lighting fixtures

Abstract

To reduce the number of installed lighting devices that can achieve almost uniform illumination intensity in a wide range.SOLUTION: A lighting device includes a light source and a multi-lens plate. In the multi-lens plate, a plurality of lens parts are two-dimensionally arranged on a virtual light incident surface or a virtual light emission surface. The lens parts respectively include inclined planes surrounding the centers of the lens parts. In the steepest inclined plane of the inclined planes, the angle of the virtual light incident surface or the virtual light emission surface to a normal line is 35-60°. In the light emitted from the multi-lens plate, a maximum value of light intensity is obtained in an oblique direction from an optical axis direction in each cross section in an x-direction and a y-direction orthogonal to the optical axis direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] There are two types of lighting fixtures: those with a narrow light distribution angle (narrow angle) for brightly illuminating a small area, and those with a wide light distribution angle (wide angle) for evenly illuminating a wide area.

[0003] The lighting fixture described in Patent Document 1 generates illumination light by passing light emitted from an LED module through a light distribution panel equipped with numerous prisms each consisting of a truncated quadrangular pyramid-shaped depression. The light distribution panel is said to be able to reduce discomfort glare by concentrating the illumination light.

[0004] The lighting fixture described in Patent Document 2 also includes a lighting cover having many minute protrusions, and the lighting cover is said to be able to reduce light at an angle θ in the range of 60 to 90 degrees and significantly reduce glare.

[0005] Patent Document 2 shows that the problem of the luminance dispersion of the light source when looking at the light source through the lighting cover, that is, the problem of the point light source pattern being visible, has been improved. However, looking at Figure 7(f) of Patent Document 2, it seems that the point light source pattern is still 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 in the left and right directions (a bud wing-shaped light distribution) by having a prism section with multiple prism sections extending in the longitudinal direction. [Prior art documents] [Patent documents]

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

[0008] The inventors are aiming to create a lighting fixture that can provide a substantially uniform illuminance over a wide range. [Means for solving the problem]

[0009] The present invention provides a lighting fixture including a light source and a multi-lens plate, the multi-lens plate has a plurality of lens portions arranged on a virtual light incident surface or a virtual light exit surface, the lens portion includes a slope surrounding the center of the lens portion, the steepest slope among the slopes has an angle of 35° or more and 60° or less with respect to a normal to the virtual light incident surface or the virtual light exit surface; The light emitted from the multi-lens plate has a maximum luminous intensity in a direction oblique to the optical axis direction in each cross section in the x direction and y direction perpendicular to the optical axis direction.

[0010] In the present invention, the inclined surfaces include a first inclined surface located near the center of the lens portion, a second inclined surface surrounding the first inclined surface, and a third inclined surface surrounding the second inclined surface, The angle of the second inclined surface relative to a normal to the virtual light incident surface or the virtual light exit surface may be steeper than the angles of the first inclined surface and the second inclined surface.

[0011] In the present invention, the lens portions may be concave lens portions, and the boundaries between the concave lens portions may be ridge lines.

[0012] In the present invention, the lens portions may be convex lens portions, and the boundaries between the convex lens portions may be valleys.

[0013] The present invention provides a lighting fixture comprising a light source, a diffusion panel, and a multi-lens plate, The diffusion panel is a plate having light diffusing properties, the multi-lens plate has a plurality of lens portions arranged on a virtual light incident surface on the light source side, The distance between the light source and the surface of the diffusion panel facing the light source is D Z and the distance between the surface of the diffusion panel facing the multi-lens plate and the surface of the multi-lens plate facing the diffusion panel is D Z It is less than 1 / 10 of that.

[0014] In the present invention, the light source may be plural, and the plural light sources may be arranged in a row.

[0015] In the present invention, the light source may have a Lambertian light distribution characteristic, and the 1 / 2 beam angle of the lighting fixture may be 125° or more and 160° or less. [Effects of the Invention]

[0016] The lighting fixture according to the present invention can provide a substantially uniform illuminance over a wide range, making it possible to reduce the number of lighting fixtures that need to be installed. [Brief explanation of the drawings]

[0017] [Figure 1] View of a system ceiling with lighting fixtures installed from below [Figure 2] Lighting fixture cross section [Figure 3] Cross section of the light source unit [Figure 4] Top view of the board [Figure 5] Enlarged cross-sectional view of a multi-lens plate with integrated concave lenses [Figure 6] Enlarged plan view of a multi-lens plate with integrated concave lenses [Figure 7] An explanatory diagram of the shape of the light exit surface of a multi-lens plate [Figure 8] Further enlarged cross section of the multi-lens plate with integrated concave lens sections [Figure 9] Light distribution characteristics and illuminance characteristics of the lighting fixture of embodiment 1 [Figure 10] Light distribution characteristics and illuminance characteristics of another example of the lighting fixture according to the first embodiment [Figure 11] Illuminance distribution of the lighting fixture of the first embodiment and the comparative example [Figure 12] Enlarged cross-sectional view of a multi-lens plate with integrated convex lenses [Figure 13] Plan view of a multi-lens plate with integrated convex lens sections [Figure 14] Further enlarged cross section of a multi-lens plate with integrated convex lenses [Figure 15] 10 is a perspective view of a lighting fixture according to a second embodiment. [Figure 16] Partial side and partial cross-sectional view of a lighting fixture according to a second embodiment [Figure 17] 10 is a plan view of a light source according to a second embodiment of the present invention; [Figure 18] Light distribution characteristics and illuminance characteristics of the lighting fixture of embodiment 2 [Figure 19] 10 is a perspective view of a lighting fixture according to a third embodiment. [Figure 20] Cross-section of the fixture body and light source unit [Figure 21] Cross-sectional view of the light source unit from another direction [Figure 22] 1 is a front view, a cross-sectional view, and a plan view of a lighting fixture according to a fourth embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0018] <Embodiment 1> <Summary> FIG. 1 shows a view from below of a system ceiling 199 to which a lighting fixture 100 according to this embodiment is attached. T-bars 195 are attached to the system ceiling with a lattice spacing L GThe T-bars are attached in a grid pattern with a spacing of 600 mm (for example), and within the compartments separated by the T-bars, lighting fixtures 100, air conditioning equipment 180, ceiling panels 190, and ceiling panels 191 equipped with various equipment (inspection hatches, speakers, wireless equipment (wireless repeaters, etc.)) 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 the lighting fixtures 100 and air conditioning equipment 180 are attached to the T-bars 195 to prevent them from falling in the event of an earthquake or the like. Note that while the T-bars 195 are shown in Figure 1 for the sake of explanation, they are usually installed so that they are hidden when viewed from below.

[0019] The lighting fixture 100 comprises 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 underside for mounting the light source unit 120, and a power supply 114 attached to its top surface. A wireless module 115, which is a communication device for lighting control, is attached to the power supply 114, and is capable of communicating with a wireless communication unit 172 of a lighting control device 170. A light source drive line is connected from the power supply 114 to the light source unit 120.

[0020] <Lighting control device> The lighting control device 170 in FIG. 1 is comprised of a tablet, smartphone, PC, or the like, and is equipped with a touch panel 171 that serves as a display and input unit, a wireless communication unit 172, and a lighting control program 173 (not shown) installed. The user can change the lighting conditions by operating the lighting control program 173 and wirelessly communicating with the lighting fixture 100 via wireless signals sent and received by the wireless communication unit 172. The lighting conditions include color (color adjustment), brightness (dimming), and on / off, and the device is equipped with an interface for manually controlling these as needed. It is also possible to perform scheduled operation, which automatically changes the lighting conditions at set times according to pre-registered times and lighting conditions.

[0021] Note that lighting control device 170 is not essential, and even if lighting control device 170 is not provided, lighting device 100 can be turned on / off by turning a switch on / off on the power line. The lighting control device may be a wired control device such as PWM (Pulse Width Modulation) dimming or phase dimming.

[0022] <Light source unit> A cross-sectional view of light source unit 120 is shown in Fig. 3. Light source unit 120 includes a substrate 122, a diffusion panel 125, a multi-lens plate 127, and a frame 130. Hereinafter, the optical axis direction will be referred to as the z direction, the direction perpendicular to the z direction in Fig. 3 will be referred to as the x direction, and the direction perpendicular to the z direction and y direction (the depth direction in Fig. 3) will be referred to as the y direction.

[0023] <Substrate / light source> As shown in Fig. 3, the substrate 122 is a long printed circuit board on which a plurality of light sources 123 made of surface-mounted LEDs are arranged in rows at intervals in the longitudinal direction. The number of rows in which the light sources 123 are arranged is four as shown in Fig. 3, but it may be one row or three or more rows depending on the width of the substrate 122.

[0024] The surface-mounted LED serving as light source 123 is, for example, a 3 mm square package in which a blue LED chip with an InGaN light-emitting layer is sealed with phosphor-containing sealing resin. The emitted light color can be adjusted by the type and amount of phosphor.

[0025] Light source 123 exhibits a light distribution that follows the cosθ law, which is called a Lambertian light distribution characteristic, and the light distribution angle (half beam angle) where the luminous intensity is half of the axial luminous intensity is approximately 120°. However, the actual light distribution angle of an LED is approximately 114 to 118°. Note that the half beam angle may also be the angle on one side from the optical axis, in which case the theoretical value of the half beam angle on one side is 60°, and the actual measured value is, for example, approximately 58°. Note that in the present invention, a Lambertian light distribution is defined as a half beam angle of 110° to 122°.

[0026] For example, only LEDs of one emitting color may be used as the light source 123. Alternatively, LEDs of two emitting colors (for example, daylight white (color temperature 6500K) and incandescent white (color temperature 2700K)) may be arranged alternately. By using these two LEDs, it is possible to change (adjust) the color to approximately match the blackbody radiation.

[0027] Furthermore, LEDs with three different light colors can be arranged as a light source so that the colors are mixed. However, when using two or three color LEDs, color unevenness is likely to occur in addition to brightness unevenness (uneven brightness caused by the light source pattern being visible, also known as graininess), making it more difficult to eliminate brightness unevenness and color unevenness on the light output surface of the lighting fixture.

[0028] As an example of a light source of three luminous colors, for example, by using LEDs of three colors, red (R), green (G), and blue (B), it is possible to obtain an extremely wide range of luminous colors.

[0029] Another example of a light source with three luminous colors may be a combination of a red LED, a yellow-white LED, and a blue-white LED, as described below.

[0030] A red LED (R) emits light with a chromaticity in the range enclosed by (0.66, 0.23), (0.423, 0.355), (0.5, 0.5), and (0.736, 0.264) in the CIE 1931 chromaticity coordinates, an example being (0.60, 0.38).

[0031] A yellow-white LED (Yw) emits light with a chromaticity in the range surrounded by the CIE 1931 chromaticity coordinates (0.5, 0.5), (0.423, 0.355), (0.342, 0.312), (0.352, 0.44), (0.37, 0.63) and chromaticity boundaries, such as (0.44, 0.47).

[0032] A bluish-white LED (Bw) emits light with a chromaticity in the range enclosed by (0.336, 0.24), (0.352, 0.44), (0.15, 0.2), and (0.2, 0.1) in the CIE 1931 chromaticity coordinates, an example of which is (0.23, 0.26).

[0033] Compared to B (blue) light, which has a spectrum close to monochromatic, Bw (bluish-white) light, which is a mixture of light from other spectra with high relative luminous efficiency, has a higher luminous efficiency. For this reason, using light-emitting elements with the three colors R, Yw, and Bw has the advantage of being able to achieve a relatively good power-to-luminous flux conversion efficiency (lm / W) compared to using light-emitting elements with the three primary colors R, G, and B.

[0034] Although the light source 123 has been described as a surface-mounted LED, a COB (Chip On Board) type LED in which a blue LED chip is mounted on a substrate and sealed with a phosphor-containing resin, or a CSP (Chip Scale Package) type LED in which multiple blue LED chips sealed with a phosphor-containing resin are integrated may also be used.

[0035] 4 is a plan view illustrating the arrangement of LEDs on the substrate 122. When three-color LED light sources are used, the light source group interval L is set so that light sources 123A, 123B, and 123C, each of which emits light of different colors, form one light source group 123G as shown in FIG. Y In order to prevent uneven brightness, the horizontal spacing L of the light source groups should be set to be equal to or smaller than 1 / 3 of the horizontal spacing L. X and the vertical spacing of the light source groups L Y are preferably approximately equal.

[0036] Similarly, when two-color LEDs are used, the light source group interval L is set so that the light source 123A and the light source 123B are grouped into one light source group 123G. Y When using LEDs of one color, they are not grouped together, but the horizontal spacing L X and the vertical light source spacing L Y It is preferable to arrange them so that

[0037] <Multi-lens plate 127> FIG. 5 shows an enlarged cross-sectional view of the multi-lens plate 127 with integrated concave lens portions, including the z- and x-axes, and FIG. 6 shows an enlarged plan view including the x- and y-axes. The multi-lens plate 127 has a virtual light-incident surface 127F (assuming no concave lens portions 128) on the light-incident side, and a light-exiting surface 127B on the light-exiting side. The virtual light-incident surface is, for example, a plane connecting ridge vertices 129P (described below). The concave lens portions 128 refract, for example, incident light ray B1 into internal light ray B2 and output light ray B3 in the diagonal x direction in FIG. 5, thereby reducing the light distribution in the forward direction (z direction) and increasing the light distribution in the diagonal x direction and diagonal y direction. Also, as shown in FIG. 5 as incident light ray C1, internal light ray C2, and internally reflected light ray C3, there is also internally reflected light ray C3, which is totally reflected by the multi-lens plate 127 and returns to the incident side. The larger the angle θ0 of the slope of the concave lens portion 128 relative to the z-axis, which is the normal to the virtual light incident surface 127F, the larger the light component distributed in the diagonal x-direction, but the larger the proportion of internally reflected light, which tends to reduce the light extraction efficiency.

[0038] Since the concave lens portion of the multi-lens plate 127 is provided on the side where light is incident, 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, which has the advantage of increasing the outgoing light component in the diagonal horizontal direction.

[0039] FIG. 6 shows a plan view of the multi-lens plate 127. The concave lens portions 128 are repeatedly arranged two-dimensionally in the x direction and in a direction diagonal at 60 degrees from the x direction. The boundary shape is hexagonal to achieve this honeycomb-like planar arrangement. The interior of the concave lens portion 128 has a concentric circular shape, as shown in the cross-sectional view of FIG. 5 and the contour lines 128C1 and 128C2 of FIG. 6. The ridge lines 129 that form the boundaries of the concave lens portions 128 are connected, resulting in a continuous thick portion, thereby maintaining the strength of the multi-lens plate 127. The ridge lines 129 connect ridge vertices 129P, which are the boundaries between the three concave lens portions 128, with ridge saddle 129B, which is the lowest part of the ridge lines 129 (the word "saddle" is derived from a horse-riding term and is used in geometry to refer to "the lower part of a ridge that is higher than the surrounding areas"). The ridge saddle 129B is slightly lower than the ridge apex 129P, that is, the distance to the light exit surface of the multi-lens plate 127 at that portion is short.

[0040] By forming the ridge line 129 into a shape having a ridge line vertex 129P and a ridge line saddle portion 129B, the entire interior of the concave lens portion 128, whose boundary plane shape is hexagonal, can have concentric slopes, thereby realizing an isotropic light distribution.

[0041] The spacing p1 of the concave lens portions 128 in the x direction and the spacing p2 in the y direction 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 arranged at the vertices of an equilateral triangle, with spacing p1 corresponding to the length of the base of the equilateral triangle and spacing p2 corresponding to the height from the center of the base of the equilateral triangle to the other vertex. Since a smaller depth d allows the thickness of the multi-lens plate 127 to be thinner, it is preferable that the depth d is 2 mm or less, and more preferably 1 mm or less. From the viewpoint that the light source pattern becomes difficult to see, spacing p1 is set to be smaller than the light source spacing (light source group spacing) L in the x direction. X It is preferable that the distance is 1 / 3 or less, and more preferable that the distance is 1 / 10 or less (in the y direction and L YOn the other hand, if the interval p1 is too small, not only will it be difficult to manufacture, but the diffraction effect of light will become unignorable, so it is preferable that the interval p1 be 0.005 mm or more, which is 10 times the wavelength of light, 0.5 μm, and more preferably 0.1 mm or more (the same applies to the interval p2).

[0042] 5(a), light exit surface 127B is flat, but may be light exit surface 127BR having a light scattering structure, as shown in Fig. 7(a), a perspective view of the shape of the light exit surface of a multi-lens plate, and Fig. 7(b), a cross-sectional view thereof. Here, light exit surface 127BR has an uneven structure with the same pitch as concave lens portion 128, but the present invention is not limited to this.

[0043] 8 shows a further enlarged cross-sectional view of multi-lens plate 127, taken along a plane including the z- and x-axes connecting ridge saddle portion 129B. The cross-sectional shape of the slope of concave lens portion 128 is a continuous curve, but for the sake of explanation, it is assumed to consist of first slope 128P, second slope 128Q, and third slope 128R.

[0044] First inclined surface 128P is an inclined surface located near the center of concave lens portion 128, and is an area that forms a larger angle with the z-axis than second inclined surface 128Q. Since light rays that are incident on the bottom of first inclined surface 128P have an angle closer to the z-axis direction than incident light ray D1, the amount of light incident on first inclined surface 128P is limited.

[0045] The second inclined surface 128Q is a region surrounding the center of the concave lens portion 128 or the first inclined surface 128P, and is a region that includes the part where the angle between the z axis and the tangent line 128S is the steepest (smallest) angle θ0, and the incident light is refracted by the angle θ0, contributing to the oblique light distribution of the multi-lens plate 127.

[0046] Third inclined surface 128R is an area surrounding the center of concave lens portion 128, first inclined surface 128P, or second inclined surface 128Q, and is an area that forms a larger angle with the z-axis than the second inclined surface. Therefore, as shown in Fig. 8, incident light ray E1 toward third inclined surface 128R contributes as internal light ray E2 to the oblique light distribution of multi-lens plate 127. In other words, the proportion of internal light ray E2 that hits the inclined surface of an adjacent concave lens portion 128 and is totally reflected is reduced.

[0047] The concave lens portion 128 may not have the third inclined surface 128R and may be configured only with the first inclined surface 128P and the second inclined surface 128Q, or may be configured only with the second inclined surface 128Q.

[0048] <Diffusion panel> The bottom surface of the diffusion panel 125 is D Z Distant position (distance D between light source and diffusion panel) Z ) The diffusion panel 125 is a plate with flat surfaces on both sides, which has a uniform light diffusion property due to the addition of a diffusing material. Suitable materials for the panel are, for example, polycarbonate or acrylic. The surface can also be roughened to provide uniform light diffusion.

[0049] As a design concept of the present invention, the diffusion panel 125 has the role of converting the light from the light source 123 into a flat light source with little unevenness in brightness and color. X (Light source group spacing L X ) for D Z Ratio D Z / L X On the other hand, experiments have shown that D Z / L X Increasing D reduces the light extraction efficiency. Z / L X We have conducted a study to find the optimum value for the light source pattern, and have obtained a design where the light source pattern is almost non-existent when the value is 0.6 or more. In addition, in order to make the device body thin, it is desirable to install the diffusion panel 125 close to the multi-lens plate, and it may be in contact with it. "Close" means that the D ZThe distance should be less than 1 / 10 of the normal distance.

[0050] 5, there is also an internally reflected ray C3 that is totally reflected by the multi-lens plate 127 and returns to the incident side, as shown by the incident ray C1, internal ray C2, and internally reflected ray C3. The diffusion panel 125 also serves to direct such light rays back toward the multi-lens plate 127, and for this reason, it is preferable to install the diffusion panel 125 near the multi-lens plate 127.

[0051] The material of the multi-lens plate 127 is acrylic (PMMA, polymethyl methacrylate) and the calculations are performed assuming a refractive index of 1.485, but the material of the multi-lens plate 127 is not particularly limited as long as it is a transparent material, and it may also be PC (polycarbonate) or glass.

[0052] <frame> The frame 130 shown in FIG. 3 has a lower surface that functions to support the substrate 122, and a side surface that functions to support the diffusion panel 125 and the multi-lens plate 127.

[0053] <Light distribution characteristics and illuminance distribution> Figures 9(a) and 9(b) show the light distribution characteristics 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 notable feature is that the illuminance curve is not a typical circle, but is nearly flat on the bottom, meaning that there is a wide range where the illuminance is almost constant.

[0054] Figures 10(a) and 10(b) show the light distribution characteristics 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 too, the illuminance curve is not a typical circle, but is nearly flat on the bottom, meaning that there is a wide range where the illuminance is almost constant.

[0055] Without the structure of the present invention, the light distribution angle is, for example, about 120°, and the direction in which the luminous intensity is greatest is the 0° direction. However, when a multi-lens plate 127 with the steepest slope angle θ0 set to 39.3° is used, the luminous intensity is greatest at 30 to 32° in both the x and y directions, as shown in Fig. 9(a). Furthermore, when a multi-lens plate 127 with the steepest slope angle θ0 set to 47.2° is used, the luminous intensity is greatest at 18 to 23° in both the x and y directions, as shown in Fig. 10(a).

[0056] The fact that there is a maximum value of luminous intensity in this oblique direction is the reason why relatively uniform illuminance characteristics can be obtained. On the floor surface away from directly below the lighting fixture, light is incident obliquely at an angle θ, so the illuminance is 1 / cosθ, and in addition, there is a decrease in illuminance due to the distance being the square of 1 / cosθ, but if there is a maximum value of luminous intensity in the oblique direction, this decrease in illuminance can be compensated for.

[0057] Therefore, the angle at which the luminous intensity reaches its maximum value is preferably 10° or more and 45° or less, more preferably 20° or more and 40° or less, and even more preferably 25° or more and 35° or less.

[0058] In response to this, it has been found that 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 has been found that the angle θ0 of the slope is preferably 60 degrees or less, and more preferably 55 degrees or less.

[0059] When the lighting fixture of the present invention is defined by its light source and half beam angle, the light source is a Lambertian light source, and the half beam angle is preferably greater than that, 125° or greater, and more preferably 128° or greater. On the other hand, taking into consideration the decrease in efficiency caused by total reflection that occurs when the light distribution angle is widened, the light distribution angle is preferably 160° or less, and more preferably 150° or less.

[0060] <Illuminance distribution> FIG. 11(a), a comparative example, shows the illuminance distribution (unit: lx) when 16 conventional lighting fixtures are installed vertically and 16 horizontally at 180cm intervals in a room measuring 28.8m square, while FIG. 11(b), an example, shows the calculation results of the illuminance distribution when 12 lighting fixtures 100 of this embodiment are installed vertically and 12 horizontally at 240cm intervals in a room measuring 28.8m square. Note that the lighting fixture installation conditions were set so that 750lx or more can be obtained on a desk. The desk height is assumed to be 70cm and the ceiling height is 3.5m, and the distance from the ceiling to the desk is Upper This is the illuminance distribution at a height of 2.8 m.

[0061] In the comparative example, the power consumption of each lighting fixture is 22.4 W, and the total power consumption is 5734 W. On the other hand, when lighting fixture 100 is used, the power consumption of each lighting fixture 100 is 30.4 W, and the total power consumption is 4378 W. This value is about 76% of that of the comparative example, achieving a significant reduction in power consumption. In addition, the number of units installed is 56% of that of the comparative example, enabling a significant reduction in installation costs.

[0062] <Multi-lens plate 137> In this embodiment, a multi-lens plate 137 with integrated convex lenses can be used instead of the multi-lens plate 127 with integrated concave lenses. FIG. 12 shows an enlarged cross-sectional view of the multi-lens plate 137. The multi-lens plate 137 has a virtual light incident surface 137F, which is assumed to have no convex lens portions 139, on the light incident side, and a light exit surface 137B on the light exit side. The virtual light incident surface is, for example, a plane connecting the vertices of the convex lens portions 139. Although the light exit surface 137B is shown as a flat surface in FIG. 12, it may have a light-scattering shape. The convex lens portions 139 refract, for example, incident light ray B31 into internal light ray B32 and exit light ray B33 in the diagonal x direction in FIG. 12, thereby reducing the light distribution in the z direction (downward in the figure) and increasing the light distribution in the diagonal x direction. 12, there is also an internally reflected ray C33 that is totally reflected in multi-lens plate 137 and returns to the incident side, as shown by incident ray C31, internal ray C32, and internally reflected ray C33. As the angle θ0 of the slope of convex lens portion 139 relative to the z-axis, which is the normal to virtual light incident surface 137F, increases, the light component distributed laterally increases, but the proportion of internally reflected light also increases, tending to reduce the light extraction efficiency. The close similarity between FIG. 5, which is a cross-sectional view of concave lens portion-integrated multi-lens plate 127, and FIG. 12, which is a cross-sectional view of convex lens portion-integrated multi-lens plate 137, reveals a similar tendency in the dependence of the light distribution characteristics on angle θ0.

[0063] FIG. 13 shows a plan view of the multi-lens plate 137. The convex lens portions 139 are arranged two-dimensionally, repeatedly in the x direction and in a direction oblique by 60 degrees from the x direction. To achieve this honeycomb-like planar arrangement, the planar shape of the valleys 138 that form the boundaries between the convex lens portions 139 is hexagonal. The convex lens portions 139 have concentric circular shapes as shown by contour lines 138C1 and 138C2 in FIG. 13. The valleys 138 connect deep valley portions 138D that form the boundaries between three convex lens portions 139 with shallow valley portions 138B that form the boundaries between two convex lens portions 139.

[0064] By making valley 138 a shape that connects shallow valley portion 138B and deeper valley portion 138D, convex lens portion 139, the plane shape of the boundary of which is hexagonal, can have concentric slopes, thereby realizing isotropic light distribution.

[0065] The spacing p31 of the convex lens portions 139 in the x direction and the spacing p32 in the y direction are 1.0 mm and 0.89 mm, respectively, and the depth d1 in the z direction is 0.7 mm. Since a smaller depth d1 allows the thickness of the multi-lens plate 137 to be thinner, it is preferable that the depth d1 is 2 mm or less, and more preferably 1 mm or less. From the viewpoint that the light source pattern becomes difficult to see, the spacing p31 is set to be smaller than the light source spacing (light source group spacing) L X On the other hand, if the interval p1 is too small, not only will it be difficult to manufacture, but the diffraction effect of light will become unnegligible, so it is preferably 0.005 mm or more, which is 10 times the wavelength of light, 0.5 μm, and more preferably 0.1 mm or more.

[0066] 14 shows a further enlarged cross-sectional view of a cross section connecting shallow valley portions 138B of multi-lens plate 137. The cross-sectional shape of the slope of convex lens portion 139 is a continuous curve, but for the sake of explanation, it is assumed to be made up of first slope 139P, second slope 139Q, and third slope 139R.

[0067] First inclined surface 139P is an inclined surface located near the boundary of convex lens portion 139, and is an area that forms a larger angle with the z axis than second inclined surface 139Q.

[0068] The second inclined surface 139Q is a region surrounding the boundary of the convex lens portion 139 or the first inclined surface 139P, and is a region that includes the portion where the angle between the z axis and the tangent line 139S is the steepest (smallest) angle θ0. The angle θ0 refracts the incident light, contributing to the oblique light distribution of the multi-lens plate 137.

[0069] Third inclined surface 139R is a region surrounding the boundary of convex lens portion 139, first inclined surface 139P, or second inclined surface 139Q, and forms a larger angle with the z axis than the second inclined surface.

[0070] Convex lens portion 139 may not include third inclined surface 139R and may be configured only with first inclined surface 139P and second inclined surface 139Q, or may be configured only with second inclined surface 139Q.

[0071] <Variation 1> In the first embodiment, lighting device 100 is described as having a structure in which light from light source 123 enters diffusion panel 125 and then exits via multi-lens plate 127 (or multi-lens plate 137). However, diffusion panel 125 may be omitted. In this case, brightness non-uniformity is likely to occur, but the distance D between light source 123 and multi-lens plate 127 can be reduced. Z The light source spacing L X By making it larger than , the brightness non-uniformity can be reduced.

[0072] <Variation 2> Alternatively, the light from the light source 123 may be incident on the multi-lens plate 127 (or the multi-lens plate 137) and then emitted via the diffusion panel 125. In this case, the light that has been made into a wide light distribution by the multi-lens plate 127 is isotropically diffused by the diffusion panel 125, so the effect of "wide light distribution" is reduced, but the distance D Z This structure is suitable for a "thin" display with little brightness non-uniformity even when the size is small.

[0073] <Variation 3> In multi-lens plate 127, a concave lens portion may be provided on the virtual light exit surface, which is the side from which light is emitted. In this case, it is possible to change the angle at which the emitted light is at its maximum simply by turning multi-lens plate 127 over. Furthermore, lens portions (concave lens portions or convex lens portions, which will be described later) may be provided on both the virtual light entrance surface and the virtual light exit surface of the multi-lens plate.

[0074] <Embodiment 2> <Configuration> 15 shows a perspective view of lighting fixture 200 of this embodiment. Lighting fixture 200 is a spotlight type lighting fixture that can be attached to wiring duct 280, and can be controlled by lighting control device 170.

[0075] In the following description, the z-axis in Figure 15 is used as the reference, and the z direction (z-axis) is the forward direction, the y direction is the upward direction perpendicular to the z-axis, and of the two axes perpendicular to the z-axis, the direction perpendicular to the z-y directions is sometimes referred to as the x-direction.

[0076] 15, lighting fixture 200 includes a lighting body 210, an arm 270 rotatably attached to the side of lighting body 210, and a mounting part 278 at the other end of arm 270 that is attached to wiring duct 280. Inside arm 270 is electric light wire 238 for transmitting commercial power supplied to wiring duct 280 to power source 225.

[0077] 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, by rotating the lighting body 210 in the θ direction relative to the arm 270, the orientation can be changed from downward to upward as appropriate.

[0078] 16 is a partial side view and partial cross-sectional view including the z-axis of lighting fixture 200. Inside lighting fixture 200, there are a heat sink 221, a light source 223 which is a COB type LED, a reflector 228, a multi-lens plate 227, a power supply 225, and a wireless module 226. Wireless module 226 is detachable from a socket connected to power supply 225. Multi-lens plate 227 has the same structure as concave lens integrated type multi-lens plate 127 of embodiment 1, with only the size changed so that it can fit into lighting body 210.

[0079] 17 is a plan view of light source 223. Sixteen each of surface-mount LED packages 223A (red), 223B (yellowish-white), and 223C (bluish-white), each measuring 2.8 mm in height and 3.5 mm in width, are mounted on substrate 222. When the dimming rate is set to, for example, about 3%, the images of the individual LEDs are visible on multi-lens plate 227, but when the dimming rate is set to a normal value, the brightness increases and multi-lens plate 227 cannot be seen directly, so the problem of individual LED images being visible and color unevenness does not occur.

[0080] FIG. 18(a) shows the light distribution characteristic of lighting fixture 200 (distribution of luminous intensity (cd) with respect to the angle θ direction). In lighting fixture 200, light emitted from light source 223 is bent diagonally horizontally by multi-lens plate 227, so that a wide light distribution characteristic for a spot lens, with a 1 / 2 beam angle of 102°, is obtained, as shown in FIG. 18(a). As shown in FIG. 18(a), the luminous intensity is maximized at 25 to 30°. Note that although the same concave lens integrated multi-lens plate 227 as in embodiment 1 is used, the light source arrangement is different from that in embodiment 1 and the diffusion panel used in embodiment 1 is not used, so the light distribution characteristic is slightly different.

[0081] FIG. 18(b) shows the illuminance characteristics of lighting fixture 200 (isolux curves of 500, 200, 100, 50, and 20 lx, with the distance from the light source on the vertical axis and the distance from the optical axis on the horizontal axis). The total luminous flux of the light source is assumed to be 1000 lm. While FIG. 18(a) shows that the luminous intensity decreases in the z-axis direction, FIG. 18(b) shows that the 1 / 2 illuminance angle is 79° in the x-y direction, resulting in a relatively uniform illuminance distribution. This is because, in addition to the decrease in illuminance due to the longer distance from the light source in oblique directions, the increase in luminous intensity in oblique directions compensates for the decrease in illuminance due to the oblique incidence of light.

[0082] <Embodiment 3> <Summary> A perspective view of lighting fixture 300 according to this embodiment is shown in Fig. 19. Lighting fixture 300 comprises a fixture body 310 that is directly attached to the ceiling, and a light source unit 320 that is attached to fixture body 310. Because fixture body 310 and light source unit 320 are separable, the screws or hanging bolts used to attach fixture body 310 to the ceiling can be hidden by light source unit 320. The lighting device has a width of 2 cm, for example, and a length of 120 cm, for example, and is narrower in the short direction than lighting fixture 100, resulting in a fixture shape that takes design into consideration.

[0083] Cross-sectional views of the fixture body 310 and the light source unit 320 are shown in FIGS. 20(a) and 20(b), respectively.

[0084] <Device body> The device body 310 includes a box-shaped housing 315 with an open bottom, a spring locking portion 311, and a connector 312.

[0085] <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, a diffusion panel 331 and a multi-lens plate 333, which will be described with reference to Fig. 21, and the cover 324 includes cover end faces (a left cover end face 324L and a right cover end face 324r). By arranging a plurality of light source units 320 so that the cover end faces face each other, the entire plurality of light source units 320 can be configured as a continuous, long light source.

[0086] The substrate 322 is a long printed circuit board, and has a plurality of light sources 323, each made of a surface-mounted LED, arranged in a row at intervals in the longitudinal direction. The number of rows of the light sources 323 is one.

[0087] 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 source 325.

[0088] The power supply 325 converts commercial AC power to DC and has three drive output channels to respectively drive the three color 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 then sends the control signal to the power supply 325, which controls the power supply 325. The three drive output channels are independently controlled by the control signal, allowing the light source unit 320 to emit light of any chromaticity within the chromaticity of the three LEDs.

[0089] <Light source unit> 21, which is 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 D Z = 1.1 mm.

[0090] The cover 324 includes a relatively transparent front cover portion 324A, a light-diffusing side cover portion 324B, and protrusions 324C for securing 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. The only difference is the external size. The front cover portion 324A and the side cover portion 324B are integrally extruded using a two-color molding method. The cover 324 is made of a resin, preferably polycarbonate or acrylic. The multi-lens plate 333 may be equivalent to the multi-lens plate 137 with integrated convex lens portions.

[0091] The distance between the light exit surface of diffusion panel 331 and the virtual light entrance surface of multi-lens plate 333 is preferably either in contact with each other or 0.2 mm or less, which allows the lighting fixture to be made thinner.

[0092] <Light distribution characteristics> In this embodiment, the light distribution in the downward direction is suppressed, resulting in a wider light distribution characteristic, so even if the light source spacing is wider than in the past, it is possible to maintain a certain degree of uniformity in illuminance on the desk surface.

[0093] <Embodiment 4> <Summary> The lighting fixture 500 according to this embodiment is a so-called ceiling light, and has a substantially axisymmetric light distribution characteristic.

[0094] <Configuration> The left side of Figure 22(a) is a front view of lighting fixture 500, and the right side is a cross-sectional view seen from the front. The upper side of Figure 22(b) is a plan view of lighting fixture 500 (a front view seen from below when the lighting fixture is installed on the ceiling), and the lower side is a front view of the interior with cover 524, also known as a shade, removed.

[0095] 22(a), mounting adapter 510 is a part that can be attached to a ceiling hook or rosette installed on a ceiling, and is separable from other parts of lighting fixture 500. Cover 524 has front cover portion 524A and side cover portion 524B. Board 522 and power supply 525 are attached on base 521.

[0096] 22(b), five substrates 522 are attached to a base 521. On each substrate 522, 33 light sources 523, which are surface-mounted LEDs, are mounted in four rows.

[0097] <Installing lighting fixtures on the ceiling> The plug / fixing portion of the mounting adapter 510 is turned to attach it to a ceiling hook or rosette installed in the ceiling. 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 upward, the protrusion 512 (claw) of the mounting adapter 510 comes into contact with the base 521 and moves inward. When the base 521 is further moved upward, the protrusion 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 comes into contact with the ceiling, allowing the lighting fixture 500 to be installed parallel to the ceiling. Then, the cover 524 is attached to the base 521.

[0098] <Installation of multi-lens plate> Spacing L between light sources 523 A For example, the minimum distance L is 24 mm. A is not necessarily the distance in the x-direction or y-direction). On the other hand, the light incident surface of the multi-lens plate 527 is spaced apart from the surface of the light source 523 by a distance L A The same distance D Z The multi-lens plate 527 is installed by the multi-lens plate support part 526 with a distance of 24 mm between the concave lens parts p1 as described above, and L A 22(a) , the diffusion degree can be reduced to the extent that an image of the light source is not generated on the cover 524, i.e., it can be made nearly transparent, and the light extraction efficiency can be improved.

[0099] <Modifications and other changes> The above describes an embodiment of the lighting fixture according to the present invention, but the lighting fixture exemplified can also be modified, for example, as described below, and it goes without saying that the present invention is not limited to the lighting fixture as shown in the above embodiment.

[0100] Although a honeycomb arrangement has been described as an example of the arrangement of lens portions in the multi-lens plate, other two-dimensional arrangements such as a lattice arrangement in which the lens portions are arranged two-dimensionally and repeatedly in the x and y directions may also be used.

[0101] In the above example, a concave lens integrated multi-lens plate has a ridgeline having a ridgeline apex and a ridgeline saddle between the concave lens portions, but the distance of the ridgeline from the virtual incident plane is not particularly limited. In the above example, a convex lens integrated multi-lens plate has a deep valley portion and a shallow valley portion between the concave lens portions, but the distance of the valley from the virtual incident plane is not particularly limited.

[0102] In the first and third embodiments, the configuration of a lighting fixture equipped with a multi-lens plate and a diffusion panel is described using a lighting fixture for a system ceiling and a lighting fixture with a separate fixture body and light source unit as examples, respectively. However, the configuration of the first and third embodiments may be applied to lighting fixtures in other embodiments as appropriate, for example, the configuration of the third embodiment, which has a relatively transparent front cover portion, may be applied to another embodiment.

[0103] 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 specified angle relative to the amount of transmitted light in the 0-degree direction, is determined, and the degree of dispersion is defined as the angle at which the amount of transmitted light is 50% of the amount of transmitted light at 0 degrees. The degree of dispersion of a diffusion panel is preferably 5 degrees or more, and more preferably 10 degrees or more. On the other hand, the degree of dispersion of a relatively transparent cover is preferably 4 degrees or less, and more preferably 2 degrees or less. The degree of dispersion of a multi-lens plate is also preferably 4 degrees or less, and more preferably 2 degrees or less. In addition to the degree of dispersion, the diffusivity may also be determined by the haze value.

[0104] In the above description, a light diffusing material is mixed into the diffusion panel to provide light diffusing properties, but light diffusing properties can also be provided by roughening the light entrance surface or light exit surface. A light diffusing material may be mixed in and the light entrance surface or light exit surface may also be roughened.

[0105] The light source may be mounted directly on the frame 130, the mounting plate 321, the base 521, or the like, without being mounted on a substrate.

[0106] Each light source may be equipped with a lens that widens the light distribution, for example. In this case, an even wider light distribution angle can be achieved by the synergistic effect of the increase in the light distribution angle due to the lens and the increase in the light distribution angle due to the multi-lens plate of the present invention.

[0107] The substrate is not limited to a printed circuit board, but may be a metal core substrate (a substrate in which an insulating film is provided on the surface of a metal plate and a wiring pattern is provided on top of that) or a ceramic substrate with a wiring pattern formed on its surface. In this way, the material of the substrate is not particularly limited. In addition, the board part of a COB type LED or the package part of a surface-mounted LED may serve as the substrate, eliminating the need for a printed circuit board.

[0108] The configuration of each part of the present invention is not limited to the above-described embodiment and modified examples, and various modifications are possible within the technical scope of the claims. For example, the configuration of each part of the lighting fixture described above can be applied to various lighting fixtures, not limited to LED lighting fixtures.

[0109] The above-described embodiments and modifications may be partially combined. [Explanation of symbols]

[0110] 100, 200, 300, 500 lighting fixtures 110, 310 fixture body 112 recess 114, 225, 325, 525 power supply 115, 226, 326 Wireless Module 120, 320 light source unit 122, 222, 322, 522 board 123, 123A, 123B, 123C, 223, 323, 523 light source 123G light source group 125, 331 Diffusion Panel 127, 137, 227, 333, 527 Multi-lens plate 127F, 137F Virtual light incident surface 127B, 127BR, 137B light exit surface 128 Concave lens part 128P, 139P 1st slope 128Q, 139Q 2nd slope 128R, 139R 3rd slope 128S, 139S tangent 129 Ridgeline 129B Ridge saddle 129P Ridge apex 130 slots 139 Convex lens part 138 Valley 138B Tani Asabe 138D Deep valley 170 Lighting control device 171 Touch Panel 172 Radio Communication Department 173 Lighting Control Program 180 Air conditioning equipment 190, 191 Ceiling panels 195 T-bar 199 System Ceiling 210 Light body 238 Electric Light Line 270 Arm 278 Mounting part 280 Wiring Duct 311 Spring locking part 312, 328 Connectors 315 Case 321 Mounting plate 324, 524 cover 324A, 524A front cover 324B, 524B cover side 324C protrusion 327 Mounting spring 510 Mounting Adapter 512 Protrusion 521 Base 526 Multi-lens plate support 528 Cushion

Claims

1. A lighting fixture comprising a plurality of light sources and a multi-lens plate, the multi-lens plate has a plurality of lens portions two-dimensionally arranged on a virtual light incident surface or a virtual light exit surface, and the shape of the boundaries of the plurality of lens portions is a hexagon; the lens portion includes a slope surrounding the center of the lens portion, the steepest slope among the slopes has an angle of 35° or more and 60° or less with respect to a normal to the virtual light incident surface or the virtual light exit surface; The light emitted from the multi-lens plate has a maximum luminous intensity in a direction oblique to the optical axis direction in each cross section in the x direction and the y direction perpendicular to the optical axis direction, The distance between the centers of the lens portions is equal to or less than 1 / 3 of the distance between the light sources. Lighting fixtures.

2. The distance between the centers of the lens units is 1 / 10 or less of the distance between the light sources.

2. The lighting fixture of claim 1.

3. The lens portion is a concave lens portion, and the depth of the concave portion is 2 mm or less.

3. The lighting fixture according to claim 1 or 2.

4. The distance between the centers of the lens portions is different in the x direction and the y direction.

3. The lighting fixture according to claim 1 or 2.

5. The lighting device further includes a diffusion panel between the light source and the multi-lens plate, the diffusion panel being a plate having light diffusion properties; The distance between the light source and the surface of the diffusion panel on the light source side is D Ｚ and the distance between the surface of the diffusion panel facing the multi-lens plate and the surface of the multi-lens plate facing the diffusion panel is D Ｚ is less than 1 / 10 of 3. The lighting fixture according to claim 1 or 2.

6. There are a plurality of the light sources, and the plurality of the light sources are arranged in a row.

3. The lighting fixture according to claim 1 or 2.

7. The light source has a Lambertian light distribution characteristic, and the 1 / 2 beam angle of the lighting device is 125° or more and 160° or less.

3. The lighting fixture according to claim 1 or 2.

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