KR101159352B1 - LCD and drive method thereof - Google Patents

Abstract

The present invention provides a liquid crystal display device capable of automatically adjusting a high potential power voltage value according to a magnitude of white data and black data, comprising: a liquid crystal display panel having a plurality of data lines formed therein; A timing controller for controlling a high potential power supply voltage value according to the magnitude of the black data and the white data supplied to the plurality of data lines; A high potential voltage controller for controlling generation of a high potential power voltage according to the control of the timing controller; And a high potential voltage supply means for generating and supplying a high potential power voltage having a high potential power voltage value controlled by the high potential voltage controller.

Description

Liquid crystal display and driving method thereof

1 is an equivalent circuit diagram of a pixel formed in a general liquid crystal display device.

2 is a block diagram of a conventional liquid crystal display device.

3 is a circuit diagram of a high potential voltage generator included in a conventional liquid crystal display device.

4 is a configuration diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

5 is a circuit diagram of a high potential voltage generator included in the liquid crystal display according to the present invention.

6 is a flowchart illustrating a method of driving a liquid crystal display according to the present invention.

Explanation of symbols on the main parts of the drawings

200: liquid crystal display 210: timing controller

220: high potential voltage control unit 230: high potential voltage supply unit

231: high potential voltage generator

232-1 232-n: first to nth high potential voltage determination units

233: switching unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a driving method thereof capable of automatically adjusting a high potential power supply voltage (VDD) according to the magnitude of white data and black data.

A liquid crystal display device displays an image by adjusting light transmittance of liquid crystal cells according to a video signal, and an active matrix type liquid crystal display device in which a switching element is formed for each liquid crystal cell enables active control of the switching element. This is advantageous for video implementation. As the switching element used in the active matrix liquid crystal display device, a thin film transistor (hereinafter referred to as TFT) is mainly used as shown in FIG. 1.

Referring to FIG. 1, an active matrix type liquid crystal display converts digital input data into an analog data voltage based on a gamma reference voltage and supplies it to the data line DL and simultaneously supplies scan pulses to the gate line GL. The liquid crystal cell Clc is charged.

The gate electrode of the TFT is connected to the gate line GL, the source electrode is connected to the data line DL, and the drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc and one electrode of the storage capacitor Cst. Connected.

A common voltage Vcom is supplied to the common electrode of the liquid crystal cell Clc.

The storage capacitor Cst serves to charge the data voltage applied from the data line DL when the TFT is turned on to maintain the voltage of the liquid crystal cell Clc constant.

When a scan pulse is applied to the gate line GL, the TFT is turned on to form a channel between the source electrode and the drain electrode to apply a voltage on the data line DL to the pixel electrode of the liquid crystal cell Clc Supply. At this time, the liquid crystal molecules of the liquid crystal cell Clc modulate the incident light by changing the arrangement by the electric field between the pixel electrode and the common electrode.

A configuration of a conventional liquid crystal display device having pixels having such a structure will be described with reference to FIG. 2.

2 is a block diagram of a conventional liquid crystal display device.

Referring to FIG. 2, the liquid crystal display 100 according to the related art includes a thin film transistor for driving the liquid crystal cell Clc at the intersection of the data lines DL1 to DLm and the gate lines GL1 to GLn. TFT: a thin film transistor (110) having a thin film transistor (110), a data driver (120) for supplying data to the data lines (DL1 to DLm) of the liquid crystal display panel 110, the liquid crystal display panel 110 A gate driver 130 for supplying scan pulses to the gate lines GL1 to GLn of the gate line, a gamma reference voltage generator 140 for generating a gamma reference voltage and supplying it to the data driver 120, and a common voltage ( A common voltage generator 150 for generating Vcom and supplying it to the common electrode of the liquid crystal cell Clc of the liquid crystal display panel 110, and generating a gate high voltage VGH and a gate low voltage VGL to generate a gate. The gate driving voltage generator 160 and the data driver 120 for supplying the driver 130. ) And a high-potential for supplying the gamma reference voltage generator 140 and the common voltage generator 150 by generating a timing controller 170 for controlling the gate driver 130 and a high potential power voltage VDD. The voltage supply unit 180 is provided.

In the liquid crystal display panel 110, liquid crystal is injected between two glass substrates. On the lower glass substrate of the liquid crystal display panel 110, the data lines DL1 to DLm and the gate lines GL1 to GLn are orthogonal. TFTs are formed at intersections of the data lines DL1 to DLm and the gate lines GL1 to GLn. The TFT supplies the data on the data lines DL1 to DLm to the liquid crystal cell Clc in response to the scan pulse. The gate electrodes of the TFTs are connected to the gate lines GL1 to GLn, and the source electrodes of the TFTs are connected to the data lines DL1 to DLm. The drain electrode of the TFT is connected to the pixel electrode of the liquid crystal cell Clc and the storage capacitor Cst.

The TFT is turned on in response to the scan pulse supplied to the gate terminal via the gate lines GL1 to GLn. When the TFT is turned on, video data on the data lines DL1 to DLm is supplied to the pixel electrode of the liquid crystal cell Clc.

The data driver 120 supplies data to the data lines DL1 to DLm in response to the data driving control signal DDC supplied from the timing controller 170, and digital video data supplied from the timing controller 170. After sampling and latching the RGB, the liquid crystal cell Clc of the liquid crystal display panel 110 is converted into an analog data voltage capable of expressing gray scale based on the gamma reference voltage supplied from the gamma reference voltage generator 140. Supply to the data lines DL1 to DLm.

The gate driver 130 sequentially generates scan pulses, that is, gate pulses, in response to the gate driving control signal GDC and the gate shift clock GSC supplied from the timing controller 170, thereby providing the gate lines GL1 to GLn. Feed the fields. In this case, the gate driver 130 determines the high level voltage and the low level voltage of the scan pulse according to the gate high voltage VGH and the gate low voltage VGL supplied from the gate driving voltage generator 160.

The gamma reference voltage generator 140 receives a high potential power voltage VDD of 8V to 9V from the high potential voltage supply unit 180 to generate a positive gamma reference voltage and a negative gamma reference voltage to generate the data driver 120. Will output

The common voltage generator 150 receives the high potential power voltage VDD of 8V to 9V from the high potential voltage supply unit 180 to generate a common voltage Vcom to be provided in each pixel of the liquid crystal display panel 110. Supply to common electrodes of liquid crystal cells Clc.

The gate driving voltage generator 160 receives the 3.3V power supply voltage VCC supplied from the system to generate the gate high voltage VGH and the gate low voltage VGL to supply the gate driver 130 to the gate driver 130. Here, the gate driving voltage generation unit 160 generates a gate high voltage VGH that is greater than or equal to the threshold voltage of the TFTs provided in each pixel of the liquid crystal display panel 110 and generates a gate low voltage that is less than the threshold voltage of the TFT. VGL). The gate high voltage VGH and the gate low voltage VGL generated in this way are used to determine the high level voltage and the low level voltage of the scan pulse generated by the gate driver 130, respectively.

The timing controller 170 supplies digital video data RGB, which is supplied from a digital video card (not shown), to the data driver 120, and also the horizontal / vertical synchronization signals H and V according to the clock signal CLK. The data driving control signal DDC and the gate driving control signal GDC may be generated and supplied to the data driver 120 and the gate driver 130, respectively. The data driving control signal DDC includes a source shift clock SSC, a source start pulse SSP, a polarity control signal POL, a source output enable signal SOE, and a gate driving control signal GDC. ) Includes a gate start pulse (GSP) and a gate output enable (GOE).

The high potential voltage supply unit 180 receives a high voltage supply voltage VDD of 8V to 9V by receiving a DC voltage DC of 3.3V provided from the system to generate a gamma reference voltage generator 140 and a common voltage generator. 150, which is described in more detail with reference to FIG. 3 as follows.

As shown in FIG. 3, the high potential voltage supply unit 180 receives a DC voltage of 3.3 V and generates a high potential voltage generator 181 and a high potential voltage generator 181 to generate a high potential power voltage VDD. Resistors R1 and R2 connected in parallel with the output terminal of

Here, the DC voltage 3.3V is input through the input terminal Vin, the high potential power supply voltage VDD is output through the output terminal Vout, and the feedback current is fed back through the feedback terminal FB. The resistors R1 and R2 are connected in parallel with the output terminal Vout of the high potential voltage generator 181, and are connected in series between the output terminal Vout and the ground.

The high potential voltage generator 181 receives the DC voltage 3.3V from the system to generate the high potential power voltage VDD. However, since the high feedback voltage VDD has a constant feedback current, the resistance ( R1, R2). Accordingly, the high potential voltage supply unit 180 generates only a constant high potential power voltage VDD.

In the conventional liquid crystal display device having the high potential voltage supply unit 180 as described above, although a high potential power voltage VDD higher than 9 V may be applied, the white and black characteristics may be improved. Since the high potential voltage supply unit 180 supplies only a constant high potential power voltage VDD of 8V to 9V, the high potential power voltage VDD can not be arbitrarily adjusted and supplied according to the magnitude of white data and black data. Accordingly, white characteristics and black characteristics could not be improved. In addition, if there is little black data or a lot of white data, high power supply voltage (VDD) lower than 8V should be supplied, so that only the high power supply voltage (VDD) of about 9V is always applied, so that black and white characteristics cannot be improved. In addition, there was a problem of wasting power unnecessarily.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device and a driving method thereof capable of automatically adjusting a high potential power supply voltage (VDD) according to the magnitude of white data and black data. To provide.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device and a driving method thereof capable of improving black characteristics and white characteristics by automatically adjusting a high potential power supply voltage (VDD) according to the magnitude of white data and black data. .

Disclosure of Invention An object of the present invention is to provide a liquid crystal display device and a driving method thereof, by automatically adjusting a high potential power supply voltage (VDD) value according to the magnitude of white data and black data, thereby preventing unnecessary power consumption. There is.

The present invention for achieving the above object, a liquid crystal display panel having a plurality of data lines formed; A timing controller for controlling a high potential power voltage value according to a magnitude of black data and white data supplied to the plurality of data lines; A high potential voltage adjusting unit for controlling generation of a high potential power voltage under control of the timing controller; And a high potential voltage supply means for generating and supplying a high potential power voltage having a high potential power voltage value controlled by the high potential voltage controller.

The present invention includes a high potential voltage supply means for supplying a high potential power voltage, wherein the high potential voltage supply means comprises: a high potential voltage generator for generating a high potential power voltage by receiving a DC voltage; First to nth high potential voltage determination units for determining a high potential power voltage value generated from the high potential voltage generator; And a switching unit for switching such that the feedback is made through the high potential voltage determination unit determining the high potential power voltage value among the first to nth high potential voltage determination units according to a supply control command of the high potential power voltage. It features.

The present invention provides a method of supplying black data and white data to data lines of a liquid crystal display panel; Determining whether the black data is larger than white data; A third step of increasing the supply high potential power voltage in proportion to the black data if the black data is large as a result of the determination; And a fourth step of reducing the supply high potential power supply voltage in proportion to the white data if the white data is large as a result of the determination.

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

4 is a configuration diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 4, in the liquid crystal display device 200 of the present invention, the liquid crystal display panel 110, the data driver 120, the gate driver 130, and the gamma reference voltage generator 140 are similar to those of FIG. 2. And a common voltage generator 150 and a gate driving voltage generator 160, and control the data driver 120 and the gate driver 130, and according to the magnitude of the black data and the white data, VDD), the timing controller 210 for controlling the value, the high potential voltage controller 220 for controlling the generation of the high potential power voltage VDD under the control of the timing controller 210, and the high potential voltage adjustment. A high potential for generating a high potential power voltage VDD having a high potential power voltage VDD controlled by the unit 220 to supply the gamma reference voltage generator 140 and the common voltage generator 150. The voltage supply unit 230 is provided.

The timing controller 210 supplies digital video data RGB, which is supplied from a digital video card (not shown), to the data driver 120, and also horizontal / vertical synchronization signals H and V according to the clock signal CLK. The data driving control signal DDC and the gate driving control signal GDC may be generated and supplied to the data driver 120 and the gate driver 130, respectively. The data driving control signal DDC includes a source shift clock SSC, a source start pulse SSP, a polarity control signal POL, a source output enable signal SOE, and a gate driving control signal GDC. ) Includes a gate start pulse (GSP) and a gate output enable (GOE).

In addition, the timing controller 210 compares the magnitude of the black data and the white data supplied to the data lines DL1 to DLm, and adjusts the high potential voltage to increase or decrease the high potential power voltage VDD according to the comparison result. The unit 220 is controlled. That is, when there is more black data than the white data as a result of the comparison, the timing controller 210 controls the high potential voltage controller 220 to increase the high potential power voltage VDD. On the contrary, if there is more white data than the black data as a result of the comparison, the timing controller 210 controls the high potential voltage controller 220 to reduce the high potential power voltage VDD.

The high potential voltage controller 220 controls the high potential power voltage VDD generated from the high potential voltage supply unit 230 under the control of the timing controller 210, and supplies the high potential power from the timing controller 210. When a control signal instructing to increase the voltage VDD is input, the generated high potential power supply voltage VDD of the high potential voltage supply unit 230 is adjusted to generate a high high potential power supply voltage VDD. When the control signal instructing to reduce the high potential power voltage VDD is input from the controller 210, the high potential power voltage VDD is generated to generate a low high potential power voltage VDD. Adjust the value.

The high potential voltage supply unit 230 receives a DC voltage (DC) 3.3V provided from the system to generate a high potential power voltage (VDD) and supplies the gamma reference voltage generator 140 and the common voltage generator 150. do. In particular, the high potential voltage supply unit 230 generates a high potential power voltage VDD controlled by the high potential voltage controller 220.

A circuit configuration of the high potential voltage supply unit 230 having such a function will be described with reference to FIG. 5.

Referring to FIG. 5, the high potential voltage generator 230 is a high potential voltage generator 231 and a high potential voltage generator for generating a high potential power voltage VDD by applying a DC voltage of 3.3V. The first to nth high potential voltage determination units 232-1 to 232-n for determining the high potential power voltage VDD value generated from 231 and the high potential voltage control unit 220. Accordingly, the switching unit 233 for switching such that feedback is made through the high potential voltage determining unit determining the high potential power voltage VDD value among the first to nth high potential voltage determining units 232-1 to 232-n. ).

The high potential voltage generator 231 receives a DC voltage of 3.3 V through the input terminal Vin, generates a high potential power voltage VDD, and outputs the output voltage through the output terminal Vout. The value is determined by the high potential voltage determiner fed back through any one of the plurality of feedback terminals FB1 to FBn.

The first to nth high potential voltage determination units 232-1 to 232-n respectively include first to nth nodes N1 to Nn spaced apart from each other at regular intervals on the output side of the high potential voltage generator 231. It is composed of two resistors connected in parallel with the output terminal (Vout) of the high potential voltage generator 231 and connected in series between the node and the ground, in particular the contact between the resistors and the high potential voltage generator 231 It is selectively switched by the switching unit 233 connected between the feedback terminals FB1 to FBn of) so that feedback is formed.

For example, the first high potential voltage determiner 232-1 may be in parallel with the output terminal Vout of the high potential voltage generator 231 based on the first node N1 located at the output side of the high potential voltage generator 231. It is connected but consists of two resistors R1-1 and R1-2 connected in series between the first node N1 and ground. In particular, since the switching unit 233 is connected between the contact between the two resistors (R1-1, R1-2) and the feedback terminal (FB1) of the high potential voltage generator 231, by the switching unit 233 When the feedback is formed between the contact between the two resistors (R1-1, R1-2) and the feedback terminal (FB1) of the high potential voltage generator 231, the high voltage output from the high potential voltage generator (231) The power supply voltage VDD is determined by the resistances of the two resistors R1-1 and R1-2.

The second high potential voltage determiner 232-2 is connected in parallel with the output terminal Vout of the high potential voltage generator 231 based on the second node N2 positioned at the output side of the high potential voltage generator 231. It consists of two resistors R2-1 and R2-2 connected in series between the second node N2 and ground. In particular, since the switching unit 233 is connected between the contact between the two resistors (R2-1, R2-2) and the feedback terminal (FB2) of the high potential voltage generator 231, by the switching unit 233 When the feedback is formed between the contact between the two resistors (R2-1, R2-2) and the feedback terminal (FB2) of the high potential voltage generator 231, the high voltage output from the high potential voltage generator 231 The power supply voltage VDD is determined by the resistance of the two resistors R2-1 and R2-2.

The nth high potential voltage determiner 232-n is connected in parallel with the output terminal Vout of the high potential voltage generator 231 on the basis of the nth node Nn positioned at the output side of the high potential voltage generator 231. 2 resistors Rn-1 and Rn-2 connected in series between the nth node Nn and ground. In particular, since the switching unit 233 is connected between the contact between the two resistors (Rn-1, Rn-2) and the feedback terminal (FBn) of the high potential voltage generator 231, by the switching unit 233 When the feedback is formed between the contact between the two resistors (Rn-1, Rn-2) and the feedback terminal (FBn) of the high potential voltage generator 231, the high voltage output from the high potential voltage generator 231 The power supply voltage VDD is determined by the resistances of the two resistors Rn-1 and Rn-2.

The third to n-1th high potential voltage determination units 232-3 to 232-(n-1) may include the first, second and nth high potential voltage determination units 232-1, 232-2, 232-n) has the same configuration and function, but consists of resistors having different resistance values. Further, in the present invention, the resistance values of the resistors provided in the first to nth high potential voltage determination units 232-1 to 232-n increase in order, but are not limited thereto.

Meanwhile, although the first to nth high potential voltage determination units 232-1 to 232-n each include two resistors connected in series, the present invention is not limited thereto. That is, the technical idea of the present invention is to allow the first to nth high potential voltage determination units 232-1 to 232-n to have different resistance values, thereby selectively adjusting the high potential power voltage VDD. Since the first to nth high potential voltage determination units 232-1 to 232-n may include one or more resistors, it may be obvious that the resistors may be connected in parallel or in series if a plurality of resistors are provided. It is one reason.

The switching unit 233 is connected to the first to n-th high potential voltage determining unit 232-1 to 232-n and the feedback terminals FB1 to FBn of the high potential voltage generator 231, respectively. It consists of 1st-nth switches SW1-SWn.

For example, the first switch SW1 may be a contact between the resistors R1-1 and R1-2 of the first high potential voltage determiner 232-1 and a feedback terminal FB1 of the high potential voltage generator 231. ) And switching is controlled by the high potential voltage control unit 220. If the first switch SW1 is switched, since the feedback is formed through the contacts between the resistors R1-1 and R1-2, the high potential power voltage VDD generated from the high potential voltage generator 231. Is determined by the resistance values of the resistors R1-1 and R1-2 of the first high potential voltage determiner 232-1. In the present invention, since the first high potential voltage determination unit 232-1 is formed of resistors R 1-1 and R 1-2 having the lowest resistance values, the high potential power voltage VDD is used. When determined by the resistance values of the resistors R1-1 and R1-2 of the first high potential voltage determination unit 232-1, the high potential voltage supply unit 230 has the lowest high potential power voltage VDD. Will be supplied.

The second switch SW2 is disposed between the contact between the resistors R2-1 and R2-2 of the second high potential voltage determining unit 232-2 and the feedback terminal FB2 of the high potential voltage generator 231. The switching is controlled by the high potential voltage control unit 220. If the second switch SW2 is switched, the high potential power voltage VDD generated from the high potential voltage generator 231 because feedback is formed through the contacts between the resistors R2-1 and R2-2. Is determined by the resistance values of the resistors R2-1 and R2-2 of the second high potential voltage determiner 232-2.

The n-th switch SWn is disposed between the contact between the resistors Rn-1 and Rn-2 of the nth high potential voltage determiner 232-n and the feedback terminal FBn of the high potential voltage generator 231. The switching is controlled by the high potential voltage control unit 220. If the n-th switch SWn is switched, the high potential power voltage VDD generated from the high potential voltage generator 231 because feedback is formed through the contacts between the resistors Rn-1 and Rn-2. Is determined by the resistance values of the resistors Rn-1 and Rn-2 of the nth high potential voltage determiner 232-n. In the present invention, since the n-th high potential voltage determination unit 232-n is formed of resistors Rn-1 and Rn-2 having the highest resistance values, the high potential power voltage VDD is provided. When determined by the resistance values of the resistors Rn-1 and Rn-2 of the nth high potential voltage determining unit 232-n, the high potential voltage supply unit 230 has the highest high potential power supply voltage VDD. Will be supplied.

A process of adjusting the high potential power voltage VDD in the liquid crystal display of the present invention having the configuration and function as described above will be described with reference to the flowchart shown in FIG. 6.

Referring to FIG. 6, in a state where the data driver 120 converts digital black data and white data provided from the timing controller 210 into analog black data and white data and supplies them to the data lines DL1 to DLm. In operation S601, the timing controller 210 determines whether the black data supplied to the data lines DL1 to DLm is larger than the white data (S602).

If the determination result is a large amount of black data, the timing controller 210 controls the high potential voltage control unit 220 to increase the high potential power voltage VDD in proportion to the black data, but the high potential power voltage VDD to be increased. Generates a control signal including a) value and outputs it to the high potential voltage controller 220 (S603). In response to the control signal, the high potential voltage adjusting unit 220 switches any one of the plurality of switches SW1 to SWn to switch the first to nth high potential voltage determining units 232-1 to 232-. The feedback is formed through any one of the high potential voltage determination units of n), and the feedback is made through the high potential voltage determination unit generating a high high potential power voltage VDD included in the control signal (S604).

If the determination resulted in a large amount of white data, the timing controller 210 controls the high potential voltage control unit 220 to reduce the high potential power voltage VDD in proportion to the white data, but reduces the high potential power voltage VDD. Generates a control signal including a value and outputs to the high potential voltage control unit 220 (S605). In response to the control signal, the high potential voltage adjusting unit 220 switches any one of the plurality of switches SW1 to SWn to switch the first to nth high potential voltage determining units 232-1 to 232-. The feedback is formed through any one of the high potential voltage determination units of n), and the feedback is made through the high potential voltage determination unit generating a low high potential power voltage VDD included in the control signal (S606).

As described above, the present invention improves black characteristics by supplying a high high potential power voltage (VDD) when there is a lot of black data, and improves white characteristics by supplying a low high potential power voltage (VDD) when there is a lot of white data. In addition, unnecessary power consumption can be prevented.

As described above, the present invention automatically adjusts the high potential power supply voltage (VDD) value according to the magnitude of the white data and the black data, thereby improving the black and white characteristics and preventing unnecessary consumption of power. have.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

Claims (13)

A liquid crystal display panel in which a plurality of data lines are formed; A timing controller for controlling a high potential power voltage value according to a magnitude of black data and white data supplied to the plurality of data lines; A high potential voltage adjusting unit for controlling generation of a high potential power voltage under control of the timing controller; And High potential voltage supply means for generating and supplying a high potential power voltage having a high potential power voltage value controlled by the high potential voltage controller. Liquid crystal display comprising a. The method of claim 1, The high potential voltage supply means, A high potential voltage generator for generating a high potential power voltage by receiving a DC voltage; First to nth high potential voltage determination units for determining a high potential power voltage value generated from the high potential voltage generator; And A switching unit for switching so that feedback is made through the high potential voltage determining unit determining the high potential power voltage value among the first to nth high potential voltage determining units under the control of the high potential voltage adjusting unit. Liquid crystal display comprising a. The method of claim 2, The first to n-th high potential voltage determiner, respectively, And an output terminal of the high potential voltage generator in parallel. The method of claim 3, wherein The first to n-th high potential voltage determiner, respectively, And a resistor connected between the output side of the high potential voltage generator and a ground, the resistor having a different resistance value. The method of claim 3, wherein The first to n-th high potential voltage determiner, respectively, And a plurality of resistors connected in series between the output side of the high potential voltage generator and a ground, wherein the resistors have different resistance values. The method of claim 3, wherein The switching unit, And a first to n-th switch correspondingly connected between the first to n-th high potential voltage determination units and the feedback terminals of the high potential voltage generator, respectively, wherein the first to n-th switches are the high potential voltages. Liquid crystal display device characterized in that the switching selectively by the control unit. 7. The method according to any one of claims 1 to 6, And the timing controller controls to increase the high potential power voltage when the black data is larger than the white data, and reduces the high potential power voltage when the white data is larger than the black data. A high potential voltage supply means for supplying a high potential power voltage, The high potential voltage supply means, A high potential voltage generator for generating a high potential power voltage by receiving a DC voltage; First to nth high potential voltage determination units for determining a high potential power voltage value generated from the high potential voltage generator; And And a switching unit for switching the feedback to be made through the high potential voltage determining unit determining the high potential power voltage value among the first to nth high potential voltage determining units according to a supply control command of the high potential power voltage. A liquid crystal display device. The method of claim 8, The first to n-th high potential voltage determiner, respectively, And an output terminal of the high potential voltage generator in parallel. The method of claim 9, The first to n-th high potential voltage determiner, respectively, And a resistor connected between the output side of the high potential voltage generator and a ground, the resistor having a different resistance value. The method of claim 9, The first to n-th high potential voltage determiner, respectively, And a plurality of resistors connected in series between the output side of the high potential voltage generator and a ground, wherein the resistors have different resistance values. The method according to any one of claims 8 to 11, The switching unit, A first to nth switches correspondingly connected between the first to nth high potential voltage determination units and feedback terminals of the high potential voltage generator, respectively, wherein the first to nth switches are selectively switched. Liquid crystal display device characterized in that. Supplying black data and white data to data lines of a liquid crystal display panel; Determining whether the black data is larger than white data; A third step of increasing the supply high potential power voltage in proportion to the black data if the black data is large as a result of the determination; And A fourth step of reducing the supply high potential power voltage in proportion to the white data if the white data is large as a result of the determination; Method of driving a liquid crystal display comprising a.

Images