Lighting device

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] In the lighting fixture described in Patent Document 1, light emitted from an LED module passes through a light distribution panel equipped with numerous prisms each consisting of a quadrangular pyramid-shaped depression, generating illumination light. It is said that the light distribution panel can concentrate the illumination light, thereby suppressing unpleasant glare.

[0004] The lighting fixture described in Patent Document 2 also includes a lighting cover having a large number of minute protrusions, and the lighting cover is said to be capable of reducing light with an angle θ in the range of 60 to 90 degrees and significantly reducing 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, as shown in Figure 7(f) of Patent Document 2, the point light source pattern seems to still be slightly visible.

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

[0007] [Patent Document 1] JP 2017-59518 A [Patent Document 2] JP 2015-032474 A [Patent Document 3] JP 2017-191747 A 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 nearly uniform illuminance over a wide range. [Means for solving the problem]

[0009] The present invention provides a lighting device 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 a center of the lens portion, the steepest slope of 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 surface includes 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 with respect to a normal line of the virtual light entrance 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 boundaries between the concave lens portions may be ridge lines.

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

[0013] The present invention provides a lighting device including 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 multiple, and the multiple 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 device may be 125° or more and 160° or less. Effect 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 description of the drawings]

[0017] [Figure 1] View of a system ceiling with lighting fixtures installed from below [Diagram 2] Lighting fixture cross section [Diagram 3] Cross-sectional view of the light source unit [Figure 4] Top view of the board [Diagram 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 a multi-lens plate with integrated concave lenses [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 lenses [Figure 14] Further enlarged view of the cross section of a multi-lens plate with integrated convex lenses [Figure 15] FIG. 13 is a perspective view of a lighting fixture according to a second embodiment. [Figure 16] A partial side view and partial cross-sectional view of a lighting fixture according to a second embodiment. [Figure 17] FIG. 11 is a plan view of a light source according to a second embodiment. [Figure 18] Light distribution characteristics and illuminance characteristics of the lighting fixture of the second embodiment [Figure 19] FIG. 11 is a perspective view of a lighting fixture according to a third embodiment. [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] FIG. 1 is a front view, a cross-sectional view, and a plan view of a lighting fixture according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] <Embodiment 1> <Summary> FIG. 1 shows a system ceiling 199 to which a lighting fixture 100 according to this embodiment is attached, viewed from below. The system ceiling has T-bars 195 with a lattice spacing L G(e.g. 600 mm) in a lattice pattern, and within the compartments separated by the T-bars, lighting fixtures 100, air conditioning equipment 180, ceiling panel 190, and ceiling panel 191 equipped with various equipment (inspection hatches, speakers, wireless equipment (wireless repeaters, etc.)) are installed. The T-bars 195 are attached to a 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, etc. Note that while the T-bars 195 are shown in FIG. 1 for the sake of explanation, they are usually constructed so that they are hidden when viewed from below.

[0019] The lighting fixture 100 is composed of a fixture body 110 and a light source unit 120. A cross-sectional view of this is shown in Fig. 2. The fixture body 110 has a recess 112 on its underside for mounting the light source unit 120, and a power source 114 attached to its upper surface. A wireless module 115, which is a communication device for lighting control, is attached to the power source 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 source 114 to the light source unit 120.

[0020] <Lighting control device> The lighting control device 170 in Fig. 1 is composed of a tablet, a smartphone, a PC, etc., and is equipped with a touch panel 171, which is a display and input unit, a wireless communication unit 172, and a lighting control program 173 (not shown) installed. A user can operate the lighting control program 173 to wirelessly communicate with the lighting fixture 100 by wireless signals transmitted and received by the wireless communication unit 172, and change the lighting conditions. The lighting conditions include color tone (adjusting the color), brightness (dimming), and turning on / off, and an interface is provided for manually controlling these as appropriate. In addition, a scheduled operation can be performed to automatically change the lighting conditions at a set time according to a pre-registered time and lighting conditions.

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

[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 is defined as the z direction, the direction perpendicular to the z direction in Fig. 3 is defined as the x direction, and the direction perpendicular to the z direction and y direction (depth direction in Fig. 3) is defined 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 the 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 a phosphor-containing sealing resin. The emitted light color can be adjusted by the type and amount of phosphor.

[0025] The light source 123 exhibits a light distribution characteristic that is approximately in accordance with the cosθ law, which is called a Lambertian light distribution characteristic, and the light distribution angle (1 / 2 beam angle) at which the luminous intensity relative to the axial luminous intensity is 1 / 2 is approximately 120°. However, the light distribution angle of an actual LED is approximately 114 to 118°. Note that the 1 / 2 beam angle may be 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 actual measured value is, for example, approximately 58°. Note that in the present invention, a Lambertian light distribution is one in which the 1 / 2 beam angle is 110° to 122°.

[0026] For example, only LEDs of one luminous color may be used as the light source 123. Also, LEDs of two luminous 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 almost in line with the black body radiation.

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

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

[0029] Another example of a light source having 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 chromaticity boundaries and (0.5,0.5), (0.423,0.355), (0.342,0.312), (0.352,0.44), (0.37,0.63) in the CIE 1931 chromaticity coordinates, and an example is (0.44,0.47).

[0032] A blue-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 being (0.23, 0.26).

[0033] Compared to B (blue) light, which has a spectrum that is 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-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 phosphor-containing resin, or a CSP (Chip Scale Package) type LED in which multiple blue LED chips sealed with 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 the light sources 123A, 123B, and 123C, each of which has a different light emission color, 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 1 / 3 of the normal spacing L. X and the vertical light source group spacing L Y are preferably approximately equal.

[0036] In addition, in the case of using two-color LEDs, the light source 123A and the light source 123B are arranged in a single light source group 123G by setting the light source group interval L 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 they are approximately the same.

[0037] <Multi-lens plate 127> FIG. 5 shows an enlarged cross-sectional view including the z- and x-axes of the multi-lens plate 127 with integrated concave lens portions, 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, which is assumed to have no concave lens portions 128, on the side where light enters, and a light exit surface 127B on the side where light exits. The virtual light incident surface is, for example, a plane connecting ridge vertices 129P, which will be described later. The concave lens portions 128 refract, for example, an incident light ray B1 into an internal light ray B2 and an exit 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. In addition, as shown in FIG. 5 as an incident light ray C1, an internal light ray C2, and an internally reflected light ray C3, there is also an internally reflected light ray C3 that is totally reflected by the multi-lens plate 127 and returns to the incident side. The angle θ 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 0 As this is increased, the light component distributed in the oblique x direction increases, but the proportion of internally reflected light also increases, tending to decrease the light extraction efficiency.

[0038] Since the concave lens portion is provided on the side where light is incident in the multi-lens plate 127, the incident light ray B1 becomes an internal light ray B2 by the first refraction, and the internal light ray B2 becomes an outgoing light ray B3 by the first refraction, which has the advantage of increasing the outgoing light components in the diagonal horizontal direction.

[0039] FIG. 6 shows a plan view of the multi-lens plate 127. The concave lens portions 128 are arranged two-dimensionally in the x direction and in a direction diagonal at 60 degrees from the x direction. The boundary shape is hexagonal so that the planar arrangement is honeycomb-like. The inside of the concave lens portion 128 has a concentric 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, which are the boundaries of the concave lens portions 128, are connected, so that the thick parts are continuous, and the strength of the multi-lens plate 127 can be maintained. The ridge line 129 connects the ridge line apex 129P, which is the boundary between the three concave lens portions 128, and the ridge line saddle part 129B, which is the lowest part of the ridge line 129 (the saddle part is a derivative of a horse riding term and is used in geometry to refer to "the lower part of a ridge line that is higher than the surroundings"). Ridge saddle portion 129B is slightly lower than ridge apex 129P, that is, the distance to the light exit surface of multi-lens plate 127 at that portion is short.

[0040] By forming ridge 129 in a shape having ridge vertex 129P and ridge saddle portion 129B, it is possible to have concentric slopes throughout the entire interior of concave lens portion 128, the planar shape of the boundary of which is hexagonal, thereby achieving an isotropic light distribution.

[0041] The interval p1 between the concave lens portions 128 in the x direction and the interval 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 disposed at the vertices of an equilateral triangle, with the interval p1 corresponding to the length of the base of the equilateral triangle and the interval 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 made 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, the interval p1 is set to be smaller than the light source interval (light source group interval) 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 significant, so it is preferable that the interval p1 is 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] Although light exit surface 127B is a flat surface in Fig. 5(a), it may be light exit surface 127BR having a light scattering structure, as shown in Fig. 7(a) which is a perspective view of the shape of the light exit surface of a multi-lens plate, and Fig. 7(b) which is a cross-sectional view. Light exit surface 127BR has a concave-convex structure with the same pitch as concave lens portion 128 here, but is not limited thereto.

[0043] 8 shows a further enlarged cross-sectional view of a cross section including the z·x axes connecting ridge saddle portion 129B of multi-lens plate 127. The cross-sectional shape of the slope of concave lens portion 128 is a continuous curve, but for the sake of explanation, it is considered to be composed 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 have an angle closer to the z-axis direction than incident light ray D1 are incident on the bottom of first inclined surface 128P, 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 the angle between the z axis and the tangent line 128S is the steepest (smallest) angle θ 0 The area includes the part where the angle θ 0 The incident light is refracted by this, which contributes to the oblique light distribution of the multi-lens plate 127.

[0046] The third inclined surface 128R is a region surrounding the center of the concave lens portion 128, the first inclined surface 128P, or the second inclined surface 128Q, and is a region that forms a larger angle with the z-axis than the second inclined surface. Therefore, as shown in Fig. 8, the incident light ray E1 toward the third inclined surface 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 the internal light ray E2 that hits the inclined surface of the adjacent concave lens portion 128 and is totally reflected is reduced.

[0047] The concave lens portion 128 may not include 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 having flat surfaces on both sides and having uniform light diffusion properties due to the incorporation of a diffusion material. Suitable materials for the panel are, for example, polycarbonate or acrylic. Note that the surface can be roughened to provide uniform light diffusion properties.

[0049] As a design concept of the present invention, the diffusion panel 125 has a role of converting the light of the light source 123 into a flat light source with less unevenness in luminance and color. X (Light source group spacing L X ) for D Z Ratio D Z / L X For example, we can increase the value to 1 or more. Z / L X Increasing D reduces the light extraction efficiency. Z / L X We have conducted a study to determine the pattern of the light source, and have obtained a design in which the pattern of the light source is almost absent when the pattern is 0.6 or more. In addition, in order to make the main body of the device thin, it is preferable to install the diffusion panel 125 close to the multi-lens plate, and it may be in contact with it. ZThe distance should be about 1 / 10 or less.

[0050] 5, there is 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 multi-lens plate 127 is acrylic (PMMA, polymethyl methacrylate) and the calculations are performed with a refractive index of 1.485, but the material of multi-lens plate 127 is not particularly limited as long as it is a transparent material, and may be PC (polycarbonate) or glass.

[0052] <Frame> The bottom surface of the frame 130 shown in FIG. 3 serves to support the substrate 122, and the side surfaces of the frame 130 serve to support the diffusion panel 125 and the multi-lens plate 127.

[0053] <Light distribution characteristics and illuminance distribution> In Fig. 9(a) and Fig. 9(b), the steepest slope angle θ 0 The light distribution characteristics and illuminance characteristics are shown for the case where a multi-lens plate 127 is used with a beam angle of 39.3 degrees. The 1 / 2 beam angle (both sides) is 134° in the x direction and 140° in the y direction. Additionally, 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] In Fig. 10(a) and Fig. 10(b), the steepest slope angle θ 0 The figures show the light distribution characteristics and illuminance characteristics when using a multi-lens plate 127 with a 47.2 degree angle. The 1 / 2 beam angle (both sides) is 126° in the x direction and 131° in the y direction. Additionally, the 1 / 2 illuminance angle (one side) is 75° in the x direction and 76° in the y direction. Again, this case is characterized by the fact 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.

[0055] When the structure of the present invention is not used, the light distribution angle is, for example, about 120°, and the direction in which the luminous intensity is maximum is the 0° direction. 0 When the multi-lens plate 127 with the angle θ of 39.3 degrees is used, the luminous intensity is maximized at 30 to 32 degrees in both the x and y directions as shown in FIG. 0 When a multi-lens plate 127 with a 47.2° angle is used, the luminous intensity becomes maximum at angles of 18° to 23° in both the x and y directions, as shown in FIG. 10(a).

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

[0057] Therefore, the angle at which the luminous intensity is at 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] Corresponding to that point, the steepest slope angle θ 0 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, the angle θ 0 It was found that the angle 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 1 / 2 beam angle, the light source is a Lambertian light source, and the 1 / 2 beam angle is preferably greater than that, 125° or more, and more preferably 128° or more. On the other hand, taking into consideration the decrease in efficiency caused by total reflection resulting from widening the light distribution angle, the light distribution angle is preferably 160° or less, and more preferably 150° or less.

[0060] <Illuminance distribution> FIG. 11(a), which is a comparative example, shows the illuminance distribution (unit: lx) when 16 conventional luminaires are installed vertically and 16 horizontally at intervals of 180 cm in a room measuring 28.8 m square, while FIG. 11(b), which is an example, shows the calculation result of the illuminance distribution when 12 luminaires 100 of this embodiment are installed vertically and 12 horizontally at intervals of 240 cm in a room measuring 28.8 m square. Note that the installation conditions for the luminaires were set so that 750 lx or more can be obtained on a desk. The illuminance distribution is assumed when the desk height is 70 cm, the ceiling height is 3.5 m, and the height from the ceiling to the top of the desk is 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, and a significant reduction in power consumption is achieved. In addition, the number of units installed is 56% of that of the comparative example, and a significant reduction in installation costs can also be achieved.

[0062] <Multi-lens plate 137> In this embodiment, instead of the concave lens portion integrated multi-lens plate 127, a convex lens portion integrated multi-lens plate 137 can be used. Fig. 12 shows an enlarged cross-sectional view of the multi-lens plate 137. The multi-lens plate 137 is provided with a plurality of convex lens portions 139 on a virtual light incident surface 137F that is assumed to have no convex lens portion 139 on the side where light is incident, and includes 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 portions 139. Although the light emission surface 137B is shown as a plane in Fig. 12, a light scattering shape may be provided. By the convex lens portion 139, for example, the incident light ray B31 is refracted in the internal light ray B32 and the outgoing light ray B33 in the diagonal x direction in Fig. 12, thereby reducing the light distribution in the z direction (the downward direction in the figure) and increasing the light distribution in the diagonal x direction. Also, as shown as the incident light ray C31, the internal light ray C32, and the internal reflected light ray C33 in Fig. 12, there is also an internal reflected light ray C33 that is totally reflected in the multi-lens plate 137 and returns to the incident side. The angle θ of the inclined surface of the convex lens portion 139 with respect to the z-axis that is the normal line of the virtual light incident surface 137F 0 The larger the angle is, the larger the light component distributed in the lateral direction becomes. On the other hand, the ratio of the internal reflected light also increases, and there is a tendency for the light extraction efficiency to decrease. From the fact that Fig. 5, which is a cross-sectional view of the concave lens portion integrated multi-lens plate 127, and Fig. 12, which is a cross-sectional view of the convex lens portion integrated multi-lens plate 137, are very similar, it can be seen that the same tendency is recognized for the angle θ 0 dependency of the light distribution characteristics.

[0063] Fig. 13 shows a plan view of the multi-lens plate 137. The convex lens portions 139 are repeatedly arranged two-dimensionally in the x direction and in the direction inclined 60 degrees from the x direction. In this way, the planar shape of the valley 138, which is the boundary of the convex lens portions 139, is hexagonal so as to have a honeycomb-like planar arrangement. The convex lens portions 139 have a concentric shape shown by the contour lines 138C1 and 138C2 shown in Fig. 13. The valley 138 is formed by connecting the deep valley portion 138D that is the boundary of three convex lens portions 139 and the shallow valley portion 138B that is the boundary of 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 planar shape of the boundary of which is hexagonal, can have concentric slopes, thereby achieving 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 light diffraction effect will become significant, so the interval p1 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] Second inclined surface 139Q is a boundary of convex lens portion 139 or a region surrounding first inclined surface 139P, and the angle between the z axis and tangent line 139S is the steepest (smallest) angle θ 0 The area includes the part where the angle θ 0 The incident light is refracted by this, which contributes 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 configuration of the first embodiment, lighting device 100 has been described as having a structure in which light from light source 123 enters diffusion panel 125 and is then emitted via multi-lens plate 127 (or multi-lens plate 137), but diffusion panel 125 may be omitted. In that case, luminance 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 interval L X By making it larger than , the luminance non-uniformity can be reduced.

[0072] <Variation 2> Also, 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 wide-distributed by the multi-lens plate 127 is isotropically diffused by the diffusion panel 125, so the effect of "wide-distribution of light" is reduced, but the distance D Z This structure is suitable for a "thin" display with little luminance non-uniformity even if the size is reduced.

[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 that case, it is possible to change the angle at which the emitted light is at its maximum by simply turning over multi-lens plate 127. In addition, 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> A perspective view of a lighting fixture 200 of this embodiment is shown in Fig. 15. The lighting fixture 200 is a spotlight type lighting fixture that can be attached to a wiring duct 280, and can be controlled by a 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 which is attached to a wiring duct 280. Inside arm 270 is an electric light line 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 light 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 the lighting fixture 200. Inside the 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 source 225, and a wireless module 226. The wireless module 226 is detachable from a socket connected to the power source 225. The multi-lens plate 227 has the same structure as the concave lens portion integrated type multi-lens plate 127 of the first embodiment, and only the size is changed so that it can fit into the lighting body 210.

[0079] 17 is a plan view of light source 223. Sixteen each of surface mount type LED packages 223A (red), 223B (yellowish white), and 223C (blueish 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 the lighting device 200 (distribution of luminous intensity (cd) with respect to the angle θ direction). In the lighting device 200, the light emitted from the light source 223 is bent diagonally horizontally by the multi-lens plate 227, so that as shown in FIG. 18(a), a wide light distribution characteristic for a spot lens is obtained with a 1 / 2 beam angle of 102°. As shown in FIG. 18(a), the luminous intensity is maximized at 25 to 30°. Note that although the same concave lens portion integrated type multi-lens plate 227 as in the first embodiment is used, the light source arrangement is different from that in the first embodiment, and the diffusion panel used in the first embodiment 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. FIG. 18(a) shows that the luminance is smaller in the z-axis direction, but FIG. 18(b) shows that the 1 / 2 illuminance angle is 79° in the x-y direction, and a relatively uniform illuminance distribution was obtained. This is because, in the oblique direction, the distance from the light source is longer and the illuminance decreases, and there is also a decrease in illuminance due to the light being incident obliquely, but the increase in luminance in the oblique direction compensates for this decrease in illuminance.

[0082] <Embodiment 3> <Summary> A perspective view of a lighting fixture 300 according to this embodiment is shown in Fig. 19. The 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 the fixture body 310. Because the fixture body 310 and the light source unit 320 are separable, the screws or hanging bolts for attaching the fixture body 310 to the ceiling can be hidden by the 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 the lighting fixture 100, with the fixture shape being designed with design in mind.

[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] <Main unit> 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 source 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 cover left end face 324L and a cover right end face 324r). By arranging the multiple light source units 320 so that the cover end faces face each other, the multiple light source units 320 as a whole can be a long, continuous light source.

[0086] The substrate 322 is a long printed circuit board, and includes a plurality of light sources 323, each of which is 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 into DC and has three-channel drive outputs to drive the three color LEDs, each of which 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-channel drive outputs are independently controlled by the control signal, allowing the light source unit 320 to emit light of any chromaticity surrounded by the chromaticities 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 entrance surface of the diffusion panel 331 is D Z = 1.1 mm away.

[0090] The cover 324 includes a relatively transparent cover front part 324A, a light-diffusing cover side part 324B, and a diffusion panel 331 and a protrusion 324C for fixing 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, and is a multi-lens plate with concave lens parts arranged in a honeycomb shape on the virtual light incident surface, and has almost the same design, but differs only in the size of the outer shape. The cover front part 324A and the cover side part 324B are integrally extrusion molded by a two-color molding method. The material of the cover 324 is a resin, and polycarbonate or acrylic is preferably used. The multi-lens plate 333 may be equivalent to the multi-lens plate 137 with integrated convex lens parts.

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

[0092] <Light distribution characteristics> In this embodiment as well, the light distribution in the downward direction is suppressed, resulting in a wider light distribution characteristic, so that even if the light source spacing is wider than in the past, a certain degree of uniformity in illuminance on the desk surface can be maintained.

[0093] <Embodiment 4> <Summary> Illumination device 500 according to this embodiment is a so-called ceiling light, and has a substantially axially symmetric light distribution characteristic.

[0094] <Configuration> The left side of Fig. 22(a) is a front view of lighting fixture 500, and the right side is a cross-sectional view seen from the front direction. The upper side of Fig. 22(b) is a plan view of lighting fixture 500 (a front view seen from below when the lighting fixture is installed on a ceiling), and the lower side is a front view of the inside with cover 524, also called 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 can be separated from other parts of lighting fixture 500. Cover 524 has cover front part 524A and cover side part 524B. Substrate 522 and power supply 525 are attached on base 521.

[0096] 22(b), five boards 522 are attached on a base 521. On the boards 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 part of the mounting adapter 510 is turned and attached to a ceiling hook or rosette provided on the ceiling. When the hole part of the base 521 of the lighting fixture 500 with the cover 524 removed is inserted into the mounting adapter 510 facing upward, the protrusion 512 (claw) of the mounting adapter 510 comes into contact with the base 521 and moves inward, and when the base 521 is further moved upward, the protrusion 512 of the mounting adapter 510 returns to its original state and supports the base 521, so that the base 521 is attached to the mounting adapter 510. At this time, the cushion 528 hits the ceiling, so that the lighting fixture 500 can be installed parallel to the ceiling. After that, the cover 524 is attached to the base 521.

[0098] <Installation of multi-lens plate> Spacing L of light source 523 A For example, the minimum distance L is 24 mm. A (where is not necessarily the distance in the x or y directions). On the other hand, the light incidence 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 lens plates 527 are mounted on the multi-lens plate support 526 with a distance of 24 mm between the concave lens portions. A 22(a), the degree of diffusion can be reduced to the extent that an image of the light source is not generated on the cover 524, that is, the cover 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. However, the exemplified lighting fixture can 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] As an example of the arrangement of the lens portions in the multi-lens plate, a honeycomb-like arrangement has been described, but other two-dimensional arrangements such as a lattice pattern that is repeatedly arranged two-dimensionally in the x and y directions may also be used.

[0101] As an example of the ridge line having a ridge line vertex and a ridge line saddle between the concave lens portions in the concave lens portion integrated multi-lens plate, the distance from the virtual incident surface of the ridge line is not particularly limited. Regarding the valley portion in the convex lens integrated multi-lens plate, an example having a valley depth portion and a valley shallower portion has been described, but the distance from the virtual incident surface of the valley is not particularly limited.

[0102] In Embodiments 1 and 3, the configurations of the lighting fixtures including the multi-lens plate and the diffusion panel have been described by taking the lighting fixture for a system ceiling and the lighting fixture with a separated fixture body and light source unit as examples, respectively. However, the configuration of Embodiment 3 having a relatively transparent front cover portion may be applied to lighting fixtures in other embodiments as appropriate, such as applying the configuration of Embodiment 3 to lighting fixtures in other embodiments.

[0103] As an index of the diffusibility of an optical component, there is a dispersion degree. A diffusion distribution, which is the amount of transmitted light at a predetermined angle with respect to the amount of transmitted light in the 0-degree direction when light in the 0-degree direction (usually laser light) is incident, is obtained, and the angle at which the amount of transmitted light becomes 50% of the amount of transmitted light in the 0-degree direction is defined as the dispersion degree. The light diffusibility of the diffusion panel preferably has a dispersion degree of 5 degrees or more, and more preferably 10 degrees or more. On the other hand, the dispersion degree of a relatively transparent cover is preferably 4 degrees or less, and more preferably 2 degrees or less. Also, the dispersion degree of the multi-lens plate is preferably 4 degrees or less, and more preferably 2 degrees or less. In addition to the dispersion degree, the diffusibility may be defined by a haze value.

[0104] In order to give light diffusibility to the diffusion panel, the case where a light diffusing material is mixed has been described, but light diffusibility can also be given by making the light incident surface or the light emitting surface a rough surface. A light diffusing material may be mixed, and further, the light incident surface or the light emitting surface may be made a rough surface.

[0105] The light source may be mounted directly on the frame 130, the mounting plate 321, the base 521, etc., 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 realized by the synergistic effect of the increase in the light distribution angle by the lens and the increase in the light distribution angle by the multi-lens plate according to 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 the insulating film), or a ceramic substrate on which a wiring pattern is formed on the 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 mount type LED may function as the substrate, and a printed circuit board or the like may not be used.

[0108] The configuration of each part of the present invention is not limited to the above-mentioned embodiment and modified example, and various modifications are possible within the technical scope of the claims. For example, the configuration of each part of the above-mentioned lighting fixture can be applied to various lighting fixtures that are 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 Equipment 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 incidence 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 Asabu 138D Deep valley 170 Lighting control device 171 Touch Panel 172 Wireless Communication Department 173 Lighting Control Program 180 Air conditioning equipment 190, 191 Ceiling panel 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 Cover front part 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 device including a light source 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, The lens portion includes a slope surrounding a center of the lens portion, the steepest slope of 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. Lighting fixtures.

2. the inclined surface includes a first inclined surface located near a center of the lens portion, a second inclined surface surrounding the first inclined surface, and a third inclined surface surrounding the second inclined surface, an angle of the second inclined surface with respect to a normal line of the virtual light incident surface or the virtual light exit surface is steeper than angles of the first inclined surface and the second inclined surface; 2. A lighting device according to claim 1.

3. The lens portions are concave lens portions, and the boundaries between the concave lens portions are ridge lines.

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

4. The lens portions are convex lens portions, and boundaries between the convex lens portions are valleys.

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

5. A lighting device 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 two-dimensionally arranged on a virtual light incident surface or a virtual light exit surface, 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 is 1 / 10 or less of Lighting fixtures.

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

6. A lighting fixture according to claim 1 or 5.

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.

6. A lighting fixture according to claim 1 or 5.

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