KR20150110141A - Lens, a light emitting device and a backlight unit including the same - Google Patents

Abstract

In a lens changing the path of light inputted from a light source according to the embodiment of the present invention, a concave part is formed in a first region facing the light source, in a second region facing the first region, a central region is concave in the direction of the central region. The surface of the concave part includes a (1-1)^th region facing the center of the light source, a (1-3)^th region of an edge, and a (1-2)^th region which is located between the (1-1)^th region and the (1-3)^th region. The curvatures of the (1-1)^th region, the (1-2)^th region, and the (1-3)^th region are different.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a lens, a light emitting device package including the lens, and a backlight unit.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens, a light emitting device package including the same, and a backlight unit. More particularly, the present invention is intended to increase the light output angle of the light emitting device package and improve the light efficiency of the backlight unit.

GaN, and AlGaN are widely used for optoelectronics and electronic devices due to their advantages such as wide and easy bandgap energy.

Particularly, a light emitting device such as a light emitting diode or a laser diode using a semiconductor material of a 3-5 group or a 2-6 group compound semiconductor has been widely used in various fields such as red, green, blue and ultraviolet rays It can realize various colors, and it can realize efficient white light by using fluorescent material or color combination. It has low power consumption, semi-permanent lifetime, fast response speed, safety, and environment compared to conventional light sources such as fluorescent lamps and incandescent lamps Affinity.

Therefore, a transmission module of the optical communication means, a light emitting diode backlight replacing a cold cathode fluorescent lamp (CCFL) constituting a backlight of an LCD (Liquid Crystal Display) display device, a white light emitting element capable of replacing a fluorescent lamp or an incandescent lamp Diode lighting, automotive headlights, and traffic lights.

The LCD display device includes a liquid crystal layer and a TFT substrate and a color filter substrate facing each other with the liquid crystal layer sandwiched therebetween. Since there is no self-luminous force, an image can be displayed using light provided from the backlight unit.

When a light emitting device package is used as a light source of an LCD display device, the light emitting device package can be classified into a side view type and a direct under type according to the position of the light source. In the case of the direct-type type, the light guide plate may be omitted, so that it may be slim and light in weight. However, when light emitted from each light emitting device package does not advance sufficiently in the direction of the optical sheet or the liquid crystal layer, Mura and the like may occur.

If the distance between the light emitting device package and the optical sheet is increased, the occurrence of interference or scattering can be reduced, but the thickness of the LCD display device is increased.

Embodiments are intended to increase the light output angle of the light emitting device package, reduce the thickness of the backlight unit using the light emitting device package as a light source, and prevent the occurrence of optical interference and dust.

In an embodiment of the present invention, there is provided a lens for changing the path of light incident from a light source, the lens having a concave portion formed in a first region facing the light source, and a second region facing the first region, And the surface of the concave portion has a first 1-1 zone and a 1-2 second zone between the 1-1 and 1-3 zones facing the center of the light source, And the curvatures of the 1-1 zone, the 1-2 zone and the 1-3 zone are different from each other.

The first-first region may be disposed in the range of 0 to 45 degrees from the center axis, and the central axis may be disposed in the center of the second region from the light source.

The first-second region may be disposed in the range of 30 to 80 degrees from the central axis, and the first-third region may be disposed in the range of 60 to 90 degrees from the central axis.

The 1-1 zone, the 1-2 zone and the 1-3 zone both have a positive curvature, or both can have a negative curvature.

The 1-1 and 1-3 regions have a positive curvature and the 1-2 region has a negative curvature or the 1-1 and 1-3 regions have a negative curvature and the 1- 2 region may have a positive curvature.

The ratio of the height of the lens to the height difference between the highest point and the lowest point of the second region of the lens may be less than 0.7 to 1: 1.

According to another embodiment of the present invention, there is provided a lens for changing the path of light incident from a light source, the lens having a concave portion formed in a first region facing the light source, and a second region facing the first region, , And the surface of the concave portion has a first 1-1 region facing the center of the light source and a 1st 1-3 region of the edge and a second 1-2 region between the first 1-1 region and the 1-3 region, And a refracting angle of the light emitted from the light source and passing through the first-first region, the first-second region, and the first-third region is different from each other.

The light emitted from the light source and passing through the 1-1 zone can be refracted in the direction of the central axis.

The light emitted from the light source and passing through the first-second region can be refracted in the direction of the central axis.

The light emitted from the light source and passing through the first to third regions can be refracted in the direction of the central axis.

The refraction angle may be the largest light emitted from the light source and passing through the 1-2 zone.

The angle between the light passing through the 1-1 zone and the central axis of the light refracted in the first area and proceeding to the second area may be the smallest.

The angle between the light passing through the first to third regions and the central axis of the light refracted in the first region and proceeding to the second region may be largest.

The refraction angle may be the smallest light emitted from the light source and passing through the first to third regions.

Another embodiment includes a first lead frame and a second lead frame; A light emitting element electrically connected to the first lead frame and the second lead frame; A molding part surrounding the light emitting device; And the above-described lens including the light emitting device package as a light source, wherein a part of the light emitting device package is inserted into the concave portion of the lens.

Another embodiment includes a bottom chassis; An optical sheet disposed opposite to the bottom chassis; And the above-described light emitting device package disposed on the bottom chassis and spaced apart from the optical sheet, wherein the optical sheet and the light emitting device package are disposed at a distance of 10 millimeters to 15 millimeters.

The backlight unit in which the lens and the light emitting device package according to the embodiment are disposed can prevent the light emitted from the light emitting device package from advancing sufficiently to the side due to the action of the lens, Can be prevented.

1 is a view showing a first embodiment of a lens,
FIG. 2A is a view showing the size of the lens of FIG. 1,
2B to 2F are views showing the 'A' region of FIG. 1 in detail,
Figures 3A-3C are perspective and side cross-sectional views of the lens,
4A and 4B are views showing the light paths of the light emitting device package,
5A to 5C are views showing a first embodiment of a light emitting device package,
6A to 6C are views showing a second embodiment of the light emitting device package,
7A and 7B are views showing a third embodiment of the light emitting device package,
8A to 8C are views showing a fourth embodiment of the light emitting device package,
FIG. 9 and FIG. 10 show a display device including a light emitting device package,
11 is a view showing the improvement of the light leakage in the light emitting device package according to the embodiment,
12A and 12B are views showing the effect of improving the dark area in the backlight unit of the display device according to the embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

In the description of embodiments according to the present invention, in the case of being described as being formed "on or under" of each element, the upper (upper) or lower (lower) or under are all such that two elements are in direct contact with each other or one or more other elements are 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 view showing a first embodiment of a lens.

The lens 100 may be disposed in a light source such as a light emitting device package to change the path of light incident from the light source. The lens 100 may be made of a light-transmitting material. For example, the lens 100 may be made of polycarbonate, silicone resin, or the like.

The lens 100 according to the present embodiment has a concave portion formed in a first region 120 which is an incident surface facing the light emitting device package 200 as a light source so that at least a part of the light emitting device package 200 is provided in the concave portion Can be inserted and arranged.

The central region of the second region 130 facing the first region 120 is concave in the direction of the first region 120, and the light can be totally reflected as shown in FIG. The third region 135 on the side surface may function as a light outgoing surface through which light reflected from the second region 130, which is a total reflection surface, and a part of the light incident from the first region 120, have.

A protrusion 140 may be formed on the lower portion of the third region 135 and at least three supports 150 may be formed on the lower portion of the lens 100. The support 150 may serve to support the lens 100 on a bottom chassis or the like when the lens 100 is fixed to a display device or the like to be described later.

FIG. 2A is a view showing the size of the lens of FIG. 1. FIG.

The height (h a lens height (h ₁₎ and the second region 130, peaks and valleys height difference (h ₂₎ ratio is 1: 0.7 to 1: 1 there can be less than, the lens 100 of the 100 ₁ is the vertical distance from the bottom surface of the support 150 of the lens 100 to the highest point of the second area 130 of the lens 100 and the difference in height between the highest point and the lowest point of the second area 130 ₂ may be a concave depth of the second region 130, specifically, a distance in the vertical direction from the highest region of the second region 130 to the lowest region of the concave portion.

The height (h ₁₎ and the second region peaks and if the height difference ratio of (h ₂₎ of the lowest point is less than one-to-0.7, the second area of the incident light from the light incident surface of the 130 of the lens 100 ( 130 may be reduced.

The height (h ₁₎ of the lens 100 and the height difference ratio of (h ₂₎ of the peaks and troughs of the second region 130 to about 1: 1 is to be the second region 130 of the lens 100 is flat And if the ratio is more than 1: 1, the second area 130 of the lens 100 may be flat or the center may be convex.

The distance W ₁ between the projections 140 may be larger than the length W ₂ of the lens 100 in the transverse direction. For example, the length W ₂ of the lens 100 in the transverse direction may be 18 mm number and the distance (W ₁₎ may be 21.5 mm. distance (W ₁₎ and the lens (100) between the width of the projecting portion 140 is projected (Δw) is the aforementioned projecting portion 140 between the projections 140, can be a half of the difference between the length (W ₂₎ in the transverse direction, if the width is too small, the above-described (Δw) may not be sufficient to support the Extrusions in the injection step of the lenses, it is too large to change the optical path The size of the entire lens in the lateral direction may become too large as compared with the area where the lens is made. The projecting portion 140 may be formed as needed to support the injection molding in the injection process of the lens.

The width of the concave portion formed in the lower portion of the lens (100) (W ₃₎ may be greater than the width of the light exit portion of the light emitting device package. Here, the width of the light output portion of the light emitting device package may be, for example, the width shown by 'a' in FIG. 5A.

2B to 2F are views showing the 'A' region of FIG. 1 in detail.

The first region 120 in which light is incident from the light source may be the surface of the cavity described above. The first region 120a facing the center of the light source, the first through third regions 120c and 120c, 1-1 zone 120a and the 1-2 zone 120b between the 1-1 zone 120a and the 1-3 zone 120c, And the first to third regions 120c may have different curvatures.

An imaginary line connecting the center of the second region 130 from the light source is a central axis, the angle? _A formed between the first region 120a and the central axis is 0 to 45 degrees, The angle? _B formed by the 1-2 region 120b with the central axis is 30 to 80 degrees and the angle? _C formed by the first to third regions 120c with the central axis is 60 degrees to 90 degrees. have.

The first 1-1 region 120a, the 1-2 region 120b, and the 1-3 region 120c may have a curvature without being flat. As described above, the curvatures of the regions may be different from each other The curvature of each region may have a positive curvature or may have a negative curvature, and the curvature of the first-first region 120a, the first-second region 120b, and the first- Can be difficult to distinguish in FIG. 2B and the like.

For example, as shown in FIG. 2B, the first-first region 120a, the first-second region 120b, and the first-third region 120c both have a positive curvature, All of which can have a negative curvature. 2E, the first-first region 120a and the first-third region 120c have a positive curvature, the first-second region 120b has a negative curvature, or the first- The first-first region 120a and the first-third region 120c may have a negative curvature and the first-second region 120b may have a positive curvature as shown in FIG.

FIGS. 3A and 3B are perspective views and side sectional views of the lens, and as shown, the lens 100 may have a top-center depressed shape.

In FIG. 3B, the lens may be provided with two supports. However, as shown in FIG. 3C, the lens may be provided with three supports or four or more supports. In FIG. 3C, the three supports are arranged in the form of a triangle. However, the number and arrangement of the supports may have various shapes, and the width, thickness, height, and the like of some of the supports may be formed differently. Do not.

4A and 4B are views showing a light path of a light emitting device package.

In FIG. 4A, the light emitting device package 200a and the lens 100a according to the embodiment shown in FIGS. 5A to 5C are described, but the present invention can be applied to other embodiments.

The light emitted from the light emitting device package 200a, which is a light source, is incident on a first region, which is an incident surface of the lens 100a. The first region is a region between the 1-1 region facing the center of the light source, And the 1-2 zone between the 1-1 zone and the 1-3 zone.

In FIG. 4A, light (L ₁ ) passing through the 1-1 zone, light (L ₂ ) passing through the 1-2 zone and light (L ₃ ) passing through the 1-3 zone are shown, The light L ₁ passing through the 1-1 zone may be different from the light L ₂ passing through the 1-2 zone and the light L ₃ passing through the 1-3 zone may be different from each other.

In FIG. 4B, the light L ₁ emitted from the light source and passing through the 1-1 region is refracted in the direction of the central axis, and the light L ₁ passing through the 1-1 region forms an angle (θ _a) it may make up the central axis after refraction angle (θ _a1) is smaller than where the "center axis" is as described above in Fig. 2c.

The light L ₂ emitted from the light source and passing through the first-second region is refracted in the direction of the central axis, and the light L ₂ passing through the first-second region forms an angle? _the angle? _b1 between the center axis and the center axis after refraction may be smaller.

The light L ₃ emitted from the light source and passing through the first to third regions is also refracted in the direction of the central axis and the light L ₃ passing through the first to _third regions forms an angle? _the angle? _c1 with the central axis after refraction may be smaller.

When a change in the angle of the light L ₁ , L ₂ , L ₃ with respect to the central axis before and after refraction is defined as a refraction angle, the refraction angle is the angle at which the light passing through the first- And the light passing through the first to third regions may be the smallest.

Of the lights (L ₁ , L ₂ , L ₃ ) refracted in the first region and traveling to the second region, the angle (? _C ) between the light (L ₁ ) Can be the smallest. The angle (? _C1 ) between the light (L ₃ ) passing through the first to _third regions and the central axis among the light (L ₁ , L ₂ , L ₃ ) refracted in the first region and traveling to the second region, Can be the largest.

5A to 5C are views showing a first embodiment of a light emitting device package.

5A, the first lead frame 210 and the second lead frame 210 are electrically separated from each other by the insulating member 220, the light emitting device 250a is bonded to the wires 240, The side wall 230 is disposed around the light emitting device 250 and the light emitting device 250 is spaced apart from the light emitting device 250. The molding part 270 may be formed, and the lens will be described later in Fig. 5C.

The side wall 230 and the insulating member 220 may form a package body, and may be formed of a silicon material, a synthetic resin material, or a metal material. The first lead frame 210 and the second lead frame 210 may reflect light emitted from the light emitting device 250a to increase light efficiency and may discharge heat generated from the light emitting device 250a to the outside. A separate reflective member (not shown) may be disposed on the first and second lead frames 210 and 210 to reflect the light emitted from the light emitting device 250a. However, the present invention is not limited thereto.

The molding part 270 may surround and protect the light emitting device 250a and a phosphor may be included in the molding part 270 to change the wavelength of light emitted from the light emitting device 250a .

5A, a region where light is emitted from the light emitting device package 200a may be a cavity defined by the first lead frame 210 and the second lead frame 210 and the side wall 230, The width (a) at the center can be, for example, from 1.9 mm to 2.3 mm. The width at the entrance of the cavity is not limited thereto and may have a different value depending on the size of the light emitting device package or the lens.

Fig. 5B shows the light emitting device of Fig. 5A.

The light emitting device 250a is a horizontal light emitting device and includes a substrate 251, a buffer layer 252 disposed on the substrate 251, a first conductive semiconductor layer 253a, an active layer 253b, The light emitting structure 253 including the first conductivity type semiconductor layer 253a and the second conductivity type semiconductor layer 253c on the light emitting structure 253 and the light transmitting structure 253 on the light emitting structure 253, And a first electrode 257 and a second electrode 258, respectively. The buffer layer 252 may be disposed between the substrate 251 and the light emitting structure 253 as shown in FIG. 5B, but is not limited thereto.

The substrate 251 may be formed of a material suitable for semiconductor material growth or a carrier wafer, may be formed of a material having excellent thermal conductivity, and may include a conductive substrate or an insulating substrate. For example, at least one of sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, Si, GaAs, GaN, ZnO, GaP, InP, Ge and Ga ₂ O ₃ can be used.

When the substrate 251 is formed of sapphire or the like and the light emitting structure 253 including GaN or AlGaN is disposed on the substrate 251, lattice mismatch between GaN and AlGaN and sapphire is very large Since the difference in thermal expansion coefficient between them is also very large, dislocations, melt-backs, cracks, pits, and surface morphology defects that deteriorate the crystallinity may occur The buffer layer 252 can be formed of AlN or the like.

The first conductive semiconductor layer 253a may be disposed on the substrate 251 and may be formed of a compound semiconductor such as a group III-V or II-VI group. The first conductive semiconductor layer 253a may be doped with a first conductive dopant, Semiconductor layer. The first conductive semiconductor layer 253a may be a semiconductor material having a composition formula of Al _x In _y Ga _(1-xy) N (0? X? 1, 0? _Y? 1, 0? _X + y? , GaN, InAlGaN, AlGaAs, GaP, GaAs, GaAsP, and AlGaInP.

When the first conductivity type semiconductor layer 253a is an n-type semiconductor layer, the first conductivity type dopant may include n-type dopants such as Si, Ge, Sn, Se, and Te. The first conductive semiconductor layer 253a may be formed as a single layer or a multilayer, but is not limited thereto.

The active layer 253b may be disposed on the upper surface of the first conductivity type semiconductor layer 253a and may have a structure such as a double well structure, a multi-well structure, a single quantum well structure, a multi quantum well (MQW) ) Structure, a quantum dot structure, or a quantum wire structure.

InGaN / InGaN, InGaN / InGaN, InGaN / GaN, InAlGaN / GaN, GaAs (InGaAs), and the active layer 253b may be formed using a compound semiconductor material of Group III- / AlGaAs, GaP (InGaP) / AlGaP, but is not limited thereto. The well layer may be formed of a material having an energy band gap smaller than the energy band gap of the barrier layer.

The second conductivity type semiconductor layer 253c may be formed of a semiconductor compound on the active layer 253b. The second conductive semiconductor layer 253c may be formed of a compound semiconductor such as a group III-V or a group II-VI, and may be doped with a second conductive dopant. The second conductivity type semiconductor layer 253c is formed of a semiconductor material having a composition formula of In _x Al _y Ga _{1 -x- y} N (0 = x = 1, 0 = y = 1, 0 = x + y = 1) The second conductivity type semiconductor layer 253c may be formed of any one or more of AlGaN, GaN AlInN, AlGaAs, GaP, GaAs, GaAsP and AlGaInP. When the second conductivity type semiconductor layer 253c is a p-type semiconductor layer, the second conductivity type dopant may be a p-type dopant such as Mg, Zn, Ca, Sr, or Ba. The second conductivity type semiconductor layer 253c may be formed as a single layer or a multilayer, but is not limited thereto.

In this embodiment, the first conductivity type semiconductor layer 253a may be an n-type semiconductor layer, and the second conductivity type semiconductor layer 253c may be a p-type semiconductor layer. However, The second conductivity type semiconductor layer 253c may be a p-type semiconductor layer, the second conductivity type semiconductor layer 253c may be an n-type semiconductor layer, and the second conductivity type semiconductor layer 253c may have a polarity opposite to that of the second conductivity type. 3 conductivity type semiconductor layer can be formed. Accordingly, the light emitting structure can be realized by a structure such as an n-p junction structure, a p-n junction structure, an n-p-n junction structure, or a p-n-p junction structure.

Although not shown, an electron blocking layer may be disposed between the active layer 253b and the second conductive semiconductor layer 253c. The electron blocking layer may have a superlattice structure. For example, the superlattice may include AlGaN doped with a second conductive dopant, and GaN having a different composition ratio of aluminum may be formed as a layer And a plurality of these may be alternately arranged.

A part of the active layer 253b and the first conductivity type semiconductor layer 253a are mesa-etched from the second conductivity type semiconductor layer 253 in a part of the light emitting structure 253 to form a part of the first conductivity type semiconductor layer 253a The surface may be exposed.

The first electrode 257 and the second electrode 258 are disposed on the exposed surface of the first conductive type semiconductor layer 253a and the second conductive type semiconductor layer 253c, The two electrodes 258 may be formed as a single layer or a multilayer structure including at least one of aluminum (Al), titanium (Ti), chrome (Cr), nickel (Ni), copper (Cu) , Respectively, to a wire (not shown).

5C shows the light emitting device package 200a including the lens 100a. The light emitting device package 200a is inserted into the recess formed in the light incident surface under the lens 100a.

6A to 6C are views showing a second embodiment of a light emitting device package.

The light emitting device package 200b in FIG. 6A is similar to the embodiment shown in FIG. 5A, but differs in that the light emitting device 250b is arranged in a flip chip type so that the wires can be omitted, An equilibrium light emitting element can be used.

The first lead frame 210 and the second lead frame 210 are electrically separated by the insulating member 220, and the side walls 230 constitute a package body. The first lead frame and the second lead frame 210 constitute the bottom surface of the cavity, and the molding part 270 can be filled in the cavity.

In FIG. 6A, a flip chip type light emitting device in which wires are omitted, as described later, may be disposed in the light emitting device package 200b, so that the light extracting efficiency may be better. Therefore, it is possible to make the area where the light exits from the surface of the light emitting device package to be smaller, and the width (b) at the entrance of the cavity, which is a region where light is emitted as shown in the figure, can be, for example, 15 mm to 18 mm have. The width at the entrance of the cavity is not limited thereto and may have a different value depending on the size of the light emitting device package or the lens.

6B shows the light emitting device of Fig. 6A.

The first electrode pad 261 and the second electrode pad 262 are disposed on the submount 260 and the first electrode pad 261 and the second electrode pad 262 are connected to each other through the bumps 267 and 268 One electrode 257 and the second electrode 258, respectively.

6C shows a light emitting device package 200b including a lens 100b. The light emitting device package 200b is inserted into a concave portion formed on a light incident surface under the lens 100b, The size of the recess formed in the incident surface may be the same as or different from the size of the cavity in FIG. 5C.

7A to 7B are views showing a third embodiment of a light emitting device package.

The light emitting device package 200c according to the present embodiment differs from the above-described embodiments in that two lenses are disposed.

In Fig. 7A, the light emitting device package 200c is similar to the light emitting device package shown in Fig. 6A. In FIG. 7A, the horizontal light emitting device 250a shown in FIG. 5A is disposed, but a vertical light emitting device or a flip chip type light emitting device may be used, and a conic lens 290 may be disposed on the light output surface of the cavity As shown in FIG. The conic lens 290 may be referred to as a first lens and the upper lens 100c may be referred to as a second lens in order to distinguish the two lenses.

The conic lens 290 is for reducing the area of light projected by narrowing the directivity angle of the light emitted from the light emitting device package, and may be a size that can be inserted into the concave portion of the lower portion of the lens as shown in FIG. 7B. The width Wc of the conic lens 290 may be 2.1 millimeters or more and the height Hc may be 1.2 millimeters to 1.5 millimeters. If the width Wc of the conic lens 290 is less than 2.1 millimeters, the directivity angle of the entire light emitted from the light emitting device package may not be reduced. If the height Hc is less than 1.2 millimeters, And if it is larger than 1.5 mm, the concave portion of the lower portion of the lens may be formed too deep to realize the desired optical characteristics.

In Fig. 7B, the conical lens 290 is arranged on the light emitting device package 200c of Fig. 7A, and the lens 100c is arranged. The light incidence plane of the lens 100c is formed with a recess. Since the light emitting device package 200c and the conical lens 290 can be inserted, the size of the recess can be larger than that of the above embodiments.

The light emitting device package 200c according to the present embodiment has the conical lens 290 disposed under the lens 100c so that the light emitted from the light emitting device package 200c passes through the conic lens 290, So that light passing through the lens 100c can spread more widely to the left and right sides.

8A to 8C are views showing a fourth embodiment of a light emitting device package. The light emitting device may be arranged in a COB (Chip on board) type of light emitting device package according to the present embodiment.

In the light emitting device package 200d, a light emitting element 250c is disposed on a lead frame 210 that can act as a substrate, and a phosphor 280 is formed on the light emitting element 250c by a method of conformal coating And one electrode of the light emitting element 250c may be electrically connected to the lead frame 210 by the wire 240. [

The light emitting device 250c may be a vertical light emitting device as shown in FIG. 8B, and may be a vertical light emitting device or a flip chip type light emitting device.

The light emitting device 250c according to the present embodiment includes a light emitting structure including a first conductivity type semiconductor layer 253a, an active layer 253b, and a second conductivity type semiconductor layer 253c on a second electrode 265 253 are disposed, and the composition of the light emitting structure 253 is as described above.

The second electrode 265 may include at least one of a bonding layer 265c, a reflective layer 265b, and an ohmic layer 265a on a conductive supporting substrate 265d.

Since the conductive supporting substrate 265d can use a metal having excellent electrical conductivity and sufficiently generate heat generated during operation of the device, a metal having high thermal conductivity can be used. The conductive support substrate 265d may be made of a material selected from the group consisting of molybdenum (Mo), silicon (Si), tungsten (W), copper (Cu), and aluminum (Al) gold (Au), copper alloy (Cu alloy), nickel (Ni), copper-tungsten (Cu-W), carrier wafer (for example: GaN, Si, Ge, GaAs , ZnO, SiGe, SiC, SiGe, Ga 2 O _3, etc.), and the like.

In addition, the conductive supporting substrate 265d may have a mechanical strength enough to be separated into separate chips through a scribing process and a breaking process without causing warping of the entire nitride semiconductor. have.

The bonding layer 265c couples the reflective layer 265b to the conductive support substrate 265d and the reflective layer 265b may function as an adhesion layer. The bonding layer 265c is formed from a group consisting of gold (Au), tin (Sn), indium (In), aluminum (Al), silicon (Si), silver (Ag), nickel (Ni) and copper The material to be selected or an alloy thereof

The reflective layer 265b may be about 2500 Angstroms thick. The reflective layer 265b may be formed of a metal layer containing aluminum (Al), silver (Ag), nickel (Ni), platinum (Pt), rhodium (Rh), or an alloy containing Al, Ag, Pt or Rh . Aluminum, silver, or the like can effectively reflect the light generated in the active layer 253b, thereby greatly improving the light extraction efficiency of the light emitting device.

The light emitting structure 253, particularly the second conductivity type semiconductor layer 253b, has a low impurity doping concentration and may have a high contact resistance, which may result in poor ohmic characteristics. Therefore, in order to improve such ohmic characteristics, .

The ohmic layer 265a may be about 200 Angstroms thick. The ohmic layer 265a may be formed of indium tin oxide (ITO), indium zinc oxide (IZO), indium zinc oxide (IZTO), indium aluminum zinc oxide (IAZO), indium gallium zinc oxide ZnO, ZnO, IrOx, AlGaO, AlGaO, AZO, ATO, GZO, IZO, RuOx, NiO, RuOx / ITO, Ni / IrOx / Au, and Ni / IrOx / Au / ITO, Ag, Ni, Cr, Ti, Al, Rh, Pd, Ir, Sn, In, Ru, , Au, and Hf, and is not limited to such a material.

A current blocking layer 262 made of an insulating material may be disposed under the light emitting structure 253 to allow the current to flow uniformly over the entire region of the light emitting structure 253, A channel layer 264 made of a material may be formed.

The surface of the light emitting structure 253 may be patterned to improve the light extraction efficiency and the surface of the light emitting structure 253 in the region where the first electrode 257 is disposed may not have irregularities.

A passivation layer 259 may be formed on the side surface of the light emitting structure 253. The passivation layer 259 may be made of an insulating material. For example, the insulating material may be made of a non-conductive oxide or nitride, or may be composed of a silicon oxide (SiO ₂ ) layer, an oxynitride layer, or an aluminum oxide layer.

8C shows the light emitting device package 200d including the lens 100d. The light emitting device package 200d is inserted into the recess formed in the light incident surface under the lens 100d, The size of the recess formed in the incident surface may be the same as or different from the size of the recess in FIG. 5C.

9 and 10 show a display device including a light emitting device package.

The display device 400 according to the embodiment includes a bottom chassis 435, an optical sheet 420 disposed to face the bottom chassis 435, and an optical sheet 420 disposed on the bottom chassis 435, And a light emitting device package that is spaced apart from the light emitting device package.

9, a driving unit cover 440 that surrounds the driving unit 455 and the driving unit 455 may be disposed on the bottom chassis 435 of the display device 400.

The front cover 430 may include a transparent front panel (not shown) that transmits light. The front panel protects the liquid crystal panel 430a at a predetermined interval, and the light emitted from the optical sheet 420 The image displayed on the liquid crystal panel 430a can be viewed from the outside.

The bottom cover 435 may be combined with the front cover 430 to protect the optical sheet 420 and the liquid crystal panel 430a.

A driving unit 455 may be disposed on one surface of the bottom cover 435.

The driving unit 455 may include a driving control unit 455a, a main board 455b, and a power supply unit 455c. The driving control unit 455a may be a timing controller and is a driving unit for adjusting the operation timing of each driver IC of the liquid crystal panel 430a. The main board 455b includes a V-sync, H- B resolution signal, and the power supply unit 455c is a driving unit for applying power to the liquid crystal panel 430a.

The driving unit 455 may be provided on the bottom cover 435 and may be surrounded by the driving unit cover 440.

The bottom cover 435 may include a plurality of holes to connect the liquid crystal panel 430a and the driving unit 455 and a stand 460 for supporting the display device 400. [

10, a reflective sheet 435a is disposed on a surface of a bottom cover 435, a light emitting device package 200 is disposed on a reflective sheet 435a, a lens 100 is mounted on a front surface of the light emitting device package 200, .

The light emitted from the light emitting device package 200 and emitted from the lens 100 may be transmitted to the optical sheets 421 to 423 through the light transmission area 435b have.

The light having passed through the optical sheets 421 to 423 can be directed to the liquid crystal panel 430a.

10, the distance d ₁ between the reflective sheet 435a and the optical sheet 421 may be 10 to 15 mm and the height d ₂ of the light emitting device package 200 including the lens 100 may be 7 mm, and may be smaller than the distance d ₁ between the reflective sheet 435a and the optical sheet 421.

Even if the distance d ₁ between the reflective sheet 435a and the optical sheet 421 is narrowed to 15 millimeters or less because the light emitted from the light emitting device package sufficiently advances to the side by the action of the lens as described above, And the generation of dust can be prevented. Considering that the height d ₂ of the light emitting device package 200 including the lens 100 is about 7 millimeters, the distance d ₁ between the reflective sheet 435a and the optical sheet 421 is 10 millimeters The damage caused by the collision of the optical sheet 421 and the lens 100 can be prevented.

11 is a view showing the improvement of the light leakage in the light emitting device package according to the embodiment.

In FIG. 11, the horizontal axis represents the distance from the central region in one backlight unit, and the vertical axis represents the intensity of light emitted from each light source.

In the comparative examples 1 and 2 of the conventional light emitting device package, mura that occurs when light is concentrated at one place, for example, at the upper part of the lens, occurs. In the case of the light emitting device package according to the first and second embodiments, As a result, the angle of incidence is widened to the side as described above, and the generation of dust is reduced.

11, the left side corresponds to the light emitting device package in the center region in one backlight unit and the right side corresponds to the light emitting device package in the nearest side, and therefore the light amount in the central region is relatively more . The improvement of the arm portion described as " improvement " in Fig. 11 will be described with reference to Figs. 12A and 12B.

12A and 12B are diagrams illustrating the effect of improving the dark area in the backlight unit of the display device according to the embodiment, wherein the horizontal axis and the vertical axis respectively indicate positions in the backlight unit.

FIG. 12A is a diagram showing luminance in a backlight unit in which one embodiment of the light emitting device package described above is arranged in a direct-type, FIG. 12B is a diagram showing luminance in a backlight unit in which conventional light emitting device packages are arranged in a direct- to be.

In the backlight unit of FIG. 12B, the area indicated by the right vertical bar is a dark area where the light amount is relatively small and is measured in a pink color series. Using the light emitting device packages according to the above- Is lower than the conventional one.

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 will be understood 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 (18)

A lens for changing a path of light incident from a light source,
A concave portion is formed in a first region facing the light source, and a second region facing the first region is concave in the direction of the first region,
The surface of the concave portion includes a 1-1 zone region facing the center of the light source, a 1-3 zone edge zone, and a 1-2 zone between the 1-1 zone and 1-3 zone And the curvatures of the 1-1 zone, the 1-2 zone and the 1-3 zone are different from each other. The method according to claim 1,
Wherein the first-first region is disposed in the range of 0 to 45 degrees from the central axis, and the central axis is disposed in the center of the second region from the light source. The method according to claim 1,
Wherein the first-second region is disposed in the range of 30 to 80 degrees from the central axis, and the central axis is disposed at the center of the second region from the light source. The method according to claim 1,
Wherein the first to third regions are disposed in the range of 60 to 90 degrees from the central axis, and the central axis is disposed at the center of the second region from the light source. The method according to claim 1,
Wherein the first-first region, the first-second region, and the first-third region all have a positive curvature or both have a negative curvature. The method according to claim 1,
Wherein the first-first region and the first-third region have a positive curvature, and the first-second region has a negative curvature. The method according to claim 1,
The first-first region and the first-third region have a negative curvature, and the first-second region has a positive curvature. The method according to claim 1,
Wherein the ratio of the height of the lens to the height difference between the highest point and the lowest point of the second region of the lens is 1 to 0.7 or more and less than 1 to 1. A lens for changing a path of light incident from a light source,
A concave portion is formed in a first region facing the light source, and a second region facing the first region is concave in the direction of the first region,
The surface of the concave portion includes a 1-1 zone region facing the center of the light source, a 1-3 zone edge zone, and a 1-2 zone between the 1-1 zone and 1-3 zone And a refracted angle of light emitted from the light source and passing through the first-first region, the first-second region, and the first-third region is different. 10. The method of claim 9,
And the light emitted from the light source and passing through the 1-1 zone is refracted in the direction of the central axis. 10. The method of claim 9,
And the light emitted from the light source and passing through the first-second region is refracted in the direction of the central axis. 10. The method of claim 9,
And the light emitted from the light source and passing through the first to third regions is refracted in the direction of the central axis. 10. The method of claim 9,
And the refractive angle is the largest light emitted from the light source and passing through the 1-2 zone. 10. The method of claim 9,
And the angle between the light passing through the 1-1 zone and the central axis among the light refracted in the first area and proceeding to the second area is the smallest. 10. The method of claim 9,
And the angle between the light passing through the first to third regions and the central axis is the largest among the light that is refracted in the first region and proceeds to the second region. 10. The method of claim 9,
And the refractive angle is the smallest light emitted from the light source and passing through the first to third regions. A first lead frame and a second lead frame;
A light emitting element electrically connected to the first lead frame and the second lead frame;
A molding part surrounding the light emitting device; And
The light emitting device package according to any one of claims 1 to 6, wherein the light emitting device package is a light source,
And a part of the light emitting device package is inserted into the concave part of the lens. Bottom chassis;
An optical sheet disposed opposite to the bottom chassis; And
And a light emitting device package according to claim 16 disposed on the bottom chassis and spaced apart from the optical sheet,
Wherein the optical sheet and the light emitting device package are disposed at a distance of 10 millimeters to 15 millimeters.

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