KR20060078870A - A flat display device for shielding emi - Google Patents

Abstract

The present invention relates to a flat panel display for EMI shielding. To this end, the flat panel display device according to the present invention is a flat panel display panel for displaying an image, a flexible printed circuit board that is electrically connected to the flat panel display panel and transmits a driving signal to the flat panel display panel, a flat printed circuit board A control board that provides a driving signal for driving the display panel, and a shield case that covers and protects the control board and has a insertion hole for inserting a flexible printed circuit board to be connected to the control board. Here, the insertion hole is formed in close proximity to surround the flexible printed circuit board.

EMI, shield case, flexible printed circuit board, shielded

Description

Flat display device for EMI shielding {A FLAT DISPLAY DEVICE FOR SHIELDING EMI}

1 is an exploded perspective view of a flat panel display device according to an exemplary embodiment of the present invention.

2 is a rear perspective view of a flat panel display device according to an exemplary embodiment of the present invention.

FIG. 3 is an enlarged view of a shield case seen at point A of FIG. 2.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display for shielding electromagnetic shielding (EMI), and more particularly, to a flat panel display for shielding EMI by modifying a structure of a shield case that houses a control board. It is about.

With the recent rapid development of semiconductor technology, the demand for liquid crystal display devices having improved performance while being smaller and lighter is exploding.

Recently, liquid crystal displays (LCDs), which have been in the spotlight, have advantages such as miniaturization, light weight, and low power consumption, and as an alternative means to overcome the disadvantages of the conventional cathode ray tube (CRT). It has been attracting attention and is currently used in almost all information processing equipment that requires a display device.

A general liquid crystal display device applies voltage to a specific molecular array of a liquid crystal to convert it into another molecular array, and visually changes optical properties such as birefringence, photoreactivity, dichroism, and light scattering characteristics of the liquid crystal cell emitted by the molecular array. It is a light-receiving display device which converts into a change and displays information using the modulation of the light by a liquid crystal cell.

In the case of such a liquid crystal display, a driving signal is applied from a printed circuit board (PCB) electrically connected to a thin film transistor (TFT) substrate. The printed circuit board is again electrically connected to a flexible printed circuit board (FPC board) to receive a driving signal for the liquid crystal display panel generated from a control board.

Since the flexible printed circuit board is bent to secure a certain amount of fluidity in order to connect the printed circuit board and the control board, the flexible printed circuit board is exposed to the outside of the liquid crystal display without being separately shielded. In addition, since the flexible printed circuit board is thin and fastened to a connector mounted on the control board in a clamp type, misalignment may occur when fastening and fastening the fastening fixing part. Exposed to the outside.

Such a structure prevents the shielding of EMI generated at the connection area between the flexible printed circuit board and the control board. Therefore, EMI causes many problems such as excitation of malfunctions of other components mounted on a printed circuit board.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and to provide a flat panel display device having a shield case having a structure capable of shielding EMI.

A flat panel display device according to the present invention for achieving the above object, a flexible printed circuit board that is electrically connected to the flat panel display panel for displaying an image, and transmits a drive signal to the flat panel display panel , FPC board), a control board connected to the flexible printed circuit board to provide a driving signal for driving the flat panel display panel, and a cover to protect the control board and insert the flexible printed circuit board to connect with the control board. It includes a shield case (shield case) formed with an insertion hole to be. Here, the insertion hole is formed in close proximity to surround the flexible printed circuit board.

The insertion hole is preferably formed on one side of the shield case.

An opening may be formed in the shield case to fasten and fix the flexible printed circuit board to the control board.

A connector for fastening and fixing the flexible printed circuit board to the control board is mounted, and the connector may be exposed to the outside through an opening formed in the shield case.

It is preferable that the plate member for sealing the opening formed in the shield case is attached.

It is preferable that a plate member consists of aluminum or magnesium.

The flat panel display device according to the present invention further includes a backlight assembly for supplying light to the flat panel display panel, and the shield case is preferably seated and fixed on the backlight assembly.

Here, the flat panel display panel may be a liquid crystal display panel.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3. These embodiments of the present invention are merely for illustrating the present invention, but the present invention is not limited thereto.

1 is an exploded perspective view of a flat panel display device 100 according to an exemplary embodiment of the present invention, in which a plurality of light sources 76 are arranged side by side toward a liquid crystal display panel 50 that is a flat panel display panel. Indicates.

Although the liquid crystal display panel 50 is shown as an example of a flat panel display panel in FIG. 1, this is merely to illustrate the present invention, and the present invention is not limited thereto. Therefore, the present invention can be applied to other flat panel display panels. In particular, although FIG. 1 shows a backlight assembly 70 required for a light receiving flat panel display panel, this is merely to illustrate the present invention, and the present invention is not limited thereto. Therefore, the present invention can be applied to a self-luminous flat panel display panel such as an organic light emitting diode (OLED) that does not use a backlight assembly. In addition, the structure of the flat panel display device 100 shown in FIG. 1 is only for illustration of this invention, Comprising: This invention is not limited to this. Therefore, the present invention can be applied to flat panel display devices having other structures.

The flat panel display device 100 shown in FIG. 1 includes a backlight assembly 70 for supplying light and a liquid crystal display panel 50 for displaying an image corresponding to the light. In addition, it includes a top chassis 60 for holding and holding the liquid crystal display panel 50 on the backlight assembly 70, and may include other necessary parts.

The backlight assembly 70 supplies light to the liquid crystal display panel 50 and guides the light to improve brightness, and the liquid crystal display panel assembly 40 positioned on the backlight assembly 70 displays an image. Control 50.

The liquid crystal display panel assembly 40 includes a liquid crystal display panel 50, a chip on film (COF) 43 and 44 connected to the liquid crystal display panel 50 to drive the liquid crystal display panel 50, and printing. And circuit boards 41 and 42. The liquid crystal display panel 50 includes a TFT substrate 51 composed of a plurality of TFTs (thin film transistors), a color filter substrate 53 positioned on the TFT substrate 51, and a liquid crystal (injected therebetween). Not shown). Polarizing plates (not shown) are attached to the upper portion of the color filter substrate 53 and the lower portion of the TFT substrate 51 to polarize light.

The TFT substrate 51 is a transparent glass substrate on which a matrix thin film transistor is formed, a data line is connected to a source terminal, and a gate line is connected to a gate terminal. In the drain terminal, a pixel electrode made of transparent indium tin oxide (ITO) as a conductive material is formed.                     

When electrical signals are input from the printed circuit boards 41 and 42 to the data lines and the gate lines of the liquid crystal display panel 50 described above, electrical signals are input to the source terminal and the gate terminal of the TFT, respectively. According to the input of the TFT, the TFT is turned on or turned off so that an electrical signal necessary for pixel formation is output to the drain terminal.

On the other hand, the color filter substrate 53 is disposed thereon opposite the TFT substrate 51. The color filter substrate 53 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, and a common electrode made of ITO is coated on the entire surface thereof. When power is applied to the gate terminal and the source terminal of the TFT and the thin film transistor is turned on, an electric field is formed between the pixel electrode and the common electrode of the color filter substrate. By this electric field, the arrangement angle of the liquid crystal injected between the TFT substrate 51 and the color filter substrate 53 is changed, and the light transmittance is changed according to the changed arrangement angle to obtain a desired pixel.

In order to control the alignment angle of the liquid crystals and the timing at which the liquid crystals are arranged in the liquid crystal display panel 50, a driving signal and a timing signal are applied to the gate line and the data line of the TFT, and the timing of applying the gate driving signal and the data driving signal is determined. COFs 43 and 44 are attached to determine this.

The gate PCB 41 for receiving a video signal from the outside of the liquid crystal display panel 50 and applying a driving signal to the gate line is connected to the gate COF 43 attached to the liquid crystal display panel 50. In addition, the data PCB 42 for applying the driving signal to the data line is connected to the flexible printed circuit board 48 to receive the driving signal and is connected to the data COF 44 attached to the liquid crystal display panel 50. To transmit the drive signal. The PCBs 41 and 42 generate data signals for driving the flat plate market value 100, gate driving signals, and a plurality of driving signals for applying these signals at appropriate times to generate the gate driving signals and the data driving signals. The COFs 43 and 44 are applied to the gate line and the data line of the liquid crystal display panel 50, respectively.

The backlight assembly 70 is provided below the liquid crystal display panel assembly 40 to provide uniform light to the liquid crystal display panel assembly 40.

A mold frame 71 is positioned at an upper portion of the backlight assembly 70, and a bottom chassis 75 is positioned at the lower portion thereof to accommodate a plurality of components including a light source 76 therebetween. The backlight assembly 70 is accommodated adjacent to the bottom surface of the bottom chassis 75 and the plurality of light sources 76 arranged to be fixedly spaced apart by a predetermined distance on the bottom chassis 75 and exit from the light source 76. The reflective sheet 79 for reflecting light, the frame mold side 78 for holding and supporting the light source 76 at both ends of the light source 76, and the luminance characteristics of the light from the light source 76 are ensured. An optical sheet 72 and a diffusion plate 74 for providing light to the liquid crystal display panel 50 are included. Although a lamp is shown as an example of a light source in FIG. 1, this is merely to illustrate the present invention, and the present invention is not limited thereto. Therefore, a light emitting diode (LED) may be used as the light source, or a light source in the form of a linear light source or a surface light source may be used.

On the back of the bottom chassis 75, an inverter 73 (shown below in FIG. 2), which is a power supply PCB, and a control board 49 (shown below in FIG. 2), which is another printed circuit board, are installed. . The inverter 73 transforms an external power supply to a constant voltage level and applies a driving voltage to the light source 76. To this end, the light source 76 is connected to the inverter 73 via a light source wire 761 (shown in FIG. 2) and a socket 763 (shown in FIG. 2) connected to the electrode. In addition, the control board 49 is connected to the above-described data PCB 42 and the flexible printed circuit board 48 connected thereto to convert the analog data signal into a digital data signal which is a driving signal, and then to the liquid crystal display panel 50. to provide.

Although the driving signal is shown in FIG. 1 as being transmitted through a pair of flexible printed circuit boards 48 in which a plurality of wirings are formed, this is merely to illustrate the present invention, and the present invention is not limited thereto. Therefore, the number of flexible printed circuit boards 48 may be different.

An inverter cover 77 is seated and fixed on the backlight assembly 70 while covering the inverter 73 to protect the inverter 73. A plurality of holes 771 are formed on the upper surface of the inverter cover 77 to help heat dissipation of the inverter 73. Meanwhile, in order to protect the control board 49 from the outside, the shield case 10 covering the control board 49 is seated and fixed on the backlight assembly 70. In the shield case 10, a flexible printed circuit board 48 is inserted to form an insertion hole 101 to be connected to the control board 49. The insertion hole 101 may be formed separately for each flexible printed circuit board 48.

The top chassis 60 is provided on the liquid crystal display panel 50 to prevent the liquid crystal display panel 50 from being separated from the bottom chassis 75 while bending the COFs 43 and 44 to the outside of the mold frame 71. do. Although not shown in FIG. 1, the front case and the rear case are positioned at the top of the top chassis 60 and the bottom of the bottom chassis 75, respectively, to form the flat panel display device 100 by combining them.

Hereinafter, the structure of the shield case 10 serving as an EMI core for EMI shielding will be described in more detail with reference to FIGS. 2 and 3. The structure of the shield case 10 shown in Figs. 2 and 3 is merely to illustrate the present invention, but the present invention is not limited thereto. Therefore, the structure of the shield case 10 can be modified in other forms.

FIG. 2 is a rear perspective view of the flat panel display device 100 according to an embodiment of the present invention. After combining all the internal parts of the flat panel display device 100 shown in FIG. Indicates.

The opening 103 is formed in the upper surface of the shield case 10 shown in FIG. The connector 491 for connecting the flexible printed circuit board 48 and the control board 49 is exposed through the opening 103. Accordingly, the flexible printed circuit board 48 may be easily fastened to the control board 49 through the opening 103. In particular, since the flexible printed circuit board 48 has a very thin thickness, the flexible printed circuit board 48 is fastened and fixed to the connector 491 in a clamp type, and thus, the opening 103 in the shield case 10 as shown in FIG. 2. Forming can confirm the fastening state visually. Therefore, the flexible printed circuit board 48 may be fastened and fixed to the control board 49 while being precisely aligned.

Another connector 493 mounted on the control board 49 is externally connected to drive the flat panel display 100. For this purpose, some side surfaces of the shield case 10 are opened.

FIG. 3 is an enlarged view of a shield case 10 viewed at point A of FIG. 2, and enlarges the shield case 10 positioned at a connection portion of the flexible printed circuit board 48 and the control board 49. Indicates.

The insertion hole 101 formed in the shield case 10 is formed close to the periphery of the flexible printed circuit board 48. According to such a structure, the shield case 10 serves as an EMI core to shield the EMI emitted from the flexible printed circuit board 48. That is, since the flexible printed circuit board 48 is inserted to be adjacent to the insertion hole 101, it eliminates a gap from which EMI can escape.

The insertion hole 101 may be formed on any surface of the shield case 10. However, the insertion hole 101 may be formed on one side of the shield case 10 along the X-axis direction, and may be bent along the inner surface of the top chassis 60. It is advantageous to house the printed circuit board 48. Therefore, since the stress does not act on the flexible printed circuit board 48, there is no fear of disconnection.

The connector 491 mounted on the control board 49 is exposed through the opening 103 formed in the shield case 10. The connector 491 is formed with a plurality of connector pins to be electrically connected to a plurality of wirings formed on the flexible printed circuit board 48. Since the connector 491 is exposed to the outside through the opening 103, the flexible printed circuit board 48 having a thin thickness can be easily fastened to the control board 49, thereby simplifying work.

Meanwhile, after connecting the flexible printed circuit board 48 to the control board 49, the shield case 10 may be covered by covering the opening 103 with a plate member 30 having excellent EMI shielding performance for EMI shielding. Seal it. The plate member 30 serving as the EMI core may be made of aluminum or magnesium having excellent EMI shielding effect. The plate member 30 can be attached to the shield case 10 in the form of a tape, and can also be attached in various other ways.

The shield case 10 having the structure shown in FIG. 3 can shield the EMI emitted from the flexible printed circuit board 48 and the control board 49 without using a separate EMI core, thereby simplifying the manufacturing process. Not only that, but also the cost of the component is reduced.

As described above, in the flat panel display device according to the present invention, since insertion holes formed in the shield case are formed adjacent to surround the flexible printed circuit board, EMI shielding can be efficiently performed without using a separate EMI core. have.

In addition, the insertion hole is formed on one side of the shield case to shield the EMI while preventing excessive force from acting on the flexible printed circuit board.

Openings are formed in the shield case to fasten and fix the flexible printed circuit board to the control board, so that the flexible printed circuit board can be easily fastened to the control board.

Since the connector mounted on the control board is exposed to the outside through the opening formed in the shield case, the flexible printed circuit board can be accurately aligned and fixed to the connector.

Since the plate-shaped member for sealing the opening formed in the shield case is attached to the shield case, EMI emission through the opening can be prevented.

Since the plate member is made of aluminum or magnesium, the EMI shielding effect is excellent.

The flat panel display device according to the present invention further includes a backlight assembly, and the shield case is seated and fixed thereto, so that the shield case can be firmly fixed.

Since the flat panel display panel is a liquid crystal display panel, there is an advantage that the application possibility is excellent.

Although the present invention has been described above, it will be readily understood by those skilled in the art that various modifications and variations are possible without departing from the spirit and scope of the claims set out below.

Claims (8)

Flat panel display panel for displaying images, A flexible printed circuit board (FPC board) electrically connected to the flat panel display panel to transmit driving signals to the flat panel display panel; A control board connected to the flexible printed circuit board and providing a driving signal for driving the flat panel display panel; A shield case which covers and protects the control board and has an insertion hole for inserting the flexible printed circuit board to be connected to the control board. Including, And the insertion hole is formed adjacent to surround the flexible printed circuit board. In claim 1, The insertion hole is a flat panel display device formed on one side of the shield case. In claim 1, And an opening in the shield case for fastening and fixing the flexible printed circuit board to the control board. In claim 3, And a connector for fastening and fixing the flexible printed circuit board to the control board, wherein the connector is exposed to the outside through an opening formed in the shield case. In claim 3, And a plate member for sealing an opening formed in the shield case. In claim 5, And the plate member is made of aluminum or magnesium. In claim 1, And a backlight assembly for supplying light to the flat panel display panel, wherein the shield case is seated and fixed on the backlight assembly. In claim 7, And the flat panel display panel is a liquid crystal display panel.

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