KR20060004319A - Reflection sheet and method of manufacture thereof, back light assembly and liquid crystal display having thereof - Google Patents

Abstract

In the reflective sheet having improved bright lines, a method of manufacturing the same, and a backlight assembly and a liquid crystal display device having the same, the reflective sheet extends from an edge of the first reflective surface and a first reflective surface that reflects light in a first direction, thereby suppressing light. It has a 2nd reflecting surface which reflects in two directions. The first reflecting surface and the second reflecting surface are folded at an obtuse angle by a groove formed by pressing in the longitudinal direction of the edge where the first reflecting surface and the second reflecting surface are contacted by the mold. Accordingly, light leakage between the light guide plate and the reflective sheet and bright lines generated on the screen can be removed.

Light guide plate, reflective sheet, adhesion, bright line improvement

Description

REFLECTION SHEET AND METHOD OF MANUFACTURE THEREOF, BACK LIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY HAVING THEREOF

1 is a schematic diagram of a liquid crystal display device having a backlight assembly according to an embodiment of the present invention.

FIG. 2 is a detailed view of the reflective sheet of the backlight assembly of FIG. 1.

3 is a schematic diagram of a liquid crystal display device having a backlight assembly according to another embodiment of the present invention.

4 is a detailed view of a reflective sheet according to the first embodiment of the backlight assembly shown in FIG. 3.

FIG. 5 is a detailed view of the reflective sheet according to the second embodiment of the backlight assembly shown in FIG. 3.

6 is a view for explaining a manufacturing method for the reflective sheet shown in FIG.

FIG. 7 is a view for explaining a path of light traveling by the backlight assembly illustrated in FIG. 3.

<Description of the symbols for the main parts of the drawings>

110: bottom chassis 120: backlight assembly                 

121: lamp 122: light guide plate

124,125: optical sheet 130: reflective sheet

125 lamp cover 140 mold frame

250: liquid crystal panel 260: top chassis

The present invention relates to a backlight assembly, and more particularly to a backlight assembly for improving the bright line on the screen.

In general, the liquid crystal display includes a liquid crystal panel having a liquid crystal layer between the lower substrate and the upper substrate, and applies a voltage to the liquid crystal to convert the molecular arrangement of the liquid crystal into a predetermined molecular arrangement to display an image.

Since the liquid crystal display (LCD) does not emit light by itself, it displays information by reflecting extraneous light passing through the liquid crystal panel, or installs a separate light source, that is, a backlight assembly, on the back of the liquid crystal panel to provide information. Display.

The backlight assembly may include a lamp unit for emitting light, a light guide plate for guiding light emitted from the lamp unit toward the liquid crystal panel, a reflection sheet provided at a lower portion of the light guide plate to reflect the leaked light to the light guide plate, and transmitted from the light guide plate. Optical sheets such as diffusion sheets, prism sheets, and the like, which increase the luminance of the emitted light.                         

In the backlight assembly as described above, light leakage is generated at the light incident part side of the light guide plate by a gap between the light guide plate and the reflective sheet. Due to such light leakage, a bright line is generated on the screen of the liquid crystal display.

Accordingly, the technical problem of the present invention is to solve such a conventional problem, and a first object of the present invention is to provide a reflective sheet for improving the bright line on the screen.

The second object of the present invention described above is to provide a method for producing the reflective sheet.

It is a third object of the present invention to provide a backlight assembly having the reflective sheet.

It is a fourth object of the present invention to provide a liquid crystal display device having the backlight assembly.

The reflective sheet according to the embodiment for realizing the first object of the present invention described above has a first reflective surface and a second reflective surface. The first reflecting surface reflects light in a first direction, and the second reflecting surface extends from an edge of the first reflecting surface to reflect the light in a second direction.

According to a second aspect of the present invention, there is provided a method of manufacturing a reflective sheet, the method comprising: contacting a pointed portion of a mold on one surface of a sheet in a first longitudinal direction, and the mold adhered to the sheet. Pressurizing water to form the first longitudinal groove partitioning the first reflective surface and the second reflective surface and folding the first reflective surface and the second reflective surface at an obtuse angle.

The backlight assembly according to the embodiment for realizing the third object of the present invention includes a lamp, a light guide plate, and a reflective sheet. The lamp emits light, and the light guide plate guides the first light of the light emitted from the lamp incident through the light incident part and emits the light through the exit part. The reflective sheet is disposed on a lower surface of the light guide plate to first reflect the light leaked from the light guide plate to the light guide plate, and extends at an obtuse angle from an edge of the first reflective surface to emit light from the lamp. It has a 2nd reflecting surface which reflects a 2nd light among them.

A liquid crystal display device according to an embodiment for realizing the fourth object of the present invention described above includes a liquid crystal panel and a backlight assembly. The liquid crystal panel has a liquid crystal layer between the upper substrate, the lower substrate, and the substrates. The backlight assembly has a light guide plate for guiding a first light of the light emitted from a lamp to the liquid crystal panel, a first reflection surface for first reflecting light leaked from the light guide plate, and an obtuse angle from an edge of the first reflection surface. And a reflecting sheet having a second reflecting surface that extends to reflect the second light of the light emitted from the lamp.

According to such a reflective sheet, a method of manufacturing the same, and a backlight assembly and a liquid crystal display having the same, the light emitted from the lamp by the reflective sheet having a reflective surface folded at an obtuse angle toward the light incident portion of the light guide plate is reflected to an exit portion away from the light incident portion. As a result, it is possible to remove a bright line where light is focused on a specific portion of the screen.

In addition, by forming the thickness of the reflective sheet on the light-receiving part side of the light guide plate thick, the adhesion between the light guide plate and the reflective sheet can be improved to prevent light leakage.

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

1 is a schematic view of a liquid crystal display device having a backlight assembly according to an embodiment of the present invention.

Referring to FIG. 1, the liquid crystal display includes a bottom chassis 110 defining a predetermined storage space, a backlight assembly 120 mounted on the bottom chassis 110, and a mold frame 140 disposed on the backlight assembly 120. The liquid crystal panel 150 is mounted on the stepped portion formed in the mold frame 140, and the top chassis 160 blocks the separation of the liquid crystal panel 150 through fastening with the bottom chassis 110.

The bottom chassis 110 has a rectangular shape corresponding to the liquid crystal panel 150, and a storage space having a predetermined depth is formed from an upper surface to a lower surface to accommodate the backlight assembly 120. Although not shown in the drawings, some members of the upper portion of the bottom chassis 110 are bent in the protruding and inward directions to block the separation of the mold frame 140, and a separate member for fastening with the top chassis 160 disposed at the outer portion. The fastening groove is further formed. In addition, although the drawing shows that a certain curvature is formed on the bottom surface of the bottom chassis 110 in conjunction with the shape of the backlight assembly 120, it may have a flat shape.

The backlight assembly 120 includes a lamp 121, a light guide plate 122, a reflective sheet 130 disposed under the light guide plate 122, optical sheets 124 and 125 disposed on the light guide plate 122, and a light guide plate ( And a lamp cover 125 for receiving the lamp 121 through the combination of the upper portion of the 122 and the reflective sheet 130.

Here, the reflective sheet 130 has a first thickness corresponding to the bottom surface of the light guide plate 122, and has a second thickness thicker than the first thickness to correspond to an area corresponding to the light incident part of the light guide plate 122. Reflected light is reflected by the light guide plate.

Since the light guide plate 122 and the reflective sheet 130 are fixed by the bottom chassis 110 having a predetermined size, the adhesion between the light guide plate 122 and the reflective sheet 130 on the light-receiving side is reflected with the light guide plate 122 on the other side. It is superior to the adhesion of the sheet 130. Therefore, bright lines generated on the screen of the liquid crystal display device can be removed by preventing light leakage on the light incident part side.

The mold frame 140 is disposed on the backlight assembly 120 disposed in the storage space formed in the bottom chassis 110 to be engaged with the bottom chassis 110, and supports the liquid crystal panel 150 through a step formed inward. And, it is fastened to the top chassis 160 that will be seated in the future. In addition, the mold frame 140 preferably has a fixing guide structure for fixing the wire 142 for supplying power to the lamp 121.

The liquid crystal panel 150 includes an array substrate 152, a color filter substrate 154 that opposes and accommodates a liquid crystal layer (not shown), a first polarizing plate 156 formed on a rear surface of the array substrate 152, and Including the second polarizing plate 158 formed on the rear surface of the color filter substrate 154, it is mounted on the upper surface of the mold frame 140, preferably the upper side of the support member extending inwardly to display image information.

The top chassis 160 is covered on the upper portion of the liquid crystal panel 150 to block the separation of the liquid crystal panel 150 through the fastening of the mold frame 140 and the bottom chassis 10.

FIG. 2 is a detailed view of the reflective sheet 130 of the liquid crystal display shown in FIG. 1.

1 and 2, the reflective sheet 130 may include a first reflective surface having a first thickness corresponding to a bottom surface of the light guide plate 122, and a region corresponding to a light incident portion of the light guide plate 122. And a second reflective surface having a second thickness that is thicker than one thickness.

The end portion 131 of the predetermined width W1 of the reflective sheet 130 having the first thickness T1 is folded in the “A” direction to be attached to the rear surface of the reflective sheet 130. An adhesive member 137 is formed on the rear surface of the end portion 131, and the rear surface of the end portion 131 and the rear surface of the reflective sheet 130 are attached by the adhesive member 137. Therefore, the reflective sheet 130 having the first thickness T1 overlaps two layers and has a second reflective surface having the second thickness T2.

The first reflective surface having the first thickness T1 is in close contact with the rear surface of the light guide plate 122, and the second reflective surface having the second thickness T2 is in close contact with the rear surface of the light incident part side of the light guide plate 122. Thereby, the light leakage of the light-receiving part side of the light guide plate 122 with which the light guide plate 122 and the reflective sheet 130 are relatively in close contact can be prevented.

3 is a view for explaining a liquid crystal display device having a backlight assembly according to another embodiment of the present invention.

Referring to FIG. 3, the liquid crystal display includes a bottom chassis 210 defining a predetermined storage space, a backlight assembly 220 mounted on the bottom chassis 210, and a mold frame 240 disposed on the backlight assembly 220. The liquid crystal panel 250 is mounted on the stepped portion formed in the mold frame 240, and the top chassis 260 blocks the separation of the liquid crystal panel 250 through fastening with the bottom chassis 210.

The bottom chassis 210 has a rectangular shape corresponding to the liquid crystal panel 250, and a storage space having a predetermined depth is formed from the top surface to the bottom surface to accommodate the backlight assembly 220. Although not shown in the drawings, some members of the upper part of the bottom chassis 210 are bent in the protruding and inward direction to block the detachment of the mold frame 20, and a separate part for fastening with the top chassis 260 disposed at the outer part. The fastening groove is further formed. In addition, although the drawing shows that a certain curvature is formed on the bottom surface of the bottom chassis 210 in conjunction with the shape of the backlight assembly 220, it may have a flat shape.

The backlight assembly 220 includes a lamp 221, a light guide plate 222, a reflective sheet 230 disposed below the light guide plate 222, optical sheets 224 and 225 disposed above the light guide plate 222, and a light guide plate ( And a lamp cover 225 for receiving the lamp 221 through coupling of the top of the 222 and the reflective sheet 230.

Here, the reflective sheet 230 is disposed in close contact with the lower surface of the light guide plate 222 and the light incident part side to reflect the light emitted from the lamp 221. That is, the reflective sheet 230 is disposed on a lower surface of the light guide plate 222 to first reflect the light leaked from the light guide plate 222 to the light guide plate 222, and an obtuse angle from an edge of the first reflective surface. It has a second reflecting surface extending to have a second reflecting of the second light of the light emitted from the lamp 221. In addition, the third light passed from the lamp cover 225 is third reflected.

The mold frame 240 is disposed on the backlight assembly 220 disposed in the storage space formed in the bottom chassis 210 to be engaged with the bottom chassis 210, and the liquid crystal panel 250 is formed through the stepped inward direction. It supports and is fastened with the top chassis 260 to be seated in the future. In addition, the mold frame 240 preferably has a fixing guide structure for fixing the wire 242 for supplying power to the lamp 221.

The liquid crystal panel 250 includes an array substrate 252, a color filter substrate 254 that opposes and accommodates a liquid crystal layer (not shown), and a first polarizing plate 256 formed on a rear surface of the array substrate 252. Including a second polarizing plate 258 formed on the rear surface of the color filter substrate 254, it is mounted on the upper surface of the mold frame 240, preferably the upper side of the support member extending inwardly to display image information.

The top chassis 260 is covered on the upper portion of the liquid crystal panel 250 to block the separation of the liquid crystal panel 30 through the fastening of the mold frame 240 and the bottom chassis 210.

FIG. 4 shows a first embodiment of the reflective sheet of the backlight assembly shown in FIG. 3.

3 and 4, the reflective sheet 130 is disposed on the lower surface of the light guide plate 222 to first reflect the light leaked from the light guide plate 222 to the light guide plate 222. And a second reflecting surface 132 extending at an obtuse angle θ from an edge of the first reflecting surface 131 to reflect the second light among the light emitted from the lamp 221. The reflective sheet 130 is pressed by a mold to form a groove 233 in the longitudinal direction of the lamp 221, and at the same time the first reflective surface 131 and the second reflective surface 132 have an obtuse angle ( θ).

As shown, the second reflective surface 132 is folded along the groove 233 in the "B" direction to maintain an obtuse angle θ with respect to the first reflective surface 131.

Therefore, the first reflective surface 131 and the second reflective surface 132 of the reflective sheet 130 are brought into close contact with the lower surface and the light incident portion of the light guide plate 222 by the gap between the light guide plate 222 and the reflective sheet 130. Can prevent light leakage.

In addition, the light reflected by the second reflective surface 132 folded at an obtuse angle toward the light incident part may be reflected to an exit part of the light guide plate 222 far from the light incident part, thereby preventing the light from being concentrated on the light incident part side.

FIG. 5 is a view showing a second embodiment of the reflective sheet of the backlight assembly shown in FIG.

3 and 5, the reflective sheet 430 is disposed on the lower surface of the light guide plate 222 to first reflect the light leaked from the light guide plate 222 to the light guide plate 222. The second reflecting surface 432 extends at an obtuse angle from an edge of the first reflecting surface 431 to reflect the second light among the light emitted from the lamp 221. A fold line 433 is formed at an edge portion where the first reflective surface 431 and the second reflective surface 432 contact each other. The fold line 433 has a plurality of holes 435 spaced at regular intervals, and preferably, the length of the hole 435 to the spaced distance between the holes 435 is 4: 1.

As shown, the second reflective surface 432 folds along the fold line 4333 in the “C” direction to maintain an obtuse angle θ with respect to the first reflective surface 431.

Accordingly, the first reflective surface 431 and the second reflective surface 432 of the reflective sheet 430 are brought into close contact with the lower surface and the light incident portion of the light guide plate 222 to thereby form a gap between the light guide plate 222 and the reflective sheet 430. Can prevent light leakage. In addition, the light reflected by the second reflecting surface 432 folded at an oblique angle θ toward the light incidence part is reflected to the exit part of the light guide plate 222 far from the light incidence part, thereby preventing the light from being condensed on the light incidence part side. Can be.

FIG. 6 is a view for explaining a method of manufacturing the reflective sheet shown in FIG. 3.

Referring to FIG. 6A, the pointed portion 510 of the mold 500 having a 'V' shape in close contact with a specific portion of one surface of the flat sheet 330 may be in close contact with the first longitudinal direction.

Referring to FIG. 6B, the sheet 330 is pressed using the mold 500 in close contact with the sheet 330. By the pressing of the pointed portion 510, a groove 333 is formed on the sheet 330 and divided into a first reflection surface 331 and a second reflection surface 332, and at the same time, the second reflection surface 332 is formed. ) Is folded at an obtuse angle θ with respect to the first reflective surface 331. That is, the second reflecting surface 332 having an area relatively smaller than that of the first reflecting surface 331 is bent by pressing by the pointed portion 510 of the mold 500.

Thereafter, by removing the mold 500 from the sheet 330, a reflective sheet having a second reflective surface 132 folded at an obtuse angle with respect to the first reflective surface 131 as shown in FIG. 3 is obtained. .

7 is a view for explaining a path of the light by the backlight assembly according to a second embodiment of the present invention.

Referring to FIG. 7, the first light I having the first direction among the light provided from the lamp 221 is reflected by the lamp cover 225 and guided to the second light II having the second direction. Here, the first light I is reflected from the upper surface of the lamp cover 225 adjacent to the exit surface of the light guide plate 222.

The second light II is reflected by the second reflecting surface 232 folded at an obtuse angle toward the light incident part side of the light guide plate 222 and guided to the third light III having the third direction.

The third light III is guided to the fourth light IV incident on the light incident part of the light guide plate 22 and refracted in the fourth direction. The fourth light IV is refracted in the fifth direction at the exit portion of the light guide plate 222 and is emitted as the fifth light V. FIG.

As described above, the path of the first light I is changed to the second to fourth light by the second reflecting surface 232 folded at an obtuse angle, and the fifth light V passes through the emission part far from the light incident part side. Will be emitted. Therefore, a bright line does not generate | occur | produce on the screen on the side of a light incident part.

Meanwhile, when the reflective sheet 230 does not have the second reflective surface 232, the second light II is reflected from the lower side of the lamp cover 225 to have the sixth light VI having the sixth direction. Guided by. The sixth light VI is guided to the seventh light VII incident on the light incident part of the light guide plate 222 and refracted in the seventh direction. The seventh light VII is refracted in the eighth direction again at the exit portion of the light guide plate 222 and is emitted as the eighth light VIII. Here, the eighth light VIII is emitted through the light exit part on the light incident part side.

As shown in the drawing, in the case of the reflective sheet not having the second reflective surface, light is gathered to the light incident part to generate bright lines on the screen.

As described above, the first reflective surface 231 and the second reflective surface 232 of the reflective sheet 230 are in close contact with the lower surface and the light incident portion of the light guide plate 222 so that the light guide plate 222 and the reflective sheet 230 Light leakage due to gaps in the liver can be prevented.                     

In addition, the light reflected by the second reflecting surface 432 of the reflective sheet folded at an obtuse angle toward the light incidence part is reflected to the exit part of the light guide plate 222 far from the light incidence part to prevent the light from being condensed on the light incidence side. Can be.

As described above, according to the present invention, light leakage caused by the gap between the reflective sheet and the light guide plate can be prevented. In addition, by reflecting the light emitted from the lamp by the second reflecting surface folded at an obtuse angle toward the light incident part side of the light guide plate to an exit part far away from the light incident part side of the light guide plate, the ridge generated on the light incident part side can be removed. Therefore, the bright line on the screen can be improved.

Although described above with reference to the embodiments, those skilled in the art can be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below. I can understand.

Claims (15)

A first reflecting surface that reflects light in a first direction; And And a second reflecting surface extending from an edge of the first reflecting surface to reflect the light in a second direction. The method of claim 1, wherein the first reflective surface and the second reflective surface is folded at an obtuse angle by a groove formed by pressing in the longitudinal direction of the edge contacting the first reflective surface and the second reflective surface by a mold. Reflective sheet. The reflective sheet of claim 1, wherein an area of the first reflective surface is larger than an area of the second reflective surface. Contacting the pointed portion of the mold on a first longitudinal direction on one surface of the sheet; Pressing the mold in close contact with the sheet to form the first longitudinal groove defining the first reflective surface and the second reflective surface, and simultaneously folding the first reflective surface and the second reflective surface at an obtuse angle. Method of producing a reflective sheet comprising the step. The method of manufacturing a reflective sheet according to claim 4, wherein an area of the first reflective surface is larger than an area of the second reflective surface. A lamp for emitting light; A light guide plate for guiding a first light from the light emitted from the lamp incident through the light incident part and outputting the light through the output part; And A first reflection surface disposed on a lower surface of the light guide plate to first reflect light leaked from the light guide plate to the light guide plate, and a second light of the light emitted from the edge of the light reflection plate to extend at an obtuse angle from an edge of the first light reflection plate; And a reflective sheet having a second reflective surface for second reflecting light. The backlight assembly of claim 6, wherein the reflective sheet is folded at an obtuse angle by the groove formed by pressing a mold in the longitudinal direction of the lamp. The backlight assembly of claim 6, wherein the second reflecting surface reflects the second light toward an exit portion away from the light incident portion of the light guide plate. The method of claim 6, further comprising a lamp cover for covering the lamp, And the reflective sheet reflects third light through the lamp cover. The method of claim 6, wherein the reflective sheet has a plurality of holes having a predetermined interval in the longitudinal direction of the lamp, characterized in that the first reflective surface and the second reflective surface is folded at an obtuse angle by the plurality of holes. Backlight assembly. The backlight assembly of claim 10, wherein the formation length of the holes and the spacing are substantially 4: 1. A lamp for emitting light; A light guide plate for guiding a first light from the light emitted from the lamp incident through the light incident part and outputting the light through the output part; And A reflection having a first thickness corresponding to a lower surface of the light guide plate, a second thickness thicker than the first thickness corresponding to a region corresponding to an incident part of the light guide plate, and reflecting light leaked from the light guide plate to the light guide plate; Backlight assembly comprising a sheet. The backlight assembly of claim 12, wherein the second thickness is a thickness of a side of the reflective sheet having the first thickness and abutted. A liquid crystal panel having an upper substrate, a lower substrate, and a liquid crystal layer between the substrates; And A light guide plate for guiding a first light from the lamp to the liquid crystal panel, a first reflection surface that reflects light leaked from the light guide plate, and an obtuse angle extending from an edge of the first reflection surface to extend the oblique angle And a backlight assembly comprising a reflective sheet having a second reflective surface for second reflecting a second light of the light emitted from the second light. The liquid crystal display device according to claim 14, wherein the reflective sheet is folded at an obtuse angle by the groove formed by pressing a mold in the longitudinal direction of the lamp.

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