KR20080004797A - Liquid crystal display device - Google Patents

Abstract

An LCD(Liquid Crystal Display) is provided to prevent a small well deficiency which is caused as a window expands at a high temperature to contact with a liquid crystal panel, by having a window made of materials each with a different expansion rate. A liquid crystal panel(100) displays an image. A mold frame(400) receives the liquid crystal panel(100). A window(600) is disposed at an upper side of the liquid crystal panel(100) and includes an upper surface(610) and a lower surface(620) which are made of materials each with a different expansion rate. The upper surface(610) of the window(600) has higher expansion rate than that of the lower surface(620). The upper and lower surfaces(610,620) of the window(600) are separately formed and attached.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

1 is a cross-sectional view schematically showing a conventional liquid crystal display.

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

3 is a cross-sectional view showing the expansion of the window in the section taken along the line II 'shown in FIG.

<Explanation of symbols for the main parts of the drawings>

100: liquid crystal display panel 110: color filter substrate

120: thin film transistor substrate 200: panel driver

210: drive integrated circuit 220: flexible printed circuit

300: backlight assembly 305: light source unit

310: Light guide plate 320: Reflective sheet

330: diffusion sheet 340: prism sheet

400: mold frame 500: adhesive member

600: window 610: top view

615: adhesive 620: when

The present invention relates to a liquid crystal display, and more particularly, to a liquid crystal display including a window formed of a material having different expansion coefficients.

As the modern society becomes information socialized, the importance of the liquid crystal display, which is one of the information display devices, is gradually increasing. In general, a liquid crystal display device includes two substrates on which electric field generating electrodes are formed, such that the surfaces on which the two electrodes are formed face each other, inject liquid crystal between the two substrates, and apply an electric field to the two electrodes. By moving the liquid crystal molecules by means of the device to express the image by the transmittance of light that varies accordingly.

In general, a liquid crystal display device includes a liquid crystal display panel for displaying an image, a panel driver for driving a liquid crystal display panel, a backlight assembly for supplying light to the liquid crystal display panel, a mold frame for accommodating the liquid crystal display panel and the backlight assembly, The top chassis which fixes these is provided. Here, the liquid crystal display device used in the mobile phone is provided with a window instead of the top chassis for fixing and protecting the liquid crystal display panel.

1 is a cross-sectional view schematically showing a conventional liquid crystal display.

Referring to FIG. 1, in the liquid crystal display device, the window 600 is attached to the upper portion of the mold frame 400 containing the liquid crystal display panel 100 through the adhesive member 500. Here, the liquid crystal display used in the slim mobile phone reduces the thickness of the window 600 to reduce the thickness. The slim cell phone window 600 is reduced in thickness so that the window 600 is easily inflated by heat during the high temperature storage test. In this case, the lower surface of the window 600 is in contact with the liquid crystal display panel 100 due to the expansion of the lower surface of the window 600 due to the adhesive member 500 fixing the window 600 at the outer edge of the window 600. In addition, the window 600 is in contact with the liquid crystal display panel 100 to press the active area of the liquid crystal display panel 100 to generate a torsional defect, which is caused by a display defect such as a wave pattern when an image is displayed.

The technical problem to be achieved by the present invention relates to a liquid crystal display device in which the window is formed of a material having a different expansion ratio in order to prevent the window protecting the liquid crystal display panel from contacting the liquid crystal display panel.

In order to achieve the above technical problem, the present invention is disposed on the upper side of the liquid crystal display panel for displaying an image, the mold frame for accommodating the liquid crystal display panel and the liquid crystal display panel, the expansion rate is formed of the upper and lower surfaces A liquid crystal display device including a window is provided.

More specifically, the upper surface of the window is formed with a relatively high expansion rate than the lower surface.

The upper and lower surfaces of the window are formed to be bonded to each other.

In this case, the window further includes an adhesive for bonding the upper surface and the lower surface.

In addition, the upper surface and the lower surface of the window is formed integrally.

Here, the window is attached to the mold frame using an adhesive member.

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

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 and 3.

FIG. 2 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 3 is a cross-sectional view illustrating expansion of a window in a cross section taken along line II ′ of FIG. 2.

2 and 3, the liquid crystal display according to the present invention includes a liquid crystal display panel 100 for displaying an image, a mold frame 400 for accommodating the liquid crystal display panel 100, and a liquid crystal display panel 100. It is disposed on the upper side, and includes a window 600 formed of the upper surface 610 and the lower surface 620 made of different materials.

Specifically, the liquid crystal display panel 100 includes a liquid crystal (not shown) for adjusting the amount of light transmitted, and a color filter substrate 110 and a thin film transistor substrate 120 bonded together with the liquid crystal interposed therebetween.

The color filter substrate 110 forms a vertical matrix with a black matrix for preventing light leakage, a color filter for color implementation, and a pixel electrode formed on the thin film transistor substrate 120 on a transparent insulating substrate such as glass or plastic. And a common electrode and an alignment film formed thereon for alignment of liquid crystals.

The thin film transistor substrate 120 includes a gate line and a data line intersecting each other on a transparent insulating substrate such as glass or plastic, a thin film transistor formed at an intersection of the gate line and the data line, and a pixel electrode connected to the thin film transistor. And an alignment film formed thereon for alignment of liquid crystals.

The panel driver 200 is connected to one side of the thin film transistor substrate 120 to supply driving signals to gates and data lines of the liquid crystal display panel 100. The panel driver 200 includes an integrated circuit (“IC”) 210 including a gate driver for driving a gate line formed in the liquid crystal display panel 100 and a data driver for driving a data line. ). The gate driver of the driving IC 210 may be mounted on the thin film transistor substrate 120 in the form of a chip on glass (COG) or integrated on the thin film transistor substrate 120. In addition, the driving IC 210 may be mounted on a tape carrier package (hereinafter referred to as “TCP”) in a film form and electrically connected to the liquid crystal display panel 100 through a TCP bonding process. Here, an example in which the driving IC 210 is mounted on one side of the thin film transistor substrate 120 in the form of COG will be described. In this case, the driving IC 210 further includes a timing controller for supplying signals for controlling the gate driver and the data driver and a power supply for supplying a gate on / off voltage to the gate driver.

One side of the thin film transistor substrate 120 on which the driving IC 210 is mounted is attached to a metal pad connected to the driving IC 210 to supply an image signal from the outside to the driving IC 210. (Hereinafter referred to as "FPC") 220 is formed. The FPC 220 is formed of a plurality of signal lines so that one side is connected to a metal pad formed on one side of the thin film transistor substrate 120, and the other side is formed to be connected to an apparatus for supplying an image signal from the outside.

The backlight assembly 300 is formed below the liquid crystal display panel 100 to supply light to the liquid crystal display panel 100. The backlight assembly 300 reflects the light source unit 305 for generating light, the light guide plate 310 for guiding the light generated from the light source unit 305, and the light flowing out of the light guide plate 310 to the upper part of the light guide plate 310. And an optical sheet including a reflective sheet 320, a diffusion sheet 330, and a freeze sheet 340.

Here, the light source unit 305 is mounted with a plurality of light emitting diodes (LEDs) on the light source substrate for power supply at equal intervals, and is driven through a drive signal supplied through the light source substrate to generate light. The light source board is formed of an FPC or a printed circuit board (PCB). In addition, the light source substrate is formed to be connected to the power supply unit in addition to the region in which the light emitting diodes are mounted. Electrodes are formed at both ends of the light source substrate to supply driving power to the light emitting diodes from the outside.

The light guide plate 310 converts the line light source supplied through the incident surface into a surface light source to guide the liquid crystal display panel 100. The light guide plate 310 is formed with a plurality of 'V'-shaped grooves or protrusions to supply the light supplied to the incident surface to the opposite surface.

The reflective sheet 320 is attached to the rear surface of the light guide plate 310 to reflect the light supplied to the bottom of the light guide plate 310 upward. For this purpose, it is preferable that the reflective sheet 320 uses a plate having a high light reflectivity.

The diffusion sheet 330 scatters and diffuses the light supplied by the light guide plate 310, and the freeze sheet 340 concentrates the light diffused through the diffusion sheet 330 to improve luminance. Here, the diffusion sheet 330 and the prism sheet 340 are composed of two or more sheets in accordance with the characteristics of the liquid crystal display device.

The backlight assembly 300 is accommodated in the mold frame 400 and fixed. The mold frame 400 accommodates the liquid crystal display panel 100 on the upper side of the backlight assembly 300 after the backlight assembly 300 is received. The mold frame 400 accommodates the liquid crystal display panel 100 and the backlight assembly 300 to protect them from external shocks and to prevent flow, thereby preventing the liquid crystal display panel 100 and the backlight assembly 300 from being damaged.

The window 600 is formed above the liquid crystal display panel 100 and attached to the mold frame 400 using the adhesive member 500. Here, the window 600 is formed of a transparent material so that the image of the liquid crystal display panel 100 can be seen from the outside. In addition, the window 600 may be thinly formed to reduce the overall thickness of the liquid crystal display.

The window 600 is inflated by temperature, and the bottom surface 620 is expanded than the top surface 610 by the adhesive member 500 attached to the outer edge of the window 600 when the window 600 is inflated. The inflated window 600 contacts the upper surface of the liquid crystal display panel 100 to generate poor torsion when an image is displayed on the liquid crystal display panel 100. Therefore, the window 600 should have a relatively high expansion rate when the upper surface 610 is lower than the lower surface 620.

The upper surface 610 and the lower surface 620 of the window 600 are formed of materials having different expansion ratios. In addition, as shown in FIG. 3, the upper surface 610 is formed of a material having a relatively high expansion ratio as compared to the lower surface 620, so that the window is expanded to the upper side of the window 600 when inflated. Here, the window 600 is formed by bonding the upper surface 610 and the lower surface 620 formed separately to each other through the adhesive 615. At this time, the adhesive 615 is preferably formed so that the upper surface 610 and the lower surface 620 do not fall apart from each other due to expansion.

In addition, the window 600 may be formed by forming the upper surface 610 and the lower surface 620 made of a material having a different expansion ratio and compressed at high pressure.

Meanwhile, the window 600 may be formed of an upper surface 610 and a lower surface 620 integrally formed of materials having different expansion rates. For example, the window 600 is injection molded such that the upper surface 610 and the lower surface 620 are integrally formed of a material having a high expansion rate and a low expansion rate. Here, the window 600 is formed of a material forming the upper surface 610 and the lower surface 620 uniformly, the window 600 should be uniformly inflated.

The window 600 protects the liquid crystal display panel 100 from an external impact and blocks the inflow of foreign matters, thereby preventing the liquid crystal display panel 100 from being damaged and the display failure caused by the foreign matters. Therefore, the window 600 is formed to be at least as large as or larger than the liquid crystal display panel 100.

The adhesive member 500 is attached to the edge of the lower surface 620 of the window 600, the upper surface of the mold frame 400, and the upper portion of the non-display area of the liquid crystal display panel 100. Herein, the adhesive member 500 may have a weak adhesive force between the lower surface 620 and the mold frame 400 and the upper surface of the liquid crystal display panel 100 as the window 600 expands. Therefore, the adhesive member 500 may be formed of a material that maintains adhesion between the window 600 and the mold frame 400 even when the window 600 is inflated.

As described above, the liquid crystal display according to the present invention prevents the window from contacting the liquid crystal display panel by forming a thin window with a material having different expansion ratios for use in a slim mobile phone. Accordingly, the liquid crystal display prevents poor torsion caused by the window being expanded at a high temperature and the window contacting the liquid crystal display panel.

While the present invention described above has been described with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the technical field described in the claims to be described later and It will be appreciated that various modifications and variations can be made in the present invention without departing from the 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 (6)

A liquid crystal display panel which displays an image; A mold frame accommodating the liquid crystal display panel; And And a window disposed on the upper side of the liquid crystal display panel and having upper and lower surfaces formed of materials having different expansion ratios. The method of claim 1, The upper surface of the window is a liquid crystal display device characterized in that the expansion coefficient is formed relatively higher than the lower surface. The method of claim 2, An upper surface and a lower surface of the window are formed to be bonded to each other. The method of claim 3, wherein The window further comprises an adhesive for bonding the upper surface and the lower surface. The method of claim 2, An upper surface and a lower surface of the window are integrally formed. The method of claim 1, And the window is attached to the mold frame using an adhesive member.

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