KR101149942B1 - Liquid crystal display - Google Patents

Abstract

The present invention relates to a liquid crystal display device, comprising: a liquid crystal panel including gate lines, data lines, and a plurality of pixels; A data driver for outputting a data voltage of a 2-dot inversion type to the data lines, in which the polarity of the image data is inverted by one pixel unit in a horizontal direction and by 2 pixel units in a vertical direction; A gate driver configured to output a gate high voltage to the gate lines; And a timing controller configured to control the gate driver and the data driver, wherein data voltages having opposite polarities are written in pixels adjacent to each other up and down in the liquid crystal panel, and the pixels adjacent to the left and right neighboring pixels in the liquid crystal panel are written to each other. The data voltages of opposite polarities are written so that the pixels of the liquid crystal panel charge the data voltages whose polarities are reversed in the form of 1 dot inversion.

Liquid crystal display, dot inversion, power consumption

Description

[0001] Liquid crystal display [0002]

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

2 is a schematic configuration diagram of a liquid crystal display for explaining a driving method of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a waveform diagram of a gate high voltage signal provided to gate lines of a liquid crystal display according to an exemplary embodiment of the present invention.

4 is a schematic configuration diagram of a liquid crystal display for explaining a driving method of a liquid crystal display according to another exemplary embodiment of the present invention.

5 is a waveform diagram of a gate high voltage signal provided to gate lines of a liquid crystal display according to another exemplary embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

20: liquid crystal panel 40: data driver

60: gate driver 80: timing controller

100: common voltage generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, a data driver provides an image data whose polarity is inverted in a 2-dot or 4-dot inversion scheme, while adjusting the driving order of gate lines, thereby providing a 1-dot inversion scheme. It relates to a liquid crystal display device which can be driven by.

Recently, due to the rapid progress of semiconductor technology, the demand for flat panel display devices as an electronic display device suitable for a new environment is rapidly increasing in accordance with the trend of low voltage and low power of various electronic devices, and miniaturization, thinness, and light weight of electronic devices. It is increasing. Accordingly, flat panel display devices such as a liquid crystal display (LCD), a plasma display device (PDP), an organic EL display device (OELD), and the like have been developed, and among these flat panel display devices, it is easy to miniaturize, light weight, and thinner. In particular, liquid crystal display devices having low power consumption and low driving voltage are drawing attention.

In the liquid crystal display, a liquid crystal material having an anisotropic dielectric constant is injected between an upper transparent insulating substrate on which a common electrode, a color filter, a black matrix, and the like are formed, and a lower transparent insulating substrate on which a switching element and a pixel electrode are formed. By applying different potentials to the electrodes and the common electrode, the intensity of the electric field formed in the liquid crystal material is adjusted to change the molecular arrangement of the liquid crystal material, thereby controlling the amount of light transmitted through the transparent insulating substrate to express a desired image. It is a display device. In the liquid crystal display, a thin film transistor liquid crystal display (TFT LCD) using a thin film transistor (TFT) element as a switching element is mainly used.

The liquid crystal display device includes a liquid crystal panel in which pixels in a matrix form are formed, and a driving circuit for driving the liquid crystal panel. The driving circuit drives the liquid crystal panel so that image information is displayed on the pixels of the liquid crystal panel. In order to remove flicker, the liquid crystal display drives inversions such as a frame inversion system, a line inversion system, and a dot inversion system on the pixels of the liquid crystal panel. The method is used. The frame inversion method inverts the polarity of the image data provided to the pixels of the liquid crystal panel every time the frame is changed. The line inversion method inverts the polarity of the image data provided to the pixels along the lines of the liquid crystal panel. The dot inversion method inverts the polarity of the image data in predetermined pixel units adjacent to each pixel of the liquid crystal panel in the vertical and horizontal directions, and inverts the polarity of the image data provided to all the pixels of the liquid crystal panel every frame. Of these inversion methods, the dot inversion method provides an image having excellent image quality compared to the frame inversion method and the line inversion method. In particular, the one-dot inversion method of the dot inversion method provides the best image quality.

However, in the conventional liquid crystal display device driven by the one dot inversion method, since the data driver provides image data whose polarity is inverted every dot, the power consumption of the data driver is very large, and the temperature of the driving circuit including the data driver is increased. An increasing problem has been caused. Conventional liquid crystal display devices driven by two-dot or four-dot inversion methods provide image data in which polarity is inverted every two or four dots, thereby reducing power consumption of the data driver. Problems such as deterioration of image quality characteristics have occurred.

An object of the present invention is to provide a liquid crystal display device capable of providing image data whose polarity is reversed in a 2-dot or 4-dot inversion scheme and driving the liquid crystal panel in a 1-dot inversion scheme.

The technical objects to be achieved by the present invention are not limited to the technical matters mentioned above, and other technical subjects which are not mentioned can be clearly understood by those skilled in the art from the following description. There will be.

According to an exemplary embodiment, there is provided a liquid crystal display including: a liquid crystal panel including gate lines, data lines, and a plurality of pixels; A data driver for outputting a data voltage of a 2-dot inversion type to the data lines, in which the polarity of the image data is inverted by one pixel unit in a horizontal direction and by 2 pixel units in a vertical direction; A gate driver configured to output a gate high voltage to the gate lines; And a timing controller configured to control the gate driver and the data driver, wherein data voltages having opposite polarities are written in pixels adjacent to each other up and down in the liquid crystal panel, and the pixels adjacent to the left and right neighboring pixels in the liquid crystal panel are written to each other. The data voltages of opposite polarities are written so that the pixels of the liquid crystal panel charge the data voltages whose polarities are reversed in the form of 1 dot inversion.
The gate driver provides the gate high voltage signal to the gate lines in the order of the first gate line, the third gate line, the second gate line, and the fourth gate line.
The providing time of the gate high voltage signal provided to the first gate line and the second gate line is longer than that of the gate high voltage signal provided to the remaining gate line.
In another embodiment, a liquid crystal display includes: a liquid crystal panel including gate lines, data lines, and a plurality of pixels; A data driver for outputting a data voltage of a 4-dot inversion type to the data lines in which the polarity of the image data is inverted by one pixel unit in a horizontal direction and by 4 pixel units in a vertical direction to the data lines; A gate driver configured to output a gate high voltage to the gate lines; And a timing controller configured to control the gate driver and the data driver, wherein data voltages having opposite polarities are written in pixels adjacent to each other up and down in the liquid crystal panel, and the pixels adjacent to the left and right neighboring pixels in the liquid crystal panel are written to each other. The data voltages of opposite polarities are written so that the pixels of the liquid crystal panel charge the data voltages whose polarities are reversed in the form of 1 dot inversion.

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Specific details of other embodiments are included in the detailed description and drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

Referring to FIG. 1, a liquid crystal display according to exemplary embodiments of the present invention will be described. 1 is a configuration diagram of a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 1, a liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel 20, a data driver 40, a gate driver 60, a timing controller 80, and a common voltage generation. The unit 100 is included.

The timing controller 80 receives a data clock, a horizontal synchronization signal, a vertical synchronization signal, a data enable signal, image data R, G, and B from an external system. The timing controller 80 which has received the image data R, G, and B aligns the image data R, G, and B and provides them to the data driver 40. The timing controller 80 receiving the data clock, the horizontal synchronizing signal, the vertical synchronizing signal, and the data enable signal receives timing signals and a polarity inversion signal POL for controlling timing of the data driver 40 and the gate driver 60. Control signals such as a) are generated and provided to the data driver 40 and the gate driver 60.

In the liquid crystal panel 20, pixels arranged in a matrix form are formed at intersections of the n gate lines GL1 to GLn and the m data lines DL1 to DLm, and each pixel is a thin film transistor TFT. ) And a liquid crystal cell connected to the thin film transistor TFT.

The thin film transistor TFT transfers image data R, G, and B from the data lines DL1 to DLm to the liquid crystal cell in response to the gate high voltage signal Vgh from the gate lines GL1 to GLn. do. Since the liquid crystal cell is composed of a common electrode facing each other with a liquid crystal interposed therebetween and a pixel electrode connected to the thin film transistor TFT, the liquid crystal cell may be equivalently represented as a liquid crystal capacitor Clc. The liquid crystal cell has storage connected to the gate line of the front end to maintain the image data (R, G, B) voltage charged in the liquid crystal capacitor (Clc) until the next image data (R, G, B) voltage is charged. Capacitor Cst is included.

The data driver 40 converts the image data R, G, and B provided from the timing controller 80 into an analog signal so that the gate high voltage signal Vgh is provided to the gate lines GL1 through GLn. The image data R, G, and B in line units are provided to the data lines DL1 through DLm every period. The data driver 40 has image data such that the polarities of the image data R, G, and B are inverted by one pixel unit in the horizontal direction and 2 pixel units in the vertical direction on the data lines DL1 through DLm. (R, G, B) or the polarity of the image data R, G, B in the data lines DL1 to DLm is inverted by one pixel unit in the horizontal direction, and 4 pixel units in the vertical direction. The image data R, G, and B are provided so as to be inverted. The image data R, G, and B provided on the data lines DL1 to DLm as described above are charged in the liquid crystal cell until the next image data R, G, and B are provided. At this time, a predetermined image is displayed on the pixel of the liquid crystal panel 20 corresponding to the image data R, G, and B filled in the liquid crystal cell. Here, the image actually displayed on the liquid crystal panel 20 is displayed by the difference value between the charged image data R, G, and B and the common voltage Vcom.

The gate driver 60 includes four adjacent gate lines among the gate lines GL1 to GLn (see FIG. 2, GL (k) to GL (k + 3)) according to a control signal from the timing controller 80. Drives by sequentially providing a gate high voltage signal Vgh in units, and among the four gate lines GL (k) to GL (k + 3), the first gate line GL (k) and the third gate line ( The gate high voltage signal Vgh is sequentially supplied to and driven by GL (k + 2), the second gate line GL (k + 1), and the fourth gate line GL (k + 3). Alternatively, the gate driver 60 may include eight adjacent gate lines among the gate lines GL1 to GLn according to a control signal from the timing controller 80 (see FIG. 4, GL (k) to GL (k + 7)). Drive by sequentially supplying the gate high voltage signal Vgh, and the first gate line GL (k) and the third gate line among the eight gate lines GL (k) to GL (k + 7). (GL (k + 2)), fifth gate line (GL (k + 4)), seventh gate line (GL (k + 6)), second gate line (GL (k + 1)), fourth gate line The gate high voltage signal Vgh is sequentially driven to (GL (k + 3)), the sixth gate line GL (k + 5), and the eighth gate line GL (k + 7).

The common voltage generator 100 generates a common voltage Vcom and provides the common voltage Vcom to a common electrode which is one side of the liquid crystal capacitor Clc of the liquid crystal panel 20.

2 and 3, a driving method of a liquid crystal display according to an exemplary embodiment of the present invention will be described. 2 is a schematic configuration diagram of a liquid crystal display for explaining a driving method of a liquid crystal display according to an exemplary embodiment of the present invention. 3 is a waveform diagram of a gate high voltage signal Vgh provided to gate lines of a liquid crystal display according to an exemplary embodiment of the present invention.

As illustrated in FIG. 2, in the data driver 40 of the liquid crystal display according to the exemplary embodiment, the polarity of the image data R, G, and B is 1 in the horizontal direction due to the polarity inversion signal POL. The image data R, G, and B are provided to the data lines DL1 to DLm so as to be inverted in pixel units and inverted in units of 2 pixels in the vertical direction.

As shown in FIG. 3, the gate driver of the liquid crystal display according to the exemplary embodiment of the present invention may include four adjacent gate lines GL (k) to GL (k + 3) among the gate lines GL1 to GLn. The gate-high voltage signal Vgh is sequentially provided and driven in units of), and the first gate line GL (k) and the third gate of the four gate lines GL (k) to GL (k + 3) are driven. The gate high voltage signal Vgh is sequentially driven to the line GL (k + 2), the second gate line GL (k + 1), and the fourth gate line GL (k + 3). That is, the odd-numbered gate lines GL (k) and GL (k + 2) are first driven among the four gate lines GL (k) to GL (k + 3), and the even-numbered gate lines GL (k + 1), GL (k + 3)) are driven later.

As a result, the data driver 40 outputs the image data voltages R, G, and B, whose polarities are inverted in a 2-dot inversion manner, to the data lines DL1 to M, but the upper and lower sides of the liquid crystal panel 20 are up and down. In the left and right neighboring pixels, data voltages having opposite polarities are written as shown in FIG. 2. Accordingly, the data driver 40 outputs the data voltage of the two dot inversion method, whereas the image data (R, G, B) voltage whose polarity is inverted in the one dot inversion method to the pixels of the liquid crystal panel 20. Is written. As a result, the present invention displays the image data on the liquid crystal panel 20 in a one-dot inversion manner, thereby effectively suppressing deterioration in image quality characteristics such as the occurrence of horizontal lines, while providing a driving circuit including the data driver 40. It is possible to effectively reduce the power consumption and to prevent the temperature of the driving circuit including the data driver 40 from increasing.

Meanwhile, as shown in FIG. 3, by the gate driver 60, the first gate line GL (k) and the second gate line (of the four gate lines GL (k) to GL (k + 3)) are used. The provision time T1 of the gate high voltage signal Vgh provided to GL (k + 1) is the gate high voltage signal provided to the remaining gate lines GL (k + 2) and GL (k + 3). Longer than the provision time T2 of (Vgh). That is, the gate driver 60 gates the gate driver 60 for a longer time T1 than the gate lines GL (k) and GL (k + 1) provided with the polarities of the image data R, G, and B being inverted. Provide a high voltage signal (Vgh).

Thereby, the different image data R, G, B charging conditions of the gate lines GL (k) to GL (k + 3) can be compensated for, so that the gate lines GL (k) to GL ( It is possible to effectively suppress the occurrence of the luminance difference between k + 3)).

4 and 5, a driving scheme of a liquid crystal display according to another exemplary embodiment of the present invention will be described. 4 is a schematic configuration diagram of a liquid crystal display for explaining a driving method of a liquid crystal display according to another exemplary embodiment of the present invention. 5 is a waveform diagram of a gate high voltage signal Vgh provided to gate lines of a liquid crystal display according to another exemplary embodiment of the present invention.

As shown in FIG. 4, the data driver 40 of the liquid crystal display according to the exemplary embodiment of the present invention has a polarity of 1 in the horizontal direction due to the polarity inversion signal POL. The image data R, G, and B are provided to the data lines DL1 to DLm so as to be inverted in pixel units and inverted in units of 4 pixels in the vertical direction.

As shown in FIG. 5, the gate driver 60 of the liquid crystal display according to the exemplary embodiment of the present invention may include eight adjacent gate lines GL (k) to GL (of the gate lines GL1 to GLn). k + 7)) in order to provide and drive the gate high voltage signal Vgh sequentially, and the first gate line GL (k) of the eight gate lines GL (k) to GL (k + 7). , Third gate line GL (k + 2), fifth gate line GL (k + 4), seventh gate line GL (k + 6), second gate line GL (k + 1) To sequentially supply the gate high voltage signal Vgh to the fourth gate line GL (k + 3), the sixth gate line GL (k + 5), and the eighth gate line GL (k + 7). To drive. That is, the odd-numbered gate lines GL (k), GL (k + 2), GL (k + 4), and GL (k +) among the eight gate lines GL (k) to GL (k + 7). 6)) first, and even-numbered gate lines GL (k + 1), GL (k + 3), GL (k + 5), and GL (k + 7) are driven later.

Thereby, the data driver 40 provides the image data R, G, and B whose polarities are inverted in the 4-dot inversion method, but the image data R in the 1-dot inversion method for the pixels of the liquid crystal panel 20. , G, and B) can be displayed, and the power consumption of the driving circuit including the data driver 40 can be reduced more effectively while effectively suppressing deterioration of image quality characteristics such as horizontal lines occurring in the liquid crystal panel 20. The temperature of the driving circuit including the data driver 40 can be prevented from increasing.

On the other hand, as shown in Figure 5, by the gate driver 60, the first gate line (GL (k)) and the second gate line of the eight gate lines (GL (k) to GL (k + 7)) ( The provision time T1 of the gate high voltage signal Vgh provided to GL (k + 1) is the gate high voltage signal provided to the remaining gate lines GL (k + 2) to GL (k + 7). Longer than the provision time T2 of (Vgh). That is, the gate driver 60 gates the gate driver 60 for a longer time T1 than the gate lines GL (k) and GL (k + 1) provided with the polarities of the image data R, G, and B being inverted. Provide a high voltage signal (Vgh).

Thereby, it is possible to compensate for different image data R, G, B charging conditions of the gate lines GL (k) to GL (k + 7), so that the gate lines GL (k) to GL ( It is possible to effectively suppress the occurrence of the luminance difference between k + 7)).

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that. Therefore, the above-described embodiments will be described in detail so that the disclosure of the present invention may be completed, and those skilled in the art may easily implement the technical idea of the present invention. It is to be understood to be illustrative and not limitative in all respects, as it is provided to fully inform the person skilled in the art the scope of the invention, and the invention is defined only by the scope of the claims. .

In the liquid crystal display according to the exemplary embodiments of the present invention, the data driver provides image data whose polarity is inverted by the 2-dot inversion method or the 4-dot inversion method, but by adjusting the driving order of the gate lines. Since the image data can be displayed on the pixels of the liquid crystal panel by the one-dot inversion method, the power consumption of the driving circuit including the data driver is further reduced while effectively suppressing the deterioration of image quality characteristics such as the occurrence of horizontal lines in the liquid crystal panel. It can effectively reduce and prevent the temperature of the driving circuit including the data driver from increasing.

Claims (4)

A liquid crystal panel including gate lines, data lines, and a plurality of pixels; A data driver for outputting a data voltage of a 2-dot inversion type to the data lines, in which the polarity of the image data is inverted by one pixel unit in a horizontal direction and by 2 pixel units in a vertical direction; A gate driver configured to output a gate high voltage to the gate lines; And A timing controller controlling the gate driver and the data driver, In the liquid crystal panel, data voltages having opposite polarities are written in pixels adjacent to each other up and down, and in the liquid crystal panel, data voltages having polarities opposite to each other are written in neighboring pixels at left and right sides, so that the pixels of the liquid crystal panel have 1 dot. Charge the data voltage whose polarity is reversed in the version form, The gate driver provides the gate high voltage signal to the gate lines in the order of a first gate line, a third gate line, a second gate line, and a fourth gate line, And the providing time of the gate high voltage signal provided to the first gate line and the second gate line is longer than that of the gate high voltage signal provided to the remaining gate line. delete A liquid crystal panel including gate lines, data lines, and a plurality of pixels; A data driver for outputting a data voltage of a 4-dot inversion type to the data lines in which the polarity of the image data is inverted by one pixel unit in a horizontal direction and by 4 pixel units in a vertical direction; A gate driver configured to output a gate high voltage to the gate lines; And A timing controller controlling the gate driver and the data driver, In the liquid crystal panel, data voltages having opposite polarities are written in pixels adjacent to each other up and down, and in the liquid crystal panel, data voltages having polarities opposite to each other are written in neighboring pixels at left and right sides, so that the pixels of the liquid crystal panel have 1 dot. Charge the data voltage whose polarity is reversed in the version form, The gate driver gates the gate high voltage signal in order of a first gate line, a third gate line, a fifth gate line, a seventh gate line, a second gate line, a fourth gate line, a sixth gate line, and an eighth gate line. To the lines, And the providing time of the gate high voltage signal provided to the first gate line and the second gate line is longer than that of the gate high voltage signal provided to the remaining gate line. delete

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