JP2014006488A - Luminous flux control member, luminescent device, and illumination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminescent flux control member capable of controlling distribution of light emitted from a luminous element to uniformly and efficiently irradiate a target surface when the luminous element is located at an angle with respect to the target surface.SOLUTION: A luminous flux control member 160 has an incident region 162 for light emitted by a luminous element 140 to enter and an exit region 164 for the light entering from the incident region 162 to exit. The incident region 162 includes a first lens region 10 having a first Fresnel lens section 170 or a refracting section 168 and a second lens region 50 having a second Fresnel lens section 180. An optical path conversion angle θ2 of light R20 entering the second Fresnel lens section 180 is greater than an optical path conversion angle θ1 of light R10 entering the first Fresnel lens section 170 or the refracting section 168.

Description

  The present invention relates to a light flux controlling member that controls light distribution of light emitted from a light emitting element. The present invention also relates to a light emitting device having the light flux controlling member and an illumination device having the light emitting device.

  In recent years, from the viewpoint of energy saving, a light emitting diode (hereinafter referred to as “LED”) has been used as a light source for illumination instead of a fluorescent lamp or a halogen lamp. Such a light-emitting device using an LED as a light source may be disposed obliquely with respect to the irradiated surface, not directly above the irradiated surface depending on the application.

  For example, when a plant is cultivated using a cultivation shelf installed indoors, a light emitting device may be arranged obliquely with respect to the shelf board to illuminate the plant arranged on the shelf board. When the light emitting device is disposed obliquely with respect to the planar irradiated surface in this way, if the LED is used as it is, most of the light emitted from the LED becomes unnecessary light that does not go to the irradiated surface. Therefore, the irradiated surface cannot be illuminated efficiently. Further, since unnecessary light enters the eyes of the worker, the worker becomes difficult to work. As a means for solving the above problem, it is conceivable to use a lens for controlling the light distribution of the light emitted from the LED in combination with the LED (for example, see Patent Document 1).

  Patent Document 1 describes an illumination device having a planar irradiated surface, a plurality of LEDs arranged in a line on a straight line parallel to the irradiated surface, and a single compound lens that covers the plurality of LEDs. ing. In the illuminating device of Patent Document 1, a plurality of LEDs and a compound lens are arranged so that the light emitting surface of the LED and the exit surface of the compound lens are both perpendicular to the irradiated surface. The cross-sectional shape of the compound lens in the direction orthogonal to the LED arrangement direction is the same at any point of the compound lens. Moreover, the shape of the incident area (area facing the LED) of the compound lens is asymmetric with respect to a plane that passes through the optical axis of the LED and is parallel to the LED arrangement direction. As described above, the illumination device described in Patent Document 1 has an asymmetric shape between the irradiated surface side and the anti-irradiated surface side, so that even if the compound lens is not arranged directly above the irradiated surface, The irradiated surface can be illuminated uniformly to some extent.

JP 2008-153154 A

  In the illumination device of Patent Document 1, since the cross-sectional shape of the compound lens in the direction orthogonal to the LED arrangement direction does not change, the light distribution in the LED arrangement direction cannot be controlled. For this reason, light cannot be collected on the irradiated surface, and unnecessary light that does not go to the irradiated surface may be generated.

  The present invention has been made in view of such a point, and emits light so that light can be evenly and efficiently irradiated onto an irradiated surface when it is disposed obliquely with respect to the irradiated surface. An object of the present invention is to provide a light flux controlling member capable of controlling the light distribution of the light emitted from the element. Another object of the present invention is to provide a light emitting device and a lighting device having the light flux controlling member.

  The light flux controlling member of the present invention is a light flux controlling member that controls the light distribution of the light emitted from the light emitting element, and includes an incident area where the light emitted from the light emitting element is incident, and light incident from the incident area. An emission region that emits light, and the incident region has a first inclined surface on which a part of the light emitted from the light emitting element is incident and light incident from the first inclined surface is directed toward the emission region. The first Fresnel lens portion in which a plurality of first protrusions having a circular arc shape in plan view having a second inclined surface to be reflected are arranged concentrically or a part of the light emitted from the light emitting element is emitted. A first lens region having a fan-shaped refracting portion that is refracted toward the region, a third inclined surface that allows another part of the light emitted from the light emitting element to enter, and the third inclined surface. Directed light toward the exit area. A second lens region having a second Fresnel lens portion in which a plurality of second projections having a circular arc shape having a fourth inclined surface to be reflected are arranged concentrically, and the optical axis from the light emitting element The light path conversion angle of light that is emitted at an angle θ with respect to the optical axis is emitted from the light emitting element at the angle θ with respect to its optical axis, and the first Fresnel lens portion or the A configuration larger than the optical path conversion angle of the light passing through the refracting portion is adopted.

  The light emitting device of the present invention includes the light flux controlling member and the light emitting element, and adopts a configuration in which the optical axis of the light emitting element coincides with the central axis of the light flux controlling member.

  The illumination device of the present invention includes the light emitting device and a planar irradiated surface, and the light emitting device has an optical axis of the light emitting element and the irradiated surface intersecting at an acute angle, and the first lens region. Further, the second lens region is arranged so as to be closer to the irradiated surface.

  The light emitting device having the light flux controlling member of the present invention can irradiate light to the irradiated surface uniformly and efficiently when it is arranged obliquely with respect to the irradiated surface. In addition, the illumination device of the present invention can irradiate the irradiated surface with light uniformly and efficiently.

1A and 1B are diagrams illustrating a configuration of the light-emitting device of Embodiment 1. FIG. 2A and 2B are external views of the light flux controlling member of the first embodiment. 3 is a cross-sectional view of a light flux controlling member according to Embodiment 1. FIG. FIG. 3 is an optical path diagram of the light emitting device according to the first embodiment. 1 is a diagram illustrating a configuration of a lighting device according to Embodiment 1. FIG. 6A to 6D are diagrams showing a configuration of a conventional light flux controlling member. 7A to 7D are diagrams showing the configuration of the light flux controlling member of the second embodiment. FIG. 10 is a bottom view of a light flux controlling member according to a modification of the second embodiment. 9A to 9C are schematic diagrams and graphs showing simulation results of the illuminance distribution on the irradiated surface. 10A to 10D are diagrams illustrating the configuration of the light flux controlling member according to the third embodiment. 11A and 11B are optical path diagrams of the light emitting device of the third embodiment.

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

(Embodiment 1)
In Embodiment 1, a light flux controlling member in which the first lens region has a first Fresnel lens portion and a refracting portion, and the second lens region has a second Fresnel lens portion will be described.

[Configuration of Light Emitting Device and Light Beam Control Member]
FIG. 1 is a diagram showing a configuration of a light emitting device 100 according to Embodiment 1 of the present invention. 1A is a cross-sectional view of the light-emitting device 100, and FIG. 1B is a bottom view of the light-emitting device 100. FIG. FIG. 1A illustrates a state where the light emitting device 100 is fixed on the substrate 120. In FIG. 1B, the substrate 120 is removed, and the position of the light emitting element 140 in the light emitting device 100 is shown.

  As shown in FIG. 1, the light emitting device 100 includes a light emitting element 140 and a light flux controlling member 160. The light emitting element 140 is a light emitting diode (LED) such as a white light emitting diode. The light flux controlling member 160 controls the light distribution of the light emitted from the light emitting element 140. The light flux controlling member 160 is disposed so that the central axis CA coincides with the optical axis LA of the light emitting element 140.

  2 and 3 are diagrams showing the configuration of the light flux controlling member 160 of the first embodiment. 2A is a plan view of the light flux controlling member 160, and FIG. 2B is a bottom view of the light flux controlling member 160. FIG. 3 is a cross-sectional view taken along line AA in FIGS. 2A and 2B.

  As shown in FIGS. 2 and 3, the light flux controlling member 160 is located on the opposite side of the incident region 162 where the light emitted from the light emitting element 140 is incident, and the light incident from the incident region 162. , And a leg portion 166 that positions the incident region 162 and the emission region 164.

  The light flux controlling member 160 has a shape like a bottomed cylinder. An incident region 162 is formed on one surface (a surface facing the inside of the cylinder) of the circular plate-like portion corresponding to the bottom plate, and an emission region 164 is formed on the other surface. Moreover, the substantially cylindrical leg portion 166 supports the plate-like portion where the incident region 162 and the emission region 164 are formed from the incident region 162 side.

  The light flux controlling member 160 is formed by integral molding. The material of the light flux controlling member 160 is not particularly limited as long as it allows light having a desired wavelength to pass therethrough. For example, the material of the light flux controlling member 160 is a light transmissive resin such as polymethyl methacrylate (PMMA), polycarbonate (PC), and epoxy resin (EP), or glass.

  The incident area 162 is an area where a part of the light emitted from the light emitting element 140 is incident on the light flux controlling member 160. The incident region 162 is formed in a facing portion of the light flux controlling member 160 facing the light emitting element 140 in the light emitting device 100 (located on the opposite side of the emitting region 164). The incident region 162 includes a first lens region 10 disposed in a part of the facing portion and a second lens region 50 disposed in the remaining portion of the facing portion.

  The first lens region 10 has a first Fresnel lens part 170 and a refraction part 168. The first Fresnel lens unit 170 causes a part of the light emitted from the light emitting element 140 to enter the light flux controlling member 160 and reflects the incident light toward the emission region at a predetermined angle. The first Fresnel lens unit 170 has a semicircular shape when viewed in plan. The first Fresnel lens unit 170 includes a plurality of first protrusions 172 that are concentrically arranged and have a circular arc shape in plan view. That is, the first Fresnel lens portion 170 can be said to be a part of a reflective Fresnel lens having a plurality of annular projections arranged concentrically. In this specification, a straight line passing through the center of the concentric circle and parallel to the optical axis LA of the light emitting element 140 is defined as a central axis CA of the light flux controlling member 160.

  The plurality of first protrusions 172 respectively reflect the first inclined surface 174 that is an incident surface on which light emitted from the light emitting element 140 is incident and the light incident from the first inclined surface 174 toward the emission region 164. And a second inclined surface 176 which is a reflective surface. In each first protrusion 172, the first inclined surface 174 is located on the inner side (center axis CA side), and the second inclined surface 176 is located on the outer side (leg portion 166 side). In each first protrusion 172, the first inclined surface 174 and the second inclined surface 176 may be continuous or discontinuous. In the former case, a ridge line is formed between the first inclined surface 174 and the second inclined surface 176. In the latter case, another surface is formed between the first inclined surface 174 and the second inclined surface 176. Productivity can be improved by providing another surface between the first inclined surface 174 and the second inclined surface 176 and eliminating the acute angle portion (ridge line portion).

  The generatrix of the first inclined surface 174 (the first inclined surface 174 in the cross section of the first protrusion 172 (the cross section of the light flux controlling member 160 including the central axis CA)) may be a straight line or a curved line. . The angle of the first inclined surface 174 with respect to the optical axis LA of the light emitting element 140 is not particularly limited as long as the light incident from the first inclined surface 174 can be refracted to the second inclined surface 176 side. It can be set as appropriate according to the position. When the bus line of the first inclined surface 174 is a curve, the “angle of the first inclined surface 174” refers to the angle of the tangent line of the bus line of the first inclined surface 174. From the viewpoint of manufacturability, the first inclined surface 174 is 0 to 20 with respect to the optical axis LA of the light emitting element 140 so that the emission area 164 side is closer to the optical axis LA of the light emitting element 140 than the incident area 162 side. It is preferable to be inclined by about °. Considering the draft angle from the mold when the light flux controlling member 160 is injection-molded and the light propagation efficiency of the light incident from the first inclined surface 174 to the second inclined surface 176, the first inclined surface 174 is: More preferably, it is inclined by about 3 to 5 °. In addition, the angle of the 1st inclined surface 174 of each 1st protrusion 172 may be the same, and may differ.

  The generatrix of second inclined surface 176 (second inclined surface 176 in the cross section of first protrusion 172 (the cross section of light flux controlling member 160 including central axis CA)) may be a straight line or a curved line. . The angle of the second inclined surface 176 with respect to the optical axis LA of the light emitting element 140 is not particularly limited as long as the light incident from the first inclined surface 174 can be reflected at a predetermined angle toward the emission region 164 side. It can be set as appropriate according to the light characteristics and the like. When the bus line of the second inclined surface 176 is a curve, the “angle of the second inclined surface 176” refers to the angle of the tangent line of the bus line of the second inclined surface 176. Usually, the incident region 162 side is closer to the optical axis LA of the light emitting element 140 than the emission region 164 side, and the first inclined surface is inclined by about 20 to 60 ° with respect to the optical axis LA of the light emitting element 140. It is formed so that the light incident from 174 is totally reflected. The angle of the second inclined surface 176 of each first protrusion 172 may be the same or different.

  The refracting portion 168 is formed at a position facing the light emitting element 140 so as to intersect the central axis CA of the light flux controlling member 160. The refracting unit 168 causes a part of the light emitted from the light emitting element 140 (mainly light emitted in the forward direction and near the optical axis LA of the light emitting element 140) to enter the light flux controlling member 160 and the incident light. Is refracted toward the emission region 164. The shape of the refracting portion 168 is not particularly limited, and may be a flat surface, a spherical surface, an aspherical surface, or a refractive Fresnel lens.

  The second lens region 50 has a second Fresnel lens portion 180. The second Fresnel lens unit 180 causes another part of the light emitted from the light emitting element 140 to enter the light flux control member 160 and reflects the incident light toward the emission region at a predetermined angle. The second Fresnel lens unit 180 has a semi-annular shape when viewed in plan. The second Fresnel lens unit 180 has a plurality of second protrusions 182 that are concentrically arranged and have a circular arc shape in plan view. That is, the second Fresnel lens portion 180 can be said to be a part of a reflective Fresnel lens having a plurality of annular projections arranged concentrically. Here, the central axis of the arc-shaped second protrusion 182 (a straight line passing through the center of the concentric circle and parallel to the optical axis LA of the light emitting element 140) is the central axis of the arc-shaped first protrusion 172 (light flux controlling member). 160 and the central axis CA).

  The plurality of second protrusions 182 reflect the light incident from the third inclined surface 184 that is an incident surface on which light emitted from the light emitting element 140 is incident and the light incident from the third inclined surface 184 toward the emission region 164. And a fourth inclined surface 186 which is a reflective surface. In each second protrusion 182, the third inclined surface 184 is located on the inner side (center axis CA side), and the fourth inclined surface 186 is located on the outer side (leg portion 166 side). In each second protrusion 182, the third inclined surface 184 and the fourth inclined surface 186 may be continuous or discontinuous. In the former case, a ridge line is formed between the third inclined surface 184 and the fourth inclined surface 186. In the latter case, another surface is formed between the third inclined surface 184 and the fourth inclined surface 186. Productivity can be improved by providing another surface between the third inclined surface 184 and the fourth inclined surface 186 and eliminating the acute angle portion (ridge line portion).

  The generatrix of the third inclined surface 184 (the third inclined surface 184 in the cross section of the second protrusion 182 (the cross section of the light flux controlling member 160 including the central axis CA)) may be a straight line or a curved line. . The angle of the third inclined surface 184 with respect to the optical axis LA of the light emitting element 140 is not particularly limited as long as light incident from the third inclined surface 184 can be refracted to the fourth inclined surface 186 side. It can be set as appropriate according to the position. When the bus line of the third inclined surface 184 is a curve, the “angle of the third inclined surface 184” refers to the angle of the tangent line of the bus line of the third inclined surface 184. From the viewpoint of manufacturability, the third inclined surface 184 is 0 to 20 with respect to the optical axis LA of the light emitting element 140 such that the emission area 164 side is closer to the optical axis LA of the light emitting element 140 than the incident area 162 side. It is preferable to be inclined by about °. Considering the draft angle from the mold when the light flux controlling member 160 is injection-molded and the light propagation efficiency of the light incident from the third inclined surface 184 to the fourth inclined surface 186, the third inclined surface 184 is: More preferably, it is inclined by about 3 to 5 °. In addition, the angle of the 3rd inclined surface 184 of each 2nd protrusion 182 may be the same, and may differ.

  The generatrix of the fourth inclined surface 186 (the fourth inclined surface 186 in the cross section of the second protrusion 182 (the cross section of the light flux controlling member 160 including the central axis CA)) may be a straight line or a curved line. . The angle of the fourth inclined surface 186 with respect to the optical axis LA of the light emitting element 140 is not particularly limited as long as the light incident from the third inclined surface 184 can be reflected at a predetermined angle toward the emission region 164 side. It can be set as appropriate according to the light characteristics and the like. When the bus line of the fourth inclined surface 186 is a curve, the “angle of the fourth inclined surface 186” refers to the angle of the tangent line of the bus line of the fourth inclined surface 186. Usually, the incident region 162 side is closer to the optical axis LA of the light emitting element 140 than the emission region 164 side, and is inclined by about 20 to 60 ° with respect to the optical axis LA of the light emitting element 140, and the third inclined surface. The light incident from 184 is totally reflected. The angle of the fourth inclined surface 186 of each second protrusion 182 may be the same or different.

  The emission region 164 is a region for emitting the light incident from the incident region 162. The emission region 164 is a plane formed on the irradiated surface side opposite to the light emitting element 140. In the present embodiment, the emission region 164 is formed so as to be orthogonal to the optical axis LA of the light emitting element 140.

  The leg 166 is a member that positions the light flux controlling member 160 with respect to the light emitting element 140. The leg portion 166 is located on the outer peripheral portion of the light flux controlling member 160 and is formed in a substantially cylindrical shape. The leg portion 166 supports the circular plate-like portion where the incident region 162 and the emission region 164 are formed, and transmits light from the light emitting element 140 that has not entered the incident region 162 to the outside. At the lower end of the leg portion 166, an installation portion 167 that increases the installation area with respect to the substrate is provided (see FIG. 3). The installation portion 167 is an annular plate extending in the radial direction from the lower end of the leg portion 166.

  FIG. 4 is an optical path diagram of the light emitting device of the first embodiment. The light incident on the first Fresnel lens unit 170 (first lens region 10) and the second Fresnel lens unit 180 (second lens region 50) has an optical path in a direction approaching or intersecting with the optical axis LA of the light emitting element 140. The light is converted and emitted from the emission region 164. FIG. 4 shows light R10 emitted at the same angle θ with respect to the optical axis LA in each of the first Fresnel lens unit 170 (first lens region 10) and the second Fresnel lens unit 180 (second lens region 50). And R20 show how the light path is changed by the light flux controlling member 160.

  The light path conversion angle θ2 with respect to the incident light R20 of the light R21 emitted from the light emitting element 140 at an angle θ and emitted from the emission region 164 via the second Fresnel lens unit 180 is emitted from the light emitting element 140 at the same angle θ. It is larger than the optical path conversion angle θ1 of the light R11 emitted from the emission region 164 via the first Fresnel lens portion 170 with respect to the incident light R10. The method for making θ2 larger than θ1 is not particularly limited. For example, the angle of the first inclined surface 174 with respect to the optical axis LA of the light emitting element 140 and the angle of the third inclined surface 184 with respect to the optical axis LA of the light emitting element 140 are the same, and the light emitting element 140 of the second inclined surface 176 has The angle with respect to the optical axis LA may be made larger than the angle of the fourth inclined surface 186 with respect to the optical axis LA of the light emitting element 140. Further, even if the angle of the first inclined surface 174 with respect to the optical axis LA of the light emitting element 140 and the angle of the third inclined surface 184 with respect to the optical axis LA of the light emitting element 140 are not the same angle, the light emitting element 140 of the first inclined surface 174. Of the second inclined surface 176 with respect to the optical axis LA of the light emitting element 140, and the angle of the third inclined surface 184 with respect to the optical axis LA of the light emitting element 140 and the light emitting element 140 of the fourth inclined surface 186. By appropriately adjusting the angle with respect to the optical axis LA, θ2 can be made larger than θ1. Compared with the outer first protrusion 172, the innermost first protrusion 172 is incident with light emitted in a direction in which a high luminous intensity is obtained in the light distribution characteristics of the emitted light of the light emitting element 140. Similarly, the light emitted in the direction in which the luminous intensity of the light emitted from the light emitting element 140 is higher than that of the second outer protrusion 182 is incident on the innermost second protrusion 182. When light emitted from the light emitting element 140 at an angle θ is incident on the innermost first protrusion 172 and the innermost second protrusion 182, the light is incident on the first Fresnel lens unit 170 and the second Fresnel lens unit 180. The first protrusion 172 and the second protrusion 182 are formed so that at least high intensity light among the light satisfies θ2> θ1.

[Configuration of lighting device]
Next, the illuminating device 190 of Embodiment 1 which has the light-emitting device 100 of Embodiment 1 is demonstrated.

  FIG. 5 is a diagram illustrating a configuration of the illumination device 190 according to the first embodiment. 5A is a side view of the lighting device 190, and FIG. 5B is a plan view of the lighting device 190. FIG. As illustrated in FIG. 5, the lighting device 190 includes a plurality of light emitting devices 100 and a planar irradiated surface 192. As described above, the light emitting device 100 includes the light flux controlling member 160 and the light emitting element 140.

  In the plurality of light emitting devices 100, the optical axis LA of the light emitting element 140 and the irradiated surface 192 intersect each other at an acute angle θ 3, and the second lens region 50 is closer to the irradiated surface 192 than the first lens region 10. Is arranged. Specifically, the light emitting devices 100 are arranged at regular intervals, respectively, immediately above the pair of long sides of the irradiated surface 192. Each light emitting device 100 is supported by a support member (not shown) so as to have a predetermined height from the irradiated surface 192 and so that the irradiated surface 192 and the optical axis LA of the light emitting element 140 intersect at 45 °. Note that the angle θ3 at which the irradiated surface 192 and the optical axis LA of the light emitting element 140 intersect is not particularly limited, and is more than 0 ° and less than 90 °, and the illuminance uniformity of the irradiated surface 192 becomes high. It is adjusted to such an angle.

[effect]
In light flux controlling member 160 of Embodiment 1, the shapes of first lens region 10 (first Fresnel lens portion 170 and refracting portion 168) and second lens region 50 (second Fresnel lens portion 180) are asymmetric. The angles of the light emitted through each of the light-emitting elements 140 with respect to the optical axis LA are different from each other (see FIG. 4). The light emitting device 100 having the light flux controlling member 160 according to Embodiment 1 passes through the second lens region 50 disposed on the irradiated surface side (lower side) when disposed obliquely with respect to the irradiated surface 192. Since the optical path conversion angle θ2 of the light to be transmitted is larger than the optical path conversion angle θ1 of the light passing through the first lens region 10 disposed on the side opposite to the irradiated surface (upper side), the vicinity of the light emitting device 100 on the irradiated surface 192 The irradiated surface 192 can be uniformly and efficiently illuminated without causing high-luminance light to reach the region.

  In light flux controlling member 160 of Embodiment 1, the projections (first projection 172 and second projection 182) of first Fresnel lens unit 170 and second Fresnel lens unit 180 for controlling the light distribution are circular. Since it is formed in an arc shape, light emitted at a large angle with respect to the optical axis LA of the light emitting element 140 is appropriately condensed. For this reason, the light emitting device 100 having the light flux controlling member 160 of Embodiment 1 can irradiate the irradiated surface 192 more uniformly and efficiently.

  FIG. 6 is a diagram showing a configuration of a conventional light flux controlling member. 6A and 6B are diagrams showing a configuration of a light flux controlling member (protective cover) that does not have a Fresnel structure in the incident region. 6C and 6D are diagrams showing the configuration of a light flux controlling member having a rotationally symmetric (circularly symmetric) Fresnel structure in the incident region. 6A and 6C are cross-sectional views, and FIGS. 6B and 6D are bottom views. The conventional light flux controlling member shown in FIGS. 6A and 6B does not have a Fresnel structure in the incident region, and cannot efficiently irradiate the irradiated surface with light emitted from the light emitting element. 6C and 6D, since the Fresnel structure has a rotationally symmetric shape, when the light emitting device is arranged obliquely with respect to the irradiated surface, the irradiated surface is made uniform. Cannot irradiate. On the other hand, in light flux controlling member 160 of Embodiment 1, the shape of the Fresnel structure is asymmetric on the irradiated surface side (lower side) and the anti-irradiated surface side (upper side), so that irradiated surface 192 is uniformly and efficiently formed. Can be irradiated.

(Embodiment 2)
In Embodiment 2, the first lens region has a first Fresnel lens portion and a refracting portion, the second lens region has a second Fresnel lens portion, and the first Fresnel lens portion and the second Fresnel lens portion. A description will be given of the light flux controlling member that is separated from each other.

  The illuminating device and the light emitting device according to the second embodiment of the present invention include the illuminating device 190 according to the first embodiment and the light emitting device 190 according to the first embodiment in that the luminous flux control member 260 according to the second embodiment is provided instead of the luminous flux control member 160 according to the first embodiment. Different from the light emitting device 100. Therefore, in the present embodiment, only the light flux controlling member 260 of the second embodiment will be described.

[Configuration of luminous flux control member]
FIG. 7 is a diagram illustrating a configuration of the light flux controlling member 260 of the second embodiment. 7A is a plan view of the light flux controlling member 260, FIG. 7B is a bottom view of the light flux controlling member 260, FIG. 7C is a sectional view taken along line BB in FIGS. 7A and 7B, and FIG. These are sectional drawings of the CC line in Drawing 7A and Drawing 7B. In addition, about the component same as the light beam control member 160 of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 7A to 7D, the light flux controlling member 260 has an incident region 262, an exit region 164, and a leg portion 166.

  The incident area 262 includes a first lens area 20 and a second lens area 60. The first lens region 20 is a semicircular region in plan view, and includes a first Fresnel lens portion 270 and a refracting portion 168. The second lens region 60 is a semicircular region when viewed in plan, and has a second Fresnel lens portion 280. As shown in FIG. 7B, the first Fresnel lens part 270 and the second Fresnel lens part 280 are separated from each other.

  If the first Fresnel lens part 270 and the second Fresnel lens part 280 are arranged so that the first Fresnel lens part 270 and the second Fresnel lens part 280 are not continuous, the shape of the gap 282 generated when the first Fresnel lens part 270 and the second Fresnel lens part 280 are separated from each other is formed. There is no particular limitation. For example, as shown in FIG. 7B, the center angles of the first Fresnel lens portion 270 and the second Fresnel lens portion 280 may be configured to be less than 180 °. The gap 282 is formed in a planar shape. At this time, the central angle of the gap 282 is preferably 10 to 60 ° (for example, 30 °). In this case, the center angles of the first Fresnel lens part 270 and the second Fresnel lens part 280 may be set to 170 to 120 ° (for example, 150 °). FIG. 7B illustrates a light flux controlling member 260 having an angle between the end of the first Fresnel lens unit 270 and the end of the second Fresnel lens unit 280 of 30 °. Further, the shape of the gap 282 may be the shape shown in FIG.

  In the present embodiment, the case where the shape of the gap 282 is symmetric with respect to the line CC in FIG. 7B has been shown, but the shape of the gap 282 is asymmetric with respect to the line CC. Also good.

[Illuminance distribution simulation]
The illuminance distribution on the irradiated surface was simulated for the light emitting device 200 having the light flux controlling member 260 of the second embodiment shown in FIG. For comparison, a light beam control member simulating a conventional technique (the cross-sectional shape in the minor axis direction is the cross section of FIG. 7D at any point, and the plurality of first protrusions and the plurality of second protrusions are parallel to each other). The illuminance distribution on the irradiated surface 192 was also simulated for the light emitting device having the light flux controlling member. As shown in FIG. 5A, all the light emitting devices are assumed to be installed at a height of 220 mm from the irradiated surface so that the angle between the optical axis LA of the light emitting element 140 and the irradiated surface is 45 °. did.

  FIG. 9A is a schematic plan view for explaining an illuminance measurement place. As shown in FIG. 9A, 450 mm from the point immediately below the light emitting device 200 on a straight line (Y axis) passing through the point immediately below the light emitting device 200 and the intersection of the optical axis LA of the light emitting element 140 and the irradiated surface. The point was taken as the reference position. The illuminance was simulated within a range of ± 800 mm in the X-axis direction and the Y-axis direction around the reference position.

  FIG. 9B is a simulation result of the light emitting device 200 having the light flux controlling member 260 of Embodiment 2, and FIG. 9C is a simulation result of the light emitting device having the light flux controlling member imitating the prior art.

  9B and 9C, when comparing the illuminance distribution (broken line) in the X-axis direction, the light flux control member 260 of the second embodiment emits light compared to the light flux control member imitating the prior art. It can be seen that the light is condensed (the peak width is narrow). On the other hand, when comparing the illuminance distribution (solid line) in the Y-axis direction, the illuminance at the reference position is higher in the light flux control member 260 of the second embodiment than in the light flux control member simulating the conventional technique. You can see that In comparison of the illuminance distribution in the Y-axis direction, the light flux control member 260 of the second embodiment has a wider base of the distribution curve than the light flux control member simulating the prior art, It can be seen that the range in which the illuminance value is obtained extends in the Y-axis direction. For example, when the range in which about 35 lux or more is obtained is compared, the light flux control member imitating the conventional technique has a range of −500 mm to 0 mm, but the light flux control member 260 of Embodiment 2 has a range of −500 mm to +100 mm. .

  From these results, the light flux controlling member of the present invention suppresses the spread of the emitted light in the X-axis direction to some extent, and also directs the light toward the region near the light emitting device on the irradiated surface to a position far from the light emitting device. It can be seen that generation of bright portions in the vicinity of the light emitting device and generation of dark portions at positions far from the light emitting device can be suppressed.

[effect]
In addition to the effect of the light emitting device 100 of the first embodiment, the light emitting device 200 having the light flux controlling member 260 of the second embodiment does not collect the light incident from the gap 282, and thus also in the lateral direction of the light emitting device 200. Light can be appropriately spread and the irradiated surface 192 can be illuminated more uniformly.

(Embodiment 3)
In Embodiment 3, a light flux controlling member in which the first lens region has a refracting portion and a first protrusion and the second lens region has a second Fresnel lens portion will be described.

  The illuminating device and the light emitting device according to the third embodiment of the present invention include the illuminating device 190 according to the first embodiment and the light emitting device 190 according to the first embodiment in that the light beam controlling member 360 according to the third embodiment is provided instead of the light flux controlling member 160 according to the first embodiment. Different from the light emitting device 100. Therefore, in the present embodiment, only the light flux controlling member 360 of the third embodiment will be described.

[Configuration of luminous flux control member]
FIG. 10 is a diagram illustrating a configuration of the light flux controlling member 360 according to the third embodiment. 10A is a plan view of the light flux controlling member 360, FIG. 10B is a bottom view of the light flux controlling member 360, FIG. 10C is a cross-sectional view taken along line EE in FIG. 10A, and FIG. It is sectional drawing of the FF line | wire in 10A and FIG. 10B. In addition, about the component same as the light beam control member 160 of Embodiment 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As illustrated in FIGS. 10A to 10D, the light flux controlling member 360 includes an incident region 362, an exit region 164, and a leg portion 366.

  The incident region 362 has a first lens region 30 and a second lens region 70. The first lens region 30 has a refracting portion 268 and a first protrusion 370 disposed outside the refracting portion 268.

  The refraction unit 268 causes a part of the light emitted from the light emitting element 140 to enter the light flux controlling member 360 and refracts the incident light toward the emission region 164 at a predetermined angle. The refracting portion 268 has a sector shape (semicircle) with a central angle of 180 ° when viewed in plan. The thickness of the light flux controlling member 360 in the refracting portion 268 gradually decreases as the distance from the optical axis LA of the light emitting element 140 increases. That is, the refraction part 268 can be said to be a part of a conical surface. A bus line of the refracting portion 268 (a cross section of the refracting portion 268 (a cross section of the light flux controlling member 360 including the central axis CA) is a straight line.

  The first protrusion 370 causes light emitted from the light emitting element 140 at a large angle with respect to the optical axis LA to enter the light flux control member 360 and reflects the incident light toward the emission region 164 at a predetermined angle. The first protrusion 370 is a first inclined surface 374 that is an incident surface on which light emitted from the light emitting element 140 is incident, and a reflective surface that reflects light incident from the first inclined surface 374 toward the emission region 164. A second inclined surface 376. In the first protrusion 370, the first inclined surface 374 is located on the inner side (center axis CA side), and the second inclined surface 376 is located on the outer side (leg portion 366 side). Further, in the first protrusion 370, the first inclined surface 374 and the second inclined surface 376 may be continuous or discontinuous. In the former case, a ridge line is formed between the first inclined surface 374 and the second inclined surface 376. In the latter case, another surface is formed between the first inclined surface 374 and the second inclined surface 376. Productivity can be improved by providing another surface between the first inclined surface 374 and the second inclined surface 376 and eliminating the acute angle portion (ridge line portion). In the third embodiment, one first protrusion 370 is shown, but a plurality of first protrusions 370 may be formed. Thereby, the light which goes to a to-be-irradiated surface can be increased.

  The second lens region 70 has a second Fresnel lens portion 280. A refracting surface 269 may be formed at the center of the second Fresnel lens portion 280. The refracting surface 269 has a fan-shaped (semicircle) shape with a central angle of 180 ° when viewed in plan. The thickness of the light flux controlling member 360 on the refracting surface 269 gradually decreases as the distance from the optical axis LA of the light emitting element 140 increases. That is, the refractive surface 269 can be said to be a part of a conical surface. The generatrix of the refracting surface 269 (the cross section of the refracting surface 269 (the cross section of the light flux controlling member 360 including the central axis CA) is a straight line.

  The leg portion 366 has a protrusion 169 that determines the direction in which the light flux controlling member 360 is installed on the back surface of the installation portion 167.

  FIG. 11 is an optical path diagram of the light emitting device of the third embodiment. 11A is an optical path diagram of light emitted from the light emitting element 140 at a small angle (angle θ ′) with respect to the optical axis LA, and FIG. 11B is a large angle (angle) with respect to the optical axis LA from the light emitting element 140. It is an optical path diagram of light emitted at θ ″).

  FIG. 11A shows how light R30 and R40 emitted from the light emitting element 140 at the same angle θ ′ and incident on the refracting portion 268 or the second Fresnel lens portion 280 are optically path-converted by the light flux controlling member 360. ing. FIG. 11B shows how light R50 and R60 emitted from the light emitting element 140 at an angle θ ″ and incident on the first protrusion 370 or the second Fresnel lens portion 280 are optically path-converted by the light flux controlling member 360. ing.

  As shown in FIG. 11A, the light path conversion angle θ4 of the light R41 emitted from the light emitting element 140 at an angle θ ′ and emitted from the emission region 164 via the second Fresnel lens portion 280 with respect to the incident light R40 is 140 is larger than the optical path conversion angle θ3 with respect to the incident light R30 of the light R31 emitted from the emission region 164 via the refracting portion 268 through the angle θ ′. The optical path conversion using total reflection can make the optical path conversion angle larger than the optical path conversion by refraction. Therefore, the second Fresnel lens unit 280 for greatly converting the angle of the light emitted from the light emitting element 140 in the direction toward the outside of the irradiated surface and directing the light into the irradiated surface, An inclined surface to be reflected (fourth inclined surface) is essential. On the other hand, since the first lens region 30 is sufficient to change the angle so that the light is directed toward the region away from the vicinity of the light emitting device 100 in the irradiated surface, an inclined surface for total reflection is not essential. . Adjusting the inclination angle of the incident inclined surface (third inclined surface), the total reflection inclined surface (fourth inclined surface), and the refracting portion 268 of the first lens region 30 in the second Fresnel lens portion 280. Thus, adjustment may be made so that θ4> θ3.

  Further, as shown in FIG. 11B, the optical path conversion angle θ6 of the light R61 emitted from the light emitting element 140 at an angle θ ″ and emitted from the emission region 164 via the second Fresnel lens unit 280 with respect to the incident light R60 is The light R1 emitted from the light emitting element 140 at an angle θ ″ and emitted from the emission region 164 via the first protrusion 370 is larger than the optical path conversion angle θ5 with respect to the incident light R50. The method of making θ6 larger than θ5 is the same as that of light flux controlling member 160 of the first embodiment.

[effect]
The light emitting device having light flux controlling member 360 of the third embodiment has the same effect as light emitting device 100 of the first embodiment.

  The light flux controlling member, the light emitting device, and the illuminating device of the present invention can uniformly and efficiently irradiate light emitted from the light emitting element onto a planar irradiated surface. The light emitting device and the lighting device of the present invention are useful as, for example, lighting for plant cultivation, task light (table lighting), reading light, and the like.

10, 20, 30 First lens area 50, 60, 70 Second lens area 100, 200 Light emitting device 120 Substrate 140 Light emitting element 160, 260, 360 Light flux controlling member 162, 262, 362 Incident area 164 Emission area 166, 366 Leg Part 167 Installation part 168, 268 Refraction part 169 Protrusion 170, 270 First Fresnel lens part 172, 370 First protrusion 174, 374 First inclined surface 176, 376 Second inclined surface 180, 280 Second Fresnel lens part 182 Second Protrusion 184 Third inclined surface 186 Fourth inclined surface 190 Illuminating device 192 Irradiated surface 269 Refractive surface 282 Gap CA Central axis LA Optical axis

Claims (8)

A light flux controlling member for controlling the light distribution of the light emitted from the light emitting element,
An incident region for entering light emitted from the light emitting element;
An exit region that emits light incident from the entrance region, and
The incident area is
A planar view shape having a first inclined surface for entering a part of the light emitted from the light emitting element and a second inclined surface for reflecting the light incident from the first inclined surface toward the emission region is an arc shape. A first Fresnel lens portion in which a plurality of first protrusions are concentrically arranged, or a fan-shaped refracting portion having a plan view shape that refracts a part of light emitted from the light emitting element toward the emission region. A first lens region having;
The shape in plan view having a third inclined surface for allowing another part of the light emitted from the light emitting element to enter and a fourth inclined surface for reflecting the light incident from the third inclined surface toward the emission region is a circle. A second lens region having a second Fresnel lens portion in which a plurality of arc-shaped second protrusions are arranged concentrically;
Including
The light emitting element emits light at an angle θ with respect to the optical axis, and the light path conversion angle of the light passing through the second Fresnel lens unit is emitted from the light emitting element with respect to the optical axis at the angle θ. Larger than the optical path conversion angle of the light passing through the first Fresnel lens part or the refraction part,
Luminous flux control member.   2. The light flux controlling member according to claim 1, wherein the first lens region includes the refracting portion and the first protrusion disposed outside the refracting portion.   The light flux controlling member according to claim 1, wherein the first lens region includes the first Fresnel lens portion. The first inclined surface and the third inclined surface are formed at angles capable of refracting incident light toward the second inclined surface and the fourth inclined surface, respectively.
An angle of the second inclined surface with respect to the optical axis of the light emitting element is larger than an angle of the fourth inclined surface with respect to the optical axis of the light emitting element.
The light flux controlling member according to claim 3.   The light flux controlling member according to claim 3, wherein the first Fresnel lens part and the second Fresnel lens part are separated from each other. The first lens region has the refractive part,
2. The light flux controlling member according to claim 1, wherein the thickness of the light flux controlling member in the refracting portion gradually decreases with increasing distance from the optical axis of the light emitting element. The light flux controlling member according to any one of claims 1 to 6 and a light emitting element,
The optical axis of the light emitting element coincides with the central axis of the light flux controlling member,
Light emitting device. The light emitting device according to claim 7 and a planar irradiated surface,
The light emitting device is disposed such that an optical axis of the light emitting element and the irradiated surface intersect at an acute angle, and the second lens region is closer to the irradiated surface than the first lens region.
Lighting device.