KR20070005806A - Backlight assembly and liquid crystal display using the same - Google Patents

Abstract

A backlight assembly and an LCD using the same are provided to prevent the damage of a flexible circuit board, by disposing a buffer member for absorbing an impact between the flexible circuit board and a lower container of the backlight assembly. An LCD panel(100) is configured to display an image. A backlight unit(2000) is configured to irradiate the LCD panel with a light. A containing member(300) contains the LCD panel and the backlight unit. A PCB(Printed Circuit Board)(210) is positioned at an outside bottom surface of the containing member, and applies signals to the LCD panel. A flexible circuit board(230) has a conductive path for connecting the PCB and the LCD panel. A buffer member(900) is formed between the flexible circuit board and the containing member.

Description

BACKLIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY USING THE SAME}

1 is an exploded perspective view of a liquid crystal display according to a first embodiment of the present invention.

FIG. 2 is a schematic perspective view of a portion of the liquid crystal display of FIG. 1. FIG.

3 is a simplified cross-sectional view of a part of the liquid crystal display of FIG. 1.

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

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

6 is a perspective view schematically illustrating a portion of the liquid crystal display of FIG. 5.

<Explanation of symbols for main parts of the drawings>

100 liquid crystal display panel 110 color filter substrate

120: TFT substrate 210: printed circuit board

200: driving circuit unit 230: flexible circuit board

300: upper storage member 800: lower storage member

900: buffer member

The present invention relates to a backlight assembly and a liquid crystal display using the same, and more particularly, to a backlight assembly capable of preventing damage to a flexible circuit board and a liquid crystal display using the same.

In general, a liquid crystal display (LCD) has advantages of small size, light weight, and large screen compared to a conventional display device, CRT (Cathode Ray Tube), and its development has been actively performed. In particular, the liquid crystal display device has been developed to perform a sufficient role as a flat panel display device, and is used not only as a liquid crystal for mobile phones, PDAs, digital cameras, camcorders, but also for monitors and large display devices of desktop computers. His range of use is expanding rapidly.

Such a liquid crystal display includes a liquid crystal display panel for displaying a desired image on a screen by adjusting the amount of light transmitted according to image signals applied to a plurality of control switches arranged in a matrix form, and a driving circuit for transmitting an external signal thereto. It includes a printed circuit board, a backlight unit for irradiating light to the liquid crystal display panel, and a lower housing member surrounding the printed circuit board.

A liquid crystal display device connects a liquid crystal display panel and a printed circuit board including a driving circuit, couples a backlight unit to a lower portion of the liquid crystal display panel, and fixes them with upper and lower housing members.

In this case, the liquid crystal display panel and the printed circuit board are electrically connected through the flexible circuit board. Conventionally, a flexible circuit board was bent and the printed circuit board was arrange | positioned under the liquid crystal display pattern. As described above, the conventional flexible circuit board having the bending characteristic has a problem in that the metal wiring is formed between two thin films, and thus is easily damaged when exposed to an external impact. That is, since the flexible circuit board is bent and in contact with a portion of the hard lower housing member, when an impact is applied to this region, the impact is transmitted to the flexible circuit board as it is, causing abnormal operation when driving the product. In addition, since the flexible circuit board is bent along the refractive surface of the lower housing member, when a shock is applied to the refractive surface, the metal wiring in the flexible circuit board is disconnected, which causes the liquid crystal display device not to operate.

Accordingly, an object of the present invention is to provide a backlight assembly capable of preventing damage to a flexible circuit board from external impact and a liquid crystal display using the same.

In order to achieve the above object, a liquid crystal display panel for displaying an image according to the present invention, a backlight unit for irradiating light to the liquid crystal display panel, a housing member for accommodating the liquid crystal display panel and the backlight unit, and the liquid crystal A flexible printed circuit board having a signal applied to the display panel, a printed circuit board disposed on an outer bottom surface of the housing member, a conductive path for connecting the printed circuit board to the liquid crystal display panel, and the flexible printed circuit board; A liquid crystal display device including a buffer member formed between members is provided.

Here, it is preferable to use a shock absorbing material such as rubber, urethane or sponge as the buffer member.

The buffer member may be formed on the accommodating member in contact with the flexible circuit board, and the buffer member may be formed above or below the flexible circuit board.

And, the buffer member is preferably attached using an adhesive or double-sided tape.

Meanwhile, a driving circuit may be formed on the flexible circuit board or a driving circuit may be formed on the liquid crystal display panel.

The above-described flexible circuit board is bent, and it is effective that the buffer member located below the bent region has a predetermined curved surface.

Further, in the backlight assembly for a liquid crystal display according to the present invention, a lamp unit for generating light, a plurality of optical sheets positioned on the lamp unit, and a housing member for accommodating the lamp unit and the plurality of optical sheets And a buffer member formed on a portion of the top surface and the outer surface of the bottom surface and the outer wall of the accommodation member.

Here, the buffer member is preferably formed on a part of the upper surface and the outer surface of the bottom surface and the outer wall of the housing member to be in contact with the flexible printed circuit board.

In addition, it is effective to use a shock absorbing material such as rubber, urethane, or sponge as the buffer member.

Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like numbers refer to like elements in the figures.

<First Embodiment>

1 is an exploded perspective view of a liquid crystal display according to a first exemplary embodiment of the present invention, FIG. 2 is a perspective view schematically showing a part of the liquid crystal display of FIG. 1, and FIG. 3 is a part of the liquid crystal display of FIG. 1. It is a simplified cross section.

1 to 3, the liquid crystal display according to the first exemplary embodiment of the present invention includes an edge type backlight and a display assembly 1000 disposed thereon as a liquid crystal display of a chip on glass (COG) mounting method. And a backlight assembly 2000 disposed below.

The display assembly 1000 includes a liquid crystal display panel 100, a driving circuit unit 200, and an upper accommodating member 300.

The liquid crystal display panel 100 includes a color filter substrate 110 and a thin firm transistor (TFT) substrate 120. At this time, the color filter substrate 110 is a substrate in which RGB pixels, which are color pixels in which a predetermined color is expressed while light passes, are formed by a thin film process. A common electrode made of a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on the front surface of the color filter substrate 110.

The TFT substrate 120 is a transparent glass substrate on which TFTs in matrix form are formed. The data line is connected to the source terminal of the TFTs, and the gate line is connected to the gate terminal. In addition, a pixel electrode made of a transparent electrode made of a transparent conductive material is formed in the drain terminal. When an electrical signal is input to the data line and the gate line, each TFT is turned on or turned off to apply an electrical signal necessary for pixel formation of the drain terminal. When the TFT is turned on by applying power to the gate terminal and the source terminal of the TFT substrate 120, an electric field is formed between the pixel electrode and the common electrode of the color filter substrate 110, thereby forming the TFT substrate 120 and the color. The arrangement of the liquid crystals injected between the filter substrates 110 is changed, and the light transmittance is changed according to the changed arrangement to obtain a desired image. At one edge of the TFT substrate 120, a plurality of pads and circuit patterns to be connected to an external circuit are formed. That is, a driving IC 111 for transmitting an image signal and a gate signal to a data line and a gate line, respectively, is provided, and the driving IC 111 or data line is electrically connected to an external driving circuit unit 200. And a plurality of metal pads extending from the gate line and exposing a portion of the ends thereof.

The driving circuit unit 200 connected to the liquid crystal display panel includes a printed circuit board 210 for mounting a control IC and applying predetermined data signals and gate signals to data lines and gate lines of the TFT substrate 120, and a printed circuit. And a flexible circuit board 230 for connecting between the substrate 210 and the TFT substrate 120. In the drawing, the printed circuit board 210 is formed on one side of the liquid crystal display panel to simultaneously apply an image signal and a gate driving signal, but the present invention is not limited thereto. It may be formed separately from the printed circuit board and the data-side printed circuit board.

The upper accommodating member 300 is bent at a right angle to prevent the components of the display assembly 1000 from being detached and to protect the liquid crystal display panel 100 or the backlight assembly 2000 which are fragile by an impact applied from the outside. It is manufactured in the form of a square frame having a flat portion and a side wall portion.

The backlight assembly 2000 may include a lamp unit 400, a light guide plate 500 coupled to the lamp unit 400, a reflector plate 600 disposed below the light guide plate 500, and a plurality of light guide plates 500. The lower sheet member 800 for receiving the optical sheet 700, the reflecting plate 600, the light guide plate 500, and the optical sheet 700, and the flexible circuit board 230. It is formed on the buffer member 900 to protect the flexible circuit board 230 from an external impact.

The lamp unit 400 is composed of a lamp 410 and a lamp clamp 411. The lamp 410 is effective to use a cold cathode ray tube lamp. In addition, the shape of the lamp 410 may be an I-shape as shown, and is not limited thereto, and may have various shapes such as an N-shape, an M-shape, and a meandering shape. The lamp clamp 411 reflects the light emitted radially from the cold cathode ray tube lamp in one direction to maximize the light utilization efficiency.

The light guide plate 500 is coupled to the lamp clamp 411 to change light having an optical distribution in the form of a line light source generated by the lamp unit 400 to light having an optical distribution in the form of a surface light source. As the light guide plate 500, a wedge type plate or a parallel flat plate may be used.

As the reflecting plate 600, a plate having a high light reflectance is used, which is installed to contact the bottom surface of the lower housing member 800. Although the reflective plate 600 is illustrated as having a flat shape in the drawing, the reflective plate 600 may be manufactured in a curved shape having a reference reflective surface and a triangular protrusion protruding from the reference reflective surface. In addition, the reflective plate 600 may be omitted by forming a material having excellent reflection efficiency on the bottom surface of the lower housing member 800.

The optical sheet 700 is disposed on the light guide plate 500 to uniform the luminance distribution of the light emitted from the light guide plate 500.

The lower accommodating member 800 is formed in a box shape of a rectangular parallelepiped in which an upper surface is opened, and an accommodating space having a predetermined depth is formed therein. The lower accommodating member 800 includes a bottom surface and sidewalls extending vertically from each edge from the bottom surface.

The buffer member 900 is positioned between the lower accommodating member 800 and the flexible circuit board 230 bent downward from the upper accommodating member 800. In the present embodiment, the buffer member 900 is formed on at least a portion of the upper surface and the outer surface and the bottom surface of the side wall of the lower housing member 800. In the drawing, the buffer member 900 having a predetermined thickness and width is formed on the top, outer and bottom surfaces of the sidewalls on which the flexible circuit board is bent, but is not limited thereto. The buffer member 900 may be formed only at least in part. As the buffer member 900, it is preferable to use a shock absorbing material such as rubber, urethane, or sponge. In the present exemplary embodiment, the shock absorbing material is bonded onto the lower housing member 900 by using a predetermined adhesive, double-sided tape, or screws. However, the present invention is not limited thereto, and the shock absorbing material may be bonded to the lower portion of the flexible circuit board 230.

When fabricating the liquid crystal display device by assembling the display assembly 1000 and the backlight assembly 2000 as described above, the printed circuit board 210 is backlit by bending the flexible circuit board 230 to reduce the size of the liquid crystal display device. Place it to the rear of the assembly 2000. At this time, when the display assembly 1000 and the backlight assembly 2000 are assembled, the shock absorbing on the rear surface of the flexible circuit board 230 is absorbed by the buffer member 900 formed in the lower accommodating member 800.

Hereinafter, the structure of the buffer member formed between the overlapping region of the lower housing member and the flexible circuit board will be described in detail with reference to the accompanying drawings. 2 and 3 illustrate a thick thickness of the flexible printed circuit board 230 for convenience of description. In addition, although the printed circuit board 210 is bent by 90 degrees in the direction of arrow A in FIG. 2, the shape before the bending is shown here for convenience.

2 and 3, in the liquid crystal display according to the present invention, a shock absorbing material buffer member 900 is formed between the lower housing member 800 and the flexible circuit board 230 to absorb shock from the outside. This prevents damage to the flexible circuit board 230.

First, the flexible circuit board 230 of the present invention includes a base film that is flexible and easily bent, and a plurality of metal wires for conducting an electrical signal by patterning a conductive material on the base film. The metal wiring includes a plurality of ground wires and a plurality of input / output wires for inputting and outputting a predetermined signal. The input / output wiring includes a data wiring for transmitting a data signal, a clock wiring for transmitting a clock signal, and a voltage wiring for transmitting a power supply voltage. The apparatus may further include a dummy wiring to which a signal is not input.

One end of the metal wiring of the flexible circuit board 230 is connected to the pad of the liquid crystal display panel 100, and the other end of the metal wiring is connected to the printed circuit board 210. Meanwhile, the buffer member 900 is formed along the outer surface of the lower housing member 800 in the region to which the flexible circuit board 230 is connected. Preferably, as shown in (a) of FIG. 3, it is effective to form the shock absorbing member 900 in a region where the flexible circuit board 230 and the lower accommodating member 800 overlap. Of course, as shown in (b) of FIG. 3, the cushioning member 900 formed in a region where two surfaces of the lower housing member 800 meet and form a right angle is curved (see (b) and K region of FIG. 3). When the flexible circuit board 230 is bent, damage such as breaking of the metal wiring inside the flexible circuit board 230 may be reduced. Thereafter, the flexible circuit board 230 is refracted as shown in the drawing to place the printed circuit board 230 on the bottom surface of the lower housing member 800. In addition, a buffer member 901 may be further formed between the upper accommodating member 300 and the flexible circuit board 230 to absorb the shock due to the pressure when the constant accommodating member 300 is coupled.

Although the liquid crystal display device having the edge type backlight assembly is illustrated in the first embodiment, the connection method of the present invention is not limited thereto and may be applied to liquid crystal display devices having various shapes. For example, a separate conductive frame for supporting the liquid crystal display panel may be further included, and the configuration of the lamp may also be formed in a direct type. In the following, an example of such a possibility will be described with reference to the drawings. In this case, description overlapping with the above-described embodiment will be omitted.

Second Embodiment

4 is an exploded perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention. Since the second embodiment is the same as the first embodiment except that the backlight assembly is a direct type and the mold frame is disposed below the liquid crystal display panel, the second embodiment will be described based on the backlight assembly and the mold frame.

Referring to FIG. 4, the backlight assembly 2000 according to the present exemplary embodiment includes a lamp unit 400 for generating light, a reflector plate 600 disposed under the lamp unit 400, and an upper portion of the lamp unit 400. A diffuser plate 720 and an optical plate 710 disposed thereon, and a lower housing member 800 for accommodating the reflector plate 600, the lamp unit 400, the diffuser plate 720, and the optical plate 710. do.

The lamp unit 400 includes a plurality of bar lamps 410 arranged in parallel, a plurality of lamp fixing parts 420 for fixing the lamps, and a lamp support part 430 in which the plurality of lamp fixing parts 420 are accommodated. ). The plurality of lamps 410 mainly use a cold cathode fluorescent lamp, each of the lamps 410 is composed of a glass tube, the inert gas contained in the glass tube, the negative electrode and the positive electrode is provided at both ends of the glass tube. Each of the lamp fixing parts 420 includes a base substrate on which one end of the lamp 410 is seated, and a fixing clip and a fixing protrusion for protruding from the base substrate to fix the lamp. The lamp support 430 includes a bottom surface on which the plurality of lamp fixing parts 420 are mounted and a sidewall extending vertically from the bottom surface. In this case, the lamp fixing part 420 may be formed of a conductive material to apply power to the electrode of the lamp 410. In this case, the lamp support part 430 is formed of an insulating material to electrically insulate the electrode of the lamp 410 from the lower housing member 800.

The reflector plate 600 includes a reflective bottom surface at which the lamp 410 is positioned at an upper portion thereof, and first and second reflective inclined surfaces having predetermined slopes from the reflective bottom surface at edges corresponding to opposite sides of the lamp unit 400. Include. The reflective plate 600 may be attached to the lower accommodating member 800 by an adhesive, a double-sided adhesive tape, or may be fastened to the lower accommodating member 800 by using a screw.

The diffusion plate 720 directs the light incident from the plurality of lamps toward the front of the liquid crystal display panel 100 and diffuses the light to have a uniform distribution in a wide range to irradiate the liquid crystal display panel 100. The plate 710 serves to change the light incident at an oblique angle among the light incident to the optical plate 710 to be emitted vertically.

The lower accommodating member 800 is formed in a box shape of a rectangular parallelepiped with an upper surface open, and an accommodating space having a predetermined depth is formed therein. That is, the lower accommodating member 800 includes a bottom surface and first to fourth sidewalls which protrude vertically at each edge from the bottom surface. Further, the first and third side walls facing each other located on opposite sides of the outermost lamp are further formed with first and second inclined surfaces inclined at a predetermined angle therefrom and extending toward the bottom surface. In addition, a stepped stepped surface is formed at an upper end between the first and third sidewalls and the first and second inclined surfaces. Thus, the bottom surface and the inclined surface of the reflecting plate 600 are located on the bottom surface and the inclined surface of the lower housing member 800, respectively, and the diffusion plate 720 and the optical plate 710 may be sequentially mounted on the stepped step surface. have.

Here, the buffer member 900 may be disposed on the upper and outer surfaces of the sidewalls having a region overlapping the flexible circuit board 230 among the first to fourth sidewalls of the lower accommodating member 800, and a part of the bottom surface adjacent to the sidewalls. Form. Of course, the buffer member 900 may be formed on the upper and outer surfaces of the first to fourth sidewalls and a part of the bottom surface of the lower housing member. As described in the foregoing embodiment, the buffer member 900 is formed in a region between the lower housing member 900 and the flexible circuit board 230 to protect the flexible circuit board 230 from damage from external shock.

In addition, the conductive mold frame 350 is formed in a rectangular frame shape and includes a flat portion and sidewall portions bent at right angles therefrom. In addition, as shown in the drawing, a mounting portion, such as a fixing protrusion for connecting and aligning each of the edge side surfaces of the liquid crystal display panel 100 to form an alignment position, is formed on the flat portion to mount the liquid crystal display panel 100. The seating portion may be formed using a predetermined stepped step surface. The optical plate 710, the diffusion plate 720, the lamp unit 400, and the reflecting plate 600 are fixed to the conductive mold frame 350 with the lower chassis 800. Here, when the flexible circuit board 230 is connected to the conductive mold frame 350, a buffer member 900 may be formed between the conductive mold frame 350 and the flexible circuit board 230.

The upper chassis 300, the liquid crystal display panel 100, the mold frame 900, and the backlight assembly 2000 are assembled to manufacture a liquid crystal display device.

In the above embodiments, a COG (chip on glass) mounting liquid crystal display device is exemplified. However, the present invention is not limited thereto, and the present invention may be applied to a liquid crystal display device having a tape-automated bonding (TAB) mounting method, and a flexible circuit. A buffer member may be formed below the substrate. In the following, an example of such a possibility will be described with reference to the drawings. In this case, description overlapping with the above-described embodiments will be omitted.

Third Embodiment

5 is an exploded perspective view of a liquid crystal display according to a third exemplary embodiment of the present invention, and FIG. 6 is a perspective view schematically illustrating a part of the liquid crystal display of FIG. 5.

5 and 6, the liquid crystal display according to the present exemplary embodiment includes a display assembly 1000 having an edge type backlight and a tab-automated bonding (TAB) mounting type liquid crystal display device disposed thereon, and a lower portion thereof. It includes a backlight assembly 2000 disposed in.

The display assembly 1000 includes a liquid crystal display panel 100, a driving circuit unit 200, and an upper chassis 300. The liquid crystal display panel 100 includes a color filter substrate 110 and a TFT substrate 120.

The driving circuit unit 200 includes a predetermined IC, and includes a printed circuit board 210, a printed circuit board 210, which controls a signal applied to a gate line and a drain line of a thin film transistor of the TFT substrate 120. And a flexible circuit board 230 for electrically connecting the TFT substrate 120. At this time, the flexible circuit board 230 is equipped with a tap (TAB) IC 232, RGB (Read, Green, Blue) signal, SSC (Shift Start Clock) signal, LP generated from the printed circuit board 210 A latch pulse signal, a gamma analog ground signal, a digital ground signal, a digital power supply, a common voltage of an analog power supply, a stored voltage, and the like are transmitted to the liquid crystal display panel 100.

In this case, the buffer member 900 is formed under the flexible circuit board 230, so that the flexible circuit board 230 may be protected from an external shock. It is preferable to attach the shock absorbing material such as rubber, urethane, sponge, or the like to the lower portion of the flexible circuit board 230 using a predetermined adhesive or a double-sided tape as the buffer member 900. In addition, the present invention is not limited thereto, and the buffer member 900 may be attached to the upper portion of the flexible circuit board to protect the flexible circuit board 230.

As described above, a shock absorbing member may be disposed between the flexible circuit board and the lower housing member of the backlight assembly to prevent damage to the flexible circuit board.

As described above, the liquid crystal display according to the present invention may prevent damage to the flexible circuit board by providing a shock absorbing member between the flexible circuit board and the lower housing member of the backlight assembly.

Although the invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the invention is not limited thereto, but is defined by the claims that follow. Accordingly, one of ordinary skill in the art may variously modify and modify the present invention without departing from the spirit of the following claims.

Claims (11)

A liquid crystal display panel which displays an image; A backlight unit radiating light onto the liquid crystal display panel; An accommodation member accommodating the liquid crystal display panel and the backlight unit; A printed circuit board applying a signal to the liquid crystal display panel and positioned on an outer bottom surface of the housing member; A flexible circuit board having a conductive path for connecting the printed circuit board and the liquid crystal display panel; And And a buffer member formed between the flexible circuit board and the housing member. The method according to claim 1, And a shock absorbing material such as rubber, urethane, or sponge as the buffer member. The method according to claim 1, And the buffer member is formed on the housing member in contact with the flexible circuit board. The method according to claim 1, The buffer member is formed above or below the flexible circuit board. The method according to claim 1, The buffer member is attached to the liquid crystal display using an adhesive or double-sided tape. The method according to claim 1, And a driving circuit formed on the flexible circuit board. The method according to claim 1, And a driving circuit formed on the liquid crystal display panel. The method according to claim 1, The flexible circuit board is bent, and the buffer member positioned below the bent region has a predetermined curved surface. In the backlight assembly for a liquid crystal display device, A lamp unit for generating light; A plurality of optical sheets positioned on the lamp unit; An accommodation member accommodating the lamp unit and the plurality of optical sheets; And And a buffer member formed on a portion of the top surface and the outer surface of the bottom surface and the outer wall of the accommodation member. The method according to claim 9, The buffer member is formed on a portion of the top surface and the outer surface of the bottom surface and the outer wall of the housing member to be in contact with the flexible printed circuit board. The method according to claim 9, The buffer member is a backlight assembly using a shock absorbing material, such as rubber, urethane, sponge.

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