Reflective diffusion lens and light emitting module including the same

Abstract

According to an embodiment, a reflective diffusion lens is provided, which controls light emitted from a light emitting element. The reflective diffusion lens is a reflective diffusion lens that controls light emitted from a light emitting element, and may include: a light incident portion, which is formed concavely toward the upper side and has an incident surface, and the light emitted from the light emitting element is incident on the incident surface; a light emitting portion, which has an exit surface that emits the light incident on the incident surface; a reflection portion, which is arranged on the upper side of the light incident portion and is formed concavely toward the lower side and has a reflection surface, and a part of the light emitted from the light incident portion is reflected on the reflection surface; and a re-reflection portion, which is formed on the outer side of the light incident portion in the radial direction, is located on the lower surface of the lens connecting the light incident portion and the light exit portion, and has a re-reflection surface, and another part of the light emitted from the incident surface is reflected on the re-reflection surface.

Description

Technical Field

[0001] The present disclosure relates to a reflective diffusion lens and a light emitting module including the reflective diffusion lens. More particularly, the present disclosure relates to a reflective diffusion lens that is disposed on an LED panel to control a path of emitted light. Background Art

[0002] Typically, a plurality of light emitting modules are arranged in a backlight unit used by a liquid crystal display (LCD). The light emitting module includes a light emitting element and a diffusion lens, wherein the light emitting element may use, for example, a light emitting diode (hereinafter referred to as LED). In recent years, LEDs have been widely used as light sources due to their small size and low power consumption. Since the straightness of light emitted from an LED is relatively high, a diffusion lens is used to disperse and emit the light emitted from an optical element at a wide angle. A plurality of light emitting modules can irradiate light to a large area of ​​the backlight unit through the diffusion lens.

[0003] The types of diffusion lenses include refractive diffusion lenses and reflective diffusion lenses. The refractive diffusion lens basically has a structure in which the light is refracted by forming the light exiting surface of the lens into a curved surface.

[0004] Korean Patent Publication No. KR10-2015-0024125 discloses a refractive diffusion lens including a lower surface formed with a concave portion and an upper surface having a concave surface close to a central axis and a convex surface connected to the concave surface. However, since the portion capable of reflecting light is not sufficiently provided in the corresponding diffusion lens, there is a problem that it is difficult to achieve a sufficient degree of light diffusion.

[0005] A reflective diffusion lens has been developed to disperse light emitted from a light emitting element at a larger angle. When the reflective diffusion lens is used, light can be uniformly irradiated over a large area of ​​the backlight unit, and the number of light emitting elements used can be reduced.

[0006] However, a higher degree of light diffusion is still required, and there is a problem that the brightness of the backlight unit is uneven due to brightness mura on the emission surface, thereby reducing the display quality of the LCD. If the number of LED light emitting elements is increased to prevent such mura, there is a problem of increased cost and power consumption. Summary of the invention

[0007] Technical issues

[0008] The various embodiments of the present disclosure are intended to improve the diffusion of light by increasing the amount of reflection of the reflected light inside the lens. In addition, an object of the present disclosure is to provide a diffusion lens and a light emitting module including the diffusion lens, which minimizes the occurrence of brightness moire and evenly distributes light.

[0009] Technical Solution

[0010] According to an embodiment of the present disclosure, a reflective diffusion lens is a reflective diffusion lens that controls light emitted from a light emitting element, and the reflective diffusion lens may include: a light incident portion, which is formed concavely toward the upper side and has an incident surface, and the light emitted from the light emitting element is incident on the incident surface; a light emitting portion, which has an exit surface that emits the light incident on the incident surface; a reflecting portion, which is arranged on the upper side of the light incident portion and is formed concavely toward the lower side and has a reflecting surface, and a part of the light emitted from the light incident portion is reflected by the reflecting surface; and a re-reflecting portion, which is formed on the outer side of the light incident portion in the radial direction, is located on the lower surface of the lens connecting the light incident portion and the light exit portion, and has a re-reflecting surface, and another part of the light emitted from the incident surface is reflected by the re-reflecting surface.

[0011] According to an embodiment, the incident surface may include an upper surface and a side surface formed around an edge of the upper surface, and the upper surface may include a conical surface in a conical shape and a circumferential surface surrounding the conical surface.

[0012] According to an embodiment, the peripheral surface may have a downwardly convex shape and include an edge surface formed to be inclined toward a center of the peripheral surface.

[0013] According to embodiments, a micro pattern having an irregular concavo-convex shape may be formed on the upper surface.

[0014] According to an embodiment, the side surface may be configured as a concave surface in which a diameter of a lower side in a height direction of the lens is larger than a diameter of an upper side.

[0015] According to an embodiment, the light emitting portion may include: a first emitting surface, onto which light reflected on the reflecting surface is emitted; and a second emitting surface formed below the first emitting surface, and the lowest point of the reflecting portion may be formed below a boundary between the first emitting surface and the second emitting surface based on the height direction.

[0016] According to an embodiment, the first emission surface may be configured as an inclined surface whose lower diameter is greater than or equal to the upper diameter, and an angle between the inclined surface and the height direction may be between 0° and 5°.

[0017] According to an embodiment, the second emission surface may be configured as a convex surface with a lower diameter greater than an upper diameter.

[0018] According to an embodiment, the light reflected by the upper surface of the incident surface may be arranged to be incident on the light incident portion first, and then reflected by the re-reflective surface or emitted to the light emitting portion through the re-reflective surface.

[0019] According to an embodiment, the re-reflecting surface may include: a first re-reflecting surface formed to be inclined toward an edge of the re-reflecting portion; and a second re-reflecting surface formed to be inclined in a direction opposite to the first re-reflecting surface to form a predetermined angle with the first re-reflecting surface.

[0020] According to an embodiment, the reflective surface may include: a first reflective surface connected to one side of the first emitting surface and formed to be inclined toward the central axis direction of the lens; and a second reflective surface connected to the curved surface on one side of the first reflective surface.

[0021] According to an embodiment of the present invention, a light emitting module may include: a circuit board; a light emitting element mounted on the circuit board; and a reflective diffusion lens disposed on the circuit board and located above the light emitting element and controlling light emitted from the light emitting element.

[0022] Beneficial Effects

[0023] According to an embodiment of the present disclosure, the diffusion of light can be improved by forming a re-reflection surface at the lower portion of the diffusion lens. Further, the brightness moire can be improved by forming a micro pattern on the upper surface of the light incident portion of the diffusion lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a perspective view showing a light emitting module according to an embodiment of the present disclosure.

[0025] Figure 2 is shown along Figure 1 The structure of the optical transmission module shown is a cross-sectional view taken along line II.

[0026] Figure 3 It is used to illustrate Figure 1 A perspective view of the structure of the light incident portion of the reflective diffusion lens shown.

[0027] Figure 4 Is used to explain the passage Figure 1 A view of the optical path of light in the optical transmitter module is shown.

[0028] Figure 5 yes Figure 4 A represents an enlarged view of a partially enlarged portion.

[0029] Figure 6 is a view for explaining an optical path of light passing through a light emitting module according to a first comparative example.

[0030] Figure 7 yes Figure 6 B represents an enlarged view of the partial enlargement.

[0031] Figure 8 2 is a view for explaining a light path of light passing through a light transmitting module according to an embodiment of the present disclosure.

[0032] Fig. 9 yes Figure 8 C represents an enlarged view of the enlarged portion.

[0033] Fig.10 It is used to explain the Figure 6 FIG. 1 is a graph showing the brightness of a light emitting module of a comparative example.

[0034] Fig.11 is a diagram for explaining the brightness of a light emitting module according to an embodiment of the present disclosure.

[0035] Fig.12 is a graph for explaining brightness moire in a light transmission module according to a comparative example and brightness moire in a light transmission module according to an example.

[0036] Fig.13 It is used to explain the Figure 2 A graph of light diffusion is shown as the tilt angle of the re-reflecting surface changes.

[0037] Fig.14 It is used to explain the Figure 2 A graph of the full width at half maximum for variations in the tilt angle of the re-reflecting surface is shown.

[0038] Fig.15 : is a diagram for explaining the brightness in the central axis direction as a second comparative example according to the comparative example without the first reflecting surface.

[0039] Fig.16 It is used to illustrate that according to Figure 2 A graph of brightness in the central axis direction of an example of the first reflective surface shown.

[0040] Fig.17A and Fig. 17B It is a comparison and explanation Fig.15 and Fig.16 Figure of the graph shown.

[0041] Fig.18 is a diagram illustrating light diffusion of a refractive diffusion lens as a third comparative example according to comparative examples.

[0042] Fig.19 2 is a diagram for explaining light diffusion of a reflective diffusion lens according to an embodiment of the present disclosure.

[0043] Fig. 20A and Fig. 20B is a graph for comparing light diffusion of a refractive diffusion lens according to a third comparative example with light diffusion of a reflective diffusion lens according to an embodiment.

[0044] Fig.21 is a diagram for explaining an illumination area of ​​a refractive diffusion lens according to a third comparative example.

[0045] Fig. 22 is a diagram for explaining an illumination area of ​​a reflective diffusion lens according to an embodiment of the present disclosure.

[0046] Fig.23 is a graph for explaining the brightness of a refractive diffusion lens according to a comparative example and the brightness of a reflective diffusion lens according to an embodiment.

[0047] The reference numerals are described as follows:

[0048] 1: Optical transmitter module

[0049] 10: Reflective diffusion lens

[0050] 11: Light incident part

[0051] 12: Light emitting part

[0052] 13: Reflection part

[0053] 14: Re-reflection part

[0054] 20: Light emitting element

[0055] 30: Circuit Board

[0056] 110: Incident surface

[0057] 120: Ejection surface

[0058] 130: Reflective surface

[0059] 140: Re-reflecting surface DETAILED DESCRIPTION

[0060] For the purpose of explaining the technical spirit of the present disclosure, the embodiments of the present disclosure are given as examples. The scope of the present disclosure is not limited to the embodiments described below or the detailed description of these embodiments.

[0061] Unless otherwise defined, all technical and scientific terms used in this disclosure have the meanings commonly understood by those of ordinary skill in the art to which this disclosure belongs. All terms used in this disclosure are selected for the purpose of more clearly describing this disclosure but are not selected for limiting the scope of this disclosure.

[0062] Expressions such as “including,” “comprising,” “having,” etc. used in this disclosure will be understood as open-ended terms implying the possibility of including other embodiments unless otherwise stated in the phrase or sentence including these expressions.

[0063] Unless otherwise specified, singular forms described in the present disclosure may also include a meaning of plural forms, and this applies even to expressions in singular forms described in the accompanying claims.

[0064] Expressions such as “first”, “second”, etc. used in the present disclosure are used to distinguish a plurality of components from one another, and do not limit the order or importance of the corresponding components.

[0065] In the present disclosure, when it is mentioned that a component is “connected to” or “accessed to” another component, it is understood that the component may be directly connected to or accessed to another component, or connected to or accessed to another component via another new component.

[0066] Directional indications such as "upward", "up" used in the present disclosure are based on the direction in which the lens is positioned relative to the light emitting element in the drawings, while directional indications such as "downward", "down", etc. refer to the opposite direction. The lenses and light emitting elements shown in the drawings may be aligned differently, and the above directional indications may be interpreted accordingly.

[0067] The coordinate system shown in the drawings of the present disclosure shows an X-axis, a Y-axis, and a Z-axis. The X-axis direction refers to a direction parallel to the circuit board, the Y-axis direction refers to a direction perpendicular to the circuit board, and the Z-axis direction refers to a height direction of the lens. In addition, the (+) direction of the X-axis refers to the radial outer side of the lens and the (-) direction refers to the radial inner side of the lens. In addition, the (+) direction of the Z-axis refers to the upper side of the height direction and the (-) direction refers to the lower side of the height direction.

[0068] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, similar or corresponding components may be given similar reference numerals. In addition, in the description of the following embodiments, repeated descriptions of similar or corresponding components will be omitted. However, even if the description of a component is omitted, it is not intended that the component is not included in any embodiment.

[0069] Figure 1 is a perspective view showing a light emitting module according to an embodiment of the present disclosure. Figure 2 is shown along Figure 1 The structure of the optical transmission module shown is a cross-sectional view taken along line II.

[0070] A backlight unit (not shown) is disposed behind a liquid crystal display (not shown) to irradiate light toward a front surface of the liquid crystal display, thereby realizing a recognizable image on the display device. The light emitting module 1 included as a part of the backlight unit (not shown) may include a reflective diffusion lens 10, a light emitting element 20, and a circuit board 30.

[0071] The light emitting element 20 may be mounted on the circuit board 30, and the circuit board 30 may be configured to control and supply power to the light emitting element 20. The light emitting element 20 may be configured by, for example, an LED lamp. In order to control and diffuse the light emitted from the light emitting element 20, the reflective diffusion lens 10 may be disposed on the circuit board 30 to be located above the light emitting element 20.

[0072] exist Figure 1 In the embodiment, a plurality of light emitting elements 20 may be mounted on a circuit board 30 to have a configuration extending in the X-axis direction so as to be regularly spaced apart from each other. The reflective diffusion lenses 10 are provided in a number corresponding to the number of the plurality of light emitting elements 20 and may be provided on the circuit board 30 to be located on each light emitting element 20.

[0073] exist Figure 2 In the embodiment, the reflective diffusion lens 10 may include a light incident portion 11, a light emitting portion 12, and a reflective portion 13. The reflective diffusion lens 10 may have a cylindrical shape with the height direction (Z direction) as a whole being the central axis. That is, when the reflective diffusion lens 10 is cut along the XY plane, a circular cross section may be shown.

[0074] The light incident portion 11 may be formed concavely upward in the height direction (Z direction) to form an incident surface 110 to which light emitted from the light emitting element 20 is incident. The incident surface 110 may include an upper surface 111 and a side surface 115 formed around the edge of the upper surface 111. In addition, the upper surface 111 may include a conical surface 112 having a cone shape and a peripheral surface 113 surrounding the conical surface 112. A micro pattern having an irregular uneven shape may be formed on the upper surface 111, and this will be described in detail below.

[0075] The peripheral surface 113 of the light incident portion 11 may have a shape in which the outer edge in the radial direction (X direction) is slightly raised in the height direction (Z direction). The peripheral surface 113 may have a downwardly convex shape, and may include an edge surface 114 formed to be inclined toward the center of the peripheral surface 113. That is, the lowest point of the peripheral surface 113 in the height direction (Z direction) may be formed at a position lower than the edge surface 114.

[0076] The light emitting portion 12 may include an emission surface 120, and light passing through the incident surface 110 or refracted by the incident surface 110 is emitted to the outside of the diffusion lens through the emission surface 120. The emission surface 120 may include a first emission surface 121 and a second emission surface 122 formed below the first emission surface 121 in the height direction (Z direction). A flange surface 123 parallel to the height direction (Z direction) may be formed below the second emission surface 122. The flange surface 123 does not substantially affect the optical path.

[0077] The first emitting surface 121 may be configured as an inclined surface in which the diameter of the lower side is greater than or equal to the diameter of the upper side in the height direction (Z direction). For example, the angle θ1 between the first emitting surface 121 and the height direction (Z direction) may be between 0° and 5°. For example, the angle θ1 may be approximately 3°.

[0078] Each of the first and second emission surfaces 121 and 122 may have an uneven shape by performing an EDM method. Accordingly, the light emitted from the light emitting element 20 and passing through the first and second emission surfaces 121 and 122 may be controlled to diffuse without overlapping each other at predetermined positions.

[0079] The reflective portion 13 formed on the upper side of the height direction (Z direction) of the diffuser lens may form a reflective surface 130, which is formed concavely toward the lower side of the height direction (Z direction) to reflect a portion of the light passing through the light incident portion 11. The reflective surface 130 may have a substantially conical shape. That is, the reflective diffuser lens 10 may have a shape that is concave from the top to the bottom.

[0080] The reflective surface 130 may include: a first reflective surface 131 formed to be inclined in the direction of the central axis of the reflective diffusion lens 10 according to the present embodiment; and a second reflective surface 132 connected in a curved manner from one side of the first reflective surface 131. Figure 2 When the cross section of the light emitting module 1 is shown, the second reflective surface 132 can be configured as a curved surface. Unlike the second reflective surface 132, the first reflective surface 131 is formed as a plane, which can improve the brightness in the central axis direction of the reflective diffusion lens 10. On the other hand, it will be clear that, in addition to the plane, the first reflective surface 131 can be formed with a predetermined curvature that can improve the brightness of the reflective diffusion lens 10 in the central axis direction.

[0081] The lowest point 135 formed at the radial center of the reflecting portion 13 may be formed below the boundary BL based on the height direction (Z direction) between the first emitting surface 121 and the second emitting surface 122. In addition, the lowest point 135 may be located adjacent to the upper end portion 112A of the tapered surface 112. Accordingly, the reflecting surface 130 has an area several times larger than that of the incident surface 110, and may reflect a considerable amount of light passing through the incident surface 110.

[0082] A portion of the light passing through the conical surface 112 or the circumferential surface 113 of the incident surface 110 may be reflected on the reflective surface 130 and emitted through the first emission surface 121. An angle θ2 between the radial direction (X direction) and the reflective surface 130 may be approximately 15° to 25°, so that the light reflected on the reflective surface 130 is guided to the first emission surface 121. For example, the angle θ2 may be 21.5°.

[0083] The reflective diffusion lens 10 may include a re-reflecting portion 14 formed outside the radial direction (X direction) of the light incident portion 11 and formed concavely upward in the height direction (Z direction) to form a re-reflecting surface 140, and another part of the light passing through the incident surface 110 is reflected on the re-reflecting surface 140. The light reflected on the upper surface 111 of the light incident to the incident surface 110 may be configured to be reflected on the re-reflecting surface 140 or emitted to the light emitting portion 12 through the re-reflecting surface 140. More specifically, the light reflected on the upper surface 111 of the light incident to the incident surface 110 may be configured to be emitted to the second emitting surface 122 of the emitting surface 120.

[0084] The re-reflecting surface 140 may include: a first re-reflecting surface 141 formed to be inclined toward the edge of the re-reflecting portion 14 (i.e., the outer side of the radial direction (X direction)); and a second re-reflecting surface 142 formed to be inclined in a direction opposite to the first re-reflecting surface 141. The first re-reflecting surface 141 may form a predetermined angle θ3 with the radial direction (X direction), and will be described in detail below.

[0085] Figure 3 It is used to illustrate Figure 1 The illustrated perspective view is a perspective view of the arrangement of the light incident portion 11 of the reflective diffusion lens 10 and is a perspective view in which the reflective diffusion lens is cut away and viewed from the bottom. Figure 4 Is used to explain the passage Figure 1 A view of the optical path of light in the optical transmission module 1 is shown. Figure 5 yes Figure 4 A represents an enlarged view of a partially enlarged portion.

[0086] exist Figure 3, the side surface 115 of the light incident portion 11 may be configured as a concave surface in which the diameter of the lower side is larger than the diameter of the upper side in the height direction (Z direction). Correspondingly, the side surface 115 may function as a concave lens, and light passing through the side surface 115 is dispersed upward and downward in the height direction (Z direction) from the inside of the reflective diffusion lens 10. Thus, since the amount of light dispersed from the inside of the reflective diffusion lens 10 increases, the light diffusion of the reflective diffusion lens 10 is improved.

[0087] The second emitting surface 122 may be formed of a convex surface with a diameter of the lower side greater than that of the upper side. Since the second emitting surface 122 may function as a convex lens, the amount of light passing through the second emitting surface 122 increases toward one side of the reflective diffusion lens 10, thereby improving the light diffusion of the reflective diffusion lens 10.

[0088] Reference Figure 4 , the LED beam angle θ4 can be formed to be, for example, about 120°. At this time, a considerable amount of light emitted from the light emitting element 20 passes through the edge surface 114 as the corner portion of the light incident portion 11. In order to control the light path of the corner portion, a micro pattern having an irregular concave-convex shape may be formed on the upper surface 111. More specifically, a micro pattern having an irregular concave-convex shape may be formed on the edge surface 114 of the upper surface 111. The micro pattern may improve the diffusion of light passing through the corner portion of the light incident portion 11. The micro pattern may be formed by, for example, performing an EDM method on the edge portion of the upper surface 111 at the lower side of the light incident portion 11.

[0089] Reference Figure 4 , the light L1 passing through the conical surface 112 or the peripheral surface 113 of the light incident portion 11 may be reflected on the reflection surface 130 and emitted through the first emission surface 121. Among the light L1, there may be light that is not reflected on the reflection surface 130, which is refracted in the radial direction (X direction) when passing through the first emission surface 121.

[0090] Reference Figure 4 and Figure 5 , the light L2 that passes through the edge surface 114 or the side surface 115 of the light incident portion 11 may be emitted through the second exit surface 122 as it is. Meanwhile, the light L3 that is incident on the second re-reflection surface 142 after being reflected on the peripheral surface 113 is refracted when passing through the second re-reflection surface 142 and is incident on the first re-reflection surface 141. In addition, the light L3 may be refracted when passing through the first re-reflection surface 141 and then be emitted through the second exit surface 122. In addition, the light L4 that is incident on the first re-reflection surface 141 after being reflected on the peripheral surface 113 may be re-reflected on the first re-reflection surface 141 and then be emitted through the second exit surface 122.

[0091] Reference Figure 5Since the light L3 and light L4 incident on the re-reflecting portion 14 are emitted through the second emission surface 122, the amount of light reaching the area not directly irradiated by the light emitting element 20 can be increased. Therefore, the diffusion of light passing through the reflective diffusion lens 10 can be improved.

[0092] Figure 6 1 is a view for explaining the optical path of light passing through the light transmission module 1B according to the first comparative example. Figure 7 yes Figure 6 B represents an enlarged view of the partial enlargement.

[0093] Figure 6 and Figure 7 The first comparative example shown represents a reflective diffusion lens 10B having a light incident portion 11B, in which a micro pattern is not formed on an edge surface 114B of the light incident portion 11B. Figure 7 , the amount of light reflected from the lower side of the peripheral surface 113B or the edge surface 114B may increase at the corner of the light incident portion 11B. Figure 6 As in the area indicated by X1 in FIG. 1 , an area that is not irradiated with a sufficient amount of light may occur.

[0094] Figure 8 is a view for explaining an optical path of light passing through the light transmission module 1 according to an embodiment of the present disclosure. Fig. 9 yes Figure 8 C represents an enlarged view of the enlarged portion.

[0095] The micro pattern may be formed on the edge surface 114 of the light incident portion 11 of the reflective diffusion lens 10 according to an embodiment of the present disclosure. Fig. 9 In the figure, for convenience of explanation, the micro pattern formed on the edge surface 114 is represented as a slightly convex surface, but it can actually be formed as a narrower and more compact pattern.

[0096] Reference Fig. 9 Since the micro pattern is formed on the edge surface 114 of the light incident portion 11, it is feasible to reduce the amount of light reflected on the edge surface 114 or the peripheral surface 113 but increase the amount of light passing through the edge surface 114 or the peripheral surface 113. Therefore, it can be determined that the light passing through the corner portion of the light incident portion 11 can be sufficiently distributed in Figure 8 The X2 in FIG.

[0097] Fig.10 It is used to explain the Figure 6 FIG. 1 is a graph showing the brightness of a light emitting module of a comparative example. Fig.11 2 is a diagram for explaining the brightness of the light transmitting module 1 according to the embodiment of the present disclosure. Fig.12 is a graph for explaining brightness moire in a light emitting module according to a comparative example and a light emitting module according to an embodiment.

[0098] Reference Fig.10 In the case of the comparative example where no micro pattern is formed, the light distortion at the corner of the light incident portion 11B may generate dark mura. Fig.10 It is recognized as a dark spot (moiré) generated in the area indicated by D1. Fig.10 The difference is that, referring to Fig.11 , it can be determined that in the area indicated by D2 (corresponding to Fig.10 The dark spot in the D1 position in the image has been significantly reduced. Fig.10 In the figure, the contrast between dark and light spots is clearly shown, while in Fig.11 In the embodiment of the present invention, it can be determined that the difference in brightness between the dark spot and the bright spot is reduced.

[0099] exist Fig.12 In the graph of , the X-axis represents the position corresponding to the radial direction, and the Y-axis represents the luminance mura at the corresponding position. The luminance mura is ideally close to 0, and on average, the (-) value represents a relatively dark situation, while the (+) value represents a relatively bright situation.

[0100] Reference Fig.12 , it can be determined that in the case of the comparative example (without the micropattern), the degree of difference between the brightness moire value and 0 is greater than that of the embodiment (with the micropattern). Therefore, in the case of the embodiment, it can be determined that by forming the micropattern on the edge surface, the brightness moire can be minimized.

[0101] Reference Figure 2 The first re-reflecting surface 141 and the second re-reflecting surface 142 of the re-reflecting portion 14 may form a predetermined angle θ3. By changing the angle θ3 formed between the first re-reflecting surface 141 and the second re-reflecting surface 142, light reflected from the light incident portion 11 may be re-reflected to maximize light diffusion.

[0102] Fig.13 and Fig.14 is used to explain the inclination angle θ3 (reference Figure 2 ) changes in light diffusion and full width at half maximum.

[0103] exist Fig.13 , the X-axis represents positions spaced apart from the center position of the reflective diffusion lens 10 in the radial direction (X direction), and the Y-axis represents the relative brightness of each position corresponding to the X-axis. Therefore, the center position becomes the reference brightness (100%), and the relative brightness gradually decreases from the center position toward the edge. Fig.13The relative sizes of the angles θ3 of the lines 1-10 shown are classified from level 1 to level 10 and indicate the corresponding relative brightness.

[0104] exist Fig.13 In the figure, the angle θ3 corresponding to level 1 is the largest, while the angle θ3 corresponding to level 10 is the smallest. Therefore, it can be determined that as the tilt angle θ3 increases rapidly, the light diffusion decreases. Therefore, it is necessary to adjust the angle θ3 value to an appropriate degree to avoid excessive increase.

[0105] Reference Fig.14 , the X-axis represents the 1st to 10th level of the angle θ3 value, and the Y-axis represents the half-maximum full width. Fig.14 , when the angle θ3 value is less than or equal to a certain level (level 6 or higher), the size of the half-maximum full width may be saturated. Therefore, when the angle θ3 value reaches any critical angle, the light diffusion may be saturated.

[0106] Fig.15 1 is a diagram for explaining brightness in the central axis direction as a second comparative example in the case where the first reflecting surface 13 is not provided according to the comparative example. Fig.16 It is used to illustrate that according to Figure 2 A graph of brightness in the central axis direction of an exemplary embodiment of the first reflective surface 131 is shown. Fig.17A and Fig. 17B It is a comparison and explanation Fig.15 and Fig.16 Unlike the reflective diffusion lens according to the embodiment of the present disclosure, the reflective diffusion lens of the second comparative example does not have the first reflective surface 131. Figures 15 to 17B In the graph shown, the X-axis represents the position inside the lens, and the Y-axis represents the brightness (Nit) corresponding to each position.

[0107] Reference Fig.15 It can be confirmed from the picture shown on the left side that the light passing through the reflective diffusion lens according to the second comparative example has a dark brightness in the central axis direction of the lens. Fig.17A , it can be confirmed that the light passing through the reflective diffusion lens according to the second comparative example has a maximum brightness value at a position outside a predetermined distance from the center.

[0108] refer to Fig.16 As shown in the picture on the left side of FIG. 1 , it can be confirmed that the light passing through the reflective diffusion lens 10 according to the embodiment of the present disclosure has a bright brightness in the central axis direction of the lens. Fig. 17B , it can be determined that the brightness of the central part of the embodiment of the present disclosure presents the maximum brightness value. Therefore, since the first reflective surface 131 of the reflective diffusion lens 10 according to the embodiment is formed as a plane (for example, when viewed from the perspective of Figure 2When observing the light emitting module in the cross section shown in the figure), therefore, the brightness in the central axis direction can be improved.

[0109] Fig.18 is a diagram illustrating light diffusion of a refractive diffusion lens as a third comparative example. Fig.19 1 is a diagram for explaining light diffusion of the reflective diffusion lens 10 according to the embodiment of the present disclosure. Fig. 20A and Fig. 20B : is a graph for comparing light diffusion of the refractive diffusion lens according to the third comparative example with light diffusion of the reflective diffusion lens 10 according to the embodiment. In the refractive diffusion lens of the third comparative example, structures such as the reflective portion 13 and the re-reflective portion 14 of the reflective diffusion lens 10 according to the embodiment of the present disclosure are not present. Figures 18 to 20B In the graph shown, the X-axis represents the position inside the lens, and the Y-axis represents the brightness (Nit) corresponding to each position.

[0110] Reference Fig.18 , it can be confirmed that the light passing through the reflective diffusion lens according to the third comparative example has a clear contrast between the center portion and the edge portion. Fig. 20A It can be confirmed that the brightness of the light passing through the refractive diffusion lens according to the third comparative example has a maximum brightness value at the center portion, while the brightness at the edge portion of the lens is substantially close to 0.

[0111] Reference Fig.19 From the picture shown on the left side of FIG. 1 , it can be confirmed that the difference in contrast between the center portion and the edge portion of the light passing through the reflective diffusion lens 10 according to the embodiment of the present disclosure is relatively small. Fig. 20B The brightness (maximum brightness value) of the central part of the example disclosed in the present invention is significantly lower than Fig. 20A The brightness of the central part of the third comparative example is shown in FIG. 1 . Therefore, it can be determined that in the case of the example of the present disclosure, the difference between the brightness values ​​at the central part and the edge part is significantly reduced. Therefore, since the reflective diffusion lens 10 according to the embodiment of the present disclosure has a higher light diffusion than the refractive diffusion lens of the third comparative example, the number of light emitting modules arranged in the backlight to be used can be reduced while uniformly irradiating light to a large area of ​​the backlight unit.

[0112] Fig.21 is a diagram for explaining an illumination area of ​​a refractive diffusion lens according to a third comparative example. Fig. 22 1 is a diagram for explaining an illumination area of ​​the reflective diffusion lens 10 according to an embodiment of the present disclosure. Fig.23 is a graph for explaining the brightness of the refractive diffusion lens according to the comparative example and the brightness of the reflective diffusion lens according to the embodiment. Figure 21 to Figure 23In the graph shown, the X-axis represents the position inside the lens, and the Y-axis represents the relative brightness (%) corresponding to each position. The full width at half maximum of the reflective diffusion lens 10 may be about 20% greater than that of the refractive diffusion lens.

[0113] Reference Fig.21 , since the difference between the brightness value of the edge portion and the brightness value of the central portion of the refractive diffusion lens of the third comparative example is large, it can be determined that, Fig.21 The upper and lower ends of the figure shown on the upper side (indicated by dotted circles) are dark. In addition, it can be determined that Fig.21 In the curve graph shown at the bottom of , the brightness value is not uniform as a whole, and Fig.21 The brightness of the figure shown on the upper side is uneven.

[0114] On the contrary, reference Fig. 22 It can be determined that the brightness value of the reflective diffusion lens 10 according to the embodiment of the present disclosure is uniform as a whole, and Fig. 22 The brightness of the graph shown on the upper side is also relatively evenly distributed.

[0115] Reference Fig.23 , the brightness profiles of the refractive diffuser lens and the reflective diffuser lens 10 can be compared. As described above, since the beam angle θ4 of the reflective diffuser lens 10 according to the embodiment of the present disclosure is wider than the beam angle of the refractive diffuser lens of the third comparative example, the reflective diffuser lens 10 according to the embodiment of the present disclosure has a more uniform light distribution than the refractive diffuser lens of the third comparative example.

[0116] Although the technical concept of the present disclosure has been described based on some of the above embodiments and the examples shown in the accompanying drawings, it should be recognized that various substitutions, modifications and changes can be made within the technical spirit and scope of the present disclosure that can be understood by a person of ordinary skill in the art to which the present disclosure belongs. In addition, it should be understood that these substitutions, modifications and changes will be deemed to be within the scope of the appended claims.

Claims

1. A reflective diffusion lens, which controls light emitted from a light emitting element, the reflective diffusion lens comprising: a light incident portion formed concavely toward the upper side and having an incident surface on which light emitted from the light emitting element is incident; a light emitting portion having an emitting surface for emitting light incident on the incident surface; a reflecting portion disposed on an upper side of the light incident portion and formed concavely toward a lower side and having a reflecting surface by which a portion of the light emitted from the light incident portion is reflected; as well as A re-reflecting portion is formed on the outer side of the light incident portion in the radial direction, is located on the lower surface of the lens connecting the light incident portion and the light emitting portion, and has a re-reflecting surface, another part of the light emitted from the incident surface is reflected by the re-reflecting surface, and among the light incident on the light incident portion, the light reflected by the incident surface is set to be partially reflected by the re-reflecting surface and partially emitted to the light emitting portion through the re-reflecting surface.

2. The reflective diffusion lens according to claim 1, wherein: The incident surface includes an upper surface and a side surface formed around an edge of the upper surface, and The upper surface includes a conical surface and a peripheral surface surrounding the conical surface.

3. The reflective diffusion lens according to claim 2, wherein: The peripheral surface has a downwardly convex shape and includes an edge surface, and the edge surface is formed to be inclined toward the center of the peripheral surface.

4. The reflective diffusion lens according to claim 2, wherein: A micro pattern having an irregular concavo-convex shape is formed on an edge surface of the upper surface.

5. The reflective diffusion lens according to claim 2, wherein: The side surface is configured as a concave surface in which a diameter of a lower side in a height direction of the lens is larger than a diameter of an upper side.

6. The reflective diffusion lens according to claim 1, wherein: The light emitting portion includes: a first emitting surface, onto which light reflected on the reflecting surface is emitted; and a second emitting surface formed below the first emitting surface. The lowest point of the reflection portion is formed below a boundary between the first emission surface and the second emission surface in a height direction of the lens.

7. The reflective diffusion lens according to claim 6, wherein: The first emitting surface is configured as an inclined surface whose lower diameter is greater than or equal to the upper diameter. The angle between the inclined surface and the height direction is between 0° and 5°.

8. The reflective diffusion lens according to claim 6, wherein: The second emission surface is configured as a convex surface with a lower diameter larger than an upper diameter.

9. The reflective diffusion lens according to claim 1, wherein: The re-reflection surface includes: a first re-reflection surface formed to be inclined toward an edge of the re-reflection portion; and a second re-reflection surface formed to be inclined in a direction opposite to the first re-reflection surface and forming a predetermined angle with the first re-reflection surface.

10. The reflective diffusion lens according to claim 6, wherein: The reflective surface comprises: A first reflecting surface connected to one side of the first emitting surface and formed to be inclined toward the central axis direction of the lens; and The second reflecting surface is connected to one side of the first reflecting surface in a curved manner.

11. An optical transmission module, comprising: Circuit boards; A light emitting element is mounted on the circuit board; as well as The reflective diffusion lens according to any one of claims 1 to 10, which is disposed on the circuit board and above the light emitting element, and controls light emitted from the light emitting element.

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