KR20180062283A - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display device capable of effectively discharging static electricity in a liquid crystal display device with a plastic front cover. The liquid crystal display device according to the present invention includes a liquid crystal panel, a light source unit positioned on the back surface of the liquid crystal panel, a bottom cover for accommodating the liquid crystal panel and the light source unit, and a front case disposed on the liquid crystal panel to be coupled to the bottom cover and having a discharge pattern floating on a position corresponding to the non-display region of the liquid crystal panel on the inner surface facing the liquid crystal panel. The front case is preferably made of a plastic material.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

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 capable of effectively discharging static electricity in a liquid crystal display device using a plastic front cover.

2. Description of the Related Art Recently, various portable electronic devices such as a mobile phone, a PDA, and a notebook computer have been developed. Accordingly, there is a growing need for a flat panel display device for a light and small size. As such flat panel display devices, a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED) and a vacuum fluorescent display (VFD) have been actively studied. However, Liquid crystal displays (LCDs) are now in the spotlight because of their implementation. Among them, a liquid crystal display (LCD) display device having an in-plane switching mode (IPS mode) having a wide viewing angle characteristic has been widely used in actual mass production. The IPS mode liquid crystal display device includes at least a pair of pixel electrodes and a common electrode arranged in parallel in a pixel. These pixel electrodes and the common electrode generate a transverse electric field to orient the liquid crystal molecules in a plane.

In the IPS mode liquid crystal display device, since the pixel electrodes and the common electrode are all located on the lower substrate, a color filter is formed on the upper substrate and no additional conductive material is formed. As a result, the conventional IPS mode liquid crystal display device has a problem that whitening occurs due to electrostatic discharge (ESD) generated on the upper substrate. In order to solve such a problem, a conductive pattern is formed on the upper surface of the upper substrate by using a transparent conductive material, and the conductive pattern and the ground pattern of the lower substrate are connected to each other through conductive dots or the like, An IPS mode liquid crystal display device has been proposed which discharges toward the ground pattern of the substrate and additionally has a metal front case to discharge the static electricity to the metal front case side. However, the liquid crystal display device having a metal front case increases in weight and manufacturing cost as it becomes larger on a display screen, and attempts have been made to replace it with a material such as plastic. In this case, static electricity generated on the upper substrate side can not be applied to the plastic front case, and static electricity is generated in a region closer to the lower substrate than the distance from the conductive dot in the upper substrate, or static electricity having a high voltage level The static electricity is not discharged toward the conductive dots but is directly applied to the lower substrate in the direction of the lower substrate, thereby causing a defect in the thin film transistor located on the lower substrate.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a liquid crystal display device capable of effectively discharging static electricity in a liquid crystal display device using a plastic front cover.

According to an aspect of the present invention, there is provided a liquid crystal display device including a liquid crystal panel, a light source unit disposed on a back surface of the liquid crystal panel, a bottom cover storing the liquid crystal panel and the light source unit, And a front case having a discharge pattern floated on a position corresponding to a non-display area of the liquid crystal panel on an inner surface of the panel facing the liquid crystal panel. The front case is preferably made of a plastic material.

The lower substrate of the liquid crystal panel is provided with a ground pattern, and the upper surface of the upper substrate may be provided with a conductive pattern. The conductive pattern and the ground pattern are connected to each other by metal dots formed through the upper substrate.

 The liquid crystal display device according to the present invention has the effect of greatly reducing the peak voltage of the static electricity by forming a discharge pattern on the inner surface of the front case. That is, according to the present invention, since the peak voltage of the static electricity is greatly reduced, even if the static electricity is generated on the side of the upper substrate and directly applied to the thin film transistor side without passing through the metal dot, the peak voltage is lowered, Is not generated.

1 is an exemplary diagram for explaining a pixel and a driving circuit of a liquid crystal display device according to the present invention.
2 is a schematic view for explaining a liquid crystal display according to an embodiment of the present invention.
FIG. 3 is a front view for explaining a liquid crystal panel of a liquid crystal display device according to the present invention, and FIG. 4 is a cross-sectional view for explaining the portion II 'of FIG.
5 is an exemplary view for explaining an example of the electrostatic induction pattern according to the present invention.
6 is a schematic view for explaining the position of a discharge pattern as viewed from the lower side of the front cover according to the present invention.
7 is an exemplary view for explaining a liquid crystal display device according to the present invention to which a multiple ground pattern is applied.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a detailed description of known technologies or configurations related to the present invention will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured. The component names used in the following description are selected in consideration of easiness of specification, and may be different from the parts names of actual products.

The term " on "or " on" of another element encompasses not only the element just above the other element layer but also intervening layers or other elements in the middle. On the other hand, an element or layer is referred to as being "tangential " to another element, indicating that no other element or layer is interposed.

The sizes and thicknesses of the respective components shown in the figures are shown for convenience of explanation, and the present invention is not necessarily limited to the sizes and thicknesses of the components shown.

1 is an exemplary diagram for explaining a pixel and a driving circuit of a liquid crystal display device according to the present invention.

The liquid crystal display device according to the present invention includes a liquid crystal panel 200 defined in a region where a plurality of gate lines GL and data lines DL intersect and including a plurality of pixels arranged in a matrix form, A timing controller 4 for aligning the video signals to be supplied to the liquid crystal panel 200 and controlling the operation timing of each pixel, And a gate driver 3 and a data driver 2 for driving the line DL.

Each pixel is provided with a thin film transistor (TFT) and a liquid crystal capacitor Clc connected to the thin film transistor. The liquid crystal capacitor Clc is composed of a pixel electrode connected to the thin film transistor, and a common electrode Vcom arranged between the pixel electrode and the liquid crystal. The thin film transistor supplies a video signal from each data line DL to the pixel electrode in response to a scan pulse from each gate line GL.

The liquid crystal capacitor Clc charges the difference voltage between the video signal supplied to the pixel electrode and the common voltage Vcom applied to the common electrode and adjusts the light transmittance by varying the arrangement of the liquid crystal molecules according to the difference voltage, . ≪ / RTI >

2 is a schematic view for explaining a liquid crystal display according to an embodiment of the present invention.

The liquid crystal display device according to an embodiment of the present invention includes a liquid crystal panel 200 including a lower substrate 210 and an upper substrate 220 bonded together by a sealing material 400, A light source unit 100 that emits light from the lower portion of the liquid crystal panel 200 to the liquid crystal panel 200, a bottom cover 500 in which the liquid crystal panel 200 and the light source unit 100 are housed, And a front case 600 positioned above the liquid crystal panel 200 and the light source unit 100 and coupled to the bottom cover 500. In the front case 600, the surface A / A is formed to be transparent so that light from the liquid crystal panel 200 is transmitted and the edge portion of the display surface A / A is opaque, However, the present invention is not limited thereto.

A discharge pattern 601 is provided on the inner surface of the front case 600 corresponding to the outer non-display area of the liquid crystal panel 200. The front case 600 may be formed of a transparent material such as glass at a position corresponding to the display region of the liquid crystal panel 200 to transmit an image displayed from the liquid crystal panel 200, .

The specific structure of the liquid crystal panel 200 and the discharge pattern 601 will be described later.

FIG. 3 is a front view for explaining the liquid crystal panel 200 of the liquid crystal display device according to the present invention. FIG. 4 is a front view of the front cover 600 positioned at the portion II 'of FIG. 2 and the liquid crystal panel 200 Sectional view for explaining the structure.

3 and 4, the liquid crystal panel 200 is defined as a display area A / A and a non-display area N / A. A ground pattern 281 is provided in a non-display area located outside the display area A / A of the lower substrate 210. The ground pattern 281 may be connected to various wirings of the display area A / A to supply a ground voltage to each pixel of the display area A / A.

Referring to FIG. 4, a conductive pattern 221 is provided on the upper substrate 220. The conductive pattern 221 is formed on the entire surface of the upper substrate 220 with a transparent conductive material (TCO) such as ITO, IZO, IGZO, or IGZO. The conductive pattern 221 is formed to penetrate the upper substrate 220 and is connected to the metal dot 223 connected to the ground pattern 281 of the lower substrate 210. The metal dot 223 is formed of a metal material such as Ag, Cu, Al, Mg, Au or the like and electrically connected to the ground pattern 281 of the lower substrate 210 by electrostatic force applied to the upper surface conductive pattern 221 of the upper substrate 220 ) Direction.

A thin film transistor, a pixel electrode 131 and a common electrode 132 are formed in a display area A / A of the lower substrate 100.

In detail, the lower substrate 210 includes a gate electrode 211, a gate insulating layer 212 formed on the gate electrode 211, a semiconductor layer 213 disposed on the gate insulating layer, An ohmic contact layer 214 provided on both sides of the semiconductor layer 213, an interlayer insulating layer 215 formed to expose the ohmic contact layer 214 and an ohmic contact layer 214 formed on both sides of the semiconductor layer 213, A source electrode 216 and a drain electrode 217 connected to one side of the layer 214 and a pixel electrode 218 extending from the drain electrode 217; And a common electrode 221 provided on the first lower passivation film 219 so as to be spaced apart from the pixel electrode 218. The first lower passivation film 219 is formed on the first lower passivation film 219,

A second lower passivation film 229 may be further provided on the common electrode 221.

On the upper substrate 220, a color filter 230 positioned to correspond to each pixel region, a black matrix 232 located between each pixel region, and a color filter 230 covering the color filter 230 and the black matrix 232 And an upper passivation film 233 is provided.

A polarizer (not shown) may be further provided on the outer sides of the lower substrate 210 and the upper substrate 220.

The light source unit 100 includes a light source (not shown) including an LED or a cold cathode lamp, a light guide plate, and a plurality of optical sheets (not shown) in the bottom cover 500. The light source unit 100 guides light emitted from a light source (not shown) through a light guide plate, an optical sheet, and the like to emit light in the direction of the liquid crystal panel 200.

Referring to FIG. 1, a discharge pattern 601 is provided on the inner surface of the front case 600, as described above. At this time, the discharge pattern 601 is disposed to face the non-display area N / A of the liquid crystal panel 200 and is spaced apart from the upper substrate 220 to be floated. The front case 600 is formed of an insulating material such as plastic. In the case where the front case 600 is formed of a material such as plastic, since the static electricity is not applied to the front case 600, the metal dots 223 The static electricity is directly applied to the lower substrate 210, thereby causing defects in the thin film transistor and the like. The discharge pattern 601 is formed on the inner surface of the front case 600 with a conductive material.

When static electricity is generated on the side of the upper substrate 220, the liquid crystal display according to the present invention is configured such that the conductive pattern 221 located on the upper substrate 220 passes through the metal dot 223 to the ground pattern 281 side Thereby preventing the static electricity from being directly applied to the display region A / A on the lower substrate 210 side.

In this case, the conductive pattern 221 is formed of a transparent conductive material such as ITO having a small thickness on the entire surface of the upper substrate 220. In this case, the conductive pattern 221 not only has a high surface resistance and a high capacitance, The discharge path is very narrow due to the discharge only to the dot 223 side, so that it takes a relatively long time to discharge the applied static electricity. If the static electricity becomes higher than a certain level, the element such as the thin film transistor of the discharging element lower substrate 210 may be damaged directly to the lower substrate 210 which is the shortest path.

In order to solve such a problem, the liquid crystal display according to the present invention forms a discharge pattern 601 on the inner surface of the front case 600. Therefore, even if the front case 600 is formed of an insulating material, the static electricity generated from the upper substrate 220 is not directly applied to the lower substrate 210, and the voltage due to the static electricity toward the discharge pattern 601 of the front case 600 So that the peak voltage due to static electricity is lowered. When the peak voltage due to the static electricity is lowered, even when static electricity is applied to the lower substrate 210, the peak voltage is lowered to a voltage level not damaging the elements such as the thin film transistor, Thereby preventing damage to elements such as a thin film transistor provided on the side of the first electrode 210.

The discharge pattern 601 can be formed using various materials having high conductivity. For example, the discharge pattern 601 can be easily formed by attaching a conductive tape to the inner surface of the front case 600 corresponding to the outline of the display surface A / A, but it is not limited thereto.

The discharge pattern 601 may further include a static induction pattern 602 that protrudes a part of the area to guide the static electricity toward the discharge pattern 601. [ Referring to FIG. 4, the static induction pattern 602 protrudes toward the upper substrate 220 with a corner or a vertex so as to perform a role similar to that of the lightning rod. The liquid crystal display device having the electrostatic induction pattern 602 is more likely to apply the static electricity generated on the side of the upper substrate 220 to the electrostatic induction pattern 602 so that the thin film transistor on the side of the lower substrate 210 The circuits can be protected.

5 is an exemplary view for explaining another example of the electrostatic induction pattern 602. FIG. 5 shows a part of the inner surface of the front case 600. As shown in Fig. 5, the electrostatic induction pattern 602 may be located on the inner surface of the front case 600 and protrude so as to have a sawtooth shape in the direction of the display surface A / A side of the front case 600. Similarly, the electrostatic induction pattern 602 serves as a lightning rod, thereby guiding the static electricity generated on the upper substrate 220 side to the electrostatic induction pattern 602 side.

The distance between the upper substrate 220 and the front case 600 may be increased because the static induction pattern 602 protrudes toward the upper substrate 220. However, The electrostatic induction pattern 602 can be formed without an increase in the distance between the upper substrate 220 and the front case 600 by protruding in the lateral direction of the pattern 601. [

6 is a schematic view for explaining the position of the discharge pattern 601 when the front case 600 is viewed from below. As shown in FIG. 5, the discharge pattern 601 may be formed on the inner surface of the front case 602 so as to correspond to all the frame portions of the outer surface of the display surface A / A, or may be formed only partially of the outer frame portions.

When the discharge pattern 601 is formed so as to correspond to all of the outer edges of the display surface A / A, the discharge pattern 601 may be formed to surround the display surface A / A when viewed from the front side. have.

7 is an exemplary view for explaining a liquid crystal display device according to the present invention to which a multiple ground pattern is applied.

The ground pattern of the liquid crystal display device can be applied in a multiple structure. At this time, the multi-ground pattern is divided into a first ground pattern 241 provided on the outer rim of the display surface A / A and a second ground pattern 241 spaced apart from the first ground pattern 241, And at least one connection pattern 243 electrically connecting the second ground pattern 242 formed on the outer periphery and the first and second ground patterns 241 and 242.

Since the static electricity generated in the upper substrate 220 corresponding to the display surface A / A is applied to the second ground pattern 242 through the first ground pattern 241, the movement path of the static electricity increases Thereby minimizing the influence of static electricity.

In the liquid crystal display device using the multi-ground pattern, the connection pattern 243 connecting the first and second ground patterns 241 and 242 with the static electricity generated in the upper substrate 220 does not pass through the metal dot 223 The influence of the static electricity can be increased because the movement path of the static electricity is greatly reduced.

In this case, in order to reduce the voltage peak of the static electricity applied to the connection pattern 243, the discharge pattern 601 of the front case 600 in the liquid crystal display device using the multi- Or may be provided only at a position corresponding to the upper side. In this case, since the formation of the discharge pattern 601 is greatly reduced, when the discharge pattern 601 is formed using the conductive tape, the amount of the conductive tape required can be greatly reduced, and the process cost can be reduced.

The above-described liquid crystal display device according to the present invention has the effect of reducing the peak voltage of static electricity by 5 kV or more according to the experiment by forming the discharge pattern 601 on the inner surface of the front case 600. That is, according to the present invention, since the peak voltage of the static electricity is largely reduced, static electricity is generated on the side of the upper substrate 220, and even if the static electricity is directly applied to the thin film transistor side without passing through the metal dot 223, There is no damage to the internal circuit including the capacitor.

The foregoing description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the spirit of the present invention. Accordingly, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed according to the following claims, and all the techniques within the scope of equivalents should be construed as being included in the scope of the present invention.

200: liquid crystal panel 2: data driver
3: Gate driver 4: Timing controller
210: lower substrate 220: upper substrate
221: conductive pattern 281: ground pattern
223: metal dot 211: gate electrode
212: gate insulating film 213: semiconductor layer
214: Ohmic contact layer 215: Interlayer insulating film
216, 217: source and drain electrodes 219: first lower passivation film
218: pixel electrode 221: common electrode
Color filter (230) 232: Black matrix
233: upper passivation film 600: front case
601: discharge pattern 100: light source unit
500: bottom cover 602: electrostatic induction pattern
241, 242: first and second ground patterns 243: connection pattern

Claims (11)

A liquid crystal panel including a plurality of pixels located in a matrix form in a region where a plurality of gate lines and data lines of a display region are formed to cross each other,
A light source unit disposed on a rear surface of the liquid crystal panel,
A bottom cover for accommodating the liquid crystal panel and the light source unit,
And a front case having a discharge pattern positioned on the liquid crystal panel to be coupled to the bottom cover and positioned to be floated on a surface facing the liquid crystal panel. The method according to claim 1,
Wherein the front case is made of a plastic material. The method according to claim 1,
Wherein the discharge pattern is made of a conductive tape positioned so as to correspond to a display surface edge portion of the liquid crystal panel on the inner surface of the front case. The method according to claim 1,
In the liquid crystal panel,
A lower substrate including a plurality of first and second electrodes for generating a thin film transistor and a transverse electric field provided in a display region, an upper substrate including a color filter, and a lower substrate interposed between the upper substrate and the lower substrate, A liquid crystal layer,
Wherein the lower substrate includes a ground pattern positioned at an edge of the display region,
Wherein the upper substrate includes a conductive pattern located on an upper surface of the upper substrate,
Wherein the conductive pattern and the ground pattern are electrically connected by a conductive dot pattern passing through the upper substrate. 5. The method of claim 4,
Wherein the conductive pattern and the discharge pattern are spaced apart from each other. 6. The method of claim 5,
Wherein the discharge pattern includes an electrostatic induction pattern in which a part of the electrostatic induction pattern protrudes. The method according to claim 6,
Wherein the electrostatic induction pattern has a shape protruding toward the upper substrate. The method according to claim 6,
And the electrostatic induction pattern protrudes in the direction of the display surface of the front cover. 5. The method of claim 4,
Wherein the ground pattern comprises: a first ground pattern provided outside the display surface of the display panel;
A second ground pattern disposed on an outer periphery of the first ground pattern and spaced apart from the first ground pattern,
And a connection pattern connecting the first and second ground patterns. The method according to claim 1,
Wherein the discharge pattern is located in a region corresponding to all edge portions of an outer periphery of the display region. 10. The method of claim 9,
Wherein the discharge pattern is located only in a region overlapping the connection pattern on the connection pattern.

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