Lighting device and correction method

Abstract

To suppress variation in color temperature of a lighting device having a plurality of light-emitting elements with different color temperatures.SOLUTION: A lighting device includes a first light-emitting element and a second light-emitting element that emit light at different color temperatures, a power supply circuit that supplies lighting power individually to the first light-emitting element and the second light-emitting element, and a control unit that controls the lighting power supplied to the first light-emitting element and the second light-emitting element on the basis of a correction value set in accordance with the variation in color temperature of the first light-emitting element and the second light-emitting element.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to an illumination device having a plurality of light-emitting elements with different color temperatures, and a correction method for the illumination device. [Background technology]

[0002] Conventionally, lighting devices capable of adjusting the amount and color of emitted light are known. For example, Patent Document 1 discloses that in a lighting fixture having multiple light sources with different light colors, the amount of light from each of the multiple light sources is adjusted to obtain a desired illumination light. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-170445 A Summary of the Invention [Problem to be solved by the invention]

[0004] As described in Patent Document 1, when a composite light of a desired light color is irradiated by a plurality of types of light sources with different light colors, the power supplied to each light source is adjusted. For example, in the case of a lighting device having a first light-emitting element with a correlated color temperature of 5000K and a second light-emitting element with a correlated color temperature of 3000K, a composite light with a correlated color temperature of 4000K, which is an intermediate color, can be generated by adjusting the ratio of the power supplied to the first light-emitting element and the second light-emitting element. However, there are variations in color temperature and luminous flux even among the same type of light-emitting element, and the variation in color temperature and luminous flux of the composite light is within a range in which the variations in color temperature and luminous flux of the first light-emitting element and the second light-emitting element are added together. As a result, even when the ratio of the power supplied to the first light-emitting element and the second light-emitting element is adjusted to be the same in a plurality of lighting devices and turned on, the color temperature differs depending on the lighting device, causing a sense of discomfort to the user.

[0005] The present disclosure is devised to solve the above-mentioned problems, and has an object to suppress variation in color temperature in an illumination device having a plurality of light-emitting elements with different color temperatures. [Means for solving the problem]

[0006] The lighting device according to the present disclosure includes a first light-emitting element and a second light-emitting element that emit light at different color temperatures, a power supply circuit that supplies lighting power individually to the first light-emitting element and the second light-emitting element, and a control unit that controls the lighting power supplied to the first light-emitting element and the second light-emitting element based on a correction value set in accordance with the variation in color temperature of the first light-emitting element and the second light-emitting element.

[0007] The correction method according to the present disclosure is a correction method for a lighting device including a first light-emitting element and a second light-emitting element that emit light at different color temperatures, and includes the steps of turning on only the first light-emitting element and specifying the chromaticity coordinates of the first light-emitting element, turning on only the second light-emitting element and specifying the chromaticity coordinates of the second light-emitting element, specifying pre-correction chromaticity coordinates, which are the chromaticity coordinates of a composite light of the first light-emitting element and the second light-emitting element, and determining a correction value based on the chromaticity coordinates of the first light-emitting element, the chromaticity coordinates of the second light-emitting element, the pre-correction chromaticity coordinates, and the isocolor temperature lines of the target composite light. Effect of the Invention

[0008] According to the lighting device and correction method disclosed herein, the variation in color temperature of the lighting device can be suppressed by controlling the lighting power supplied to each light-emitting element based on a correction value set in accordance with the variation in color temperature of multiple light-emitting elements having different color temperatures. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a lighting device according to a first embodiment. [Diagram 2] 1 is an exploded perspective view of a lighting device according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view of a lamp of the lighting device according to the first embodiment. [Figure 4] 2 is a diagram illustrating the configuration of a light source unit and a power supply unit of the illumination device according to the first embodiment. FIG. [Diagram 5] 5 is a chromaticity diagram illustrating the variation in color temperature of the lighting device according to the first embodiment. FIG. [Figure 6] 5 is a flowchart showing a flow of a correction value acquisition process in the first embodiment. [Figure 7] FIG. 4 is a chromaticity diagram illustrating the correction value acquisition process according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the lighting device according to the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are used to denote the same or equivalent parts, and this is common throughout the entire specification. Note that in each drawing, the relative dimensional relationship or shape of each component may differ from the actual one.

[0011] Embodiment 1 Fig. 1 is a perspective view of the lighting device 100 according to the first embodiment. Fig. 2 is an exploded perspective view of the lighting device 100 according to the first embodiment. Fig. 3 is a perspective view of a luminaire 101 of the lighting device 100 according to the first embodiment. Note that Figs. 1 and 2 are views of the lighting device 100 as viewed from below, and Fig. 3 is a view of the luminaire 101 of the lighting device 100 as viewed from above.

[0012] 1, the lighting device 100 of the present embodiment is long and attached to a ceiling, a wall, or the like to irradiate light into an illumination space such as an indoor space. The lighting device 100 includes a long luminaire 101 that irradiates light into the illumination space, and a long fixture 102 that is attached and fixed to the ceiling, a wall, or the like.

[0013] As shown in Figures 1 to 3, the lighting fixture 101 has a light source unit 1, a base unit 2, a power supply unit 3, a connector 4, and a cover 5. As shown in Figures 1 and 2, the fixture 102 has a fixture body 6, a terminal block 7, and a holder 8. The lighting fixture 101 is attached to the fixture 102 in a detachable manner.

[0014] First, the configuration of the lighting fixture 101 will be described with reference to Figs. 1 to 3. As shown in Figs. 1 and 2, the light source unit 1 includes a plurality of light-emitting elements 13. Although some of the light-emitting elements 13 are omitted in Figs. 1 and 2, the light-emitting elements 13 are actually mounted continuously along the longitudinal direction of the lighting fixture 101. The plurality of light-emitting elements 13 include a plurality of first light-emitting elements 13a and a plurality of second light-emitting elements 13b (Fig. 4), which will be described later.

[0015] The base 2 is a long, flat plate extending along the longitudinal direction of the lamp 101, and the light source unit 1 is provided on the underside of the base 2, which is the irradiating side. As shown in Fig. 3, the power supply unit 3 and the connector 4 are provided on the upper surface of the base 2. The base 2 is made of sheet metal, and has a heat dissipation function for dissipating the operating heat of the light source unit 1 or the power supply unit 3. Note that the base 2 may be made partially or entirely of synthetic resin or ceramic other than metal, as long as it has a heat dissipation function.

[0016] The power supply unit 3 has a function as a power supply that supplies the power supplied from the terminal block 7 to the light emitting element 13, and a function of controlling the lighting power supplied to the light emitting element 13. Note that the power supply unit 3 does not need to be configured as a part of the lighting fixture 101, and may be configured as a part of the appliance 102.

[0017] The connector 4 is a member that engages with the holder 8 provided on the fixture 102 and attaches the luminaire 101 to the fixture 102. The connector 4 is, for example, plate-shaped, and has an opening through which the holder 8 is inserted. The connectors 4 are provided at positions corresponding to the holders 8, at both ends in the longitudinal direction of the base 2. The positions and number of the connectors 4 are not limited to the example in FIG. 3, and are appropriately determined according to the shape and size of the lighting device 100. The structure of the connector 4 is not limited to the example in FIG. 3, and may be other structures as long as it can hold the holder 8. The connector 4 may be provided on the fixture 102, and the holder 8 may be provided on the luminaire 101.

[0018] The cover 5 is made of a light-transmitting material and is a member that covers the periphery of the light-emitting element 13 of the light source unit 1. Light emitted from the light-emitting element 13 is irradiated into the illumination space through the cover 5. The light-transmitting material is, for example, a synthetic resin such as polycarbonate, acrylic, or polypropylene. The cover 5 is formed by injection molding, extrusion molding, three-dimensional additive manufacturing, or the like, depending on the material used. The cover 5 is attached to the base unit 2 by an attachment portion (not shown) provided along the longitudinal direction.

[0019] Next, the configuration of the device 102 will be described with reference to Figures 1 and 2. The device 102 is, as an example, a so-called V-type direct-mount device. The device 102 is not limited to the direct-mount device shown in the figures, and may be in other forms. As described above, the device 102 has a device main body 6, a terminal block 7, and a holder 8. The device main body 6 has a main body portion 60 extending along the longitudinal direction, and end plate portions 61 attached to both ends of the main body portion 60.

[0020] The main body 60 is formed by bending a metal sheet so that the cross section in the short side direction has a concave shape, and the lighting fixture 101 is attached inside the concave shape. The bottom surface of the main body 60 is formed with a plurality of mounting holes through which suspension bolts or screws or the like for mounting the fixture 102 to a ceiling can be passed. The fixture 102 is attached by joining it to the ceiling with the suspension bolts or screws or the like. In addition, the bottom surface of the main body 60 is formed with wire passing holes through which external electric wires can be passed inside the lighting device 100. The external electric wires are connected to the terminal block 7 inside the main body 60.

[0021] The end plate portion 61 is attached to both ends in the longitudinal direction of the main body portion 60 so as to close both end faces in the longitudinal direction of the main body portion 60. Note that the end plate portion 61 may be provided with a knockout that can be opened to pass a power cable through when multiple lighting devices 100 are connected and installed in the longitudinal direction.

[0022] A terminal block 7 and a holder 8 are provided inside the recess formed by the bottom and side surfaces of the main body 60. The terminal block 7 is fixed to the bottom surface of the main body 60. The terminal block 7 is connected to fixed wiring (not shown) provided in a building or the like to receive power from a commercial power source and to relay control communications. The terminal block 7 is connected to the power supply unit 3 via an electric wire having a connector at one end.

[0023] The holder 8 is provided to engage with the connector 4 to attach the lighting device 101 to the fixture 102. The holder 8 is made of an elastic material such as stainless steel, and is a leaf spring formed by bending a strip-shaped plate material. The base end of the holder 8 is attached to the bottom surface of the main body 60. In the example of FIG. 3, the holders 8 are provided at positions corresponding to the connector 4, one at each end in the longitudinal direction of the main body 60. Note that the positions and number of the holders 8 are not limited to those in the example of FIG. 3, and are determined appropriately depending on the shape and size of the lighting device 100.

[0024] The holder 8 is not limited to a plate-shaped elastic member, and may be an elastic member other than a plate spring, such as a wire spring, as long as it can hold the lamp 101. Furthermore, the lamp 101 may be attached to the fixture 102 using a fastener such as a screw or a rivet, without using the holder 8 and the connector 4.

[0025] Fig. 4 is a diagram illustrating the configuration of the light source unit 1 and the power supply unit 3 of the lighting device 100 according to the first embodiment. As shown in Fig. 4, the light source unit 1 includes a first light source circuit 11 having a plurality of first light-emitting elements 13a, a second light source circuit 12 having a plurality of second light-emitting elements 13b, and a substrate 14 on which the first light source circuit 11 and the second light source circuit 12 are mounted. Note that the number of the first light-emitting elements 13a and the second light-emitting elements 13b is not limited to a plurality, and may be one or more.

[0026] The first light emitting element 13a and the second light emitting element 13b are LEDs of a bullet type, a surface mount type (SMD type), or a chip on board type (COB type), or the first light emitting element 13a and the second light emitting element 13b may be a laser light source or an organic EL light source.

[0027] The first light-emitting element 13a emits white light with a correlated color temperature of 5000K. The color temperature variation range of the first light-emitting element 13a exceeds one step of a MacAdam ellipse including a 5000K isochromatic temperature line, for example, a range equivalent to three steps. The second light-emitting element 13b emits white light with a correlated color temperature of 3000K. The color temperature variation range of the second light-emitting element 13b exceeds one step of a MacAdam ellipse including a 3000K isochromatic temperature line, for example, a range equivalent to three steps.

[0028] The specifications of the first light-emitting element 13a and the second light-emitting element 13b are not limited to the above and can be appropriately selected according to the specifications of the lighting device 100. For example, the color temperatures of the first light-emitting element 13a and the second light-emitting element 13b are not limited to the above example and, for example, the correlated color temperature of the first light-emitting element 13a may be 6500K and the correlated color temperature of the second light-emitting element 13b may be 2700K.

[0029] A conductive circuit pattern that serves as a path for supplying lighting power to the first light-emitting element 13a and the second light-emitting element 13b individually is formed on the substrate 14. When the first light-emitting element 13a and the second light-emitting element 13b are of a surface mount type (SMD type), the first light source circuit 11 and the second light source circuit 12 are configured by fixing them on the substrate 14 by a reflow soldering process.

[0030] In FIG. 4, for the sake of explanation, the first light-emitting elements 13a and the second light-emitting elements 13b are arranged in a line, but in reality, the first light-emitting elements 13a and the second light-emitting elements 13b are arranged so that they are alternately arranged one by one. Alternatively, two or more first light-emitting elements 13a and two or more second light-emitting elements 13b may be arranged in a set and arranged in an alternating manner. However, the more the number of light-emitting elements of the same type that constitute a set, the more noticeable the visual chromaticity difference between adjacent sets of different light-emitting elements becomes. Therefore, the visual chromaticity difference is less noticeable when the first light-emitting elements 13a and the second light-emitting elements 13b with different color temperatures are arranged in an alternating manner one by one.

[0031] The number of columns or rows when mounting the first light emitting element 13a and the second light emitting element 13b is determined by the dimensions and shapes of the substrate 14 or the first light emitting element 13a and the second light emitting element 13b. The first light emitting element 13a and the second light emitting element 13b may be mounted in one row or in multiple rows. The number of columns or rows when mounting the first light emitting element 13a and the second light emitting element 13b is also determined by the configuration of the first light source circuit 11 and the second light source circuit 12, that is, the number of parallel and series of the first light emitting element 13a and the second light emitting element 13b. In addition, the power consumed by the first light source circuit 11 and the second light source circuit 12 is also determined by the configuration of the first light source circuit 11 and the second light source circuit 12.

[0032] The substrate 14 is a rigid substrate, a flexible substrate, or a rigid-flexible substrate. The flame retardancy of the substrate 14 can be appropriately selected in consideration of product specifications, economic efficiency, and the like, but general-purpose products such as FR-1 to FR-5, CEM1, and CEM3 (NEMA / ANSI standard) are preferred. Specifically, the substrate 14 is a paper phenol substrate, a paper epoxy substrate, a glass epoxy substrate, a composite substrate epoxy substrate, or a glass composite substrate. The substrate 14 may also be a metal-based substrate (metal core substrate). The shape of the substrate 14 is not particularly limited, and can be selected from various shapes such as a rectangular shape, a square shape, a polygonal shape, a perfect circle shape, and an elliptical shape according to the specifications of the lighting device 100.

[0033] As shown in FIG. 4, the power supply unit 3 includes a control unit 31 and a power supply circuit 32. The control unit 31 is configured with hardware such as a dedicated single circuit or composite circuit, a microcomputer or processor and memory that executes a program, or a combination of these. The control unit 31 receives a control command from the outside, and transmits an output command to the power supply circuit 32 to control the lighting power supplied to the first light source circuit 11 and the second light source circuit 12 based on the received control command. The control command is transmitted to the control unit 31 by wired or wireless communication from a dedicated controller of the lighting device 100 or a user's smartphone, etc., using various methods such as a PWM control method or a DALI (registered trademark) method.

[0034] The control command controls at least one of "color adjustment" which changes the color temperature range and "dimming" which changes the brightness. Dimming can be adjusted from 0% output, which is the off state, to 100% output. Color adjustment is determined by the type of light-emitting element installed. For example, in the case of a lighting device 100 having a first light-emitting element 13a of 5000K and a second light-emitting element 13b of 3000K as in this embodiment, the correlated color temperature range can be adjusted from 5000K to 3000K.

[0035] The power supply circuit 32 converts external power supplied from a power supply 200 external to the lighting device 100, such as a commercial AC power supply or a DC power supply, into lighting power for lighting the first light-emitting element 13a and the second light-emitting element 13b. The power supply circuit 32 has a first connector 321 connected to the first light source circuit 11 and a second connector 322 connected to the second light source circuit 12. The power supply circuit 32 supplies lighting power to the first light source circuit 11 and the second light source circuit 12 individually from the first connector 321 and the second connector 322. The ratio of the lighting power supplied to the first light source circuit 11 and the second light source circuit 12, i.e., the ratio of the current flowing through the first light-emitting element 13a and the second light-emitting element 13b, is determined based on an output command from the control unit 31.

[0036] Next, suppression of color temperature variation in the lighting device 100 will be described. Fig. 5 is a chromaticity diagram illustrating variation in color temperature of the lighting device 100 according to embodiment 1. The dashed-dotted line in Fig. 5 indicates a color temperature isoline of 5000K, which is the color temperature of the first light-emitting element 13a. The dashed-two-dotted line in Fig. 5 indicates a color temperature isoline of 3000K, which is the color temperature of the second light-emitting element 13b. The solid line in Fig. 5 indicates a color temperature isoline of 4000K, which is an example of a target value of the combined light of the first light-emitting element 13a and the second light-emitting element 13b.

[0037] Moreover, the dashed-dotted ellipse in Fig. 5 is the variation range R1 of the first light-emitting element 13a, which is, for example, a range equivalent to three steps of a MacAdam ellipse. The two-dot-dotted ellipse in Fig. 5 is the variation range R2 of the second light-emitting element 13b, which is, for example, a range equivalent to three steps of a MacAdam ellipse. The solid-line ellipse in Fig. 5 is the target variation range Rt of the combined light of the first light-emitting element 13a and the second light-emitting element 13b, which is, for example, a range equivalent to three steps of a MacAdam ellipse. Note that the target variation range Rt of the combined light of the first light-emitting element 13a and the second light-emitting element 13b may be a range equal to or smaller than three steps of a MacAdam ellipse.

[0038] Generally, the color temperature of each of the light-emitting elements such as the first light-emitting element 13a and the second light-emitting element 13b is determined as a part specification, but the color temperature also varies due to manufacturing variations in the manufacturing process. This variation usually shows a normal distribution, and not all light-emitting elements are located at the center of the color temperature determined as the part specification. Therefore, light-emitting elements purchased (produced) at different times may have different color temperatures even if they have the same part specifications. If they are used as light sources for the same lighting device, the apparent color tone may differ between adjacent light-emitting elements mounted on a board, leading to a visual discomfort.

[0039] Usually, chromaticity is defined as chromaticity coordinates in the xy coordinate notation on the CIE chromaticity diagram. Also, on the chromaticity diagram, iso-color temperature lines are defined for each color temperature equivalent to white (6500K daylight color to 2700K incandescent color) centered on the blackbody locus. Then, an ellipse is drawn to define the extent of the variation range from the central coordinate of each color, and is expressed as a MacAdam ellipse step. Usually, if the variation is within the range of three MacAdam ellipse steps as described above, it is difficult to notice visually and does not feel strange even if there is variation. Note that it is possible to further narrow the variation range beyond the three MacAdam ellipse steps by using a more accurate light-emitting element group or by using a combination of chromaticity coordinates.

[0040] When emitting a composite light of a plurality of light-emitting elements with different color temperatures as in the lighting device 100 of the present embodiment, even if the variation range of each light-emitting element is within 3 steps, the variation range of the composite light is expanded by using two types of light-emitting elements in combination. For example, the variation range of the composite light of the first light-emitting element 13a and the second light-emitting element 13b is the variation range R3 shown by the dashed ellipse in Fig. 5, which is a color matching range equivalent to, for example, a MacAdam ellipse of 5.8 steps.

[0041] The variation in the first light-emitting element 13a and the second light-emitting element 13b is due to the variation in color and luminous flux of each light-emitting element group, and the output variation of the power supply circuit 32 that supplies lighting power to each light-emitting element group. One method for suppressing this variation is to limit the range of color variation and luminous flux variation of the light-emitting elements delivered by the manufacturer, and to selectively mount them. However, in this case, there are problems such as an increase in the purchase cost of the light-emitting elements, an increase in the amount of adjustment work required in the manufacturing process when mounting in layers, and a possibility of incorrect mounting by personnel. In addition, in order to suppress the output variation of the power supply circuit 32, it is necessary to use high-precision parts.

[0042] Therefore, in the lighting device 100 of the present embodiment, the variation in color temperature of the combined light of the first light-emitting element 13a and the second light-emitting element 13b is suppressed by correcting the ratio of the lighting power supplied to each light-emitting element from the power supply circuit 32. The correction value used when correcting the ratio of the lighting power is determined in accordance with the actual variation of the first light-emitting element 13a and the second light-emitting element 13b during the manufacture of the lighting device 100.

[0043] 6 is a flowchart showing the flow of the correction value acquisition process in the first embodiment. This process is performed by a calculation computer and each measuring device at the stage when the light source unit 1 or the lighting device 100 is completed during the manufacture of the lighting device 100. First, all the first light-emitting elements 13a included in the first light source circuit 11 are turned on, and the luminous flux of the first light-emitting elements 13a is measured (S1). Here, only the first light-emitting elements 13a are turned on, and the second light-emitting elements 13b are not turned on. Then, the color temperature of the first light-emitting elements 13a is measured, and the chromaticity coordinates are identified (S2).

[0044] Next, all the second light-emitting elements 13b included in the second light source circuit 12 are turned on, and the luminous flux of the second light-emitting elements 13b is measured (S3). Here, only the second light-emitting elements 13b are turned on, and the first light-emitting elements 13a are not turned on. Then, the color temperature of the second light-emitting elements 13b is measured, and the chromaticity coordinates are identified (S4).

[0045] Then, the chromaticity coordinates of the combined light are calculated from the identified chromaticity coordinates of the first light-emitting element 13a and the second light-emitting element 13b (S5). Here, the chromaticity coordinates are calculated when the ratio of the lighting power supplied to the first light source circuit 11 and the second light source circuit 12 is 50%:50%, that is, the chromaticity coordinates of the combined light near 4000K before correction. The chromaticity coordinates of the combined light calculated here are referred to as "pre-correction chromaticity coordinates."

[0046] Then, the coordinates of the intersection between the line connecting the chromaticity coordinates of the first light-emitting element 13a and the chromaticity coordinates of the second light-emitting element 13b and the 4000K isochromaticity line, which is the color temperature of the target color of the composite light, are calculated (S6). Then, the difference between the uncorrected chromaticity coordinates and the intersection coordinates is calculated (S7). Then, a correction value corresponding to the calculated difference is set and stored in the memory of the control unit 31 (S8).

[0047] The correction value is, for example, a coefficient α (0<α<2) by which the basic ratio of the lighting power supplied to the first light source circuit 11 is multiplied. The correction value is obtained by the following procedure. First, a ratio (D1 / D2) of the distance (difference) D1 between the pre-correction chromaticity coordinates (x3, y3) and the intersection coordinates (xt, yt) to the distance (difference) D2 between the chromaticity coordinates (x1, y1) of the first light-emitting element 13a and the chromaticity coordinates (x2, y2) of the second light-emitting element 13b is obtained. Then, the target luminous fluxes of the first light-emitting element 13a and the second light-emitting element 13b are obtained from the obtained ratio. Then, the target current values ​​of the first light-emitting element 13a and the second light-emitting element 13b for obtaining each target luminous flux are obtained, and the ratio of the target current value to the current value during the measurement in steps S1 to S4 is set as the correction value. Note that in steps S1 to S4, each light-emitting element may be turned on under the same condition or different conditions. When turning on the elements under different conditions, the conditions may be reflected in the calculation of the correction value.

[0048] FIG. 7 is a chromaticity diagram for explaining the correction value acquisition process in the first embodiment. In FIG. 7, the chromaticity coordinates (x1, y1) of the first light-emitting element 13a, the chromaticity coordinates (x2, y2) of the second light-emitting element 13b, and the pre-correction chromaticity coordinates (x3, y3) identified in the correction value acquisition process are indicated by black circles. Then, as shown in FIG. 7, the intersection coordinates (xt, yt) between the line L connecting the chromaticity coordinates (x1, y1) of the first light-emitting element 13a and the chromaticity coordinates (x2, y2) of the second light-emitting element 13b and the iso-color temperature line of 4000K, which is the color temperature of the composite light, are calculated. Then, the difference between the pre-correction chromaticity coordinates (x3, y3) and the intersection coordinates (xt, yt) is calculated, and a correction value that eliminates this difference is obtained. This makes it possible to obtain a correction value according to the actual variation of the first light-emitting element 13a and the second light-emitting element 13b.

[0049] When the control unit 31 receives a control command while the lighting device 100 is in use, the control unit 31 corrects the control command based on the correction value stored in the memory and transmits an output command to the power supply circuit 32. The output command by the control unit 31 will be described. First, when the color adjustment in the control command is 5000K, the control unit 31 transmits an output command to the power supply circuit 32 with the ratio of the lighting power supplied to the first light source circuit 11 and the second light source circuit 12 set to 100%:0%. When the color adjustment in the control command is 3000K, the control unit 31 transmits an output command to the power supply circuit 32 with the ratio of the lighting power supplied to the first light source circuit 11 and the second light source circuit 12 set to 0%:100%.

[0050] In addition, when the color adjustment in the control command is other than 5000K and 3000K, the control unit 31 corrects the basic ratio of the lighting power supplied to the first light source circuit 11 and the second light source circuit 12 with a correction value, sets it as an output command, and transmits it to the power supply circuit 32. For example, when the color adjustment in the control command is 4000K, the control unit 31 corrects the basic ratio of 50% to 50% in the case of 4000K with a correction value, and transmits an output command of, for example, 53% to 47% to the power supply circuit 32. In detail, the control unit 31 multiplies the basic ratio of 50% of the lighting power supplied to the first light source circuit 11 by a correction value (for example, 1.06) to obtain the corrected ratio, and multiplies the basic ratio of 50% of the lighting power supplied to the second light source circuit 12 by a correction value (for example, 0.94) to obtain the corrected ratio. As a result, even if there is variation between the first light-emitting element 13a and the second light-emitting element 13b, the lighting device 100 can irradiate light with a color temperature of 4000K, which is the target color. The corrected ratio of the lighting power supplied to the second light source circuit 12 may be calculated by subtracting the corrected ratio of the lighting power supplied to the first light source circuit 11 from 100%. In this case, the total ratio is 100%, and the power before and after the correction is unchanged.

[0051] As described above, in the present embodiment, the variation in color temperature of a plurality of light-emitting elements having different color temperatures is actually measured for each lighting device 100, and a correction value for suppressing the variation in color temperature of the combined light is obtained. Then, the obtained correction value is used to adjust the output of the power supply unit 3, thereby making it possible to suppress the variation in color temperature when the combined light of the lighting device 100 is emitted. This makes it possible to suppress the sense of discomfort felt by the user even when a plurality of lighting devices 100 are installed next to each other.

[0052] In addition, according to the present embodiment, it is not necessary to make the selection criteria (allowable variation) of the light-emitting elements more strict than necessary, and it is also not necessary to reselect light-emitting elements with similar color temperature distributions and arrange them in layers, so that it is possible to suppress an increase in costs. In addition, it is possible to suppress the number of light-emitting elements that are not used, and it is possible to expect effects such as reduction in disposal losses and reduction in environmental load.

[0053] The above is a description of the embodiment, but the present disclosure is not limited to the above embodiment and can be modified in various ways without departing from the spirit of the present disclosure. For example, the configuration and use of the lighting device 100 are not limited to those of the first embodiment, and various configurations and uses may be used, such as facility lighting, general household lighting, or store lighting. In addition, the installation environment of the lighting device 100 is not particularly limited, and the lighting device 100 may be for indoor use, outdoor use, or special use (such as salt-resistant type, high-temperature type, or low-temperature type).

[0054] Furthermore, the lighting device 100 may be such that the above-mentioned lamp 101 and the fixture 102 are separable, and the lamp 101 and the fixture 102 can be sold separately. Alternatively, the combination of the lamp 101 and the fixture 102 may be changeable according to the customer's desire. Alternatively, the lamp 101 and the fixture 102 may be an inseparable integrated unit. Furthermore, the shape of the lighting device 100 is not limited to the example of the above embodiment, and may be a shape other than elongated (such as a square or a circle).

[0055] Furthermore, the lighting device 100 may be one in which a plurality of luminaires 101 are attached to the fixture 102 .

[0056] Furthermore, the lighting device 100 may include three or more types of light-emitting elements with different color temperatures. In this case, the chromaticity coordinates of the three or more types of light-emitting elements are actually measured to obtain correction values, and the ratio of the lighting power supplied to the three or more types of light-emitting elements is adjusted according to the correction values, thereby suppressing the variation in the composite light. Furthermore, in the above embodiment, the target color temperature of the composite light is set to an intermediate color of 4000K, but a correction value may be obtained for each target color temperature during manufacturing, and the ratio of the lighting power to each light-emitting element may be adjusted using the correction value according to the target color temperature.

[0057] 6, the order of the processes from step S1 to step S4 may be changed. Instead of step S5, all the first light-emitting elements 13a included in the first light source circuit 11 and all the second light-emitting elements 13b included in the second light source circuit 12 may be turned on to identify the chromaticity coordinates of the composite light, which may be set as the pre-correction chromaticity coordinates. The order of the processes in steps S5 and S6 may be changed.

[0058] 6, the chromaticity coordinates before correction (chromaticity coordinates of the composite light) in step S5 may be calculated from the measured luminous flux of the first light-emitting element 13a and the identified chromaticity coordinates of the first light-emitting element 13a, and the measured luminous flux of the second light-emitting element 13b and the identified chromaticity coordinates of the second light-emitting element 13b. In this case, it is preferable that the range of variation in brightness when the first light-emitting element 13a and the second light-emitting element 13b are individually caused to emit light is within ±20% of the reference brightness determined as the component specifications of each element.

[0059] 6, the process of steps S1 and S3 is exemplified as a method of measuring luminous flux as a method of measuring brightness, but it may be a method of measuring illuminance, luminance, luminous intensity, etc. In the above correction value acquisition method, the correction value is calculated based on the target luminous flux of the first light-emitting element 13a and the second light-emitting element 13b, but illuminance, luminance, or luminous intensity may be used as the target brightness of the first light-emitting element 13a and the second light-emitting element 13b.

[0060] Various aspects of the present disclosure are summarized below as appendices.

[0061] (Appendix 1) A first light emitting element and a second light emitting element each emitting light at a different color temperature; a power supply circuit that supplies lighting power to the first light emitting element and the second light emitting element individually; a control unit that controls the lighting power supplied to the first light emitting element and the second light emitting element based on a correction value set according to a variation in color temperature of the first light emitting element and the second light emitting element; A lighting device comprising: (Appendix 2) The lighting device according to claim 1, wherein the color temperature variation range of the first light-emitting element and the second light-emitting element exceeds one step of a MacAdam ellipse. (Appendix 3) 3. The lighting device according to claim 1, wherein a variation range of color temperature of the combined light of the first light-emitting element and the second light-emitting element is within a range of 3 steps of a MacAdam ellipse or less. (Appendix 4) 4. The lighting device according to claim 1, wherein the correction value is obtained from a variation range of color temperatures of the first light emitting element and the second light emitting element. (Appendix 5) The lighting device according to any one of appendix 1 to 3, wherein the correction value is obtained from a range of variation in color temperature of the first light-emitting element and the second light-emitting element, and a range of variation in brightness when the first light-emitting element and the second light-emitting element are caused to emit light individually. (Appendix 6) The lighting device according to claim 5, wherein the range of variation in brightness when the first light-emitting element and the second light-emitting element are caused to emit light individually is within ±20% of the respective reference brightness. (Appendix 7) The lighting device according to any one of claims 1 to 6, wherein the control unit corrects a ratio between the lighting power supplied to the first light-emitting element and the lighting power supplied to the second light-emitting element using the correction value. [Explanation of symbols]

[0062] 1 light source unit, 2 base unit, 3 power supply unit, 4 connector, 5 cover, 6 fixture body, 7 terminal block, 8 holder, 11 first light source circuit, 12 second light source circuit, 13 light-emitting element, 13a first light-emitting element, 13b second light-emitting element, 14 board, 31 control unit, 32 power supply circuit, 60 main body unit, 61 end plate unit, 100 lighting device, 101 luminaire, 102 fixture, 200 power supply, 321 first connector, 322 second connector.

Claims

1. a first light-emitting element and a second light-emitting element that emit light at different color temperatures; a power supply circuit that supplies lighting power to the first light emitting element and the second light emitting element individually; a control unit that controls the lighting power supplied to the first light-emitting element and the second light-emitting element based on a correction value set in accordance with a variation in color temperature of the first light-emitting element and the second light-emitting element; A lighting device comprising:

2. The lighting device according to claim 1 , wherein a variation range of the color temperature of the combined light of the first light emitting element and the second light emitting element is a range of 3 steps of a MacAdam ellipse or less.

3. The lighting device according to claim 1 , wherein the correction value is obtained from a variation range of color temperatures of the first light-emitting element and the second light-emitting element.

4. 3. The lighting device according to claim 1, wherein the correction value is obtained from a range of variation in color temperature of the first light-emitting element and the second light-emitting element, and a range of variation in brightness when the first light-emitting element and the second light-emitting element are caused to emit light individually.

5. 3 . The lighting device according to claim 1 , wherein the control unit corrects a ratio between the lighting power supplied to the first light-emitting element and the lighting power supplied to the second light-emitting element using the correction value.

6. 1. A method for correcting an illumination device including a first light-emitting element and a second light-emitting element that emit light at different color temperatures, the method comprising: turning on only the first light-emitting element and identifying the chromaticity coordinates of the first light-emitting element; turning on only the second light-emitting element and determining the chromaticity coordinates of the second light-emitting element; specifying pre-correction chromaticity coordinates that are chromaticity coordinates of combined light of the first light-emitting element and the second light-emitting element; and calculating a correction value based on the chromaticity coordinates of the first light-emitting element, the chromaticity coordinates of the second light-emitting element, the pre-correction chromaticity coordinates, and a target isocolor temperature line of the combined light.

7. The step of determining the correction value includes: determining an intersection between a straight line connecting the chromaticity coordinates of the first light-emitting element and the chromaticity coordinates of the second light-emitting element and the isocolor temperature line of the combined light; 7. The correction method according to claim 6, further comprising the step of determining a correction value for the chromaticity coordinates in accordance with a difference between the intersection and the uncorrected chromaticity coordinates.

8. The step of specifying the pre-correction chromaticity coordinates includes:

8. The correction method according to claim 6, further comprising the step of calculating chromaticity coordinates of the combined light from the chromaticity coordinates of the first light-emitting element and the chromaticity coordinates of the second light-emitting element, and setting the calculated chromaticity coordinates of the combined light as the pre-correction chromaticity coordinates.

9. The step of specifying the pre-correction chromaticity coordinates includes: The correction method according to claim 6 or claim 7, wherein the correction method is a step of turning on both the first light-emitting element and the second light-emitting element, acquiring the chromaticity coordinates of the combined light, and setting the acquired chromaticity coordinates of the combined light as the pre-correction chromaticity coordinates.

10. 1. A method for correcting an illumination device including a first light-emitting element and a second light-emitting element that emit light at different color temperatures, the method comprising: turning on only the first light-emitting element and identifying the chromaticity coordinates of the first light-emitting element; turning on only the second light-emitting element and determining the chromaticity coordinates of the second light-emitting element; specifying pre-correction chromaticity coordinates that are chromaticity coordinates of combined light of the first light-emitting element and the second light-emitting element; and calculating a correction value based on the brightness of the first light-emitting element and the second light-emitting element in the target combined light, the brightness being calculated based on the chromaticity coordinates of the first light-emitting element, the chromaticity coordinates of the second light-emitting element, and the pre-correction chromaticity coordinates.

11. 1. A method for correcting an illumination device including a first light-emitting element and a second light-emitting element that emit light at different color temperatures, the method comprising: turning on only the first light-emitting element and specifying the brightness and chromaticity coordinates of the first light-emitting element; turning on only the second light-emitting element and specifying the brightness and chromaticity coordinates of the second light-emitting element; specifying pre-correction chromaticity coordinates that are chromaticity coordinates of combined light of the first light-emitting element and the second light-emitting element; determining a correction value based on the brightness and chromaticity coordinates of the first light-emitting element, the brightness and chromaticity coordinates of the second light-emitting element, and the pre-correction chromaticity coordinates.

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