KR101704024B1 - Backlight Unit and Display Apparatus using thereof - Google Patents

Abstract

A backlight unit according to an embodiment includes a light guide plate; A plurality of first light emitting elements disposed on a first side surface of the light guide plate; And a plurality of second light emitting devices disposed on a second side surface of the light guide plate facing the first side surface, the second light emitting devices being arranged to be interlaced with the plurality of first light emitting devices.

Description

BACKLIT UNIT AND DISPLAY APPARATUS USING THE SAME

The embodiment relates to a backlight unit and a display device using the same.

Background Art [0002] A liquid crystal display device (LCD), which has been popular in recent years, has advantages such as miniaturization, light weight, and low power consumption, and is an alternative means to overcome the disadvantages of a conventional cathode ray tube And has been used in almost all information processing apparatuses requiring a display device at present.

Since such a liquid crystal display device is not a self-luminous display device, a separate light source such as a backlight unit (BLU) is required. Many studies have been conducted to effectively utilize the light emitted from the backlight unit to provide a high quality image.

The embodiment provides a backlight unit of a new structure and a display device using the same.

Embodiments provide a backlight unit with a small optical loss and a display device using the same.

A backlight unit according to an embodiment includes a light guide plate; A plurality of first light emitting elements disposed on a first side surface of the light guide plate; And a plurality of second light emitting devices disposed on a second side surface of the light guide plate facing the first side surface, the second light emitting devices being arranged to be interlaced with the plurality of first light emitting devices.

A display device according to an embodiment of the present invention includes a light guide plate, a plurality of first light emitting elements disposed on a first side face of the light guide plate, a second light emitting element disposed on a second side face of the light guide plate facing the first side face, A backlight unit including a plurality of second light emitting elements arranged to be staggered with the device; And a display panel disposed on the backlight unit.

The embodiment can provide a backlight unit of a new structure and a display device using the same.

Embodiments can provide a backlight unit having less light loss and a display device using the same.

1 is an exploded perspective view of a display device according to an embodiment;
2 is a cross-sectional view taken along line AA in Fig. 1
3 is a perspective view of a backlight unit according to an embodiment.
Fig. 4 is a top view of the backlight unit of Fig. 3
Figure 5 is a cross-sectional view of the backlight unit of Figure 3;
6 is a view showing the shape of a reflection pattern film formed on the side surface of the light guide plate of the backlight unit of Fig. 3
7 is a view showing the arrangement relationship between a plurality of light emitting devices of the backlight unit according to the embodiment and the light guide plate;
8 is a view showing a light emitting module part and a light guide plate of a backlight unit according to another embodiment

In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be formed "on" or "under" a substrate, each layer The terms " on "and " under " include both being formed" directly "or" indirectly " Also, the criteria for top, bottom, or bottom of 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.

Hereinafter, a backlight unit according to an embodiment and a display device using the same will be described with reference to the drawings.

1 is an exploded perspective view of a display device 1 according to an embodiment.

Referring to FIG. 1, a display device 1 according to an embodiment includes a display module 200, a front cover 300 and a back cover 400 surrounding the display module 200.

The front cover 300 may have a frame shape and may fix the peripheral region of the display module 200 to the back cover 400.

The back cover 400 may be formed as an outer surface of the back surface of the display module 200 and may include a storage space for accommodating the display module 200.

The display module 200, the front cover 300, and the back cover 400 form the appearance of the display device 1 and may have various shapes according to the design.

2 is a cross-sectional view taken along line A-A in Fig. 1, and shows a cross section of the display module 200. Fig.

2, the display module 200 includes a display panel 210 for displaying an image, a backlight unit 100 for providing light to the display panel 210, And a top cover 230 that supports the display panel 210 from above and forms the rim of the display module 200. The display panel 210 includes a display panel 210,

The backlight unit 100 includes a light guide plate 15, a light emitting module 13 for providing light on at least two opposite sides of the light guide plate 15, And a bottom cover 110 for accommodating the light guide plate 15 and the light emitting module unit 13 and forming a lower outer appearance of the display module 200. [ The backlight unit 100 will be described later in detail.

The bottom cover 110 may be formed in a box shape having an opened upper surface to accommodate the backlight unit 100, but the shape of the bottom cover 110 is not limited thereto.

The bottom cover 110 may be formed of a metal material or a resin material, and may be manufactured using a process such as press molding or extrusion molding.

One side of the bottom cover 110 may be fixed to one side of the top cover 230. For example, a fastening member such as a screw is passed through the side of the display module 200, that is, the side where the bottom cover 110 and the top cover 230 are overlapped, The top cover 230 can be fixed. However, the present invention is not limited thereto.

Although not shown in detail, the display panel 210 includes a lower substrate 211 and an upper substrate 222 bonded to each other so as to maintain a uniform cell gap, and a liquid crystal layer . ≪ / RTI > A plurality of gate lines and a plurality of data lines intersecting the plurality of gate lines are formed on the lower substrate 211. Thin film transistors (TFT) are formed in the intersections of the gate lines and the data lines . Color filters may be formed on the upper substrate 212. However, the structure of the display panel 210 is not limited thereto, and the display panel 210 may have various structures. For example, the lower substrate 211 may include a color filter as well as a thin film transistor. In addition, the display panel 210 may have various structures according to a method of driving the liquid crystal layer.

Although not shown, a gate driving printed circuit board (PCB) for supplying a scan signal to a gate line is formed at an edge of the display panel 210, a data driving printed circuit board (PCB) May be provided.

A polarizing film (not shown) may be disposed on at least one of the upper side and the lower side of the display panel 210.

The optical sheet 220 may be disposed between the display panel 210 and the backlight unit 100. The optical sheet 220 may include a diffusion sheet and / or a prism sheet. The diffusing sheet diffuses the light emitted from the light guide plate evenly, and the diffused light can be focused on the display panel by the prism sheet. Here, the prism sheet may be selectively formed using a horizontal or vertical prism sheet, one or more roughness enhancing films, or the like. The types and the number of the optical sheets 220 may be added or deleted within the technical scope of the embodiments, but the invention is not limited thereto.

Hereinafter, the configuration of the backlight unit 100 will be described in detail.

FIG. 3 is a perspective view of the backlight unit 100, FIG. 4 is a top view of the backlight unit 100, and FIG. 5 is a cross-sectional view of the backlight unit 100.

3 to 5, the backlight unit 100 includes a light guide plate 15, a light emitting module unit 13 for providing light to at least two opposite side surfaces of the light guide plate 15, A reflection pattern film 16 formed on a side surface of the display module 15 and a bottom cover 110 for accommodating the light guide plate 15 and the light emitting module portion 13 and forming a lower outer appearance of the display module 200 can do.

The light guide plate 15 diffuses the light provided from the light emitting module unit 13 to form a surface light source, and provides the light to the display panel 210.

The light guide plate 15 may be formed of a transparent material, for example, acrylic resin such as PMMA (polymethyl methacrylate), polyethylene terephthalate (PET), polycarbonate (PC), cycloolefin copolymer (COC) and polyethylene naphthalate resin.

The light guide plate 15 may have a substantially constant thickness with respect to the entire area, or may have a shape in which the thickness gradually decreases in one direction, but the present invention is not limited thereto.

In addition, a scattering pattern or a prism pattern may be formed on at least one of the upper surface and the lower surface of the light guide plate 15. The scattering pattern may have a predetermined pattern such as a dot pattern and diffuse the incident light to improve light uniformity on the entire surface of the light guide plate 15. In addition, the prism pattern may cause the light emitted from the light guide plate 15 to be incident in the vertical direction toward the display panel.

A reflective member 17 may be formed on the lower surface of the light guide plate 15. Therefore, the light incident on the side of the light emitting module section 13 can be guided in the light guide plate 15, reflected by the reflection member 17, and then emitted to the upper surface of the light guide plate 15.

The light emitting module part 13 may be disposed on at least two opposite side surfaces of the light guide plate 15 to provide light to the light guide plate 15. The light emitting module unit 13 may include a substrate 12 and a plurality of light emitting devices 11 mounted on the substrate 12 in an array.

The substrate 12 may be a printed circuit board (PCB), for example, at least one of a metal core PCB (MCPCB), an FR-4 PCB, a general PCB, or a flexible PCB .

The light emitting device 11 may be a light emitting diode (LED), for example, a colored light emitting diode that emits red, green, blue, or white colored light, or may emit ultraviolet UV light emitting diodes, but it is not limited thereto.

4, the plurality of light emitting devices 11 include a plurality of first light emitting devices 11a disposed on a first side surface of the light guide plate 15 and a plurality of second light emitting devices 11b disposed on the light guide plate And a plurality of second light emitting devices 11b disposed on a second side of the first light emitting device 15 and arranged to be staggered with the plurality of first light emitting devices 11a.

The plurality of first light emitting devices 11a and the plurality of second light emitting devices 11b may be disposed in a staggered arrangement so that the plurality of first light emitting devices 11a, The elements 11b may be arranged such that only a part thereof does not overlap or overlap in the horizontal direction.

The plurality of first light emitting devices 11a and the plurality of second light emitting devices 11b are disposed in a staggered arrangement so that light energy and heat energy emitted from the light emitting devices provided on one side face each other It is possible to minimize the absorption by the light emitting element provided on the side surface. That is, the arrangement of the first and second light emitting devices 11a and 11b may contribute to the heat dissipation efficiency and the optical loss reduction of the backlight unit 100 according to the embodiment.

In the backlight unit 100 according to the embodiment, the reflection pattern film 16 is formed on the side surface of the light guide plate 15 except for a region where light emitted from at least the plurality of light emitting devices 11 is incident. .

Fig. 6 is a view showing the shape of the reflection pattern film 16, and Fig. 7 is a diagram showing the arrangement relationship between the plurality of light emitting elements 11 and the light guide plate 15. Fig.

Referring to FIGS. 6 and 7, the reflection pattern film 16 may include a plurality of holes 15a in which light emitted from the plurality of light emitting devices 11 is incident.

The shape and the width x of the plurality of holes 15a are determined by a directing angle of light emitted from the light emitting device 11 and a distance D between the light emitting device 11 and the light guide plate 15. [ A pitch P between the plurality of light emitting devices 11, and a width L of the light emitting device 11, for example. In the embodiment, the directivity angle? Indicates an angle at which light emitted from the light emitting element 11 spreads in the vertical direction, and the pitch P indicates a center distance between the adjacent light emitting elements 11 Point.

As shown in FIG. 6 (a), the plurality of holes 15a may have a rectangular shape, or may have various shapes such as a circle, an ellipse, and a polygon. And the width (x) of the plurality of holes 15a may be L + 2 占 · sin ?.

Alternatively, as shown in FIG. 6 (b), the plurality of holes 15a and the reflection pattern film 16 may be alternately formed in a stripe shape.

That is, the present invention is not limited to the shape of the reflection pattern film 16 and the plurality of holes 15a, and may be variously modified according to the design of the backlight unit 100.

The reflection pattern film 16 including the plurality of holes 15a is emitted from the light emitting device 11 provided on the first side face of the light guide plate 15 and is incident on the second side face facing the first side face By reflecting the light, the light loss of the backlight unit 100 can be reduced.

In particular, since the plurality of first light emitting devices 11a and the plurality of second light emitting devices 11b are arranged to be staggered from each other, the light emitted from the first and second light emitting devices 11a and 11b may have a direct- The effect of reducing the light loss due to the reflection pattern film 16 can be increased. In the case of a light emitting diode (LED), since the LED having a high luminance and a high output tend to emit light having strong straightness, the effect of reducing the light loss due to the reflection pattern film 16 can be maximized.

The reflection pattern film 16 may be formed of a metal material having high reflection efficiency such as TiO ₂ , white PSR, or Ag, Al, or Pt. On the other hand, when the reflection pattern film 16 has a scattering property such as TiO _{2 that} reflects incident light while scattering the light, the loss of light quantity is reduced by the reflection pattern film 16, 15). ≪ / RTI >

The reflection pattern film 16 may be formed on the entire region of the side surface of the light guide plate 15 on which the plurality of light emitting devices 11 are not disposed so as not to include the plurality of holes 15a.

Hereinafter, the backlight unit according to another embodiment will be described in detail. However, the description overlapping with the foregoing description will be omitted or briefly explained.

8 is a view illustrating a light emitting module part and a light guide plate of a backlight unit according to another embodiment.

8A, the area of the side surface of the light guide plate 15 where the reflection pattern film 16 is formed is protruded or recessed relative to the peripheral area where the reflection pattern film 16 is not formed, ).

The reflective pattern layer 16 may be formed by a coating method such as corona coating or plasma coating so that the reflective pattern layer 16 is formed to have a height different from that of the surrounding region. Can be simplified. Some coating methods, such as corona coating and plasma coating, can easily apply the coating material selectively only to the protruded or recessed surfaces.

Referring to FIG. 8 (b), the area where the plurality of holes 15b are formed in the side surface of the light guide plate 15 may have a concave groove shape. Referring to FIG. 8 (c), a region where a plurality of holes 15c are formed in the side surface of the light guide plate 15 may be formed to have irregularities. The groove shape and the concavity and convexity may function to effectively enter the light entering from the plurality of light emitting devices 11 into the light guide plate 15. [

That is, the shape of the light guide plate may be variously changed in order to improve the light efficiency of the backlight unit 100 according to the embodiment, but it is 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.

1: display device 200: display module 210: display panel 240: panel supporter 300: front cover 400: back cover 230: top cover 15: light guide plate 13:

Claims (18)

A light guide plate;
A plurality of first light emitting elements disposed on a first side surface of the light guide plate;
A plurality of second light emitting devices disposed on a second side surface of the light guide plate facing the first side surface, the second light emitting devices being arranged to be interlaced with the plurality of first light emitting devices; And
And a reflection pattern film disposed on the first side surface and the second side surface of the light guide plate,
Wherein the reflective pattern film includes a plurality of holes. The method according to claim 1,
Wherein the plurality of first light emitting devices and the plurality of second light emitting devices are partially overlapped in a horizontal direction. The method according to claim 1,
Wherein the plurality of first light emitting devices and the plurality of second light emitting devices do not overlap in a horizontal direction. The method according to claim 2 or 3,
And the plurality of holes arranged on the first side are arranged to be staggered with the plurality of second light emitting elements arranged on the second side. 5. The method of claim 4,
Wherein the reflection pattern film includes a first reflection pattern film and a second reflection pattern film which are disposed apart from each other. 5. The method of claim 4,
Wherein the plurality of holes have a shape of a rectangle, a circle, an ellipse or a polygon. 5. The method of claim 4,
The plurality of holes and the reflection pattern film alternate in a stripe form,
Wherein the reflective pattern film is formed of any one of TiO ₂ , white PSR, or metal material,
Wherein the plurality of light emitting devices include at least one light emitting diode. delete 5. The method of claim 4,
And a distance between adjacent light emitting elements is P, a width of the light emitting element is L, and a distance between the light emitting element and the light pipe is D When you say,
And the width of the plurality of holes is L + 2 D? Sin ?. delete 5. The method of claim 4,
Wherein a region of the first side surface and the second side surface of the light guide plate where the reflective pattern film is formed is recessed or protruded as compared with a peripheral region. delete 6. The method of claim 5,
Wherein the plurality of apertured areas of the first side surface and the second side surface of the light guide plate have concavely recessed grooves or irregularities. delete delete 5. The method of claim 4,
Wherein a plurality of holes of the reflection pattern film are disposed in an area excluding an area where light emitted from the plurality of light emitting devices is incident. delete delete

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