KR100488067B1 - Image display device and operating method thereof - Google Patents

Abstract

According to an aspect of the present invention, there is provided a video display device comprising: a transmitter having a transmitter for providing an image data signal and a control signal converter for converting and applying a control signal to a liquid crystal panel; A receiver for receiving an image data signal transmitted from the transmitter, a data register for storing the image data signal received by the receiver, a data latch unit for storing the image data signal stored in the data register for a predetermined time, and the data Converts a digital image data signal into an analog signal by using a shift register for shifting a signal stored in the latch unit, the image data signal transmitted from the data latch unit, and a gamma voltage, and then outputs the image data signal to the liquid crystal panel. A source drive IC having a digital / analog converter; And a gate drive IC for applying a driving signal to the liquid crystal panel by a gate start pulse (GSP) signal and a gate start clock (GSC) signal generated by the control signal converter of the transmitter. .

Description

Image display device and operating method

The present invention relates to an image display device and a method of driving the same , and more particularly, to supply a signal for displaying an image on a liquid crystal panel, by integrating the image signal supply unit and directly transmitting the signal to a gate / source drive IC. The present invention relates to an image display apparatus and a driving method thereof, which can reduce the image quality and prevent degradation of image quality due to electromagnetic interference (EMI) .

BACKGROUND ART A liquid crystal display (LCD), which is generally used as a flat panel display device, is a display device that combines a liquid crystal technology and a semiconductor technology using optical properties of a liquid crystal whose molecular arrangement is changed by an electric field.

The liquid crystal display is composed of two glass substrates and liquid crystals enclosed therebetween, and the gate line, the data line, the thin film transistor, and the pixel electrode are disposed on the lower substrate of the two glass substrates, and are used to display color. The color filter layer is disposed on the upper substrate.

That is, the lower substrate includes a plurality of gate lines, a plurality of data lines arranged in a direction crossing the gate line, a thin film transistor formed at an intersection of each gate line and the data line, and a drain electrode of the thin film transistor. And a pixel electrode connected to the upper substrate, an R, G, and B color filter layer on the upper substrate, a black matrix layer for blocking light from being transmitted to a portion other than the pixel electrode, and a voltage to the liquid crystal together with the pixel electrode. The common electrode for application is arranged.

The thin film transistor includes a gate electrode extending from the gate line on the lower glass substrate, a semiconductor layer used as a channel region of the thin film transistor through a gate insulating layer on the gate electrode, and a source facing each other on the semiconductor layer. And a drain electrode.

Such a liquid crystal display device employs a thin film transistor (TFT) as a switching element for switching whether or not signal data is applied to each pixel electrode. The thin film transistor is turned on or off by turning the thin film transistor on or off. On / off is determined. The gate driving circuit used to determine the on / off of the thin film transistor sequentially drives the gates of the thin film transistors formed in each of the pixels one by one, so that data is transferred from the source drive IC to each pixel through the data line. To be delivered.

When a signal is applied to the liquid crystal display to display an image, when a gray voltage of the same polarity is continuously applied to the pixel electrodes, ionic impurities in the liquid crystal material are precipitated due to the characteristics of the liquid crystal, and thus Electrical and chemical changes occur, resulting in a decrease in brightness or an afterimage.

To prevent this, frame inversion, line inversion, and dot inversion methods are applied according to the period of inversion of the polarity to periodically invert the polarity of the gray voltage applied to the pixel electrode. Doing.

As described above, the data signal driving signal applied to display the liquid crystal display device combines the graphic signal transmitted from the system and the signal uniformly converted in the module circuit of the liquid crystal display device to the drive IC attached to the liquid crystal display panel. The signal is transmitted, and the signal is transmitted in the pixel area of the matrix of the liquid crystal display using the same.

1 is a view for explaining an image display in the liquid crystal display according to the prior art.

As shown in FIG. 1, in a system 8 for generating a graphic signal, for example, an image signal supply unit, digital signals and various control signals are applied to a module circuit of a liquid crystal display device. The data signals and the control signals applied to the?) Are supplied with the driving signal and the data signal to the source drive 5 and the gate drive 3 through a constant conversion.

At this time, the source drive (5), by using a gamma voltage to be applied from the input R, G, B graphics signal and a gamma voltage generator (6) which converts the digital graphic signal into an analog signal pixel of the liquid crystal panel (1) Apply a signal to the area.

In order to turn ON the TFT elements arranged in the pixel region of the liquid crystal panel 1, a driving signal is controlled by the control unit 7 and then applied to the gate drive 3, and the gate drive 3. ), A driving signal is applied to a plurality of gate bus lines on a pixel area of the liquid crystal display device.

The TFT is turned on when a signal is applied to each of the gate electrodes arranged in the gate pixels for each gate bus line according to the driving signal applied from the gate drive 3. Whereby when the state in which the TFT on, applied to the pixel electrode with a data signal applied from the drive source (5) is contact with the drain electrode of the TFT to generate an electric field for driving the image.

In general, 1024 x 3 (RGB) data bus lines exist in a liquid crystal panel having an XGA (1024 x 768 pixels) resolution. Therefore, for example, eight source drives having 384 channel output stages (384 x 8 = 3072) are used in a liquid crystal display device having an XGA-class resolution, and four gate drivers having 200 output stages are generally used.

2 is a view for explaining a signal transmission step from a system to a drive IC according to the prior art.

As shown in FIG. 2, a video image signal transmitted from a system, for example, a video signal supply unit, is first transmitted from a system transmitter to a receiver having a liquid crystal display module circuit mounted thereon. Then, the receiving end transmits the R, G, and B image signals and the horizontal and vertical synchronizing signals to the timing control part, and the timing control part distributes the R , G and B signals to the source drive IC while driving the gate drive IC. Control the signal.

That is, the timing control unit adjusts whether or not a signal is applied to the pixel according to the timing of the source drive IC and the gate drive IC.

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3A and 3B illustrate signal waveforms used in FIG. 2.

As shown in FIG. 3A, when a signal is transmitted from a transmitting end of a system to a receiving end of a PCB on which a module circuit of a liquid crystal display device is mounted, a video data signal is transmitted using a transmission minimized differential signaling ( TMDS ) timing method. a method of transferring data signals 3pair (RXE1, RXE2, RXE3) by the signal (RXEC).

The 8-bit R, G, and B data signals RXE1, RXE2, and RXE3 are respectively transmitted through three transmission lines by the pair pair clock signal RXEC. As shown in FIG. Are sent. It can be seen that the first transmitted signal is an enable signal and a 4-bit video signal.

The signal transmitted through the transmitting end of the system is input to the receiving end in which the module circuit of the liquid crystal display device is mounted . The receiving end transmits the signal to the timing control unit together with the vertical and horizontal synchronizing signals applied from the external module circuit.

That is, when the video signal is transmitted from the system by the TMDS Timing method, the signal is applied to the timing control unit together with the vertical and horizontal synchronization signals in the LCD module circuit.

The timing controller transmits a signal to the gate or source drive IC by adjusting the vertical and horizontal synchronization signals with the transmitted R, G, and B image signals.

The gate drive IC applies a signal while scanning a driving signal in a line direction, and turns on / off the TFTs disposed in each line by a driving signal applied to a predetermined line so that a data signal is applied to a pixel. .

The timing controller generates a signal for controlling the on / off of each line at a predetermined time and applies the driving signal to the gate drive IC.

The data signal is transmitted through the data bus line at a predetermined time so that the image may be applied to the source drive IC along with the gamma voltage in accordance with the R, G, and B signals and the vertical horizontal synchronization signal.

In this case, the timing control unit transmits a signal to a gate or source drive IC using a reduced swing differential signaling ( RSDS ) timing method.

3B illustrates signals applied to the drive IC by the timing controller.

12pair data signals (RSR1N / P, RSR2N / P, RSR3N / P, RSR4N / P, RSG1N / P, RSG2N / P, RSG3N / P ) by 1pair clock signal (RSCLKN / P) from the timing controller RSG4N / P, RSB1N / P, RSB2N / P, RSB3N / P, RSB4N / P) are transmitted.

Compared to the TMDS Timing method, the data compression rate is higher, indicating that 8-bit R, G, and B data signals are transmitted during one clock signal cycle. Each R signal is transmitted to the drive IC through a 4pair signal. have.

However, in the liquid crystal display transmission structure having the above structure, since the graphic data generated in the system is received at the receiving end of the liquid crystal display module circuit at the transmitting end and then transmitted to the drive IC via the timing control unit, the electrical interference phenomenon is intensified. There is a problem.

In addition, since the signals to be transmitted are controlled by the receiving terminal and the control, which are each independently arranged, and then transmitted to the drive IC, the number of components is increased, and the circuit pattern of the PCB of the LCD is complicated.

The present invention provides a novel signal for transmitting six pairs of R, G, and B signals by one pair of clock signals so that the image signal and the driving signal applied from the image signal supply unit can be directly transmitted to the drive IC of the liquid crystal display module circuit. by adopting such a transmission method, to provide an image display device and a driving method thereof, as well as to remove the medium components for signal processing, to prevent the electrical interference caused by the signal transmission it is an object.

In order to achieve the above object, the image display device according to the present invention,

In order to supply a video signal, the transmitter comprising a control signal conversion unit for applying a transmitter and converts the control signal to the liquid crystal panel to provide an image data signal;

A receiver for receiving an image data signal transmitted from the transmitter , a data register for storing the image data signal received by the receiver, a data latch unit for storing the image data signal stored in the data register for a predetermined time, and the data Converts a digital image data signal into an analog signal by using a shift register for shifting a signal stored in the latch unit, the image data signal transmitted from the data latch unit, and a gamma voltage, and then outputs the image data signal to the liquid crystal panel. A source drive IC having a digital / analog converter; And

And a gate drive IC for applying a driving signal to the liquid crystal panel by a gate start pulse (GSP) signal and a gate start clock (GSC) signal generated by the control signal converter of the transmitter .

Here, the transmitter transmits six pairs of R, G, and B data signals to the receiver by one pair of clock signals .

In addition, the image display device driving method according to the present invention comprises the steps of converting a control signal for driving the liquid crystal panel in a transmitting end for supplying a video signal; Transmitting a control signal converted at the transmitting end to a source driver IC and a gate driver IC for driving the liquid crystal panel, and transmitting R, G, and B data signals to the source driver IC at the transmitting end; Driving the liquid crystal panel and displaying an image by the transmitted control signal and the R, G, and B data signals; In that it comprises the features.

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The transmitter may transmit six pairs of R, G, and B data signals to the source driver IC based on one pair of clock signals .

According to the present invention, when a video digital signal used in a liquid crystal display device is transmitted to a drive IC, a single pair clock signal and a six pair data signal processed by a timing control are transmitted directly to the drive IC. By doing so, it is possible to reduce the number of components for signal transmission and to minimize the electromagnetic interference.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a view for explaining signal transmission in the image display apparatus according to the present invention .

As shown in FIG. 4 , a video signal applied by a system, for example, a video signal supply unit , is directly supplied with a data signal, a control signal, and a clock signal from a transmitter to a drive IC.

That is, after converting the control signals applied to the vertical and horizontal synchronization signals and the drive IC in the transmitting end of the system, the converted signals are applied to the drive IC together with the image data signal.

The control signal applied to the drive IC includes a gate start clock signal, a gate pulse signal, and enable signals applied to a latch circuit of the source drive IC.

The transmitter of the system applies a signal to a gate or source drive IC directly by the control signal applying line, a data signal line capable of applying an image data signal, and a clock signal applying line.

5 is a view for explaining signal transmission between components in the image display apparatus according to the present invention .

As shown in FIG. 5, a signal is directly applied to the gate drive IC 20 and the source drive IC 10 at the transmitting end 11 of the system. Since the R, G, and B image data are applied to the source drive IC 10, the following description will focus on signal processing in the source drive IC 10. FIG.

First, the transmitting unit 12 of the transmitting end 11 of the system includes six pairs of R, G, B, data signals (RSR1N / P, RSR2N / P, RSG1N / P, RSG2N / P, RSB1N / P). RSB2N / P is directly transmitted to the receiving unit 14 of the source drive IC 10, and the transmitting end 11 includes a control signal converting unit 13 for converting control signals HSYNC, VSYNC . In this case, the control signals SSP, SOE, GSP, and GSC applied to the gate drive IC 20 and the source drive IC 10 are integrally transmitted through separate lines.

That is, the control signal converter 13 converts a signal that can be finally driven by the gate drive IC 20 and the source drive IC 10 in the system transmitter 11 to convert R, G, and B data. Similar to the transmission, it was sent directly to the drive IC.

And the source drive IC (10) includes a receiving unit 14 for receiving a video data signal, a data register 15 for storing the received data information from the receiving unit 14, a data signal stored in the data register 15 It is configured to include a data latch unit 17 receives the transmission .

At this time, when a signal is applied to the data latch unit 17, a shift signal by vertical and horizontal synchronization signals is received from the shift register 16 so as to transmit a data signal while shifting for each data bus line.

After the gamma voltages applied from the digital / analog converter unit 18 are selected by the R, G, and B signals latched by the data latch unit 17, the selected signal is stored in the buffer unit 19 , and the stored The signals are applied to the matrix pixels of the liquid crystal panel, respectively.

In addition, a control signal is converted and transmitted by the system transmitter 11, and the control signal transmitted by the transmitter 11 is as follows. First, the vertical and horizontal synchronizing signals VSYNC and HSYNC are converted by the control signal converter 13 and then applied to the shift register 16 embedded in the source drive IC 10. First, the source start pulse SSP Signal is applied to the shift register 16 to start an operation, and then image data transferred from the data register 15 to the data latch unit 17 can be applied to the liquid crystal display pixel.

The transmitter 11 generates a GSP signal to be applied to the gate drive IC 20 and a GSC signal, and a gate start pulse (GSP) signal enables the gate drive IC 20 to operate for the first time. The GSC (Gate Start Clock) signal is a signal for applying a driving signal while being sequentially shifted along the gate bus line.

In addition, the transmitting end 11 applies an SOE signal to the data latch unit 17 in the source drive IC 10. The SOE signal source outputs an image signal latched to the data latch unit 17 . This is a signal for transmitting to the digital / analog converter unit 18 .

6 is a view for explaining a signal waveform transmitted from the image display device according to the present invention .

In FIG. 6, the signal is transmitted from the transmitting end of the system to the source drive IC. The system transmitter is capable of transmitting image data signals, clock signals, vertical and horizontal synchronization signals, and control signals used in the module circuits of the liquid crystal display, and converts signals to be applied to the drive ICs inside the transmitter. A control signal converter is provided .

The transmitter transmits data using two lines, each of which is divided into R, G, and B signals of the system ((RSR1N / P, RSR2N / P), (RSG1N / P, RSG2N / P). ), (RSB1N / P, RSB2N / P)) .

In the present invention, the signal processed at the system transmitter can be transmitted to the drive IC immediately after removing the intermediate transfer procedure . It can be seen that all 8-bit data signals are transmitted during two cycles of the clock signal .

In addition, the control signal applied to the drive IC is integrally transmitted through a separate line, and only the R, G, and B image data signals can transmit data by 4 bits through the six lines.

In the two lines per cycle of the clock signal, the R data signal is transmitted with 4 bits of 2 bits each, and 8 bits of the data signal are transmitted with 4 bits of 2 bits each of the clock signal.

Similarly, G and B data signals are transmitted in the same way.

As described above, in the present invention, a signal applied to the drive IC by the system, for example, the image signal supply unit , is integrated and the source data and the drive signal are directly applied by the source drive IC and the gate drive IC without intermediate signal intermediation.

Thus, there is an advantage that can reduce noise, electromagnetic interference, and components due to signal transmission.

As described in detail above, the present invention integrates a signal used in a module circuit in a transmitting end of a system for supplying a graphic signal to directly output 6-pair R, G, and B data signals by a one-pair clock signal. By applying to, there is an effect that can reduce the number of parts.

In addition, compared with the prior art, the intermediate part for mediating the signals applied to the drive IC of the liquid crystal display device is removed, which not only simplifies the manufacturing work but also prevents signal interference due to electromagnetic interference (EMI) . It has an effect.

The present invention is not limited to the above-described embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

1 is a view for explaining an image display in the liquid crystal display device according to the prior art.

2 is a diagram for explaining a signal transmission step from a system to a drive IC according to the prior art;

3A and 3B show signal waveforms used in FIG.

4 is a diagram for explaining signal transmission in an image display device according to the present invention;

FIG. 5 is a view for explaining signal transmission between components in an image display apparatus according to the present invention; FIG.

6 is a view for explaining a signal waveform transmitted from the image display device according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: source drive IC 11: transmitter

12: transmitter 13: control signal converter

14: receiver 15: data register

16: shift register 17: data latch portion

18: digital / analog converter section 19: buffer section

20: gate drive IC

Claims (7)

In order to supply a video signal, the transmitter comprising a control signal conversion unit for applying a transmitter and converts the control signal to the liquid crystal panel to provide an image data signal; A receiver for receiving an image data signal transmitted from the transmitter , a data register for storing the image data signal received by the receiver, a data latch unit for storing the image data signal stored in the data register for a predetermined time, and the data Converts a digital image data signal into an analog signal by using a shift register for shifting a signal stored in the latch unit, the image data signal transmitted from the data latch unit, and a gamma voltage, and then outputs the image data signal to the liquid crystal panel. A source drive IC having a digital / analog converter; And By a gate start pulse (GSP) signal and the gate start clock (GSC) signal generated by the conversion control signal of the transmitter section gate drive IC for applying a driving signal to the liquid crystal panel; image display device comprising the . The method of claim 1, The transmission unit is a video display device, characterized in that six pairs of transmitting R, G, B data signals by the first pair of clock signals to the receiver. delete The method of claim 1, And the control signal converting unit transmits a source output enable signal and a source start pulse signal to the source drive IC. Converting a control signal for driving the liquid crystal panel in a transmitter for supplying a video signal; Transmitting a control signal converted at the transmitting end to a source driver IC and a gate driver IC for driving the liquid crystal panel, and transmitting R, G, and B data signals to the source driver IC at the transmitting end; Driving the liquid crystal panel and displaying an image by the transmitted control signal and the R, G, and B data signals; Image display device driving method comprising a. The method of claim 5, wherein The control signal converted at the transmitting end and provided to the source driver IC and the gate driver IC includes a source output enable (SOE) signal, a source start pulse (SSP) signal, a gate start clock (GSC) signal, and a gate start pulse ( And a GSP) signal. The method of claim 5, And the transmitting end transmits six pairs of R, G, and B data signals to the source driver IC according to one pair of clock signals.