KR20150010323A - Back light unit - Google Patents

Abstract

The present invention relates to a back light unit which can increase optical coupling efficiency, reduce the thickness of a bezel, and minimize harmful influence according to thermal expansion and heat dissipation efficiency. The back light unit of the present invention may include: a first light guide body; and a first reflection part which is installed in the first light guide body in order to reflect a first direction light to a second direction light in the first light guide body, and has a first slope to be slant toward one direction.

Description

BACK LIGHT UNIT

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a backlight unit capable of increasing a light coupling efficiency, reducing a thickness of a bezel, and minimizing adverse effects due to heat radiation efficiency and thermal expansion.

A display device is a term collectively referred to as a device capable of reproducing various still images or moving pictures such as a TV, a computer monitor, or a liquid crystal of a notebook computer. The display device may include a panel on which an image is formed, a backlight unit coupled to the rear of the panel to project light onto the panel, and a frame to which the backlight unit is coupled.

As the panel, a liquid crystal display (LCD) can be mainly used, and a liquid crystal is put between two glass substrates. LCD has a disadvantage that it is slow in response and relatively expensive, but because it is produced by a semiconductor process, resolution can be advantageous over PDP (Plasma Display Panel). Recently, it has been attracting attention as a next generation display device such as a mobile phone, a computer monitor, and a television.

However, since the LCD panel is manufactured in such a manner that the light transmittance of the LCD panel can not be controlled by itself, it is necessary to project light onto the LCD panel in order to form a predetermined image on the LCD panel.

This function is handled by a back light unit. The backlight unit includes a direct light type in which a light source is disposed on one plane side of an LCD panel to directly illuminate the entire surface of the LCD panel and a light source or point light source is disposed on one side or multiple sides of the LCD panel, And a diffusion edge method. Currently, devices such as mobile phones and monitors mainly employ the latter edge method.

A conventional edge type backlight unit has a light source disposed on a side surface of a light guide body for uniformly dispersing light on a screen, and a thick bezel, which does not form a screen, must be provided at the edge of the screen.

In addition, the conventional edge type backlight unit has a problem that the light-guiding body collides with the light emitting element due to thermal expansion and heat shrinkage, which frequently occur in the longitudinal direction of the light guiding body, so that internal parts are damaged or malfunction occurs .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to improve the luminous efficiency by increasing the optical coupling efficiency between the light emitting device and the light guiding body using the total internal reflection property, It is possible to reduce the thickness of the bezel and to minimize the thermal stress between parts due to thermal expansion and thermal shrinkage of the light guiding body and to easily place the heat dissipating structure in the light source arranged in the thickness direction of the light guiding body And it is an object of the present invention to provide a backlight unit which can be installed and improve the heat radiation efficiency. However, these problems are exemplary and do not limit the scope of the present invention.

According to an aspect of the present invention, there is provided a backlight unit comprising: a first light-guiding body; And a first reflector provided on the first light-guiding body to reflect the first direction light in the first light-guiding body by the second direction light and having a first inclination angle inclined in one direction .

According to an aspect of the present invention, the first reflective portion may include a reflective metallic body.

In addition, the backlight unit according to the present invention may be formed by extending an extended length from the first reflecting portion on one surface of the first light-guiding body so that the light primarily reflected by the first reflecting portion is secondarily reflected And an extended reflector.

According to an aspect of the present invention, at least one of the first reflecting portions may be provided at an intermediate portion of the first light guiding body.

The backlight unit according to the present invention is installed in the thickness direction of the first light-guiding body so as to prevent interference with the first light-guiding body in which thermal expansion may occur in the longitudinal direction, And a first light emitting device capable of emitting light to the first light emitting device.

According to an aspect of the present invention, the first light emitting device may be installed with a larger inclined installation angle with respect to the thickness direction of the first light guiding body as the light distribution angle increases, so as to increase the total reflectance.

According to an aspect of the present invention, the first light emitting device may be inserted into the light emitting device receiving groove formed in the first light guiding body.

According to an aspect of the present invention, the first reflector may be provided on at least one end of the first light-guiding body.

The backlight unit according to the present invention may further include: a second light-guiding body positioned on the same plane as the first light-guiding body; A second reflector provided on the second light-guiding body to reflect the third light in the second light-guiding body by the fourth light, the second reflector having a second inclination angle; And a second light emitting body provided in a thickness direction of the second light guiding body to prevent interference between the first light guiding body and the second light guiding body in which thermal expansion may occur in the longitudinal direction, Device.

According to an aspect of the present invention, the first reflecting portion includes a total reflection surface that induces total or partial total reflection, and the second reflecting portion is provided so as to face the first reflecting portion, .

The backlight unit according to an aspect of the present invention may further include a third reflector that is connected to the first reflector and has a third inclination angle.

According to some embodiments of the present invention as described above, it is possible to improve the luminous efficiency, reduce the thickness of the bezel, minimize the thermal stress between parts, and improve the heat radiation efficiency . Of course, the scope of the present invention is not limited by these effects.

1 is a cross-sectional view illustrating a backlight unit according to some embodiments of the present invention.
2 is a cross-sectional view illustrating a backlight unit according to some alternative embodiments of the present invention.
3 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
4 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
5 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
6 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
7 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
8 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
9 is a cross-sectional view illustrating a backlight unit according to still another embodiment of the present invention.
10 is a perspective view showing an example of Fig.

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

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, The present invention is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more thorough and complete, and will fully convey the concept of the invention to those skilled in the art. In the drawings, the thickness and size of each layer are exaggerated for convenience and clarity of explanation.

It is to be understood that throughout the specification, when an element such as a film, region or substrate is referred to as being "on", "connected to", "laminated" or "coupled to" another element, It will be appreciated that elements may be directly "on", "connected", "laminated" or "coupled" to another element, or there may be other elements intervening therebetween. On the other hand, when one element is referred to as being "directly on", "directly connected", or "directly coupled" to another element, it is interpreted that there are no other components intervening therebetween do. Like numbers refer to like elements. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

Also, relative terms such as "top" or "above" and "under" or "below" can be used herein to describe the relationship of certain elements to other elements as illustrated in the Figures. Relative terms are intended to include different orientations of the device in addition to those depicted in the Figures. For example, in the figures the elements are turned over so that the elements depicted as being on the top surface of the other elements are oriented on the bottom surface of the other elements. Thus, the example "top" may include both "under" and "top" directions depending on the particular orientation of the figure. If the elements are oriented in different directions (rotated 90 degrees with respect to the other direction), the relative descriptions used herein can be interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the figures, for example, variations in the shape shown may be expected, depending on manufacturing techniques and / or tolerances. Accordingly, the embodiments of the present invention should not be construed as limited to the particular shapes of the regions shown herein, but should include, for example, changes in shape resulting from manufacturing.

1 is a cross-sectional view showing a backlight unit 100 according to some embodiments of the present invention, and Fig. 10 is a perspective view showing an example of Fig.

1, a backlight unit 100 according to some embodiments of the present invention includes a first light guide body 10, a first reflector 20, and a first light emitting element 30 ).

For example, the first light-guiding body 10 may be a transparent material such as glass, acrylic, crystal, epoxy, polyethylene, polypropylene, or vinyl chloride, or a plate-like structure that can be made of a translucent material.

Although not shown, the first light-guiding body 10 may be provided with a semi-transparent film, reflection grains, a scattering layer, a reflective groove, a reflective projection, a light guide groove, a light projection, etc. so as to disperse the light evenly .

The first reflector 20 is installed in the first light-guiding body 10 so as to reflect the first direction light in the first light-guiding body 10 by the second direction light, And is inclined to have the first inclination angle K1.

Here, for example, the first inclination angle K1 may be about 35 degrees to 55 degrees, more specifically about 45 degrees, based on the horizontal plane.

As shown in FIG. 1, for example, the first reflecting portion 20 may have a total reflection surface for guiding at least all or a part of total reflection.

In addition, the first reflector 20 may be formed by selecting at least one of a reflective mirror, a reflective multilayer film, a Bragg reflection surface, an air gap reflective surface, and combinations thereof.

1, the first light emitting device 30 can prevent interference with the first light guiding body 10, which may generate thermal expansion in the longitudinal direction L, for example, 1, the first light-guiding body 10 can be installed in the thickness direction T of the first light-guiding body 10, that is, the first light-guiding body 10, It is a kind of light source.

1, when the light distribution angle A1 is small so as to increase the total reflectance, the first light emitting device 30 has a thickness direction T of the first light guiding body 10 As a standard, there is no tilted installation angle or it can be installed very small.

As shown in FIGS. 1 and 10, at least one or more of the first reflecting portions 20 may be installed at one end or both ends of the first light-guiding body 10.

Accordingly, the backlight unit 100 according to some embodiments of the present invention can improve the light-emitting efficiency by increasing the light coupling efficiency between the light-emitting device such as the LED and the light-guiding body using the total reflection characteristic, It is possible to reduce the thickness of the bezel and to minimize the thermal stress between parts due to thermal expansion and thermal contraction of the light guiding body 10 and to prevent the heat conduction of the light guiding body 10 The heat dissipation structure can be easily installed in the light source arranged in the thickness direction T without restriction of the space, and the heat dissipation efficiency can be improved.

2 is a cross-sectional view illustrating a backlight unit 200 according to some alternative embodiments of the present invention.

As shown in FIG. 2, the first light emitting device 31 has a tilted installation angle T 2 with respect to the thickness direction T of the first light guiding body 10 as the light distribution angle A 2 increases, (B1).

For example, when the light distribution angle A2 of the first light emitting device 31 is approximately 50 degrees, a considerable amount of light may escape to the outside of the light guiding body 10 without total reflection. Therefore, it is necessary to adjust the tilt installation angle B1 to increase the total reflectance.

However, when the light distribution angle A2 of the first light emitting device 31 is approximately 18 degrees, all the light can be totally reflected. Therefore, the first light emitting device 31 need not be inclined.

For example, when the light distribution angle A2 of the first light emitting device 31 is approximately 40 degrees, as shown in FIG. 2, the thickness direction T of the first light guiding body 10 may be increased, The first light emitting device 31 can be installed with the inclination angle B1 set to approximately 11 degrees.

3 is a cross-sectional view illustrating a backlight unit 300 in accordance with some further embodiments of the present invention.

As shown in FIG. 3, the first reflecting portion 21 may include, for example, a first reflecting metallic body 21-1.

3, the backlight unit 300 according to still another embodiment of the present invention may be configured such that the light reflected by the first reflector 21 is secondarily reflected, The light guiding body 10 may further include an extended reflector 22 extending from the first reflector 21 by a predetermined extension length, for example, a first extension length L1.

More specifically, the extended reflector 22 may include a second reflective metallic body 22-1.

Therefore, the light generated from the light emitting device 30 may be partially totally reflected by the first reflector 21, and the remaining light may be reflected by the metal layer. Then, the reflected light is reflected by the extended reflector 22 to be uniformly dispersed into the light guide body 10 and irradiated.

4 is a cross-sectional view illustrating a backlight unit 400 in accordance with some further embodiments of the present invention.

4, the first reflecting portion 23 of the backlight unit 400 according to some other embodiments of the present invention may be provided at the middle portion of the first light-guiding body 10, for example, At least one can be arranged at a predetermined interval.

Accordingly, a plurality of the light emitting devices 30 can be arranged in a middle portion of the light guiding body 10 in a required area.

5 is a cross-sectional view illustrating a backlight unit 500 in accordance with some further embodiments of the present invention.

5, the first light emitting device 30 of the backlight unit 500 according to still another embodiment of the present invention includes a light emitting element receiving groove 10a (not shown) formed in the first light guiding body 10, As shown in FIG.

Therefore, since the first light emitting device 30 is inserted into the first light guiding body 10, space utilization can be further increased.

6 is a cross-sectional view illustrating a backlight unit 600 in accordance with some further embodiments of the present invention.

6, a backlight unit 600 according to still another embodiment of the present invention includes a second light-guiding body 40, a second reflector 50, a second light-emitting element 60 A second light-guiding body 40, a second reflector 50, and a second light-emitting element 60. The second light-

Here, the second light-guiding body 40 may be located on the same plane as the first light-guiding body 10, for example, apart from the first light-guiding body 10.

The second reflector 50 is installed in the second light-guiding body 40 so as to reflect the third light in the second light-guiding body 40 as the fourth light, It may be a portion having an inclination angle K2.

The second light emitting device 60 may include a second light emitting body 40 to prevent interference with the second light emitting body 40 in which thermal expansion may occur in the longitudinal direction T. For example, In the thickness direction (T).

The second light emitting device 60 is a kind of light source that can irradiate the second reflecting portion 50 with light.

Therefore, a plurality of the light emitting elements 30 can be arranged in a middle part and a middle part in a necessary part of the screen.

7 is a cross-sectional view illustrating a backlight unit 700 according to still another embodiment of the present invention.

7, the backlight unit 700 according to still another embodiment of the present invention may include a total reflection surface in which the first reflection portion 20 induces all or a part of total reflection .

The second reflecting portion 70 may be disposed opposite to the first reflecting portion 20 and may include a first reflecting metallic body 70-1.

Here, for example, the backlight unit 700 according to still another embodiment of the present invention may be configured such that the first light-guiding body (the light-guiding body) 40 may include an extended reflector 71 extending from the second reflector 70 by a second extension length L2.

The extended reflector 71 may include a second reflective metallic member 71-1.

Accordingly, a plurality of the light emitting elements 30 (60) can be arranged in a necessary portion in the screen in the middle and in the middle, and a part of the light can be totally reflected, and a part can be reflected by the metal body.

8 is a cross-sectional view illustrating a backlight unit 800 in accordance with some further embodiments of the present invention.

8, the backlight unit 800 according to still another embodiment of the present invention may include a third reflective portion (e.g., a second reflective portion) (80).

Therefore, the light generated from the light emitting device 30 can be firstly reflected by the first reflector 20, secondly reflected by the third reflector 80, Can be uniformly dispersed and irradiated.

9 is a cross-sectional view illustrating a backlight unit 900 in accordance with some further embodiments of the present invention.

9, a backlight unit 900 according to still another embodiment of the present invention includes a first reflecting portion 21 and a second reflecting portion 22 so that light firstly reflected by the first reflecting portion 21 is secondarily reflected, (L3) from the third reflecting portion (24) on the upper surface of the first light-guiding body (10), and a third reflecting portion (24) The extended reflector 22 may be formed by extending an extended reflector 22 as shown in FIG.

More specifically, the first reflector 21, the third reflector 24, and the extended reflector 22 are all formed of reflective metallic bodies 21-1, 24-1, 22-2, 1).

Therefore, the light generated from the light emitting device 30 can be firstly reflected by the first reflecting portion 21 and then reflected by the third reflecting portion 24 and the extended reflecting portion 22, The light is reflected by the third order, and is uniformly dispersed into the light guide body 10 and irradiated.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: first light-guiding body
20, 21, 23:
K1: First inclination angle
100, 200, 300, 400, 500, 600, 700, 800: backlight unit
L: longitudinal direction
T: thickness direction
30, 31: first light emitting element
A1, A2: light distribution angle
B1: Tilt mounting angle
21-1, 70-1: a first reflective metallic body
L1, L2: Extension length
22, 71: extended reflector
22-1, 71-1: a second reflective metallic body
10a: light emitting element housing groove
40: second light-guiding body
K2: 2nd inclination angle
50, 70: a second reflecting portion
60: second light emitting element
K3: Third inclination angle
80: Third reflective part

Claims (11)

A first light-guiding body; And
A first reflector provided on the first light-guiding body so as to reflect the first direction light in the first light-guiding body with the second direction light, the first reflector having a first inclination angle inclined in one direction;
And a backlight unit. The method according to claim 1,
Wherein the first reflective portion includes a reflective metal body. The method according to claim 1,
An extended reflector formed on one surface of the first light-guiding body to extend from the first reflector by a predetermined length so that the light firstly reflected by the first reflector is secondarily reflected;
Further comprising a backlight unit. The method according to claim 1,
Wherein at least one of the first reflecting portions is provided at an intermediate portion of the first light guiding body. The method according to claim 1,
The first light emitting body being provided in the thickness direction of the first light guiding body so as to prevent interference with the first light guiding body in which longitudinal thermal expansion may occur, ;
Further comprising a backlight unit. The method according to claim 1,
Wherein the first light emitting device is installed with an inclined installation angle larger with respect to a thickness direction of the first light guiding body as the light distribution angle is increased so as to increase the total reflectance. The method according to claim 1,
Wherein the first light emitting element is inserted into the light emitting element receiving groove formed in the first light guiding body. The method according to claim 1,
Wherein at least one of the first reflective portions is provided at one end of the first light-guiding body. The method according to claim 1,
A second light-guiding body positioned on the same plane as the first light-guiding body;
A second reflector provided on the second light-guiding body to reflect the third light in the second light-guiding body by the fourth light, the second reflector having a second inclination angle; And
And a second light emitting body provided in the thickness direction of the second light guiding body so as to prevent interference with the second light guiding body in which thermal expansion may occur in the longitudinal direction, ;
Further comprising a backlight unit. 10. The method of claim 9,
Wherein the first reflecting portion includes a total reflection surface that induces total or partial total reflection,
Wherein the second reflective portion is provided so as to face the first reflective portion, and includes a reflective metallic body. The method according to claim 1,
A third reflector provided adjacent to the first reflector and having a third inclination angle;
Further comprising a backlight unit.

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