KR20070015799A - Backlight assembly and liquid crystal display included the same - Google Patents

Abstract

Provided are a backlight assembly and a liquid crystal display device including the same, which can improve the defects such as scratches and white spots by preventing the light guide plate from flowing up and down. The backlight assembly is composed of a lamp, a light guide plate positioned adjacent to one side of the lamp and uniformly transmitting light from the lamp to the top, and sidewalls extending from the bottom and edges of the bottom, and by sidewalls. A lamp and the light guide plate are accommodated in the formed space, and the first lower storage container includes a protrusion formed to overlap an upper surface of the light guide plate from the side wall.

Backlight Assembly, Light Guide Plate, Protrusion, Liquid Crystal Display

Description

Backlight assembly and liquid crystal display including the same

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

FIG. 2 is a cross-sectional view taken along line II to II ′ after assembling the liquid crystal display of FIG. 1.

3 is a perspective view of the first lower housing of the backlight assembly according to an embodiment of the present invention.

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

100 liquid crystal display device 10 liquid crystal panel assembly

15: drive assembly 17: gate TPC

18 data CD 19 printed circuit board

20: backlight assembly 30: first lower storage container

35: protrusion 40: reflector

60: light guide plate 70: optical sheet

80: upper storage container 90: second lower storage container

360: first protrusion 370: second protrusion

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 having a protrusion preventing the flow of the light guide plate and a liquid crystal display including the same.

In recent years, liquid crystal displays have been in the spotlight as display means. The liquid crystal display performs display functions by using the electrical and optical properties of the liquid crystal injected into the liquid crystal panel, and is widely applied in various fields such as a computer monitor or a mobile communication terminal due to advantages such as small size, light weight, and low power consumption. It is becoming a trend.

The liquid crystal display device has an active matrix display method using a switching element and a twisted nematic liquid crystal and a passive matrix display method using a super twisted nematic liquid crystal according to a difference in driving method. It can be divided largely.

The configuration and operation of an active matrix liquid crystal display device will be briefly described as follows.

A liquid crystal display device using an active matrix display system includes a liquid crystal panel, a backlight assembly for irradiating light to the liquid crystal panel, an inverter for supplying power to the backlight assembly, and the like.

The liquid crystal panel includes a common electrode display panel including a color filter, a thin film transistor array panel including a thin film transistor, and a liquid crystal layer filled in a space therebetween. That is, the liquid crystal display device using the active matrix display method rearranges the liquid crystal molecules of the liquid crystal layer by applying a voltage to the electrodes of the common electrode panel and the thin film transistor array panel, thereby adjusting the amount of light transmitted from the backlight assembly. The device is configured to display a predetermined image.

The backlight assembly applied to the liquid crystal display device includes a lamp as a light source, a reflector for reflecting light generated by the lamp, components such as an optical sheet for condensing and diffusing light, an accommodating member, and the like. . The storage member includes a lower storage container, and functions to stably receive by fixing and supporting them by coupling with respective components.

In addition, the backlight assembly may be classified into two types, a direct type and an edge type, depending on the position of the light source.

In the direct type, the light source is located at the bottom of the liquid crystal panel to directly illuminate the front surface of the liquid crystal panel, so that there is no need for a light guide plate for converting the linear light of the lamp into surface light. And an optical sheet for condensing and diffusing the emitted light.

In addition, since it can be provided with a large number of light sources and high light utilization efficiency, it is mainly used in a large screen liquid crystal display device requiring high brightness.

On the other hand, the edge type is installed on the side of the light guide plate for guiding the light, and when the size of the liquid crystal display is enlarged, the luminance is lowered. However, the edge type is advantageous in thinning, so it is often used in liquid crystal displays having a relatively small size such as a computer monitor. Is used.

Usually, such an edge type backlight assembly is provided with a light guide plate for scattering and homogenizing light on the side of a fluorescent lamp which is a light source, and a reflecting plate is disposed on the bottom surface of the light guide plate. In addition, the upper surface of the light guide plate is formed with a pair of prism sheets for switching the light path, and to derive the brightness and a diffusion sheet for increasing the uniformity of the light incident on the liquid crystal panel. In addition, the components of the backlight assembly are supported and fixed by the lower housing.

In addition, due to the high price of the prism sheet, a manufacturing cost is lowered by using a prism light guide plate in which a plurality of prism acids are formed on the light guide plate.

However, the conventional light guide plate can be supported and fixed to the lower housing through the shape of the ear or stopper (stopper), while the prism light guide plate is impossible to process the shape is fixed to the lower housing using a double-sided tape.

Here, white spots, scratches, etc. are generated due to the up and down flow of the light guide plate, which causes a problem of degrading the quality of the liquid crystal display.

An object of the present invention is to provide a backlight assembly that prevents the light guide plate from flowing.

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.

In accordance with one aspect of the present invention, a backlight assembly includes a lamp, a light guide plate positioned adjacent to one side of a lamp, and uniformly transferring light transmitted from the lamp to the top, a bottom surface, and a bottom. And a lower storage container including a side wall extending from an edge of the surface and accommodating the lamp and the light guide plate in a space formed by the side wall, and having a protrusion formed to overlap the upper surface of the light guide plate from the side wall.

According to another aspect of the present invention, there is provided a liquid crystal display device including a backlight assembly and a liquid crystal panel assembly positioned on an upper portion of the backlight assembly and displaying an image by light supplied from the backlight assembly. It includes.

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, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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

As shown in FIG. 1 and FIG. 2, the liquid crystal display device 100 generally includes a backlight assembly 20, a liquid crystal panel assembly 10, an upper accommodating container 80, a lower accommodating container 30, 90, and the like. It is configured to include.

In addition, the lower storage containers 30 and 90 are combined with the first lower storage container 30 in which the backlight assembly 20 and the like are accommodated, and the first lower storage container 30 and the upper storage container 80. It is divided into a second lower container 90 that can form the frame of the device (100).

The liquid crystal panel assembly 10 includes a thin film transistor array panel 11, a common electrode display panel 13, a liquid crystal layer (not shown), a driving assembly 15, and the like, and the driving assembly 15 may include a gate tape. A carrier package 17, a data PC 18, a printed circuit board 19, and the like.

The thin film transistor array panel 11 includes a plurality of gate lines, data lines, and pixel electrodes. The gate lines extend in the row direction to carry the gate signal, and the data lines extend in the column direction and carry the data signal. The pixel is connected to the gate line and the data line and includes a switching element and a storage capacitor.

Here, the switching element is formed at the intersection of the gate line and the data line, and the sustain capacitor and the liquid crystal capacitor are connected to the output terminal of the switching element. In addition, the switching element is implemented as a thin film transistor having amorphous silicon and poly-silicon as a channel layer.

The other terminal of the holding capacitor is connected to a common voltage or to a gate line immediately above. Here, the former connection method is called a separate wire type, and the latter connection method is called a front gate type.

The common electrode display panel 13 is positioned to face the upper portion of the thin film transistor array panel 11 and includes a red, green, or blue color filter in a region corresponding to the pixel electrode so that colors can be displayed for each pixel. The color filter may be formed above or below the pixel electrode. In addition, a common electrode made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is formed on the color filter.

The liquid crystal layer (not shown) is filled between the common electrode display panel 13 and the thin film transistor array panel 11 and has a dielectric anisotropy. The liquid crystal layer (not shown) has a thickness of about 5 μm and has a twisted nematic (TN) arrangement. The liquid crystal layer (not shown) adjusts the transmittance of light passing through the liquid crystal layer (not shown) by changing the arrangement direction by a voltage applied from the outside.

The drive assembly 15 receives a gate control signal, a data control signal, a data signal related thereto, and the like from the printed circuit board 19 through an input terminal, and outputs a gate TPC 17 and a data TPC 18 as output terminals. The gate driving signal and the data driving signal are respectively provided to the gate line and the data line formed on the thin film transistor array panel 11 through the gate driving signal and the data driving signal.

At this time, the gate TPC 17 is connected to each gate line formed in the thin film transistor array panel 11, and the data TPC 18 is connected to each data line formed in the thin film transistor array panel 11.

Meanwhile, the printed circuit board 19 may process various gate driving signals and data driving signals so that the gate driving signal can be input to the gate TC 17 and the data driving signal can be input to the data TC 18. The parts are mounted.

The backlight assembly 20 includes a first lower container 30, a light guide plate 60, a lamp 50, an optical sheet 70, and the like.

In addition, a reflecting plate 40 may be further included on the lower surface of the light guide plate 60.

The light guide plate 60 serves to guide the light supplied to the liquid crystal panel assembly 10 and is made of a transparent material of plastics such as acrylic. Various patterns for converting the traveling direction of light incident into the light guide plate 60 toward the liquid crystal panel assembly 10 may be printed on the bottom surface of the light guide plate 60.

In addition, the light guide plate 60 may be configured as a prism light guide plate having a plurality of prism acids having a triangular cross section. This can reduce the two prism sheets included in the optical sheet 70 to one sheet, and can suppress the increase in the unit cost due to the expensive prism sheet.

The lamp 50 is inserted into one side of the light guide plate 60 to generate such light. The lamp 50 may include, for example, a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), an external electrofluorescent lamp (EEFL), and the like.

The reflecting plate 40 is installed under the light guide plate 60 to reflect the light leaking to the bottom of the light guide plate 60 to the top. The reflector 40 is positioned on the lower surface of the light guide plate 60, and reflects the light that is not reflected by the minute pattern on the bottom surface of the light guide plate 60 back toward the exit surface of the light guide plate 60, thereby providing the liquid crystal panel assembly 11 with the liquid crystal panel assembly 11. While reducing the light loss of the incident light serves to improve the uniformity of the light transmitted to the exit surface of the light guide plate 60.

The optical sheet 70 is mounted on the upper surface of the light guide plate 60 to collect and diffuse light transmitted from the light guide plate 60. In addition, the optical sheet 70 may be constituted by a plurality of sheets such as a diffusion sheet and a prism sheet.

Here, the prism sheet is formed on the top surface with a regular array of prism acids. The prism sheet is generally composed of two sheets, and the arrays of the prism acids are arranged such that the arrays of the prism acids are staggered from each other at a predetermined angle to spread light from the diffusion sheet. Condenses in the direction perpendicular to (11). As a result, the light passing through the prism sheet almost runs vertically so that the luminance distribution on the protective sheet is uniformly obtained. That is, the light transmitted from the light guide plate 60 is diffused to have the same brightness by the diffusion sheet and then collected by the prism sheet or the like and transferred to the liquid crystal panel assembly 11.

The first lower storage container 30 is formed of a bottom surface and sidewalls extending from an edge of the bottom surface, and accommodates the light guide plate 60, the lamp 50, the reflecting plate 40, and the like in an inner space. The first lower storage container 30 is combined with the second lower storage container 90 or the upper storage container 80 to form a frame of the liquid crystal display device 100.

Here, the protrusion 35 is formed on the sidewall of the first lower storage container 30 to support and fix the light guide plate 60. That is, since the protrusion 35 overlapping the upper surface of the light guide plate 60 is formed on the sidewall of the first lower storage container 30, the first lower storage container 30 does not need to process the light guide plate 60. To be supported and fixed.

These protrusions 35 are formed on side walls of the first lower storage container 30 that face each other, and have a predetermined length and thickness.

In addition, the protrusion 35 overlaps the upper surface of the light guide plate 60, and the length d from the bottom surface of the first lower storage container 30 to the protrusion 35 is the thickness t1 of the light guide plate 60 and the reflecting plate. It is formed to be equal to or slightly smaller than the sum of the thickness t2 of the 40 (d = t1 + t2). This is to allow the protrusion 35 to support and fix the light guide plate 60 at a predetermined pressure.

The optical sheet 70 and the liquid crystal panel assembly 10 are positioned on an upper surface of the light guide plate 60.

As described above, the optical sheet 70 collects and diffuses light transmitted from the light guide plate 60 and may be configured by a plurality of sheets such as a diffusion sheet and a prism sheet. The optical sheet 70 is spaced apart from the liquid crystal panel assembly 10 by a predetermined distance, and may be spaced apart from the protrusion 35 by a predetermined distance in consideration of the thermal expansion coefficient of the optical sheet 70.

In addition, the first lower storage container 30 may be formed of a plastic material, and may be formed of the same material as the second lower storage container 90 or the upper storage container 80, that is, a metal structure.

This first lower container 30 will be described in detail with reference to FIG. 3.

3 is a perspective view of the first lower housing of the backlight assembly according to an embodiment of the present invention.

As shown in FIG. 3, the first lower receptacle 30 has a bottom surface 310 and first to fourth sidewalls 320, 330, 340 and 350 extending from an edge of the bottom surface 310. ), And further include protrusions 35 formed on the sidewalls 320, 330, 340, and 350.

In addition, the first lower storage container 30 accommodates a lamp (not shown) and a light guide plate (not shown) in a space formed by the sidewalls 320, 330, 340, and 350, and an optical sheet (not shown) on the upper surface thereof. A liquid crystal panel assembly (not shown) may be located.

Here, the protrusions 35 are formed on the sidewalls 320, 330, 340, and 350 of the first lower storage container 30 to contact the upper surface of the light guide plate to support and fix the light guide plate.

The protrusion 35 may include a first protrusion 360 formed inward from the first side wall 350 and the first lower storage container 30, and a second side wall 340 positioned to face the first side wall 350. It consists of a second protrusion 370 formed inward of the first lower storage container (30). In addition, the first and second protrusions 360 and 370 may be formed in the fourth sidewall 330 which is disposed to face the third sidewall 320 and the third sidewall 320 of the first lower storage container 30. In addition, all sidewalls 320, 330, 340, and 350 of the first lower storage container 30 may be formed in common.

Here, the first and second protrusions 360 and 370 are formed to be spaced apart from the bottom surface 310 of the first lower storage container 30 by a predetermined distance, which is a light guide plate accommodated in the first lower storage container 30. And the thickness of the reflecting plate, and preferably equal to the sum of the thicknesses of the light guide plate and the reflecting plate.

In addition, the first and second protrusions 360 and 370 may be in contact with one end of the optical sheet positioned on the upper surface of the light guide plate, and may have a predetermined protrusion length and thickness to maintain an appropriate separation distance between the optical sheet and the liquid crystal panel assembly. do.

The protrusions 360 and 370 may be integrally formed with the side walls 320, 330, 340, and 350 of the first lower storage container 30, and may be formed of the same material as the first lower storage container 30. have.

In the present embodiment, for example, two protrusions 360 and 370 are formed in the first lower storage container 30. However, the present invention is not limited thereto, and the plurality of protrusions 35 may include the first lower storage container. 30, and may protrude from any one of the side walls 320, 330, 340, and 350 of the first lower storage container 30.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. 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 light guide plate may be prevented from flowing up and down, thereby improving defects such as white spots and scratches.

Claims (7)

lamp; A light guide plate positioned adjacent to one side of the lamp and uniformly transferring light transmitted from the lamp to an upper side; A first lower part including a bottom surface and a side wall extending from an edge of the bottom surface, the first lower part including the lamp and the light guide plate in a space formed by the side wall, and having a protrusion overlapping the upper surface of the light guide plate inwardly from the side wall; Back light assembly including a container. According to claim 1, The protrusion includes a first protrusion formed on a first sidewall of the first lower storage container, and a second protrusion formed on a second sidewall facing the first sidewall. According to claim 1, And a reflector disposed under the light guide plate and reflecting light leaked from the lamp to the light guide plate. The method of claim 2 or 3, And a distance from the bottom surface of the first lower container to the protrusion is substantially equal to the sum of the thicknesses of the light guide plate and the reflecting plate. According to claim 1, And an optical sheet positioned on the light guide plate to collect and diffuse light incident from the light guide plate. According to claim 1, The light guide plate is a prism light guide plate having a plurality of prismatic acid formed on the upper surface. The backlight assembly according to any one of claims 1 to 6; And And a liquid crystal panel assembly positioned above the backlight assembly and configured to display an image by light supplied from the backlight assembly.

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