KR100664982B1 - Backlight module using LED for LCD - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight module of an LCD (Liquid Crystal Display) using LED, and more particularly, to an LCD backlight module using LED having excellent energy efficiency and long lifespan.

The present invention, the LCD backlight module located on the rear of the LCD panel, the light source means including an LED; A light guide plate for dispersing light generated from the light source means; A diffuser plate for uniformly distributing light passing through the light guide plate; A prism for guiding light from the diffusion plate into a predetermined area of the LCD panel; And a fluorescent material included in at least one of the light guide plate, the diffusion plate, and the prism. The LCD backlight module uses the LED to convert light generated from the light source unit into white light.

Therefore, according to the present invention, by changing the color of the fluorescent material to simply generate the light of the required color, it is possible to miniaturize, high efficiency compared to the conventional light source (light source), durability is improved, the backlight module of a simpler structure The effect of providing can be obtained.

Light source, light guide plate, diffuser plate, backlight, prism

Description

LC backlight module using LED {Backlight module using LED for LCD}             

1 is an exploded perspective view of a conventional backlight module.

2 is an exploded perspective view of the LCD backlight module using the LED according to the present invention.

3 is a cross-sectional view of the LCD backlight module using the LED according to the present invention.

4 is a cross-sectional view illustrating an application example of the LCD backlight module using the LED according to the present invention.

5 is a cross-sectional view illustrating another application example of the LCD backlight module using the LED according to the present invention.

Explanation of symbols on the main parts of the drawings

10,110 ..... light source means 12 ..... substrate

14 ..... LED 16 ..... Light source cover

16a ..... Coupling groove 32,114 ..... Light guide plate

34,116 ..... Diffusion Plate 50,118 ..... Prism

52,54 ..... 1st, 2nd prism 70 ..... fluorescent material

112 ..... CCFL

The present invention relates to a backlight module of an LCD (Liquid Crystal Display) using LED, and more particularly, to an LCD backlight module using LED having excellent energy efficiency and long lifespan.

As the electronics industry develops, various display devices having small size and low energy consumption are being developed, and imaging devices, computers, and mobile communication terminals using the same are being developed. LCDs (Liquid Crystal Display), which have appeared in response to this trend, are now attracting attention as display devices such as monitors and mobile communication terminals.

Since the LCD described above does not spontaneously generate light, it is common to have a backlight composed of a light source and a light guide plate that generate light on the back of the LCD panel. In this case, the backlight generates white light so that the color of the image implemented by the LCD panel can be reproduced close to the actual color.

As described above, the backlight of the LCD has conventionally used CCFL (Cold Cathode Fluorescent Lamp) or EEFL (External Electrode Fluorescent Lamp) as a light source.

That is, as shown in FIG. 1, the LCD backlight module 100 using the conventional CCFL is disposed from the CCFL 112 by arranging the light source unit 110 using the CCFL 112 on one side of the light guide plate 114. The light generated is configured to be supplied to a predetermined region of the LCD panel (not shown) through the light guide plate 114, the diffusion plate 116, and the prism 118. In this case, the conventional backlight light sources such as the CCFL 112 are light sources using a plasma principle, and implement white.

However, the above-described conventional light sources have the following problems. That is, as the plasma gas pressure changes, the lifetime is shortened, and an inverter for obtaining a high operating voltage of several hundred volts required for plasma discharge is required.

In addition, when applied to a portable product, most of the power is consumed by the backlight, in which the conventional light source such as CCFL or EEFL has a problem that the power consumption efficiency is not good, resulting in excessive power consumption.

In order to solve the above problems, a backlight module using a light emitting diode (LED) has been proposed.

An LED is a light emitting device that generates light by using a light emission phenomenon (also called electric field light emission) generated when a voltage is applied to a semiconductor.

As the material of the LED, materials that satisfy the conditions such that the light emission wavelength is present in the visible or near infrared region, the light emission efficiency is high, and the p-n junction can be manufactured are suitable.

Such materials include gallium nitride (GaN), gallium arsenide (GaAs), gallium phosphide (GaP), gallium-arsenide-phosphorus (GaAs1-x Px), gallium-aluminum-arsenic (Ga1-xAlxAs), and indium phosphide (InP). ), Compound semiconductors such as indium-gallium-phosphorus (ln1-xGaxP) are used.

The light emission is largely divided by recombination of free carriers and recombination at an impurity emission center. At this time, the wavelength of the light generated by the recombination at the impurity emission center varies depending on the type of the impurity added to the semiconductor. In the case of gallium phosphide, light emission involving zinc and oxygen atoms is red (wavelength 700 nm), and light emission involving nitrogen atoms is green (wavelength 550 nm).

That is, depending on the type of impurities and the semiconductor material, the light generated from the LEDs has different colors (wavelengths).

Such LEDs have advantages in that they are smaller than conventional light sources, have a long lifetime, and have high energy efficiency and low operating voltages because electrical energy are directly converted into light energy.

Therefore, a method of generating white light using an LED having such an advantage as a light source of an LCD backlight module has been proposed. That is, white light is generated by mixing light by combining LEDs generating light of various colors, but this has a problem in that the structure of the backlight module is complicated.

In addition, a method of using a white light emitting LED has been proposed, but the LED generating white light has a problem that it is difficult to be used as a light source of the backlight module of the LCD.

The present invention is to solve the above-mentioned conventional problems, by constructing a backlight module using the LED as a light source, and by applying a phosphor to the diffusion plate, light guide plate, prism, etc. to convert the light generated from the LED into white light excellent energy efficiency Its purpose is to provide an LCD backlight module using a long-life LED.

The present invention to achieve the above object,

In the LCD backlight module located on the back of the LCD panel,

Light source means including an LED;

A light guide plate for dispersing light generated from the light source means;

A diffuser plate for uniformly distributing light passing through the light guide plate;

A prism for guiding light from the diffusion plate into a predetermined area of the LCD panel; And

It provides an LCD backlight module using an LED to convert the light generated from the light source means to white light, including; a fluorescent material contained in at least one of the light guide plate, the diffusion plate, and the prism.

Preferably, the light source means may be disposed on the side of the light guide plate including a substrate on which the LED is mounted.

Preferably, the fluorescent material is a fluorescent material, and may be coated on at least one surface of the light guide plate, the diffusion plate, and the prism.

In addition, the fluorescent material may be mixed in at least one of a light guide plate, a diffusion plate, and a prism.

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

2 is an exploded perspective view of the LCD backlight module using the LED according to the present invention.

3 is a cross-sectional view of the LCD backlight module using the LED according to the present invention.

4 is a cross-sectional view illustrating an application example of the LCD backlight module using the LED according to the present invention.

5 is a cross-sectional view illustrating another application example of the LCD backlight module using the LED according to the present invention.

2 is an exploded perspective view of the LCD backlight module 1 using the LED according to the present invention.

As shown in FIG. 2, the LCD backlight module 1 using the LED according to the present invention includes a light source means 10, a light guide plate 32, a diffusion plate 34, and a prism 50. The light source means 10 is composed of a substrate 12 and a plurality of LEDs (Light Emitting Diode) 14. At this time, the LED 14 is configured to be electrically insulated or mounted on the substrate 12 by heat insulation or reheating.

Meanwhile, as described above, the substrate 12 having the plurality of LEDs 14 mounted thereon is inserted into and fixed to the light source cover 16. In this case, the light source cover 16 may have a rectangular pipe shape having one side open, and a coupling groove 16a is formed in a longitudinal direction of the light source cover 16 on an inner side thereof, so that the substrate 12 is formed. It is inserted into and fixed to the coupling groove 16a.

Next, the light guide plate 32 will be described.

As shown in Figure 2 and 3, the light guide plate 32 is a flat plate-like size similar to the LCD panel, it is generally formed of a transparent acrylic. In this case, one side of the light guide plate 32 is disposed to be adjacent to one open side of the light source cover 16.

The light guide plate 32 serves to receive the light generated from the LED of the light source means 10 and to disperse the light over the entire upper surface of the light guide plate 32. Only the upper surface of the light guide plate 32 is guided.

Next, the diffusion plate 34 will be described.

The diffusion plate 34 has a flat plate shape having the same shape as that of the light guide plate 32, and is disposed on an upper surface of the light guide plate 32. The diffusion plate 34 uniformly distributes the light passing through the light guide plate 32.

Next, the prism 50 is demonstrated.

As shown in FIG. 3, a prism 50 is disposed on an upper surface of the diffusion plate 34 disposed on the upper surface of the light guide plate 32, and the prism 50 receives light from the diffusion plate 34. It guides into a certain area (image forming area) of the LCD panel.

In this case, the prism 50 may be composed of two prisms, a first prism 52 and a second prism 54, and each of the prisms 52 and 54 passes through the diffusion plate 34. Are guided in the horizontal and vertical directions, respectively, so as to be concentrated in a predetermined area of the LCD panel disposed on the upper surface of the prism 50.

In addition, a protective sheet 56 that protects the prism 50 may be disposed on an upper surface of the prism 50.

Next, the fluorescent material 70 will be described.

As shown in FIG. 4, the fluorescent material 70 is a fluorescent material having a specific color, and may be included in at least one of the light guide plate 32, the diffusion plate 34, and the prism 50. That is, the fluorescent material 70 may be applied to at least one surface of the light guide plate 32, the diffusion plate 34, and the prism 50.

Unlike the above, the fluorescent material 70 may be mixed with at least one of the light guide plate 32, the diffusion plate 34, and the prism 50. That is, the fluorescent material is mixed with the materials forming the light guide plate 32, the diffusion plate 34, and the prism 50, respectively, to form the light guide plate 32, the diffusion plate 34, and the prism 50. Can be formed.

At this time, the fluorescent material 70 may be variously applied as follows.

For example, as shown in FIG. 4, when the LED 14 emits blue light, yellow or red and green fluorescent materials are included in the light guide plate 32, the diffusion plate 34, and the prism 50. The blue light may be converted into white light.

That is, the red and green fluorescent materials 70 may be applied to the surfaces of the light guide plate 32 and the diffusion plate 34, or may be mixed in a material forming the light guide plate 32 and the diffusion plate 34. .

Accordingly, the blue light emitted from the LED 14 is changed to magenta by the red phosphor included in the light guide plate 32, and then passes through the diffusion plate 34 and is changed into white light by the green phosphor. .

This is based on the principle that when all three primary colors of light, red, green, and blue, are mixed, they become white.

In addition, the fluorescent material 70 may be variously changed according to the color of light generated from the LED, and included in any one or more of the light guide plate 32, the diffusion plate 34, and the prism 50. As described above, the color of the light generated from the LED 14 can be changed to white.

Further, FIG. 5 shows another application example. In the LCD backlight module using the LED according to the present invention, the fluorescent material 70 may be applied to the first and second prisms 52 and 54, respectively.

Therefore, when the LED 14 of the light source means 10 is replaced with an LED that generates light of a different wavelength, it is possible to easily realize white light by replacing only the prisms 52 and 54. In this case, the fluorescent material 70 may be configured to be mixed into the first and second prisms 52 and 54.

Meanwhile, although the backlight module for generating white light has been described above, the color or position of the fluorescent material 70 may be changed in various ways to generate not only white light but also various colors of light.

The backlight module configured as described above is disposed on the rear surface of the LCD panel and serves as a backlight by illuminating the rear surface.

According to the present invention as described above, by changing the color of the fluorescent material using the three primary colors of light simply to generate the light of the required color, it is possible to miniaturize, high efficiency compared to the conventional light source (light source), durability is improved, more It is possible to provide a backlight module having a simple structure.

In addition, low-cost LEDs generating a specific color can easily obtain not only white light but also various colors of light.

While the invention has been shown and described in connection with specific embodiments, it is to be understood that various changes and modifications can be made in the art without departing from the spirit or the scope of the invention as set forth in the claims below. It will be appreciated that those skilled in the art can easily know.

As described above, according to the present invention, by changing the color of the fluorescent material to simply generate the light of the required color, it is possible to reduce the size and efficiency, compared with the conventional light source, improve durability, improve the backlight module of a simpler structure The effect of providing can be obtained.

In addition, the low-cost LED for generating a specific color can be obtained easily to generate a variety of light as well as white light.

Claims (13)

In the LCD backlight module located on the back of the LCD panel, Light source means including an LED; A light guide plate for dispersing light generated from the light source means; Reflecting means for reflecting light dispersed in the light guide plate to an upper surface; A diffuser plate for uniformly distributing light passing through the light guide plate; A prism for guiding light from the diffusion plate into a predetermined image area of the LCD panel; And A protective sheet positioned on an upper surface of the prism to protect the prism; At least two of them, The light source means includes a substrate on which the LED is mounted, and the LED mounted on the substrate in a heat insulating or double row is disposed on the side or the back of the light guide plate and converts the light generated from the LED into light of a different color. LCD backlight module using an LED, characterized in that the conversion of the fluorescent material to at least one of the light guide plate, the diffusion plate, prism. delete delete delete delete In the LCD backlight module located on the back of the LCD panel, Light source means including an LED; A diffusion plate for uniformly distributing light generated from the light source means; A prism for guiding light from the diffusion plate into a predetermined area of the LCD panel; And And a color conversion fluorescent material included in at least one of the diffusion plate and the prism. The LCD backlight module using the LED converts the light generated from the light source unit into white light. 7. The LCD backlight module of claim 6, wherein the light source means is disposed on the side or the rear of the diffusion plate including the substrate on which the LED is mounted. delete The LCD backlight module of claim 6, wherein the color conversion phosphor is coated on at least one of a diffusion plate and a prism. The LCD backlight module of claim 6, wherein the color conversion phosphor is mixed in at least one of a diffusion plate and a prism. The LCD backlight module of claim 1, wherein the light source means is inserted into and fixed to a coupling groove in a longitudinal direction in a pipe shape light source cover having one side open. The method of claim 1, wherein the stacking order of the light guide plate, the diffusion plate, and the prism is stacked in the order of the prism, the diffusion plate, and the light guide plate from the LCD panel, and the prism has a plurality of prism patterns and the light from the light source is fixed to the LCD panel. LCD backlight module using LED, characterized in that leading to the image area. According to claim 1, wherein the prism is composed of a two-layer structure of the first prism and the second prism, the prism is to guide the light from the LED in the vertical and horizontal directions, respectively, LCD backlight module using an LED, characterized in that it leads to a certain image area.

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