KR20070000558A - Liquid crystal display and method for restraining electrostatic discharge in the liquid crystal display - Google Patents

Abstract

An LCD and a method for suppressing the discharge of static electricity in the LCD are provided to effectively suppress the insulating breakdown, by connecting a common electrode line to a ground electrode when a voltage having a predetermined voltage level or more is applied to the common electrode line. An LCD panel comprises a first substrate(100) and a second substrate(200). The first substrate has a first common electrode line(170), and the second substrate has a second common electrode line electrically connected to the first common electrode line. A PCB(Printed Circuit Board)(300) supplies a driving signal to the LCD panel, wherein the PCB has a ground electrode. A ground electrode connecting part(400) connects the first or second common electrode line to the ground electrode when a voltage having a reference voltage level or more is applied to the first or second common voltage.

Description

Liquid crystal display and method for restraining electrostatic discharge in the liquid crystal display

1 is a configuration diagram of a liquid crystal panel of a conventional liquid crystal display device.

FIG. 2 is a detailed configuration diagram of the lower substrate of FIG. 1.

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

4 is a detailed block diagram of the second substrate of FIG. 3.

(Explanation of symbols for the main parts of the drawing)

100: first substrate 200: second substrate

300: printed circuit board 400: ground electrode connection

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method of suppressing electrostatic discharge in a liquid crystal display device, and more particularly, to a printed circuit board when a voltage equal to or greater than a predetermined voltage is applied to a common electrode line formed in a liquid crystal panel. By connecting the common electrode line to a ground electrode formed on a circuit board (PCB), a liquid crystal display device and a liquid crystal capable of effectively suppressing screen abnormalities of the liquid crystal panel as well as insulation breakdown caused by electrostatic discharge. The present invention relates to a method of suppressing electrostatic discharge in a display device.

In today's information society, the role of electronic displays has become very important, and various electronic displays have been widely used in various industrial fields. In the electronic display device field, electronic display devices having new functions suitable for the demands of the information society, which have been continuously developed and diversified, are continuously being developed. In general, an electronic display device refers to a device that transmits various pieces of information to a human through vision. That is, an electronic display device refers to an electronic device that converts an electronic information signal output from various electronic devices into an optical information signal that can be recognized by a human eye, and is a device that plays a role of a bridge between humans and electronic devices. It can be said.

In such an electronic display device, when an optical information signal is displayed by a light emitting phenomenon, it is referred to as a light emitting display device, and when it is displayed by light modulation due to reflection, scattering, or interference phenomenon, it is called a light receiving display device. Light emitting displays, also called active display devices, include cathode ray tube (CRT), plasma display panel (PDP), organic electroluminescent display (OLD), and light emitting diodes (LED). Light Emitting Diode (LED) etc. can be mentioned. The light receiving display device, which is called a passive display device, may include a liquid crystal display (LCD), an electrophoretic image display (EPID), and the like.

Cathode ray tube display device, which is used for television and computer monitor, and has the longest history, has the highest market share in terms of economy, but has many disadvantages such as heavy weight, large volume and high power consumption. .

Recently, due to the rapid progress of semiconductor technology, there is a demand for a flat panel display device as an electronic display device suitable for a new environment in accordance with the trend of lowering and lowering power of various electronic devices and miniaturization, thinning, and lightening of electronic devices. It is rapidly increasing. Accordingly, flat panel display devices such as a liquid crystal display (LCD), a plasma display device (PDP), an organic EL display device (OELD), and the like have been developed, and among these flat panel display devices, it is easy to miniaturize, light weight, and thinner. In particular, liquid crystal display devices having low power consumption and low driving voltage are drawing attention.

A liquid crystal panel of a liquid crystal display device injects a liquid crystal material having an anisotropic dielectric constant between an upper insulating substrate on which a common electrode, a color filter, a black matrix, and the like is formed, and a lower substrate on which a switching element and a pixel electrode are formed. By applying different voltages to the electrodes and the common electrode, the intensity of the electric field formed in the liquid crystal material is adjusted to change the molecular arrangement of the liquid crystal material, thereby controlling the amount of light transmitted to the upper substrate and the lower substrate, thereby desired image data It is a display device for expressing. In the liquid crystal display, a thin film transistor liquid crystal display (TFT LCD) using a thin film transistor (TFT) element as a switching element is mainly used.

With reference to FIG. 1 and FIG. 2, the liquid crystal panel of the conventional liquid crystal display device is demonstrated. 1 is a configuration diagram of a liquid crystal panel of a conventional liquid crystal display device. FIG. 2 is a detailed configuration diagram of the lower substrate of FIG. 1.

As shown in FIG. 1, a liquid crystal panel of a conventional liquid crystal display device includes an upper substrate 1, a lower substrate 2, and a liquid crystal layer between the upper substrate 1 and the lower substrate 2 formed to face each other. Not shown). The first common electrode line 17 is formed outside the pixel 11 on the upper substrate 1, and silver dots for connecting to the second common electrode line 27 formed on the lower substrate 2. (15) is formed.

As shown in FIG. 2, m * n liquid crystal cells (not shown) are arranged in a matrix type on the lower substrate 2, and m data lines D1 to Dm and n gate lines G1 to The pixel 21 is formed at the intersection of Gn, and the second common electrode line 27 is formed outside the pixel 21. The common voltage Vcom is applied to the first common electrode line 17 formed on the upper substrate 1 and the second common electrode line 27 formed on the lower substrate 2 through the silver dots 15. To be authorized.

One end of each of the gate lines G1 to Gn and the data lines D1 to Dm is connected to the second common electrode line 27 to prevent internal and external electrostatic discharges (EDS). The antistatic element 22 is formed. Here, in the case where an electrostatic discharge occurs so that an electrostatic voltage of considerable high pressure (for example, 1,000 V) flows into the lower substrate 2 or the upper substrate 1, the data lines D1 to Dm or the gate The lines G1 to Gn are connected through the second common electrode line 27 and the antistatic element 22. That is, when a significant high voltage static voltage flows into the lower substrate 2 or the upper substrate 1, the data lines D1 to Dm or the gate lines G1 to Gn are connected to the second common electrode line 27. Shorted. Thus, even if a high voltage electrostatic voltage is introduced into the lower substrate 2 or the upper substrate 1 by the electrostatic discharge, there is no voltage difference between the upper substrate 1 and the lower substrate 2, so that the electrostatic discharge Insulation breakdown of the liquid crystal panel can be prevented.

By the way, in the liquid crystal panel of the conventional liquid crystal display device, when the electrostatic discharge is generated and a significant high voltage electrostatic voltage flows into the lower substrate 2 or the upper substrate 1, the lower substrate 2 and the upper substrate 1 Since there is no current path capable of releasing the electrostatic voltage only by eliminating the voltage difference between), the electrostatic voltage remained on the upper substrate 1 or the lower substrate 2 of the liquid crystal panel. Due to such residual electrostatic voltage, the liquid crystal panel does not express desired image data and causes a problem that causes screen abnormality.

Therefore, the technical problem to be achieved by the present invention is that the common electrode is formed on a printed circuit board (PCB) when a voltage equal to or greater than a predetermined voltage is applied to the common electrode line formed in the liquid crystal panel. By connecting the electrode lines, it is an object of the present invention to provide a liquid crystal display device capable of effectively suppressing abnormalities in the screen of the liquid crystal panel as well as insulation breakdown caused by electrostatic discharge.

Another object of the present invention is to provide a method of suppressing electrostatic discharge in the above-described liquid crystal display device.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In the liquid crystal display according to the exemplary embodiment of the present invention, a first substrate on which a first common electrode line is formed and a second common electrode line connected to the first common electrode line are formed. A liquid crystal panel composed of a second substrate having a second substrate, a driving signal provided to the liquid crystal panel, and a reference voltage is applied to the first common electrode line or the second common electrode line and the printed circuit board on which the ground electrode is formed. And a ground electrode connecting portion connecting the first common electrode line or the second common electrode line to the ground electrode formed on the printed circuit board.

In the liquid crystal display according to the exemplary embodiment, the reference voltage is preferably 100 V to 4,000 V.

In addition, in the liquid crystal display according to the exemplary embodiment of the present invention, it is preferable that the ground electrode connection part is formed of a Zener diode.

In the liquid crystal display according to the exemplary embodiment of the present disclosure, a method of suppressing electrostatic discharge is connected to a first common electrode line or a first common electrode line formed on a first substrate. Applying a reference voltage or more to a second common electrode line formed on the second substrate, and forming the first common electrode line or the second common electrode line on a printed circuit board through a ground electrode connection part. Connecting to the ground electrode.

In the method of suppressing electrostatic discharge in the liquid crystal display according to the exemplary embodiment of the present invention, when the reference voltage or more is applied, the reference voltage is preferably 100 V to 4,000 V.

In the liquid crystal display according to the exemplary embodiment of the present invention, in the method of suppressing the electrostatic discharge, in the step of connecting the ground electrode to the ground electrode, the ground electrode connection part is preferably formed of a Zener diode.

Specific details of other embodiments are included in the detailed description and the drawings. Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. Like reference numerals refer to like elements throughout.

3 and 4, a method of suppressing electrostatic discharge in a liquid crystal display and a liquid crystal display according to an exemplary embodiment of the present invention will be described. 3 is a block diagram of a liquid crystal display according to an exemplary embodiment of the present invention. 4 is a detailed block diagram of the second substrate of FIG. 3.

As shown in FIG. 3, the liquid crystal display according to the exemplary embodiment of the present invention includes a liquid crystal panel, a printed circuit board (PCB) 300, and a ground electrode connector 400. The liquid crystal panel of the liquid crystal display device is a liquid crystal layer (not shown) between the first substrate 100, the second substrate 200, and the first substrate 100 and the second substrate 200 formed to face each other. consist of. The first common electrode line 170 is formed outside the pixel 110 on the first substrate 100, and is connected to the second common electrode line 270 formed on the second substrate 200. Silver dot 150 is formed. Here, the silver dot 150 does not necessarily need to be formed on the first substrate 100, but may be formed on the second substrate 200.

As shown in FIG. 4, m * n liquid crystal cells (not shown) are arranged in a matrix type on the second substrate 200, m data lines D1 to Dm and n gate lines G1. Pixels 210 are formed at intersections of the lines Gn to Gn, and second common electrode lines 270 are formed outside the pixels 210. A common voltage may be applied to the first common electrode line 170 formed on the first substrate 100 and the second common electrode line 270 formed on the second substrate 200 through the silver dot 150. Vcom) is authorized.

At one end of each of the gate lines G1 to Gn and the data lines D1 to Dm, an antistatic protection connected to the second common electrode line 270 as a protection against internal and external electrostatic discharge (EDS) Element 220 is formed. Here, in the case where an electrostatic discharge occurs so that an electrostatic voltage of considerable high pressure (for example, 1,000 V) is introduced into the second substrate 200 or the first substrate 100, the data lines D1 to Dm are provided. Alternatively, the gate lines G1 to Gn are connected to the second common electrode line 270 through the antistatic device 220. That is, when a significant high voltage electrostatic voltage is introduced into the second substrate 200 or the first substrate 100, the data lines D1 to Dm or the gate lines G1 to Gn are connected to the second common electrode line 270. ) And short.

Direct circuits (eg, gate drivers or data drivers) that provide driving signals to the liquid crystal panel are mounted on the printed circuit board 300 to transmit the driving signals to the liquid crystal panel through the printed circuit board 300. The ground electrode PCB GND is formed on the printed circuit board 300 to transmit a ground voltage to the liquid crystal panel.

When the ground electrode connection unit 400 is electrostatic discharge is generated, and the electrostatic voltage of the reference voltage or more is applied to the first common electrode line 170 or the second common electrode line 270, the first common electrode line 170. ) Or the second common electrode line 270 to the ground electrode PCB GND formed on the printed circuit board 300.

As a result, the liquid crystal display according to the exemplary embodiment of the present invention may include the first substrate 100 and the first substrate 100 even when a high voltage electrostatic voltage is introduced into the second substrate 200 or the first substrate 100 by electrostatic discharge. Since there is no voltage difference between the two substrates 200, dielectric breakdown of the liquid crystal panel can be prevented by electrostatic discharge. In addition, unlike the conventional liquid crystal display device, the ground electrode (PCB) formed on the printed circuit board 300 to the electrostatic voltage remaining on the first substrate 100 or the second substrate 200 of the liquid crystal panel GND). Therefore, the liquid crystal display according to the exemplary embodiment of the present invention can effectively suppress screen abnormality of the liquid crystal panel as well as insulation breakdown caused by electrostatic discharge.

Here, the reference voltage is 100 V to 4,000 V, and the ground electrode connector 400 may be configured as a Zener diode (ZD). When the ground electrode connection unit 400 is formed of the zener diode ZD, when the reference voltage or less is applied to the first common electrode line 170 or the second common electrode line 270, the ground electrode connection unit 400 is formed on the printed circuit board 300. The formed ground electrode PCB GND, the first common electrode line 170 and the second common electrode line 270 are not connected, and the reference voltage is greater than or equal to the first common electrode line 170 or the second common electrode line. When applied to 270, the ground electrode PCB GND formed on the printed circuit board 300 may be connected to the first common electrode line 170 or the second common electrode line 270. Since the magnitude of the reference voltage may be determined by the breakdown voltage of the zener diode ZD, the zener diode ZD may be selected according to the use of the liquid crystal display. That is, in the case of a liquid crystal display sensitive to electrostatic discharge, the reference voltage is determined at about 100V, and the ground electrode connector 400 is formed of a zener diode (ZD) having a breakdown voltage of about 100V, and the liquid crystal less sensitive to electrostatic discharge. In the case of the display device, the reference voltage is determined at about 4,000V, and the ground electrode connector 400 is formed of the zener diode ZD having a breakdown voltage of about 4,000V.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. I can understand that. Therefore, the above-described embodiments will be described in detail so that the disclosure of the present invention may be completed, and those skilled in the art may easily implement the technical idea of the present invention. It is to be understood to be illustrative and not limitative in all respects, as it is provided to fully inform the person skilled in the art the scope of the invention, and the invention is defined only by the scope of the claims. .

In the liquid crystal display device and the liquid crystal display device according to an embodiment of the present invention made as described above is a printed circuit board when a voltage of a predetermined voltage or more is applied to the common electrode line formed on the liquid crystal panel By connecting the common electrode line to a ground electrode formed on a printed circuit board (PCB), it is possible to effectively suppress abnormalities in the screen of the liquid crystal panel as well as insulation breakdown caused by electrostatic discharge.

Claims (6)

A liquid crystal panel comprising a first substrate having a first common electrode line formed thereon and a second substrate having a second common electrode line connected to the first common electrode line formed therein; A printed circuit board providing a driving signal to the liquid crystal panel and having a ground electrode formed thereon; And The first common electrode line or the second common electrode line is connected to the ground electrode formed on the printed circuit board when a reference voltage or more is applied to the first common electrode line or the second common electrode line. And a ground electrode connecting portion. The method of claim 1, The reference voltage is a liquid crystal display, characterized in that 100V ~ 4,000V. The method of claim 1, And the ground electrode connection part is formed of a zener diode. Applying a reference voltage or more to a second common electrode line formed on a second substrate, the first common electrode line formed on a first substrate, or connected to the first common electrode line; And And connecting the first common electrode line or the second common electrode line to a ground electrode formed on a printed circuit board through a ground electrode connection unit. The method of claim 4, wherein In the step of applying the reference voltage or more, the reference voltage is a method of suppressing electrostatic discharge in the liquid crystal display, characterized in that. The method of claim 4, wherein And connecting the ground electrode to the ground electrode, wherein the ground electrode connection part is formed of a Zener diode.

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