KR20110038870A - Backlight unit and liquid crystal display device having the same - Google Patents

Abstract

PURPOSE: A backlight unit of a liquid crystal display device is provided to prevent the transformation of a bottom cover from an external impact. CONSTITUTION: A backlight unit comprises: a light guide plate which is arranged parallel with a light source; a reflective sheet installed on the rear part of the light guide plate; a first support part(710) installed in the rear part of the reflective sheet including a bottom cover; a second support part(730) which is connected to a first bending part and the first support part; a third support part(740) installed on the side of the light guide plate; and a fourth support part(760) which is connected with a second bending part(750) and the third support part.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

Embodiments relate to a backlight unit, and more particularly, to a backlight unit having a bending part capable of increasing mechanical strength in a bottom cover, and a liquid crystal display device having the same.

Display devices used in a computer monitor or TV include organic light emitting displays (OLEDs), vacuum fluorescence displays (VFDs), and electroluminescent devices (VFDs). FED (Field Emission Display), Plasma Display Panel (PDP), etc. Liquid crystal display (LCD) that does not emit light by itself and requires a light source.

A general liquid crystal display device includes two substrates provided with a field generating electrode and a liquid crystal layer having dielectric anisotropy interposed therebetween. A voltage is applied to the field generating electrode to generate an electric field in the liquid crystal layer, and the voltage is changed to adjust the intensity of the electric field to adjust the transmittance of light passing through the liquid crystal layer to display a desired image.

Liquid crystal display devices have been used in various fields as well as notebook PC and monitor market due to small size, light weight and low power consumption.

Since the LCD does not emit light by itself, a separate light source such as a backlight is required. Accordingly, the liquid crystal display device includes a liquid crystal panel and a backlight unit. The backlight unit provides light to the liquid crystal panel, and the light passes through the liquid crystal panel. In this case, the liquid crystal panel displays an image by adjusting the transmittance of the light.

The backlight unit is classified into an edge type and a direct type according to the shape of the light source. In the edge type, the light source is disposed on the side of the liquid crystal panel. In addition, the light guide plate is disposed on the rear surface of the liquid crystal panel, and guides the light provided from the side surface of the liquid crystal panel to the rear surface of the liquid crystal panel. In contrast, the direct type has a plurality of light sources on the back of the liquid crystal panel, and the light emitted from the plurality of light sources is directly provided to the back of the liquid crystal panel.

As the light source, EL (Electro Luminescence), CCFL (Cold Cathode Fluorescent Lamp), HCFL (Hot Cathode Fluorescent Lamp), Light Emitting Diode (LED) and the like are used. Among them, the light emitting diodes (LEDs) have low power consumption and excellent light emitting efficiency.

The bottom cover, which is a part of the backlight, is formed by primarily bending an outer portion ("L" shaped structure). However, the bottom cover of the L-shaped structure is deformed upon impact of the liquid crystal display module (LCM). Therefore, lamp cracks are generated due to damage to the lamp assembly due to deformation of the module.

The embodiment provides a backlight unit and a liquid crystal display device having the same to prevent deformation caused when the LCM impacts.

Embodiments include a light source; A light guide plate disposed in parallel with the light source; A reflective sheet disposed on a rear surface of the light guide plate; And a bottom cover on which the reflective sheet is seated, wherein the bottom cover is connected to a first support part disposed on a rear surface of the reflective sheet, a first bending part connected to the first support part, and the first bending part. And a second support portion to be formed on a side surface of the light guide plate, a second bending portion connected to the third support portion, and a fourth support portion connected to the second bending portion, wherein the second support portion The unit and the fourth support unit provide a backlight unit connected thereto.

Another embodiment is a liquid crystal display panel; A light source disposed on a rear surface of the liquid crystal display panel; A light guide plate disposed in parallel with the light source; A reflective sheet disposed on a rear surface of the light guide plate; And a bottom cover on which the reflective sheet is seated, wherein the bottom cover is connected to a first support part disposed on a rear surface of the reflective sheet, a first bending part connected to the first support part, and the first bending part. And a second support portion to be formed on a side surface of the light guide plate, a second bending portion connected to the third support portion, and a fourth support portion connected to the second bending portion, wherein the second support portion And the fourth support unit are connected to each other.

The embodiment provides a backlight unit having a double bending part in a bottom cover. That is, the embodiment forms a bending by structurally bending the bottom surface and one side of the bottom cover. Therefore, the embodiment prevents deformation occurring during the LCM impact, thereby increasing the mechanical strength of the liquid crystal display device.

In addition, since the mechanical strength is increased due to the double bending portion, the thickness of the bottom cover can be reduced to reduce manufacturing costs and the like.

In addition, since the double bending portion can be easily modified without additional parts, the manufacturing cost can be reduced.

In the description of the embodiments, each panel, member, frame, sheet, plate, or substrate is formed on or under the "on" of each panel, member, frame, sheet, plate, or substrate. When described as being "in" and "under" includes both those that are formed "directly" or "indirectly" through other components. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

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

1 is an exploded perspective view illustrating a liquid crystal display device having a backlight unit according to an exemplary embodiment.

Referring to FIG. 1, a liquid crystal display according to an exemplary embodiment includes a liquid crystal display panel 100 displaying an image, a backlight unit 300 disposed under the liquid crystal display panel 100, and providing light to the liquid crystal display panel 100. The panel guide 200 supports an edge of the display panel 100 and is coupled to the backlight unit 300.

Although not shown in detail, the liquid crystal display panel 100 is bonded to a thin film transistor (TFT) substrate, a color filter substrate disposed on the thin film transistor substrate, and the two so as to maintain a uniform cell gap facing each other. It includes a liquid crystal layer interposed between the substrate.

A plurality of gate lines are formed in the thin film transistor substrate, a plurality of data lines in which the plurality of gate lines intersect are formed, and a thin film transistor TFT is formed in an intersection area of the gate line and the data line. The color filter substrate disposed on the thin film transistor substrate is a substrate in which R, G, and B color filters, which display color as light passes, are formed by a thin film process, and are commonly formed of ITO on the R, G, and B color filters. The electrode is deposited.

In addition, one end of the thin film transistor substrate includes an integrated circuit chip (IC CHIP). The integrated circuit chip generates an image signal, a scan signal, and a plurality of timing signals for applying the signals, and drives the image signal and the scan signal on the gate line and the data line of the liquid crystal display panel 100. To apply.

The backlight unit 300 is disposed on the rear surface of the liquid crystal display panel 100 to provide light. The backlight unit 300 is disposed on a light source 510, a light source housing 520 surrounding the light source 510, a light guide plate 400 disposed in parallel with the light source 510, and a lower surface of the light guide plate 400. The reflective sheet 600 and the bottom cover 700 on which the reflective sheet 600 is seated are included.

In addition, the backlight unit 300 includes optical sheets 310, 320, and 330 disposed on the light guide plate 400 to diffuse and collect light.

The light source 510 is disposed in parallel with the light guide plate 400. It may be a cold cathode fluorescent lamp (CCFL) having an electrode inside both ends of the glass tube, an external electrode fluorescent lamp (EEFL) having a structure surrounding both ends of the glass tube.

In addition, although the lamp is disposed on one side of the light guide plate 400 as the light source 510, the lamp is not limited thereto, and the lamp may be disposed on both sides of the light guide plate 400, and the light source 510 emits light in addition to the lamp. Diodes (LEDs) can be used.

The light source housing 520 increases the efficiency of the light emitted from the light source 510 and prevents the loss of light. In addition, the light source housing 520 protects the light source 510.

The light guide plate 400 may be made of polymethyl methacrylate (PMMA). In addition, although not shown in detail in the drawings, the light source 510 may be formed in a wedge shape that becomes thinner away from the incident surface disposed. A prism pattern may be formed on the rear surface of the light guide plate 400 to refracted incident light toward the optical sheets 310, 320, and 330.

The light guide plate 400 converts linear or pointed light into surface light and guides the light incident from the light source 510 toward the liquid crystal display panel 100.

The reflective sheet 600 is disposed on the lower surface of the light guide plate 400. When the light incident on the light guide plate 400 is emitted to the rear surface of the light guide plate 400, the reflective sheet 600 receives the light emitted to the rear surface of the light guide plate 400 and the optical sheets 310, 320, and 330. Reflect in the direction. The reflective sheet 600 may be made of a material such as PET having high reflectance.

The optical sheets 310, 320, and 330 include a diffusion sheet 310 for diffusing light, a light condensing sheet 320 for condensing light, and a protective sheet 330 for protecting the light condensing sheet 320. The diffusion sheet 310, the light collecting sheet 320, and the protective sheet 330 are sequentially disposed on the light guide plate 400.

The diffusion sheet 310 has a region overlapped with the light guide plate 400, and protrudes further from the other side of the light guide plate 400 facing the area where the light source 510 is disposed than the other side of the light guide plate 400. It may be made of a structure. An upper surface area of the diffusion sheet 310 may be larger than an upper surface of the light guide plate 400.

The light collecting sheet 320 and the protective sheet 330 overlap all of the regions with the diffusion sheet 310 and the light guide plate 400. Lower surface areas of the light collecting sheet 320 and the protective sheet 330 may be smaller than or equal to the upper surface area of the light guide plate 400.

The bottom cover 700 has a structure in which an upper surface thereof is opened. The bottom cover 700 protects the backlight unit 300. The bottom cover 700 is formed of a metal material to serve to reinforce the firmness of the backlight unit 300. The bottom cover 700 has a structure having a lower surface and a side surface in the major axis direction (the second side surface of the bottom cover) and a side surface in the minor axis direction (the first side surface of the bottom cover). The bending part according to the embodiment may be formed on the bottom surface 700a and the one side 700b of the bottom cover 700. The one side 700b may be a side in the long axis direction.

2 and 3 illustrate a portion of a bottom cover according to one embodiment. 4 is a cross-sectional view illustrating a AA ′ portion of FIG. 1. 5 illustrates a portion of a structure in which a light source housing corresponds to a shape including an inclined surface of a first bending portion and a second bending portion, according to an exemplary embodiment.

2 and 3, the liquid crystal display according to the exemplary embodiment provides a backlight unit 300 having double bending parts 720 and 750 in the bottom cover 700. The double bending parts 720 and 750 are formed by structurally bending the bottom surface 700a and the one side 700b of the bottom cover 700. The one side 700b includes both a side in the long axis direction and a side in the short axis direction. Preferably, a bending part is formed on a side surface of the one side surface 700b in the long axis direction.

In an embodiment, the bottom cover 700 may include a first support part 710 disposed on the rear surface of the reflective sheet 600, a first bending part 720 connected to the first support part 710, and The second support part 730 connected to the first bending part 720 and the third support part 740 disposed on the side surface of the light guide plate 400 and the second support part 740 connected to the third support part 740. And a fourth support part 760 connected to the bending part 750 and the second bending part 750.

In one embodiment, the first bending part 720 and the second bending part 750 are respectively supported from the first support part 710 to the second support part 730 and the third support part 740 by the fourth support part. The portion 760 may be formed in an inclined shape. That is, the first bending part 720 and the second bending part 750 are respectively the first support part 710 to the second support part 730 and the third support part 740 to the fourth support part ( 760 may be formed in a diagonal direction.

The angle of inclination based on the line perpendicular to the end of the first support part 710 connected to the first bending part 720 may vary depending on the design of the backlight unit. Preferably, the angle of inclination may be 30 ° to 60 °. More preferably, the angle of inclination may be 40 ° to 45 °.

Due to this structure, the bottom cover 700 according to the embodiment is dispersed in the force during the LCM impact in the direction as shown in FIG. When the force is dispersed, the liquid crystal display device becomes firm without cracking easily from external impact.

Accordingly, one embodiment may prevent deformation caused when the LCM impacts, thereby increasing the mechanical strength of the liquid crystal display. In addition, since the mechanical strength is increased due to the double bending part, the thickness of the bottom cover 700 may be reduced to reduce manufacturing costs and the like. In addition, since the double bending portion can be easily modified without additional parts, the manufacturing cost can be reduced.

Referring to FIG. 4, in one embodiment, the first support part 710 is formed on the second support part 730. That is, the first support part 710 is formed to have a different height from the second support part 730 and is connected to each other in an inclined direction such as a diagonal line. In addition, the width W1 of the first support part 710 may be larger than the width W2 of the second support part 730. That is, the first bending part 720 is formed at a portion close to one side 700b of the bottom cover 700, and the first support part 710, the first bending part 720, and the second support part ( 730 may be formed at a location that minimizes the impact of the LCM impact. Accordingly, an embodiment can provide a liquid crystal display device having a backlight unit that can withstand an impact from the outside.

In another embodiment, the third support part 740 is formed closer to the light guide plate 400 than the fourth support part 760. In addition, the width W3 of the third support part 740 and the width W4 of the second support part 760 may be formed to correspond to each other. That is, the third support part 740, the second bending part 750, and the fourth support part 760 may be formed at a position capable of distributing the force applied to the one side 700b at the time of the LCM impact. .

In addition, the second bending part 750 may be formed in a long axis direction or a short axis direction of one side 700b of the bottom cover 700. Preferably, one side surface 700b on which the second bending part 750 is formed is a side surface in a long axis direction. That is, when the second bending part 750 is formed at the side in the long axis direction, the force applied to the one side 700b during LCM impact may be better distributed than at the side in the minor axis direction.

In addition, as shown in FIG. 5, the surface of the light source housing 520 surrounding the light source 510 may correspond to the shape including the inclined surfaces of the first bending part 720 and the second bending part 750. Can be. As the area corresponding to the surface of the light source housing 520 and the inclined surfaces formed by the bending portions 720 and 750 increases, the impact of the impact becomes smaller, so that the impact of the LCM impact can be minimized in the same structure as in an embodiment. Can be. That is, the structure of the bending portion and the area increase corresponding to the light source housing 520 may exert a synergy effect during the LCM impact and thus may withstand the impact much more.

The structure according to an embodiment may form a space between the bending portions. Therefore, the design can be free because space such as wire can be secured.

Although the above description has been made with reference to the embodiments, these are merely examples and are not intended to limit the present invention. Those skilled in the art to which the present invention pertains are not illustrated above without departing from the essential characteristics of the present embodiments. It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 is an exploded perspective view illustrating a liquid crystal display device having a backlight unit according to an exemplary embodiment.

FIG. 2 is a detailed view of the P region of FIG. 1.

3 illustrates that the deformation received by the bottom cover portion of FIG. 2 is dispersed.

4 is a cross-sectional view illustrating a AA ′ portion of FIG. 1.

5 illustrates a portion of a structure in which a light source housing corresponds to a shape including an inclined surface of a first bending portion and a second bending portion, according to an exemplary embodiment.

Claims (8)

Light source; A light guide plate disposed in parallel with the light source; A reflective sheet disposed on a rear surface of the light guide plate; And A bottom cover on which the reflective sheet is seated; The bottom cover is disposed on a first support part disposed on a rear surface of the reflective sheet, a first bending part connected to the first support part, a second support part connected to the first bending part, and a side surface of the light guide plate. And a third support part, a second bending part connected to the third support part, and a fourth support part connected to the second bending part, wherein the second support part and the fourth support part are connected to each other. Backlight unit. The method of claim 1, And the first support part is formed on the second support part. The method of claim 1, And a width of the first support portion is greater than a width of the second support portion. The method of claim 1, And the third support part is formed closer to the light guide plate than the fourth support part. The method of claim 1, And a width of the third support portion and the width of the fourth support portion correspond to each other. The method of claim 1, And the second bending part is formed on a second side of the bottom cover including a second side longer than the first side. The method of claim 1, The surface of the light source housing surrounding the light source is formed to correspond to the shape including the inclined surface of the first bending portion and the second bending portion. A liquid crystal display panel; A light source disposed on a rear surface of the liquid crystal display panel; A light guide plate disposed in parallel with the light source; A reflective sheet disposed on a rear surface of the light guide plate; And A bottom cover on which the reflective sheet is seated; The bottom cover is formed on a first support part disposed on a rear surface of the reflective sheet, a first bending part connected to the first support part, a second support part connected to the first bending part, and a side surface of the light guide plate. And a third support part, a second bending part connected to the third support part, and a fourth support part connected to the second bending part, wherein the second support part and the fourth support part are connected to each other. LCD display device.

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