KR20070098217A - Liquid crystal display - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to confirm shift of an optical sheet through a double tape and uniformly maintain contact areas between the optical sheet and the double tape and between a mold frame and the double tape, thereby preventing delamination faults of an LCD panel attached on the double tape. An LCD(Liquid Crystal Display)(10) includes an LCD panel(20), an optical sheet(180) which is placed in a lower part of the LCD panel, a mold frame(210) for stably mounting the LCD panel and the optical sheet, and a double tape(230) which is placed between the LCD panel and the optical sheet and fixes the LCD panel and the optical sheet to the mold frame. The double tape has an exposure unit for exposing an edge of the optical sheet.

Description

Liquid Crystal Display {LIQUID CRYSTAL DISPLAY}

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1.

3 is a view showing the light source unit of FIG.

4 is a view showing a first embodiment of the double-sided tape of FIG.

FIG. 5 is a front view illustrating the double-sided tape of FIG. 4 and the first diffusion sheet attached thereto.

FIG. 6 is a rear view of the double-sided tape of FIG. 4 and the first diffusion sheet attached thereto.

7 is a view showing a second embodiment of the double-sided tape of FIG.

FIG. 8 shows a third embodiment of the double-sided tape of FIG.

<Code Description of Main Parts of Drawing>

10 liquid crystal display device 20 liquid crystal display panel

50: lower polarizing plate 120: light source unit

160: light guide plate 170: reflective sheet

180: optical sheet 190: first diffusion sheet

200: second diffusion sheet 210: mold frame

230: double-sided tape 240: exposed part

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 preventing a floating defect of a liquid crystal display panel.

In general, a personal mobile communication device such as a mobile phone is equipped with a liquid crystal display device as a display device for displaying the function according to the situation. The liquid crystal display device is electrically connected to a printed circuit board in the personal mobile communication device to display various information, that is, pictures, texts, videos, etc. by electric signals. To this end, the liquid crystal display device includes a liquid crystal display panel for displaying an image, a driving circuit for driving the liquid crystal display panel, and a backlight unit for providing light to the liquid crystal display panel.

The conventional liquid crystal display device having the above structure adopts a structure for fixing the liquid crystal display panel on the mold frame of the backlight unit by using a double-sided tape disposed between the liquid crystal display panel and the optical sheet of the backlight unit. However, when the optical sheet flows during manufacturing of the liquid crystal display device, the adhesion area between the double-sided tape and the mold frame is reduced on at least one side, and thus the liquid crystal display panel may not be properly fixed on the mold frame by the double-sided tape. Can be. As a result, floating defects occur in the liquid crystal display panel, which results in light leakage defects, thereby reducing productivity and yield of the liquid crystal display device.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of preventing a floating defect of a liquid crystal display panel.

The present invention provides a liquid crystal display panel; An optical sheet disposed below the liquid crystal display panel; A mold frame for mounting the liquid crystal display panel and the optical sheet; A double-sided tape disposed between the liquid crystal display panel and the optical sheet to fix the liquid crystal display panel and the optical sheet to the mold frame, wherein the double-sided tape has an exposed portion exposing an edge of the optical sheet. A liquid crystal display device is provided.

Other features of the present invention will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II 'of FIG. 1.

1 and 2, a liquid crystal display device 10 according to an embodiment of the present invention includes a liquid crystal display panel 20 for displaying an image, a driving circuit 70 for driving the liquid crystal display panel 20, and a liquid crystal display panel 20. The backlight unit 110 provides light to the liquid crystal display panel 20.

The liquid crystal display panel 20 includes a thin film transistor substrate 30 and a color filter substrate 40 bonded to each other with a liquid crystal interposed therebetween, and a lower polarizer plate attached to an outer surface of each of the thin film transistor substrate 30 and the color filter substrate 40. 50 and an upper polarizing plate 60 are provided.

The thin film transistor substrate 30 is a substrate in which a thin film transistor, which is a switching element, and a pixel electrode made of a transparent conductive material are formed by a thin film process. A gate line and a data line are respectively connected to the gate electrode and the source electrode of the thin film transistor, and the pixel electrode is connected to the drain electrode of the thin film transistor. The pixel electrode applies the data voltage from the drain electrode to the liquid crystal when the thin film transistor is turned on by the scan signal from the gate electrode.

The color filter substrate 40 is a substrate on which a red, green, and blue color filter that implements color, and a common electrode made of a transparent conductive material are formed by a thin film process. The common electrode applies a common voltage to the liquid crystal. At this time, the liquid crystal is rotated by the difference between the common voltage from the common electrode and the data voltage from the pixel electrode to adjust the transmittance of light from the backlight unit 110.

The lower polarizer 50 polarizes the light from the backlight unit 110 in a specific direction and provides it to the liquid crystal. The upper polarizer 60 polarizes the light passing through the liquid crystal in a specific direction.

The driving circuit 70 is mounted on a thin film transistor substrate 30 in a chip on glass (COG) manner and provides a data for supplying a data voltage to a gate driving circuit and a data line for supplying a scan signal to a gate line. It consists of a driving circuit. Here, at least one of the gate driving circuit and the data driving circuit may be integrated on the thin film transistor substrate 30. The driving circuit 70 is electrically connected to the flexible printed circuit board 80 connected to the thin film transistor substrate 30 through the anisotropic conductive film. In the flexible printed circuit board 80, a plurality of electronic devices 90 generating power signals, data signals, various control signals, etc. are mounted in a soldering manner to drive the driving circuit 70. Power signals, data signals, and various control signals generated by the plurality of electronic devices 90 are supplied to the driving circuit 70 through the driving signal line 100.

The backlight unit 110 includes a light source unit 120 for providing light, a light guide plate 160 for guiding light from the light source unit 120, a reflective sheet 170 disposed under the light guide plate 160, and a light guide plate. The optical sheet 180 and the light source unit 120, the light guide plate 160, the reflective sheet 170, and the optical sheet 180 are disposed on the upper portion of the optical sheet 180, and the liquid crystal display panel 20 is mounted thereon. It is provided with a mold frame 210 for. The mold frame 210 on which the light source unit 120, the light guide plate 160, the reflective sheet 170, and the optical sheet 180 are seated is received and fixed in the bottom chassis 220.

As illustrated in FIG. 3, the light source unit 120 includes an LED unit 130 for generating light and an LED flexible substrate 140 for fixing the LED unit 130.

The LED unit 130 has a package body having a cup-shaped cavity for accommodating the LED chip therein and is attached to the LED flexible substrate 140 by soldering. The LED chip receives light from the LED driving signal line 150 to generate light.

The LED unit 130 is attached to the back of the LED flexible substrate 140 by a soldering method. In order to apply driving power to the LED unit 130, a plurality of LED driving signal lines 150 are formed in the LED flexible substrate 140.

The light guide plate 160 is mounted on the rear surface of the mold frame 210 to guide the light emitted from the LED unit 130 to the liquid crystal display panel 20.

The reflective sheet 170 is mounted on the rear surface of the mold frame 210 to reflect light emitted from the lower portion of the light guide plate 160 toward the light guide plate 160. To this end, the reflective sheet 170 is coated with a material having a high reflectance on the base material.

The optical sheet 180 is positioned above the light guide plate 160 and below the liquid crystal display panel 20 to uniformly disperse and collect light to the liquid crystal display panel 20. The optical sheet 180 includes a diffusion sheet that scatters light and spreads the light evenly, a prism sheet that refracts and condenses the light, a protection sheet that protects the prism sheet that is easily scratched, and a moiré phenomenon may occur. In general, two or more pieces of the brightness improving sheet to improve the characteristics of the liquid crystal display device 10 are provided. For example, if the optical sheet 180 is composed of two sheets, the optical sheet 180 may be configured in a structure in which two diffusion sheets are stacked or in a structure in which one diffusion sheet and one prism sheet are stacked. And, if the optical sheet 180 is composed of three, the optical sheet 180 may be configured in a structure in which one diffusion sheet, two prism sheets are stacked. In addition, if the optical sheet 180 is composed of four sheets, one diffusion sheet, two prism sheets, one luminance enhancement sheet are laminated or one diffusion sheet, two prism sheets, and one protective sheet are laminated. Optical sheet 180 may be configured to be a structure. However, the optical sheet 180 may have a different stacking structure in accordance with the characteristics of the liquid crystal display 10 in addition to the stacking structure described above. That is, the optical sheet 180 positioned on the uppermost layer of the optical sheet 180 may be any one of a diffusion sheet, a prism sheet, a protective sheet, and a luminance improving sheet. Hereinafter, a structure in which two diffusion sheets, that is, first and second diffusion sheets 190 and 200 are stacked, will be described for convenience of description.

As described above, each of the first and second diffusion sheets 190 and 200 scatters light to spread the light evenly. The double-sided tape 230 is attached to an edge of the first diffusion sheet 190 positioned on the uppermost layer of the first and second diffusion sheets 190 and 200. In addition, the double-sided tape 230 is also attached to the mold frame 210, so that the first diffusion sheet 190 is fixed to the mold frame 210. At this time, the adhesive surface to be bonded to the first diffusion sheet 190 and the mold frame 210 of the adhesive surface on both sides of the double-sided tape 230 is the same. Meanwhile, the liquid crystal display panel 20 is bonded to the first diffusion sheet 190 and the mold frame 210 that are not adhered to both of the adhesive surfaces of the double-sided tape 230, and thus the liquid crystal display panel 20 is It is fixed to the mold frame 210. That is, the liquid crystal display panel 20 and the first diffusion sheet 190 are fixed to the mold frame 210 by the double-sided tape 230 disposed between the liquid crystal display panel 20 and the first diffusion sheet 190. .

As shown in FIG. 4, the double-sided tape 230 is formed in a rectangular shape having an opening in the center thereof so that light from the LED unit can be supplied to the liquid crystal display panel. Here, the double-sided tape 230 is preferably made of an opaque material to prevent light leakage.

On the other hand, the double-sided tape 230 is provided with an exposed portion 240 formed by cutting in a semi-circular shape at a predetermined position of the upper / lower side. 5 and 6, this is to reveal the edge of the first diffusion sheet 190, specifically, the top and bottom sides of the first diffusion sheet 190. Through this, the adhesive areas of the upper and lower sides of the first diffusion sheet 190 bonded to the double-sided tape 230 of the opaque material may be the same. This may result in the same adhesive area that is bonded to the mold frame 210 on the upper / lower side of the double-sided tape 230. That is, the adhesive area bonded between the upper and lower sides of the first diffusion sheet 190 and the upper and lower sides of the double-sided tape 230 and the upper and lower sides of the mold frame 210 and the upper and lower sides of the double-sided tape 230. The area can be kept constant. For this reason, the liquid crystal display device 10 according to the exemplary embodiment of the present invention may check the flow of the first diffusion sheet 190 before attaching the liquid crystal display panel 20 to the double-sided tape 230. In addition, since the first diffusion sheet 190 and the mold frame 210 are bonded to each other by the double-sided tape 230 so as to have a uniform adhesive area, the liquid crystal display panel 20 is connected to the mold frame by the double-sided tape 230. It can be firmly fixed on the 210 and can prevent the lifting failure of the liquid crystal display panel 20.

As illustrated in FIG. 7, the exposed part 240 may be formed on the upper and lower sides of the double-sided tape 230 in a straight line shape, and as shown in FIG. 8, the upper and lower sides of the double-sided tape 230. It can be formed in a semicircle on each of the left / right sides. However, the shape and position of the exposed portion 240 is not limited to the above. That is, the exposed part 240 may be formed to expose at least two of the top, bottom, left and right sides of the first diffusion sheet.

Meanwhile, the optical sheet adhered to the double-sided tape according to the optical sheet configuration may be a prism sheet, a protective sheet, and a luminance improving sheet.

The liquid crystal display of the present invention includes a double-sided tape having an exposed portion for exposing the edge of the optical sheet. By the double-sided tape, the flow of the optical sheet can be confirmed, and the area bonded between the optical sheet and the double-sided tape and the area bonded between the mold frame and the double-sided tape can be kept constant. For this reason, the lifting failure of the liquid crystal display panel attached on the double-sided tape can be prevented. This not only increases the productivity and yield of the liquid crystal display but also improves the display quality of the liquid crystal display.

In the detailed description of the present invention described above with reference to the preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge of the present invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the spirit and scope of the art.

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 (4)

A liquid crystal display panel; An optical sheet disposed below the liquid crystal display panel; A mold frame for mounting the liquid crystal display panel and the optical sheet; A double-sided tape disposed between the liquid crystal display panel and the optical sheet to fix the liquid crystal display panel and the optical sheet to the mold frame; And the double-sided tape has an exposed portion exposing the edge of the optical sheet. The method of claim 1, And the exposed part exposes at least two of top, bottom, left, and right sides of the optical sheet. The method of claim 1, The optical sheet is any one of a diffusion sheet to spread the light evenly, a prism sheet for refracting and condensing the light, a protective sheet for protecting the prism sheet, and a brightness enhancement sheet for improving the brightness. Liquid crystal display device. The method according to any one of claims 1 to 3, A driving circuit for driving the liquid crystal display panel; A light source unit providing the light; A light guide plate for guiding the light to the liquid crystal display panel; And a reflective sheet disposed under the light guide plate.

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