KR20110016633A - Led backlight unit - Google Patents

Abstract

PURPOSE: An LED backlight unit is provided to easily and inexpensively fix a light guide plate, thereby increasing reliability of the LED backlight. CONSTITUTION: A PCB arranges a plurality of LEDs. A light guide plate is located between the PCB and a side. A fixing unit(100) is protruded from the PCB. The fixing unit keeps the interval between the light guide unit and an LED light emitting unit constant. A cover supports the PCB and the light guide plate.

Description

LED backlight unit

The present invention relates to a LED backlight unit, and more particularly to a light emitting diode (LED) backlight unit having a fixing device for fixing a light guide plate.

In general, typical large display devices include liquid crystal displays (LCDs) and plasma display panels (PDPs).

Unlike the self-luminous PDP, an LCD requires a separate backlight unit due to the absence of its own light emitting device.

The backlight unit used in LCD is classified into an edge type backlight unit and a direct type backlight unit according to the position of the light source. In the edge type, the light source is disposed on the left and right sides or the top and bottom sides of the LCD panel and the light guide plate is used. Since the light is evenly distributed on the front surface, the light is uniform and the panel thickness can be made ultra thin.

The direct method is a technology that is usually used for displays of 20 inches or more. Since a plurality of light sources are disposed under the panel, it has an advantage of superior light efficiency compared to the edge method, and is mainly used for large displays requiring high brightness.

CCFL (Cold Cathode Fluorescent Lamp) was used as the light source of the existing edge type or direct type backlight unit.

However, since the CCFL-based backlight unit is always powered by the CCFL, a considerable amount of power is consumed, and the problems of environmental pollution due to the addition of about 70% color reproduction rate and mercury are pointed out as disadvantages.

As a substitute for solving the above problems, research on a backlight unit using an LED (Light Emitting Diode) has been actively conducted.

When the LED is used as a backlight unit, the LED array can be locally turned on and off, which can drastically reduce power consumption. For RGB LED, it exceeds 100% of the NTSC (National Television System Committee) color reproduction range specification. To provide consumers with more vivid picture quality.

In addition, the LED produced by the semiconductor process is characterized by harmless to the environment.

LCD products employing LEDs with the above advantages are being released one after another. However, since the driving mechanism is different from the existing CCFL light source, driving drivers and PCB substrates are expensive.

Therefore, the LED backlight unit is still applied only to expensive LCD products.

On the other hand, the LED backlight unit is a light guide plate for guiding the light generated from the LED light emitting unit, a reflection plate positioned below the light guide plate to reflect the light of the light guide plate, and a diffuser plate located above the light guide plate to diffuse the light of the light guide plate to the outside It may be configured to include.

Therefore, since the light guide plate must be kept at a predetermined distance from the LED light emitting part for reliability, it must be fixed to the fixing mechanism so that the same distance is always maintained.

An object of the present invention is to provide an LED backlight unit that can be easily fixed at a low cost to improve the reliability.

LED backlight unit according to the present invention, a plurality of LEDs are arranged, the light guide plate which is positioned to have a predetermined distance between the PCB and the side, and the PCB is supported by the projecting protruding, fixing the side of the light guide plate to light the light guide plate and LED It may be configured to include a fixing part for maintaining a constant gap between the parts, and a cover for supporting the PCB and the light guide plate.

Here, the fixing portion is a projection which contacts on the PCB between the LEDs and protrudes an edge region so as to have a groove in the center region, a head portion is positioned on the groove surface of the protrusion, and a body portion is positioned inside the cover through the protrusion and the PCB. It may be configured to include a fixing screw for fixing.

At this time, the groove depth of the protrusion is preferably determined in the range that the head portion of the fixing screw does not protrude to the top of the groove.

The fixing part may also comprise a protrusion located on the PCB between the LEDs, a protrusion having a flat top surface, and an adhesive positioned between the bottom surface of the protrusion and the top surface of the PCB to adhere the protrusion onto the PCB.

The fixing portion includes a protrusion positioned on the PCB between the LEDs, the protrusion having a flat upper surface, and an elastic body positioned between the lower surface of the protrusion and the upper surface of the PCB to allow the protrusion to move up and down according to a predetermined force. Can be configured.

Next, the fixing part includes a protrusion located on the PCB between the LEDs and having a flat upper surface, and a moving screw attached to the lower surface of the protrusion through the cover and the PCB and moving the protrusion up and down by an external force. It may be configured.

Other objects, features and advantages of the invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

LED backlight unit according to the present invention has the following effects.

The present invention forms a fixing part for fixing the light guide plate to the LED light emitting part, thereby maintaining a constant distance between the light guide plate and the light emitting part, thereby eliminating complicated additional steps such as cutting the light guide plate, thereby significantly reducing manufacturing and assembly costs. Can be.

In addition, the present invention does not require a complicated and precise additional process, such as a cutting process of the light guide plate, thereby reducing process errors and improving reliability.

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

FIG. 1 is a side view illustrating a general edge type LED backlight unit, FIG. 2 is a front view of FIG. 1, and FIG. 3 is a view showing an LED light emitting unit of FIG. 1.

As shown in FIGS. 1 and 2, a diffuser plate 60 for diffusing light is formed on the light guide plate 40, and a reflector plate 50 for reflecting light is formed under the light guide plate 40. .

The LED light emitting part 10 is formed on the side surface of the light guide plate 40 at predetermined intervals.

Here, the LED light emitting unit 10 is, as shown in Figure 3, a plurality of LEDs are arranged side by side at a predetermined interval on the printed circuit board (PCB) (13).

Subsequently, a cover 30 supporting and protecting the light guide plate 40 and the LED light emitting unit 10 is formed, and the cover 30 supports the LED light emitting unit 10 to cover the side surface of the LED backlight unit. The first cover 30a and the second cover 30b supporting the reflector 50 to cover the lower surface of the LED backlight unit may be included.

In addition, the light guide plate fixing mechanism 20 protrudes from the second cover 30b so that the light guide plate 40 and the LED light emitting part 10 maintain proper intervals, and the light guide plate fixing mechanism 20 is the light guide plate 40. It is inserted through the hole formed at the edge of the fixing the light guide plate 40.

Two holes formed in the light guide plate 40 are formed at each corner of the light guide plate 40, and the light guide plate fixing mechanism 20 protruding from the second cover 30b is inserted into the corresponding hole to fix the light guide plate 40. have.

However, such a structure requires a cutting process to form a hole in the light guide plate 40, and corresponds to the hole of the light guide plate 40 when the light guide plate fixing mechanism 20 is formed in the second cover 30b. Therefore, precise manufacturing process is required because it must be formed at the correct position.

Therefore, an additional process cost according to the cutting process of the light guide plate 40 increases, and due to an error occurring when the light guide plate fixing mechanism 20 is manufactured to correspond to the hole of the light guide plate 40, manufacturing reliability is lowered. Problems may appear.

4 is a front view showing an LED backlight unit according to the present invention, Figure 5 is a view showing the position of the fixing portion of FIG.

As shown in FIG. 4, the present invention may include an LED light emitting unit 120, a light guide plate 40, a fixing unit 100, and a cover 110.

Here, the LED light emitting unit 120 has a structure in which a plurality of LEDs 124 are arranged on the PCB 122, as shown in FIG.

In addition, the cover 110 supports the PCB 122 and simultaneously supports the lower part of the light guide plate 40 to protect the LED backlight unit.

Subsequently, the side surface of the light guide plate 40 is spaced apart from the PCB 122 at a predetermined distance, and the fixing part 100 is supported by the PCB 122 to protrude, and the side surface of the light guide plate 40 is fixed to the light guide plate 40. And it serves to maintain a constant gap between the LED light emitting unit 120.

Here, the fixing part 100 protrudes in the direction in which the light of the LED 124 is emitted, thereby fixing the side surface of the light guide plate 40.

As shown in FIG. 5, at least one fixing part 100 may be formed on the PCB 122.

Here, the fixing part 100 is positioned on the PCB 122 between the LEDs 124, and about 2-10 LEDs 124 may be arranged between the fixing part 100 and the fixing part 100.

The number of LEDs 124 arranged between the fixing unit 100 and the fixing unit 100 may vary depending on the type and size of the display using the LED backlight unit.

At this time, it is preferable that the same number of LEDs 124 are arranged between the fixing part 100 and the fixing part 100.

The reason is that the light of the LED 124 is uniformly transmitted to the light guide plate 40.

Meanwhile, each side of the light guide plate 40 is fixed by at least one fixing part 100, and the number of fixing parts 100 may be determined according to the size of the light guide plate 40.

That is, as the size of the light guide plate 40 increases, the number of the fixing parts 100 may increase.

6 is a side view showing the fixing part of FIG. 4 according to the first embodiment of the present invention. As shown in FIG. 6, the fixing part 100 may include a protrusion 104 and a fixing screw 102. .

Here, the protrusion 104 is in contact with the PCB 122 between the LED 124, the edge region is projected so as to have a groove in the center region.

At this time, the groove depth of the protrusion 104 is preferably determined in the range that the head portion of the fixing screw 102 does not protrude to the top of the groove.

The reason is that when the head of the fixing screw 102 protrudes above the groove, it is difficult for the protrusion 104 to fix the side surface of the light guide plate 40 due to the obstruction of the head.

In addition, the protrusion 104 is preferably made of a non-conductive material, and may be made of an elastic material such as rubber, plastic, nonmetal, or the like.

In some cases, the protrusion 104 may use a metallic material.

Next, the fixing screw 102 may be positioned on the groove surface of the protrusion 104, and the body may be positioned inside the cover 110 to fix the protrusion by penetrating the protrusion 104 and the PCB 122.

In some cases, when the thickness of the PCB 122 is thick, the fixing screw 102 may not penetrate to the inside of the cover 110.

FIG. 7 is a side view showing the fixing part of FIG. 4 according to the second exemplary embodiment of the present invention. As shown in FIG. 7, the fixing part 100 may include a protrusion 104 and an adhesive 106.

Here, the protrusion 104 is located above the PCB 122 between the LEDs 124 and has a flat top surface.

In addition, the adhesive 106 is positioned between the lower surface of the protrusion 104 and the upper surface of the PCB 122 to serve to adhere the protrusion 104 to the PCB 122.

Here, it is preferable that the adhesive 106 uses an adhesive made of a material resistant to heat.

FIG. 8 is a side view showing the fixing part of FIG. 4 according to the third exemplary embodiment of the present invention. As shown in FIG. 8, the fixing part 100 may include a protrusion 104 and an elastic body 108.

Here, the protrusion 104 is located above the PCB 122 between the LEDs 124 and has a flat top surface.

In addition, the elastic body 108 may be positioned between the lower surface of the protrusion 104 and the upper surface of the PCB 122 to serve to allow the protrusion 104 to move up and down according to a predetermined force.

The reason why the elastic body 108 is used is that since the LED backlight unit is absorbed by the elastic body 108 even when the external shock is applied, there is an effect of always keeping the distance between the light guide plate 40 and the LED light emitting part 120 constant. Because there is.

Here, the elastic body 108 may use a compression coil spring, a leaf spring, and the like.

FIG. 9 is a side view showing the fixing part of FIG. 4 according to the fourth exemplary embodiment of the present invention. As shown in FIG. 9, the fixing part 100 may include a protrusion 104 and a moving screw 109. .

Here, the protrusion 104 is located above the PCB 122 between the LEDs 124 and has a flat top surface.

The moving screw 109 penetrates the cover 110 and the PCB 122 and is attached to the lower surface of the protrusion 104 to move the protrusion 104 up and down by an external force.

Here, the moving screw 109 is a screw that moves vertically by a rotating force, which is a very effective fixing method when the distance between the four side surfaces of the light guide plate 40 and the LED light emitting unit 120 must be maintained differently. .

As described above, the present invention can form the fixing mechanism in various embodiments, and the reliability of the fixed phase is greatly improved by managing and maintaining the gap between the light guide plate and the LED light emitting part with a minimum error.

In addition, since a complicated additional process is not required in fabricating the fixing mechanism for fixing the light guide plate, manufacturing cost and assembly cost can be significantly reduced.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

1 is a side view showing a typical edge-type LED backlight unit

FIG. 2 is a front view of FIG. 1

3 is a view showing an LED light emitting unit of FIG.

4 is a front view showing the LED backlight unit according to the present invention

5 is a view showing the position of the fixing part of FIG.

6 is a side view showing the fixing part of FIG. 4 according to the first embodiment of the present invention;

7 is a side view showing the fixing part of FIG. 4 according to the second embodiment of the present invention.

8 is a side view showing the fixing part of FIG. 4 according to the third embodiment of the present invention.

9 is a side view showing the fixing part of FIG. 4 according to the fourth embodiment of the present invention.

Claims (13)

A PCB on which a plurality of LEDs are arranged; A light guide plate spaced apart from each other to have a predetermined distance between the PCB and the side surface; A fixing part which is supported by the PCB and protrudes and fixes a side surface of the light guide plate to maintain a constant distance between the light guide plate and the LED light emitting part; And, LED backlight unit comprising a cover for supporting the PCB and the light guide plate. The LED backlight unit of claim 1, wherein the fixing part protrudes in a direction in which light of the LED is emitted. The LED backlight unit of claim 1, wherein at least one fixing part is formed on the PCB. The LED backlight unit of claim 1, wherein the fixing part is positioned on the PCB between the LEDs. The LED backlight unit of claim 1, wherein 2-10 LEDs are arranged between the fixing part and the fixing part. The LED backlight unit of claim 1, wherein an equal number of LEDs are arranged between the fixing unit and the fixing unit. The LED backlight unit of claim 1, wherein each side of the light guide plate is fixed by at least one fixing part. The method of claim 1, wherein the fixing unit, A protrusion contacting the PCB between the LEDs and protruding an edge region to have a groove in a central region; The head unit is located on the groove surface of the protrusion, the LED backlight unit characterized in that it comprises a fixing screw for fixing the protrusion by the body portion is located inside the cover through the protrusion and the PCB. 9. The LED backlight unit of claim 8, wherein the groove depth of the protrusion is determined in a range in which the head of the fixing screw does not protrude above the groove. The LED backlight unit of claim 8, wherein the protrusion is made of a non-conductive material. The method of claim 1, wherein the fixing unit, A protrusion located on the PCB between the LEDs and having a flat top surface; Located between the lower surface of the protrusion and the upper surface of the PCB, LED backlight unit comprising a adhesive for bonding the protrusion on the PCB. The method of claim 1, wherein the fixing unit, A protrusion located on the PCB between the LEDs and having a flat top surface; And an elastic body positioned between the lower surface of the protrusion and the upper surface of the PCB to enable the protrusion to move up and down in accordance with a predetermined force. The method of claim 1, wherein the fixing unit, A protrusion located on the PCB between the LEDs and having a flat top surface; And a moving screw attached to the lower surface of the protrusion through the cover and the PCB and moving the protrusion up and down by an external force.

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