WO2009131333A2

WO2009131333A2 - Illuminator, backlight unit comprising the illuminator and display device using the backlight unit

Info

Publication number: WO2009131333A2
Application number: PCT/KR2009/001974
Authority: WO
Inventors: 이상철
Original assignee: Lee Sangcheol
Priority date: 2008-04-21
Filing date: 2009-04-16
Publication date: 2009-10-29
Also published as: WO2009131333A3; KR100912426B1

Abstract

Disclosed are an illuminator, a backlight unit comprising the illuminator and a display device using the backlight unit, wherein the illuminator has a structure that efficiently emits heat generated while irradiating light from plural light sources installed on plural substrates. The disclosed illuminator is characterized by including: plural substrates that are stacked with a space therebeween, and plural light sources that are respectively mounted on each substrate which irradiate light. A light-transmitting unit is formed on the upper substrate among the plural substrates so that the light irradiated from the light source installed on the lower substrate may pass through the light-transmitting unit.

Description

Lighting device, backlight unit employing the same, and display unit employing the backlight unit

The present invention relates to a lighting device, a backlight unit employing the same, and a display device employing the backlight unit, and more particularly, to efficiently radiate heat generated from a light source in illumination through a plurality of light sources mounted on a substrate. The present invention relates to a lighting device having a structure, a backlight unit employing the same, and a display device employing the backlight unit.

In general, a liquid crystal display device, which is a kind of light receiving type flat panel display, does not have its own light emitting capability, and thus forms an image by selectively transmitting illumination light emitted from the outside. To this end, a backlight unit for illuminating light is provided on the back of the liquid crystal display.

The backlight unit is classified into a direct light type and an edge light type according to the arrangement position of the light source. The direct emission type is a method of directly irradiating light directly to the liquid crystal panel from a light source provided directly below the liquid crystal panel. On the other hand, the edge emission type is a method of transferring the light emitted from the light source installed at the edge of the light guide plate to the liquid crystal panel by converting the path through the light guide plate.

As a light source of the backlight unit, a cold cathode fluorescent lamp (CCFL), which is a linear light source, is mainly used, and a light emitting diode (LED) has recently emerged.

Unlike the CCFL, the light emitting diode is a point light source, and has the advantages of longer life, wider operating temperature range, environmental friendliness, and high color reproducibility than the CCFL. In addition, there is an advantage that it is possible to illuminate the light of a high luminance depending on the structure. In addition, when the direct light emitting type backlight unit is configured using the LED, there is an advantage that the light can be uniformly illuminated over the entire large area of the liquid crystal panel.

In constructing a direct-emitting backlight unit, when LED is used as a light source, several LED is mounted on one board | substrate. For example, about 200 LEDs are used in a backlight unit of a 30-inch TFT-LCD. Here, when the power consumption of each LED is 1W, considering that the ratio of heat generated from the power consumption of 1W is more than 70%, heat of about 140W is generated when using 200 LEDs. The generated heat may cause deterioration of operational reliability of an electronic circuit or the like, and may cause thermal deformation of the product.

In addition, when applying a power consumption of 1W LED to increase the brightness, or to make the liquid crystal panel large screen, such as 42 inches, 47 inches, increasing the number of LEDs used in the backlight unit is required, An increase is inevitable. Accordingly, a configuration for dissipating heat generated in a backlight unit using a light emitting diode as a light source is required.

1 is a cross-sectional view of a backlight unit having a conventional heat dissipation structure.

Referring to the drawings, a conventional backlight unit includes a substrate 1, a plurality of LEDs 3 mounted on the substrate 1, and a reflective sheet provided so that the LEDs 3 are exposed on the substrate 1. 5) and a heat dissipation fin 7 provided below the substrate 1 to radiate heat to the outside.

The conventional backlight unit configured as described above has a practical limitation in increasing the surface area of the heat dissipation fin in consideration of the trend toward higher density of LED arrangements and slimming trends of display devices. In addition, even if the surface area of the heat dissipation fin is widened, the distance between the heat absorbing portion and the heat dissipating portion becomes far, and thus there is a limit to improving the heat dissipation efficiency.

In addition, the conventional backlight unit may further include a heat dissipation fan that is rotated at high speed in order to increase heat dissipation efficiency. In this case, there is a problem in slimming, accompanied by power consumption for driving the heat radiating fan, there is a problem that noise is generated when driving the heat radiating fan.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides an illumination device having a structure capable of attaining slimming and thermal stability at the same time, a backlight unit employing the same, and a display device employing the backlight unit. There is this.

In order to achieve the above object, a lighting apparatus according to the present invention comprises: a plurality of substrates stacked and spaced apart from each other; A plurality of light sources which are separately mounted on each of the plurality of substrates, and include a plurality of light sources for irradiating light, wherein a light transmitting part through which light emitted from a light source mounted on a lower substrate is passed to a substrate disposed on an upper layer of the plurality of substrates; Formed.

Here, the substrate disposed below the plurality of substrates includes a plurality of mounting portions on which some of the plurality of light sources are mounted, and a space portion formed between the plurality of mounting portions, wherein the mounting portion and the space portion are the It can be arranged alternately on the substrate.

The light source may include a light emitting diode.

The plurality of substrates may include: a first substrate having a plurality of first mounting portions on which some of the plurality of light sources are mounted, and a blank portion formed between the plurality of first mounting regions; A second substrate formed on the first substrate, the second substrate having a second mounting part spaced apart from the blank part and mounted with the remaining light sources among the plurality of light sources, wherein the light transmitting part is provided in the first mounting part; It is formed at a predetermined position of the opposite second substrate, can transmit the light irradiated from the light source mounted on the first substrate.

In order to achieve the above object, the backlight unit includes: the lighting device; It is disposed on the lighting device, and includes a diffuser plate to diffuse the light illuminated in the lighting device.

In order to achieve the above object, a display device according to the present invention includes: the backlight unit; And a liquid crystal panel which displays an image by selectively transmitting the light illuminated by the backlight unit.

Since the lighting apparatus according to the present invention configured as described above can be mounted by dividing a plurality of light sources into a plurality of substrates, the number of light sources mounted on one substrate can be reduced, and the distance between neighboring light sources can be kept wide. The thermal interference between light sources can be reduced. Accordingly, the heat dissipation efficiency can be improved without adopting a heat dissipation structure such as a heat dissipation plate, and a slim product can be secured.

In addition, the backlight unit employing the lighting device configured as described above and the display device employing the backlight unit can also ensure thermal stability and slimmer product without employing a heat dissipation structure.

1 is a cross-sectional view showing a backlight unit having a conventional heat dissipation structure.

2 is a partial cross-sectional view showing a lighting apparatus according to a first embodiment of the present invention.

Figure 3 is an exploded perspective view showing a lighting apparatus according to a first embodiment of the present invention.

4 is a plan view showing a lighting apparatus according to a first embodiment of the present invention.

5 is a partial cross-sectional view showing a lighting apparatus according to a second embodiment of the present invention.

6 is a partial cross-sectional view showing a backlight unit according to an embodiment of the present invention.

7 is a partial cross-sectional view showing a display device according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10, 51: substrate 11, 111: first substrate

11a and 111a: first mounting part 11b: blank part

13, 113:

2nd board

13a, 113a: 2nd mounting part

14, 114: light transmitting unit 115: third substrate

115a: 3rd mounting part 20 and 55: light source

21: base 23: light emitting diode

25: lens 31: spacer

131: first spacer 135: second spacer

50, 71: lighting device 60, 75: diffuser plate

70: backlight unit 80: liquid crystal panel

Hereinafter, an illumination device, a backlight unit employing the same, and a display device employing the backlight unit according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 to 4 are each a partial cross-sectional view, an exploded perspective view and a plan view showing the lighting apparatus according to the first embodiment of the present invention.

Referring to the drawings, the lighting apparatus according to the first embodiment of the present invention is divided into a plurality of substrates 10 and a plurality of substrates 10 which are stacked and spaced apart from each other by a spacer 31 or the like, and are mounted with light. It includes a plurality of light sources 20 to be irradiated.

2 to 4 illustrate a case where the first substrate 11 and the second substrate 13 are employed as the plurality of substrates 10.

The second substrate 12 positioned on the upper layer is formed with a light transmitting portion 14 through which light emitted from the light source 20a mounted on the first substrate 11 positioned on the lower layer passes.

The first substrate 11 includes a plurality of first mounting portions 11a on which the first light source 20a, which is part of the plurality of light sources 20, is mounted, and a blank portion 11b formed between the first mounting portions 11a. ) Here, the first mounting portion 11a and the blank portion 11b may be alternately formed in the horizontal and vertical directions on the first substrate 11 as shown in FIG. 3. In this case, the distance between the first light sources 20a mounted on the first substrate 11 can be increased.

The second substrate 13 is spaced apart from the first substrate 11 by the spacer 31, and is disposed to face the space 11b and is the second light source remaining from the plurality of light sources 20. It has the 2nd mounting part 13a by which 20b is mounted. The light transmitting portion 14 of the second substrate 13 is formed to penetrate the light emitted from the first light source 20a mounted on the first substrate 11.

Each of the plurality of light sources 20 mounted on the first and

second substrates

11 and 13 may be configured as a light emitting diode module including a base 21, a light emitting diode 23, and a lens 25. . The light emitting diodes 23 are mounted on the base 21 and irradiate light. The lens 25 is installed on the base 21 to cover the light emitting diodes 23 and focuses the light irradiated from the light emitting diodes 23.

In the present embodiment, the spacer 31 is used to separate the second substrate 13 with respect to the first substrate 11 as an example, but the spacer 31 is merely exemplary and various modifications. Yes it is possible.

Referring to FIG. 5, the lighting apparatus according to the second exemplary embodiment of the present invention includes a plurality of substrates 10 stacked and spaced apart from each other, and a plurality of light sources mounted on each of the plurality of substrates 10 and irradiating light. And 20.

FIG. 5 illustrates a case where the first to

third substrates

111, 113, and 115 are employed as the plurality of substrates 10.

The first substrate 111 may include a plurality of first mounting portions 111a on which the first light source 120a, which is a part of the plurality of light sources 20, is mounted, and a blank portion formed between the plurality of first mounting portions 111a. 111b). Here, the blank portion 111b is formed at a position opposite to the second and third mounting

portions

113a and 115a to be described later, and is alternately formed in the horizontal and vertical directions with respect to the first mounting portion 111a. Can be.

The second substrate 113 is disposed on the first substrate 111 so as to be spaced apart by the first spacer 131, and the second mounting unit is disposed to face the space 111b of the first substrate 111. (113a). The second light source 120b, which is another part of the plurality of light sources 20, is mounted on the second mounting unit 113a.

The third substrate 115 is disposed on the second substrate 113 so as to be spaced apart from each other by the second spacer 135, and avoids portions facing the first and second mounting

portions

111a and 113a, respectively. And a third mounting portion 115a positioned. The third light source 120c, which is the remainder of the light sources 20, is mounted on the third mounting unit 115a.

The light transmitting part 114 has a predetermined position of the second substrate 113 facing the first mounting portion 111a and a predetermined position of the third substrate 115 facing the first and second mounting

portions

111a and 113a. Are formed at each location. Accordingly, light emitted from the first and second

light sources

120a and 120b mounted on the first and second mounting

portions

111a and 113a is formed on the second and

third substrates

113 and 115. It may be illuminated through the light emitting unit 114.

Each of the plurality of light sources 20 may be configured as a light emitting diode module including a base 21, a light emitting diode 23, and a lens 25 as described above.

In the above description, the two substrates 11, 12 and three

substrates

111, 112, and 113 are described as examples of the plurality of substrates 10, but the number of substrates may be increased as necessary. In addition, the size of each of the plurality of substrates 10 may also vary as necessary.

As described above, when mounting a plurality of light sources on the substrate, when mounting the light source 20 divided into the plurality of substrates 10 as in the present invention as compared to the case where the light source is disposed on a conventional single substrate Can reduce the number of light sources mounted on one substrate. In addition, since the distance between neighboring light sources can be kept wide, thermal interference between neighboring light sources can be reduced. Accordingly, the heat dissipation efficiency can be improved without adopting a heat dissipation structure such as a heat dissipation plate, thereby preventing deterioration of operation reliability of the electronic circuit and the like, and thermal deformation of the product.

Referring to FIG. 6, a backlight unit according to an exemplary embodiment of the present invention illuminates uniform light on a display device, and includes an illumination device 50 and a diffuser plate 60 disposed on the illumination device 50. do.

The illumination device 50 is a direct light emission type, and includes a plurality of substrates 51 and a plurality of light sources 55 mounted on each of the plurality of substrates 51 and irradiating light. Since the lighting device 50 is substantially the same as the lighting device 50 according to the embodiment of the present invention described with reference to FIGS. 2 to 5, a detailed description thereof will be omitted.

The diffusion plate 60 diffuses the light emitted from the plurality of light sources 55 disposed on the substrate 51 so that uniform light is illuminated on the display panel.

7 is a partial cross-sectional view showing a display device employing a backlight unit according to an embodiment of the present invention.

Referring to FIG. 7, a display apparatus according to an exemplary embodiment of the present invention includes a backlight unit 70 and a liquid crystal panel 80 that implements an image by selectively transmitting the light illuminated by the backlight unit 70. Include.

The backlight unit 70 includes an illumination device 71 for illuminating light and a diffuser plate 75 for diffusing the illuminated light to be uniform light. Since the backlight unit 70 is substantially the same as the backlight unit according to the exemplary embodiment of the present invention described with reference to FIG. 6, a detailed description thereof will be omitted.

As described above, in configuring the backlight unit and the display apparatus employing the same, by dividing the light sources on a plurality of substrates, the distance between neighboring light sources can be kept wide and the number of light sources mounted on one substrate can be reduced. As a result, the heat radiation efficiency can be improved. Therefore, it is possible to prevent deterioration of operation reliability and thermal deformation of the product without using a heat dissipation structure such as a heat sink.

The above embodiments are merely exemplary, and various modifications and equivalent other embodiments are possible to those skilled in the art. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the invention described in the claims below.

The present invention can be applied to an illumination device using a light source such as an LED, a backlight unit employing such an illumination device, and a display device employing such a backlight unit.

Claims

In the lighting device,

A plurality of substrates stacked and spaced apart from each other;

Is divided into each of the plurality of substrates is mounted, and includes a plurality of light sources for irradiating light,

And a light transmitting portion through which light emitted from a light source mounted on a lower substrate is formed in a substrate disposed on an upper layer among the plurality of substrates.
The method of claim 1,

The substrate disposed below the plurality of substrates includes a plurality of mounting portions on which some of the plurality of light sources are mounted, and a blank portion formed between the plurality of mounting portions,

And the mounting portion and the blank portion are alternately disposed on the substrate.
The method of claim 2,

The light source comprises a light emitting diode.
The method of claim 3,

The plurality of substrates,

A first substrate having a plurality of first mounting portions on which some of the plurality of light sources are mounted, and a blank portion formed between the plurality of first mounting regions; A second substrate formed on the first substrate and spaced apart from each other and having a second mounting portion on which the remaining light sources of the plurality of light sources are mounted;

The light transmitting unit,

And an illumination device formed at a predetermined position of the second substrate opposite to the first mounting unit to transmit light emitted from a light source mounted on the first substrate.
In the backlight unit,

A lighting apparatus according to any one of claims 1 to 4;

And a diffuser plate disposed on the illumination device to diffuse the light illuminated by the illumination device.
In the display device,

A backlight unit according to claim 5;

And a liquid crystal panel for displaying an image by selectively transmitting the light illuminated by the backlight unit.