KR20080057913A - Liquid crystal display - Google Patents

Abstract

An LCD is provided to supply a ground electrode to a black matrix by using a seal pattern to allow the black matrix to be performed as an EMI(Electromagnetic Interference) blocking filter. A black matrix(562) is formed in a non-display region of an upper substrate(520). A ground electrode line(591) is formed in a lower substrate, and is connected with a ground terminal. A common electrode line(581), formed in the lower substrate, receives a common voltage. A seal pattern(561) connects with the black matrix and the ground electrode line, and seals and combines the upper substrates and the lower substrate in the non-display region. A dot(580) is formed at an internal side of the seal pattern. The dot connects the common electrode line with a common electrode formed in the upper substrate. An insulating film(583) electrically isolates the common electrode line and the seal pattern.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

1 is a diagram illustrating an internal configuration of a general liquid crystal display device.

2 is an exemplary view illustrating an upper substrate region of a general liquid crystal display device.

3 is a cross-sectional view of the liquid crystal panel cut along the line AA ′ in FIG. 2.

4 is a cross-sectional view of the liquid crystal panel cut along the line B-B 'in FIG.

5 is an internal configuration diagram of a liquid crystal display device according to the present invention.

6 is an exemplary view showing an upper substrate region of a liquid crystal display according to the present invention.

FIG. 7 is a cross-sectional view of the liquid crystal panel cut along the line CC ′ in FIG. 6.

8 is a cross-sectional view of the liquid crystal panel cut along the line D-D 'in FIG.

<Description of Symbols for Main Parts of Drawings>

580: silver dot 581: common electrode line

591: earthing electrode line 561: seal pattern

562 black matrix 583 insulating film

521 common electrode

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of blocking electromagnetic interference (EMI).

In general, the liquid crystal display device displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix and a driving circuit for driving the liquid crystal panel.

1 is a diagram illustrating an internal configuration of a general liquid crystal display device. In addition, FIG. 2 is a diagram illustrating an upper substrate region of a general liquid crystal display, and illustrates an region in which the upper substrate 120 and the lower substrate 110 overlap each other in FIG. 1.

The liquid crystal panel 100 includes a color filter substrate 120 (hereinafter referred to simply as an upper substrate) 120 as an upper substrate and a thin film transistor substrate 110 (hereinafter referred to simply as a lower substrate) 110 as a lower substrate and the two substrates. It consists of a liquid crystal layer (not shown) interposed between the substrate (110, 120).

Among the components constituting the liquid crystal panel 100, the lower substrate 110 is slightly larger than the upper substrate 120, and the upper substrate when the upper substrate 120 is bonded to the upper substrate 120. Pad portions 111 and 112 are formed in a predetermined region on the upper side and one side which do not overlap with 120. The pads 111 and 112 may include gate pads formed in the active area AA for displaying an image and connected to a plurality of gate lines 150 and data lines 140 that cross each other to define a pixel area. And a data pad (not shown), wherein the gate pad and the data pad include a printed circuit board (PCB) 200 including a driving circuit for driving the liquid crystal panel 100. The data is connected to the tape carrier package (TCP) 131 and the gate TCP 132.

The liquid crystal panel 100 is divided into an active area (AA) 170 that displays a screen and a non-display area NA that does not display a screen, and the non-display area NA is the upper substrate 120. The first non-display area 160 except the active area AA 170 and the second non-display area 113 corresponding to the pad parts 111 and 112 are included.

As shown in FIG. 2, light leakage due to light transmission of an area in which the liquid crystal is abnormally driven is shown in the first non-display area NA 160 around the active area AA 170 of the upper substrate 120. In order to prevent the phenomenon, a black matrix (BM: Black Metrix) 162 is formed. However, the black matrix 162 is not only formed in the first non-display area 160, but is also formed in the active area 170 to distinguish each liquid crystal cell K from each other.

In addition, a seal pattern 161 is formed in the first non-display area 160 to couple the upper substrate 120 and the lower substrate 110 at regular intervals.

In addition, as illustrated in FIGS. 1 and 2, the upper substrate 120 and the lower substrate 110 may be formed of silver dots 180 and 190 in the first non-display area NA 160. Are electrically connected to each other, and the silver dots 180 and 190 are connected to the driving circuit.

FIG. 3 is a cross-sectional view of the liquid crystal panel cut along the line A-A 'in FIG. 2 and includes a first silver dot 180 for applying a common voltage to the upper substrate 120.

The black matrix 162 is formed in the first non-display area 160 of the upper substrate 120 as described above, and the printing is formed in the region of the lower substrate 110 opposite to the black matrix 162 region. The common electrode line 181 for applying the common voltage Vcom (usually 3.3V) is formed from the circuit board 200. The common electrode line 181 is connected to the common electrode 121 of the upper substrate 120 by the first silver dot 180.

In addition, the seal pattern 161 is formed inside the first silver dot 180, and the liquid crystal 163 is stacked inside the seal pattern 161. The liquid crystal 163 is rotated by the thin film transistors 164 formed for each liquid crystal cell K, thereby displaying an image by passing or blocking light emitted from the backlight unit (not shown).

FIG. 4 is a cross-sectional view of the liquid crystal panel cut along the BB ′ direction in FIG. 2, wherein the black matrix 162 formed in the first non-display area 160 is electrically set to 0V, and thus the black matrix 162 is formed. Is a cross section including a second silver dot 190 for use as an electromagnetic cut filter.

In the liquid crystal display device, electromagnetic interference (EMI) is generated by the driving circuits, and the electromagnetic interference affects a region of the liquid crystal panel 100, and is generally formed on the liquid crystal panel 100. The black matrix 162 is used as an electromagnetic wave blocking filter. That is, by keeping the potential of the black matrix 162 at 0 V, the electromagnetic interference (EMI) generated by the driving circuit disposed under the liquid crystal panel 100 does not pass through the liquid crystal panel 100. The method is used.

For this purpose, a black matrix 162 made of a black-based metal material is formed in the first non-display area 160 of the upper substrate 120 and faces the black matrix 162 area. A ground line 191 connected to a ground terminal (ground) of the printed circuit board 200 is formed in an area of the lower substrate 110. The ground line 191 is connected to the black matrix 162 of the upper substrate 120 by the second silver dot 190.

In addition, the seal pattern 161 is formed inside the second silver dot 190, and the liquid crystal 163 is stacked inside the seal pattern 161.

That is, in the conventional liquid crystal display device as described above, the first silver dot 180 and the second silver dot 190 are formed on the outer side of the seal pattern 161 to apply a common voltage to the liquid crystal panel. On the other hand, the electromagnetic interference (EMI) is blocked by keeping the black matrix 162 at 0V potential.

However, in the conventional liquid crystal display having the above-described configuration, since the process itself of the first silver dot 180 and the second silver dot 190 has a large deviation (10 Ω to 10 KΩ), the black matrix 161 is used. ) Has a problem that the function as an electromagnetic wave blocking filter is deteriorated.

In addition, since the conventional liquid crystal display device transmits the common electrode signal and the ground electrode signal using the first silver dot and the second silver dot, there is a probability that a short of the first silver dot and the second silver dot occurs. This increases, which causes a problem that the manufacturing yield of the liquid crystal display device is reduced.

That is, as described in Equation 1 below, when the resistance of the silver dot is increased, the overall resistance is increased, so that the black matrix or the silver dot acts as an antenna rather than functioning to block electromagnetic waves. It is occurring.

Total EMI Resistance = BM Resistance itself

                      + BM CD deviation + Ag Dotting Contact Resistance

Accordingly, an object of the present invention is to provide a liquid crystal display device for applying a ground electrode to a black matrix using a seal pattern so that the black matrix functions as an electromagnetic wave blocking filter.

In order to achieve the above object, the liquid crystal display device according to the present invention comprises a printed circuit board including a drive circuit and a liquid crystal panel comprising an upper substrate and a lower substrate, in the non-display area of the upper substrate Formed black matrix; A ground electrode line formed on the lower substrate and connected to a ground terminal; A common electrode line formed on the lower substrate and to which a common voltage is applied; A seal pattern connected to the black matrix and the ground electrode line and sealingly coupling the upper substrate and the lower substrate in the non-display area; A dot formed inside the seal pattern and connecting the common electrode line and the common electrode formed on the upper substrate; And an insulating layer electrically insulating the common electrode line from the seal pattern.

Other objects and advantages of the present invention in addition to the above object will become apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

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

5 is a diagram illustrating an internal configuration of a liquid crystal display according to the present invention. 6 illustrates an upper substrate region of the liquid crystal display according to the present invention. In FIG. 5, the upper substrate 520 and the lower substrate 510 overlap each other.

The liquid crystal display according to the present invention displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display according to the present invention includes a liquid crystal panel 500 in which liquid crystal cells are arranged in a matrix and driving circuits 210, 531a, and 532a for driving the liquid crystal panel.

The liquid crystal panel 500 includes a color filter substrate (hereinafter, simply referred to as an upper substrate) 520, which is an upper substrate, and a thin film transistor substrate (hereinafter, simply referred to as a “lower substrate,” 510), which is a lower substrate. It consists of a liquid crystal layer (not shown) interposed between two substrates 510 and 520.

Among the components constituting the liquid crystal panel 500, the lower substrate 510 is slightly larger than the upper substrate 520, and the upper substrate is bonded to the upper substrate 520 among the lower substrates 510. Pad portions 511 and 512 are formed in a predetermined region on the upper side and one side which do not overlap with 520. Gate pads 511 and 512 are formed in the active area AA that displays an image, and are connected to a plurality of gate lines 550 and data lines 540 that cross each other to define a pixel area. And a data pad (not shown), the gate pad and the data pad including a driving circuit 210 for driving the liquid crystal panel 500. Is connected to the data TCP (tape carrier package) 531 and the gate TCP (532).

First, in the liquid crystal panel 500, the liquid crystal cells are positioned in the region where the gate lines 550 and the data lines 540 are arranged to cross each other, and the gate lines and the data lines cross each other. The liquid crystal panel 500 is provided with pixel electrodes and a common electrode for applying an electric field to each of the liquid crystal cells. Each of the pixel electrodes is connected to one of the data lines 540 via source and drain terminals of a thin film transistor, which is a switching element. The gate terminal of the thin film transistor is connected to any one of the gate lines 550 to allow the pixel voltage signal to be applied to the pixel electrodes of one line.

Next, the driving circuit includes a gate driver for driving the gate lines, a data driver for driving the data lines, a timing controller 210 for controlling the gate driver and the data driver, and various kinds of liquid crystal display devices. And a power supply unit (not shown) for supplying driving voltages. The timing controller 210 controls the driving timing of the gate driver and the data driver, and supplies the pixel data signal to the data driver. The power supply unit generates driving voltages such as the common voltage VCOM, the gate high voltage VGH, and the gate low voltage VGL required by the liquid crystal display using the input power. The gate driver sequentially supplies the scanning signals to the gate lines to sequentially drive the liquid crystal cells on the liquid crystal panel by one line. The data driver supplies a pixel voltage signal to each of the data lines whenever a scanning signal is supplied to any one of the gate lines. Accordingly, the liquid crystal display displays an image by adjusting light transmittance by an electric field applied between the pixel electrode and the common electrode according to the pixel voltage signal for each liquid crystal cell.

Among them, the data driver and the gate driver connected to the liquid crystal panel 500 are integrated into a plurality of integrated circuits (ICs). Each of the integrated data drive IC 531a and the gate drive IC 532a is mounted on a tape carrier package (TCP) 531 and 532, as shown in FIG. 5, to form a liquid crystal panel using a tape automated bonding (TAB) method. It is connected to the 500, or mounted on the liquid crystal panel 500 in a chip on glass (COG) method.

That is, as shown in FIG. 5, the drive ICs 531a and 532a connected to the liquid crystal panel in a TAB manner through TCP are mounted on a printed circuit board 200 connected to the TCP 531 and 532. Control signals and DC voltages input from the outside through signal lines are supplied and interconnected. Meanwhile, in FIG. 5, the gate TCP 532 is formed in a line on glass (LOG) method, and is configured to be connected to the PCB 200 through the data TCP 531.

The COG method, which is another method, uses a line on glass (hereinafter, LOG) method in which signal lines of drive ICs mounted on the liquid crystal panel 500 are mounted on the liquid crystal panel, that is, the lower substrate 510. In addition to being interconnected, control signals and driving voltages from the timing controller 210 and the power supply are supplied.

In addition to the above configuration, the driving circuits 210, 531a, and 532a may be disposed on the liquid crystal panel in various forms.

The liquid crystal panel 500 is divided into an active area (AA) 570 for displaying a screen and a non-display area NA for not displaying a screen, and the non-display area NA is the upper substrate 520. A first non-display area 560 except for the active areas AA and 570, and a second non-display area 513 corresponding to the pad parts 511 and 512 are included.

In the first non-display area (NA) 560 of the upper substrate 520 around the active area (AA) 570, as shown in FIG. In order to prevent the phenomenon, a black matrix (BM: Black Metrix) 562 is formed. However, the black matrix 562 is not only formed in the first non-display area 560, but is also formed in the active area 570 to distinguish each liquid crystal cell K from each other.

As illustrated in FIG. 6, the upper substrate 520 and the lower substrate 510 are electrically connected to each other by a silver dot 580 in the first non-display area NA 560. . The silver dot 580 is for transmitting the common voltage transmitted from the PCB 200 to a common electrode formed on the upper substrate 520. The lower substrate 510 is connected to the silver dot 580. The common electrode line 581 is connected to the PCB 200 through the data TCP, data drive IC, gate TCP, gate drive IC, etc., and is connected to the upper substrate 510 with the silver dot 580. The common electrode is formed.

In addition, a seal pattern 561 of a conductive material is formed in the first non-display area 560 to seal-fit the upper substrate 520 and the lower substrate 510 at regular intervals. The seal pattern 561 electrically grounds the black matrix 562 so that the black matrix 562 functions as an electromagnetic wave blocking filter, and is connected to the seal pattern 561 on the lower substrate 510. The ground line 591 is connected to the PCB 200 through the data TCP, the data drive IC, the gate TCP, and the gate drive IC, and is connected to the seal pattern 561 on the upper substrate 510. A black matrix 562 is formed. The PCB 200 has a ground terminal to which the ground line 591 is connected so that the black matrix 562 connected to the seal pattern 561 has a potential of 0V.

FIG. 7 is a cross-sectional view of the liquid crystal panel cut along the C-C 'direction in FIG. 6, and includes a silver dot 580 for applying a common voltage to the upper substrate 520.

As described above, a black matrix 562 is formed in the first non-display area 560 of the upper substrate 520, and the PCB is located in an area of the lower substrate 510 opposite to the black matrix 562. A common electrode line 581 is formed from 200 to apply a common voltage Vcom (usually 3.3V). The common electrode line 581 is connected to the common electrode 521 of the upper substrate 520 by the silver dot 580.

As shown in FIG. 7, the silver dot 580 is formed inside the seal pattern 561, and since the common electrode line 581 is also formed of a conductive material, the silver dot 580 is formed. And seal pattern 561 may be shorted. Therefore, in order to prevent a short at an overlapping portion of the common electrode line 581 connected to the silver dot 580 and overlapping the seal pattern 561, as shown in FIGS. 6 and 7. Similarly, an insulating film 583 is deposited on the overlapping portion to electrically isolate the common electrode line 581 and the seal pattern 561.

On the other hand, the liquid crystal 563 is laminated inside the seal pattern 561. The liquid crystal 563 is rotated by the thin film transistors 564 formed for each liquid crystal cell K, thereby displaying an image by passing or blocking light emitted from the backlight unit (not shown). Since the configuration of the thin film transistor 564 is a configuration of a general thin film transistor, a detailed description thereof will be omitted.

FIG. 8 is a cross-sectional view of the liquid crystal panel cut along the DD ′ direction of FIG. 6, wherein the black matrix 562 formed in the first non-display area 560 is electrically set to 0V, and the black matrix 562 is formed. A cross section including a seal pattern 561 of a conductive material for use as an electromagnetic wave blocking filter is shown.

In the liquid crystal display, electromagnetic interference (EMI) is generated by the driving circuits 210, 531a, and 532a and the plurality of electronic elements disposed on the PCB 200. In particular, the driving circuit and the plurality of electrons are generated. Since the PCB 200 including elements is disposed on the rear surface of the lower substrate 510 of the liquid crystal panel 500 in a module process, various electromagnetic interferences generated from the PCB 200 may be caused by the liquid crystal panel 500. It will also affect the area. The electromagnetic interference interferes with the normal operation of the liquid crystal panel and interferes with communication of various communication systems (notebook computers, PDAs, mobile phones, PMPs, etc.) to which the liquid crystal display device is applied.

Therefore, the present invention utilizes the black matrix 162 formed on the upper portion of the liquid crystal panel 100 as an electromagnetic wave blocking filter to prevent the electromagnetic interference from being emitted to the outside through the liquid crystal panel 500.

That is, the present invention maintains the electric potential of the black matrix 562 at 0V, whereby electromagnetic interference (EMI) generated by a driving circuit on the PCB 200 disposed under the liquid crystal panel 500 is generated. It is using a method to prevent the passing of 500.

For the above purpose, a black matrix 562 made of a black-based metal material is formed in the first non-display area 560 of the upper substrate 520 and faces the black matrix 562 area. A ground line 591 connected to the ground terminal (ground) of the PCB 200 is formed in an area of the lower substrate 510. The ground line 591 is connected to the black matrix 562 of the upper substrate 520 through the seal pattern 561.

On the other hand, the liquid crystal 563 is laminated inside the seal pattern 561. The liquid crystal 563 is rotated by the thin film transistors 564 formed for each liquid crystal cell K, thereby displaying an image by passing or blocking light emitted from the backlight unit (not shown). Since the configuration of the thin film transistor 564 is a configuration of a general thin film transistor, a detailed description thereof will be omitted.

In the liquid crystal display according to the present invention as described above, the silver dot 580 is formed inside the seal pattern 561 to apply a common voltage to the liquid crystal panel, and the seal pattern 561. By keeping the black matrix 162 at 0V potential, the electromagnetic interference (EMI) is blocked.

Meanwhile, although the common voltage is transmitted to the common electrode 521 using the silver dot 580, the present invention is not limited thereto, and various conductive dots may be used.

As described above, the liquid crystal display according to the present invention applies a common voltage to the liquid crystal panel using one silver dot, and grounds the black matrix to 0V through a seal pattern, thereby preventing the black matrix electromagnetic wave filter function. There is an excellent effect that it can be improved.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A liquid crystal display comprising a printed circuit board including a driving circuit and a liquid crystal panel including an upper substrate and a lower substrate. A black matrix formed in the non-display area of the upper substrate; A ground electrode line formed on the lower substrate and connected to a ground terminal; A common electrode line formed on the lower substrate and to which a common voltage is applied; A seal pattern connected to the black matrix and the ground electrode line and sealingly coupling the upper substrate and the lower substrate in the non-display area; A dot formed inside the seal pattern and connecting the common electrode line and the common electrode formed on the upper substrate; And And an insulating layer electrically insulating the common electrode line from the seal pattern. The method of claim 1, And the insulating layer is formed at an overlapping portion where the common electrode line and the seal pattern overlap each other. The method of claim 1, Wherein said dot is a silver dot. The method of claim 1, And the ground terminal is formed on the printed circuit board. The method of claim 1, And the common voltage is applied from the driving circuit.

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