KR101748694B1 - Liquid crystal display device - Google Patents

Abstract

The liquid crystal display element of the present invention is for preventing a wire connecting a backlight LED to an external driving element from being leaked due to an external impact or the like, and includes a liquid crystal panel for realizing an image; A backlight unit including an LED substrate on which a plurality of LEDs (Light Emitting Device) are mounted, the backlight unit being disposed below the liquid crystal panel and supplying light to the liquid crystal panel; A wire connecting an external driving element and the LED substrate; A guide panel for supporting the liquid crystal panel; A lower cover coupled to the guide panel to assemble the liquid crystal panel and the backlight; A fixing part formed along a side wall of the lower cover or the guide panel to form a groove into which the wire is inserted; And at least one pad for hooking and coupling a wire fixed to at least one of the side wall and the fixing portion of the lower cover or the guide panel.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED backlight and a liquid crystal display device having the same, and more particularly, to an LED backlight and a liquid crystal display device having the same that can prevent defective wiring from being connected to an LED.

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. Therefore, in a liquid crystal display element, a back light, which is a light source that transmits the liquid crystal layer for displaying an image, is provided. Generally, the backlight can be roughly divided into two types.

The first is a side-view backlight that is installed on the side of the liquid crystal panel to provide light to the liquid crystal layer, and the second is a direct-type backlight that provides light directly below the liquid crystal panel.

The side-type backlight is provided on the side surface of the liquid crystal panel and can supply light to the liquid crystal layer through the reflection plate and the light guide plate. Therefore, since the thickness can be made thinner, it is mainly used for a notebook or the like requiring a thin display device. However, the side-type backlight is difficult to apply to a large-area liquid crystal panel because the lamp that emits light is located on the side surface of the liquid crystal panel, and light is supplied through the light guide plate. Therefore, there has been a problem in that it is not suitable for large-area liquid crystal panel for LCD TV, which has recently been spotlighted.

The direct-type backlight is mainly used to fabricate a liquid crystal panel for LCD TV since light emitted from a lamp is directly supplied to the liquid crystal layer and thus can be applied to a large-area liquid crystal panel as well as a high luminance.

On the other hand, as a backlight lamp, a light source that emits light by itself such as a light emitting device instead of a fluorescent lamp is used. Since the light emitting device emits R, G, and B monochromatic light, the color reproduction ratio is good when applied to a backlight and the driving power can be reduced.

FIG. 1 is an exploded perspective view showing a structure of a conventional liquid crystal display device having a backlight including the LED as described above, and FIG. 2 is a sectional view of a liquid crystal display device in which a backlight and a liquid crystal panel are assembled.

 As shown in FIGS. 1 and 2, the liquid crystal display device includes a first substrate 1 and a second substrate 3, and a liquid crystal layer (not shown) between the first substrate 1 and the second substrate 3, An LED substrate 32 mounted on the lower side surface of the liquid crystal panel 10 and having a plurality of LEDs 34 for emitting light and mounted on the lower surface of the liquid crystal panel 10; And a light guide plate 35 disposed between the liquid crystal panel 10 and the light guide plate 35 for guiding light emitted from the LED 34 to the liquid crystal panel 10, An optical sheet 38 composed of a diffusing sheet 38a and prism sheets 38b and 38c for diffusing and condensing the light supplied to the liquid crystal panel 10 and a light guide plate 35 disposed below the light guide plate 35, And the reflector 36, the light guide plate 35, the optical sheet 38, and the LED substrate 32 are accommodated A light guide plate 35 and an optical sheet 38 are assembled together with the lower cover 40 and the liquid crystal panel 10 is placed thereon, And a top cover 60 coupled with the guide panel 50 to assemble the liquid crystal panel 10.

The first substrate 1 of the liquid crystal panel 10 is a thin film transistor array substrate on which thin film transistors are formed. In addition to the thin film transistors, various wirings and pixel electrodes are formed on the first substrate 1. The second substrate 2 is a color filter substrate, and a color filter layer and a black matrix are formed.

The lower cover 40 assembles a backlight including a reflective layer 36, a light guide plate 35, an optical sheet 38, an LED 34, and the like. The wall surface extends upward from the bottom surface, The backlight is assembled by placing parts inside the wall surface. The upper cover 60 is assembled with the guide panel 50 and the lower cover 40 to assemble the backlight with the liquid crystal panel 10.

In the case of using a fluorescent lamp as a light source, in order to prevent light emitted from the fluorescent lamp from leaking to a place other than the light guide plate 35, a lamp housing made of metal is disposed on the side of the light guide plate, Was placed in the lamp housing. However, in the structure using the LED 34 as a light source, a reflection plate 36 is used instead of the expensive metal lamp housing for cost reduction.

1 and 2, the reflection plate 36 extends upwardly along the four sides of the light guide plate 35 as well as the lower side of the light guide plate 35, and faces the four sides of the light guide plate 35.

The LED substrate 32 is disposed on the rear surface of the reflection plate 36. Therefore, the front surface of the LED substrate 32, that is, the surface on which the LED 34 is mounted, is located on the rear surface of the reflector 36. [ At this time, a plurality of windows 36a are formed on the surface of the reflection plate 36 on the side where the LED substrate 32 is disposed, facing the light guide plate 35. [ The window 36a is aligned with the LED 34 mounted on the LED substrate 32 so that the LED 34 faces the side surface of the light guide plate 35 through the window 36a. In other words, the reflector 36 is located on the front surface of the LED substrate 32, and only the LED 34 protrudes through the window 36a to face the light guide plate 35.

A flexible circuit board 33a is attached to one end of the LED substrate 32 and a wire 33b is attached to an end of the flexible circuit board 33a. The flexible circuit board 33a and the wire 33b electrically connect the LED 34 mounted on the LED substrate 32 to the driving circuit portion of the liquid crystal display device so that a signal is applied from the driving circuit portion to the LED 34 . That is, the flexible circuit board 33a is attached to the end portion of the LED substrate 32 and folded along the inner side wall surface of the lower cover 40. The wire 33b is led out of the backlight through the lead- And supplies power from an external inverter to the LED 34. [

At this time, the wire 33b is fixed to the wall surface of the lower cover 40 and guided, and then drawn out to the outside through the draw-

1, a fixing portion 42 is formed on one side of the lower cover 40, that is, on the side of the side where the wire 33b is guided, to fix the wire 33b. The fixing portion 42 is formed from the end of the flexible circuit board 33a to the lead portion 44 and is formed with a groove spaced from the wall surface of the lower cover 40 by a predetermined distance, Is inserted and fixed.

3A shows a state in which the wire 33b is fixed by the fixing portion 42. In the figure, a groove 45 formed by the wall surface of the lower cover 40 and the fixing portion 42 is provided for convenience of explanation. As shown in Fig.

3A, the fixing portion 42 is formed to be spaced apart from the wall surface of the lower cover 40 by a predetermined distance to form a groove 45 having a predetermined width from the wall surface of the lower cover 40 . The width of the groove 45 is substantially equal to the diameter of the cylindrical wire 33b so that when the wire 33b is inserted into the groove 45, 33b are fixed.

However, in the case of the above structure, the following problems may occur. That is, since the width of the groove 45 is substantially similar to the diameter of the wire 33b, the wire 33b is normally fixed. However, when an impact or the like is applied from the outside, 45), and is discharged to the outside of the groove (45).

In order to prevent such a wire 33b from coming off, a protrusion 46 is formed in the groove 45 as shown in FIG. 3B, and further pressure is applied to the fixed wire 33b. In this case, The wire 33b can not be completely prevented from flowing out of the groove 45 due to an impact due to the fine flow of the wire 33b inside the groove 45. [

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal display element which is capable of preventing defects from occurring due to exiting of a wire fixed by a fixing portion due to an external impact or the like.

According to an aspect of the present invention, there is provided a liquid crystal display device comprising: a liquid crystal panel for implementing an image; A backlight unit including an LED substrate on which a plurality of LEDs (Light Emitting Device) are mounted, the backlight unit being disposed below the liquid crystal panel and supplying light to the liquid crystal panel; A wire connecting an external driving element and the LED substrate; A guide panel for supporting the liquid crystal panel; A lower cover coupled to the guide panel to assemble the liquid crystal panel and the backlight; A fixing part formed along a side wall of the lower cover or the guide panel to form a groove into which the wire is inserted; And at least one pad for hooking and coupling a wire fixed to at least one of the side wall and the fixing portion of the lower cover or the guide panel.

The pads are disposed integrally with at least one of the lower cover or the guide panel and at least one of the side walls and the fixing portion along the fixing portion, or a plurality of the pads are disposed along at least one of the side cover and the fixing portion of the lower cover or the guide panel along the fixing portion.

Also, the pads are arranged in a shape facing each other on the side wall and the fixing portion of the lower cover or the guide panel, or in a shape staggered with the side wall and the fixing portion of the lower cover or the guide panel.

According to the present invention, a pad is formed on the fixing portion, and a wire connecting an LED to an external driving element is hooked and coupled so that the wire flows due to an external impact or the like, thereby effectively preventing the wire from being detached from the fixing portion.

1 is an exploded perspective view showing the structure of a conventional liquid crystal display element;
2 is a cross-sectional view of a conventional liquid crystal display device.
Figs. 3A and 3B are diagrams showing that wires are fixed by a fixing portion in a conventional liquid crystal display element. Fig.
4 is an exploded perspective view showing a structure of a liquid crystal display element according to the present invention.
5A and 5B are cross-sectional views showing the structure of a liquid crystal display element according to the present invention.
6 is a view showing that a wire is fixed by a fixing portion in a liquid crystal display element according to the present invention.

Hereinafter, a backlight according to the present invention and a liquid crystal display device having the same will be described in detail with reference to the accompanying drawings.

4, 5A and 5B are views showing the structure of a liquid crystal display device according to the present invention, wherein FIG. 4 is an exploded perspective view, and FIGS. 5A and 5B are sectional views showing a combined structure. 5A and 5B are views of the liquid crystal display elements shown in FIG. 4 when they are viewed in a direction perpendicular to each other.

4, 5A and 5B, the liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal panel 110 and a backlight. The liquid crystal panel 110 includes a first substrate 101 and a second substrate 103, and a liquid crystal layer (not shown) between the first substrate 101 and the second substrate 103, and implements an image as a signal is applied from the outside.

The backlight includes an LED substrate 132 disposed on the lower side of the liquid crystal panel 110 and having a plurality of light emitting devices 134 mounted thereon for emitting light, A light guide plate 135 for guiding the light emitted from the light guide plate 134 to the liquid crystal panel 110 and supplying the light to the liquid crystal panel 110 and a light guide plate 135 provided between the liquid crystal panel 110 and the light guide plate 135, An optical sheet 138 composed of a diffusing sheet 138a and prism sheets 138b and 138c for diffusing and condensing the light supplied to the light guide plate 110 and guiding the light guide plate 35 below the light guide plate 35, And a reflection plate 136 for reflecting the light.

The reflection plate 136, the light guide plate 135 and the optical sheet 138 of the backlight are housed in the lower cover 140 and then assembled as the lower cover 140 and the guide panel 150 are coupled.

A liquid crystal panel (110) is placed on the guide panel (150). The guide panel 150 is formed in a rectangular shape so that an edge area of the liquid crystal panel 110 is placed on the guide panel 150.

An upper cover 160 is placed on an upper edge region of the liquid crystal panel 110. The upper cover 160 is coupled to the lower cover 140 and the guide panel 150 to allow the liquid crystal panel 110 and the backlight to be assembled Thereby completing the liquid crystal display element.

Though not shown in the figure, a plurality of gate lines and data lines are vertically and horizontally arranged on the first substrate 101 to define a plurality of pixel regions, and a thin film transistor serving as a switching element is formed in each pixel region A pixel electrode formed on the pixel region is formed. The thin film transistor includes a gate electrode connected to a gate line, a semiconductor layer formed by stacking amorphous silicon or the like on the gate electrode, and a source electrode and a drain electrode formed on the semiconductor layer and connected to the data line and the pixel electrode .

The second substrate 102 includes a color filter composed of a plurality of sub-color filters embodying colors of red (R), green (G) and blue (B) And a black matrix for blocking light passing through the liquid crystal layer.

The first substrate 101 and the second substrate 102 constituted as described above are adhered to each other by a sealant (not shown) formed on the periphery of the image display region to constitute a liquid crystal panel, and the first substrate 101 (Not shown) formed on the first substrate 101 or the second substrate 102. As shown in FIG.

Although not shown in the drawing, a first polarizer and a second polarizer are attached to the first substrate 101 and the second substrate 102, respectively, to polarize light input to and output from the liquid crystal panel 110, .

The light guide plate 135 guides the light input from the LED 134 to the liquid crystal panel 110. The light incident on one side of the light guide plate 135 is reflected by the upper surface and the lower surface of the light guide plate 135, And then outputted to the outside of the light guide plate 135. At this time, the light guide plate 135 is formed of a rectangular parallelepiped, and a pattern or a groove may be formed on the bottom surface thereof in order to scatter incident light.

The optical sheet 138 is supplied to the liquid crystal panel 110 by improving the efficiency of light output from the light guide plate 135. The optical sheet 138 includes a diffusion sheet 138a for diffusing the light output from the light guide plate 138 and a first diffusion sheet 138a for condensing light diffused by the diffusion sheet to supply uniform light to the liquid crystal panel 110. [ A prism sheet 138b and a second prism sheet 138c. At this time, the diffusion sheet 138a is provided with one sheet, but the prism sheet includes a first prism sheet 138b and a second prism sheet 138c in which the prism crosses vertically in the x-, y- The light is refracted in the axial direction to improve the linearity of the light.

As the LED 134, R, G, B LEDs emitting white light of R (Red), G (Green) and B (Blue), or LED devices emitting white light may be used.

When monochromatic LEDs emitting monochromatic light are arranged, monochromatic LEDs of R, G, and B are alternately arranged at regular intervals to mix monochromatic light emitted from the LEDs into white light and then to the liquid crystal panel 110, A plurality of LED elements are arranged at regular intervals to supply white light to the liquid crystal panel 110. [

The white light LED device comprises a blue LED that emits blue light and a phosphor that emits yellow light by absorbing blue monochromatic light. The blue monochromatic light output from the blue LED and the yellow monochromatic light emitted from the phosphor are mixed to form a liquid crystal And is supplied to the panel 110. Although the LED 134 is disposed on one side of the light guide plate 135 in the drawing, the LED 134 may be disposed on both sides of the light plate 135.

The LED 134 is mounted on an LED substrate 132 made of a metal or a flexible film. The LED substrate 132 is disposed along the side surface of the light guide plate 135 and faces a side surface of the light guide plate 135. An LED 134 is mounted on the LED substrate 132, The light from the LED 134 is incident on the light guide plate 135. [

A flexible circuit board 133a is attached to an end of the LED substrate 132 and a wire 133b is attached to an end of the flexible circuit board 133a. The flexible circuit board 133a and the wire 133b are connected to a driving circuit portion outside the liquid crystal display device so that the LED 134 mounted on the LED substrate 132 is connected to the driving circuit portion of the liquid crystal display device, The LED controller drives the LED 134 according to the input signal. A signal wiring is formed on the upper surface and / or the lower surface of the flexible circuit board 133a and the signal wiring is electrically connected to the wire 133b so that the signal of the driving circuit portion is transmitted to the wire 133b and the signal of the flexible circuit board 133a And is input to the LED substrate 132 through the wiring.

The guide panel 150 is coupled to the lower cover 140 in such a manner that the upper surface thereof surrounds the edge of the optical sheet 138 of the liquid crystal panel 110 and the side surface of the lower cover 140. A liquid crystal panel 110 is mounted on the upper surface of the guide panel 150 and an outer cover 160 of the liquid crystal panel 110 is covered with the liquid crystal panel 110 to form a backlight.

The lower cover 140 includes a reflective layer 136, a light guide plate 135, and a light guide plate 135. The lower cover 140 includes a bottom surface positioned below the reflection plate 136, a side surface of the light guide plate 135 and a rear surface of the LED substrate 132, The optical sheet 138, and the like are accommodated and the backlight is assembled. An external driver 160 is provided outside the lower cover 140 to apply a signal to the liquid crystal panel 110 and the LED 134.

The reflection plate 136 extends not only to the lower surface of the light guide plate 135 but also to a side surface and a part of the upper surface of the light guide plate 135. That is, the reflective plate 136 on the side where the LED 134 is disposed is removed from the area corresponding to the LED 134 to form the window 136a, and the LED 134 is disposed on the window 136a.

In the liquid crystal display device having the above structure, the reflection plate 136, the light guide plate 135, and the optical sheet 138 are positioned on the lower cover 140, and the guide panel 150 is disposed thereon. On the guide panel 150 After the liquid crystal panel 110 is disposed, the lower cover 140 and the guide panel 150 are assembled by being fastened to the upper cover 160.

A fixing portion 142 is formed on one side of the lower cover 140. The fixing part 142 is for guiding the wire 133b to the lead part 144. The fixing part 142 is formed to be spaced apart from the wall surface of the lower cover 140 by a predetermined distance, And a groove 145 having a constant width from the wall surface of the lower cover 140 is formed. The width of the groove 145 is substantially equal to the diameter of the cylindrical wire 133b so that when the wire 133b is inserted into the groove 145, 133b are fixed.

At this time, the wire 133b is fixed to the wall surface of the lower cover 140 and is guided to the outside through the lead-out portion 144. [

6 is a view showing the structure of the fixing portion 142 to which the wire 133b is fixed. Here, for convenience of description, the groove 145 formed by the wall surface of the lower cover 140 and the fixing portion 142 is shown in a perspective sectional view.

6, the fixing portion 142 is formed to be spaced apart from the wall surface of the lower cover 140 by a predetermined distance to form a groove 145 having a constant width from the wall surface of the lower cover 140 . On the wall surface of the fixing portion 142, a pad 146 having a set width is formed. The pad 146 is for fixing the wire 133b inserted into the fixing portion 142 and is provided with a predetermined thickness from the wall surface of the fixing portion 142. [

The pad 146 may be formed along the entire fixed portion 142 or may have a plurality of pads 146 of a predetermined length. Although only the structure in which the pad 146 is formed on the fixing portion 142 is shown in the drawing, the pad 146 may be formed on the wall surface of the lower cover 140. [ As described above, even when the pad 146 is formed on the wall surface of the lower cover 140, the pad 146 may be formed along the entire fixed portion 142 or may have a plurality of pads 146 of a predetermined length, 145 are fixed by the pads 146 formed on the lower cover 140. As shown in Fig.

In addition, the pad 146 may be formed on the wall surface of the fixing portion 142 and the lower cover 140. In this case, the pad 146 may be formed to be opposed to the fixing portion 142 and the lower cover 140, or alternatively may be formed alternately along the longitudinal direction of the fixing portion 142.

Normally, since the wire 133b has a coating on its outer surface, it has elasticity. Therefore, when the wire 146 is inserted into the groove 145 formed with the pad 146 by applying pressure to the wire 133b, the covering of the region where the pad 146 is formed is pressed by the pad 146, As shown in FIG. Since the covering of the inserted wire 133b has elasticity, it is restored to its original shape.

The diameter of the wire 133b is larger than the width of the groove 145 in which the pad 146 is formed so that the wire 133b is bent by an external impact or the like, The pad 146 functions as a stopper for preventing the wire 133b from escaping from the wire 133b.

In other words, since the fixing portion 142 is formed of a hooking structure, the wire 133b inserted into the fixing portion 142 is hooked to the fixing portion 142, It is possible to prevent the wire 133b from deviating from the groove.

Meanwhile, the pad 146 may be formed of an elastic material such as resin. When the pad 146 is formed of such an elastic material, the wire 133b can be hooked to the fixing portion 142 even when the outer surface of the wire 133b is formed of a material having no elasticity .

As described above, in the present invention, at least one pad 146 is formed on a fixing portion 142 for fixing a backlight LED 134 and a wire 133b connecting an external driving element, The wire 133b can be prevented from flowing out of the groove 145 due to an external impact or the like by causing the wire 145 to be hooked to the groove 145 formed by the fixing portion.

On the other hand, liquid crystal display devices are usually made in various sizes and shapes. Accordingly, the structure in which the wire 133b is fixed according to the model of the liquid crystal display element can be changed. For example, although the wire 133b is fixed by the fixing portion 142 formed on the lower cover 140, the fixing portion may be formed on the guide panel 150 in the above description. In this case, the shape of the fixing part may be the same as that of the fixing part 142 formed on the lower cover 140. [ That is, one side wall of the guide panel 140 and the fixing part are spaced apart from each other by a predetermined distance to form a groove, and one or a plurality of pads are formed in the groove to hook the wire 133b to the groove, And can be prevented from falling out due to external impact.

In the drawing, an LED 134, to which a flexible circuit board 133a is attached to an LED substrate 132 and a wire 133b is connected to the flexible circuit board 133a, and which is mounted on the LED substrate 132, The wire 133b and the wire 133b may be connected to the external driving element by the wire 133a and the wire 133b.

Therefore, the liquid crystal display device using the basic concept of the present invention can be easily created by any person skilled in the art to which the present invention belongs.

110: liquid crystal panel 138: optical sheet
135: light guide plate 132: LED
133a: Flexible circuit board 133b: Wire
134: LED substrate 140: bottom cover
150: Guide panel

Claims (9)

A liquid crystal panel for realizing an image;
A backlight unit including an LED substrate on which a plurality of LEDs (Light Emitting Device) are mounted, the backlight unit being disposed below the liquid crystal panel and supplying light to the liquid crystal panel;
A wire connecting an external driving element and the LED substrate;
A guide panel for supporting the liquid crystal panel;
A lower cover fastened to the guide panel to assemble the liquid crystal panel and the backlight, and the LED substrate is disposed along the inner wall;
The LED substrate is formed along the inner wall adjacent to the inner wall of the inner cover of the lower cover to form a groove into which the wire is inserted so that the liquid crystal panel and the backlight are assembled to the lead- A fixing part for fixing the wire inside the lower cover; And
And at least one pad provided on at least one of the side wall and the fixing portion of the lower cover to hook and bond the wire fixed to the groove. The liquid crystal display element according to claim 1, wherein the pad is disposed integrally with at least one of the side wall of the lower cover and the fixing portion along the fixing portion. The liquid crystal display device according to claim 1, wherein a plurality of the pads are disposed on at least one of a side wall of the lower cover and the fixing portion along the fixing portion. The liquid crystal display device according to claim 1, wherein the pads are disposed on the side wall and the fixing portion of the lower cover so as to face each other. The liquid crystal display device according to claim 1, wherein the pads are arranged in a shape staggered with the side wall and the fixing portion of the lower cover. The liquid crystal display element according to claim 1, further comprising a flexible circuit board having one end attached to the LED substrate and the other end connected to the wire. The backlight unit according to claim 1,
A light guide plate for guiding the light emitted from the LED to the liquid crystal panel;
An optical sheet disposed on the light guide plate to improve efficiency of light supplied to the liquid crystal panel;
And a reflector disposed under the light guide plate and reflecting the incident light back to the light guide plate. The liquid crystal display device according to claim 1, further comprising an upper cover surrounding the upper edge of the liquid crystal panel and coupled with the lower cover and the guide panel to couple the liquid crystal panel and the backlight. The liquid crystal display device according to claim 1, further comprising a lead portion formed on the lower cover to lead out the wire to the outside.

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