KR100656903B1 - Liquid crystal display apparatus for reduction of flickering - Google Patents

Abstract

The present invention is a liquid crystal display for reducing flickering.

The data driver inverts the polarities of the dots arranged successively on the LCD panel and outputs a plurality of data driving voltages for randomly inverting the polarities of the dots arranged successively on the LCD panel. At this time, the random REV generator outputs a plurality of random REV signals, which are polarity signals obtained by randomly multiplying one period of the horizontal synchronization signal at a fundamental frequency, and the data drive IC receives a plurality of random REV signals and is continuously arranged on the LCD panel. A plurality of data driving voltages for inverting the polarity of the dots are respectively output.

As a result, the flickering phenomenon recognized in the dot pattern can be eliminated by applying an arbitrary random signal to the multiplication component having the horizontal frequency as the fundamental frequency as the polarity signal that is the signal for determining the polarity of the data driver IC output terminal.

Flickering, Timing Control, Frequency Multiplication, Gamma Voltage, Random, Dot Inversion

Description

Liquid crystal display apparatus for reduction of flickering

1A to 1B are diagrams for explaining conventional 1 * 1 dot inversion driving.

2 is a block diagram of a liquid crystal display for reducing flickering according to an exemplary embodiment of the present invention.

3 is a waveform diagram illustrating a plurality of REV signals output from a random REV generator according to the present invention.

4 is a configuration diagram of a liquid crystal display for reducing flickering according to another exemplary embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

100, 600: timing controller 200: gray voltage generator

300, 700: data driver 310, 610: random REV generator

320: data drive IC unit 400: gate driving voltage generator

450: gate driver 500: LCD panel

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device for reducing flickering.

Recently, display devices are also required to be lighter and thinner in accordance with lighter and thinner personal computers and televisions, and flat panel displays such as liquid crystal displays (LCDs) are being developed instead of cathode ray tubes (CRTs). It is being used in various fields.

An LCD is a display device that obtains a desired image signal by applying an electric field to a liquid crystal material having an anisotropic dielectric constant injected between two substrates, and controlling the amount of light transmitted through the substrate by adjusting the intensity of the electric field. Such LCDs are typical of portable flat panel display devices, and among them, TFT-LCDs using thin film transistors (TFTs) as switching elements are mainly used.

In general, an LCD includes a plurality of gate lines for transmitting a scan signal and data lines formed to intersect the gate lines and for transmitting image data, and are formed in an area surrounded by the gate lines and the data lines, respectively, and are connected to the gate lines and the data lines, respectively. It includes a plurality of pixels in the form of a matrix connected through the device.

The method of applying image data to each pixel in such an LCD is as follows.

First, when a gate-on signal, which is a scanning signal, is sequentially applied to the gate lines, the switching elements connected to the gate lines are sequentially turned on, and at the same time, an image signal to be applied to the pixel row corresponding to the gate line, more specifically, a gray level. Supply voltage to each data line. Then, the image signal supplied to the data line is applied to each pixel through the turned-on switching element. In this case, the gate-on signal is sequentially applied to all the gate lines during one frame period to apply the pixel signal to all the pixel rows, thereby displaying an image of one frame.

In general, when the electric field in the same direction is continuously applied due to the characteristics of the liquid crystal material, there is a problem in that the liquid crystal material is deteriorated. That is, if the polarity of the applied voltage of one pixel receives the positive signal voltage, the next frame must receive the negative signal voltage.

For this reason, the Frame Inversion Method (FIM) that inverts the polarity in units of frames to invert the TFT-LCD, the Line Inversion Method (LIM) that inverts the polarity in lines, and columns A column inversion method (CIM) for inverting polarity in units, a dot inversion method (DIM) for inverting polarity in pixels, and the like have been adopted for production.

However, these inversion driving methods show limitations due to the high resolution trend. In the line inversion driving method, the vertical crosstalk problem is serious in the horizontal crosstalk and column inversion driving methods. The dot inversion driving is good in terms of crosstalk, but the flickering problem is vulnerable, since the TFT-LCD is often used in a graphic environment such as a computer, and thus a dot screen configuration is often displayed.

In general, flickering is an image quality characteristic that occurs when the transmittance difference between two polarities occurs in a process of periodically inverting the charging polarity of the liquid crystal to the positive (+) and the negative (-) polarities. This is a phenomenon caused by the fact that the RC delay occurs depending on the length of the panel because the voltage is distributed and the voltage for controlling the dots is controlled in only one direction, so that the same voltage cannot be applied to each dot.

1 * 1 dot inversion driving method, which is a pattern that appears frequently in a general PC environment, is shown in FIGS. 1A to 1B as one of inversion driving to prevent deterioration of the liquid crystal.

FIG. 1A is a diagram for describing an m-th frame, and FIG. 1B is a diagram for describing an (m + 1) th frame.

As shown, flickering is visually recognized every time every frame is converted in a 1 * 1 dot pattern, thereby degrading display quality.

As such, even in the case of well-tuned modules, the degree of flickering tends to become more severe when the driving environment is changed and in the long-term use, and a lot of effort and cost are used to reduce flickering in the LCD module development. There is a problem that cannot be eliminated.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and an object of the present invention is to recognize a dot pattern by applying a polarity signal, which is a signal for determining the output terminal polarity of the data driver IC, as a random signal in a liquid crystal display device. The present invention provides a liquid crystal display for eliminating flickering.

According to one aspect of the present invention, there is provided a liquid crystal display device for reducing flickering, including: switching elements connected to a plurality of gate lines and data lines, respectively, and connected to and responding to operations of the switching elements. An LCD panel having a dot electrode, and a gate driver for outputting a gate driving voltage to each of the gate lines to output a plurality of gate driving voltages for controlling an on / off operation of the switching element, the polarities being different for each frame. In the liquid crystal display device which is inverted so that

 And a data driver outputting a plurality of data driving voltages for inverting the polarities of the dots sequentially arranged on the LCD panel and for randomly inverting the polarities of the dots sequentially arranged on the LCD panel.

In addition, a liquid crystal display device for reducing flickering according to another aspect for realizing the object of the present invention, a switching element connected to each of a plurality of gate lines and data lines, and connected to the switching element to the operation thereof; An LCD panel having a dot electrode responsive, and a gate driver for outputting a gate driving voltage to each of the gate lines to output a plurality of gate driving voltages for controlling an on / off operation of the switching element. In a liquid crystal display device that is inverted so as to have a different polarity,

A timing controller having a random REV generator for outputting at least one random REV signal which is a polarity signal that is randomly multiplied by one period of the horizontal synchronization signal at a fundamental frequency; And

Inverting the polarity of the consecutively arranged dots on the LCD panel, and receiving a plurality of at least one random REV signal from each of the random REV generator, driving a plurality of data to invert the polarity of the consecutively arranged dots on the LCD panel It includes a data driver that outputs a voltage.

According to the liquid crystal display device for reducing such flickering, flickering recognized in a dot pattern by applying an arbitrary random signal to a multiplication component having a fundamental frequency of one horizontal period as a polarity signal that defines a polarity of an output terminal of a data driver IC The phenomenon can be eliminated.

In this case, the concept of flickering is eliminated by visually applying positive / negative polarity data to each dot in one frame, thereby visually preventing the imbalance of the positive / negative gamma voltage.

Then, embodiments will be described so that those skilled in the art can easily implement the present invention.

2 is a block diagram of a liquid crystal display for reducing flickering according to an exemplary embodiment of the present invention.

As shown in FIG. 2, a liquid crystal display for reducing flicker according to an exemplary embodiment of the present invention includes a timing controller 100, a gray voltage generator 200, a data driver 300, and a gate driving voltage generator. 400, a gate driver 450, and an LCD panel 500.

The timing controller 100 receives R, G, and B data and a vertical sync signal Vsync, a frame discrimination signal, a horizontal sync signal Hsync, and a line discrimination signal from a graphic controller (not shown) outside the LCD module. The digital signal for driving the data driver 300 and the gate driver 450 is output by receiving the high signal DE and the main clock signal MCLK only during the data output period to indicate the zone.

In more detail, the timing controller 100 starts inputting the digital data signals R (0: N), G (0: N), and B (0: N) from the graphics controller to the data driver 300. The signal (Hstart) for commanding the signal, the data is converted to the analog in the data driver 300 and the signal (LOAD) for commanding to apply the converted analog value to the LCD panel 500, the data shift in the data driver 300 The clock signal HCLK for outputting the signal is output to the data driver 300.

In addition, the timing controller 100 receives a gate-on signal into the gate line of the LCD panel 500 by the gate driver 450. The timing controller 100 sequentially performs a Vstart and a gate-on signal to the gate line. The gate clock signal Gate clk is output to the gate driver 450.

The gray voltage generator 200 generates a gray voltage suitable for a digital code value according to the number of bits of RGB data provided from the graphic controller and provides the gray voltage to the data driver 300. For example, when R data is applied with 6 bits (R (0: 5)), 2 ⁶ = 64 gray levels can be generated and 64 gray levels can be represented.

The data driver 300 includes a random REV generator 310 and a data drive IC unit 320 to output the R, G, and B digital data [R (0: N), G (0: N) from the timing controller 100. ), B (0: N)] is received, stored and stored in the LCD panel 500. When a load signal LOAD is applied, the voltage corresponding to each data is selected to select the LCD panel 500. The data voltages V _R1 , V _G1 , V _B1 , V _R2 ,..., V _Gn and V _Bn are outputted to transmit the voltages.

At this time, the random REV generator 310 outputs a polarity signal having a multiplication time of an integer multiple of one random horizontal period to the data drive IC unit 320.

In addition, the data drive IC unit 320 includes a plurality of data drive ICs. Each data drive IC receives a random REV signal provided from the random REV generator 310 to generate a data driving voltage having an irregular output polarity. Output to the data line.

3 is a waveform diagram illustrating a plurality of REV signals output from a random REV generator according to the present invention.

As shown in FIG. 3, the first random REV signal REV1 is applied to the first data drive IC, the second random REV signal REV2 is applied to the second data drive IC, and the third random REV signal ( REV3) is applied to the third data drive IC so that each random REV signal is applied to each data drive IC. In this case, each random REV signal is a multiplication component obtained by using a horizontal synchronization signal as a fundamental frequency and is a random signal.

The gate driving voltage generator 400 may include a voltage Von for making a gate-on signal, a voltage Voff for making a gate-off signal, and a common voltage Vcom serving as a reference for the data voltage difference in the TFT. To 450).

The gate driver 450 receives a gate clock signal and a vertical line start signal from the timing controller 100, including a shift register, a level shifter, a buffer, and the like, and supplies voltages Von and Voff from the gate driving voltage generator 400. , And Vcom) open the way for the voltage value of each pixel on the LCD panel 500 to be transferred to the pixel.

The LCD panel 500 includes a plurality of gate lines that transmit gate voltages G1, G2,..., And Gm, which are scan signals provided from the gate driver 450, and data voltages that are image signals crossing the gate lines. A plurality of data lines for transmitting (V _R1 , V _G1 , V _B1 , V _R2 , ..., V _Gn, and V _Bn ), and formed in an area surrounded by the gate lines and the data lines, so that each gate line and data A switching element connected to the line, and a dot electrode connected to the switching element and responsive to the operation of the switching element.

At this time, each of the dot electrodes represent any one of the RGB dot electrodes, and the RGB dot electrodes are arranged in a matrix type (preferably, R dots, G dots, and B dots are continuously arranged), and are provided from the gate driver 450. Data voltages V _R1 , V _G1 , V _B1 , V _R2 , ..., V provided from the data driver 300 as the gate voltages G1, G2,..., And Gm are applied to the corresponding pixels. In response to _Gn and V _Bn ), the corresponding embedded R, G, and B dots are driven.

As described above, in the liquid crystal display according to the exemplary embodiment of the present invention, a random REV generator for generating a random REV signal is disposed in the data driver, and a plurality of random REV signals output from the random REV generator are output from each of the data driver ICs. By applying to, a random data driving voltage can be output to each data line of the LCD panel.

4 is a configuration diagram of a liquid crystal display for reducing flickering according to another exemplary embodiment of the present invention.

As shown in FIG. 4, a liquid crystal display for reducing flicker according to another exemplary embodiment of the present invention includes a timing controller 600, a gray voltage generator 200, and a data driver 700 having a random REV generator 610. And a gate driving voltage generator 400, a gate driver 450, and an LCD panel 500, and the same reference numerals are assigned to components that perform the same function in FIG. 2.

2 and 4, the random REV generator 310 disposed in the data driver 300 illustrated in FIG. 2 is symmetrical to the random REV generator 610 disposed in the timing controller 100 illustrated in FIG. 4. Since the basic operation does not depart from the gist of FIG. 2, a detailed description thereof will be omitted.

As described above, in the liquid crystal display according to another exemplary embodiment of the present invention, a random REV generator for generating a plurality of random REV signals is disposed in a timing controller to output a plurality of random REV signals output from the random REV generator. By applying to each of the ICs, a random data driving voltage can be output to each of the data lines of the LCD panel.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

As described above, according to the present invention, a flickering phenomenon recognized in a dot pattern is applied by applying a polarity signal, which is a signal for determining the output terminal polarity of the data driver IC, as a random signal to the timing controller or by arranging it in the data driver. Can be removed.

Claims (3)

An LCD panel having a switching element connected to a plurality of gate lines and data lines, a dot electrode connected to the switching element and responsive to its operation, and a gate driving voltage output to each of the gate lines, In the liquid crystal display device including a gate driver for outputting a plurality of gate driving voltage for controlling the on / off operation, inverted driving to have a different polarity for each frame,  A random REV generator for outputting at least one random REV signal which is a polarity signal that is randomly multiplied by one period of the horizontal synchronization signal at a fundamental frequency; And A data driver having a plurality of data driver ICs respectively receiving the random REV signals and outputting a plurality of data driving voltages for inverting and driving the polarities of dots arranged consecutively on the LCD panel; Liquid crystal display for reducing flickering comprising a. delete An LCD panel having a switching element connected to a plurality of gate lines and data lines, a dot electrode connected to the switching element and responsive to its operation, and a gate driving voltage output to each of the gate lines, In the liquid crystal display device including a gate driver for outputting a plurality of gate driving voltage for controlling the on / off operation, inverted driving to have a different polarity for each frame, A timing controller having a random REV generator for outputting at least one random REV signal which is a polarity signal that is randomly multiplied by one period of the horizontal synchronization signal at a fundamental frequency; And A data driver that receives the at least one random REV signal from the random REV generator and outputs a plurality of data driving voltages for inverting the polarity of dots consecutively arranged on the LCD panel Liquid crystal display for reducing flickering comprising a.

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