KR20080015177A - Lcd device, driving method of the same and used color filter substrate - Google Patents

Abstract

An LCD, a method for driving the same, and a color filter substrate used for the same are provided to supply appropriate common voltages to common electrodes, which are electrically isolated from each other, according to surface resistance values of the common electrodes, thereby preventing the deterioration of picture quality due to a surface resistance difference of the common electrodes. An LCD comprises an LCD panel(100) for displaying an image by voltage differences between pixel electrodes and at least two common electrodes distanced from each other, and at least two common voltage generators(140,145) for supplying different voltages to the common electrodes. For driving the LCD, surface resistance values of the common electrodes are measured respectively. The common voltage generators set common voltages corresponding to the measured surface resistance values. The generated common voltages are supplied to the common electrodes, respectively.

Description

Liquid crystal display device, driving method thereof, and color filter substrate used therein {LCD device, driving method of the same and used color filter substrate}

1 is a block diagram schematically illustrating a configuration of a general liquid crystal display device.

FIG. 2 is a perspective view schematically illustrating a configuration of a liquid crystal panel in the liquid crystal display of FIG. 1.

3 is a block diagram schematically illustrating a configuration of a liquid crystal display according to an exemplary embodiment of the present invention.

4 is a perspective view schematically illustrating a configuration of a liquid crystal panel in the liquid crystal display of FIG. 3.

5A is a cross-sectional view taken along the line IV-IV of FIG. 4.

5B is a cross-sectional view of a portion of the liquid crystal panel of the liquid crystal display according to another exemplary embodiment of the present invention.

The present invention relates to a liquid crystal display device, a driving method thereof, and a color filter substrate used therein. More particularly, the common electrode formed over the entire area of the upper substrate is electrically spaced apart from each other to have two or more areas. The present invention relates to a liquid crystal display device which eliminates the difference in the amount of pixel voltage drop ΔVp due to different sheet resistances on the left and right sides of an electrode, a driving method thereof, and a color filter substrate used therein.

In general, liquid crystal display devices have low power consumption and are capable of thinning and realizing large screens. Therefore, liquid crystal display devices have been spotlighted as next-generation high-end display devices with high added value as display devices such as notebook computers and large screen TVs. .

The image realization principle of the liquid crystal display device uses the optical anisotropy and polarization of the liquid crystal. The liquid crystal has a thin and long molecular structure and has an optical anisotropy having an orientation in orientation and a molecule according to its size when placed in an electric field. It has a polarization property in which the direction of arrangement changes. Therefore, the liquid crystal display device is an essential component of a liquid crystal panel composed of a pair of transparent substrates, each having a liquid crystal layer interposed therebetween by a predetermined distance, and having an electric field generating electrode formed therebetween. Through this, the alignment direction of the liquid crystal molecules is artificially adjusted and the light transmittance is changed accordingly to display various images.

Here, the pair of transparent substrates each include an array substrate on which a plurality of switching elements and pixel electrodes are formed in a matrix form, and a color filter substrate on which color filters and a common electrode are formed, and the pixel electrodes and the color filters of the array substrate. The liquid crystal molecules are controlled by a vertical electric field formed between the common electrodes of the substrate.

FIG. 1 is a block diagram schematically illustrating a configuration of a general liquid crystal display device, and FIG. 2 is a perspective view schematically illustrating a configuration of a liquid crystal panel in the liquid crystal display device of FIG. 1, and includes a liquid crystal panel in which a switching element T is formed. 10, the driving circuit unit 20 for driving the liquid crystal panel 10, the power supply unit 30 for supplying power to the driving circuit unit 20, and the common voltage generation for generating the common voltage Vcom. It is comprised by the part 40.

More specifically, the liquid crystal panel 10 includes a thin film transistor, which is a switching element T formed at a point where a plurality of gate lines GL and data lines DL intersect in a matrix form, and a pixel electrode 11 connected thereto. An array substrate 13 comprising a color filter, a color filter 14 in which RGB three primary colors are respectively colored, and a color filter substrate including a black matrix (BM) and a common electrode 16 for distinguishing the RGB three primary colors, respectively. The liquid crystal layer in which the liquid crystal LC is injected therebetween is bonded to each other at a predetermined distance.

The driving circuit unit 20 is connected to the gate driving circuit 22 for supplying a turn-on / off signal of the switching device T through the gate line GL, and to the pixel electrode through the data line DL. And a control unit 26 for controlling the gate and the data driving circuits 22 and 24 in response to an external signal.

The power supply unit 30 supplies power to the driving circuit unit 20 and the common voltage generation unit 40 for driving.

The common voltage generator 40 generates a common voltage Vcom and supplies the common voltage Vcom to the common electrode 16 included in the color filter substrate 19 of the liquid crystal panel 10.

The liquid crystal display device displays an image by changing the angle of the liquid crystal by an electric field formed between the pixel electrode 11 and the common electrode 16 and adjusting the amount of light irradiated from a light source provided separately.

In the liquid crystal display, the common electrode 16 is formed over the entire color filter substrate 19, and is connected to the common voltage generator 40 at one end of the common electrode 16 to receive the common voltage Vcom. do.

In addition, the common electrode 16 is generally formed of indium thin oxide (ITO), which is a transparent conductive material, which exhibits high reflectance in the infrared region and high transmittance in the visible region. Eggplants are well known for their excellent electrical conductivity. Therefore, it is actively used for an anode electrode of an organic electroluminescent element or a common electrode of a liquid crystal display device.

 In general, ITO is known to have a specific resistance of about 200 uPa · m and a transmittance of about 90 to 95%.

As described above, since the ITO is formed over the entire portion in the TN mode liquid crystal panel, the value of the sheet resistance on the left side and the right side of the liquid crystal panel is different. In particular, the larger the area of the liquid crystal panel, the greater the difference in the value of the sheet resistance between the left and right sides.

As a result, the value of the pixel voltage drop ΔVp on the left side and the right side of the liquid crystal panel is different, resulting in a deterioration in image quality.

The present invention has been made to solve the above-described problems, a liquid crystal display device for preventing the degradation of the image quality of the liquid crystal display device caused by the difference in the sheet resistance of the left and right sides of the liquid crystal panel, a driving method thereof, and The purpose is to provide a color filter substrate.

In order to achieve the above object, a liquid crystal display device according to an embodiment of the present invention, the liquid crystal panel for displaying an image by the voltage difference between the pixel electrode and the common electrode having at least two electrically separated areas; And at least two common voltage generators supplying common voltages which are different voltage values to the common electrodes.

The common electrode may be electrically spaced from the center of the liquid crystal panel to the left and right, respectively.

In order to achieve the above object, a liquid crystal display device driving method according to an embodiment of the present invention, the liquid crystal panel for displaying an image by the voltage difference between the pixel electrode and the common electrode having at least two electrically spaced areas and the common A driving method of a liquid crystal display device comprising two or more common voltage generators for supplying common voltages that are different voltage values to electrodes, the method comprising: measuring sheet resistance values of the common electrodes; Setting, by the common voltage generation generator, the common voltage corresponding to the measured sheet resistance value; And supplying the common voltage to the common electrode, respectively.

In order to achieve the above object, the color filter substrate used in the liquid crystal display device according to an embodiment of the present invention, the black matrix formed in a lattice form on the substrate; An R, G, and B color filter formed to be spaced apart from the black matrix by a predetermined distance; A spacing bar formed on one of the vertical lines of the black matrix; And a common electrode formed on the color filter and the black matrix and having two or more electrically separated areas by the spacer bar.

The black matrix is formed of one of a polymer material, chromium (Cr), and chromium oxide (CrOx).

The spacer bar is formed of the same material as the black matrix.

The spacing bar is formed of a material having a larger resistance value than the black matrix.

The separation bar may be formed in a shape in which the width thereof is narrowed in the forming direction of the common electrode.

Hereinafter, a liquid crystal display according to an exemplary embodiment of the present invention, a driving method thereof, and a color filter substrate used therein will be described with reference to the accompanying drawings.

3 is a block diagram schematically showing the configuration of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 4 is a perspective view schematically showing the configuration of a liquid crystal panel in the liquid crystal display of FIG. A liquid crystal panel 100 comprising a left side surface 100a and a right side surface 100b and including a thin film transistor defined by first and second switching elements T1 and T2 according to a position where the left side surface 100a and a right side surface 100b are disposed, and the liquid crystal panel ( The driving circuit unit 120 driving the 100, the power supply unit 130 supplying power to the driving circuit unit 120, and the first common voltage generation generating the first and second common voltages Vcom1 and Vcom2. The unit 140 includes a second common voltage generation unit 145.

More specifically, the liquid crystal panel 100 includes thin film transistors which are first and second switching elements T1 and T2 formed at points where a plurality of gate lines GL and data lines DL intersect in a matrix form. An array substrate 113 including the pixel electrode 111 connected thereto, a color filter 114 in which RGB three primary colors are respectively colored, a BM (Black Matrix) 115 for distinguishing the three RGB primary colors, and a first And a liquid crystal layer in which the color filter substrate 119 including the second common electrodes 116a and 116b is bonded to each other at a predetermined distance, and the liquid crystal LC is injected therebetween.

Here, the BM 115 further includes a spaced bar 150 formed into the common electrode 116 and the color filter substrate 119, and thus the first and second common electrodes 116a and 116b. Are electrically separated from each other.

The driving circuit unit 120 supplies a gate driving circuit 122 to supply a turn-on / off signal of the switching device T through the gate line GL, and to the pixel electrode through the data line DL. And a control unit 126 for controlling the gate and the data driving circuits 122 and 124 in response to an external signal.

The power supply unit 130 supplies power to the driving circuit unit 120 and the first and second common voltage generation units 140 and 145 for driving.

The first and second common voltage generators 140 and 145 generate the first and second common voltages Vcom1 and Vcom2, respectively, and are included in the color filter substrate 119 of the liquid crystal panel 100. 2 common electrodes 116a and 116b.

Here, the first and second common electrodes 116a and 116b are formed on the left and right sides of the color filter substrate 119, respectively, and each of the first and second common electrodes 116a and 116b is disposed at one end of each of the first and second common electrodes 116a and 116b. And the second common voltage generation unit 140 and 145 to receive the first and second common voltages Vcom1 and Vcom2, respectively.

In this case, sizes of the first and second common voltages Vcom1 and Vcom2 are determined by a setter, and sizes of sheet resistances of the first and second common electrodes 116a and 116b are considered.

In other words, the sheet resistance measurement value RS1 of the first common electrode 166a included in the left surface 100a of the liquid crystal panel 100 is included in the second common electrode included in the right surface 100b of the liquid crystal panel 100. When smaller than the sheet resistance measurement value RS2 of 166b (RS1 <RS2), the magnitude of the first common voltage Vcom is set smaller than the magnitude of the second common voltage Vcom2. (Vcom1 <Vcom2) In the opposite case (RS1> RS2), it is set correspondingly (Vcom1> Vcom2).

Accordingly, in the liquid crystal display according to the exemplary embodiment of the present invention, the pixel voltage drop amount ΔVp of the left side 100a and the right side 100b of the liquid crystal panel 100 is set to be the same, and the pixel electrode 111 The angle of the liquid crystal is changed by an electric field formed between the first and second common electrodes 116a and 116b, and the image is displayed by controlling the amount of light from a light source separately provided therethrough.

FIG. 5A is a cross-sectional view taken along the line IV-IV of FIG. 4. Referring to FIG. 5A, a color filter 114 on a color filter substrate 119 and a black matrix (BM) on the color filter 114 are illustrated. 115 is stacked and the common electrodes 116a and 116b are stacked on top of each other.

The BM 115 may be formed of one of an opaque polymer material, chromium (Cr) and chromium oxide (CrOx).

At this time, the separation bar 150 is formed on the upper end of the BM 115 positioned vertically in the center of the liquid crystal panel (not shown) of the BM 115 to the ends of the common electrodes 116a and 116b.

When the spacer bar 150 is formed of an insulator such as the polymer material or chromium oxide (CrOx), the spacer bar 150 may be formed of a material having the same material as that of the BM 115, and the BM 115 may be formed of the chromium (Cr). If it is not formed of an insulator such as), it may be formed of an insulating material having a higher resistance than that.

Here, the spacing bar 150 is a lithography process of the color filter substrate 119, after applying the forming material of the BM 115, and after applying the forming material forming the spacer bar 150 on the top of the BM 115. It can be formed by etching simultaneously.

In addition, as shown in FIG. 5B, the spacing bar may be formed in a form 152 in which the width becomes narrower toward the common electrodes 116a and 116b using a halftone mask in the lithography process.

Accordingly, the common electrodes 116a and 116b are electrically spaced apart from each other.

In addition, although not shown, the separation bar is formed on the BM in another area other than the central part of the liquid crystal panel to divide the common electrode into three or more electrically separated areas, and further include a common voltage generation unit corresponding thereto. In addition, it is possible to compensate for a difference in the locally generated pixel voltage enhancement amount ΔVp.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the present invention described in the claims below I can understand that you can.

Accordingly, the liquid crystal display of the present invention, the driving method thereof, and the color filter substrate used therein electrically separate the common electrodes formed on the entire region of the liquid crystal panel into two or more regions, and the sheet resistance of each of the two or more common electrodes. By providing a common voltage generation unit for supplying a common voltage having a size corresponding to, there is an effect that can prevent the degradation of the image quality due to the sheet resistance of the common electrode.

Claims (8)

A liquid crystal panel configured to display an image with a voltage difference between the pixel electrode and the common electrode having two or more regions spaced apart from each other; At least two common voltage generators supplying common voltages which are different voltage values to the common electrodes; Liquid crystal display comprising a. According to claim 1, And the common electrodes are electrically spaced from the center of the liquid crystal panel to the left and right, respectively. A liquid crystal display including a liquid crystal panel for displaying an image with a voltage difference between a pixel electrode, a common electrode having two or more regions spaced apart from each other, and two or more common voltage generators for supplying a common voltage, which is a different voltage value, to the common electrode. In the driving method of, Measuring sheet resistance of the common electrode; Setting, by the common voltage generation generator, the common voltage corresponding to the measured sheet resistance value; Supplying the common voltage to the common electrode, respectively; Method of driving a liquid crystal display device comprising a. A black matrix formed in a lattice form on the substrate; An R, G, and B color filter formed to be spaced apart from the black matrix by a predetermined distance; A spacing bar formed on one of the vertical lines of the black matrix; A common electrode formed on the color filter and the black matrix and having two or more electrically separated regions by the spacer bar; Color filter substrate of the liquid crystal display device comprising a; The method of claim 4, wherein The black matrix is a color filter substrate of a liquid crystal display device, characterized in that formed of one of a polymer material, chromium (Cr), chromium oxide (CrOx). The method of claim 5, The separation bar is a color filter substrate of a liquid crystal display, characterized in that formed of the same material as the black matrix. The method of claim 5, The separation bar is a color filter substrate of a liquid crystal display device, characterized in that formed of a material having a larger resistance value than the black matrix. The method of claim 5, The separation bar is a color filter substrate of the liquid crystal display device, characterized in that the width is formed in a narrow direction in the direction of forming the common electrode.

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