KR20140096854A - Backlight unit thereof - Google Patents

Abstract

A light emitting package according to the present invention includes a light emitting device module which includes a substrate and a light emitting device package which is electrically connected to the substrate; a chassis which includes at a first region where the light emitting device module is arranged and second regions which are arranged at both sides of the first region and include a parabola; a diffusion sheet which is separated from the upper part of the light emitting device module; and a reflection member which faces the light emitting device module.

Description

BACKLIGHT UNIT {BACKLIGHT UNIT THEREOF}

An embodiment relates to a backlight unit.

Light Emitting Diode (LED) is a device that converts electrical signals into light by using the characteristics of compound semiconductors. It is widely used in household appliances, remote control, electric signboard, display, and various automation devices. There is a trend.

When a forward voltage is applied to the light emitting device, electrons in the n-layer and holes in the p-layer are coupled to emit energy corresponding to the energy gap between the conduction band and the valance band. It is mainly emitted in the form of heat or light, and when emitted in the form of light, it becomes an LED.

Nitride semiconductors have attracted great interest in the development of optical devices and high output electronic devices due to their high thermal stability and wide band gap energy. Particularly, blue light emitting devices, green light emitting devices, ultraviolet (UV) light emitting devices, and the like using nitride semiconductors have been commercialized and widely used.

The light emitting device package is manufactured by manufacturing a light emitting device on a substrate, separating the light emitting device chip through dieseparation, which is a sawing process, and then diebonding the light emitting device chip to a package body. Wire bonding and molding can be performed, and the test can proceed.

As the fabrication process of the light emitting device chip and the packaging process are performed separately, various complex processes and various substrates may be required.

The backlight unit may need to study the direction of efficiently designing the light and light grapes by using a small number of light emitting device packages.

One embodiment of the present invention provides a backlight unit that reduces the number of light emitting device modules and improves light scattering using a chassis having a parabolic surface.

One embodiment of the present invention provides a backlight unit that reduces the number of light emitting device modules and improves light scattering using a chassis having a parabolic surface.

The backlight unit according to an embodiment of the present invention can allow the chassis forming the parabolic surface to uniformly supply light to the diffusion sheet.

The backlight unit according to the embodiment of the present invention can prevent the reflection member from reflecting the light irradiated from the light emitting device package back to the chassis to generate a hot spot on the diffusion sheet.

The backlight unit according to an embodiment of the present invention can form a parabolic surface extending in the direction of the diffusion sheet at both ends of the chassis to uniformly supply light to the confident sheet.

1 is a cross-sectional view showing a cross-section of a backlight unit according to an embodiment,
FIG. 2 is a perspective view showing a part of a backlight unit according to an embodiment,
FIG. 3 is a perspective view illustrating a light emitting device module included in a backlight unit according to an embodiment,
4 is a perspective view illustrating a backlight unit according to an embodiment,
5 is a cross-sectional view illustrating a backlight unit according to an embodiment,
6 is a perspective view illustrating a light emitting device package included in a backlight unit according to an exemplary embodiment.
7 is a perspective view illustrating a liquid crystal display device including a backlight unit according to an exemplary embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terms spatially relative, "below", "beneath", "lower", "above", "upper" May be used to readily describe a device or a relationship of components to other devices or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions. The elements can also be oriented in different directions, so that spatially relative terms can be interpreted according to orientation.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs. Also, commonly used predefined terms are not ideally or excessively interpreted unless explicitly defined otherwise.

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 and area of each component do not entirely reflect actual size or area.

Further, the angle and direction mentioned in the description of the structure of the light emitting device in the embodiment are based on those shown in the drawings. In the description of the structure of the light emitting device in the specification, reference points and positional relationship with respect to angles are not explicitly referred to, refer to the related drawings.

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

1 is a cross-sectional view of a backlight unit according to an embodiment.

1, a backlight unit 100 according to an exemplary embodiment includes a light emitting device module 160 including a substrate 120 and a light emitting device package 110 electrically connected to the substrate 120, A chassis 130 including a first region 132 in which the light emitting device module 160 is disposed and a plurality of second regions 134 disposed on both sides of the first region 132 and including a parabolic surface, And a reflective member 150 disposed to face the diffusion sheet 140 and the light emitting element module 160 and disposed to face the diffusion sheet 140 and reflect light.

The substrate 120 may be electrically connected to the light emitting device package 110. When the substrate 120 uses a conductive material as a body, an insulating material may be coated on the conductive material to be a body. The substrate 120 may be provided with a pattern or the like for forming electrodes on the insulating material. The substrate 120 may be electrically connected to the light emitting device package 110 by a pattern for forming the electrodes.

The light emitting device package 110 may include a light emitting device (not shown) that emits light and a lead frame that supplies electricity to the light emitting device. The light emitting element (not shown) may be electrically connected to the lead frame (not shown) and the connecting member. That is, they may be electrically connected by a wire bonding method, a flip chip method, or a die bonding method.

The light emitting device (not shown) may be one of a horizontal type in which all the electric terminals are formed on the upper surface, a vertical type formed in the upper and lower surfaces, or a flip chip.

The light emitting device may include a first semiconductor layer (not shown), an active layer (not shown), and a second semiconductor layer (not shown). The first semiconductor layer (not shown) And an active layer (not shown) interposed therebetween.

The chassis 130 may include a light emitting device module 160. The chassis 130 may support the backlight unit 100. The chassis 130 may be assembled with the light emitting device module 160. The chassis 130 may be bonded to the light emitting device module 160 with an adhesive material, but the present invention is not limited thereto.

The chassis 130 may include a parabolic surface. The chassis 130 can form a plurality of parabolic surfaces on both sides of a region where the light emitting device modules are disposed. The chassis 130 may include a first region 132 in which the light emitting device module 160 is disposed and a second region 134 in which a parabolic surface is formed on both sides of the first region 132. The first region 132 may be flat. The second region 134 may form a parabolic surface. The second region 134 may be formed in the longitudinal direction so as to be parallel to the long axis of the light emitting device module 160.

The second region 134 may be in the form of a rectangle having long parabolic lines in the longitudinal direction. The second region 134 may be formed on both sides of the first region 132 so as to be parallel to the long axis of the first region 132.

A reflective sheet may be provided on the upper surface on which the light emitting device module 160 of the chassis 130 is disposed. The reflection sheet (not shown) may be directly irradiated by the light emitting element module 160, or may reflect light reflected by the reflection member 150 in the direction of the diffusion sheet. The reflective sheet (not shown) may be disposed in the first area 132 and the second area 134, but is not limited thereto. In other embodiments, the reflective sheet (not shown) may be disposed only in the second region 134, but is not limited thereto.

The diffusion sheet 140 may be disposed on the top of the chassis 130. The diffusion sheet 140 may be disposed in a direction in which the light emitting element module 160 emits light. The diffusion sheet 140 can diffuse the light.

The diffusion sheet 140 may be formed of PMMA (polymethylmethacrylate) or transparent acrylic resin in a flat type or wedge type and may be formed of a glass material. No. The diffusion sheet 140 may form various patterns on the upper surface or the lower surface to uniformly distribute the light emitted from the upper surface.

2 is a perspective view illustrating a part of a backlight unit according to an exemplary embodiment.

Referring to FIG. 2, the diffusion sheet 140 may have a reflective member 150 on one side thereof. The reflective member 150 may be attached to one side of the diffusion sheet 140. The reflective member 150 may be formed by applying a highly reflective material to one surface of the diffusion sheet 140. [

The reflective member 150 may be disposed on one surface of the diffusion sheet 140 facing the light emitting device module 160. The reflective member 150 may be regularly or irregularly disposed on one side of the diffusion sheet 140, but is not limited thereto.

The reflective member 150 may be plural. The plurality of reflective members 150 may be different. The plurality of reflective members 150 may have different shapes or different sizes. For example, at least one of the plurality of reflective members 150 may be vertically overlapped with the light emitting device package 110. For example, when the number of the light emitting device packages 110 included in the light emitting device module 160 is three, the number of the reflective members 150 vertically overlapping the three light emitting device packages 110 may be three.

The size of the reflective member 150 may be increased or the spacing of the pattern may be reduced as the reflective member 150 is further away from the region vertically overlapping the light emitting device package 110 of the diffusion sheet 140. However, the present invention is not limited thereto. The reflective member 150 may be positioned within the directional angle range of the light emitting device package 110. For example, the reflective member 150 may be positioned in a range of 142% to 180% of the width of the light emitting device package 110 laterally at a portion vertically overlapping the light emitting device package 110 of the diffusion sheet 140 .

The reflective member 150 is disposed on both sides of the diffusion sheet 140 at a portion vertically overlapping the light emitting device package 110 in a range of less than 142% of the width of the light emitting device package 110 , Efficiency may be reduced due to failure to cover all the range within the directivity angle of the light emitting device package 110. When the reflective member 150 is disposed in a range exceeding 180% You may not be able to increase efficiency, because you can not do much.

3 is a perspective view illustrating a light emitting device module included in a backlight unit according to an exemplary embodiment.

Referring to FIG. 3, the light emitting device package 110 may be mounted on the substrate 120 in a multi-color, multi-row manner to form a module. The light emitting device package 110 may be mounted on the substrate 120 at equal intervals.

In other embodiments, the light emitting device package 110 may be mounted on the substrate 120 with various spacings to adjust light distribution and the like, but is not limited thereto.

The substrate 120 may be a MCPCB (Metal Core PCB) or FR4 PCB, but is not limited thereto. The substrate 120 may comprise an insulating material or a conductive material.

3, the light emitting device module is illustrated as having three light emitting device packages 110 on a substrate 120, but is not limited to the number of light emitting device packages 110.

4 is a perspective view illustrating a backlight unit according to an exemplary embodiment.

Referring to FIG. 4, the reflective member 150 may be a plurality of reflective members.

The number of the reflective members 150 of the plurality of reflective members 150, such as the number of the light emitting device packages 110, may be matched with the plurality of the light emitting device packages 110, respectively.

For example, the reflection member 150 may be disposed on the vertical surface of the light emitting surface of the light emitting device package 110. The reflective member 150 matched to the light emitting device package 110 may reflect the light emitted from the light emitting device package 110.

The light reflected by the reflective member 150 may be irradiated to the chassis 130. The chassis 130 may form a parabolic surface. The parasitic surface of the chassis 130 may reflect the light emitted from the light emitting device package 110 or the light reflected by the reflecting member 150 toward the diffusion sheet 140.

The reflective member 150 may be plural. The reflective member 150 may be regularly or irregularly arranged on one side of the diffusion sheet 140 by optical consideration. The reflective member 150 may be disposed inside the directional angle of the light emitting device package 110 so that light can be uniformly distributed throughout the diffusion sheet 140. [

5 is a cross-sectional view illustrating a backlight unit according to an embodiment.

Referring to FIG. 5, the chassis 130 may have an extended edge.

The chassis 130 may extend in the direction of the diffusion sheet 140 at an edge parallel to the long axis of the substrate 120. The chassis 130 may be curved at corners. The chassis 130 may be bent and extended to an upper corner where the diffusion sheet 140 is disposed.

The chassis 130 may form a parabolic surface inside the portion 132 extending in the direction of the diffusion sheet 140. The portion 132 of the chassis 130 extending in the direction of the diffusion sheet 140 forms a parabolic surface and can reflect light to the parabolic surface of the second region of the diffusion sheet 140 or the chassis 130. [

6 is a perspective view illustrating a light emitting device package included in a backlight unit according to an exemplary embodiment.

Referring to FIG. 6, a direct type backlight unit that directly irradiates light to the bottom surface of the diffusion sheet may include a lens-type light emitting device package 200.

The lens-type light emitting device package 200 includes a light emitting element 220, a lead frame 230 electrically connected to the light emitting element 220, a lens (not shown) covering the light emitting element 220 and the lead frame 230 240). The lead frame 230 may be surrounded by the body 210.

The lens 240 may enclose the light emitting device 220 or the lead frame 230 to block the entry of foreign substances. The lens 240 may be formed of a transparent resin such as silicon (Silicone) or epoxy (Epoxy), but is not limited thereto. The lens 240 may be injection molded, but is not limited to the process method. The lens 240 may include a dome shape. The lens 240 may control the brightness or the directivity angle of the light emitting device package 200 by controlling the degree of curvature of the surface.

The lens 240 may minimize the total reflection of light generated in the light emitting device 220. The lens 240 may allow the light generated by the light emitting device 220 to be emitted to the outside as much as possible. According to Snell's law, total reflection refers to a phenomenon in which light travels from a material having a large refractive index to a material having a small refractive index, and is totally reflected at the interface between two materials having different refractive indices when the angle of incident light is larger than a critical angle.

The lens 240 may increase the critical angle of the surface of the lens 240 so that the light generated by the light emitting device 220 is diverted to the outside. The lens 240 can reduce the total reflection of light traveling to the outside of the light emitting device 220, thereby improving the light extraction efficiency of the light emitting device package 200. The lens-type light emitting device package 200 may have a directivity angle of 135 to 145 占 but is not limited thereto.

7 is a perspective view illustrating a liquid crystal display device including a backlight unit according to an exemplary embodiment.

7 is a liquid crystal display device 600 of a direct lowering type according to the embodiment. The liquid crystal display device 600 may include a liquid crystal display panel 680 and a backlight unit 670 for providing light to the liquid crystal display panel 680.

The liquid crystal display panel 680 can display an image using light provided from the backlight unit 670. The liquid crystal display panel 680 may include a color filter substrate 615 and a thin film transistor substrate 614 facing each other with a liquid crystal therebetween.

The color filter substrate 615 can realize the color of an image to be displayed through the liquid crystal display panel 610. [

The thin film transistor substrate 614 is electrically connected to a printed circuit board 618 on which a plurality of circuit components are mounted through a driving film 617. The thin film transistor substrate 614 can apply a driving voltage provided from the printed circuit board 618 to the liquid crystal in response to a driving signal provided from the printed circuit board 618. [

The thin film transistor substrate 614 may include a thin film transistor and a pixel electrode formed as a thin film on another substrate of a transparent material such as glass or plastic.

The backlight unit 670 includes a plurality of light emitting element modules 623, a chassis 630 in which the light emitting element modules 723 are disposed, a diffusion sheet 650 disposed on the upper portion of the light emitting element module 623, A reflective member 640 and a plurality of optical films 660 disposed on the lower surface of the reflective film 640.

The light emitting device module 623 may include a substrate 620 to mount a plurality of light emitting device packages 610 and a plurality of light emitting device packages 610 to form a module.

Light generated in the light emitting element module 623 is incident on the diffusion sheet 650 and an optical film 660 may be disposed on the diffusion sheet 650. The optical film 660 may include a diffusion film 666, a prism film 652, and a protective film 664.

The configuration and the method of the embodiments described above are not limitedly applied, but the embodiments may be modified so that all or some of the embodiments are selectively combined so that various modifications can be made. .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

100: Backlight unit
110: Light emitting device package
120: substrate
130: chassis
140: diffusion sheet
150: reflective member

Claims (12)

A light emitting device module including a substrate and a light emitting device package electrically connected to the substrate;
A chassis having a first region in which the light emitting element module is disposed and a second region disposed on both sides of the first region and including a parabolic surface;
A diffusion sheet disposed on an upper portion of the light emitting device module; And
And a reflective member disposed to face the light emitting element module. The method according to claim 1,
Wherein the reflective member is disposed on an upper portion of the light emitting device package. The method according to claim 1,
Wherein the reflective member has a circular or polygonal surface facing the light emitting device package. The method according to claim 1,
And the second region is formed in parallel with the substrate. The method according to claim 1,
And the reflective member is disposed to face the second region. The method according to claim 1,
And a reflective sheet disposed in the second region and reflecting light. The method according to claim 1,
Wherein the chassis extends in the direction of the diffusion sheet at an edge parallel to the long axis of the substrate. 8. The method of claim 7,
Wherein the chassis defines a parabolic surface inside a portion extending in the direction of the diffusion sheet. The method according to claim 1,
Wherein the light emitting device package includes a light emitting element and a lens for adjusting a directivity angle of the light emitted from the light emitting element. The method according to claim 1,
Wherein the reflective member comprises any one of silver (Ag), aluminum (Al), and titanium oxide (TiO2). The method according to claim 1,
Wherein the second region is a rectangular shape. The method according to claim 1,
Wherein the reflective member is located within a range of 142% to 180% of a width of the light emitting device package in a portion vertically overlapping the light emitting device package of the diffusion sheet.

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