2. Light distribution lens and illumination device

Abstract

In indoor lighting, the goal is to reduce the number of lighting fixtures installed and lessen the cluttered appearance of the ceiling. [Solution] A two-way light distribution lens 325 used in an illumination device 300 that distributes light emitted from a light source 322 in two directions, wherein the two-way light distribution lens 325 has a circular outer shape and is provided with a left-convex lens region 325U(1) and a right-convex lens region 325U(2) on the lens-forming surface, which is at least one of the light incident surface or light emission surface, respectively, and these are regions of a virtual outer shape having a center point which is the point where the cross section of the convex lens shape is thickest, cut out by a center line V passing through the center of the two-way light distribution lens 325 and the outer shape of the two-way light distribution lens 325, and the thickness of the lens decreases as it moves away from the horizontal axis in the y direction.

Description

[Technical Field]

[0001] The present invention relates to a lighting device having multiple light distribution directions. [Background technology]

[0002] When using standard lighting fixtures to illuminate multiple locations, it is common practice to install as many fixtures as there are areas to be illuminated. Therefore, when illuminating multiple locations such as desks and walls in a store, it becomes necessary to install numerous fixtures on the ceiling, which can make the ceiling appear somewhat cluttered.

[0003] Although the challenges are different, Patent Document 1 describes a two-way light distribution lighting device used for road lighting and the like as a technology related to the present invention. This device aims to illuminate a horizontally elongated area by using a lens with a pair of side-convex portions for each of the multiple light sources to distribute light in the left-right direction. Although the amount of light distributed in the central direction is small, the distance in the central direction is also small, so it is said that the drop in illuminance in the central part is suppressed and illumination with reduced unevenness in illuminance can be suppressed in a horizontally elongated area. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-093233 [Overview of the project] [Problems that the invention aims to solve]

[0005] The lighting device described in Patent Document 1 is intended to illuminate a horizontally elongated area relatively uniformly and does not illuminate in two directions. Furthermore, since it is an outdoor lighting device, it does not reduce the cluttered appearance of the ceiling.

[0006] The present invention aims to reduce the number of lighting devices installed and the complexity of the ceiling in indoor lighting. Also, in outdoor lighting, it is an object to reduce the number of lighting devices installed and the complexity caused by a large number of lighting devices. Furthermore, it is an object to reduce installation costs and the like.

Means for Solving the Problems

[0007] The present invention is a two-beam light distribution lens used in a lighting device that distributes light emitted from a light source in two directions, the outer shape of the two-beam light distribution lens is circular, the two-beam light distribution lens includes a left convex lens region and a right convex lens region on at least one of the lens forming surfaces, which are the light incident surface or the light exit surface, the left convex lens region and the right convex lens region are regions of a virtual outer shape having a center point, which is the point where the cross-section of the convex lens shape is thickest, within the lens forming surface, and are cut off by a center line passing through the center of the two-beam light distribution lens and the outer shape, the direction of the horizontal axis connecting the center point of the left convex lens region and the center point of the right convex lens region is the x direction, and the direction orthogonal to the x direction within the lens forming surface is the y direction, the left convex lens region and the right convex lens region are two-beam light distribution lenses in which the lens thickness decreases as they move away from the horizontal axis in the y direction.

[0008] In the two-beam light distribution lens of the present invention, the ratio of the distance between the center point of the left convex lens region and the center point of the right convex lens region to the diameter of the two-beam light distribution lens may be 45% or more and 100% or less.

[0009] In the two-beam light distribution lens of the present invention, the virtual outer shape of the left convex lens region or the right convex lens region may be circular, and the ratio of the diameter of the circle to the diameter of the two-beam light distribution lens may be 60% or more and 120% or less.

[0010] In the two-light distribution lens of the present invention, the lens forming surface may include a scattering region which is the portion other than the left-convex lens region and the right-convex lens region.

[0011] In the two-light distribution lens of the present invention, the surface of the light incident surface and the light emission surface that is not the lens forming surface may be a flat surface.

[0012] The present invention is a lighting device comprising a light source having a light source center, and two light distribution lenses according to the present invention, which are arranged away from the light source on an optical axis passing through the light source center. The lighting device may have a light body containing the light source inside, and the opening of the light body may be equipped with the two light distribution lenses.

[0013] In the lighting device of the present invention, the two light distribution lenses may be detachable without removing the lighting device from its installation location.

[0014] In the lighting device of the present invention, the lighting device may further include a reflector that reflects the light emitted from the light source and directs it toward the two light distribution lenses.

[0015] In the lighting device of the present invention, the reflector may reflect the light emitted from the center of the light source at an angle of 5 degrees or more outward from the optical axis direction. [Effects of the Invention]

[0016] According to the present invention, by distributing light in two directions in a lighting device, the number of lighting devices to be installed can be reduced, thereby reducing the cluttered feeling that can result from installing a large number of lighting devices on the ceiling or outdoors.

[0017] Consequently, the cost of installing lighting equipment can also be reduced. [Brief explanation of the drawing]

[0018] [Figure 1] Side cross-sectional view of the lighting device of Embodiment 1 in its installed state. [Figure 2]Cross-sectional view illustrating the reflector and light ray of the lighting device of Embodiment 1 [Figure 3] Plan view of the two light-distributing optical elements of the illumination device of Embodiment 1, as seen from the light-emitting surface side. [Figure 4] Simulation results of the light distribution characteristics in the lighting device of Embodiment 1 [Figure 5] Simulation results of illuminance distribution in the lighting device of Embodiment 1 [Figure 6] Plan view of the two light-distributing optical elements of the illumination device of Embodiment 1, as seen from the light-emitting surface side. [Figure 7] Simulation results of the light distribution characteristics in the lighting device of Embodiment 1 [Figure 8] Simulation results of illuminance distribution in the lighting device of Embodiment 1 [Figure 9] Side cross-sectional view of the lighting device of Embodiment 1 with the light fixture rotated. [Figure 10] Simulation results of illuminance distribution on the desk surface and wall surface when the light fixture is rotated in the lighting device of Embodiment 1. [Figure 11] Schematic cross-sectional view showing the positional relationship between the light source, reflector, and two-way optical element of the lighting device of Embodiment 2. [Figure 12] Simulation results of the light distribution characteristics of the lighting device of Embodiment 2 [Figure 13] Simulation results of the illuminance distribution of the lighting device in Embodiment 2 [Figure 14] Side cross-sectional view of the lighting device of Embodiment 3 [Figure 15] Side cross-sectional view of the lighting device of Embodiment 4 [Figure 16] Side cross-sectional view of the lighting device of Embodiment 5 [Figure 17] Plan view of the two light-distributing optical elements and their mounting portion of the illumination device of Embodiment 6, as seen from the light-emitting surface side. [Figure 18] Simulation diagram showing the illumination of a corridor by the lighting device of Embodiment 6. [Figure 19] Plan view and cross-sectional view of the two light-distributing optical elements of the illumination device of Embodiment 7, as seen from the light-emitting surface side. [Figure 20]Simulation results of illuminance distribution in the lighting device of Embodiment 7 [Figure 21] Simulation diagram of the light distribution characteristics in the lighting device of Embodiment 7 [Figure 22] Plan view of the two light-distributing optical elements of the illumination device of Embodiment 8, as seen from the light-emitting surface side. [Figure 23] Simulation results of illuminance distribution in the lighting device of Embodiment 8 [Figure 24] Simulation diagram of the light distribution characteristics in the lighting device of Embodiment 8 [Figure 25] chromaticity diagram to explain the chromaticity of LEDs [Figure 26] Cross-sectional view of the main part of the light fixture of the lighting device of Embodiment 9, which uses a dual-distribution prism as a dual-distribution optical element. [Figure 27] Cross-sectional view of the main part of the light fixture of the lighting device of Embodiment 10, which uses a dual-distribution Fresnel prism as a dual-distribution optical element. [Figure 28] Cross-sectional view of the main part of the light fixture of the lighting device of Embodiment 11, which uses a dual-distribution multiprism as a dual-distribution optical element. [Figure 29] Cross-sectional view of the main part of the lighting device of Embodiment 12, in which the angle between two light distributions can be changed. [Figure 30] External view of the light fixture of Embodiment 12 [Figure 31] Cross-sectional view of the light fixture of Embodiment 12 [Figure 32] Calculation results of light distribution characteristics in the lighting device of Embodiment 12 [Figure 33] Cross-sectional view of a modified example of Embodiment 12 [Figure 34] External view of the main parts of the lighting device of Embodiment 13, in which the angle between two light distribution points can be changed by a motor. [Figure 35] Interface of the lighting control device that controls the lighting device of Embodiment 13 [Figure 36] External perspective view of the lighting device (spotlight) of Embodiment 14 [Figure 37] Cross-sectional view of the lamp body of Embodiment 14 [Figure 38]Cross-sectional view of a modified example of Embodiment 14 (with a multiprism as an optional filter) [Figure 39] Illuminance distribution of Embodiment 14 and its modified form [Figure 40] Cross-sectional view of the lamp body of Embodiment 15 [Figure 41] Light rays in the lighting device of Embodiment 15 [Modes for carrying out the invention]

[0019] <Embodiment 1> <Basic configuration> The lighting device 300 of this embodiment is a two-way light distribution type lighting device that performs light distribution BL on the left side and light distribution BR on the right side. Figure 1 shows a side cross-sectional view of the lighting device 300 installed in a hole 391 provided in the ceiling panel of the ceiling 390.

[0020] The frame 310, which is installed in the hole 391, is equipped with three mounting springs 312 (only one is shown in Figure 1).

[0021] The light fixture fixing section 330 includes a light shielding plate 334 and is fixed to the frame 310.

[0022] The lamp body 320 comprises a heat sink 321, a light source 322 which is a COB type LED (with a light-emitting part diameter of 9 mm), a COB holder 323, a reflector 324, a dual-beam lens 325 which is a dual-beam optical element, a lamp body side 326, and a lamp body front 327. The distance H between the center of the surface of the light source 322 and the bottom surface of the dual-beam lens 325 is 28 mm. The lamp body 320 is installed on the lamp body fixing part 330 so that its axial rotation and axial tilt are variable.

[0023] The lighting device 300 also includes a power supply 340, a terminal block 341, a power supply unit 342, a wireless module 347, a lighting line 348, and a power supply line 349.

[0024] <Installation work> To install the lighting device 300 in the ceiling 390, the following installation work is required: (1) drill a hole 391 in the ceiling 390, (2) if a power line 348 is not available, install a power line 348, (3) pull the power line 348 out of the hole 391 and connect it to the terminal block 341, (4) place the power supply 340 in the ceiling 390 through the hole 391, (5) attach the frame 310 to the hole 391, and (6) attach the light fixture fixing part 330 and the light fixture 320 to the frame 310. This work incurs labor and transportation costs. Therefore, reducing the number of locations where lighting devices are installed not only eliminates the cluttered appearance of the ceiling but also leads to a reduction in installation costs.

[0025] <Lighting control> The lighting device 300 is wirelessly controllable by a lighting control device 370. The lighting control device 370 is, for example, a tablet, smartphone, or PC, and has lighting control software 371 (not shown) installed on it. The lighting control software 371 in the lighting control device 370 wirelessly transmits a dimming and color tuning signal from the lighting control device 370. The dimming and color tuning signal is received by a wireless module 347 in the lighting device 300. The wireless module 347 transmits a control signal to a power supply 340, and the power supply 340 supplies drive power controlled by the control signal to the light source 322, which is a COB type LED, through a power supply line 349.

[0026] Lighting control can be manually changed using the lighting control device 370 when the user wants to change the lighting conditions. In addition, the lighting control software 371 can be used to set a schedule in advance, enabling automatic control, for example, by lowering the brightness and color temperature of the lighting device 300 in the evening.

[0027] <Light rays and reflectors> As an example of light rays in the lighting device 300, as shown in Figure 1, when we look at the component of the light distribution BL in the leftward direction, we see that light ray B originates from the center of the light source, is reflected by the reflector 324 and passes through the two-way light distribution lens 325. 14 And, light ray B, which originates from the center of the light source and passes directly through the lens. 24 There is.

[0028] Light ray B 11 is reflected by the reflecting mirror 324 and enters the two - light - distribution lens 325 as light ray B 12 and transmits through it as light ray B 123 and exits as light ray B 14 . Light ray B 21 enters the two - light - distribution lens 325 and transmits through it as light ray B 23 and exits as light ray B 24 .

[0029] Fig. 2 shows a cross - sectional view in a plane including the optical axis AX for explaining the reflecting mirror 324 and light rays of the illumination device 300. The reflecting mirror 324 is arranged in a shape surrounding the optical axis AX, specifically, it is axially symmetric with respect to the optical axis AX. Although a commonly used reflecting mirror reflects the light of a light source in the optical - axis direction, in the reflecting mirror 324, the light ray B 11 emitted from the light - source center 322C on the optical axis is reflected by the reflecting mirror 324 and becomes a light ray B 12 having an angle of 25° with respect to the optical axis AX in the lower - left direction. Therefore, the light ray B 13 transmitted through the two - light - distribution lens 325 and exiting as light ray B 14 is distributed outside the optical - axis AX direction as shown in Fig. 1, so the light - distribution component in the optical - axis AX direction is reduced. By combining the reflecting mirror 324 and the two - light - distribution lens 325, it is possible to realize an illumination device 300 that suppresses the light in the optical - axis AX direction and distributes light in two diagonal directions with respect to the optical axis.

[0030] Note that the light ray B 12 reflected by the reflecting mirror 324 preferably faces outward by 5 degrees or more with respect to the optical axis AX, and more preferably faces outward by more than 10 degrees. The reflected light ray does not need to be a parallel light ray in the cross - sectional view including the optical axis AX.

[0031] <Two - light - distribution lens and light - distribution characteristics (1)> Figure 3(b) shows a plan view of the two-light distribution lens 325 as seen from the light-emitting surface side. Figures 3(a) and (b) show the two-light distribution lenses 325S and 325T, respectively, which are variations in the spacing Lc (described later) of the two-light distribution lens 325. In Figures 3(a), (b), and (c), the horizontal direction is the x-direction and the vertical direction is the y-direction. The two-light distribution lens 325 shown in Figure 3(b) will be described below as a representative example.

[0032] The outer shape of the dual-beam lens 325 (dual-beam lens 325S, 325T) is circular. Therefore, conventional downlight components that distribute light in one direction, specifically, for example, the luminaire 320, can be used.

[0033] The upper surface (light-emitting surface) of the two-light-distribution lens 325 is divided into a left-convex lens region 325(1), which is the left-light-distribution region on one side (left side) in the x-direction, a right-convex lens region 325(2), which is the right-light-distribution region on the other side (right side), a first scattering region 325(3), and a second scattering region 325(4). The left-convex lens region 325(1) and the right-convex lens region 325(2) are regions up to the center line V, where a convex lens (virtual light-distribution region) with a virtual outline shown by a dotted line is cut out by the outline of the two-light-distribution lens 325, and does not overlap with the other convex lens regions. In this embodiment, the left-convex lens region 325(1) and the right-convex lens region 325(2) are symmetrical with respect to the center line V.

[0034] The diameter of the two-light distribution lens 325 is 48 mm, and the diameters of the virtual circular outlines shown by the dotted lines of the left-convex lens region 325(1) and the right-convex lens region 325(2) are both 45 mm. The distance Lc between the center line J1 of the left-convex lens region 325(1) and the center line J2 of the right-convex lens region 325(2) is 30 mm. The lower surface (light incident surface) of the two-light distribution lens 325 (325S, 325T) is flat.

[0035] On the upper surface of the two-light distribution lens 325, in order to suppress color unevenness when a light source emitting multiple colors is used, the left convex lens region 325(1) and the right convex lens region 325(2) are provided with a textured surface for light scattering, and the first scattering region 325(3) and the second scattering region 325(4) are provided with a linear uneven structure.

[0036] Figure 3(a) shows the dual-distribution lens 325S. The distance Lcs between the center line J1 of the left-convex lens region 325S(1) and the center line J2 of the right-convex lens region 325S(2) is wide at 40 mm. As a result, the overlap between the left-convex lens region 325S(1) and the right-convex lens region 325S(2) is reduced, and the first scattering region 325S(3) and the second scattering region 325S(4) are widened.

[0037] Figure 3(c) shows the two-distribution lens 325T. The distance Lct between the center line J1 of the left-convex lens region 325T(1) and the center line J2 of the right-convex lens region 325T(2) is narrow at 20 mm. As a result, the overlap between the left-convex lens region 325T(1) and the right-convex lens region 325T(2) is large, and the first scattering region 325T(3) and the second scattering region 325T(4) are narrowed.

[0038] Figures 4(a), (b), and (c) show the simulation results of the light distribution characteristics in the x-direction (luminous intensity as a function of the beam angle) when the total luminous flux of the light source is 1000 lm.

[0039] In the case of the two-beam lens 325 shown in Figure 4(b), it can be seen that there are beam peaks in the left and right 16° directions, and the luminous intensity in the 0° direction (center direction) is about half (43%) of that peak. In this way, by not having a beam peak in the 0° direction and setting the luminous intensity in the 0° direction to less than 70% of the peak, the two beams are clearly separated, making it a light source that is easy to use for the purpose of illuminating two directions. Furthermore, by setting the luminous intensity in the 0° direction to more than 20% of the peak, it is advantageous that the illumination in the center direction can be moderately reduced so that it does not feel dark.

[0040] In the case of the 2-light distribution lens 325S shown in Figure 4(a), there are light distribution peaks in the left and right 20° directions, and the light distribution in the 0° direction is about 10% of the peak, indicating that the light distribution is clearly divided into two directions.

[0041] In the case of the 2-beam lens 325T shown in Figure 4(c), it can be seen that there are peaks in the light distribution in both the left and right 10° directions, and the light distribution in the 0° direction is 82% of the peak, indicating that there is not much of a drop-off.

[0042] Figures 5(a), (b), and (c) show the simulation results of the illuminance distribution at a distance of 2.8m from the light source, assuming a total luminous flux of 1000lm. In each figure, the horizontal direction is the x-direction and the vertical direction is the y-direction, and the numerical values ​​in the figures represent illuminance (lx).

[0043] In the case of the two-beam lens 325 shown in Figure 5(b), it can be seen that there are two distinct spot illumination areas aligned in the x-direction.

[0044] In the case of the 2-beam lens 325S shown in Figure 5(a), it can be seen that there are two distinct spot illumination areas aligned in the x-direction, with a dark area between them.

[0045] In the case of the 2-beam lens 325T shown in Figure 5(c), the illumination area is elongated horizontally in the x-direction. This deviates from the original objective of obtaining two illumination areas from two beams, but a relatively uniform illumination area is achieved horizontally.

[0046] Therefore, for the purpose of separating and illuminating two regions, it is preferable that the two-way light distribution lens has two convex lens regions on the light emission surface, the light incidence surface, or both, and that these two convex lens regions are spaced apart to a certain extent. Specifically, the ratio of the distance between the centers of the two convex lens regions to the diameter of the two-way light distribution lens is preferably 45% or more, and more preferably 60% or more. On the other hand, if they are too far apart, the area of ​​the first and second scattering regions, which are not convex lens regions, increases, so it is preferable that the ratio is 100% or less, and more preferably 80% or less.

[0047] <2. Light distribution lenses and light distribution characteristics (2)> Figure 6(b) shows a plan view of the two-part optical distribution lens 325 as seen from the light-emitting surface side. Figures 3(a) and (c) show the two-part optical distribution lenses 325M and 325N, which are hypothetical diameter variations of the convex lens regions 325(1) and (2) of the two-part optical distribution lens 325, respectively. In Figures 6(a), (b), and (c), the horizontal direction is the x-direction and the vertical direction is the y-direction.

[0048] The diameter of the two-light distribution lens 325 is 48 mm. The diameters of the outer shapes (circular) of the virtual light distribution regions indicated by the dotted lines of the left-convex lens region 325(1) and the right-convex lens region 325(2) are 55 mm, 45 mm, and 30 mm for the two-light distribution lenses 325M, 325, and 325N, respectively. The portions of the virtual outer shapes indicated by the dotted lines of the left-convex lens region 325(1) and the right-convex lens region 325(2) that extend beyond the two-light distribution lens 325 are cut off, and the left-convex lens region 325(1) and the right-convex lens region 325(2) with virtual circular outer shapes are formed up to the center line V. The distance Lc between the center line J1 of the left-convex lens region 325(1) and the center line J2 of the right-convex lens region 325(2) is 30 mm. The lower surfaces (light incident surfaces) of the two-light distribution lenses 325M, 325, and 325N are flat.

[0049] Figure 6(a) shows the two-distribution lens 325M. The distance Lc between the center line J1 of the left-convex lens region 325M(1) and the center line J2 of the right-convex lens region 325M(2) is 30 mm, but because the diameter of the virtual outer shape (circular) of the left-convex lens region 325M(1) and the right-convex lens region 325M(2) has become large at 55 mm, the first scattering region 325M(3) and the second scattering region 325M(4) have almost disappeared.

[0050] Figure 6(c) shows the two-distribution lens 325N. The distance Lc between the center line J1 of the left-convex lens region 325N(1) and the center line J2 of the right-convex lens region 325N(2) is 30 mm, but because the diameter of the virtual outer shape (circular) of the left-convex lens region 325N(1) and the right-convex lens region 325N(2) has become smaller at 35 mm, the first scattering region 325N(3) and the second scattering region 325N(4) have become wider.

[0051] Figures 7(a), (b), and (c) show the simulation results of the light distribution characteristics in the x-direction when the total luminous flux of the light source is 1000 lm.

[0052] In Figures 7(a), (b), and (c), the angles at which the light distribution peaks are 14°, 18°, and 20° to the left and right of the center, respectively. The luminous intensity in the direction of the center is 47%, 43%, and 38% of the luminous intensity at the angles at which the light distribution peaks, respectively.

[0053] Figures 8(a), (b), and (c) show the simulation results of the illuminance distribution at a distance of 2.8m from the light source, assuming a total luminous flux of 1000lm. In each figure, the horizontal direction is the x-direction and the vertical direction is the y-direction, and the numerical values ​​in the figures represent illuminance (lx).

[0054] In Figures 8(a), (b), and (c), it can be seen that two locations in the x-direction are illuminated separately. However, in Figure 8(c), the illuminance is slightly reduced. This is thought to be because the proportion of the first scattering region 325N(3) and the second scattering region 325N(4), which are outside the convex lens region, has increased.

[0055] Based on the above, the ratio of the convex lens region to the diameter of the two light distribution lenses is appropriate if it is between 60% and 120%, and more preferably between 80% and 110% (indicating more efficient use of light).

[0056] <Use as a universal downlight> Figure 9 shows the lighting device 300 with the lamp body 320 rotated relative to the frame 310 and lamp body fixing part 330 to change the direction of light distribution. Since the lighting device 300 is a downlight (universal downlight) whose light distribution direction can be changed, for example, the light distribution BL can be set to illuminate downwards, and the light distribution BR can be set to illuminate diagonally.

[0057] Figure 10(a) shows the simulation results of the illuminance distribution on a desk 382 placed on the floor 380, when the total luminous flux of the light source of the lighting device 300 is set to 1000 lm and oriented as shown in Figure 9, with the light distribution BL illuminating the desk 382. Figure 10(b) shows the simulation results of the illuminance distribution on a wall 385 when the wall 385 is illuminated with the light distribution BR, and Figure 10(c) shows the simulation results of the illuminance distribution on the surface at the height of the desk 382 when the desk 382 is illuminated with the light distribution BL. The values ​​in the figures represent illuminance (lx). The ceiling height was assumed to be 2.80 m. In reality, the total luminous flux of the light source of the lighting device 300 is about 1000 lm, so it was found that an illuminance of about 500 lx, which is preferred in restaurants, can be obtained on the desk 382 and on the wall 385.

[0058] <Embodiment 2> <Configuration of light source, reflector, and lens> In this embodiment, as a variation of Embodiment 1, the case in which the distance between the light source 322 and the two-light distribution lens 325, which is a two-light distribution optical element, is changed is shown. This makes it possible to change the angle between the two light distribution directions (for simplicity, this is also called the "angle between the two light distribution directions").

[0059] Figures 11(a), (b), and (c) show schematic cross-sectional diagrams including the optical axis of lighting devices 300A, 300, and 300C, illustrating the positional relationship between the light source, reflector, and dual-beam lens when the distance from the light source 322 to the bottom surface of the dual-beam lens 325 is varied in three ways: 40 mm, 28 mm, and 14 mm (Figure (b) is the same as in Embodiment 1). In each figure, the horizontal direction is the x-direction and the vertical direction is the z-direction. Note that lighting devices 300A and 300C use reflectors 324A and 324C respectively, and the length of the lamp body is changed accordingly, but the other configurations are the same as lighting device 300.

[0060] Figures 12(a), (b), and (c) show the simulation results of the light distribution characteristics of lighting devices 300A, 300, and 300C. In lighting device 300A, the two light distributions are strongly distributed at 14° from the center, and in lighting device 300C, they are strongly distributed at 35°. It can be seen that the luminous intensity in the direction of the center relative to the luminous intensity in the direction of the light distribution peak is 41% and 14%, respectively, for lighting devices 300A and 300C. Note that lighting device 300C has less light distribution in the 0° direction, but this is because the 2-light distribution lens 325 was reused from lighting device 300, and it is possible to adjust the amount of light distribution in the 0° direction by redesigning the lens.

[0061] Figures 13(a), (b), and (c) show the simulation results of the illuminance distribution for lighting devices 300A, 300, and 300C, assuming a total luminous flux of 1000 lm for the light source and a distance of 2.8 m from the lighting device to the floor. In each figure, the horizontal direction is the x-direction and the vertical direction is the y-direction, and the values ​​in the figures represent illuminance (lx). Lighting devices 300A, 300, and 300C all show an illuminance distribution separated into two in the x-direction, indicating that the smaller H value, the more the light is focused on areas further away.

[0062] <Embodiment 3> The lighting device 300D, whose main cross-sectional view is shown in Figure 14, is a variation of the lighting device 300C and uses a two-light distribution lens 325D. The two-light distribution lens 325D has two convex lens regions formed on the light incident surface side (light source 322 side) and a flat surface on the light emission surface side. As a result, the light ray B that travels from the light source center 322C towards the top of the reflector 324D 51 However, the reflected light ray B 52 , ray B after incident light from 2-light distribution lens 325D 53 , ray B after emission from 2-beam lens 325D 54 Therefore, it can be used effectively.

[0063] In the lighting device 300C, the illuminance in the central part of the illuminance distribution was low. However, in the two-light distribution lens 325D having two convex lens regions, as shown in Embodiment 1, the light distribution can be optimized by changing the distance between the centers of the two convex lens regions, changing the focal length of the convex lens region, or increasing the light diffusion due to a textured surface.

[0064] <Embodiment 4> The lighting device 300G, whose main cross-sectional view is shown in Figure 15, is a variation of the lighting device 300 and uses a two-light distribution lens 325G. The two-light distribution lens 325G has a shape obtained by bending the two-light distribution lens 325, and the optical axis RX(1) of the left convex lens region 325G(1) and the optical axis RX(2) of the right convex lens region 325G(2) pass near the light source center 322C of the light source 322 and are oblique to the optical axis of the light source.

[0065] The light incident surface of the dual-distribution lens 325G may be bent as shown in the figure, but it may also be a flat or curved surface.

[0066] <Embodiment 5> The lighting device 300F, whose main cross-sectional view is shown in Figure 16, is a variation of the lighting device 300 and uses a two-light distribution lens 325F. The two-light distribution lens 325F has a Fresnel lens shape as shown in the figure, with a left-convex lens region 325F(1) and a right-convex lens region 325F(2). This makes it possible to make the lens thinner and lighter.

[0067] A diffusing shape, such as a textured surface to prevent color unevenness, may be superimposed on the Fresnel lens shape. However, since providing both a Fresnel lens shape and a diffusing shape results in a very complex shape, for example, the Fresnel lens shape may be provided on the light-emitting surface side and the textured surface on the light-incoming surface side.

[0068] <Embodiment 6> Embodiment 6 is a configuration in which a dual-light distribution lens 325E, which is a dual-light distribution optical element, is detachably mounted on the lighting device 300E while it is installed. Various methods can be considered for attaching and detaching only the dual-light distribution lens 325E without removing the lighting device 300E. As an example, as shown in Figure 17, a plan view from the light emission surface side, a mounting portion 325E(5) is provided on the lens 325E, and a screw fixing portion 325E(6) provided on the mounting portion 325E(5) is fitted onto two screws 328E provided on the front surface 327E of the lighting device 300E and fixed in place. By loosening the screws 328E and rotating the dual-light distribution lens 325E counterclockwise, the dual-light distribution lens 325E can be removed and replaced with another dual-light distribution lens to obtain the desired light distribution characteristics. Therefore, after installing the lighting device 300E, only the dual-beam lens 325E can be replaced to obtain the desired light distribution characteristics.

[0069] Other attachment methods include, for example, using a frame with screw threads, and providing matching grooves on the front of the receiving light fixture, with the lens fixed to the frame. Alternatively, like interchangeable lenses for SLR cameras, a mount may be provided on the lighting device side, and the lens fixed to the frame may be attached to the mount.

[0070] Figure 18 is a simulation diagram showing the illumination of a corridor by lighting device 300E. The lighting device 300E, which is a downlight with a fixed light distribution direction, is installed on the corridor ceiling 390E and illuminates the corridor walls 385EL, 385ER, and the corridor floor 380E.

[0071] Because the lighting device 300E has a light distribution characteristic that centers light distribution on the left side (BL) and the right side (BR), both walls become brighter, making the corridor feel brighter to pedestrians. Therefore, a lighting device 300E with a smaller total luminous flux can be used, resulting in energy savings.

[0072] When installed in a corridor, the detachable dual-beam lens 325E can be replaced with an appropriate one depending on the width of the corridor and the height of the ceiling.

[0073] <Embodiment 7> The lighting device 300U of this embodiment is modified in which the two-light distribution lens 325 of Embodiment 1 is replaced with a two-light distribution lens 325U. A plan view of the two-light distribution lens 325U as seen from the light emission surface side is shown in Figure 19(a), and a cross-sectional view thereof is shown in Figure 19(b).

[0074] The upper surface (light-emitting surface) of the two-distribution lens 325U is divided into a left-convex lens region 325U(1) on one side (left side) in the x-direction, a right-convex lens region 325U(2) on the other side (right side), a first scattering region 325U(3), and a second scattering region 325U(4). The left-convex lens region 325U(1) and the right-convex lens region 325U(2) are regions up to the center line V, where a convex lens having a virtual outline shown by a dotted line is cut out by the outline of the two-distribution lens 325U, and does not overlap with the other convex lens regions. In this embodiment, the left-convex lens region 325U(1) and the right-convex lens region 325U(2) are symmetrical with respect to the center line V.

[0075] On the upper surface of the two-color light distribution lens 325U, in order to suppress color unevenness when using a light source that emits multiple colors, multiple linear protrusions 325U(2)s are provided in the left-convex lens region 325U(1) and the right-convex lens region 325U(2), arranged in the y-direction (other direction) along the x-direction (one direction). Referring to Figure 19(b), a cross-sectional view along the center line J2, the light ray B propagated in the z-direction by the protrusions 325U(2)s y1 B y2 As a result of slight refraction in the y direction, the light diffuses in the y direction. The light incident surface 325U(0), which is the lower surface of the two-distribution lens 325U, is a plane as shown in Figure 19(b).

[0076] Figure 20 shows the simulation results of the illuminance distribution at a distance of 2.8m from the light source, when the total luminous flux of the light source is 1000lm. The values ​​in the figure represent illuminance (lx). For example, compared to Figure 5(b), it can be seen that the light is spreading in the y direction (vertical direction in the figure), and consequently the illuminance value has decreased.

[0077] Figure 21 shows the simulation results of the light distribution characteristics of the lighting device 300U. In the lighting device 300U, two light distributions are strongly distributed in the direction of 20° from the center, and the luminous intensity in the direction of the center is 3% of the luminous intensity in the direction of the light distribution peak, indicating that there is little light distribution in the 0° direction.

[0078] Note that instead of multiple protrusions 325U(2)s aligned in one direction, multiple recesses may be used. The one direction does not need to be strictly the same direction and is not limited to the x-direction.

[0079] <Embodiment 8> The 300W lighting device of this embodiment is a modified version of Embodiment 1, in which the two-light distribution lens 325 is replaced with a two-light distribution lens 325W, enabling bright illumination in a relatively narrow area and moderately bright illumination in a relatively wide area with a single lighting device.

[0080] Figure 22 shows a plan view of the two-light distribution lens 325W as seen from the light emission surface side. The upper surface (light emission surface) of the two-light distribution lens 325W is divided into a left-convex lens region 325W(1) on one side (left side) in the x-direction, a right-convex lens region 325W(2) on the other side (right side), a first scattering region 325W(3), and a second scattering region 325W(4). The left-convex lens region 325W(1) and the right-convex lens region 325W(2) are regions up to the center line V, where a convex lens with a hypothetical outline shown by a dotted line is cut out by the outline of the two-light distribution lens 325W, and does not overlap with the other convex lens regions. In this embodiment, the left-convex lens region 325W(1) and the right-convex lens region 325W(2) are symmetrical with respect to the center line V.

[0081] In this embodiment, the light scattering shapes on the surfaces of the left-convex lens region 325W(1) and the right-convex lens region 325W(2) are made different. The left-convex lens region 325W(1) has the same textured surface as the left-convex lens region 325(1). On the other hand, the right-convex lens region 325W(2) has multiple linear protrusions 325U(2)s arranged in the y direction, which are aligned along the x-direction, just like the right-convex lens region 325U(2).

[0082] Figure 23 shows the simulation results of the illuminance distribution at a distance of 2.8m from the light source, when the total luminous flux of the light source is 1000lm. The values ​​in the figure represent illuminance (lx). The left side shows a relatively circular illumination area, while the right side shows a vertically elongated illumination area due to scattering by multiple protrusions 325U(2)s.

[0083] Figure 24 shows the simulation results of the light distribution characteristics of the lighting device 300U. In the lighting device 300U, two light distributions are strongly distributed 15° to the left and 20° to the right of the center, and the luminous intensity in the central direction is 22% of the luminous intensity in the peak direction of the light distribution.

[0084] <Embodiment 9> In this embodiment, a two-light distribution prism 125 is used as the two-light distribution optical element.

[0085] <Basic configuration> Figure 26(a) shows a cross-sectional view of the main part of the lamp body 120 of the lighting device 100 of this embodiment. Referring also to the plan view in Figure 26(b), the two-light distribution prism 125 consists of a left light distribution region 125L where the incident surface is a plane and the exit surface is an inclined plane that forms an angle with the incident surface, and a right light distribution region 125R where the exit surface is an inclined plane that forms an angle with the incident surface. The two-light distribution prism 125 functions as a prism depending on the angle between the exit surface and the incident surface.

[0086] Light ray B emitted from light source 122 P1 and B P2 The light ray B is incident on the two-beam prism 125, its direction of travel is changed to move away from the optical axis AX, and it is emitted to the outside. P3 The light, after being reflected by the reflector 124, enters the two-way light distribution prism 125, where its direction of propagation is changed to move away from the optical axis AX before being emitted to the outside. By distributing the light in different directions in the left light distribution region 125L and the right light distribution region 125R, a two-way light distribution can be realized in the illumination device 100, where a stronger light intensity is obtained in two directions different from the optical axis direction than in the optical axis direction.

[0087] <Embodiment 10> In this embodiment, a dual-distribution Fresnel prism 225 is used as the dual-distribution optical element.

[0088] <Basic configuration> Figure 27(a) shows a cross-sectional view of the main part of the lamp body 220 of the lighting device 200 of this embodiment. The dual-beam Fresnel prism 225, also referring to the plan view in Figure 27(b), has a planar exit surface and consists of a left beam distribution region 225L made up of multiple inclined planes where the incident surface is at an angle to the exit surface, and a right beam distribution region 225R made up of multiple inclined planes where the exit surface is at an angle to the incident surface. The dual-beam Fresnel prism 225 functions as a prism depending on the angle between the exit surface and the incident surface, and its cross-section is made roughly sawtooth-shaped to keep it thin, unlike a Fresnel lens. As a result, the dual-beam Fresnel prism 225 is lighter than the dual-beam prism 125. Note that the number of inclined planes can be any number, and although Figure 27 shows a considerably smaller number of inclined planes than the prototype for illustrative purposes, the actual number can be around this number (8 planes on one side), or even fewer.

[0089] Light ray B emitted from light source 222 FP1 and B FP2 The light rays B are incident on the two-beam Fresnel prism 225, and their direction of propagation is changed to move away from the optical axis AX before being emitted to the outside. FP3 The light, after being reflected by the reflector 224, enters the two-way Fresnel prism 225, where its direction of propagation is changed to move away from the optical axis AX before being emitted to the outside. By distributing the light in different directions in the left light distribution region 225L and the right light distribution region 225R, a two-way light distribution can be realized in the illumination device 200, where stronger light intensity is obtained in two directions different from the optical axis direction than in the optical axis direction.

[0090] <Embodiment 11> In this embodiment, a dual-distribution multiprism 425 is used as the dual-distribution optical element.

[0091] <Basic configuration> Figure 28(a) shows a cross-sectional view of the main part of the lamp body 420 of the lighting device 400 of this embodiment. The two-beam multiprism 425, also referring to the plan view in Figure 28(b), has a planar surface at the exit surface and consists of a pattern in which multiple inclined surfaces 425R and 425L, where the incident surface forms an angle with the exit surface, are alternately repeated. The two-beam multiprism 425 functions as a multiprism by the angle between the inclined surface 425R or inclined surface 425L and the exit surface, while maintaining a thin thickness. Therefore, the two-beam multiprism 425 is lighter than the two-beam prism 125. Note that the number of inclined surfaces can be any number, and although Figure 28 shows a number of inclined surfaces considerably fewer than the prototype for clarity in illustration, this number may actually be sufficient, or even fewer.

[0092] Light ray B emitted from light source 422 MPR2 and B MPL2 The light rays B enter the incident surfaces 425R and 425L of the two-beam multiprism 425, respectively, and their direction of travel is changed to move away from the optical axis AX before being emitted to the outside. As a result, even in the two-beam multiprism 425 to the right of the optical axis AX, the light rays B are directed to the left. MPL1 Even with a 2-way light distribution multiprism 425 located to the left of the optical axis AX, there is a light ray B directed towards the right. MPR3 In this way, by distributing the light in different directions, the lighting device 400 can achieve a dual light distribution, where a stronger light intensity is obtained in two directions different from the optical axis direction than in the optical axis direction.

[0093] In Embodiments 9, 10, and 11, one surface is flat, but this flat surface may be made into a curved surface with a convex lens shape to provide a convex lens effect. This has the effect of increasing light focusing. Also, in Embodiment 9, if the light emission surface is made into a curved surface with a convex lens shape, it becomes similar to the two-light distribution lens 325 shown in Embodiment 1, for example.

[0094] Furthermore, in embodiments 9, 10, and 11, a light scattering shape, such as the aforementioned textured surface for light scattering, may be formed on at least one of the light emitting surface or the light incident surface. This reduces color unevenness and light intensity unevenness in the illumination light.

[0095] <Embodiment 12> In this embodiment, a universal downlight is provided, which is a lighting device that can continuously change the angle between two light distributions by continuously changing the distance H from the light source to the light distribution lens.

[0096] <Basic configuration> Figure 29 shows a cross-sectional view of the main parts of the lighting device 500 of this embodiment. It comprises a frame 510, a lamp body fixing part 530 fixed to the frame 510, a lamp body 520 rotatably fixed to the lamp body fixing part 530, and a power supply, etc., similar to that of Embodiment 1 (see Figure 1).

[0097] Figure 30 shows an external view of the lamp body 520, which is the main part of the lighting device 500 of this embodiment. The lamp body 520 comprises a heat sink 521, a light source 522 which is a COB type LED attached to the heat sink 521 (explained in the cross-sectional view described later), a lens barrel 523, and a two-way light distribution lens 525 attached to the lens barrel 523. The lens barrel 523 is attached to the lamp body fixing part 530 so that the axial rotation and tilt of the lamp body are variable. This makes the lighting device 500 mainly emit light in the BL direction and light in the BR direction. On the front side of the lens barrel 523 and the back side which is not visible in this figure, there is a slit 533 and a fixing screw 534. The fixing screw 534 is attached to a screw receiver 536 which is integrated with the heat sink 521 so as to tighten the lens barrel 523, thereby fixing the position of the lens barrel 523 and the heat sink 521. This allows the distance H between the lower surface of the two-way light distribution lens 525 attached to the lens barrel 523 and the surface of the light source 522 attached to the heat sink 521 to be fixed in an adjusted state.

[0098] Figures 31(a), (b), and (c) are cross-sectional views of the lamp body 520 when the distance H between the upper surface of the light source 522 and the lower surface of the two-light distribution lens 525 is Ha, Hb, and Hc, respectively. Note that only one fixing screw 534 and one screw receiver 536 are shown, and the slit 533 is not shown.

[0099] To allow the distance between the light source 322 and the dual-beam lens 325 to be changed, the reflector was divided into two parts: a rear reflector 524L that can be moved together with the light source 322, and a front reflector 524U that can be moved together with the dual-beam lens 325.

[0100] Height H along the optical axis AX from the virtual plane including the upper end of the rear reflector 524L to the light source 322 L In the case of the shortest distance Hc shown in Figure 31(c), the positions of the rear reflector 524L and the dual-beam lens 325 are such that they do not interfere with each other. L It is preferable to set Hc to ≤ Hc.

[0101] Height H along the optical axis AX from the virtual plane including the lower end of the front reflector 524U to the lower surface of the two-light distribution lens 325 U In the case of Figure 31(c), where the distance Hc is shortest, the positions of the front reflector 524U and the light source 322 are such that they do not interfere with each other. U It is preferable to set Hc to ≤ Hc, and if there is an obstacle to the front reflector 524U near the light source 322, such as a light source holder or a reflector base, the distance from that obstacle to the 2-light distribution lens 325 is set as H'c. U It is preferable that H'c be less than or equal to ≤ H'c.

[0102] Height H of rear reflector 524L L and the height H of the front reflector 524U U The sum of these may be equal to or greater than the maximum distance H, which is distance Ha, as shown in Figure 31(a).

[0103] In this embodiment, the basic design is such that the reflective surfaces of the front reflector 524U and the rear reflector 524L are continuous when the distance H is at its maximum, Ha. However, because the reflectors have thickness, the upper end 524U2 of the reflective surface of the front reflector 524U is positioned slightly outward with respect to the optical axis AX than the upper end 524L1 of the reflective surface of the rear reflector 524L.

[0104] As shown in Figures 31(a), (b), and (c), as the distance H decreases, the rear reflector 524L moves inside the area enclosed by the front reflector 524U. Also, the heat sink 521 moves inside the lens barrel 523.

[0105] Figure 32 shows the calculated light distribution characteristics of the lighting device 500 of this embodiment when the distance H is Ha, Hb, and Hc, respectively. The angle between the two light distributions is 40° (20° left and right with respect to the optical axis AX) in Figure 32(a), 48° (24° left and right) in Figure 32(b), and 52° (26° left and right) in Figure 32(c).

[0106] In this embodiment, the lighting device 500 is a universal downlight whose orientation can be changed, but it may also be a downlight whose orientation cannot be changed. In that case, it can be used to illuminate two opposing walls in a corridor with a single lighting device, and it can also be suitably used to illuminate both shelves in a store by installing a downlight between two shelves with a single lighting device.

[0107] <Example 1> Figures 33(a), (b), and (c) show cross-sectional views of the lamp body 520B when the rear reflector 524L and front reflector 524U in the lamp body 520 of the lighting device 500 are replaced with a rear reflector 524BL and a front reflector 524BU.

[0108] In this modified example, the rear reflector 524BL is designed so that, at the minimum distance Hc, the light ray RX emitted from the light source center 522C of the light source 522 and passing through the upper end of the rear reflector 524L reaches the right and left ends of the two-light distribution lens 525 (Figure 33(c)). As a result, the light distribution characteristics at distance Hc approach those of Embodiment 2, where the reflector is not divided, and the angle between the two light distributions increases.

[0109] Consequently, in the case of distance Ha, where distance H is the maximum value, as shown in Figure 33(a), the lower end 524BU2 of the front reflector 524BU needs to be located outside the optical axis AX relative to the upper end 524BL1 of the rear reflector 524BL. As a result, the inclination of the reflective surface of the front reflector 524BU becomes steep, and it does not become continuous with the reflective surface of the rear reflector 524BL, but the effect is limited.

[0110] Based on the findings of the above embodiment and modified examples, suitable rear and front reflectors can be summarized as follows: Rear reflector height H as exemplified by rear reflectors 524L and 524BL. L and the height H of the front reflector as exemplified by front reflector 524U and 524BU. U It is preferable that the height H is the same as or shorter than the height Hc when the distance H is at its minimum. U and height H L The sum of these values ​​is preferably equal to or longer than Ha when the distance H is at its maximum.

[0111] <Embodiment 13> While Embodiment 12 allowed for manual adjustment of the distance H, this embodiment allows for motor-driven adjustment of the distance H. In this case, even after the lighting device has been installed, it becomes possible to change the distance H and alter the angle between the two light distribution points.

[0112] Figure 34 shows an external view of the lamp body 520V, which is the main part of the lighting device 500V of this embodiment. The lamp body 520V comprises a heat sink 521, a light source 522 which is a COB type LED attached to the heat sink 521 (explained in the cross-sectional view described later), a lens barrel 523, and a two-way light distribution lens 525 attached to the lens barrel 523. The lens barrel 523 is attached to the lamp body fixing part 530 so that the axial rotation and tilt of the lamp body are variable. This results in a lighting device 500 that mainly emits light in the BL direction and light in the BR direction. On the front side of the lens barrel 523 and the back side which is not visible in this figure, there is a slit 533 and a guide pin 535.

[0113] The 520V light unit includes a motor 551 fixed to a heat sink 521, a lead screw shaft 552 that transmits the rotation of the motor 551 and has a screw at its tip, and a screw receiver 553 that receives the tip of the lead screw shaft 552. The screw receiver 553 is attached to the telescope tube 523, and as the motor rotates, the lead screw shaft 552 rotates, causing the screw receiver 553 and thus the telescope tube 523 to move back and forth with the guide pin 535 inside the slit 533, thereby changing the distance H between the surface of the light source 522 and the bottom surface of the two-way light distribution lens 525.

[0114] The motor 551 is controlled using a lighting control device 570V, which is a modified version of the lighting control device 370 shown in Figure 1. The touch panel, which is the interface of the lighting control device 570V, is shown in Figure 35. On the touch panel, the installed lighting control software 571 can display the color temperature interface 573C, the dimming interface 573B, and the two-beam angle interface 573A. The two-beam angle interface 573A allows the angle between the two beams to be changed by moving the setting point 574A2 on the slider bar 574A1 (minimum 30°, maximum 60° in the figure), and the set angle is displayed as the set angle display 574A3 (two-beam angle of 45 degrees in the figure). Furthermore, in the color temperature interface 573C, the color temperature can be changed by moving the setting point 574C2 on the slider bar 574C1 (minimum 2700K, maximum 6500K in the diagram), and the set color temperature is displayed as the set color temperature display 574C3 (6500K in the diagram). In the dimming interface 573B, the dimming rate can be changed by moving the setting point 574B2 on the slider bar 574B1 (minimum 0%, maximum 100%), and the set dimming rate is displayed as the set dimming rate display 574B3 (80% in the diagram).

[0115] <Embodiment 14> The lighting device 700 of this embodiment is a spotlight capable of continuously changing the angle between two light distributions.

[0116] As shown in Figure 36(a) in external perspective view, the lighting device 700 includes a light unit 720 consisting of a rear light unit 720L and a front light unit 720U. By changing the distance between the rear light unit 720L and the front light unit 720U, the distance between the two light units can be fixed by tightening the mounting screws 734 that protrude through the slit 733. As a result, as shown in Figure 36(b), an intermediate light unit 720E between the rear light unit 720L and the front light unit 720U becomes visible. The rear light unit 720L is rotatably connected to the arm 730 in the φ direction, and the arm 730 is rotatably connected to the power supply 740 in the ψ direction, thereby changing the orientation of the light unit 720. The power supply 740 can be detachably fixed to the lighting rail 790 by turning the lever 745, which allows the connection parts 746 and 747 to be attached to the lighting rail 790. The lighting device 700 can be dimmed and its color adjusted by a lighting control device 770 (such as a smartphone, tablet, or personal computer) on which the lighting control software 771 is installed. While it is also possible to control the angle θ between the two light distributions using the structure described in the above embodiment, the following description will focus on a structure that allows the angle θ between the two light distributions to be changed manually.

[0117] Figure 37 is a cross-sectional view showing the inside of the lamp body 720. By changing the distance between the light source 722, which is part of the rear lamp body 720L, and the two-light distribution lens 725, which is part of the front lamp body 720U, as shown in Figures 37(a), (b), and (c), the angle θ of the light distribution BL in the left diagonal direction and the light distribution BR in the right diagonal direction (angle θ between the two light distributions) can be changed.

[0118] The rear light unit 720L comprises a heat sink 721, a light source 722 attached to the heat sink 721, and a rear reflector 724L, and is provided with a slit 733 as shown in Figure 36.

[0119] The front light unit 720U comprises an intermediate light unit 720E, mounting screws 734 attached to the intermediate light unit 720E, a front reflector 724U, and a dual-beam lens 725.

[0120] By reducing the distance between the rear light unit 720L and the front light unit 720U as shown in Figures 37(a), (b), and (c), the distance between the light source 722 and the two light distribution lenses is reduced, and the rear reflector 724L is enclosed within the area surrounded by the front reflector 724U. This makes it possible to change the angle θ between the two light distributions.

[0121] <Variation> This modified example involves attaching a multiprism 726, an optional filter, to the lamp body 720 of the lighting device 700.

[0122] Figure 38 is a cross-sectional view showing the inside of the light fixture 720F, which is a light fixture to which the multiprism 726 is attached. By changing the distance H from the light source 722, which is part of the rear light fixture 720L, to the lower surface of the two-light distribution lens 725, which is part of the front light fixture 720U, from Ha in Figure 38(a) to Hc in Figure 38(c), the angle θ (angle between the two light distributions θ) of the light distribution BL in the left diagonal direction and the light distribution BR in the right diagonal direction can be changed from θa to θc.

[0123] Here, the multiprism 726, through its refractive surfaces, the incident surfaces 726L and 726R, further decomposes the light distribution BL into BL1, which points further to the left, and BL2, which points towards the center, and the light distribution BR into BR1, which points towards the center, and BR2, which points further to the right. As a result, compared to the absence of the multiprism 726, the light distribution spreads to the left and right, and also directs light towards the center.

[0124] Figure 39(a) shows the illuminance distribution on the wall 785 when the light from lamp body 720 (without multiprism 726) is shone on the wall 785, and Figure 39(b) shows the illuminance distribution on the wall 785 when the light from lamp body 720F, which has the multiprism 726 attached to lamp body 720, is shone on the wall 785. It can be seen that the light from lamp body 720 has a distribution that is split into two directions, whereas the light from lamp body 720F has a horizontally elongated distribution with less of a drop in light intensity in the central direction.

[0125] <Embodiment 15> The lighting device 900 of this embodiment is a spotlight capable of continuously changing the angle between two light distributions.

[0126] Figure 40 is a cross-sectional view showing the inside of the lamp body 920. Referring to Figure 40(a), the light emitted from the light source center 922C of the light source 922 and directed to the left passes through the left light distribution region 925L of the dual-beam Fresnel prism 925 and becomes a ray BL that continues to the left. The light emitted from the light source center 922C of the light source 922 and directed to the right passes through the right light distribution region 925R of the dual-beam Fresnel prism 925 and becomes a ray BR that continues to the right.

[0127] If the direction of the light rays BL and BR is defined as the direction of the strongest light intensity, then by changing the distance H between the light source 922, which is part of the rear light unit 920L, and the dual-beam Fresnel prism 925, which is part of the front light unit 920U, from Ha in the case of Figure 40(a) to Hc in the case of Figure 40(c), the angle θ between the diagonal beam BL to the left and the diagonal beam BR to the right (angle θ between the two beams) can be changed from θa to θc.

[0128] Referring to Figure 40(c), the front aperture of the rear reflector 924L is widened so that even when the distance H is small as Hc, the light from the light source 922 can utilize the entire area of ​​the bi-directional Fresnel prism 925. Accordingly, the front reflector 924U is made cylindrical to avoid interference with the position of the rear reflector 924L.

[0129] Figures 41(a) and (b) show the calculation results of the light rays when the distance H between the light source center 922C and the two-beam Fresnel prism 925 (aperture D) is varied to long and short. Here, the refractive index of the Fresnel prism is assumed to be 1.49 (assuming acrylic), the angle between the incident and exit surfaces is 40 degrees, and the thickness of the Fresnel prism is assumed to be sufficiently small (although it is drawn large in the figure to show the structure, the thickness is not visible in this figure). As can be seen in Figure 41, the angle between the two beams changes by changing H.

[0130] <Points common to each embodiment> <led> When a COB-type LED light source is used as the light source 322, the light distribution of the light emitted from the light source 322 will be close to the so-called Lambertian distribution, where the relative luminous intensity in the θ direction from the optical axis is cosθ.

[0131] The COB-type LED light source 322 is a white LED in which multiple blue LED chips, each with an InGaN light-emitting layer, are arranged on a substrate, and the top and sides of the blue LED chips are covered with a phosphor-containing resin.

[0132] The COB-type LED light source 322 may be an LED with a fixed emission color, or it may be an LED whose emission area is divided into two regions, emitting high-color-temperature white light in the first region and low-color-temperature white light in the second region, with the emission amount of the first and second regions being individually controlled.

[0133] Instead of a COB-type LED light source, a CSP-type LED light source may be used, for example, in which a high color temperature white LED CSP (Chip Scale Package) with a color temperature of 6500K and a low color temperature white LED CSP with a color temperature of 3000K are arranged on a substrate.

[0134] For the CSP-type LED light source, three types of LEDs may be used: a blue-white LED (Bw), a red LED (R), and a yellow-white LED (Yw).

[0135] A blue-white LED (Bw) is an InGaN-based blue LED chip in which the top and sides are covered with a resin containing green phosphor particles or yellow phosphor particles. It may also contain red phosphor particles.

[0136] Yellow-white LEDs (Yw), like Bw, have an InGaN-based blue LED chip placed at the bottom of the package, with the top and sides of the InGaN-based blue LED chip covered with a resin containing green or yellow phosphor particles, but the phosphor concentration is higher than that of Bw. Furthermore, red phosphor particles may also be included.

[0137] The red LED (R) is one in which the upper surface and the side surfaces of an InGaN-based blue LED chip are covered with a resin containing red phosphor particles. As the red LED (R), an AlGaInP-based LED chip may be used instead of the InGaN-based blue LED chip and covered with a phosphor-free resin. When an LED package using an AlGaInP-based LED chip is used as the red LED (R), it is preferable in that the emission spectrum does not contain blue, but since the drive voltage is different from that of the blue-white LED (Bw) and the yellow-white LED (Yw), the drive circuit becomes complicated. In the case of an LED package combining a blue LED chip and a red phosphor as the red LED (R), a process for reducing the blue contained in the emission spectrum is required. For example, it is preferable to increase the concentration of the red phosphor to reduce the ratio of the light from the blue LED chip radiated to the outside, but a filter that absorbs blue may also be used.

[0138] Although it is larger in size than the CSP type LED, an SMD (Surface Mount Device) type LED (surface-mounted LED) may be used, and it can be suitably used particularly as a light source for a lighting fixture having a large diameter.

[0139] In each of the above LEDs, as the yellow phosphor particles, for example, (Y 1-x Gd x )3Al5O 12 :Ce 2+ (0 ≦ x ≦ 1), as the green phosphor particles, for example, Lu3Al5O 12 :Ce 2+ , and as the red phosphor, for example, Sr x Ca 1-x AlSiN3:Eu 3+ (0 ≦ x ≦ 1) phosphor, Sr[LiAl3N4]:Eu 2+ or K2SiF6:Mn 4+ 0Phosphors can be suitably used. Quantum dots can also be suitably used.

[0140] <Chromaticity of LED> Figure 25 is a chromaticity diagram (chromaticity coordinate diagram) illustrating the chromaticity of a blue-white LED (Bw), a red LED (R), and a yellow-white LED (Yw). For reference, dotted lines connect the chromaticity of blackbody radiation at each color temperature. Note that while Yw appears close to yellow on the chromaticity diagram, it can appear closer to green when Bw and R are lit simultaneously.

[0141] The blue-white LED (Bw) emits light within the chromaticity range enclosed by (0.336, 0.24), (0.352, 0.44), (0.15, 0.2), and (0.2, 0.1) in the CIE1931 chromaticity coordinates shown in Figure 25, with (0.23, 0.26) being an example.

[0142] The red LED (R) emits light at chromaticity ranges enclosed by the chromaticity boundary line E, as shown in the chromaticity coordinates of Figure 25: (0.66, 0.23), (0.423, 0.355), (0.5, 0.5), and (0.60, 0.38) as an example. Note that this is not the same as the general definition of red.

[0143] The yellow-white LED (Yw) emits light at chromaticities within the range enclosed by the chromaticity boundary line E, as shown in the chromaticity coordinates of Figure 25: (0.5, 0.5), (0.423, 0.355), (0.342, 0.312), (0.352, 0.44), (0.37, 0.63), and (0.44, 0.47), with (0.44, 0.47) being one example.

[0144] Within the chromaticity range of a yellow-white LED (Yw), the line connecting the chromaticities of blackbody radiation at each color temperature is d uv A positive range is preferable, d uv A value between +0.03 and 0 is particularly preferable.

[0145] The chromaticity of blue-white LEDs (Bw) and red LEDs (R) is measured from the line connecting the chromaticities of blackbody radiation at each color temperature. uv A range of +0.03 to -0.03 is particularly preferable.

[0146] Note d uv The value 1000 times that value is sometimes called Duv (with the first 'd' capitalized).

[0147] It is also possible to display the coordinates using CIE1976 chromaticity coordinates (u',v') instead of CIE1931 chromaticity coordinates (x,y), and the two can be converted to each other using the conversion formulas u'=4x / (-2x+12y+3) and v'=9y / (-2x+12y+3). Other chromaticity coordinate systems may also be used.

[0148] <Variations> While examples of three-color LEDs have been described using red (R), yellow-white (Yw), and blue-white (Bw), other three-color LEDs may also be used. For example, R, Yw, and blue (B) (LEDs with chromaticity coordinates x≦0.2, y≦0.2) may be used, in which case Yw is the most preferable LED for the ends, and R should be avoided. Three-color LEDs of R, green (G) (LEDs with chromaticity coordinates x≦0.35, y≧0.4), and B may also be used.

[0149] The lighting fixtures are not limited to ceiling-mounted universal downlights or simple downlights; spotlights may also be used.

[0150] The lighting device may also be a bulb-type LED that can be attached to a standard light bulb socket.

[0151] In this invention, the term "two-way optical element" is a concept that includes "two-way lenses," "two-way prisms," "two-way Fresnel prisms," and "two-way multiprisms," and is an optical element that, upon incident light, emits at least one beam of light directed diagonally to the left and another beam of light directed diagonally to the right. Of these, "two-way lenses," "two-way prisms," and "two-way Fresnel prisms" can be classified as two-region type two-way optical elements, while "two-way multiprisms" can be classified as region-mixing type two-way optical elements. Two-region type two-way optical elements can be particularly suitably used in lighting devices that change the angle between the two beams by changing the distance H.

[0152] In this invention, a "two-way optical element," such as a "two-way optical lens," means a lens that distributes light in at least two directions. Therefore, even a three-way or four-way optical lens, for example, having three or four convex lens regions, is included within the scope of this invention. The same applies to prism regions, not just convex lens regions. For example, a three-way optical element that distributes light in three directions—in the optical axis direction, diagonally to the left of the optical axis, and diagonally to the right of the optical axis—can be considered. An example of a lighting device using such a three-way optical element is a lighting device that illuminates the left and right walls of a corridor while also ensuring sufficient illumination of the floor surface with light in the optical axis direction.

[0153] The light distribution region, such as the convex lens region in the present invention, is not limited to having a circular virtual shape; for example, the virtual shape may be elliptical or rectangular. The virtual shape may be rectangular and have a cross-section of a part of the same cylinder along one of its sides.

[0154] The shape of the reflector exemplified in Figure 2 in this invention, which reflects light emitted from the center of the light source in a direction different from the optical axis direction, can also be applied to the rear reflector and the front reflector.

[0155] In a bi-directional lens, the convex lens function and the bi-directional lens function may be separated and performed using a single convex lens and a bi-directional lens prism. Alternatively, these two functions may be integrated, for example, by using a bi-directional lens optical element where the incident surface is a bi-directional lens prism and the exit surface is a convex lens.

[0156] In a system where the angle between two light distributions can be controlled using a motor and a lighting control device, for example, scheduled operation can be performed to change the angle between the two light distributions according to the time. Furthermore, sensor-linked operation can be performed. As an example of sensor-linked operation, the lighting device of the present invention can be used to illuminate a hospital corridor, where the angle between the two light distributions is normally small, and when a bed passes by, a motion sensor increases the angle between the two light distributions to reduce the amount of downward light that can be dazzling to patients lying in bed and looking upwards.

[0157] By eliminating the two light-distribution optical elements in embodiments 12, 13, 14, and 15, or by replacing the two light-distribution optical elements with a single light-distribution optical element such as a general convex lens, concave lens, or diffuser, the spread of light distribution (beam angle) in illumination in one direction can be changed. The basic structure can be understood as "variable light distribution illumination equipped with a rear reflector and a front reflector, in which the spread of light distribution can be changed by changing the position of the light source and the upper end of the front reflector." In the absence of two light-distribution optical elements, the distance H can be defined as the distance on the optical axis between the plane including the upper end of the front reflector and the light source. A characteristic of the configuration is that, for example, when the distance H is at its minimum value, the rear reflector is positioned inside the front reflector.

[0158] Furthermore, the embodiments disclosed herein are illustrative in all respects and do not constitute a limiting interpretation. Therefore, the technical scope of the present invention is not construed solely by the embodiments described above, but is defined based on the claims. This also includes all modifications within the meaning and scope of the equivalents of the claims. [Explanation of Symbols]

[0159] 100, 200, 300, 300A, 300C, 300D, 300G, 300F, 300E, 400, 500, 500V, 700, 900 Lighting equipment 120, 220, 320, 420, 520, 520B, 520V, 720, 920 light body 720U, 920U front light body 720L, 920L rear light body 720E Intermediate light body 122, 222, 322, 422, 522, 722, 922 light source 124, 224, 324 reflector 321, 521, 721 Heatsinks 524L, 724L, 924L rear reflector 524U, 724U, 924U front reflector 125 2-beam prism 225, 925 2-beam Fresnel prism 325, 525, 725 2-beam lenses 425 2-beam multiprism 551 Motor 552 Lead screw shaft 553 Screw receiver 370, 570V, 770V Lighting Control Device 371, 571, 771 Lighting control software< / led>

Claims

1. A two-way light distribution lens used in a lighting device that distributes light emitted from a light source in two directions, The outer shape of the two light distribution lenses is circular. The two light distribution lenses are provided with a left-convex lens region and a right-convex lens region on the lens-forming surface which is at least one of the light incident surface or the light emission surface. The left convex lens region and the right convex lens region are formed by cutting out virtual regions with an outline within the lens-forming surface, each having a center point which is the point where the cross-section of the convex lens is thickest, using a center line passing through the center of the two light-distributing lenses and the outline. The direction of the horizontal axis connecting the center point of the left convex lens region and the center point of the right convex lens region is the x-direction, and the direction perpendicular to the x-direction within the lens-forming surface is the y-direction. The left-convex lens region and the right-convex lens region are two-part lenses in which the thickness of the lenses decreases as they move away from the horizontal axis in the y-direction.

2. The ratio of the distance between the center point of the left-convex lens region and the center point of the right-convex lens region to the diameter of the two light-distributing lenses is 45% or more and 100% or less. The two-light distribution lens according to claim 1.

3. The virtual outer shape of the left-convex lens region or the right-convex lens region is circular, and the ratio of the diameter of the circle to the diameter of the two light-distribution lenses is 60% or more and 120% or less. The two-light distribution lens according to claim 1.

4. The lens-forming surface includes a scattering region which is the portion other than the left-convex lens region and the right-convex lens region. The two-light distribution lens according to claim 1.

5. Of the light incident surface and the light output surface, the surface that is not the lens forming surface is flat. The two-light distribution lens according to claim 1.

6. An illumination device comprising a light source having a light source center, and two light distribution lenses according to claim 1, which are positioned away from the light source on an optical axis passing through the light source center, The lighting device comprises a lamp body containing the light source inside, and the opening of the lamp body is equipped with the two light distribution lenses.

7. The two light distribution lenses can be attached and detached without removing the lighting device from its installation location. The lighting device according to claim 6.

8. The lighting device further includes a reflector that reflects the light emitted from the light source and directs it toward the two light distribution lenses. The lighting device according to claim 6.

9. The reflecting mirror reflects the light emitted from the center of the light source at an angle of 5 degrees or more outward from the optical axis direction. The lighting device according to claim 8.

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