KR20010004914A - Liquid Crystal Display multi-driving method - Google Patents

Abstract

PURPOSE: A multiple driving method of LCD is provided to display various driving methods such as a frame inversion, a line inversion and a column inversion with changing their array orders, thereby reducing flicker. CONSTITUTION: The multiple driving method of LCD comprises a step outputting first/second polarity signals(POL1,POL2), source voltage signals and ground source signals with changing their array orders, thereby alternately utilizing a dot reverse method and a column reverse method. The first polarity signals are inversed every one period of a data enable signal(DE). The second polarity signals are the inversion signals of the first polarity signals. A multiplexor(MUX) for selecting first/second selection signals(SEL1,SEL2) is used to generate a module polarity signal(MPOL) embodying the various driving methods different every one frame.

Description

Liquid Crystal Display multi-driving method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display (hereinafter referred to as LCD) multiple driving method, and more specifically, flickering phenomenon by using various LCD driving methods used in a different arrangement order. It relates to a driving method for reducing the.

In thin film transistor-liquid crystal displays (hereinafter referred to as TFT-LCDs), when the voltage applied to the panel is a DC voltage, the panel is deteriorated and the performance is degraded. Therefore, an AC voltage is applied to the panel to prevent the panel from deteriorating as described above.

As such, a method for applying an alternating voltage to the LCD panel generally includes an inversion method for inverting polarity every frame unit, a line inversion method for inverting polarity for each line, and a column ( A column inversion method for inverting polarity for each column) and a dot inversion method for inverting polarity for each pixel by mixing the line inversion method and the column inversion method.

However, when an alternating voltage is applied to the panel, the average voltage when the applied voltage is a positive voltage and a negative voltage is different so that a luminance difference occurs and flickering occurs accordingly.

FIG. 1A illustrates a display pattern of a frame reversal method and a flickering pattern.

In general, a frame having a period of 60 Hz causes flickering of the screen at a period of 30 Hz due to a different luminance difference in each frame. In particular, the flickering phenomenon is a green state that is noticeable to a human. Is observed.

In order to prevent flicker in the frame inversion method as described above, a line inversion method and a column inversion method are used. In the line inversion method and the column inversion method, the screen is compromised by applying a voltage having a different polarity for each line and column. Flickering is reduced by the Spatial Averaging effect, but flickering still occurs on a line or column basis.

1B and 1C show the display patterns in the line inversion method and the column inversion method, respectively, and the flickering phenomenon can be easily observed when the above pattern is used.

There is a dot inversion method in which the two methods are mixed as a method for improving the line inversion method and the column inversion method, which further reduces flickering by applying a voltage having a different polarity to each pixel.

However, even in the dot inversion method, when using the display pattern as shown in Fig. 1D, flickering occurs and the quality of the screen is degraded.

The present invention has been made to solve the above problems, and an object thereof is to provide an improved driving method for reducing flicker by displaying the various driving methods in a different arrangement order.

1A is a view illustrating a display pattern in a frame inversion method of a liquid crystal display;

1B is a view showing a display pattern in the line inversion method of the liquid crystal display,

1C is a view showing a display pattern in the column inversion method of the liquid crystal display,

1D is a view showing a display pattern in the dot inversion method of the liquid crystal display,

2 is a circuit diagram for implementing a multiple driving method of a liquid crystal display according to an embodiment of the present invention;

3A is a waveform diagram of a signal input to the circuit diagram of FIG. 2 and a module polarity signal according thereto;

3B illustrates a display pattern according to the module polarity signal of FIG. 3A.

4 is a diagram illustrating a module polarity signal and a display pattern according to the method of driving a liquid crystal display according to an embodiment of the present invention.

(Name of the code for the main part of the drawing)

MUX: Multiplexer

In order to achieve the above object of the present invention, the present invention is characterized by using a multiple driving method for displaying various liquid crystal display driving methods on a panel in a different arrangement order.

In the multiple driving method, a first polarity signal inverted every one period of the data enable signal, a second polarity signal which is an inversion signal of the first polarity signal, a power supply voltage signal, and a ground power supply signal are selected as inputs. And a multiplexer for generating a module polarity signal for driving the liquid crystal display according to the signal.

The multiple driving method is characterized by adjusting the order in which the dot inversion method and the column inversion method are displayed by changing the order of the input signals selected by the first and second selection signals.

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

2 illustrates a circuit for generating a module polarity signal for displaying various driving methods in an arrangement order in the liquid crystal display driving method according to an exemplary embodiment of the present invention. Referring to FIG. 2, the present invention provides a multiplexer for selecting an input signal according to the first and second selection signals SEL1 and SEL2 to generate a module polarity signal MPOL that implements various driving methods in different frames. Use (MUX).

2 illustrates a case where an input signal is applied to alternately display the dot inversion method and the column inversion method. The input signal applied to the multiplexer MUX includes a power supply voltage Vcc, a first polarity signal POL1 that is inverted every one period of the data enable signal DE, and an inverted signal of the first polarity signal POL1. A second polarity signal POL2 and a ground power supply.

As the first and second selection signals SEL1 and SEL2 transition sequentially, the input signal for generating the module polarity signal MPOL is also sequentially selected and output accordingly.

3A illustrates a module polarity signal MPOL generated according to the first and second polarity signals POL1 and POL2, the first and second selection signals SEL1 and SEL2, and the selection signals SEL1 and SEL2. It is shown. In order to apply different module polarity signals MPOL to the four frames, the first selection signal SEL1 uses a signal inverted for each blanking period of the data enable signal DE and a second selection. The signal SEL2 uses a signal inverted every time the data enable signal DE falls.

The above-described module polarity signal MPOL is formed when the first and second selection signals SEL1 and SEL2 transition in the order of "00", "10", "01", and "11" in frame units. The output signal in the case of selecting one of the polarity signal POL1, the ground power supply, the second polarity signal POL2, and the power supply voltage Vcc in this order is shown.

That is, when the first and second selection signals SEL1 and SEL2 are "00", the first polarity signal POL1 is output as the module polarity signal MPOL, and when "10", the ground power supply is the module polarity. It is output as a signal MPOL. Further, when the first and second selection signals SEL1 and SEL2 are "01", the second polarity signal POL2 is output as the module polarity signal MPOL, and when "11", the power supply voltage Vcc. It is output as this module polarity signal MPOL.

FIG. 3B illustrates a display pattern for each frame appearing on the panel when the module polarity signal MPOL is applied as described above. Referring to FIG. 3B, the first frame is displayed in a dot inversion method, the second frame is displayed in a column inversion method, and the third frame is displayed in a dot inversion method in which polarity is inverted from the first frame. In the frame, it can be seen that the polarity of the second frame is displayed in a column inversion scheme.

In addition, by changing the order of the signals input to the multiplexer MUX, the arrangement order in which the dot inversion method and the column inversion method are displayed can be changed.

For example, when the first and second selection signals of the multiplexer MUX are transitioned in the order of "00", "10", "01", and "11" for each frame, the first polarity for each frame. The signal POL1, the second polarity signal POL2, the ground power source, and the power supply voltage Vcc may be output in the order.

The module polarity signal MPOL in the case of outputting the input signal in the above order is shown in FIG. 4A. Referring to FIG. 4A, the module polarity signal MPOL is displayed in the order of 1 frame-> 3 frame-> 2 frame-> 4 frame. Changed. That is, the first frame is displayed in a dot inversion scheme, the second frame is displayed in a dot inversion scheme in which the polarity is inverted, the third frame is displayed in a column inversion scheme, and the fourth frame is displayed in the dot inversion scheme. The three frames and the polarity are displayed in the inverted column inversion scheme.

Therefore, by changing the order of the input signals selected according to the first and second selection signals SEL1 and SEL2 of the multiplexer MUX, the arrangement of the dot inversion method and the column inversion method can be displayed in a different order.

As described in detail above, according to the liquid crystal display multiple driving method of the present invention, by displaying various driving methods in a different arrangement order, screen flickering may be reduced and screen quality may be improved.

Hereinafter, this invention can be implemented in various changes in the range which does not deviate from the summary.

Claims (2)

In the liquid crystal display driving method for reducing the flicker phenomenon, By outputting the first polarity signal inverted every one period of the data enable signal, the second polarity signal which is the inverted signal of the first polarity signal, the power supply voltage signal, and the ground power supply signal in a different arrangement order, A liquid crystal display multiple driving method characterized by driving a liquid crystal display by using a dot inversion method and a column inversion method alternately. The method of claim 1, wherein the arrangement order A multiplexer receiving the first and second polarity signals, a power supply voltage signal, and a ground power supply signal as inputs; And a first selection signal and a second selection signal to adjust the order in which the plurality of signals input to the multiplexer are output.