JP7064762B2 - Lighting equipment and optics - Google Patents

Description

The present invention relates to a lighting device including an optical member that controls light distribution from a light source unit.

For example, Patent Document 1 is a lighting device including an optical member for controlling light distribution.
The lighting device described in Patent Document 1 includes "a light source, a first surface arranged on the light source side, and a second surface from which light incident from the first surface is emitted, and light incident from the light source. The optical member includes a translucent optical member that controls the light distribution of the light, and the optical member controls the optical path of the light by totally reflecting at least a part of the light incident from the light source. The second surface comprises a controlled light region in which the fully reflected light is emitted and a non-controlled light region in which the light not totally reflected is emitted, among the light incident on the total reflecting portion. In addition, at least a part of the non-controlled light region diffuses the emitted light more than at least a part of the controlled light region. "

Japanese Unexamined Patent Publication No. 2017-50187

The lighting device is optically designed as a single device. That is, the lighting device is optically designed by combining an optical member and a reflecting member, and it is difficult to use the optical member for another lighting device having a different reflecting member.
An object of the present invention is to provide a lighting device provided with a highly versatile optical member and a highly versatile optical member.

The lighting device according to the present invention includes a light source unit including a light emitting element as a light source, an optical member for controlling the orientation of light generated from the light source unit, and a reflecting member for reflecting light emitted from the optical member. The optical member emits light emitted from the light source unit in a direction away from the central axis of the optical member within a range not directed toward the reflecting member.

The optical member according to the present invention is an optical member for controlling the orientation of light generated from a light source unit, in which a flat portion formed at a portion facing the light source unit and a convex state on the opposite side to the light source unit. It has a curved portion that curves from the peripheral edge of the flat portion to the side where the light source unit exists, and from a plurality of concentric ridges centered on the central axis on the surface of the curved portion on the light source unit side. The Fresnel lens is formed, and the multiple ridges include a group of small ridges having a low height in a direction parallel to the central axis of the ridges and a group of large ridges having a high height.
The small ridges are located on the flat portion side, and the ridges included in the small ridges are a peripheral surface portion extending in parallel with the central axis and an end portion of the peripheral surface portion located on the light source unit side. It has a Fresnel lens portion extending in a curved shape from the above to the end portion located on the opposite side of the light source unit on the peripheral surface portion of the other convex stripes adjacent to the outer peripheral side of the convex stripes, and the small convex stripes group. The height of the peripheral surface portion of the included ridges in the central axis direction is within a range of 0.4 times or more and 0.6 times or less with respect to the radial length of the ridges.

According to the above configuration, the optical member alone can secure a 1/2 illuminance angle of 60 [°] or more without using the reflective member, and even when used in combination with the reflective member having a larger opening than the light source member, 60 [ °] Or more 1/2 illuminance angle can be obtained.

(A) is a perspective view of the lighting device seen from the front side, and (b) is a perspective view of the lighting device seen from the back side. It is a perspective view which looked at the disassembled state of a lighting apparatus from the front side. It is a perspective view which looked at the disassembled state of a lighting device from the back side. It is a cross-sectional perspective view of a lighting device, (a) is a view seen from the front side, and (b) is a view seen from the back side. It is the figure which looked at the optical unit from the upper side, and is the figure which showed the arrangement relation of the LED element in an optical unit. It is a cross-sectional enlarged view of the peripheral part of an optical member. (A) is a view of the optical member viewed from the front side, and (b) is a view of the optical member viewed from the back side. (A) and (b) are diagrams for explaining an optical path when the optical unit emits light. It is an orientation characteristic diagram of the lighting apparatus which does not have a reflective member. (A), (b), and (c) are orientation characteristic diagrams of lighting devices having different reflecting members.

<Overview>
The lighting device according to one embodiment of the embodiment includes a light source unit including a light emitting element as a light source, an optical member for controlling the orientation of light generated from the light source unit, and reflection for reflecting light emitted from the optical member. The optical member includes a member, and the optical member emits light emitted from the light source unit in a direction away from the central axis of the optical member within a range not directed toward the reflecting member.
In the lighting device according to another embodiment of the embodiment, the optical member has a flat portion formed at a portion facing the light source unit and a convex state on the opposite side to the light source unit, from the peripheral edge of the flat portion. It has a curved portion that curves to the side where the light source unit exists, and a Fresnel lens composed of a plurality of concentric ridges centered on the central axis is formed on the surface of the curved portion on the light source unit side. There is. As a result, it is possible to secure a 1/2 illuminance angle of 60 [°] or more with the optical member alone.

In the lighting device according to another embodiment of the embodiment, the plurality of ridges are a group of small ridges having a low height in a direction parallel to the central axis of the ridges and a group of large ridges having a high height. The small ridges are located on the flat portion side, and the ridges included in the small ridges are located on the peripheral surface portion extending in parallel with the central axis and on the light source unit side in the peripheral surface portion. It has a Fresnel lens portion that extends in a curved shape from the end portion to the end portion located on the opposite side of the light source unit on the peripheral surface portion of another convex strip adjacent to the outer peripheral side of the convex strip. The height of the peripheral surface of the convex strip included in the strip group in the central axis direction is within a range of 0.4 times or more and 0.6 times or less with respect to the radial length of the convex strip. As a result, it is possible to secure a 1/2 illuminance angle of 60 [°] or more with the optical member alone.

<First Embodiment>
1. 1. Outline As shown in FIG. 1, the lighting device 1 according to the embodiment is a so-called downlight used in a state of being fitted to an opening (not shown) of an installation surface such as a ceiling wall.
The lighting device 1 is a device that illuminates one side in a direction orthogonal to the installation surface. When the installation surface is a ceiling wall, the irradiation direction is downward. Here, the light emission direction is the front side or the lower side, and the installation surface side is the back side or the upper side.
As shown in FIGS. 2 and 3, the lighting device 1 includes a light source unit 2, an optical member 3, and a reflection member 4. In the lighting device 1, the light emitted from the light source unit 2 is oriented and controlled by the optical member 3, and a part of the controlled light and the light reflected by the reflecting member 4 are emitted from the device.

Here, the lighting device 1 includes a heat radiating member 5 on which the light source unit 2 is mounted, and a holder 6 for mounting the light source unit 2 on the radiating member 5. The lighting device 1 includes a frame 7 for fixing the reflective member 4.
That is, the lighting device 1 as an example is emitted from the light source unit 2, the heat radiation member 5 having the light source unit 2 mounted on the surface, the holder 6 for fixing the light source unit 2 to the heat radiation member 5, and the light source unit 2. It includes an optical member 3 that controls the distribution of the light, a reflection member 4 that reflects a part of the light emitted from the optical member 3, and a frame 7 that holds the optical member 3 and the reflection member 4.
The lighting device 1 includes a plurality of (here, two) mounting springs 81 for mounting the device on the installation surface.
Hereinafter, each part will be described.

2. 2. Configuration of each part (1) Light source part This section will be mainly described with reference to FIGS. 2 and 3.
The light source unit 2 includes one or a plurality of LED elements as a light source, and the LED elements are mounted on the substrate 21. The LED element is covered with the translucent resin 23. Therefore, the LED element does not appear in FIG. The arrangement of the LED elements will be described later with reference to FIG.

(2) Heat-dissipating member As shown in FIGS. 2 and 3, the heat-dissipating member 5 has a mounting member 51 and a plurality of fins 53. The heat radiating member 5 here has a positioning plate 52 that prevents interference of a plurality of fins 53. The light source unit 2 is mounted on the mounting member 51 via the insulating sheet 82.

(2-1) Mounting member The mounting member 51 has a disk shape and has a light source unit mounting portion 511 in the central portion thereof. The mounting member 51 has a plurality of screw holes 513 for fixing fins. The mounting member 51 has a screw hole 515 for fixing the holder. The mounting member 51 has a through hole 516 for assembly. The mounting member 51 has a chipped portion 517 for a fixture 83 for fixing a power feeding cable (not shown) for supplying power to the light source unit 2. The mounting member 51 has a screw hole 519 for a screw 91 that fixes the ground wire 84.

(2-2) Fins The fins 53 are made of a thin plate material. The fin 53 is composed of a plurality of fin plates 55 and 57. The fin plate 55 is processed into a "U" shape having a pair of fin portions 551 and a connecting portion 553 connecting the pair of fin portions 551. The fin plate 57 is processed into an "L" shape having a fin portion 571 on the long side and a fin portion 573 on the short side.
The two fin plates 57 and the three fin plates 55 are fixed from the screws 92 screwed into the screw holes 513 of the mounting member 51 in a state where the three fin plates 55 to be arranged side by side are sandwiched from the outside in the parallel arrangement direction. Has been done.

(3) Holder Hereinafter, the description will be made mainly with reference to FIGS. 3 and 4.
The holder 6 has a function of holding the light source unit 2 mounted on the surface of the heat radiating member 5 (mounting member 51). The light source unit 2 is attached so that the translucent resin 23 is exposed on the front side.
The holder 6 has a plate-shaped portion 62 having an opening 61 for the translucent resin 23 of the light source unit 2. The holder 6 has a plurality of through holes 63 in the plate-shaped portion 62, and the screw 93 through which the through hole 63 is inserted is screwed into the screw hole 515 of the mounting member 51. As a result, the light source unit 2 is attached to the mounting member 51 in a state of pressing (supporting) the substrate 21 against the mounting member 51.
The holder 6 has a chipped portion 64 for the fixing tool 83 for fixing the power feeding cable in the plate-shaped portion 62. The holder 6 has a plurality (for example, three) plate-shaped portions 62 having chipped portions 65 for screws 94 for fixing the frame 7 to the heat radiating member 5 (mounting member 51) at intervals in the circumferential direction.

(4) Optical Member The optical member 3 will be described with reference to FIG.
The optical member 3 is made of a translucent resin. The optical member 3 has a spherical crown shape as a whole, and has a flat portion 31 facing the light source unit 2 and a curved portion 32 curved from the peripheral edge of the flat portion 31 to the back side.
As shown in the enlarged view of FIG. 6A, irregular dimples 33 are formed on the surfaces of the flat portion 31 and the curved portion 32. A plurality of ridges (grooves) 34 constituting the Fresnel lens are concentrically formed on the back surface of the curved portion 32.
The optical member 3 has a stepped portion 35 (see FIG. 4) formed on the outer peripheral edge of the curved portion 32. The optical member 3 is attached to the holder 6 by using the step portion 35.
The optical member 3 is configured such that the 1/2 illuminance angle on an illuminance plane 3 [m] away is 60 [°] or more in a lighting device not provided with the reflection member 4.
The dimples 33 and the ridges 34 will be described in detail later.

(5) Reflective member The reflective member 4 has a cylindrical portion 41 having a cylindrical shape that expands on the front side, and a reflective surface 43 formed on the inner peripheral surface of the tubular portion 41. The reflective member 4 has a plurality (three) of overhanging portions 45 projecting outward in the radial direction at the back end portion of the tubular portion 41 at equal intervals in the circumferential direction. The overhanging portion 45 engages with the engaging portion 741 of the back inner flange portion 74 of the frame 7, which will be described later. The reflective surface 43 here is composed of a high-reflectance white paint applied to the inner peripheral surface of the tubular portion 41.
As shown in FIG. 4, the back opening of the tubular portion 41 of the reflective member 4 fits with the stepped portion 35 of the optical member 3 when the optical member 3, the reflective member 4, and the frame 7 are mounted on the heat radiation member 5. do.

(6) Frame This will be described mainly with reference to FIGS. 2 and 3.
The frame 7 has a tubular portion 71 that can accommodate the reflective member 4 inside.
The frame 7 has an outer flange portion 72 protruding outward in the radial direction at the front end portion of the tubular portion 71. When the lighting device 1 is attached to the opening of the installation surface, the outer flange portion 72 faces the peripheral portion of the opening of the installation surface.
The frame 7 has a fixing portion 73 for fixing the mounting spring 81 on the outer peripheral surface of the tubular portion 71. The fixing portion 73 is composed of a fitting groove or the like that fits with the mounting portion 811 of the mounting spring 81.
As shown in FIG. 3, the frame 7 has a back inner flange portion 74 projecting inward in the radial direction at a portion close to the back end of the tubular portion 71. The frame 7 has a plurality (three) of an engaging portion 741 that engages with the overhanging portion 45 of the reflective member 4 and a chipped portion 742 that receives the overhanging portion 45 at intervals in the circumferential direction. There is.
The frame 7 has a boss portion 75 projecting to the back side in the back inner flange portion 74. A screw hole 751 is provided in the boss portion 75, and a screw 94 through which the through hole 516 of the mounting member 51 is inserted is screwed into the screw hole 751. As a result, the optical member 3, the reflection member 4, and the frame 7 are attached to the heat dissipation member 5.

3. 3. Optical member The optical member 3 is optically designed so as to reflect and refract the light emitted from the light source unit 2 to reduce the light directed to the reflecting member 4. Specifically, the light incident at an angle with respect to the main emission direction of the LED element (the direction orthogonal to the light emitting layer of the LED and including the parallel direction) is spread with respect to the central axis of the optical member 3. Is refracted to. As a result, the amount of light that reaches the reflective member 4 from the optical member 3 can be reduced, and even if the optical member is used for a different lighting device of the reflective member 4, the influence of the reflective member can be reduced.

Hereinafter, a specific description will be given.
(1) Light Source Unit First, the arrangement of the LED elements of the light source unit 2 will be described. As shown in FIG. 5, the light source unit 2 includes 18 LED elements 25. The 18 LED elements 25 have a square shape with a side of 1.3 [mm] when viewed from the light emission direction. The 18 LED elements 25 are of the same type, and the four LED elements 25 are arranged in a straight line in the center of the LED substrate (row A in FIG. 5). These four LED elements 25 are referred to as a group A. The pitch of the two LED elements 25 on the center side in the group A is 2.2 [mm], and the pitch between the two LED elements 25 in the center and the LED elements 25 on the outside thereof is 2.1 [mm]. ].

Four LED elements 25 are arranged on both sides of the LED element 25 of the A group. These four LED elements 25 are group B (column B in FIG. 5). The B group is separated from the A group at a pitch of 1.4 [mm] in a direction orthogonal to the arrangement direction of the A group. The pitch of the two LED elements 25 on the center side in the B group is 2.0 [mm], and the pitch between the two LED elements 25 in the center and the LED element 25 on the outside thereof is 1.8 [mm]. ].

The three LED elements 25 are arranged on the side orthogonal to the arrangement direction of the A group with respect to the two B groups and on the side where the A group does not exist (column C in FIG. 5). These three LED elements 25 are group C. The C group is separated from the B group at a pitch of 1.4 [mm] in a direction orthogonal to the arrangement direction of the A group. The pitch of the three LED elements 25 in the C group is 1.4 [mm], and the pitch of the LED element 25 in the center of the C group in the direction orthogonal to the arrangement direction of the A group is 1.8 [. mm].
The translucent resin 23 has a circular shape when viewed from the light emission direction, and its diameter D (see FIG. 6) is 9.8 [mm].
The average pitch of the 18 LED elements 25 in the arrangement direction of the A group is 1.78 [mm], and the pitch in the direction orthogonal to the arrangement direction is 1.46 [mm].
The 12 LED elements 25 located on the outside of the 18 LED elements 25 are arranged so that the center is substantially located on the circumference having a diameter of 6.4 [mm]. The circle in which the 12 LED elements 25 are located is also referred to as an LED element mounting circle.

(2) Overall Optical Member As described above, the optical member 3 has a flat portion 31 and a curved portion 32, and an amorphous dimple 33 (see (a) in FIG. 7) is formed on the front surface thereof, and the back surface thereof is formed. A ridge 34 for a Fresnel lens (see (b) in FIG. 7) is formed.

(2-1) Flat portion The flat portion 31 has a circular shape as shown in FIG. 7, and its diameter is larger than the diameter of the translucent resin 23 of the light source unit 2 as shown in FIG. Here, the diameter D1 of the flat portion 31 is 12.9 [mm], which is 1.1 times or more and 1.5 times or less, preferably 1.2 times, the diameter D of the translucent resin 23. It should be within the range of 1.4 times or more. Based on the mounting circle of the LED element 25, the diameter D1 of the flat portion 31 is about twice the diameter of the mounting circle, preferably 1.5 times or more and 2.5 times or less. As a result, the illuminance directly underneath can be secured.
The distance between the flat portion 31 and the interface (surface) of the light source unit 2 is 5.4 [mm], which is within the range of 0.4 times or more and 0.7 times or less with respect to the diameter D of the translucent resin 23. It is preferable that the diameter is within the range of 0.6 times or more and 1.0 times or less with respect to the diameter of the mounting circle. As a result, the illuminance directly underneath can be secured.
The flat portion 31 constitutes a concave lens on the front surface and the back surface thereof, and most of the light incident on the flat portion 31 from the light source unit 2 is emitted in a state where the angle between the flat portion 31 and the central axis is widened (for example). , Optical path L1 and optical path L2 shown in FIG. 8). As a result, most of the light emitted from the flat portion 31 can be less affected by the reflective member 4.

(2-2) Curved portion The surface of the cross section of the curved portion 32 has an arc shape (see FIG. 6). This makes it possible to enhance the design of the optical member 3 when the lighting device 1 is viewed from the front side.
The curved portion 32 is such that the light emitted from the light source unit 2 and directed away from the central axis is separated from the central axis by the ridges 34 on the back surface and the front surface in a region close to the central axis so as not to face the reflecting surface 43. In addition, in the region away from the central axis, it is configured so as to be away from the central axis or close to the central axis within a range not facing the reflection surface 43.

As can be seen from FIGS. 6 and 7 (b), the ridges 34 are formed concentrically. As shown in FIG. 6, the ridge 34 connects a peripheral surface portion having a peripheral surface parallel to the central axis and a front end surface portion of the peripheral surface portion of the ridge surface located outside the ridge surface portion from the back side end of the peripheral surface portion. It consists of a curved surface and a Fresnel lens.
From the inner peripheral side, the ridges 34 are the first ridge 341, the second ridge 342, the third ridge 343, the fourth ridge 344, the fifth ridge 345, the sixth ridge 346, and the seventh ridge. The number is 347, which is concentric and has a total of 7 (7 layers).
As shown in FIG. 6, the plurality of ridges 34 belong to the small ridge group 36 having a small protrusion amount (the dimension in the central axis direction is small) and the protrusion amount is larger than that of the small ridge group (central axis). Some belong to the large convex strip group 37 (which has a large dimension in the direction).
Here, the ridges 34 belonging to the small ridges 36 are the first ridges 341 to the fourth ridges 344, and the ridges 34 belonging to the large ridges 37 are the fifth ridges 345 to the seventh. There are three ridges 347.

The radial pitch of the seven ridges 34 is substantially constant. The pitch referred to here is half the difference between the diameter of the apex of the convex strip adjacent to the outside in the radial direction of the target convex strip and the diameter of the apex of the target convex strip in the target convex strip. For example, the pitch of the first ridge 341 is calculated by (D2-D1) / 2, where the diameter of the apex of the second ridge 342 is D2 and the diameter of the apex of the first ridge 341 is D1. The radial pitch of the ridges 34 is also the radial length of the Fresnel lens portion of the ridges 34.
Further, substantially constant means that the pitch of each convex strip 34 is within the range of 0.85 to 1.15 times the average value with respect to the average pitch of all the convex strips 34 (1.6 [mm]). It means that it is in.
Here, the diameter D1 of the apex of the first ridge 341 is the same as the diameter of the flat portion 31, and is 12.9 [mm]. The diameter D2 of the apex of the second ridge 342 is 15.9 [mm], the diameter D3 of the apex of the third ridge 343 is 19.2 [mm], and the diameter D4 of the apex of the fourth ridge 344. Is 22.5 [mm], the diameter D5 of the apex of the fifth ridge 345 is 25.6 [mm], and the diameter D6 of the apex of the sixth ridge 346 is 28.8 [mm]. The diameter D6 of the apex of the seventh ridge 347 is 32.0 [mm], and the diameter D8 of the front end of the Frenel lens portion of the seventh ridge 347 is 35.3 [mm].
The average pitch of the ridges 34 is in the range of 0.6 times or more and 1.3 times or less with respect to the pitches of the plurality of LED elements 25. As a result, a large amount of light from the light source unit 2 can be diffused.

The heights H1 of the four first ridges 341 belonging to the small ridges 36 to the height H4 of the fourth ridges 344 are substantially constant. The height here is a dimension in the direction of the central axis. In other words, the ridge 34 is also the length of the peripheral surface portion in the central axis direction. Here, "substantially constant" means that the heights H1 to H4 of the respective ridges 341 to 344 are the average values with respect to the average of the heights H1 of the first ridges 341 to the heights H4 of the fourth ridges 344. It means that it is within the range of 0.85 times or more and 1.15 times or less of. The heights H1 to H4 of the four ridges 34 belonging to the small ridge group 36 are 0.8 [mm].
In the first ridge 341 to the fourth ridge 344, the height is in the range of 0.4 times or more and 0.6 times or less with respect to the radial length. As a result, the amount of light incident on the peripheral surface of the protrusion 34 from the light source unit 2 can be reduced, and the efficiency of extracting light from the light source unit 2 can be improved. The light incident on each Fresnel lens portion of the small convex stripe group 36 from the light source unit 2 is emitted in a state of spreading from the central axis (for example, the optical paths L3 to L6 shown in FIG. 8).

The heights of the three fifth ridges 345 to 347 belonging to the large ridge group 37 are substantially constant. Here, "substantially constant" means that each height H5 to H7 is 0.85 times or more and 1.15 times the average height H7 of the fifth ridge 345 to the height H7 of the seventh ridge 347. It means that it is within the following range. The height H5 of the fifth ridge 345 belonging to the large ridge group 37 is 2.3 [mm], the height H6 of the sixth ridge 346 is 2.2 [mm], and the seventh convex. The height H7 of the strip 347 is 3.0 [mm].
In the fifth ridge 345 to the seventh ridge 347, the height H is in the range of 1.4 times or more and 1.8 times or less with respect to the length in the radial direction. As a result, the light incident on the peripheral surface of the ridges of the large ridges 37 from the light source unit 2 is reflected by the Fresnel lens portion and approaches the central axis (for example, the optical path L8 shown in FIG. 8). It will be emitted in a state of spreading from the central axis (for example, the optical path L9 shown in FIG. 8).

In relation to the light source unit 2, as shown in FIG. 6, one virtual line K1 indicating a 1/2 beam angle (for example, 60 [°]) of the LED element 25 located on the mounting circle of the LED element 25. Crosses the Frenell lens portion (near the outer peripheral edge of) of the fourth ridge 344 (close to the LED element) located on the outermost periphery of the small ridge group 36, and shows a 1/2 beam angle. The flat portion 31 and the small portion so that the line K2 intersects the Frenel lens portion (near the inner peripheral edge of) of the first ridge 341 (at a distance far from the LED element) located on the innermost circumference of the small ridge group 36. The ridge group 36 is configured. As a result, the light emitted from the LED element 25 can be effectively used.

The heights of the four first small ridges 341 to 344 belonging to the small ridges 36 are the heights of the three fifth ridges 345 to 347 belonging to the large ridges 37. It is within the range of 0.2 times or more and 0.3 times or less with respect to the height.

(3) Dimples The dimples 33 have an amorphous shape as shown in FIG. 7A. The term "indeterminate form" as used herein means that in any dimple 33a, the shapes of the other dimples 33b to 33g adjacent to the dimple 33a are different. The area of one of the dimples 33 when viewed from the front side is within the range of 0.39 [mm ² ] or more and 0.75 [mm ² ] or less. This makes it possible to enhance the diffusion effect.

(4) Optical Path FIG. 8 is a diagram showing an optical path emitted from a lighting device using the optical member 3 and the light source unit 2 described in the embodiment.
The optical member 3 is designed to reduce the amount of light directed to the reflecting surface 43.
As shown in FIG. 8, the light directed from the light source unit 2 to the flat portion 31 of the optical member 3 is inclined and incident on the central axis of the lighting device 1 (optical member 3) like the optical paths L1 and L2. The light is emitted from the optical member 3 so as to be separated (diffused) from the central axis. In this case, the light emitted from the optical member 3 is not reflected by the reflecting surface 43.

As shown in the optical paths L3 to L6, the light directed from the light source unit 2 to the Fresnel lens portion of the small convex stripe group 36 is emitted from the optical member 3 in a direction away from the central axis without facing the reflecting surface 43.
The light directed from the light source unit 2 to the peripheral surface portion of the small convex stripe group 36 is reflected to the back side on the surface of the curved portion 32 as shown in the optical paths L9 to L12. At this time, the outer circumference of the flat portion 31 in which the ratio (height / length) of the height of the peripheral surface portion of the small convex strip group 36 to the length in the radial direction is smaller than 1, and the small convex strip group 36 is larger than the light source unit 2. Since it is located on the side, the amount of light incident on the peripheral surface of the small convex stripe group 36 from the light source unit 2 can be reduced.

By reducing the height of the ridges 34 of the small ridges 36, the light incident on the peripheral surface of the ridges 34 can be reduced, but it is difficult to control the angle of the light emitted from the surface of the curved portion 32. Become. Further, due to the positional relationship between the light source unit 2 and the small ridges 36, the light incident on the peripheral surface of the small ridges 36 from the light source unit 2 and directed toward the Fresnel lens portion of the ridges 34 (large ridges 37). There is almost no optical path (corresponding to L7 and L8) in.
As shown in the optical paths L7 and L8, the light directed from the light source unit 2 toward the peripheral surface portion of the large convex stripe group 37 is incident from the peripheral surface portion and reflected by the Fresnel lens portion to move away from or approach the central axis (optical path L7). It is emitted from the curved portion 32 as in the optical path L8). There is almost no light directed from the light source unit 2 to the Fresnel lens portion of the large convex stripe group 37 due to the light emission characteristics of the LED element 25.
In this way, the optical member 3 can be made less susceptible to the influence of the reflecting surface 43.

(5) Orientation characteristics FIG. 9 is an orientation characteristic diagram of a lighting device not provided with a reflective member.
The orientation characteristic diagram is the analysis result, and the 1/2 illuminance angle described later is also the analysis result.
The lighting device includes the above-mentioned optical member 3. As shown in FIG. 9, in a lighting device not provided with a reflective member, the 1/2 illuminance angle is 68.8 [°], and the target 1/2 illuminance angle is 60 [°] or more. ..
The 1/2 illuminance angle refers to the angle between the line connecting the line directly under the lighting device and the line connecting the points having the horizontal plane illuminance of 1/2 of the horizontal plane illuminance directly under the lighting device. The illuminance surface of the analysis is a surface separated from the illuminating device by 3,000 [mm].
FIG. 10 is an orientation characteristic diagram of three types of lighting devices having different sizes of reflective members.
The lighting device includes the above optical member.
In FIG. 6A, the height H8 in FIG. 6 is 30.2 [mm], the diameter D9 is 70 [mm], and the angle of the reflecting surface 43 with respect to the central axis is 22.8 [°], which is 1 /. 2 The illuminance angle is 63.5 [°].
In FIG. 6B, the height H8 in FIG. 6 is 42.0 [mm], the diameter D9 is 100 [mm], and the angle of the reflecting surface with respect to the central axis is 32.1 [°], which is 1/2. The illuminance angle is 62.8 [°].
In FIG. 6C, the height H8 in FIG. 6 is 64.0 [mm], the diameter D9 is 150 [mm], and the angle of the reflecting surface with respect to the central axis is 39.5 [°], which is 1/2. The illuminance angle is 65.8 [°]. As described above, the lighting device provided with the optical member 3 is not easily affected by the reflective member 4, and can obtain an orientation characteristic having a 1/2 illuminance angle of 60 [°] or more.

Although the embodiments have been described above, the present invention is not limited to this embodiment, and even if there are examples not described in the embodiments or design changes within a range not deviating from the gist, the present invention is used. included.

1 Lighting device 2 Light source unit 3 Optical member 4 Reflective member

Claims (4)

A light source unit equipped with a light emitting element as a light source, and
An optical member that controls the orientation of the light generated from the light source unit, and
It is provided with a reflective member that reflects the light emitted from the optical member.
The optical member is a lighting device that emits light emitted from the light source unit in a direction away from the central axis of the optical member within a range not directed toward the reflective member. The optical member is
A flat portion formed on a portion facing the light source unit and
It has a curved portion that is convex to the opposite side of the light source unit and curves from the peripheral edge of the flat portion to the side where the light source unit exists.
The illuminating device according to claim 1, wherein a Fresnel lens composed of a plurality of concentric ridges centered on the central axis is formed on a surface of the curved portion on the light source unit side. The multiple ridges include a group of small ridges having a low height in a direction parallel to the central axis of the ridges and a group of large ridges having a high height.
The small ridges are located on the flat side and are located on the flat side.
The ridges included in the small ridges include a peripheral surface portion extending in parallel with the central axis and other ridges adjacent to the outer peripheral side of the ridges from an end portion of the peripheral surface portion located on the light source unit side. It has a Fresnel lens portion that extends in a curved shape to an end portion located on the opposite side of the light source unit on the peripheral surface portion of the above.
The height in the central axial direction of the peripheral surface of the ridges included in the small ridges is within a range of 0.4 times or more and 0.6 times or less with respect to the radial length of the ridges. The lighting device according to claim 2. In an optical member that controls the orientation of light generated from a light source unit,
A flat portion formed on a portion facing the light source unit and
It has a curved portion that is convex to the opposite side of the light source unit and curves from the peripheral edge of the flat portion to the side where the light source unit exists.
A Fresnel lens composed of a plurality of concentric ridges centered on the central axis is formed on the surface of the curved portion on the light source unit side.
The multiple ridges include a group of small ridges having a low height in a direction parallel to the central axis of the ridges and a group of large ridges having a high height.
The small ridges are located on the flat side and are located on the flat side.
The ridges included in the small ridges include a peripheral surface portion extending in parallel with the central axis and other ridges adjacent to the outer peripheral side of the ridges from an end portion of the peripheral surface portion located on the light source unit side. It has a Fresnel lens portion that extends in a curved shape to an end portion located on the opposite side of the light source unit on the peripheral surface portion of the above.
The height in the central axial direction of the peripheral surface of the ridges included in the small ridges is within the range of 0.4 times or more and 0.6 times or less with respect to the radial length of the ridges. Optical member.

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