KR100785141B1 - Apparatus for liquid crystal display - Google Patents

Abstract

The present invention relates to a liquid crystal display device, comprising: a lower substrate formed in a matrix such that a gate line and a data line form a plurality of pixel rows; An upper substrate having a black matrix formed thereon; In the liquid crystal display device including a driving electrode formed on the inner surface of the lower substrate or the upper substrate, a backlight device having a light source is disposed on the outer surface of the lower substrate, the light source is located in the center of the backlight device diffusion plate Irradiates light to the lower substrate through the black matrix, and the size of the black matrix corresponding to the several pixel row pixels closest to the backlight is larger than the size of the black matrix corresponding to the other pixels, or the several pixel row pixels closest to the backlight. The driving electrode corresponding to the pixel is formed of an opaque conductor, or the pixel rows of pixels closest to the backlight are formed of a driving electrode pattern having a large storage capacitance, or a combination thereof. LCD screen by reducing the aperture ratio of several pixels The overall quality of the screen is improved, and also, it is possible to reduce the manufacturing cost and secure the design margin since there is no need to use the light leakage prevention tape.

Description

Liquid Crystal Display {APPARATUS FOR LIQUID CRYSTAL DISPLAY}

1 is a cross-sectional view of a direct type backlight device.

2 is a perspective view of a liquid crystal panel having a direct backlight device according to the present invention;

3 is a plan view of a unit pixel in which part of a pixel is blocked by a black matrix according to the present invention;

4 is a plan view of a unit pixel having a driving electrode pattern composed of an opaque conductor according to the present invention;

5 is a plan view of a storage on gate unit pixel according to the present invention;

6 is a plan view of a storage on common unit pixel according to the present invention;

Explanation of symbols on the main parts of the drawings

1; mold frame 3; lamp housing

5; fluorescent lamp 7; rubber connector

9 diffuser plate

12; low opening ratio region 13; backlight device

17; gate line 19; data line

21; pixel 23; black matrix

25; pixel electrode 26; opaque conductor pattern                 

27; common electrode

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 in which screen quality is improved by compensating for a difference in brightness of a pixel row by relatively reducing the aperture ratio of several pixels closest to a backlight.

In general, a liquid crystal display device is one of an image graph display device using a thin film transistor as a switching element, and has an advantage of realizing a thin and small size and low power consumption compared to a cathode ray tube (CRT), which is another image graph display device.

The structure of a conventional liquid crystal display device includes a lower substrate on which gate lines and data lines arranged in a matrix form, an upper substrate on which a color filter layer is formed, and a liquid crystal layer interposed between the upper and lower substrates. do.

On the other hand, since the liquid crystal display device does not emit light by itself unlike a cathode ray, a backlight is required. A thin film transistor, which is a switching element, is formed on the lower substrate near an intersection point of the gate line and the data line. Drive electrodes (relative electrodes and pixel electrodes) for driving liquid crystal molecules in the liquid crystal layer are formed on the inner side of the lower substrate and / or the upper substrate.

In the conventional liquid crystal display device having such a structure, when a scan signal is applied to any one of the gate lines and a display signal is applied to the data line, the thin film is positioned near the intersection of the gate line and the data line to which the signal is applied. The transistor is turned on. Then, the display signal of the data line is transmitted to the pixel electrode through the thin film transistor and the common signal is continuously applied to the counter electrode, so that an electric field is generated between the electrodes.

Then, the liquid crystal molecules in the liquid crystal layer are arranged parallel to the electric field (in the case of positive dielectric anisotropy) or perpendicularly (in the case of negative dielectric anisotropy) according to the dielectric anisotropy to leak light to implement a predetermined image.

However, the conventional liquid crystal display has the following problems.

In the conventional liquid crystal display, when the operating voltage Von pulse is applied to the front gate line, the stop voltage Voff is applied to the other gate line. If the transistors in the row are turned off, that is, in a state where the stop voltage Voff is applied, the operating voltage Von is applied to the front gate line so that the potential Vg of the front gate line varies from -7V to + 20V. 27V rise. Then, the potential of the pixel electrodes of the row also increases, and the liquid crystal capacitance Clc and other parasitic capacitances change together, resulting in a brighter display of the first row of the liquid crystal display than other rows, resulting in deterioration of screen quality. .

Accordingly, the present invention has been made to solve the problems of the liquid crystal display according to the prior art, and an object of the present invention is to reduce the aperture ratio of several rows of pixels immediately above the backlight in the liquid crystal display, It is to provide a liquid crystal display device with improved screen quality by reducing the difference therefrom.

According to an aspect of the present invention, there is provided a liquid crystal display device comprising: a lower substrate formed in a matrix form such that a gate line and a data line form a plurality of pixel rows; An upper substrate having a black matrix formed thereon; In the liquid crystal display device including a driving electrode formed on the inner surface of the lower substrate or the upper substrate, a backlight device having a light source is disposed on the outer surface of the lower substrate, the light source is located in the center of the backlight device diffusion plate Irradiates light to the lower substrate through the black matrix, and the size of the black matrix corresponding to the several pixel row pixels closest to the backlight is larger than the size of the black matrix corresponding to the other pixels, or the several pixel row pixels closest to the backlight. The driving electrode corresponding to the pixel is formed of an opaque conductor, or the several pixel row pixels closest to the backlight are formed of a driving electrode pattern having a large storage capacitance or a combination thereof.

Hereinafter, a liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a direct backlight device, FIG. 2 is a perspective view of a liquid crystal panel having a direct backlight device according to the present invention, and FIG. 3 is a plan view of a unit pixel in which a part of the pixels is covered with a black matrix according to the present invention. 4 is a plan view of a unit pixel having a driving electrode pattern composed of an opaque conductor according to the present invention, FIG. 5 is a plan view of a storage on gate type unit pixel according to the present invention, and FIG. 6 is a storage according to the present invention. A plan view of an on common unit pixel.                     

The liquid crystal display device according to the present invention uses, for example, a fluorescent lamp (COLD CATHODE FLUORESCENT LAMP) as a light source of the backlight device, and a direct backlight device and an edge-light backlight according to the installation position of the lamp. It is divided into devices. The edge-light backlight device has a structure in which light from the fluorescent lamp is incident on the liquid crystal panel through the light guide plate. However, the direct-type backlight device according to the present invention, as shown in FIG. Is located at the center of the lamp housing 3, and a diffusion plate 9 for passing light through the lower substrate 11 is disposed on the upper portion of the lamp housing 3, and the lower substrate 11 and the mold frame 1 are disposed. It is comprised including the rubber connector 7 to connect.

As shown in FIG. 2, the direct backlight device 13 is disposed on an outer surface of the lower substrate 11, that is, on a lower surface thereof, and a gate line 17 on an inner surface of the lower substrate 11, that is, on an upper surface thereof. ) And the data line 19 are formed in a matrix form to form a plurality of pixel rows.

Meanwhile, although not shown in FIG. 2, the upper substrate on which the black matrix is formed is disposed on the lower substrate under the liquid crystal layer to form a liquid crystal panel. Meanwhile, a driving electrode (not shown) including a counter electrode and a pixel electrode is formed on an inner surface of the lower substrate 11. Here, a driving electrode may also be formed on the upper substrate.

In the liquid crystal display according to the present invention, as shown in FIG. 2, the backlight device 13 is located at the center of the outer surface of the lower substrate 11 so that the light emitted from the backlight device 13 is diffused. It is irradiated to the lower substrate 11 via 9). Here, in order to reduce the aperture ratio of the pixel row pixels closest to the backlight device 13 as in the low-opening area indicated by reference numeral 12, the liquid crystal display device is constructed as follows in the present invention.

A configuration for reducing the aperture ratio of several pixel row pixels closest to the backlight device according to the present invention is, as shown in FIG. 3, the black matrix 23 corresponding to the pixel row pixels 21 closest to the backlight device. The size is larger than the size of the black matrix corresponding to the other pixel. Here, the black matrix 23 is typically formed on the upper substrate, but in the present invention, may be formed on the inner surface of the lower substrate 11.

Another configuration for lowering the aperture ratio of several pixel row pixels closest to the backlight device according to the present invention is defined by the gate line 17 and the data line 19, as shown in FIG. The driving electrode in the pixel row pixel closest to the pixel, more specifically, the predetermined portion 26 of the pixel electrode 25 is formed of an opaque conductor. When the predetermined portion 26 of the pixel electrode 25 is made of an opaque conductor, preferably aluminum (Al), thymine (Ti), or molybdenum (Mo), the amount of light transmitted is reduced to decrease the aperture ratio. Will be.

Another configuration for reducing the aperture ratio of several pixel row pixels closest to the backlight device according to the present invention is that a driving electrode pattern having a large storage capacitance is formed as shown in FIGS. 5 and 6.                     

STORAGE CAPACITANCE is formed by two patterns as follows.

In the first pattern (STORAGE ON GATE) having a large storage capacitance according to the present invention, as shown in FIG. 5, the relatively wide gate line 17 and the pixel electrode 25 partially overlap each other. Thus, storage capacitance is formed. In the above structure, the gate line 17 is formed relatively large to lower the aperture ratio.

In the second pattern (STORAGE ON COMMON) having a large storage capacitance according to the present invention, as shown in FIG. 6, the common electrode 27 and the pixel electrode 25 formed separately in the unit pixel are partially overlapped. It is formed. In the above structure, since the common electrode 27 is formed in the unit pixel, the aperture ratio is lowered.

Further, another configuration for lowering the aperture ratio of several pixel row pixels closest to the backlight device according to the present invention may be a combination of the respective configurations.

Meanwhile, in the present invention, it is preferable that the number of several pixel rows closest to the backlight device is 1 to 3, and the aperture ratio of several pixel row pixels closest to the backlight device is 40 to 70 of the aperture ratio of the other row pixels. It is preferably about%.

Various embodiments can be easily carried out as well as obvious to those skilled in the art without departing from the spirit and spirit of the present invention. Accordingly, the claims appended hereto are not limited to those already described above, and the following claims are intended to cover all of the novel and patented matters inherent in the invention, and are also common in the art to which the invention pertains. Includes all features that are processed evenly by the knowledgeable.

As described above, the liquid crystal display according to the present invention has the following effects.

In the present invention, the screen quality of the entire LCD screen is improved by reducing the aperture ratio of several pixels located immediately above the backlight of the LCD screen.

In addition, in the present invention, it is not necessary to use the light leakage preventing tape, thereby reducing the manufacturing cost and ensuring the design margin.

Claims (6)

A lower substrate formed in a matrix so that the gate line and the data line form a plurality of pixel rows; An upper substrate having a black matrix formed thereon; In the liquid crystal display device including a driving electrode formed on the inner surface of the lower substrate or the upper substrate, A backlight device having a light source is disposed on an outer surface of the lower substrate, wherein the light source is positioned at the center of the backlight device to irradiate light onto the lower substrate through a diffusion plate, and to close the backlight to several pixel rows. The black matrix corresponding to the pixel is larger than the size of the black matrix corresponding to the other pixel, or the driving electrodes corresponding to the pixel rows of the pixels closest to the backlight are formed of an opaque conductor, or several images adjacent to the backlight. The attenuating pixel is a drive electrode pattern having a large storage capacitance, or a combination thereof. The method of claim 1, And the opaque conductor comprises aluminum, thymine, or molybdenum. The method of claim 1, The driving electrode pattern having the large storage capacitance is formed by partially overlapping pixel electrodes and gate lines. The method of claim 1, And a driving electrode pattern having a large storage capacitance comprises a pixel electrode and a common electrode formed separately in the unit pixel. The method according to any one of claims 1 to 4, The number of several pixel rows closest to the backlight is 1 to 3, the liquid crystal display device. The method according to any one of claims 1 to 4, And an aperture ratio of the pixel row pixels closest to the backlight is 40 to 70% of the aperture ratio of the other row pixels.

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