KR20160002569A - liquid crystal display device - Google Patents

Abstract

Provided is a liquid crystal display device, which comprises: a liquid crystal panel; a backlight unit positioned at a lower portion of the liquid crystal panel, and including a reflection plate, a light guide plate, and a plurality of light sources; a support main surrounding the edges of the backlight unit; a bottom cover which is assembled and fastened to the support main; and a printed circuit board (PCB) on which the light sources are mounted. The light sources are formed to be spaced apart from each other, and also, formed to correspond to the light guide plate so as to guide light emitted from the light sources to allow the same to be incident to the light guide plate. In addition, the liquid crystal display device further comprises a partial housing including a plurality of first parts which are fastened to an upper portion of the light sources, and are positioned between the PCB and the light guide plate, and a second part which is perpendicular to the first parts, and can cover the light sources and a part of the edges of the light guide plate.

Description

[0001] The present invention relates to a liquid crystal display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device using an LED as a light source, and more particularly to a liquid crystal display device capable of preventing light loss as well as light source pressing due to expansion of a light guide plate.

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.

Here, as a light source of the backlight unit, a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp, a light emitting diode (LED) .

In particular, LEDs are widely used as light sources for displays, having characteristics such as small size, low power consumption, and high reliability.

1 is a cross-sectional view of a backlight of a liquid crystal display device using a general LED as a light source.

As shown in the figure, a typical backlight is composed of a support main body 1, a cover bottom 2, a light source 5, a light guide plate 4, and a plurality of optical sheets 3.

The backlight unit includes a plurality of light sources 5 arranged along the height direction of at least one edge of the support main body 1, a white or silver reflective plate 7 seated on the cover bottom 2, And a plurality of optical sheets 3 interposed therebetween. Further, an LED housing (not shown in the drawings) for emitting heat generated from the light source 5 to the outside is further formed.

At this time, a plurality of light sources 5 emitting white light are formed on one side of the light guide plate 4 and mounted on a PCB (printed circuit board: hereinafter referred to as PCB).

The liquid crystal panel (not shown) and the backlight unit are covered with a top cover (not shown) which covers the top edge of the liquid crystal panel (not shown) with the edges thereof being surrounded by the support main body 1, And the bottoms 2 are joined at the front and rear sides, respectively, to be integrated via the support main body 1.

As shown in the figure, a plurality of light sources 5 are arranged along one side of the light guide plate 4 of the modularized liquid crystal display module, and the plurality of light sources 5 are mounted on the PCB 6. Here, the PCB 6 may be a metal core printed circuit board (MCPCB) formed of a metal to discharge heat generated from the plurality of light sources 5 to the outside.

The plurality of light sources 5 are fixed in position by a method such as adhesion or the like and the light emitted is confronted with the light incidence surface of the light guide plate 4. For this purpose, the cover bottom 2 is bent at one edge to form a side .

At this time, in order to discharge heat generated from the plurality of light source LEDs 5 to the outside, the bottom surface of the PCB 6 and the cover bottoms 2 formed of a metal material are in contact with each other. That is, the heat generated from the plurality of light sources 5 is emitted to the outside through the PCB 6 and the cover bottom 2.

Such conventional liquid crystal display devices have the following problems.

First, the light guide plate 4 is formed of resin, which is a material weak in heat. As a result, the light guide plate expands due to heat at a high temperature, and the expanded light guide plate presses the light source 5, and there is a problem that the light source 2 and the light guide plate are deformed.

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The light emitting surface of the light source 5 and the light incident surface of the light guide plate 4 must correspond to each other to align the light emitted from the light source 5 efficiently to the light guide plate 4,

However, due to such deformation of the light guide plate 4 and the light source 5, the light guide plate 4 and the light source 5 are tilted to generate a gap, and light emitted from the light source 5 through the generated gaps is totally reflected by the light guide plate 4, There is a problem of leakage of light to the outside.

The present invention provides a liquid crystal display device capable of preventing light loss as well as preventing damage of a light source due to expansion of a light guide plate.

The present invention relates to a liquid crystal display device, comprising: a liquid crystal panel; A backlight unit located at a lower portion of the liquid crystal panel and including a reflection plate, a light guide plate, and a plurality of light sources; A support main body surrounding an edge of the backlight unit; And a cover bottom mounted on the support main body, wherein the plurality of light sources are spaced apart from each other, and the plurality of light sources also guide the light emitted from the light source, A plurality of first portions formed corresponding to the light guide plate so as to be incident on the light guide plate and interposed between the PCB and the light guide plate fastened to the upper portion of the light source, And a partial housing including a second portion that can cover up to a portion of the first housing.

The partial housing is formed in a shape of ' ┍ ', and the plurality of first portions are formed by being fastened between the plurality of light sources

The first part protrudes toward the light guide plate rather than the light source to prevent the light source from being pressed due to the expansion of the light guide plate, and the partial housing is made of a material having a thermal expansion coefficient larger than that of the resin.

The width of the first portion is smaller than the distance between the light sources.

The inside of the partial housing is a reflective layer for reflecting light or an absorbing layer for absorbing light. Further, the partial housing is formed by further assembling with the cover bottom, and the liquid crystal display device includes a liquid crystal display device having a curved shape.

The present invention provides a partial housing between the light source and the light guide plate to prevent the light guide plate from expanding due to heat and pressing the light source.

In addition, the present invention has an effect of solving light leakage generated from a gap generated when the light guide plate and the light source are turned due to the light source and the second portion formed on the upper portion of the partial housing.

In addition, the present invention has the effect of improving the luminance and image quality of a liquid crystal display device, since light emitted due to the reflective layer formed inside the partial housing can be incident on the light guide plate without loss.

1 is a sectional view of a general liquid crystal display device.
2 is a sectional view of a liquid crystal display device according to an embodiment of the present invention;
3 is a cross-sectional view showing a liquid crystal display device cut along a line A-A 'in FIG.
4 is a perspective view illustrating a partial housing according to a second embodiment of the present invention;
5 is a perspective view illustrating a partial housing according to a third embodiment of the present invention;
6 is a cross-sectional view of the partial housing of the present invention

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

2 is a cross-sectional view of a liquid crystal display module according to an embodiment of the present invention.

The liquid crystal display device module may include a liquid crystal panel (not shown), a backlight unit, a support main body 10, a cover bottom 20, and a top cover (not shown).

First, although not shown, the liquid crystal panel is a part that plays a key role in image display, and includes a first substrate and a second substrate 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 to define a pixel on the inner surface of the first substrate called a lower substrate or an array substrate. Thin film transistors (TFTs) are formed at the intersections of the gate lines and the data lines, respectively, and are connected to the corresponding pixel electrodes.

On the inner surface of the second substrate, which is called an upper substrate or a color filter substrate, a color filter of red, green, and blue is formed as an example corresponding to each pixel. In addition, a black matrix is provided to cover the non-display elements of the first substrate, such as the gate lines, the data lines, and the thin film transistors. Here, when the liquid crystal display device is driven in the vertical electric field mode, a common electrode covering the color filter and the black matrix may be further formed on the second substrate.

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

In addition, the liquid crystal panel is connected to the printed circuit board via a connecting member such as a flexible circuit board or a tape carrier package (TCP) along at least one edge.

The backlight unit is located, for example, on the back surface of the liquid crystal panel and serves to supply light to the liquid crystal panel.

The backlight unit includes a plurality of light sources 50, a white or silver reflection plate 170, a light guide plate 40 that is seated on the reflection plate 70, and a plurality of optical sheets 30 interposed therebetween .

The plurality of light sources 50 are located at one side of the light guide plate 40 so as to face the light incident side of the light guide plate 40. The plurality of light sources 50 are mounted on the PCB 60 at regular intervals .

At this time, the plurality of light sources 50 emit light having red, green, and blue colors respectively forward to the light incoming surface of the light guide plate 40, and by turning on the plurality of RGB light sources 50 at once, Can be implemented.

On the other hand, by using the light source 50 constituted by a light source chip (not shown) that emits all the colors of RGB, the white light can be realized in each light source 50, or a white A light source 50 that emits light may be used.

The PCB 560 may be a metal core printed circuit board (MCPCB) having a heat dissipating function. That is, by using the metal PCB 60 having a high thermal conductivity, the heat of high temperature generated from the light source 50 can be rapidly discharged to the outside. In this case, when the PCB 60 is formed of MCPCB, an insulating layer (not shown) such as a polyimide resin material for electrical insulation between a metal core and a wiring pattern (not shown) may be formed .

The light guide plate 40 disperses the light emitted from the light source 50 to provide a surface light source to the liquid crystal panel. Specifically, the light emitted from the light source 50 is totally reflected several times in the light guide plate 40. Accordingly, the light is evenly spread over a wide area of the light guide plate 40, and is incident on the liquid crystal panel as a surface light source.

At this time, the light guide plate 40 may include, for example, a pattern of a specific shape on its back surface to supply a uniform surface light source to the liquid crystal panel. The pattern may be formed in various shapes such as an elliptical pattern, a polygon pattern, a hologram pattern, and the like in order to guide light incident into the light guide plate 40 . Such a pattern is formed on the back surface of the light guide plate 14 by a printing method or an injection method.

The reflection plate 70 is disposed on the back surface of the light guide plate 40 and reflects light passing through the back surface of the light guide plate 40 toward the liquid crystal panel to improve the brightness of light.

The plurality of optical sheets 30 on the light guide plate 40 include a diffusion sheet and at least one light collecting sheet and diffuse or condense light passing through the light guide plate 40 to form a more uniform surface light source Let it enter.

The liquid crystal panel and the backlight unit are modularized through a top cover (not shown), a support main body 10, and a cover bottom 20.

The cover bottom 20, on which the liquid crystal panel and the backlight unit are mounted and which is the basis for assembling the entire structure of the liquid crystal display device module, is formed as a horizontally flat plate-like shape.

At this time, the PCB is formed on one edge perpendicular to the horizontal plane of the cover bottom 20. Also,

The support main body 10 surrounds the outer periphery of the cover bottom 20 and is fastened.

 The light source 50 includes a light source 50 and a second portion covering one side edge of the upper portion of the light guide plate 40 so that the light emitted from the light source 50 can be efficiently incident on the light guide plate 40. [ 80 are formed. Accordingly, the light emitted from the light source 50 can be concentrated in the direction of the light guide plate 40, thereby preventing light loss.

At this time, the partial housing 80 includes a first portion formed between the PCB 60 and the light guide plate 40 while being fastened between the plurality of light sources 50. Therefore, it is possible to prevent the light guide plate 40 from being inflated or pushed to press or press the light source 50.

The backlight unit having the above-described structure is generally called a side light type, and a plurality of light sources 50 may be arranged in multiple layers on the PCB 60 according to the purpose. Further, it is apparent to those skilled in the art that a plurality of light sources 50 may be provided to correspond to each other along both edges of the cover bottom 20 facing each other.

Hereinafter, Figs. 3 to 5 show respective embodiments of the liquid crystal display device cut along the line A-A '. 3 to 5, the cover bottom 20, the plurality of light sources 50 and the partial housing 80 of the present invention will be described in more detail.

3, a PCB 60 is formed on one edge of the cover bottom 20 perpendicular to the horizontal bottom, and a plurality of light sources 50 are mounted on the PCB 60. [

A plurality of first portions 80b inserted between the plurality of light sources 50 and a plurality of first portions 80b extending in a direction perpendicular to the plurality of first portions and partially covering the upper surface of the light source 50 and a portion of the edge of the light guide plate And a part housing 80 including a second portion 80a covering it is fastened to the light source.

And can be further fixed with an adhesive between the partial housing 80 and the PCB 60.

The partial housing 80 is formed integrally as a material of PC, metal, or the like, which is stronger in heat than resin.

The first portion 80b and the second portion 80a are connected to each other to form a "print" shape.

Here, the width of the first portion 80b may have a smaller value than the interval between the plurality of light sources. The thickness of the first portion 80b is larger than the thickness of the light source 50 and protrudes toward the light guide plate 40 from the light source 50. [ At this time, it is possible to prevent the light guide plate 40 from being damaged by being pushed or pushed by heat to press the light source 50.

The second portion 80a covering the edge portion of the light guide plate 40 and the upper surface of the light source 50 relieves the alignment of the light guide plate 40 and the light source 50, It plays a role.

 4 is a cross-sectional view schematically illustrating a light-incident portion according to a second embodiment of the present invention taken along the line A-A '.

Hereinafter, a second embodiment of the partial housing of the present invention will be described with reference to FIG.

First, description of the same or similar parts to those of the first embodiment will be omitted.

As shown in FIG. 4, in the second embodiment of the present invention, a fastening portion 81c is further formed in the partial housing 81. As shown in FIG.

Concretely, the fastening portion 81c of the partial housing 81 and the cover bottom 21 are assembled and fastened to each other. For this purpose, the fastening portion 81c is formed to extend vertically in the direction from the second portion 81a to the first portion 81b.

At this time, the fastening portion 81c surrounds the outer surface of the cover bottom 21 and is completely assembled and fastened through a screw or a hook.

The partial housing 81 prevents the cover bottom 21 and the partial housing 81 from separating and flowing even under an external impact so that the partial housing 81 guides the light guide plate 41 and the plurality of light sources 51 more stably .

The second portion 81a of the partial housing 81 covers the upper surface of the plurality of light sources 51 and a part of the edge of the light guide plate 41 to prevent the light from being leaked from the light source 51 Is as described above. Therefore, the first portion 81b protrudes from the light source 51 in the direction of the light guide plate 41, thereby preventing the light source 51 from being damaged by the expansion and the swelling of the light guide plate.

5 is a cross-sectional view schematically illustrating a light-incident portion according to a third embodiment of the present invention taken along the line A-A '.

Hereinafter, description of parts similar to those of the first and second embodiments with respect to the third embodiment of Fig. 5 will be omitted.

As shown in FIG. 5, the first portion 81a of the partial housing 82 is fastened one to two of the plurality of light sources 52 one by one.

Specifically, the first portion 82b is not formed between the plurality of light sources 52, but is formed between two or more light sources. Here, the partial housing 82 may further include a fastening portion to be fastened to the cover bottom 22.

Figure 6 shows a sectional view of a partial housing of the present invention.

6, the partial housing 86 of the present invention includes a first portion 86a and a second portion 86b.

Specifically, a reflection layer 90 for reflecting light is formed on the inner surface of the partial housing 86. The reflective layer 90 reflects the light emitted from the light source 50 and enters the light guide plate 40 (FIG. 2). To this end, the reflective layer 90 is formed only on the inner wall surface of the first portion 86b of the partial housing 86 or on the inner wall surface of the first portion 86b and the second portion 86a.

A reflection film RP having high light reflection efficiency is formed on the reflection layer 90 of the partial housing 86. At this time, the reflective film RP may be formed, for example, by bonding a material used for a reflector (70 in FIG. 2) or by coating a synthetic resin or the like with high reflection efficiency. Also, if the partial housing 86 is made of metal, the inner surface may be mirror-finished.

Therefore, the plurality of light sources (50 in FIG. 2) efficiently reflect the light emitted from the plurality of light sources through the reflection layer 90 formed in the partial housing to the light guide plate (40 in FIG. 2) Guiding the incident light to the light guide plate without loss.

An absorbing layer 91 for absorbing light may be formed on the inner wall surface of the second portion 86a of the partial housing. Specifically, the absorbing layer 91 can prevent light emitted from the light source (50 in FIG. 2) from leaking to the outside by attaching a shielding tape, for example, a gray or black pad or a double-sided tape capable of blocking light. Therefore, in order to prevent the light emitted from the light source from leaking to the outside, a gray or black light absorbing layer 91 may be coated on the inner wall surface of the first portion 86a.

The light absorbing layer 91 is formed on the light absorbing layer 91 such that a gap is formed as the alignment of the light guide plate 40 and the plurality of light sources 50 in FIG. 2 is turned, so that hot spots are not generated, Lt; / RTI >

The embodiment of the present invention described above is an example of the present invention, and variations are possible within the spirit of the present invention. Accordingly, the invention includes modifications of the invention within the scope of the appended claims and equivalents thereof.

10: Support main 20: Cover cover
30: optical sheet 40: light guide plate
50: light source 60: PCB
70: reflector 80: partial housing
80a: second part 80b: first part
90: reflective layer 91: light absorbing layer

Claims (11)

A liquid crystal panel;
A backlight unit positioned at a lower portion of the liquid crystal panel and including a reflection plate, a light guide plate, and a plurality of light sources;
A support main body surrounding an edge of the backlight unit;
And a cover bottom which is assembled with the support main body,
A PCB mounting the plurality of light sources,
A plurality of first portions which are fastened to the upper portion of the light source and are positioned between the PCB and the light guide plate and a second portion which is perpendicular to the first portion and can cover up to the edge portions of the light source and the light guide plate, Is further formed,
The plurality of light sources are spaced apart from each other. The plurality of light sources guide light emitted from the light source and enter the light guide plate.
Liquid crystal display device.
The method according to claim 1,
The plurality of the first portion is engaged between the plurality of light sources having a '┍' shape
Liquid crystal display device. 3. The method of claim 2,
The thickness of the first portion is larger than the thickness of the light source
Liquid crystal display device.
The method according to claim 1,
The partial housing is formed of a material that is stronger than the resin
Liquid crystal display device.
3. The method of claim 2,
Wherein a width of the first portion is smaller than an interval between the light sources.
3. The method of claim 2,
Wherein the first portion is formed correspondingly between the plurality of light sources.
3. The method of claim 2,
The first portion is formed to protrude from the light source toward the light guide plate
Liquid crystal display device.
The method according to claim 1,
The inner side of the partial housing has a reflective layer for reflecting light
Liquid crystal display device.
The method according to claim 1,
An inner side of the second portion of the partial housing is formed with an absorbing layer for absorbing light
Is a liquid crystal display device.
The method according to claim 1,
The partial housing includes a fastening portion for fastening further with the cover bolt
Liquid crystal display device.
The method according to claim 1,
Wherein the liquid crystal display device has a curved shape.

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