KR20080001239A - Backlight assembly and liquid crystal display device having the same - Google Patents

Abstract

A backlight assembly and an LCD(Liquid Crystal Display) having the same are provided to prevent a support main from being bent by impact or separated to the outside by fixing protrusions of a sheet to through holes of the support main, thereby improving reliability. A backlight unit includes an optical sheet(67) having plural protrusions(65a) in an edge area. A support main(71) supports the backlight unit. In the support main, plural through holes(71a) corresponding to the protrusions of the optical sheet are formed. The protrusions of the optical sheet are fixed to the through holes of the support main. The optical sheet includes a diffuser sheet(59), first and second prism sheets(61,63) and a protection sheet(65).

Description

Backlight assembly and liquid crystal display device having the same {Backlight assembly and liquid crystal display device having the same}

1 is a view showing a conventional liquid crystal display device.

2 is a view schematically showing a liquid crystal display device of the present invention.

3 is a cross-sectional view taken along the line AA ′ of FIG. 2.

4 is a cross-sectional view taken along the line BB ′ of FIG. 2.

5 is a view showing the shape of the protective sheet of FIG.

FIG. 6 is a view illustrating a state in which the upper portion of the protrusion is bent when the height of the protrusion of the protective sheet is greater than the thickness of the extension of the support main in FIG. 3.

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

65: protective sheet 65a: protrusion

67: optical sheet 69: liquid crystal panel

71: support main 71a: through hole

71b: extension

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a backlight assembly capable of preventing defects and improving reliability and productivity, and a liquid crystal display device having the same.

The active matrix liquid crystal display device displays a natural moving image using a thin film transistor (TFT) as a switching element. Such a liquid crystal display device can be miniaturized compared to a CRT and commercialized as a monitor such as a portable television or a laptop-type personal computer.

1 is a view showing a conventional liquid crystal display device. As shown in FIG. 1, a conventional liquid crystal display device includes a support main 32, a backlight unit and a liquid crystal panel 30 stacked inside the support main 32, and a support main 32. A cover bottom (36) surrounding one bottom and side and a top case (34) surrounding the edge and the cover bottom 36 of the liquid crystal panel 30 are provided.

The support main 32 serves to support the entire liquid crystal display, and the backlight unit and the liquid crystal panel 30 are stacked therein.

The liquid crystal panel 30 includes a color filter array including a black matrix on a substrate, a top plate 30b in which a common electrode and an alignment layer are sequentially formed, and a pixel electrode and an alignment layer including a TFT array formed on the substrate. The lower plate 30c sequentially formed, the upper polarizing plate 30a attached on the upper plate 30b, the lower polarizing plate 30d attached below the lower plate 30c, and the illustration of maintaining the gap between the upper plate and the lower plate. The spacer, which is not shown, and the upper plate and the lower plate are bonded by a sealant (not shown) and are composed of liquid crystal injected into a space between the upper and lower plates.

The top case 34 is installed to surround the surface edges and sides of the liquid crystal panel 30 and various optical sheets. The top case 34 protects the liquid crystal panel 30 from external impact by wrapping the edge of the liquid crystal panel 30.

The backlight unit includes a lamp 10 for generating light, a lamp housing 12 installed to surround the lamp 10, a light guide plate 14 for converting light incident from the lamp 10 into a surface light source, A reflector 16 positioned below the light guide plate 14 to reflect light traveling toward the bottom and side surfaces of the light guide plate 14 toward the upper surface, and a diffuser sheet for diffusing light through the light guide plate 14; ), First and second prism sheets 20 and 22 for adjusting the advancing direction of light via the diffusion sheet 18, and second prism sheets 22 formed on the second prism sheet 22. A protective sheet 24 for protecting is provided.

As the lamp 10 used in the backlight unit, a cold cathode fluorescent lamp is mainly used, and the light generated from the lamp 10 is incident on the light guide plate 14 through an incident surface existing on the side of the light guide plate 14.

The lamp housing 12 has a reflecting surface on its inner surface to reflect light from the lamp 10 toward the incident surface of the light guide plate 14.

The rear side of the light guide plate 14 is provided so that the reflecting plate 16 faces. The light guide plate 14 allows the light incident from the lamp 10 to reach a distance far from the lamp 10. The light guide plate 14 is generally formed of polymethylmethacrylate (PMMA) having high strength and not easily being deformed or broken and having good transmittance.

The reflector 16 serves to reduce light loss by reflecting light incident to itself through the rear surface of the light guide plate 14 toward the light guide plate 14. When the light from the lamp 10 is incident on the light guide plate 14, the light is reflected at a predetermined inclination angle by the reflecting plate 16 on the rear surface and is uniformly directed toward the exit surface. At this time, the light propagated toward the lower surface and the side surface of the light guide plate 14 is reflected by the reflecting plate 16 and proceeds toward the exit surface. Light emitted through the exit surface of the light guide plate 14 is diffused to the entire area by the diffusion sheet 18. On the other hand, when the light incident on the liquid crystal panel is vertical, the light efficiency is increased. To this end, two prism sheets 20 and 22 are laminated so that the traveling angle of the light emitted from the light guide plate 14 is perpendicular to the liquid crystal panel.

The diffusion sheet 18, the first and second prism sheets 20 and 22, and the protective sheet 24 are collectively called an optical sheet.

The first and second prism sheets 20 and 22 are in the form of a plurality of prism rods having hills and valleys. The two prism sheets 20 and 22 collect light emitted from the diffusion sheet 18 in a direction perpendicular to the screen.

The protective sheet 24 protects the prism in the form of the mountain of the second prism sheet 22 and allows the light passing through the second prism sheet 22 toward the liquid crystal panel 30.

As shown in FIG. 1, since the optical sheet is simply seated on the light guide plate 14 and is not fixed separately, the optical sheet is easy to flow, and if only a little care is taken during assembling, the optical sheet may be displaced from the correct position, causing assembly failure. There is a problem.

On the other hand, the support main 32 is made of a resin material is easy to deform. Accordingly, when the impact test is performed, the support main 32 may be bent to the outside in the direction in which the impact is applied by the light guide plate 14, and in some cases, the support main 32 may be defective.

Accordingly, an object of the present invention is to provide a backlight assembly and a liquid crystal display device having the same, by fixing the support main and the optical sheet to prevent the defects of the support main and the optical sheet due to flow or impact and improving reliability. .

According to a first embodiment of the present invention for achieving the above object, the backlight assembly includes a backlight unit including an optical sheet having a plurality of protrusions in the edge region; And a support main supporting the backlight unit and having a plurality of through holes corresponding to the protrusions of the optical sheet, wherein the protrusions of the optical sheet are fixed to the through holes of the support main.

According to a second embodiment of the present invention, a liquid crystal display includes a cover bottom; A backlight unit mounted on the cover bottom and including an optical sheet having a plurality of protrusions in an edge region; A support main supporting the backlight unit and having a plurality of through holes corresponding to the protrusions of the optical sheet; A liquid crystal panel seated on the support main; And a top case surrounding the edge of the liquid crystal panel and the cover bottom, and the protrusion of the optical sheet is fixed to the through hole of the support main.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

FIG. 2 is a schematic view illustrating a liquid crystal display of the present invention, FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. 2, and FIG. 4 is a cross-sectional view taken along the line B-B ′ of FIG. 2.

In the present invention, the same components as in the prior art will be omitted for convenience of description. Parts not described in the present invention will be readily understood with reference to FIG. 1 and the prior art.

2 to 4, the light guide plate 55 is seated on the cover bottom 73, a reflecting plate 57 is attached to a bottom surface of the light guide plate 55, and a side surface of the light guide plate 55. A lamp housing 53 having a lamp 51 is provided. In addition, the diffusion sheet 59, the first and second prism sheets 61 and 63, and the protective sheet 65 are stacked on the light guide plate 55. The optical sheet 67 is formed by the diffusion sheet 59, the first and second prism sheets 61 and 63, and the protective sheet 65.

A support main 71 for fixing the light guide plate 55, the optical sheet 67, and the lamp housing 53 is provided at the side of the light guide plate 55 and the lamp housing 53. In addition, the support main 71 is responsible for the overall support of the liquid crystal display.

According to the present invention, the optical sheet 67 and the support main 71 may be fixed to prevent defects caused by the flow of the optical sheet 67 and defects caused by the impact of the support main 71 at the same time.

To this end, the optical sheet 67 has a plurality of protrusions 65a protruding upward in the edge region thereof. A plurality of protrusions 65a may be formed along each surface of the optical sheet 67. Since the optical sheet 67 is made of a resin material, the strength may be weak, and it is preferable to form as many protrusions 65a as possible to compensate for this.

As described above, the optical sheet 67 includes the diffusion sheet 59, the first and second prism sheets 61 and 63, and the protective sheet 65, and protrusions 65a on each of these sheets. ) May be formed, but a plurality of protrusions 65a may be formed in any one of these sheets.

3 and 4 illustrate that the protruding portion 65a is formed on the protective sheet 65, the protruding portion 65a of the present invention may be a diffusion sheet 59, a first prism sheet 61, or It may also be formed on the two prism sheets 63.

As shown in FIG. 5, the protruding portion 65a is cut at an interval from the end of the protective sheet 65 to a predetermined interval therein, and then the standing protective sheet 65 is raised in an upward direction, and then fixed by applying heat. Can be formed.

Alternatively, the protruding portion 65a may be formed to stand in an upward direction at the end of the protective sheet 65 by a molding process.

The support main 71 has a plurality of through holes 71a corresponding to the plurality of protrusions 65a of the protective sheet 65. Therefore, the through hole 71a may be formed in the extension part 71b of the support main 71. The extension part 71b extends in the horizontal direction from an upper side of the support main 71.

The extension part 71b is formed to seat the liquid crystal panel 69. A plurality of through holes 71a are formed in the extension part 71b formed as described above.

Therefore, when the protective sheet 65 is seated on the light guide plate 55 and the support main 71 is fastened to the cover bottom 73, the protrusion 65a of the protective sheet 65 is the support main 71. It is inserted through the through hole (71a) of.

The diameter of the through hole 71a is formed to be at least larger than the diameter of the protrusion 65a. As such, since the diameter of the through hole 71a is at least larger than the diameter of the protrusion 65a, the protrusion 65a can be stably inserted without being pinched in the through hole 71a.

The height of the protrusion 65a is preferably at least smaller than the thickness of the extension 71b of the support main 71. As such, when the height of the protrusion 65a is at least smaller than the thickness of the extension 71b of the support main 71, the protrusion 65a is inserted even if the protrusion 65a is inserted into the through hole 71a. Is not protruded higher than the upper surface of the extension part 71b through the through hole 71a, so that the liquid crystal panel 69 does not come into contact with the liquid crystal panel 69 seated on the extension part 71b of the support main 71. Will not.

However, even if the height of the protrusion 65a is larger than the thickness of the extension 71b of the support main 71, there is no problem at all. On the contrary, when the height of the protrusion 65a is formed to be larger than the thickness of the extension 71b of the support main 71 by a predetermined interval, a better effect can be obtained. That is, as shown in FIG. 6, when the height of the protrusion 65a is larger than the thickness of the extension 71b of the support main 71 by a predetermined distance d, the protrusion 65a is formed. When inserted into the through hole 71a, the protrusion 65a penetrates the through hole 71a to protrude higher than an upper surface of the extension part 71b. In this case, when the liquid crystal panel 69 is seated on the extension part 71b of the support main 71, the protrusion part protruding higher than the upper surface of the extension part 71b by the liquid crystal panel 69 is formed. 65a is pressed, and the protrusion 65a protruding through the through-hole 71a by itself and protruding from the upper surface of the extension part 71b is bent and fixed by the liquid crystal panel 69, so that the optical sheet Weakening of the strength of (67) can be compensated for. In this configuration, the support main 71 and the optical sheet 67 are sufficiently formed even if the number of the protruding portion 65a of the protective sheet 65 and the through-hole 71a of the support main 71 is smaller. Can be firmly fixed.

The assembly procedure of the liquid crystal display device configured as described above will be described.

First, the light guide plate 55 is seated on the cover bottom 73. A lamp housing 53 having a lamp 51 is provided on the side surface of the light guide plate 55. The assembly order of the light guide plate 55 and the lamp housing 53 can also be changed. That is, the lamp housing 53 may be installed first, and then the light guide plate 55 may be seated on the cover bottom 73.

Subsequently, the optical sheet 67 including the diffusion sheets 59, the first and second prism sheets 61 and 63, and the protective sheet 65 is mounted on the light guide plate 55. In this case, a plurality of protrusions 65a are formed in the edge region of the protective sheet 65.

The support main 71 is engaged with the cover bottom 73 by pressing in the vertical downward direction while matching the edge of the cover bottom 73. In this case, a plurality of through holes 71a corresponding to the plurality of protrusions 65a formed on the protective sheet 65 are formed in the extension part 71b of the support main 71. Therefore, the protruding portion 65a of the protective sheet 65 is inserted and fixed through the through hole 71a formed in the extension portion 71b of the support main 71.

Subsequently, the liquid crystal panel 69 is seated on the extension part 71b of the support main 71.

The edge of the liquid crystal panel 69 and the side surface of the cover bottom 73 are wrapped with the top case 75.

As described above, according to the present invention, by fixing the protrusion of the sheet to the through-hole of the support main, the optical sheet is not fixed to the light guide plate to be seated to prevent defects caused by easy flow, support main Since the impact can be prevented from being bent or severely separated by the impact, it is expected to improve the reliability.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification should be defined by the claims.

Claims (18)

A backlight unit including an optical sheet having a plurality of protrusions in an edge region; And A support main supporting the backlight unit and having a plurality of through holes corresponding to the protrusion of the optical sheet; The projection of the optical sheet is a backlight assembly, characterized in that fixed to the through-hole of the support main. The backlight assembly of claim 1, wherein the optical sheet comprises a diffusion sheet, first and second prism sheets, and a protective sheet. The backlight assembly of claim 2, wherein the backlight assembly is formed on the diffusion sheet, the first and second prism sheets, and the protective sheet. The backlight assembly of claim 2, wherein the backlight assembly is formed on any one of the diffusion sheet, the first and second prism sheets, and the protective sheet. The backlight assembly of claim 1, wherein the support main unit includes an extension extending in a horizontal direction. The backlight assembly of claim 5, wherein the through hole is formed on the extension part corresponding to the protrusion of the optical sheet. The backlight assembly of claim 6, wherein the height of the protrusion is at least smaller than the thickness of the extension. The backlight assembly of claim 6, wherein a height of the protrusion is formed at a predetermined interval greater than a thickness of the extension. The backlight assembly of claim 8, wherein the predetermined intervals higher than the thickness of the extension are artificially bent along the surface of the extension. Cover bottom; A backlight unit mounted on the cover bottom and including an optical sheet having a plurality of protrusions in an edge region; A support main supporting the backlight unit and having a plurality of through holes corresponding to the protrusions of the optical sheet; A liquid crystal panel seated on the support main; And A top case surrounding an edge of the liquid crystal panel and the cover bottom, The protrusion of the optical sheet is fixed to the through hole of the support main. The liquid crystal display of claim 10, wherein the optical sheet comprises a diffusion sheet, first and second prism sheets, and a protective sheet. 12. The liquid crystal display device according to claim 11, wherein the diffusion sheet, the first and second prism sheets, and the protective sheet are formed on the diffusion sheet. 12. The liquid crystal display device according to claim 11, wherein the diffusion sheet, the first and second prism sheets, and the protective sheet are formed on any one of the sheets. The liquid crystal display of claim 10, wherein the support main unit includes an extension part extending in a horizontal direction. The liquid crystal display of claim 14, wherein the through hole is formed on the extension part corresponding to the protrusion of the optical sheet. The liquid crystal display device according to claim 15, wherein a height of the protrusion is at least smaller than a thickness of the extension part. The liquid crystal display device according to claim 15, wherein the height of the protrusion is formed at a predetermined interval more than the thickness of the extension. 18. The liquid crystal display device according to claim 17, wherein protrusions having a predetermined interval higher than the thickness of the extension part are pressed and fixed by the liquid crystal panel.

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