KR101604138B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a liquid crystal display comprising a first cover bottom disposed under a light source and a second cover bottom remote from the light source relative to the first cover bottom. The first cover bottom has a higher thermal conductivity than the second cover bottom.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a liquid crystal display device including a backlight unit.

BACKGROUND ART [0002] Liquid crystal display devices are becoming increasingly widespread due to features such as light weight, thinness, and low power consumption driving. This liquid crystal display device is used as a portable computer such as a notebook PC, an office automation device, an audio / video device, and an indoor / outdoor advertisement display device. A transmissive liquid crystal display device that occupies most of the liquid crystal display device controls an electric field applied to the liquid crystal layer to modulate light incident from the backlight unit to display an image.

The backlight unit is roughly divided into a direct type and an edge type. The edge type backlight unit has a structure in which a light source is disposed so as to face the side face of the light guide plate and a plurality of optical sheets are disposed between the liquid crystal display panel and the light guide plate. In the edge type backlight unit, the light source irradiates light to one side of the light guide plate, and the light guide plate converts the linear light source or point light source into a planar light source. The direct-type backlight unit has a structure in which a plurality of light sources are disposed under the liquid crystal display panel.

Recently, a light emitting diode (hereinafter referred to as "LED") has been spotlighted as a light source of a backlight unit. The higher the temperature, the lower the efficiency and lifetime of the LED. Therefore, various heat dissipation designs are applied to the LED package.

In order to increase the heat dissipation effect of the LED, the heat conduction flow to the peripheral parts of the LED should be desirable. For this purpose, it may be considered to fabricate a cover bottom around the LED with a material having a high thermal conductivity, but the strength may be lowered.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in an effort to solve the problems of the prior art, and it is an object of the present invention to provide a liquid crystal display device which enhances thermal conductivity and reinforce strength of a cover bottom disposed around a light source.

To achieve the above object, a liquid crystal display device of the present invention includes: a liquid crystal display panel; A backlight unit including a light source for emitting light to the liquid crystal display panel; And a cover bottom disposed under the backlight unit.

The cover bottom includes a first cover bottom disposed under the light source and a second cover bottom spaced apart from the light source relative to the first cover bottom.

The first cover bottom has a higher thermal conductivity than the second cover bottom.

Wherein one of the first and second cover bottoms includes one or more protruding bars and the other includes a hole into which the protruding bar is inserted so that the first and second cover bottoms are coupled by the engagement of the protruding bar and the hole.

In the present invention, the cover bottom is divided into a light source cover bottom and a non-light source cover bottom so that the light source cover bottom is made of a material with high thermal conductivity and the non-light source cover bottom is made of a high strength material. In addition, the present invention minimizes the number of additional screws required to join the separate cover bottoms by fastening the light source cover bottom and the non-light source cover bottom with a relatively wide projecting bar and hole coupling. Therefore, the present invention can enhance the thermal conductivity and reinforce the thermal conductivity of the cover bottom disposed around the light source, and can easily and firmly fasten the separated cover bottoms.

A manufacturing method of a liquid crystal display device of the present invention is a manufacturing method of a liquid crystal display device including a step of cleaning a substrate of a liquid crystal display panel, a step of patterning a substrate, an alignment film forming / rubbing step, a step of adhering a substrate and dropping a liquid crystal, a driving circuit mounting step, And the like.

The substrate cleaning process removes impurities from the upper glass substrate and the lower glass substrate surface of the liquid crystal display panel with a cleaning liquid. The substrate patterning process includes the steps of forming and patterning various thin film materials such as signal lines, data lines and gate lines, thin film transistors (TFT), and pixel electrodes on a lower glass substrate, , A color filter, and a common electrode, and patterning the thin film material. In the alignment film forming / rubbing process, an alignment film is applied on glass substrates and the alignment film is rubbed with a rubbing film or optically aligned. Through the series of processes, the lower glass substrate of the liquid crystal display panel is provided with data lines to which video data voltages are supplied, gate lines that intersect the data lines and are supplied with scan signals, that is, gate pulses sequentially, TFTs formed at the intersections of the gate lines, pixels including the pixel electrodes of the liquid crystal cell connected to the TFTs at 1: 1, storage capacitors, and the like and a TFT array are formed. The shift register of the gate drive circuit for generating the scan signal can be formed simultaneously with the pixel and the TFT array in the substrate patterning process. A black matrix, a color filter, a common electrode, and the like are formed on the upper glass substrate of the liquid crystal display panel. The common electrode is formed on the upper glass substrate in a vertical electric field driving method such as a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode, and a horizontal electric field such as IPS (In Plane Switching) mode and FFS (Fringe Field Switching) Is formed on the lower glass substrate together with the pixel electrode in the driving method. A polarizing plate and a polarizing plate protective film are attached to the upper glass substrate and the lower glass substrate, respectively.

The substrate coalescence and liquid crystal dropping process draws a sealant on one of the upper and lower glass substrates of the liquid crystal display panel and drops the liquid crystal on another substrate. For example, when a liquid crystal is dropped on a lower glass substrate, an ultraviolet curable sealant is formed on the upper glass substrate in a vacuum chamber, the upper glass substrate on which the sealant is formed is inverted and fixed on the upper stage, And the lower glass substrate is fixed to the lower stage. Subsequently, after the upper glass substrate and the lower glass substrate are aligned, a vacuum pump is driven to apply pressure to any one of the upper and lower glass substrates while adjusting the pressure of the vacuum chamber to a vacuum pressure The upper glass substrate and the lower glass substrate are bonded together. At this time, the cell gap of the liquid crystal layer is larger than the designed cell gap. When the pressure of the vacuum chamber is adjusted to atmospheric pressure by injecting nitrogen (N ₂ ) into the vacuum chamber, the cell gap of the liquid crystal display panel is adjusted to the cell gap of the liquid crystal display panel by the pressure difference between the glass substrates and the vacuum chamber. When the ultraviolet light source is irradiated to the ultraviolet curable sealant through the upper glass substrate or the lower glass substrate of the liquid crystal display panel in a state where the cell gap is adjusted to the designed value, the sealant is cured.

In the driving circuit mounting process, an integrated circuit (IC) of a data driving circuit is mounted on a lower glass substrate of a liquid crystal display panel by using a COG (Chip On Glass) process or a TAB (Tape Automated Bonding) process. The gate driving circuit may be formed directly on the lower glass substrate of the liquid crystal display panel as described above, or may be attached on the lower glass substrate by the TAB process in the driving circuit mounting process. Subsequently, the driving circuit mounting process connects an integrated circuit (IC) and a printed circuit board (PCB) with a flexible printed circuit board (FPC) or a flexible flat cable (FFC).

The assembling process of the backlight unit connects the wiring to the light source and connects it to the light source driving circuit. The light source may include one or more light sources such as LEDs, cold cathode fluorescent lamps (CCFLs), and lamps such as an External Electrode Fluorescent Lamp (EEFL).

The assembling process of the liquid crystal module is performed by using a guide panel, a support main, a cover bottom, a case top, and the like to mount the liquid crystal display panel and the backlight unit, Assemble by module.

A method of manufacturing a liquid crystal display device according to an embodiment of the present invention may further include an inspection step and a re-peeling step.

The inspection process includes an inspection for an integrated circuit, a signal wiring such as a data line and a gate line formed on a lower glass substrate, an electrical inspection for detecting defects of a TFT and a pixel electrode, an electrical inspection performed after a substrate adhesion and liquid crystal dropping process, And a lighting inspection for detecting defective of the liquid crystal module by lighting the backlight unit of the liquid crystal module. The repair process repairs signal wiring defects and TFT defects that are determined to be repairable by the inspection process.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like reference numerals throughout the specification denote substantially identical components. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Referring to Fig. 1, the liquid crystal display of the present invention includes a liquid crystal display panel 12, and an edge type backlight unit disposed under the liquid crystal display panel 12.

In the liquid crystal display panel 12, a liquid crystal layer is formed between the upper glass substrate and the lower glass substrate as described above, and any liquid crystal mode can be implemented.

The edge type backlight unit includes a light source 15, a light guide plate 16 and a plurality of optical sheets 14 so that light from the light source 15 passes through the light guide plate 16 and the optical sheets 14, Converts the light into a light source, and irradiates the liquid crystal display panel 12 with light. The light source 15 irradiates light to the side surface of the light guide plate 16 in correspondence with at least one side surface of the light guide plate 16. The optical sheets 14 include at least one prism sheet and at least one diffusing sheet to diffuse the light incident from the light guide plate 14 and to transmit light at an angle substantially perpendicular to the light incident surface of the liquid crystal display panel 12 Refract the path of light. The optical sheets 14 may comprise a dual brightness enhancement film (DBEF).

Under the light source 15 and the light guide plate 16, cover bottoms 17A and 17B are disposed. The cover bottoms 17A and 17B include a first cover bottom 17A disposed in the vicinity of the PCB 15 on which the light source 15 and the light source 15 are mounted and a second cover bottom 17B disposed in a position relatively far from the light source 15. [ (17A). The first cover bottom 17A is a cover part of the light source cover close to the light source 15 and includes a material having a high thermal conductivity such that heat from the light source 15 can be reliably discharged to the outside. For example, the first cover bottom 17A may be made of an aluminum-based metal plate such as aluminum or aluminum nitride (AlN). The aluminum-based metal plate may be coated with a high conductivity material to promote heat transfer. The second cover bottom 17B is a non-light source cover bottom disposed at a relatively far position from the light source 12. The second cover bottom 17B may be a high strength steel plate such as an electro galvanized steel plate (EGI), stainless steel (SUS) Aluminum-plated steel sheet (aka ALCOSTA), tin-plated steel sheet (SPTE), and the like.

A guide panel (13) and a case top (11) are arranged at the edges of the liquid crystal display panel (12). The guide panel 13 is a rectangular mold frame in which glass fiber is mixed in a synthetic resin such as polycarbonate or the like, and surrounds the upper surface edge and the side surface of the liquid crystal display panel 12 and surrounds the side surface of the backlight unit. The guide panel 13 supports the liquid crystal display panel 12 and keeps the gap between the liquid crystal display panel 12 and the optical sheets 14 constant. The case top 11 is made of a metal material such as a galvanized steel sheet and has a structure to cover the upper and side surfaces of the guide panel 13 and is provided with hooks or the like on at least one of the guide panel 13 and the bottom covers 17A and 17B. And fixed with a screw.

The first and second cover bottoms 17A and 17B can be fastened with a joint structure of a protruding bar and a hole as shown in FIGS.

2 to 5, the first cover bottom 17A includes at least one protruding bar 21 protruding toward the second cover bottom 17B. The protruding bar 21 is bent down from the inner end of the first cover bottom 17A by the thickness of the first cover bottom 17A and extended parallel to the second cover bottom 17B. The second cover bottom 17B is provided with at least one hole 31 into which the protruding bar 21 of the first cover bottom 17A is inserted in a one-to-one relationship and a receiving portion 32 formed below the hole 31 .

The first and second cover bottoms 17A and 17B) are assembled as follows. The divided cover bottoms 17A and 17B are aligned so that the holes of the protruding bar 21 of the first cover bottom 17A and the holes of the second cover bottom 17B face each other and the first cover bottom 17A Is pushed toward the second cover bottom 17B like the slide fastening method. At this time, the protruding bar 21 of the first cover bottom 17A is inserted into the hole 31 of the second cover bottom 17B. The protruding bar 21 of the first cover bottom 17A is inserted into the hole 31 of the second cover bottom 17B to support the second cover bottom 17B from below and the protruding bar 21 of the second cover bottom 17B The support portion 32 supports the projecting bar 21 from below. Accordingly, the first and second cover bottoms 17A and 17B are engaged with each other due to the structure of the protrusion bar 21 and the hole 31. [ The positions of the projecting bar 21 and the hole 31 can be changed. For example, the protruding bar 21 is formed on the second cover bottom 17B, and the hole 31 and the receiving portion 32 may be formed on the first cover bottom 17A.

Further screws may be fastened to the first and second cover bottoms 17A, 17B. For example, as shown in Figs. 2 and 3, screw holes 23 and 33, which are opposed to each other at the left end and the right end of the first and second cover bottoms 17A and 17B, are formed, The screw 22 can be fastened. Since the first and second cover bottoms 17A and 17B are fastened to each other at the central portion thereof by the engagement structure of the protruding bar 21 and the hole 31, no separate screwing is required at the central portion thereof. As shown in Fig. 6, the protruding bar 21 can be fixed with the screw 61 in the state where the first and second cover bottoms 17A and 17B are fastened, but such a screw 61 is not essential. The screw 61 can fix the protruding bar 21 inserted in the hole 31 passing through any one of the first and second cover bottoms 17A and 17B. No welding is required in a state where the first and second cover bottoms 17A and 17B are fastened.

The first and second cover bottoms 17A and 17B are fastened by the engagement structure of the relatively large area protruding bar 21 and the hole 31 to widen the fastening area thereof. Even if the first cover bottom 17A undergoes bending deformation due to external force or heat due to such a fastening structure, deformation of the first cover bottom 17A is suppressed by the second cover bottom 17B so that the cover bottoms 17A, It is possible to maintain the strength and prevent deformation.

7 and 8 show the bottom cover structure of the liquid crystal display device in which the light sources 15 are disposed on both sides of the light guide plate 16. [

7 and 8, when the light sources 15 are disposed on the upper and lower sides or the left and right sides of the light guide plate 16, the first cover bottom 17A is disposed below each of the light sources 15, And is separated on both sides with the bottom 17B therebetween.

 The first cover bottom 17A is a light source cover bottom near the light source 15 and the PCB on which the light source 15 is mounted, and is made of a material having a high thermal conductivity. The second cover bottom 17B is a non-light source cover bottom at a relatively far central position from the light sources 15, and is made of a high-strength steel plate.

In the second embodiment shown in Figs. 7 and 8, the two first cover bottoms 17A and one second cover bottom 17A are fixed in substantially the same manner as in the first embodiment described above. The first cover bottoms 17A and the second cover bottom 17B are fastened by the fastening structure of the protruding bar 21 projecting with a relatively wide width and the hole 31 into which the protruding bar 21 is inserted.

As can be seen from FIGS. 7 and 8, the number of the first cover bottoms 17A may vary depending on the number and positions of the light sources 15. FIG. For example, if the light sources 15 are disposed opposite to the upper and lower sides of the light guide plate and the four sides of the left and right sides, the first cover bottom 17A is divided into four portions corresponding to the respective light sources 15. Therefore, it should be noted that the present invention is not limited to the above-described embodiments.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. 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.

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

Fig. 2 is a perspective view showing a state in which the divided cover bottoms are assembled. Fig.

3 is an exploded perspective view of the divided cover bottoms.

4 is a front perspective view showing an enlarged view of a fastening part of the divided cover bottoms.

5 is a rear perspective view showing an enlarged view of the fastening portion of the divided cover bottoms.

6 is a front perspective view showing an example in which a screw is coupled to the fastening portion of the divided cover bottoms.

7 is a perspective view showing an assembled state of the divided cover bottoms according to another embodiment of the present invention.

8 is a perspective view showing an assembled state of the cover bottoms shown in Fig.

Description of the Related Art

12: liquid crystal display panel 14: optical sheet

15: light source 16: light guide plate

17A, 17B: Cover bottom

Claims (8)

A liquid crystal display panel; A backlight unit including a light source for emitting light to the liquid crystal display panel; And And a cover bottom disposed under the backlight unit, Wherein the cover bottom comprises a first cover bottom disposed below the light source and a second cover bottom spaced apart from the light source relative to the first cover bottom, Wherein the first cover bottom has a higher thermal conductivity than the second cover bottom, Wherein one of the first and second cover bottoms includes one or more protruding bars and the other includes a hole into which the protruding bar is inserted so that the first and second cover bottoms are fastened by engagement of the protruding bar and the hole Wherein the liquid crystal display device is a liquid crystal display device. delete The method according to claim 1, And a cover bottom including the hole among the first and second cover bottoms further comprises a support portion for supporting the protruding bar from below. The method according to claim 1, Wherein the second cover bottom has a higher strength than the first cover bottom. The method according to claim 1, Wherein the first and second cover bottoms are coupled with each other by the engagement of the protruding bar and the hole at a central portion of the boundary, and both sides of the boundary are fastened with screws. The method according to claim 1, And the protruding bar inserted in the hole is fixed by a screw passing through any one of the first and second cover bottoms. The method according to claim 1, The backlight unit includes: And a light guide plate for converting the light from the light source into a surface light source, Wherein the light source faces at least one side of the light guide plate. 8. The method of claim 7, The light sources are opposed to two or more sides of the light guide plate, Wherein the first cover bottom is divided into two or more portions with the second cover bottom interposed therebetween so as to be disposed below each of the light sources.

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