KR20070047393A - Back light assembly and liquid crystal display device having the same - Google Patents

Abstract

A backlight assembly capable of improving display quality and a liquid crystal display having the same are disclosed. The backlight assembly includes a container, lamps, a diffusion plate, and a lamp fixing member. The storage container consists of a bottom portion and a side portion to form a storage space. The lamps are arranged parallel to each other on the bottom of the container. The diffuser plate is arranged on top of the lamps. The lamp fixing member includes a body portion extending in a direction intersecting the lamps, a buffer portion protruding from the body portion in the direction of the diffusion plate, a diffusion plate support portion protruding from the buffer portion to support the diffusion plate, and a lamp portion formed in the body portion. It includes a lamp fixing portion for fixing. In this way, by forming an elastic buffer part in the region where the diffuser plate support part of the lamp fixing member is formed, the friction between the diffuser plate and the diffuser plate support part can be reduced and the display quality can be improved.

Description

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

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

FIG. 2 is a plan view illustrating a storage state of the diffusion plate illustrated in FIG. 1.

3 is a perspective view showing in detail the lamp fixing member shown in FIG.

4 is a cross-sectional view illustrating a cross section of the lamp fixing member illustrated in FIG. 3.

5 is a cross-sectional view showing a lamp fixing member according to another embodiment of the present invention.

6 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: lamp fixing member

410: body portion 420: buffer portion

430: diffuser plate support 440: lamp fixing portion

450: coupling portion 350: diffuser plate

360: optical sheet 370: side mold

700: liquid crystal display 800: display unit

810: liquid crystal display panel 820: driving circuit

910: middle mold 920: 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 display defects due to the flow of the diffusion plate.

In general, a liquid crystal display is a flat panel display that displays an image using liquid crystal, and is thinner and lighter than other display devices, and has advantages such as low driving voltage and low power consumption. Has Due to these advantages, liquid crystal displays are used in various products such as notebooks, monitors, and TVs.

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

The backlight assembly includes a lamp for generating light. In this case, a cold cathode fluorescent lamp (CCFL) having a long thin cylindrical shape is mainly used. The backlight assembly is classified into an edge type and a 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 type backlight assembly, as the size of the LCD increases, the length of the lamp becomes longer and the size of the diffusion plate becomes larger. Accordingly, the backlight assembly includes a lamp fixing member that supports the diffuser plate while fixing the lamp.

The lamp fixing member includes a lamp fixing part for fixing the lamp and a diffusion plate support part for supporting the diffuser plate. However, when the diffuser plate flows due to vibration of the liquid crystal display device, there is a problem in that a display quality defect occurs such that the friction region of the diffuser plate is recognized in a dot form by friction with the diffuser plate support part.

Accordingly, the present invention has been made in view of such a conventional problem, and the present invention provides a backlight assembly capable of improving display quality by preventing display quality defects caused by friction between the diffusion plate and the lamp fixing member.

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

According to an aspect of the present invention, a backlight assembly includes a container, lamps, a diffusion plate, and a lamp fixing member. The storage container consists of a bottom portion and a side portion to form a storage space. The lamps are arranged parallel to each other on the bottom of the container. The diffuser plate is disposed on top of the lamps. The lamp fixing member may include a body part extending in a direction crossing the lamps, a buffer part protruding from the body part in the direction of the diffusion plate, a diffusion plate support part protruding from the buffer part to support the diffusion plate, and the It is formed in the body portion includes a lamp fixing portion for fixing the lamps.

The buffer portion has a trapezoidal shape in cross section cut along the longitudinal direction of the body portion. Unlike this, the shock absorbing portion may have an arch shape in which the cross section cut along the longitudinal direction of the body portion.

A liquid crystal display according to an aspect of the present invention includes a backlight assembly and a display unit. The backlight assembly may include a storage container, a plurality of lamps disposed in parallel with each other on a bottom portion of the storage container, a diffusion plate disposed on the lamps, and a lamp fixing member coupled to the storage container to fix the lamps. Include. The lamp fixing member may include a body part extending in a direction crossing the lamps, a buffer part protruding from the body part in the direction of the diffusion plate, a diffusion plate support part protruding from the buffer part to support the diffusion plate, and the It is formed in the body portion includes a lamp fixing for fixing the lamps. The display unit includes a liquid crystal display panel disposed on the diffusion plate to display an image and a driving circuit unit to drive the liquid crystal display panel.

According to such a backlight assembly and a liquid crystal display having the same, by forming a buffer having elasticity in an area where the diffusion plate support of the lamp fixing member is formed, the friction between the diffusion plate and the diffusion plate support can be reduced and the display quality can be improved. Can be.

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.

Referring to FIG. 1, the backlight assembly 100 according to an embodiment of the present invention includes a storage container 200, a plurality of lamps 300, a diffusion plate 350, and a lamp fixing member 400.

The storage container 200 includes a bottom portion 210 and a side portion 220 extending from an edge of the bottom portion 210 to form a storage space. The storage container 200 is, for example, made of a metal having excellent strength and little deformation.

The first diffusion plate guide part 222 for guiding a fixed position of the diffusion plate 350 is formed at the side portion 220 corresponding to the long side direction of the storage container 200. The first diffusion plate guide part 222 protrudes from the upper surface of the side part 220 to a predetermined height to guide the storage position of the diffusion plate 350.

The lamps 300 are disposed parallel to each other on the bottom portion 210 of the storage container 200. The lamps 300 generate light in response to driving power applied from the outside. The lamps 300 are made of a cold Cathode Fluorescent Lamp (CCFL) having an elongated cylindrical shape. In contrast, the lamps 300 may be formed of an external electrode fluorescent lamp (EEFL) having external electrodes formed at both ends thereof. In addition, the lamps 300 may have a structure bent in a U shape.

Both ends of the lamps 300 are fitted into and fixed to the lamp holders 310, and the lamp holders 310 are coupled to and fixed to the storage container 200.

The diffusion plate 350 is disposed above the lamps 300. The diffusion plate 350 diffuses the light generated from the lamps 300 to improve the brightness uniformity of the light. The diffusion plate 350 is formed in a plate shape having a predetermined thickness and is spaced apart from the lamps 300 by a predetermined distance.

The diffusion plate 350 is made of a transparent material for transmitting light, and includes a diffusion agent for diffusing light. The diffusion plate 350 is made of, for example, polymethyl methacrylate (PMMA) material.

The backlight assembly 100 may further include at least one optical sheet 360 disposed on the diffuser plate 350. The optical sheet 360 changes the path of the light diffused through the diffusion plate 350 to improve the luminance characteristic. The optical sheet 360 may include a light collecting sheet for condensing the light diffused through the diffusion plate 350 in the front direction to improve the front brightness of the light. In addition, the optical sheet 360 may include a diffusion sheet for diffusing the light diffused through the diffusion plate 350 once again. Meanwhile, the backlight assembly 100 may further include an optical sheet having various functions, such as a reflective polarizing sheet, in accordance with required luminance characteristics.

The lamp fixing member 400 is fixed to the bottom portion 210 of the storage container 200 to fix the lamps 300. Since the longer the length of the lamp 300, the greater the possibility of bending or deformation, the lamp fixing member 400 to stably fix the central portion of the lamp 300 to prevent sagging and deformation of the lamp 300.

The number of lamp fixing members 400 is determined according to the number of lamps 300. For example, four lamps 300 are fixed to one lamp fixing member 400.

When there are two or more lamp fixing members 400, the lamp fixing members 400 are arranged in a zigzag form along a direction perpendicular to the length direction of the lamp 300. When the lamp fixing members 400 are disposed in a straight line, a poor quality such as a dark line in which only the area in which the lamp fixing members 400 are located may appear dark may occur. Therefore, by arranging the lamp fixing members 400 in a zigzag form so as not to be disposed in a straight line, quality defects such as dark lines can be removed.

Each lamp 300 is fixed by one lamp fixing member 400. However, when the length of the lamp 300 is longer, by increasing the number of the lamp fixing member 400, each lamp 300 is at least two lamp holding members spaced apart by a predetermined distance along the longitudinal direction ( 400). Even in this case, the lamp fixing members 400 are disposed in a zigzag form along a direction perpendicular to the longitudinal direction of the lamp 300.

The backlight assembly 100 may further include side molds 370 disposed corresponding to both ends of the lamps 300. The side mold 370 is coupled to the receiving container 200 while covering both ends of the lamps 300. The side mold 370 shields both ends of the lamps 300, which are relatively lower in brightness than other areas, that is, the electrode area of the lamp 300, thereby eliminating brightness unevenness. In addition, the side mold 370 guides the storage position of the diffusion plate 350 while supporting the edge of the diffusion plate 350 disposed thereon. The side mold 370 is provided with a second diffusion plate guide part 372 for guiding the fixed position of the short side of the diffusion plate 350. The second diffusion plate guide part 372 protrudes from the upper surface of the side mold 370 to a predetermined height to guide the storage position of the diffusion plate 350.

Although not shown, the backlight assembly 100 may further include a middle mold for fixing the diffusion plate 350 and the optical sheet 360. The middle mold is coupled to the receiving container 200 from the top of the optical sheet 360 to fix the edges of the diffusion plate 350 and the optical sheet 360.

FIG. 2 is a plan view illustrating a storage state of the diffusion plate illustrated in FIG. 1.

1 and 2, the diffusion plate 350 is supported by the storage container 200 and the side mold 370.

In detail, the long side of the diffusion plate 350 is supported by the side portion 220 of the storage container 200, and the short side of the diffusion plate 350 is supported by the side mold 370. At this time, the diffusion plate 350 is guided by the first diffusion plate guide part 222 of the storage container 200 and the second diffusion plate guide part 372 of the side mold 370.

The diffusion plate 350 is easily deformed by heat and moisture. Therefore, the diffusion plate 350 is accommodated so as to be spaced apart from the first diffusion plate guide part 222 and the second diffusion plate guide part 372 by a predetermined distance d in consideration of the degree of deformation. For example, the diffusion plate 350 is accommodated to be spaced apart from the first diffusion plate guide part 222 and the second diffusion plate guide part 372 by about 1.5 mm.

Meanwhile, a sheet fixing protrusion 374 for fixing the optical sheet 360 is formed in the second diffusion plate guide part 372.

3 is a perspective view showing in detail the lamp fixing member shown in Figure 1, Figure 4 is a cross-sectional view showing a cross-section of the lamp holding member shown in FIG.

3 and 4, the lamp fixing member 400 includes a body 410, a buffer 420, a diffusion plate support 430, and a lamp fixing 440.

The body portion 410 is formed to extend in a direction crossing the lamps 300. The body portion 410 is formed to open in correspondence with the buffer portion 420. On the contrary, the body 410 may be integrally formed to cover the lower portion of the buffer 420.

The buffer part 420 is formed to protrude from the body part 410 toward the diffusion plate 350. One buffer unit 420 is formed in the center of the body portion 410. Unlike this, the buffer part 420 may be formed in plural so as to be spaced apart at predetermined intervals along the longitudinal direction of the body part 410.

The shock absorbing portion 420 is formed in a shape having a predetermined elasticity to cushion the force applied to the spreading plate support part 430 by the deflection and flow of the diffusion plate 350. The buffer portion 420 is formed in a substantially trapezoidal shape in cross section cut along the longitudinal direction of the body portion 410.

The diffusion plate support part 430 protrudes from the buffer part 420 to a position higher than the lamp fixing part 440 to support the diffusion plate 350. As the diffusion plate 350 becomes larger, the center portion sags downward. Therefore, the diffuser plate supporter 430 prevents the diffusion plate 350 from sagging to maintain a constant distance between the lamp 300 fixed to the lamp fixing part 440 and the diffuser plate 350. The diffuser plate support 430 has a conical shape, for example.

Therefore, when friction occurs between the diffusion plate 350 and the diffusion plate support part 430 due to the flow of the diffusion plate 350, the diffusion plate 350 and the diffusion plate support part 430 are caused by the elasticity of the buffer part 420. The friction force between) is minimized.

The lamp fixing part 440 is formed on the upper surface of the body part 410 to fix the lamps 300. The lamp fixing part 440 protrudes upward from the body part 410 and has an opening 442 for inserting the lamp 300.

The width of the opening 442 is determined according to the diameter of the lamp 300. The larger the width of the opening 442, the easier it is to insert the lamp 300 into the lamp fixing portion 440. However, if the width of the opening 442 is too large, the lamp 300 can be easily removed from the lamp fixing portion 440. Can be disengaged. Accordingly, the width of the opening 442 of the lamp fixing portion 440 preferably has a range of about 80% to about 90% of the diameter of the lamp 300. For example, when the diameter of the lamp 300 is about 4 mm, the width of the opening 442 is formed to be about 3.3 mm.

One or more lamp fixing parts 440 are formed on both sides of the buffer part 420. The lamp fixing member 400 has four lamp fixing parts 440. Unlike this, the lamp fixing member 400 may include various numbers of lamp fixing parts 440.

The lamp fixing member 400 further includes at least one coupling part 450 for coupling with the storage container 200. Coupling portion 450 is formed on the lower surface of the body portion 410. Forming position and the number of the coupling portion 450 may be variously modified.

Meanwhile, the backlight assembly 100 further includes a reflecting plate 380 disposed between the storage container 200 and the lamps 300. The reflector 380 reflects light generated from the lamps 300 toward the diffuser plate 350 to improve light utilization efficiency. The reflecting plate 380 is attached to and fixed to the bottom portion 210 of the storage container 200, for example.

The reflecting plate 380 and the bottom portion 210 of the storage container 200 are opened to correspond to the coupling portion 450 of the lamp fixing member 400. The coupling part 450 penetrates through the open areas of the reflector plate 380 and the bottom part 210, and then is hooked with the bottom part 210.

5 is a cross-sectional view showing a lamp fixing member according to another embodiment of the present invention.

Referring to FIG. 5, the lamp fixing member 500 according to another embodiment may include a body part 510, a buffer part 520, a diffusion plate support part 530, a lamp fixing part 540, and a coupling part 550. Include. Since the rest of the configuration except for the buffer unit 520 has the same structure as that shown in FIG. 4, detailed description thereof will be omitted.

The buffer part 520 is formed to protrude upward from the body part 510. One buffer unit 520 is formed at the center of the body unit 510. Unlike this, the shock absorbing portion 520 may be formed in plurality so as to be spaced apart at predetermined intervals along the longitudinal direction of the body portion 510.

The buffer part 520 is formed in a shape having a predetermined elasticity in order to buffer a force that the diffusion plate support part 530 receives due to deflection and flow of the diffusion plate disposed thereon. The buffer part 520 is formed so that the cross section cut along the longitudinal direction of the body part 510 has an arch shape substantially.

In addition, the diffusion plate support 530 may have a structure in which the inside of the diffusion plate support 530 is empty to improve the elastic force.

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

Referring to FIG. 6, the liquid crystal display 700 according to the exemplary embodiment includes a backlight assembly 100 for supplying light and a display unit 800 for displaying an image.

Since the backlight assembly 100 has the same structure as shown in FIGS. 1 to 5, the same reference numerals are used for the same components, and detailed description thereof will be omitted.

The display unit 800 includes a liquid crystal display panel 810 for displaying an image using light supplied from the backlight assembly 100, and a driving circuit unit 820 for driving the liquid crystal display panel 810.

The liquid crystal display panel 810 includes a first substrate 812, a second substrate 814 coupled to the first substrate 812, and a liquid crystal interposed between the first substrate 812 and the second substrate 814. Layer 816.

The first substrate 812 is a substrate in which a thin film transistor (hereinafter, referred to as TFT), which is a switching element, is formed in a matrix form. For example, the first substrate 812 is made of glass. 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.

The second substrate 814 is a substrate in which an RGB color filter for realizing color is formed in a thin film form. The second substrate 814 is made of, for example, a glass material. The common electrode made of a transparent conductive material is formed on the second 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 arrangement of the liquid crystal molecules of the liquid crystal layer 816 interposed between the first substrate 812 and the second substrate 814 is changed by this electric field, and is supplied from the backlight assembly 100 according to the arrangement change of the liquid crystal molecules. The transmittance of light 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 include a driving chip. 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).

The data printed circuit board 822 is disposed on the side or the back of the receiving container 200 by the bending of the data driving circuit film 826, and the gate printed circuit board 824 is connected to the bending of the gate driving circuit film 828. It is disposed on the side or back of the storage container 200 by. Meanwhile, the gate printed circuit board 824 may be removed by forming separate signal wires on the liquid crystal display panel 810 and the gate driving circuit film 828.

The liquid crystal display device 700 may further include a middle mold 910 disposed between the optical sheet 360 and the liquid crystal display panel 810. The middle mold 910 supports the liquid crystal display panel 810 while fixing the optical sheet 360 and the diffusion plate 350. The middle mold 910 is formed integrally in a frame shape. Alternatively, the middle mold 910 may have a structure divided into two pieces having a “C” shape. In addition, the middle mold 910 may have a structure divided into four pieces having an "a" shape.

The liquid crystal display 700 may further include a top chassis 920 for fixing the display unit 800. The top chassis 920 is coupled to the storage container 200 while surrounding the edge of the liquid crystal display panel 810 to fix the liquid crystal display panel 810 to the upper portion of the middle mold 910. The top chassis 920 prevents the liquid crystal display panel 810 from being damaged by an external impact and prevents the liquid crystal display panel 810 from being separated from the middle mold 910. The top chassis 920 is formed integrally in a frame shape. Alternatively, the top chassis 920 may have a structure divided into two pieces having a "c" shape or four pieces having a "a" shape.

According to such a backlight assembly and a liquid crystal display having the same, by forming a buffer having elasticity in the area where the diffusion plate support of the lamp fixing member is formed, the friction between the diffusion plate and the diffusion plate support is minimized, and the diffusion plate due to friction The display quality can be improved by preventing the occurrence of cracking.

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 (15)

A storage container formed of a bottom portion and a side portion to form a storage space; A plurality of lamps disposed in parallel with each other on the bottom of the storage container; A diffuser plate disposed above the lamps; And A body portion extending in a direction crossing the lamps, a buffer portion protruding from the body portion in the direction of the diffusion plate, a diffusion plate support portion protruding from the buffer portion to support the diffusion plate, and the body portion And a lamp fixing member having a lamp fixing part for fixing the lamps. The backlight assembly of claim 1, wherein the buffer part has a trapezoidal cross section cut along a length direction of the body part. The backlight assembly of claim 1, wherein a cross section cut along the longitudinal direction of the body part has an arch shape. The backlight assembly of claim 1, wherein the buffer part is formed at the center of the body part. The backlight assembly of claim 1, wherein the body part is opened to correspond to the buffer part. The backlight assembly of claim 1, wherein the diffuser support has a conical shape. The backlight assembly of claim 1, wherein the lamp fixing portion protrudes upward from the body portion and has an opening for insertion of the lamp. The backlight assembly of claim 7, wherein at least one lamp fixing part is formed at each of both sides of the buffer part. The backlight assembly of claim 1, wherein the lamp fixing member further comprises a coupling part formed at a lower surface of the body part and coupled to a bottom part of the storage container. The backlight assembly of claim 1, wherein the lamp fixing member is disposed in a zigzag form along a direction perpendicular to the longitudinal direction of the lamp. A backlight assembly including a storage container, a plurality of lamps disposed in parallel with each other on a bottom portion of the storage container, a diffusion plate disposed on the lamps, and a lamp fixing member coupled to the storage container to fix the lamps. ; And A display unit disposed on the diffusion plate and including a liquid crystal display panel for displaying an image and a driving circuit unit for driving the liquid crystal display panel; The lamp fixing member A body part extending in a direction crossing the lamps; A buffer part protruding from the body part toward the diffusion plate, A diffusion plate support part protruding from the buffer part to support the diffusion plate, and And a lamp fixing part formed on the body to fix the lamps. 12. The liquid crystal display device according to claim 11, wherein the buffer part protrudes in a trapezoidal or arch shape to have a predetermined elasticity. 12. The liquid crystal display device according to claim 11, wherein the buffer part is formed at the center of the body part, and the body part is opened corresponding to the buffer part. 12. The liquid crystal display of claim 11, wherein at least one lamp fixing part is formed at both sides of the buffer part, and has an opening for inserting the lamp. The method of claim 11, wherein the backlight assembly A reflector disposed below the lamps; And And a further optical sheet disposed on the diffusion plate.

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