KR20110074812A - Back light unit and method for assembling the same - Google Patents

Abstract

PURPOSE: A backlight unit and a method for assembling the same are provided to simplify the assembling process of the backlight unit and uniform the brightness. CONSTITUTION: A backlight unit comprises an array substrate(120) in which a plurality of light source(122) are mounted and allocated to a predetermined areas, a bottom cover(124) in which each array substrate is arranged using one or more guide pin(302), a plurality of light guide plates(114) which is respectively arranged by the guide pin, and a plurality of holding pin(402) which fixes each array substrate and each light guide plate to the bottom cover.

Description

BACK LIGHT UNIT AND METHOD FOR ASSEMBLING THE SAME}

The present invention relates to a backlight unit and a method for assembling the same, which makes the assembling process of the backlight unit easier by using a plurality of guide pins and holding pins, and also makes the emission luminance uniform.

In general, a liquid crystal display (Liquid Crystal Display) is a flat panel display device that displays an image using a liquid crystal, it is thinner and lighter than other image display devices, and has the 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 because the liquid crystal display panel for displaying an image is a non-light emitting module which cannot emit light by itself.

The backlight unit is classified into a direct type backlight unit and an edge type backlight unit according to the structural difference. In recent years, the LCD unit is a module capable of dividing and driving an area in which an image is displayed in accordance with the trend of larger LCDs. Modular back-light units are used.

The modular backlight unit is designed to be dividedly driven according to the display area of the image by arranging a plurality of edge-type backlights, and may utilize all the advantages of the edge-type backlight unit and the direct backlight unit.

The modular backlight unit is constructed by assembling a plurality of backlights, that is, a plurality of light emitting blocks, each of which has a light guide plate or the like arranged corresponding to each of a plurality of light source arrays which are driven separately. These light emitting blocks are assembled to be coupled up, down, left and right through a coupling screw or screw.

However, the conventional modular backlight unit as described above has a disadvantage that the assembly process is difficult because a plurality of light emitting blocks are assembled and arranged. In other words, in the process of assembling and arranging a plurality of light emitting blocks, light emitting blocks are frequently distorted, and as the number of blocks of the light guiding block increases, the assembly process becomes more difficult. When the light emitting blocks are distorted, 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 to each other through coupling screws or screws, damages such as cracks are severely generated by external forces applied to coupling screws or screws having a large friction force. As a result, the manufacturing cost and manufacturing time increased, and the manufacturing efficiency was significantly reduced.

The present invention is to solve the above problems, a backlight unit that can be made easier to assemble the backlight unit by using a plurality of guide pins and holding pins, and also the luminance of the light is uniform. And an assembly method thereof.

According to an embodiment of the present invention, a backlight unit includes a plurality of array substrates on which a plurality of light sources are mounted and disposed for each preset division region, and at least one guide pin in each division region. A bottom cover for aligning each of the array substrates to each divided area, a plurality of light guide plates each formed to correspond to the array substrates, and aligned with the array substrates by the guide pins, the plurality of array substrates and the light guide plates And a plurality of holding pins fastened to penetrate the bottom cover to fix each of the array substrates and the light guide plates configured for each divided area to the bottom cover.

A reflection sheet and a plurality of reflection sheets which are formed on the front surface of the array substrate and the bottom cover except for a plurality of light sources so as to be aligned and fixed by the guide pins and the holding pins and reflect light emitted from each of the light guide plates toward the light guide plate again. It is characterized by further comprising a plurality of optical sheets formed on the light guide plate for condensing and diffusing the light from the light guide plate.

The reflective sheet is formed with reflective support holes for allowing the respective holding pins to pass therethrough, and is fixed by the respective holding pins, and each of the light guide plates has a plurality of fixed support holes for allowing the respective holding pins to pass therethrough. A plurality of substrate support holes are formed in the respective array substrates to allow the respective holding pins to pass therethrough, and are fixed by the respective holding pins, and a plurality of the bottom covers. A cover support hole is formed to allow the plurality of holding pins to be penetrated and fixed to the plurality of cover support holes, so that each of the array substrate, the light guide plate, and the reflective sheet is fixed to the bottom cover itself.

Each of the holding pins may be formed at a side surface or a rear surface of the plurality of light sources, and may be formed at a contact portion to simultaneously fix the array substrates adjacent to each other.

The holding pins are integrally formed with a support portion and a support portion for applying pressure to the light guide plate, the reflective sheet, and the array substrate, which are located at the front and located at the front side thereof, and are fixed to the support hole, the reflection support hole, the substrate support hole, and the cover. And a holder for fixing the light guide plate, the reflective sheet, and the array substrate to the bottom cover by being fixed through the support hole.

In addition, a method of assembling a backlight unit according to an embodiment of the present invention for achieving the above object comprises the steps of preparing a plurality of array substrate so that a plurality of light sources are mounted and arranged for each of the predetermined divided region; Aligning each array substrate with each of the divided regions in a bottom cover having at least one guide pin in each of the divided regions; Forming a plurality of light guide plates to be aligned by the respective guide pins at respective positions corresponding to the respective array substrates, and fastening the plurality of holding pins to penetrate the plurality of array substrates, the light guide plate, and the bottom cover, respectively. And fixing each of the array substrates and the light guide plates configured for each region to the bottom cover.

Forming a reflective sheet on the front surface of each of the array substrate and the bottom cover except the plurality of light sources to be fastened by the holding pins, and condensing and diffusing light from each of the light guide plates to emit the plurality of light guide plates. It characterized in that it further comprises the step of forming a plurality of optical sheets on.

The forming of the reflective sheet may include fastening the respective holding pins to the reflective supporting holes formed in the reflective sheet, and the forming of each light guide plate may include the plurality of fixed support holes provided in the respective light guide plates. Allowing each holding pin to be fastened, wherein each array substrate forming step includes allowing each holding pin to pass through a plurality of substrate support holes provided in the respective array substrate, And a plurality of holding pins coupled to each cover supporting hole of the bottom cover to fix the respective array substrate, the light guide plate, and the reflective sheet to the bottom cover itself.

Each of the holding pins may be formed at a side surface or a rear surface of the plurality of light sources, and may be formed at a contact portion to simultaneously fix the array substrates adjacent to each other.

The backlight unit and its assembling method according to an embodiment of the present invention having the above characteristics can shorten the assembly time by making the assembly process of the backlight unit easier by using a plurality of guide pins and holding pins. have. In addition, the light emission luminance from the backlight unit can be made more uniform.

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

1 is a perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II of FIG. 1.

The liquid crystal display shown in FIG. 1 includes a liquid crystal display panel 140 including a plurality of liquid crystal cells to display an image; A backlight unit 110 for irradiating light onto the liquid crystal display panel 140; A mold frame 142 supporting the liquid crystal display panel 140 and a top case 144 for covering and fixing the peripheral portions of the liquid crystal display panel 140 and the mold frame 142 are provided.

In the liquid crystal display panel 140, liquid crystal cells are arranged in an active matrix between upper and lower substrates, and thin film transistors for switching video signals are formed in each of the liquid crystal cells. The liquid crystal display panel 140 displays an image corresponding to the video signal by changing the refractive index of each of the liquid crystal cells according to the video signal.

The top case 144 is manufactured in the form of a square strip having a flat portion and a side portion bent at a right angle. The top case 144 surrounds the edge of the liquid crystal display panel 140 and is fastened to the side of the mold frame 142.

The mold frame 142 is formed of a plastic material or an aluminum alloy, and the side wall surface thereof is formed into a stepped stepped surface. The liquid crystal display panel 140 is mounted 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 in which a plurality of light sources 122 are mounted and disposed for each divided region; A bottom cover 124 having at least one guide pin 302 in each divided area to align each array substrate 120 to each divided area; A plurality of light guide plates each formed to correspond to the respective array substrates 120 and aligned with the respective array substrates 120 by the guide pins 302, and converting a light propagation direction from each light source 122 ( 114); A plurality of array substrates 120, which are mounted to penetrate the plurality of array substrates 120, the light guide plate 114, and the bottom cover 124, respectively, to fix the array substrate 120 and the light guide plates 114 configured for each divided area to the bottom cover 124. Holding pin 402; It is formed on the front surface of each array substrate 120 and the bottom cover 124 excluding the plurality of light sources 122 to be aligned and fixed by each guide pin 302 and the holding pin 402 and exit from each light guide plate 114 Reflective sheet 128 for reflecting the light back toward the light guide plate 114; And a plurality of optical sheets 134 formed on the plurality of light guide plates 114 to diffuse light from each of the light guide plates 114.

The plurality of light sources 122 are mounted on at least one of the array substrates 120 to 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 having a side view in which an emission direction of the light is directed toward the side light incident part of each light guide plate 114. In other words, the light source 122 may be a side view type light emitting diode of a side emission type.

Each array substrate 120 to which at least one light source 122 is fixed to supply driving power to the respective light sources 122 may be any one of a flexible plastic substrate, a metal PCB substrate, and a FR4 substrate. Can be done.

As illustrated in FIG. 2, one array substrate 120 including at least one light source 122 and one light guide plate 114 corresponding thereto may be paired to provide one light providing block BL. Form. As shown in FIG. 1, the liquid crystal display panel 140 may be divided into display areas corresponding to the number of light providing blocks BL, that is, predetermined divided areas, wherein each light providing block BL is divided into a corresponding partition. Provide light to the area, respectively. Each light providing block BL is divided and driven to be driven by a local dimming method. For example, when the light sources 122 of any of the unit light providing blocks BL of each 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. It 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 to be coupled to the mold frame 142 while covering all the back directions of the backlight unit 110. At least one guide pin 302 is formed on the inner surface of the bottom cover 124 to correspond to the divided regions. Each of the guide pins 302 is formed to more easily align each of the array substrate 120 and the light guide plate 114 seated in the corresponding divided region. In addition, the bottom cover 124 is further provided with a plurality of cover support holes 500 to correspond to the divided regions. The plurality of cover support holes 500 are formed to fix the array substrate 120 and the light guide plate 114 to the bottom cover 124 itself by allowing the plurality of holding pins 402 to be fastened therethrough.

The reflective sheet 128 is formed between the plurality of light guide plates 114 and the plurality of array substrates 120, that is, on the front surface of each array substrate 120 and the bottom cover 124 except for the plurality of light sources 122. do. In this case, the reflective sheet 128 includes a plurality of first through holes 304 through which the guide pins 302 pass, and reflective support holes 406 through the holding pins 402. And are aligned and fixed by respective guide pins 302 and holding pins 402. Meanwhile, a plurality of light source accommodating holes 118 through which the plurality of light sources 122 penetrate are also formed in the reflective sheet 128 so that the plurality of light sources 122 protrude in the direction of the light guide plate 114. The reflective sheet 128 configured as described above reflects the light emitted from each light guide plate 114 toward the light guide plate 114 to prevent light loss.

Each light guide plate 114 is disposed for each divided region so as to correspond to each light source 122 mounted on each array substrate 120. Each of the light guide plates 114 propagates light incident from each light source 122 toward the liquid crystal display panel 140. In this case, each of the light guide plates 114 includes a plurality of second through holes 306 through which the guide pins 302 pass, and a fixed support hole 404 through which the plurality of holding pins 402 are fastened. It is formed and aligned and fixed by each guide pin 302 and holding pin 402.

The plurality of optical sheets 134 scatter and condense the light emitted from the plurality of light guide plates 114 and increase the luminance to improve the efficiency of the light and supply it to the liquid crystal display panel 140. To this end, the plurality of optical sheets 134 include a light collecting sheet, a diffusion sheet, and a polarizing sheet.

3 is a view illustrating in detail the structure of the bottom cover and one array substrate of FIG.

As shown in FIG. 3, a plurality of light sources 122 are fixed to one surface of the array substrate 120, and an illustration for supplying driving power to the light sources 122 is provided on the other surface of the array substrate 120. Some connectors may be provided.

Each of the array substrates 120 has a plurality of third through holes 301 through which the respective guide pins 302 pass and a substrate support hole 408 through which the holding pins 402 are fastened. And are aligned and fixed by respective guide pins 302 and holding pins 402. Each of the guide pins 302 is first inserted into the third through hole 301 of each array substrate 120, thereby aligning the array substrate 120 first on the bottom cover 124. The remaining array substrates 120 are also arranged on the bottom cover 124 so as to be arranged for each divided area.

Each guide pin 302 is preferably positioned so that the traveling direction of the light generated from the plurality of light sources 122 does not change, that is, the influence on the traveling direction of the light is minimized. Accordingly, 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, wherein the guide pins 302 are to be located on the front or rear side of the respective light sources 122 Can be.

The holding pins 402 provided to more easily fasten the respective light guide plate 114, the reflective sheet 128, and the array substrate 120 may also be used so that the traveling direction of the light generated from the respective light sources 122 does not change. In this case, it is preferable that the influence on the traveling direction of the light be minimized. Accordingly, each of the holding pins 402 may be formed at a side surface or a rear surface of the plurality of light sources 122 and may be formed at a contact portion to simultaneously fix the adjacent array substrates 120.

4A and 4B are perspective views illustrating in detail one of the holding pins of the plurality of holding pins shown in FIG. 1.

The holding pins 402 illustrated in FIGS. 4A and 4B have a support part 402a which is located at the frontmost surface and pressurizes the light guide plate 114 and the reflective sheet 128 and the array substrate 120 which are located at the rear surface thereof. The light guide plate 114 and the reflective sheet are formed integrally with the support part 402b to be penetrated and fixed to the fixed support hole 404, the reflective 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 part 402b and the holder 402b may be formed of a reflective plastic material or may be formed by coating a reflective material on a plastic material to reflect light from each light source 122.

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

As shown in FIG. 5, the bottom cover 124 houses the above-described array substrate 120, the reflective sheet 128, and the plurality of light guide plates 114. The surface-formed guide pins 302 may include a third through hole 301 of the array substrate 120, a first through hole 304 of the reflective sheet 128, and a second through hole 306 of the light guide plate 114. ) So that the light providing blocks BL are aligned with each other.

In addition, the plurality of holding pins 402 may include a fixed support hole 404 of the light guide plate 114, a reflective support hole 406 of the reflective sheet 128, a substrate support hole 408 and a bottom of the array substrate 120. The light guide plate 114, the reflective 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.

Referring to the backlight unit assembly method of the present invention configured as described above as follows.

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 on each preset division is prepared.

Next, each array substrate 120 is aligned with each divided area 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. .

Subsequently, the reflective sheet 128 is 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. In this case, each of the light sources 122 protrudes from each of the light source receiving holes 118.

Next, a plurality of light guide plates 114 corresponding to the number of array substrates 120 are prepared to align the light guide plates 114 on one side of each array substrate 120. In this case, each of the light guide plates 114 is aligned such that the at least one guide pin 302 penetrates through the second through holes 306 of the light guide plate 114.

Thereafter, the plurality of holding pins 402 are fixed to the support holes 404 of the light guide plate 114, the reflection support holes 406 of the reflective sheet 128, the substrate support holes 408 and the bottom of the array substrate 120. The light guide plate 114, the reflective sheet 128, and the array substrate 120 are fixed to the bottom cover 124 by fastening 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 of the light guide plates 114 to be assembled with the liquid crystal display panel 114 together with the mold frame 142.

As described above, the backlight unit and the assembly method thereof according to the present invention allow the respective light providing blocks BL to be easily aligned by the plurality of guide pins 302. In addition, the plurality of holding pins 402 may be fastened to easily fix the respective light providing blocks BL to the bottom cover 124.

Thus, as a whole, the assembly process of the backlight unit becomes easier, so that the assembly time may be shortened, and the defects in which the light providing blocks BL are broken by external pressure may be prevented. In addition, since the respective light providing blocks BL, that is, the array substrate 120, the reflective sheet 128 and the light guide plate 114, can be prevented from being twisted by the respective guide pins 302, The light emission luminance becomes more uniform.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the art that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be evident to those who have knowledge of.

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

FIG. 2 is a cross-sectional view taken along line II of FIG. 1. FIG.

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

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

FIG. 5 is an assembly view 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 and disposed for each preset division region, A bottom cover having at least one guide pin in each divided area to align the array substrate to each divided area; A plurality of light guide plates respectively formed to correspond to the array substrates and aligned with the array substrates by the guide pins; And a plurality of holding pins fastened to penetrate the plurality of array substrates, the light guide plate, and the bottom cover to fix the array substrate and the light guide plates configured for each divided area to the bottom cover. The method of claim 1, A reflection sheet which is formed on the front surface of the array substrate and the bottom cover except a plurality of light sources to be aligned and fixed by the guide pins and the holding pins and reflects the light emitted from each of the light guide plates in the direction of the light guide plate; And a plurality of optical sheets formed on the plurality of light guide plates for condensing and diffusing light from each of the light guide plates. The method of claim 2, The reflective sheet Reflective support holes are formed to allow the respective holding pins to pass therethrough, and are fixed by the respective holding pins. Each of the light guide plates is provided with a plurality of fixed support holes for allowing the respective holding pins to pass therethrough, and are fixed by the respective holding pins. A plurality of substrate support holes are formed in each of the array substrates to allow the respective holding pins to pass therethrough and are fixed by the respective holding pins. A plurality of cover support holes are formed in the bottom cover to fix the plurality of holding pins through the plurality of cover support holes, thereby fixing the respective array substrate, the light guide plate, and the reflective sheet to the bottom cover itself. Backlight unit to say. The method of claim 3, wherein Each holding pin And a contact portion which is formed to be positioned in the side or rear direction of the plurality of light sources and which is capable of simultaneously fixing the array substrates adjacent to each other. The method of claim 4, wherein Each holding pin is A support unit for applying pressure to the light guide plate, the reflective sheet, and the array substrate, which are located at the front and located at the rear thereof; And a holder which is integrally formed with the support part and fixed to the fixed support hole, the reflective support hole, the substrate support hole, and the cover support hole to fix the light guide plate, the reflective sheet, and the array substrate to the bottom cover. Back light unit. Preparing a plurality of array substrates such that a plurality of light sources are mounted and disposed for each preset division region; Aligning each array substrate with each of the divided regions in a bottom cover having at least one guide pin in each divided region; Forming a plurality of light guide plates to be aligned by the respective guide pins at respective positions corresponding to the respective array substrates; And Assembling a plurality of holding pins to penetrate the plurality of array substrates, the light guide plate, and the bottom cover, thereby fixing the array substrate and the light guide plates configured for each divided area to the bottom cover. Way. The method of claim 6, Forming a reflective sheet on the front surface of each array substrate and the bottom cover except the plurality of light sources to be fastened by the holding pins, and And forming a plurality of optical sheets on the plurality of light guide plates so as to focus and diffuse light from each of the light guide plates to emit the light. The method of claim 7, wherein The reflective sheet forming step Comprising the step of allowing the respective holding pin is fastened to the reflective support hole formed in the reflective sheet, Wherein each light guide plate forming step includes the step of allowing the respective holding pin is fastened to a plurality of fixed support holes provided in the light guide plate, Wherein each array substrate forming step includes allowing each of the holding pins to pass through a plurality of substrate support holes provided in the respective array substrates, And fixing the respective array substrates, the light guide plate, and the reflective sheet to the bottom cover itself by fastening a plurality of holding pins to each cover support hole of the bottom cover. The method of claim 8, Each holding pin And a contact portion which is formed to be positioned at the side or rear direction of the plurality of light sources, and is formed at a contact portion to simultaneously fix the array substrates adjacent to each other.

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