KR20070069320A - Back light assembly and liquid crystal display apparatus having the same - Google Patents

Abstract

A backlight assembly and an LCD(Liquid Crystal Display) having the backlight assembly are provided to prevent a combining plane of a mold frame from coming into contact with the side of a receiving container, thereby removing friction generated when the combining plane of the mold frame comes into contact with the side of the receiving container and preventing noise caused by the friction. A backlight assembly(100) includes a receiving container(200), a plurality of lamps(300), an optical member(400), and a mold frame(500). The lamps are accommodated in the receiving container and generate light. The optical member is located on the lamps. The mold frame is combined with the receiving container, envelops the side of the receiving container, and fixes the optical member. The mold frame has protrusions(512) formed on a plane(510) opposite to the side of the receiving container.

Description

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

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

2 is an enlarged perspective view illustrating a part of the backlight assembly of FIG.

3 is a perspective view illustrating an embodiment of a protrusion formed on an engagement surface of the mold frame illustrated in FIG. 1.

4 is a cross-sectional view illustrating an embodiment of a cross section taken along line II ′ of FIG. 3.

FIG. 5 is a cross-sectional view illustrating another example of a cross section taken along line II ′ of FIG. 3.

6 is a perspective view showing another embodiment of the protrusion formed on the engaging surface of the mold frame shown in FIG.

FIG. 7 is a perspective view illustrating still another embodiment of a protrusion formed on an engagement surface of the mold frame illustrated in FIG. 1.

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

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

100: backlight assembly 200: storage container

300: lamp 400: optical member

410: diffuser plate 420: optical sheet

500: mold frame 510: mating surface

512: protrusion 600: reflector

700: liquid crystal display 800: display unit

810: liquid crystal display panel 820: driving circuit

900: 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, which can prevent noise while maintaining assembly.

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.

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

In the conventional backlight assembly, an elongated cylindrical cold cathode fluorescent lamp (CCFL) is mainly used as a light source.

Recently, as a liquid crystal display device is enlarged, a backlight assembly having high brightness and providing uniform light over a large area is required. In order to meet this demand, the backlight assembly needs a plurality of lamps. Here, the plurality of lamps are arranged in parallel on the same plane.

On the other hand, the backlight assembly is a housing for accommodating the lamps, an optical member disposed above the lamps to improve the characteristics of the light generated from the lamps and a mold coupled to the storage container to surround the side of the storage container to fix the optical member It further includes a frame. Here, the storage container is made of a metal material, unlike the mold frame made of a polymer material, the storage container has a substantially lower coefficient of thermal expansion and shrinkage than the mold frame. In addition, the side of the storage container is spaced apart from the mating surface of the mold frame with an assembly tolerance of 0.3 mm.

As described above, since the storage container and the mold frame have different thermal expansion rates and shrinkage rates, when a temperature difference occurs in the liquid crystal display device instantaneously, such as when the power supply of the liquid crystal display device is turned on / off, The stress for maintaining a distance of 0.3 mm is temporarily canceled between the side and the mating surface of the mold frame so that a part of the mating surface of the mold frame makes direct surface contact with the side of the storage container. This surface contact causes friction between the container container side and the engaging surface of the mold frame, whereby noise is generated.

However, in order to solve this problem, although the assembly tolerance between the side of the storage container and the mating surface of the mold frame can be increased, surface contact can be prevented. .

Accordingly, the present invention has been made in view of such a problem, and the present invention provides a backlight assembly capable of preventing noise while maintaining assembly.

In addition, the present invention provides a liquid crystal display device having the backlight assembly as described above.

The backlight assembly according to an aspect of the present invention described above includes a storage container, a plurality of lamps, an optical member, and a mold frame. The lamps are stored in the storage container to generate light. The optical member is disposed above the lamps. The mold frame is coupled to the storage container to surround the side of the storage container to fix the optical member, and a protrusion protruding to a predetermined height is formed on a mating surface facing the side of the storage container.

According to an aspect of the present invention, there is provided a liquid crystal display device including a backlight assembly for supplying light, a liquid crystal display panel for displaying an image using light from the backlight assembly, and a driving circuit unit for driving the liquid crystal display panel. And a top chassis that secures the unit and the display unit. The backlight assembly may be combined with the storage container to surround a storage container, a plurality of lamps stored in the storage container to generate light, an optical member disposed on the lamps, and a side of the storage container. And a mold frame having a protrusion protruding to a predetermined height on an engaging surface facing the side of the storage container. The display unit includes a liquid crystal display panel for displaying an image and a driving circuit unit for driving the liquid crystal display panel.

According to such a backlight assembly and a liquid crystal display having the same, a protrusion protruding to a predetermined height may be formed on a mating surface of the mold frame facing the side of the storage container so that the side surface of the container is in surface contact with the mold frame. By preventing it, it is possible to prevent the noise generated by removing the friction generated during surface contact.

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

1 is an exploded perspective view illustrating a backlight assembly according to an exemplary embodiment of the present invention, and FIG. 2 is an enlarged perspective view of a part of the backlight assembly of FIG.

1 and 2, the backlight assembly 100 according to an embodiment of the present invention includes a storage container 200, a lamp 300, an optical member 400, and a mold frame 500.

The storage container 200 is formed of a bottom portion 210 and four side portions 220 extending vertically from the bottom portion 210 to form a storage space therein to accommodate the lamp 300. The side portion 220 of the storage container 200 is bent with a predetermined area thereon to support the optical member 400 to be disposed thereon.

The storage container 200 is made of, for example, a metal material having low deformation and excellent strength. In other words, the storage container 200 has a lower thermal expansion rate and shrinkage rate than other materials, in particular, a polymer material.

A plurality of lamps 300 are arranged parallel to each other on the same plane. The lamps 300 generate light in response to driving power applied from the outside. For example, the lamps 300 may be formed of a cold cathode fluorescent lamp 300 (CFL) having an elongated cylindrical shape. 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. In addition, the electrode 300 may be formed of an external electrode fluorescent lamp (EEEL) having external electrodes formed at both ends of the lamps 300.

The optical member 400 is supported by the side portion 220 of the storage container 200 while being disposed above the lamps 300 so as to improve brightness characteristics of light generated from the lamps 300. The optical member 400 includes a diffusion plate 410 disposed on the lamps 300 and at least one optical sheet 420 disposed on the diffusion plate 410.

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 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 further include a diffusion sheet for diffusing the light diffused through the diffusion plate 410 once again. Meanwhile, an optical sheet 420 having various functions may be further added to the backlight assembly 100 according to required luminance characteristics.

The mold frame 500 is coupled to the storage container 200 to surround the side portion 220 of the storage container 200. In addition, the mold frame 500 fixes the edge of the optical member 400 supported by the storage container 200.

The mold frame 500 is made of, for example, a polymer material that is easy to manufacture using a mold. That is, the mold frame 500 has a higher characteristic than the storage container 200 which is a material having a different thermal expansion rate and shrinkage rate, in particular, a metal material.

Therefore, the mold frame 500 enclosing the side 220 of the storage container 200 is relatively bulkier than the side 220 of the storage container 200 with respect to the instantaneous temperature rise of the backlight assembly 100. When the temperature drops again, the volume becomes relatively small.

In view of this, there is a mechanical assembly tolerance between the side portion 220 of the storage container 200 and the engaging surface 510 of the mold frame 500. The assembly tolerance is preferably 0.3 mm, and if exceeded, there is a possibility of affecting the assemblability of the product.

In the mold frame 500, a protrusion 512 protruding to a predetermined height is formed on a coupling surface 510 facing the side portion 220 of the storage container 200. The protruding portion 512 is a side portion 220 of the storage container 200 while maintaining an assembly tolerance of 0.3 mm uniformly between the side 220 of the storage container 200 and the engaging surface 510 of the mold frame 500. And the coupling surface 510 of the mold frame 500 prevent surface contact. On the contrary, the protrusion 512 is formed at the side of the storage container 200 facing the coupling surface 510 of the mold frame 500 so that the protrusion 512 of the coupling surface 510 and the storage container 200 of the mold frame 500 is formed. The side part 220 can be prevented from making surface contact.

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

3 is a perspective view illustrating an embodiment of a protrusion formed on a coupling surface of the mold frame illustrated in FIG. 1, and FIG. 4 is a cross-sectional view illustrating an example of a cross section taken along line II ′ of FIG. 3.

3 and 4, the mold frame 500 extends in a direction perpendicular to the longitudinal direction of the coupling surface 510 and includes protrusions 512 formed at regular intervals along the longitudinal direction of the coupling surface 510. Include.

The protruding portion 512 has a semicircular longitudinal section that is a cross section cut along the longitudinal direction of the engaging surface 510. Unlike this, the longitudinal cross-section of the protrusion 512 may have various shapes such that the side surface 220 of the storage container 200 and the coupling surface 510 of the mold frame 500 may make line contact. .

The protrusion 512 protrudes from the mating surface 510 to a height of 0.3 mm to 0.7 mm while maintaining an assembly tolerance of 0.3 mm with the side 220 of the storage container 200. Here, the protrusion 512 is preferably protruded to 0.5mm. In addition, the protrusion 512 is formed by changing a mold for manufacturing the mold frame 500.

Accordingly, the mold frame 500 is in linear contact with the side portion 220 of the storage container 200 by the protrusion 512 formed on the engaging surface 510, thereby receiving the storage container 200 and the mold frame 500. Noise caused by the difference between the expansion rate and the shrinkage rate with respect to the heat can be prevented. In addition, the protrusion 512 may maintain an assembly tolerance of 0.3 mm with the side portion 220 of the storage container 200, thereby maintaining the existing assembly.

FIG. 5 is a cross-sectional view illustrating another example of a cross section taken along line II ′ of FIG. 3.

Referring to FIG. 5, the protrusion 518 protruding from the engaging surface 516 of the mold frame 515 has a triangular shape in longitudinal section.

In this way, the protrusion 518 is such that the side portion 220 of the storage container 200 and the mating surface 516 of the mold frame 515 are in line contact with each other, such that the storage container 200 side portion 220 and the mold frame 515 are in line contact with each other. Friction of the engaging surface 516 of In contrast, the protrusion 516 may have various shapes in which the side portion 220 of the storage container 200 and the coupling surface 516 of the mold frame 515 may be in line contact with each other.

6 is a perspective view showing another embodiment of the protrusion formed on the engaging surface of the mold frame shown in FIG.

Referring to FIG. 6, the mold frame 520 extends in the longitudinal direction of the coupling surface 530 and includes protrusions 532 formed at regular intervals in a direction perpendicular to the longitudinal direction of the coupling surface 530.

Protruding portion 532 has a semi-circular longitudinal cross-section cut along the direction perpendicular to the longitudinal direction of the coupling surface 530. In contrast, the longitudinal cross-section of the protrusion 532 may have various shapes such that the side portion 220 of the storage container 200, 200, such as a triangle, and the coupling surface 530 of the mold frame 520 may be in line contact. .

The protrusion 532 protrudes from the coupling surface 530 to a height of 0.3 mm to 0.7 mm while maintaining an assembly tolerance of 0.3 mm with the side 220 of the storage containers 200 and 200. Here, the protrusion 532 is preferably protruded to 0.5mm. In addition, the protrusion 532 is formed by changing a mold for manufacturing the mold frame 520.

FIG. 7 is a perspective view illustrating still another embodiment of a protrusion formed on an engagement surface of the mold frame illustrated in FIG. 1.

Referring to FIG. 7, the mold frame 540 includes a protrusion 552 having a hemispherical shape protruding at regular intervals.

The protrusion 552 may be in point contact with the side portion 220 of the storage container 200, and may have various shapes capable of point contact in addition to the hemispherical shape.

The protrusion 552 has a maximum height from the engagement surface 550 of 0.3 mm to 0.7 mm while maintaining an assembly tolerance of 0.3 mm with the side 220 of the storage container 200. Here, the maximum height of the protrusion 552 is preferably 0.5mm. In addition, the protrusion 552 is formed by changing a mold for manufacturing the mold frame 540.

Accordingly, the mold frame 540 is in point contact with the side portion 220 of the storage container 200 by the protrusion 552 formed on the mating surface 550, whereby the storage container 200 and the mold frame 540 are in contact with each other. Noise caused by the difference between the expansion rate and the shrinkage rate with respect to the heat can be prevented.

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

Referring to FIG. 8, the liquid crystal display device 700 according to an exemplary embodiment may include a backlight assembly 100 that supplies light, a display unit 800 that displays an image using the light, and a display unit 800. A top chassis 900 for fixing).

In the present embodiment, since the backlight assembly 100 has the same structure as shown in FIGS. 1 to 7, the same reference numerals are used, and detailed description thereof will be omitted.

The display unit 800 includes a liquid crystal display panel 810 for displaying an image and a driving circuit unit 820 for driving the liquid crystal display panel 810.

The liquid crystal display panel 810 is injected between the array substrate 812 for displaying pixels, the color filter substrate 814 facing the array substrate 812, and the array substrate 812 and the color filter substrate 814. The liquid crystal layer 816 is included.

The array substrate 812 is a TFT substrate in which thin film transistors (hereinafter referred to as TFTs) as switching elements are formed in a matrix form. A data line and a gate line are respectively connected to the source terminal and the gate terminal of the TFTs, and a pixel electrode made of a transparent conductive material is connected to the drain terminal.

In the color filter substrate 814, RGB pixels for realizing color are formed in a thin film form. The common electrode made of a transparent conductive material is formed on the color filter substrate 814.

In the liquid crystal display panel 810 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. The electric field changes the arrangement of the liquid crystal molecules of the liquid crystal layer 816 interposed between the array substrate 812 and the color filter substrate 814, and the light supplied from the backlight assembly 100 according to the arrangement change of the liquid crystal molecules. The transmittance is changed to display an image of a desired gray scale.

The driving circuit unit 820 may include a data printed circuit board 822 for supplying a data driving signal to the liquid crystal display panel 810, a gate printed circuit board 824 for supplying a gate driving signal to the liquid crystal display panel 810, and data printing. A data driving circuit film 826 connecting the circuit board 822 to the liquid crystal display panel 810, and a gate driving circuit film 828 connecting the gate printed circuit board 824 to the liquid crystal display panel 810. .

The data driving circuit film 826 and the gate driving circuit film 828 are formed of, for example, a tape carrier package (TCP) or a chip on film (COF). Meanwhile, the gate printed circuit board 824 may be removed by forming separate signal lines on the liquid crystal display panel 810 and the gate driving circuit film 828.

The top chassis 900 is coupled to the storage container 200 to fix the edge of the liquid crystal display panel 810. In this case, the data printed circuit board 822 is bent by the data driving circuit film 826 and fixed to the bottom portion 210 or the side portion 220 of the storage container 200. The top chassis 900 is made of, for example, a metal having little deformation and excellent strength.

According to such a backlight assembly and a liquid crystal display having the same, a protrusion protruding at a predetermined height is formed on the mating surface of the mold frame facing the side of the storage container while maintaining 0.3 mm, which is a conventional assembly tolerance, according to a change in temperature. Due to the difference in thermal expansion rate and shrinkage rate between the storage container and the mold frame, the engagement surface of the mold frame is prevented from surface contacting the side of the storage container, thereby eliminating friction generated during surface contact.

In addition, it is possible to prevent noise generated due to such friction.

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 (9)

A storage container; A plurality of lamps housed in the storage container to generate light; An optical member disposed above the lamps; And And a mold frame coupled to the storage container so as to surround a side of the storage container, to fix the optical member, and a protrusion formed to protrude to a predetermined height on a coupling surface facing the side of the storage container. The backlight assembly of claim 1, wherein the protrusion extends in a direction perpendicular to the length direction of the coupling surface and is formed at regular intervals along the length direction of the coupling surface. The backlight assembly of claim 1, wherein the protrusion extends in the lengthwise direction of the coupling surface and is formed at regular intervals along a direction perpendicular to the lengthwise direction of the coupling surface. The backlight assembly of claim 1, wherein the protrusion has a semicircular cross section. The backlight assembly of claim 1, wherein the protrusion has a triangular shape in longitudinal section. The backlight assembly of claim 1, wherein the protrusion has a hemispherical shape protruding at regular intervals. The backlight assembly of claim 1, wherein the protrusion protrudes from a height of 0.3 mm to 0.7 mm from the coupling surface. A backlight assembly for supplying light; A display unit including a liquid crystal display panel for displaying an image using light from the backlight assembly and a driving circuit unit for driving the liquid crystal display panel; And A top chassis fixing the display unit, The backlight assembly Storage Container, A plurality of lamps stored in the storage container to generate light, An optical member disposed above the lamps, and And a mold frame coupled to the storage container so as to surround a side of the storage container, and fixing the optical member, and having a protrusion protruding to a predetermined height on a coupling surface facing the side of the storage container. LCD display device. The liquid crystal display device of claim 8, wherein the protrusion protrudes from a height of 0.3 mm to 0.7 mm from the coupling surface.

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