KR102509964B1 - Backlight unit bar - Google Patents

Abstract

A backlight unit bar is disclosed. The backlight unit bar is disposed on a PCB, a plurality of light emitting elements disposed on the PCB in a row in the direction of the long axis of the PCB, and an upper portion of the PCB, so that the area where each of the plurality of light emitting elements is disposed is open and surrounds the open area. It may include a reflector forming a disposed first layer and a second layer disposed to surround the first layer, and the reflector and the PCB may be coupled through guide pins and guide holes. By providing the backlight unit bar, process efficiency can be improved.

Description

Backlight unit bar {BACKLIGHT UNIT BAR}

The present invention relates to a backlight unit bar applied to an edge type display device.

A liquid crystal display (LCD) has been widely used as a flat panel display until recently. A liquid crystal display device is a non-luminous display that cannot emit light by itself and requires a light source to supply light from the outside. A device that supplies light from the back of the liquid crystal display device is referred to as a backlight unit (BLU).

As a light source in the backlight unit, a cold cathode fluorescent lamp (CCFL), which is inexpensive and easy to assemble, has been used. However, backlight units using CCFLs have disadvantages such as difficulty in realizing local dimming or impulsive partial driving, environmental pollution caused by mercury, and slow response speed. To overcome this problem, LED instead of CCFL has been proposed as a light source in the backlight unit.

In general, the structure of the LED backlight unit is divided into a direct type and an edge type. In the edge method, a bar-shaped light source is located on the side or bottom of the liquid crystal panel to irradiate light toward the liquid crystal panel through a light guide plate, and in the direct method, the liquid crystal panel is directly illuminated from a surface light source located below the liquid crystal panel. The bar-shaped light source may be referred to as a backlight unit bar.

In the conventional edge method, in the COB type LED light source, the shape, direction, and thickness of the light source could be controlled by forming a reflector dam. A method of attaching using an adhesive tape was mainly used.

When manufacturing by applying the reflector dam injection molding, a method of attaching a tape to the bottom of the dam injection molding to be bonded to the PCB and bonding it to the PCB can be used. Process materials flowed into the hole, which could cause problems with uneven height and poor surface shape, which eventually led to product defects.

In order to improve this, tape should be attached to the entire area, including the dam extrudate and dam guide pin protrusion, so that they adhere closely when bonding to the PCB. Attachment may be limited, and even if tape attachment is possible, the process unit price increases and the process capacity. Since deterioration occurs, mass production is difficult. For this reason, the COB type light source that joins the extrudates of the dam is mainly applied with the CSP PKG alone, encapsulated. Since the resin material dispensing process (the process of applying the fluorescent material) is not applied, the development of the light source is inevitably limited.

Accordingly, a method for improving this is required.

On the other hand, the above information is presented only as background information to help the understanding of the present invention. No determination has been made, nor is any assertion made, as to whether any of the foregoing is applicable as prior art with respect to the present invention.

Registered Patent Publication No. 10-1646666 (registration date: 2016.08.02)

In order to solve the above problems, one object of the present invention is to provide a backlight unit bar that is applied to an edge type display device and emits uniform light.

Another object of the present invention is to provide a method for improving process defects when producing a backlight unit bar.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

A backlight unit bar according to an embodiment of the present invention includes a printed circuit board (PCB); a plurality of light emitting elements disposed on the PCB in a row in a long axis direction of the PCB; And disposed above the PCB, the area where each of the plurality of light emitting elements is disposed is open, and a first layer disposed to surround the open area and a second layer disposed to surround the first layer are formed. A reflector may be included.

Here, the reflector and the PCB may be coupled through a guide pin and a guide hole.

The backlight unit bar may further include a phosphor layer disposed to cover the open area of the reflector and the first layer.

The reflector may include a third layer disposed on an upper part of the second layer and including two protruding regions spaced apart from each other in a short axis direction of the PCB to support the light guide plate.

Light from the plurality of light emitting devices may be combined through an empty space between each of the two protruding regions and uniformly output through the light guide plate.

The guide pin may be disposed under the reflector and the guide hole may be formed in the PCB.

When the fluorescent material forming the fluorescent layer is injected, the first layer of the reflector is formed so that the fluorescent material does not flow into the guide hole of the PCB, and the open area of the reflector and the guide hole of the PCB are formed into the guide hole. It may be arranged at a predetermined distance so that the fluorescent material does not flow.

The backlight unit bar may include two barrier ribs disposed above the second layer of the reflector, disposed adjacent to the third layer, and spaced apart from each other in a short axis direction of the PCB.

The two barrier ribs may be formed corresponding to a length of the phosphor layer in a long axis direction.

The first to third layers of the reflector may be integrally formed and may be formed by injection molding.

The reflector and the PCB may be coupled by an adhesive containing an epoxy component.

The guide pins of the reflector may be positioned in a downward direction vertically penetrating a predetermined area of the second layer of the reflector.

The guide pin of the reflector may be located at a protrusion extending in a direction of a short axis of the PCB in the second layer.

By providing the backlight unit bar according to an embodiment of the present invention, process defects such as air void and fluorescent material flow can be improved, uniform light can be emitted, and process cost can be reduced. .

The effects obtainable in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

1 is a top view of a backlight unit bar according to an embodiment of the present invention;
2 is a cross-sectional view of a backlight unit bar according to an embodiment of the present invention;
3(a) is a top view of a backlight unit bar according to another embodiment of the present invention;
3(b) is a view showing a cross section of a plurality of areas of a backlight unit bar;
4 is a top view of a backlight unit bar according to another embodiment of the present invention;
5 is a view of the backlight unit bar shown in FIG. 4 viewed from the bottom;
6 is a view showing a lower surface of a reflector according to an embodiment of the present invention, and
7 is a view for explaining a backlight unit bar in a state in which a light guide plate is disposed according to an embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are illustrative, so the present invention is not limited to the details shown. Like reference numbers designate like elements throughout the specification.

In addition, in describing the present invention, if it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other, or can be implemented together in association. may be

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

1 and 2 are views for explaining a backlight unit bar 100 mounted in an edge type display device according to an embodiment of the present invention, and FIG. 1 is a view 100A of the backlight unit bar 100 viewed from above. ((100)), and Figure 2 is a cross-sectional view 100B (100) in which the backlight unit bar 100 is cut (A to A'). It will be described with reference to reference numerals, and FIG. Before layer F is formed, FIG. 2 shows the backlight unit bar 100 after phosphor layer F is formed.

The backlight unit bar 100 is a module for irradiating light to a light guide plate in which light emitting elements are arranged like a bar, and includes a printed circuit board (PCB) and a plurality of light emitting elements (e.g., , LED1 to LED4) may be included.

The PCB includes an integrated circuit necessary for a plurality of light emitting elements to output light, and the plurality of light emitting elements (LED1 to LED4) may be implemented as LEDs (light emitting diodes), but depending on the embodiment, implemented with various elements It can be.

The backlight unit bar 100 may include a reflector Dam1 for setting the light output direction of the plurality of light emitting devices LED1 to LED4 to the upper part of the PCB. The reflector Dam1 is disposed on the upper part of the PCB and is a dam type It can be implemented as, and it can be implemented by forming a layer.

Specifically, in the reflector Dam1, an area where each of the plurality of light emitting devices LED1 to LED4 is disposed is opened, a first layer R1 disposed to surround the open area, and a second layer disposed to surround the first layer. A third layer (eg, R3a and R3d) disposed on an upper part of the layer R2 and the second layer R2 and including two protruding regions (eg, R3a and R3d) disposed apart from each other in the direction of the short axis of the PCB to support the light guide plate ( R3) and guide pins RG1 to RG3 which are structures for coupling with the PCB.

The reflector Dam1 may integrally include a first layer R1 , a second layer R2 , a third layer R3 , and guide pins RG1 to RG3 . Also, the reflector Dam1 may be formed by injection, but the embodiment is not limited thereto.

The reflector Dam1 is formed as a white-based dam to have an excellent reflectance and can reflect the output light of the plurality of light emitting devices LED1 to LED4. Accordingly, light loss may be reduced, excellent optical properties may be secured, and a high-reflection PSR ink or film lamination method may not be applied, which may be effective in terms of manufacturing cost.

The PCB and the reflector Dam1 may be primarily coupled through a guide hole formed in the PCB and the guide pins RG1 to RG3 disposed below the reflector Dam1.

In addition, the PCB and the reflector may be secondarily bonded by an adhesive (eg, G1) containing an epoxy component. In this double reflector dam structure, an air gap is not formed in the area where the PCB and the reflector (Dam1), which is a dam injection product, are bonded by applying a liquid or solid adhesive material, resulting in air void phenomenon, liquid flow phenomenon, and surface unevenness. Process defects such as development can be prevented.

The backlight unit bar 100 may include a phosphor layer F disposed to cover the open area of the reflector Dam1 and the first layer R1. The fluorescent layer F may be formed by injecting (eg, dispensing) a fluorescent material.

When the fluorescent material forming the fluorescent layer F is injected, the first layer R1 of the reflector Dam1 is formed as shown in FIGS. 1 and 2 so that the fluorescent material does not flow into the guide hole of the PCB. Accordingly, loss of the fluorescent material may be structurally prevented through the first layer R1 of the reflector Dam1. In addition, since the open area of the reflector Dam1 and the guide hole of the PCB form a predetermined margin (distance), the fluorescent material may not flow into the guide hole.

3(a) is a view of a backlight unit bar according to another embodiment of the present invention viewed from the top, and FIG. 3(b) is a cross section (B to B) of a plurality of regions of the backlight unit bar shown in FIG. 3(a). ', C ~ C').

The backlight unit bar 100C is obtained by adding barrier ribs (eg, W1a and W1b) to the backlight unit bars 100 (100A and 100B) shown in FIGS. 1 and 2 .

The backlight unit bar 100 is disposed above the second layer R2 of the reflector Dam2, is disposed adjacent to the third layer R3, and is spaced apart from each other in the short axis direction of the PCB. W1b) (W2a, W2b). The two barrier ribs W1a and W1b (W2a and W2b) may be formed to correspond to the length of the phosphor layer F in the long axis direction. Accordingly, optical loss on the side surface is prevented, and the amount of light reaching the light guide plate from the plurality of light emitting devices (LED1 to LED4) can be increased.

In addition, in the backlight unit bar 100, the light from the plurality of light emitting devices LED1 to LED4 is combined through an empty space between each of the two protruding regions (eg, R3a and R3d) of the third layer R3 to be uniform through the light guide plate. can be output.

In addition, the heights of the barrier ribs W1a and W1b and the two protruding regions (eg, (R3a, R3d) and (R3b, R3e)) may be implemented to be the same as shown. In addition, the barrier ribs W1a and W1b may also be used together to support the light guide plate, but the embodiment is not limited thereto.

FIG. 4 is a view of the backlight unit bar 100 (100D) shown in another embodiment of the present invention viewed from the top, and FIG. 5 is a view of the backlight unit bar 100 (100D) shown in FIG. 4 viewed from the bottom. am.

The reflector Dam3 may include protruding portions Ex1 to Ex3 extending in the direction of the short axis of the PCB. Guide pins RG4 to RG6 may be disposed on lower surfaces of the protruding portions Ex1 to Ex3.

This can secure a larger margin than when the guide pins of the reflectors Dam1 and Dam2 of FIGS. 1 to 3 are disposed at predetermined points H1, H2, and H3. Accordingly, a predetermined distance is maintained between the guide pins RG4 to RG6 and the phosphor layer F, so that an air void phenomenon or a liquid flow phenomenon caused by the flow of fluorescent materials can be prevented.

6 shows a lower surface of a reflector Dam4 according to an embodiment of the present invention. The reflector Dam4 shown in FIG. 6 may be similar to the reflectors Dam1 and Dam2 shown in FIGS. 1 to 3 .

The guide pins RG7 and RG8 of the reflector Dam4 may be positioned in a downward direction vertically penetrating a predetermined area of the second layer R2 of the reflector.

In addition, the adhesive G3 is applied to the bottom of the reflector Dam4 so that the PCB and the reflector Dam4 can be coupled, and air voids can be eliminated.

7 is a view for explaining the backlight unit bar 100 in a state in which the light guide plate DP is disposed according to an exemplary embodiment.

The backlight unit bar 100 can support the light guide plate DP through the third layer R3, even if there is no separate structure for supporting the light guide plate DP (eg, a stopper in the display device manufacturing process). (R3) may support the light guide plate DP.

In addition, an empty space is disposed between the two protruding portions of the third layer R3 (eg, R3a and R3d in FIG. 1 ), so that light output from the plurality of light emitting elements LED1 to LED4 can be merged and output. Accordingly, the light can be uniformly dimmed through the light guide plate DP.

Although this specification contains many specific implementation details, they should not be construed as limiting on the scope of any invention or what is claimed, but rather as a description of features that may be unique to a particular embodiment of a particular invention. It should be understood. Likewise, certain features that are described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable subcombination. Further, while features may operate in particular combinations and are initially depicted as such claimed, one or more features from a claimed combination may in some cases be excluded from that combination, and the claimed combination is a subcombination. or sub-combination variations.

In addition, although operations are depicted in the drawings in a specific order in this specification, it is not to be understood that such operations must be performed in the specific order shown or sequential order or that all illustrated operations must be performed in order to obtain desired results. Can not be done. In certain cases, it is possible to transfer one or multiple elements at the same time.

As such, this specification is not intended to limit the invention to the specific terms presented. Therefore, although the present invention has been described in detail with reference to the above-described examples, those skilled in the art may make alterations, changes, and modifications to the present examples without departing from the scope of the present invention. The scope of the present invention is indicated by the following claims rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: backlight unit bar.

Claims (10)

As a backlight unit bar,
printed circuit boards (PCBs);
a plurality of light emitting elements disposed on the PCB in a row in a long axis direction of the PCB; and
A reflector disposed above the PCB, in which an area where each of the plurality of light emitting elements is disposed is open, and a first layer disposed to cover the open area and a second layer disposed to surround the first layer are formed. (reflector) included,
The reflector and the PCB are coupled through a guide pin and a guide hole,
A fluorescent layer disposed to cover the open area of the reflector and the first layer is formed by injecting a fluorescent material,
The first layer is disposed so that the fluorescent material does not flow into the PCB and the guide hole, and the open area and the guide hole are disposed at a predetermined distance so that the fluorescent material does not flow into the guide hole. . delete According to claim 1,
The reflector is
a third layer disposed on an upper portion of the second layer and including two protruding regions spaced apart from each other in a short axis direction of the PCB to support a light guide plate;
The backlight unit bar of claim 1 , wherein light from the plurality of light emitting elements is combined through an empty space between each of the two protruding regions and uniformly output through the light guide plate. According to claim 3,
The guide pin is disposed under the reflector and the guide hole is formed in the PCB,
When the fluorescent material forming the fluorescent layer is injected, the first layer of the reflector is formed so that the fluorescent material does not flow into the guide hole of the PCB, and the open area of the reflector and the guide hole of the PCB are formed into the guide hole. A backlight unit bar disposed at a predetermined distance so that the fluorescent material does not flow in. According to claim 4,
A backlight unit bar comprising two barrier ribs disposed above the second layer of the reflector, disposed adjacent to the third layer, and spaced apart from each other in a short axis direction of the PCB. According to claim 5,
Wherein the two barrier ribs are formed corresponding to the length of the fluorescent layer in the long axis direction, the backlight unit bar. According to claim 5,
The backlight unit bar of claim 1 , wherein the first to third layers of the reflector are integrally formed and formed by injection molding. According to claim 4,
The reflector and the PCB are coupled by an adhesive containing an epoxy component, the backlight unit bar. According to claim 4,
The guide pin of the reflector,
A backlight unit bar positioned in a downward direction vertically penetrating a predetermined area of the second layer of the reflector. According to claim 4,
The guide pin of the reflector,
A backlight unit bar positioned at a protrusion extending in a direction of a short axis of the PCB in the second layer.

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