KR20080061053A - Back light assembly and liquid crystal display device - Google Patents

Abstract

A back light assembly and an LCD(Liquid Crystal Display) having the same are provided to include a bottom chassis having a side wall portion curved doubly for encompassing a bottom portion and a mold frame. A light guide panel(200) is arranged at a side of the light source. A mold frame(400) covers the edge of the light source and the light guide panel. A bottom chassis(500) is combined with the mold frame and receives the light source and the light guide panel. The bottom chassis also has a bottom member and a sidewall member extended from the bottom member and curved dually for encompassing the mold frame. The sidewall member includes the first combining member extended from the bottom member and combined with the outer surface of the mold frame. The second combining member is extended from the first combining member and combined with the upper surface of the mold frame. The third combining member is extended from the second combining member and combined with the inner side surface of the mold frame.

Description

BACK LIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY DEVICE}

1 is an exploded perspective view showing a backlight assembly according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating an embodiment of the bottom chassis illustrated in FIG. 1.

3 is a cross-sectional view taken along the line II ′ of FIG. 1.

FIG. 4 is a perspective view specifically showing another embodiment of the bottom chassis shown in FIG. 1. FIG.

5 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100: backlight assembly 200: light source

300: light guide plate 400: mold frame

410: first frame 420: second frame

430: third frame 440: fourth frame

500: bottom chassis 510: bottom

520: side wall portion 522: first coupling portion

524: second coupling portion 526: third coupling portion

700: liquid crystal display panel 1000: liquid crystal display device

The present invention relates to a backlight assembly and a liquid crystal display device having the same, and more particularly, to a backlight assembly and a liquid crystal display device having the same that can reinforce strength.

In general, the liquid crystal display device is thin and light, and has advantages of low driving voltage and low power consumption. In particular, liquid crystal displays are widely used in portable electronic devices such as mobile communication terminals for this reason.

The liquid crystal display device includes a liquid crystal display panel for displaying an image and a backlight assembly for supplying light to the liquid crystal display panel. Here, when the liquid crystal display device is used in a mobile communication terminal, the backlight assembly includes a small light emitting diode (LED) as a light source.

Specifically, the backlight assembly further includes a light guide plate disposed on one side of the light emitting diode, a mold frame covering the edges of the light emitting diode and the light guide plate, and a bottom chassis to receive the light emitting diode and the light guide plate in combination with the mold frame.

Meanwhile, the liquid crystal display panel includes first and second glass substrates and a liquid crystal layer interposed therebetween. The shape of the backlight assembly and the liquid crystal display panel is maintained by a metal bottom chassis. The conventional bottom chassis consists of a bottom portion and sidewall portions extending from the bottom portion and engaging with the outer surface of the mold frame.

However, as the mobile communication terminal has recently been slimmer, the height of the side wall of the bottom chassis is also lowered, thereby lowering the rigidity of the bottom chassis, and thus, the first and second substrates of the liquid crystal display panel are damaged due to external impact.

Accordingly, the present invention has been made in view of the above problems, and the present invention provides a backlight assembly capable of reinforcing strength by changing the structure of the bottom chassis and a liquid crystal display having the same.

The backlight assembly according to an aspect of the present invention includes a light source, a light guide plate, a mold frame, and a bottom chassis. The light guide plate is disposed on one side of the light source. The mold frame covers an edge of the light source and the light guide plate. The bottom chassis is coupled to the mold frame to receive the light source and the light guide plate, and has a bottom portion and a sidewall portion that is double bent to extend from the bottom portion to surround the mold frame.

The side wall portion extends from the bottom portion to engage with an outer surface of the mold frame, a second coupling portion extending from the first coupling portion and engaging with an upper surface of the mold frame, and the second coupling portion from A third engaging portion extending and engaging with the inner surface of the mold frame.

The mold frame may include a first frame corresponding to the light source, second and third frames connected to both ends of the first frame, and a fourth frame connected to the second and third frames so as to face the first frame. It includes. Thus, the side wall portion may be formed corresponding to the second, third and fourth frames. In addition, the side wall portion of the bottom chassis may be elongated along the second, third and fourth frames.

The sidewall part may further include a recess formed in at least one of an edge where the first and second coupling parts meet and an edge where the second and third coupling parts meet. On the other hand, the mold frame may be integrally formed according to the bottom chassis and the injection molding method.

According to an aspect of the present invention, there is provided a liquid crystal display (LCD) including a backlight assembly and a liquid crystal display panel disposed on the light guide plate of the backlight assembly to display an image.

According to such a backlight assembly and a liquid crystal display device having the same, the bottom chassis includes a double bent side wall portion surrounding the bottom portion and the mold frame to structurally protect the liquid crystal display panel. The panel can be prevented from being broken.

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

1 is an exploded perspective view showing a backlight assembly according to an embodiment of the present invention, Figure 2 is a perspective view showing an embodiment of the bottom chassis shown in Figure 1, Figure 3 is a line II 'of FIG. Sectional view cut along the side.

1, 2 and 3, the backlight assembly 100 according to an embodiment of the present invention includes a light source 200, a light guide plate 300, a mold frame 400, and a bottom chassis 500. .

The light source 200 generates light having a point shape. A plurality of light sources 200 are disposed at regular intervals along the first direction x. The light source 200 is formed of a light emitting diode that generates light using semiconductor characteristics. The light source 200 has a feature of emitting light in one direction. In detail, the light source 200 emits light along a second direction y perpendicular to the first direction x. In this case, the backlight assembly 100 may include a separate light source driving film 250 to apply a driving voltage to the light source 200.

The light guide plate 300 is disposed on one side of the light source 200. Specifically, the light guide plate 300 is disposed on one side of the light source 200 corresponding to the second direction y from which light is emitted, and has a rectangular plate shape. The light guide plate 300 serves to guide the light emitted from the light source 200 to the upper portion.

The mold frame 400 covers edges of the light source 200 and the light guide plate 300. Specifically, the mold frame 400 serves to guide the light guide plate 300 and the light source 200 positions. In addition, the mold frame 400 may serve to support the optical sheet 650 to be disposed on the light guide plate 300. The mold frame 400 is made of a resin material having excellent workability.

The mold frame 400 includes four first, second, third and fourth frames 410, 420, 430, and 440 as the light guide plate 300 has a rectangular ring shape. In detail, the first frame 410 is formed at a position corresponding to the light source 200. The second and third frames 420 and 430 are formed at positions connected to both ends of the first frame 410. The fourth frame 440 is formed at a position connected to the second and third frames 420 and 430 so as to face the first frame 410.

Here, the first frame 410 may be formed with a cutout groove 412 on the upper side in order to apply the flexible circuit film for applying a driving voltage to the light source 200 to the outside. In addition, a step 425 for supporting the optical sheet 650 may be formed in the second and third frames 420 and 430.

The bottom chassis 500 is coupled to the mold frame 400 to receive the light source 200 and the light guide plate 300. The bottom chassis 500 has a bottom portion 510 and a sidewall portion 520. The bottom part 510 is coupled to the bottom surface of the mold frame 400 while covering the bottom surface of the light guide plate 300. The side wall portion 520 has a double bent structure extending from the edge of the bottom portion 510 to surround the mold frame 400. Thus, the side wall portion 520 is combined with the mold frame 400 serves to reinforce the strength.

The bottom chassis 500 is made of a metal material having excellent strength. The bottom chassis 500 is made of, for example, a stainless material having excellent corrosion resistance. That is, the bottom chassis 500 provides mechanical strength to maintain the overall shape of the backlight assembly 100. Accordingly, the bottom chassis 500 uses a thickness of about 0.1 mm to about 0.2 mm as the liquid crystal display including the backlight assembly 100 of the present invention has recently become slimmer. In this case, the bottom chassis 500 may have a thickness of about 0.15 mm.

In detail, the sidewall portion 520 may provide strength against warping or flipping of the backlight assembly 100. As a result, the sidewall part 520 may be disposed on the light guide plate 300, and the liquid crystal display panel including the glass substrates may be prevented from being damaged by an external impact.

The sidewall part 520 includes a first coupling part 522, a second coupling part 524, and a third coupling part 526. The first coupling part 522 extends from the bottom part 510. The first coupling part 522 is coupled to the outer surface of the mold frame 400. The second coupling part 524 extends from an end of the first coupling part 522 opposite to the bottom part 510. The second coupling part 524 is coupled to the top surface of the mold frame 400. The third coupling part 526 extends to face the first coupling part 522 from an end of the second coupling part 524 that is opposite to the first coupling part 522. The third coupling part 526 is coupled to the inner surface of the mold frame 400.

The bottom chassis 500 is manufactured through a mold. That is, the side wall portion 520 of the bottom chassis 500 may be manufactured by bending a stainless plate through a mold. Accordingly, the first and second coupling parts 522 and 524 of the side wall portions 520 of the bottom chassis 500 need to have a minimum length for bending. Specifically, the length of the first coupling portion 522 needs to be about 0.8 mm or more, and the second coupling portion 524 needs to be about 0.5 mm.

The mold frame 400 may be manufactured according to an injection molding method based on the bottom chassis 500. To explain this briefly, first, the bottom chassis 500 is manufactured using a mold to form the bottom part 510 and the side wall part 520. Subsequently, the bottom chassis 500 is disposed in a mold formed in the shape of the mold frame 400. Then, the resin liquid is injected into the mold. In this case, it is necessary to apply a separate adhesive material to the bottom chassis 500 so that the resin liquid can be adhered well. Finally, when the resin liquid solidifies after a certain time, the mold frame is removed to complete the combination of the mold frame 400 and the bottom chassis 500.

The mold frame 400 manufactured in this manner may completely remove a predetermined gap that may occur when the mold frame 400 is separately manufactured and coupled to the bottom chassis 500. That is, in the recent slimming trend of the liquid crystal display device, it may contribute to reducing the thickness thereof.

In addition, by removing the gap, the coupling force of the bottom chassis 500 and the mold frame 400 may be further improved. This may contribute to the improvement of the strength of the liquid crystal display device. In addition, when the mold frame 400 is separately manufactured and coupled to the bottom chassis 500, the structure of the mold frame 400 and the bottom chassis 500 may be simplified by removing the necessary coupling structure.

The side wall part 520 is disposed corresponding to the second, third and fourth frames 410, 420, 430, and 440 except for the first frame 410 of the mold frame 400. That is, the side wall portion 520 may reinforce the bending strength based on the second and third frames 420 and 430 and may reinforce the bending strength based on the fourth frame 440.

On the other hand, the side wall 520 may not be formed in the first frame 410 of the mold frame 400, the thickness of the first frame 410 is the light source 200 and the light source driving film 250 is disposed This is because it is relatively thin. The first frame 410 has a thickness of about 0.8 mm or less, which is the minimum length of the first coupling portion 522. In addition, since the panel driving film 800 to be electrically connected to the liquid crystal display panel is bent in the first frame 410, the thickness of the first frame 410 becomes thin.

Accordingly, the bottom chassis 500 may have only the first coupling part 522 extending from the bottom part 510 corresponding to the first frame 410 of the mold frame 400. On the other hand, if the side wall portion 520 of the bottom chassis 500 forms the height of the first frame 410 of the mold frame 400 to about 0.8 mm or more, the first, second and third coupling portions 522, Both 524 and 526 may be formed.

The side wall part 520 is formed to be elongated along the second, third and fourth frames 420, 430, and 440 of the mold frame 400. This is to form the side wall portion 520 to be coupled to the frame of the mold frame 400 as much as possible to reinforce the strength as much as possible.

On the contrary, the side wall portion 520 may be configured to replace the second, third and fourth frames 420, 430, and 440 of the mold frame 400 if the backlight assembly 100 including the same has priority over weight reduction. It can be formed at regular intervals. In addition, the side wall portion 520 is formed along the second, third and fourth frames 420, 430, and 440 with respect to the first and second coupling portions 522 and 524, and the third coupling portion 526. ) May be formed at regular intervals along the second, third and fourth frames 420, 430, and 440. In addition, the side wall portion 520 has a predetermined length in which the first, second and third coupling portions 522, 524, and 526 correspond to the central portion of the second, third and fourth frames 420, 430, and 440. It may be formed to be long enough.

Accordingly, the bottom chassis 500 includes a bottom portion 510 and a sidewall portion 520 that is double bent so as to extend from the bottom portion 510 to surround the mold frame 400, thereby providing a backlight assembly 100 against external impact. ) Can be protected. That is, it is possible to prevent the liquid crystal display panel from being disposed on the light guide plate 300 against external impact through the bottom chassis 500 of the present invention and including glass substrates.

The backlight assembly may further include a reflective sheet 600 disposed between the light guide plate and the bottom of the bottom chassis and an optical sheet 650 disposed on the light guide plate.

FIG. 4 is a perspective view specifically showing another embodiment of the bottom chassis shown in FIG. 1. FIG.

1 and 4, the bottom chassis 550 further includes a depression 575 to reinforce the bending strength at the bent position of the side wall portion 570.

The depression 575 has a first corner 576 where the first coupling part 572 and the second coupling part 573 meet, and a second corner where the second coupling part 573 and the third coupling part 574 meet. It is formed in at least one of 577. In detail, the recesses 575 may be alternately formed at the first edge 576 and the second edge 577 at a predetermined interval. This is because the second coupling portion 573 may not have a thickness sufficient to form the depressions 575 at the first and second edges 576 and 577 in the same position.

The depression 575 has a rounded shape. This is to facilitate the formation process while efficiently reinforcing the bending strength by the depression 575. On the contrary, the depression 575 may have an angular shape at the center thereof.

The depression 575 generally forms all of the first, second and third coupling portions 573, 573, 574 of the sidewall portion 570, and then uses a punching bar of a machine tool such as a press or puncher. Can be formed. In this case, the depth of the depression 575 may be determined by the stroke of the punching bar.

Accordingly, the bottom chassis 550 forms depressions 575 at the first and second edges 576 and 577 of the sidewall portion 570, thereby enhancing bending strength to improve the overall strength of the backlight assembly 100. You can.

On the other hand, such a depression 575 when the mold frame 400 and the bottom chassis 550 is separately manufactured and combined, it can further maximize the effect. This is because, when the mold frame 400 and the bottom chassis 550 are coupled, the bending stress is weak at the first and second corners 576 and 577, and thus a lifting phenomenon may occur.

5 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

In the present embodiment, since the backlight assembly is the same as the structure shown in Figs. 1, 2, 3 and 4, the same reference numerals are used, and detailed description thereof will be omitted.

Referring to FIG. 5, the liquid crystal display device 900 according to the exemplary embodiment of the present invention includes a backlight assembly 100 and a liquid crystal display panel 700.

The liquid crystal display panel 700 displays an image by using light from the backlight assembly 100. The liquid crystal display panel 700 includes a first substrate 710, a second substrate 720 facing the first substrate 710, and a liquid crystal layer interposed between the first substrate 710 and the second substrate 720. 730. Here, the first substrate 710 is a TFT substrate in which thin film transistors (hereinafter referred to as TFTs) as switching elements are formed in a matrix form. The second substrate 720 is a color filter substrate in which RGB pixels for implementing colors are formed in a thin film form. The first substrate 710 and the second substrate 720 are made of a glass material that is transparent and weak to external impact.

Accordingly, the backlight assembly 100 may include the first substrate 710 and the second substrate through the bottom chassis 500 including the bottom portion 510 and the side wall portion 520 extending from the bottom portion 510 to be reinforced with strength. It is possible to protect the first and second substrates 710 and 720 from being damaged by protecting the 720 from an external impact.

The liquid crystal display panel 700 further includes a driving chip 740 disposed on the first substrate 710 to generate a control signal to the first substrate 710 and the second substrate 720. In addition, the liquid crystal display device 900 further includes a panel driving film 800 connected to an end of the first substrate 710 to apply a driving signal to the driving chip 740 from the outside.

The liquid crystal display device 900 may further include a top chassis (not shown) coupled to the side wall portion 520 of the bottom chassis 500 while fixing the edge of the liquid crystal display panel 700.

According to such a backlight assembly and a liquid crystal display having the same, the bottom chassis includes a double bent side wall to surround the bottom part and the mold frame to structurally protect the liquid crystal display panel having the first and second substrates of glass material. As a result, the strength can be reinforced to prevent the first and second substrates from being damaged, i.e., broken, against external shocks.

Although the detailed description of the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art will have the idea of the present invention described in the claims to be described later. It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (8)

Light source; A light guide plate disposed on one side of the light source; A mold frame covering an edge of the light source and the light guide plate; And And a bottom chassis coupled to the mold frame to receive the light source and the light guide plate, the bottom chassis having a bottom portion and a sidewall portion that is double bent to surround the mold frame. The method of claim 1, wherein the side wall portion A first coupling part extending from the bottom part and engaged with an outer surface of the mold frame; A second coupling part extending from the first coupling part to engage with an upper surface of the mold frame; And And a third coupling part extending from the second coupling part to engage with the inner surface of the mold frame. The method of claim 2, wherein the mold frame A first frame corresponding to the light source; Second and third frames connected to both ends of the first frame; And A fourth frame connected to the second and third frames so as to face the first frame, And the side wall portion is formed corresponding to the second, third and fourth frames. 4. The backlight assembly of claim 3, wherein the sidewall portion is formed to extend along the second, third, and fourth frames. 3. The backlight assembly of claim 2, wherein the sidewall part further comprises a recess formed in at least one of an edge where the first and second coupling parts meet and an edge where the second and third coupling parts meet. The backlight assembly of claim 1, wherein the mold frame is integrally formed with the bottom chassis and an injection molding method. The backlight assembly of claim 1, wherein the light source comprises a light emitting diode. A light source, a light guide plate disposed on one side of the light source, a mold frame covering edges of the light source and the light guide plate, and the mold frame to receive the light source and the light guide plate, and extend from a bottom part and the bottom part. A backlight assembly comprising a bottom chassis having a sidewall portion double bent to enclose the mold frame; And And a liquid crystal display panel disposed on the light guide plate to display an image.

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