KR20170080220A - Backlight unit and liquid crystal display device having the same - Google Patents

Abstract

The backlight unit and the liquid crystal display device having the same according to the present invention can be used for the flow of the light guide plate and / or the optical sheet through the ribs of the guide panel between the support part of the light guide plate and the light emitting diode (LED) Thereby preventing damage to the LED flexible circuit board.
According to this, the lighting failure of the LED is prevented, and the flow of the light guide plate is guided, thereby reducing the rattle noise due to the flow of the light guide plate.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a backlight unit capable of preventing the light guide plate from flowing and a liquid crystal display device having the backlight unit.

In recent information society, the importance of display devices as visual information delivery media is getting more emphasized, and in order to take a major position in the future, it is necessary to meet requirements such as low power consumption, thinning, light weight, and high image quality.

The display device includes a cathode ray tube (CRT), an electroluminescence (EL), a light emitting diode (LED), a vacuum fluorescent display (VFD) A non-light emitting type in which light can not be emitted, such as a light emitting type such as a field emission display (FED), a plasma display panel (PDP), and a liquid crystal display (LCD) .

The liquid crystal display device is an apparatus for displaying an image using the optical anisotropy of a liquid crystal, and is superior in visibility compared to a conventional cathode-ray tube and has a smaller average power consumption than a cathode-ray tube of the same screen size, have.

Hereinafter, a general liquid crystal display device will be described.

In general, a liquid crystal display device can display a desired image by individually supplying data signals according to image information to pixels arranged in a matrix form, and adjusting light transmittance of pixels.

Accordingly, a liquid crystal display device is provided with a liquid crystal panel in which pixels are arranged in a matrix form, a driver for driving the pixels, and a backlight unit for supplying light to the liquid crystal panel.

1 is an exploded perspective view schematically showing a structure of a general liquid crystal display device.

1, a typical liquid crystal display device includes a liquid crystal panel 10 in which pixels are arranged in a matrix form to output an image, a driving unit (not shown) for driving the pixels, and a liquid crystal panel 10 And a backlight unit 40 that emits light over the entire surface of the liquid crystal panel 10.

In addition, a general liquid crystal display device includes a lower cover 50 for receiving and fixing the liquid crystal panel 10 and the backlight unit 40.

The liquid crystal panel 10 includes a color filter substrate 5 and a color filter substrate 5. The color filter substrate 5 and the color filter substrate 5 are arranged in a cell gap between the color filter substrate 5 and the array substrate 15 so as to maintain a uniform cell gap. And a liquid crystal layer (not shown).

An upper and a lower polarizer plate (not shown) are attached to the outside of the liquid crystal panel 10, respectively. At this time, the lower polarizer plate polarizes the light transmitted through the backlight unit 40 and the upper polarizer plate passes through the liquid crystal panel 10 Polarizes the light.

A light emitting diode (LED) assembly 30 for generating light is provided on one side of a light guide plate 42. The light guide plate 42 includes a light emitting diode And a reflection plate 41 is provided on the back surface.

The LED assembly 30 includes an LED array 31 and a LED printed circuit board (PCB) 32 for driving the LED array 31.

The light emitted from the LED array 31 is incident on the side surface of the light guide plate 42 of transparent material and the reflection plate 41 disposed on the back surface of the light guide plate 42 reflects light transmitted through the back surface of the light guide plate 42 to the light guide plate 42 To the optical sheets 43 on the upper surface, thereby reducing the loss of light and improving the uniformity.

The liquid crystal panel 10 composed of the color filter substrate 5 and the array substrate 15 is seated on the upper part of the backlight unit 40 constructed as described above through the guide panel 45 and the lower cover 50 is coupled Thereby constituting a liquid crystal display device.

At this time, it is important that the liquid crystal display device is configured such that the LED assembly 30 of the backlight unit 40, the light guide plate 42, and the optical sheets 43 are not allowed to flow.

Particularly, when the light guide plate 42 flows due to an external impact or vibration, a large number of LEDs of the LED array 31 are broken or a crack is generated in the LED printed circuit board 32, do. This may cause a problem that the optical characteristics of the liquid crystal display device are changed and the image quality is deteriorated. In addition, rattle noise occurs due to the flow of the light guide plate 42 and the optical sheets 43.

As described above, in the present backlight unit 40 structure, there is no means for reducing or preventing damage to the LED assembly 30 when the light guide plate 42 flows due to external impact or vibration.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight unit and a liquid crystal display device having the same that prevent damage to the LED flexible printed circuit board due to the flow of a light guide plate and / or an optical sheet.

Other objects and features of the present invention will be described in the following description of the invention and the claims.

According to an aspect of the present invention, there is provided a backlight unit including a light guide plate having a supporting portion at an edge of a light incidence surface, a plurality of light sources provided in front of the light entrance surface of the light guide plate, A light source assembly made of a substrate, and a lower cover for accommodating the light guide plate and the light source assembly.

Here, the backlight unit according to an embodiment of the present invention includes a guide panel that has a rib interposed between the supporting portion of the light guide plate and the flexible circuit board, and surrounds the side surface of the lower cover.

The liquid crystal display device according to an embodiment of the present invention may further include a liquid crystal panel provided on the upper surface of the light guide plate in the backlight unit.

At this time, the light guide plate may be provided with a guide groove at one side edge of the light-receiving optical surface opposite to the light incidence surface.

And a pad of translucent material having the same shape as the guide groove and inserted into the guide groove.

The lower cover may include a square shaped bottom portion and side portions extending vertically from each corner of the bottom portion.

The guide panel may have a rectangular shape, and may include a horizontal part lying on a side part of the lower cover and a vertical part extending downward from one end of the horizontal part to surround the side parts of the lower cover.

The support portion may have a rectangular or trapezoidal protruding shape.

The flexible circuit board may be bent once at the support portion of the light guide plate to contact the two side portions of the lower cover.

The rib may be provided on a rear surface of the guide panel and may extend from the horizontal portion toward a bottom portion of the lower cover on the inner side of the vertical portion.

The rib may have an "L" shape along a space between two sides of the support portion of the light guide plate and the flexible circuit board.

The rib may be formed to surround not only two sides but also the other side of the support along a space between two sides of the support portion of the light guide plate and the flexible circuit board.

As described above, the backlight unit and the liquid crystal display device having the same according to an embodiment of the present invention can prevent the LED flexible printed circuit board from being damaged by the flow of the light guide plate and / or the optical sheet. As a result, the lighting failure of the LED is prevented to increase the reliability of the product, and the flow of the light guide plate is guided, thereby reducing the rattle noise due to the flow of the light guide plate.

1 is an exploded perspective view schematically showing a structure of a general liquid crystal display device.
2 is an exploded perspective view schematically showing a structure of a liquid crystal display device according to a first embodiment of the present invention.
FIG. 3 is a schematic view showing a part of a cross section of the liquid crystal display device according to the first embodiment of the present invention shown in FIG. 2;
FIG. 4 is a perspective view schematically showing a part of a structure of a liquid crystal display according to a first embodiment of the present invention shown in FIG. 2; FIG.
5 is a rear view schematically showing a part of a structure of a guide panel according to a first embodiment of the present invention;
FIG. 6 is a perspective view schematically showing a part of a structure of a liquid crystal display device according to a second embodiment of the present invention; FIG.
FIG. 7 is a rear view schematically showing a part of a structure of a guide panel according to a second embodiment of the present invention; FIG.

Hereinafter, preferred embodiments of a backlight unit and a liquid crystal display device having the same according to the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of the layers and regions in the figures may be exaggerated for clarity of illustration.

It will be understood that when an element or layer is referred to as being another element or "on" or "on ", it includes both intervening layers or other elements in the middle, do. On the other hand, when a device is referred to as "directly on" or "directly above ", it does not intervene another device or layer in the middle.

The terms spatially relative, "below," "lower," "above," "upper," and the like, And may be used to easily describe the correlation with other elements or components. Spatially relative terms should be understood to include, in addition to the directions shown in the drawings, terms that include the different directions of the elements in use, or in operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprise "and / or" comprising ", as used in the specification, means that the presence of stated elements, Or additions.

2 is an exploded perspective view schematically showing a structure of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 3 is a schematic view showing a part of a cross section of the liquid crystal display device according to the first embodiment of the present invention shown in FIG. 2, showing a part of a cross section taken along the line A-A '.

FIG. 4 is a perspective view schematically showing a part of a structure of a liquid crystal display device according to the first embodiment of the present invention shown in FIG. 2, illustrating the structure of a backlight unit at the lower left of a liquid crystal display device.

5 is a rear view schematically showing a part of the structure of the guide panel according to the first embodiment of the present invention.

2 to 5, the liquid crystal display according to the first embodiment of the present invention mainly includes a liquid crystal panel 110 for outputting images, a liquid crystal panel 110 disposed on the back surface of the liquid crystal panel 110, A backlight unit 140 for emitting light over the entire surface and a guide panel 145 for fastening and fixing the liquid crystal panel 110 and the backlight unit 140 to each other and a lower cover 150.

The liquid crystal panel 110 outputs pixels by arranging the pixels in a matrix form.

The liquid crystal panel 110 includes a color filter substrate 105 and a color filter substrate 105. The color filter substrate 105 and the color filter substrate 105 are formed in a cell gap between the array substrate 115 and the color filter substrate 105, And a liquid crystal layer (not shown).

Although not shown, a common electrode and a pixel electrode are formed on the liquid crystal panel 110 in which the color filter substrate 105 and the array substrate 115 are bonded together to apply an electric field to the liquid crystal layer. In a state where a voltage is applied to the common electrode The voltage of the data signal applied to the pixel electrode can be controlled. Then, the liquid crystal of the liquid crystal layer rotates by the dielectric anisotropy according to the electric field between the common electrode and the pixel electrode, so that light or an image can be displayed by transmitting or blocking light for each pixel.

At this time, a switching element such as a thin film transistor (TFT) may be separately provided in the pixels to control the voltage of the data signal applied to the pixel electrode on a pixel-by-pixel basis.

That is, a gate line and a data line are vertically and horizontally arranged on the array substrate 115 to define a pixel region, and a thin film transistor, which is a switching device, may be formed in a crossing region between the gate line and the data line.

The thin film transistor may include a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode connected to the pixel electrode.

The color filter substrate 105 includes a color filter composed of a plurality of sub-color filters that realize red, green, and blue, a black matrix that separates sub-color filters and blocks light transmitting through the liquid crystal layer, Filter and an overcoat layer formed over the black matrix.

Polarizing plates 101 and 111 may be respectively attached to the outer sides of the color filter substrate 105 and the array substrate 115. The lower polarizing plate 111 polarizes the light transmitted through the backlight unit 140, (101) polarizes light passing through the liquid crystal panel (110).

The lower cover 150 may include a bottom portion 150a and a plurality of side portions 150b. The bottom portion 150a may have a rectangular shape. The side portions 150b may extend vertically to have a predetermined height from the respective edges of the bottom portion 150a.

The edges of the side portions 150b adjacent to each other can be connected to each other. The space enclosed by the side portions 150b and the bottom portion 150a can form a storage space in which the liquid crystal panel 110 and the backlight unit 140 are housed.

However, the present invention is not limited to the structure of the lower cover 150 described above.

The guide panel 145 can be placed on the side portion 150b of the lower cover 150. [

The guide panel 145 serves to support the liquid crystal panel 110. For this purpose, the guide panel 145 may include a vertical portion 145a and a horizontal portion 145b.

That is, the guide panel 145 has a rectangular shape for housing the liquid crystal panel 110 and for covering the edge of the backlight unit 140, and includes a vertical part 145a surrounding the side surface of the backlight unit 140, And a horizontal portion 145b that divides the positions of the liquid crystal panel 110 and the backlight unit 140 from each other.

The horizontal portion 145b may be placed on the side portion 150b of the lower cover 150 and the vertical portion 145a may extend downward from one end of the horizontal portion 145b to extend along the side portion 150b of the lower cover 150 It can be wrapped.

The liquid crystal panel 110 may be attached and fixed on the horizontal portion 145b of the guide panel 145 through a bonding means 130 such as a double-sided tape.

The liquid crystal panel 110 including the color filter substrate 105 and the array substrate 115 can be mounted on the upper part of the backlight unit 140 through the guide panel 145 and the lower cover 150 So that a liquid crystal display device can be constructed.

Next, the backlight unit 140 will be concretely described. The light guide plate 142 includes a light emitting diode (LED) assembly 130 (light emitting diode) including a light source for emitting light And a reflection plate 141 may be provided on the back surface of the light guide plate 142. [

A plurality of optical sheets 143 may be disposed on the upper surface of the light guide plate 142 to improve the efficiency of light emitted from the light guide plate 142 and illuminate the liquid crystal panel 110.

However, the present invention is not limited to the structure of the above-described backlight unit 140, and any backlight unit 140 having any structure can be applied to the liquid crystal display device according to the present invention.

The light guide plate 142 receives light from the light source and guides the light to the liquid crystal panel 110 side. At this time, the light provided from the light source may be provided to the light incoming surface of the light guide plate 142. The light incidence surface faces one side portion 150b of the side portions 150b of the lower cover 150. [

That is, the light guide plate 142 is composed of a light incidence surface corresponding to the LED assembly 130, a light incidence surface opposite to the light incidence surface, and opposite side surfaces facing each other. The light incident surface of the light guide plate 142 faces the light exit surface of the light source.

The light guide plate 142 may include a pattern of a specific shape on the bottom surface to supply a uniform surface light source. The pattern may be formed in various shapes such as an elliptical pattern, a polygonal pattern, and a hologram pattern in order to guide light incident into the light guide plate 142. The pattern can be formed on the lower surface of the light guide plate 142 by a printing method or an injection method.

The liquid crystal display according to the first embodiment of the present invention includes a light guide plate 142 and a light guide plate 142. The light guide plate 142 includes a light guide plate 142, And a support portion 142b for maintaining an optical separation distance between the LED assembly 130 and the LED assembly 130. [

That is, in the backlight unit 140, a gap between an optical gap or an air gap, that is, a distance between the LED assembly 130 and the light incident surface of the light guide plate 142 is the most important role of the backlight unit 140 Which is one of the optical designs for supplying the high-quality surface light source to the liquid crystal panel 110. [

Therefore, by providing the support portion 142b on the light-incoming surface of the light guide plate 142, the gap between the LED assembly 130 and the light entrance surface of the light guide plate 142 can be kept constant, .

The support portions 142b may be provided at both side edges of the light incidence surface of the light guide plate 142. [

The support portion 142b may have a rectangular or trapezoidal protruding shape.

A guide groove 142h is formed at one side edge of the light-receiving optical surface opposite to the light-incident surface provided with the support portion 142b. The guide groove 142h is formed of a translucent material for preventing the light- The pad 142a is positioned.

That is, the pad 142a is made of a semi-transparent material and may have a bar shape having a predetermined thickness. The guide groove 142h may be formed to have substantially the same shape as the pad 142a.

Accordingly, the light guide plate 142 according to the first embodiment of the present invention can be fixed in the liquid crystal display device in which the set is coupled through the pad 142a inserted into the guide groove 142h. Accordingly, it is possible to prevent the light guide plate 142 from flowing horizontally or vertically due to external impact or vibration when the light guide plate 142 is housed in the lower cover 150.

Here, the pad 142a may be formed to have a larger size than the guide groove 142h. For example, the pad 142a may be formed approximately 1.1 to 1.2 times larger than the guide groove 142h. When the size of the pad 142a is 1.2 times larger than the size of the guide groove 142h, it is difficult to insert the pad 142a into the guide groove 142h. On the other hand, when the pad 142a has the same size as the guide groove 142h, the light guide plate 142 can not be pushed diagonally from one corner where the pad 142a is positioned by the pad 142a, ) May not be completely blocked.

At this time, the pad 142a may be formed such that the lower surface of the pad 142a facing the reflection plate 141 has a smaller width than the upper surface. For this, the pad 142a may be formed to have an inclined surface inclined at an angle between the lower surface and the side surface. The pad 142a can be easily inserted into the guide groove 142h of the light guide plate 142 by inserting the pad 142a having a larger size than the guide groove 142h into the guide groove 142h of the light guide plate 142 142h, respectively.

The light guide plate 142 may be made of PMMA (polymethyl methacrylate) or PC (polycarbonate) plastic.

The reflection plate 141 may be positioned between the lower cover 150 and the back surface of the light guide plate 142.

The light source is a means for emitting light. For example, a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an external electroluminescence lamp (EEFL) Do not. Hereinafter, for convenience of explanation, a case where an LED is used as a light source is taken as an example.

The LED array 131 may comprise a light emitting package having at least one LED. The light emitting package may be a light emitting package having different colors, for example, a red light emitting diode, a green light emitting diode, and a blue light emitting diode.

For example, in recent years, a blue LED including a blue LED chip having excellent luminous efficiency and luminance has been used for improving the luminous efficiency and brightness, and a 'yttrium aluminum garnet doped with cerium', that is, a yellow phosphor Can be used. The blue light emitted from the LED is transmitted through the phosphor and mixed with the yellow light emitted by the phosphor, thereby realizing white light.

The LED array 131 may be installed on the LED flexible circuit board 132 such that the light emitting surface faces the light incoming surface of the light guide plate 142. That is, the LED array 131 may be arranged along at least one side portion 150b of the lower cover 150 in the longitudinal direction.

The LED flexible circuit board 132 may be positioned between the light incident surface of the light guide plate 142 and the side surface portions 150b of the lower cover 150. [

The LED flexible circuit board 132 may include a plurality of power lines (not shown) and electrical components (not shown) for transmitting power to the light source.

The light source is connected to an inverter (not shown) to receive power and emit light.

The light emitted from the light source is incident on the side surface of the light guide plate 142 made of a transparent material. The reflective sheet 141 disposed on the back surface of the light guide plate 142 reflects the light transmitted to the back surface of the light guide plate 142 toward the optical sheets 143 on the upper surface of the light guide plate 142 to reduce light loss, Can be improved.

At this time, the optical sheets 143 include a diffuser sheet and an upper and a lower prism sheet, and a protective sheet may be added.

The optical sheets 143 are provided between the upper surface of the light guide plate 142 and the rear surface of the liquid crystal panel 110 so that the edges of the optical sheets 143 can be covered by the horizontal portion 145b of the guide panel 145 have.

The prism sheet condenses light from the light guide plate 142, and the diffusion sheet can diffuse the light from the prism sheet. And, the protective sheet can serve to protect these prism sheets and the diffusion sheet. Light passing through the protective sheet may be provided to the liquid crystal panel 110 side.

As described above, the liquid crystal display according to the first embodiment of the present invention has the guide groove 142h formed at one side edge of the light-incoming surface of the light guide plate 142, and the pad 142a is formed in the guide groove 142h. The flow of the light guide plate 142 can be prevented.

Accordingly, it is possible to prevent a plurality of LEDs from being damaged by the flow of the light guide plate 142.

However, it is necessary to further guide the flow of the light guide plate 142 and / or the optical sheets 143 during an external impact such as a vehicle or a transportation environment test.

For example, in the transportation environment test, the flow of the light guide plate 142 and / or the optical sheets 143 occurs, which may cause damage to the light guide plate 142 or the LED flexible printed circuit board 132. As a result, a crack occurs in the LED flexible circuit board 132, and lighting failure of the light source may occur.

2 to 4 show an example in which the LED flexible circuit board 132 is bent at one corner of the light guide plate 142 and contacts the two side portions 150b of the lower cover 150. However, But is not limited thereto. At this time, when the curvature of the curved LED flexible circuit board 132 is large, the LED flexible circuit board 132 is more likely to be damaged even if the light guide plate 142 is small in flow. That is, when the blow test is performed, the LED flexible circuit board 132 may be damaged by the edge of the light guide plate 142 in the backlight unit 140.

Therefore, in the first embodiment of the present invention, between the support portion 142b of the light guide plate 142 and the LED flexible circuit board 132, the light guide plate 142 and the light guide plate 142 are interposed between the ribs 145c of the guide panel 145, And / or to prevent the LED flexible printed circuit board 132 from being damaged by the flow of the optical sheets 143. [

According to this, the lighting failure of the LED is prevented, and at the same time, the flow of the light guide plate 142 is guided, thereby reducing the rattle noise due to the flow of the light guide plate 142.

The rib 145c may be provided on the lower edge of the guide panel 145 where the support portion 142b of the light guide plate 142 is located.

The rib 145c is formed on the back surface of the guide panel 145 and may extend downward from the horizontal portion 145b on the inner side of the vertical portion 145a.

That is, the rib 145c may extend from the horizontal portion 145b of the guide panel 145 toward the bottom portion 150a of the lower cover 150.

The ribs 145c may have an "L" shape along the edge of the light guide plate 142, i.e., between the two sides of the support portion 142b and the LED flexible circuit board 132. [

At this time, the support portion 142b has three side surfaces exposed to the outside, and thus both sides of the support portion 142b refer to the side that faces the LED flexible circuit board 132. [

The rib 145c may contact the light guide plate 142 but not the LED flexible circuit board 132. [

The present invention can further reduce the flow of the light guide plate by changing the shape of the rib so as to cover the two sides of the support as well as the other side, which will be described in detail through the following second embodiment of the present invention.

FIG. 6 is a perspective view schematically showing a part of a structure of a liquid crystal display device according to a second embodiment of the present invention, and shows a structure of a backlight unit at the lower left of a liquid crystal display device as an example.

7 is a rear view schematically showing a part of the structure of the guide panel according to the second embodiment of the present invention.

The liquid crystal display according to the second embodiment of the present invention shown in Figs. 6 and 7 has substantially the same structure as the liquid crystal display according to the second embodiment of the present invention except for the structure of the guide panel Lt; / RTI >

6 and 7, the liquid crystal display according to the second embodiment of the present invention mainly includes a liquid crystal panel (not shown) for outputting an image, a liquid crystal panel And a guide panel 245 and a lower cover 250 for fixing and fixing the liquid crystal panel and the backlight unit to each other.

In a liquid crystal panel, pixels are arranged in a matrix form to output an image.

The liquid crystal panel may be composed of a color filter substrate and a liquid crystal layer formed in a cell gap between the array substrate and the color filter substrate and the array substrate so as to maintain a uniform cell gap to face each other.

At this time, a gate line and a data line are vertically and horizontally arranged on the array substrate to define a pixel region, and a thin film transistor, which is a switching device, may be formed in a crossing region between the gate line and the data line.

The thin film transistor may include a gate electrode connected to the gate line, a source electrode connected to the data line, and a drain electrode connected to the pixel electrode.

The color filter substrate includes a color filter composed of a plurality of sub-color filters that realize red, green, and blue, a black matrix that separates the sub-color filters and blocks light transmitting through the liquid crystal layer, And an overcoat layer formed on the matrix.

A polarizer may be attached to the outer sides of the color filter substrate and the array substrate, wherein the lower polarizer polarizes the light passing through the backlight unit, and the upper polarizer polarizes the light transmitted through the liquid crystal panel.

The lower cover 250 may include a bottom portion and a plurality of side portions. The bottom can have a square shape. The side portions may extend vertically to have a predetermined height from each edge of the bottom portion.

The edges of the side portions adjacent to each other can be connected to each other. The space surrounded by the side portions and the bottom portion can form a storage space in which the liquid crystal panel and the backlight unit are housed.

However, the present invention is not limited to the structure of the lower cover 250 described above.

The guide panel 245 can be placed on the side surface of the lower cover 250.

The guide panel 245 serves to support the liquid crystal panel. For this purpose, the guide panel 245 may include a vertical portion 245a and a horizontal portion 245b.

That is, the guide panel 245 includes a vertical portion 245a surrounding a side surface of the backlight unit and a liquid crystal panel and a backlight unit 245a inside the vertical portion 245a. The guide panel 245 accommodates the liquid crystal panel and surrounds the edge of the backlight unit. And a horizontal part 245b for distinguishing the position of the horizontal part 245b.

The horizontal portion 245b may be disposed on a side portion of the lower cover 250 and the vertical portion 245a may extend downward from one end of the horizontal portion 245b to cover the side portion of the lower cover 250. [

The liquid crystal panel can be attached and fixed on the horizontal portion 245b of the guide panel 245 through an adhesive means (not shown) such as a double-sided tape.

As described above, the liquid crystal panel including the color filter substrate and the array substrate can be mounted on the upper part of the backlight unit through the guide panel 245, and the lower cover 250 can be coupled to the lower part to constitute the liquid crystal display device.

The LED assembly 230 may include a light source that generates light on one side of the light guide plate 242. A reflector (not shown) may be installed on the back side of the light guide plate 242 have.

On the upper surface of the light guide plate 242, a plurality of optical sheets (not shown) for improving the efficiency of light emitted from the light guide plate 242 and irradiating the liquid crystal panel can be disposed.

However, the present invention is not limited to the structure of the above-described backlight unit, and any backlight unit of any structure can be applied to the liquid crystal display according to the present invention.

The light guide plate 242 receives light from the light source and guides the light to the liquid crystal panel side. At this time, the light provided from the light source may be provided to the light incoming surface of the light guide plate 242. This light incidence surface faces one of the side portions of the lower cover 250.

That is, the light guide plate 242 has a light incidence surface corresponding to the LED assembly 230, a light incidence surface opposite to the light incidence surface, and opposite side surfaces facing each other. The light incident surface of the light guide plate 242 faces the light exit surface of the light source.

The light guide plate 242 may include a pattern of a specific shape on the bottom surface to supply a uniform surface light source. The pattern may be formed in various shapes such as an elliptical pattern, a polygonal pattern, and a hologram pattern in order to guide light incident into the light guide plate 242. The pattern can be formed on the lower surface of the light guide plate 242 by a printing method or an injection method.

The liquid crystal display according to the second embodiment of the present invention includes a light guide plate 242 and a light guide plate 242. The light guide plate 242 includes a light guide plate 242, And a support portion 242b for maintaining an optical separation distance between the LED assembly 230 and the LED assembly 230.

The support portions 242b may be provided at both side edges of the light incidence surface of the light guide plate 242. [

The support portion 242b may have a rectangular or trapezoidal protruding shape.

A guide groove (not shown) is formed at one side edge of the light-receiving optical surface opposite to the light-incident surface provided with the support portion 242b. A pad made of a translucent material for preventing the flow of the light- Not shown).

That is, the pad is made of a translucent material and can be formed to have a bar shape having a predetermined thickness. The guide groove may be formed to have substantially the same shape as the pad.

Accordingly, the position of the light guide plate 242 according to the second embodiment of the present invention can be fixed in a liquid crystal display device in which a set is coupled through a pad inserted into a guide groove. Therefore, it is possible to prevent the light guide plate 242 from flowing horizontally or vertically due to external impact or vibration when the light guide plate 242 is accommodated in the lower cover 250.

Here, the pad may be formed to have a larger size than the guide groove. For example, the pads may be formed to be about 1.1 to 1.2 times larger than the guide grooves.

At this time, the pad may be formed so that the lower surface facing the reflector has a narrower width than the upper surface. To this end, the pad may be formed to have an inclined surface inclined at an angle between the lower surface and the side surface.

The light guide plate 242 may be made of plastic of PMMA or PC.

The reflection plate may be positioned between the bottom cover 250 and the back surface of the light guide plate 242.

The light source is a means for emitting light, for example, CCFL, HCFL, EEFL or LED, but the present invention is not limited thereto. Hereinafter, for convenience of explanation, a case where an LED is used as a light source is taken as an example.

The LED array 231 may comprise a light emitting package having at least one LED. The light emitting package may be a light emitting package having different colors, for example, a red light emitting diode, a green light emitting diode, and a blue light emitting diode.

The LED array 231 may be mounted on the LED flexible circuit board 232 such that the light emitting surface faces the light incoming surface of the light guide plate 242. That is, the LED array 231 may be arranged along at least one side surface in the longitudinal direction of the lower cover 250.

The LED flexible circuit board 232 may be positioned between the light incident side of the light guide plate 242 and the side portions of the lower cover 250.

The LED flexible circuit board 232 may include a plurality of power lines (not shown) and electrical components (not shown) for transmitting power to the light source.

The light source is connected to an inverter (not shown) to receive power and emit light.

The light emitted from the light source is incident on the side surface of the light guide plate 242 made of a transparent material. The reflective sheet disposed on the back surface of the light guide plate 242 reflects light transmitted to the back surface of the light guide plate 242 toward the optical sheets on the upper surface of the light guide plate 242, thereby reducing loss of light and improving uniformity.

At this time, the optical sheets include a diffusion sheet and upper and lower prism sheets, and a protective sheet may be added.

The optical sheets are provided between the upper surface of the light guide plate 242 and the rear surface of the liquid crystal panel, and the edges of the optical sheets can be covered by the horizontal portion of the guide panel 245.

6 illustrates an example in which the LED flexible circuit board 232 is bent once at the edge of the light guide plate 242 and contacts two side portions of the lower cover 250. However, the present invention is not limited thereto .

In the liquid crystal display device according to the second embodiment of the present invention having such a structure, guide grooves are formed at one side edge of the light-introducing light surface of the light guide plate 242 and pads are inserted into the guide grooves, Flow can be prevented.

In the second embodiment of the present invention, the light guide plate 242 and / or the light guide plate 242 are interposed between the support portion 242b of the light guide plate 242 and the LED flexible circuit board 232 via the rib 245c of the guide panel 245. [ Thereby further preventing the LED flexible printed circuit board 232 from being damaged by the flow of the sheets.

According to this, the lighting failure of the LED is prevented, and at the same time, the flow of the light guide plate 242 is guided to provide the effect of reducing the noise due to the flow of the light guide plate 242.

The rib 245c may be provided at the lower edge of the guide panel 245 where the support portion 242b of the light guide plate 242 is located.

The rib 245c may be formed on the rear surface of the guide panel 245 and may extend downward from the horizontal portion 245b on the inner side of the vertical portion 245a.

That is, the rib 245c may extend from the horizontal portion 245b of the guide panel 245 toward the bottom of the lower cover 250. [

Particularly, the rib 245c according to the second embodiment of the present invention has the rib 245c along the edge of the light guide plate 242, that is, the space between the two sides of the support portion 242b and the LED flexible circuit board 232, And is formed so as to enclose not only the two sides but also the other side. Accordingly, the second embodiment of the present invention can further reduce the flow of the light guide plate 142 compared to the first embodiment of the present invention described above.

The ribs 245c may be in contact with the light guide plate 242, but not in contact with the LED flexible circuit board 232.

While a great many are described in the foregoing description, it should be construed as an example of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

130, 230: LED assembly 131, 231: LED array
132, 232: LED flexible printed circuit boards 142, 242:
142a: pad 142b, 242b:
142h: Guide groove 145, 455: Guide panel
145a, 245a: vertical part 145b, 245b: horizontal part
145c and 245c: ribs 150 and 250:

Claims (17)

A light guide plate positioned below the liquid crystal panel and having a supporting portion at an edge of the light entrance surface;
A light source assembly including a plurality of light sources provided in front of an entrance surface of the light guide plate and a flexible circuit board on which the light source is mounted;
A lower cover for accommodating the liquid crystal panel, the light guide plate, and the light source assembly; And
And a guide panel having a rib interposed between the supporting portion of the light guide plate and the flexible circuit board, the guide panel surrounding the side surface of the lower cover. The liquid crystal display of claim 1, wherein the light guide plate is provided with a guide groove at one side edge of a light-receiving optical surface opposite to the light-incident surface. The liquid crystal display of claim 1, further comprising a pad of translucent material having the same shape as the guide groove and being inserted into the guide groove. The apparatus according to claim 1,
A square shaped bottom; And
And side portions extending vertically from the respective edges of the bottom portion. [6] The apparatus of claim 4, wherein the guide panel has a rectangular frame shape,
A horizontal part lying on a side part of the lower cover; And
And a vertical portion extending downward from one end of the horizontal portion and surrounding side portions of the lower cover. The liquid crystal display of claim 1, wherein the supporting portion has a protruding shape of a quadrangle or a trapezoid. The liquid crystal display of claim 4, wherein the flexible circuit board is bent once at a support portion of the light guide plate to contact two side portions of the lower cover. The liquid crystal display of claim 5, wherein the rib is provided on a rear surface of the guide panel and extends from the horizontal portion toward the bottom of the lower cover. The liquid crystal display of claim 7, wherein the rib has an "L" shape along a space between two sides of the support portion of the light guide plate and the flexible circuit board. [8] The liquid crystal display of claim 7, wherein the ribs are arranged to cover not only two sides of the support portion but also the other side along a space between two sides of the support portion of the light guide plate and the flexible circuit board. A light guide plate having a supporting portion at an edge of the light incidence surface;
A light source assembly including a plurality of light sources provided in front of an entrance surface of the light guide plate and a flexible circuit board on which the light source is mounted;
A lower cover for receiving the light guide plate and the light source assembly; And
And a guide panel surrounding the side surface of the lower cover, the guide panel including a rib interposed between the supporting portion of the light guide plate and the flexible circuit board. [12] The apparatus of claim 11, wherein the guide panel has a rectangular frame shape,
A horizontal part lying on an upper surface of the lower cover; And
And a vertical portion extending downward from one end of the horizontal portion and surrounding a side surface of the lower cover. 12. The backlight unit according to claim 11, wherein the support portion has a protruding shape of a quadrangle or a trapezoid. 13. The backlight unit of claim 12, wherein the flexible circuit board is bent once at a support portion of the light guide plate to contact two side surfaces of the lower cover. 13. The backlight unit according to claim 12, wherein the ribs are provided on a rear surface of the guide panel and extend downward from the horizontal portion inside the vertical portion. 15. The backlight unit according to claim 14, wherein the rib has an "L" shape along a space between two sides of the support portion of the light guide plate and the flexible circuit board. 15. The backlight unit according to claim 14, wherein the ribs are provided so as to surround not only two sides but also the other side of the support along a space between two sides of the support portion of the light guide plate and the flexible circuit board.

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