
An optical sheet for diffusing the light projected from the backlight unit;
A panel provided on the optical sheet and implementing an image by projected light; And
And a bottom cover accommodating the backlight unit and the optical sheet.

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