Backlight unit and liquid crystal display including the same

A backlight unit includes a light source portion configured to provide light to a display panel, a reflection sheet arranged on a lower part of the light source portion, a mold frame accommodating the light source portion, and a support frame which supports the mold frame and includes a bottom portion, first and second side wall portions which extend upward from both end sides of the bottom portion and face each other, a ceiling portion which extends in a horizontal direction from an upper end of the first side wall portion, and a slant portion slanted downward from an end part of the ceiling portion and having one end that comes in contact with the end part of the ceiling portion and the other end that comes in contact with an upper end of the second side wall portion.

This application is claims priority to Korean Patent Application No. 10-2014-0012162, filed on Feb. 3, 2014, and all the benefits accruing therefrom under 35 U.S.C. §119, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The invention relates to a backlight unit and a liquid crystal display including the same.

2. Description of the Prior Art

A liquid crystal display (“LCD”) includes a LCD module that is connected to an external case. The LCD module includes a liquid crystal panel that is composed of two substrates between which a liquid crystal layer is interposed, and a backlight unit that is positioned in the rear of the liquid crystal panel to supply light to the liquid crystal layer. The liquid crystal panel displays an image through adjustment of permeability of light that is provided from the backlight unit.

The backlight unit is classified into a direct type and a photometric type depending on the position of light sources. In the direct type backlight unit, light sources are provided in the rear of a display panel, and in the photometric type backlight unit, light sources are provided on one side of a rear portion of the display panel.

Recently, with the trend of lightweight of a display device, various efforts to reduce the total weight of the display device have been made. As a part of such efforts, in order to reduce the total weight of a backlight unit, various technical researches in structure and material have been made.

SUMMARY

Accordingly, one subject to be solved by the invention is to provide a backlight unit, which can effectively reduce the total weight.

Another subject to be solved by the invention is to provide a liquid crystal display (“LCD”), which can effectively reduce the total weight.

In one exemplary embodiment of the invention, there is provided a backlight unit including a light source portion configured to provide light to a display panel, a reflection sheet arranged on a lower part of the light source portion, a mold frame accommodating the light source portion and a support frame which supports the mold frame and includes a bottom portion, first and second side wall portions which extend upward from both end sides of the bottom portion and face each other, a ceiling portion which extends in a horizontal direction from an upper end of the first side wall portion and a slant portion slanted downward from an end part of the ceiling portion and having one end that contacts the end part of the ceiling portion and the other end that contacts an upper end of the second side wall portion.

According to another exemplary embodiment of the invention, there is provided a LCD including a backlight unit, a diffusion plate arranged on an upper part of the backlight unit, at least one optical sheet arranged on an upper part of the diffusion plate, and a display panel arranged on the at least one optical sheet, where the backlight unit includes a light source portion configured to provide light to the display panel, a reflection sheet arranged on a lower part of the light source portion, a mold frame which accommodates the light source portion and a support frame which supports the mold frame and includes, a bottom portion, first and second side wall portions which extend upward from both end sides of the bottom portion and facing each other, a ceiling portion which extends in a horizontal direction from an upper end of the first side wall portion and a slant portion slanted downward from an end part of the ceiling portion and having one end that contacts the end part of the ceiling portion and the other end that contacts with an upper end of the second side wall portion.

The detailed items of other embodiments are included in the detailed description and drawings.

According to the exemplary embodiments of the invention, at least the following effects can be achieved.

That is, by omitting and replacing a bottom chassis by the hollow support frame, the total weight of the backlight unit can be reduced.

Further, by reducing the total weight of the backlight unit, the total weight of the LCD can be reduced.

The effects according to the invention are not limited to the contents as exemplified above, but further various effects are included in the description.

DETAILED DESCRIPTION

The exemplary embodiments and features of the invention and methods for achieving the exemplary embodiments and features will be apparent by referring to the exemplary embodiments to be described in detail with reference to the accompanying drawings. However, the invention is not limited to the exemplary embodiments disclosed hereinafter, but can be implemented in diverse forms. The matters defined in the description, such as the detailed construction and elements, are nothing but specific details provided to assist those of ordinary skill in the art in a comprehensive understanding of the invention, and the invention is only defined within the scope of the appended claims.

The term “on” that is used to designate that an element is on another element or located on a different layer or a layer includes both a case where an element is located directly on another element or a layer and a case where an element is located on another element via another layer or still another element. In the entire description of the invention, the same drawing reference numerals are used for the same elements across various figures.

Although the terms “first, second, and so forth” are used to describe diverse constituent elements, such constituent elements are not limited by the terms. The terms are used only to discriminate a constituent element from other constituent elements. Accordingly, in the following description, a first constituent element may be a second constituent element.

FIG. 1is a partial cross-sectional view of a backlight unit according to an exemplary embodiment of the invention.

Referring toFIG. 1, a backlight unit according to an exemplary embodiment of the invention includes a light source portion600providing light to a display panel150, a reflection sheet arranged on a lower part of the light source portion600, a mold frame200accommodating the light source portion600, and a support frame100supporting the mold frame200, where the support frame100includes a bottom portion100_1, first and second side wall portions100_2and100_3provided to extend upward from both sides of the bottom portion100_1and facing each other, a ceiling portion100_5provided to extend in a horizontal direction from an upper end of the first side wall portion100_2, and a slant portion100_4slanted downward from an end part of the ceiling portion100_5and having one end that comes in contact with the end part of the ceiling portion100_5and the other end that comes in contact with an upper end of the second side wall portion100_3.

The light source portion600may serve to provide light to a display panel150which will be described later. In an exemplary embodiment, the light source portion600may be arranged on a lower part of the display panel150to emit light toward an upper part thereof. That is, the backlight unit according to an exemplary embodiment of the invention may be a direct type backlight unit, for example.

In an exemplary embodiment, the light source portion600may include a plurality of line light sources extending in a length direction. In another exemplary embodiment, the light source portion600may include a plurality of point light sources that are arranged in the matrix having a plurality of rows and columns.

In an exemplary embodiment, the light source portion600may include at least one light emitting portion. The light emitting portion may include at least one of a light emitting diode (“LED”), a cold cathode fluorescent lamp (“CCFL”), and an organic light emitting diode (“OLED”). However, the above-described light emitting portion is an exemplary embodiment, and the invention is not limited thereto.

In another exemplary embodiment, the light source portion600may include a printed circuit board (“PCB”) and light emitting lamps mounted on the PCB. The details thereof will be described later.

The mold frame200may serve to accommodate the light source portion600. In an exemplary embodiment, the mold frame200may serve to support a diffusion plate130, an optical sheet140, and the display panel150which will be described later.

In an exemplary embodiment, the mold frame200may be in a rectangular frame shape in a plan view. That is, the mold frame200may be in a rectangular shape having four sides, and the light source portion600may be arranged in a space defined by the four sides.

In an exemplary embodiment, the mold frame200may include a hard material. In an exemplary embodiment, the mold frame200may include a metal material, for example. However, the material of the mold frame200is not limited thereto, and the mold frame200may include a plastic material, for example.

The mold frame200includes a side wall portion200_1extending in a vertical direction, a seat portion200_2provided to project from the side wall portion200_1, and a support200_3arranged at an upper end of the side wall portion200_1.

The side wall portion200_1may be provided to extend in the vertical direction. The side wall portion200_1may be arranged on the outline of the backlight unit according to some embodiments of the invention. That is, the side wall portion200_1may surround other constituent elements of the backlight unit and may define a circumference of the backlight unit.

Further, in an exemplary embodiment, the lower end part of the side wall portion200_1may be fastened to a first side wall portion100_2of a support frame100which will be described later. That is, the inside of the side wall portion200_1of the mold frame200and the outside of the first side wall portion100_2of the support frame100may come in contact with each other to be fastened to each other. This will be described later.

The seat portion200_2may be provided to project in the horizontal direction from the side wall portion200_1. That is, the seat portion200_2may be provided to project from the center part of the side wall portion200_1. In an exemplary embodiment, the angle defined between the seat portion200_2and the side wall portion200_1may be about 90 degrees, but the angle defined between the seat portion200_2and the side wall portion200_1is not limited thereto.

The seat portion200_2may be seated on a ceiling portion100_5of the support frame100which will be described later. That is, the lower surface of the seat portion200_2and the upper surface of the ceiling portion100_5may come in contact with each other, and the seat portion200_2and the ceiling portion100_5may be fastened to each other. The details thereof will be described later.

The support200_3may be arranged at the upper end of the mold frame200. The support200_3may serve to support the diffusion plate130, the optical sheet140, and the display panel150which will be described later. In an exemplary embodiment, the support200_3may have a step portion structure. When the support200_3has the step portion structure, the side ends and the lower ends of the display panel150, the optical sheet140, and the diffusion plate130are firmly supported by the step portion. In an exemplary embodiment, the optical sheet140may include diffusion sheet140_1, a luminance improvement sheet140_2and a reflection polarizing sheet140_3.

The support frame100may serve to support the mold frame200and a reflection sheet400which will be described later. In an exemplary embodiment, the support frame100may be in a rectangular frame shape that corresponds to the mold frame200. That is, the support frame100may be in the rectangle shape having four sides that correspond to four side of a tetragon, and the light source portion600may be arranged in a space defined by the four sides.

The support frame100may include a bottom portion100_1extending in a horizontal direction, first and second side wall portions100_2and100_3extending in a vertical direction from both sides of the bottom portion100_1and facing each other, a ceiling portion100_5extending in the horizontal direction from an upper end of the first side wall portion100_2and facing the bottom portion100_1, and a slant portion100_4slanted downward from an end part of the ceiling portion100_5and having one end that comes in contact with an upper end of the ceiling portion100_5and the other end that comes in contact with an upper end of the second side wall portion100_3.

The bottom portion100_1is arranged on the lowermost part of the support frame100to support other constituent elements of the support frame100. The bottom portion100_1may include a flat surface that extends in the horizontal direction.

The first side wall portion100_2and the second side wall portion100_3may be provided to extend in the vertical direction from both sides of the bottom portion100_1. The first side wall portion100_2and the second side wall portion100_3may face each other. However, the extension lengths of the first side wall portion200_2and the second side wall portion100_3may differ from each other. That is, the extension length of the first side wall portion100_2may be larger than the extension length of the second side wall portion100_3. Accordingly, the slant portion100_4which will be described later may be provided.

The ceiling portion100_5may be provided to extend in the horizontal direction from the upper end of the first side wall portion100_2. That is, the ceiling portion100_5may face the bottom portion100_1.

The slant portion100_4may be provided to be slanted downward from the end part of the ceiling portion100_5. That is, the slant portion100_4may be provided to be downwardly slanted from the outside to the inside of the backlight unit.

One end of the slant portion100_4may come in contact with the end part of the ceiling portion100_5, and the other end of the slant portion100_4may come in contact with the upper end of the second side wall portion100_3. Accordingly, the cross section of the support frame100may be in a closed polygonal shape through the bottom portion100_1, the first side wall portion100_2, the second side wall portion100_3, the ceiling portion100_5, and the slant portion100_4.

A cavity may be defined, which is an inner space that is defined by the bottom portion100_1, the first side wall portion100_2, the second side wall portion100_3, the ceiling portion100_5, and the slant portion100_4. That is, the cavity may be a space between the bottom portion100_1and the ceiling portion100_5or a space between the first side wall portion100_2and the second side wall portion100_3.

The cavity may extend along the extension direction of the support frame100. That is, in an exemplary embodiment, the support frame100may be provided to extend in the length direction, and the cavity may extend along the support frame100.

When the cavity is defined in the support frame100, the total weight of the support frame100may be reduced. Accordingly, the total weight of the backlight unit can be reduced.

The reflection sheet400may be arranged on the lower part of the light source portion600. The reflection sheet400may serve to guide light, which is emitted from the light source portion600and is directed to the lower part of the backlight unit, to the upper part thereof again. That is, the reflection sheet400guides the light, which is emitted from the light source portion600to the lower part of the backlight unit, to the display panel150again to reduce a light loss.

In an exemplary embodiment, the reflection sheet400may include polyethylene terephthalate (“PET”), but the material of the reflection sheet400is not limited thereto. In another exemplary embodiment, the reflection sheet400may include crystalline PET resin.

The reflection sheet400that is arranged on the lower part of the light source portion600may extend to be bent toward the support frame100. That is, the reflection sheet400may include a bent portion, and may extend to be slanted upward at a predetermined angle from the bent portion. For convenience in explanation, the upwardly slanted portion of the reflection sheet400is referred to as a slant region400_2, and one end of the slant region400_2which meets the horizontal region of the reflection sheet400is referred to as a slant point400_1.

In an exemplary embodiment, the slant region400_2may be supported by the slant portion100_4of the support frame100. In this case, the slope of the slant portion100_4of the support frame100may be substantially equal to the slope of the slant region400_2.

The end part of the slant region400_2may be arranged adjacent to the support frame100. That is, the end part of the slant region400_2that is supported by the slant portion100_4of the support frame100may continuously extend to come in contact with the side wall portion200_1of the mold frame200.

Hereinafter, detailed embodiments of the invention will be described. In the following embodiments, the same reference numerals are used for the same constituent elements as the constituent elements as described above, and the duplicate explanation thereof will be omitted.

FIG. 2is a partial exploded perspective view of a backlight unit according to another exemplary embodiment of the invention, andFIG. 3is a cross-sectional view taken along lint I-I′ ofFIG. 2.

Referring toFIGS. 2 and 3, a backlight unit according to another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that it includes at least one support bar that crosses facing support frames.

The support bar300may serve to support a reflection sheet400that is arranged on the support bar300. In an exemplary embodiment of the invention as described above, the backlight unit omits the bottom chassis to reduce the weight. In other words, the reflection sheet400may be supported by the slant portion100_4of the support frame100, or may maintain the shape by a stress of the material itself.

In contrast, when the support bar300is arranged between the facing support frames100according to another exemplary embodiment of the invention, the reflection sheet400can be supported more stably.

The support bar300may be arranged to cross the facing sides of the support frames100. That is, in an exemplary embodiment in which the support frame100is in a rectangular frame shape, the support bar300may be arranged to cross two facing sides of the support frames100. That is, in exemplary embodiment in which the support frame100includes a first side100a, a second side100b, a third side100c, and a fourth side100d, the support bar300may be in parallel to the first side100aand the second side100b, and may be perpendicular to the third side100cand the fourth side100d. That is, one end of the support bar300may be fastened to the third side100c, and the other end thereof may be fastened to the fourth side100d. A plurality of support bars300may be spaced apart at predetermined intervals and may be arranged in parallel to each other.FIG. 2exemplarily illustrates that eight support bars300are arranged. However, this is an exemplary embodiment, and the number of support bars300is not limited thereto.

In an exemplary embodiment, the support bar300may include a rigid material, for example. That is, the support bar300may be provided to include a metal material, but is not limited thereto. In another exemplary embodiment, the support bar300may include a plastic material, for example.

At least one support column310may be disposed on the support bar300.

The support column310may serve to support the diffusion plate130which will be described later. The support column310may be provided to project vertically from the support bar300.

In an exemplary embodiment, the support column310that is arranged on the one support bar300may be aligned along the length direction of the support bar300.FIG. 2exemplarily illustrates that three support columns310are disposed on one support bar300, but the number of support columns310is not limited thereto.

Although not illustrated in the drawing, in an exemplary embodiment in which the support columns310are arranged, the reflection sheet400may include insertion ports that correspond to the support columns310. That is, the support columns310may be inserted into the insertion ports of the reflection sheet400, and thus the reflection sheet400may be supported to come in contact with the support bars300.

That is, the support column310may penetrate the insertion ports of the reflection sheet400to support the diffusion plate150.

FIG. 4is a partial perspective view of a backlight unit according to still another exemplary embodiment of the invention.FIG. 5is a partial enlarged view of the backlight unit ofFIG. 4, andFIG. 6is an exploded perspective view ofFIG. 5.

Referring toFIGS. 4 to 6, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that a support frame includes four separated sub-support frames.

In an exemplary embodiment, a support frame101may include four separated sub-support frames. That is, four sub-support frames having a bar shape may be combined to provide a support frame101having a rectangular frame shape.

For convenience in explanation, the four sub-support frames are called a first sub-support frame101a, a second sub-support frame101b, a third sub-support frame101c, and a fourth sub-support frame101d.

Further, the sub-support frame may have substantially the same structure as the structure of the support frame100according to an exemplary embodiment of the invention as described above. That is, the sub-support frame may have a bottom portion, a first side wall portion, a second side wall portion, a ceiling portion, and a slant portion. Since the structure has been described with reference toFIG. 1, the detailed explanation thereof will be omitted.

In an exemplary embodiment, the first sub-support frame101amay face the to second sub-support frame101b, and the third sub-support frame101cmay face the fourth sub-support frame101d.

That is, the first sub-support frame101aand the second sub-support frame101bmay be parallel to each other, the third sub-support frame101cand the fourth sub-support frame101dmay be parallel to each other, and the first sub-support frame101aand the third sub-support frame101cmay be perpendicular to each other.

Further, one end of the first sub-support frame101amay be fastened to the third sub-support frame101c, and the other end thereof may be fastened to the fourth sub-support frame101d. In the same manner, one end of the second sub-support frame101bmay be fastened to the third sub-support frame101c, and the other end thereof may be fastened to the fourth sub-support frame101d.

A method for fastening the respective sub-support frames will be described with reference toFIGS. 5 and 6.

In an exemplary embodiment, the sub-support frames may be fastened by an “L”-shaped fastening member. For convenience in explanation, the above structure is referred to as an L-type fastening member151. Specifically, in a state where the end part of the first sub-support frame101aand the end part of the third sub-support frame101ccome in contact with each other, the L-type fastening member151may come in contact with the inner surface of the first sub-support frame101aand the inner surface of the third sub-support frame101c. That is, the first sub-support frame101aand the third sub-support frame101care divided based on a bend line151c, and the first sub-support frame101aand the third sub-support frame101cmay be fixed by fastening one side151ato the inner surface of the first sub-support frame101aand fastening the other side151bthereof to the inner surface of the third sub-support frame101c, respectively.

In an exemplary embodiment, the L-type fastening member151and the respective sub-support frames may be fastened in a screw fitting method.FIGS. 4 and 5exemplify a case where the L-type fastening member151and the respective sub-support frames are fastened using two screws152. However, the invention is not limited thereto, and the number of screws151is not limited thereto.

Further, in the case of fastening the L-type fastening member151and the respective sub-support frames using the screws152, engagement ports153(refers toFIG. 6) that correspond to the screws152may be defined in the side surfaces of the respective sub-support frames.

FIGS. 5 and 6exemplify a case where the first sub-support frame101aand the third sub-support frame101care fastened. However, other sub-support frames can be fastened in substantially the same manner.

FIG. 7is a partial perspective view of a backlight unit according to still another exemplary embodiment of the invention, andFIG. 8is a cross-sectional view of the backlight unit ofFIG. 7.

Referring toFIGS. 7 and 8, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that a mold frame and a support frame are fastened by a fastening projection arranged on a lower surface of a seat portion and an engagement screw that penetrates a side wall portion of the mold frame and a first side wall portion of the support frame.

The support frame102includes a bottom portion102_1, first and second side wall portions102_2and102_3provided to extend upward from both sides of the bottom portion102_1and facing each other, a ceiling portion102_5provided to extend in a horizontal direction from an upper end of the first side wall portion102_2, and a slant portion102_4slanted downward from an end part of the ceiling portion102_5and having one end that comes in contact with the end part of the ceiling portion102_5and the other end that comes in contact with an upper end of the second side wall portion102_3.

The mold frame201includes a side wall portion201_1extending in a vertical direction, a seat portion201_2provided to project from the side wall portion201_1, and a support201_3arranged at an upper end of the side wall portion200_1

As described above, a side wall portion201_1of a mold frame201may be fastened to a first side wall portion102_2of a support frame102, and a seat portion201_2of the mold frame201may be fastened to a ceiling portion102_5of the support frame102.

In an exemplary embodiment, the side wall portion201_1of the mold frame201may be fastened to the first side wall portion102_2of the support frame102by an engagement screw161that penetrates the side wall portion201_1of the mold frame201and the first side wall portion102_2of the support frame102. The engagement screw161may be inserted from the outside of the side wall portion201_1of the mold frame201into the inside of the first side wall portion102_2of the support frame102. That is, a head part of the engagement screw162may be arranged on the outside of the side wall portion201_1of the mold frame201, and a body part of the engagement screw162may be inserted into the inside of the first side wall portion102_2of the support frame102.

In this regard, engagement holes201_4and102_2athat correspond to the engagement screw161may be defined in the side wall portion201_1of the mold frame201and the first side wall portion102_2of the support frame102, respectively. The engagement hole201_4that is defined in the side wall portion201_1of the mold frame201may overlap the engagement hole102_2athat is defined in the first side wall portion102_2of the support frame102. Accordingly, the side wall portion201_1of the mold frame201and the first side wall portion102_2of the support frame102may be engaged with each other by one engagement screw161.

A fastening projection162may be disposed on the seat portion201_2of the mold frame201. That is, the fastening projection162may be disposed to project by a predetermined distance from the lower surface of the seat portion201_2. A fastening hole102_5amay be defined in the ceiling portion102_5of the support frame102to correspond to the fastening projection162. The size of the fastening hole102_5amay be substantially equal to or smaller than the size of the fastening projection162. In an exemplary embodiment, since the fastening projection162and the fastening hole102_5aare fastened by interference fitting, the seat portion201_2of the mold frame201and the ceiling portion102_5of the support frame102may be fastened to each other.

FIG. 9is a partial cross-sectional view of a backlight unit according to still another exemplary embodiment of the invention.

Referring toFIG. 9, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that a mold frame and a support frame are provided in a body.

In an exemplary embodiment, a support frame103may be integrally provided with a mold frame. That is, the support frame103having a modified shape may serve as the mold frame.

The support frame103includes a bottom portion103_1, first and second side wall portions103_2and103_3provided to extend upward from both sides of the bottom portion103_1and facing each other, a ceiling portion103_5provided to extend in a horizontal direction from an upper end of the first side wall portion103_2, and a slant portion103_4slanted downward from an end part of the ceiling portion103_5and having one end that comes in contact with the end part of the ceiling portion103_5and the other end that comes in contact with an upper end of the second side wall portion103_3.

In this regard, a side wall portion103_6of the mold frame may be provided to extend in the vertical direction from an upper end of a first side wall portion103_2. A support103_3may be arranged at an upper end of the side wall portion103_6of the mold frame, and the support103_6may be substantially the same as the support of the mold frame of the backlight unit according to some embodiments of the invention.

The support103-6amay be arranged at the upper end of the support103_6. The support103-6amay serve to support the diffusion plate130, the optical sheet140, and the display panel150which will be described later. In an exemplary embodiment, the support103-6amay have a step portion structure. When the support103-6ahas the step portion structure, the side ends and the lower ends of the display panel150, the optical sheet140, and the diffusion plate130are firmly supported by the step portion.

FIG. 10is a partial cross-sectional view of a backlight unit according to still another exemplary embodiment of the invention.

Referring toFIG. 10, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that a side wall portion of a mold frame further includes a fixing hole103_6bfor fastening an end part of a reflection sheet401.

As described above, the reflection sheet401may extend to be bent and may be supported by a slant portion103_4of a support frame103. An end part of the reflection sheet401may be arranged adjacent to a mold frame or a side wall portion103_6of the mold frame.

In an exemplary embodiment, an end part of the reflection sheet401may be inserted into the fixing hole103_6bdefined on the side wall portion103_6of the mold frame to be fixed. Accordingly, the reflection sheet401can be fixed more firmly.

Since other elements of the support frame103have the same structure with those of the support frame103described with reference toFIG. 9, the detailed explanation thereof will be omitted.

FIG. 11is a partial cross-sectional view of a backlight unit according to still another exemplary embodiment of the invention.

Referring toFIG. 11, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that at least one opening is defined in a slant portion104_4of a support frame104.

The support frame104includes a bottom portion104_1, first and second side wall portions104_2and104_3provided to extend upward from both sides of the bottom portion104_1and facing each other, a ceiling portion104_5provided to extend in a horizontal direction from an upper end of the first side wall portion104_2, and a slant portion104_4slanted downward from an end part of the ceiling portion104_5and having one end that comes in contact with the end part of the ceiling portion104_5and the other end that comes in contact with an upper end of the second side wall portion104_3.

In this regard, a side wall portion104_6of the mold frame may be provided to extend in the vertical direction from an upper end of a first side wall portion104_2. A support104_3may be arranged at an upper end of the side wall portion104_6of the mold frame, and the support104_6may be substantially the same as the support of the mold frame of the backlight unit according to some embodiments of the invention.

In an exemplary embodiment, at least one opening104_4amay be defined in a slant portion104_4of the support frame104.FIG. 11exemplifies that the opening104_4ais in a rectangular shape, but the shape of the opening104_4ais not limited thereto. In another exemplary embodiment, the opening104_4amay have a circular shape or a shape including a curve at least partly.

In an exemplary embodiment, a plurality of openings104_4amay be arranged at predetermined intervals. When the opening104_4ais defined in the slant portion104_4, the total weight of the support frame104may be relatively reduced. Accordingly, the total weight of the backlight unit may be reduced.

Since other elements of the support frame104have the same structure with those of the support frame103described with reference toFIG. 9, the detailed explanation thereof will be omitted

FIG. 12is a partial cross-sectional view of a backlight unit according to still another exemplary embodiment of the invention.FIG. 13is a partial perspective view of the backlight unit ofFIG. 12, andFIG. 14is a partial perspective view of the backlight unit ofFIG. 12.

Referring toFIGS. 12 to 14, a backlight unit according to still another exemplary embodiment of the invention is different from the backlight unit according to the exemplary embodiment ofFIG. 1in that a light source portion includes a first PCB and light emitting lamps mounted on the first PCB.

The support frame105includes a bottom portion105_1, first and second side wall portions105_2and105_3provided to extend upward from both sides of the bottom portion105_1and facing each other, a ceiling portion105_5provided to extend in a horizontal direction from an upper end of the first side wall portion105_2, and a slant portion105_4slanted downward from an end part of the ceiling portion105_5and having one end that comes in contact with the end part of the ceiling portion105_5and the other end that comes in contact with an upper end of the second side wall portion105_3.

In this regard, a side wall portion104_6of the mold frame may be provided to extend in the vertical direction from an upper end of a first side wall portion104_2. A support104_3may be arranged at an upper end of the side wall portion104_6of the mold frame, and the support104_6may be substantially the same as the support of the mold frame of the backlight unit according to some embodiments of the invention.

In an exemplary embodiment, a light source portion600may include a first PCB600_1of a bar shape that extends in the length direction and a plurality of light emitting lamps600_2mounted on the first PCB600_1.

A plurality of first PCBs600_1may be arranged in a line to be spaced apart from each other at predetermined intervals.

The first PCB600_1may transfer a signal for controlling the light emitting lamps600_2mounted on the first PCB600_1or may transfer a power to the light emitting lamps600_2. The first PCB600_1may be electrically connected to the second PCB500_1which will be described later, through an opening400_3defined in a reflection sheet402and may receive a control signal that is output from the second PCB500_1to control the light emitting lamps600_2.

In an exemplary embodiment, the first PCB600_1may be arranged to be in parallel to the third side and the fourth side of a support frame105and perpendicular to the first side and the second side. In an exemplary embodiment in which the backlight unit further includes support bars, the support bars and the first PCB600_1may perpendicularly cross each other.

In exemplary embodiments of the invention, the backlight unit may further include a second PCB500_1and connection sockets500_2electrically connecting the second PCB500_1and the first PCB600_1to each other. Further, an insertion groove105_3a(refers toFIG. 15) and a connection socket insertion groove105_3bmay be defined in a second side wall portion105_3. This will be described in more detail with reference toFIGS. 15 to 17.

FIG. 15is a partial perspective view of a backlight unit according to still another exemplary embodiment of the invention.FIG. 16is an exploded perspective view of the backlight unit according to the exemplary embodiment ofFIG. 15, andFIG. 17is a perspective view of the backlight unit according to the exemplary embodiment ofFIG. 15.

Referring toFIGS. 15 to 17, a second PCB500_1may be connected to a plurality of first PCBs600_1to totally control the plurality of first PCBs600_1. That is, the second PCB500_1may transfer a control signal to the first PCBs600_1, or may provide a power required to drive light emitting lamps600_2. The second PCB500_1may be arranged in an inner space, that is, a cavity, of a support frame105. In an exemplary embodiment, the second PCB500_1may be arranged on an upper surface of a bottom portion105_1, and may be provided to extend along the length direction of the support frame105. That is, the second PCB500_1may be arranged on any one selected from first to fourth sides of the support frame105.

The connection socket500_2may electrically connect the first PCB600_1and the second PCB500_1to each other. In an exemplary embodiment, a plurality of connection sockets500_2may be aligned along the length direction in which the second PCB500_1extends. The respective connection sockets500_2may be fastened to the first PCB600_1to be electrically connected thereto. That is, the connection terminal600_1aof the first PCB600_1may be inserted into and fastened to the connection socket500_2, and thus the first PCB600_1and the second PCB500_1may be electrically connected to each other.

The connection socket500_2and the second PCB500_1may be inserted into the support frame105to be arranged in the cavity of the support frame105. In this regard, an insertion groove105_3a, into which the connection socket500_2and the second PCB500_1can be inserted, may be defined in a second side wall portion105_3of the support frame105. The insertion groove105_3amay be defined to extend along the length direction of the support frame105, and in an exemplary embodiment, the height of the insertion groove105_3athat corresponds to the connection socket500_2may be higher than the height of the insertion groove105_3athat corresponds to the second PCB500_1. A connection socket insertion groove105_3bmay be further defined in the second side wall portion105_3. The connection socket500_2may be inserted through the connection socket insertion groove105_3b. In an exemplary embodiment, a height of the connection socket insertion groove may be equal to or greater than that of the connection socket insertion groove105_3b.

A part of the connection socket500_2may be arranged in the cavity, and the remaining part thereof may be arranged to project for a predetermined distance from the second side wall portion105_3.

FIG. 18is an exploded perspective view of a liquid crystal display (“LCD”) according to an exemplary embodiment of the invention.

Referring toFIG. 18, a LCD1000according to an exemplary embodiment of the invention includes a backlight unit1500, a diffusion plate arranged on an upper portion of the backlight unit, at least one optical sheet arranged on the diffusion plate, and a display panel arranged on the optical sheet. The backlight unit includes a light source portion providing light to the display panel, a reflection sheet arranged on a lower part of the light source portion, a mold frame accommodating the light source portion, and a support frame supporting the mold frame, where the support frame includes a bottom portion, first and second side wall portions provided to extend upward from both sides of the bottom portion and facing each other, a ceiling portion provided to extend in a horizontal direction from an upper end of the first side wall portion, and a slant portion slanted downward from an end part of the ceiling portion and having one end that comes in contact with the end part of the ceiling portion and the other end that comes in contact with an upper end of the second side wall portion.

The backlight unit1500may be substantially the same as the backlight unit1500according to some embodiments of the invention as described above. Accordingly, the detailed explanation thereof will be omitted.

A diffusion plate130may be arranged on the backlight unit1500. The diffusion plate130may diffuse a part of light that is emitted from the backlight unit1500, transfer the diffused light to the display panel150arranged on the upper portion of the diffusion plate130, and reflect the other part of the light to the lower portion of the diffusion plate130again. In an exemplary embodiment, the diffusion plate130may include at least one material including Polymethyl methacrylate (“PMMA”), Polystyrene (“PS”), Polycarbonate (“PC”), Cyclo-olefin copolymers (“COC”), Polyethylene terephthalate (“PET”), Polybutyleneterephtalate (“PBT”), and a plastic material alloy. However, the material of the diffusion plate130is not limited thereto. Further, the diffusion plate130may be provided as a single layer, but is not limited thereto. The diffusion plate130may have a stacked structure in which a plurality of layers is stacked.

On the upper portion of the diffusion plate130, at least one optical sheet140for modulating the optical characteristic of the light that penetrates the diffusion plate130may be arranged.

The optical sheet140may include at least one sheet. In an exemplary embodiment, the optical sheet140may include a diffusion sheet140_1, a luminance improvement sheet140_2, and a reflection polarizing sheet140_3. The plurality of optical sheets140may be arranged on an upper portion of the diffusion plate130to increase the efficiency of the light emitted from the diffusion plate130and to provide uniform light luminance distribution.

The diffusion sheet140_1makes the light incident from the lower diffusion plate130be directed toward the front surface of the display panel530, and diffuses the light so that the light has uniform distribution in a wide range to irradiate the display panel530with the diffused light. The diffusion sheet140_1may be a film that is composed of a transparent resin of which both surfaces are coated with a predetermined light diffusion member.

The luminance improvement sheet140_2may change the slantingly incident light of the light incident to the luminance improvement sheet140_2to be vertically emitted. This is because the light efficiency becomes higher when the light incident to the display panel150becomes perpendicular to the display panel200.

The reflection polarizing sheet140_3transmits the light that is in parallel to its penetration axis, and reflects the light that is perpendicular to the penetration axis. In order to heighten the penetration efficiency, the penetration axis of the reflection polarizing sheet140_3may be in the same direction as the direction of the polarizing axis of the luminance improvement sheet140_2, but is not limited thereto.

The display panel150may be arranged on the optical sheet140. Further, a top chassis750may be arranged on the display panel150.

The display panel150includes a display region and a non-display region. Further, the display panel150may include a first substrate151, a second substrate152that faces the first substrate151, a liquid crystal layer, and a driving portion154and a flexible circuit board157attached to the first substrate151.

The display region of the display panel150may include a region where an image is displayed, and the non-display region of the display panel150may include a region where the image is not displayed. The display region may be positioned in a center portion of a region where the first substrate151and the second substrate152overlap each other, and the non-display region may be positioned in an edge portion of the region where the first substrate151and the second substrate152overlap each other. Further, the display region may be a region where the display panel150and the top chassis750do not overlap each other, and the non-display region may be a region where the display panel150and the top chassis750overlap each other. Further, the shape of the display region may be similar to the shape of the second substrate152, but the internal area of the display region may be smaller than the internal area of the second substrate152. Further, boundary lines between the display region and the non-display region may be in parallel to facing sides of the second substrate152. Further, the shape of the boundary line between the display region and the non-display region may be a rectangle.

At least a part of the first substrate151may overlap the second substrate152. The center portion of the region where the first substrate151and the second substrate152overlap each other may be the display region, and the edge portion of the region where the first substrate151and the second substrate152overlap each other may be the non-display region. The driving portion154and the flexible circuit board157may be attached to the region where the first substrate151and the second substrate152do not overlap each other.

The second substrate152may be arranged to face the first substrate151. The liquid crystal layer may be interposed between the first substrate151and the second substrate152. Between the first substrate151and the second substrate152, a sealing member, such as a sealant, may be arranged along the edge portions of the first substrate151and the second substrate152to adhere and seal the first substrate151and the second substrate152.

The first substrate151and the second substrate152may be in a cuboidal shape. For convenience in explanation, it is illustrated that the first substrate151and the second substrate152are in a cuboidal shape, but are not limited thereto. The first substrate151and the second substrate152may be manufactured in various shapes depending on the shape of the display panel150.

The driving portion154may apply various signals, such as driving signals required to display an image on the display region. The flexible circuit board157may output various kinds of signals to the driving portion154.

The top chassis750may cover the edge of the display panel150and may surround side surfaces of the display panel150and the backlight unit1500.