KR101695286B1 - Back light unit and method for assembling the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and a method of assembling the backlight unit, which can facilitate the assembling process of the backlight unit by using a plurality of guide pins and holding pins, A plurality of array substrates mounted with a light source and arranged for each of the predetermined divided areas, a bottom cover having at least one guide pin in each of the divided areas to align the array substrates with the respective divided areas, A plurality of light guide plates formed to be aligned with the respective array substrates by the guide pins, a plurality of array substrates, light guide plates, and bottom cover, And a plurality of holding pins fixed to the bottom cover The.

Modular back-light unit, light-providing block,

Description

BACK LIGHT UNIT AND METHOD FOR ASSEMBLING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and a method of assembling the backlight unit, which can facilitate the assembling process of the backlight unit by using a plurality of guide pins and holding pins,

In general, a liquid crystal display (LCD) is one of flat panel display devices for displaying images using liquid crystal. It is thin and light compared to other image display devices, has advantages of low driving voltage and low power consumption, It is widely used throughout.

Such a liquid crystal display device requires a backlight unit for supplying light since a liquid crystal display panel for displaying an image is a non-luminescent module that does not emit light by itself.

BACKGROUND ART [0002] A backlight unit is divided into a direct-type backlight unit and an edge-type backlight unit according to its structural difference. Recently, a liquid crystal display A Modular Back-light Unit is used.

The modular backlight unit is designed so that a plurality of edge type backlights are arranged and can be dividedly driven according to the display region of an image, and both of the advantages of the edge type backlight unit and the direct type backlight unit can be utilized.

The modular backlight unit is configured by assembling a plurality of backlights, that is, a plurality of light emitting blocks, each having a light guide plate and the like arranged corresponding to each of the plurality of light source arrays divided and driven. These light emitting blocks are assembled to be coupled vertically, horizontally and vertically through a coupling screw or a screw.

However, since the conventional modular backlight unit as described above requires a plurality of light emitting blocks to be assembled and arranged, the assembling process is complicated. In other words, in the process of assembling and arranging a plurality of light emitting blocks, the light emitting blocks are often turned off, and the assembly process becomes complicated as the number of the light blocking blocks increases. When the light emitting blocks are turned off, the uniformity of light emission of the backlight unit is lowered, which affects the image quality of the display image.

In addition, since the light emitting blocks of the modular backlight unit are assembled to be coupled with each other through a coupling screw or a screw, damages such as cracks are generated due to an external force applied to a coupling screw or a screw having a large frictional force. Thus, the manufacturing cost and the manufacturing time were increased, and the production efficiency was remarkably lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a backlight unit capable of easily fabricating a backlight unit by using a plurality of guide pins and a holding pin, And a method of assembling the same.

According to an aspect of the present invention, there is provided a backlight unit including a plurality of array substrates mounted with a plurality of light sources and arranged in each of a predetermined division region, at least one guide pin A plurality of light guide plates arranged to correspond to the respective array substrates and aligned with the array substrates by the guide pins; a plurality of light guide plates, And a plurality of holding pins fastened to the bottom cover through the bottom cover to fix the array substrate and the light guide plates to the bottom cover.

A reflective sheet formed on a front surface of the array substrate and the bottom cover excluding a plurality of light sources so as to be aligned and fixed by the guide pins and the holding pins to reflect the light emitted from each of the light guide plates toward the light guide plate, And a plurality of optical sheets that are formed on the light guide plate and condense and diffuse the light from the light guide plates and emit the light.

Wherein each of the light guide plates includes a plurality of fixed support holes through which the respective holding pins are inserted, and the light guide plate includes a plurality of fixed support holes for allowing the respective holding pins to pass therethrough, And the plurality of holding pins are formed in the respective array substrates so as to be penetrated by the holding pins and are fixed by the respective holding pins, and a plurality of And the plurality of holding pins are fixedly passed through the plurality of cover supporting holes so that the array substrate, the light guide plate, and the reflective sheet are fixed to the bottom cover.

And each of the holding pins is formed at a contact portion for simultaneously fixing the array substrates adjacent to each other.

Each of the holding pins has a support portion for placing pressure on the light guide plate, the reflective sheet, and the array substrate, which are positioned at the frontmost positions on the front surface, and a support portion integrally formed with the support portion, And a holder for fixing the light guide plate, the reflection sheet, and the array substrate to the bottom cover by being passed through the support hole.

According to another aspect of the present invention, there is provided a method of assembling a backlight unit, comprising: preparing a plurality of array substrates so that a plurality of light sources are mounted on the substrate; Aligning each of the array substrates to each of the divided areas in a bottom cover having at least one guide pin in each of the divided areas; Forming a plurality of light guide plates so as to be aligned with the guide pins at respective positions corresponding to the respective array substrates, and fastening a plurality of holding pins through the plurality of array substrates, the light guide plate and the bottom cover, And fixing the array substrate and the light guide plates to the bottom cover.

Forming a reflective sheet on a front surface of each of the array substrates and the bottom cover except for the plurality of light sources to be coupled by the holding pins, and projecting the light from the light guide plates to the light guide plate And forming a plurality of optical sheets on the substrate.

Wherein the step of forming the reflective sheet includes the step of fastening the respective holding pins to the reflective support holes formed in the reflective sheet, wherein each of the light guide plates includes a plurality of fixing holes formed in the light guide plates, And each of the holding pins is fastened to each of the plurality of substrate supporting holes, wherein each of the array substrate forming steps includes a step of allowing each of the holding pins to pass through a plurality of substrate supporting holes provided in the respective array substrates, And fixing each of the array substrate, the light guide plate, and the reflection sheet to the bottom cover itself by fastening a plurality of holding pins to each cover support hole of the bottom cover.

And each of the holding pins is formed at a contact portion for simultaneously fixing the array substrates adjacent to each other.

The backlight unit and the method for assembling the backlight unit according to the present invention having the above-described features can facilitate the assembling process of the backlight unit using the plurality of guide pins and the holding pins, have. Further, the light emission luminance from the backlight unit can be made more uniform.

Hereinafter, a backlight unit and an assembling method thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along a line I-I in FIG.

The liquid crystal display device shown in FIG. 1 includes a liquid crystal display panel 140 having a plurality of liquid crystal cells and displaying an image; A backlight unit 110 for emitting light to the liquid crystal display panel 140; A mold frame 142 for supporting the liquid crystal display panel 140 and a top case 144 for covering and fixing the periphery of the liquid crystal display panel 140 and the mold frame 142.

In the liquid crystal display panel 140, liquid crystal cells are arranged in an active matrix form between the upper and lower substrates, and a thin film transistor for switching video signals is formed in each of the liquid crystal cells. In this liquid crystal display panel 140, the refractive index of each liquid crystal cell changes according to the video signal, thereby displaying an image corresponding to the video signal.

The top case 144 is formed in the shape of a rectangular band having a flat portion bent at right angles and a side portion. The top case 144 surrounds the edge of the liquid crystal display panel 140 and is fastened to the side surface of the mold frame 142.

The mold frame 142 is made of a plastic material or an aluminum alloy, and the sidewall surface of the mold frame 142 is formed into a stepped step. The liquid crystal display panel 140 is seated on the stepped surface of the mold frame 142.

The backlight unit 110 shown in FIGS. 1 and 2 includes a plurality of array substrates 120 on which a plurality of light sources 122 are mounted and are arranged for respective predetermined division regions; A bottom cover (124) provided with at least one guide pin (302) in each divided region to align each array substrate (120) to each divided region; And a plurality of light guide plates (not shown) which are respectively formed to correspond to the respective array substrates 120 and aligned with the respective array substrates 120 by the respective guide pins 302 and which change the light traveling direction from the light sources 122 114); And a plurality of array substrates 120 and light guide plates 114 that are mounted to penetrate the plurality of array substrates 120, the light guide plate 114 and the bottom cover 124, The holding pin 402 of the holder 300; Is formed on the front surface of each of the array substrate 120 and the bottom cover 124 excluding the plurality of light sources 122 so as to be aligned and fixed by the guide pins 302 and the holding pins 402, A reflection sheet 128 for reflecting the light to the light guide plate 114 in the direction of the light guide plate 114; And a plurality of optical sheets 134 formed on the plurality of light guide plates 114 to diffuse the light from the respective light guide plates 114.

The plurality of light sources 122 are mounted on the array substrate 120 at least one by one, and receive driving power from a light source driving circuit (not shown) to generate light. Each of the light sources 122 includes a light emitting diode of a side view type in which the direction of light emission is directed to the side light incident portion of each light guide plate 114. In other words, the light source 122 may be a side emission type light emitting diode.

Each of the array substrates 120, which are fixed to at least one light source 122 and supply driving power to the light sources 122, may be any one of a flexible plastic substrate, a metal PCB substrate, and a FR4 substrate Lt; / RTI >

2, one of the array substrates 120 including at least one light source 122 and one of the light guide plates 114 corresponding to the one array substrate 120 may be combined into a pair of light providing blocks BL . 1, the liquid crystal display panel 140 may be divided into a display area corresponding to the number of the light providing blocks BL, that is, predetermined divided areas. At this time, Respectively. Each light providing block BL is dividedly driven to be driven by a local dimming method. For example, when the light sources 122 of any one of the light providing blocks BL are turned on, the light sources 122 of the remaining light providing blocks BL are turned off or turned on But may be turned on at a lower luminance than the light sources 122 of the light providing block BL.

The bottom cover 124 is formed so as to engage with the mold frame 142 while covering the entire back direction of the backlight unit 110. On the inner surface of the bottom cover 124, at least one guide pin 302 is formed to correspond to the divided regions. Each of the guide pins 302 is formed to more easily align the light guide plates 114 with the respective array substrates 120 that are seated in the corresponding divided areas. In addition, a plurality of cover supporting holes 500 are formed in the bottom cover 124 to correspond to the divided regions. The plurality of cover support holes 500 are formed to allow the plurality of holding pins 402 to be penetrated so that the array substrate 120 and the light guide plate 114 are fixed to the bottom cover 124 itself.

The reflective sheet 128 is formed on the entire surfaces of the array substrate 120 and the bottom cover 124 except for the plurality of light sources 122, that is, between the plurality of light guide plates 114 and the plurality of array substrates 120 do. The reflection sheet 128 is formed with a plurality of first through holes 304 through which the guide pins 302 are inserted and a plurality of reflection holes 406 through which the plurality of the holding pins 402 are inserted And are aligned and fixed by the guide pins 302 and the holding pins 402, respectively. A plurality of light source receiving holes 118 are formed in the reflective sheet 128 so that the plurality of light sources 122 pass through the plurality of light source receiving holes 118 so that the plurality of light sources 122 protrude toward the light guide plate 114. The reflective sheet 128 thus configured reflects the light emitted from each of the light guide plates 114 toward the light guide plate 114 to prevent light loss.

Each of the light guide plates 114 is disposed for each of the divided regions so as to correspond to the respective light sources 122 mounted on the respective array substrates 120. Each of the light guide plates 114 guides light incident from each light source 122 toward the liquid crystal display panel 140. Each of the light guide plates 114 is provided with a plurality of second through holes 306 through which the respective guide pins 302 are inserted and fixed support holes 404 for fastening the plurality of the holding pins 402 And are aligned and fixed by the guide pins 302 and the holding pins 402, respectively.

The plurality of optical sheets 134 scatter and condense light emitted from the plurality of light guide plates 114 and increase the brightness, thereby improving light efficiency and supplying the light to the liquid crystal display panel 140. To this end, the plurality of optical sheets 134 include a light converging sheet, a diffusion sheet, and a polarizing sheet.

FIG. 3 is a detailed view showing the structure of the bottom cover and one array substrate of FIG. 1. FIG.

3, a plurality of light sources 122 are fixed to one surface of the array substrate 120. A plurality of light sources 122 are arranged on the other surface of the array substrate 120, Connectors may be provided.

A plurality of third through holes 301 through which the respective guide pins 302 are passed and a substrate support hole 408 through which the plurality of holding pins 402 are fastened are formed on the respective array substrates 120 And are aligned and fixed by the guide pins 302 and the holding pins 402, respectively. Each guide pin 302 is first fitted into the third through hole 301 of each array substrate 120 so that the array substrate 120 is first aligned on the bottom cover 124. And the remaining array substrates 120 are aligned on the bottom cover 124 so as to be arranged for each of the divided regions.

Each of the guide pins 302 is preferably positioned such that the direction of light generated from the plurality of light sources 122 is not changed, that is, the influence of the light on the traveling direction of the light is minimized. Each of the guide pins 302 may be formed to be positioned between a plurality of light sources adjacent to each other among the light sources 122. The guide pins 302 may be formed on the front surface or the rear surface of the light sources 122 .

The holding pins 402 provided to more easily fasten the light guide plate 114, the reflection sheet 128 and the array substrate 120 are also arranged so that the direction of light generated from each light source 122 does not change , So that the influence exerted on the traveling direction of the light is minimized. Accordingly, each of the holding pins 402 may be formed at a contact portion for simultaneously fixing adjacent array substrates 120.

4A and 4B are perspective views illustrating a holding pin of any one of the plurality of holding pins shown in FIG.

The holding pins 402 shown in Figs. 4A and 4B include a light guide plate 114 positioned at the frontmost position and a back surface thereof, a supporting portion 402a for applying pressure to the reflective sheet 128 and the array substrate 120, The light guide plate 114 is integrally formed with the support portion 402b and fixed through the fixing support hole 404, the reflection support hole 406, the substrate support hole 408 and the cover support hole 500, 128) and a holder (402b) for fixing the array substrate (120) to the bottom cover (124). Here, the support portion 402b and the holder 402b may be formed of a reflective plastic material or may be formed by applying a reflective material to a plastic material, thereby reflecting light from each light source 122. [

Fig. 5 is an assembled view of the bottom cover and one array substrate of Fig. 1 in different directions. Fig.

5, the bottom cover 124 accommodates the above-described array substrate 120, the reflective sheet 128, and the plurality of light guide plates 114. Inside the bottom cover 124, The plurality of guide pins 302 formed on the surface of the light guide plate 114 are formed in the third through holes 301 of the array substrate 120, the first through holes 304 of the reflective sheet 128, and the second through holes 306 of the light guide plate 114 , The light-providing blocks BL are aligned in a non-shifting manner.

The plurality of holding pins 402 are inserted into the fixing support holes 404 of the light guide plate 114, the reflection support holes 406 of the reflective sheet 128, the substrate support holes 408 of the array substrate 120, The light guide plate 114 and the reflection sheet 128 and the array substrate 120 are fixed to the bottom cover 124 by being fixed through the cover support hole 500 of the cover 124.

The method of assembling the backlight unit of the present invention constructed as described above will now be described.

First, a plurality of array substrates 120 on which at least one light source 122 is mounted are prepared. In addition, a bottom cover 124 having at least one guide pin 302 formed in each of the divided areas is prepared.

Next, each array substrate 120 is aligned in each divided region of the bottom cover 124 so that the at least one guide pin 302 penetrates through the third through holes 301 of each array substrate 120 .

The reflective sheet 128 is then aligned on the front surface of the bottom cover 124 so that the at least one guide pin 302 penetrates through the first through holes 304 of the reflective sheet 128. At this time, the respective light sources 122 protrude into the light source receiving holes 118.

Next, a plurality of light guide plates 114 corresponding to the number of the array substrates 120 are prepared, and the light guide plates 114 are aligned on one side of each array substrate 120. At this time, the light guide plates 114 are aligned so that the at least one guide pin 302 passes through the second through holes 306 of the light guide plate 114.

Thereafter, the plurality of holding pins 402 are inserted into the fixed support holes 404 of the light guide plate 114, the reflection support holes 406 of the reflective sheet 128, the substrate support holes 408 of the array substrate 120, The light guide plate 114 and the reflective sheet 128 and the array substrate 120 are fixed to the bottom cover 124 by fastening them to the cover support hole 500 of the cover 124.

Finally, at least one optical sheet 134 may be disposed on the front surface of each light guide plate 114 to be assembled with the liquid crystal display panel 114 together with the mold frame 142.

As described above, in the backlight unit and the method of assembling the same according to the present invention, each of the light providing blocks BL is easily aligned by the plurality of guide pins 302. Then, the plurality of holding pins 402 are fastened to easily fix each of the light providing blocks BL to the bottom cover 124.

Accordingly, the assembling process of the backlight unit as a whole becomes easier, so that the assembling time can be shortened, and defects in which the light-providing blocks BL are damaged by the external pressure can be prevented. It is also possible to prevent the light guide plate (302) from being tilted by the respective guide pins (302), that is, the array substrate (120), the reflective sheet (128) and the light guide plate (114) The light emission luminance becomes more uniform.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. Will be clear to those who have knowledge of.

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

2 is a cross-sectional view taken along a line I-I in Fig.

3 is a detailed view showing the structure of the bottom cover and one array substrate of FIG. 1;

FIGS. 4A and 4B are perspective views illustrating a holding pin of any one of the plurality of holding pins shown in FIG. 1. FIG.

Fig. 5 is an assembly drawing showing the bottom cover and one array substrate of Fig. 1 in different directions. Fig.

Claims (9)

A plurality of array substrates on which a plurality of light sources are mounted, A bottom cover having at least one guide pin in each of the divided areas to align the array substrates with the respective divided areas, A plurality of light guide plates positioned corresponding to the array substrates and aligned with the array substrates by the guide pins, The array substrate and the light guide plates, which are positioned so as to correspond to the contact portions of the array substrates so as to be able to simultaneously fix the array substrates adjacent to each other, and which are connected to the array substrate, the light guide plate, and the bottom cover, A plurality of holding pins fixed to the bottom cover, A reflective sheet positioned on a front surface of the array substrate and the bottom cover excluding a plurality of light sources so as to be aligned and fixed by the guide pins and the holding pins and reflecting the light emitted from each of the light guide plates toward the light guide plate; And a plurality of optical sheets which are positioned on the plurality of light guide plates and condense and diffuse the light from the light guide plates and emit the light. delete The method according to claim 1, The reflective sheet And each of the holding pins has a reflecting support hole through which the holding pins are inserted, Wherein each of the light guide plates is provided with a plurality of fixed support holes through which the respective holding pins are inserted and fixed by the respective holding pins, Wherein each of the array substrates is provided with a plurality of substrate support holes through which the respective holding pins are inserted and fixed by the respective holding pins, The bottom cover is provided with a plurality of cover support holes to allow the plurality of holding pins to pass through the plurality of cover support holes to fix the respective array substrates and the light guide plate and the reflection sheet to the bottom cover itself. . delete The method of claim 3, Each of the holding pins A support portion for placing pressure on the light guide plate, the reflective sheet and the array substrate, And a backlight unit having a holder for fixing the light guide plate, the reflection sheet, and the array substrate to the bottom cover by being fixed to the fixed support holes, the reflection support holes, the substrate support holes and the cover support holes, . Preparing a plurality of array substrates so that a plurality of light sources are mounted and arranged in each of the predetermined division regions; Aligning each array substrate with each of the divided areas in a bottom cover having at least one guide pin in each of the divided areas; Forming a reflective sheet on the front surface of each of the array substrate and the bottom cover excluding the plurality of light sources so as to be fixed by the guide pin; Forming a plurality of light guide plates to be aligned by the guide pins at respective positions corresponding to the respective array substrates; A plurality of holding pins are coupled to the plurality of array substrates, the reflection sheet, the light guide plate, and the bottom cover at positions corresponding to the contact portions of the array substrates so as to fix the array substrates adjacent to each other, Fixing the array substrate and the light guide plates to the bottom cover; And And forming a plurality of optical sheets on the plurality of light guide plates so that light from the light guide plates is condensed and diffused and emitted. delete The method according to claim 6, The reflective sheet forming step And fixing each of the holding pins to a reflecting support hole formed in the reflective sheet, Wherein each of the light guide plates includes a plurality of fixing holes formed in the light guide plate to fasten the respective holding pins to each other, And fixing a plurality of holding pins to each of the cover supporting holes of the bottom cover so that the array substrate, the light guide plate, and the reflection sheet are fixed to the bottom cover itself. 6. The method of claim 5, The support portion and the holder are made of a reflective plastic material, or a plastic material is applied to a reflective material.

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