Light source device, lighting device, and lighting system

Abstract

The present disclosure addresses the problem of improving the reproducibility of white and its peripheral emission colors. This light source device is provided with: a first LED that emits light of a first emission color; a second LED that emits light of a second emission color; a third LED that emits light of a third emission color; and a fourth LED that emits light of a fourth emission color. The light source device has a quadrilateral emission color region (S1) having four sides of a first line segment (L1), a second line segment (L2), a third line segment (L3), and a fourth line segment (L4) on an xy chromaticity diagram. The first line segment (L1) is a line segment connecting two chromaticity coordinates (C11, C12). The second line segment (L2) is a line segment connecting two chromaticity coordinates (C12, C13). The third line segment (L3) is a line segment connecting two chromaticity coordinates (C13, C14). The fourth line segment (L4) is a line segment connecting two chromaticity coordinates (C14, C11). The emission color region (S1) includes emission colors that are white and whitish as defined in JIS Z8110, and pale chromatic colors located outside the whitish emission colors.

Description

Light source device, lighting device, and lighting system

[0001] The present disclosure relates to a light source device, a lighting device, and a lighting system, and more particularly to a light source device with variable emission color, a lighting device including the light source device, and a lighting system including the lighting device.

[0002] As a conventional example, an illumination light source (light source device) described in Patent Document 1 is exemplified. The illumination light source described in Patent Document 1 (hereinafter referred to as the conventional example) is configured by mounting four types (four colors) of light-emitting diodes on the surface of a substrate so that they are spaced apart from each other at a central angle of 90° on the same circumference. These four types of light-emitting diodes are a red light-emitting diode, a green light-emitting diode, and two blue light-emitting diodes with different peak emission wavelengths.

[0003] The conventional example aims to achieve high luminous flux and an improved general color rendering index by including two blue light-emitting diodes with different peak emission wavelengths.

[0004] In the field of stage lighting, there is a demand for improved reproducibility of white and its surrounding luminous colors on the xy chromaticity diagram.

[0005] Japanese Patent Application Laid-Open No. 2007-258202

[0006] An object of the present disclosure is to provide a light source device, a lighting device, and a lighting system that can improve the reproducibility of white and surrounding emitted colors.

[0007] A light source device according to one aspect of the present disclosure includes a first light-emitting element that emits light of a first emitted color, a second light-emitting element that emits light of a second emitted color, a third light-emitting element that emits light of a third emitted color, and a fourth light-emitting element that emits light of a fourth emitted color. The chromaticity coordinates of the first emitted color lie in the red or yellow-red region of an xy chromaticity diagram of an XYZ color system. The chromaticity coordinates of the second emitted color lie in the yellow-green or green region of the xy chromaticity diagram. The chromaticity coordinates of the third emitted color lie in the blue-green or blue region of the xy chromaticity diagram. The chromaticity coordinates of the fourth emitted color lie in the blue or blue-purple region of the xy chromaticity diagram. The light source device has a quadrilateral emitted color region on the xy chromaticity diagram, with a first line segment, a second line segment, a third line segment, and a fourth line segment as its four sides. The first line segment is a line segment that connects the chromaticity coordinates of the first emitted color and the chromaticity coordinates of the second emitted color. The second line segment is a line segment connecting the chromaticity coordinates of the second luminous color and the chromaticity coordinates of the third luminous color. The third line segment is a line segment connecting the chromaticity coordinates of the third luminous color and the chromaticity coordinates of the fourth luminous color. The fourth line segment is a line segment connecting the chromaticity coordinates of the fourth luminous color and the chromaticity coordinates of the first luminous color. The luminous color region includes white and white-based luminous colors specified in JIS Z8110, as well as pale chromatic colors outside the white-based luminous colors.

[0008] An illumination device according to one aspect of the present disclosure includes the light source device and a lighting device that turns on the light source device.

[0009] A lighting system according to one aspect of the present disclosure includes the lighting device and a control device that controls the lighting device.

[0010] FIG. 1 is a block diagram of a light source device, an illumination device, and an illumination system according to an embodiment of the present disclosure. FIG. 2 is a side view of the illumination device. FIG. 3 is an exploded perspective view of a light source unit in the illumination device. FIG. 4 is a chromaticity diagram showing an emission color region of a first combination in the light source device. FIG. 5 is another chromaticity diagram showing an emission color region of the first combination in the light source device. FIG. 6 is another chromaticity diagram showing an emission color region of a second combination in the light source device. FIG. 7 is another chromaticity diagram showing an emission color region of the second combination in the light source device. FIG. 8 is a chromaticity diagram showing an emission color region of a third combination in the light source device. FIG. 9 is another chromaticity diagram showing an emission color region of the third combination in the light source device. FIG. 10 is a chromaticity diagram showing an emission color region of a fourth combination in the light source device. FIG. 11 is another chromaticity diagram showing an emission color region of the fourth combination in the light source device. Fig. 12 is a partially abbreviated front view of a first arrangement example of the light source device of the same. Fig. 13 is a partially abbreviated front view of a second arrangement example of the same. Fig. 14 is a partially abbreviated front view of a third arrangement example of the same. Fig. 15 is a side view of a modified example 1 of the same lighting device. Fig. 16 is a side view of a modified example 2 of the same lighting device.

[0011] Hereinafter, light source devices, lighting devices, and lighting systems according to embodiments of the present disclosure will be described in detail with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components do not necessarily reflect the actual dimensional ratios. Note that the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0012] (1) Overview The light source device 1 according to the embodiment includes a first light-emitting element (first LED 11) that emits light of a first emitted color, a second light-emitting element (second LED 12) that emits light of a second emitted color, a third light-emitting element (third LED 13) that emits light of a third emitted color, and a fourth light-emitting element (fourth LED 14) that emits light of a fourth emitted color (see FIG. 1).

[0013] The chromaticity coordinate C11 of the first emitted color lies in the red region RD or the yellow-red region YR in the xy chromaticity diagram of the XYZ color system. The chromaticity coordinate C12 of the second emitted color lies in the yellow-green region YG or the green region GR in the xy chromaticity diagram. The chromaticity coordinate C13 of the third emitted color lies in the blue-green region BG or the blue region BL in the xy chromaticity diagram. The chromaticity coordinate C14 of the fourth emitted color lies in the blue region BL or the blue-purple region PB in the xy chromaticity diagram (see FIGS. 4, 6, 8, and 10). Note that in FIGS. 4, 6, 8, and 10, "PL" represents the purple region, "PR" represents the red-purple region, and "YL" represents the yellow region.

[0014] Furthermore, the light source device 1 according to the embodiment has a quadrilateral luminous color region S1 on an xy chromaticity diagram, with four sides defined by a first line segment L1, a second line segment L2, a third line segment L3, and a fourth line segment L4 (see FIGS. 4, 6, 8, and 10). The first line segment L1 connects the chromaticity coordinate C11 of the first luminous color with the chromaticity coordinate C12 of the second luminous color. The second line segment L2 connects the chromaticity coordinate C12 of the second luminous color with the chromaticity coordinate C13 of the third luminous color. The third line segment L3 connects the chromaticity coordinate C13 of the third luminous color with the chromaticity coordinate C14 of the fourth luminous color. The fourth line segment L4 connects the chromaticity coordinate C14 of the fourth luminous color with the chromaticity coordinate C11 of the first luminous color. The luminous color region S1 includes white and white-based luminous colors as defined in JIS Z8110, as well as light chromatic colors outside the white-based luminous colors. The "light chromatic colors" are nine colors: light pink, light yellow-red, light yellow, light green-yellow, light green, light blue-green, light blue, light blue-purple, and light purple (see Figure 4).

[0015] Thus, the light source device 1 according to the embodiment can emit light of an emission color region S1 that includes white and white-based emission colors and light chromatic colors outside the white-based emission color by mixing one to four of the four colors of light emitted from four types of light-emitting elements (first LED 11, second LED 12, third LED 13, and fourth LED 14). As a result, the light source device 1 according to the embodiment can improve the reproducibility of white and its surrounding emission colors. Note that, since the light source device 1 according to the embodiment can reproduce white and white-based emission colors by mixing up to four emission colors, it can also improve color rendering properties (average color rendering index and specific color rendering index).

[0016] Also, an illumination device 2 according to the embodiment includes the light source device 1 according to the embodiment and a lighting device 20 that turns on the light source device 1 (see FIG. 1 ). Furthermore, an illumination system 9 according to the embodiment includes the illumination device 2 according to the embodiment and a control device 90 that controls the illumination device 2 (see FIG. 1 ).

[0017] Thus, the lighting device 2 and the lighting system 9 according to the embodiment can improve the reproducibility of white and its surrounding emitted colors, similar to the light source device 1 according to the embodiment.

[0018] (2) Details (2-1) Details of the Lighting Device and Lighting System According to the Embodiment The lighting system 9 according to the embodiment (hereinafter abbreviated as lighting system 9) includes a lighting device 2 according to the embodiment (hereinafter abbreviated as lighting device 2) and a control device 90 (see FIG. 1). It is desirable that the lighting system 9 includes a plurality of lighting devices 2. The lighting system 9 is used for purposes such as stage lighting and performance lighting. However, the lighting system 9 may also be used for purposes other than stage lighting and performance lighting.

[0019] The control device 90 is, for example, a stage lighting controller called a dimmer console. The control device 90 has at least two input devices called faders. The operating position of one fader corresponds to the light intensity of the illumination light of the lighting device 2, and the operating position of the other fader corresponds to the light color of the illumination light of the lighting device 2. In other words, the control device 90 generates light intensity instruction values ​​and light color instruction values ​​for each lighting device 2 based on the operating position of the fader operated by an operator, and transmits commands (control signals) including the generated instruction values ​​to each lighting device 2 via a communication cable.

[0020] Each lighting device 2 includes a light source device 1 according to the embodiment (hereinafter, abbreviated as light source device 1) and a lighting device 20 that turns on the light source device 1 (see FIG. 1 ). Each lighting device 2 further includes a control circuit 25 that controls the lighting device 20 and a communication circuit 26 that communicates with the control device 90.

[0021] The lighting device 20 has a first lighting circuit 21, a second lighting circuit 22, a third lighting circuit 23, and a fourth lighting circuit 24. Since the first lighting circuit 21, the second lighting circuit 22, the third lighting circuit 23, and the fourth lighting circuit 24 have the same circuit configuration, the circuit configuration of the first lighting circuit 21 will be described as a representative.

[0022] The first lighting circuit 21 includes a rectifier circuit, a power factor correction circuit, a DC / DC converter, and the like. The rectifier circuit is, for example, a diode bridge and performs full-wave rectification of the AC voltage supplied from the AC power system. The power factor correction circuit is, for example, a step-up chopper circuit and improves the power factor by boosting the pulsating voltage output from the rectifier circuit. The DC / DC converter is, for example, a step-down chopper circuit and reduces the DC voltage output from the power factor correction circuit, supplying a DC current (load current) to the light source device 1 to cause the light source device 1 to emit light (light up). However, the rectifier circuit and the power factor correction circuit may be configured separately from the first lighting circuit 21, the second lighting circuit 22, the third lighting circuit 23, and the fourth lighting circuit 24. In other words, a single set of the rectifier circuit and the power factor correction circuit may supply a DC voltage to the first lighting circuit 21, the second lighting circuit 22, the third lighting circuit 23, and the fourth lighting circuit 24.

[0023] The communication circuit 26 is configured to be able to communicate with the control device 90 via a communication cable. The communication circuit 26 has a function of transmitting and receiving digital control signals (hereinafter referred to as DMX signals) that comply with a communication standard suitable for lighting control, such as DMX (Digital Multiplex) 512A. However, the communication circuit 26 may also have a function of transmitting and receiving control signals that comply with a communication standard other than DMX 512A, such as DALI (Digital Addressable Lighting Interface: registered trademark) or wired LAN standards such as 100BASE-T and 1000BASE-T.

[0024] The control circuit 25 mainly comprises a microcontroller, which executes a lighting control program to control the lighting device 20 in response to commands received from the control device 90 via the communication circuit 26, thereby controlling the blinking, dimming, color adjustment, etc. of the light source device 1.

[0025] 2 and 3, the lighting device 2 includes a light source unit 4 and a control unit 3. The lighting device 2 is a so-called horizon light (lower horizon light) used for purposes (stage lighting, production lighting) such as illuminating a wall surface (horizon surface) that serves as a background in a television studio or stage.

[0026] The control unit 3 has a metal housing 30 and a pair of arms 31. The housing 30 is formed in a box shape and accommodates the lighting device 20, the control circuit 25, the communication circuit 26, and the like.

[0027] Each of the pair of arms 31 is formed in an arc shape from a metal plate. An arc-shaped groove 310 penetrates each of the pair of arms 31 in the thickness direction of the arm 31. The pair of arms 31 are screwed to both ends of the housing 30 in the longitudinal direction by two thumb screws 32, one inserted into each groove 310. The front ends of the pair of arms 31 are fixed to the rear surface of the main body 40 (see FIG. 3 ) of the light source unit 4.

[0028] The light source unit 4 includes a main body 40, two LED modules 41, a lens unit 42, and a diffusion member 43 (see FIG. 3). The two LED modules 41 correspond to the light source device 1 according to the embodiment. In the following description, unless otherwise specified, the front-rear, left-right, and up-down directions indicated by arrows in FIG. 3 are defined as the front-rear, left-right, and up-down directions of the light source unit 4.

[0029] The main body 40 is formed into a long rectangular parallelepiped shape from a material with good thermal conductivity, such as aluminum or an aluminum alloy (see FIG. 3 ). Two LED modules 41 are supported side by side in the longitudinal direction (left and right direction) on the front surface 400 of the main body 40. The two LED modules 41 are fixed to the front surface 400 of the main body 40 by, for example, screws.

[0030] The two LED modules 41 have a common configuration. The LED module 41 has a rectangular substrate 410 and a plurality of LEDs 411 mounted on the front surface of the substrate 410 (see FIG. 3). The plurality of LEDs 411 are four types of LEDs (first LED 11, second LED 12, third LED 13, and fourth LED 14) that emit different colors of light. However, the LED module 41 (light source device 1) will be described in detail in the section "(2-3) Configuration of the Light Source Device."

[0031] The diffusion member 43 is formed in the shape of a rectangular flat plate from a light-transmitting synthetic resin material such as acrylic resin or polycarbonate resin (see FIG. 3).

[0032] The diffusing member 43 is formed by filling a synthetic resin material with a filler such as titanium oxide, glass beads, or mica, and is configured to diffuse the light that passes through it. Alternatively, the diffusing member 43 may be configured to diffuse the light that passes through it by having an uneven or textured surface or both the front and back surfaces thereof.

[0033] The lens unit 42 has a first lens block 421, a second lens block 422, and a base 420 (see FIG. 3). The first lens block 421, the second lens block 422, and the base 420 are integrally formed as a molded body of a light-transmitting synthetic resin such as an acrylic resin or a polycarbonate resin.

[0034] The base 420 is formed in the shape of a rectangular plate. A first lens block 421 and a second lens block 422 are provided on the rear surface of the base 420. The first lens block 421 is provided on the lower side of the rear surface of the base 420 along the longitudinal direction of the base 420. The second lens block 422 is provided on the upper side of the rear surface of the base 420 along the longitudinal direction of the base 420. Therefore, the front surface of the base 420 serves as the emission surface of the first lens block 421 and the second lens block 422. The first lens block 421 and the second lens block 422 are configured to control the light distribution of light emitted from the LED module 41, respectively.

[0035] Here, the lens unit 42 is attached to the main body 40 so as to cover the two LED modules 41 from the front. The diffusion member 43 is attached to the main body 40 so as to cover the front surface of the base 420 of the lens unit 42.

[0036] The light source unit 4 is rotatably attached to the housing 30 of the control unit 3 by two hinges 33 (see FIG. 2). However, the light source unit 4 is rotatable along the grooves 310 of the pair of arms 31, and is fixed at any position on the arms 31 by tightening two thumb screws 32.

[0037] (2-3) Configuration of the Light Source Device The light source device 1 has a plurality of each of four types of LEDs: a first LED 11, a second LED 12, a third LED 13, and a fourth LED 14. These four types of LEDs are so-called packaged (surface-mounted) LEDs. A packaged LED has an LED chip that emits light when excited by current, a substrate on which the LED chip is mounted, an anode electrode and a cathode electrode supported on the substrate, bonding wires that electrically connect the LED chip to the anode electrode and the cathode electrode, and a sealing portion that seals at least the LED chip and the bonding wire.

[0038] The encapsulation portion is formed of a translucent synthetic resin such as silicone resin. However, the synthetic resin forming the encapsulation portion may contain a fluorescent material for wavelength conversion. In other words, in an LED that does not contain a fluorescent material in the encapsulation portion (hereinafter referred to as an "LED (without fluorescent material)"), the color of the light emitted from the LED chip is the same as the color of the light transmitted through the encapsulation portion and emitted to the outside of the LED. In contrast, in an LED that contains a fluorescent material in the encapsulation portion (hereinafter referred to as an "LED (with fluorescent material)"), the color of the light emitted from the LED chip is different from the color of the light transmitted through the encapsulation portion and emitted to the outside of the LED. In the following description, unless otherwise specified, the "emission color of an LED" refers to the color of the light transmitted through the encapsulation portion and emitted to the outside of the LED. The emission color of the first LED 11 is referred to as the first emission color, the emission color of the second LED 12 as the second emission color, the emission color of the third LED 13 as the third emission color, and the emission color of the fourth LED 14 as the fourth emission color.

[0039] In the embodiment, the first LED 11, the second LED 12, the third LED 13 and the fourth LED 14 are all LEDs (with phosphor) having an LED chip with a blue light emission color and a sealing portion in which a phosphor is mixed, and the light emission color of each LED differs depending on the type of phosphor, etc.

[0040] For example, the chromaticity coordinates C11 of the first emitted color of the first LED 11 are x = 0.595, y = 0.368, and the chromaticity coordinates C12 of the second emitted color of the second LED 12 are x = 0.321, y = 0.550. The chromaticity coordinates C13 of the third emitted color of the third LED 13 are x = 0.179, y = 0.290, and the chromaticity coordinates C14 of the fourth emitted color of the fourth LED 14 are x = 0.165, y = 0.125. Figures 4 and 5 show xy chromaticity diagrams of the XYZ color system, plotting the chromaticity coordinates C11 of the first emitted color, the chromaticity coordinates C12 of the second emitted color, the chromaticity coordinates C13 of the third emitted color, and the chromaticity coordinates C14 of the fourth emitted color. The xy chromaticity diagram in Figure 4 corresponds to Reference Figure 1 of JIS Z8110.

[0041] As shown in Figure 4, the chromaticity coordinate C11 of the first luminous color is in the yellow-red region YR on the xy chromaticity diagram. The chromaticity coordinate C12 of the second luminous color is in the yellow-green region YG on the xy chromaticity diagram. The chromaticity coordinate C13 of the third luminous color is in the blue-green region BG on the xy chromaticity diagram. The chromaticity coordinate C14 of the fourth luminous color is in the blue region BL on the xy chromaticity diagram.

[0042] Here, on the xy chromaticity diagram, a quadrilateral luminous color region S1 is assumed, whose four sides are four line segments: a first line segment L1, a second line segment L2, a third line segment L3, and a fourth line segment L4 (see FIG. 4 ). The first line segment L1 connects the chromaticity coordinate C11 of the first luminous color with the chromaticity coordinate C12 of the second luminous color. The second line segment L2 connects the chromaticity coordinate C12 of the second luminous color with the chromaticity coordinate C13 of the third luminous color. The third line segment L3 connects the chromaticity coordinate C13 of the third luminous color with the chromaticity coordinate C14 of the fourth luminous color. The fourth line segment L4 connects the chromaticity coordinate C14 of the fourth luminous color with the chromaticity coordinate C11 of the first luminous color.

[0043] As shown in FIG. 4 , the luminous color region S1 includes the white region WH and the whitish luminous color region defined in JIS Z8110, as well as the pale chromatic color region outside the white luminous color. The whitish luminous color region includes five regions: the pale pink region LPK, the yellowish white region YW, the greenish white region GW, the bluish white region BW, and the purplish white region PW. In the embodiment, the pale chromatic color region includes the pale yellow-red region LYR, the pale yellow region LY, the pale green-yellow region LYG, the pale green region LG, the pale blue-green region LBG, the pale blue region LB, the pale blue-purple region LPB, and the pale purple region LPL. However, in the embodiment, the purplish pink region PP, the pink region PK, and the orange-pink region OP are not included in the pale chromatic color region.

[0044] The light source device 1 can emit light of any emission color within the emission color region S1 as a mixture of at least one or more of the first emission color, the second emission color, the third emission color, and the fourth emission color by adjusting the light intensity of the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14. The light intensity of the first LED 11 is proportional to the current flowing through the first LED 11 (the load current of the first lighting circuit 21), and the light intensity of the second LED 12 is proportional to the current flowing through the second LED 12 (the load current of the second lighting circuit 22). Similarly, the light intensity of the third LED 13 is proportional to the current flowing through the third LED 13 (the load current of the third lighting circuit 23), and the light intensity of the fourth LED 14 is proportional to the current flowing through the fourth LED 14 (the load current of the fourth lighting circuit 24).

[0045] Here, the control circuit 25 is primarily composed of a microcontroller. Therefore, the control circuit 25 can only discretely adjust the DC current supplied from the lighting device 20 to the light source device 1. In other words, the number of chromaticity coordinates that can be adjusted by the control circuit 25 is determined by the memory capacity of the microcontroller. Therefore, unless the memory capacity of the control circuit 25 is increased, the wider the emission color region on the xy chromaticity diagram, the more chromaticity coordinates that the control circuit 25 cannot adjust.

[0046] In contrast, the light source device 1 includes white and white-based emitted colors and pale chromatic colors outside the white-based emitted colors in an emitted color region S1 surrounded by a line segment L1-L4 connecting the chromaticity coordinates C11-C14 of the four emitted colors. In other words, the light source device 1 can improve the reproducibility of white and white-based emitted colors and pale chromatic colors outside the white-based emitted colors (increase the number of reproducible chromaticity coordinates) while suppressing an increase in memory capacity.

[0047] Here, it is preferable that at least one of the four sides of the luminous color region S1 (first line segment L1, second line segment L2, third line segment L3, and fourth line segment L4) contact or intersect with the outer boundary of the light chromatic color regions LPK, LYR, LY, LYG, LG, LBG, LB, LPB, and LPL (the side away from the white region WH). Note that "intersecting the boundary" means that at least one of the chromaticity coordinates passing through each of the first line segment L1, second line segment L2, third line segment L3, and fourth line segment L4 on the xy chromaticity diagram coincides with a chromaticity coordinate belonging to the "boundary." Furthermore, "contacting the boundary" means that the shortest distance between the chromaticity coordinates passing through each line segment and the chromaticity coordinates belonging to the "boundary" falls within a predetermined range. The "predetermined range" here is preferably a numerical range that is within the range of error (such as measurement error) when calculating the chromaticity coordinates of the LED. However, the "predetermined range" is not limited to the above-mentioned numerical range.

[0048] Therefore, the light source device 1 has at least one of the four sides of the luminous color region S1 contact or intersect with the outer boundary line of the pale chromatic color region, thereby further improving the reproducibility of the white and white-based luminous colors and the pale chromatic luminous colors outside the white-based luminous color.

[0049] In order to satisfy the above-mentioned condition that the third line segment L3 touches or intersects with the outer boundary line of the luminous color region S1, the light source device 1 differentiates the region where the chromaticity coordinate C13 of the third luminous color exists from the region where the chromaticity coordinate C14 of the fourth luminous color exists (see FIG. 4 ). In other words, by differentiating the region where the chromaticity coordinate C13 of the third luminous color exists from the region where the chromaticity coordinate C14 of the fourth luminous color exists, the light source device 1 can move the third line segment L3 closer to the outer boundary line of the luminous color region S1. As a result, the light source device 1 can further improve the reproducibility of white and its surrounding luminous colors.

[0050] Furthermore, to satisfy the above-mentioned condition that the fourth line segment L4 touches or intersects with the outer boundary of the luminous color region S1, the light source device 1 overlaps the fourth line segment L4 with at least one of the pink region PK and the purplish pink region PP in the xy chromaticity diagram (see FIG. 4 ). In other words, by overlapping the fourth line segment L4 with at least one of the pink region PK and the purplish pink region PP, the light source device 1 can bring the fourth line segment L4 closer to the outer boundary of the luminous color region S1. As a result, the light source device 1 can further improve the reproducibility of white and its surrounding luminous colors.

[0051] Furthermore, the light source device 1 has an emission color region S1 that encompasses all chromaticity ranges of daylight, daylight white, white, warm white, and incandescent light, as defined in JIS Z9112 (see FIG. 5). The correlated color temperatures of daylight, daylight white, white, warm white, and incandescent light are 5700K-7100K, 4600K-5500K, 3800K-4500K, 3250K-3800K, and 2600K-3250K, respectively.

[0052] Therefore, by including all chromaticity ranges of daylight, natural white, white, warm white and incandescent color in the light emitting color region S1, the light source device 1 can further improve the reproducibility of the emitted color of so-called white (daylight, natural white, white, warm white and incandescent color) and improve the color rendering properties.

[0053] Furthermore, the light source device 1 includes in its emission color region S1 a chromaticity range with a correlated color temperature lower than that of incandescent light (see FIG. 5 ). Note that the solid curve CL1 in FIG. 5 indicates the blackbody locus, and the points and numerical values ​​on the curve CL1 indicate correlated color temperatures (unit: K (Kelvin)). The lower limit of the chromaticity range with a correlated color temperature lower than that of incandescent light is preferably, for example, 2000 K or 1563 K. Note that 1563 K is the lower limit of the correlated color temperature listed in Table B.1 of Annex B of JIS Z8725.

[0054] Thus, the light source device 1 can reproduce emission colors with correlated color temperatures lower than that of incandescent light by including in the emission color region S1 a chromaticity range with a lower correlated color temperature than that of incandescent light.

[0055] The combinations of the chromaticity coordinates C11 to C14 of the first emission color to the fourth emission color are not limited to the above-described combination (called the first combination). For example, the following three combinations may be used:

[0056] In the second combination, the chromaticity coordinates C11 of the first emitted color of the first LED 11 are x = 0.571, y = 0.332, and the chromaticity coordinates C12 of the second emitted color of the second LED 12 are x = 0.363, y = 0.542. The chromaticity coordinates C13 of the third emitted color of the third LED 13 are x = 0.141, y = 0.302, and the chromaticity coordinates C14 of the fourth emitted color of the fourth LED 14 are x = 0.198, y = 0.152. Figures 6 and 7 show xy chromaticity diagrams of the XYZ color system, plotting the chromaticity coordinates C11 of the first emitted color, the chromaticity coordinates C12 of the second emitted color, the chromaticity coordinates C13 of the third emitted color, and the chromaticity coordinates C14 of the fourth emitted color in the second combination. As shown in Figure 6, the chromaticity coordinate C11 of the first emitted color is located in the red region RD on the xy chromaticity diagram. The chromaticity coordinate C12 of the second luminous color is in the yellow-green region YG on the xy chromaticity diagram, the chromaticity coordinate C13 of the third luminous color is in the blue-green region BG on the xy chromaticity diagram, and the chromaticity coordinate C14 of the fourth luminous color is in the purplish-blue region PB on the xy chromaticity diagram.

[0057] In the third combination, the chromaticity coordinates C11 of the first emitted color of the first LED 11 are x = 0.681, y = 0.315, and the chromaticity coordinates C12 of the second emitted color of the second LED 12 are x = 0.321, y = 0.545. The chromaticity coordinates C13 of the third emitted color of the third LED 13 are x = 0.179, y = 0.290, and the chromaticity coordinates C14 of the fourth emitted color of the fourth LED 14 are x = 0.165, y = 0.155. Figures 8 and 9 show xy chromaticity diagrams of the XYZ color system, plotting the chromaticity coordinates C11 of the first emitted color, the chromaticity coordinates C12 of the second emitted color, the chromaticity coordinates C13 of the third emitted color, and the chromaticity coordinates C14 of the fourth emitted color in the third combination. As shown in Figure 8, the chromaticity coordinate C11 of the first emitted color is located in the red region RD on the xy chromaticity diagram. The chromaticity coordinate C12 of the second emitted color is in the yellow-green region YG on the xy chromaticity diagram, the chromaticity coordinate C13 of the third emitted color is in the blue-green region BG on the xy chromaticity diagram, and the chromaticity coordinate C14 of the fourth emitted color is in the blue region BL on the xy chromaticity diagram.

[0058] In the fourth combination, the chromaticity coordinates C11 of the first emitted color of the first LED 11 are x = 0.601, y = 0.395, and the chromaticity coordinates C12 of the second emitted color of the second LED 12 are x = 0.315, y = 0.530. The chromaticity coordinates C13 of the third emitted color of the third LED 13 are x = 0.161, y = 0.260, and the chromaticity coordinates C14 of the fourth emitted color of the fourth LED 14 are x = 0.202, y = 0.126. Figures 10 and 11 show xy chromaticity diagrams of the XYZ color system, plotting the chromaticity coordinates C11 of the first emitted color, the chromaticity coordinates C12 of the second emitted color, the chromaticity coordinates C13 of the third emitted color, and the chromaticity coordinates C14 of the fourth emitted color in the fourth combination. 10, the chromaticity coordinate C11 of the first luminous color is in the yellowish-red region YR on the xy chromaticity diagram. The chromaticity coordinate C12 of the second luminous color is in the yellowish-green region YG on the xy chromaticity diagram. The chromaticity coordinate C13 of the third luminous color is in the blue-green region BG on the xy chromaticity diagram. The chromaticity coordinate C14 of the fourth luminous color is in the purplish-blue region PB on the xy chromaticity diagram.

[0059] When the light source device 1 adopts any of the second, third, and fourth combinations, it is possible to improve the reproducibility and color rendering of the white and white-based emitted colors and the light chromatic colors outside the white-based emitted color, just as when the first combination is adopted.

[0060] In the third combination, the area surrounded by the first line segment L1, the fourth line segment L4, and the outer boundary of the luminous color region S1 is larger than the areas surrounded by the boundaries of the first line segment L1 and the second line segment L2, the second line segment L2 and the third line segment L3, and the third line segment L3 and the fourth line segment L4 (see FIG. 8). In other words, when the third combination is employed, the light source device 1 can reproduce a white luminous color with a correlated color temperature of 2000 K or higher (see FIG. 9). When the fourth combination is employed, the light source device 1 can reproduce a white luminous color with an even lower correlated color temperature (1500 K or higher) (see FIG. 11).

[0061] In the third and fourth combinations, it is preferable that the first LED 11 is an LED (without phosphor), and the second LED 12, the third LED 13, and the fourth LED 14 are LEDs (with phosphor). That is, the chromaticity coordinates of the first emitted color in each of the third and fourth combinations are all on the red spectrum locus in the xy chromaticity diagram, and therefore, by configuring the first LED 11 with an LED (without phosphor), it is possible to improve the luminous efficiency.

[0062] (2-4) Arrangement of LEDs in Light Source Device Next, the arrangement of the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 in the light source device 1 will be described with reference to the drawings. Note that in the following three arrangement examples, the longitudinal direction of the elongated substrate 15 on which the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 are mounted is defined as a first direction D1, and the lateral direction of the substrate 15 is defined as a second direction D2 (see FIG. 12 ).

[0063] (2-4-1) First Arrangement Example As shown in FIG. 12 , in the first arrangement example, the first LEDs 11 and the fourth LEDs 14 are arranged alternately in a row along the first direction D1. Also, in the first arrangement example, the second LEDs 12 and the third LEDs 13 are arranged alternately in a row along the first direction D1. Furthermore, the first LEDs 11 and the third LEDs 13 are arranged side by side in the second direction D2, and the second LEDs 12 and the fourth LEDs 14 are arranged side by side in the second direction D2. The distance d2 between the first LEDs 11 and the third LEDs 13 along the second direction D2 and the distance d2 between the second LEDs 12 and the fourth LEDs 14 along the second direction D2 are narrower than the distance d1 between the first LEDs 11 and the fourth LEDs 14 along the first direction D1 and the distance d1 between the second LEDs 12 and the third LEDs 13 along the first direction D1 (d2<d1). However, the intervals d1 and d2 between the LEDs are equal to the distance between the LED chips of the LEDs.

[0064] When the light source device 1 reproduces light in the white region WH of the xy chromaticity diagram shown in Figures 4, 6, 8, and 10, it is necessary to make four types of LEDs (first LED 11, second LED 12, third LED 13, and fourth LED 14) emit light.

[0065] In the first arrangement example, the light source device 1 arranges a pair of the first LED 11 and the third LED 13, which have chromaticity coordinates C11 and C13, at diagonal positions in the light-emitting color region S1, and a pair of the second LED 12 and the fourth LED 14, which have chromaticity coordinates C12 and C14, along the second direction D2. Therefore, the light source device 1 can adjust the light emitted by mixing the first and third light colors and the light emitted by mixing the second and fourth light colors to the light emitted by the white region WH. Furthermore, the light source device 1 arranges the spacing d2 between the LEDs along the second direction D2 narrower than the spacing d1 between the LEDs along the first direction D1. As a result, the light source device 1 can suppress color unevenness when reproducing light in the white region WH.

[0066] (2-4-2) Second Arrangement Example The second arrangement example is basically the same as the first arrangement example, except that in the second arrangement example, the light source device 1 alternates between the first LED 11 and the third LED 13, and the second LED 12 and the fourth LED 14 in the second direction D2 along the first direction D1 (see FIG. 13 ).

[0067] That is, in the first arrangement example, the light source device 1 has the first LED 11 and the fourth LED 14 arranged alternately in a line along the first direction D1, and the second LED 12 and the third LED 13 arranged alternately in a line along the first direction D1. In contrast, in the second arrangement example, the light source device 1 has the same arrangement along the second direction D2 as the first arrangement example, but has the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 arranged sequentially in a line along the first direction D1 (see FIG. 13 ). Therefore, as in the first arrangement example, the light source device 1 can adjust the emission color obtained by mixing the first emission color and the third emission color and the emission color obtained by mixing the second emission color and the fourth emission color to the emission color in the white region WH. Furthermore, by adopting the second arrangement example, the light source device 1 can further reduce color unevenness in the second direction D2 compared to the first arrangement example.

[0068] (2-4-3) Third Arrangement Example In the third arrangement example, the light source device 1 has the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 arranged in a line along the first direction D1 (see FIG. 14 ). Furthermore, the light source device 1 arranges the first LED 11 and the second LED 12, and the third LED 13 and the fourth LED 14 so that they are not adjacent to each other (see FIG. 14 ). Specifically, the light source device 1 arranges the third LED 13 and the fourth LED 14 next to the first LED 11, and the third LED 13 and the fourth LED 14 next to the second LED 12. In other words, the light source device 1 arranges the third LED 13 and the fourth LED 14 alternately between the first LED 11 and the second LED 12.

[0069] In the third arrangement example, four types of LEDs are arranged in a row so as to satisfy the following two conditions.

[0070] The first condition is that the first LED 11 and the third LED 13, which are located at diagonal corners of the light-emitting color region S1, are arranged next to each other, and the second LED 12 and the fourth LED 14, which are also located at diagonal corners of the light-emitting color region S1, are arranged next to each other.

[0071] The second condition is that when LEDs that are not located at diagonal corners of the light-emitting color region S1 are arranged adjacent to each other, the LEDs that have the largest distance between them should be arranged adjacent to each other. Specifically, in the light source device 1, the fourth line segment L4 is longer than the first line segment L1, so the fourth LED 14, not the second LED 12, is arranged adjacent to the first LED 11.

[0072] Thus, by adopting the third arrangement example, the light source device 1 can prevent LEDs that are relatively close to each other on the xy chromaticity diagram from being adjacent to each other when the four types of LEDs are arranged in a row along the longitudinal direction (first direction D1) of the substrate 15. As a result, the light source device 1 can suppress color unevenness when reproducing light in the white region WH.

[0073] (2-5) Modifications of the Illumination Device of the Embodiment Finally, several modifications of the illumination device of the embodiment will be described.

[0074] (2-5-1) Modification 1 In a lighting device 5 of modification 1, as shown in FIG. 15, the light source device according to the embodiment is applied to a bulb-shaped LED lamp.

[0075] The lighting device 5 of Modification 1 includes a truncated conical lamp body 50, a cover 51 attached to the large-diameter bottom surface of the lamp body 50, and a base 52 attached to the small-diameter bottom surface of the lamp body 50. A light source device and a lighting device are housed within the lamp body 50. The cover 51 is spherically formed from glass or a translucent synthetic resin. However, the light source device of Modification 1 preferably has the first LED 11, the second LED 12, the third LED 13, and the fourth LED 14 mounted circumferentially on the surface of a disc-shaped substrate, for example. The cover 51 is attached to the lamp body 50 so as to cover the light source device. Illumination light emitted from the light source device is diffused as it passes through the cover 51 and irradiates the illumination space. The lighting device is electrically connected to the base 52. The lighting device 5 is attached to a lighting fixture, for example, by attaching the base 52 to a socket of the lighting fixture for incandescent bulbs.

[0076] (2-5-2) Modification 2 The lighting device 6 of modification 2 includes a light source device 1 formed of a so-called straight-tube LED lamp, a fixture body 60, a pair of lamp sockets 61, and a power supply unit 62 (see FIG. 16).

[0077] The light source device 1 includes a cover 100 formed into a long cylindrical shape from a translucent synthetic resin such as acrylic resin or polycarbonate resin, and a pair of bases 101 provided on both ends of the cover 100. An LED module is housed inside the cover 100. The LED module is configured by mounting four types of LEDs (a first LED, a second LED, a third LED, and a fourth LED) on the surface of a long substrate.

[0078] The fixture body 60 is made of metal plate and has a long, pyramidal shape. The fixture body 60 is directly attached to the ceiling. A pair of lamp sockets 61 protrude from both ends of the bottom surface of the fixture body 60 in the longitudinal direction. The fixture body 60 also houses a power supply unit 62, which houses a lighting device, control circuit, and communication circuit in a case.

[0079] The lighting device 6 of the second modification is configured by attaching the light source device 1 to the fixture body 60 by attaching the pair of bases 101 to the pair of lamp sockets 61, respectively. The light source device 1 is turned on (emits light) when a direct current is supplied from the power supply unit 62 through the pair of lamp sockets 61 and the pair of bases 101.

[0080] (3) Summary The light source device (1) according to the first aspect of the present disclosure includes a first light-emitting element (first LED 11) that emits light of a first emitted color, a second light-emitting element (second LED 12) that emits light of a second emitted color, a third light-emitting element (third LED 13) that emits light of a third emitted color, and a fourth light-emitting element (fourth LED 14) that emits light of a fourth emitted color. The chromaticity coordinate (C11) of the first emitted color is in the red region (RD) or the yellow-red region (YR) of the xy chromaticity diagram of the XYZ color system. The chromaticity coordinate (C12) of the second emitted color is in the yellow-green region (YG) or the green region (GR) of the xy chromaticity diagram. The chromaticity coordinate (C13) of the third emitted color is in the blue-green region (BG) or the blue region (BL) of the xy chromaticity diagram. The chromaticity coordinate (C14) of the fourth emitted color is located in the blue region (BL) or the blue-violet region (PB) on the xy chromaticity diagram. The light source device (1) according to the first aspect has a quadrilateral emitted color region (S1) on the xy chromaticity diagram, with a first line segment (L1), a second line segment (L2), a third line segment (L3), and a fourth line segment (L4) as its four sides. The first line segment (L1) connects the chromaticity coordinate (C11) of the first emitted color with the chromaticity coordinate (C12) of the second emitted color. The second line segment (L2) connects the chromaticity coordinate (C12) of the second emitted color with the chromaticity coordinate (C13) of the third emitted color. The third line segment (L3) connects the chromaticity coordinate (C13) of the third emitted color with the chromaticity coordinate (C14) of the fourth emitted color. The fourth line segment (L4) is a line segment connecting the chromaticity coordinate (C14) of the fourth luminous color and the chromaticity coordinate (C11) of the first luminous color. The luminous color region (S1) includes white and whitish luminous colors specified in JIS Z8110, as well as light chromatic colors outside the whitish luminous colors.

[0081] The light source device (1) according to the first aspect can emit light of an emission color in an emission color region (S1) that includes white and whitish emission colors as well as light chromatic colors outside the whitish emission color by mixing four colors of light emitted from four types of light-emitting elements (first LED 11, second LED 12, third LED 13, and fourth LED 14). As a result, the light source device (1) according to the first aspect can improve the reproducibility of white and its surrounding emission colors.

[0082] A light source device (1) according to a second aspect of the present disclosure can be realized by combining it with the first aspect. In the light source device (1) according to the second aspect, it is preferable that at least one of the first line segment (L1), the second line segment (L2), the third line segment (L3), and the fourth line segment (L4) contact or intersect with an outer boundary line of the light chromatic color.

[0083] The light source device (1) according to the second aspect can further improve the reproducibility of white and its surrounding emitted colors.

[0084] A light source device (1) according to a third aspect of the present disclosure can be realized by combining it with the second aspect. In the light source device (1) according to the third aspect, it is preferable that the region where the chromaticity coordinate (C13) of the third emitted color exists is different from the region where the chromaticity coordinate (C14) of the fourth emitted color exists.

[0085] The light source device (1) according to the third aspect can further improve the reproducibility of white and the surrounding emitted colors by bringing the third line segment (L3) closer to the outer boundary of the emitted color region (S1).

[0086] A light source device (1) according to a fourth aspect of the present disclosure can be realized by combining it with any one of aspects 1 to 3. In the light source device (1) according to the fourth aspect, it is preferable that the fourth line segment (L4) overlaps at least one of the pink region (PK) and the purplish pink region (PP) in the xy chromaticity diagram.

[0087] In the light source device (1) according to the fourth aspect, by overlapping the fourth line segment (L4) with at least one of the pink region (PK) and the purplish pink region (PP), the fourth line segment (L4) can be brought closer to the outer boundary line of the luminous color region (S1). As a result, the light source device (1) according to the fourth aspect can further improve the reproducibility of white and the luminous colors around it.

[0088] A light source device (1) according to a fifth aspect of the present disclosure can be realized by combining it with any one of aspects 1 to 4. In the light source device (1) according to the fifth aspect, it is preferable that the area surrounded by the first line segment (L1), the fourth line segment (L4), and the outer boundary line of the light chromatic color is larger than the areas surrounded by the boundaries of the first line segment (L1) and the second line segment (L2), the second line segment (L2) and the third line segment (L3), and the third line segment (L3) and the fourth line segment (L4).

[0089] The light source device (1) according to the fifth aspect can reproduce emitted colors with lower correlated color temperatures.

[0090] A light source device (1) according to a sixth aspect of the present disclosure can be realized by combining it with any of aspects 1 to 5. In the light source device (1) according to the sixth aspect, it is preferable that the emission color region (S1) encompasses all chromaticity ranges of daylight, neutral white, white, warm white, and incandescent white as defined in JIS Z9112.

[0091] The light source device (1) according to the sixth aspect can further improve the reproducibility of the emitted color of so-called white (daylight color, neutral white, white, warm white, and incandescent color).

[0092] A light source device (1) according to a seventh aspect of the present disclosure can be realized by combining it with the sixth aspect. In the light source device (1) according to the seventh aspect, it is preferable that the emission color region (S1) includes a chromaticity range having a correlated color temperature lower than that of incandescent light.

[0093] The light source device (1) according to the seventh aspect can reproduce emission colors with correlated color temperatures lower than that of incandescent light by including in the emission color region (S1) a chromaticity range with a lower correlated color temperature than that of incandescent light.

[0094] A light source device (1) according to an eighth aspect of the present disclosure can be realized by combining it with any one of the first to seventh aspects. In the light source device (1) according to the eighth aspect, the first light-emitting element is preferably configured to emit light emitted from the semiconductor element without wavelength conversion. The second light-emitting element, the third light-emitting element, and the fourth light-emitting element are preferably configured to convert the wavelength of a portion of the light emitted from their respective semiconductor elements and then emit the converted light.

[0095] The light source device (1) according to the eighth aspect is configured such that the first light emitting element is configured to emit light emitted from the semiconductor element without wavelength conversion, thereby making it possible to improve the light emitting efficiency.

[0096] A light source device (1) according to a ninth aspect of the present disclosure can be realized by combining any one of the first to eighth aspects. In the light source device (1) according to the ninth aspect, the plurality of first light-emitting elements and the plurality of fourth light-emitting elements are preferably arranged alternately in a row along the first direction (D1). The plurality of second light-emitting elements and the plurality of third light-emitting elements are preferably arranged alternately in a row along the first direction (D1). The first light-emitting elements and the third light-emitting elements are preferably arranged side by side along a second direction (D2) intersecting the first direction (D1). The second light-emitting elements and the fourth light-emitting elements are preferably arranged side by side along the second direction (D2). The distance (d2) between the first light-emitting element and the third light-emitting element along the second direction (D2) and the distance (d2) between the second light-emitting element and the fourth light-emitting element along the second direction (D2) are preferably narrower than the distance (d1) between the first light-emitting element and the fourth light-emitting element along the first direction (D1) and the distance (d1) between the second light-emitting element and the third light-emitting element along the first direction (D1).

[0097] The light source device (1) according to the ninth aspect can suppress color unevenness when reproducing light in the white region (WH).

[0098] A light source device (1) according to a tenth aspect of the present disclosure can be realized by combining with the ninth aspect. In the light source device (1) according to the tenth aspect, it is preferable that the arrangements of the first light-emitting element and the third light-emitting element, and the second light-emitting element and the fourth light-emitting element in the second direction (D2) are alternately switched along the first direction (D1).

[0099] The light source device (1) according to the tenth aspect can further suppress color unevenness in the second direction (D2).

[0100] A light source device (1) according to an eleventh aspect of the present disclosure can be realized by combining with the ninth aspect. In the light source device (1) according to the eleventh aspect, it is preferable that the plurality of first light-emitting elements, the plurality of second light-emitting elements, the plurality of third light-emitting elements, and the plurality of fourth light-emitting elements are arranged in a row along the first direction (D1), and that the first light-emitting element and the second light-emitting element, and the third light-emitting element and the fourth light-emitting element are not adjacent to each other.

[0101] The light source device (1) according to the eleventh aspect can suppress color unevenness when reproducing light in the white region (WH).

[0102] An illumination device (2; 5; 6) according to a twelfth aspect of the present disclosure comprises a light source device (1) according to any one of the first to eleventh aspects and a lighting device (20) that lights up the light source device (1).

[0103] The lighting device (2; 5; 6) according to the twelfth aspect can improve the reproducibility of white and surrounding emitted colors.

[0104] A lighting system (9) according to a thirteenth aspect of the present disclosure includes a lighting device (2; 5; 6) according to the twelfth aspect and a control device (90) that controls the lighting device (2; 5; 6).

[0105] The lighting system (9) according to the thirteenth aspect can improve the reproducibility of white and its surrounding emitted colors.

[0106] REFERENCE SIGNS LIST 1 Light source device 2 Lighting device 5 Lighting device 6 Lighting device 9 Lighting system 11 First LED (first light-emitting element) 12 Second LED (second light-emitting element) 13 Third LED (third light-emitting element) 14 Fourth LED (fourth light-emitting element) 20 Lighting device 90 Control device C11 Chromaticity coordinates of first emitted color C12 Chromaticity coordinates of second emitted color C13 Chromaticity coordinates of third emitted color C14 Chromaticity coordinates of fourth emitted color L1 First line segment L2 Second line segment L3 Third line segment L4 Fourth line segment RD Red region YR Yellow-red region YG Yellow-green region GR Green region BG Blue-green region BL Blue region PB Blue-purple region S1 Emitted color region PK Pink region PP Purplish-pink region D1 First direction D2 Second direction d1 Distance between the first light-emitting element and the fourth light-emitting element: d2 Distance between the second light-emitting element and the fourth light-emitting element

Claims

1. A light emitting element comprising a first light emitting element emitting light of a first emitted color, a second light emitting element emitting light of a second emitted color, a third light emitting element emitting light of a third emitted color, and a fourth light emitting element emitting light of a fourth emitted color, wherein the chromaticity coordinates of the first emitted color are in the red or yellow-red region of an xy chromaticity diagram of an XYZ color system, the chromaticity coordinates of the second emitted color are in the yellow-green or green region of the xy chromaticity diagram, the chromaticity coordinates of the third emitted color are in the blue-green or blue region of the xy chromaticity diagram, and the chromaticity coordinates of the fourth emitted color are in the blue or blue-purple region of the xy chromaticity diagram, a first line segment connecting the chromaticity coordinates of the first emitted color and the chromaticity coordinates of the second emitted color on the xy chromaticity diagram, a second line segment connecting the chromaticity coordinates of the second emitted color and the chromaticity coordinates of the third emitted color, a third line segment connecting the chromaticity coordinates of the third emitted color and the chromaticity coordinates of the fourth emitted color, and a fourth line segment connecting the chromaticity coordinates of the fourth emitted color and the chromaticity coordinates of the first emitted color, wherein the luminous color region includes white and white-based emitted colors as defined in JIS Z8110, and pale chromatic colors outside the white-based emitted color.

2. The light source device according to claim 1, wherein at least one of the first line segment, the second line segment, the third line segment and the fourth line segment contacts or intersects with an outer boundary line of the light chromatic color.

3. The light source device according to claim 2, wherein an area in which the chromaticity of the third luminescent color exists is different from an area in which the chromaticity of the fourth luminescent color exists.

4. A light source device according to any one of claims 1 to 3, wherein the fourth line segment overlaps with at least one of a pink region and a purplish pink region in the xy chromaticity diagram.

5. A light source device as described in any one of claims 1 to 4, wherein an area surrounded by the first line segment, the fourth line segment, and the outer boundary line of the light chromatic color is larger than an area surrounded by each of the first line segment and the second line segment, the second line segment and the third line segment, and the third line segment and the fourth line segment and the boundary line.

6. A light source device according to any one of claims 1 to 5, wherein the emission color range includes all chromaticity ranges of daylight color, natural white color, white color, warm white color and incandescent color as defined in JIS Z9112.

7. The light source device according to claim 6, wherein the emission color region includes a chromaticity range having a lower correlated color temperature than the incandescent light color.

8. A light source device as described in any one of claims 1 to 7, wherein the first light-emitting element is configured to emit light emitted from a semiconductor element without wavelength conversion, and the second light-emitting element, the third light-emitting element and the fourth light-emitting element are configured to emit a portion of the light emitted from their respective semiconductor elements after wavelength conversion.

9. A light source device as described in any one of claims 1 to 8, wherein a plurality of the first light-emitting elements and a plurality of the fourth light-emitting elements are arranged alternately in a row along a first direction, a plurality of the second light-emitting elements and a plurality of the third light-emitting elements are arranged alternately in a row along the first direction, the first light-emitting elements and the third light-emitting elements are arranged alternately in a row along the first direction, the first light-emitting elements and the third light-emitting elements are arranged aligned along a second direction intersecting the first direction, the second light-emitting elements and the fourth light-emitting elements are arranged aligned along the second direction, and a distance between the first light-emitting elements and the third light-emitting elements along the second direction and a distance between the second light-emitting elements and the fourth light-emitting elements along the second direction are narrower than a distance between the first light-emitting elements and the fourth light-emitting elements along the first direction and a distance between the second light-emitting elements and the third light-emitting elements along the first direction.

10. A light source device according to claim 9, wherein the first light-emitting element and the third light-emitting element, and the second light-emitting element and the fourth light-emitting element, are arranged alternately in the second direction along the first direction.

11. A light source device as described in claim 9, wherein the plurality of first light-emitting elements, the plurality of second light-emitting elements, the plurality of third light-emitting elements, and the plurality of fourth light-emitting elements are arranged in a row along the first direction, and the first light-emitting elements and the second light-emitting elements, and the third light-emitting elements and the fourth light-emitting elements are arranged so that they are not adjacent to each other.

12. An illumination device comprising: a light source device according to any one of claims 1 to 11; and a lighting device for lighting the light source device.

13. A lighting system comprising: a lighting device according to claim 12; and a control device for controlling said lighting device.

Images