KR20080049249A - Light emitting diode cluster and backlight unit using the same - Google Patents

Abstract

A light emitting diode cluster and a backlight unit using the same are provided to diffuse uniformly light by forming an air layer in an inside of a housing. A light emitting diode cluster(40) includes a light-transmitting type housing(42), an air layer formed in the inside of the housing, and a plurality of light emitting diodes arranged in the inside of the air layer. The housing is semi-cylindrical. The light emitting diode cluster further includes a parallel part parallel to a bottom surface of the housing and a curved part. The curved part is rounded from the parallel part to the bottom surface. A light-scattering pattern is formed on one of an inner wall and an outer wall of the housing.

Description

Light Emitting Diode Cluster and Backlight Unit using the same

1 is a backlight unit using a conventional light emitting diode.

2 is a conventional light emitting diode optical compensation structure

3 is a perspective view showing a backlight unit according to the present invention;

4A and 4B are a perspective view and a front view of the light emitting diode cluster according to the first embodiment;

Fig. 5 is a schematic diagram showing an optical path of light via the light emitting diode cluster according to the first embodiment.

FIG. 6 is a diagram showing an optical path simulation of light via a light emitting diode cluster according to the first embodiment; FIG.

7A and 7B are a perspective view and a front view of the light emitting diode cluster according to the second embodiment;

FIG. 8 is a diagram showing an optical path simulation of light via a light emitting diode cluster according to the second embodiment; FIG.

9A and 9B are perspective and front views showing a light emitting diode cluster according to a second embodiment;

Fig. 10 is a diagram showing an optical path simulation of light via a light emitting diode cluster according to the third embodiment.

<Description of Main Reference Codes>

2,12,32,52: base substrate 28,48,68: light emitting diode

22,42,62: Housing

The present invention relates to a light emitting diode cluster and a backlight unit using the same. More particularly, the present invention relates to a light emitting diode cluster and a backlight unit using the same.

Currently, the display device as a visual information transmission medium is mainly made of cathode ray tubes, but has a disadvantage in that weight and volume are large. In order to overcome such disadvantages of cathode ray tubes, the use of flat panel displays is increasing, and among them, liquid crystal displays (hereinafter referred to as "LCDs") are lightweight, thin, and low power consumption. Due to its advantages, its application range is gradually widening. The LCD displays a desired image on a screen by adjusting the transmission amount of the light beam according to an image signal applied to a plurality of control switches arranged in a matrix form. That is, since the gray scale is expressed by adjusting the amount of light transmitted to the degree of deflection of the liquid crystal inside the panel, and it is not a self-luminous display device, a light source such as a back light is required.

The light source used in the backlight unit may use a fluorescent lamp and a light emitting diode. Among them, light emitting diodes are being used as a light source of a backlight due to their low power consumption.

1 is a view schematically showing a direct type backlight unit using a conventional light emitting diode. In the direct type backlight unit using the light emitting diode, as shown in the drawing, several light emitting diodes 6 are arranged on the base substrate 2 at regular intervals. In this case, the light emitting diode has a difficulty in supplying light of uniform luminance to the panel due to the point light source, and thus there is a problem of luminance unevenness where the light source is located and where it is not.

In order to solve this problem, as shown in FIG. 2, an optical compensation structure 4 for dispersing light in the appearance of the light emitting diode may be formed.

Although the optical compensation structure 4 somewhat improves the problem of the luminance unevenness, the optical compensation structure 4 has the disadvantage of increasing the manufacturing cost due to the reason for forming a separate structure in each light emitting diode.

In order to reduce the manufacturing cost in solving the problem of improving the luminance, a backlight unit of a cluster structure in which an optical compensation structure is selected by tying several light emitting diodes has been proposed, but in the conventional cluster structure, the problem of luminance unevenness is completely solved. It was not easy to solve. In particular, conventionally, the LED cluster has a disadvantage in that the light emitted from the light emitting diodes of the three primary colors is not evenly mixed in the cluster.

Accordingly, an object of the present invention is to provide a backlight unit using a light emitting diode capable of smoothing color mixing and supplying light with uniform brightness to a panel.

In order to achieve the above object, the LED cluster according to the present invention includes a light transmitting housing, an air layer formed inside the housing, and several light emitting diodes arranged in the air layer.

The housing may be formed in a semi-cylindrical shape.

Or it may be a form containing the parallel part parallel to a base surface, and the curved part which has a round shape from a parallel part to a base surface.

And the light scattering pattern may be formed on the surface of the housing wall.

The backlight unit according to the present invention includes a base substrate and a cluster in which a plurality of light emitting diodes are formed on an air layer inside the housing of the light transmitting type.

The base substrate is preferably such that the surface on which the cluster is formed is the light reflection surface.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3 to 10.

3 is a view illustrating a backlight unit of the liquid crystal display according to the present invention.

In the panel 10 illustrated in FIG. 3, liquid crystals are aligned, and thus, a desired image is expressed by adjusting a transmission degree of light incident on the panel 10.

The backlight unit for supplying light to the panel 10 includes a plurality of LED clusters 20 formed on the base substrate 12.

The light emitting diode cluster 20 is aligned with the base substrate 12. The number of light emitting diode clusters 20 depends on the number of light emitting diodes included in the light emitting diode cluster 20 and the size of the panel. In addition, the light emitting diode clusters 20 are preferably arranged at uniform intervals to supply light having uniform brightness to the panel.

Some examples of light emitting diode clusters are as follows.

4A and 4B are a perspective view and a cross-sectional view showing a light emitting diode cluster according to a first embodiment of the present invention.

4A and 4B, the LED cluster 20 includes a light transmitting housing 22, an air layer 24 formed in the housing 22, and several light emitting diodes arranged in the air layer 24. And (28).

The light emitting diode 28 uses a light emitting diode emitting white light or at least one light emitting diode emitting red, green, and blue light.

The housing 22 uses a light transmissive material. The housing 22 is formed in a semi-cylindrical shape on the base substrate 12. That is, the base substrate 12 is formed in a semi-cylindrical shape having a semicircular front face and a rectangular side face. In addition, an air layer 24 is formed inside the housing 22.

The base substrate 12 uses a material capable of reflecting light in order to increase the efficiency of the light emitted from the light emitting diode 28 and the light transmitted through the housing 22.

A path in which light is emitted by the LED cluster according to the first embodiment is schematically illustrated in FIG. 5.

The light incident perpendicularly to the panel as in ① proceeds vertically without refraction of light in the course of passing through the housing 22.

In general, the direction of light travels as shown by ②. The light irradiated from the light emitting diodes 28 is first refracted by the difference of the medium in the process of being incident to the housing 22 via the air layer 24, and then the housing 22 In the process of passing through), the secondary refraction is caused by the difference of the medium between the housing 22 and the air.

Then, the light irradiated to the base substrate 12, which is the opposite surface of the panel as shown in ③, is reflected by the base substrate 12, and is refracted twice in the process of entering and transmitting the housing 22 as shown in ②. Irradiated in the panel direction.

The optical path by the light emitting diode cluster 20 according to the first embodiment can be seen in FIG. 6 showing a simulation result.

As described above, according to the LED cluster according to the present invention, light diffuses widely while refracting in the process of passing through the housing. As a result, light with uniform luminance can be irradiated to the panel. In particular, the light emitting diode cluster 20 according to the present invention includes the air layer 24 in the housing 22 even when each light emitting diode 28 emitting three primary colors of light instead of white light is used. The color purity can be increased because the light of the three primary colors can be mixed evenly within.

7A and 7B are a perspective view and a cross-sectional view showing a light emitting diode cluster 40 according to a second embodiment of the present invention.

7A and 7B, the light emitting diode cluster 40 according to the second embodiment of the present invention includes a light transmitting housing 42, an air layer 44 formed inside the housing 42, and an air layer 44. There are several light emitting diodes 48 arranged therein.

The light emitting diode 48 uses a light emitting diode emitting white light or at least one light emitting diode emitting red, green, and blue light.

The housing 42 uses a light transmissive material. The housing 42 has a shape in which the curvature of the upper layer is removed from the tunnel to include a flat horizontal portion P. The light emitting diode cluster 40 diffuses light widely by causing two refractions to occur in the process of the light emitted from the light emitting diodes 48 passing through the housing 42. In particular, the LED cluster 40 according to the second embodiment includes a housing 42 having a shape in which the curvature is removed from the upper layer, so that the light can be more efficiently dispersed as shown in the simulation result of FIG. 8.

9A and 9B are a perspective view and a cross-sectional view illustrating a light emitting diode cluster according to a third embodiment of the present invention.

9A and 9B, the LED cluster according to the third embodiment of the present invention includes a light transmissive housing 62, an air layer 64 formed inside the housing 62, and an air layer 64. Several light emitting diodes 68 are arranged.

The light emitting diode 68 uses a light emitting diode emitting white light or at least one light emitting diode emitting red, green, and blue light.

The housing 62 uses a light transmissive material. The housing 62 has a shape including a flat horizontal portion P by removing curvature of the upper layer portion in a tunnel shape, and a light scattering pattern is formed on a surface thereof. The light scattering pattern may be formed through a haze treatment on the surface. The LED cluster 60 diffuses the light widely by causing two refractions in the process of the light emitted from the LED 68 passing through the housing 62. In particular, in the light emitting diode cluster 60 according to the third embodiment of the present invention, light is more efficiently dispersed by roughening the inner and outer walls of the housing 62.

This effect can also be seen in FIG. 10, which is a simulation result showing the optical path through the LED cluster 60.

Embodiments of the present invention may be implemented in various forms in addition to the above-described embodiments. The housing may be formed in a hemispherical shape including an air layer therein instead of a tunnel type, or may be formed in other shapes.

Further, it is apparent that the roughening treatment of the third embodiment may be formed on the surface of the shape in which the curvature of the upper layer portion of the housing is removed, and can be used in other types of housings.

As described above, according to the light emitting diode cluster and the backlight using the light emitting diode cluster according to the present invention, the light emitted from the light emitting diode as the point light source may be uniformly incident on the panel. Thereby, the image fall of the display surface by a luminance nonuniformity can be prevented.

Since the LED cluster and the backlight using the same do not form a structure in each of the light emitting diodes, the manufacturing cost required to individually form the structures in the light emitting diodes may be reduced.

In particular, the light emitting diode cluster according to the present invention includes an air layer inside the housing, so that the light is uniformly diffused, and when using the light emitting diodes of three primary colors, it is advantageous to secure enough space to mix the light to generate white light. It can increase.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (6)

Light transmissive housing; An air layer formed inside the housing; Light emitting diode cluster comprising a plurality of light emitting diodes arranged in the air layer. The method of claim 1, The housing is a light emitting diode cluster, characterized in that the semi-cylindrical. The method of claim 1, A parallel portion parallel to the bottom of the housing; Light emitting diode cluster comprising a curved portion formed in a round shape from the parallel to the bottom surface. The method according to any one of claims 2 to 3, The housing is a light emitting diode cluster, characterized in that the light scattering pattern is formed on at least one surface of the inner wall and the outer wall. A base substrate; And a cluster having a plurality of light emitting diodes formed in the air layer inside the light transmissive housing and formed on the base substrate. The method of claim 5, wherein And the base substrate has a surface where the cluster is formed is a light reflecting surface.

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