KR20140057785A - Side emitting light emitting diode lens, back light unit and display device including the same - Google Patents

Abstract

The present invention relates to a side emitting LED lens capable of reducing the total volume thereof and facilitating a manufacturing process. Also, the present invention relates to a backlight unit and a display device including the LED lens. But, the different configurations of the backlight unit and the display device are easily formed by a person with common general knowledge in a technology field to which the present invention belongs. Thereby, the detailed description about the above elements is omitted in the present specification.

Description

TECHNICAL FIELD [0001] The present invention relates to a lens for a side-emitting type light emitting diode, a backlight unit having the same and a display device therefor. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

The present invention relates to a lens for a side-emitting type light emitting diode, a backlight unit having the same and a display device, and more particularly, to a lens for a side-emitting type light emitting diode which can reduce the overall volume but is easy to manufacture, A backlight unit (BLU) and a display device.

2. Description of the Related Art Generally, a liquid crystal display (LCD) is provided in a display device used for a computer monitor or a TV. However, such a liquid crystal display device requires a separate light source because it can not emit light by itself .

As a light source for a liquid crystal display device, a plurality of fluorescent lamps such as CCFL (Cold Cathode Fluorescent Lamp) and EEFL (External Electrode Fluorescent Lamp) are used, or a plurality of light emitting diodes (LED) Such a light source is provided in a backlight unit (BLU) together with a light guide plate, a plurality of optical sheets, and a reflection plate.

In recent years, light emitting diodes among these light sources have been attracting attention as a next generation light source because they have low power consumption, good durability, and low manufacturing cost. However, when a light emitting diode is used as a light source, light tends to concentrate and diverge into a narrow area. In order to apply this to a surface light source such as a display device, it is necessary to distribute light evenly over a wide area.

In recent years, studies on a lens for a light-emitting diode that performs such a function have been actively carried out, and as a representative prior art, US Patent No. 6679621 (hereinafter referred to as "Prior Art 1") describes a "SIDE EMITTING LED LENS Korean Patent No. 10-0651550 (hereinafter referred to as " Prior Art 2 ") discloses a lens for an LED light source composed of upper, middle, and lower portions that overcomes the problems of the prior art 1 . However, there is a problem that the prior arts 1 and 2 are not easy to manufacture.

As another prior art, Korean Patent No. 10-0688767 (hereinafter referred to as "Prior Art 3") discloses a "LED for a light source of LED". The prior art 3 has a problem that the manufacturing is easy, have.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide a side emission type light emitting diode lens which can reduce the overall volume but is easy to manufacture and a back light unit (BLU) and a display device.

According to an aspect of the present invention, there is provided a side-emitting type light emitting diode lens for emitting light emitted from a light emitting diode (LED) to a side surface, wherein the light emitted from the light emitting diode is incident Bottom; An upper surface reflecting light directly incident on the bottom surface; And a side surface connecting the bottom surface and the top surface, wherein the side surface is connected to the top surface and has an emission surface through which light reflected from the top surface emits, and a light incident surface that is connected to the bottom surface and the emission surface, And a lower reflection surface for reflecting light directly incident on the side surface to the upper surface, wherein the upper surface reflects the light reflected by the lower reflection surface to the emission surface.

According to another aspect of the present invention, there is provided a side emitting type light emitting diode lens for emitting light emitted from a light emitting diode (LED) to a side surface, A base on which light is incident; A top surface that is symmetrical with respect to an optical axis of the light emitting diode and reflects light in a center region diverging from the light emitting diode within a predetermined angle range with reference to an optical axis of the light emitting diode; And a side surface connecting the bottom surface and the top surface, wherein the side surface is connected to the top surface and has an emitting surface for emitting light reflected from the top surface, and a light emitting diode connected to the bottom surface and the emitting surface, And a lower reflecting surface for reflecting the light of the peripheral region diverging to the region outside the central region to the upper surface, wherein the upper surface reflects the light reflected by the lower reflecting surface to the emitting surface .

Meanwhile, a backlight unit according to the present invention is a backlight unit (BLU) using a light emitting diode (LED) as a light source, and a lens having the above- .

In addition, a display device according to the present invention is a display device using a light emitting diode (LED) as a light source, in which a lens having the above-described configuration is provided on the light emitting diode .

According to the lens for a side-emitting type LED according to the present invention, it is possible to reduce the volume of the entire body and to manufacture the lens at the time of injection molding, thereby reducing the material cost and simplifying the manufacturing process .

1 is a vertical sectional view showing a lens for a side-emitting light emitting diode according to the present invention,
2 to 5 are views for explaining the effect of the lens according to the present invention,
FIGS. 6 to 8 are views for explaining embodiments of the upper surface,
9 to 11 are views for explaining embodiments of the lower reflection surface,
12 is a partially enlarged view of an enlarged step,
Figs. 13 and 14 are diagrams for explaining embodiments of a step portion,
15 and 16 are schematic plan views of a lens according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims.

In the accompanying drawings, the thickness and the size are exaggerated for clarity of description and the present invention is not limited by the relative size or thickness shown in the attached drawings.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a lens for a side-emitting type light emitting diode which is easy to manufacture while reducing the overall volume. The present invention also relates to a backlight unit (BLU) including a lens for a light emitting diode and a display device. However, other configurations of the backlight unit and the display device except the lens for a light emitting diode according to the present invention can be easily carried out by those having ordinary skill in the art to which the present invention belongs. Therefore, It is omitted.

1 is a vertical cross-sectional view illustrating a lens for a side-emitting light emitting diode according to the present invention.

1, a lens 10 for a light emitting diode (LED) according to the present invention is incident on a bottom surface 20 and a bottom surface 20 on which light emitted from the LED 11 is incident, And includes a top surface 30 for reflecting light L1 incident directly on one side and a side surface 40 connecting the bottom surface 20 and the top surface 30. [

The side surface 40 is connected to the top surface 30 and has an emission surface 41 through which the light L2 reflected from the top surface 30 is emitted and a bottom surface 20 connected to the bottom surface 20 and the emission surface 41, And a lower reflecting surface 42 for reflecting the light L3 directly incident on the side surface 40 to the upper surface 20. The upper surface 30 includes not only direct incident light L1, And reflects the light L4 reflected by the slope 42 to the exit surface 41. [

The groove 21 may be a space for accommodating the LED 11 and the light emitted from the LED 11 may be provided on the bottom surface 20, And the shape may be various shapes such as a spherical surface and an aspherical surface, and the present invention is not limited thereto.

The upper surface 30 and the lower reflecting surface 42 may be provided to reflect light incident directly using a coating or a separate member, but it is preferably optically designed to totally reflect the incident light. A detailed description thereof will be described later.

The upper surface 30 is configured to reflect light in a central region that is symmetrical to the optical axis 12 of the LED 11 and diverges within a predetermined angle range with reference to the optical axis 12 among the light emitted from the LED 11, The lower reflecting surface 42 reflects the light of the peripheral region diverging from the central region of the light emitted from the LED 11 to the upper surface 30. Therefore, in the lens 10 according to the present invention, almost all the light emitted from the LED 11 is reflected or totally reflected by the upper surface 30 or the lower reflection surface 42 and is emitted to the emission surface 41 of the side surface 40 .

The lens 10 according to the present invention may further include a leg 50 extending downward from a connection portion between the lower reflection surface 42 and the emission surface 41 to support the lens 10.

The lower reflecting surface 42 may be curved downwardly and the emitting surface 41 may include a first emitting surface 43 connected to the upper surface 30 and extending downwardly, And a step 44 connecting the lower reflection surface 43 and the lower reflection surface 42 and stepping inward. Then, the volume is reduced by the lower reflecting surface 42 and the stepped portion 44, so that the material cost can be reduced.

The light-emitting diode lens is a transparent material having excellent transmittance such as glass, acrylic resin, polymethylmethacrylate (PMMA), polycarbonate (PC), and polyethyleneterephthalate (PET) When the lens is manufactured by injection molding, the lens 10 according to the present invention is advantageous in that the lens 10 according to the present invention can reduce the volume as compared with the prior art, thereby reducing the material cost and facilitating the manufacture .

Hereinafter, effects of the lens according to the present invention will be described in detail with reference to the drawings.

FIGS. 2 to 5 are views for explaining the effect of the lens according to the present invention. FIG. 2 is a view schematically showing a state in which the prior art 1 is manufactured by injection molding, and FIG. 3 is a cross- Fig. 4 is a view showing a prior art 3, and Fig. 5 is a view schematically showing a state in which a lens according to the present invention is manufactured by injection molding.

2, when the lens 1 according to the prior art 1 (US 6679621) is manufactured by injection molding, the upper mold 51 and the lower mold 51, which are separated into upper and lower parts, respectively, 52, as well as a sliding die 53 which slides laterally after injection molding. This is because of the shape of the first refracting surface 2 in which the lens 1 according to the prior art 1 is tilted inward to the side and the shape of the second refracting surface 3 extending downward in the outwardly convex shape. If the sliding mold 53 is required when the lens is formed by injection molding, the manufacturing cost becomes complicated as well as the additional cost for manufacturing the mold, which is not preferable.

3, in the case of the lens 4 according to the prior art 2 (Korean Patent No. 10-0651550) which has solved the problem according to the prior art 1, A sliding die 53 is required for molding.

As shown in FIG. 4, the lens 6 according to the prior art 3 (Korean Patent No. 10-0688767) is disclosed as another embodiment of the side-emitting type LED lens. In the case of the lens 6, unlike the prior arts 1 and 2, since the side surface is parallel to the optical axis of the LED, there is an advantage in that it is possible to fabricate only the upper and lower molds without using a sliding mold during injection molding. However, Almost all light must be incident on the upper surface so as not to be incident on the side surface and all the light incident on the upper surface must be reflected to the side surface.

5, the lens 10 according to the present invention can be injection-molded even if only the upper and lower molds 51 and 52 are used, unlike the prior arts 1 and 2. This is possible because the shape of the side surface 40 of the lens 10 according to the present invention, for example, the shape of the lower reflecting surface 42 is curved downward.

The lens 10 according to the present invention differs from the prior art 3 in that the shape of the side surface 40 is, for example, a shape in which the shape of the step 44 and the lower reflecting surface 42 is inclined substantially inward The volume can be reduced.

In the lens 10 according to the present invention, the light in the central region of the light emitted from the LED 11 is reflected by the upper surface 30 to be emitted to the side surface 40, So that all the light emitted from the LED 11 is emitted directly to the upper surface 30, unlike the prior art 3, and then reflected by the upper surface 30, The total volume can be further reduced since it is not necessary to reflect the incident light.

As described above, the lens 10 according to the present invention is advantageous in that the overall volume can be reduced as compared with the prior arts, but it is easy to manufacture. Hereinafter, the configuration of the lens according to the present invention will be described in detail.

The upper surface 30 is preferably optically designed to totally reflect incident light. Embodiments of such a top surface 30 will now be described in detail with reference to the drawings.

6 is a view for explaining an embodiment of the upper surface.

6, when an intersection point between the optical axis 12 of the LED 11 and the LED 11 is defined as a first reference point P1, an arbitrary point P on the top surface 30 and a first reference point P1 ) of any point (P) and the distance to R _1, increment of the α ₁ of the first reference point (P1) on a connection line and the optical axis 12, the angle forming α _1, the upper surface (30 a) Δα _1, any point on the R ₁ increment (decrease or increase) the ΔR _1, the upper surface (30) an arbitrary point (P) normal (13) and the straight line that is, the upper surface 30 of the on of about Δα ₁ (P) and second if the refractive index of the material of the first reference point (P1) is β _1, lenses 10 each forming a straight line connecting the a n, the upper surface 30 is _{ΔR 1 / (R 1 Δα 1} )> 1 / √ (n ² -1) condition.

Figs. 7 and 8 are views for explaining another embodiment of the upper surface. Fig.

Unlike the embodiment described in Fig. 6, the optical condition of the top surface 30 according to Figs. 7 and 8 is a condition applicable when the light source of the LED 11 is considered as a surface light source other than a point light source. In fact, since the lens 10 does not have a much larger volume than the LED 11, it is preferable to consider the light source of the LED 11 as a surface light source in designing the lens 10.

7, when the light source of the LED 11 is considered as a surface light source other than the point light source, not only the light emitted from the center point of the LED 11, that is, the first reference point P1, The light emitted from the points P2 and P3 must be taken into consideration and the light emitted from the end point P2 of the LED 11 on the same side as the arbitrary point P on the basis of the optical axis 12, The angle? ₁ formed by the light L5 incident on the point P with the normal line 13 at the arbitrary point P diverges from the first reference point P1 and the other endpoint P3, Is smaller than the case. Therefore, if the upper surface 30 is provided to totally reflect incident light L5 emitted from the end point P2 of the same LED 11, even if the light source of the LED 11 is considered as a surface light source, 11 so that almost all the light incident on the upper surface 30 can be totally reflected.

8, the end point P2 of the LED 11 on the same side as the arbitrary point P on the upper surface 30 is referred to as the second reference point P2 with respect to the optical axis 12, The angle formed by the straight line connecting the arbitrary point P and the second reference point P2 on the upper surface 30 with the reference axis 15 is α ₂ and an arbitrary point P on the upper surface 30, and second if the index of refraction of material 2, the distance of the reference point (P2), R _2, forms a ΔR _2, lens 10, the increment of R ₂ for the increment of the α ₂ in Δα _2, Δα ₂ to n, the upper surface ( 30) can be configured to satisfy the condition of? R ₂ / (R ₂ ?? ₂ )> 1 /? (N ² -1).

Like the upper surface 30, the lower reflecting surface 42 is preferably optically designed to totally reflect incident light. Hereinafter, embodiments of such a lower reflecting surface 42 will be described in detail with reference to the drawings.

9 is a view for explaining an embodiment of the lower reflecting surface. 9, when an intersection point of the optical axis 12 and the LED 11 is defined as a first reference point P1, a point P on the lower reflection surface 42 is connected to a first reference point P1 of the distance of the straight line and the optical axis 12 and an arbitrary point (P) and the first reference point (P1) on a horizontal axis (16) forms a vertical angle α _3, the lower reflecting surface (42) R _3, wherein α ₃ If the increment of R ₃ for Δα ₃ and Δα ₃ is ΔR ₃ and the refractive index of the material of the lens 10 is n, the lower reflecting surface 42 is ΔR ₃ / (R ₃ Δα ₃ )> 1 / (N ² -1) condition.

10 and 11 are views for explaining another embodiment of the lower reflecting surface.

Unlike the embodiment described in Fig. 9, the optical condition of the lower reflecting surface 42 according to Figs. 10 and 11 is a condition applicable when the light source of the LED 11 is considered as a surface light source other than a point light source.

10, when the light source of the LED 11 is considered as a surface light source other than a point light source, not only the light emitted from the center point of the LED 11, that is, the first reference point P1, It is necessary to consider the light diverging from the points P 2 and P 3 and in this case, it is necessary to consider the point P on the lower reflection surface 42 with respect to the optical axis 12 and the divergence from the end point P 3 of the LED 11 on the other side The angle? ₂ formed by the light L6 entering the arbitrary point P with the normal line 14 at the arbitrary point P is the same as the first reference point P1 ) Is smaller than that in the case where the incident light is incident. Therefore, even if the light source of the LED 11 is considered as a surface light source, the lower reflection surface 42 may be formed by totally reflecting the incident light L6 diverging from the end point P3 of the other side LED 11. [ Can totally reflect almost all the light that is emitted from the LED 11 and is incident on the lower reflection surface 42.

11, an arbitrary point P on the lower reflecting surface 42 and an end point P3 of the LED 11 on the opposite side to the optical axis 12 are defined as a third reference point The angle formed between the straight line connecting the arbitrary point P on the lower reflection surface 42 and the third reference point P3 and the horizontal axis 16 perpendicular to the optical axis 12 is? ₄ , an arbitrary point (P) and the distance to R _4, the increment of R ₄ to an increment of the α ₄ in Δα _4, Δα ₄ ΔR _4, the lens 10 of the third reference point (P3) on the reflecting surface 42 The lower reflecting surface 42 can be configured to satisfy the condition of? R ₄ / (R ₄ ?? ₄ )> 1 /? (N ² -1).

12 is a partially enlarged view of an enlarged step.

12, the stepped portion 44 includes a plurality of discontinuous second emission surfaces 45 for emitting the light reflected from the upper surface 30 and a connection surface 46 for connecting the second emission surface 45 ). ≪ / RTI >

It is preferable that the second emitting surface 45 is formed in parallel with or inclined inward with the optical axis 12 of the LED 11. Then, the lens 10 can be manufactured by injection molding only with the upper and lower molds 51 and 52, and the manufacturing process can be simplified.

The connection surface 46 is preferably parallel to the path of the chief ray of the light L2 reflected from the top surface 30. Almost all of the light L2 reflected from the upper surface 30 can be incident on the second exit surface 45 and emitted therefrom so that it is easy to control the exit angle of the light L2, It is possible to reduce the optical loss caused by incidence on the surface 46. Here, the path of the chief ray is a path through which the center light passes in the path of the light rays 12 reflected from a certain point on the upper surface 30.

Figs. 13 and 14 are views for explaining embodiments of a step portion.

13, the starting end 47 of the stepped portion 44, which is the contact point between the lower reflecting surface 42 and the stepped portion 44, and the connecting surface 46 located at the uppermost one of the plurality of connecting surfaces 46, The angle? ₃ formed by the hypothetical connecting line 17 connecting the upper end 48 of the LED 46 with the hypothetical reference axis 15 parallel to the optical axis 12 of the LED 11, Of the light L7 emitted from the first reference point P1 at the intersection of the optical axis 12 and the optical axis 12 and entering the start end 47 as the upper end of the lower reflection surface 42 with the reference axis 15 ₄ and the upper end of each second exit surface 45 or the upper end of the connecting surface 46 is preferably located outside the connecting line 17 with respect to the reference axis 15. [ Thus, light emitted directly from the light emitted from the LED 11 is not incident on the step portion 44, and accordingly, light loss caused by direct incidence and emission of the light into the stepped portion 44 can be reduced.

Unlike the embodiment described in Fig. 13, the condition of the step 44 according to Fig. 14 is a condition applicable when the light source of the LED 11 is considered as a surface light source other than a point light source. That is, when the light source of the LED 11 is considered as a surface light source other than the point light source, not only the light emitted from the first reference point P1, which is the center point of the LED 11, but also the light emitted from both ends P2 and P3 of the LED 11 In this case, the light L8 emitted from the end point P3 of the LED 11 on the opposite side of the start end 47 and entering the start end 47 intersects with the reference axis 15 The angle? ₆ corresponds to an angle? ₄ formed by the light emitted from the first reference point P1 and incident on the start end 47 with respect to the optical axis 12 and the start point 47 with respect to the optical axis 12, Is larger than an angle? ₅ formed by the light emitted from the end point P2 of the LED 11 on the same side and incident on the start end 47 with the reference axis 15. The angle? ₃ formed by the imaginary connecting line 17 with the reference axis 15 is set such that the end point P3 of the LED 11 on the opposite side to the starting end 47 on the optical axis 12 The light L8 emitted from the third reference point P3 and incident on the start end 47 is larger than the angle? ₆ formed by the reference axis 15 with respect to the reference point P3, If the upper end of the second emitting surface 45 or the upper end of the connecting surface 46 is located outside the connection line 17 with respect to the reference axis 15 and the light source of the LED 11 is considered as a surface light source There is no light directly incident on the step section 44 and emitted therefrom, thereby reducing the light loss caused by direct incidence and emission of the light into the step section 44. [

15 and 16 are schematic plan views of a lens according to an embodiment of the present invention.

15 and 16, the lens 10 according to an embodiment of the present invention may have a substantially circular shape in a horizontal section, and the legs 50 may be formed in a shape of a circle extending from the LED 11 And may be provided at a predetermined distance in a plurality of intervals at predetermined angles. Alternatively, as shown in FIG. 16, the LEDs 11 may be provided at a predetermined distance continuously, that is, in a substantially circular band shape.

The light emitted from the LED 11 and incident on the leg 50 in the direction of the leg 50 is transmitted to the lower half The light is reflected or totally reflected by the inclined surface 42 and is incident on the upper surface 30, so that light loss due to the light incident on the leg 50 can be remarkably reduced.

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. Accordingly, the present invention is not limited to the embodiments disclosed herein, and all changes which can be made by those skilled in the art are also within the scope of the present invention.

10: lens 11: light emitting diode
12: optical axis 20: bottom surface
30: upper surface 40: side surface
41: exit surface 42: lower reflecting surface
43: first emitting surface 44: stepped portion
45: second emitting surface 46: connecting surface

Claims (16)

A side-emitting type light emitting diode lens for emitting light emitted from a light emitting diode (LED) to a side surface,
A bottom surface on which light emitted from the light emitting diode is incident;
An upper surface reflecting light directly incident on the bottom surface; And
And a side surface connecting the bottom surface and the top surface,
The side surface being connected to the top surface and emitting light reflected from the top surface, and a bottom half connected to the bottom surface and the outgoing surface to reflect light incident on the bottom surface and directly incident on the side surface to the top surface, Including slopes,
Wherein the upper surface reflects the light reflected by the lower reflection surface to the emission surface. The method according to claim 1,
Wherein an angle formed by a straight line connecting an arbitrary point on the upper surface with the first reference point (P1) and the optical axis is defined as α ₁ , the arbitrary point and the refractive index of the first reference point (P1) the increment of R ₁ for the increment of the α ₁ on Δα _1, Δα ₁ ΔR _1, the R _1, the distance constituting the lens material on the upper surface of n In this case,
Wherein the upper surface is configured to satisfy a condition of? R ₁ / (R ₁ ?? ₁ )> 1 /? (N ² -1). The method according to claim 1,
When an end point of the light emitting diode on the same side as an arbitrary point on the upper surface is defined as a second reference point (P2) with respect to an optical axis of the light emitting diode, an arbitrary point on the upper surface and the second reference point And a virtual reference axis parallel to the optical axis is α ₂ , a distance between an arbitrary point on the upper surface and the second reference point is R ₂ , an increment of α ₂ is Δα ₂ , Δα ₂ an increment of R ₂ for ΔR _2, assuming that the refractive index of the material of the lens to n,
Wherein the upper surface is configured to satisfy a condition of? R ₂ / (R ₂ ?? ₂ )> 1 /? (N ² -1). The method according to claim 1,
Wherein a straight line connecting an arbitrary point on the lower reflecting surface with the first reference point (P1) and a horizontal axis perpendicular to the optical axis (P1) are defined as a first reference point (P1) at an intersection of the optical axis of the light emitting diode for the angle α _3, the R ₃ increments of the increment of the α ₃ to Δα _3, Δα ₃ ΔR _3, the distance of any point from the first reference point (P1) on the lower reflecting surface R _3, wherein Assuming that the refractive index of the material forming the lens is n,
Wherein the lower reflecting surface is configured to satisfy a condition of? R ₃ / (R ₃ ?? ₃ )> 1 /? (N ² -1). The method according to claim 1,
And an end point of the light emitting diode on a side opposite to an arbitrary point on the lower reflection surface with respect to an optical axis of the light emitting diode is a third reference point (P3), an arbitrary point on the lower reflection surface and a third reference point the angle P3) straight line and the optical axis normal to the horizontal axis connecting the forms α _4, the arbitrary point on the lower reflecting surface and the third increment of the distance between the reference point (P3) R _4, wherein α ₄ Δα ₄ , the increment of R ₄ to Δα ₄ ΔR _4, assuming that the refractive index of the material of the lens to n,
Wherein the lower reflecting surface is configured to satisfy a condition of? R ₄ / (R ₄ ?? ₄ )> 1 /? (N ² -1). The method according to claim 1,
Wherein the lower reflection surface has a downward curved shape. The method according to claim 1,
Wherein the emitting surface comprises a first emitting surface connected to the top surface and extending downwardly and a stepped portion connected to the first emitting surface and the bottom reflecting surface and stepped inward, lens. 8. The method of claim 7,
Wherein the step portion includes a plurality of discontinuous second emitting surfaces for emitting the light reflected from the upper surface and a connecting surface connecting the second emitting surface. 9. The method of claim 8,
Wherein the second emitting surface has a shape that is parallel to or inwardly inclined with respect to an optical axis of the light emitting diode. 9. The method of claim 8,
Wherein the connection surface is parallel to a path of a chief ray of light reflected from the upper surface. 9. The method of claim 8,
And a virtual connecting line connecting the starting end of the stepped portion, which is the contact between the lower reflecting surface and the step portion, and the upper end of the connecting surface located at the uppermost one of the plurality of connecting surfaces with an imaginary reference axis parallel to the optical axis of the light emitting diode The angle? ₃ is the angle at which the light emitted from the first reference point P1 and incident on the starting end, which is the upper end of the lower reflecting surface, when the intersection of the light emitting diode and the optical axis is defined as the first reference point P1 Is larger than an angle (? ₄ ) formed with the reference axis,
Wherein an upper end of each of the second emitting surfaces is located outside the connecting line with respect to the reference axis. 9. The method of claim 8,
And a virtual connecting line connecting the starting end of the stepped portion, which is the contact between the lower reflecting surface and the step portion, and the upper end of the connecting surface located at the uppermost one of the plurality of connecting surfaces with an imaginary reference axis parallel to the optical axis of the light emitting diode The angle? ₃ is an angle of incidence at the third reference point P3 when the end point of the light emitting diode on the side opposite to the start end is the third reference point P3, Is larger than an angle (? ₆ ) formed between the reference axis
Wherein an upper end of each of the second emitting surfaces is located outside the connecting line with respect to the reference axis. The method according to claim 1,
Wherein the lens further comprises a leg extending downward from a connection portion between the lower reflection surface and the emission surface and supporting the lens. A side-emitting type light emitting diode lens for emitting light emitted from a light emitting diode (LED) to a side surface,
A bottom surface on which light emitted from the light emitting diode is incident;
A top surface that is symmetrical with respect to an optical axis of the light emitting diode and reflects light in a center region diverging from the light emitting diode within a predetermined angle range with reference to an optical axis of the light emitting diode; And
And a side surface connecting the bottom surface and the top surface,
The side surface being connected to the upper surface to emit light reflected from the upper surface, and a light source for emitting light in a peripheral region, which is connected to the bottom surface and the emission surface and emits light from the light emitting diode, And a lower reflecting surface for reflecting the light toward the upper surface,
Wherein the upper surface reflects the light reflected by the lower reflection surface to the emission surface. In a backlight unit (BLU) using a light emitting diode (LED) as a light source,
The backlight unit according to any one of claims 1 to 14, further comprising a lens for a light emitting diode on the light emitting diode. A display device using a light emitting diode (LED) as a light source,
And a light emitting diode lens according to any one of claims 1 to 14 is provided on the light emitting diode.

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