KR20070046683A - Liquid crytal display device including printed circuit board ditecting connecting error of flexible printed circuit connector - Google Patents

Abstract

The present invention relates to a liquid crystal display device having a printed circuit board that can determine a connection failure between the printed circuit board and the system board, the liquid crystal display panel; A gate driver and a data driver connected to the liquid crystal display panel; A printed circuit board on which driving circuits for providing a control signal to the gate driver and the data driver are mounted; A system board connected to the printed circuit board; A first flexible printed circuit film (first FPC film) connecting the printed circuit board and the system board to each other; An FPC connector for substantially connecting the first FPC film and the printed circuit board; It provides a liquid crystal display device having a wiring for supplying power to the liquid crystal display panel from the printed circuit board via the system board, the user can easily detect the connection failure between the printed circuit board and the system board. .

Printed Circuit Boards, FPC Connectors, System Boards, FPC, PCB

Description

 Liquid crystal display having a printed circuit board capable of detecting defective connection of FPC connector {LIQUID CRYTAL DISPLAY DEVICE INCLUDING PRINTED CIRCUIT BOARD DITECTING CONNECTING ERROR OF FLEXIBLE PRINTED CIRCUIT CONNECTOR}

1 is a plan view showing a connection structure of a conventional liquid crystal display panel, a printed circuit board and a system board.

2 is an exploded perspective view of a liquid crystal display of the present invention.

3 is a plan view illustrating a connection structure between a liquid crystal display panel, a printed circuit board, and a system board of the present invention.

*********** Explanation of symbols for main parts of drawing ***********

210: liquid crystal display panel 220: gate driver

230: Data driver 231, 304: FPC film

301: printed circuit board 305: power supply

306: power supply wiring 303: FPC connector

302: system board

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a printed circuit board capable of detecting the departure of the FPC connector.

Today, information processing devices are rapidly developing to have various forms, various functions, and faster information processing speed. Such an information processing apparatus has information of an electrical signal state, and requires a display apparatus that visualizes the information so that the user can see it with the naked eye.

Recently, instead of the CPT monitor, which is a representative display device, a high resolution liquid crystal display device that is light and simple and can implement natural colors has been actively used.

A liquid crystal display device includes a liquid crystal display panel (LCD panel) having two glass substrates facing each other and a liquid crystal layer filled therebetween as a display device for controlling liquid crystals having electric field anisotropy and optical anisotropy using an electric field.

The LCD panel includes an array substrate, a color filter substrate facing the array substrate, and a liquid crystal layer filled therebetween. A plurality of unit pixels are arranged in a matrix on the array substrate, and a color filter layer for displaying colors in natural colors is formed on the color filter substrate.

An electric field is applied to the liquid crystal by electrodes formed on the array substrate and the color filter substrate, respectively to control the liquid crystal. The liquid crystal is a polymer material having dielectric anisotropy, optical anisotropy, and electric field anisotropy, and displays unit pixels while the arrangement direction is controlled according to an electric field.

In order to control the liquid crystal, M x N unit pixels are arranged in a matrix form, and each unit pixel is controlled by a switching element, which may be a thin film transistor.

A plurality of gate lines defining unit pixels and a plurality of data lines vertically intersecting the gate lines are formed on the array substrate, and a drive IC for providing a gate signal and a data signal to each gate line and data line is connected.

The drive IC includes a gate driver for providing a scan signal to a gate line and a data driver for providing an image signal to a data line, and are mounted on the array substrate in the horizontal and vertical directions.

In addition, the driver ICs are connected to a printed circuit board (PCB) by a flexible printed circuit (FPC).

The FPC is a polymer film with fine wiring printed thereon and having ductility. The edges of the substrate may be simplified by hiding the driving ICs mounted on the liquid crystal display panel by using the FPC film to the back of the LCD panel.

A printed circuit board (PCB) is a circuit board designed by a method of printing fine wiring on a thin polymer thin film, and various devices, for example, a DC-DC converter and a timing controller, are mounted thereon. The devices are connected to printed circuits formed on the printed circuit board to provide a signal to the liquid crystal display panel.

In addition, the printed circuit board is connected to an external system board to receive an external signal.

Hereinafter, a connection structure of a general liquid crystal display panel and a printed circuit board connected thereto will be described with reference to FIG. 1.

Referring to FIG. 1, the gate driver 102 and the data driver 103 are connected to the liquid crystal display panel 101 in the vertical and horizontal directions, respectively. The gate driver or data driver may be configured by mounting a gate drive IC or a data drive IC on a tape on which a circuit is designed.

The gate driver 102 and the data driver 103 provide driving signals to gate lines and data lines formed in the liquid crystal display panel 101.

The gate driver 102 and the data driver 103 are connected to the outside by a first FPC film 104 in which wiring is formed on a flexible film made of plastic. After the first FPC film 104 is connected to the liquid crystal display panel 101, the first FPC film 104 is folded and hidden behind the display panel. The first FPC film 104 is connected to a printed circuit board 105 on which various driving elements such as a timing controller are mounted. Therefore, the liquid crystal display panel is substantially driven by driving elements mounted on the printed circuit board 105. The first FPC film 104 only serves as a wiring.

The printed circuit board 105 is a circuit formed on a flat film made of phenol resin or epoxy resin to mount various kinds of components. The printed circuit board 105 electrically connects electronic components to mechanically fix the role of wiring and electronic components. It was to play a role at the same time.

One end of the printed circuit board 105 is connected to the first FPC film 104, and the other end is connected to the system board 106. The system board generates substantial image information, and may be, for example, a main board of a personal computer.

In some electronic products, the printed circuit board 105 and the system board 106 are connected to each other by a second FPC film 108. The second FPC film 108 extends from the system board 106 and is substantially connected to the printed circuit board 105 by an FPC connector 108 formed at one end of the printed circuit board 108. do.

The FPC connector 108 is a plurality of connection terminals are arranged at regular intervals so as to be connected to each of the wiring terminals of the second FPC film 107, the user can connect the second FPC film 107 to the FPC connector 108 You can access or leave.

However, after the liquid crystal display panel and the system board are connected to each other by the FPC connector 108, a connection failure may occur in which the FPC connector 108 is separated from the system board 106 by use or due to a coupling error. have. If a bad connection occurs, the screen cannot be driven normally because information from the system board is not transferred to the LCD panel smoothly. That is, a signal that is provided from the system board 106 is blocked due to a bad connection of the FPC connector 108 and a defect that cannot be transmitted to the liquid crystal display panel 101 occurs. However, since there are various causes of screen defects, it is difficult to determine that even if a bad screen occurs, the cause is due to the FPC connector.

1A shows that the FPC connector 108 and the second FPC film 107 are poorly connected.

Therefore, the present invention improves the defect that the screen is not displayed due to the poor connection of the system board and the FPC connector when a signal is transmitted from the system board to the liquid crystal display panel, and has a FPC connector connection structure that can be easily confirmed when such a failure occurs An object of the present invention is to provide a liquid crystal display device.

The present invention for the above object and the liquid crystal display panel; A gate driver and a data driver connected to the liquid crystal display panel; A printed circuit board on which driving circuits for providing a control signal to the gate driver and the data driver are mounted; A system board connected to the printed circuit board; A first flexible printed circuit film (first FPC film) connecting the printed circuit board and the system board to each other; An FPC connector for substantially connecting the first FPC film and the printed circuit board; Provided is a liquid crystal display device including a wiring for supplying power to the liquid crystal display panel from the printed circuit board via the system board.

The present invention connects a printed circuit board on which drive elements for providing a signal directly to a liquid crystal display panel is mounted and a system board for providing information to be displayed on a screen, wherein a power wiring formed on the printed circuit board is connected to an FPC connector. And by providing the wiring structure that can be provided to the liquid crystal display panel via the system board, if the connection failure of the FPC connector occurs, the Vdd and Vcc voltage generated from the printed circuit board is essentially not provided to the liquid crystal display panel. By not driving, it is possible to determine the connection failure of the FPC connector only by the screen state.

Hereinafter, an exploded perspective view of the liquid crystal display of the present invention will be described with reference to FIG. 2. It looks at with reference to FIG.

2 is a schematic exploded perspective view of a liquid crystal display of the present invention. 3 is a plan view illustrating a liquid crystal display panel implementing a screen, a printed circuit board connected thereto, and a wiring structure of the liquid crystal display device according to the present invention.

Referring to FIG. 2, a liquid crystal display includes a display panel 210 in which pixels are arranged in a matrix form; A gate driver 220 and a data driver 230 connected to side surfaces of the display panel 210, respectively; The backlight unit 240 may be disposed on the rear or side surfaces of the display panel 210.

The display panel 210 maintains a uniform cell-gap facing each other and includes a bonded TFT array substrate, a color filter substrate, and a liquid crystal layer formed in a space between the two substrates.

A common electrode and a pixel electrode are formed on the liquid crystal display panel where the TFT array substrate and the color filter substrate are bonded to apply an electric field to the liquid crystal layer.

Therefore, when the voltage of the data signal applied to the pixel electrode is controlled while the voltage is applied to the common electrode, the liquid crystal of the liquid crystal layer rotates by electric field anisotropy according to the electric field between the common electrode and the pixel electrode. Characters or images are displayed by transmitting or blocking light for each pixel.

In addition, in order to control the voltage of the data signal applied to the pixel electrode for each pixel, a switching element such as a thin film transistor is provided in each pixel individually.

The gate driver 220 and the data driver 230 are coupled to the display panel 210 in various forms to supply scan signals and image signals to gate lines and data lines formed on the display panel 210. The pixels of the panel 210 are driven.

The gate driver and the data driver are connected to the outside by the FPC film 231.

The backlight assembly 240 may include a light guide plate 241 disposed on a rear surface of the display panel 210; Lamps 242 and 243 (in the case of edge type) disposed on both sides or one side of the light guide plate 241; The rear surface of the light guide plate 241 includes a reflection plate 244, and further includes a plurality of optical sheets 245 between the display panel 210 and the light guide plate 241.

Light generated by the lamps 242 and 243 is incident on the side surface of the light guide plate 241 formed of a transparent material.

The reflective plate 244 disposed on the rear surface of the light guide plate 241 reflects the light transmitted to the rear surface of the light guide plate 241 to the top surface of the light guide plate 241 to reduce the loss of light and is transmitted to the top surface of the light guide plate 241. Improves light uniformity

Accordingly, the light guide plate 241 transmits the light generated by the lamps 242 and 243 together with the reflective plate 244 to the upper surface.

For the optical sheet 245 disposed between the display panel 210 and the light guide plate 241, a diffusion sheet and a prism sheet may be applied, and a protective sheet may be added.

The diffusion sheet disperses the light incident from the light guide plate 241, thereby preventing the light from being partially concentrated and causing stains on an image displayed on the display panel 210, and preventing the light from entering the light guide plate 241. Refract vertically.

The prism sheet collects light incident from the diffusion sheet to be uniformly distributed on the entire surface of the display panel 210.

The protective sheet protects the optical sheet 245 which is sensitive to dust and scratches, prevents the optical sheet 245 from flowing when the backlight assembly 240 is transported, and diffuses light incident from the prism sheet. It can have a function to make the light more uniformly distributed.

On the other hand, the backlight unit 240 has an edge method with lamps 242 and 243 applied to both side surfaces of the light guide plate 241, but an edge method with a lamp may be applied to only one side of the light guide plate 241. Alternatively, a direct method may be applied in which the lamp is disposed to correspond to the entire rear surface of the display panel 210.

The display panel 210 and the backlight assembly 240 are stacked on the main support 250, and side surfaces of the stacked display panel 210 and the backlight assembly 240 are supported by the main support 250.

The top edge of the display panel 210 is compressed by the top case 251, and the top case 251 is coupled to the main support 250 by a screw.

Meanwhile, the backlight assembly 240 having the main support 50, the light guide plate 241, the diffusion plate, and the prism sheet is stacked on the lower cover 252 while being supported by the main support 250 and the lower cover. 252 and the main support 250 is coupled to each other by a hook method or the like.

Meanwhile, the liquid crystal display panel 210 is connected to the printed circuit board and the system board by the FPC film and receives a signal from the outside.

Hereinafter, a structure of a printed circuit board and a system board connected to the liquid crystal display panel and an FPC connector connecting the printed circuit board and the system board will be described with reference to FIG. 3.

Referring to FIG. 3, the liquid crystal display of the present invention includes a liquid crystal display panel 210, a gate driver 220, and a data driver 230 that may be formed at an edge of the liquid crystal display panel. The data driver 230 receives an external signal by the first FPC film 231 in which fine circuits are designed. The first FPC film 231 is connected to a printed circuit board 301 on which various driving elements, for example, a DC-DC coverter and a timing controller, which provide a driving signal to the data driver 230 are mounted. . The printed circuit board 301 is connected to the system board 302 which generates an image signal to be substantially displayed on the liquid crystal display panel through the second FPC film 304.

In order to connect the printed circuit board 301 and the system board 302, an FPC connector 303 is formed at one side of the printed circuit board 301, and a second FPC film is formed on the FPC connector 303. 304 is connected. Therefore, one end of the second FPC film 304 is composed of a plurality of pins that can be connected to the FPC connector 303.

Meanwhile, the driving circuit parts 220 and 230 connected to the liquid crystal display panel 210 are formed by mounting the driving circuit ICs 220a and 230a on a substrate of the liquid crystal display panel 210 or by forming a wiring. The drive circuits may be mounted on a tape.

3 illustrates a chip on glass (COG) type in which driving circuit ICs are mounted on a substrate.

The gate driver 220 and the data driver 230 are connected to the printed circuit board 301 by a first FPC film 231 in which wiring is formed on a polymer film such as an epoxy resin.

The printed circuit board 301 is a flat circuit board on which various driving circuit chips, for example, a timing controller, are mounted, and a power supply unit (not shown) is formed thereon. The power supply block receives an external power to generate power for driving the liquid crystal display panel.

The power supply includes Vdd, which is the drain power supply of the data driver, and Vcc, where the gate and data drivers are logic power supplies. The Vdd and Vcc are supplied to the gate driver 220 and the data driver 230 through the wiring formed on the printed circuit board and the first FPC film 231, respectively.

However, the present invention provides the Vdd and Vcc power supplies formed on the printed circuit board 301 to the gate and data drivers 220 and 230 via the system board 302.

For this structure, a wiring 306 providing Vdd and Vcc power to the gate and data drivers 220 and 230 is connected to the FPC connector 303. In addition, the second FPC film 304 connected to the FPC connector 303 is further provided with a connection terminal connected to the FPC connector 303, the corresponding connection terminal is further formed in the FPC connector 303 do.

In addition, wiring is further formed on the system board 302 so that the power wiring 306 can be provided to the gate driver 210 and the data driver 230 via the system board 302.

The Vdd and Vcc have a power supply wiring separately. Since the power wiring 306 is for detecting a poor connection between the second FPC film 304 and the FPC connector 303, the connection terminal in the FPC connector 303 to which the power wiring 306 is connected is an FPC connector. It is preferable that it is formed in the outermost part of 303. This is because poor connection usually occurs through separation of the edge of the FPC connector 303.

In the above embodiment, two wires, that is, the Vdd power wiring and the Vcc power wiring are connected to the FPC connector 303, respectively, in order to detect a poor connection between the FPC connector 303 and the second FPC film 304. Without being limited, it is also possible to design only the power wiring of either Vdd or Vcc power wiring via the system board.

In addition, the wiring of any drive circuit mounted on the printed circuit board 301 can be configured to pass from the printed circuit board to the system board.

As described above, the Vdd and Vcc powers are supplied from the printed circuit board 301 to the gate driver and the data driver via the system board 302, thereby forming the FPC connector 303 formed on the printed circuit board 301. When the connection failure of the second FPC film 304 occurs, the connection failure may be detected only by changing the screen of the liquid crystal display panel.

That is, when a connection failure occurs between the FPC connector 303 and the second FPC film 304, since the Vdd and Vcc powers are not provided to the gate driver and the data driver, information is not displayed on the liquid crystal display panel. That is, even if information is provided from the system board, it only maintains the normally white or black state.

The user can easily determine the connection failure of the printed circuit board and the system board by detecting this.

As described above, in the present invention, in detecting a connection failure between the printed circuit board and the system board, the user can easily connect the printed circuit board and the system board by changing only the wiring design of the conventional printed circuit board without adding new components. Make it possible to detect a defect. Thus, it is possible to promptly resolve the problem caused by the connection failure, thereby improving productivity.

Claims (7)

A liquid crystal display panel; A gate driver and a data driver connected to the liquid crystal display panel; A printed circuit board on which driving circuits for providing a control signal to the gate driver and the data driver are mounted; A system board connected to the printed circuit board; A first flexible printed circuit film (first FPC film) connecting the printed circuit board and the system board to each other; An FPC connector for substantially connecting the first FPC film and the printed circuit board; And a wiring for supplying power to the liquid crystal display panel from the printed circuit board via the system board. The liquid crystal display of claim 1, further comprising a second FPC film connecting the printed circuit board to the gate driver and the data driver. The liquid crystal display device according to claim 1, wherein the power source is Vdd or Vcc. The liquid crystal display device according to claim 3, wherein the wiring is a separate wiring connected to the Vdd and Vcc, respectively. 4. The liquid crystal display device according to claim 3, wherein the FPC connector includes a connection terminal connected to the Vdd and Vcc. 6. The liquid crystal display device according to claim 5, wherein the first FPC film includes a connection terminal corresponding to the connection terminal. 6. The liquid crystal display device according to claim 5, wherein the connection terminal is formed at an end of the FPC connector.

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