KR100733885B1 - Method For Driving Data lines and Licquid Crystal Display Apparatus Using The same - Google Patents

Abstract

The present invention relates to a data line driving method and a liquid crystal display for precharging and initializing data lines using a sampling switch control signal of a data line.

The present invention eliminates the need for generating a separate precharge control signal by precharging the data lines to a predetermined level in response to a control signal for sampling the data lines.

Description

Data line driving method and liquid crystal display device using the same {Method For Driving Data lines and Licquid Crystal Display Apparatus Using The same}

1 is a view showing a conventional liquid crystal display device.

FIG. 2 is a waveform diagram illustrating data line driving signals of the liquid crystal display shown in FIG. 1.

3 is a diagram illustrating a voltage variation of a data line shown in FIG. 1.

4 is a view showing another conventional liquid crystal display device.

5 illustrates a liquid crystal display according to a first embodiment of the present invention.

FIG. 6 is a diagram illustrating a data driver of the liquid crystal display illustrated in FIG. 5.

7 is a view showing in detail the configuration of the output unit of the data driver shown in FIG.

FIG. 8 is a waveform diagram illustrating data line driving signals of the liquid crystal display illustrated in FIG. 5.

9 illustrates a liquid crystal display device according to a second embodiment of the present invention.

10 illustrates a liquid crystal display according to a third embodiment of the present invention.

FIG. 11 illustrates a liquid crystal display according to a fourth embodiment of the present invention. FIG.

<Description of Symbols for Main Parts of Drawings>

10,40: pixel array 20: sampling switch unit

30: precharge switch unit 32: precharge control signal generator

50: precharge / sampling switch unit 54: data driver

22, 52, 62: demultiplexer control signal generator

The present invention relates to a data line driving method of a liquid crystal display, and more particularly, to a data line driving method and a liquid crystal display for precharging and initializing data lines by using a sampling switch control signal of a data line.

Liquid crystal displays are flat panel displays having the advantages of small size, thinness, and low power consumption. Such liquid crystal displays are being used as notebook PCs, office automation devices, audio / video devices, and the like. In particular, an active matrix type liquid crystal display device is suitable for displaying a dynamic image by using a thin film transistor (hereinafter referred to as TFT) as a switch element. Recently, research has been actively conducted on polysilicon TFTs in which more peripheral driving circuits can be integrated than conventional amorphous silicon TFTs.

In the liquid crystal display, pixels are arranged in a matrix at an intersection of Nn data lines DL11, DL12, .. DLNn and m gate lines GL1, GL2,..., GLm as shown in FIG. 1. The pixel array 10 is provided between the N video bus lines VL1, VL2, ..., VLN and the Nn data lines DL11, DL12, .. DLNn, and the video signals Video1, Video2, And a sampling switch section 20 for supplying ... VideoN to the data lines DL11, DL12, .. DLNn. The sampling switch section 20 supplies the N video signals Video1, Video2, ... VideoN to the Nn data lines DL11, DL12, .. DLNn, thereby providing the video bus lines VL1, VL2, ... Will reduce the number of VLNs). The sampling switch unit 20 includes N demultiplexers DMX1, ..., DMXN connected between any one of the N video bus lines VL1, VL2, ..., VLN and n data lines. And each of the demultiplexers DMX1, ..., DMXN includes n TFTs.

Each of the TFTs T11, T12, ..., TNn is turned on in accordance with the control signals .phi.1, .phi.2, ..., .phi.n, so that the N video bus lines VL1, VL2,. The video signal supplied via the demultiplexer input lines DIL1, ..., DILN connected to any one of the .V, VLN lines is supplied to the data line. The control signals? 1,? 2, ...,? N supplied to the gate terminals of the TFTs T11, T12, ..., TNn are generated by the demultiplexer control signal generator 22. Each of these control signals phi 1, phi 2, ..., phi n is sequentially changed to high logic in synchronization with the video signal during one horizontal synchronous signal 1H as shown in FIG. In response to the control signals φ1, φ2, ..., φn, each of the TFTs T11, T12, ..., TNn is sequentially turned on to display the corresponding video signals in the data lines DL11, DL12, ... ., DLNn).

On the other hand, in order to improve the image quality, adjacent data lines DL11, DL12, ..., DLNn are supplied with data voltages having opposite polarities. Accordingly, the pixels are charged / discharged at different voltage levels to generate a voltage difference. The voltage difference between these pixels causes color signal difference and luminance difference between adjacent pixels, thereby degrading image quality. For example, as illustrated in FIG. 3, the red pixels connected to the first data line DL11 are charged to 6V, the adjacent green pixels are charged to 0V, and the red pixels connected to the fourth data line DL14 are 4V. The charged and adjacent blue and green pixels are charged to 10V. In this case, each of the red pixels connected to the first data line DL11 and the pixels connected to the fourth data line DL14 is changed to 5.8V and 4.2V by coupling with adjacent pixels so that a desired color signal is obtained. And luminance cannot be obtained. In addition, when data voltages having opposite polarities are supplied to the data lines DL11, DL12,..., DLNn, the power difference is increased because the voltage difference appears as large as the voltage variation between the data line or the pixel. .

To this end, the liquid crystal display includes a precharge switch unit 30 for charging the data lines DL11, DL12, ..., DLNn to an arbitrary intermediate level as shown in FIG. The precharge switch unit 30 charges all of the data lines DL11, DL12,..., DLNn with the precharge signal Vpc before the video signal is supplied, and supplies the data lines DL11, DL12,..., DLNn. ) Will be initialized. The precharge signal Vpc is supplied from the precharge line PCL formed at the lower end of the pixel array 10. The precharge switch unit 30 includes Nn TFTs CT11, CT12, .. CTNn connected between the data lines DL11, DL12,..., DLNn and the precharge line PCL. Each of the TFTs CT11, CT12, ..., CTNn is turned on according to the precharge control signal Pre-EN to close all of the data lines DL11, DL12, ..., DLNn. It is connected to the precharge line PCL. As shown in FIG. 2, the precharge control signal Pre-EN is generated from the precharge control signal generator 32 before the video signals are supplied to the data lines DL11, DL12,..., DLNn. do.

As such, when the data lines DL11, DL12, ..., DLNn are charged to an intermediate voltage before data is supplied, voltage fluctuations are reduced by 1/2 during charging / discharging of the data lines or pixels, and thus, between adjacent data lines or pixels. The coupling of is reduced, and the image quality characteristic is improved. In addition, as the voltage fluctuation width is reduced by the precharge, not only power consumption is reduced, but also an output signal of a data driver (not shown) for supplying a video signal to the video bus lines VL1, VL2, ..., VLN. Since the swing width is reduced to 1/2, the data line or pixel charge time is reduced.

Meanwhile, as illustrated in FIG. 4, the precharge line PCL may be formed on the upper portion of the pixel array 10. In this case, the precharge TFTs CT11, CT12, ... CTNn are formed between the precharge line PCL and the demultiplexer TFTs T11, T12, ..., TNn.

However, since the conventional precharge switch unit 30 requires separate TFTs (CT11, CT12, .. CTNn) and the precharge control signal generator 32, the effective display area of the display panel is reduced, and in the related art, The precharge control signal has a disadvantage in that manufacturing cost increases, such as adding a level shifter to generate a high voltage pulse of 15 to 20 Vpp. In addition, the conventional precharge switch unit 30 has a problem in that a leakage current is generated by the TFTs CT1, CT12,... CTNn, causing a voltage variation of data lines or pixels, thereby deteriorating image quality.

Accordingly, an object of the present invention is to provide a data line driving method that does not require a separate precharge circuit and a liquid crystal display using the same.

Another object of the present invention is to provide a data line driving method for reducing precharge time and a liquid crystal display using the same.

In order to achieve the above object, the data line driving method of the present invention charges the data lines to a predetermined level in response to a control signal for sampling the data lines.

The data line driving method of the present invention includes charging data lines to a predetermined level in response to a control signal, and supplying video signals to the data lines in response to the control signal.

The data line driving method of the present invention comprises the steps of: shorting data lines mutually in response to a control signal, charging the data lines to a predetermined level, opening a path between the data lines in response to the control signal; And sequentially supplying video signals to the data lines in response to the control signal.

The liquid crystal display of the present invention is provided with data driving means for generating a precharge signal of a predetermined level, control signal generating means for generating a control signal, and is provided between video signal input lines and data lines to respond to the control signal. Switching means for charging the data lines with the precharge signal.

The liquid crystal display device of the present invention comprises a precharge signal source for generating a precharge signal of a predetermined level, control signal generating means for generating a control signal, and switching between a video signal input line and a data line in response to the control signal. And a precharge line for supplying the precharge signal to the data lines in common, and a precharge switch element for switching the precharge line in response to the control signal.

The liquid crystal display of the present invention provides a precharge signal source for generating a precharge signal of a predetermined level, control signal generating means for generating a control signal, and supplies one video signal to a plurality of data lines in response to the control signal. And a precharge switch for supplying a precharge signal, and a precharge switch element for switching between an input line and a precharge line of the demultiplexer in response to a control signal.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 5 to 11.

5 and 6, the liquid crystal display according to the first exemplary embodiment of the present invention includes Nn data lines DL11, DL12, .. DLNn and m gate lines GL1, GL2,. Pixel array 40 in which pixels are arranged in a matrix at the intersection of GLm, N video bus lines VL1, VL2, ..., VLN and Nn data lines DL11, DL12, ..., A precharge / sampling switch unit 50 provided between the DLNn to sequentially supply the precharge signal and the video signals Video1, ..., VideoN to the data lines DL11, DL12, .. DLNn. And a data driver 54 for generating precharge signals and video signals Video1, ..., VideoN. The precharge / sampling switch unit 50 supplies the precharge signal to all of the data lines DL11, DL12, ..., DLNn, and then sequentially supplies the video signals Video1, Video2, ... VideoN. It will play a role. The video / sampling switch section 50 includes N demultiplexers DMX1, ..., connected between any one of the N video bus lines VL1, VL2, ..., VLN and n data lines. DMXN), and each of the demultiplexers DMX1, ..., DMXN includes n TFTs. Each of the TFTs T11, T12, ..., TNn is turned on in accordance with the control signals .phi.1, .phi.2, ..., .phi.n, so that the N video bus lines VL1, VL2,. The pre-charge signal and the video signals (Video1, Video2, ..., VideoN) supplied via the demultiplexer input lines (DIL1, ..., DILN) connected to any one of the .., VLN data lines. It is supplied to (DL1, DL2, ..., DLNn). The control signals? 1,? 2, ...,? N supplied to the gate terminals of the TFTs T11, T12, ..., TNn are generated from the demultiplexer control signal generator 52. The data driver 54 is commonly connected to the video bus lines VL1, VL2,..., And VLN so that the precharge signal and the video signals Video1, Video2,..., VideoN are sequentially connected to the video bus lines VL1. , VL2, ..., VLN).

As shown in FIG. 7, the data driver 54 includes buffers BF1, BF2, ..., BFN connected to each of the video bus lines VL1, VL2, ..., VLN, and video signals Video1, Video2. Video signal switching switches (SWA1, SWA2, ..., SWAN) for switching, ..., VideoN, capacitor (C) for charging / discharging supply voltage (Vcc), capacitor (C) Precharge signal switching switches SWB1, SWB2, ..., SWBN for supplying the charging voltage Vc to the video bus lines VL1, VL2, ..., VLN. The buffers BF1, BF2, ..., BFN level match the voltage levels of the video signals Video1, Video2, ..., VideoN to a level suitable for the pixel array 40. The video signal switching switches SWA1, SWA2, ..., SWAN are closed in the period in which the capacitor C is charged, while they are opened in the period in which the capacitor C is discharged. The precharge signal switching switches SWB1, SWB2, ..., SWBN are opened in the period in which the capacitor C is charged, while being closed in the period in which the capacitor C is discharged. The capacitor C charges the supply voltage Vcc while the precharge signal switching switches SWB1, SWB2, ..., SWBN are open, and the capacitors of the video signals Video1, Video2, ..., VideoN. The precharge signal is generated by discharging the charged voltage in a period in which the supply is cut off, that is, in a period in which the precharge signal switching switches SWB1, SWB2, ..., SWBN are closed.

Each of the control signals φ1, φ2, ..., φn is changed to high logic at the same time during one horizontal synchronous signal 1H as shown in Fig. 8, and then synchronized with the video signals Video1, Video2, ..., VideoN. In order to change to high logic. In detail, the horizontal synchronizing signal H is changed to the high logic and all of the first to n th control signals? 1,? 2, ...,? N are changed to the high level. Then, the first to n th TFTs T11, T12,..., And TNn are simultaneously turned on in response to the first to n th control signals. Commonly supplied to the lines DL11, DL12, ..., DLNn. At this time, the video signal switching switches SWA1, SWA2, SWAN remain open, while the precharge signal switching switches SWB1, SWB2, SWBN are closed. Will be maintained. After the precharge signal is supplied, the first control signal φ1 maintains high logic while the second to nth control signals φ2 to φn are inverted to low logic. At the same time, the video signal switching switches SWA1, SWA2, ..., SWAN are closed, and the precharge signal switching switches SWB1, SWB2, ..., SWBN are opened. Accordingly, the first TFT T11 maintains the turn-on state in response to the first control signal .phi.1, and transmits the video signals Video1, Video2, ..., VideoN to the data lines DL11, DL12, ... And DLNn, and the second to nth TFTs T12, T13, ..T1n, ..TN2, TN3 .., TNn are turned off. Subsequently, the first control signal φ1 is inverted to low logic, while the second to nth control signals φ2 to φn are sequentially changed to high logic. At this time, the video signal switching switches SWA1, SWA2, ..., SWAN remain closed, while the precharge signal switching switches SWB1, SWB2, SWBN remain open. Done. Accordingly, the second to n-th TFTs T12, T13, ..T1n, ..TN2, TN3, ..TNn are sequentially turned on to output the video signals Video1, Video2, ..., Video. Lines DL12, DL13, .. DL1n, .. DLN2, DLN3, .. DLNn.

As described above, the liquid crystal display according to the first exemplary embodiment of the present invention precharges the control signals φ1, φ2, ..., φn generated from the demultiplexer control signal generator 52 and the data lines. (DL11, DL12, ..., DLNn) are driven. As a result, the driving circuit and the precharge signal switching TFTs for generating a separate precharge control signal are unnecessary. In addition, the precharge time can be reduced by using a demultiplexer TFT having excellent charging or driving ability as the precharge TFT. On the other hand, when both the output line or the output pin of the data driver 54 are shorted, the capacitor C is switched to a floating state to generate a precharge signal or a separate voltage supply source instead of the capacitor C is used as a precharge signal. May occur.

Referring to FIG. 9, the liquid crystal display according to the second exemplary embodiment of the present invention is connected in series between the data lines DL11, DL12, .. DLNn to share the data lines DL11, DL12, .. DLNn in common. Precharging TFTs (CTa1, CTb1, .., CTbn) for connection to each other.

The precharge TFTs CTa1, CTb1,..., CTbn are arranged such that two precharge TFTs are connected in series between an adjacent data line, for example, the first data line DL11 and the second data line DL12. Is placed. In addition, the precharge TFTs CTa1, CTb1, .., CTbn are two precharge charges between adjacent demultiplexer TFTs, for example, a first demultiplexer TFT T11 and a second demultiplexer TFT T12. TFTs are arranged to be connected in series. That is, the first and second precharge TFTs CTa1 and CTb1 connected between the first and second data lines DL11 and DL12 are connected in series between the first and second demultiplexer TFTs T11 and T12. Is connected. The control signal supplied to the precharge TFTs CTa1, CTb1, ..., CTbn is the same as the control signal of the demultiplexer TFTs connected to the adjacent data lines. Accordingly, each of the precharge TFTs CTa1, CTb1,..., CTbn has adjacent data in response to the control signals φ1, φ2,..., Φn generated from the demultiplexer control signal generator 62. It is controlled simultaneously with the TFT for demultiplexer connected to the line. For example, the second control signal φ2 generated from the demultiplexer control signal generator 62 is a second demultiplexer TFT (T12), a second precharge TFT (CTb1), and a third precharge TFT (CTa2). ) Will be controlled at the same time. Accordingly, the second control signal? 2 becomes the control signals? J1 and? I2 for controlling the second precharge TFT CTb1 and the third precharge TFT CTa2.

Each of the control signals φ1, φ2, ..., φn is substantially the same as in FIG. That is, each of the control signals φ1, φ2, ..., φn is changed to high logic at the same time during one horizontal synchronous signal 1H. Accordingly, the horizontal synchronizing signal H is changed to high logic and all of the first to nth control signals φ1, φ2, ..., φn are changed to high level so that the precharge TFTs CTa1, CTb1, ..., CTbn are turned on at the same time, shorting all of the data lines DL11, DL12,..., DLNn. At this time, as shown in FIG. 6, the data driver 54 supplies a data signal for supplying the video signals Video1, Video2, ..., VideoN to the data lines DL11, DL12, ..., DLNn. It generates a signal corresponding to the average value of. This signal is supplied to the data lines DL11, DL12, ..., DLNn while the precharging TFTs CTa1, CTb1, ..., CTb1n are turned on, and the data lines DL11, DL12,. .., DLNn) will all be precharged to the same level. After the data lines DL11, DL12, ..., DLNn are precharged, each of the control signals φ1, φ2, ..., φn is synchronized with the video signals Video1, Video2, ..., VideoN. In turn, the logic changes to high logic. On the other hand, while the video signals Video1, Video2, ..., VideoN are supplied, since two precharge TFTs are connected in series between adjacent data lines, the precharge TFTs connected between adjacent data lines are connected to the video signal ( Video1, Video2, ..., VideoN) are not turned on at the same time while being supplied. Therefore, the precharge TFTs CTa1, CTb1, ..., CTbn affect the video signals Video1, Video2, ..., VideoN supplied to the data lines DL11, DL12, ..., DLNn. Will not give. In other words, while the video signals Video1, Video2, ..., VideoN are supplied, the precharge TFTs connected between adjacent data lines are not turned on at the same time, thus preventing the adjacent data lines from being shorted. Will be.

As described above, the liquid crystal display shown in FIG. 9 uses the control signals φ1, φ2, ..., φn generated from the demultiplexer control signal generator 52, and the data lines DL11, DL12, ..., ... By precharging DLNn, a separate precharge control signal generator is unnecessary. Further, in the liquid crystal display shown in FIG. 9, since the precharge TFTs connected in series between adjacent data lines have a larger resistance value than one precharge TFT, the data lines DL11, DL12, .. DLNn It is possible to minimize the leakage current applied to the side. On the other hand, the control signals φ i1, φ j1,..., Φ in, φ jn for controlling the precharge TFTs connected between adjacent data lines are supplied while the video signals Video 1, Video 2, ..., VideoN are supplied. It is preferable not to adjoin so that adjacent data lines are not shorted. Further, it is preferable that the loads of the control signals φ i1, φ j1,..., Φ in, φ jn remain the same. This is to maintain image quality uniformity by maintaining the rising time and the falling time of the control signals φ i1, φ j1,..., Φ in, φ jn.

Referring to FIG. 10, the liquid crystal display according to the third exemplary embodiment of the present invention is connected in series between the data lines DL11, DL12, .. DLNn and the precharge line PCL to receive the precharge signal Vpc. Pre-charging TFTs CTa1, CTb1, .., CTbn for supplying to the data lines DL11, DL12, .. DLNn in common. The precharge TFTs CTa1, CTb1,..., CTbn have two precharge lines between one data line and a precharge line PCL, for example, a first data line DL11 and a precharge line PCL. The charge TFTs CTa1 and CTa2 are arranged to be connected in series. The control signal supplied to the precharge TFTs CTa1, CTb1, ..., CTbn is the same as the control signal of the demultiplexer TFTs connected to the adjacent data lines. Accordingly, each of the precharge TFTs CTa1, CTb1,..., CTbn has adjacent data in response to the control signals φ1, φ2,..., Φn generated from the demultiplexer control signal generator 62. It is controlled simultaneously with the TFT for demultiplexer connected to the line.

Each of the control signals φ1, φ2, ..., φn is substantially the same as in FIG. That is, each of the control signals φ1, φ2, ..., φn is changed to high logic at the same time during one horizontal synchronous signal 1H. Accordingly, the horizontal synchronizing signal H is changed to high logic and all of the first to nth control signals φ1, φ2, ..., φn are changed to high level so that the precharge TFTs CTa1, CTb1, CTbn are turned on at the same time, shorting all of the data lines DL11, DL12, ..., DLNn to the precharge line PCL. At this time, the precharge signal Vpc is supplied to the precharge line PCL to precharge all of the data lines DL11, DL12, ..., DLNn to the same level. After the data lines DL11, DL12, ..., DLNn are precharged, each of the control signals φ1, φ2, ..., φn is synchronized with the video signals Video1, Video2, ..., VideoN. In turn, the logic changes to high logic.

The liquid crystal display shown in FIG. 10 is precharged compared to the liquid crystal display shown in FIG. 9 by supplying a precharge signal Vpc suitable for precharging the data lines DL11, DL12, ..., DLNn. The voltages of the data lines DL11, DL12, ..., DLNn can be made uniform.

Referring to FIG. 11, the liquid crystal display according to the fourth exemplary embodiment of the present invention is connected in series between the demultiplexer input lines DIL1,..., DILN and the precharge line PCL to precharge signal Vpc. Precharge TFTs CTa1, CTb1, .., CTb1 / n for commonly supplying to the data lines DL11, DL12, .. DLNn.

The precharge TFTs CTa1, CTb1,..., CTb1 / n have one demultiplexer input line and a precharge line PCL, for example, between the first demultiplexer input line DIL1 and the precharge line PCL. Two precharge TFTs CTa1 and CTb1 are arranged in series to each other. The control signal supplied to the precharge TFTs CTa1, CTb1, ..., CTb1 / n is the same as the control signal of the demultiplexer TFTs connected to the adjacent data lines. Accordingly, each of the precharge TFTs CTa1, CTb1,..., CTb1 / n responds to the control signals φ1, φ2,..., Φn generated from the demultiplexer control signal generator 62. Controlled simultaneously with the demultiplexer TFTs connected to adjacent data lines.

Each of the control signals φ1, φ2, ..., φn is substantially the same as in FIG. That is, each of the control signals φ1, φ2, ..., φn is changed to high logic at the same time during one horizontal synchronous signal 1H. Accordingly, the horizontal synchronizing signal H is changed to high logic and all of the first to nth control signals φ1, φ2, ..., φn are changed to high level so that the precharge TFTs CTa1, CTb1, ..., CTb1 / n are turned on at the same time to shorten all of the data lines DL11, DL12,..., DLNn to the precharge line PCL. After the data lines DL11, DL12, ..., DLNn are precharged, each of the control signals φ1, φ2, ..., φn is synchronized with the video signals Video1, Video2, ..., VideoN. In turn, the logic changes to high logic.

When the liquid crystal display shown in FIG. 11 is compared with the liquid crystal display shown in FIGS. 9 and 10, the precharge TFTs CTa1, CTb1,..., CTbn have demultiplexer input lines DIL1,... Since the DILN and the precharge line PCL are connected in series, the number of the precharge TFTs CTa1, CTb1, ..., CTb1 / n is reduced by at least 1 / n. Accordingly, the liquid crystal display shown in FIG. 11 can reduce the area occupied by the precharge circuit as compared with those shown in FIGS. 9 and 10. In addition, since the precharge circuit is located above the sampling switch unit, it is possible to minimize the deterioration of image quality due to the precharge circuit.

As described above, the data line driving method and the liquid crystal display using the same according to the present invention precharge the data lines by using the sampling switch and the sampling control signal to separate the precharge switch, the precharge control signal generation circuit, and the like. No charge circuit is required. The data line driving method and the liquid crystal display using the same according to the present invention can reduce the precharge time by precharging the data lines using a sampling switch having a large driving capability.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (22)

A data line driving method of a liquid crystal display for precharging data lines to which a video signal is supplied via video signal input lines and pixels connected to the data lines, A control signal generating step of generating a first control signal using a single control signal generating means, A precharge step of simultaneously precharging the data lines to a predetermined level in response to the first control signal; And a video signal supplying step of sequentially supplying video signals to the data lines through a switching element located between the video signal input lines and the data lines in response to the first control signal. And a precharge signal and the video signal for supplying the precharge to the data lines through the switching element. The method of claim 1, Charging a precharge signal source while a video signal is supplied to the data lines, And the precharge signal source generates the precharge signal by discharging the charged voltage while the data lines are precharged. The method of claim 1, wherein the precharge step, Shorting the data lines with each other in response to the control signal; Precharging the data lines to a predetermined level; And opening the data lines mutually in response to the control signal. A liquid crystal display for precharging data lines to which a video signal is supplied via video signal input lines and pixels connected to the data lines. Data driving means for generating a precharge signal of a predetermined level; Control signal generating means for generating a first control signal; In response to the first control signal, the precharge signal is simultaneously supplied to the data lines through the video signal input lines to precharge the data lines, and then the video signals are sequentially supplied to the data lines. It is provided with a switching means for And the switching means is provided between the video signal input lines and the data lines, and the precharge signal and the video signal are supplied to the data lines through the switching means. delete The method of claim 4, wherein The switching means comprises a plurality of demultiplexers connected between one of the video signal input lines and a plurality of the data lines, And each of the demultiplexers connects the data lines to the video signal input lines in a period during which the data lines are precharged in response to the first control signal. The method of claim 6, Each of the demultiplexers includes a plurality of transistors having input electrodes connected to the same video signal input line, output electrodes connected to different data lines, and control electrodes commonly connected to the control signal generating means, And the precharge signal and the video signal are supplied to the data lines through the plurality of transistors. The method of claim 4, wherein The data driving means short-circuits the video signal input lines while the data lines are precharged, And opening the video signal input lines mutually after the data lines are precharged. The method of claim 8, And the data driving means supplies a video signal to the data lines after the data lines are precharged. The method of claim 4, wherein The data driving means includes a plurality of output electrodes connected in series to the video signal input lines, respectively; A plurality of first switch elements connected in series to each of the output electrodes; A precharge signal source for generating the precharge signal; And a second switch for switching a path between the precharge signal source and the video signal input line. The method of claim 10, And the precharge signal source is a capacitor which generates the precharge signal by discharging a charged voltage while the data lines are precharged. A liquid crystal display for precharging data lines to which a video signal is supplied via video signal input lines and pixels connected to the data lines. Control signal generating means for generating a first control signal; A sampling switch element for switching between the video signal input line and the data line in response to the first control signal; A precharge switch element for simultaneously precharging the data lines by mutually shorting the data lines in response to the first control signal and supplying a precharge signal of a predetermined level, After the precharge signal is simultaneously supplied to the data lines through the sampling switch element under the control of the first control signal, the video signal is passed through the sampling switch element under the control of the first control signal. The liquid crystal display device, characterized in that sequentially supplied to the data lines. The method of claim 12, The precharge switch element is connected in plural in series between data lines, And the sampling switch element and the precharge switch element connected adjacent to the data line connected to the sampling switch element are simultaneously controlled. The method of claim 12, And data driving means for supplying a signal corresponding to an average value of the video signal to the data lines while the data lines are shorted to each other. delete delete delete A liquid crystal display for precharging data lines to which a video signal is supplied via video signal input lines and pixels connected to the data lines and the data lines. A precharge signal source for generating a precharge signal of a predetermined level; Control signal generating means for generating a first control signal; A demultiplexer for supplying one video signal to a plurality of data lines in response to the first control signal; A precharge line to which the precharge signal is supplied; A precharge switch element for simultaneously precharging the data lines by switching between an input line and the precharge line of the demultiplexer in response to the first control signal, After the precharge signal is simultaneously supplied to the data lines through the demultiplexer under the control of the first control signal, the video signal is transmitted to the data lines through the demultiplexer under the control of the first control signal. Liquid crystal display characterized in that the supply sequentially. The method of claim 18, And a plurality of the precharge switch elements are connected in series between an input line of the demultiplexer and the precharge line. The method of claim 18, And the precharge signal and the video signal are supplied to the data lines through an input line of the demultiplexer. delete delete

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