KR20110065756A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A liquid crystal display device and a method of manufacturing the same are provided to improve reliability and productivity. CONSTITUTION: A liquid crystal display device(100) comprises a liquid crystal panel(200) including a common electrode(Vcom), a source PCB which is connected with the liquid crystal panel through a FPCB, and a scaler board(SB) in which a common voltage circuit is mounted for generating a common voltage corresponding to a common voltage generating data. The common voltage is supplied to the common electrode.

Description

Liquid crystal display device and method of manufacturing the same

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a manufacturing method thereof.

As the information society develops, the demand for display devices for displaying images is increasing in various forms. Recently, liquid crystal displays (LCDs), plasma display panels (PDPs), organic fields Various flat display devices such as organic electroluminescent display devices (OELD) are being utilized.

Among these flat panel display devices, liquid crystal display devices have advantages of miniaturization, light weight, thinness, and low power driving, and are widely used in recent years.

As the liquid crystal display device, an active matrix type liquid crystal display device in which a switching transistor is formed in each of the pixels arranged in a matrix form is commonly used.

In such an active matrix type liquid crystal display device, when a gate wiring is scanned, a scan pulse having a gate high voltage is applied to turn on the switching transistor. In synchronization with this, the data voltage is transferred through the data wiring and applied to the corresponding pixel. Accordingly, the data voltage is applied to the pixel electrode of the pixel. On the other hand, a common voltage is applied to the common electrode of the pixel. As described above, an electric field is formed between the electrodes at the voltage applied to the pixel electrode and the common electrode, and the arrangement of the liquid crystals is changed according to the electric field thus formed to display an image.

In such a liquid crystal display device, the driving thereof is controlled through a timing controller which is generally a control circuit. The timing controller is mounted on a so-called control printed circuit board (PCB), and generates a control signal for controlling various driving circuits provided in the liquid crystal display device to control the operation of the driving circuit.

On the other hand, the control PCB is provided with a common voltage IC that is manufactured in an IC form and generates a common voltage. The common voltage IC generates a common voltage based on the common voltage generation data stored in the internal memory. The generated common voltage is transferred to the liquid crystal panel and applied to the common electrode.

Generally, a primary manufacturer of a liquid crystal display device manufactures a liquid crystal display module in which components such as a control PCB, a source PCB, and a liquid crystal panel are assembled. The liquid crystal display module manufactured as described above is delivered to a secondary manufacturer of a liquid crystal display device, for example, a TV set company. The TV set manufacturer attaches the components necessary for TV production to the LCD module, completes the manufacture of the LCD TV, and ships the finished product. Hereinafter, for convenience of description, the primary manufacturer may be referred to as an LCM manufacturer.

In recent years, however, LCM manufacturers have manufactured LCD modules, eliminating control PCBs in which parts such as timing controllers and common voltage ICs are mounted, and supplying them to TV set makers. Doing. In such a case, a TV set company attaches a so-called scaler board to a supplied liquid crystal display module. In such a scale board, a circuit component having a function such as a timing controller and a common voltage IC mounted in the control PCB is mounted.

As such, for a liquid crystal display device model in which the control PCB is removed, the TV set maker must perform a task of finding a common voltage suitable for the characteristics of the liquid crystal panel while adjusting the common voltage itself. If a suitable common voltage is specified through the above operation, common voltage generation data for generating such a common voltage may be specified. The common voltage IC may generate a corresponding common voltage with reference to the common voltage data set as described above.

By the way, the work for setting the common voltage suitable for the characteristics of the liquid crystal panel as described above, it will be most suitable to perform at the LCM manufacturer, as it is performed by the TV set manufacturers, the time is increased to increase the productivity (tact time) There is a reduced problem.

In addition, due to inadequate common voltage setting in TV set companies, the possibility of generating a common voltage which is not suitable for the characteristics of the liquid crystal panel is increased, resulting in poor image quality and the like, which may lower the reliability of the liquid crystal display device. Becomes high.

The present invention has a problem to provide a liquid crystal display device and a method of manufacturing the same that can improve productivity and reliability.

In order to achieve the above object, the present invention is a liquid crystal panel comprising a common electrode; A source PCB mounted with an EEPROM storing common voltage generation data for generating a common voltage suitable for the liquid crystal panel characteristics, and connected to the liquid crystal panel through a flexible circuit film; A common voltage circuit for receiving the common voltage generation data stored in the EEPROM and generating a common voltage corresponding to the received common voltage generation data is mounted, and includes a scaler board connected to the source PCB, and generated in the common voltage circuit. The provided common voltage provides a liquid crystal display device which is supplied to the common electrode.

In this case, when power is applied to the liquid crystal display, the common voltage generation data stored in the EEPROM may be read and written to the memory of the common voltage circuit.

In another aspect, the present invention comprises the steps of connecting a liquid crystal panel including a common electrode and a source PCB on which the EEPROM is mounted via a flexible circuit film; Connecting an inspection device to a source PCB connected to the liquid crystal panel; Specifying a common voltage suitable for the liquid crystal panel characteristics by using the inspection device; Storing common voltage generation data corresponding to the specified common voltage in the EEPROM; It provides a method for manufacturing a liquid crystal display device comprising the step of disconnecting the inspection device and the source PCB.

The method may further include connecting the source PCB and the scaler board on which the common voltage circuit is mounted after disconnecting the test device from the source PCB, wherein the common voltage generation data stored in the EEPROM is the common voltage. The common voltage circuit may be input to a circuit to generate a common voltage corresponding to the input common voltage generation data.

When power is applied to the liquid crystal display, the common voltage generation data stored in the EEPROM may be read and written to the memory of the common voltage circuit.

The inspection apparatus includes an inspection control PCB mounted with an inspection common voltage circuit and an inspection device, and common voltage generation data corresponding to the specified common voltage is recorded in the inspection common voltage circuit, Common voltage generation data recorded in the common voltage circuit may be recorded and stored in the EEPROM.

In the present invention, the EEPROM is configured in the source PCB, the common voltage generation data suitable for the characteristics of the liquid crystal panel is specified in the inspection process, and the EEPROM is stored in the EEPROM. As described above, the common voltage generation data stored in the EEPROM can be input to the common voltage circuit mounted on the scale board after the scale board is connected to the source PCB. Accordingly, the common voltage circuit can generate a common voltage suitable for the liquid crystal panel characteristics and supply it to the liquid crystal panel.

As described above, in the liquid crystal display device not using the control PCB, since the operation related to the common voltage is performed by the primary manufacturer, the secondary manufacturer does not need to separately perform the operation related to the common voltage setting.

Therefore, the working time on the secondary manufacturer side can be reduced and the productivity can be improved. In addition, since the common voltage suitable for the characteristics of the liquid crystal panel is set, the possibility of defects such as deterioration of image quality is lowered, and the reliability of the liquid crystal display device can be improved.

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

1 is a view schematically showing a liquid crystal display device according to an embodiment of the present invention, FIG. 2 is an equivalent circuit diagram schematically showing a pixel of a liquid crystal panel according to an embodiment of the present invention, and FIG. 3 is a view of the present invention. A diagram schematically illustrating an EEPROM mounted on a source PCB according to an embodiment.

As illustrated, the liquid crystal display device 100 according to the exemplary embodiment of the present invention may include a liquid crystal panel 200, a scaler board SB, a source PCB SPCB, and a backlight 400. .

The liquid crystal panel 200 includes two substrates facing each other, for example, an array substrate AS and an opposite substrate OS, and a liquid crystal layer positioned between the two substrates.

In the array substrate AS of the liquid crystal panel 200, a plurality of gate lines GL extending in a first direction and a plurality of data lines DL extending in a second direction cross each other to form a matrix. A plurality of pixels P arranged in the form of) is defined.

Referring to FIG. 2, in each pixel P, a switching transistor T connected to the gate line and the data line GL and DL is formed. The switching transistor T is connected to the pixel electrode. Meanwhile, a common electrode is formed corresponding to the pixel electrode. When a data voltage is applied to the pixel electrode and a common voltage Vcom is applied to the common electrode, an electric field is formed therebetween to drive the liquid crystal. The pixel electrode, the common electrode, and the liquid crystal positioned between these electrodes constitute a liquid crystal capacitor Clc. Meanwhile, a storage capacitor Cst is further configured in each pixel P, which stores a data voltage applied to the pixel electrode until the next frame.

The backlight 400 serves to supply light to the liquid crystal panel 200. As the backlight 400, a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), a light emitting diode (LED), or the like may be used.

A plurality of driving circuits are located on the scaler board SB corresponding to the control board. For example, the control circuit 310, the common voltage circuit 320, and the like are positioned. The control circuit 310 and the common voltage circuit 320 may be manufactured, for example, in an IC form and mounted on the scaler board SB.

The control circuit 310 generates and supplies control signals for controlling the driving circuits provided in the liquid crystal display device 100. For example, a source control signal for controlling the source driver circuit and a gate control signal for controlling the gate driver circuit are generated. In addition, the control circuit 310 aligns the input image data and transfers it to the source driving circuit. As such, the control circuit 310 has a function similar to that of the timing controller.

The common voltage circuit 320 generates the common voltage Vcom with reference to the common voltage generation data DV. The common voltage Vcom generated as described above is transferred to the liquid crystal panel 200 and applied to the common electrode.

The common voltage circuit 320 reads the common voltage generation data DV from the EEPROM 330 mounted in the source PCB SPCB. As such, in transmitting the common voltage generation data DV, the EEPROM 330 and the common voltage circuit 320 may perform I2C communication, for example.

The common voltage generation data DV read in this way may be stored in, for example, a memory (not shown) provided in the common voltage circuit 320. Accordingly, the common voltage Vcom corresponding to the common voltage generation data DV stored in the memory is generated in the common voltage circuit 320.

The EEPROM 330 as described above is mounted on the source PCB (SPCB). The common voltage generation data DV is stored in the EEPROM 330 corresponding to the nonvolatile memory.

Referring to FIG. 3, the EEPROM 330 may include a plurality of terminals. For example, the terminals A0 to A2, the GND terminal, the Vcc terminal, the WP terminal, the SCL terminal, and the SDA terminal may be provided.

Here, terminals A0 to A2 are terminals used to set an address of the EEPROM 330 for I2C communication.

The GND terminal corresponds to the ground terminal, and the Vcc terminal corresponds to a terminal to which a power voltage Vcc is applied to drive the EEPROM 330.

In addition, the SCL terminal and the SDA terminal correspond to a terminal for transmitting a clock CLK and data DATA for I2C communication. Through the SCL terminal and the SDA terminal, the EEPROM 330 can perform I 2 C communication with peripheral devices, for example, the common voltage circuit 320. Accordingly, data recorded in the EEPROM 330, for example, common voltage generation data DV, can be transmitted to the common voltage circuit 320.

Meanwhile, if necessary, the EEPROM 330 may communicate with other driving devices to transmit and receive data. For example, I2C communication with a device for writing data to the EEPROM 330 may be performed.

As described above, the above elements for performing I2C communication with the EEPROM 330 also have an SCL terminal and an SDA terminal, and an SCL channel and an SDA channel are provided therebetween so that I2C communication can be performed.

The WP terminal corresponds to a terminal associated with the write protection function of the EEPROM 330. For example, when a low voltage is applied to the WP terminal, the write protection function for the EEPROM 330 is deactivated. In such a case, both data reading / writing is possible for the EEPROM 330.

On the other hand, when a high voltage is applied to the WP terminal, the write protection function for the EEPROM 330 is activated. In such a case, only data reading is possible for the EEPROM 330.

As described above, the source PCB SPCB and the scaler board SB are connected to each other through a flexible cable, for example, a flexible flat cable (FFC). Through such FFC, the source PCB SPCB and the scaleboard SB can transmit necessary signals.

The source PCB (SPCB) and the liquid crystal panel 200 may be connected through a plurality of flexible circuit films, for example, a tape carrier package (TCP) film (TCPS). In each of the TCP films TCPS, a source IC S-IC may be mounted. Such a plurality of source ICs (S-IC) may constitute a source driving circuit. For convenience of description, the TCP film (TCPS) on which the source IC (S-IC) is mounted is called a source TCP film.

The source TCP film TCPS is connected to one side of the array substrate AS of the liquid crystal panel 200. The source TCP film TCPS transmits the source control signal and the image data output from the control circuit 310 and transmitted via the source PCB SPCB to the source IC S-IC. The source IC (S-IC) outputs a data voltage in response to such a source control signal and video data. The data voltage output from the source IC S-IC is supplied to the corresponding data line DL through the source TCP film TCPS.

On the other hand, the other side of the array substrate AS of the liquid crystal panel 200, a plurality of flexible circuit film, for example TCP film (TCPG) can be connected. In each of the TCP films TCPG, a gate IC G-IC may be mounted. Such a plurality of gate ICs (G-IC) may constitute a gate driving circuit. For convenience of description, the TCP film (TCPG) on which the gate IC (G-IC) is mounted is called a gate TCP film.

The gate IC G-IC outputs a gate control signal output from the control circuit 310, for example, a source PCB (SPCB), a source TCP film (TCPS), and an array substrate (AS) of the liquid crystal panel 200. And via the gate TCP film (TCPG), can be delivered. Here, the source TCP film (TCPS) for transmitting the gate control signal, for example, the source TCP film (TCPS) that is located closest to the portion where the gate IC (G-IC) is disposed, that is, the leftmost in the drawing It may correspond to a source TCP film (TCPS).

The gate IC G-IC may sequentially apply scan pulses to the plurality of gate lines GL in response to the transferred gate control signal. For example, a plurality of gate lines GL are sequentially selected during each frame, and scan pulses are output for the selected gate lines GL. By the turn-on voltage of the scan pulse, for example, the gate high voltage, the switching transistor T located in the corresponding row line is turned on. On the other hand, the turn-off voltage, for example, the gate-low voltage, is supplied to the gate wiring GL until the next frame random scan, so that the switching transistor T is maintained in the turn-off state.

On the other hand, in the embodiment of the present invention, a case where a gate IC (G-IC) mounted on a gate TCP film (TCPG) is used as the gate driving circuit is described as an example. Alternatively, the gate IC G-IC may be directly mounted on the array substrate AS, or a gate driving circuit may be directly formed on the array substrate AS. In such a case, a gate TCP film (TCPG) will not be needed. The gate driving circuit is formed directly on the array substrate AS, which is called a GIP (gate in panel) method. In such a GIP method, in the process of forming an array element including the switching transistor T, the gate wiring GL, and the data wiring DL on the array substrate AS, the gate driving circuit is connected to the array substrate AS. It can be formed directly.

Hereinafter, a method of manufacturing the liquid crystal display device 100 as described above will be described in more detail with reference to FIGS. 4 and 5.

4 and 5 schematically illustrate a method of manufacturing a liquid crystal display according to an embodiment of the present invention. 4 and 5, the gate TCP film (TCPG in FIG. 1) and the backlight (see 400 in FIG. 1) are omitted.

First, referring to FIG. 4, for example, an LCM manufacturer, which is a primary manufacturer, manufactures a liquid crystal panel 200. In this regard, for example, an array substrate AS and an opposite substrate OS are manufactured, these two substrates are bonded together, and liquid crystal is injected between the two substrates.

Thereafter, the assembly process of connecting the peripheral parts to the liquid crystal panel 200 is performed. For example, the source TCP film TCPS and the gate TCP film may be coupled to the liquid crystal panel 200, and the source PCB SPCB may be coupled to the source TCP film TCPS.

On the other hand, in addition to the assembly of the components related to the driving of the liquid crystal display device as described above may be further involved in the assembly of mechanical components. For example, although not shown, a so-called top case positioned at the front of the liquid crystal panel 200 and having an opening, a so-called main support surrounding the liquid crystal panel 200 and the side surface of the backlight, In addition, a process of combining mechanical parts such as a bottom case in which the backlight and the liquid crystal panel 200 are mounted may be performed.

On the other hand, the order of the assembly process as described above, may be changed, depending on the needs of the LCM manufacturer.

As described above, the inspection apparatus 500 is connected to the source PCB (SPCB) side at least in a state in which the driving circuit components TCPS and SPCB and the liquid crystal panel 200 are coupled to each other. The inspection apparatus 500 may inspect, for example, driving and image display of the liquid crystal display in the combined state as described above.

The inspection apparatus 500 may include, for example, an inspection control PCB (ICPCB) and an inspection apparatus 510.

The inspection control PCB (ICPCB) and the inspection unit 510 are connected to each other via a flexible cable (ICBL), and the necessary signals are transmitted between them. The inspection control PCB (ICPCB) is connected to the source PCB (SPCB) via an inspection flexible cable, for example inspection FFC (IFFC), and the necessary signals are transmitted therebetween.

The inspection control PCB (ICPCB) is similar to the configuration of the control PCB used in the conventional liquid crystal display device. For example, a test timing controller ITCON, a test common voltage circuit IVIC, or the like may be mounted in the test control PCB (ICPCB). Here, the test timing controller ITCON and the test common voltage circuit IVIC may be manufactured in an IC form.

In the inspection process, the inspection timing controller ITCON generates an inspection control signal for controlling the source driving circuit and the gate driving circuit, and transmits the inspection image data.

The inspection common voltage circuit IVIC generates a common voltage Vcom and supplies the same to the liquid crystal panel 200 in the inspection process of the liquid crystal display.

The inspector 510 transmits various signals necessary for the inspection process, for example, inspection image data and inspection control signals to the inspection control PCB (ICPCB). The inspection signals transmitted as described above are transmitted to the driving circuits provided in the inspection control PCB (ICPCB).

On the other hand, in performing the inspection process as described above, the operation of setting the common voltage (Vcom) suitable for the characteristics of the liquid crystal panel 200 will be accompanied.

In this regard, for example, the common voltage Vcom suitable for the characteristics of the liquid crystal panel 200 is found while adjusting the common voltage Vcom output from the inspection common voltage circuit IVIC. Through this operation, when a suitable common voltage Vcom is specified, the common voltage generation data DV for generating such a common voltage Vcom is recorded in the inspection common voltage circuit IVIC.

Thereafter, the tester 510 reads the common voltage generation data DV stored in the inspection common voltage circuit IVIC and writes the data DV to the EEPROM 330 mounted on the source PCB SPCB. . As such, the process of reading and writing the common voltage generation data DV may be performed through, for example, I2C communication. That is, a process of transmitting and receiving common voltage generation data DV between the tester 510, the test common voltage circuit IVIC, and the EEPROM 330 is performed through I2C communication. The common voltage generation data DV recorded in the IVIC) can be written to the EEPROM 330.

As described above, when the writing process of the common voltage generation data DV to the EEPROM 330 and other inspection processes are completed, the inspection apparatus 500 is disconnected from the source PCB (SPCB). As such, even when the connection between the inspection apparatus 500 and the source PCB (SPCB) is released, since the EEPROM is a nonvolatile memory, the common voltage generation data DV suitable for the characteristics of the liquid crystal panel 200 is continuously stored in the EEPROM 330. It becomes.

After the above process is completed, the LCM manufacturer will supply the liquid crystal display module in which the driving parts, the mechanical parts, and the liquid crystal panel 200 are modularized to a secondary manufacturer, for example, a TV set company.

Referring to FIG. 5, a TV set company receiving a liquid crystal display module connects the scaler board SB to a source PCB SPCB. On the other hand, TV set companies, in addition to the scale board (SB), proceeds with the assembly process of assembling the necessary drive parts and mechanical parts, it is possible to complete the manufacturing of the liquid crystal display TV.

For the liquid crystal display manufactured as described above, for example, when power is applied and the liquid crystal display is turned on, the common voltage circuit 320 mounted on the scaler board SB is connected to the source PCB through I2C communication. The process of reading the common voltage generation data DV stored in the EEPROM 330 of the SPCB and writing the same to the memory included in the common voltage circuit 330 may be automatically performed.

Accordingly, the common voltage generation data DV suitable for the characteristics of the liquid crystal panel 200 may be loaded into the common voltage circuit 320. Accordingly, the common voltage circuit 320 may generate the corresponding common voltage Vcom with reference to the input common voltage generation data DV. The common voltage Vcom generated as described above is transferred to the liquid crystal panel 200 via the FFC and the source TCP film TCPS, and may be applied to the common electrode.

On the other hand, when the memory of the common voltage circuit 320 in which the common voltage generation data DV is stored is volatile, when the power is cut off and the liquid crystal display is turned off, the common voltage generation data DV is erased. Will be. However, when the liquid crystal display is turned on again, the common voltage generation data DV is input again from the EEPROM 330 to the common voltage circuit 320 to generate the corresponding common voltage Vcom.

As described above, in the embodiment of the present invention, the EEPROM is configured in the source PCB, and common voltage generation data suitable for the characteristics of the liquid crystal panel are specified in the inspection process, and the EEPROM is stored in the EEPROM. As described above, the common voltage generation data stored in the EEPROM can be input to the common voltage circuit mounted on the scale board after the scale board is connected to the source PCB. Accordingly, the common voltage circuit can generate a common voltage suitable for the liquid crystal panel characteristics and supply it to the liquid crystal panel.

As described above, in the liquid crystal display device not using the control PCB, since the operation related to the common voltage is performed by the primary manufacturer, the secondary manufacturer does not need to separately perform the operation related to the common voltage setting.

Therefore, the working time on the secondary manufacturer side can be reduced and the productivity can be improved. In addition, since the common voltage suitable for the characteristics of the liquid crystal panel is set, the possibility of defects such as deterioration of image quality is lowered, and the reliability of the liquid crystal display device can be improved.

Embodiment of the present invention described above is an example of the present invention, it is possible to change freely within the scope included in the spirit of the present invention. Accordingly, the invention includes modifications of the invention within the scope of the appended claims and their equivalents.

1 is a view schematically showing a liquid crystal display device according to an embodiment of the present invention.

2 is an equivalent circuit diagram schematically illustrating pixels of a liquid crystal panel according to an exemplary embodiment of the present invention.

3 schematically illustrates an EEPROM mounted on a source PCB according to an embodiment of the present invention.

4 and 5 schematically illustrate a method of manufacturing a liquid crystal display according to an embodiment of the present invention.

Description of the Related Art

100: liquid crystal display device 200: liquid crystal panel

310: control circuit 320: common voltage circuit

330: EEPROM 400: Backlight

SB: Scaler SPCB: Source PCB

AS: Array Board OS: Opposing Board

TCPS: Source TCP Film TCPG: Gate TCP Film

S-IC: Source IC G-IC: Gate IC

Vcom: Common Voltage DV: Common Voltage Generation Data

Claims (6)

A liquid crystal panel including a common electrode; A source PCB mounted with an EEPROM storing common voltage generation data for generating a common voltage suitable for the liquid crystal panel characteristics, and connected to the liquid crystal panel through a flexible circuit film; A common voltage circuit configured to receive the common voltage generation data stored in the EEPROM and generate a common voltage corresponding to the input common voltage generation data, and includes a scaler board connected to the source PCB; The common voltage generated in the common voltage circuit is supplied to the common electrode. LCD display device. The method of claim 1, When power is applied to the liquid crystal display, the common voltage generation data stored in the EEPROM is read and written to the memory of the common voltage circuit. LCD display device. Connecting the liquid crystal panel including the common electrode and the source PCB on which the EEPROM is mounted through the flexible circuit film; Connecting an inspection device to a source PCB connected to the liquid crystal panel; Specifying a common voltage suitable for the liquid crystal panel characteristics by using the inspection device; Storing common voltage generation data corresponding to the specified common voltage in the EEPROM; Disconnecting the inspection device from the source PCB; Liquid crystal display device manufacturing method comprising a. The method of claim 3, wherein After disconnecting the inspection device and the source PCB, Connecting the source PCB and a scaler board on which a common voltage circuit is mounted; Common voltage generation data stored in the EEPROM is input to the common voltage circuit, The common voltage circuit generates a common voltage corresponding to the input common voltage generation data. Liquid crystal display device manufacturing method. The method of claim 4, wherein When power is applied to the liquid crystal display, the common voltage generation data stored in the EEPROM is read and written to the memory of the common voltage circuit. Liquid crystal display device manufacturing method. The method of claim 3, wherein The inspection apparatus includes an inspection control PCB mounted with a common voltage circuit for inspection and an inspection machine, Common voltage generation data corresponding to the specified common voltage is recorded in the inspection common voltage circuit, Common voltage generation data recorded in the common voltage circuit for inspection is recorded and stored in the EEPROM. Liquid crystal display device manufacturing method.

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