JP7284657B2 - lighting equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to lighting fixtures equipped with LEDs (Light Emitting Diodes).

2. Description of the Related Art Conventionally, lighting fixtures capable of reproducing the appearance of the sky have been proposed. For example, the lighting fixture described in Patent Document 1 is configured to reproduce the appearance of the sky by controlling the emission of blue light, yellow light, orange light, red light, and white light using LEDs of a plurality of colors. It has become.

JP 2019-102166 A

However, in the lighting fixture described in Patent Document 1, since emission of blue light, yellow light, orange light, red light, and white light is controlled, it is difficult to control toning as synthetic light. Reproducibility may decrease.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems described above and to provide a lighting fixture with improved color reproducibility of the sky.

A lighting fixture according to the present invention includes a blue LED module having a blue LED, a white LED, and a green LED, a light guide plate that diffuses the light of the blue LED module and emits surface light, and a blue LED module. A light control unit for reproducing the color of the sky by light control, a white LED module for emitting white light, and a diffusion plate for emitting the light of the white LED module from at least two directions, wherein the dominant wavelength of the blue LED is 470 nm or less , and the diffuser plate is arranged around the light guide plate .

According to the lighting fixture according to the present invention, by setting the dominant wavelength of the blue LED of the LED module for blue to 470 nm or less, it is possible to suppress variations in toning as synthesized light and provide lighting capable of reproducing the sky of natural light. can.

1 is a perspective view showing an appearance of a lighting fixture according to Embodiment 1; FIG. 1 is an exploded perspective view showing the configuration of a lighting fixture according to Embodiment 1; FIG. 2 is an exploded perspective view showing the configuration of the light source unit of the lighting fixture according to Embodiment 1. FIG. 2 is an exploded perspective view showing the configuration of the light source unit of the lighting fixture according to Embodiment 1. FIG. 1 is a schematic cross-sectional view showing the configuration of a lighting fixture according to Embodiment 1; FIG. 1 is a diagram showing a schematic configuration of a blue LED module according to Embodiment 1; FIG. 3 is a control block diagram of the lighting fixture according to Embodiment 1. FIG. 4 is a graph showing the amount of light of the LED module for blue according to Embodiment 1. FIG. 5 is a graph for explaining dimming control of the LED module for blue according to Embodiment 1. FIG. 4 is a chromaticity diagram showing chromaticity coordinates of light emitted from the LED module for blue according to Embodiment 1. FIG. FIG. 4 is a chromaticity diagram when the dominant wavelength of a blue LED is 480 nm to 470 nm; FIG. 4 is a chromaticity diagram when the dominant wavelength of a blue LED is 470 nm to 460 nm; FIG. 4 is a chromaticity diagram when the dominant wavelength of a blue LED is 460 nm to 450 nm;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a lighting fixture according to the present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention. Further, the present invention includes all possible combinations of the configurations shown in the following embodiments. Also, in each figure, the same reference numerals denote the same or corresponding parts, which are common throughout the specification. In addition, throughout the specification, the vertical direction from the floor surface to the ceiling is called "upward direction", and the ceiling side is called "upper side". Similarly, the vertical direction from the ceiling to the floor will be called "downward", and the floor side will be called "lower". In each drawing, the relative dimensional relationship, shape, etc. of each component may differ from the actual one.

Embodiment 1.
FIG. 1 is a perspective view showing the appearance of a lighting fixture 1 according to Embodiment 1. FIG. The lighting fixture 1 is a ceiling-embedded lighting fixture, and includes a fixture body 50 embedded in the ceiling and a light source unit 10 attached to the fixture body 50 . The light source unit 10 includes a diffusion cover 13 that emits white light and a light guide plate 17 that emits blue light. The lighting fixture 1 can provide illumination with a visual effect of depth, such as looking at the sky through a window frame, by blue light from the light guide plate 17 and white light from the diffusion cover 13 .

FIG. 2 is an exploded perspective view showing the configuration of the lighting fixture 1 according to Embodiment 1. FIG. The luminaire 1 is embedded in an embedded hole H provided in the ceiling C and installed. As shown in FIG. 2, the fixture main body 50 of the lighting fixture 1 is formed in a rectangular box shape and has an open bottom. The instrument body 50 has a main surface 51 and four side surfaces 52 . Each of the side surfaces 52 is provided so as to vertically extend downward from each of the four sides of the main surface 51 .

V-spring fittings 53 are attached to the inner surfaces of the two opposing side surfaces 52 of the four side surfaces 52 of the instrument body 50 . The V-spring mounting bracket 53 hooks and holds a V-spring 12, which is provided in the light source unit 10 and will be described later. Further, bolt holes 51-1 are provided at the four corners of the main surface 51. As shown in FIG. A suspension bolt B is suspended from an embedded hole H in the ceiling C. The apparatus main body 50 is fixed to the ceiling C by inserting the suspension bolt B into the bolt hole 51-1 and then tightening the suspension bolt B with the nut 61. As shown in FIG.

A wire hole 51-2 is formed in the main surface 51, and a terminal block 54 is provided. The terminal block 54 has a power terminal block and a signal line terminal block. In FIG. 2, the power supply terminal block and the signal line terminal block are omitted. An electric wire and a signal wire are drawn out from the electric wire hole 51-2. The electric wire pulled out from the electric wire hole 51-2 is electrically connected to the power supply terminal block of the terminal block 54. As shown in FIG. Also, the signal line drawn out from the wire hole 51-2 is electrically connected to the signal line terminal block of the terminal block 54. As shown in FIG.

The light source unit 10 is arranged inside the opening of the fixture body 50 . The light source unit 10 includes an upper cover 27 , a flange portion 11 , a V spring 12 , a diffusion cover 13 and a light guide plate 17 . The upper cover 27 is formed in the shape of a truncated pyramid with an open lower end. Each of the four side surfaces of the upper cover 27 is formed in a trapezoidal shape, and the length of the upper side is shorter than the length of the lower side. The flange portion 11 is formed in a rectangular frame shape in plan view. As shown in FIG. 2, the flange portion 11 is arranged to protrude outward in the horizontal direction from the lower end of the upper cover 27 .

The V spring 12 is a wire spring formed by bending a metal wire into a V shape, and is attached to the upper surface of the flange portion 11 . A total of four V-springs 12 are provided in accordance with the positions of the V-spring fittings 53 of the instrument body 50 . By engaging the V spring 12 with the V spring fitting 53 , the light source unit 10 is suspended and held by the fixture body 50 . In addition, when the lighting fixture 1 is attached to the embedded hole H of the ceiling C, the flange portion 11 covers the edge of the embedded hole H. As shown in FIG. Therefore, when the luminaire 1 is attached to the embedded hole H of the ceiling C, the embedded hole H is invisible to the user.

3 and 4 are exploded perspective views showing the configuration of the light source unit 10 of the lighting fixture 1 according to Embodiment 1. FIG. The light source unit 10 consists of the components shown in FIG. 3 and the components shown in FIG. 3 shows components provided in the lower portion of the light source unit 10, and FIG. 4 shows components provided in the upper portion of the light source unit 10. FIG.

Among the constituent elements of the light source unit 10, first, the constituent elements shown in FIG. 3 will be described. As shown in FIG. 3 , light source unit 10 includes flange portion 11 , V spring 12 , packing 21 , diffusion cover 13 , packing 22 , white LED module 14 , and module holding portion 15 .

The flange portion 11 is formed in a rectangular frame shape as described above. The flange portion 11 is made of metal, for example. A total of four V springs 12 are provided on the upper surface of the flange portion 11 .

The module holding portion 15 is formed in a rectangular frame shape in plan view. The module holding portion 15 is configured by combining four members. Each of the four members has an L-shaped cross section as shown in FIG. 5, which will be described later. Further, as shown in FIG. 3, mounting flanges 15-1 are provided at the lower ends of the four members of the module holding portion 15, respectively. The mounting flange 15-1 is attached to the flange portion 11 by screws.

The white LED module 14 has three substrates 140 and two types of white LEDs 141 and 142 with different color temperatures provided inside each of the three substrates 140 . The three substrates 140 of the white LED module 14 are arranged in a U shape in plan view so as to form three sides of a rectangle. The angle between adjacent substrates 140 is 90°. The white LED module 14 emits white light from three directions forming a U-shape.

The white LED 141 is, for example, a daylight LED with a color temperature of 4000 to 5000 (K), and the white LED 142 is, for example, an incandescent LED with a color temperature of 2600 to 3000 (K). The white LED module 14 can emit white light with various color temperatures and various amounts of light by changing the dimming rate of the white LEDs 141 and 142 . Moreover, the white LED 141 and the white LED 142 may be dimmed according to time. For example, the white LED 141 and the white LED 142 are dimmed so that the amount of light is 100% during the day, 50% at dawn and dusk, and 20% at night. Further, the white LED 141 and the white LED 142 are dimmed so that, for example, the color temperature is daytime white with a color temperature of 4500K, the color temperature is light bulb color with a color temperature of 3000 to 3500K in the evening, and the color temperature is 4000 to 3800K at night. .

As the light source of the white LED module 14, a light-emitting element or a light-emitting device other than the LED may be used. Also, the white LED module 14 may include only one type of white LED, or may include three or more types of white LEDs. The white LED module 14 is arranged inside the module holding portion 15 and held by the module holding portion 15 .

The packing 22 is formed in a rectangular thin frame shape in a plan view. The packing 22 is arranged between the upper end surface of the diffusion cover 13 and the lower surface, which is the emission surface of the light guide plate 17 shown in FIG. The packing 22 blocks light emitted from a blue LED module 18 to be described later so as not to enter the upper end surface of the diffusion cover 13 from the emission surface of the light guide plate 17 . In addition, the packing 22 blocks the white light emitted from the white LED module 14 from entering the emission surface of the light guide plate 17 from the upper end face of the diffusion cover 13 . Furthermore, the packing 22 also functions as a cushioning material when the lighting fixture 1 shakes due to an earthquake or the like.

The diffusion cover 13 is made of, for example, white resin, and has a rectangular frame shape in a plan view. The diffusion cover 13 has a truncated quadrangular pyramid shape with upper and lower openings. That is, each of the four side surfaces of the diffusion cover 13 is inclined at a preset angle with respect to the vertical direction. Each of the four side surfaces of the diffusion cover 13 is composed of a trapezoidal diffusion plate, and the length of the upper side is shorter than the length of the lower side. In addition, since each of the four side surfaces of the diffusion cover 13 is inclined, the upper side is positioned inside the lower side in plan view. As a result, the internal space of the diffusion cover 13 is tapered downward. The diffusion cover 13 may be formed by combining four trapezoidal diffusion plates, or may be integrally formed.

Of the four side surfaces of the diffusion cover 13, three surfaces are light emitting surfaces 13-1 and the other surface is a non-light emitting surface 13-2. The three light emitting surfaces 13-1 are arranged in a U-shape. Here, in each of the four side surfaces of the diffusion cover 13, the inner surface facing the internal space of the diffusion cover 13 is called the front surface, and the outer surface is called the rear surface.

The diffusion cover 13 is arranged inside the white LED module 14 . That is, the white LED modules 14 are arranged on the rear side of each of the light emitting surfaces 13-1 of the diffusion cover 13. As shown in FIG. The white light emitted from the white LED module 14 enters from the rear surface of the light emitting surface 13-1 of the diffusion cover 13, passes through the light emitting surface 13-1, and is emitted from the front surface of the light emitting surface 13-1. Since each of the light emitting surfaces 13-1 is inclined, the white light emitted from the front surfaces of the three light emitting surfaces 13-1 illuminates obliquely downward.

A light-shielding sheet (not shown) is attached to the rear surface of the non-light-emitting surface 13-2 of the diffusion cover 13 to prevent light from leaking from the non-light-emitting surface 13-2.

In this way, the diffusion cover 13 has a structure in which three light-emitting surfaces 13-1 that emit white light and one non-light-emitting surface 13-2 that does not emit light are combined. As a result, the light emitted from the diffusion cover 13 is light from three directions, giving a sense of depth as if light from the outside is coming in through a window frame in the sunshine illuminated by sunlight or a window frame in the shade. A certain visual effect can be produced.

The diffusion cover 13 is placed on the flange portion 11 via the packing 21 . The packing 21 is formed in a rectangular thin frame shape in plan view. The packing 21 prevents direct contact with each other when the flange portion 11 or the diffusion cover 13 vibrates. In addition, the elasticity of the packing 21 reduces the force applied from the flange portion 11 to the diffusion cover 13 , and damage to the diffusion cover 13 can be suppressed. Furthermore, by providing the packing 21 between the flange portion 11 and the diffusion cover 13, it is possible to give an impression of a window frame. In particular, when the packing 21 has a white color tone, the impression of the window frame can be enhanced. The packing 21 also functions as a light shielding portion that prevents white light from leaking through the gap between the diffusion cover 13 and the flange portion 11 .

Next, among the constituent elements of the light source unit 10, the constituent elements shown in FIG. 4 will be described. As shown in FIG. 4, the light source unit 10 further includes a lower guide plate 16, a light guide plate 17, a blue LED module 18, an upper guide plate 19, an insulating portion 23, a module holding portion 24, and a fixing portion. A member 25 , a light guide plate cover 26 and an upper cover 27 are provided. The light source unit 10 further includes a power supply device 31 arranged on the upper surface of the upper cover 27 and a light control unit 32 .

The lower guide plate 16 is placed on the module holding portion 15 shown in FIG. The lower guide plate 16 is composed of two rod-shaped members, and is arranged below the light guide plate 17 along the ends extending in the longitudinal direction of the light guide plate 17 . At both ends of the two rod-like members forming the lower guide plate 16, projections 16-3 are provided. The protrusion 16-3 extends vertically upward. The protrusion 16-3 comes into contact with an end face 17-2 extending in the lateral direction of the light guide plate 17, and restricts movement of the light guide plate 17 in the longitudinal direction.

The upper guide plate 19 is placed on the light guide plate 17 . The upper guide plate 19 is composed of two rod-shaped members and arranged along the longitudinally extending end of the light guide plate 17 .

The light guide plate 17 is formed in a rectangular plate shape in plan view. The light guide plate 17 diffuses the light emitted from the LED module 18 for blue, and emits blue light from the lower surface, which is the emission surface. The light guide plate 17 is made of acrylic resin and contains, for example, silica as a scatterer that is a particle that scatters light. Longitudinal ends of the light guide plate 17 are vertically sandwiched between the lower guide plate 16 and the upper guide plate 19 .

The upper surface of the light guide plate 17 is smooth for total reflection. The upper surface of the light guide plate 17 is desirably mirror-finished. If the top surface of the light guide plate 17 is scratched during the assembly work of the lighting device 1, total reflection is less likely to occur at the scratched portion. Therefore, a portion of the lower surface corresponding to the scratched portion of the upper surface appears whitish. Therefore, in order to prevent the top surface of the light guide plate 17 from being damaged, the top surface of the light guide plate 17 may be covered with a reflective sheet (not shown).

The blue LED module 18 is arranged parallel to the end surface 17-1 of the light guide plate 17 extending in the longitudinal direction. The blue LED module 18 includes two substrates 180 and a plurality of LEDs arranged on each substrate 180 . A plurality of through holes 18-1 are provided in the upper portion of the substrate 180. As shown in FIG. The configuration and dimming control of the blue LED module 18 will be detailed later.

The blue LED module 18 is attached to the module holding portion 24 with a fixing member 25 . A cylindrical protrusion 25-1 is provided on the surface of the fixing member 25 on the blue LED module 18 side. The protrusions 25-1 are inserted into the through holes 18-1 of the substrate 180 of the LED module 18 for blue. The fixing member 25 is screwed to the module holding portion 24 while the protrusion 25-1 is inserted into the through hole 18-1.

The module holding portion 24 is formed of sheet metal having an L-shaped cross section. The module holding portion 24 not only holds the substrate 180 of the LED module 18 for blue, but also functions as a radiator plate that releases heat from the LED module 18 for blue to the outside. The module holding portion 24 is attached to the upper surface of the module holding portion 15 shown in FIG. Also, the blue LED module 18 is attached to the module holding portion 24 via the insulating portion 23 . If the substrate 180 of the blue LED module 18 is not a double-sided substrate, the insulating portion 23 may be omitted.

The light guide plate cover 26 is placed on the upper guide plate 19 . The light guide plate cover 26 covers the light guide plate 17 from above and protects the light guide plate 17 . The upper cover 27 covers and protects the components of the light source unit 10 shown in FIGS. 3 and 4 . A power supply device 31 and a light control unit 32 are placed on the upper surface of the upper cover 27 .

The power supply device 31 supplies power to the blue LED module 18 and the white LED module 14 . The dimming unit 32 dims each LED provided in the blue LED module 18 and the white LED module 14 . The power supply device 31 and the light control unit 32 are electrically connected by wiring such as transition wiring. In addition, the power supply device 31 and the light control unit 32 are electrically connected to the power terminal block and the signal terminal block of the terminal block 54 of the fixture body 50 when the light source unit 10 is attached to the fixture body 50 .

FIG. 5 is a schematic cross-sectional view showing the configuration of the lighting fixture 1 according to Embodiment 1. As shown in FIG. FIG. 5 schematically shows a cross section of the lighting device 1 taken along a plane parallel to one side surface in the short direction at the central portion in the longitudinal direction.

As shown in FIG. 5 , the light source unit 10 is arranged inside the opening at the lower end of the fixture body 50 . A V spring 12 is provided on the upper surface of the flange portion 11 of the light source unit 10 . The V-spring 12 is held in a state of being hooked on a V-spring fitting 53 provided on the instrument body 50 . As a result, the light source unit 10 and the fixture body 50 are engaged, and the light source unit 10 is held by the fixture body 50 .

The white LED module 14 is held by the module holding portion 15 and arranged on the rear surface of the diffusion cover 13 . Further, the blue LED module 18 is held by the module holding portion 24 fixed to the upper surface of the module holding portion 15, and arranged to face the end face 17-1 of the light guide plate 17 with the gap 33 interposed therebetween. The diffusion cover 13 and the light guide plate 17 are arranged in directions that cross each other. Specifically, the light guide plate 17 is arranged parallel to the ceiling C, and the diffusion cover 13 is arranged so as to extend obliquely downward from the light guide plate 17 .

The white light emitted from the white LED module 14 enters from the rear surface of the diffusion cover 13 and is emitted from the front surface of the light emitting surface 13-1 of the diffusion cover 13. FIG. Since the light emitting surface 13-1 is inclined, the white light emitted from the front surface of the light emitting surface 13-1 illuminates obliquely downward. The light emitted from the blue LED module 18 is incident on the end surface 17-1 of the light guide plate 17 and travels through the light guide plate 17 while being totally reflected by the upper and lower surfaces of the light guide plate 17. FIG. Part of the light that travels through the light guide plate 17 hits the scatterers in the light guide plate 17 and is diffused, and surface-emitted from the lower surface of the light guide plate 17 .

Next, the configuration and dimming control of the blue LED module 18 in this embodiment will be described. FIG. 6 is a diagram showing a schematic configuration of the blue LED module 18 according to Embodiment 1. As shown in FIG. FIG. 6 shows a schematic configuration of one substrate 180 in the LED module 18 for blue, and the configuration of another substrate 180 is similar to that of FIG. As shown in FIG. 6 , a plurality of white LEDs 181 , blue LEDs 182 and green LEDs 183 are arranged on the substrate 180 of the blue LED module 18 . More specifically, on the substrate 180, a plurality of sets of two white LEDs 181, two blue LEDs 182, and one green LED 183 are arranged in a line.

The number and arrangement of white LEDs 181, blue LEDs 182, and green LEDs 183 arranged on substrate 180 of blue LED module 18 are not limited to the example in FIG. For example, white LED 181 , blue LED 182 , and green LED 183 may be arranged in the lower area of substrate 180 . In this case, the light guide plate 17 and the diffusion cover 13 can be arranged close to each other, and the blue light from the light guide plate 17 and the white light from the diffusion cover 13 can be emitted in close proximity. Alternatively, the white LED 181, the blue LED 182, and the green LED 183 may be arranged with their positions shifted in the vertical direction. The arrangement of the white LEDs 181, the blue LEDs 182, and the green LEDs 183 may be appropriately determined in consideration of color variation and substrate design. However, in order to reproduce the color of the sky, the ratio of the number of white LEDs 181, blue LEDs 182, and green LEDs 183 to the total number of LEDs in blue LED module 18 is preferably 2:2:1.

A plurality of through holes 18-1 are provided in the upper portion of the substrate 180 of the LED module 18 for blue. A through hole 18-1 (not shown) provided in the central portion of the substrate 180 is circular, and the other through holes 18-1 are elliptical extending in the longitudinal direction. The substrate 180 of the LED module 18 for blue thermally expands and contracts due to the heat emitted from the white LEDs 181 , the blue LEDs 182 and the green LEDs 183 . Therefore, when the blue LED module 18 is fixed to the module holding portion 24, the substrate 180 of the blue LED module 18 may be warped or distorted due to thermal expansion and contraction.

Therefore, in the present embodiment, an elliptical through hole 18-1 is provided in the substrate 180 so that the projection 25-1 of the fixing member 25 can be inserted into the through hole 18-1 with play. As a result, even when the substrate 180 of the blue LED module 18 thermally expands and contracts, the protrusion 25-1 can move in the longitudinal direction within the elliptical through hole 18-1. Warpage or distortion can be suppressed.

The white LED 181 is, for example, an LED with a color temperature of 5000 (K) and a forward voltage of 6V. The blue LED 182 has a dominant wavelength of 470 nm or less and a forward voltage of 3V. The green LED 183 is, for example, an LED with a dominant wavelength of 510 to 570 nm and a forward voltage of 3V. White LED 181 has a higher forward voltage than blue LED 182 and green LED 183 and emits brighter light than blue LED 182 and green LED 183 when the same current flows. That is, the output balance of each LED in the LED module 18 for blue becomes white LED181>blue LED182>green LED183.

Blue LED module 18 of the present embodiment controls the light emission of white LED 181, blue LED 182, and green LED 183 to reproduce the color of the sky, particularly blue sky. By using three colors of white, blue and green in this way, the color rendering can be improved compared to the case of using three colors of red, blue and green.

FIG. 7 is a control block diagram of the lighting fixture 1 according to Embodiment 1. As shown in FIG. As shown in FIG. 7, the power supply device 31 includes a first power supply device 31a, a second power supply device 31b, a second power supply device 31b, and a second power supply device 31b for supplying currents to the white LED 181, the blue LED 182, and the green LED 183 of the blue LED module 18, respectively. 3 power supply device 31c. By individually providing a power supply for each LED, it is possible to two-dimensionally control the emission color of the LED module 18 for blue, so that various blue skies can be reproduced. The power supply device 31 further includes a fourth power supply device 31d and a fifth power supply device 31e that apply current to the white LED 141 and the white LED 142 of the white LED module 14, respectively.

The dimming unit 32 also includes a first control circuit 32a that transmits a first dimming signal to the first power supply 31a and the second power supply 31b, and a second control circuit 32a that transmits a second dimming signal to the third power supply 31c. 2 control circuit 32b. That is, the first control circuit 32a controls the light emission of the white LED 181 and the blue LED 182 of the LED module 18 for blue, and the second control circuit 32b controls the light emission of the green LED 183 of the LED module 18 for blue.

The dimming unit 32 further includes a third control circuit 32c that transmits a third dimming signal to the fourth power supply device 31d, and a fourth control circuit 32d that transmits a fourth dimming signal to the fifth power supply device 31e. And prepare. That is, the third control circuit 32c controls light emission of the white LED 141 of the LED module 14 for white, and the fourth control circuit 32d controls light emission of the white LED 142 of the LED module 14 for white. The first to fourth control circuits 32a to 32d are, for example, microcomputers having timers (not shown), and control the first to fifth power supply devices 31a to 32e according to time.

As described above, in the present embodiment, the same control is performed on both the white LED 181 and the blue LED 182 of the blue LED module 18 by the first control circuit 32a. As a result, illumination control can be simplified and the number of control circuits can be reduced as compared with the case where a control circuit is provided for each LED. In the case of this embodiment, the number of control circuits can be four, which facilitates the development of the lighting fixture 1. FIG.

The first to fifth dimming signals are, for example, PWM (Pulse Width Modulation) signals, and the amount of light is changed according to the duty ratio of the PWM signal. The power supply device 31 performs dimming control of the blue LED module 18 and the white LED module 14 by changing the current flowing through each LED based on the PWM signal.

FIG. 8 is a graph showing the amount of light of the blue LED module 18 according to the first embodiment. The horizontal axis of FIG. 8 indicates the time, and the vertical axis indicates the amount of light from the LED module 18 for blue. As with the white LED module 14, the blue LED module 18 of this embodiment changes the amount of light according to the time. Specifically, as shown in FIG. 8, the amount of light in the daytime (for example, from 8:00 to 16:00) is 100%, and the amount of light in the morning (for example, from 6:00 to 8:00) and in the evening (for example, from 16:00 to 18:00) is 50%. %, and the amount of light at night (for example, from 18:00 to 6:00) is 20%. Note that the time shown in FIG. 8 is merely an example, and is not limited to the example of FIG. 8, and may be set as appropriate. Also, the amount of light at each time may be changed according to the season. For example, when the season is summer, the daytime hours in which the light amount of the blue LED module 18 is 100% may be longer than in winter. Also, depending on the season, not only the amount of light of the blue LED module 18 but also the chromaticity may be changed.

FIG. 9 is a graph for explaining dimming control of the blue LED module 18 according to the first embodiment. The horizontal axis of FIG. 9 indicates time, and the vertical axis indicates the duty ratio of the dimming signal. Further, the solid line in FIG. 9 indicates the first dimming signal output from the first control circuit 32a, and the dashed line indicates the second dimming signal output from the second control circuit 32b. As shown in FIG. 9, the first control circuit 32a and the second control circuit 32b set the duty ratio of the first dimming signal and the second dimming signal to 1 in the daytime.

Then, in the evening (for example, 16:00), the first control circuit 32a reduces the duty ratio of the first dimming signal to 0.2 at a preset first reduction rate. Also, the second control circuit 32b reduces the duty ratio of the second dimming signal to 0.2 at a second reduction rate that is greater than the first reduction rate. As a result, the light amount of the green LED 183 is first reduced to 20%, and then the white LED 181 and the blue LED 182 are reduced to 20%.

Also, in the early morning, the opposite control to that in the evening is performed. Specifically, first, the first control circuit 32a increases the duty ratio of the first dimming signal to 1 at a preset first increase rate. The second control circuit 32b increases the duty ratio of the second dimming signal to be greater than the first increase rate after a predetermined time has passed (for example, 6 o'clock) after the duty ratio is increased by the first control circuit 32a. Increase to 1 at the second rate of increase.

FIG. 10 is a chromaticity diagram showing chromaticity coordinates of light emitted from the blue LED module 18 according to the first embodiment. In FIG. 10, the dashed triangle indicates the adjustable chromaticity range including the natural light coordinates, and the dashed circle indicates the natural light chromaticity coordinates. Also, in FIG. 10, the triangle formed by the thin solid line indicates the adjustable chromaticity range including the coordinates of the light according to the comparative example, and the circle formed by the thin solid line indicates the chromaticity of the light according to the comparative example. Show the coordinates. Furthermore, in FIG. 10, the triangle formed by the thick solid line indicates the adjustable chromaticity range including the light coordinates of the blue LED module 18 of the present embodiment, and the circle formed by the thick solid line indicates the chromaticity coordinates of the light from the blue LED module 18 of this embodiment. The comparative example is an example in which a blue LED having a dominant wavelength greater than 470 nm is used as the blue LED 182 of the LED module 18 for blue.

The blue LED module 18 of the present embodiment reproduces the color of the sky by synthetic light obtained by mixing the emission colors of the white LED 181, the blue LED 182, and the green LED 183. FIG. However, if the emission colors of the white LED 181, the blue LED 182 and the green LED 183 vary due to product errors, the color of the sky cannot be reproduced. As shown in FIG. 10, especially in the blue LED 182, the larger the dominant wavelength, the larger the change in the Y value.

As shown in the comparative example of FIG. 10, when the dominant wavelength of the blue LED becomes a value larger than 470 nm due to product error, the chromaticity range of the emitted color and the Y value of the chromaticity coordinates deviate from the Y value of natural light. As a result, the reproducibility of the sky color becomes low. The chromaticity range and deviation of chromaticity coordinates will be described with reference to FIGS. 11 to 13. FIG. FIG. 11 is a chromaticity diagram when the dominant wavelength of the blue LED 182 is 480 nm to 470 nm. FIG. 12 is a chromaticity diagram when the dominant wavelength of the blue LED 182 is 470 nm to 460 nm. FIG. 13 is a chromaticity diagram when the dominant wavelength of the blue LED 182 is 460 nm to 450 nm. As shown in FIG. 11, when the dominant wavelength of the blue LED 182 is 480 nm to 470 nm, the difference in the chromaticity range due to the variation is large, and the deviation of the Y value of the chromaticity coordinates is also large, as indicated by the dashed arrow. As shown in FIG. 12, when the dominant wavelength of the blue LED 182 is 470 nm to 460 nm, the difference in chromaticity range due to variation is smaller than in the case shown in FIG. Differences in values are also small. Furthermore, as shown in FIG. 13, when the dominant wavelength of the blue LED 182 is 460 nm to 450 nm, the difference in the chromaticity range due to variation is smaller than in the case shown in FIG. deviation is also small. Therefore, when the dominant wavelength of the blue LEDs 182 is greater than 470 nm, the chromaticity coordinates of the blue LEDs fluctuate greatly due to variations in the blue LEDs, and the chromaticity range also fluctuates greatly. In this case, adjustment in the X direction is possible, but adjustment in the Y direction (downward) is impossible.

Therefore, in this embodiment, an LED having a dominant wavelength of 470 nm or less is used as the blue LED 182 . In this case, as shown in FIG. 10, the chromaticity adjustment range of the light emitted from the blue LED module 18 can sufficiently include the chromaticity range of natural light, and the reproducibility of the color of the sky can be enhanced. . Also, even if there is a variation due to product error, if the dominant wavelength is 470 nm or less, as shown in FIGS. 11 and 12, the amount of change in chromaticity in the Y direction is small. be able to.

An LED having a dominant wavelength of 400 nm or more is preferably used as the blue LED 182 . An LED with a dominant wavelength of less than 400 nm is not preferable because the energy of the light is so strong that it may damage the constituent elements of the lighting device 1 or the object to be illuminated. Also, an LED with a dominant wavelength of less than 400 nm cannot be used as visible light. Furthermore, as the blue LED 182, for example, an LED with a dominant wavelength of 440 to 460 nm may be used. An LED with a dominant wavelength of 440 to 460 nm is generally called deep blue, can be used as visible light, and has small variations in chromaticity as described above.

As described above, in the lighting fixture 1 of the present embodiment, blue light that reproduces the color of the sky is emitted from the light guide plate 17 arranged parallel to the ceiling C, and white light is emitted from three directions surrounding the light guide plate 17 . Light is emitted. As a result, it is possible to produce a visual effect with a sense of depth, such as looking at a blue sky through a sunny or shaded window frame illuminated by sunlight. In addition, blue light equivalent to natural light can be emitted from the blue LED module 18, variations in synthetic light can be suppressed, and the reproducibility of the color of the sky can be improved.

In addition, although Embodiment 1 has been described on the assumption that the lighting device 1 is attached to the ceiling C, the lighting device 1 may be installed on an indoor wall. However, in that case, the white LED module 14 is L-shaped in plan view. In accordance with this, of the four side surfaces of the diffusion cover 13, two adjacent surfaces are used as light-emitting surfaces 13-1, and the other two surfaces are used as non-light-emitting surfaces 13-2. Other configurations are the same as those of the first embodiment. As a result, even when the lighting device 1 is installed on the wall of the room, similarly to the case where the lighting device 1 is installed on the ceiling C, the blue sky with a sense of depth can be seen through the window frame in the sun or in the shade illuminated by sunlight. It is possible to produce a visual effect that looks like Moreover, the shape of the lighting fixture 1 is not limited to a rectangle, and may be a square box shape.

Further, in Embodiment 1, the first to fifth power supply devices 31a to 31e are provided for each LED, but the present invention is not limited to this. For example, the white LED 181 and the blue LED 182 of the blue LED module 18 may share a power supply. As a result, the number of parts can be further reduced, and cost reduction and downsizing of the lighting fixture 1 can be realized.

Further, in Embodiment 1, the control circuit for the white LED 181 and the blue LED 182 is shared, and the same dimming signal is used for dimming, but the present invention is not limited to this. The white LED 181 and the blue LED 182 may each have separate control circuits and be controlled by separate dimming signals.

Furthermore, the structure for holding blue LED module 18 is not limited to the structure described in the first embodiment. Moreover, in the lighting device 1, the white LED module 14 may be omitted and only the blue LED module 18 may be provided as a light source.

1 lighting fixture, 10 light source unit, 11 flange, 13 diffusion cover, 13-1 light-emitting surface, 13-2 non-light-emitting surface, 14 white LED module, 15 module holder, 15-1 mounting flange, 16 lower guide plate , 16-3 protrusion, 17 light guide plate, 17-1 end surface, 17-2 end surface, 18 blue LED module, 18-1 through hole, 19 upper guide plate, 21 packing, 22 packing, 23 insulating section, 24 module holding portion, 25 fixing member, 25-1 protrusion, 26 light guide plate cover, 27 upper cover, 31 power supply device, 31a first power supply device, 31b second power supply device, 31c third power supply device, 31d fourth power supply device, 31e fifth power supply device, 32 dimming unit, 32a first control circuit, 32b second control circuit, 32c third control circuit, 32d fourth control circuit, 33 air gap, 50 instrument main body, 51 main surface, 51-1 volt hole, 51-2 wire hole, 52 side surface, 53 mounting bracket, 54 terminal block, 61 nut, 140 substrate, 141 white LED, 142 white LED, 180 substrate, 181 white LED, 182 blue LED, 183 green LED, B suspension Lower bolt, C ceiling, H recessed hole.

Claims (6)

a blue LED module having a blue LED, a white LED, and a green LED;
a light guide plate that diffuses the light from the blue LED module and emits surface light;
a dimming unit that dims the blue LED module to reproduce the color of the sky;
a white LED module that emits white light;
a diffusion plate that emits light from the white LED module in at least two directions,
A dominant wavelength of the blue LED is 470 nm or less,
The diffusion plate is arranged around the light guide plate
lighting equipment. The lighting fixture according to claim 1, wherein the dominant wavelength of the blue LED is 400 nm or more. The lighting fixture according to claim 1 or 2, wherein the dominant wavelength of the blue LED is between 440nm and 460nm. The lighting fixture according to any one of claims 1 to 3, wherein the dimming unit dims the blue LED module according to time. The lighting fixture according to any one of claims 1 to 4, wherein the dimming unit dims the blue LED module according to the season. The white LED module has two types of white LEDs with different color temperatures,
The diffusion plate emits the light of the white LED module from three directions.
A luminaire according to any one of claims 1 to 5.

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