Lens array and lighting fixture equipped with the lens array

Abstract

To provide a lens array capable of light distribution control with small color unevenness and luminance unevenness of illumination light, and a lighting fixture with the lens array.SOLUTION: A lens array comprises a plurality of lenses which are provided to respective LED elements, one to one, and control distribution of light that the LED elements emit. A lens has a concave part which is formed on an incidence-side end surface and has an LED element arranged inside, and a lens outside surface which forms an outer surface of the lens and totally reflects light entering the lens from the concave part along the optical axis. The lens is constituted in a polyhedral shape having the lens outside surface divided into a plurality of faces or has a microlens part provided on the concave surface or an emission surface of the lens. Some or all of the plurality of lenses are arranged so as to differ in circumferential direction around the optical axis as an axis of rotation.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present disclosure relates to a lens array that controls the distribution of light emitted from a plurality of LED modules, and a lighting fixture that includes the lens array. [Background technology]

[0002] Conventionally, lighting fixtures that are installed on ceilings or the like and irradiate lighting spaces such as indoor spaces with light have been known. For example, lighting fixtures installed in high-ceilinged spaces such as factories, warehouses, or gymnasiums require a large amount of light so that they can illuminate brightly even from high positions, while there is a strong demand for low power consumption and compact size and weight reduction. Therefore, in order to achieve illumination with good optical efficiency (light extraction efficiency), light distribution control is performed to narrow the beam using a lens that is matched to the height of the ceiling.

[0003] For example, Patent Document 1 discloses a lens array and a lighting fixture that can perform light distribution control with good optical efficiency for a plurality of LED modules without increasing the size. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-133005 Summary of the Invention [Problem to be solved by the invention]

[0005] The lens array and lighting fixture disclosed in Patent Document 1 can efficiently narrow the light distribution without increasing the lens diameter. However, there is room for improvement in the lens array in terms of controlling the light distribution with less unevenness in color and illuminance of the illumination light.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a lens array and a lighting fixture equipped with the lens array that can perform light distribution control with little unevenness in color and illuminance of illumination light. [Means for solving the problem]

[0007] The lens array according to the present disclosure is a lens array that controls the distribution of light emitted from a plurality of LED elements, and includes a plurality of lenses that are provided one-to-one with each of the LED elements and control the distribution of light emitted by the LED elements, and the lenses each have a recess formed on an end surface on the incident side and in which the LED element is disposed, and a lens outer surface that forms the outer surface of the lens and totally reflects light that enters the lens from the recess in the direction of the optical axis, and the lens outer surface is divided into a plurality of surfaces to form a polyhedron. The outer peripheral shape of the outer surface of the lens when viewed in the optical axis direction is a regular polygon. Composition, and The microlens section is a collection of microlenses arranged in a honeycomb pattern. the recess or the exit surface of the lens to The lens has at least one of the provided configurations, and some or all of the lenses are arranged so that their circumferential orientations differ with the optical axis direction as the axis of rotation.

[0008] The lighting fixture according to the present disclosure includes an LED module in which a plurality of surface-mounted LED packages each having an LED element are mounted on a substrate, and the lens array. [Effects of the Invention]

[0009] According to the present disclosure, some or all of the multiple lenses are arranged so that their circumferential orientations are different with the optical axis direction as the axis of rotation, thereby allowing light to be mixed in the rotational direction, and color unevenness and illuminance unevenness to be suppressed without worsening the light distribution shape. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view of a lighting fixture according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the lens array according to the embodiment from the incident side. [Figure 3] FIG. 2 is a perspective view showing the lens array according to the embodiment from the irradiation side. [Figure 4] FIG. 2 is a perspective view showing a fixing member of the lighting fixture according to the embodiment. [Figure 5] 10 is an explanatory diagram showing the lighting fixture according to the embodiment, in which the lens array is fixed to the heat sink using a fixing member. FIG. [Figure 6] FIG. 2 is a perspective view of a lens of the lens array according to the embodiment, as viewed from the incident side. [Figure 7] FIG. 2 is a perspective view of a lens of the lens array according to the embodiment, as viewed from the irradiation side. [Figure 8] FIG. 2 is a plan view of lenses of the lens array according to the embodiment, viewed from the incident side. [Figure 9] FIG. 2 is a plan view of lenses of the lens array according to the embodiment, viewed from the irradiation side. [Figure 10] FIG. 2 is a longitudinal cross-sectional view of a portion of the lens array according to the embodiment. [Figure 11] FIG. 3 is a ray diagram showing the optical paths of light passing through lenses of the lens array according to the embodiment. [Figure 12] 1 is a graph showing a light distribution curve of a lighting fixture according to an embodiment. [Figure 13] 1 is an explanatory diagram showing a comparison between a simulation result of light emitted from a lighting device 100 according to an embodiment and a simulation result of light emitted from a conventional lighting device. [Figure 14] 10 is an explanatory diagram showing a comparison between a simulation result of an image of an illuminated surface of a lighting device according to an embodiment and a simulation result of an image of an illuminated surface of a conventional lighting device; FIG. [Figure 15] 10A and 10B are explanatory diagrams illustrating an example of lens arrangement in the embodiment in comparison with a conventional example of lens arrangement. [Figure 16] 10A to 10C are explanatory diagrams illustrating different examples of lens arrangements according to the embodiment in comparison with conventional lens arrangement examples. [Figure 17] 10A and 10B are explanatory diagrams showing modified examples of lenses of the lens array according to the embodiment. [Figure 18] 10A and 10B are explanatory diagrams showing modified examples of lenses of the lens array according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and their description will be omitted or simplified as appropriate. Furthermore, the shape, size, arrangement, etc. of the configurations shown in each drawing may be changed as appropriate within the scope of this disclosure.

[0012] Embodiment FIG. 1 is an exploded perspective view of a lighting fixture 100 according to an embodiment. In FIG. 1, the upper side is the ceiling side and the lower side is the illumination side. FIG. 2 is a perspective view of a lens array 3 according to an embodiment, viewed from the incident side. FIG. 3 is a perspective view of a lens array 3 according to an embodiment, viewed from the illumination side. FIG. 4 is a perspective view of a fixing member 7 of a lighting fixture 100 according to an embodiment. FIG. 5 is an explanatory diagram showing a lighting fixture 100 according to an embodiment in which the lens array 3 is fixed to a heat sink 1 using the fixing member 7.

[0013] The lighting fixture 100 according to this embodiment is suitable for use in spaces with high ceilings, such as factories, warehouses, or gymnasiums, but may also be used as a downlight or system ceiling. As shown in Fig. 1, the lighting fixture 100 includes a heat sink 1, an LED module 2, a lens array 3, and a protective cover 6. The lighting fixture 100 is arranged in this order from the upper side, which is the ceiling side, to the lower side, which is the illumination space side.

[0014] (heat sink 1) As shown in Fig. 1, the heat sink 1 has a flat base 10 and a plurality of heat dissipation fins 11 extending from the upper surface of the base 10. The heat sink 1 is formed by forcing a metal with high thermal conductivity, such as an aluminum alloy, into a casting mold. The LED module 2 is attached to the lower surface of the base 10 via a thermally conductive sheet 5. The thermally conductive sheet 5 is provided to fill the gap between the base 10 of the heat sink 1 and the substrate 20 of the LED module 2, thereby enhancing thermal conduction to the heat sink 1.

[0015] The base portion 10 has a plurality of joining holes formed therein for attaching the LED modules 2 and the protective cover 6. Furthermore, as shown in Fig. 5, a screw hole 10a is formed in the center of the base portion 10, into which a fixing member 7 for fixing the lens array 3 is screwed. The heat dissipation fins 11 are plate-shaped and have a surface that is approximately perpendicular to the upper surface of the base portion 10. The heat sink 1 dissipates heat transferred from the LED modules 2 attached to the lower surface of the base portion 10 from the heat dissipation fins 11 into the air.

[0016] (LED module 2) As shown in Fig. 1, the LED module 2 has a configuration in which a plurality of LED packages 21, each having an LED (Light Emitting Diode) element, are arranged on a substantially circular substrate 20. The LED packages 21 are of the SMD (Surface Mounted Device) type. The LED packages 21 emit white light. The light-emitting surface of the LED module 2 on which the LED packages 21 are arranged faces the irradiation direction.

[0017] A through-hole 20a is formed in the center of the substrate 20 for passing through the shaft of the fixing member 7 that fixes the lens array 3 to the heat sink 1. Although not shown, the substrate 20 also has a bonding hole formed therein for passing through a bonding member that joins the LED module 2 to the base 10 of the heat sink 1. The bonding member is, for example, a screw. The LED module 2 is fixed to the base 10 by abutting the substrate 20 against the underside of the base 10 of the heat sink 1 via the thermally conductive sheet 5, and then screwing the bonding member, which has passed through the bonding hole, into the bonding hole formed in the base 10 of the heat sink 1. The thermally conductive sheet 5 also has a through-hole formed therein for passing through the shaft of the bonding member.

[0018] It should be noted that a general characteristic of LEDs is that the luminous efficiency (1 m / W) of the LED package 21 itself increases as the current flowing through the LED package 21 or the temperature of the LED element decreases. Mounting many LED packages 21 to obtain the required amount of light can reduce the current flowing per LED package 21 and suppress heat concentration. Therefore, mounting many small LED packages 21 on a board can increase the luminous efficiency (1 m / W) while obtaining the same amount of light emission (luminous flux) rather than passing a large current through a large LED package 21 to emit light.

[0019] (Lens array 3) 1, the lens array 3 controls the distribution of light emitted from the LED package 21. The lens array 3 is made of a light-transmitting material such as resin or glass, but may also be made of a material that contains a diffusion material.

[0020] The lens array 3 has approximately the same size as the substrate 20 of the LED module 2 in a plan view. As shown in FIG. 2, the lens array 3 has a plurality of lenses 4 that protrude toward the LED module 2. The lens array 3 has a frame portion 30 as an outer periphery that surrounds the periphery of the plurality of lenses 4. The lens array 3 is formed by integrally molding the plurality of lenses 4 and the frame portion 30. The lens array 3 is arranged to cover the light-emitting surface of the LED module 2, and is fixed to the heat sink 1 with the LED module 2 and a thermally conductive sheet 5 sandwiched therebetween.

[0021] The lenses 4 are provided in one-to-one correspondence with each LED package 21, and control the light distribution so that the light emitted from the LED packages 21 travels in a target direction. By controlling the light distribution of the omnidirectional light emitted from each LED package 21 with the corresponding lenses 4, it is possible to improve optical efficiency (light extraction efficiency). The detailed structure and light distribution of the lenses 4 will be described later.

[0022] The number of lenses 4 does not have to match the number of LED packages 21. In other words, it is sufficient that there is a one-to-one relationship between the lenses 4 and the LED packages 21 that face each other, and there may be lenses 4 on which no LED packages 21 are mounted.

[0023] As shown in FIG. 2 , the frame 30 is provided with bosses 31 that protrude toward the LED module 2. The bosses 31 are molded integrally with the frame 30. Eight bosses 31 are provided at regular intervals around the circumferential direction of the frame 30. The bosses 31 are provided to suppress warping of the lens array 3 toward the LED module 2. When the lens array 3 tries to warp toward the LED module 2, the bosses 31 abut against the substrate 20 of the LED module 2, thereby suppressing the warping. In addition, the bosses 31 abut against the substrate 20 of the LED module 2, thereby suppressing misalignment of the lens array 3. The number of bosses 31 is not limited to eight as shown in the figure, and may be changed as appropriate depending on the size and shape of the lens array 3.

[0024] 2 and 3, a fixing portion 32 is formed in the center of the lens array 3 for passing the fixing member 7 shown in FIG. 4 through. The fixing portion 32 has a cylindrical shape that protrudes toward the LED module 2. As shown in FIG. 5, the fixing portion 32 has a first hole 32a formed on the irradiation side and a second hole 32b formed on the LED module side. The second hole 32b has a larger diameter than the first hole 32a, and a step 32c is formed between the second hole 32b and the first hole 32a.

[0025] As shown in FIGS. 4 and 5 , the fixing member 7 is, for example, a screw. The shank of the fixing member 7 includes a first shank 71 extending axially from a screw head 70 and a second shank 72 extending axially from the distal end surface of the first shank 71. The first shank 71 and the second shank 72 are cylindrical. The first shank 71 has a larger diameter than the second shank 72. The first shank 71 is longer than the second hole 32b. Although not shown, the outer surface of the second shank 72 has a helical thread groove. The shank of the fixing member 7 is inserted into the fixing portion 32 of the lens array 3 from the irradiation side, and the shank is passed through the through-hole 20a in the substrate 20 of the LED module 2 and the through-hole formed in the thermal conduction sheet 5. The second shank 72 is screwed into the screw hole 10a formed in the base portion 10 of the heat sink 1. At this time, as shown in FIG. 5 , the screw head 70 abuts against the step 32c between the first hole 32a and the second hole 32b and fits into the first hole 32a. The first shank 71 fits into the second hole 32b of the fixing part 32. In this embodiment, the first shank 71 is longer than the second hole 32b. Therefore, when the fixing member 7 is tightened, the end face of the first shank 71 can abut against the substrate 20 of the LED module 2. This prevents the resin fixing part 32 from coming into strong contact with the substrate 20 and being crushed by the fastening force. In this manner, the lens array 3 and the LED module 2 are fastened together by the fixing member 7 inserted into the fixing part 32, and the lens array 3 is fixed to the base part 10 of the heat sink 1.

[0026] (Protective cover 6) As shown in FIG. 1 , the protective cover 6 covers and protects the LED module 2 and the lens array 3. The protective cover 6 is a transparent cover that transmits light emitted by the LED module 2. The protective cover 6 is concave and has a flange portion 60 that protrudes outward along the edge of the opening on the top surface. With the LED module 2 and the lens array 3 housed inside the concave, the protective cover 6 is attached to the base portion 10 of the heat sink 1 by placing the upper surface of the flange portion 60 against the base portion 10 of the heat sink 1 and using connecting members such as screws that are inserted through through holes formed in the flange portion 60. Even if the lighting fixture 100 receives an external impact, such as a ball thrown by a child playing in a gymnasium, the LED module 2 and the lens array 3 are protected by the protective cover 6, preventing malfunctions such as failure to light.

[0027] Next, the structure and light distribution of the lens array 3 according to the present embodiment will be described in detail with reference to FIGS. 6 to 13. FIG. 6 is a perspective view of a lens 4 of the lens array 3 according to the embodiment, as viewed from the incident side. FIG. 7 is a perspective view of a lens 4 of the lens array 3 according to the embodiment, as viewed from the illumination side. FIG. 8 is a plan view of a lens 4 of the lens array 3 according to the embodiment, as viewed from the incident side. FIG. 9 is a plan view of a lens 4 of the lens array 3 according to the embodiment, as viewed from the illumination side. FIG. 10 is a longitudinal cross-sectional view of a portion of the lens array 3 according to the embodiment. FIG. 11 is a ray diagram showing the optical paths of light passing through the lens 4 of the lens array 3 according to the embodiment. FIG. 12 is a graph showing the light distribution curve of the lighting fixture 100 according to the embodiment. In FIG. 12, the horizontal axis represents the angle of the emission direction when the optical axis direction P is set to 0°, and the vertical axis represents luminous intensity [cd].

[0028] FIG. 13 is an explanatory diagram comparing the simulation results of light irradiated from the lighting fixture 100 according to the embodiment with the simulation results of light irradiated from a conventional lighting fixture. FIG. 13(a) shows the simulation results of light irradiated from the conventional lighting fixture. FIG. 13(b) shows the simulation results of light irradiated from the lighting fixture 100 according to the embodiment. FIG. 14 is an explanatory diagram comparing the simulation results of the illumination surface image of the lighting fixture 100 according to the embodiment with the simulation results of the illumination surface image of the conventional lighting fixture. FIG. 14(a) shows the simulation results of the illumination surface image of the conventional lighting fixture. FIG. 14(b) shows the simulation results of the illumination surface image of the lighting fixture 100 according to the embodiment. FIG. 15 is an explanatory diagram comparing an example of the arrangement of the lens 4 according to the embodiment with an example of the arrangement of the conventional lens. FIG. 15(a) shows an example of the arrangement of the conventional lens. FIG. 15(b) shows an example of the arrangement of the lens 4 according to the embodiment.

[0029] As shown in Figures 6 to 10, the lens 4 has a truncated cone shape. The lens 4 has a first recess 41 formed on its incident-side end face and a second recess 42 formed on its irradiation-side end face. A flat lens center portion 43 (see Figure 10) is provided between the first recess 41 and the second recess 42. The upper surface of the lens center portion 43 forms the groove bottom surface of the first recess 41, and the lower surface forms the groove bottom surface of the second recess 42.

[0030] 10 , when the LED module 2 and the lens array 3 are combined, the light-emitting portion of the LED package 21 is disposed inside the first recess 41 of the lens 4. Light emitted from the LED package 21 enters the lens 4 from the groove side surface 41 a and the groove bottom surface of the first recess 41. By surrounding the convex portion that serves as the light-emitting portion of the LED package 21 with the groove side surface 41 a of the first recess 41, the light emitted from the LED package 21 and spreading in a hemispherical direction can be efficiently taken into the groove side surface 41 a of the first recess 41.

[0031] 10, the groove side surface 41a of the first recess 41 has a gentle S-curve shape from the opening surface toward the bottom surface, and is formed so that the hole diameter decreases from the opening surface toward the groove bottom surface. This increases the amount of light entering through the groove side surface 41a, while providing a sufficient space between the groove side surface 41a of the first recess 41 and the light-emitting portion of the LED package 21 arranged inside the first recess 41, allowing the LED package 21 to be arranged so as not to interfere with the lens 4. Note that the groove side surface 41a of the first recess 41 is not limited to the illustrated S-curve shape, and may be, for example, a linear inclined surface, two inclined surfaces with different angles, or any other shape.

[0032] The groove bottom surface of the first recess 41 is flat. A microlens portion 44 is provided on the groove bottom surface of the first recess 41. The microlens portion 44 is an assembly of hexagonal (honeycomb) microlenses. By providing the microlens portion 44, it is possible to appropriately diffuse (diffuse with directionality) the light incident on the lens center portion 43, and to suppress color unevenness irradiated from the outer surface 45a of the convex portion 45. Note that the microlens portion 44 is not limited to the hexagonal (honeycomb) shape shown in the figure, and may be, for example, an assembly of round microlenses or another shape.

[0033] 6 to 10, the lens 4 has a lens outer surface 40 that forms the outer surface of a truncated cone and is formed so as to describe a gentle arc between an upper base portion and a lower base portion. The lens outer surface 40 is a polyhedron divided into a plurality of surfaces, and is configured to totally reflect light that enters the lens 4 from the groove side surface 41a of the first recess 41 in the optical axis direction P.

[0034] Although the illustrated lens 4 has a configuration including a polyhedral lens outer surface 40 and a microlens portion 44, it is sufficient if the lens 4 has at least one of these. For example, if the lens 4 has a configuration including a microlens portion 44, the lens outer surface 40 may be configured as a single curved surface rather than a polyhedral surface. Furthermore, if the illustrated lens 4 has a configuration including a polyhedral lens outer surface 40, the microlens portion 44 may be omitted.

[0035] The groove side of the second recess 42 has an inwardly concave curved surface portion 42a extending from the opening surface to the intermediate portion, and a flat, inclined surface portion 42b extending from the end of the curved surface portion 42a to the groove bottom. The curved surface portion 42a and the inclined surface portion 42b are formed continuously. The second recess 42 is formed so that the hole diameter decreases from the opening surface to the bottom surface. The intermediate portion is the approximate center portion between the opening surface and the groove bottom surface of the second recess 42 in the vertical direction of the lighting fixture 100.

[0036] A convex portion 45 protruding toward the irradiation side is provided on the groove bottom surface of the second recess 42. The convex portion 45 has a truncated cone shape that narrows toward the irradiation side. The convex portion 45 has a polyhedral shape in which an outer surface 45a of the truncated cone is divided into multiple surfaces. The outer diameter of the convex portion 45 is larger than the inner diameter of the groove bottom surface of the first recess 41 on which the microlens portion 44 is provided. By providing the convex portion 45 in this manner, as shown in FIG. 11 , light that enters the groove bottom surface (microlens portion 44) of the first recess 41 is refracted inward by the outer surface 45a of the convex portion 45 and is emitted from the second recess 42 into the irradiation space without re-entering the lens 4, thereby enabling efficient (high light extraction efficiency) narrowing of the light distribution.

[0037] Next, the optical path of light passing through lens 4 of lens array 3 according to the embodiment will be described with reference to Fig. 11. In lighting device 100 according to the present embodiment, as shown in Fig. 11, of the light emitted from LED package 21, the light that enters lens 4 from groove side surface 41a of first recess 41 is totally reflected by polyhedral lens outer surface 40 in optical axis direction P, passes through curved surface 42a of second recess 42, and is irradiated into the illumination space. In this way, by totally reflecting the light that enters lens 4 from groove side surface 41a of first recess 41 on lens outer surface 40, it is possible to narrow the light distribution to a small diameter and efficiently.

[0038] 11 , in the lighting device 100 according to the present embodiment, the light emitted from the LED package 21 and passing through the groove bottom surface (microlens portion 44) of the first recess 41 passes through the groove bottom surface of the second recess 42 and the convex portion 45, and is emitted into the illumination space. Of the light passing through the convex portion 45, the light passing through the outer surface 45a of the convex portion 45 is refracted toward the optical axis direction P and is emitted from the second recess 42 into the illumination space without re-entering the lens 4. That is, in the lighting device 100, by providing the convex portion 45 with the polyhedral outer surface 45a, the light distribution can be narrowed, and the optical efficiency is improved by preventing the light from re-entering the lens 4. On the other hand, of the light passing through the convex portion 45, the light passing through the tip surface of the convex portion 45 is emitted into the illumination space without being refracted.

[0039] 12 compares the light distribution when the lens 4 of this embodiment is used with the light distribution when only the LED module 2 is used without using the lens 4. As shown in Fig. 12, when the lens 4 of this embodiment is used, the beam angle is narrowed and the central luminous intensity is increased, so that direct illuminance can be obtained efficiently in, for example, a lighting fixture for a high ceiling.

[0040] Generally, white LED packages produce white light by mixing the blue light emitted by the LED element with the yellow-based light emitted by a phosphor using this as excitation light, but the light color tends to be biased toward blue or yellow depending on the direction due to differences in the distance the blue light travels through the phosphor layer. When the light from this white LED is controlled using a lens or other device, the bias in the color of the light source depending on the direction is further emphasized, which can appear as color unevenness on the illuminated surface.

[0041] To address this issue, conventional approaches have involved roughening the lens's entrance or exit surface to provide diffusion. However, while the more the lens's entrance or exit surface is roughened, the more unevenness is reduced, the worse the light distribution pattern and optical efficiency tend to be. Therefore, the lighting fixture 100 according to this embodiment is configured with a polyhedral lens outer surface 40 and microlens portion 44, which are divided into multiple surfaces. This allows for optimal light mixing and suppression of color unevenness while minimizing deterioration of the light distribution pattern and optical efficiency. Figure 13 shows an image of the illumination surface (simulation results) demonstrating this effect. Figure 13(a) is an explanatory diagram showing light emitted from a conventional lighting fixture. Figure 13(b) is an explanatory diagram showing light emitted from the lighting fixture 100 according to this embodiment. As shown in Figure 13(b), the lighting fixture 100 according to this embodiment not only suppresses color unevenness but also alleviates the projection of the LED chip image seen in the absence of a mixing means, resulting in a natural, circular illumination image.

[0042] However, the rougher the polyhedral lens outer surface 40 and microlens portion 44, the greater the degree of light mixing. However, when light is shone onto a wall close to the lighting fixture 100, the roughness of the shape of the polyhedral lens outer surface 40 and microlens portion 44 may appear as unevenness on the wall, as shown in Figure 14(a). As mentioned above, this unevenness can be improved by lightly roughening the entrance or exit surface of the lens, but this will significantly deteriorate the optical efficiency and light distribution.

[0043] Therefore, in the lens array 3 according to this embodiment, all of the lenses 4 are arranged so that their circumferential orientations differ with the optical axis direction P as the axis of rotation. For example, as shown in FIG. 15 , if the polyhedron formed on the lens outer surface 40 is divided into eight pieces in the circumferential direction around the optical axis direction P, the inclination of one divided surface is 45 degrees, and therefore each lens 4 is rotated by a rotation angle smaller than 45 degrees. For example, if nine lenses 4 are arranged, the rotation angles are set to 0 degrees, 5 degrees, 10 degrees, 40 degrees, and so on, each differing by 5 degrees. In this case, a rotation angle of 45 degrees is the same as a rotation angle of 0 degrees.

[0044] 14(b), it can be seen that there is no unevenness in the lens array 3 in which the lenses 4 are arranged so that their orientations in the circumferential direction differ with the optical axis direction P as the axis of rotation. This is because the orientations of the lenses 4 are different, which allows the light to be mixed in the rotational direction. In other words, with the lighting device 100 according to this embodiment, it is possible to mix the light in the rotational direction, thereby suppressing the unevenness of light that occurs due to the roughness of the shape of the polyhedral lens outer surfaces 40 and the microlens portions 44, and it is possible to efficiently control the light distribution with little unevenness in color and illuminance.

[0045] In the lens array 3 according to the present embodiment, some of the lenses 4 may be arranged so that their circumferential directions differ with respect to the optical axis direction P as the axis of rotation. Even in this case, light diffusion (moderate diffusion with directionality) can be obtained, and therefore unevenness in light caused by the roughness of the shape of the polyhedral lens outer surface 40 and the microlens portion 44 can be suppressed.

[0046] 15(b), the lens array 3 according to this embodiment may be configured such that nine lenses 4 are arranged in different circumferential directions around the optical axis direction P as a rotation axis, forming one block, and a plurality of such blocks are arranged side by side. The number of lenses 4 in one block is not limited to nine as shown in the figure, and other numbers may be used. Even in this case, light diffusion (moderate diffusion with directionality) can be obtained, so that unevenness in light caused by the roughness of the shape of the polyhedral lens outer surface 40 and the microlens portion 44 can be suppressed, and light distribution control with little unevenness in color and illuminance of the illumination light can be performed.

[0047] FIG. 16 is an explanatory diagram comparing different arrangements of lenses 4 according to the embodiment with conventional lens arrangements. FIG. 16(a) shows an example of a conventional lens arrangement. FIG. 16(b) shows a different arrangement of lenses 4 according to the embodiment. The lens array 3 shown in FIG. 16(b) has a configuration in which, among the multiple lenses 4, lenses 4 are arranged in a rotationally symmetrical manner, with the optical axis direction P as the axis of rotation, and the lenses 4 are arranged so that their circumferential orientations differ. Even in this case, light diffusion can be achieved, so that light unevenness caused by the roughness of the shape of the polyhedral lens outer surface 40 and the microlens portion 44 can be suppressed, and light distribution control with less color unevenness and illuminance unevenness in the illumination light can be performed.

[0048] 17 and 18 are explanatory diagrams showing modified examples of the lens 4 of the lens array 3 according to the embodiment. (a) is a perspective view of the lens 4 as seen from the incident side, (b) is a perspective view of the lens 4 as seen from the irradiation side, and (c) is a longitudinal cross-sectional view of the lens 4. As shown in FIGS. 17 and 18, the positions of the microlens portion 44 and the convex portion 45 may be interchanged. The lens 4 shown in FIG. 17 has a configuration in which the convex portion 45 is formed in the portion where the microlens portion 44 is provided in FIGS. 6 to 10, and the microlens portion 44 is provided in the portion where the convex portion 45 is provided in FIGS. 6 to 10. Furthermore, the lens 4 shown in FIG. 18 has a configuration in which the microlens portion 44 is provided on the exit surface of the lens 4. Specifically, the opening surface of the second recess 42 is covered with a flat surface, and the microlens portion 44 is provided on the flat surface, which serves as the exit surface.

[0049] The lens array 3 and the lighting fixture 100 including the lens array 3 have been described above based on the embodiment, but the lens array 3 and the lighting fixture 100 including the lens array 3 are not limited to the configuration of the above-described embodiment. The configuration of the lens array 3 and the lighting fixture 100 including the lens array 3 is one example, and the lighting fixture 100 may include other components. In short, the lens array 3 and the lighting fixture 100 including the lens array 3 include design modifications and application variations that are normally made by a person skilled in the art, as long as they do not deviate from the technical concept thereof. [Explanation of symbols]

[0050] 1 heat sink, 2 LED module, 3 lens array, 4 lens, 5 thermal conduction sheet, 6 protective cover, 7 fixing member, 10 base portion, 10a screw hole, 11 heat dissipation fin, 20 substrate, 20a through hole, 21 LED package, 30 frame portion, 31 boss portion, 32 fixing portion, 32a first hole portion, 32b second hole portion, 32c step portion, 40 lens outer surface, 41 first recessed portion, 41a groove side surface, 42 second recessed portion, 42a curved surface portion, 42b inclined surface portion, 43 lens center portion, 44 microlens portion, 45 convex portion, 45a outer surface, 60 flange portion, 70 screw head, 71 first axis portion, 72 second axis portion, 100 lighting fixture, P optical axis direction.

Claims

1. A lens array that controls the distribution of light emitted from a plurality of LED elements, a plurality of lenses provided one-to-one with each of the LED elements to control the distribution of light emitted by the LED elements; the lens has a recess formed on an end surface on the incident side, the recess having the LED element disposed therein; a lens outer surface that forms the outer surface of the lens and totally reflects light that has entered the lens from the recess toward the optical axis, The lens is The lens outer surface is divided into a plurality of surfaces to form a polyhedron, and the outer peripheral shape of the lens outer surface when viewed in the optical axis direction is a regular polygon; and A microlens portion, which is an assembly of microlenses arranged in a honeycomb pattern, is provided in the recess or on the light exit surface of the lens. It has at least one of the following configurations: A lens array in which some or all of the lenses among the plurality of lenses are arranged so that their circumferential orientations differ with respect to the optical axis direction as the axis of rotation.

2. 2. The lens array according to claim 1, wherein the plurality of lenses are arranged in a block, with some of the lenses arranged so that their circumferential orientations differ with the optical axis direction as the axis of rotation, and multiple such blocks are arranged side by side.

3. The lens array according to claim 1 , wherein the plurality of lenses are arranged in rotational symmetry with the optical axis direction as the axis of rotation, and the lenses are arranged so that their circumferential orientations differ.

4. an LED module in which a plurality of surface-mounted LED packages each having an LED element are mounted on a substrate; A lighting fixture comprising the lens array according to any one of claims 1 to 3.

5. a heat sink for dissipating heat generated by the LED module; The lighting fixture according to claim 4 , wherein the LED module and the lens array are fixed to the heat sink by a common fixing member.

6. The lighting fixture according to claim 4 or 5, further comprising a protective cover that covers and protects the LED module and the lens array.

Images