Lighting fixtures

Abstract

To provide lighting fixtures that offer nearly uniform illumination over a wide area, thereby reducing the number of fixtures required. [Solution] A lighting fixture comprising a light source and a multi-lens plate, wherein the multi-lens plate has a plurality of lens portions arranged two-dimensionally on a virtual light incident surface or virtual light emission surface, the lens portions have a slope surrounding the center of the lens portion, and the angle of the steepest slope among the slopes with respect to the normal of the virtual light incident surface or virtual light emission surface is 35° or more and 60° or less, and the light emitted from the multi-lens plate obtains the maximum luminous intensity in the direction oblique to the optical axis in each cross section in the x and y directions perpendicular to the optical axis.

Description

[Technical Field]

[0001] The present invention relates to lighting fixtures, and more particularly to lighting fixtures capable of distributing light over a wide area. [Background technology]

[0002] Lighting fixtures can be broadly categorized into those with a narrow beam angle (narrow-angle) designed to brightly illuminate a small area, and those with a wide beam angle (wide-angle) designed to evenly illuminate a wide area.

[0003] The lighting fixture described in Patent Document 1 is said to produce illumination light when light emitted from an LED module passes through a light distribution panel equipped with numerous prisms made up of truncated square pyramidal recesses. The light distribution panel concentrates the illumination light, thereby suppressing unpleasant glare.

[0004] The lighting fixture described in Patent Document 2 also features a lighting cover with numerous minute protrusions, and it is stated that this lighting cover can reduce light in the angle range θ of 60 to 90 degrees, thereby significantly reducing glare.

[0005] Patent Document 2 shows that the problem of luminance dispersion of the light source, that is, the problem of the point light source pattern being visible when viewing the light source through the lighting cover, has been improved. However, judging from Figure 7(f) of Patent Document 2, the point light source pattern still appears to be slightly visible.

[0006] On the other hand, the lighting fixture described in Patent Document 3 is said to be able to achieve a light distribution that spreads out to the left and right (a bat-wing-shaped light distribution) by having a prism section provided with multiple prism sections that extend in the longitudinal direction. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-59518 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-032474 [Patent Document 3] Japanese Patent Application Laid-Open No. 2017-191747 [Summary of the Invention] [Problems to be Solved by the Invention]

[0008] The inventor aims at a lighting fixture that can obtain substantially uniform illuminance over a wide range. [Means for Solving the Problems]

[0009] The present invention is a lighting fixture including a light source and a multi-lens plate, wherein a plurality of concave lens portions are two-dimensionally arranged on the surface of the multi-lens plate, the boundaries of the concave lens portions are formed as ridgelines, the ridgelines include ridgeline vertices and ridgeline saddle portions lower than the ridgeline vertices, and the ridgeline saddle portions are located between two of the ridgeline vertices.

[0010] In the present invention, the surface may be an incident surface on which light from the light source is incident or an exit surface located on the side opposite to the incident surface.

[0011] In the present invention, the planar shape of the boundary may be hexagonal.

[0012] In the present invention, the concave lens portion includes a first inclined surface located near the center of the concave lens portion, a second inclined surface surrounding the first inclined surface, and a third inclined surface surrounding the second inclined surface, and an angle of the second inclined surface with respect to a normal line of the surface may be smaller than angles of the first inclined surface and the third inclined surface with respect to the normal line of the surface.

[0013] In the present invention, for light emitted from the multi-lens plate, a maximum value of luminous intensity may be obtained in a direction obliquely from the optical axis direction in each cross section in the x direction and the y direction orthogonal to the optical axis direction. [Effects of the Invention]

[0014] Since the lighting fixture according to the present invention can obtain a substantially uniform illuminance over a wide range, it is possible to reduce the number of lighting fixtures to be installed.

Brief Description of the Drawings

[0015] [Figure 1] View of the system ceiling with the lighting fixture attached, looking up from below [Figure 2] Cross-sectional view of the lighting fixture [Figure 3] Cross-sectional view of the light source unit [Figure 4] Plan view of the substrate [Figure 5] Enlarged cross-sectional view of the multi-lens plate with concave lens portions integrated [Figure 6] Enlarged plan view of the multi-lens plate with concave lens portions integrated [Figure 7] Explanatory view of the shape of the light-emitting surface of the multi-lens plate [Figure 8] Further enlarged cross-sectional view of the multi-lens plate with concave lens portions integrated [Figure 9] Light distribution characteristics and illuminance characteristics of the lighting fixture of Embodiment 1 [Figure 10] Light distribution characteristics and illuminance characteristics of the lighting fixture of another example of Embodiment 1 [Figure 11] Illuminance distribution of the lighting fixture of Embodiment 1 and the comparative example [Figure 12] Enlarged cross-sectional view of the multi-lens plate with convex lens portions integrated [Figure 13] Plan view of the multi-lens plate with convex lens portions integrated [Figure 14] Further enlarged cross-sectional view of the multi-lens plate with convex lens portions integrated [Figure 15] Perspective view of the lighting fixture of Embodiment 2 [Figure 16] Partial side view and partial cross-sectional view of the lighting fixture of Embodiment 2 [Figure 17] Plan view of the light source of Embodiment 2 [Figure 18] Light distribution characteristics and illuminance characteristics of the lighting fixture of Embodiment 2 [Figure 19] Perspective view of the lighting fixture of Embodiment 3 [Figure 20] Cross-sectional view of the fixture body and light source unit. [Figure 21] Cross-sectional view of the light source unit from a different angle. [Figure 22] Front view, cross-sectional view, and top view of the lighting fixture of Embodiment 4 [Modes for carrying out the invention]

[0016] <Embodiment 1> <Overview> Figure 1 shows a view from below of a system ceiling 199 on which the lighting fixture 100 according to this embodiment is installed. T-bars 195 are installed on the system ceiling at grid intervals L G The T-bars are installed in a grid pattern (for example, 600 mm apart), and within the sections separated by the T-bars, lighting fixtures 100, air conditioning equipment 180, ceiling panels 190, and ceiling panels 191 equipped with various devices (inspection hatches, speakers, wireless equipment (such as wireless repeaters)) are installed. The T-bars 195 are attached to the slab (a reinforced concrete ceiling that also serves as the floor of the upper floor) with suspension bolts, and heavy objects such as lighting fixtures 100 and air conditioning equipment 180 are attached to the T-bars 195 to prevent them from falling during earthquakes or other events. Note that although the T-bars 195 are shown in Figure 1 for illustrative purposes, they are usually constructed so that they are hidden when viewed from below.

[0017] The lighting fixture 100 consists of a fixture body 110 and a light source unit 120. A cross-sectional view of this is shown in Figure 2. The fixture body 110 has a recess 112 on its lower surface for attaching the light source unit 120, and a power supply 114 is attached to its upper surface. A wireless module 115, which is a communication device for lighting control, is attached to the power supply 114 and can communicate with the wireless communication unit 172 of the lighting control device 170. A light source drive line is connected from the power supply 114 to the light source unit 120.

[0018] <Lighting control device> The lighting control device 170 in Figure 1 consists of a tablet, smartphone, PC, etc., and is equipped with a touch panel 171 which serves as both a display and input unit, a wireless communication unit 172, and has a lighting control program 173 (not shown) installed. The user can operate the lighting control program 173 to wirelessly communicate with the lighting fixture 100 via wireless signals transmitted and received by the wireless communication unit 172, and change the lighting conditions. The lighting conditions include color temperature (color adjustment), brightness (dimming), and on / off, and an interface is provided for manual control of these as needed. In addition, scheduled operation can be performed to automatically change the lighting conditions at set times according to pre-registered times and lighting conditions.

[0019] Note that the lighting control device 170 is not mandatory, and even if the lighting control device 170 is not provided, the lighting fixture 100 can be turned on and off by switching the power line switch ON / OFF. The lighting control device may be a wired control device such as PWM (Pulse Width Modulation) dimming or phase dimming.

[0020] <Light source unit> A cross-sectional view of the light source unit 120 is shown in Figure 3. The light source unit 120 comprises a substrate 122, a diffusion panel 125, a multi-lens plate 127, and a frame 130. Hereinafter, the direction of the optical axis is referred to as the z direction, the direction perpendicular to the z direction in Figure 3 is referred to as the x direction, and the direction perpendicular to both the z and y directions (the depth direction in Figure 3) is referred to as the y direction.

[0021] <Substrate / Light Source> As shown in Figure 3, the substrate 122 is a long printed circuit board on which multiple light sources 123, consisting of surface-mount LEDs, are arranged in rows with spacing in the longitudinal direction. The number of rows in which the light sources 123 are arranged is four, as shown in Figure 3, but it may be one row or three or more rows depending on the width of the substrate 122.

[0022] The surface-mount LED light source 123 is, for example, a blue LED chip with an InGaN light-emitting layer, enclosed in a phosphor-containing encapsulating resin in a 3mm square package. The light-emitting color can be adjusted by the type and amount of phosphor used.

[0023] Light source 123 exhibits a light distribution that follows the cosθ law, known as Lambertsian light distribution, and the beam angle at which the luminous intensity is 1 / 2 of the on-axis luminous intensity (1 / 2 beam angle) is approximately 120°. However, the actual beam angle of an LED is around 114-118°. In some cases, the 1 / 2 beam angle is defined as the angle on one side from the optical axis, in which case the theoretical value of the 1 / 2 beam angle on one side is 60°, and the measured value is, for example, around 58°. In this invention, Lambertsian light distribution is defined as a 1 / 2 beam angle of 110°-122°.

[0024] For the light source 123, for example, only one LED of a single color may be used. Alternatively, two LEDs of different colors (for example, daylight white (color temperature 6500K) and incandescent (color temperature 2700K)) may be arranged alternately. By using these two LEDs, it becomes possible to change (tune) the color in a manner that closely follows blackbody radiation.

[0025] Furthermore, three LEDs of different colors may be arranged as a light source so that the colors are mixed. However, when using two-color or three-color LEDs, color unevenness is more likely to occur in addition to brightness unevenness (brightness inconsistency caused by the visibility of the light source pattern, also known as a grainy appearance), making it more difficult to eliminate brightness unevenness and color unevenness on the light-emitting surface of the lighting fixture.

[0026] As an example of a light source with three emission colors, using, for instance, three LEDs of red (R), green (G), and blue (B) allows for a very wide range of emission colors.

[0027] Another example of a light source with three different emission colors is a combination of the following red, yellow-white, and blue-white LEDs.

[0028] The red LED (R) emits light within the range of CIE1931 chromaticity coordinates enclosed by (0.66, 0.23), (0.423, 0.355), (0.5, 0.5), and (0.736, 0.264), with (0.60, 0.38) being an example.

[0029] Yellow-white LEDs (Yw) emit light at chromaticities within the range enclosed by the CIE1931 chromaticity coordinates (0.5,0.5), (0.423,0.355), (0.342,0.312), (0.352,0.44), (0.37,0.63), and the chromaticity boundary line, with (0.44,0.47) being one example.

[0030] A 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 coordinate system, with (0.23, 0.26) being an example.

[0031] For reasons such as the fact that Bw (bluish-white) light, which is a mixture of light from other spectra with high luminous efficiency, has higher luminous efficiency than B (blue) light, which has a nearly monochromatic spectrum, using three light-emitting elements of R, Yw, and Bw has the advantage of being able to achieve a relatively good power luminous flux conversion efficiency (lm / W) compared to using three primary color light-emitting elements of R, G, and B.

[0032] As the light source 123 has been described as a surface-mount LED, a COB (Chip On Board) type LED, in which a blue LED chip is mounted on a substrate and sealed with phosphor-containing resin, or a CSP (Chip Scale Package) type LED, which integrates multiple blue LED chips sealed with phosphor-containing resin, may also be used.

[0033] Figure 4 shows a plan view illustrating the arrangement of LEDs on substrate 122. When using three-color LED light sources, the light sources 123A, 123B, and 123C, each emitting a different color, form a single light source group 123G as shown in Figure 4, with a light source group spacing L. YBy arranging them closer together than 1 / 3 of the distance, color unevenness can be reduced. Also, from the viewpoint of preventing brightness unevenness, the horizontal spacing L of the light source group X and vertical light source group spacing L Y It is preferable that they are approximately equal.

[0034] Similarly, when using two-color LEDs, the light sources 123A and 123B should be arranged to form a single light source group 123G, with a light source group spacing L. Y It is preferable to arrange them closer together than 1 / 2 of the distance. When using a single-color LED, it does not constitute a group of light sources, but the lateral spacing L of the light sources X and vertical light source spacing L Y It is preferable to arrange them so that they are approximately the same size.

[0035] <Multi-lens plate 127> Figure 5 shows an enlarged cross-sectional view including the z·x axis of the concave lens integrated multi-lens plate 127, and Figure 6 shows an enlarged plan view including the x·y axis. The multi-lens plate 127 has multiple concave lens sections 128 provided on a virtual light incident surface 127F, which is assumed to be the side where light is incident, assuming that there are no concave lens sections 128, and a light exit surface 127B on the side where light is emitted. The virtual light incident surface is, for example, a plane connecting the vertices 129P of the ridge lines, which will be described later. The concave lens sections 128 have the function of reducing the light distribution in the forward (z direction) and increasing the light distribution in the oblique x and oblique y directions by refracting, for example, the incident light ray B1 into the internal light ray B2 and the exit light ray B3 in the oblique x direction in Figure 5. In addition, as shown in Figure 5 as the incident light ray C1, internal light ray C2, and internally reflected light ray C3, there is also an internally reflected light ray C3 that is totally reflected in the multi-lens plate 127 and returns to the incident side. The larger the angle θ0 of the inclined surface of the concave lens portion 128 with respect to the z-axis, which is the normal to the virtual light incident surface 127F, the larger the light component distributed in the oblique x-direction becomes. However, the proportion of internally reflected light also increases, and the light extraction efficiency tends to decrease.

[0036] In the multi-lens plate 127, the concave lens portion is provided on the side where light is incident. As a result, the incident light ray B1 becomes the internal light ray B2 after the first refraction, and the internal light ray B2 becomes the outgoing light ray B3 after the first refraction. Therefore, there is an advantage in that the outgoing light component in the oblique lateral direction increases.

[0037] Figure 6 shows a plan view of the multi-lens plate 127. The concave lens portions 128 are repeatedly arranged in two dimensions in the x-direction and in directions 60 degrees diagonally from the x-direction. The boundary shape is hexagonal so that it forms a honeycomb-like planar arrangement. The interior of the concave lens portions 128 has a concentric circular shape as shown in the cross-sectional view in Figure 5 and the contour lines 128C1 and 128C2 in Figure 6. The ridges 129 that form the boundaries of the concave lens portions 128 are connected, so that the thicker parts are continuous, and the strength of the multi-lens plate 127 can be maintained. The ridge 129 is formed by connecting the ridge vertex 129P which is the boundary of the three concave lens portions 128 and the ridge saddle 129B which is the lowest part of the ridge 129 (the term "saddle" is derived from equestrian terminology and is used in geometry to refer to "the lowest part of a ridge that is higher than its surroundings"). The ridge saddle 129B is slightly lower than the ridge apex 129P. This means that the distance to the light-emitting surface of the multi-lens plate 127 in that area is shorter.

[0038] By giving the ridge line 129 a shape having a ridge line vertex 129P and a ridge line saddle 129B, the planar shape of the boundary can have concentric slopes throughout the entire interior of the hexagonal concave lens portion 128, thereby achieving isotropic light distribution.

[0039] The interval p1 in the x - direction and the interval p2 in the y - direction of the concave lens portion 128 are 1.0 mm and 0.89 mm respectively, and the depth d in the z - direction is 0.7 mm. The three concave lens portions 128 are respectively arranged at the vertices of an equilateral triangle. The interval p1 corresponds to the length of the base of the equilateral triangle, and the interval p2 corresponds to the height from the center of the base of the equilateral triangle to another vertex. Since a smaller depth d can reduce the thickness of the multi - lens plate 127, it is preferably 2 mm or less, and more preferably 1 mm or less. From the perspective that the pattern of the light source becomes difficult to see, the interval p1 is preferably 1 / 3 or less of the light source interval (light source group interval) L in the x - direction X and more preferably 1 / 10 or less (the same applies to the y - direction and L Y ). On the other hand, if the interval p1 becomes too small, in addition to the difficulty of manufacturing, the diffraction effect of light cannot be ignored. Therefore, with the light wavelength being 0.5 μm, it is preferably 0.005 mm or more, which is 10 times or more of that, and more preferably 0.1 mm or more (the same applies to the interval p2).

[0040] The light - emitting surface 127B is shown as a plane in Fig. 5(a), but as shown in Fig. 7(a), which is a perspective view of the shape of the light - emitting surface of the multi - lens plate, and Fig. 7(b), which is a cross - sectional view, it may be the light - emitting surface 127BR having a light - scattering structure. Here, the light - emitting surface 127BR has an uneven structure with the same pitch as the concave lens portion 128, but it is not limited thereto.

[0041] Fig. 8 shows a further enlarged cross - sectional view of the multi - lens plate 127 in a cross - section including the z·x axis connecting the ridgeline saddle portions 129B. Although the cross - sectional shape of the slope of the concave lens portion 128 is a continuous curve, for the sake of explanation, it is assumed to be composed of the first slope 128P, the second slope 128Q, and the third slope 128R.

[0042] The first slope 128P is a slope located near the center of the concave lens portion 128 and is a region where the angle formed with the z - axis is larger than that of the second slope 128Q. At the bottom of the first slope 128P, since light rays at an angle closer to the z - axis direction than the incident light ray D1 are incident, the amount of incident light on the first slope 128P is limited.

[0043] The second slope 128Q is the region surrounding the center of the concave lens portion 128 or the first slope 128P, and includes the portion where the angle θ0 between the z-axis and the tangent 128S is the steepest (smallest) angle. The incident light ray is refracted by angle θ0, contributing to the oblique light distribution of the multi-lens plate 127.

[0044] The third slope 128R is the region surrounding the center of the concave lens portion 128, the first slope 128P, or the second slope 128Q, and has a larger angle with the z-axis than the second slope. Therefore, as shown in Figure 8, the incident light ray E1 directed toward the third slope 128R contributes to the oblique light distribution of the multi-lens plate 127 as an internal light ray E2. In other words, the proportion of internal light rays E2 that strike the slope of the adjacent concave lens portion 128 and undergo total internal reflection is reduced.

[0045] Furthermore, the concave lens portion 128 may not include a third inclined surface 128R and may consist only of the first inclined surface 128P and the second inclined surface 128Q, or it may consist only of the second inclined surface 128Q.

[0046] <Diffusion Panel> The lower surface of the diffusion panel 125 is from the upper surface of the light source 123. Z Distant position (distance between light source and diffusion panel D) Z It is provided in the ). The diffusion panel 125 is a plate with flat surfaces on both sides and uniform light diffusion properties due to the incorporation of a diffusion material. Suitable materials include, for example, polycarbonate or acrylic. Uniform light diffusion properties can also be achieved by making the surface rough.

[0047] The design concept of this invention is that the diffusion panel 125 plays a role in converting the light from the light source 123 into a planar light source with less brightness and color unevenness. To achieve this, the light source spacing L X (Light source group spacing L X D for ) Z Ratio D Z / L X For example, you can make it large enough to be 1 or more. On the other hand, according to experiments, D Z / L XIncreasing the value reduces the light extraction efficiency, so the optimal D is determined by taking both factors into consideration. Z / L X We are conducting studies to achieve this, and have obtained a design with a light source pattern that is almost invisible at a value of 0.6 or higher. In addition, in order to make the fixture body thin, it is desirable to install the diffusion panel 125 near the multi-lens plate, and it may even be in contact with it. Nearby means D Z A distance of about 1 / 10 or less of that distance is sufficient.

[0048] Furthermore, as shown in Figure 5 as incident ray C1, internal ray C2, and internally reflected ray C3, there is an internally reflected ray C3 that is totally reflected by the multi-lens plate 127 and returns to the incident side. The diffusion panel 125 also has the function of directing such rays back towards the multi-lens plate 127, and for this purpose it is preferable to install it near the multi-lens plate 127.

[0049] Note that the calculations were performed assuming the multi-lens plate 127 is made of acrylic (PMMA, polymethyl methacrylate) with a refractive index of 1.485. However, the material of the multi-lens plate 127 is not particularly limited as long as it is a transparent material, and may be PC (polycarbonate) or glass.

[0050] <frame> The frame 130 shown in Figure 3 has a lower surface that supports the substrate 122, and its sides that support the diffusion panel 125 and the multi-lens plate 127.

[0051] <Light distribution characteristics and illuminance distribution> Figures 9(a) and 9(b) show the light distribution and illuminance characteristics when using a multi-lens plate 127 with the steepest slope angle θ0 set to 39.3 degrees. The 1 / 2 beam angle (both sides) is 134° in the x direction and 140° in the y direction. The 1 / 2 illuminance angle (one side) is 79° in the x direction and 82° in the y direction. A distinctive feature is that the illuminance curve is not a typical circle, but rather nearly flat at the bottom, meaning there is a wide range where the illuminance is almost constant.

[0052] Figures 10(a) and 10(b) show the light distribution and illuminance characteristics when using a multi-lens plate 127 with the steepest slope angle θ0 set to 47.2 degrees. The 1 / 2 beam angle (both sides) is 126° in the x direction and 131° in the y direction. The 1 / 2 illuminance angle (one side) is 75° in the x direction and 76° in the y direction. In this case as well, the illuminance curve is not a typical circle, but rather has a shape that is nearly flat at the bottom, meaning that there is a wide range where the illuminance is almost constant.

[0053] When a structure like that of the present invention is not used, the beam angle is, for example, about 120°, and the direction in which the luminous intensity is maximum is the 0° direction. In contrast, when a multi-lens plate 127 with the angle θ0 of the steepest slope being 39.3 degrees is used, the luminous intensity is maximum in both the x and y directions at 30-32°, as shown in Figure 9(a). Furthermore, when a multi-lens plate 127 with the angle θ0 of the steepest slope being 47.2 degrees is used, the luminous intensity is maximum in both the x and y directions at 18-23°, as shown in Figure 10(a).

[0054] The fact that the maximum luminous intensity is located at an oblique angle is the reason why relatively uniform illuminance characteristics can be obtained. On the floor surface away from directly below the light fixture, light is incident at an oblique angle θ, thus the illuminance... ga c osθ double In addition to this, there is a decrease in illuminance due to the distance being 1 / cosθ squared, but if there is a maximum value of luminous intensity in the oblique direction, this decrease in illuminance can be compensated for.

[0055] Therefore, the angle at which the luminous intensity is maximized is preferably between 10° and 45°, more preferably between 20° and 40°, and even more preferably between 25° and 35°.

[0056] Corresponding to this point, the angle θ0 of the steepest slope is preferably 35 degrees or more, more preferably 45 degrees or more, and even more preferably 50 degrees or more. On the other hand, from the viewpoint of light utilization efficiency, it was found that the slope angle θ0 is preferably 60 degrees or less, and more preferably 55 degrees or less.

[0057] When defining the luminaire of the present invention in terms of the light source and the half beam angle, the light source is preferably a Lambertian light source, and the half beam angle is preferably 125° or greater, and more preferably 128° or greater. On the other hand, considering the decrease in efficiency due to total internal reflection caused by widening the beam angle, the beam angle is preferably 160° or less, and more preferably 150° or less.

[0058] <Illuminance distribution> Figure 11(a), a comparative example, shows the illuminance distribution (in lx) when conventional lighting fixtures are installed vertically and horizontally at 180cm intervals in a 28.8m x 28.8m room. Figure 11(b), an example, shows the calculated illuminance distribution when lighting fixtures 100 of this embodiment are installed vertically and horizontally at 240cm intervals in a 28.8m x 28.8m room. The lighting fixtures were installed under the condition that an illuminance of 750lx or more could be obtained on the desk. The desk height is assumed to be 70cm, the ceiling height 3.5m, and the illuminance distribution is calculated for a height of 2.8m from the ceiling to the top of the desk.

[0059] In the comparative example, the power consumption of each lighting fixture was 22.4W, and the total power consumption was 5734W. On the other hand, when using lighting fixture 100, the power consumption of each lighting fixture 100 was 30.4W, and the total power consumption was 4378W. This value is approximately 76% of that of the comparative example, demonstrating a significant reduction in power consumption. Furthermore, the number of units to be installed is 56% of that of the comparative example, allowing for a substantial reduction in installation costs.

[0060] <Multi-lens plate 137> In this embodiment, a multi-lens plate 137 with integrated convex lens sections can be used instead of the concave lens section-integrated multi-lens plate 127. Figure 12 shows an enlarged cross-sectional view of the multi-lens plate 137. The multi-lens plate 137 has multiple convex lens sections 139 provided on a virtual light incident surface 137F on the side where light is incident, where it is assumed that there are no convex lens sections 139, and a light emission surface 137B on the side where light is emitted. The virtual light incident surface is, for example, a plane connecting the vertices of the convex lens sections 139. In Figure 12, the light emission surface 137B is shown as a plane, but a light scattering shape may be provided. The convex lens sections 139 have the function of reducing the light distribution in the z direction (downward direction in the figure) and increasing the light distribution in the oblique x direction by refracting, for example, the incident light ray B31 with the internal light ray B32 and the emitted light ray B33 in the oblique x direction in Figure 12. Furthermore, as shown in Figure 12 as incident ray C31, internal ray C32, and internally reflected ray C33, there is also internally reflected ray C33 that is totally reflected in the multi-lens plate 137 and returns to the incident side. The larger the angle θ0 of the slope of the convex lens portion 139 with respect to the z axis, which is the normal to the virtual light incident surface 137F, the larger the light component distributed in the lateral direction becomes, but the proportion of internally reflected light also increases, and the light extraction efficiency tends to decrease. The fact that Figure 5, a cross-sectional view of the concave lens portion integrated multi-lens plate 127, and Figure 12, a cross-sectional view of the convex lens portion integrated multi-lens plate 137, are very similar indicates that a similar trend can be observed in the angle θ0 dependence of the light distribution characteristics.

[0061] Figure 13 shows a plan view of the multi-lens plate 137. The convex lens portions 139 are repeatedly arranged in two dimensions in the x-direction and in directions 60 degrees oblique to the x-direction. The planar shape of the valleys 138, which are the boundaries of the convex lens portions 139, is hexagonal in order to create this honeycomb-like planar arrangement. The convex lens portions 139 have a concentric circular shape as shown by the contour lines 138C1 and 138C2 in Figure 13. The valleys 138 connect the deep part of the valley 138D, which is the boundary between three convex lens portions 139, and the shallow part of the valley 138B, which is the boundary between two convex lens portions 139.

[0062] By making the valley 138 a shape that connects a shallow valley portion 138B and a deeper valley portion 138D, the planar shape of the boundary can have concentric slopes in the hexagonal convex lens portion 139, thereby enabling isotropic light distribution.

[0063] The x-direction spacing p31 and y-direction spacing p32 of the convex lens portion 139 are 1.0 mm and 0.89 mm, respectively, and the z-direction depth d1 is 0.7 mm. A smaller depth d1 allows for a thinner multi-lens plate 137, so it is preferable that the depth d1 be 2 mm or less, and more preferably 1 mm or less. The spacing p31 is determined from the viewpoint of the light source pattern becoming difficult to see, and the light source spacing (light source group spacing) L X It is preferable that the spacing p1 be 1 / 3 or less, and more preferably 1 / 10 or less. On the other hand, if the spacing p1 becomes too small, it becomes difficult to manufacture, and the diffraction effect of light becomes negligible. Therefore, it is preferable that the spacing be 0.005 mm or more, which is 10 times or more the wavelength of light (0.5 μm), and more preferably 0.1 mm or more.

[0064] Figure 14 shows a further enlarged cross-sectional view of the multi-lens plate 137, specifically the section connecting the shallow valleys 138B. The cross-sectional shape of the slope of the convex lens portion 139 is a continuous curve, but for the sake of explanation, it is assumed to consist of a first slope 139P, a second slope 139Q, and a third slope 139R.

[0065] The first slope 139P is a slope located near the boundary of the convex lens portion 139, and is a region where the angle it makes with the z-axis is larger than that of the second slope 139Q.

[0066] The second slope 139Q is the boundary of the convex lens portion 139 or the region surrounding the first slope 139P, and includes the portion where the angle θ0 between the z-axis and the tangent 139S is the steepest (smallest) angle. The incident light ray is refracted by angle θ0, contributing to the oblique light distribution of the multi-lens plate 137.

[0067] The third slope 139R is the boundary of the convex lens portion 139, the region surrounding the first slope 139P or the second slope 139Q, and is a region that has a larger angle with the z-axis than the second slope.

[0068] Furthermore, the convex lens portion 139 may not include the third inclined surface 139R and may consist only of the first inclined surface 139P and the second inclined surface 139Q, or it may consist only of the second inclined surface 139Q.

[0069] <Example 1> In Embodiment 1, a lighting fixture 100 was described in which light from a light source 123 is introduced into a diffusion panel 125 and then emitted through a multi-lens plate 127 (or multi-lens plate 137). However, the diffusion panel 125 may be omitted. In that case, brightness non-uniformity is more likely to occur, but the distance D between the light source 123 and the multi-lens plate 127 Z Light source interval L X By making it larger compared to [the original value], brightness non-uniformity can be reduced.

[0070] <Modification 2> Alternatively, the structure may be such that light from the light source 123 is fed into the multi-lens plate 127 (or multi-lens plate 137), and then emitted through the diffusion panel 125. In this case, the wide-beam effect is reduced because the light, which has been broadened by the multi-lens plate 127, is isotropically diffused by the diffusion panel 125, but the distance D Z Even with a smaller size, it becomes a structure suitable for "thin" designs with less brightness unevenness.

[0071] <Variation 3> In the multi-lens plate 127, a concave lens portion may be provided on the virtual light emission surface, which is the side from which light is emitted. In this case, the angle at which the emitted light is maximized can be changed simply by flipping the multi-lens plate 127 over. Alternatively, lens portions (concave lens portion or convex lens portion, as described later) may be provided on both the virtual light incidence surface and the virtual light emission surface of the multi-lens plate.

[0072] <Embodiment 2> <Structure> Figure 15 shows a perspective view of the lighting fixture 200 of this embodiment. The lighting fixture 200 is a spotlight-type lighting fixture that can be attached to the wiring duct 280 and is controllable by the lighting control device 170.

[0073] In the following explanation, using the z-axis in Figure 15 as a reference, the forward z-direction (z-axis) is sometimes referred to as the z-direction, the y-direction is perpendicular to the z-axis and points upward, and the x-direction is the direction perpendicular to the z·y-direction among the two axes perpendicular to the z-axis.

[0074] In Figure 15, the lighting fixture 200 comprises a lamp body 210, an arm 270 rotatably attached to the side of the lamp body 210, and a mounting portion 278 at the other end of the arm 270 that is attached to the wiring duct 280. Inside the arm 270 is a lighting wire 238 for transmitting commercial power supplied to the wiring duct 280 to the power source 225.

[0075] The z-axis, which is the optical axis of the lighting fixture 200, can be rotated horizontally by rotating the arm 270 in the Φ direction relative to the mounting part 278. In addition, the orientation can be changed from downward to upward in an appropriate direction by rotating the lamp body 210 in the θ direction relative to the arm 270.

[0076] Figure 16 is a partial side view and partial cross-sectional view of the lighting fixture 200, including the z-axis. Inside the lighting fixture 200 are a heat sink 221, a COB-type LED light source 223, a reflector 228, a multi-lens plate 227, a power supply 225, and a wireless module 226. The wireless module 226 is detachable from a socket connected to the power supply 225. The multi-lens plate 227 has the same structure as the concave lens integrated multi-lens plate 127 of Embodiment 1, with only the size changed to fit into the lamp body 210.

[0077] Figure 17 is a plan view of the light source 223. Sixteen surface-mount LED packages 223A (red), 223B (yellow-white), and 223C (blue-white), each measuring 2.8 mm vertically and 3.5 mm horizontally, are mounted on the substrate 222. When the dimming rate is set to, for example, about 3%, the images of individual LEDs are visible on the multi-lens plate 227. However, when the dimming rate is set to a normal value, the brightness becomes high, making it impossible to directly view the multi-lens plate 227. As a result, the problem of color unevenness caused by the individual LED images being visible does not occur.

[0078] Figure 18(a) shows the light distribution characteristics (distribution of luminous intensity (cd) in the direction of angle θ) of the lighting fixture 200. In the lighting fixture 200, the light emitted from the light source 223 is bent diagonally to the side by the multi-lens plate 227, resulting in a wide light distribution characteristic for a spot lens, with a 1 / 2 beam angle of 102°, as shown in Figure 18(a). As shown in Figure 18(a), the luminous intensity is maximum at 25-30°. Although the same concave lens integrated multi-lens plate 227 as in Embodiment 1 is used, the light distribution characteristics are slightly different because the arrangement of the light source is different from Embodiment 1 and the diffusion panel used in Embodiment 1 is not used.

[0079] Figure 18(b) shows the illuminance characteristics of lighting fixture 200 (iso-illuminance curves for 500, 200, 100, 50, and 20 lx, with the distance from the light source on the vertical axis and the distance relative to the optical axis on the horizontal axis). The total luminous flux of the light source is assumed to be 1000 lm. As seen in Figure 18(a), the luminous intensity decreases in the z-axis direction, but according to Figure 18(b), the 1 / 2 illuminance angle in the x·y directions is 79°, and a relatively uniform illuminance distribution was obtained. The reason for this is that in the oblique direction, the illuminance decreases as the distance from the light source increases, as does the decrease in illuminance due to the oblique incidence of light, but the increase in luminous intensity in the oblique direction compensates for this decrease in illuminance.

[0080] <Embodiment 3> <Overview> Figure 19 shows a perspective view of the lighting fixture 300 according to this embodiment. The lighting fixture 300 consists of a fixture body 310 directly attached to the ceiling and a light source unit 320 attached to the fixture body 310. Since the fixture body 310 and the light source unit 320 are separable, the screws or suspension bolts used to attach the fixture body 310 to the ceiling can be hidden by the light source unit 320. The width of the lighting device is, for example, 2 cm and the length is, for example, 120 cm. Compared to the lighting fixture 100, the width in the shorter direction is narrower, and the fixture shape is designed with aesthetics in mind.

[0081] Cross-sectional views of the fixture body 310 and the light source unit 320 are shown in Figures 20(a) and (b), respectively.

[0082] <Main body of the device> The main body of the device 310 comprises a box-shaped housing 315 with an open bottom, a spring locking part 311, and a connector 312.

[0083] <Light source unit> The light source unit 320 includes a mounting plate 321, a substrate 322, a light source 323, a cover 324, a power supply 325, a wireless module 326, a mounting spring 327, a connector 328, and a diffusion panel 331 and a multi-lens plate 333, which will be explained using Figure 21. The cover 324 has cover end faces (left end face 324L and right end face 324r). Multiple light source units 320 can be arranged so that their cover end faces face each other, and the entire set of multiple light source units 320 can be made into a continuous, long light source.

[0084] The substrate 322 is a long printed circuit board, and a plurality of surface-mount LEDs, each consisting of a light source 323, are arranged in a row with spacing between them in the longitudinal direction. The number of rows of light sources 323 is one.

[0085] The mounting spring 327 of the light source unit 320 is attached to the spring locking portion 311 of the fixture body 310. The connector 328 is connected to the connector 312 of the fixture body 310, and commercial power is supplied to the power supply 325.

[0086] The power supply 325 converts commercial AC power to DC power and has three drive outputs to drive three different colored LEDs, and each drive output can be controlled by an external control signal. In this embodiment, the control signal is transmitted wirelessly and received by the wireless module 326, which sends the control signal to the power supply 325, thereby controlling the power supply 325. By independently controlling the three drive outputs with the control signal, the light source unit 320 can emit light at any chromaticity enclosed by the chromaticities of the three LEDs.

[0087] <Light source unit> As shown in Figure 21, a cross-sectional view including the x·z direction, the light source unit 320 includes, in addition to the above-mentioned components, a diffusion panel 331 and a multi-lens plate 333. The light incident surface of the diffusion panel 331 is from the light output surface of the light source 323. Z They are located at a distance of 1.1 mm.

[0088] The cover 324 comprises a relatively transparent front cover portion 324A, a light-diffusing side cover portion 324B, and projections 324C for fixing the diffusion panel 331 and the multi-lens plate 333. The diffusion panel 331 is the same as the diffusion panel 125, and the multi-lens plate 333 is the same as the multi-lens plate 127, with concave lens portions arranged in a honeycomb pattern on the virtual light incident surface. They are almost identical in design, differing only in their external dimensions. The front cover portion 324A and the side cover portion 324B are integrally extruded by a two-color molding method. The material of the cover 324 is resin, and polycarbonate or acrylic is preferably used. Alternatively, a multi-lens plate equivalent to the multi-lens plate 137 with integrated convex lens portions may be used as the multi-lens plate 333.

[0089] The distance between the light-emitting surface of the diffusion panel 331 and the virtual light-incident surface of the multi-lens plate 333 is preferably either in contact or 0.2 mm or less. This enables the lighting fixture to be made thinner.

[0090] <Light distribution characteristics> In this embodiment as well, since the light distribution in the downward direction is suppressed, a wider light distribution characteristic is obtained, and even if the distance between light sources is increased compared to the conventional method, a certain degree of uniformity in illumination on the desk surface can be maintained.

[0091] <Embodiment 4> <Overview> The lighting fixture 500 according to this embodiment is a so-called ceiling light and has a nearly axially symmetric light distribution characteristic.

[0092] <Structure> The left side of Figure 22(a) is a front view of the lighting fixture 500, and the right side is a cross-sectional view taken from the front. The upper part of Figure 22(b) is a plan view of the lighting fixture 500 (a front view taken from below when the lighting fixture is installed on the ceiling), and the lower part is an internal front view with the cover 524, also called the shade, removed.

[0093] As shown in Figure 22(a), the mounting adapter 510 is a part that can be attached to a ceiling hook or rosette and is separable from the rest of the lighting fixture 500. The cover 524 comprises a front cover portion 524A and a side cover portion 524B. The circuit board 522 and power supply 525 are mounted on the base 521.

[0094] As shown in Figure 22(b), five circuit boards 522 are mounted on the base 521. Each circuit board 522 has 33 surface-mount LEDs, which are light sources 523, mounted in four rows.

[0095] <Installation of lighting fixtures on the ceiling> The plug and fixing part of the mounting adapter 510 is twisted and attached to the ceiling hook ceiling socket or rosette. When the hole in the base 521 of the lighting fixture 500 (with the cover 524 removed) is inserted into the mounting adapter 510 with the hole facing upwards, the protruding part 512 (claw) of the mounting adapter 510 comes into contact with the base 521 and moves inward. When the base 521 is moved further upwards, the protruding part 512 of the mounting adapter 510 returns to its original position and supports the base 521, thereby attaching the base 521 to the mounting adapter 510. At this time, the cushion 528 touches the ceiling, allowing the lighting fixture 500 to be installed parallel to the ceiling. After that, the cover 524 is attached to the base 521.

[0096] <Installation of multi-lens panel> Interval L of light source 523 A For example, the minimum is 24 mm (spacing L A (This is not necessarily the distance in the x or y direction). In contrast, the light incident surface of the multi-lens plate 527 is at a distance L from the surface of the light source 523. A Same distance D Z It is installed by the multi-lens plate support part 526, separated by a distance of (24 mm). The spacing p1 of the concave lens parts of the multi-lens plate 527 is 1 mm, as mentioned above, and L A Because it is less than 1 / 10 of the original, almost no image of the light source is generated on the light-emitting surface of the multi-lens plate 127. Furthermore, since the light propagates mainly in the diagonal direction indicated by the arrow in Figure 22(a), it is possible to reduce the degree of diffusion in the cover 524 to such an extent that no image of the light source is generated, i.e., to make it nearly transparent, thereby improving the light extraction efficiency.

[0097] <Variations and other variations> Although embodiments of the lighting fixture according to the present invention have been described above, it is possible to modify the exemplified lighting fixtures as follows, for example, and it goes without saying that the present invention is not limited to the lighting fixtures shown in the above embodiments.

[0098] While a honeycomb arrangement was described as an example of the lens arrangement in a multi-lens plate, other two-dimensional arrangements, such as a grid arrangement that repeats two-dimensionally in the x and y directions, are also acceptable.

[0099] In a multi-lens plate with a concave lens cluster, an example was described in which there are ridges with ridge vertices and ridge saddles between the concave lens clusters, but the distance of the ridges from the virtual incident plane is not particularly limited. Similarly, in a multi-lens plate with a convex lens cluster, an example was described in which there are deep and shallow valleys, but the distance of the valleys from the virtual incident plane is not particularly limited.

[0100] Embodiments 1 and 3 describe the configuration of lighting fixtures equipped with a multi-lens plate and a diffusion panel, using a system ceiling lighting fixture and a lighting fixture with a separate fixture body and light source unit as examples, respectively. However, the configurations of the embodiments may be applied to lighting fixtures in other embodiments as appropriate, for example, by applying the configuration of Embodiment 3, which has a relatively transparent front cover, to another embodiment.

[0101] The degree of dispersion is an index used to measure the diffusivity of optical components. When light (usually laser light) is incident in the 0-degree direction, the diffusion distribution, which is the amount of transmitted light at a predetermined angle relative to the amount of transmitted light in the 0-degree direction, is determined, and the angle at which the amount of transmitted light is 50% of the amount of transmitted light at 0 degrees is defined as the degree of dispersion. For a diffusion panel, the degree of dispersion is preferably 5 degrees or more, and more preferably 10 degrees or more. On the other hand, for a relatively transparent cover, the degree of dispersion is preferably 4 degrees or less, and more preferably 2 degrees or less. Similarly, for a multi-lens plate, the degree of dispersion is preferably 4 degrees or less, and more preferably 2 degrees or less. In addition to the degree of dispersion, the diffusivity may also be defined by the haze value.

[0102] While the case where a light-diffusing material is mixed into the diffuser panel to impart light-diffusing properties has been described, light-diffusing properties can also be imparted by making the light-incident or light-emitting surface rough. A light-diffusing material may be mixed in, and the light-incident or light-emitting surface may also be made rough.

[0103] The light source may be mounted directly to the frame 130, mounting plate 321, base 521, etc., instead of being mounted on the circuit board.

[0104] Each light source may be equipped with, for example, a lens that widens the light distribution. In that case, an even wider light distribution angle can be achieved through the synergistic effect of increasing the light distribution angle by the lens and increasing the light distribution angle by the multi-lens plate according to the present invention.

[0105] The substrate is not limited to a printed circuit board; a metal core substrate (a substrate with an insulating film on the surface of a metal plate and a wiring pattern on top of it) may be used, or a ceramic substrate with a wiring pattern formed on its surface may be used. Thus, the material of the substrate is not particularly limited. Furthermore, the board portion of a COB type LED or the package portion of a surface mount type LED may serve as the substrate, eliminating the need for a printed circuit board or the like.

[0106] The components of the present invention are not limited to the embodiments and modifications described above, and various modifications are possible within the technical scope described in the claims. For example, the components of the lighting fixture described above can be applied to various lighting fixtures, not limited to lighting fixtures related to LEDs.

[0107] The embodiments and their variations described above may be partially combined. [Explanation of Symbols]

[0108] 100, 200, 300, 500 lighting fixtures 110, 310 Main unit of the device 112 recess 114, 225, 325, 525 power supply 115, 226, 326 Wireless Modules 120, 320 light source units 122, 222, 322, 522 circuit boards 123, 123A, 123B, 123C, 223, 323, 523 light source 123G light source group 125, 331 diffusion panels 127, 137, 227, 333, 527 Multi-lens plates 127F, 137F Virtual light incident surface 127B, 127BR, 137B light exit surface 128 Concave lens section 128P, 139P First Slope 128Q, 139Q Second Slope 128R, 139R Third Slope 128S, 139S tangent 129 Ridge 129B Ridge Saddle 129P Ridge summit 130 slots 139 Convex lens section 138 Valley 138B Tani Asabe 138D Deep valley 170 Lighting control device 171 Touch Panel 172 Wireless Communication Section 173 Lighting control program 180 Air conditioning equipment 190, 191 Ceiling panels 195 T-bar 199 System Ceiling 210 Light body 238 Power lines 270 Arm 278 Mounting part 280 Wiring duct 311 Spring locking part 312, 328 connectors 315 cabinets 321 Mounting plate 324, 524 cover 324A, 524A Cover Front 324B, 524B Cover side section 324C protrusion 327 Mounting spring 510 Mounting Adapter 512 Protrusion 521 Base 526 Multi-lens plate support section 528 Cushions

Claims

1. A lighting fixture comprising a light source and a multi-lens plate, The multi-lens plate has multiple concave lens portions arranged two-dimensionally on its surface. The boundary of the concave lens portion is formed as a ridge line, A lighting fixture in which the aforementioned ridge line includes a ridge line vertex and a ridge line saddle lower than the ridge line vertex, and the ridge line saddle is located between the two aforementioned ridge line vertices.

2. The lighting fixture according to claim 1, wherein the surface is an incident surface to which light from the light source is incident.

3. The lighting fixture according to claim 1, wherein the planar shape of the boundary is hexagonal.

4. The lighting fixture according to claim 1, wherein the concave lens portion includes a first inclined surface located near the center of the concave lens portion, a second inclined surface surrounding the first inclined surface, and a third inclined surface surrounding the second inclined surface, and the angle of the second inclined surface with respect to the normal to the surface is smaller than the angle of the first and third inclined surfaces with respect to the normal to the surface.

5. The lighting fixture according to claim 1, wherein the light emitted from the multi-lens plate obtains the maximum luminous intensity in a direction oblique to the optical axis in each cross section in the x and y directions perpendicular to the optical axis.

Images