KR20060112142A - Flat panel display apparatus - Google Patents

Abstract

A flat display device is provided to improve the grounding structure of a control PCB(Printed Circuit Board), thereby easily grounding the control PCB, by optimizing contact portions of a grounding member which grounds the control PCB. A backlight assembly(20) has a reflective sheet(27). A first grounding element(28) is formed on a lower surface of the reflective sheet. A control PCB(40) controls a flat display panel(10). The control PCB has a second grounding element(44) disposed on a rear surface of the reflective sheet and contacted with the first grounding element. A chassis(30) supports the flat display panel and the backlight assembly. A grounding member(52) grounds the control PCB, and has a first contact portion contacted with the first grounding element and a second contact portion contacted with the chassis.

Description

Flat panel display device {FLAT PANEL DISPLAY APPARATUS}

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

2 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: liquid crystal panel 15: FPC

20: backlight assembly 22: lamp unit

24: LGP 26: Optical sheet

27: reflective sheet 28: first ground portion

30: chassis 40: control PCB

44: second ground portion 46: PCB cover

50: attachment member 52: ground member

The present invention relates to a flat panel display device, and more particularly, to a flat panel display device with an improved grounding structure of a control PCB.

In recent years, display devices have been replaced by flat panel displays in place of the CRT (Cathode Ray Tube), which is heavy, thick, and consumes a lot of power, and flat display devices include liquid crystal displays (LCDs) and plasma (PDPs). Display panel), VFD (Vacuum Fluorescent Display), FED (Field Emission Display) and ELD (Electro Luminescence Display).

Among such flat panel display devices, the liquid crystal display includes a liquid crystal panel having a thin film transistor substrate on which a thin film transistor is formed and a color filter substrate on which a color filter layer is formed, and a liquid crystal layer is positioned between the thin film transistor substrate and the color filter substrate. have. Since the liquid crystal panel is a non-light emitting device, a backlight assembly for irradiating light may be disposed on the rear surface of the thin film transistor substrate.

In addition, the liquid crystal panel includes a control PCB for controlling the liquid crystal panel and a drive driver IC for driving each pixel by the control PCB, and TAB (Tale Automated Bonding) is largely implemented by mounting the drive driver IC on the thin film transistor substrate and the control PCB. ) And COG (Chip On Glass) methods have been developed.

In the TAB method, the drive drive IC is mounted on a medium called a flexible data carrier package, and then both ends of the tape carrier package are mounted on the thin film transistor substrate and the control PCB, and the control PCB is bent on the back of the thin film transistor substrate. .

The COG method mounts a direct drive IC on the end of a gate line and a data line formed on a thin film transistor substrate by a flip chip method, and then thin film transistors at both ends of a flexible printed circuit (FPC). It is a way to connect the board and control PCB.

In the control PCB, electromagnetic interference (EMI), which causes deterioration of the screen, occurs when the LCD is operated. The control PCB is placed at a predetermined position of the flat panel display module to remove such EMI. Ground.

In general, the control PCB has been fixed and grounded by providing a conductive ground part of the control PCB and fastening it to the flat panel display module through a screw. Recently, as mass production of screwless products is made, a method of fixing and grounding a control PCB to a flat panel display panel by attaching aluminum tape instead of screws is being used. In the attaching process of the aluminum tape, the adhesion is not properly made, or a problem occurs that is easily separated after the attachment, and the noise is caused by the uneven adhesion.

Accordingly, it is an object of the present invention to provide a flat panel display device capable of easily grounding a control PCB.

The above object is, according to the present invention, a flat panel on which an image is displayed; A backlight assembly including a reflective sheet having a first ground portion of a conductive material on a lower surface thereof; A control PCB controlling the flat panel and having a second ground portion of a conductive material disposed on a rear surface of the reflective sheet and in contact with the first ground portion; A chassis supporting the flat panel and the flat panel backlight assembly; It is achieved by a grounding member having a first contact portion in contact with the first grounding portion and a second contact portion in contact with a predetermined area of the chassis and grounding the control PCB.

The control PCB includes one component mounting surface on which circuit components are mounted, and the second ground portion is provided on a rear surface of the component mounting surface. This is just one example for easily providing a second ground portion. In the case of a control PCB having circuit components mounted on both sides, a ground portion is formed in a predetermined region of a surface contacting the bottom chassis. The ground portion may be provided by exposing the copper foil of the control PCB, or may be formed by printing a separate pattern having a conductive material. When circuit components are mounted on only one side of the control PCB, there is an effect of facilitating the exposure or pattern formation of the copper foil.

It further includes a conductive attachment member positioned between the first ground portion and the second ground portion to attach the first ground portion and the second ground portion to each other, thereby enhancing the adhesive force between the control PCB and the bottom chassis. By connecting the branch and the second ground portion with a conductive material, the control PCB can be efficiently grounded. Such an attachment member is not an essential component and may be selectively provided for strengthening the adhesive force if any part of the ground portion or the contact portion has the adhesive force. The attachment member may be a conductive double-sided tape.

The ground member has a 'c' shape, and may be characterized by surrounding the side of the chassis and is generally made of a clip type. The structure of the grounding member is not limited to the 'c' shape, and may be connected to the second ground portion of the reflective sheet so as to contact any part of the chassis. Accordingly, the ground member may be a conductive tape. In the case of the conductive tape, since the ground member is directly attached to the chassis, the configuration is simple and the design is easy.

It is coupled to the chassis with the control PCB interposed therebetween, having a PCB cover to protect the control PCB to protect the circuit components exposed to the outside, and coupled with the chassis serves to firmly support the control PCB.

The flat panel may be a liquid crystal panel, and the shape and arrangement of the components may be variously modified according to the type of notebook, television, and desktop.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

The flat panel display device includes a liquid crystal display (LCD), a plasma display panel (PDP), a vacuum fluorescent display (VFD), a field emission display (FED), and an electroluminescence display (ELD).

Among such flat panel display devices, a liquid crystal display device applies a voltage to a specific molecular array of liquid crystals and converts the same into another molecular array, and the optical properties such as the birefringence, the photoluminescence, the dichroism, and the light scattering characteristics of the liquid crystal cell emitted by the molecular array It is a flat panel display device which converts a change of property into a visual change and uses modulation of light by a liquid crystal cell.

ELD is a flat panel display device that uses EL (Electro-Luminance) phenomenon, which generates light when a certain electric field is applied to a phosphor, and is classified into AC and DC powder type, AC and DC thin film type according to the type and driving method of the phosphor. to be.

The liquid crystal display of the chip on glass (COG) type of the flat panel display device of the present invention will be described as an example.

1 is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the liquid crystal display.

As shown, the liquid crystal display includes a liquid crystal panel 10 including an image, a backlight assembly 20 including a reflective sheet 27 having a first ground portion 28 of a conductive material on a lower surface thereof, and a liquid crystal panel. The control PCB 40, the liquid crystal panel 10, and the backlight assembly 20 which are connected to one edge of the side 10 and have a second ground portion 44 made of a conductive material in contact with the first ground portion 28. It includes a supporting chassis 30 and the first ground portion 28 and a ground member 52 in contact with a predetermined region of the chassis to ground the control PCB (40).

The liquid crystal panel 10 includes a thin film transistor substrate 11 having a switching element, a pixel electrode, and the like, a color filter substrate 12 having a color filter, and a liquid crystal layer 13 disposed between both substrates. The edge between the thin film transistor substrate 11 and the color filter substrate 12 is fixed by the sealant 14, and the sealant 14 allows the liquid crystal layer 13 to be preserved between the two substrates.

The image signal is applied to a transistor of the thin film transistor substrate 11 through a drive driver IC such as a source side drive IC and a gate side drive IC of the thin film transistor substrate 11, whereby the liquid crystal receives an electrical signal and the backlight assembly ( The light from 20) is adjusted to compose the screen. Here, the drive driver IC is directly mounted at the end of the gate line and the data line formed on the thin film transistor substrate 11, and the thin film transistor substrate 11 and the both ends of the flexible printed circuit (FPC) 15 are mounted. The control PCB 40 is connected.

The backlight assembly 20 is disposed at the rear of the liquid crystal panel 10 to provide uniform light to the liquid crystal panel 10, and the backlight assembly 20 is disposed in parallel to the rear surface of the liquid crystal panel 10. And a lamp unit 22 disposed along at least one side of the light guide plate 24 to supply light, and provided on the front surface of the light guide plate 24 to diffuse and focus light toward the liquid crystal panel 10. It consists of the optical sheet 26 and the reflective sheet 27 which is provided in the back surface of the light guide plate 24, and has a contact part of a conductive material in the lower surface.

The lamp unit 22 is composed of a lamp 22a for emitting light and a lamp reflecting plate 22b for reflecting light emitted from the lamp 22a in the opposite direction of the light guide plate 24 toward the light guide plate 24. The liquid crystal display according to the present exemplary embodiment uses an edge method in which the lamp 22a is provided on the side of the liquid crystal panel 10. Although not shown, the lamp 22a is connected to the inverter to receive power.

The light guide plate 24 has an entrance surface receiving light from the lamp 22a, an exit surface parallel to the liquid crystal panel at right angles to the entrance surface, and light irradiated from the lamp 22a to the entrance surface to the exit surface. The pattern has a backside formed. Accordingly, the light guide plate 24 changes the light emitted from the lamp 22a disposed along one side of the light guide plate 24, that is, adjacent to the incident surface, to the incident surface into planar light, and then emits the liquid crystal panel 10 through the emission surface. To be delivered uniformly. As the material of the light guide plate 24, PMMA (Polymethylmethacrylate) having high strength does not easily deform or break and has a good transmittance.

The optical sheet 26 is a diffusion sheet that partially diffuses light from the light guide plate 24 to the liquid crystal panel 10 to diffuse light so that spots do not occur in the liquid crystal panel 10, thereby further improving the uniformity of light. And a prism sheet for improving the luminance by allowing the light passing through the diffusion sheet to proceed vertically. In addition, it may further include a protective sheet for protecting the diffusion sheet and the prism sheet sensitive to dust and scratches and to prevent the external impact or foreign substances from entering.

The reflective sheet 27 reflects the light transmitted through the light guide plate 24 in the opposite direction of the liquid crystal panel 10 back to the light guide plate 24, thereby reducing the loss of light and from the light guide plate 24 toward the liquid crystal panel 10. It contributes to improving the uniformity of the light transmitted through. The reflective sheet 27 according to the present exemplary embodiment includes a first ground portion 28 made of a conductive material on a lower surface thereof, which is in contact with the second ground portion 44 of the control PCB 40. The reflective sheet 27 is connected to the ground member 52 through the first ground portion 28 to ground the control PCB 40.

The first ground portion 28 is mainly formed in such a manner that the conductive material is printed, and may have a predetermined pattern form. A portion of the first ground portion 28 is in contact with the ground member 52 and connected to the chassis 30 serving as the ground of the liquid crystal display device.

The chassis 30 supports the front edge of the backlight assembly 20 and the liquid crystal panel 10, and is connected to the control PCB 40 through the ground member 52. Supporting each structure with one chassis 30 as in this embodiment is a structure that is usually applied to a notebook, and the structure of the display device used for a personal PC or TV is different from this. However, in any structure, it is common to contact the chassis 30 with the ground member 52 for grounding the control PCB 40.

Therefore, although not shown, in addition to the chassis 30, the bottom chassis may further include a mold frame or backlight assembly 20 supporting the edges of the liquid crystal panel 10 and the backlight assembly 20.

The control PCB 40 is connected to the driving drive IC by the FPC 15 and controls the liquid crystal panel 10 as a whole by controlling the image signal transmitted to the driving drive IC. The control PCB 40 includes a component mounting surface (not shown) on which the circuit component 42 is mounted, and a back surface 40b of the mounting surface on which the second ground portion 44 is formed.

Recently, in order to prevent white spots generated during the test due to the circuit component 42, a top mounting model for exposing a component mounting surface on which the circuit component is mounted on the back surface of the backlight assembly 20 has been developed. In other words, the control PCB 40 shown in FIG. 1 is bent to the rear of the backlight assembly 20 by the FPC 15 in the module process in which the liquid crystal panel 10 is assembled, and the rear surface 40b of the mounting surface is The back surface of the reflective sheet 27 comes into contact. Conventionally, since the second ground part 44 is formed on the component mounting surface, space constraints on using the remaining space where the circuit component is not mounted have been followed. However, by forming the second ground portion 44 on the rear surface 40b of the mounting surface as in the present invention, the ground space is easily secured. The control PCB 40 has a double-sided PCB on which circuit components are mounted on both front and rear surfaces, and a single-sided PCB on which circuit components 42 are mounted on only one surface. In this embodiment, a single-sided PCB is shown as an example. . That is, it is also possible to use a double-sided PCB if necessary, in this case, the second ground portion 44 is formed in a predetermined region of the control PCB back surface 40b in contact with the back surface of the reflective sheet 27.

The second ground portion 44 is formed on the rear surface 40b of the control PCB 40 and is made of a conductive material. The second ground portion 44 may form a conductive pattern printed on the first ground portion 28 of the reflective sheet 27, and may not include a separate configuration by exposing the copper foil portion of the control PCB 40. have. Exposure of the copper foil is achieved by removing the coating covering the control PCB 40.

The PCB cover 46 is coupled to the chassis 30 with the control PCB 40 interposed between the rear side of the control PCB 40 to protect the circuit components 42 mounted on the control PCB 40. Here, the PCB cover 46 is formed of a rear surface that blocks the rear surface of the control PCB 40 to protect the control PCB 40 and the side surface that is bent from the rear surface to contact the edge of the chassis 30, the chassis 30 may be connected with a contact tape or a screw.

The attachment member 50 is provided between the second ground portion 44 of the control PCB 40 and the first ground portion 28 of the reflective sheet 27 to couple the two to each other. Tape is mainly used. If any pattern printed on the second ground portion 44 or the first ground portion 28 has adhesiveness, the attachment member 50 is not necessarily a component to be provided, and the control PCB 40 It may optionally be provided for the reinforcement of the adhesion.

The ground member 52 has a first contact portion in contact with the first ground portion 28 and a second contact portion in contact with a predetermined region of the chassis to ground the control PCB 40. The grounding member 52 surrounds the chassis 30 in a 'c' shape of a clip type and may be made of metal or formed by a press molding method.

In addition, the height of the ground member 52 is preferably included in the chassis 30. That is, the fact that the ground member 52 does not protrude from the chassis 30 may prevent the size of the liquid crystal display device from increasing or the contact of the ground member 52 with other components.

As shown in FIG. 2, the liquid crystal display device includes a liquid crystal panel 10, an optical sheet 26, a light guide plate 24, and a reflective sheet 27, which are sequentially stacked on the rear surface of the reflective sheet 27. PCB 40 is located. 2 shows a cross-sectional view of a portion in which the ground member 52 is formed in FIG. 1, so that the lamp unit 22 and the FPC 15 are not shown.

The first ground portion 28 formed on the reflective sheet 27 is connected by the second ground portion 44 formed on the rear surface 40b of the control PCB 40 and the attachment member 50, and the first ground portion ( 28 is in contact with the chassis 30 through the 'c'-shaped ground member 52 surrounding the chassis 30.

According to another embodiment of the present invention, the grounding member 52 may be a conductive tape rather than a metal or a molding. When the ground member 52 is a conductive tape, there is no need for a separate structure, for example, a shape such as a clip type, to be fixed to the chassis 30, and there is an effect of supporting the control PCB 40 due to the adhesiveness of the tape.

Although some embodiments of the invention have been shown and described, those of ordinary skill in the art will appreciate that by improving the grounding structure of the control PCB without compromising the principles or spirit of the invention, the grounding force is enhanced. It will be appreciated that embodiments may be modified. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a flat panel display device capable of easily grounding a control PCB is provided.

Claims (8)

A flat panel on which an image is displayed; A backlight assembly including a reflective sheet having a first ground portion of a conductive material on a lower surface thereof; A control PCB controlling the flat panel and having a second ground portion of a conductive material disposed on a rear surface of the reflective sheet and in contact with the first ground portion; A chassis supporting the flat panel and the flat panel backlight assembly; And a grounding member having a first contact portion in contact with the first ground portion and a second contact portion in contact with a predetermined area of the chassis, and a ground member for grounding the control PCB. The method of claim 1, The control PCB includes a component mounting surface on which a circuit component is mounted, and the second ground portion is provided on the rear surface of the component mounting surface. The method of claim 1, And a conductive attachment member positioned between the first ground portion and the second ground portion to attach the first ground portion and the second ground portion to each other. The method of claim 3, And said attachment member is a conductive double-sided tape. The method of claim 1, The grounding member has a 'c' shape, the flat panel display device characterized in that to surround the side of the chassis. The method of claim 1, And said grounding member is a conductive tape. The method of claim 1, And a PCB cover coupled to the chassis with the control PCB therebetween to protect the control PCB. The method according to any one of claims 1 to 7, And the flat panel is a liquid crystal panel.

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