KR101587093B1 - Liquid crystal display device - Google Patents

Abstract

The present invention relates to a direct-under type liquid crystal display device in which an LED assembly is arranged on the inner surface of a cover bottom, and in order to prevent damage to the flexible cable by the tab- .

The present invention prevents the flexible cable from being damaged by preventing the flexible cable located at the back face of the cover boot from coming into contact with the tab bar by embossing around the tabs protruding sharply toward the back face of the cover valve.

As a result, it is possible to prevent problems such as disconnection of the flexible cable, peeling of the cover and exposure of the electric wire to the outside, thereby preventing the driving operation failure of the liquid crystal panel or the damage of the circuit part.

LED assembly, tap hole, cover bottom, tab bar, liquid crystal display

Description

[0001] Liquid crystal display device [0002]

The present invention relates to a direct-under type liquid crystal display device in which an LED assembly is arranged on the inner surface of a cover bottom, and in order to prevent damage to the flexible cable by the tab- .

A liquid crystal display device (LCD), which is advantageous for moving picture display and has a large contrast ratio and is actively used in TVs and monitors, exhibits optical anisotropy and polarization properties of a liquid crystal, And the like.

Such a liquid crystal display device has a liquid crystal panel in which a liquid crystal panel is interposed between two adjacent substrates through a liquid crystal layer as an essential component and changes the alignment direction of the liquid crystal molecules in an electric field in the liquid crystal panel to realize a difference in transmittance do.

However, since the liquid crystal panel does not have its own light emitting element, a separate light source is required to display the difference in transmittance as an image. To this end, a backlight having a light source is disposed on the back surface of the liquid crystal panel.

1 is a sectional view of a liquid crystal display module using a general LED as a light source.

As shown in the figure, a general liquid crystal display module includes a liquid crystal panel 10, a backlight unit 20, a support main body 30, a cover bottom 50, and a top cover 40.

The liquid crystal panel 10 is constituted by first and second substrates 12 and 14 which are in contact with each other with a liquid crystal layer interposed therebetween, which plays a key role in image display.

The backlight unit 20 is provided behind the liquid crystal panel 10.

The backlight unit 20 includes a reflective plate 22, an LED assembly 28 and an optical sheet 26. At this time, a plurality of LEDs 24 are mounted on an LED PCB (printed circuit board) A plurality of LED assemblies 28 mounted on the cover bottom 50 are arranged along the inner surface of the cover bottom 50.

A reflective plate 22 of white or silver that covers the entire inner surface of the cover bottom 50 is seated and an optical sheet 26 is disposed on the upper portion of the plurality of LEDs 24.

The liquid crystal panel 10 and the backlight unit 20 are covered with a top cover 40 covering the upper edge of the liquid crystal panel 10 in a state where the edge is surrounded by the support main 30 having a rectangular frame shape, The cover bottoms 50 are integrally joined to each other at front and rear sides.

Although not shown in the drawing, a control printed circuit board or the like for controlling the gate and data printed circuit boards and the gate and data printed circuit boards is located on the backside of the cover bottom 50, and each of these printed circuit boards has a flexible And are electrically connected to each other via a flexible flat cable.

The LED assembly 28 is assembled through a fastening member (not shown) on the inner surface of the cover bottom 50. To this end, the inner surface of the cover bottom 50 is provided with a tapped hole (not shown) tab holes are formed.

2, the inner surface of the cover bottom 50 is formed with a tapped hole 53 through which the fastening member 60 passes, and a plurality of LED assemblies 50 are arranged along the inner surface of the cover bottom 50, A screw hole 22a corresponding to the tapped hole 53 formed in the cover bottom 50 is formed on the PCB 22 of the PCB 28. [

The cover bottom 50 and the LED assembly 28 are formed by inserting the fastening member 60 through the screw hole 22a formed in the PCB 22 and the tapped hole 53 formed on the inner surface of the cover bottom 50 And assembled.

However, the LED assembly 28 and the cover bottom 50 have a disadvantage in that a tab burr 55 is formed on the back surface of the cover bottom 50.

The tab bar 55 protrudes sharply toward the back surface of the cover bottom 50 in the process of forming the tab hole 53 on the inner surface of the cover bottom 55 and is formed when the tab hole 53 is formed.

Some of these tabs 55 can be removed but can not be completely removed.

Accordingly, a flexible cable (not shown) for electrically connecting a plurality of printed circuit boards (not shown) mounted on the back surface of the cover bottom 50 is damaged by the sharply projecting tab bar 55, A cable (not shown) is disconnected or the cover is peeled off, thereby causing a fatal problem such as electric wire being exposed to the outside.

As a result, a driving operation failure of the liquid crystal panel (10 of FIG. 1) may occur or a circuit portion (not shown) may be damaged.

In order to prevent the flexible cable (not shown) from being damaged by attaching an adhesive tape (not shown) or the like to the tab bar 55 protruding from the back surface of the cover bottom 50, Which is a waste of manpower and time.

SUMMARY OF THE INVENTION It is a first object of the present invention to prevent a flexible cable, which is a signal transmission connection member connecting between circuit boards, from being damaged on the back face of a cover disc.

It is a second object of the present invention to prevent a driving operation failure of the liquid crystal panel or a circuit part from being damaged.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a liquid crystal panel; A backlight unit located at a lower portion of the liquid crystal panel, the backlight unit including a reflective plate, a plurality of optical sheets, and a plurality of LED assemblies; A tab burr is formed on the inner surface of the plate shape to protrude to the back face of the cover fall to mount the plurality of LED assemblies through the fastening member and the first emboss embo) is formed; A support main body having a rectangular frame shape which surrounds the backlight unit and the edge of the liquid crystal panel and is assembled with the cover bottom; A top cover which is assembled with the cover bottom and the support main body and covers the top edge of the liquid crystal panel; A plurality of circuit boards mounted on a back surface of the cover bottom; And a signal transmission connection member disposed along the back face of the cover bottom to electrically connect the plurality of circuit boards, wherein the first emboss is provided with a liquid crystal display device that protrudes more than the tab bar with respect to the bottom face of the cover bottom do.

The plurality of LED assemblies include a PCB having a screw hole corresponding to the tapped hole and a plurality of LEDs, and a second emboss on the periphery of the tab bar, wherein the first emboss and the second emboss have a length of 14 to 20 mm Respectively.

The first and second embosses are 0.5 times higher than the height of the tab bar. The first and second embosses have a columnar surface protruding in a vertical direction from a bottom surface of the cover bottom, As shown in Fig.

Here, the signal transmission connection member is a flexible flat cable, and is composed of a plurality of conductors insulated and separated from each other through a cable holder made of an insulator such as rubber or silicone, And a data printed circuit board, a control printed circuit board, an analog / digital (A / D) board (not shown), a power board, and a backlight driver circuit.

In addition, the fastening member may be a screw composed of a shaft formed with a thread engaging with the thread and a head provided at an end of the shaft.

As described above, according to the present invention, there is an effect of preventing the flexible cable from being damaged by the tab bar by forming the embossment around the tab bar which is sharply projected with the cover fall back surface.

As a result, it is possible to prevent problems such as disconnection of the flexible cable, peeling off of the cover, and exposure of the electric wire to the outside, thereby preventing defective driving of the liquid crystal panel or damage to the circuit part.

In addition, there is an effect that the efficiency of the process can be improved by omitting the step of attaching the adhesive tape or the like to the tabs protruding from the back face of the cover disc.

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

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

1, the liquid crystal display includes a liquid crystal panel 110, a backlight unit 120, a support main body 130 for modularizing the liquid crystal panel 110 and the backlight unit 120, a cover bottom 150, (140).

The liquid crystal panel 110 is a part that plays a key role in image display and includes a first substrate 112 and a second substrate 114 which are bonded to each other with a liquid crystal layer interposed therebetween, .

At this time, a plurality of gate lines and data lines intersect with each other on the inner surface of the first substrate 112, which is usually referred to as a lower substrate or an array substrate, although pixels are not shown in the figure, A thin film transistor (TFT) is provided at each of the intersections of the pixels and is connected in a one-to-one correspondence with the transparent pixel electrodes formed in the pixels.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, a color filter of red (R), green (G), and blue (B) And a black matrix for covering non-display elements such as a gate line, a data line, and a thin film transistor. In addition, a transparent common electrode covering these elements is provided.

A polarizing plate (not shown) for selectively transmitting only specific light is attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A printed circuit board 118 is connected to at least one edge of the liquid crystal panel 110 via a flexible circuit board or a connection member 116 such as a tape carrier package (TCP) To the side of the cover 130 or the backside of the cover bottom 150, as shown in FIG.

When the thin film transistor selected for each gate line is turned on by the on / off signal of the gate driving circuit, the liquid crystal panel 110 transmits the signal voltage of the data driving circuit to the corresponding pixel electrode through the data line, The alignment direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode, resulting in a difference in transmittance.

In addition, the liquid crystal display device according to the present invention is provided with a backlight unit 120 for supplying light from the rear surface of the liquid crystal display panel so that the difference in transmittance of the liquid crystal panel 110 is externally expressed.

The backlight unit 120 includes a white or silver reflector 122, a plurality of LED assemblies 128, a transparent window 125 interposed over the plurality of LED assemblies 128, and an optical sheet 126.

Here, the plurality of LED assemblies 128 are arranged to have a uniform spacing along the longitudinal inner surface of the cover bottom 150 to emit light toward the liquid crystal panel 110, Each of the assemblies 128 includes a PCB 122 and a plurality of LEDs 124 mounted spaced apart on the PCB 122.

At this time, the plurality of LEDs 124 emit light having red (R), green (G), and blue (B) colors toward the front of the liquid crystal panel 110, By lighting all at once, white light by color mixing can be realized.

On the other hand, it is possible to use LEDs 124 (all not shown) that emit RGB colors so that white light is realized in each LED 124, or white light is emitted, LED 124 may also be used.

A plurality of LEDs 124 emitting light of RGB may be bundled into one cluster and a plurality of LEDs 124 mounted on the PCB 122 may be arrayed on the PCB 122 in a row It is also possible to arrange them in parallel or in a plurality of rows.

At this time, the PCB 122 uses a metal printed circuit board formed of a metal having high thermal conductivity such as aluminum (Al) or copper (Cu) because the high temperature To dissipate heat quickly to the outside.

The plurality of LED assemblies 128 are fastened to the inner surface of the cover bottom 150 through fastening members 160.

A plurality of tapped holes 153 are formed on the inner surface of the cover bottom for assembling the plurality of LED assemblies 128 through the fastening members 160.

The reflector 122 includes a plurality of through holes 122a through which the LEDs 124 of the plurality of LED assemblies 128 can pass so that the PCB 122 and the cover 122, And is seated on the cover bottom 150 to cover the entire inner surface of the bottoms 150.

Accordingly, some light emitted toward the back surface of the LED assembly 128 is reflected toward the liquid crystal panel 110, thereby improving the luminance of the light.

A transparent window 125 having reflective dots 125a corresponding to the plurality of LEDs 124 is formed on the LED 124 exposed through the through hole 122a of the reflection plate 122, And an optical sheet 126 for uniformity of luminance is interposed therebetween.

In addition, the optical sheet 126 may include various functional sheets such as a diffusing sheet, a reflective polarizing film called a dual brightness enhancement film (DBEF) including at least one light-condensing sheet, and the like.

The diffusion sheet and the at least one light condensing sheet diffuse or condense the light passing through the transparent window 125 to allow a more uniform surface light source to be incident on the liquid crystal panel 110.

The liquid crystal panel 110 and the backlight unit 120 are modularized through a top cover 140, a support main 130 and a cover bottom 150. The top cover 140 is disposed on the upper surface and the side surface of the liquid crystal panel 110, The top cover 140 is opened so that an image formed on the liquid crystal panel 110 is displayed.

In addition, the cover bottom 150, on which the liquid crystal panel 110 and the backlight unit 120 are mounted and which is the basis for assembling the entire structure of the liquid crystal display device, serves as a bottom case. To this end, And a pair of side supports 170 each having a bar shape are coupled to the other two edges except for these to form a predetermined space therein.

The backside of the cover bottom 150 may include a control printed circuit board and an analog / digital (A / D) board (not shown) for controlling the gate and data printed circuit boards and the gate and data printed circuit boards A system board 140 on which a power board, a backlight driver circuit, and the like are mounted, and the like, are mounted on a printed circuit board and a system board are electrically connected to each other through a flexible flat cable Lt; / RTI >

A support main body 130 having a rectangular frame shape and mounted on the cover bottom 150 and covering the edges of the liquid crystal panel 110 and the backlight unit 120 is coupled with the top cover 140 and the cover bottom 150 do.

The cover main body 130 may be referred to as a guide panel or a main support or a mold frame. The cover main body 130 may be referred to as a bottom cover or a bottom cover, I will.

The above-described structure is similar to a general liquid crystal display, but the present invention is characterized in that an emboss 200 protruding at a predetermined height from the backside of the cover bottom 150 is formed.

Accordingly, the liquid crystal display device of the present invention can prevent the flexible cable (not shown), which is a signal transmission connection member for connecting between the printed circuit boards (not shown), on the backside of the cover bottom 150, have. This will be described in more detail with reference to FIG.

4 is a perspective view schematically showing the back surface of the cover bottom.

As shown in the figure, a plurality of tabbars 155 are formed on the back surface of the cover bottom 150. Here, the tab burrs 155 fasten the cover bottom 150 and the plurality of LED assemblies 128 And is formed by protruding sharply toward the back surface of the cover bottom 150.

More specifically, a plurality of taps (153 in FIG. 3) are formed on the inner surface of the cover bottom 150 in order to assemble and fasten the plurality of LED assemblies (128 in FIG. 3) through the fastening members (160 in FIG. 3) In the process of forming a plurality of taps (153 in FIG. 3) on the inner surface of the cover bottom 150, a tab bar 155 is formed.

Accordingly, emboss 200 is formed around the tab bar 155 on the back surface of the cover bottom 150 of the present invention.

The concrete shape of the embossment 200 includes a columnar surface 200a projecting vertically from the backside of the cover bottom 150 and a horizontal surface 200b extending inwardly in the horizontal direction from the top of the columnar surface 200a.

The embossment (200) comprises one or both sides of the tab bar (155).

The embossment 200 serves to prevent a flexible cable (not shown) provided on the backside of the cover bottom 150 from contacting the tab bar 155, which is connected to the flexible cable In order to prevent damage.

FIG. 5A is a cross-sectional view schematically illustrating a state in which an LED assembly is mounted on an inner surface of a cover bottom, and FIG. 5B is a plan view schematically showing an emboss formed around a tab bar.

5A, an LED assembly 128 mounted on the PCB 122 is assembled to the inner surface of the cover bottom 150 through a fastening member 160. As shown in FIG.

A plurality of LED assemblies 128 arranged along the inner surface of the cover bottom 150 are formed on the inner surface of the cover bottom 150 to form a tab hole 153 into which the coupling member 160 can be inserted. A screw hole 125 corresponding to the tapped hole 153 formed in the cover bottom 150 is formed on the PCB 122 of the PCB 120.

The cover bottom 150 and the LED assembly 128 are inserted into the screw hole 125 formed in the PCB 122 by inserting the fastening member 160 through the tapped hole 153 formed on the inner surface of the cover bottom 150 So that they are assembled together.

Here, the fastening member 160 inserted into the screw hole 125 and the tap hole 153 includes a shaft 161 and a head 163 provided at an end of the shaft 161, similar to a general screw shape.

At this time, male threads corresponding to female threads (not shown) formed on the inner surface of the tapped hole 153 along the outer surface of the shaft 161 are formed. The screw 160 is inserted into the tapped hole 153 of the cover bottom 150 through the screw hole 125 of the PCB 122 from the end of the shaft 161.

A tab bar 155 is formed at a rear surface of the cover bottom 150 by a tapped hole 153 formed in an inner surface of the cover bottom 150. The tab bottom 155 is formed with a cover bottom 150 And an embossment 200 protruding from the back surface is formed.

Here, the shape of the emboss 200 may be any shape protruding from the backside of the cover bottom 150, such as a shape of a substantially dome convexly protruding to a vertex of the highest height, And it is most preferable to have a configuration including a columnar surface 200a projecting in the vertical direction from the back surface and a horizontal surface 200b extending in the inner horizontal direction from the upper end of the columnar surface 200a.

 Through the embossment 200, a flexible cable (not shown) provided on the back surface of the cover bottom 150 is prevented from being damaged by contact with the tab bar 155.

Although not shown in the drawing, the backside of the cover bottom 150 includes a control printed circuit board for controlling the gate and data printed circuit boards, the gate and data printed circuit boards, and the analog / digital (A / D) A system board on which a board (not shown), a power board, and a backlight driving circuit are mounted, and the like. Each of the printed circuit boards and the system board includes a flexible flat cable 170 And are electrically connected to each other through the connection terminal.

The flexible cable 170 includes a cable holder (not shown) made of an insulator such as rubber or silicone and a plurality of leads (not shown) isolated from each other. (Not shown) is very vulnerable to sharp materials.

The flexible cable 170 may be damaged if the flexible cable 170 is broken or the flexible cable 170 may be damaged when the flexible cable 170 is damaged. The coating is peeled off and the wire is exposed to the outside.

As a result, a driving operation failure of the liquid crystal panel (110 in FIG. 3) may occur, or the circuit part may be damaged.

However, the embossment 200 is formed around the tab bar 155 that protrudes sharply at the backside of the cover bottom 150 so that the flexible cable 170 is not in contact with the tab bar 155, 170 are prevented from being damaged.

The height h1 of the embossment 200 is preferably about 0.5 times higher than the height h2 of the tab bar 155 protruding from the backside of the cover bottom 150. For example, The embossment 200 is formed to have a height h1 of 1.8 to 2.1 mm, if the height h1 is 1.2 to 1.4 mm.

As a result, the flexible cable 170 provided on the back surface of the cover bottom 150 does not come into direct contact with the tab bar 155.

5B, it is preferable that the horizontal plane 200b of the embossment 200 has an area equal to or greater than a predetermined value. For example, the length d1 and the length d2 are 7 mm and 3 mm, respectively, . As a result, the flexible cable 170 can be prevented from sagging by widening the contact area between the horizontal surface 200b of the embossment 200 and the flexible cable 170.

By preventing the flexible cable 170 from sagging in this way, the flexible cable 170 is prevented from touching and being damaged by the tab bar 155.

The flexible cable 170 is prevented from moving to the tab bar 155 even if the central portion of the emboss 200 is slightly shifted from the central portion of the tab bar 155 by making the horizontal surface 200b of the emboss 200 more than a certain area. Can be prevented.

It is more preferable that at least two embossers 200 are provided in the periphery of the tab bar 155 to prevent the flexible cable 170 from sagging. At this time, it is preferable that the interval D between the embossments 200 is at least 14 to 20 mm.

As described above, by forming the embossment 200 around the tab bar 155 that protrudes sharply at the back surface of the cover bottom 150, by preventing the flexible cable 170 from contacting the tab bar 155, Thereby preventing damage to the magnetic tape 170.

This makes it possible to prevent problems such as disconnection of the flexible cable 170 or peeling off of the cover to expose the electric wire to the outside. As a result, the driving operation of the liquid crystal panel (110 of FIG. 3) Thereby preventing damage.

In addition, by omitting the step of attaching an adhesive tape (not shown) or the like to the tabs 155 protruding from the back surface of the cover bottom 150, the efficiency of the process can be improved.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

1 is a sectional view of a liquid crystal display module using a general LED as a light source.

2 is a cross-sectional view schematically showing a tab bar formed on a back face of a cover valve.

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

4 is a perspective view schematically showing the back surface of the cover bottom.

5A is a cross-sectional view schematically showing a state in which an LED assembly is mounted on an inner surface of a cover bottom.

5B is a plan view schematically showing the emboss formed around the tab bar.

Claims (8)

A liquid crystal panel; A backlight unit located at a lower portion of the liquid crystal panel, the backlight unit including a reflective plate, a plurality of optical sheets, and a plurality of LED assemblies; A tab burr formed on an inner surface of the plate-shaped inner surface for mounting the plurality of LED assemblies through a fastening member and protruding from the back surface, the tab bur being spaced apart from the tab on the first side of the tab, A cover bottom having a protruding first emboss; A support main body having a rectangular frame shape which surrounds the backlight unit and the edge of the liquid crystal panel and is assembled with the cover bottom; A top cover which is assembled with the cover bottom and the support main body and covers the top edge of the liquid crystal panel; A plurality of circuit boards mounted on a back surface of the cover bottom; And a plurality of signal connection connecting members disposed along the back face of the cover valve and electrically connecting the plurality of circuit boards, Wherein the first embossment protrudes more than the tab bar on the inner surface of the cover bottom. The method according to claim 1, Wherein the plurality of LED assemblies comprise a PCB having a screw hole corresponding to the tapped hole and a plurality of LEDs. The method according to claim 1, And a second embossed portion that is spaced apart from the tab bar and protruded to the back surface, the second embossed portion being opposite to the first side of the tab bar, wherein the first embossed portion and the second embossed portion have a gap of 14 to 20 mm, Device. The method of claim 3, The height of the first and second embossments is 0.5 times larger than the height of the tab bar. The method of claim 3, Wherein the first and second embossments are composed of a columnar surface protruding in a vertical direction from a backside of the cover bottom and a horizontal plane extending in an inner horizontal direction from an upper end of the columnar surface. The method according to claim 1, Wherein the signal transmission connection member is a flexible flat cable and is composed of a plurality of leads separated from each other through a cable holder made of an insulator such as rubber or silicone. The method according to claim 1, The plurality of circuit boards are system boards having gate and data printed circuit boards, a control printed circuit board, an analog / digital (A / D) board, a power board, and a backlight driver circuit. The method according to claim 1, Wherein the fastening member is a screw comprising a shaft formed with a thread and a head provided at an end of the shaft.

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