KR20060075292A - Back light assembly and liquid crystal display device having the same - Google Patents

Abstract

Disclosed are a backlight assembly and a liquid crystal display device having the same, which can improve assembly. The backlight assembly is coupled to a bottom chassis including a bottom chassis and a side surface extending from the bottom surface to form a storage space, lamps stored in the bottom chassis to generate light, an optical member disposed on the lamps, and a bottom chassis. It covers a distal end of the lamps and includes a mold frame having a first groove for fixing the optical member. The mold frame includes a first side extending in a direction perpendicular to the longitudinal direction of the lamps to cover the distal ends of the lamps, the first groove being formed in the first side. Therefore, the number of parts can be reduced, the assembly performance can be improved, and the manufacturing cost can be reduced.

Description

BACK LIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

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

FIG. 2 is a partially cutaway perspective view illustrating the mold frame illustrated in FIG. 1 in detail.

3 is an enlarged view illustrating an enlarged portion A of FIG. 2.

4 is a cross-sectional view illustrating a combined cross section of the backlight assembly illustrated in FIG. 1.

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: bottom chassis

300: lamp 310: lamp holder

400: optical member 410: diffuser plate

420: optical sheet 500: mold frame

510: first groove 520: first side                 

522: first groove 530: second side

600: liquid crystal display device 700: display unit

710: liquid crystal display panel 720: driving circuit unit

800: top chassis

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 reduce cost and improve productivity.

In general, the liquid crystal display is a flat panel display that displays an image by using the electrical and optical characteristics of the liquid crystal (Liquid Crystal) having the intermediate characteristics of liquid and solid, and is thinner, lighter, and lower than other display devices. There is an advantage of having a driving voltage and low power consumption, which is widely used throughout the industry.

Since the liquid crystal display device is a non-light emitting device that does not emit light by the liquid crystal display panel displaying an image, it requires a backlight assembly for supplying additional light.

The backlight assembly includes a storage container, a lamp housed in the storage container to generate light, and an optical member for controlling a path of light generated from the lamp. The backlight assembly is classified into edge type and direct type according to the position of the lamp. The edge type is a method in which one or two lamps are positioned on the side of the transparent light guide plate and the light obtained by multiple reflection of light using one side of the light guide plate is emitted to the liquid crystal display panel. The direct type is a method of reflecting and diffusing the light emitted from the lamp by placing a plurality of lamps directly under the liquid crystal display panel, a diffuser plate on the front of the lamp and a reflector plate on the back of the lamp. Therefore, the edge type is used for a relatively small liquid crystal display device such as a notebook, while the direct type is mainly used for a large liquid crystal display device requiring high brightness such as a TV.

In the case of the direct backlight assembly, in order to improve the optical and mechanical properties, a side mold supporting the optical member and a middle mold supporting the liquid crystal display panel while fixing the optical member while covering the ends of the lamps having relatively low brightness are fixed. It further includes parts of. For this reason, the direct type backlight assembly has a problem in that assembly is inferior and manufacturing cost increases.

Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to provide a backlight assembly capable of improving assembly performance and reducing manufacturing costs.

Another object of the present invention is to provide a liquid crystal display device having the above-described backlight assembly.

A backlight assembly for achieving the object of the present invention includes a bottom chassis, lamps, an optical member and a mold frame. The bottom chassis includes a bottom surface and a side surface extending from the bottom surface to form an accommodation space. The lamps are housed in the bottom chassis to generate light. The optical member is disposed above the lamps. The mold frame is coupled with the bottom chassis to cover the distal ends of the lamps and has a first groove for fixing the wing optical member.

The mold frame includes a first side part extending in a direction perpendicular to the longitudinal direction of the lamps and covering a distal end of the lamps, and a second side part extending in a direction parallel to the longitudinal direction of the lamps. In this case, the first groove is formed in the first side portion.

A liquid crystal display device for achieving another object of the present invention includes a backlight assembly and a liquid crystal display panel. The backlight assembly may include a bottom chassis having an accommodation space, lamps stored in the bottom chassis to generate light, an optical member disposed above the lamps, and a bottom chassis coupled to the bottom chassis to cover the end portions of the lamps. And a mold frame having a first groove for fixing the optical member. The liquid crystal display panel is disposed on the mold frame and displays an image using light supplied from the backlight assembly.

According to the backlight assembly and the liquid crystal display device having the same, by reducing the number of parts, it is possible to improve the assemblability and to reduce the manufacturing cost.

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 a preferred embodiment of the present invention.

Referring to FIG. 1, a backlight assembly 100 according to a preferred embodiment of the present invention includes a bottom chassis 200, lamps 300, an optical member 400, and a mold frame 500.

The bottom chassis 200 includes a bottom surface 210 and a side surface 220 extending from an edge of the bottom surface 210 to form a storage space. The bottom chassis 200 is, for example, made of a metal having high strength and low deformation.

The lamps 300 are disposed parallel to each other on the bottom surface 210 of the bottom chassis 200, and generate light in response to a driving power applied from the outside. For example, the lamps 300 may be formed of a cold cathode fluorescent lamp (CCFL) having an elongated cylindrical shape. Both ends of the lamps 300 are fixed to the lamp holders 310, and the lamp holders 310 are fixed to the bottom chassis 200. The lamps 300 are preferably arranged at equal intervals for uniformity of brightness of the backlight assembly 100, and the number of lamps 300 may vary depending on the required brightness characteristics. Meanwhile, the lamps 300 may have a U shape. In addition, the lamps 300 may be formed of an external electrode fluorescent lamp (EEFL) having external electrodes formed at both ends thereof.

The optical member 400 is disposed above the lamps 300 in order to improve luminance characteristics of light generated from the lamps 300.                     

The optical member 400 includes a diffuser plate 410 disposed above the lamps 300. The diffusion plate 410 diffuses the light generated from the lamps 300 to improve the brightness uniformity of the light. The diffusion plate 410 has a plate shape having a predetermined thickness. The diffusion plate 410 is made of a transparent material for transmitting light, and includes a diffusion agent for diffusing light. The diffusion plate 410 is made of, for example, a poly methyl methacrylate (PMMA) material.

The optical member 400 further includes at least one optical sheet 420 disposed on the diffuser plate 410. The optical sheet 420 changes the path of the light diffused through the diffusion plate 410 to improve the luminance characteristic. The optical sheet 420 may include a light collecting sheet for condensing the light diffused through the diffusion plate 410 in the front direction to improve the front brightness of the light. In addition, the optical sheet 420 may include a diffusion sheet for diffusing the light diffused through the diffusion plate 410 once again. Meanwhile, an optical sheet having various functions may be added to the backlight assembly 100 according to required luminance characteristics.

The mold frame 500 is coupled with the bottom chassis 200 to cover the distal end of the lamps 300 from the top of the bottom chassis 200. The mold frame 500 covers the end portions of the lamps 300, that is, the electrode areas of the lamps 300, which are relatively lower in brightness than the other areas of the lamps 300, thereby removing luminance unevenness. In addition, the mold frame 500 has a first groove 510 for fixing the optical member 400 disposed on the lamps 300. The first groove 510 is formed along a direction perpendicular to the longitudinal direction of the lamp 300 so that both side regions of the optical member 400 can be inserted.

In this embodiment, the optical member 400 is slid along the first groove 510 from one side of the mold frame 500 and fixed to the mold frame 500. On the contrary, if the optical member 400 has a certain degree of elasticity, the optical member 400 may be fitted into and fixed to the first grooves 510 on both sides from the top of the mold frame 500. In addition, in the present embodiment, the mold frame 500 has one frame shape, but, alternatively, the mold frame 500 may have a structure divided into two pieces having a “C” shape.

FIG. 2 is a partially cutaway perspective view illustrating the mold frame illustrated in FIG. 1 in detail, and FIG. 3 is an enlarged view of portion A of FIG. 2 enlarged.

1, 2 and 3, the mold frame 500 includes a first side 520 and a second side 530.

The first side portion 520 extends in a direction perpendicular to the longitudinal direction of the lamps 300 to cover the distal ends of the lamps 300. That is, the first side part 520 fixes the lamp holders 310 while covering the lamp holders 310 into which the end portions of the lamps 300 are inserted so as not to be exposed to the outside. The first side 520 is formed with a first groove 510 for fixing the optical member 400. The first groove 510 is formed in the mold frame 500 from the inner side to the outer side, and is formed as a whole along the longitudinal direction of the first side part 520. A second groove 522 is formed at the first side portion 520 to be coupled to the bottom chassis 200. The second groove 522 is formed in an upward direction from the lower side of the mold frame 500 so that the side surface 220 of the bottom chassis 200 can be inserted.                     

The second side portion 530 is formed to extend in a direction parallel to the longitudinal direction of the lamps 300 from the end of the first side portion 520. An opening 534 for inserting the optical member 400 may be formed in the second side portion 530. The optical member 400 is inserted into the mold frame 500 through the opening 534 and then slides along the first groove 510 to be fixed to the mold frame 500.

Meanwhile, a first hook portion 540 is formed at the first side portion 520 and the second side portion 530 to be coupled to the bottom chassis 200.

4 is a cross-sectional view illustrating a combined cross section of the backlight assembly illustrated in FIG. 1.

1 and 4, in the bottom chassis 200, lamps 300 having a distal end fitted to the lamp holder 310 are accommodated. Thereafter, in order to fix the lamp holder 310 while covering the distal ends of the lamps 300, the mold frame 500 is coupled with the bottom chassis 200 in a top down manner from an upper side of the bottom chassis 200. do. At this time, the side surface 220 of the bottom chassis 200 is fitted into the second groove 522 of the first side portion 520. On the other hand, the mold frame 500 and the bottom chassis 200 is hooked. That is, the first hook portion 540 formed on the first and second side portions 520 and 530 of the mold frame 500 is coupled to the second hook portion 222 formed on the side surface 220 of the bottom chassis 200. Thus, the mold frame 500 and the bottom chassis 200 are stably coupled.

The optical member 400 is slid along the first groove 510 and fixed to the mold frame 500 before the mold frame 500 and the bottom chassis 200 are coupled to each other. Alternatively, the optical member 400 may be fitted into the first groove 510 and fixed to the mold frame 500 after the mold frame 500 and the bottom chassis 200 are coupled to each other.

Meanwhile, the backlight assembly 100 further includes a reflector plate 560 disposed under the lamps 300. The reflector 560 reflects light directed downward from the light generated from the lamps 300 toward the optical member 400 to improve light utilization efficiency.

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

Referring to FIG. 5, the liquid crystal display 600 according to the exemplary embodiment includes a backlight assembly 100 and a display unit 700.

Since the backlight assembly 100 has the same structure as shown in FIGS. 1 to 4, the same reference numerals are used, and detailed description thereof will be omitted.

The display unit 700 includes a liquid crystal display panel 710 for displaying an image using light supplied from the backlight assembly 100, and a driving circuit unit 720 for driving the liquid crystal display panel 710.

The liquid crystal display panel 710 may include a first substrate 712, a second substrate 714 coupled to the first substrate 712 at a predetermined interval, and a liquid crystal layer disposed between the two substrates 712 and 714. 716).

The first substrate 712 is a substrate in which thin film transistors (hereinafter referred to as TFTs), which are switching elements, are formed in a matrix form. Data and gate lines are respectively connected to the source and gate terminals of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal. The second substrate 714 is a substrate in which RGB pixels as color pixels are formed by a thin film process. The second substrate 714 includes a common electrode made of a transparent conductive material formed on an RGB pixel.

In the liquid crystal display panel 710 having such a configuration, when power is applied to the gate terminal of the TFT and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode. Due to the electric field, the arrangement of liquid crystal molecules constituting the liquid crystal layer 716 is changed, and the transmittance of light supplied from the backlight assembly 100 is changed according to the arrangement change of the liquid crystal molecules, thereby displaying an image having a desired gray scale.

The driving circuit 720 includes a data printed circuit board 722 for supplying a data driving signal to the liquid crystal display panel 710, a gate printed circuit board 724 for supplying a gate driving signal to the liquid crystal display panel 710, and data printing. The data flexible circuit film 726 connects the circuit board 722 to the liquid crystal display panel 710 and the gate flexible circuit film 728 connects the gate printed circuit board 724 to the liquid crystal display panel 710. . The data flexible circuit film 726 and the gate flexible circuit film 728 are made of, for example, a tape carrier package (TCP) or a chip on film (COF). Meanwhile, the gate printed circuit board 724 may be removed by forming separate signal wires on the liquid crystal display panel 710 and the gate flexible circuit film 728.

The liquid crystal display device 600 further includes a top chassis 800 for fixing the display unit 700. The top chassis 800 is coupled to the bottom chassis 200 while surrounding the edge of the liquid crystal display panel 710 to fix the liquid crystal display panel 710 to the upper portion of the backlight assembly 100. In this case, the data printed circuit board 722 is bent by the data flexible circuit film 726 and fixed to the side or bottom of the bottom chassis 200. The top chassis 800 is made of, for example, a metal having little deformation and excellent strength.

According to the backlight assembly and the liquid crystal display having the same, the side mold for covering the end portion of the lamp and the middle mold for fixing the optical member are integrally formed, thereby reducing the number of parts and reducing the manufacturing cost, Can improve. In addition, by using only one mold frame, it is possible to prevent the occurrence of defects such as foreign matter inflow.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be 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 (11)

A bottom chassis including a bottom surface and a side surface extending from the bottom surface to form an accommodation space; Lamps stored in the bottom chassis to generate light; An optical member disposed above the lamps; And And a mold frame coupled to the bottom chassis to cover end portions of the lamps, the mold frame having a first groove for fixing the optical member. The method of claim 1, wherein the mold frame A first side portion extending in a direction perpendicular to the longitudinal direction of the lamps to cover the end portions of the lamps; And And a second side portion extending in a direction parallel to the longitudinal direction of the lamps. The backlight assembly of claim 2, wherein the first groove is formed at the first side. The backlight assembly of claim 3, wherein the optical member slides along the first groove and is fixed to the mold frame. The backlight assembly of claim 2, wherein a second groove is formed in the first side to insert a side surface of the bottom chassis. The backlight assembly of claim 5, wherein the bottom chassis and the mold frame are hooked. The method of claim 1, wherein the optical member A diffuser plate for diffusing light generated from the lamps; And And at least one optical sheet disposed on the diffusion plate. A bottom chassis having a storage space, lamps stored in the bottom chassis to generate light, an optical member disposed above the lamps, and combined with the bottom chassis to cover the end portions of the lamps, and fixing the optical member A backlight assembly comprising a mold frame having a first groove for the purpose; And a liquid crystal display panel disposed on the mold frame to display an image by using light supplied from the backlight assembly. The mold frame A first side portion extending in a direction perpendicular to the longitudinal direction of the lamps to cover the end portions of the lamps, the first groove being formed; And And a second side portion extending in a direction parallel to the longitudinal direction of the lamps. The liquid crystal display of claim 9, wherein the optical member is slid along the first groove and fixed to the mold frame. 10. The liquid crystal display of claim 9, wherein a second groove is formed in the first side to insert a side surface of the bottom chassis.

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