KR20120122756A - Liquid crystal display device having good efficience of heat rediation therefrom - Google Patents

Abstract

The present invention is to prevent the temperature of the liquid crystal display device rises by quickly discharging the heat inside the liquid crystal display device, the liquid crystal panel; A flexible printed circuit (FPC) mounted with a driving device and attached to one side of the liquid crystal panel to apply a signal to the liquid crystal panel; A backlight for supplying light to the liquid crystal panel; A guide panel and a lower cover for assembling the liquid crystal panel and the backlight; And an upper cover coupled to the lower cover and a guide panel so as to surround an upper edge of the liquid crystal panel, wherein a thickness of an upper surface of an upper cover corresponding to an area in which the driving element of the FPC is mounted is greater than a thickness of another region. It is characterized by.

Description

Liquid crystal display device with easy heat dissipation {LIQUID CRYSTAL DISPLAY DEVICE HAVING GOOD EFFICIENCE OF HEAT REDIATION THEREFROM}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device that can minimize the temperature rise of the liquid crystal display device by easily dissipating heat therein.

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, mass production technology, ease of driving means, , Liquid crystal display devices (LCDs) are mainly receiving the spotlight because of realization of a large-sized screen.

The liquid crystal display element is a transmissive display element and displays a desired image on the screen by adjusting the amount of light transmitted through the liquid crystal layer by refractive index anisotropy of liquid crystal molecules.

However, since the liquid crystal display device is a transmissive display device, a light source for supplying light to the liquid crystal layer is required. Since the light source generates heat, it becomes an important factor for raising the temperature of the liquid crystal display device. In addition, since the light emitting device used as a light source generates more heat than the fluorescent lamp used previously, the temperature of the liquid crystal display is further increased.

On the other hand, in the liquid crystal display device, a data driving device for applying a signal is mounted therein, and heat is generated in the data driving device to increase the temperature of the liquid crystal display device. Furthermore, as the liquid crystal display device becomes larger and higher in quality, not only the number of data driver devices mounted on the liquid crystal display device but also its performance are improved, so that the temperature is further increased by the data driver device.

This increase in temperature not only shortens the life of the light source and deteriorates the optical sheet, but also causes deterioration of the liquid crystal layer of the liquid crystal panel.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and by increasing the surface area of the upper surface of the upper cover or increasing the thickness of the upper cover of the region where heat is inputted by the driving element, the liquid crystal can be smoothly released by emitting heat in the liquid crystal display device. It is an object of the present invention to provide a liquid crystal display device capable of preventing a defect from occurring due to an increase in the temperature of the display device.

In order to achieve the above object, the liquid crystal display device according to the present invention comprises a liquid crystal panel; A flexible printed circuit (FPC) mounted with a driving device and attached to one side of the liquid crystal panel to apply a signal to the liquid crystal panel; A backlight for supplying light to the liquid crystal panel; A guide panel and a lower cover for assembling the liquid crystal panel and the backlight; And an upper cover coupled to the lower cover and a guide panel so as to surround an upper edge of the liquid crystal panel, wherein a thickness of an upper surface of an upper cover corresponding to an area in which the driving element of the FPC is mounted is greater than a thickness of another region. It is characterized by.

The backlight may include a light source for supplying light to the liquid crystal panel; A light guide plate disposed under the liquid crystal panel to guide light incident from a light source to the liquid crystal panel; And an optical sheet disposed on the light guide plate to improve the efficiency of light output from the light guide plate and supplied to the liquid crystal panel, wherein the light source is an LED or a fluorescent lamp disposed below or on the side of the light guide plate.

A plurality of grooves are formed in at least one upper surface of the upper cover to increase the surface area of the upper surface of the upper cover, thereby easily dissipating heat generated inside the liquid crystal display. In this case, the plurality of grooves are formed on the upper surface of the upper cover of the region where the FPC is disposed.

In the present invention, the temperature of the liquid crystal display can be prevented from rising by smoothly dissipating heat generated from the liquid crystal display. Therefore, it is possible to prevent deterioration of the optical sheet, deterioration of the liquid crystal layer, melting of the guide panel made of plastic, and the like due to the temperature rise.

1 is a perspective exploded view of a liquid crystal display device according to an embodiment of the present invention;
2 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
3 is a partial perspective view illustrating a structure of an upper cover of a liquid crystal display device according to an exemplary embodiment of the present invention.
4A and 4B are cross-sectional views illustrating a structure of a liquid crystal display device according to another exemplary embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, the heat generated from the liquid crystal display device is smoothly discharged, thereby preventing the temperature of the liquid crystal display device from rising, thereby preventing a defect from occurring in the liquid crystal display device.

As mentioned above, the temperature rise of the liquid crystal display is due to heat generated from the light source of the backlight and heat generated from the data driving device. Therefore, the present invention includes means for mainly dissipating heat generated from the light source of the liquid crystal display device and means for dissipating mainly heat generated from the data driving device. Particularly, in the present invention, the heat radiating means is provided near the data driving device to emit heat generated near the data driving device.

1 is an exploded perspective view showing the structure of a liquid crystal display device according to an embodiment of the present invention.

As shown in FIG. 1, the liquid crystal display device 101 according to the present invention includes a liquid crystal panel 110 in which pixels are arranged in a matrix to form an image, and connected to side surfaces of the liquid crystal panel 110, respectively. The driver 110 applies various signals such as scan signals and data signals to the panel 110, and a backlight 170 disposed on the rear surface of the liquid crystal panel 110 to supply light to the liquid crystal panel 110. do.

Although not shown in the drawing, the liquid crystal panel 110 is composed of a first substrate and a second substrate and a liquid crystal layer therebetween to implement an image as a signal is applied from the outside. A plurality of gate lines and data lines are formed on the first substrate to form a plurality of pixel regions arranged vertically and horizontally. In each pixel region, a thin film transistor as a switching element is formed, and a pixel electrode is formed on the pixel region. In addition, although not shown in the drawing, the thin film transistor includes a gate electrode connected to a gate line, a semiconductor layer formed by stacking amorphous silicon, etc. on the gate electrode, a source formed on the semiconductor layer and connected to a data line and a pixel electrode. It consists of an electrode and a drain electrode.

Although not shown in the drawings, the second substrate is a color filter composed of a plurality of sub-color filters for implementing colors of red (R), green (G), and blue (B), the sub-color A black matrix may be formed to separate the filters and block light passing through the liquid crystal layer.

The first and second substrates configured as described above are joined to face each other by a sealant (not shown) formed at the outer side of the image display area to form a liquid crystal panel. The first and second substrates are bonded to each other. It is made through a bonding key formed on the first substrate or the second substrate.

The backlight 170 is disposed on a lower side of the liquid crystal panel 110 to emit light, and a light source 172 such as a fluorescent lamp or a light emitting device (LED) and a light source disposed below the liquid crystal panel 110. The light guide plate 171 for guiding the light emitted from the light source 172 to the liquid crystal panel 110, and is provided between the liquid crystal panel 110 and the light guide plate 171 to be guided by the light guide plate 171 to provide a liquid crystal panel ( An optical sheet 175 including a diffusion sheet and a prism sheet for diffusing and condensing the light supplied to the 110, and a reflecting plate 174 disposed under the light guide plate 171 to reflect light directed to the bottom of the light guide plate 171. )

As the light source 172, a fluorescent lamp or an LED may be used. When the LED is used as the light source 172, an LED substrate 173 on which the LED 172 is mounted is provided so that external signals are inputted to the LED 172 through the LED substrate 173, thereby providing light from the LED 172. Light is emitted. In this case, the LED substrate 173 is disposed on the lower cover 150, a plurality of LED 172 is mounted in the LED substrate 173 along the longitudinal direction of the LED substrate 173, LED 172 Light emitted from the light is incident on the upper light guide plate 171.

As such, when the LED 172 is disposed on the lower cover 150, an area corresponding to the position of the LED 172 is removed from the reflecting plate 174 disposed on the lower cover 150 such that the window 174a is removed. Is formed. Since the LED 172 is exposed upward through the window 174a of the reflector 174, the light emitted from the LED 172 is supplied to the upper light guide plate 171 through the window 174a or the reflector ( After being reflected by 174, it is supplied to the light guide plate 171.

In addition, the LED 172 may be disposed on the side of the light guide plate 171 instead of being disposed above the lower cover 150, that is, the lower part of the light guide plate 171. In this case, the light incident on the side of the light guide plate 171 is totally reflected several times inside the light guide plate 171, propagates from one end of the light guide plate 171 to the other end and at the same time, the liquid crystal panel 110 through the top surface of the light guide plate 171. Is supplied.

When a fluorescent lamp such as a cold cathod fluorescent lamp (CCFL) or an external eletrode fluorescent lamp (EEFL) is used as the light source, the fluorescent lamp is disposed inside a lamp housing installed on the side of the light guide plate 171 to emit light from the fluorescent lamp. Light is reflected by the reflective layer formed inside the lamp housing and input through the side of the light guide plate.

The light guide plate 171 is used to guide the light input from the light source 172 to the liquid crystal panel 110, and light incident on the lower surface or one side of the light guide plate 171 is reflected inside the light guide plate 171 and propagates to the other side. After that, the light guide plate 171 is output to the outside. In this case, the light guide plate 171 may be formed of a rectangular parallelepiped, and a pattern or a groove may be formed on the bottom surface of the light guide plate 171 to scatter incident light.

The optical sheet 175 is supplied to the liquid crystal panel 110 to improve the efficiency of light output from the light guide plate 171. The optical sheet 175 includes a diffusion sheet for diffusing the light output from the light guide plate 171 and a prism sheet for condensing the light diffused by the diffusion sheet to supply uniform light to the liquid crystal panel 110. At this time, the diffusion sheet is provided with one sheet or two sheets, the prism sheet is composed of two sheets of prism perpendicularly intersecting in the x, y-axis direction, the light is refracted in the x, y-axis direction to improve the light straightness.

The driving unit 115 is coupled to the liquid crystal panel 110 in various forms to drive the pixels of the liquid crystal panel 110 by supplying scan signals and image information to gate lines and data lines formed in the liquid crystal panel 110. .

The driving unit 115 includes an FPC 115a and a printed circuit board 115b. The FPC 115a includes driving devices such as data driving devices and gate driving devices for applying signals to the liquid crystal panel through gate lines and data lines, and various wirings are formed on the printed circuit board 115b to form the driving devices. Is electrically connected to the electrical wiring of the system which is fastened to the liquid crystal display device 101.

The printed circuit board 115b is disposed on the bottom surface or the side surface of the lower cover 150. In this case, since the FPC 115a is ductile, the FPC 115a is folded back from the liquid crystal panel 110 so that the printed circuit board 115b is disposed on the side or bottom surface of the lower cover 150.

When the printed circuit board 115b is disposed on the bottom surface of the lower cover 150, a cover shield 155 is installed on the lower cover 150. The cover shield 155 is folded to the bottom of the lower cover 150 to be coupled to the bottom surface of the lower cover 150 while covering the printed circuit board 115b to cover the printed circuit board 115b with the lower cover. It is fixed to the bottom surface of 150 and at the same time protect the printed circuit board (115b).

In the drawing, although the printed circuit board 115b is formed on only one side of the liquid crystal panel 110 and the cover shield 155 is also attached to only one side of the lower cover 150, the configuration or size of the liquid crystal display device is disclosed. Accordingly, the printed circuit board 115b may be formed at both sides of the liquid crystal panel 110, and the cover shield 155 may be attached to both sides of the lower cover 150.

The liquid crystal panel 110 and the backlight 170 are assembled by the guide panel 140, the lower cover 150, and the upper cover 160. At this time, the liquid crystal panel 110 is placed on the guide panel 140, the guide panel 140 is assembled with the lower cover 150 and the upper cover 160.

A plurality of grooves 161 are formed on one side or both sides of the upper cover 160. The groove 161 extends in one direction of the upper cover 160 to increase the surface area of the upper surface of the upper cover 160.

2 is a cross-sectional view showing an assembled structure of a liquid crystal display device according to an embodiment of the present invention, with reference to this drawing will be described in more detail the liquid crystal display device according to the present invention.

As shown in FIG. 2, a plurality of LEDs 172 are disposed on the lower cover 150, and a reflecting plate 174 is disposed thereon. In this case, a window 174a is formed in the reflection plate 174 so that the LED 172 protrudes above the reflection plate 174 through the window 174a so that light emitted from the LED 172 passes through the window 174a. It is supplied to the liquid crystal panel 110. The LED 172 may be disposed on the reflector 174. At this time, the LED substrate on which the LED 172 is mounted will also be disposed on the reflector 174.

The light guide plate 171 and the optical sheet 175 are disposed on the LED 172 to be spaced apart from the LED 172 by a predetermined distance. The light guide plate 172 is made of a transparent material having high light transmittance such as acrylic, polycarbonate, epoxy, polymethyl methacrylate, and the like, and guides incident light to the liquid crystal panel 110. In this case, a pattern is formed under the light guide plate 172 so that the light is totally reflected from the lower surface when the light incident into the light guide plate 172 is guided inside the light guide plate 172 so that the light is directed to the bottom surface of the light guide plate 172. Prevents exit

The lower cover 150 is assembled with the upper cover 160 and the guide panel 140, and the liquid crystal panel 110 is placed on the guide panel 140 to be spaced apart from the optical sheet 175 by a predetermined distance. At this time, although not shown in the drawing, the lower cover 150, the upper cover 160 and the guide panel 140 may be assembled by a fastening means such as a screw.

One side of the liquid crystal panel 110 is attached to the FPC (115a). A plurality of data driving elements 115c are mounted on the rear surface of the FPC 115a, that is, the surface attached to the liquid crystal panel 110. Although not shown in the drawing, a plurality of pads are formed in the FPC 115a and are electrically connected to the pads of the liquid crystal panel 110 so that a signal output from the data driver 115c is supplied to the liquid crystal panel 110. . As shown in FIG. 1, a plurality of FPCs 115a are attached to the liquid crystal panel 110, and one or more data driving elements 115c are mounted on each FPC 115a.

Although not shown, a printed circuit board is connected to the FPC 115a, and the printed circuit board is attached to the lower cover 150.

A plurality of grooves 161 are formed on the upper surface of the upper cover 160. The groove 161 increases the surface area of the upper surface of the upper cover 160 to effectively release heat generated from the liquid crystal display. Most of the heat generated in the liquid crystal display device is generated from the light source and the driving device. Therefore, the plurality of grooves 161 formed on the upper surface of the upper cover 160 may be formed anywhere on the upper surface of the upper cover 160, but considering the heat dissipation efficiency of the heat generated in the liquid crystal display device, the driving device may be disposed. It will be preferable to be formed on the upper surface of the upper cover 160 of the side.

Of course, the groove 161 may be formed on the upper surface of the upper cover 160 that does not correspond to the region in which the driving element is disposed, or may be formed on the upper surface of all the upper covers 160.

3 is a partial perspective view illustrating the upper cover 160 in detail.

As shown in FIG. 3, a plurality of grooves 161 formed on the upper surface of the upper cover 160 are formed in a plurality of steps in a step shape along one direction of the upper surface to increase the surface area of the upper cover 160. At this time, the extending direction of the groove 161 is not limited to a specific direction but may be formed in the longitudinal direction or the width direction of the upper surface. In addition, the shape of the groove 161 may be formed in a wave shape or a triangular shape instead of a square step. In other words, in the present invention, any type of grooves 161 may be provided as long as the surface area of the upper cover can be increased to improve heat dissipation efficiency.

Where q is the heat flow, h is the heat transfer coefficient, A1 is the surface of the object to which heat is transferred, T1 is the temperature of the heating element, and T2 is the temperature of the cooling element.

As shown in Equation 1, since the heat flux of the cooling body is proportional to the heat transfer coefficient h, the surface area of the cooling body A and the temperature difference between the heating body and the cooling body, the heat transfer coefficient and heating body And assuming that the temperature of the cooling body is constant, the heat flow of the cooling body is proportional to the area of the surface area of the cooling body.

Therefore, in the present invention, as the surface area of the upper surface of the upper cover 160 is increased, heat generated from the light source and the driving element (ie, the heating body) is smoothly discharged to the outside through the upper cover 160 (ie, the cooling body). The temperature of the liquid crystal display device can be effectively reduced.

On the other hand, the upper surface of the upper cover 160 is composed of two regions of different thickness. That is, as shown in FIG. 2 and FIG. 3, the distance from the side surface of the upper cover 160 to the x distance is formed to a thickness of t2 and the remaining area is formed to a thickness of t1 (t2> t1). As such, the different thickness of the upper surface of the upper cover 160 is for the following reason.

In general, the degree of heat dissipation of a material in a material such as metal depends on the cross-sectional area of the material to which heat is conducted. Equation 2 is for the thermal resistance (R _{t, cond} ), which means that the lower the thermal resistance is smoothly conducted through the material.

Where L is the length of the object to which heat is transferred, A is the cross-sectional area, and k is a constant.

As shown in Equation 2, the thermal resistance (R _{t, cond} ) of the material conducting heat decreases as the cross-sectional area of the material increases, so that the upper surface of the upper cover 160 has a thickness, that is, the cross-sectional area (A) When it is increased, the thermal resistance is decreased, thereby improving thermal conductivity. As a result, heat generated from the liquid crystal display is easily discharged to the outside.

When the data driving device 115c is mounted to generate heat, most of the heat is transferred to the upper surface of the upper cover 160 adjacent to the area where the data driving device 115c is mounted. Thus, in the present invention, the data driving device 115c is used. The upper surface of the upper cover 160 adjacent to the mounting region is formed to a thickness of t2, and the remaining region, that is, the region covering the edge of the liquid crystal panel 110 is formed to a thickness of t1 thinner than t2.

The reason why the thickness t1 of the region covering the edge of the liquid crystal panel 110 is made thinner than the thickness t2 of the other region is that when the liquid crystal panel 110 is assembled with the same thickness, the liquid crystal panel 110 may cover the upper cover 160. This is because the liquid crystal panel 110 is damaged by contact with the upper edge of the liquid crystal panel 110. In this case, a pad 168 is formed on an upper surface of the lower cover 160 covering the edge of the liquid crystal panel 110 to absorb the impact that the upper surface of the liquid crystal panel 110 and the lower cover 160 collide with each other. 110) to prevent damage.

As described above, in the present invention, since the thickness of the upper surface of the upper cover 160 varies depending on the area, the upper cover 160 is formed by an extrusion method. In the conventional liquid crystal display device, the upper cover 160 is formed by a press method. In this case, since the upper surface cannot be formed differently and must always be constantly formed, the upper cover 160 having a different thickness as in the present invention. Could not be formed. In the present invention, since only the upper surface of all the upper surface of the upper cover 160 or the side on which the driving element is disposed has a different thickness to, in the present invention, only all the upper surface of the upper cover 160 or the upper surface of the side on which the driving element is disposed The upper surface formed by the extrusion method and formed on the side or the same thickness may be formed by the press method.

In the conventional liquid crystal display device, the upper surface of the upper cover is not flat but curved. The reason is that in the conventional liquid crystal display device, since the upper cover is formed by the pressing method, the entire upper surface is formed with the same thickness. Therefore, when the upper surface is formed flat, the upper surface of the upper cover is in contact with the outer edge of the liquid crystal panel when the lower cover is fastened. Therefore, in the conventional liquid crystal display device, the upper surface of the upper cover is bent to avoid friction caused by such contact, and in particular, the upper surface of the upper cover is prevented from contacting the upper surface of the upper cover by bending the region located at the edge of the liquid crystal panel. do. However, as the upper surface of the upper cover is formed to be bent in this manner, when assembling the liquid crystal display device, the contact area between the FPC adhered to the liquid crystal panel and the bottom of the upper cover is reduced due to the curved surface. The heat generated from the EPC can not be smoothly discharged through the upper surface of the top cover.

On the other hand, in the present invention, since the bottom of the upper surface is formed flat from the side of the upper cover 160 to a predetermined distance (that is, the area in which the data driving device is mounted), the area in contact with the bottom surface of the FPC and the upper cover is conventional. In comparison, heat generated from the data driving device is smoothly discharged through the upper surface of the FPC upper cover, thereby effectively lowering the temperature of the liquid crystal display.

4A and 4B are views illustrating a structure of a liquid crystal display device according to another exemplary embodiment of the present invention. In this case, the description of the same structure as the embodiment shown in FIG. 2 is omitted and only the other structure is omitted.

As shown in FIG. 4A, in the liquid crystal display of the present embodiment, grooves 261 are formed on the upper surface of the upper cover 260 to increase the surface area of the upper surface, and a plurality of grooves 262 are formed on the side surfaces thereof. Increase the surface area. By increasing the surface area of the side surface of the upper cover 260 not only heat is released to the top surface but also heat is released to the side smoothly. Therefore, it is possible to prevent the temperature rise of the liquid crystal display device due to the heat generated from the data driver 215c or the LED 172.

In the liquid crystal display shown in FIG. 4B, grooves 261 are formed in the upper surface of the upper cover 260 to increase the surface area of the upper surface, and a plurality of holes 263 are formed in the side surface. Accordingly, the heat generated from the data driving device 215c or the LED 272 is smoothly discharged through the upper surface of which the surface area is increased, and the heat is smoothly discharged through the hole 263 formed on the side surface thereof, so that the temperature of the liquid crystal display device is improved. The rise can be prevented.

As described above, in the present invention, a plurality of grooves are formed on the upper surface of the upper cover to smoothly discharge heat generated inside the liquid crystal display, thereby preventing the temperature of the liquid crystal display from rising. .

Meanwhile, although a liquid crystal display device having a specific structure is illustrated in the drawings, the present invention is not limited to this structure. For example, although the detailed description exemplifies an LED as a light source of a backlight, not only such an LED but also a fluorescent lamp may be used as the light source. Further, in the detailed description, although the LED is disposed under the light guide plate, the LED may be disposed on the side of the light guide plate.

In addition, the shape of the groove formed on the upper surface of the upper cover may be formed in various ways. That is, as described in the above description, although the groove may be formed to extend in a predetermined direction on the upper surface of the upper cover, a plurality of grooves such as polygonal shape or circular shape may be formed over the entire upper surface.

In other words, in the present invention, liquid crystal display devices having various structures may be applied as long as the surface area of the top cover may be increased or holes for emitting heat may be formed.

110: liquid crystal panel 115: driver
150: lower cover 160: upper cover
171: light guide plate 172: light source

Claims (13)

A liquid crystal panel;
A flexible printed circuit (FPC) mounted with a driving device and attached to one side of the liquid crystal panel to apply a signal to the liquid crystal panel;
A backlight for supplying light to the liquid crystal panel;
A guide panel and a lower cover for assembling the liquid crystal panel and the backlight; And
The upper cover is coupled to the lower cover and the guide panel to surround the upper edge of the liquid crystal panel,
And a thickness of an upper surface of the upper cover corresponding to a region in which the driving element of the FPC is mounted is larger than a thickness of another region. The method of claim 1, wherein the backlight,
A light source for supplying light to the liquid crystal panel;
A light guide plate disposed under the liquid crystal panel to guide light incident from a light source to the liquid crystal panel; And
And an optical sheet disposed on the light guide plate to improve the efficiency of light output from the light guide plate and supplied to the liquid crystal panel. The liquid crystal display device of claim 2, wherein the light source is an LED disposed below or on the side of the light guide plate. The liquid crystal display of claim 2, wherein the light source is a fluorescent lamp disposed below or on the side of the light guide plate. The liquid crystal display device of claim 1, further comprising a plurality of grooves formed on at least one upper surface of the upper cover to increase a surface area of the upper surface. The liquid crystal display of claim 5, wherein the plurality of grooves are formed on an upper surface of an upper cover of a region where the FPC is disposed. The method of claim 5,
The liquid crystal display device of claim 5, wherein the groove is formed to extend in one direction of an upper surface of the upper cover. The liquid crystal display device of claim 5, wherein the groove is disposed in a plurality of polygonal or circular shapes on an upper surface of the upper cover. The liquid crystal display device of claim 1, further comprising a printed circuit board connected to the PFC and supplying a signal to a driving device mounted on the FPC. The liquid crystal display of claim 1, wherein a bottom of an upper surface of the upper cover facing the FPC is flat to contact the FPC. The liquid crystal display device according to claim 1, wherein an upper surface of the upper cover is formed by an injection method. The liquid crystal display device of claim 1, further comprising a plurality of grooves formed on side surfaces of the upper cover. The liquid crystal display device of claim 1, further comprising a plurality of holes formed on side surfaces of the upper cover.

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