KR20070118874A - Back-light assembly and liquid crystal display having the same - Google Patents

Abstract

A backlight assembly and an LCD having the same are provided to offer uniform brightness to the whole display screen by coating directly a metal layer on a side mold. A backlight assembly includes plural lamps(143), a side mold(145), and a lower container. The plural lamps are disposed in a line. The side mold fixes at least one end of the lamp and has a reflective film(200) formed on the surface opposite to the lamp. The lower container contains the lamps and the side mold. The reflective film consists of a polymer film where a metal layer with high reflexibility is coated.

Description

Back-light assembly and liquid crystal display having the same

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

FIG. 2 is a perspective view of a liquid crystal display showing a relationship between a side mold and a lamp in the liquid crystal display of FIG. 1.

3 is a cross-sectional view taken along line III-III ′ of the liquid crystal display of FIG. 2.

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

100: liquid crystal display device 110: upper storage container

130: liquid crystal panel assembly 131: gate tape carrier package

132: data tape carrier package

133: thin film transistor array panel

134: common electrode display panel 135: printed circuit board

136: liquid crystal panel 140: backlight assembly

141: optical sheets 142: diffusion plate

143: lamp 144: reflector

145: side mold 148: lamp holder

150: storage frame 160: lower storage container

200: reflective film 210: groove

The present invention relates to a backlight assembly and a liquid crystal display including the same. More particularly, the present invention relates to a backlight assembly and a liquid crystal display including the same, which can provide uniform luminance throughout the display screen.

Liquid crystal display is one of the most widely used flat panel displays. It consists of two substrates on which electrodes are formed and a liquid crystal layer interposed between them. The display device is applied to rearrange the liquid crystal molecules of the liquid crystal layer to control the amount of light transmitted.

Such a liquid crystal display device includes a backlight assembly that provides light passing through the liquid crystal layer. Here, the backlight assembly includes a lamp, various optical sheets, and a storage container for storing them.

In general, after measuring the luminance of nine points in the display screen, the luminance uniformity of the liquid crystal display is evaluated by using a ratio of the highest luminance value and the lowest luminance value. However, a liquid crystal display using a lamp having electrodes at both ends has a problem in that luminance is lowered toward the outside of the display screen, thereby lowering luminance uniformity. In particular, liquid crystal displays used in monitors compared to televisions require high luminance uniformity because the distance between the user and the display screen is close.

An object of the present invention is to provide a backlight assembly capable of providing uniform luminance throughout the display screen.

Another object of the present invention is to provide a liquid crystal display device including the backlight assembly.

The technical problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a backlight assembly comprising: a plurality of lamps arranged side by side, a side mold having at least one end of the lamp fixed thereto, and a reflective film formed on a surface opposite to the lamp; And a lower accommodating container for accommodating the lamp and the side mold.

According to another aspect of the present invention, a liquid crystal display device includes a liquid crystal panel for displaying an image and the backlight assembly for providing light to the liquid crystal panel.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, a backlight assembly and a liquid crystal display including the same according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention. Referring to FIG. 1, the liquid crystal display device 100 includes a liquid crystal panel assembly 130, a backlight assembly 140, and an upper storage container 110 as a whole.

The liquid crystal panel assembly 130 includes a thin film transistor array panel 133, a liquid crystal panel 136 including a common electrode display panel 134, a liquid crystal (not shown), a gate tape carrier package 131, and a data tape carrier package 132. ) And a printed circuit board 135.

The liquid crystal panel 136 includes a thin film transistor array panel 133 including a gate line (not shown) and a data line (not shown), a thin film transistor array, a pixel electrode, and the like, a black matrix, a common electrode, and the like. And a common electrode display panel 134 disposed to face the thin film transistor array panel 133.

The gate tape carrier package 131 is connected to each gate line (not shown) formed on the thin film transistor array panel 133, and the data tape carrier package 132 is each data line (not shown) formed on the thin film transistor array panel 133. ) Is connected.

Meanwhile, in the printed circuit board 135, various driving processes for processing both the gate driving signal and the data driving signal for inputting the gate driving signal to the gate tape carrier package 131 and the data driving signal to the data tape carrier package 132 are performed. The part is mounted.

The backlight assembly 140 includes optical sheets 141, a diffusion plate 142, a lamp 143, and a reflector plate 144.

The lamp 143 may be a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an External Electrode Fluorescent Lamp (EEFL), or the like. The lamp 143 generates light by a lamp driving voltage applied to the lamp 143 from the outside. In addition, the lamps 143 may be spaced apart at a uniform distance and connected in phase in parallel, and may be configured in a direct type. The lamp 143 is preferably arranged in the transverse direction with respect to the liquid crystal panel 136 so that the distribution of the discharge gas inside the lamp 143 is constant to obtain uniform luminance.

The lamp holder 148 is positioned at both ends of the lamp 143 and supports and fixes the lamp 143. Here, the lamp holder 148 may include voltage applying means (not shown) for transferring a lamp driving voltage provided from the outside to the electrode of the lamp 143.

The diffusion plate 142 may be installed on the upper part of the lamp 143, and serves to improve luminance uniformity of the light generated by the lamp 143. That is, the diffusion plate 142 allows the light emitted from the lamp 143 to face the front surface of the liquid crystal panel 136 and to be incident at a wide range of angles. The diffusion plate 142 may be formed by coating a light diffusion member on both surfaces of a transparent film such as an acrylic resin.

The reflection plate 144 is installed under the lamp 143 to reflect the light emitted to the bottom of the lamp 143 to the top. The reflecting plate 144 may be integrally formed on the bottom surface of the lower storage container 160. That is, the lower receiving container 160 may be made of a material having high reflectivity such as aluminum (Al) or an aluminum alloy so that the lower receiving container 160 may perform a function of the reflecting plate 144.

The optical sheets 141 are installed on the diffusion plate 142 and serve to diffuse and collect light transmitted from the lamp 143. The optical sheets 141 include a diffusion sheet, a first prism sheet, a second prism sheet, and the like.

In this case, the diffusion sheet is positioned above the lamp 143 and serves to improve brightness and uniformity of light incident from the lamp 143.

The first prism sheet is positioned above the diffusion sheet, and one surface of the first prism sheet has a triangular prism pattern (not shown) for condensing and emitting light diffused from the diffusion sheet and having a constant arrangement. For example, a brightness enhancement film (Brightness Enhancement Film-III, BEF-III ™, manufacturer 3M) may be used as the first prism sheet.

The second prism sheet is a reflective polarizing prism sheet having a multi-layered structure positioned on the first prism sheet and condensing and polarizing light. For example, a dual brightness enhancement film (Dual Brightness Enhancement Film, DBEF ™, manufacturer 3M) may be used. However, if only the first prism sheet can sufficiently secure the luminance and the viewing angle, the second prism sheet may be excluded.

The backlight assembly 140 includes an accommodating frame 150 and a lower accommodating container 160 accommodating the optical sheets 141, the diffusion plate 142, the lamp 143, and the reflecting plate 144.

The liquid crystal panel assembly 130 is installed on the optical sheets 141 and is supported by the storage frame 150 and seated in the lower storage container 160. The storage frame 150 is formed of sidewalls formed along a rectangular edge and has a structure in which a stepped portion or a protrusion is formed on an inner wall to support the liquid crystal panel assembly 130. The lower storage container 160 has a rectangular shape and sidewalls are formed along the edge of the upper surface such that the optical sheets 141, the diffusion plate 142, the lamp 143, the reflective plate 144, and the liquid crystal panel assembly 130 are formed in the sidewalls. ) And to fix it. The lower accommodating container 160 also prevents the plurality of optical sheets 141 from bending. The printed circuit board 135 of the liquid crystal panel assembly 130 is bent along the outer wall of the lower housing 160 to be seated on the sidewall or the rear surface of the lower housing 160. Herein, according to the method of accommodating the optical sheets 141, the optical plate 142, the lamp 143, the reflecting plate 144, or the liquid crystal panel assembly 130 in the lower storage container 160, The shape may be variously modified.

When the reflecting plate 144, the lamp 143, and the lamp holder 148 are accommodated in the lower storage container 160, the side mold 145 may be coupled to both ends of the lamp 143 to store the lamp 143 and the lamp holder 148. ) Is fixed in the lower storage container 160. The side mold 145 for providing uniform luminance throughout the display screen will be described later in detail.

In addition, the upper accommodating container 110 is disposed to be coupled to the lower accommodating container 160 to cover an upper surface of the liquid crystal panel assembly 130 accommodated in the lower accommodating container 160. A window for exposing the liquid crystal panel assembly 130 to the outside is formed on an upper surface of the upper accommodating container 110.

The upper storage container 110 may be fastened to the lower storage container 160 through hook coupling (not shown) and / or screw coupling (not shown). In addition, the combination of the upper storage container 110 and the lower storage container 160 may be modified in various forms.

Hereinafter, the side mold 145 for providing uniform luminance will be described in detail with reference to FIGS. 2 and 3. 2 is a perspective view of a liquid crystal display device illustrating a relationship between a side mold and a lamp in the liquid crystal display device of FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III ′ of the liquid crystal display device of FIG. 2.

2 and 3, after storing the reflector plate 144, the lamp 143, and the lamp holder 148 in the lower storage container 160, the lamp 143 is fixed to the lower storage container 160. In order to wrap the end of the lamp 143 with the side mold 145. In general, the brightness of the lamp tends to decrease toward the end of the lamp 143 due to the electrode formed at the end of the lamp 143. In order to compensate for the decrease in luminance at the end of the lamp 143, the reflective film 200 is formed on the side mold 145 wrapped around the end of the lamp 143. The reflective film 200 reflects most of the light emitted from the lamp 143 and dispersed or absorbed at the end of the lamp 143 to increase the brightness of both sides of the liquid crystal panel.

The reflective film 200 may be a polymer film such as polyethylene terephthlate (PET) coated with a metal layer having a high reflectance such as silver (Ag) or aluminum (Al). The reflective film 200 may be laminated and fixed to the side mold 145 using an adhesive or an adhesive. In this case, in order to prevent the reflective film 200 from being separated after being fixed to the side mold 145, a plurality of grooves 210 may be formed along a portion where the reflective film 200 is folded.

In another embodiment of the present invention, a metal layer having a high reflectance such as silver (Ag) or aluminum (Al) may be used as the reflective film 200. That is, by coating the metal layer directly on the side mold 145, the same effect as in the above embodiment can be obtained.

In the above embodiment, the case where the reflective film 200 is laminated on the side mold 145 has been described as an example, but the present invention is not limited thereto, and the reflective film 200 is bonded to the side mold 145 in various ways. May be included.

In addition, when using the straight-type lamp 143 as in the above embodiment, it is preferable to arrange the side mold 145 having the reflective film 200 formed at both ends of the lamp 143. However, when the U-shaped lamp is used, since the lamp electrode is disposed only at one end of the lamp, a reflective film can be formed at least with respect to the side mold on the lamp electrode.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments, but may be manufactured in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

As described above, according to the backlight assembly and the liquid crystal display including the same, the display screen may provide uniform luminance.

Claims (7)

A plurality of lamps arranged side by side; A side mold fixing at least one end of the lamp, the side mold having a reflective film formed on a surface facing the lamp; And And a lower housing to receive the lamp and the side mold. According to claim 1, The reflective film is a backlight assembly consisting of a polymer film coated with a metal layer of high reflectance. The method of claim 2, The reflective film is a backlight assembly consisting of a PET film coated with silver or aluminum. The method of claim 2, And the reflective film is laminated to the side mold using an adhesive or an adhesive. The method of claim 2, And a plurality of grooves formed along a portion where the reflective film is folded. According to claim 1, The reflective film is made of a metal layer of high reflectivity, And the reflective film is coated on the side mold. A liquid crystal panel displaying an image; And The liquid crystal display of claim 1, wherein the backlight assembly of claim 1 provides light to the liquid crystal panel.

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