KR101036430B1 - Unified Product of Light-Guide Panel and Reflector and Method for Manufacturing the Same by Two-Shot Molding - Google Patents

Abstract

Disclosed is a component in which a light guide plate and a reflection plate applied to a backlight unit of an LCD using an LED as a light source are integrated. In such a component, the reflecting plate is composed of a bottom plate and an extension part extending upward from a side portion of the bottom plate, and the light guide plate is integrally formed to be limited by the bottom plate and the extension part on the reflecting plate. The reflective plate of such a component is combined with a PCB substrate on which a plurality of LEDs are arranged to form a backlight unit of the liquid crystal display device. Therefore, the present invention can reduce the number of parts and the assembly process step of the backlight unit of the LCD using the LED, thereby contributing to productivity.

LED, LCD, BLU, light source, backlight, light guide plate, reflector, integrated, PCB board, liquid crystal display, light emitting diode

Description

Unified Product of Light-Guide Panel and Reflector and Method for Manufacturing the Same by Two-Shot Molding}

The present invention relates to a component for a backlight unit of a liquid crystal display (LCD), and more particularly, to an arrangement of components specifically designed to use a light emitting diode (LED) as a light source of a backlight unit of an LCD. It relates to a light guide plate and a reflecting plate are integrated parts and a method of manufacturing the same by double injection. The present invention also relates to a backlight unit of a liquid crystal display device in which a reflector of such a component is formed in combination with a PCB substrate on which LEDs are arranged.

In general, a liquid crystal display (LCD) requires a light source because it does not have a self-luminous function, and the backlight unit serves as the light source. The backlight unit has a top-down method system that illuminates the entire surface of the substrate by placing a light source, or lamp, on the bottom of the liquid crystal panel, and an edge that illuminates the light evenly through the light guide plate and reflector by placing the light source on both sides or one side of the unit It is divided into edge illumination system.

The structure of the direct type backlight unit is shown in FIG. 1. That is, the direct backlight unit structure has a plurality of lamps 2 arranged in parallel on the lower plate 1. On it, the diffusion plate 3, the prism sheets 4 and 5 and the protective sheet are laminated in turn. In the case of the direct backlight unit, the light source directly illuminates the substrate, so the light utilization rate is high and the size is not limited, so it can be applied to large LCD TVs and monitors, but the light source is located very close to the panel, and the number of lamps is increased. Therefore, there is a problem that heat generation increases, and if such heat is generated excessively, it may be a main cause of shortening the lifespan of the LCD panel by causing stains on the screen.

The edge method has uniform brightness and low power consumption, so it is mainly used for small LCD monitors or notebook computers, but a light guide plate is necessary to evenly distribute light on the side.

The structure of a general edge type backlight unit is shown in FIG. 2.

In the edge type backlight unit, the light guide plate 9 is positioned at the center to transmit light of the light source located at the side of the product to the center part. The lamp 2, which is a light source, is located on one or both sides of the backlight unit, and a lamp reflector for reflecting the light of the lamp toward the light guide plate surrounds the lamp. The outside of the lamp reflector is wrapped around the lamp housing 7 to maintain the shape of the lamp and the reflector. The lower part of the light guide plate is a reflective film 8, which serves to reflect the light from the lamp through the light guide plate toward the front panel, and the lower plate of the metal material is located at the bottom of the reflective film to support the reflective film. On the upper part of the light guide plate, optical film parts such as the diffusion film 3 and the prism films 4 and 5 are positioned, and a mold frame is positioned on the entire exterior of the product to support the light guide plate, the lamp housing, the metal lower plate, and the optical film part. Maintains the shape of the backlight unit.

As the lamp used in the above structure, a cold cathode fluorescent lamp (CCFL) or an external electrode fluorescent lamp (EEFL) is mainly used. However, such a lamp is a light source based on the principle of plasma light emission. As a result, the lifetime of the lamp decreases as the gas pressure of the plasma changes, and there is a problem that an inverter for obtaining a high operating voltage of several hundred volts required for plasma discharge is required.

Recently, it has been proposed to use LED as a light source for the backlight unit of the LCD instead of the above lamp. Compared with conventional light sources, LEDs have the advantages of being energy efficient and operating at low voltage because they are small, have a long lifetime, and directly convert electrical energy into light energy. In the case of the LCD backlight module using the LED, the light source means has a structure in which a plurality of LEDs arranged in a row on the PCB substrate is disposed on the side of the light guide plate and surrounded by the light source cover. The structure and arrangement of the other parts are similar to FIG. Korean Patent No. 10-0664982 discloses such an example of an LCD backlight module using an LED.

The present inventors studied a backlight unit having a structure different from that of a conventional component arrangement structure while using LED as a light source of a backlight unit of an LCD.

Accordingly, it is an object of the present invention to provide a component in which a light guide plate and a reflecting plate are suitably applied to a backlight unit having such a new structure, and a method of manufacturing the same.

It is also an object of the present invention to provide a backlight unit of a liquid crystal display device in which the integrated component and the PCB substrate on which the LEDs are arranged are coupled.

The present invention provides a component in which a light guide plate and a reflecting plate are applied to a backlight unit of an LCD using LED as a light source. In this part, the reflector plate is composed of a bottom plate and an extension extending upwardly from the side portions of the bottom plate, and the light guide plate is integrally formed to be limited by the bottom plate and the extension on the reflector. In particular, the extending portion of the reflecting plate is a first vertical portion extending in the upper direction from the side portion of the bottom plate, a horizontal portion extending in the horizontal direction from the upper end of the first vertical portion and a second extending in the upper direction from the distal end of the horizontal portion The light guide plate is formed of a vertical portion, and the light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate and protrudes in a horizontal direction than the edge of the bottom plate of the reflecting plate on the side without an extension of the reflecting plate. And a two-layer light guide plate formed on the one-layer light guide plate to be in contact with the horizontal portion and the second vertical portion of the reflective plate, and the edge of the reflecting plate is formed to coincide with the bottom plate of the reflective plate. It is done. The extension part of the reflector may be formed at two side parts or three side parts connected to each other.

In another aspect, the present invention provides a method for manufacturing a component in which the light guide plate and the reflecting plate are integrated by a double injection method. The method of the present invention comprises the steps of forming the light guide plate by injecting and curing the light guide plate material in one mold, and forming the reflector plate shape by injecting and curing the reflector material into the mold and forming the reflection plate shape. It is to manufacture a part in which the reflector is integrated. Particularly preferably, the mold has independent cavities at the upper and lower ends thereof, and the double injection has a light guide plate shape formed at the upper cavity of the mold and the cavity at the lower end of the mold is empty. The second step of changing the position of the upper end and the lower end of the mold by rotating the mold 180 degrees, the light guide plate material is injected into the empty cavity of the upper end of the mold, the reflector material in the cavity is formed the light guide plate shape of the lower end of the mold The third step of injecting and the fourth step of drawing out the part in which the light guide plate and the reflecting plate are integrated from the lower end of the mold are performed in a continuous manner.

In another aspect, the present invention provides a backlight unit of a liquid crystal display device including a PCB substrate in which the integrated component and a plurality of light emitting diodes (LEDs) are arranged. Here, the side of the PCB substrate is characterized in that coupled to the side of the reflecting plate on the side where the extension of the reflecting plate is not formed.

The present invention can reduce the number of parts and the assembly process step of the backlight unit of the LCD using the LED, thereby contributing to productivity. In addition, the integrated parts of the present invention can be mass-produced by a simple manufacturing process.

The inventors have developed an arrangement of components specially designed for using LEDs (Light Emitting Diodes) as the light source of the backlight unit of an LCD, and thus the present invention is directed to a component in which a light guide plate and a reflecting plate are applied to it, and that by double injection It provides a manufacturing method. In the present invention, the material forming the reflecting plate is a high reflection resin composition having excellent properties of reflecting light, and such a material is generally known. Therefore, in the present invention, such a known material can be used as the reflector plate material. Also known materials for the light guide plate may be used.

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

3 shows a part of a backlight unit of the LCD to which the integrated component of the present invention is applied. 3 shows an arrangement of the PCB substrate 11 including the light guide plate, the reflector plate, and the LED 10 among the backlight units of the LCD to which the integrated parts of the present invention are applied. It is a cut section. In the cross-sectional view of FIG. 3, the LED is arranged to protrude on the PCB substrate and has a structure disposed adjacent to the side of the light guide plate. 3 does not show the light source cover for convenience.

As shown in FIG. 3, the side of the PCB substrate 12 including the LED 10 applied in the present invention is coupled with the side of the reflector 9, unlike the structure of the prior art mentioned above. Such bonding may be performed by an adhesive. As the adhesive used, a conventional adhesive may be applied. The PCB board 12 is provided with circuits and wirings for controlling the LEDs 10, which are connected to an external power source.

The reflector plate 8 has a bottom plate and also has an extension extending upwards to limit the light guide plate 9 on one side or two or three sides of the bottom plate on the side without the LED 10. In one specific embodiment as shown in Figures 4 and 5, the extension of the reflecting plate, the first vertical portion extending in the upper direction from the side portion of the bottom plate, horizontally extending from the upper end of the first vertical portion And a second vertical portion extending upward from the distal end of the horizontal portion. The light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate and protrudes in a horizontal direction from an edge of the bottom plate of the reflecting plate on a side without an extension of the reflecting plate. The light guide plate may be configured to be in contact with the horizontal portion and the second vertical portion of the reflecting plate and formed to coincide with the bottom plate of the reflecting plate at a side without an extension portion of the reflecting plate.

If the light guide plate and the reflecting plate of the present invention are to be assembled without applying the integrated parts, it may be assembled as shown in FIG. 4 illustrates an assembly structure of the arrangement of the backlight unit illustrated in FIG. 3, and FIG. 5 illustrates an arrangement state of a reflector plate, a PCB substrate, and a light guide plate manufactured by double injection.

When not using a component in which the light guide plate and the reflecting plate are integrated, as shown in FIG. 4, the first vertical portion, the horizontal portion, and the second vertical portion are sequentially attached by a sticker from the side portion of the bottom plate of the reflecting plate 8, and such a reflecting plate. The light guide plate 9 should be placed on (8). It is very difficult to perform the assembly work as shown in Figure 4 by hand and excessively work time, and also greatly depends on the skill of the operator, the production cost increases and the defect rate is raised.

Accordingly, the present invention provides a component in which the light guide plate 9 and the reflecting plate 12 are integrated so as to be applied to the structure of the backlight unit shown in FIG.

One embodiment of the integrated part according to the invention is shown in FIG. 5. The reflecting plate 12 has a bottom plate and has an extension portion extending upward from a side portion of the bottom plate. More specifically, the extension part includes a first vertical part extending in an upward direction from a side part of the bottom plate, a horizontal part extending horizontally from an upper end of the first vertical part, and a second vertical part extending upward from an end of the horizontal part. It consists of wealth. The light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate, and protrudes in a horizontal direction than the edge of the bottom plate of the reflecting plate on the side without the extension of the reflecting plate, that is, the side to which the PCB substrate is coupled. The two-layer light guide plate formed on the one-layer light guide plate and the one-layer light guide plate formed in contact with the horizontal portion and the second vertical portion of the reflective plate, and the edges of the bottom plate of the reflective plate coincide with the bottom plate without the extension portion of the reflective plate. It consists of. As shown in FIG. 5, the PCB substrate and the extension portion of the reflecting plate are preferably disposed on two successive side surfaces, that is, sides facing each other. However, the PCB substrate may be disposed on one side of the reflector and the extension of the reflector may be disposed on the other three sides.

Next, a method of manufacturing a component in which the above-mentioned reflector and light guide plate are integrated by using the double injection method will be described with reference to FIG. 6. 6 is a view schematically illustrating an example of a double injection method.

Referring to FIG. 6, in order to manufacture a component in which the reflecting plate and the light guide plate of the present invention are integrated, a mold in which an upper mold and a lower mold are paired is provided. The lower mold has two cavities at the top and bottom, respectively. The upper mold has two gates provided for feeding the material to be injected into the upper cavity and the lower cavity of the lower mold.

First, in the first step (step 4-a), the light guide plate shape 13 is already formed in the upper cavity of the mold, and the lower cavity of the mold is empty. In the second step (step 4-b), the mold is rotated 180 degrees, causing the top and bottom positions of the mold to be reversed. As a result, the upper cavity of the mold is in an empty state, and the light guide plate shape 15 is formed in the lower cavity of the mold. In the third step (step 4-c), the light guide plate material 17 is injected into the empty cavity of the upper end of the mold through the gate, and the reflector material 16 opens the gate to the cavity in which the light guide plate shape of the lower end of the mold is formed. Is injected through. The injected materials are then cured, and in the fourth step (step 4-d), the part 18 of the present invention, in which the light guide plate and the reflecting plate are integrated, is drawn out from the bottom cavity of the mold. These four steps are repeated continuously.

In the above double injection method, detailed control and procedures for forming a structure in which the above-described reflective plate and the light guide plate are integrated may be performed according to a conventional double injection method, and thus detailed description thereof will be omitted.

Although a specific double injection method has been described above as an example, the integrated parts of the present invention may be manufactured in other types of double injection methods and similar methods.

The integrated parts of the present invention manufactured as described above have a simple manufacturing process and are suitable for mass production. In addition, the backlight unit of the LCD according to the present invention, which includes a PCB substrate on which such integrated parts and LEDs are arranged, reduces the number of parts thereof and also reduces the assembly process step, thereby contributing to productivity improvement.

1 shows an example of one prior art of a backlight unit of an LCD using a direct light source.

2 shows an example of one prior art of a backlight unit of an LCD using an edge type light source.

3 shows a part of the backlight unit of the LCD to which the integrated component of the present invention is applied.

4 illustrates an assembly structure of the arrangement of the backlight unit illustrated in FIG. 3.

FIG. 5 illustrates an arrangement of an integrated reflector, a light guide plate, and a PCB substrate manufactured through double injection according to the present invention.

6 is a view schematically illustrating an example of a double injection method.

Explanation of symbols on the main parts of the drawings

1: bottom plate 2: lamp

3: diffuser plate 4, 5: prism sheet

6: protective film 7: lamp housing

8: reflector 9: light guide plate

10: LED 11: PCB

12: reflector

Claims (11)

The light guide plate and the reflecting plate are integrated, The reflector is composed of a bottom plate and an extension extending in an upward direction from the side portion of the bottom plate, the light guide plate is formed integrally to be limited by the bottom plate and the extension on the reflecting plate and Reflective plate integrated parts. The method of claim 1, The extension portion of the reflector is a first vertical portion extending in the upper direction from the side portion of the bottom plate, a horizontal portion extending in the horizontal direction from the upper end of the first vertical portion and a second vertical portion extending in the upper direction from the distal end of the horizontal portion Done, The light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate and protrudes in a horizontal direction from an edge of the bottom plate of the reflecting plate on a side without an extension of the reflecting plate. The light guide plate and the reflecting plate are formed in contact with the horizontal portion and the second vertical portion of the reflecting plate and formed on the side without the extension portion of the reflecting plate is formed so that the bottom plate and the edge of the reflecting plate coincide with each other. Integrated parts. The method of claim 1, The extension part of the reflector is formed in the light guide plate and the reflector plate, characterized in that formed in two side parts or three side parts connected to each other of the reflecting plate. Manufacturing a part in which the light guide plate and the reflecting plate are integrated by double injection, comprising: inserting and curing the light guide plate material into a mold to form a light guide plate shape; and inserting and curing the reflector material into the mold to form a reflection plate shape. and, In the integrated part, the reflecting plate is composed of a bottom plate and an extension part extending upward from a side portion of the bottom plate, and the light guide plate is integrally formed to be limited by the bottom plate and the extension part on the reflecting plate. A method of manufacturing a component in which the light guide plate and the reflecting plate are integrated. The method of claim 4, wherein The extension portion of the reflector is a first vertical portion extending in the upper direction from the side portion of the bottom plate, a horizontal portion extending in the horizontal direction from the upper end of the first vertical portion and a second vertical portion extending in the upper direction from the distal end of the horizontal portion Done, The light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate and protrudes in a horizontal direction from an edge of the bottom plate of the reflecting plate on a side without an extension of the reflecting plate. And a two-layer light guide plate formed in contact with the horizontal portion and the second vertical portion of the reflective plate, and formed so that the edge of the reflective plate and the bottom plate of the reflective plate coincide with each other. The manufacturing method of this integrated part. The method of claim 4, wherein The extension part of the reflecting plate is formed in two side parts or three side parts connected to each other of the light guide plate and the reflective plate, characterized in that the manufacturing method. The method of claim 4, wherein The mold has independent cavities at the upper and lower ends thereof, and the double injection is a first step in which a light guide plate is formed in the cavity of the upper end of the mold, and the cavity of the lower end of the mold is empty, and the mold is rotated 180 degrees. A second step of changing positions of the upper and lower ends of the mold, and injecting a light guide plate material into an empty cavity of the upper end of the mold and injecting a reflector material into a cavity in which a light guide plate shape of the lower end of the mold is formed. And a fourth step of drawing out the integrated part of the light guide plate and the reflecting plate from the lower end of the mold in a continuous repeating manner. A light guide plate and a reflecting plate are integrated, and the reflecting plate is composed of a bottom plate and an extension part extending upward from a side portion of the bottom plate, and the light guide plate is integrally limited to the bottom plate and the extension part on the reflecting plate. And a PCB substrate on which a light guide plate and a reflecting plate are integrally formed, and a plurality of LEDs are arranged, and a side surface of the PCB substrate is formed on the side where the extension portion of the reflecting plate is not formed. The backlight unit of the liquid crystal display device, characterized in that coupled to the side. The method of claim 8, In the component in which the light guide plate and the reflecting plate are integrated, an extension portion of the reflecting plate may be formed from a first vertical portion extending upward from a side portion of the bottom plate, a horizontal portion extending horizontally from an upper end portion of the first vertical portion, and an end portion of the horizontal portion. A second vertical portion extending in an upward direction, The light guide plate is formed in contact with the bottom plate and the first vertical portion of the reflecting plate and protrudes in a horizontal direction from an edge of the bottom plate of the reflecting plate on a side without an extension of the reflecting plate. And a two-layer light guide plate which is formed in contact with the horizontal portion and the second vertical portion of the reflecting plate, and is formed so that the edge of the reflecting plate is coincident with the bottom plate of the reflecting plate. Backlight unit. The method of claim 8, And an extension part of the reflecting plate in the component in which the light guide plate and the reflecting plate are integrated, are formed at two side parts or three side parts connected to each other of the reflecting plate. The method of claim 8, And coupling the side surface of the PCB substrate to the side surface of the reflecting plate by an adhesive.

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