KR20110022972A - Liquid crystal display - Google Patents

Abstract

PURPOSE: A liquid crystal display device is provided to prevent flicker and improve display quality by reducing a generation of heat in a data driver. CONSTITUTION: A liquid crystal display device comprises a plurality of gate lines(GL1~GLn), and a plurality of pixel groups(PG1 ~ PGn), a plurality of data lines(DL1 ~ DLm) which are crossing the gate lines and the pixel groups, a gate driver(GD) which operates the gate lines in order, and a data driver(DD) which provides image data signal to whole data lines when each gate line is operated. The gate lines and pixel groups are placed by turns.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

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 which can improve image quality by reducing heat generation and power consumption of a data driver and preventing flicker.

The liquid crystal display device displays an image by adjusting light transmittance of liquid crystal cells according to a video signal. In an active matrix liquid crystal display, switching elements are formed in each pixel cell, which is advantageous for displaying a moving image. As the switching device, a thin film transistor (hereinafter referred to as "TFT") is mainly used.

The liquid crystal display includes a plurality of gate lines and a plurality of data lines crossing each other, and pixels formed in each pixel region defined by the plurality of gate lines and data lines.

In order to prevent deterioration of the liquid crystal and to prevent flicker, the liquid crystal display is driven by various inversion driving such as color inversion, frame inversion and dot inversion. Of these listed inversion driving schemes, dot inversion is the best in preventing flicker, but the heat generation and power consumption of the data driver are required because an operation of inverting the polarity of the data signals corresponding to all data lines is required every horizontal period. This is followed by an increasing problem.

The present invention has been made to solve the above problems, by changing the polarity of the data supplied to the odd-numbered data lines and even-numbered data lines to reduce the power consumption and heat generation of the data driver and to prevent flicker It is an object of the present invention to provide a liquid crystal display device capable of improving image quality.

According to an aspect of the present invention, there is provided a liquid crystal display device including: a plurality of pixel groups and a plurality of gate lines alternately disposed; A plurality of data lines arranged to intersect the gate lines and the pixel groups; A plurality of pixels formed in each pixel group to be positioned between data lines adjacent to each other to display an image; A gate driver for sequentially driving the gate lines; A data driver for simultaneously supplying image data signals to all data lines each gate line is driven; the pixels included in the p (p is a natural number including 0) th pixel group are commonly connected to the p th gate line; Each of the pixels included in the 4p + 1 and 4p + 2th pixel groups is connected to a data line located at one side thereof; Each of the pixels included in the 4p + 3 and 4p + 4th pixel groups is connected to a data line located on the other side thereof; The data driver supplies data signals whose polarity is changed in units of a horizontal period and a frame period to any first data line, and all horizontal lines within one frame period to a second data line adjacent to the first first data line. It is characterized by supplying data signals whose polarity is changed in units of frame periods while being kept at a constant polarity for periods.

Each of the pixels included in the 4p + 1 and 4p + 2th pixel groups is connected to a data line located on its left side; Each of the pixels included in the 4p + 3 and 4p + 4th pixel groups is connected to a data line located at its right side.

The data lines are m (m is a natural number of 3 or more); The pixels of the 4p + 1 and 4p + 2th pixel groups are supplied with data signals from first to m-th data lines; The pixels of the 4p + 3 and 4p + 4th pixel groups receive data signals from the second to m-th data lines.

The data driver includes a 4k + 1 (k is a natural number including 0) and a 4k + 3th data line in which the polarity is changed every i (i is a natural number) horizontal period and every j (j is a natural number) frame period. Supply data signals whose polarity is changed, and supply data signals whose polarity is changed every h (h is a natural number) frame period to the 4k + 2th data line and the 4k + 4th data line; The data signal to the 4k + 1th data line and the data signal to the 4k + 3th data line in the same horizontal period and the same frame period exhibit opposite polarities; The data signal to the 4k + 2th data line and the data signal to the 4k + 4th data line in the same frame period are characterized by showing opposite polarities.

The data driver supplies data signals whose polarity is changed every two horizontal periods and whose polarity is changed every one frame period to the 4k + 1th data line and the 4k + 3th data line, and the 4k + 2th data line and 4k. And a data signal whose polarity is changed every one frame period to the + 4th data line.

The pixels included in the 4p + 1 and 4p + 3th pixel groups are composed of a plurality of red pixels for displaying a red image and a plurality of green pixels for displaying a green image; The red pixels and the green pixels are alternately located; The pixels included in the 4p + 2 and 4p + 4th pixel groups are composed of blue pixels for displaying a blue image and white pixels for displaying a white image; The blue pixels and the white pixels are alternately located.

The liquid crystal display according to the present invention has the following effects.

In the present invention, the heat generation of the data driver is reduced by changing the driving method of the data driver so that the data signals are supplied to the even-numbered data line by the frame inversion method, and the driving of the above-described data driver by changing the connection structure of the pixels in the liquid crystal panel. In spite of the method, flicker can be prevented by displaying the screen in a 2-dot horizontal and 2-dot vertical manner.

1 is a view showing a liquid crystal display device according to an 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 plurality of pixel groups PG1 to PGn and a plurality of gate lines GL1 to GLn alternately disposed with each other, and the gate line. Each of the pixel groups so as to be located between the plurality of data lines DL1 to DLm arranged to intersect the pixels GL1 to GLn and the pixel groups PG1 to PGn and adjacent data lines DL1 to DLm. A plurality of pixels R, G, B, and W formed in PG1 to PGn to display an image, a gate driver GD to sequentially drive the gate lines GL1 to GLn, and each gate line A data driver DD for simultaneously supplying image data signals to all the data lines DL1 to DLm each time it is driven, and a timing controller TC for controlling the gate driver GD and the data driver DD. It includes.

The timing controller TC generates a data control signal DCS and a gate control signal GCS by using the horizontal synchronization signal Hsync, the vertical synchronization signal Vsync, and the clock signal CLK. Supply to driver DD and gate driver GD. The data control signal DCS includes a dot clock, a source shift clock, a source enable signal, a polarity inversion signal, and the like. The gate control signal GCS is input to the gate driver GD including a gate start pulse, a gate shift clock, a gate output enable, and the like.

The data driver DD samples the image data in accordance with the data control signal DCS from the timing controller TC, and then stores the sampled image data in one line for each horizontal period (1H, 2H, ...). Each minute is latched and the latched data signals are supplied to the data lines DL1 to DLm. That is, the data driver DD converts the image data R / G / B / W Data from the timing controller TC into an analog pixel signal (data signal) by using the gamma voltage input from the power generator. Supply to the data lines DL1 to DLm.

The gate driver GD shifts a shift register that sequentially generates scan pulses in response to a gate start pulse among the gate control signals from the timing controller TC, and shifts the voltage of the scan pulses to a voltage level suitable for driving the liquid crystal cell. A level shifter. The gate driver GD sequentially supplies scan pulses to the gate lines GL1 to GLn in response to the gate control signal.

The pixels R and G included in the 4p + 1 and 4p + 3 (p is a natural number including 0) pixels include a plurality of red pixels R for displaying a red image and a plurality of green pixels for displaying a green image. It consists of green pixels G, in which the red pixels R and the green pixels G are alternately arranged in the 4p + 1 and 4p + 3th pixel groups. For example, as illustrated in FIG. 1, red pixels R and green pixels G are alternately arranged in the first pixel group PG1.

The pixels B and W included in the 4p + 2 and 4p + 4th pixel groups are composed of blue pixels B for displaying a blue image and white pixels W for displaying a white image. The blue pixels B and the white pixels W are alternately arranged in the +2 and 4p + 4th pixel groups. For example, as illustrated in FIG. 1, blue pixels B and white pixels W are alternately arranged in the second pixel group.

Each pixel (R, G, B, W) is turned on by a scan pulse from a corresponding gate line to switch a thin film transistor to switch a data signal from the corresponding data line, and receives the switched data signal from the thin film transistor. And a pixel electrode for displaying an image. The pixels R, G, B, and W having such a configuration are formed in the liquid crystal panel PN.

The pixels R, G, B, and W included in the p-th pixel group are commonly connected to the p-th gate line. For example, as illustrated in FIG. 1, the pixels R, G, B, and W included in the first pixel group PG1 are commonly connected to the first gate line GL1.

Each of the pixels R, G, B, and W included in the 4p + 1 and 4p + 2th pixel groups is individually connected to a data line located at one side thereof. Specifically, each of the pixels R, G, B, and W included in the 4p + 1 and 4p + 2th pixel groups is connected to a data line positioned on the left side of two data lines positioned on the left and right sides thereof. . For example, as illustrated in FIG. 1, each of the pixels R and G included in the first pixel group PG1 is located between two adjacent data lines DL1 to DLm. Each pixel R and G of the pixel group PG1 is connected to a data line located on its left side among the two data lines DL1 to DLm.

Each of the pixels R, G, B, and W included in the 4p + 3 and 4p + 4th pixel groups is individually connected to a data line located on the other side thereof. Specifically, each of the pixels R, G, B, and W included in the 4p + 3 and 4p + 4th pixel groups is connected to a data line positioned on the right side of two data lines positioned on the left and right sides thereof. . For example, as shown in FIG. 1, each of the pixels R and G included in the third pixel group PG3 is positioned between two adjacent data lines, and the third pixel group PG3 is disposed. Each of the pixels R and G is connected to a data line located on its right side among these two data lines.

As such, the data lines of the pixels R, G, B, and W in the 4p + 1 and 4p + 2th pixel groups and the pixels R, G, B, and W in the 4p + 3 and 4p + 4th pixel groups Since the connection structure to each other is different, the pixels R, G, B, and W in the 4p + 1 and 4p + 2th pixel groups are separated from the first to m-1th data lines DL1 to DLm-1. While the data signals are supplied, the pixels R, G, B, and W in the 4p + 3 and 4p + 4th pixel groups receive the data signals from the second to mth data lines DL2 to DLm. To this end, the 4p + 1 and 4p + 2th pixel groups are not connected to the rightmost mth data line DLm, while the 4p + 3 and 4p + 4th pixel groups are located at the leftmost first data line. It is not connected to (DL1).

The data driver DD supplies data signals whose polarity is changed in units of horizontal periods and frame periods to any data line, and is constant for all horizontal periods within one frame period to another data line adjacent to the arbitrary data line. The data signals are maintained in polarity and change in polarity on a frame period basis.

Here, the horizontal period means a period during which one gate line is driven, and this period corresponds to a pulse width of a scan pulse supplied to one gate line. The pulse width of this scan pulse means the pulse width of the active state, and the gate line supplied with this scan pulse is activated for a period corresponding to the pulse width of the active state. The thin film transistors of each of the pixels R, G, B, and W connected to the activated gate line are turned on.

The frame period is a period in which scan pulses are driven once from the first gate line to the nth gate lines GL1 to GLn, and one frame period corresponds to n horizontal periods.

The data driver DD is a 4k + 1 (k is a natural number including 0) and a 4k + 3th data line, with the polarity being changed every i (i is a natural number) horizontal period and j (j is a natural number) frame period. Each time, data signals whose polarity is changed are supplied. However, in the same horizontal period and the same frame period, the data signal to the 4k + 1th data line and the data signal to the 4k + 3th data line show opposite polarities.

For example, data signals of which the polarity is changed every two horizontal periods and the polarity is changed every one frame period may be supplied to the 4k + 1th data line and the 4k + 3th data line. Specifically, the data signals are sequentially supplied to the first data line DL1 in the order of the positive data signal, the positive data signal, the negative data signal, and the negative data signal during successive first to fourth horizontal periods. During the first to fourth horizontal periods, data signals may be supplied to the third data line in the order of the negative data signal, the negative data signal, the positive data, and the positive data signal.

In addition, the data driver DD supplies data signals whose polarity is changed every h (h is a natural number) frame period to the 4k + 2th data line and the 4k + 4th data line. However, in the same frame period, the data signal to the 4k + 2th data line and the data signal to the 4k + 4th data line show opposite polarities. For example, data signals whose polarity is changed every one frame period may be supplied to the 4k + 2th data line and the 4k + 4th data line. Specifically, while the positive data signals are continuously supplied to the second data line DL2 during the first frame period, the negative data signals are continuously supplied to the fourth data line DL4 during the first frame period. Can be. Of course, negative data signals are continuously supplied to the second data line DL2 during the second frame period, while positive data signals are continuously supplied to the fourth data line DL4 during the second frame period. .

The operation of the liquid crystal display device configured as described above will be described in detail as follows.

FIG. 2 is a diagram illustrating a portion of pixels R, G, B, and W, a portion of gate lines GL1 to GLn, and a portion of data lines of FIG. 1, and FIG. 3 is a gate line illustrated in FIG. 2. Diagram showing a timing diagram of scan pulses and data signals supplied to the first and second data lines. As shown in FIG. 3, two dots of which polarity is changed every two horizontal periods in the 4k + 1 and 4k + 3th data lines. Data signals are supplied in a dot manner. The 4k + 3 and 4k + 4th data lines are supplied with data signals in which the polarity is changed every frame period, that is, in a frame inversion method.

As shown in FIG. 2, the first scan pulse SP1 is supplied to the first gate line GL1 in the first horizontal period T1. Then, the pixels R and G in the first pixel group PG1 commonly connected to the first gate line GL1 are activated. That is, the thin film transistors included in each of the pixels R and G in the first pixel group PG1 are turned on. Then, the data signals Data1 to Data6 from the first to sixth data lines DL1 to DL6 are connected to the pixels R and G in the first pixel group PG1 through the turned-on thin film transistors. Supplied to.

As shown in FIG. 2, during the first horizontal period T1, the negative data signal Data1 is supplied to the first data line DL1, and the positive data signal DL is supplied to the second data line DL2. Data2 is supplied, a positive data signal Data3 is supplied to the third data line DL3, and a negative data signal Data4 is supplied to the fourth data line DL4.

In this manner, the data signal of the same polarity as that of the data signal supplied to the first data line DL1 is stored in the 4k + 1th data line including the fifth data line DL5 during the first horizontal period T1. The 4k + 2th data line including the sixth data line DL6 is supplied with a data signal having the same polarity as that of the data signal supplied to the second data line DL2, and the seventh data line DL7 is supplied. The data signal having the same polarity as the data signal supplied to the third data line DL3 is supplied to the 4k + 3th data line including the fourth data line, and the 4k + 4th data line including the eighth data line DL8 is supplied to the 4k + 3th data line. The data signal of the same polarity as the data signal supplied to the four data lines DL4 is supplied.

Therefore, the red and green pixels R and G in the first pixel group PG1 during the first horizontal period T1 are negatively, positively, positively and negatively, as shown in FIG. 2. The polarity of is represented repeatedly.

In the same manner, in the second horizontal period T2, the blue and white pixels B and W in the second pixel group PG2 are activated by the second scan pulse SP2, as shown in FIG. 2. The blue and white pixels B and W repeatedly exhibit polarities of negative polarity, positive polarity, positive polarity, and negative polarity.

In this manner, the remaining pixels R, G, B, and W also receive data signals in the third to nth horizontal periods T3 to Tn.

As described above, in the present invention, the heat generation of the data driver DD is reduced by changing the driving method of the data driver DD such that the data signals are supplied to the even-numbered data lines DL2, DL4, ..., DLm in a frame inversion scheme. In addition, by changing the connection structure of the pixels R, G, B, and W in the liquid crystal panel PN, the screen is displayed in a horizontal 2-dot and vertical 2-dot scheme in spite of the above-described driving method of the data driver DD. Flicker can be prevented by making it appear. That is, according to the structure of the present invention, image quality can be improved while reducing heat generation and power consumption of the data driver DD.

The present invention described above is not limited to the above-described embodiment and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

1 is a view showing a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a view illustrating some of the pixels, some of the gate lines, and some of the data lines of FIG. 1; FIG.

FIG. 3 is a timing diagram of scan pulses and data signals supplied to the gate lines and the data lines shown in FIG.

* Description of the main parts of the drawings

TC: Timing Controller DD: Data Driver

GD: gate driver PN: liquid crystal panel

DL: data line GL: gate line

PG: pixel group R: red pixel

G: green pixel B: blue pixel

W: white pixel

Claims (6)

A plurality of pixel groups and a plurality of gate lines alternately located with each other; A plurality of data lines arranged to intersect the gate lines and the pixel groups; A plurality of pixels formed in each pixel group to be positioned between data lines adjacent to each other to display an image; A gate driver for sequentially driving the gate lines; A data driver for simultaneously supplying image data signals to all data lines each gate line is driven; the pixels included in the p (p is a natural number including 0) th pixel group are commonly connected to the p th gate line; Each of the pixels included in the 4p + 1 and 4p + 2th pixel groups is connected to a data line located at one side thereof; Each of the pixels included in the 4p + 3 and 4p + 4th pixel groups is connected to a data line located on the other side thereof; And, The data driver supplies data signals whose polarity is changed in units of a horizontal period and a frame period to an arbitrary first data line, and all horizontal periods within one frame period to a second data line adjacent to the arbitrary first data line. And a data signal whose polarity is changed in units of frame periods while being kept at a constant polarity. The method of claim 1, Each of the pixels included in the 4p + 1 and 4p + 2th pixel groups is connected to a data line located on its left side; And, And each of the pixels included in the 4p + 3 and 4p + 4th pixel groups is connected to a data line located at its right side. The method of claim 2, The data lines are m (m is a natural number of 3 or more); The pixels of the 4p + 1 and 4p + 2th pixel groups are supplied with data signals from first to m-th data lines; And, And the pixels of the 4p + 3 and 4p + 4th pixel groups receive data signals from second to m-th data lines. The method of claim 3, wherein The data driver, 4k + 1 (k is a natural number including 0) data and 4k + 3th data line, where polarity is changed every i (i is a natural number) horizontal period and j (j is a natural number). Supplies signals and supplies data signals whose polarity changes every h (h is a natural number) frame period to a 4k + 2th data line and a 4k + 4th data line; The data signal to the 4k + 1th data line and the data signal to the 4k + 3th data line in the same horizontal period and the same frame period exhibit opposite polarities; And, And a data signal to a 4k + 2th data line and a 4k + 4th data line in the same frame period exhibit polarities opposite to each other. The method of claim 4, wherein The data driver, The 4k + 1th data line and the 4k + 3th data line supply data signals whose polarity changes every 2 horizontal periods and whose polarity changes every 1 frame period. And supplying data signals whose polarity is changed every one frame period. The method of claim 1, The pixels included in the 4p + 1 and 4p + 3th pixel groups are composed of a plurality of red pixels for displaying a red image and a plurality of green pixels for displaying a green image; The red pixels and the green pixels are alternately located; The pixels included in the 4p + 2 and 4p + 4th pixel groups are composed of blue pixels for displaying a blue image and white pixels for displaying a white image; And, And the blue pixels and the white pixels are alternately located.

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