KR101662240B1 - Backlight unit and display unit including the same - Google Patents

Abstract

An embodiment includes a light source array including a plurality of light sources; A light guide plate provided on one side of the light source array; And a frame accommodating the light guide plate and including a bending prevention guide and a support member on the other side except the side where the light source array is provided.

Description

BACKLIGHT UNIT AND DISPLAY APPARATUS INCLUDING THE SAME

Embodiments relate to a backlight unit and a display device including the same, and more particularly to a backlight unit frame.

BACKGROUND ART Liquid crystal displays (LCDs), which are rapidly increasing in demand, use a liquid crystal injected between a TFT (Thin Film Transistor) substrate and a color filter substrate to adjust the amount of light coming from the outside to display an image .

Since the liquid crystal display device has no self-emission capability, a separate backlight unit for irradiating the panel with light is required.

As a light source of a conventional backlight unit, a rod-shaped cold cathode fluorescent lamp (CCFL) or a dot-shaped light emitting diode (LED) is mainly used.

However, the cold-cathode tube type lamp has a high brightness, a long life, and a small amount of heat compared with an incandescent lamp, but the luminance uniformity is weak. Therefore, a backlight using a light emitting diode as a light source is widely used.

The light emitting diode is a light emitting device using a compound semiconductor material of group 3-5 or group 2-6 of a conductor and can realize various colors such as red, green, blue, white and ultraviolet rays. By using a fluorescent material or combining colors It is also possible to realize efficient white light rays.

Generally, liquid crystal displays are thin and light, and have the advantage of having a low driving voltage and a low consumption range.

Here, a light emitting diode used as a backlight of a liquid crystal display device includes an optical member such as a light guide panel (LGP), a diffusion member, and a prism sheet in order to increase luminance uniformity of a light source. member. A fluorescent sheet may be included in the prism sheet.

Normally, a yellow phosphor is provided on a light-emitting diode element emitting blue light, because the color emitted from the light-emitting diode element and the phosphor must be complementary to each other to realize white.

Therefore, the backlight using the light emitting diode has a problem that the volume and weight of the backlight are increased by the optical member.

Such an increase in the load of the backlight may increase the load applied to the frame, thereby causing a warp or a tilt in the whole frame. In addition, the edge type LED backlight can be expected to reduce the load due to the decrease in the number of light emitting diodes, but the heat and / or the force transmitted to the respective sides of the frame are different from each other, .

Embodiments of the present invention provide a light emitting diode backlight unit in which no warping or tilting occurs due to a load applied to a frame in a light emitting diode backlight unit, and a display device including the light emitting diode backlight unit.

Also, the present embodiment is intended to provide a light emitting diode backlight unit and a display device including the light emitting diode backlight unit in which a frame is not deformed even when heat and / or force transmitted to each side in the frame are different from each other.

An embodiment includes a light source array including a plurality of light sources; A light guide plate provided on one side of the light source array; And a frame accommodating the light guide plate and including a bending prevention guide and a support member on the other side except the side where the light source array is provided.

Another embodiment includes a light source array including a plurality of light sources; A light guide plate provided on one side of the light source array; A backlight unit housing the light guide plate and including a frame having a bending prevention guide and a support member on the other side except the side where the light source array is provided; An optical member for projecting the light projected from the backlight to a panel; And a panel provided on the optical member.

Here, the support member may be made of the same material as the frame.

The support member may be provided within a width of 5 cm or less.

The support member may have a thickness of less than 1 centimeter.

The bending prevention guide may be provided in parallel with one side of the frame.

The bending prevention guide may be provided in parallel with a virtual line connecting a plurality of light sources in the light source array.

In addition, the bending prevention guide may be provided with the frame having a concavo-convex shape.

The bending prevention guide may have a thickness of less than 1 centimeter.

The display device may further include a reflection plate provided between the light guide plate and the frame.

The display device may further include a color filter disposed on a front surface of the panel, the color filter selectively transmitting green light, blue light, and green light.

Effects of the backlight unit and the display device including the backlight unit according to the present embodiment will be described as follows.

First, a bending prevention guide is formed on the frame of the LED backlight unit, so that no bending or tilting occurs due to the load applied to the frame.

Second, the supporting members are provided on the respective sides of the frame of the LED backlight unit, so that the frame is not deformed even if the heat and / or the force transmitted to the sides are different from each other.

1 is a view showing an embodiment of a light emitting diode device,
2A to 3C are views showing embodiments of a backlight unit,
4A and 4B are views illustrating a display device having a backlight unit according to an embodiment of the present invention,
5 is a view showing another embodiment of the backlight unit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure is formed "on" or "under" a substrate, each layer The terms " on "and " under " encompass both being formed" directly "or" indirectly " In addition, the criteria for above or below each layer will be described with reference to the drawings.

The thickness and size of each layer in the drawings are exaggerated, omitted, or schematically shown for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size. The same components as those in the prior art are denoted by the same reference numerals and symbols, and a detailed description thereof will be omitted.

FIG. 1 is a view showing an embodiment of a light emitting diode package, and FIGS. 2a and 2b are views showing an embodiment of a backlight unit. Hereinafter, an embodiment of the backlight unit will be described with reference to Figs. 1, 2A and 2B.

As shown in the figure, the backlight unit 200 includes a light emitting diode device 100 and a support member 220 as a light source on a frame 210. Here, the frame 210 may be made of a metal having high strength, and may be made of stainless steel having excellent corrosion resistance, for example.

In accordance with the sliming trend of the backlight unit, the thickness of the frame 210 may be 0.1 to 0.2 millimeter. Here, the size of the frame 210 may vary depending on the screen size of a display device such as a liquid crystal display device in which a backlight unit is used. However, considering the screen of the display device, the frame 210 may have a rectangular shape.

Here, it is preferable that the light source 100 uses a light emitting diode device. That is, the light emitting diode device can realize various colors such as red, green, blue, white, and ultraviolet rays, and it is possible to realize a white light beam having high efficiency by using a fluorescent material or combining colors, and is preferred as a backlight source.

1, the light emitting diode package 100 includes a light emitting diode device 14 on a package body 20, a first electrode 11 and a second electrode 12 formed on the package body 18, And the light emitting diode element 14 is electrically connected.

The light emitting diode device 14 may be fixed on the package body 20 through the bonding layer 16 and may include heat dissipation pads Absorption, and release.

The package body 20 may be formed of a silicon material, a synthetic resin material, or a metal material, and an inclined surface may be formed around the light emitting device 100 to enhance light extraction efficiency.

Here, the light emitting diode device 14 may be electrically connected to the first and second electrodes 11 and 12 by a flip chip method or a die bonding method in addition to the wire bonding method 15 shown in the figure.

The first electrode layer 11 and the second electrode layer 12 are electrically isolated from each other and provide power to the light emitting device 100. The first electrode layer 11 and the second electrode layer 12 may reflect the light generated from the light emitting device 100 to increase the light efficiency. As shown in FIG.

The filler 18 can surround and protect the light emitting device 100. The filler 18 may include a phosphor to change the wavelength of the light emitted from the light emitting device 100.

The lens 17 may be formed on the filler 17 or may surround the filler 17 or may be formed on the package body 20, (20). The lens 17 can change the course of the light emitted from the light emitting diode element 14, and the lens 17 can be omitted.

An array of light emitting diode packages 100 having the above-described structure is fixed on a printed circuit board to form a light emitting diode module. As shown, the light emitting diode package 100 is fixed to one end of the frame 210 to form an edge type backlight .

The support member 220 may be formed on the edge of the frame 210 for receiving the light guide plate or the like, but may be formed on the remaining three sides except for the side where the light emitting diode package 100 module is provided. Here, the side of the frame means four sides of the frame.

The support member 220 may be separately formed and then joined to the frame 210. However, the support member 220 may be made of the same material as the frame in consideration of the convenience of the process, difficulty in fastening, and weight reduction of the backlight unit.

The support member may have a width d of less than 5 centimeters and a thickness t of less than 1 centimeter. If the thickness exceeds the width, the support member is not suitable for slimming down the backlight unit.

If the support member 220 is made of a material different from that of the frame 210, aluminum, iron, or reinforced plastic may be used. Here, aluminum is lighter than iron and has a weaker strength, and reinforced plastic may be inconveniently fastened to the frame 210. [

When the support member 220 and the frame 210 are separately manufactured, the size of the support member 220 may be adjusted to the size of the frame 210 for fastening the support member 220 and the frame 210. [ Can be formed larger.

In addition, the frame 210 may be fixed in a 'U' -shaped support member 220 by inserting the frame 210, and the two may be fastened with a resin layer or the like. Here, the 'C' shape means a shape in which the entire support member 200 surrounds the frame 210. Also, the cross section of the support member 220 may be formed to have a "C" shape to facilitate fastening with the frame 210.

In addition, the support member 220 may be provided at the edge of the frame 210 with a width of 5 cm or less. If the width of the support member 220 is larger than the above-described range, it may cause the thickness, volume, and mass of the backlight unit to increase.

For the same reason, the thickness of the support member 220 is preferably within 1 centimeter.

The backlight unit according to the present embodiment may protect the inside of the frame 210 by the frame 210 and the support member 220 at the edge of the frame. Also, even if heat and / or force are transmitted to the respective sides of the frame 210 differently, deformation of the frame 210 can be prevented.

3A and 3C are views showing another embodiment of the backlight unit. Hereinafter, another embodiment of the backlight unit will be described with reference to Figs. 3A and 3C.

In the embodiment shown in FIG. 3A, the backlight unit 200 includes a light source array such as a light emitting diode package 100 as a light source on a frame 210, and a support member such as a bending prevention guide 230. Here, the configurations of the light emitting diode package 100 and the frame 210 are the same as those of the embodiment shown in FIGS. 2A and 2B.

In addition, the bending prevention guide 230 may be provided in parallel with one side of the frame 210, and may be provided in parallel with the array of the light emitting diode packages 100. That is, the bending prevention guide 230 may be provided in parallel with a virtual line connecting the light source arrays or a printed circuit board on which the light source arrays are fixed. Here, being in parallel does not mean mathematically exactly parallel.

When the backlight unit 200 is mainly used for a liquid crystal display device or the like, and a light guide plate, a diffusion plate, and the like are provided, an excessive load may be loaded on the frame 210. Therefore, a bending prevention guide 230 is formed to withstand such a load.

Here, the bending prevention guide 230 may include the frame 210 having a concavo-convex shape. That is, if a supporting member or the like is formed not only on the rim of the frame 210 but also on the light guide plate or the liquid crystal display, the backlight unit may become an obstacle to ultra thinning and lightening.

Although the bending prevention guide 230 is shown as a dotted line in the drawing, the frame 210 is formed to have a concavo-convex shape. Here, the number of the bending prevention guides 230 is not necessarily three, but at least one bending prevention guide 230 should be formed. However, if the number of the bending prevention guides 230 is too large, it is disadvantageous in the manufacturing process.

The shape of the bending prevention guide 230 does not necessarily have to be a rectangular type, but a square type is preferable in consideration of a manufacturing process and a function of supporting a load, but it is not necessarily a rectangular shape.

In consideration of ultra thinning of the backlight unit 200, it is preferable that the bending prevention guide 230 has a thickness of less than 1 centimeter.

The frame of the backlight unit in which the above-described bending prevention guide is formed can prevent the occurrence of bending or tilting of the frame due to the load by increasing the area subjected to the load by the bending prevention guide and dispersing the direction of the load.

3B and 3C, the convex-shaped bending prevention guides 240a and 240b are provided in convex or concave shapes, that is, in different directions. However, in order to distribute the load, the convex shape and concave shape bending prevention Guides 240a and 240b are alternately formed.

4A and 4B are views showing an embodiment of a display device provided with a backlight unit.

First, the display device according to the present embodiment includes a backlight unit, a diffusion plate 300, a liquid crystal display device 310, and a color filter 320.

First, the backlight unit is as described above. That is, in the embodiment shown in FIG. 4A, the support member 220 is provided on the frame 210, and the anti-warpage guide 230 is provided on the frame 210 in the embodiment shown in FIG. 4B.

An array of light emitting diode elements 100 is provided on at least one side of the frame.

Here, the light emitting diode element is formed by forming a nitride semiconductor including a p-type semiconductor layer, an active layer, and an n-type semiconductor layer on a substrate.

The light emitted from the light emitting diode can secure the straightness by the cup-shaped structure.

The above-described backlight unit may include a reflection plate 250 and a light guide plate 260.

The light guide plate 250 scatters light emitted from the light emitting diode device 100 and uniformly distributes the light over the whole screen area of the liquid crystal display device.

Accordingly, the light guide plate 260 is made of a material having a good refractive index and transmittance. The light guide plate 260 may be formed of poly methylmethacrylate (PMMA), polycarbonate (PC), or polyethylene (PE).

The reflection plate 250 functions to totally reflect the light reflected by the lower portion of the light guide plate into the light guide plate. The reflection plate 250 reflects the light leaked to the lower portion through the bottom surface of the light guide plate 260 to the upper portion of the light guide plate 260 to increase the brightness of the display device and uniformly emit light toward the liquid crystal display element can do.

The reflective plate 250 can be made of a material having a high reflectivity and can be used as an ultra-thin type, and a polyethylene terephthalate (PET) can be used.

A diffusion plate 300 is provided on the light guide plate 260 to diffuse the light emitted from the light guide plate 260 at a predetermined angle. The diffusion plate 300 allows the light guided by the light guide plate 260 to be uniformly irradiated toward the liquid crystal display device 310.

As the diffusion plate 300, an optical sheet such as a diffusion sheet, a prism sheet, or a protective sheet may be selectively laminated, or a microlens array may be used. At this time, a plurality of optical sheets may be used, and the optical sheet may be made of a transparent resin such as an acrylic resin, a polyurethane resin, or a silicone resin. It is to be noted that the fluorescent sheet may be included in the prism sheet described above.

A liquid crystal display device 310 is provided on the front surface of the diffusion plate 300. Here, it goes without saying that other types of display devices requiring a light source besides the liquid crystal display device 310 may be provided.

In a liquid crystal display device, a liquid crystal is positioned between glass substrates, and a polarizing plate is placed on both glass substrates to utilize the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image.

A liquid crystal display device used in a display device is an active matrix type, and a transistor is used as a switch for controlling a voltage supplied to each pixel.

The configuration of a specific liquid crystal display device is the same as that of the conventional liquid crystal display device, and thus is omitted.

A color filter 320 is provided on the front surface of the liquid crystal display device 310. Here, the color filter 320 can display an image because only red, green, and blue light is transmitted for each pixel of the light projected from the liquid crystal display device 310. [

In the embodiment of the display device according to the present invention, since the support member is separately formed on the frame of the backlight or is formed by the guide having the concavo-convex shape, it can be seen that deformation of the frame due to heat generated in the light emitting diode device is prevented .

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects and the like illustrated in the embodiments can be combined and modified by other persons skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

11: first electrode 12: second electrode
14: light emitting diode element 15: wire
16: bonding layer 17: lens
18: filling material 20: package body
100: Light emitting diode package 200: Backlight unit
210: frame 220: support member
230: bending prevention guide 250: reflector
260: light guide plate 300: diffusion plate
310: liquid crystal display device 320: color filter

Claims (12)

A light source array including a plurality of light sources;
A light guide plate provided on one side of the light source array; And
And a backlight unit that houses the light guide plate and includes a frame having a bending prevention guide and a support member on the other side except for the side where the light source array is provided,
The bending prevention guide is formed in the frame so as to have a concavo-convex shape,
Wherein the convex and concave concave and convex portions are alternately arranged at predetermined intervals on the upper and lower portions of the frame. The image forming apparatus according to claim 1,
Wherein the frame is made of the same material as the frame. 3. The image forming apparatus according to claim 1 or 2,
And a width of 5 cm or less. 3. The image forming apparatus according to claim 1 or 2,
And a thickness of 1 cm or less. The apparatus according to claim 1,
Wherein the display device is provided in parallel with one side of the frame. 6. The apparatus according to claim 1 or 5,
And a virtual line connecting the plurality of light sources in the light source array. delete 6. The apparatus according to claim 1 or 5,
And a thickness of 1 cm or less. delete delete delete delete

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