KR101832307B1 - Display apparatus - Google Patents

Abstract

A backlight unit and a display device using the same, the backlight unit including a reflector, a first light guide plate disposed on the reflector and including a central area and a peripheral area surrounding the central area, An optical member disposed on the second light guide plate and a light source module disposed on a side area of the second light guide plate and having a light exit surface facing a peripheral area of the first light guide plate, .

Description

[0001]

An embodiment relates to a display device.

Typically, typical large-sized display devices include a liquid crystal display (LCD), a plasma display panel (PDP), and the like.

Unlike a self-luminous PDP, a backlight unit is indispensable because of the absence of its own light emitting device.

The backlight unit used in the LCD is divided into an edge type backlight unit and a direct-type backlight unit according to the position of the light source. In the edge type, a light source is disposed on the right and left sides or upper and lower sides of the LCD panel, Since the light is uniformly distributed over the surface, uniformity of light is good and the thickness of the panel can be made very thin.

The direct-type method is generally used for a display of 20 inches or more, and since the light source is arranged at a lower portion of the panel, the light efficiency is higher than that of the edge method. Thus, it is mainly used for a large display requiring high brightness.

CCFL (Cold Cathode Fluorescent Lamp) is used as a light source of the backlight unit of the conventional edge method or direct-down type.

However, since the backlight unit using CCFL is always supplied with power to the CCFL, a considerable amount of power is consumed, and a color reproduction ratio of about 70% as compared with CRT and environmental pollution problems caused by the addition of mercury are pointed out as disadvantages.

BACKGROUND ART [0002] As a substitute product for solving the above problem, researches on a backlight unit using an LED (Light Emitting Diode) have been actively conducted.

When the LED is used as a backlight unit, it is possible to partially turn on / off the LED array, thereby drastically reducing the power consumption. In the case of the RGB LED, the color reproduction range specification exceeding 100% of the National Television System Committee (NTSC) So that a more vivid image quality can be provided to the consumer.

Embodiments provide a display device capable of minimizing the width of a bezel.

The light guide plate includes a reflector, a first light guide plate disposed on the reflector and including a central region and a peripheral region surrounding the central region, a second light guide plate disposed in a central region of the first light guide plate, And a light source module disposed on a side area of the second light guide plate and having a light exit surface facing the peripheral area of the first light guide plate.

Here, the first light pipe and the second light pipe may be different materials.

The first and second light guide plates are made of the same material and may be integrally formed.

The first and second light guide plates may be formed of an acrylic resin such as PMMA (Polymethylmethacrylate), a polyethylene terephthalate (PET), a cyclic olefin copolymer (COC), a polyethylene naphthalate (PEN), a polycarbonate (PC) Mathacylate styrene).

The first light guide plate has a first surface facing the second light guide plate, the second light guide plate has a second surface facing the first light guide plate, and the first surface of the first light guide plate is closer to the second surface of the second light guide plate It can have a large area.

Here, the area ratio of the second light guide plate and the first light guide plate may be 1: 1.1-4.

The thickness of the first light guide plate may be greater than the thickness of the second light guide plate, and the thickness ratio of the first light guide plate and the second light guide plate may be 1: 0.9-0.1.

Next, the refractive index of the first light guide plate may be greater than the refractive index of the second light guide plate, and the refractive index of the first and second light guide plates may be 1.3 - 1.55.

In addition, the transmittance of the first light guide plate may be greater than that of the second light guide plate, the transmittance of the first light guide plate may be 80 - 99%, and the transmittance of the second light guide plate may be 35 - 79%.

The embodiment may further include a panel guide module for supporting the light source module and the display panel, and a top chassis connected to the panel guide module and the bottom chassis. The top surface of the panel guide module includes a display panel And the lower surface of the panel guide module can be in contact with the light source module.

Here, the light source module includes at least one light source disposed on the substrate and the substrate, and the light source may be a top view type light emitting diode.

Embodiments can minimize the width of the bezel and reduce the overall thickness of the display device including the backlight unit by modifying the shape of the light guide plate.

1 is a sectional view showing a backlight unit according to an embodiment.
2A and 2B are plan views of a light guide plate including first and second light guide plates.
3 is a cross-sectional view taken along the line II of Figs. 2A and 2B.
4 is a view showing a light guide plate having a concavo-convex pattern.
FIGS. 5A and 5B are views showing positions where the reflector of FIG. 1 is disposed.
6 is a view showing a display module having a backlight unit according to an embodiment.
7 and 8 are views showing a display device according to an embodiment.

Hereinafter, embodiments will be described with reference to the accompanying drawings.

In the description of the present embodiment, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) on or under includes both the two elements being directly in contact with each other or one or more other elements being indirectly formed between the two elements.

Also, when expressed as "on or under", it may include not only an upward direction but also a downward direction with respect to one element.

1 is a sectional view showing a backlight unit according to an embodiment.

1, the backlight unit includes first and second light guide plates 10 and 20, a reflector 30, an optical member 40, a light source module 40, source module 50 as shown in FIG.

The backlight unit may further include a top chassis 60, a bottom chassis 70, and a panel guide module 80.

The panel guide module 80 can support the light source module 50 and the display panel 90 and the top chassis 60 can be connected to the panel guide module 80 and the bottom chassis 70.

On the other hand, the light guide plate may be composed of the first light guide plate 10 and the second light guide plate 20, and may be manufactured in two types.

The first type is a monolithic or multilayer structure in which the first light guide plate 10 and the second light guide plate 20 are made of the same material.

The second type is a layered structure in which the first light guide plate 10 and the second light guide plate 20 are made of different materials.

Here, the first light guide plate 10 is disposed on the reflector 30 and may include a central region and a peripheral region surrounding the central region.

The second light guide plate 20 may be disposed in a central region of the first light guide plate 10.

FIGS. 2A and 2B are plan views of a light guide plate including first and second light guide plates, and FIG. 3 is a sectional view taken along the line I-I of FIGS. 2A and 2B.

As shown in FIG. 2A, the second light guide plate 20 may be located in a central region spaced apart from the four sides 10a, 10b, 10c, and 10d of the first light guide plate 10 by a predetermined distance.

The second light guide plate 20 includes first, second, third, and fourth side surfaces 20a, 20b, 20c, and 20d. The first side surface 20a of the second light guide plate 20 includes a first light guide plate The second side face 20b of the second light guide plate 20 is spaced apart from the second side face 10b of the first light guide plate 10 by a first distance d1 from the first side face 10a of the first light guide plate 10, Can be spaced apart by an interval d2.

The third side face 20c of the second light guide plate 20 may be spaced apart from the third side face 10c of the first light guide plate 10 by a third distance d3, The first light guide plate 20d may be spaced apart from the fourth side face 10d of the first light guide plate 10 by a fourth distance d4.

Here, the first, second, third, and fourth intervals d1, d2, d3, and d4 may be the same or different from each other.

In some cases, the first spacing d1 may be the same as the third spacing d3 and may be different from the second spacing d2 and the fourth spacing d4, and the second spacing d2 may be different from the fourth spacing d4 ), And may be different from the first and third intervals d1 and d3.

At this time, the light source module 50 may be disposed within at least one of the first, second, third, and fourth intervals d1, d2, d3, and d4, May be larger than the interval at which the light source module 50 is not disposed.

As shown in FIG. 2B, the second light guide plate 20 may be located at a central region of the first light guide plate 10 spaced apart from the two sides 10a and 10c.

That is, the first side surface 20a of the second light pipe 20 may be spaced apart from the first side surface 10a of the first light pipe 10 by a first distance d1, The second side face 10b of the first light guide plate 10 can be aligned with the second side face 10b without a gap.

The third side face 20c of the second light guide plate 20 may be spaced apart from the third side face 10c of the first light guide plate 10 by a third distance d3, The first side surface 10d of the first light guide plate 10 and the second side surface 20d of the first light guide plate 10 can be matched with the fourth side surface 10d of the first light guide plate 10 without a gap.

Here, the first interval d1 and the third interval d3 may be the same or different from each other.

The light source module 50 may be disposed within at least one of the first interval d1 and the third interval d3. The interval at which the light source module 50 is disposed may be an interval Lt; / RTI >

As described above, the light guide plate including the first and second light guide plates 10 and 20 is configured such that the light source module 50 is disposed at any one of the first, second, third, and fourth intervals d1, d2, d3, and d4 The light source module 50 may be disposed in the first and third spaces d1 and d3 or may be disposed in the second and fourth spaces d2 and d3, d2, d3, and d4, and the light source module 50 may be disposed in the first, second, third, and fourth intervals d1, d2, d3, Down type or a four edge type which can be all disposed.

3, the thicknesses t1 and t2 of the first light guide plate 10 and the second light guide plate 20 may be equal to each other.

In some cases, the thickness t1 of the first light guide plate 10 may be thicker than the thickness t2 of the second light guide plate 20.

That is, the thickness ratio of the thickness t1 of the first light guide plate 10 and the thickness t2 of the second light guide plate 20 may be about 1: 1 - 0.1.

Here, the thickness t2 of the second light guide plate 20 may be determined according to the height of the light source module 50. [

This is because the light source module 50 can be disposed at one side region (the interval d1, d3 between the side face of the first light guide plate and the side face of the second light guide plate in Fig. 3) of the second light guide plate 20. [

Therefore, the thickness t2 of the second light guide plate 20 may be greater than the thickness of the light source of the light source module 50, or may be equal to the thickness of the light source.

The first light guide plate 10 has a first surface facing the second light guide plate 20 and the second light guide plate 20 has a second surface facing the first light guide plate 10, 10 may have a larger area than the second side of the second light guide plate 20.

Here, the area ratio of the second surface of the second light guide plate 20 to the first surface of the first light guide plate 10 may be 1: 1.1-4.

The first and second light guide panels 10 and 20 may be formed of a material such as acrylic resin such as PMMA (Polymethylmethacrylate), polyethylene terephthalate (PET), cyclic olefin copolymers (COC), polyethylene naphthalate (PEN) Polycarbonate (PC), Polystyrene (PS), and Mathacylate styrene (MS) resin.

Here, the first light guide plate 10 and the second light guide plate 20 may have an integral structure or a stacked structure of the same material, or the first light guide plate 10 and the second light guide plate 20 may have a stacked- Structure.

For example, PMMA (Polymethylmethacrylate) material may be used for the first light pipe 10 and PC (Polycarbonate) may be used for the second light pipe 20.

The refractive index of the first light guide plate 10 may be greater than the refractive index of the second light guide plate 20.

Here, the refractive index of the first and second light guide plates 10 and 20 may be 1.3 - 1.55.

The transmittance of the first light guide plate 10 may be greater than the transmittance of the second light guide plate 20.

Here, the transmissivity of the first light guide plate 10 may be about 80-99%, and the transmissivity of the second light guide plate 20 may be about 35-79%.

The light source module 50 may include a circuit board 54 having an electrode pattern and at least one light source 52 disposed on the circuit board 54 as shown in FIG.

Here, the light source 52 of the light source module 50 may be a top view type light emitting diode.

In some cases, the light source 52 may be a side view type light emitting diode.

At least one light source 52 may be mounted on the circuit board 54 and an electrode pattern may be formed to connect the adapter 52 supplying the power source 52 with the power source.

For example, on the upper surface of the circuit board 54, a carbon nanotube electrode pattern for connecting the light source 52 and the adapter may be formed.

The circuit board 54 may be a PCB (printed circuit board) substrate made of any one material selected from the group consisting of polyethylene terephthalate (PET), glass, polycarbonate (PC) and silicon (Si) have.

The circuit board 54 may be a single-layer PCB, a multi-layer PCB, a ceramic substrate, a metal-core PCB, or the like.

The light source 52 may be a light emitting diode (LED) chip, and the light emitting diode chip may be a blue LED chip or an ultraviolet LED chip or a red LED chip, a green LED chip, a blue LED chip, ) LED chip, or a white LED chip.

The white LED may be realized by combining a yellow phosphor on a blue LED or by simultaneously using a red phosphor and a green phosphor on a blue LED, (Yellow phosphor), Red phosphor (Phosphor) and Green phosphor (Phosphor).

The light source module 50 having such a structure may be disposed in the side area of the second light guide plate 20. [

That is, the light source module 50 may be positioned between the panel guide module 80 and the peripheral area of the first light guide plate 10.

The light source 52 of the light source module 50 may be arranged to face the peripheral region of the first light guide plate 10 and the circuit board 54 of the light source module 50 may be mounted on the panel guide module 80, respectively.

The panel guide module 80 has an upper surface and a lower surface and the upper surface of the panel guide module 80 is in contact with the display panel 90. The lower surface of the panel guide module 80 is connected to the light source module 50).

The reason for disposing the light source module 50 between the panel guide module 80 and the peripheral area of the first light guide plate 10 is to minimize the width of the bezel area, It is because.

In addition, a concave-convex pattern may be formed on the surface in the peripheral region of the first light guide plate 10.

The light generated from the light source module 50 can be incident into the first light guide plate 10 without light loss by the concave-convex pattern.

4 is a view showing a light guide plate having a concavo-convex pattern.

4, the first light guide plate 10 may include a central region in contact with the second light guide plate 20 and a peripheral region in contact with the second light guide plate 20 and surrounding the central region.

The peripheral region of the first light guide plate 10 may face the light exit surface of the light source module (not shown).

Here, the peripheral region of the first light guide plate 10 may be formed with the uneven pattern 10a.

The concavo-convex pattern 10a may be a saw-tooth pattern, and the surface of the concavo-convex pattern 10a may be a flat surface or a curved surface.

The reason why the uneven pattern 10a is formed is that light generated from the light source module can be diffused to the light guide plate without loss and uniform brightness can be provided.

On the other hand, the reflector 30 may be disposed on the bottom chassis 70, as shown in Fig.

Herein, the reflector 30 may include at least one of a metal or a metal oxide and may have a high reflectance such as aluminum (Al), silver (Ag), gold (Au), or titanium dioxide (TiO ₂ ) The branch may comprise a metal or a metal oxide.

The reflector 30 may be in contact with at least one of the light source module 50, the panel guide module 80, and the first light guide plate 10.

FIGS. 5A and 5B are views showing positions where the reflector of FIG. 1 is disposed.

5A, the reflector 30 may be disposed in contact with the lower surface and the side surface of the first light guide plate 10.

The reflector 30 may also be in contact with the side of the circuit board 54 of the light source module 50 and a part of the panel guide module 80.

5B, the reflector 30 may extend from the lower surface and the side surface of the first light guide plate 10 to the lower surface of the circuit board 54 of the light source module 50. [

The thickness of the reflector 30 positioned between the bottom surface of the first light guide plate 10 and the bottom chassis 70 is set to be between the bottom surface of the circuit board 54 of the light source module 50 and the panel guide module 80 And the thickness of the reflector 30 positioned therebetween.

The thickness of the reflector 30 positioned between the bottom surface of the first light guide panel 10 and the bottom chassis 70 is set between the bottom surface of the circuit board 54 of the light source module 50 and the panel guide module 80 And may be different from the thickness of the reflector 30 positioned.

That is, the thickness of the reflector 30 positioned between the lower surface of the first light guide panel 10 and the bottom chassis 70 is set between the lower surface of the circuit board 54 of the light source module 50 and the panel guide module 80 It may be thicker than the thickness of the reflector 30 located.

The reflector 30 may be disposed on the bottom chassis 70 and may be disposed on the surface of the bottom chassis 70 located in the space between the first light guide plate 10 and the panel guide module 80. [

The reason is that light can be transmitted through the light guide plate without loss, so that light efficiency can be improved.

The reflector 30 may be formed of one of a reflective coating film and a reflective coating material layer and reflects light generated from the light source module 50 toward the first and second light guide plates 10 and 20 Can be performed.

Also, the reflector 30 may be formed with a serrated reflection pattern on the surface facing the side surface of the second light pipe 20, and the surface of the reflection pattern may be flat or curved.

The reason for forming the reflection pattern on the surface of the reflector 30 is that the light generated by the light source module can be uniformly diffused and reflected.

On the other hand, as shown in Fig. 1, the optical member 40 is disposed on the second light guide plate 20, and may have a concavo-convex pattern on its upper surface.

Here, the optical member 40 is for diffusing light emitted through the second light guide plate 20, and may form a concave-convex pattern on the upper surface to increase the diffusion effect.

That is, the optical member 40 may be formed in several layers, and the concavo-convex pattern may be on the uppermost layer or the surface of any one layer.

The concavo-convex pattern may have a strip shape arranged along the light source module 50.

At this time, the concavo-convex pattern has protrusions on the surface of the optical member 40, and the protrusions consist of a first surface and a second surface facing each other, and an angle between the first surface and the second surface may be an obtuse angle or an acute angle.

Optionally, the optical member 40 is made of at least one sheet, and may optionally include a diffusion sheet, a prism sheet, a brightness enhancement sheet, and the like.

Here, the diffusion sheet diffuses the light emitted from the light source, and the prism sheet guides the diffused light to the light emitting area, and the brightness diffusion sheet strengthens the brightness.

Next, the panel guide module 80 can fix the light source module 50 and support the display panel 90, as shown in FIG.

The panel guide module 80 has an upper surface and a lower surface and the upper surface of the panel guide module 80 is in contact with the display panel 90. The lower surface of the panel guide module 80 is connected to the light source module 50 Lt; / RTI >

The top chassis 60 can cover a part of the bottom chassis 70 and the panel guide module 80.

6 is a view showing a display module having a backlight unit according to an embodiment.

As shown in FIG. 6, the display module 200 may include a display panel 90 and a backlight unit 100.

The display panel 90 includes a color filter substrate 91 and a TFT (Thin Film Transistor) substrate 92 bonded to each other to maintain a uniform cell gap, A layer (not shown) may be interposed.

The color filter substrate 91 includes a plurality of pixels composed of red (R), green (G), and blue (B) subpixels and generates an image corresponding to red, green, .

The pixels may be composed of red, green, and blue subpixels, but the red, green, blue, and white (W) subpixels constitute one pixel.

The TFT substrate 92 can switch a pixel electrode (not shown) as an element in which switching elements are formed.

For example, the common electrode (not shown) and the pixel electrode can change the arrangement of molecules in the liquid crystal layer according to a predetermined voltage applied from outside.

The liquid crystal layer is composed of a plurality of liquid crystal molecules, and the liquid crystal molecules change their arrangement in accordance with the voltage difference generated between the pixel electrode and the common electrode.

Thereby, the light provided from the backlight unit 100 can be incident on the color filter substrate 91 in accordance with the change in the molecular arrangement of the liquid crystal layer.

The upper polarizer 93 and the lower polarizer 94 may be disposed on the upper and lower sides of the display panel 90. More specifically, the upper polarizer 93 is disposed on the upper surface of the color filter substrate 91 And the lower polarizer 94 may be disposed on the lower surface of the TFT substrate 92.

Although not shown, a gate and a data driver for generating a driving signal for driving the display panel 90 may be provided on a side surface of the display panel 90.

As shown in FIG. 6, the display module 200 can be configured by placing the backlight unit 100 in close contact with the display panel 90.

For example, the backlight unit 100 may be adhered and fixed to the lower surface of the display panel 90, more specifically, to the lower polarizer 94, and between the lower polarizer 94 and the backlight unit 100 An adhesive layer (not shown) may be formed.

By forming the backlight unit 100 in close contact with the display panel 90 as described above, the overall thickness of the display device can be reduced to improve the appearance and the additional structure for fixing the backlight unit 100 is removed The structure and manufacturing process of the display device can be simplified.

In addition, by removing the space between the backlight unit 100 and the display panel 90, it is possible to prevent a malfunction of the display device or deterioration of the image quality of the display image due to penetration of foreign matter into the space.

7 and 8 are views showing a display device according to an embodiment.

7, the display device 1 includes a display module 200, a front cover 300 and a back cover 350 surrounding the display module 200, And a driving unit cover 400 surrounding the driving unit 550 and the driving unit 550.

The front cover 300 may include a transparent front panel (not shown) that transmits light. The front panel protects the display module 200 at a predetermined interval, and the light emitted from the display module 200 So that an image displayed on the display module 200 is displayed from the outside.

Further, the front cover 300 can be made of a flat plate without the window 300a.

In this case, the front cover 300 can be made of a transparent material that transmits light, for example, an injection-molded plastic.

As such, if the front cover 300 is formed as a flat plate, the frame can be removed from the front cover 300.

The back cover 350 may be coupled with the front cover 300 to protect the display module 200.

The driving unit 550 may be disposed on one side of the back cover 350.

The driving unit 550 may include a driving control unit 550a, a main board 550b, and a power supply unit 550c.

The driving control unit 550a may be a timing controller and is a driving unit that adjusts the operation timing to each driver IC of the display module 200. The main board 550b includes a V-sync, an H- , G, and B resolution signals, and the power supply unit 550c may be a driver for applying power to the display module 200. FIG.

The driving unit 550 may be provided on the back cover 350 and may be surrounded by the driving unit cover 400.

The back cover 350 may include a plurality of holes to connect the display module 200 and the driving unit 550 and a stand 600 for supporting the display device 1.

8, the driving control unit 550a of the driving unit 550 is provided in the back cover 350, and the main board 550b and the power board 550c may be provided in the stand 600 have.

The driving unit cover 400 may cover only the driving unit 550 provided on the back cover 350.

Although the main board 550b and the power board 550c are separately formed in the embodiment, the main board 550b and the power board 550c may be formed as a single integrated board, but are not limited thereto.

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.

Claims (19)

A reflector;
A first light guide plate disposed on the reflector and including a central region and a peripheral region surrounding the central region;
A second light guide plate disposed in a central region of the first light guide plate;
An optical member disposed on the second light guide plate;
A light source module disposed in a light source accommodating space defined by a side surface of the second light guide plate and an upper surface of a peripheral region of the first light guide plate and having a light exit surface facing the upper surface of the peripheral region of the first light guide plate; And
And an uneven pattern formed on the upper surface of the peripheral region of the first light guide plate and diffusing light emitted from the light source module to the first light guide plate. delete The method according to claim 1,
Wherein the first light guide plate and the second light guide plate are made of the same material, and are integrated. delete The method according to claim 1 or 3,
Wherein the first light guide plate has a first surface facing the second light guide plate, the second light guide plate has a second surface facing the first light guide plate,
The first surface of the first light guide plate has a larger area than the second surface of the second light guide plate,
And the area ratio of the second light guide plate and the first light guide plate is 1: 1.1-4. delete The method according to claim 1 or 3,
The thickness of the first light guide plate is thicker than the thickness of the second light guide plate,
Wherein a thickness ratio of the first light pipe to the second light pipe is 1: 0.9-0.1. delete The method according to claim 1 or 3,
Wherein each of the first light guide plate and the second light guide plate has a refractive index range of 1.3 to 1.55,
Wherein a refractive index of the first light guide plate is larger than a refractive index of the second light guide plate within the refractive index range. delete The method according to claim 1 or 3,
The transmittance of the first light guide plate is larger than the transmittance of the second light guide plate,
Wherein a transmittance of the first light guide plate is 80% to 99%, and a transmittance of the second light guide plate is 35% - 79%. delete delete delete The method according to claim 1 or 3,
Further comprising a panel guide module for supporting the light source module and the display panel,
Wherein the panel guide module has an upper surface and a lower surface, the upper surface of the panel guide module is in contact with the display panel, the lower surface of the panel guide module is in contact with the light source module,
Wherein the light source module includes a substrate and at least one light source disposed on the substrate, the light source is a top view type light emitting diode, and the substrate of the light source module is in contact with the panel guide module.
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