KR20050097164A - Light source module of back-light unit for lcd - Google Patents

Abstract

Disclosed is a light source module of an LCD backlight unit. A light source module of such a backlight unit for an LCD includes a housing, a substrate provided inside the housing, and a plurality of LED packages having R, G, B tricolor chips mounted in the same space on one side thereof, and the substrate. A reflection mirror for reflecting the light emitted from the light emitting diode package to increase the overall uniformity, and a mixture of R, G, and B tricolor light provided in front of the light emitting diode package and emitted from the plurality of light emitting diode packages. It includes a lens for reducing the distance.

Description

LIGHT SOURCE MODULE OF BACK-LIGHT UNIT FOR LCD}

The present invention relates to a light source module (Module) of an LCD backlight unit using a light emitting diode element, and more particularly, R, G, B tricolor chips are mounted in the same package and used as a light source, an optical lens and a heat pipe And a reflector to reduce the light mixing distance, improve the heat dissipation effect, and improve the overall bactericidal system while achieving a directing angle favoring the light guide plate to the light source module of the LED backlight unit using the LED element. It is about.

In general, the liquid crystal display device is a device for displaying an image by changing the molecular arrangement of the liquid crystal when the power supply is largely composed of a panel unit, a driver, a backlight unit.

Such a liquid crystal display itself is non-luminous and thus cannot be used where there is no light. Due to this problem, the backlight unit may be uniformly irradiated with light on the information display surface for use in a dark place.

The backlight unit is largely composed of a light guide plate and a light source, and the light source is generally disposed to inject light into the light guide plate from the side of the light guide plate, and mainly uses a CCFL (cold cathode tube). Light emitting diodes that do not have the advantage are preferred. In particular, the use of light-emitting diodes as a light source of high-definition products is required because of the advantages of excellent color clarity, including all three primary colors of R, G, and B.

However, when the light emitting diode is used as the light source in the backlight unit as described above, a large amount of heat is inevitably generated due to the characteristics of the light emitting diode, and the heat determines the lifespan and performance of the light emitting diode.

In addition, since the light emitting diode is a point light source, a dark area or a hot spot phenomenon occurs more frequently than a conventional cold cathode tube which is a linear light source, and white light is combined with each of the three R, G, and B tricolor chips. In this case, more than a certain distance of color mixing distance is required to collect these three colors in one point.

In addition, various technologies for using a light emitting diode as a light source have been developed, and the backlight unit illustrated in FIGS. 1 and 2 is one example.

FIG. 1 shows the invention of patent 2001-88451 filed with the Korean Intellectual Property Office on December 29, 2001 under the name "backlight unit". As shown, the liquid crystal display device includes a housing 3, an LED 1 provided in the housing 3 for irradiating the R, G, and B monochromatic light, and a fluorescence for compensating for the monochromatic light of the LED 1; It has a structure including a lamp 2 and a light guide plate 4 on which light is incident.

Therefore, the LED 1 and the fluorescent lamp 2 can be used simultaneously as a light source to produce white light, thereby improving color reproducibility and luminance.

However, the backlight unit having such a structure uses a light emitting diode and a fluorescent lamp in combination with each other to secure a sufficient amount of light, thereby increasing manufacturing costs and complicating the structure.

Figure 2 shows the invention of Patent No. 2001-88492 filed with the name "Backlight Unit" to the Korean Patent Office on December 29, 2001. As shown, the backlight unit arranges the light diffusion guide bar 7 on the inner wall surface of the housing 6 in which the light emitting diodes 5 are disposed, and emits R, G, and B monochromatic light emitted from the light emitting diodes 5. By transmitting, it is made to be nearly white light, and can be made to enter the light guide plate 8.

However, in the case of the backlight unit having such a structure, a considerable loss occurs due to scattering, total reflection, and diffuse reflection in the process of the light from the light emitting diode to the light guide plate, and it is difficult to obtain a good uniformity because the orientation angle of the light emitting diode itself may change. There is a problem.

Accordingly, an object of the present invention has been proposed to solve the above problems, an object of the present invention is to reduce the mixing distance required to implement white light by using the R, G, B tricolor chip in the same package as a light source It is to provide a light source module of the backlight unit for LCD.

Another object of the present invention is to provide a light source module of an LCD backlight unit that can efficiently emit heat generated from a light emitting diode by applying a heat pipe to the light emitting diode package.

Still another object of the present invention is to provide a light source module of an LCD backlight unit which can reduce a dark area by providing a light emitting diode package having a small size between light emitting diode packages having a relatively large size.

Still another object of the present invention is to provide a light source module of an LCD backlight unit that can improve the overall balance by providing a reflector in the light emitting diode.

Still another object of the present invention is to provide a light source module of an LCD backlight unit capable of reducing a color mixing distance of three colors of R, G, and B by providing a lens in a light emitting diode.

Still another object of the present invention is to provide a light source module of an LCD backlight unit that can adjust the characteristics of the orientation angle by adjusting the height of both side walls of the substrate provided with an individual package.

In order to realize the object of the present invention mentioned above, the present invention comprises a housing; A substrate provided inside the housing and provided with a light emitting diode package having R, G, and B tricolor chips integrally mounted on one side thereof; A reflecting mirror provided on the substrate to reflect light emitted from the light emitting diode package to increase the overall bactericide; And it is provided in front of the light emitting diode package provides a light source module of the backlight unit for an LCD comprising a lens for reducing the mixing distance of R, G, B.

Hereinafter, a light source module of an LCD backlight unit according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 and 4, the light source module 10 applied to the backlight unit proposed by the present invention is disposed on one side of the light guide plate 12 and functions as a light source using a light emitting diode chip.

The light source module 10 of the backlight unit includes a housing 20, a substrate 22 provided inside the housing 20 and having light emitting diode packages 24 and 25 on one side thereof, and the substrate 22. Reflector 28 for reflecting light to increase the overall bactericidal agent, and the LED packages 24 and 25 have R, G and B three-color chips. In front, a lens 30 capable of reducing the mixing distance of three colors of R, G, and B is provided.

Therefore, when power is applied to the LED packages 24 and 25 arranged in a row on the substrate 22, white light is emitted from the packages 24 and 25, and the emitted light is reflected by the reflector 28 and the lens ( Pass 30).

In this way, the light emitted from the light source module 10 is incident to the light guide plate 12 disposed at a predetermined distance and is supplied to the liquid crystal panel 18 through the reflecting plate 14 and the diffusion sheet 16.

In the light source module 10 of the backlight unit having such a structure, a light emitting diode package 24 having a relatively large size and a light emitting diode package 25 having a relatively small size are mounted on the substrate 22. The heat transfer tubes 26 for dissipating heat from these light emitting diode packages 24 and 25 are provided.

As shown in FIG. 5, the light emitting diode packages 24 and 25 are provided with a body 40 having a partition wall formed on one side thereof in all directions, and a lower portion of the body 40. It is exposed to the bottom to perform power input and heat dissipation functions, and the lead plate 32 and R, G, B tricolor chips (R, G, B) are respectively mounted on the upper surface, and the lead plate 32 and constant It is disposed away from each other, and the lower portion thereof includes an electrode terminal 42 exposed to the bottom of the body 40 to receive power.

In the light emitting diode packages 24 and 25, R, G, and B tricolor chips R, G, and B are arranged in the same space surrounded by the partition wall.

Therefore, the light emitted from the R, G, and B tricolor chips R, G, and B may be mixed with each other within a short distance to form white light at a predetermined point and be incident to the light guide plate 12.

As a result, the light mixing distance for realizing the white light can be reduced, thereby miniaturizing the size of the backlight unit 10.

The light emitting diode packages 24 and 25 are arranged in a row with the light emitting diode packages 24 having a relatively large size, as shown in FIGS. 6 and 7, and having a relatively small size therebetween. The arrangement of the light emitting diode packages 25 is shown.

In general, when light is emitted from each LED package 24, a dark area is generated between the packages 24 according to characteristics of the LEDs themselves. The occurrence of such dark areas can be prevented by disposing the light emitting diode packages 25 therebetween.

In addition, it is possible to reduce the number of large size LED package 24 can reduce the manufacturing cost.

3 and 8, heat transfer tubes 26 are provided on the substrate 22 in order to efficiently discharge heat generated from the respective LED packages 24 and 25. As shown in FIG.

In general, in the case of the light emitting diode, when the temperature rises, the bandgap is contracted, so the dominant wavelength is shifted in the red direction, and the original color is lost. As a result, the radiation recombination rate decreases. And longevity.

Therefore, the heat transfer pipe 26 provided to prevent this has a structure in which the volatile liquid 64 is stored in the body 56 in which a predetermined volume of space is formed therein.

The body 56 is preferably copper, stainless steel, ceramics, tungsten, or the like, and an inner wall thereof is made of a material such as porous fiber. As the volatile liquid 64, methanol, acetone, water, mercury, or the like is used.

When the heat pipe 26 is heated to one side, the volatile liquid 64 evaporates and flows along a constant flow 58 to pass through the reference line 62, and passes through the reference line 62. Is moved to the other side to radiate heat, and then returns to its original position along the flow of liquid 60.

Therefore, the light emitting diode can be cooled by absorbing thermal energy from one side heated in this process and supplying and releasing thermal energy to the other side.

On the other hand, as shown in Figures 3 and 9, in front of the light emitting diode package (24, 25) is provided with a lens 30 of a predetermined shape to equalize the light emitted from the light emitting diode package (24, 25) Can be improved.

The lens 30 is made of a material having a good transmittance, and preferably, the loss of light can be reduced by applying the wavy lens 30.

In addition, the lens 30 may be mounted on the housing 20 so that the lens 30 may be disposed at an appropriate position in front of the LED packages 24 and 25.

Therefore, light emitted from the LED packages 24 and 25 passes through the lens 30, and in this process, loss due to scattering, total reflection, diffuse reflection, and the like can be prevented.

At the same time, light emitted from the tricolor chips R, G, and B of each of the LED packages 24 and 25 is incident on the lens 30 to be mixed at a shorter distance, thereby minimizing the mixing distance.

In addition, the lens 30 has been described as being limited to a wavy shape, but is not limited thereto, and the lens 50 also has other shapes, that is, the unevenness 52 is formed on one side thereof as shown in FIG. 10. Of course it can include.

3 and 9, a dummy reflector 28 is provided on the substrate 22.

In general, when the light emitting diodes are used as the light source for the backlight, the light traveling in the direction perpendicular to the light guide plate 12 is lost, which may generate a hot spot and lower the overall uniformity of the LCD.

Therefore, in order to prevent such a decrease in overall uniformity, the dummy reflector 28 is applied as described above.

The dummy reflector 28 is a conventional reflector having a constant curvature and is attached to the substrate 22 to enclose the light emitting diode packages 24 and 25. In addition, the inner surface is processed to increase the reflectance of light or a plating layer is formed.

Accordingly, light emitted from the LED packages 24 and 25 may be reflected on the inner surface of the dummy reflector 28 and pass through the lens 30 to be incident on the light guide plate 12 with a uniform uniformity.

Meanwhile, as shown in FIG. 11, the width of the orientation angle can be adjusted by protruding the sidewall 70 between each LED package 24.

In general, since the cold cathode tube is a linear light source, there is a problem such as a bright line, but it is a light source that is easy to be applied to a backlight unit. However, since the light emitting diode is a point light source instead of a linear light source, when the light emitting diode is applied as a light source of the backlight unit, problems such as a dark area, a mixing distance, and a hot spot occur.

Thus, sidewalls 70 are formed as described above to solve these various problems.

That is, sidewalls 70 are respectively formed between and on both sides of each LED package 24 on the substrate 22 on which the plurality of LED packages 24 are mounted.

Therefore, the light emitted from each LED package 24 proceeds at a predetermined angle in all directions, and in this process, the light emitted from the LED packages 24 may be reflected by the side walls 70 and 72 to overcome the disadvantage of the point light source.

As described above, the light source module of the backlight unit for an LCD according to the preferred embodiment of the present invention has the following advantages.

First, by mixing R, G, and B tricolor chips in the same LED package to configure a light source, the mixing distance required to implement white light can be reduced.

Second, by applying heat transfer tubes capable of dissipating heat to each LED package, heat generated from the LEDs can be efficiently discharged.

Third, the dark area can be reduced by providing a light emitting diode package having a small size between the light emitting diode packages having a relatively large size.

Fourth, by providing a reflector around the light emitting diode, the overall bacterium can also be improved.

Fifth, by providing a lens in front of the light emitting diode, the color mixing distance of the three colors of R, G, and B can be reduced.

Sixth, by adjusting the height by forming a side wall between the individual packages it is possible to adjust the characteristics of the orientation angle.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it is within the scope of the present invention.

1 and 2 show a light source module of a backlight unit according to the prior art.

3 is an exploded perspective view showing the structure of an LCD backlight unit according to a preferred embodiment of the present invention;

FIG. 4 is a diagram schematically showing a relationship between the light guide plate shown in FIG. 3 and a backlight unit using light emitting diode elements. FIG.

Fig. 5 is a perspective view showing a light emitting diode package in which the R, G, B tricolor chips shown in Fig. 3 are provided in the same space.

FIG. 6 is a diagram showing an arrangement relationship between the relatively large sized light emitting diode package and the small sized light emitting diode package shown in FIG.

FIG. 7 is a schematic diagram showing the light emitting diode packages shown in FIG. 6 and light emitted from these packages at a constant directivity angle; FIG.

8 is a view schematically showing the structure of a heat radiation pipe shown in FIG.

FIG. 9 is a diagram schematically showing a coupling relationship between the light guide plate, the light emitting diode package, the lens, and the reflector shown in FIG.

Fig. 10 is a perspective view showing another embodiment of the lens shown in Fig. 3;

FIG. 11 is a diagram schematically showing the adjustment of the directivity angle by adjusting the widthwise sidewall of the LED package; FIG.

Claims (8)

A housing; A substrate provided inside the housing and having a plurality of LED packages mounted on one side thereof in which R, G, and B tricolor chips are mounted in the same space; A reflecting mirror provided on the substrate to reflect light emitted from the light emitting diode package to increase the overall bactericide; And The light source module of the backlight unit for an LCD comprising a lens provided in front of the light emitting diode package to reduce the mixing distance of the R, G, B tricolor light emitted from the plurality of light emitting diode packages. The light emitting diode package of claim 1, wherein the light emitting diode package has a body in which partition walls are formed in all directions, and is provided in the body, and a lower portion thereof is exposed to a bottom of the body to perform power input and heat radiating functions. And a lead plate on which the three-color chip of B is mounted, and a predetermined distance from the lead plate, and a lower portion thereof includes an electrode terminal exposed to the bottom of the body to receive power, and the three colors R, G, and B. 3. The light source module of the backlight unit of an LCD, wherein the tricolor light emitted from the chip is reflected by the partition wall of the body to form white light and enter the light guide plate. The light source module of claim 1, wherein the plurality of light emitting diode packages may reduce a dark area by disposing a light emitting diode package having a relatively small size therebetween. According to claim 1, wherein one side of the substrate further comprises a heat transfer tube for dissipating heat, the heat transfer tube is a volume of space formed therein to store the volatile liquid, the inner wall is provided with a porous material Light source module of the backlight unit for an LCD comprising a body. The light source module of claim 1, wherein the reflector is formed to have a predetermined curvature and attached to a substrate, and is provided to surround the light emitting diode package. The light source module of claim 1, wherein the lens is provided at the front of the LED package by the housing and is formed of a material having high transmittance to prevent light loss. The light source module of claim 5, wherein the lens selectively includes a wave shape or an uneven shape. The light source module of claim 1, wherein sidewalls are formed to protrude between the plurality of light emitting diode packages to adjust a direction angle of light emitted from the light emitting diodes.