KR101786882B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device and a driving method thereof, which can improve display quality and reduce power consumption by inverting a common voltage level supplied to each pixel while improving the aperture ratio by simplifying the pixel structure, 1. A liquid crystal display device comprising: a liquid crystal panel for displaying an image with pixel regions receiving a first common voltage or a second common voltage; A gate driver for driving gate lines of the liquid crystal panel; A data driver for driving data lines of the liquid crystal panel; A common voltage supply unit for inverting and supplying the levels of the first common voltage and the second common voltage supplied to the pixel regions to each other in units of frames; And a timing controller for supplying the data driver with the image data inputted from outside and controlling the common voltage supplier and the data driver, respectively.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of improving the display quality and reducing power consumption by inverting a common voltage level supplied to each pixel while improving the aperture ratio by simplifying the pixel structure .

A liquid crystal display device displays an image using electrical and optical characteristics of a liquid crystal. Liquid crystals can have different anisotropic properties depending on the molecular axis and the direction of the short axis, such as refractive index and dielectric constant, and can easily control the molecular arrangement and optical properties. A liquid crystal display device using the same displays an image by changing the alignment direction of liquid crystal molecules according to the electric field size and adjusting the light transmittance transmitted through the polarizing plate.

The liquid crystal display device includes a liquid crystal panel in which a plurality of pixels are arranged in a matrix form, a gate driver for driving gate lines of the liquid crystal panel, and a data driver for driving the data lines of the liquid crystal panel.

In a liquid crystal display device, an inversion driving method such as a frame inversion system, a line inversion system, and a dot inversion system is used to drive pixels of a liquid crystal panel. do.

Among the inversion driving methods, the frame and line inversion methods can further reduce the power consumption as compared with the dot inversion method, but there is a problem that a difference in vertical brightness occurs and a crosstalk phenomenon occurs. On the other hand, in the case of the dot inversion method, it is possible to reduce the defective phenomenon as described above, and thus it is possible to provide an image of higher image quality than the frame and line inversion methods. However, the dot inversion method has a problem of consuming a large amount of power.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and it is an object of the present invention to solve the above problems and to provide a display device capable of improving the display quality of an image and reducing power consumption by inverting a common voltage level supplied to each pixel, And it is an object of the present invention to provide a liquid crystal display device.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a liquid crystal panel for displaying an image with pixel regions receiving a first or second common voltage; A gate driver for driving gate lines of the liquid crystal panel; A data driver for driving data lines of the liquid crystal panel; A common voltage supply unit for inverting and supplying the levels of the first common voltage and the second common voltage supplied to the pixel regions to each other in units of frames; And a timing controller for supplying the data driver with the image data inputted from outside and controlling the common voltage supplier and the data driver, respectively.

Wherein the common voltage supplier supplies the first common voltage as a negative voltage level in an odd frame period and the positive common voltage level in an even frame period under the control of the timing controller, The voltage is supplied at the voltage level of positive polarity in the odd-numbered frame period and supplied at the voltage level of negative polarity in the even-numbered frame period.

Wherein the timing controller is configured to perform a column inversion method, a 2 × 1 inversion method, a 2 × 2 inversion method, and a 2 × 2 inversion method according to a first or second common voltage supply structure of each pixel region formed in the liquid crystal panel And the 1 × 2 inversion method, and controls the data driver.

The 4n-3th pixel region and the 4n-2th pixel region (where n is a natural number excluding 0) of each odd number column among the pixel regions provided in the liquid crystal panel are connected to a first common voltage Each common electrode is connected to the supply line, and the common electrode is connected to the second common voltage supply line so that the 4n-1th pixel region and the 4nth pixel region in each odd column are supplied with the second common voltage, and 4n The 3n-th pixel region and the 4n-2th pixel region are connected to the second common voltage supply line to receive the second common voltage, and the 4n-1th pixel region and the 4nth pixel region of each even- And each common electrode is connected to the first common voltage supply line to receive the common voltage.

The liquid crystal panel is arranged such that each of the pixel regions is connected in a staggered manner to the right side of each data line and the left side of each data line in units of odd and even horizontal lines to receive a video signal from the connected data lines (4n-3) -th pixel region and a 4n-th pixel region (where n is a natural number except for 0) in each odd number column among the pixel regions are supplied to the first common voltage supply line The common electrodes are connected to the second common voltage supply line so that the 4n-2 th pixel region and the 4n-1 th pixel region of each odd column are supplied with the second common voltage, and 4n The common electrode is connected to the second common voltage supply line so that the -3nd pixel region and the 4nth pixel region receive the second common voltage, And the common electrode is connected to the first common voltage supply line so that the 4n-2 th pixel region and the 4n-1 th pixel region of the column are supplied with the first common voltage.

Wherein the liquid crystal panel is arranged such that each of the pixel regions is connected in a staggered manner to the right side of each data line and the left side of each data line in units of odd and even horizontal lines, The 4n-3th pixel region and the 4n-1th pixel region in each odd number column (where n is a natural number excluding 0) of the respective pixel regions are connected to the first common voltage supply line The common electrodes are connected to the second common voltage supply line so that the 4n-2 th pixel region and the 4n th pixel region of each odd column are connected to the second common voltage supply line to receive the second common voltage, The common electrode is connected to the second common voltage supply line so that the pixel region and the (4n-1) th pixel regions receive the second common voltage, and the 4n-2 th Region and the 4n-th pixel area are characterized in that to be fed to the first common voltage of the common electrodes connected to the first common voltage supply line.

Wherein the liquid crystal panel receives the first or second common voltage having the same polarity in the 4n-3th pixel region and the 4n-2th pixel region horizontally adjacent in the odd row, and the 4n- The pixel region and the 4n-th pixel region are configured to receive the first or second common voltage having a polarity different from that of the 4n-3th pixel region and the 4n-2th pixel region, respectively. Th pixel region and the (4n-2) th pixel region are configured to receive the first or second common voltage having a polarity different from that of the 4n-3th pixel region and the 4n-2th pixel region in the odd row, The 4n-1th pixel region and the 4nth pixel region which are horizontally adjacent to each other have the first or second common voltage having a polarity different from that of the 4n-3th pixel region and the 4n-2th pixel region horizontally adjacent to the even row, Get a supply. .

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A liquid crystal display device and a driving method thereof according to an embodiment of the present invention having the features described above can improve the display quality of an image by improving the aperture ratio and the common voltage level supplied to each pixel by simplifying the pixel structure Power consumption can be reduced.

1 is a circuit diagram showing a liquid crystal display device according to a first embodiment of the present invention;
Fig. 2 is a drive waveform diagram for driving the liquid crystal panel of Fig. 1; Fig.
3 is a circuit diagram showing a liquid crystal display device according to a second embodiment of the present invention.
Fig. 4 is a driving waveform diagram for driving the liquid crystal panel of Fig. 1; Fig.
5 is a configuration circuit diagram showing a liquid crystal display device according to a third embodiment of the present invention.
6 is a driving waveform diagram for driving the liquid crystal panel of Fig. 5;
7 is a circuit diagram showing a liquid crystal display device according to a fourth embodiment of the present invention.
8 is a drive waveform diagram for driving the liquid crystal panel of Fig.

Hereinafter, a liquid crystal display device and a driving method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a circuit diagram showing a liquid crystal display device according to a first embodiment of the present invention.

The liquid crystal display device shown in FIG. 1 includes a liquid crystal panel 2 having pixel regions to receive first and second common voltages Vcom1 and Vcom2, respectively, to display an image; A gate driver 6 for driving the gate lines GL1 to GLn of the liquid crystal panel 2; A data driver 4 for driving the data lines DL1 to DLm of the liquid crystal panel 2; A common voltage supply unit 10 for inverting and supplying the levels of the first common voltage Vcom1 and the second common voltage Vcom2 supplied to the pixel regions to each other in units of frames; And a timing controller 8 for supplying image data RGB inputted from the outside to the data driver 4 and for controlling the common voltage supplier 10 and the data driver 4 respectively.

The liquid crystal panel 2 includes a thin film transistor (TFT) formed in each pixel region defined by a plurality of gate lines GL1 to GLn and a plurality of data lines DL1 to DLm, And a capacitor Clc. The liquid crystal capacitor Clc is composed of a pixel electrode connected to the TFT, and a common electrode arranged between the pixel electrode and the liquid crystal. At this time, the common line is connected to the common electrode of each pixel region so that the first common voltage Vcom1 or the second common voltage Vcom2 is supplied according to the preset inversion method. The common line connection structure will be described later in detail with reference to various embodiments and drawings. On the other hand, the TFT supplies a video signal from each of the data lines DL1 to DLm to the pixel electrode in response to a scan pulse from each of the gate lines GL1 to GLn. The liquid crystal capacitor Clc charges the difference between the video signal supplied to the pixel electrode and the first or second common voltage Vcom1 or Vcom2 supplied to the common electrode and varies the arrangement of the liquid crystal molecules according to the difference voltage The gradation is realized by adjusting the light transmittance. At this time, the storage capacitor Cst is formed by overlapping the pixel electrode with the storage line and the insulating film interposed therebetween.

The data driver 4 receives a data control signal DCS from the timing controller 8, for example, a source start signal SSP, a source shift clock SSC, a source output enable That is, a video signal, from the timing controller 8 using a source output enable (SOE) signal and an inversion signal (Pol Signal). Specifically, the data driver 4 latches the aligned data Data through the timing controller 8 in accordance with the SSC, and then, in response to the SOE signal, supplies the scan pulses to the gate lines GL1 to GLn And supplies video signals for one horizontal line to each of the data lines DL1 to DLm for each horizontal period. At this time, the data driver 4 selects the positive or negative gamma voltage corresponding to the gradation value of the data Data arranged according to the negative signal from the timing controller 8, and outputs the selected gamma voltage as a video signal And supplies them to the respective data lines DL1 to DLm.

The gate driver 6 may be formed on one side of the image non-display region of the liquid crystal panel 2 as a part of the liquid crystal panel 2 or may be separately provided on either side of the liquid crystal panel 2 in the form of an integrated circuit . The gate driver 6 sequentially drives the gate lines GL1 to GLn in accordance with the gate control signal GCS from the timing controller 8. [ Specifically, the gate driver 4 receives a gate control signal GCS from the timing controller 8, for example, a gate start pulse (GSP), a gate shift clock (GSC) And sequentially supplies a scan pulse or a gate low voltage to each of the gate lines GL1 to GLn by using a gate output enable (GOE) signal or the like.

The common voltage supply unit 10 inverts and supplies the levels of the first common voltage Vcom1 and the second common voltage Vcom2 to each other in units of a frame period under the control of the timing controller 8. [ In other words, the common voltage supply unit 10 may supply the levels of the first common voltage Vcom1 and the second common voltage Vcom2 in an inversion manner every frame. For example, in accordance with the control from the timing controller 2, the common voltage supply unit 10 supplies the first common voltage Vcom1 at a negative voltage level of 0V in the odd frame period, In the frame period, it can be supplied at a positive voltage level (+) of 5V. At this time, the second common voltage Vcom2 may be supplied at a positive (+) level of positive polarity in the odd-numbered frame period and at a negative (-) level of negative polarity in the even-numbered frame period.

The timing controller 8 may be provided on a separate control printed circuit board or on at least one of the source PCBs to receive image data RGB and a plurality of synchronization signals DCLK, Hsync, Vsync, The data driver 4, and the gate driver 6 in accordance with the control signal DE. Specifically, the timing controller 8 arranges image data (RGB) input from the outside so as to be suitable for driving the liquid crystal panel 2, and supplies the image data to the data driver 4. A gate control signal GCS and a data control signal GCS are generated by using at least one of a synchronizing signal input from the outside, that is, a dot clock DCLK, a data enable signal DE, and horizontal and vertical synchronizing signals Hsync and Vsync DCS, and supplies them to the gate driver 6 and the data driver 4, respectively. At this time, the timing controller 8 supplies an inversion signal (Pol Signal) to the common voltage supply unit 10 so that the common voltage supply unit 10 supplies the first common voltage Vcom1 and the second common voltage Vcom2 So as to be inverted and fed in units of frames.

The timing controller 8 controls the pixel inversion in accordance with the first or second common voltage Vcom1 and Vcom2 supply structure of each pixel region formed in the liquid crystal panel 2, The inversion signal is generated so as to be driven by the version method, the 2 × 2 inversion method, or the 1 × 2 inversion method to control the data driver 4. The data driver 6 selects the positive or negative gamma voltage corresponding to the gradation value of the aligned image data Data in response to the negative signal from the timing controller 8, And supplies them to the respective data lines DL1 to DLm with video signals.

1, the first common voltage Vcom1 or the second common voltage Vcom2 is applied to the common electrode of each pixel region provided in the liquid crystal panel 2 according to a predetermined inversion method A common line is connected so as to be supplied respectively.

The 4n-3th pixel region and the 4n-2th pixel region (where n is a natural number excluding 0) of each odd number column among the pixel regions provided in the liquid crystal panel 2 of Fig. 1 are set to the first common voltage Vcom1, And the 4n-1th pixel region and the 4nth pixel region of each odd column are connected to the second common voltage Vcom2 to receive the second common voltage Vcom2 Vcom2) supply line. The 4n-3th pixel region and the 4n-2th pixel region of each even-numbered column (where n is a natural number excluding 0) are supplied to the second common voltage Vcom2 supply line to receive the second common voltage Vcom2 Common electrodes are connected and common electrodes are connected to the first common voltage Vcom1 supply line so that the 4n-1th pixel region and the 4nth pixel region of each even column are supplied with the first common voltage Vcom1.

2 is a driving waveform diagram for driving the liquid crystal panel of FIG.

Referring to FIG. 2, the data driver 6 generates a positive or negative gamma corresponding to the gray level of the image data Data arranged to be driven by the 2 × 1 version of the pixel regions of the liquid crystal panel 2, And supplies the selected gamma voltage to each of the data lines DL1 to DLm as a video signal. The common voltage supply unit 10 supplies the first common voltage Vcom1 at a negative voltage level of 0V in the odd frame period and the positive voltage level of 5V in the even frame period, Level. The second common voltage Vcom2 is supplied at a positive (+) level of positive polarity in the odd-numbered frame period and at a negative (-) level of negative polarity in the even-numbered frame period.

The liquid crystal display and its driving method shown in FIGS. 1 and 2 can improve the aperture ratio by simplifying the pixel structure by allowing each pixel region to receive only the first or second common voltage Vcom1 and Vcom2. Further, the common voltage level supplied to each pixel region is inverted to further improve the display quality of the image, and the power consumption can be reduced.

3 is a configuration circuit diagram showing a liquid crystal display device according to a second embodiment of the present invention. 4 is a driving waveform diagram for driving the liquid crystal panel of Fig.

The liquid crystal panel 2 shown in Fig. 3 has a structure in which each pixel region is arranged in a zigzag form on the right side of each of the data lines DL1 to DLm and on the left side of each of the data lines DL1 to DLm in odd- And are connected to receive image signals from the data lines DL1 to DLm connected to the data lines DL1 to DLm.

The 4n-3th pixel region and the 4nth pixel region (where n is a natural number excluding 0) of each of the pixel regions are connected to the first common voltage Vcom1 supply line And the 4n-2th pixel region and the 4n-1th pixel region of each odd column are connected to the second common voltage Vcom2 supply line to receive the second common voltage Vcom2, do. The common electrodes are connected to the second common voltage Vcom2 supply line so that the 4n-3th pixel region and the 4nth pixel region of each even row are supplied with the second common voltage Vcom2, and 4n-2 Th pixel region and the (4n-1) th pixel region are connected to the first common voltage Vcom1 supply line to receive the first common voltage Vcom1.

Referring to FIG. 4, the data driver 6 generates a positive or negative gamma corresponding to the gray level of the image data (Data) arranged so that the pixel regions of the liquid crystal panel 2 are driven in a 2x1 version manner, And supplies the selected gamma voltage to each of the data lines DL1 to DLm as a video signal. The common voltage supply unit 10 supplies the first common voltage Vcom1 at a negative voltage level of 0V in the odd frame period and the positive voltage level of 5V in the even frame period, Level. The second common voltage Vcom2 is supplied at a positive (+) level of positive polarity in the odd-numbered frame period and at a negative (-) level of negative polarity in the even-numbered frame period.

As shown in the second embodiment, the liquid crystal display device and the driving method thereof according to the present invention are configured such that each pixel region receives only the first or second common voltage Vcom1 or Vcom2 to simplify the pixel structure, Can be improved. Further, the common voltage level supplied to each pixel region is inverted to further improve the display quality of the image, and the power consumption can be reduced.

5 is a circuit diagram showing a liquid crystal display device according to a third embodiment of the present invention. 6 is a driving waveform diagram for driving the liquid crystal panel of Fig.

The liquid crystal panel 2 shown in Fig. 5 has a structure in which each pixel region is arranged in a zigzag form on the right side of each of the data lines DL1 to DLm and the left side of each of the data lines DL1 to DLm on the basis of the odd- And are arranged to receive video signals from the respective connected data lines DL1 to DLm.

The 4n-3th pixel region and the 4n-1th pixel region (where n is a natural number except for 0) of each odd number column among the pixel regions are supplied with the first common voltage Vcom1 to receive the first common voltage Vcom1 Vcom1) supply line, and the 4n-2th pixel region and the 4nth pixel region of each odd column are connected to the second common voltage Vcom2 supply line so as to receive the second common voltage Vcom2, Lt; / RTI > Each common electrode is connected to the second common voltage Vcom2 supply line so that the 4n-3th pixel region and the 4n-1th pixel region of each even row are supplied with the second common voltage Vcom2, and 4n The common electrode is connected to the first common voltage Vcom1 supply line so that the -2nd pixel region and the 4nth pixel region receive the first common voltage Vcom1.

6, the data driver 6 outputs a positive or negative gamma voltage corresponding to the gray level of the image data (Data) arranged to be driven by the column-version method of the pixel regions of the liquid crystal panel 2 And supplies the selected gamma voltage to each of the data lines DL1 to DLm as a video signal. The common voltage supply unit 10 supplies the first common voltage Vcom1 at a negative voltage level of 0V in the odd frame period and the positive voltage level of 5V in the even frame period, Level. The second common voltage Vcom2 is supplied at a positive (+) level of positive polarity in the odd-numbered frame period and at a negative (-) level of negative polarity in the even-numbered frame period.

As shown in the third embodiment, the liquid crystal display device and the driving method thereof according to the present invention are configured such that each pixel region receives only the first or second common voltages Vcom1 and Vcom2 to simplify the pixel structure, The power consumption can be reduced by inverting the common voltage level supplied to each pixel region. In addition, in this case, the display of the image quality of the image can be further improved by the same effect as the dot inversion method by driving the column as a version.

7 is a circuit diagram showing a liquid crystal display device according to a fourth embodiment of the present invention. 8 is a driving waveform diagram for driving the liquid crystal panel of Fig.

The liquid crystal panel 2 shown in FIG. 7 has two horizontally adjacent pixel regions, that is, the 4n-3th pixel region and the 4n-2th pixel region horizontally adjacent in the odd row, The 4n-1th pixel region and the 4nth pixel region horizontally adjacent in the odd row are supplied with the common voltages Vcom1 and Vcom2, respectively, and the 4n-3th pixel region and the 4n- Or the second common voltages Vcom1 and Vcom2, respectively. The 4n-3th pixel region and the 4n-2th pixel region horizontally adjacent in the odd row are connected to the first or second common voltage having a polarity different from that of the 4n-3th pixel region and the 4n- The 4n-1th pixel region and the 4nth pixel region horizontally adjacent to each other in the even row are supplied with the 4n-3th pixel region and the 4n-2th pixel region horizontally adjacent to the even row, Are configured to receive the first or second common voltages Vcom1 and Vcom2 of different polarities, respectively.

8, the data driver 6 outputs a positive or negative gamma voltage corresponding to the gray level value of the image data Data so that the pixel regions of the liquid crystal panel 2 are driven in a 1 × 2 version manner And supplies the selected gamma voltage to each of the data lines DL1 to DLm as a video signal. The common voltage supply unit 10 supplies the first common voltage Vcom1 at a negative voltage level of 0V in the odd frame period and the positive voltage level of 5V in the even frame period, Level. The second common voltage Vcom2 is supplied at a positive (+) level of positive polarity in the odd-numbered frame period and at a negative (-) level of negative polarity in the even-numbered frame period.

As shown in the fourth embodiment of the present invention, the liquid crystal display device and the driving method thereof according to the present invention simplify the pixel structure by allowing each pixel region to receive only the first or second common voltages Vcom1 and Vcom2, The power consumption can be reduced by inverting the common voltage level supplied to each pixel region.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the 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 (10)

A liquid crystal panel for displaying an image with pixel regions receiving a first or second common voltage, respectively;
A gate driver for driving gate lines of the liquid crystal panel;
A data driver for driving data lines of the liquid crystal panel;
A common voltage supply unit for inverting and supplying the levels of the first common voltage and the second common voltage supplied to the pixel regions to each other in units of frames;
A liquid crystal display comprising a timing controller for supplying image data inputted from an outside to the data driver and for controlling the common voltage supplier and the data driver,
The common voltage supply unit
And supplies the first common voltage as a negative voltage level in an odd frame period and the positive common voltage level in an even frame period under the control of the timing controller,
The second common voltage is supplied at a positive voltage level in an odd frame period and at a voltage level of a negative polarity in an even frame period,
The liquid crystal panel
Each of the pixel regions is connected to a data line on the left side and each pixel region on the right side is connected to a data line on the right side so as to receive a video signal from a data line connected to each pixel region,
The 4n-3th pixel region and the 4nth pixel region (where n is a natural number except for 0) of each of the pixel regions are supplied to the first common voltage supply line to receive the first common voltage, And the common electrode is connected to the second common voltage supply line so that the 4n-2 th pixel region and the 4n-1 th pixel region of each odd column are supplied with the second common voltage,
The common electrode is connected to the second common voltage supply line so that the 4n-3th pixel region and the 4nth pixel region of each even row are supplied with the second common voltage, and the 4n-2th pixel region and the 4n- And the common electrode is connected to the first common voltage supply line to receive the first common voltage. delete delete delete delete A liquid crystal panel for displaying an image with pixel regions receiving a first or second common voltage, respectively;
A gate driver for driving gate lines of the liquid crystal panel;
A data driver for driving data lines of the liquid crystal panel;
A common voltage supply unit for inverting and supplying the levels of the first common voltage and the second common voltage supplied to the pixel regions to each other in units of frames;
And a timing controller for supplying image data inputted from outside to the data driver and for controlling the common voltage supply unit and the data driver, the liquid crystal display comprising:
The common voltage supply unit
And supplies the first common voltage as a negative voltage level in an odd frame period and the positive common voltage level in an even frame period under the control of the timing controller,
The second common voltage is supplied at a positive voltage level in an odd frame period and at a voltage level of a negative polarity in an even frame period,
The liquid crystal panel
Each of the pixel regions of the video signal processing is connected to the left data line and each pixel region of the right video processing is connected to the right data line,
The 4n-3th pixel region and the 4n-1th pixel region in each odd number column (where n is a natural number excluding 0) of the respective pixel regions are connected to the first common voltage supply line The common electrodes are connected to the second common voltage supply line so that the 4n-2th pixel region and the 4nth pixel region of each odd column are supplied with the second common voltage,
The 4n-3 th pixel region and the 4n-1 th pixel region of each even row are connected to the second common voltage supply line to receive the second common voltage, and the 4n-2 th pixel region and the 4n And the common electrode is connected to the first common voltage supply line to receive the first common voltage. delete delete delete delete

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