Light emitting device, headlamp, and vehicle equipped with the same

Abstract

The present application provides a light emitting device capable of reducing glare, a headlamp, and a vehicle equipped with the same. The light emitting device includes a light emitting element having a peak wavelength in a range of 400 nm or more and 490 nm or less, and a wavelength conversion member including a first phosphor having a peak wavelength in a range of 480 nm or more and less than 580 nm, and a second phosphor having a peak wavelength in a range of 580 nm or more and 680 nm or less and having a composition different from that of the first phosphor. The light emitting device emits light having a first luminance ratio Ls / L of 0.9 or less, the first luminance ratio Ls / L being a ratio of a first effective radiant luminance Ls of light emitted by the light emitting device to a luminance L of the light emitted by the light emitting device, the first effective radiant luminance Ls taking into account a human photopic standard relative luminance curve prescribed by CIE (International Commission on Illumination) and a spectral sensitivity of human S cones, and the luminance L taking into account the human photopic standard relative luminance curve.

Description

Technical Field

[0001] This invention relates to a light-emitting device, a headlight, and a vehicle equipped with the same. Background Technology

[0002] Road transport vehicles such as motorized four-wheeled vehicles and motorized two-wheeled vehicles, tractors such as those used for land preparation / handling / loading, and excavators such as those used for digging can use headlights such as halogen lamps, HID (High-Intensity Discharge) lamps, or light-emitting devices that use semiconductor light-emitting elements as the excitation light source. For example, one or more automotive headlights are symmetrically installed on the left and right sides of the front of the vehicle, at a position lower than the driver's eye level. The headlights have high beam (driving headlights) and low beam (passing headlights) lamps, which can be switched. The high beam illuminates a more distant object, such as about 100 meters ahead, while the low beam illuminates a closer object, such as about 40 meters ahead, slightly below the high beam.

[0003] For example, Patent Document 1 discloses a vehicle headlight comprising a first lamp unit that illuminates in low beam mode, and a first lamp unit and a second lamp unit that simultaneously illuminate in high beam mode. Patent Document 1 discloses that the first lamp unit uses a white LED with a correlated color temperature of 4000K to 6500K as the light source, and the second lamp unit uses an HID lamp, i.e., a metal halide lamp, with a correlated color temperature of 4000K to 5000K as the light source.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-141917 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Because the light emitted from headlights can irritate the vision of drivers of vehicles ahead and oncoming vehicles, it can sometimes cause discomfort and glare, making it difficult to see objects clearly. Glare is a sensation caused by inappropriate brightness distribution or extreme brightness contrast within the field of vision, accompanied by discomfort and reduced visual acuity (JIS Z9110). Furthermore, due to the light emitted from headlights, drivers of other vehicles may also experience glare from reflected light.

[0009] One aspect of the present invention aims to provide a light-emitting device, a headlight, and a vehicle equipped with the same, capable of reducing glare.

[0010] Methods for solving problems

[0011] The first embodiment is a light-emitting device comprising: a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm and a wavelength conversion component, wherein the wavelength conversion component comprises a first phosphor having a peak emission wavelength in the range of 480 nm to 580 nm and a second phosphor having a peak emission wavelength in the range of 580 nm to 680 nm and having a composition different from that of the first phosphor, wherein the light-emitting device emits light with a first luminance ratio Ls / L of 0.9 or less derived from the following formula (1), wherein the first luminance ratio Ls / L is the ratio of the first effective radiant luminance Ls of the light emitted by the light-emitting device in the range of 380 nm to 780 nm to the luminance L of the light emitted by the light-emitting device in the range of 380 nm to 780 nm, wherein the first effective radiant luminance Ls takes into account the relative visibility curve of human photopic vision as specified by the CIE (International Commission on Illumination) and the spectral sensitivity of the human S-cone, and the luminance L takes into account the aforementioned relative visibility curve of human photopic vision.

[0012] [Mathematical Expression 1]

[0013]

[0014] (In Equation (1), S(λ) is the spectral radiance of the light emitted by the light-emitting device, V(λ) is the relative visibility curve of human photopic vision as specified by CIE, and Gs(λ) is the spectroscopic sensitivity of the human S-cone in the wavelength range of λnm above 380nm and below 550nm.)

[0015] The second method is a light-emitting device comprising: a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm and a wavelength conversion component, wherein the wavelength conversion component includes a first phosphor having a peak emission wavelength in the range of 480 nm to 580 nm and a second phosphor having a peak emission wavelength in the range of 580 nm to 680 nm and having a composition different from that of the first phosphor, wherein the light-emitting device emits light with a second luminance ratio B / A of 0.104 or less derived from the following formula (2), wherein the second luminance ratio B / A is the ratio of the second effective radiance B of the light emitted by the light-emitting device in the range of 300 nm to 800 nm to the radiance A of the light emitted by the light-emitting device in the range of 300 nm to 800 nm, wherein the second effective radiance B takes into account the scattering intensity curve relative to the wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.

[0016] [Mathematical Expression 2]

[0017]

[0018] (In equation (2), S(λ) is the spectral radiance of the light emitted by the light-emitting device, and Dc(λ) is the scattering intensity curve when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.)

[0019] The third method is a headlight equipped with the aforementioned light-emitting device.

[0020] The fourth type is a vehicle equipped with the aforementioned light-emitting device or the aforementioned headlights.

[0021] The effects of the invention

[0022] According to one aspect of the present invention, a light-emitting device capable of reducing glare, a headlight, and a vehicle equipped with the same can be provided. Attached Figure Description

[0023] Figure 1A The spectroscopic sensitivity Gs(λ) of the human S-cone disclosed in Non-Patent Document 2 is given.

[0024] Figure 1B V(λ) is the relative visibility curve of human photopic vision as specified by the CIE, as disclosed in Non-Patent Document 2.

[0025] Figure 1C The curve corresponding to VK(λ)∶K=1.260 disclosed in Non-Patent Document 2 is an example of the spectral visibility VK(λ) corresponding to glare.

[0026] Figure 2 This is a graph showing the intensity curve Dc(λ) of Rayleigh scattering when the scattering intensity at a wavelength of 300 nm is set to 1.

[0027] Figure 3A This is a schematic top view of the light-emitting device.

[0028] Figure 3B This is a schematic cross-sectional view of the light-emitting device.

[0029] Figure 3C This is a partially enlarged view of a schematic cross-section of the light-emitting device.

[0030] Figure 4 This is a graph showing the emission spectra of the light-emitting devices of Examples 1 and 2 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0031] Figure 5 This is a graph showing the emission spectra of the light-emitting devices of Examples 3 and 4 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0032] Figure 6This is a graph showing the emission spectra of the light-emitting devices of Examples 5 and 6 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0033] Figure 7 This is a graph showing the emission spectra of the light-emitting devices of Examples 7 and 8 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0034] Figure 8 This is a graph showing the emission spectra of the light-emitting devices of Examples 9 and 10 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0035] Figure 9 This is a graph showing the emission spectrum of the light-emitting device of Example 11 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0036] Figure 10 This is a graph showing the emission spectrum of the light-emitting device of Example 12 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0037] Figure 11 This is a graph showing the emission spectrum of the light-emitting device of Example 13 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0038] Figure 12 This is a graph showing the emission spectra of the light-emitting devices of Examples 14 and 15 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0039] Figure 13 This is a graph showing the emission spectra of the light-emitting devices of Examples 16, 17 and 18 and the emission spectrum of the light-emitting device of Comparative Example 1.

[0040] Figure 14 This is a graph showing the relationship between the ambient temperature and the first brightness ratio Ls / L of the light-emitting devices of Examples 7, 9 and 16 and the light-emitting device of Comparative Example 1.

[0041] Figure 15 This is a graph showing the relationship between the ambient temperature and the second brightness ratio B / A of the light-emitting devices of Examples 7, 9 and 16 and the light-emitting device of Comparative Example 1.

[0042] Figure 16 The graph shows the relationship between ambient temperature and correlated color temperature for the light-emitting devices of Examples 7 and 16 and the light-emitting device of Comparative Example 1.

[0043] Figure 17 This is an SEM image of a cross-section of a sample of the wavelength conversion component of Example 18.

[0044] Figure 18 This is an SEM image of a cross-section of a sample of the wavelength conversion component of Example 18.

[0045] Figure 19 This is an SEM image of a cross-section of a sample of the wavelength conversion component of Example 3.

[0046] Figure 20 This is a diagram showing a horizontal cross-sectional view of the headlight.

[0047] Figure 21 This is a diagram showing the front view of the headlights.

[0048] Symbol Explanation

[0049] 1: Substrate; 10: Light-emitting element; 12: Lighting control unit; 22: Outer lens; 24: Lamp body; 26: Optical filter; 28: Screw; 32: Substrate; 34: Light guide component; 40: Wavelength conversion component; 41: Wavelength converter; 41a: High-concentration layer; 41b: Low-concentration layer; 42: Light-transmitting body; 50: Semiconductor element; 60: Conductive component; 71: First phosphor; 72: Second phosphor; 80: Adhesive layer; 90: Covering component; 100, 101: Light-emitting device; 200: Headlamp. Detailed Implementation

[0050] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. The embodiments shown below are examples of a light-emitting device, a headlight, and a vehicle equipped with the same, embodying the technical concept of the present invention. The present invention is not limited to the light-emitting device, headlight, and vehicle equipped with the same shown below. Furthermore, the components shown in the claims are not limited to the components of the embodiments. In particular, regarding the dimensions, materials, shapes, and relative arrangements of the constituent components described in the embodiments, unless otherwise specified, the scope of the present invention is not limited to these, but is merely illustrative. It should be noted that the relationship between color names and chromaticity coordinates, and the relationship between the wavelength range of light and the color names of monochromatic light, etc., are based on JIS Z8110. In this specification, regarding the content of each component in the composition, if multiple substances equivalent to each component are present in the composition, unless otherwise specified, it refers to the total amount of the multiple substances present in the composition. The half-width of the emission spectrum refers to the full width at half maximum (FWHM). Regarding the half-value width, the half-value width of a light-emitting element or phosphor refers to the wavelength width of the emission spectrum that displays 50% of the maximum luminous intensity in the emission spectrum.

[0051] Vehicle headlights utilize various light sources, such as HID lamps, halogen lamps, and LEDs, based on characteristics like luminous flux and energy. The perceived glare and apparent brightness vary depending on the light source. For example, road surface brightness is also affected by the blue light component and the correlated color temperature of the light. Non-Patent Document 1 discloses an evaluation of LED light sources with color temperatures as high as 6600K causing glare, regardless of whether the person is elderly or not (Non-Patent Document 1: Hiroshi Hashimoto et al., "The Influence of Different Color Temperatures of White LEDs on Glare Levels," Japan Automobile Research Institute, Department of Safety and Safety Research, October 2006, Automotive Research, Vol. 28, No. 10, pp. 569-572). The level of glare that causes discomfort varies depending on factors such as decreased retinal illumination and deterioration of rod cells, and the degree of glare sometimes changes with age. In the cone cells, which are photoreceptor cells present in the human retina, S-cones respond to short-wavelength light. S-cones have a peak sensitivity wavelength around 440 nm. Non-Patent Document 2 discloses the following formula (3) for a new spectral visibility VK(λ) corresponding to glare, which takes into account the spectral sensitivity Gs(λ) of the human S-cone at wavelength λ in the relative visibility curve V(λ) of the human photopic vision standard used in the side lighting system of the CIE1931 colorimetric system (Non-Patent Document 2: Masayuki Kobayashi et al., "Related Research on the Influence of Spectral Distribution of Headlight Source on Unpleasant Glare", Proceedings of the Academic Lecture of the Automotive Technology Association, No. 5-10, pp. 9-14). In this specification, spectral radiance and spectral distribution have the same meaning.

[0052] [Mathematical Expression 3]

[0053] V K (λ)=1.260×Gs(λ)+V(λ) (3)

[0054] Figure 1A The spectroscopic sensitivity Gs(λ) of the human S-cone disclosed in Non-Patent Document 2 is based on... Figure 1A The spectroscopic sensitivity Gs(λ) of the human S-cone can be derived. The spectroscopic sensitivity Gs(λ) of the human S-cone has a peak value in the range of above 380 nm and below 550 nm. Figure 1B It is the relative visibility curve V(λ) of human photopic vision standard as specified by CIE, disclosed in Non-Patent Document 2. Figures 1A to 1C The relative values ​​shown are those with the peak of the relative visibility curve V(λ) for human photopic vision, as defined by the CIE, set to 1. Based on Figure 1B This allows us to derive the numerical value of the relative visibility curve V(λ) for human photopic vision as specified by the CIE. Figure 1C It is disclosed in non-patent document 2 and V KThe curve corresponding to (λ)∶K=1.260 is the spectral visibility V corresponding to glare, taking into account the relative visibility curve of human photopic vision as specified by CIE and the spectral sensitivity of the human S-cone. K Example of (λ). K is a coefficient that determines the proportion of the contribution of the human S-cone to the spectroscopic sensitivity Gs(λ). The coefficient K is 1.260 in the case of a halogen bulb.

[0055] The brightness L of the light emitted by the light-emitting device can be derived by the following equation (4). The brightness L of the light emitted by the light-emitting device is the integral value of the spectral radiance S(λ) of the light-emitting device in the range of 380 nm to 780 nm and the relative visibility curve V(λ) of human photopic vision standard specified by CIE.

[0056] [Mathematical Expression 4]

[0057]

[0058] The first effective radiance Ls of the light emitted by the light-emitting device can be derived by the following equation (5). The first effective radiance Ls of the light emitted by the light-emitting device is obtained by the following values: the spectral radiance S(λ) of the light-emitting device in the range of 380 nm to 780 nm and the human spectroscopic visibility V corresponding to the glare expressed by the above equation (3). K The integral value of (λ)(=K·Gs(λ)+V(λ)) divided by the coefficient K (=1.260) in the case of using a halogen bulb is derived by the above equation (3) as V K The peak value of (λ) is 2.3.

[0059] [Mathematical Expression 5]

[0060]

[0061] The first luminance ratio Ls / L of the light emitted by the light-emitting device is the ratio of the first effective radiant luminance Ls of the light emitted by the light-emitting device to the luminance L of the light emitted by the light-emitting device. The first effective radiant luminance Ls takes into account the relative visibility curve of human photopic vision as defined by the CIE and the spectral sensitivity of the human S-cone. The luminance L also takes into account the relative visibility curve of human photopic vision as defined by the CIE. The first luminance ratio Ls / L indicates the degree of glare reduction of the light emitted by the light-emitting device.

[0062] The light-emitting device of the first embodiment includes: a light-emitting element having a peak emission wavelength in the range of 400 nm or more and 490 nm or less; a first phosphor having a peak emission wavelength in the range of 480 nm or more and less than 580 nm; and a second phosphor having a peak emission wavelength in the range of 580 nm or more and 680 nm or less and having a composition different from that of the first phosphor. The light-emitting device emits light with a first luminance ratio Ls / L of 0.9 or less derived from the following formula (1).

[0063] [Mathematical Expression 6]

[0064]

[0065] (In Equation (1), S(λ) is the spectral radiance of the light emitted by the light-emitting device, V(λ) is the relative visibility curve of human photopic vision as specified by CIE, and Gs(λ) is the spectroscopic sensitivity of the human S-cone in the wavelength range of λnm above 380nm and below 550nm.)

[0066] When the first luminance ratio Ls / L of the light emitted by the light-emitting device is 0.9 or less, light with reduced glare can be emitted from the light-emitting device. When the first luminance ratio Ls / L of the light emitted by the light-emitting device exceeds 0.9, the luminance L of the light emitted by the light-emitting device is close to that of the light emitted by the light-emitting device without considering the spectroscopic sensitivity of the human S-cone, and glare is not reduced. In order to reduce glare that causes discomfort to people, the first luminance ratio Ls / L of the light emitted by the light-emitting device is preferably 0.85 or less, more preferably 0.83 or less, and even more preferably 0.80 or less. For the light emission of the light-emitting device, considering the spectroscopic sensitivity of the human S-cone, the first luminance ratio Ls / L can be 0.1 or more, and can be 0.2 or more.

[0067] A light-emitting device that emits light with a first luminance ratio Ls / L of 0.9 or less is preferably one that emits light with a second luminance ratio B / A of 0.104 or less, as described later. A light-emitting device that emits light with both a first luminance ratio Ls / L of 0.9 or less and a second luminance ratio B / A of 0.104 or less, as described later, can reduce glare and allow the light to reach distant locations.

[0068] The light-emitting device of the second embodiment includes: a light-emitting element having a peak emission wavelength in the range of 440 nm to 490 nm; a first phosphor having a peak emission wavelength in the range of 480 nm to 580 nm; and a second phosphor having a peak emission wavelength in the range of 580 nm to 680 nm and having a composition different from that of the first phosphor. The light-emitting device emits light with a second luminance ratio B / A of 0.104 or less derived from the following formula (2), wherein the second luminance ratio B / A is the ratio of the second effective radiant luminance B of the light emitted by the light-emitting device in the range of 300 nm to 800 nm to the radiant luminance A of the light emitted by the light-emitting device in the range of 300 nm to 800 nm, wherein the second effective radiant luminance B takes into account the scattering intensity curve relative to wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.

[0069] [Mathematical Expression 7]

[0070]

[0071] (In equation (2), S(λ) is the spectral radiance of the light emitted by the light-emitting device, and Dc(λ) is the scattering intensity curve relative to the wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.)

[0072] Light scattering, caused by the interaction between light and particles, is determined by the relative relationship between the wavelength λ of the light and the size D of the particles. The size D of the particles contained in the air is much smaller than the wavelength λ of light. Rayleigh scattering is the scattering of light caused by particles smaller than the wavelength of light. In air, the shorter the wavelength of light, the easier it is to be scattered. If light scattering is suppressed, light can reach a greater distance. A light-emitting device capable of reaching a greater distance can preferably be used for headlights in high-beam mode that illuminate a distance of approximately 100m in front. The light-emitting device of the second embodiment can suppress scattering and allow light to reach a greater distance. Furthermore, headlights using the light-emitting device of the second embodiment and vehicles equipped with such headlights can allow light to reach a greater distance.

[0073] The radiance A of the light emitted by the light-emitting device can be derived by the following equation (6). The radiance A of the light emitted by the light-emitting device is the integral value of the spectral radiance S(λ) of the light-emitting device in the range of 300 nm to 800 nm.

[0074] [Mathematical Expression 8]

[0075]

[0076] Figure 2The scattering intensity curve Dc(λ) of Rayleigh scattering at a wavelength of 300 nm is shown as a function of wavelength.

[0077] The second effective radiance B of the light emitted by the light-emitting device can be derived by the following equation (7). The second effective radiance B of the light emitted by the light-emitting device is the integral value of the above-mentioned scattering intensity curve Dc(λ) and the above-mentioned spectral radiance S(λ) of the light-emitting device in the range of 300 nm to 800 nm.

[0078] [Mathematical Expression 9]

[0079]

[0080] The second luminance ratio B / A of the light emitted by the light-emitting device is the ratio of the second effective radiance B of the light emitted by the light-emitting device in the range of 300 nm to 800 nm to the radiance A of the light emitted by the light-emitting device in the range of 300 nm to 800 nm. The second effective radiance B takes into account the scattering intensity curve relative to wavelength when the Rayleigh scattering intensity at a wavelength of 300 nm is set to 1. The second luminance ratio B / A represents the degree of scattering of the light emitted by the light-emitting device.

[0081] When the second luminance ratio B / A of the light emitted by the light-emitting device is 0.104 or less, scattering is suppressed, and light that can travel a greater distance can be emitted from the light-emitting device. When the second luminance ratio B / A of the light emitted by the light-emitting device exceeds 0.104, it is close to the radiance A of the light emitted by the light-emitting device without considering Rayleigh scattering. In order to suppress scattering and emit light that can travel a greater distance, the second luminance ratio B / A of the light emitted by the light-emitting device is preferably 0.102 or less, more preferably 0.100 or less, further preferably 0.099 or less, and even more preferably 0.098 or less. For the light emission of the light-emitting device, considering Rayleigh scattering, the second luminance ratio B / A can be 0.01 or more, or 0.02 or more.

[0082] A light-emitting device that emits light with a second luminance ratio B / A of 0.104 or less is preferably one that emits light with a first luminance ratio Ls / L of 0.9 or less. A light-emitting device that emits light with a second luminance ratio B / A of 0.104 or less and a first luminance ratio Ls / L of 0.9 or less can allow the light to reach a greater distance and can also reduce glare.

[0083] The following describes a light-emitting device that emits light with a first luminance ratio Ls / L of 0.9 or less and / or a light-emitting device that emits light with a second luminance ratio B / A of 0.104 or less. Preferably, the light-emitting device emitting light with a first luminance ratio Ls / L of 0.9 or less and the light-emitting device emitting light with a second luminance ratio B / A of 0.104 or less have the same correlated color temperature range, and can be the same type of light-emitting device using the same components.

[0084] The light-emitting device preferably emits light with a correlated color temperature of 1800K or higher and 5000K or lower, and more preferably emits light with a correlated color temperature of 2000K or higher and 5000K or lower. For example, when the correlated color temperature of the light emitted by the light-emitting device in the headlight is low, it can reduce glare felt by drivers of vehicles in front, oncoming vehicles, or the drivers of the vehicle itself.

[0085] Light-emitting element

[0086] The light-emitting element has a peak emission wavelength in the range of 400 nm to 490 nm. Preferably, the peak emission wavelength is in the range of 420 nm to 480 nm, and more preferably in the range of 440 nm to 460 nm. Since at least a portion of the light emitted by the light-emitting element is used as excitation light for the first and second phosphors, it is preferable to have a peak emission wavelength that easily excites these phosphors. The half-width of the emission spectrum of the light-emitting element is preferably 30 nm or less, more preferably 25 nm or less, and even more preferably 20 nm or less. For example, a semiconductor light-emitting element utilizing a nitride-based semiconductor is preferably used. This results in a stable light-emitting device with high efficiency, high linearity of output relative to input, and strong resistance to mechanical shock.

[0087] First fluorescent

[0088] The first phosphor is excited by the light emitted by a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm, emitting light with a peak emission wavelength in the range of 480 nm to 580 nm. The half-width of the emission spectrum of the first phosphor is preferably in the range of 90 nm to 125 nm, but can be in the range of 100 nm to 124 nm, or in the range of 110 nm to 123 nm. When the first phosphor has a peak emission wavelength in the range of 480 nm to 580 nm, the excitation light from the light-emitting element can be wavelength-converted, and the light-emitting device emits a mixed light consisting of light from the light-emitting element and light whose wavelength has been converted by the first and second phosphors.

[0089] The first phosphor preferably comprises at least one of rare earth aluminate phosphors having a composition contained in a compositional formula represented by the following formula (1A), and a first nitride phosphor having a composition contained in a compositional formula represented by the following formula (1B).

[0090] Ln 1 3(Al 1-a Ga a )5O 12 :Ce(1A)

[0091] (In formula (1A), Ln) 1 Let a be at least one element selected from Y, Gd, Tb, and Lu, and let a satisfy 0 ≤ a ≤ 0.5.

[0092] La w Ln 2 x Si6N y :Ce z (1B)

[0093] (In equation (1B), Ln) 2 It must contain at least one selected from Y and Gd, and may contain at least one selected from Sc and Lu, with 1 mole of Ln contained in the composition. 2 When the element is set to 100 mol%, Ln 2 The total amount of Y and Gd contained therein is over 90 mol%, and w, x, y, and z satisfy the following conditions: 1.2 ≤ w ≤ 2.2, 0.5 ≤ x ≤ 1.2, 10 ≤ y ≤ 12, 0.5 ≤ z ≤ 1.2, 1.80 < w + x < 2.40, and 2.9 ≤ w + x + z ≤ 3.1.

[0094] In this specification, the formula representing the composition of the fluorophore indicates the molar ratio of each element in 1 mole of the parent crystal and the fluorophore before the colon (:), and the element after the colon (:) indicates the activating element.

[0095] The first phosphor may comprise at least one phosphor selected from alkaline earth metal aluminate phosphors and alkaline earth metal halosilicate phosphors. An alkaline earth metal aluminate phosphor, for example, is a phosphor containing at least strontium and activated by europium, and for example, has the composition contained in the compositional formula represented by the following formula (1C). Alternatively, an alkaline earth metal halosilicate phosphor, for example, is a phosphor containing at least calcium and chlorine and activated by europium, and for example, has the composition contained in the compositional formula represented by the following formula (1D).

[0096] Sr4Al 14 O 25 Eu(1C)

[0097] (Ca,Sr,Ba)8MgSi4O 16(F,Cl,Br)2:Eu(1D)

[0098] In formula (1C), a portion of Sr can be replaced by at least one element selected from Mg, Ca, Ba and Zn.

[0099] Alkaline earth metal aluminate phosphors having the composition contained in the formula (1C) and alkaline earth metal halosilicate phosphors having the composition contained in the formula (1D) have emission peak wavelengths in the range of 480 nm or more and less than 520 nm, preferably in the range of 485 nm or more and less than 515 nm.

[0100] The alkaline earth metal aluminate phosphor having a composition contained in the formula represented by formula (1C) and the alkaline earth metal halosilicate phosphor having a composition contained in the formula represented by formula (1D) have a half-width in the emission spectrum of, for example, 30 nm or more, preferably 40 nm or more, more preferably 50 nm or more, and in addition, for example, 80 nm or less, preferably 70 nm or less.

[0101] In this specification, the multiple elements listed in the formula representing the composition of the fluorophore, separated by commas (,), refer to the inclusion of at least one of these multiple elements in the composition, or a combination of two or more elements selected from multiple elements.

[0102] The first phosphor may comprise at least one phosphor selected from β-silicon phosphors, first sulfide phosphors, scandium phosphors, alkaline earth metal silicate phosphors, and lanthanide phosphors. β-silicon phosphors, for example, have the composition contained in the formula represented by (1E). First sulfide phosphors, for example, have the composition contained in the formula represented by (1F). Scandium phosphors, for example, have the composition contained in the formula represented by (1G). Alkaline earth metal silicate phosphors, for example, have the composition contained in the formula represented by (1H) or the composition contained in the formula represented by (1J). Lanthanide phosphors, for example, have the composition contained in the formula represented by (1K).

[0103] Si 6-g Al g O g N 8-g Eu(0<g≤4.2)(1E)

[0104] (Sr,M 3 Ga2S4:Eu(1F)

[0105] (In formula (1F), M) 3 (It must be at least one element selected from Be, Mg, Ca, Ba, and Zn.)

[0106] (Ca,Sr)Sc2O4:Ce(1G)

[0107] (Ca,Sr)3(Sc,Mg)2Si3O 12 :Ce(1H)

[0108] (Ca,Sr,Ba)2SiO4:Eu(1J)

[0109] (La,Y,Gd,Lu)3Si6N 11 :Ce(1K)

[0110] The β-silicon phosphor, the first sulfide phosphor, the scandium phosphor, the alkaline earth metal silicate phosphor, and the lanthanide phosphor each have a peak emission wavelength in the range of 520 nm or more and less than 580 nm, preferably in the range of 525 nm or more and less than 565 nm. The half-width at half-maximum (WHM) of each of the β-silicon phosphor, the first sulfide phosphor, the scandium phosphor, the alkaline earth metal silicate phosphor, and the lanthanide phosphor in the emission spectrum is, for example, 20 nm or more, preferably 30 nm or more, and also, for example, 120 nm or less, preferably 115 nm or less.

[0111] The first phosphor may comprise at least one phosphor selected from the following: a rare earth aluminate phosphor having a composition contained in the composition expressed in formula (1A) above; a first nitride phosphor having a composition contained in the composition expressed in formula (1B) above; an alkaline earth metal aluminate phosphor having a composition contained in the composition expressed in formula (1C) above; an alkaline earth metal halosilicate phosphor having a composition contained in the composition expressed in formula (1D) above; a β-silicon phosphor having a composition contained in the composition expressed in formula (1E) above; a first sulfide phosphor having a composition contained in the composition expressed in formula (1F) above; a scandium phosphor having a composition contained in the composition expressed in formula (1G) above; an alkaline earth metal silicate phosphor having a composition contained in the composition expressed in formula (1H) above; an alkaline earth metal silicate phosphor having a composition contained in the composition expressed in formula (1J) above; and a lanthanide phosphor having a composition contained in the composition expressed in formula (1K) above. The first fluorophore may contain at least one fluorophore or two or more fluorophores.

[0112] Second fluorescent

[0113] The second phosphor is excited by the emission of a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm, and emits light having a peak emission wavelength in the range of 580 nm to 680 nm, having a composition different from that of the first phosphor. The second phosphor preferably has a half-width of 3 nm to 15 nm in the emission spectrum. As such a second phosphor, it is preferable to include, for example, a fluoride phosphor having a composition included in the composition expressed by formula (2C), or a fluoride phosphor having a composition included in the composition expressed by formula (2C'). Alternatively, it is preferable to have a half-width of 60 nm to 125 nm in the emission spectrum. As such a second phosphor, it is preferable to include, for example, a second nitride phosphor having a composition included in the composition expressed by formula (2A), a third nitride phosphor having a composition included in the composition expressed by formula (2B), or an α-silicon phosphor having a composition included in the composition expressed by formula (2G). The second phosphor converts the wavelength of the excitation light from the light-emitting element, and emits a mixed light from the light-emitting device, consisting of light from the light-emitting element and light whose wavelength has been converted by the first and second phosphors.

[0114] The second phosphor preferably comprises at least one selected from the following: a second nitride phosphor having a composition included in the composition expressed in formula (2A), a third nitride phosphor having a composition included in the composition expressed in formula (2B), a fluoride phosphor having a composition included in the composition expressed in formula (2C), a fluoride phosphor having a composition different from that expressed in formula (2C) having a composition included in the composition expressed in formula (2C'), and an α-cylon phosphor having a composition included in the composition expressed in formula (2G). In this specification, the second nitride phosphor having a composition included in the composition expressed in formula (2A) is sometimes referred to as a BSESN phosphor, and the third nitride phosphor having a composition included in the composition expressed in formula (2B) is sometimes referred to as an SCASN phosphor.

[0115] M 1 2Si5N8:Eu (2A)

[0116] (In formula (2A), M) 1 (It contains at least one alkaline earth metal element selected from Ca, Sr, and Ba.)

[0117] Sr q Ca s Al t Si u N v Eu (2B)

[0118] (In equation (2B), q, s, t, u, and v satisfy 0 ≤ q < 1, 0 < s ≤ 1, q + s ≤ 1, 0.9 ≤ t ≤ 1.1, 0.9 ≤ u ≤ 1.1, and 2.5 ≤ v ≤ 3.5, respectively.)

[0119] A c [M 2 1-b Mn 4+ b F d (2C)

[0120] (In equation (2C), A contains elements selected from K) + Li + Na + 、Rb + Cs + and NH4 + At least one of them, wherein K is preferred. + M 2 It contains at least one element selected from Group 4 and Group 14 elements, preferably Si or Ge. B satisfies 0 < b < 0.2, and c is [M]. 2 1-b Mn 4+ b F d The absolute value of the charge of an ion, d, satisfies 5 < d < 7.

[0121] A' c’ [M 2 ' 1-b’ Mn 4+ b’ F d’ (2C')

[0122] (In equation (2C'), A' contains elements selected from K) + Li + Na + 、Rb + Cs + and NH4 + At least one of them, wherein K is preferred. + M 2 It contains at least one element selected from Group 4, Group 13, and Group 14 elements, preferably Si or Al. b' satisfies 0 < b' < 0.2, and c' is [M... 2 ' 1-b’ Mn 4+ b’ F d’ The absolute value of the charge of an ion, d', satisfies 5 < d' < 7.

[0123] M8 v3 Si 12-(w3+x3) Al w3+x3 O x3 N 16-x3 Eu (2G)

[0124] (In formula (2G), M) 8 It contains at least one element selected from Li, Mg, Ca, Sr, Y, and the lanthanides (excluding La and Ce), and v3, w3, and x3 satisfy 0 < v3 ≤ 2.0, 2.0 ≤ w3 ≤ 6.0, and 0 ≤ x3 ≤ 1.0, respectively.

[0125] The second phosphor may comprise at least one phosphor selected from fluorogermanate phosphors, a fourth nitride phosphor, and a second sulfide phosphor. The fluorogermanate phosphor, for example, has the composition contained in the formula represented by the following formula (2D). The fourth nitride phosphor, for example, has the composition contained in the formula represented by the following formula (2E). The second sulfide phosphor, for example, has the composition contained in the formula represented by the following formula (2F).

[0126] (ij)MgO·(j / 2)Sc2O3·kMgF2·mCaF2·(1-n)GeO2·(n / 2)M 4 2O3:Mn(2D)

[0127] (In equation (2D), M) 4 It is selected from at least one of Al, Ga, and In. i, j, k, m, and n satisfy 2≤i≤4, 0≤j<0.5, 0<k<1.5, 0≤m<1.5, and 0≤n<0.5, respectively.

[0128] M 5 v2 M 6 w2 Al 3-y2 Si y2 N z2 M 7 (2E)

[0129] (In equation (2E), M) 5 M is at least one element selected from Ca, Sr, Ba, and Mg. 6 M is selected from at least one element chosen from Li, Na, and K. 7 For each element selected from Eu, Ce, Tb, and Mn, v², w², y², and z² satisfy 0.80 ≤ v² ≤ 1.05, 0.80 ≤ w² ≤ 1.05, 0 ≤ y² ≤ 0.5, and 3.0 ≤ z² ≤ 5.0, respectively.

[0130] (Ca,Sr)S:Eu(2F)

[0131] Fluorogermanate phosphors having compositions contained in a compositional formula represented by formula (2D) can have compositions represented by the following formula (2d).

[0132] 3.5MgO·0.5MgF2·GeO2:Mn(2d)

[0133] A fourth nitride phosphor having a composition contained in a compositional formula represented by formula (2E) may have a composition contained in a compositional formula represented by formula (2e) below.

[0134] M 5 v2 M 6 w2 M 7 x2 Al 3-y2 Si y2 N z2 (2e)

[0135] (In equation (2e), M5, M6, and M7 have the same meaning as M5, M6, and M7 in equation (2E), and are at least one element selected from Ce, Tb, and Mn. v2, w2, y2, and z2 have the same meaning as v2, w2, y2, and z2 in equation (2E), and x2 satisfies 0.001 < x2 ≤ 0.1.)

[0136] The fluorogermanate phosphor, the fourth nitride phosphor, and the second sulfide phosphor each have a peak emission wavelength in the range of 580 nm to 680 nm, preferably in the range of 600 nm to 630 nm. The half-width of the emission peak in the emission spectrum of the fluorogermanate phosphor, the fourth nitride phosphor, and the second sulfide phosphor is, for example, 5 nm to 100 nm, preferably 6 nm to 90 nm.

[0137] The second phosphor preferably comprises at least one selected from the following: a second nitride phosphor having a composition included in the composition expressed in formula (2A) above, a third nitride phosphor having a composition included in the composition expressed in formula (2B) above, a fluoride phosphor having a composition included in the composition expressed in formula (2C) above, a fluoride phosphor expressed in formula (2C') above, a fluorogermanate phosphor having a composition included in the composition expressed in formula (2D) above, a fourth nitride phosphor having a composition included in the composition expressed in formula (2E) above, a second sulfide phosphor having a composition included in the composition expressed in formula (2F) above, and an α-silicon phosphoenone phosphor having a composition included in the composition expressed in formula (2G) above. The second phosphor may comprise at least one phosphor or two or more phosphors.

[0138] The second phosphor is further preferably composed of at least one of the following: a second nitride phosphor (BSESN phosphor) having a composition included in the composition expressed in formula (2A) above, a third nitride phosphor (SCASN phosphor) having a composition included in the composition expressed in formula (2B) above, and an α-silicon phosphor having a composition included in the composition expressed in formula (2G) above. The second phosphor selected from at least one of the BSESN phosphor, SCASN phosphor, and α-silicon phosphor exhibits good temperature characteristics, with minimal change in luminescent energy caused by temperature variations. For example, in a light-emitting device equipped with a wavelength conversion component, the wavelength conversion component includes a rare-earth aluminate phosphor having the composition included in the composition expressed by formula (1A) above as a first phosphor, and includes at least one selected from BSESN phosphor, SCASN phosphor, and α-silicon phosphor as a second phosphor. Because the first and second phosphors have good temperature characteristics, even when used in a cold atmosphere, such as -40°C, or in a high-temperature atmosphere exceeding 100°C, the first luminance ratio Ls / L remains below 0.9. The rate of change of the first luminance ratio Ls / L is small, making it less susceptible to the influence of the ambient temperature of the operating environment, and enabling the light-emitting device to emit light with reduced glare. With the first luminance ratio Ls / L maintained below 0.9, even when the temperature of the operating environment of the light-emitting device changes, the temperature characteristics of the light-emitting device that emits light with a small rate of change of the first luminance ratio Ls / L are sometimes also good.

[0139] For a light-emitting device equipped with a wavelength conversion component, the wavelength conversion component includes a rare-earth aluminate phosphor having the composition included in the composition expressed by formula (1A) above as a first phosphor, and at least one selected from BSESN phosphor, SCASN phosphor, and α-silicon phosphor as a second phosphor. Because the first and second phosphors have good temperature characteristics, they are not easily affected by the ambient temperature of the operating environment, maintaining a second luminance ratio (B / A) of 0.104 or less. The rate of change of the second luminance ratio (B / A) is small, enabling the light-emitting device to emit light that is not easily affected by the ambient temperature of the operating environment, suppresses scattering, and can reach a greater distance. Even when the temperature of the operating environment of the light-emitting device changes, the temperature characteristics of the light-emitting device, which emits light with a small rate of change of the second luminance ratio (B / A), are sometimes good when the second luminance ratio (B / A) is maintained at 0.104 or less.

[0140] For a phosphor comprising a first phosphor and a second phosphor, the average particle size measured by the Fisher Sub-Sieve Sizer (hereinafter also referred to as "FSSS") method is preferably in the range of 5 μm or more and 40 μm or less, more preferably in the range of 6 μm or more and 35 μm or less, and even more preferably in the range of 7 μm or more and 30 μm or less. When the average particle size of the phosphor is in the range of 5 μm or more and 40 μm or less, the phosphor can efficiently absorb light emitted from the excitation source and perform wavelength conversion, enabling the emission of light from the light-emitting device with reduced glare or suppressed light scattering to reach a greater distance.

[0141] The light-emitting device emits light with a correlated color temperature of 1800K or higher and less than 3500K, preferably with the content of the first phosphor being 5% by mass or higher and less than 93% by mass relative to the total amount of the first and second phosphors. When the light-emitting device emits light with a correlated color temperature of 1800K or higher and less than 3500K, it can emit light with a low correlated color temperature and reduced blue light component, thus reducing glare. For the light-emitting device, if the content of the first phosphor is 5% by mass or higher and less than 93% by mass relative to the total amount of the first and second phosphors, then with a correlated color temperature of 1800K or higher and less than 3500K, it can emit light with a first luminance ratio Ls / L of 0.9 or lower. The content of the first phosphor relative to the total amount of the first phosphor and the second phosphor is more preferably in the range of 10% by mass or more and 92% by mass or less, more preferably in the range of 15% by mass or more and 90% by mass or less, particularly preferably in the range of 20% by mass or more and 88% by mass or less, and may be in the range of 30% by mass or more and 85% by mass or less, may be 40% by mass or more, or may be 50% by mass or more.

[0142] The light-emitting device emits light with a correlated color temperature of 3500K or higher and less than 4000K. Preferably, the content of the first phosphor is in the range of 20% by mass or higher and 95% by mass or lower relative to the total amount of the first and second phosphors. When the light-emitting device emits light with a correlated color temperature of 3500K or higher and less than 4000K, it can emit light with a low correlated color temperature and reduced blue light component, which can reduce glare. For the light-emitting device, if the content of the first phosphor is 20% by mass or higher and 95% by mass or lower relative to the total amount of the first and second phosphors, the correlated color temperature is 3500K or higher and less than 4000K, and it can emit light with a first luminance ratio Ls / L of 0.9 or lower. The content of the first phosphor is more preferably in the range of 30% by mass or higher and 90% by mass or lower relative to the total amount of the first and second phosphors, more preferably in the range of 40% by mass or higher and 85% by mass or lower, and can be 50% by mass or higher, 60% by mass or higher, 70% by mass or higher, or 75% by mass or higher.

[0143] The light-emitting device emits light with a correlated color temperature of 4000K or higher and 5000K or lower, preferably with the content of the first phosphor in the range of 50% by mass or higher and 99% by mass or lower relative to the total amount of the first and second phosphors. When the light-emitting device emits light with a correlated color temperature of 4000K or higher and 5000K or lower, it can emit light with a relatively reduced blue light component and a lower correlated color temperature, which can reduce glare. For the light-emitting device, if the content of the first phosphor in the range of 50% by mass or higher and 99% by mass or lower relative to the total amount of the first and second phosphors, it can emit light with a correlated color temperature of 4000K or higher and 5000K or lower and a first luminance ratio Ls / L of 0.9 or lower. The content of the first phosphor in the light-emitting device in the range of 60% by mass or higher and 98% by mass or lower relative to the total amount of the first and second phosphors is more preferably in the range of 70% by mass or higher and 95% by mass or lower, and can be 75% by mass or higher.

[0144] Light-emitting device

[0145] The method of using the light-emitting device will be explained. Figure 3A An example of a light-emitting device is shown, which is a schematic top view of light-emitting device 101. Figure 3B yes Figure 3AThe diagram shows a schematic cross-sectional view of the light-emitting device 101 along line III-III'. The light-emitting device 101 includes a light-emitting element 10 having a peak emission wavelength in the range of 400 nm to 490 nm and a wavelength conversion member 40. The wavelength conversion member 40 includes a wavelength converter 41 comprising a first phosphor 71 and a second phosphor 72 that emit light when excited by light from the light-emitting element 10, and a light-transmitting body 42 on which the wavelength converter 41 is disposed. The light-emitting element 10 is flip-chip mounted on a substrate 1 via bumps serving as conductive members 60. The wavelength converter 41 of the wavelength conversion member 40 is disposed on the light-emitting surface of the light-emitting element 10 via an adhesive layer 80. The sides of the light-emitting element 10 and the wavelength conversion member 40 are covered by a light-reflecting covering member 90. The wavelength conversion element 41 includes a first phosphor 71 that is excited by light from the light-emitting element 10 and has a peak emission wavelength in the range of 480 nm or more and less than 580 nm, and a second phosphor 72 that has a peak emission wavelength in the range of 580 nm or more and less than 680 nm and has a composition different from that of the first phosphor 71. The light-emitting element 10 receives power from an external source via wiring and conductive members 60 formed on the substrate 1, enabling the light-emitting device 101 to emit light. The light-emitting device 101 may include a semiconductor element 50, such as a protective element to prevent damage to the light-emitting element 10 due to excessive voltage. The covering member 90 is, for example, provided to cover the semiconductor element 50. Hereinafter, the components used in the light-emitting device will be described. It should be noted that for further details, please refer to, for example, the disclosure in Japanese Patent Application Publication No. 2014-112635.

[0146] Wavelength conversion component

[0147] The wavelength conversion component can be a wavelength conversion body comprising a phosphor and a light-transmitting material, or it can be a wavelength conversion component further comprising a light-transmitting body incorporating the wavelength conversion body. The wavelength conversion body preferably comprises a first phosphor, a second phosphor, and a light-transmitting material. The wavelength conversion body can be formed in a plate-like, sheet-like, or layered shape. The wavelength conversion component can have wavelength conversion bodies of other forms than plate-like, sheet-like, or layered shapes. For the wavelength conversion component or wavelength conversion body, relative to 100 parts by mass of the light-transmitting material, the total amount of phosphor can be in the range of 1 part by mass to 900 parts by mass, 10 parts by mass to 850 parts by mass, or 15 parts by mass to 800 parts by mass. The total amount of phosphor refers to the total amount of the first phosphor and the second phosphor.

[0148] In the thickness direction of the cross-section, the wavelength converter preferably comprises: a high-concentration layer with high filling rates and high concentrations of the first and second phosphors, and a low-concentration layer with low filling rates and low concentrations of the first and second phosphors. The high-concentration layer with high filling rates of the first and second phosphors makes the wavelength converter less prone to cracks and fissures. Preferably, the high-concentration layer is disposed on the light-emitting element side. By disposing the high-concentration layer on the light-emitting element side, heat generated by the light-emitting element can be dissipated via the first and second phosphors in the wavelength converter. Regarding the phosphor filling rate, the cross-section of the wavelength converter or the wavelength conversion component can be observed using a scanning electron microscope (SEM), and the phosphor filling rate can be determined based on the area ratio of resin to phosphor in the cross-section. A high-concentration layer with a high phosphor filling rate refers to a layer in which the area of ​​the phosphor is greater than the area of ​​the resin in the cross-section of the wavelength converter or the wavelength conversion component. A low-concentration layer with low phosphor filling rate refers to a layer in which the area of ​​the phosphor is smaller than the area of ​​the resin in the cross-section of the wavelength converter or the wavelength conversion component. A low-concentration layer may be a layer where phosphors are practically absent, with no phosphor area and only the area of ​​the resin visible. In the cross-section of the wavelength converter observed by SEM, regarding the ratio of the thickness of the high-concentration layer to the thickness of the low-concentration layer, with the total thickness of the wavelength converter set to 100%, the thickness of the low-concentration layer can be less than 40%, less than 35%, less than 34%, more than 3%, or more than 5%. A large ratio of low-concentration layer thickness to small ratio of high-concentration layer thickness indicates a high filling rate of the first and second phosphors in the high-concentration layer, signifying a high density of the high-concentration layer. To suppress cracks and fissures in the wavelength converter and improve heat dissipation, it is preferable that the high-concentration layer has a high filling rate and a high density of the first and second phosphors.

[0149] Figure 3C yes Figure 3B A partially enlarged view of a schematic cross-section of the light-emitting device shown, specifically P1. For illustration, sometimes... Figure 3C and Figure 3B The scales are different.

[0150] The wavelength converter 41 comprises a high-concentration layer 41a with a high filling rate of the first phosphor 71 and the second phosphor 72, and a low-concentration layer 41b with a low filling rate of the first phosphor 71 and the second phosphor 72. The high-concentration layer 41a is disposed on the light-emitting element 10 side. The low-concentration layer 41b of the wavelength converter 41 is disposed on the light-transmitting element 42 side. The wavelength converter 41 is disposed on the light-emitting surface of the light-emitting element 10 via an adhesive layer 80.

[0151] Headlights utilize high-output light-emitting devices; therefore, sometimes high-heat-resistant wavelength conversion components can be used, such as wavelength conversion components made by coating a light-transmitting body formed of high-heat-resistant glass with a resin composition containing a phosphor, or sintered bodies containing a phosphor and a light-transmitting material. Regarding the phosphor contained in the high-heat-resistant wavelength conversion component, phosphors considered to have higher heat resistance than other phosphors can sometimes be used, such as those with Y3Al5O3. 12 The composition is represented by Ce, indicating a rare-earth aluminate phosphor. For this rare-earth aluminate phosphor, the luminescence intensity is relatively low on the long wavelength side above 570 nm, therefore, in the case of headlights, it typically emits light with a correlated color temperature around 6000 K. Therefore, it can be considered that the phosphor included in the wavelength conversion component is, for example, only phosphors with a composition of Y3Al5O3. 12 In the case of rare-earth aluminate phosphors with a composition represented by Ce, it is difficult to achieve a headlight that emits light with a correlated color temperature below 5000K. The light-emitting device of the first embodiment or the light-emitting device of the second embodiment may individually include one of the first and second phosphors described above as a phosphor included in the sintered body for the wavelength conversion member, or it may include two or more of the first and second phosphors described above. Examples of phosphors included in the sintered body include, for example, the following phosphors.

[0152] (Ba,Sr,Ca)2Si5N8:Eu

[0153] (La,Y,Gd,Lu)3Si6N 11 :Ce

[0154] (Ca,Sr)AlSiN3:Eu

[0155] In addition, the sintered body used in the wavelength conversion component can be, for example, a sintered body containing a rare earth aluminate phosphor and a second nitride phosphor in one sintered body, or a sintered body formed by combining two layers of a sintered body containing a rare earth aluminate phosphor and a sintered body containing a second nitride phosphor.

[0156] Furthermore, glass can be used as the light-transmitting material for the wavelength conversion component. For example, a wavelength conversion component comprising glass and an α-silicon phosphor, wherein the α-silicon phosphor is composed of the formula M... 8 v3 (Si,Al) 12 (O,N) 16 Eu(M 8 v3 represents Li, Mg, Ca, Y, and lanthanide elements other than La and Ce, where v3 satisfies 0 < v3 ≤ 2.

[0157] It can be assumed that, using these as wavelength conversion components, the light-emitting device emits light with a correlated color temperature below 5000K. By using this light-emitting device, headlights that can reduce glare and vehicles equipped with such headlights can be provided.

[0158] Translucent materials

[0159] The light-transmitting material may be selected from at least one of resins, glass, and inorganic materials. The resin is preferably selected from at least one of epoxy resins, silicone resins, phenolic resins, and polyimide resins. The inorganic material may be selected from at least one of alumina and aluminum nitride.

[0160] When the light-transmitting material is a resin, a resin with a Shore A hardness of 30 or higher and 80 or lower is preferred. The light-transmitting material is preferably a silicone resin, and more preferably a silicone resin with a Shore A hardness of 30 or higher and 80 or lower. The Shore A hardness of the silicone resin used as the light-transmitting material is more preferably in the range of 40 or higher and 75 or lower, and even more preferably in the range of 50 or higher and 70 or lower. When the light-transmitting material is a resin, the resin expands or contracts due to light and heat. When the light-transmitting material is a silicone resin with a Shore A hardness of 30 or higher and 80 or lower, it exhibits excellent toughness and elongation. Therefore, even when the ambient temperature changes, it expands and contracts softly with temperature changes, making it less prone to cracks or fissures in the wavelength converter. It can emit light that maintains the first luminance ratio Ls / L at 0.9 or lower, and has good temperature characteristics. When the light-transmitting material is a silicone resin with a Shore A hardness of 30 or higher and below 80, it can expand and contract flexibly with temperature changes. The wavelength converter is not prone to cracks or fissures, and it can emit light with a second brightness ratio (B / A) of less than 0.104, exhibiting excellent temperature characteristics. The Shore A hardness of the resin can be measured using a type A hardness tester according to JIS K6253.

[0161] For example, when using a resin with a low Shore A hardness of about 30 as a light-transmitting material to form a wavelength converter, the wavelength converter is soft and adhesive. Therefore, when each light-emitting device is monolithically produced from a composite substrate with multiple light-emitting elements, it is difficult to cut, and there are also difficulties in transportation and packaging, resulting in poor mass production.

[0162] Therefore, by using a resin with a Shore A hardness of 30 or higher and 80 or lower as a light-transmitting material, it is possible to obtain a wavelength converter that is not prone to cracks or fissures in the wavelength converter or wavelength conversion component and has good temperature characteristics.

[0163] Transparent body

[0164] Wavelength conversion components can have a light-transmitting body. The light-transmitting body can be a plate-shaped body made of a light-transmitting material such as glass or resin. Examples of glass include borosilicate glass and quartz glass. Examples of resins include silicone resin and epoxy resin. The thickness of the light-transmitting body only needs to be sufficient to support the thickness of the wavelength conversion component without reducing its mechanical strength during the manufacturing process.

[0165] substrate

[0166] The substrate is preferably formed of an insulating material that makes it difficult for light from the light-emitting element and external light to penetrate. Examples of substrate materials include: ceramics such as alumina and aluminum nitride, phenolic resins, epoxy resins, polyimide resins, bismaleimide triazine resins (BT resins), and polyphthalamide (PPA) resins. Ceramic materials have high heat resistance and are therefore preferred as substrate materials.

[0167] Adhesive layer

[0168] An adhesive layer is used to fix the light-emitting element and the wavelength conversion component between them. The adhesive constituting the adhesive layer is preferably formed of a material capable of optically connecting the light-emitting element and the wavelength conversion component. Preferably, the material constituting the adhesive layer is at least one resin selected from epoxy resin, silicone resin, phenolic resin, and polyimide resin.

[0169] semiconductor components

[0170] Semiconductor components that are incorporated into a light-emitting device as needed include, for example, transistors for controlling the light-emitting element, and protective components for preventing damage to the light-emitting element caused by excessive voltage application, thus mitigating performance degradation. Zener diodes are an example of such protective components.

[0171] Encasing components

[0172] Insulating materials are preferred for use as the coating material. More specifically, examples include phenolic resins, epoxy resins, bismaleimide triazine resins (BT resins), polyphthalamide (PPA) resins, and silicone resins. Colorants, phosphors, and fillers may be added to the coating material as needed.

[0173] conductive components

[0174] As a conductive component, bumps can be used. As a material for bumps, Au or its alloys can be used. As other conductive components, eutectic solder (Au-Sn), Pb-Sn, lead-free solder, etc. can be used.

[0175] Manufacturing method of light-emitting device

[0176] An example of a method for manufacturing a light-emitting device will be described. It should be noted that for further details, please refer to, for example, the disclosures in Japanese Patent Application Publication No. 2014-112635 or Japanese Patent Application Publication No. 2017-117912. The preferred method for manufacturing a light-emitting device includes: a process for arranging light-emitting elements; a process for arranging semiconductor elements as needed; a process for forming a wavelength conversion member including a wavelength conversion element; a process for bonding the light-emitting elements and the wavelength conversion member; and a process for forming a covering member.

[0177] Light-emitting element configuration process

[0178] The light-emitting element is disposed on the substrate. The light-emitting element and semiconductor elements, such as flip chips, are mounted on the substrate.

[0179] Forming process of wavelength conversion component including wavelength conversion body

[0180] In the process of forming a wavelength conversion component containing a wavelength converter, the wavelength converter can be obtained by forming a plate-shaped, sheet-shaped, or layered wavelength converter on one side of a light-transmitting body using a printing method, an adhesive method, a compression molding method, or an electrodeposition method. For example, the printing method can print a wavelength converter containing a phosphor and a resin that is a light-transmitting material onto one side of a light-transmitting body to form a wavelength conversion component containing a wavelength converter.

[0181] Composition for wavelength converter

[0182] The wavelength conversion composition constituting the wavelength conversion body or wavelength conversion member includes a light-transmitting material and a first phosphor and a second phosphor, and may include a solvent. When the wavelength conversion composition includes a solvent, the viscosity of the wavelength conversion composition decreases, and during curing, the density of the first phosphor and the second phosphor increases in the direction of gravity. This allows for the manufacture of wavelength conversion bodies or wavelength conversion members with different filling rates of the first phosphor and the second phosphor in the wavelength conversion body or wavelength conversion member. Because the wavelength conversion body or wavelength conversion member contains a portion with a high filling rate of the first phosphor and the second phosphor, cracks and fissures are less likely to occur in the wavelength conversion body. By placing the high-concentration layer side of the wavelength conversion body with a high filling rate of the first phosphor and the second phosphor on the light-emitting element side, even when using a high-output light-emitting element, heat generated by the light-emitting element can be dissipated through the first phosphor and the second phosphor in the wavelength conversion body. This suppresses cracks and fissures in the resin constituting the wavelength conversion body, emitting light with a first luminance ratio Ls / L maintained at 0.9 or less, and exhibiting good temperature characteristics. By placing the high-concentration layer side with a high filling rate of the first and second phosphors of the wavelength converter on the light-emitting element side, even when using a high-output light-emitting element, the heat generated by the light-emitting element can be dissipated through the first and second phosphors in the wavelength converter. Cracks and fissures in the resin constituting the wavelength converter can be controlled, and light with the second brightness ratio B / A maintained at 0.104 or less is emitted, exhibiting good temperature characteristics.

[0183] Regarding the solvent, considering its solubility and volatility in the transparent resin, the boiling point at standard pressure (0.101 MPa) is preferably in the range of 150°C or higher and 320°C or lower, more preferably in the range of 170°C or higher and 305°C or lower, even more preferably in the range of 180°C or higher and 300°C or lower, and particularly preferably in the range of 190°C or higher and 290°C or lower. By including a solvent with a boiling point in the range of 150°C or higher and 320°C or lower at standard pressure in the composition for wavelength conversion, when the viscosity of the composition for wavelength conversion is reduced and it is cured, a high-concentration layer with a high filling rate of the first phosphor and the second phosphor in the direction of gravity and a low-concentration layer with a low filling rate of the first phosphor and the second phosphor can be formed.

[0184] The composition for wavelength conversion has a viscosity of at 25°C and 1 rpm based on an E-type viscometer, preferably in the range of 400 mPa·s or more, more preferably in the range of 6 mPa·s or more and 300 mPa·s or less, and even more preferably in the range of 8 mPa·s or more and 250 mPa·s or less.

[0185] When the light-transmitting material is an organosilicon resin, for the composition for the wavelength converter, if the total amount of phosphor contained in 100 parts by mass of the light-transmitting material is in the range of 1 part by mass or more and 900 parts by mass or less, the solvent content is preferably in the range of 1 part by mass or more and 50 parts by mass or less, more preferably in the range of 2 parts by mass or more and 40 parts by mass or less, and even more preferably in the range of 3 parts by mass or more and 30 parts by mass or less.

[0186] A solvent is a liquid organic compound that partially evaporates (volatiles) at room temperature. For example, by heating to above 180°C, the residual solvent in the wavelength converter composition can be evaporated, allowing the wavelength converter composition to solidify and form a wavelength converter or wavelength conversion component. Examples of solvents include: hydrocarbon solvents, ketone solvents, alcohol solvents, aldehyde solvents, glycol solvents, ether solvents, ester solvents, glycol ether solvents, and glycol ester solvents. Examples of hydrocarbon solvents include: hexane, xylene, heptane, decane, dodecane, and tridecane. Examples of ketone solvents include: acetone and methyl ethyl ketone. Examples of alcohol solvents include: methanol, ethanol, and isopropanol. Examples of aldehyde solvents include: nonanal and decanal. Examples of glycol solvents include: triethylene glycol. Examples of ether solvents include: diethyl ether. Examples of ester solvents include: methyl acetate and ethyl acetate. Examples of glycol ether solvents include: propylene glycol monomethyl ether. Examples of glycol ester solvents include ethylene glycol monoethyl ether acetate. The solvent is preferably selected from at least one of the following: hexadecane, xylene, heptane, acetone, ethanol, isopropanol, decane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, nonanal, decanal, and triethylene glycol. More preferably, the solvent is selected from at least one of the following: dodecane, tetradecane, pentadecane, hexadecane, and tridecane. A single solvent may be used, or two or more solvents may be used in combination.

[0187] Wavelength converter or wavelength conversion component

[0188] When the wavelength conversion composition contains a solvent, a wavelength conversion body or wavelength conversion member can be formed that, upon curing, is divided along the direction of gravity into a high-concentration layer with high fill rates of the first and second phosphors and a low-concentration layer with low fill rates of the first and second phosphors. In this specification, the high-concentration layer with high phosphor fill rate and the low-concentration layer with low phosphor fill rate can be identified in the thickness direction of the cross-section of the wavelength conversion body. As described above, the phosphor fill rate can be determined by observing the cross-section of the wavelength conversion body or the wavelength conversion member using SEM, and based on the area ratio of resin to phosphor in that cross-section. The boundary between one layer and other layers may be uneven and not linear.

[0189] Bonding process between light-emitting element and wavelength conversion component

[0190] In the bonding process between the light-emitting element and the wavelength conversion component, the wavelength conversion component is positioned opposite the light-emitting surface of the light-emitting element, and the wavelength conversion component is bonded to the light-emitting element using an adhesive layer. When the wavelength conversion component comprises a wavelength converter and a light-transmitting element, or when the wavelength converter comprises a high-concentration layer with a high phosphor fill rate and a low-concentration layer with a low phosphor fill rate, it is preferable to place the high-concentration layer with a high phosphor fill rate on the light-emitting element side, and then bond the wavelength conversion component to the light-emitting element. Since the thermal conductivity of the phosphor, which contains both a first phosphor and a second phosphor, is higher than that of the resin, by placing the high-concentration layer with a high phosphor fill rate on the light-emitting element side and bonding the wavelength conversion component, heat dissipation becomes better, cracks or fissures in the wavelength converter are less likely to occur, and the temperature characteristics are excellent.

[0191] Forming process of the covered component

[0192] In the process of forming the cladding member, the sides of the light-emitting element and the wavelength conversion member are covered by the cladding member with a composition. This cladding member is used to reflect light emitted from the light-emitting element. If the light-emitting device also includes a semiconductor element, it is preferably formed in a manner in which the semiconductor element is embedded in the cladding member. This may include a process of monolithically forming individual light-emitting devices from a composite substrate having multiple light-emitting elements and semiconductor elements on a single substrate.

[0193] For example, when a wavelength converter is formed using a resin with a low Shore A hardness of less than 30 as the light-transmitting material, the wavelength converter is soft and adhesive. Therefore, when the composite substrate with multiple light-emitting elements is monolithically divided into individual light-emitting devices, it is sometimes difficult to cut, transport, and package, resulting in poor mass production.

[0194] Therefore, by using a resin with a Shore A hardness of 30 or higher and 80 or lower as a light-transmitting material, it is possible to obtain a wavelength converter that is not prone to cracks or fissures and has good temperature characteristics.

[0195] headlamp

[0196] The light-emitting device can be disposed on a support substrate, etc., for a headlight source unit, and used as a headlight mounted on a vehicle. The headlight source unit can be, for example, the light source unit disclosed in Japanese Patent Application Publication No. 2003-317513. The light source unit, for example, includes a support substrate with a reflector, a projection lens, and the light-emitting device. The headlight source unit can be controlled to illuminate using, for example, a vehicle lighting system disclosed in Japanese Patent Application Publication No. Hei 8-67199. The light-emitting device can be used as the light source for a headlight used for a turn signal light, for example, as disclosed in Japanese Patent Application Publication No. 2005-123165. Figure 20This is a diagram showing a horizontal cross-sectional view of the headlight. Figure 21 This is a diagram showing the front view of the headlights. Figure 20 and Figure 21 The headlight 200 shown is positioned, for example, on the right side of the front of a vehicle. The headlight 200 includes a lamp body 24, an outer lens 22, multiple substrates 32, multiple light-emitting devices 100, an optical filter 26, and a light guide member 34. The lamp body 24 and the outer lens 22 form the lamp housing of the headlight 200, waterproofing and holding the multiple substrates 32 and multiple light-emitting devices 100 within this lamp housing. The lamp body 24 is formed, for example, by covering the multiple substrates 32 and multiple light-emitting devices 100 from the rear of the vehicle with resin. The optical filter 26 is fixed to the lamp body 24 by multiple screws 28. The multiple light-emitting devices 100 are each illuminated according to power received from the lighting control unit 12 via the substrates 32.

[0197] Headlights, such as those disclosed in Japanese Patent Application Publication No. 2003-317513, sometimes include a first luminaire unit, in which a single light-emitting device is arranged in a single light source unit. Additionally, headlights, such as those disclosed in Japanese Patent Application Publication No. 2005-141917, sometimes include a second luminaire unit, in which multiple reflectors, multiple projection lenses, and multiple light-emitting devices are arranged in a single light source unit integrally formed with multiple support substrates. Headlights can have two or more light-emitting devices, each with a different first brightness ratio (Ls / L). For two or more light-emitting devices with different first brightness ratios (Ls / L), each light-emitting device can be arranged in a single light source unit. Headlights can also have two or more light-emitting devices with different second brightness ratios (B / A). For two or more light-emitting devices with different second brightness ratios (B / A), each light-emitting device can be arranged in a single light source unit. Two or more light-emitting devices with different brightness ratios (B / A) can be configured in one light source unit.

[0198] The headlight may have two or more light-emitting devices, including a light-emitting device that emits light with a first brightness ratio Ls / L of 0.9 or less as the first light-emitting device and a light-emitting device that emits light with a first brightness ratio Ls / L of more than 0.9 as the second light-emitting device.

[0199] The headlight may have two or more light-emitting devices, such as the first light-emitting device that emits light with a second brightness ratio B / A of 0.104 or less, and the second light-emitting device that emits light with a second brightness ratio B / A of more than 0.104.

[0200] The second light-emitting device can be any light-emitting device that emits light with a first luminance ratio (Ls / L) exceeding 0.9 or light that emits light with a second luminance ratio (B / A) exceeding 0.104. For example, the second light-emitting device can be combined with... Figure 3A and Figure 3B The first light-emitting device shown is of the same form. Examples of the second light-emitting device include, for instance, a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm and a first phosphor having a peak emission wavelength in the range of 480 nm to 580 nm, but without a second phosphor. Examples of the first phosphor are phosphors identical to the first phosphor described above. Examples of the second light-emitting device include a device having a light-emitting element having a peak emission wavelength in the range of 400 nm to 490 nm and a rare-earth aluminate phosphor having the composition represented by formula (1A) as the first phosphor, but without a second phosphor, emitting light in the range of a first luminance ratio Ls / L exceeding 0.9, or a second luminance ratio B / A exceeding 0.104, and a correlated color temperature in the range of 5000 K to 6500 K.

[0201] vehicle

[0202] The vehicle described in the third embodiment can be any vehicle capable of being equipped with the aforementioned light-emitting device or headlight. Examples of vehicles equipped with the aforementioned light-emitting device or headlight include: road transport vehicles such as motorized two-wheeled vehicles and motorized four-wheeled vehicles; railway vehicles; tractors such as land preparation / transportation / loading machinery; and excavators such as excavating machinery.

[0203] Example

[0204] The present invention will now be described in more detail through embodiments. However, the present invention is not limited to these embodiments.

[0205] The following first phosphor and second phosphor were used in the light-emitting devices of each embodiment and comparative example.

[0206] First fluorescent

[0207] YAG-1, YAG-2, YAG-3, YAG-4, and YAG-5 were prepared as first phosphors. These phosphors have the composition contained in the compositional formula represented by the above formula (1A) and are rare earth aluminate phosphors with their own different compositions. As shown in Table 1, these first phosphors have their own different CIE chromaticity coordinates (x, y), emission peak wavelength, and half-width.

[0208] Second fluorescent

[0209] As second phosphors, the following were prepared: BSESN-1 and BSESN-2, which are second nitride phosphors having compositions included in the compositional formula represented by formula (2A) above and having different compositions; SCASN-1 and SCASN-2, which are third nitride phosphors having compositions included in the compositional formula represented by formula (2B) above and having different compositions; and an α-silicon phosphor having a composition included in the compositional formula represented by formula (2G) above. As shown in Table 1, these second phosphors have different CIE chromaticity coordinates (x, y), emission peak wavelengths, and half-widths.

[0210] The emission spectrum of phosphors

[0211] For each phosphor, a quantum efficiency measuring device (QE-2000, manufactured by Otsuka Electronics Co., Ltd.) was used to irradiate each phosphor with light of excitation wavelength 450 nm, and the emission spectrum at room temperature (approximately 25°C) was measured. Based on each emission spectrum, the x and y values, emission peak wavelength, and half-width in the CIE 1931 chromaticity coordinates were determined. The results are shown in Table 1.

[0212] Average particle size of phosphors

[0213] For each phosphor, the average particle size was determined using the FSSS method with a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). Specifically, 1 cm³ particles were measured. 3 A fraction of the sample volume of fluorophore is placed in a special tubular container, and dry air at a certain pressure is circulated through it. The specific surface area is read based on the differential pressure and converted into the average particle size (Fisher Sub-Sieve Sizer's No.).

[0214] [Table 1]

[0215]

[0216] Examples 1-13

[0217] Manufactured Figure 3A and Figure 3B The light-emitting device shown in the figure.

[0218] In the configuration process of the light-emitting element, a ceramic substrate made of aluminum nitride was used as the substrate. The light-emitting element was a nitride-based semiconductor layer with a dominant wavelength of 450 nm stacked on top. The light-emitting element was approximately square with a planar shape of about 1.0 mm square and a thickness of about 0.11 mm. The light-emitting element was configured with the light-emitting surface facing the substrate side, and flip-chip mounting was performed using bumps formed of conductive members made of Au. Furthermore, the semiconductor element was flip-chip mounted with bumps formed of conductive members made of Au at intervals from the light-emitting element.

[0219] As a light-transmitting material, silicone resin a (Shore A hardness 70) was used. In the formation process of the wavelength conversion member including the wavelength converter, a first phosphor and a second phosphor were used in the following combination as shown in Table 2, relative to 100 parts by mass of the silicone resin a, which is the light-transmitting material. In Table 2, the total phosphor amount represents the total amount of the first phosphor and the second phosphor relative to 100 parts by mass of silicone resin a. Furthermore, in Table 2, the content (mass%) of the first phosphor and the content (mass%) of the second phosphor represent the content of the first phosphor and the second phosphor when the total content of the first phosphor and the second phosphor is set to 100% by mass. As the light-transmitting material, a light-transmitting material made of borosilicate glass is provided, which is approximately a square with a length and width approximately 0.15 mm larger than the planar shape of the light-emitting element, a planar shape of approximately 1.15 mm square, and a thickness of approximately 0.10 mm. A wavelength conversion composition was printed onto one side of a roughly square-shaped transparent body using a printing method. The composition was then heated at 180°C for 2 hours to cure, forming a layered wavelength conversion body with a thickness of approximately 80 μm. This resulted in a layered or plate-like wavelength conversion body integrated with the transparent body, forming a wavelength conversion component. In this specification, the Shore A hardness of the silicone resin was measured according to JIS K6253 using a Type A hardness tester (product name: GS-709G, manufactured by TECLOCK). Furthermore, the viscosity of the wavelength conversion composition was measured using the method described later. The viscosity of the wavelength conversion composition in Example 3 was 40.4 mPa·s.

[0220] In the bonding process of the light-emitting element and the wavelength conversion component, an adhesive containing silicone resin is used to bond one side of the wavelength conversion component, which is approximately 1.15 mm square, to one side of the light-emitting element, which is approximately 1.0 mm square, forming an adhesive layer between the light-emitting element and the wavelength conversion component.

[0221] In the process of forming the encapsulation component, a composition for the encapsulation component is prepared, comprising dimethyl silicone resin and titanium dioxide particles, wherein 30 parts by mass of titanium dioxide particles are contained in 100 parts by mass of dimethyl silicone resin. The composition for the encapsulation component is used to encapsulate a light-emitting element disposed on a substrate and the side surface of a wavelength conversion element comprising a wavelength conversion element and a light-transmitting element. The composition for the encapsulation component is filled, thereby completely embedding the semiconductor element within the composition for the encapsulation component. The composition for the encapsulation component is then cured to form the encapsulation component, thereby forming a resin encapsulation and manufacturing a light-emitting device.

[0222] Example 14

[0223] As a light-transmitting material, silicone resin b (Shore A hardness 70) was used. The first phosphor and the second phosphor were used in the same combination as shown in Table 2 relative to 100 parts by weight of silicone resin b. Otherwise, the light-emitting device was manufactured in the same manner as in Example 2.

[0224] Example 15

[0225] As the first phosphor, YAG-5 as shown in Table 1 was used, and the first phosphor and the second phosphor were used in the same combination as shown in Table 2 relative to 100 parts by mass of silicone resin a. Otherwise, the light-emitting device was manufactured in the same manner as in Example 2.

[0226] Example 16

[0227] As the second phosphor, the α-silicon phosphor shown in Table 1 was used. The first and second phosphors were used in the same combination as shown in Table 2, relative to 100 parts by mass of silicone resin a. Otherwise, the light-emitting device was manufactured in the same manner as in Example 9. For the light-emitting device of Example 16, the proportions of the first and second phosphors were adjusted to produce light with chromaticity coordinates close to those of the light emitted by the light-emitting device of Example 9.

[0228] Example 17

[0229] As a light-transmitting material, silicone resin c (Shore A hardness 60) was used. The first phosphor and the second phosphor were used in the same combination as shown in Table 2 relative to 100 parts by mass of silicone resin c. Otherwise, the light-emitting device was manufactured in the same manner as in Example 2.

[0230] Example 18

[0231] As a wavelength converter composition, a wavelength converter composition containing 5 parts by mass of tridecane (boiling point 234°C) as a solvent was used relative to 100 parts by mass of silicone resin a (Shore A hardness 70). Otherwise, a light-emitting device was manufactured in the same manner as in Example 3. As described later, the wavelength converter formed using the above-described wavelength converter composition has a high-concentration layer with a high filling rate of the first phosphor and the second phosphor, and a low-concentration layer with a low filling rate of the first phosphor and the second phosphor, in the thickness direction of the wavelength converter. The light-emitting device was manufactured with the high-concentration layer with a high filling rate of the first phosphor and the second phosphor as the light-emitting element side. For the light-emitting device of Example 18, the proportions of the first phosphor and the second phosphor were adjusted so that the total amount of phosphor containing the first phosphor and the second phosphor relative to 100 parts by mass of silicone resin a reached the same value as the light-emitting device of Example 3. The viscosity of the wavelength converter composition of Example 18, measured by the method described later, was 16.3 mPa·s.

[0232] Comparative Example 1

[0233] Instead of using a second phosphor, YAG-4 as shown in Table 1 was used as the first phosphor, and the first phosphor was used in the combination shown in Table 2 relative to 100 parts by mass of silicone resin a. Otherwise, the light-emitting device was manufactured in the same manner as in Example 1.

[0234] The following measurements were performed on each luminescent device. The results are shown in Table 2. In Table 2, the "-" symbol indicates that a second phosphor was not used.

[0235] The emission spectrum, chromaticity coordinates (x, y), and correlated color temperature (K) of the light-emitting device.

[0236] For each light-emitting device, the emission spectrum at room temperature (25℃±5℃) was measured using a light measurement system consisting of a spectrophotometer (PMA-11, manufactured by Hamamatsu Photonics) and an integrating sphere. Based on the emission spectrum of each light-emitting device, the x and y values ​​in the CIE 1931 chromaticity coordinates and the correlated color temperature (K) according to JIS Z8725 were determined. Figures 4 to 13 The figure shows the emission spectra of each light-emitting device when the maximum luminous intensity is set to 1.

[0237] First brightness ratio Ls / L

[0238] The emission spectra S(λ) measured by each emission device will be analyzed according to... Figure 1A The spectroscopic sensitivity Gs(λ) of the human S-cone was calculated based on... Figure 1BSubstituting the relative visibility curve V(λ) of human photopic vision standard as specified by CIE into the above formula (1), the first brightness ratio Ls / L of the light emitted by each light-emitting device was obtained.

[0239] Second brightness ratio B / A

[0240] The emission spectra S(λ) measured by each emission device will be analyzed according to... Figure 2 Substituting the obtained scattering intensity curve Dc(λ) into the above equation (2), the second brightness ratio B / A of the light emitted by each light-emitting device was measured.

[0241] Relative luminous flux (%)

[0242] The luminous flux of each light-emitting device was measured using a total luminous flux measuring apparatus employing an integrating sphere. The luminous flux of the light-emitting device in Comparative Example 1 was set to 100%, and the relative luminous flux of each light-emitting device other than Comparative Example 1 was calculated.

[0243] Viscosity of the composition for wavelength converter

[0244] For the compositions of wavelength converters used in each wavelength conversion component, the viscosity at 25°C and 1 rpm was measured using an E-type viscometer (conical rotor (3°×R9.7): TVE-33H, manufactured by Toki Sangyo Co., Ltd.).

[0245] [Table 2]

[0246]

[0247] The light-emitting devices of Examples 1-18 emit light with a first brightness ratio Ls / L of 0.9 or less. The light-emitting devices of Examples 1-18 can emit light with reduced glare.

[0248] The light-emitting devices of Examples 1-18 emitted light with a second brightness ratio (B / A) of 0.104 or less. Light scattering in the light-emitting devices of Examples 1-18 was suppressed, allowing them to emit light that could reach a greater distance.

[0249] The light-emitting devices of Examples 1 to 4, 6 and 18 emit light with a correlated color temperature of 3500K or higher and less than 4000K. The content of the first phosphor is in the range of 70% by mass or higher and 85% by mass or lower relative to the total amount of the first phosphor and the second phosphor. They can emit light with a low correlated color temperature that reduces the blue light component, reduce glare, suppress light scattering, and emit light that can reach a greater distance.

[0250] The light-emitting devices of Examples 5, 7 to 13 and 16 emit light with a correlated color temperature of 1800K or higher and less than 3500K. The content of the first phosphor is in the range of 50% by mass or higher and 85% by mass or less relative to the total amount of the first phosphor and the second phosphor. They can emit light with a low correlated color temperature that reduces the blue light component, reduce glare, suppress light scattering, and emit light that can reach a greater distance.

[0251] The light-emitting devices of Examples 14, 15 and 17 emit light with a correlated color temperature of 4000K or higher and 5000K or lower. The content of the first phosphor is in the range of 75% by mass or higher and 95% by mass or lower relative to the total amount of the first phosphor and the second phosphor. They can emit light with a low correlated color temperature that reduces the blue light component, reduce glare, suppress light scattering, and emit light that can reach a greater distance.

[0252] The light-emitting device of Comparative Example 1 emits light with a first luminance ratio (Ls / L) exceeding 0.9, and the blue light component, which is prone to glare, is not reduced. Furthermore, the light-emitting device of Comparative Example 1 emits light with a second luminance ratio (B / A) exceeding 0.104, and light scattering is not suppressed. The light-emitting device of Comparative Example 1 emits light with a correlated color temperature exceeding 5000K, and the blue light component, which is prone to glare, is not reduced.

[0253] Figures 4-13 The emission spectra of the light-emitting devices of each embodiment and the emission spectrum of the light-emitting device of Comparative Example 1 are shown. Figures 4-12 As shown, for the emission spectra (spectral radiance) of the light-emitting devices of Examples 1 to 15 when the maximum luminous intensity is set to 1, the luminous intensity of the emission spectrum in the range of 500 nm to 700 nm is higher in each embodiment than in Comparative Example 1. Furthermore, as... Figure 13 As shown, for the emission spectra (spectral radiance) of the light-emitting devices of Examples 16 to 18 when the maximum luminous intensity is set to 1, the luminous intensity of the emission spectrum in the range of 550 nm to 700 nm is higher than that of Comparative Example 1. For the emission spectrum (spectral radiance) of the light-emitting device of Example 16, although the luminous intensity of the emission spectrum in the range of 500 nm to 550 nm is lower than that of Comparative Example 1, its temperature characteristics are excellent, as will be described later. The emission spectra (spectral radiance) of the light-emitting devices of each embodiment confirm that light with a first luminance ratio Ls / L of 0.9 or less is emitted, indicating that glare can be reduced. Furthermore, the emission spectra (spectral radiance) of the light-emitting devices of each embodiment confirm that light with a second luminance ratio B / A of 0.104 or less is emitted, indicating that light scattering can be suppressed.

[0254] Temperature characteristic evaluation 1 (rate of change of the first luminance ratio, rate of change of the second luminance ratio)

[0255] The light-emitting devices of Example 7, Example 9, Example 16, and Comparative Example 1 were powered at 1000mA and placed in constant temperature baths at ambient temperatures Ta℃ (standing time (min)): -40℃ (60 min), 0℃ (60 min), 25℃ (90 min), 85℃ (60 min), 100℃ (60 min), 110℃ (60 min), 125℃ (60 min), and 150℃ (30 min). After each standing time, the emission spectrum of each light-emitting device was measured at each ambient temperature. The standing time was defined as the time it took for the temperature in the constant temperature bath containing the light-emitting device to stabilize at each ambient temperature. The first luminance ratio Ls / L and the second luminance ratio B / A were determined based on the measured emission spectra S(λ) of each light-emitting device. Figure 14 The graph shows the relationship between the ambient temperature and the first brightness ratio of each light-emitting device. Figure 15 The graph shows the relationship between the ambient temperature and the second brightness ratio of each light-emitting device.

[0256] Based on the first luminance ratio or the second luminance ratio measured for each light-emitting device at each ambient temperature, the rate of change of the first luminance ratio or the rate of change of the second luminance ratio is calculated using the following formula (8). The rates of change of the first luminance ratio and the rate of change of the second luminance ratio for each light-emitting device are shown in Table 3.

[0257] The rate of change of the first luminance ratio or the rate of change of the second luminance ratio (%) = {(maximum value / minimum value) - 1} × 100 (8)

[0258] The maximum value in equation (8) is the maximum value of the first luminance ratio or the second luminance ratio of each light-emitting device under each ambient temperature, and the minimum value is the minimum value of the first luminance ratio or the second luminance ratio of each light-emitting device under each ambient temperature.

[0259] Temperature characteristics evaluation 2 (correlated color temperature)

[0260] The light-emitting devices of Example 7, Example 16, and Comparative Example 1 were powered with 1000mA and placed in a constant temperature bath with ambient ambient temperature Ta℃ (standing time (min)): -40℃ (60 min), 0℃ (60 min), 25℃ (90 min), 85℃ (60 min), 100℃ (60 min), 110℃ (60 min), 125℃ (60 min), and 150℃ (30 min). After each standing time, the emission spectrum of each light-emitting device was measured at each ambient ambient temperature. The correlated color temperature was determined based on the emission spectrum S(λ) of each light-emitting device. Figure 16 The diagram shows the relationship between the ambient temperature and the correlated color temperature of each light-emitting device.

[0261] [Table 3]

[0262]

[0263] As shown in Table 3, Figure 14 and Figure 15 As shown, the light-emitting devices of Example 7, Example 9, and Example 16 emit light with a first luminance ratio Ls / L of 0.9 or less and a second luminance ratio B / A of 0.104 or less, regardless of the ambient temperature. Compared to the light-emitting devices of Example 7 and Example 9, the light-emitting device of Example 16, which uses an α-silicon phosphor as the second phosphor, exhibits smaller rates of change in both the first and second luminance ratios. For the light-emitting device of Example 16, the rate of change in the first luminance ratio is also small, for example, when used in a cold atmosphere of -40°C or in a high-temperature atmosphere exceeding 100°C, resulting in light emission with reduced glare and good temperature characteristics. For the light-emitting device of Example 16, the rate of change in the second luminance ratio is also small, for example, when used in a cold atmosphere of -40°C or in a high-temperature atmosphere exceeding 100°C, resulting in suppressed scattering and emission of light that reaches a greater distance, also exhibiting good temperature characteristics.

[0264] like Figure 16 As shown, the light-emitting devices of Example 7 and Example 16 are independent of the ambient temperature and can emit light with a correlated color temperature within a given range, exhibiting good temperature characteristics. The rate of change of correlated color temperature was calculated using the formula shown in Equation (8). The results showed that the rate of change of correlated color temperature of the light-emitting device of Example 16 was 8.2%, the rate of change of correlated color temperature of the light-emitting device of Example 7 was 4.3%, and the rate of change of correlated color temperature of the light-emitting device of Comparative Example 1 was 10.7%. The maximum value in Equation (8) is the maximum value of the correlated color temperature of each light-emitting device at each ambient temperature, and the minimum value in Equation (8) is the minimum value of the correlated color temperature of each light-emitting device at each ambient temperature.

[0265] Confirmation of the phosphor filling rate in the cross section 1

[0266] The wavelength converters used in the light-emitting device of Example 3 and Example 18 were cut and their cross-sections were observed using a scanning electron microscope (SEM). For the wavelength converters used in the light-emitting devices of Example 3 and Example 18, the total amount of the first and second phosphors was 240 parts by mass relative to 100 parts by mass of the transparent material. Compared to the wavelength converter used in the light-emitting device of Example 3, the wavelength converter used in the light-emitting device of Example 18 had a lower viscosity composition due to the use of tridecane as a solvent, allowing for the observation of a high-concentration layer with a high filling rate in the cross-section of the wavelength converter.

[0267] Temperature characteristic evaluation 3

[0268] The light-emitting devices of Example 18 and Example 3 were powered on at a junction temperature Tj of 150°C and a current of 1200 mA, and then placed in a constant temperature bath at an ambient temperature Ta of 85°C and a relative humidity of 85%RH for 1000 hours to confirm the state of each device. After the light-emitting device of Example 18 was powered on at 1200 mA and continuously lit for 1000 hours at an ambient temperature of 85°C and a relative humidity of 85%RH, the surface of the wavelength conversion component in the light-emitting device was examined using a microscope (manufactured by HIROX Corporation), and no resin cracks or the like were observed. Because the composition for forming the wavelength conversion body in the light-emitting device of Example 18 contains a solvent, the viscosity of the composition is reduced, resulting in a layer with a high phosphor filling rate in the thickness direction of the wavelength conversion body. Since this high phosphor filling rate layer is positioned on the light-emitting element side, heat from the light-emitting element can be dissipated via the phosphor, thus suppressing cracks and fissures in the resin constituting the wavelength conversion body.

[0269] Temperature characteristic evaluation 4

[0270] The light-emitting device of Example 17 was powered on at a junction temperature Tj of 150°C and a current of 1200mA, and then placed in a constant temperature bath at an ambient temperature Ta of 85°C and a relative humidity of 85%RH for 1000 hours to confirm the condition of each light-emitting device. Even when powered on at 1200mA and continuously lit for 1000 hours at 85°C and 85%RH, no resin cracks were observed on the surface of the wavelength conversion component in the light-emitting device using a microscope (manufactured by HIROX). The silicone resin used in the wavelength conversion composition of Example 17 has a Shore A hardness of 60. Because the silicone resin used in the wavelength conversion composition of Example 17 has a lower Shore A hardness, it can expand and contract flexibly even when continuously lit at a relatively high temperature of 85°C and a high humidity of 85%RH, thus suppressing cracks and fissures in the resin constituting the wavelength conversion component.

[0271] Confirmation of the phosphor filling rate in the cross section 2

[0272] The following evaluations were made of the wavelength conversion component used in the light-emitting device of Example 3, the wavelength conversion component used in the light-emitting device of Example 18, the wavelength conversion component used in the light-emitting device of Example 19, and the wavelength conversion component used in Example 20.

[0273] Example 19

[0274] As a wavelength converter composition, a wavelength converter composition comprising 5 parts by mass of dodecane (boiling point 214°C to 216°C) as a solvent was used relative to 100 parts by mass of silicone resin a (Shore A hardness 70). Otherwise, a light-emitting device was manufactured in the same manner as in Example 3. The wavelength converter formed using the above-described wavelength converter composition, as described below, has a high-concentration layer with a high filling rate of the first and second phosphors and a low-concentration layer with a low filling rate of the first and second phosphors formed in the thickness direction of the wavelength converter. The light-emitting device was manufactured with the high-concentration layer with a high filling rate of the first and second phosphors as the light-emitting element side. For the light-emitting device of Example 19, the proportions of the first and second phosphors were adjusted so that the total amount of phosphors containing the first and second phosphors relative to 100 parts by mass of silicone resin a reached the same value as the light-emitting device of Example 3.

[0275] Example 20

[0276] As a wavelength converter composition, a wavelength converter composition comprising 5 parts by mass of hexadecane (boiling point 287°C) as a solvent was used relative to 100 parts by mass of silicone resin a (Shore A hardness 70). Otherwise, a light-emitting device was manufactured in the same manner as in Example 3. The wavelength converter formed using the above-described wavelength converter composition, as described below, has a high-concentration layer with a high filling rate of the first and second phosphors and a low-concentration layer with a low filling rate of the first and second phosphors formed in the thickness direction of the wavelength converter. The light-emitting device was manufactured with the high-concentration layer with a high filling rate of the first and second phosphors as the light-emitting element side. For the light-emitting device of Example 20, the proportions of the first and second phosphors were adjusted so that the total amount of phosphors containing the first and second phosphors relative to 100 parts by mass of silicone resin a reached the same value as the light-emitting device of Example 3.

[0277] The ratio of the thickness of the high-concentration layer to the thickness of the low-concentration layer

[0278] For the compositions of wavelength converters in Examples 3, 18-20, the viscosity was measured in the same manner as described above. Furthermore, for the wavelength conversion components of Examples 3, 18-20, the cross-section of the samples was confirmed by SEM (SU3500, manufactured by Hitachi High-Tech). Figure 17 The image shows a cross-sectional SEM photograph of a sample of the wavelength converter of Example 18. Figure 17 In the diagram, the white solid and dashed lines are used to explain the thickness (height) T1 to T5, which will be described later. Based on Figure 17The SEM images are used to explain the calculation method for the thickness of the high-concentration layer 41a and the low-concentration layer 41b. The overall thickness (height) of the wavelength conversion body 41 of the wavelength conversion component 40 is defined as the first height T1. In the cross-section of the wavelength conversion body 41 in the SEM image, the layer where the combined area of ​​the first phosphor and the second phosphor is greater than the area of ​​the resin is defined as the high-concentration layer 41a. In the cross-section of the wavelength conversion body 41 in the SEM image, the layer where the combined area of ​​the first phosphor and the second phosphor is less than the area of ​​the resin is defined as the low-concentration layer 41b. The boundary between the high-concentration layer 41a and the low-concentration layer 41b cannot be represented by a straight line and forms an uneven surface according to the shape of the first phosphor and the second phosphor. The distance from the portion of the first or second phosphor contained in the high-concentration layer 41a closest to the light-transmitting body 42 to the lower surface 41c of the wavelength conversion body 41 is defined as the second height T2. The distance from the portion of the first and second phosphors contained in the high-concentration layer 41a that is closest to the lower surface 41c of the wavelength converter to the lower surface 41c of the wavelength converter 41 is defined as the third height T3. The average of the second height T2 and the third height T3 is defined as the fourth height T4, and the fourth height T4 is taken as the thickness (height) T4 of the high-concentration layer 41a. The fifth height T5 obtained by subtracting the fourth height T4, which represents the thickness of the high-concentration layer 41a, from the first height T1, which represents the thickness of the wavelength converter 41, is taken as the thickness (height) T5 of the low-concentration layer 41b. The thickness T4 of the high-concentration layer 41a and the thickness T5 of the low-concentration layer 41b of the wavelength converter 41 in the SEM image can be calculated by the following equations (9) and (10). In the following equations (9) and (10), T1 to T5 are as described above.

[0279] The thickness (height) of the high-concentration layer is T4 = (T2 + T3) / 2 (9)

[0280] The thickness (height) of the low-concentration layer, T5, is equal to T1 - T4 (10).

[0281] Table 4 shows the formulation ratios and viscosities of the wavelength converter compositions of Examples 3, 18-20, as well as the ratios of the thicknesses (heights) of the high-concentration and low-concentration layers of the wavelength converters of Examples 3, 18-20. In Table 4, the total phosphor content represents the total amount of the first and second phosphors relative to 100 parts by mass of the silicone resin. Furthermore, in Table 4, the first phosphor content (mass%) and second phosphor content (mass%) represent the content of the first phosphor and the second phosphor when the total content of the first and second phosphors is set to 100% by mass. In Table 4, the solvent content (parts by mass) represents the amount of solvent relative to 100 parts by mass of the silicone resin. Table 4 shows the ratios of the thicknesses (heights) of the high-concentration layer and the low-concentration layer when the overall thickness (height) of the wavelength converter is set to 100%.

[0282] [Table 4]

[0283]

[0284] The wavelength converters of Examples 3, 18-20 all possess a high-concentration layer with a high filling rate of the first and second phosphors, and a low-concentration layer with a low filling rate of the first and second phosphors. Relative to 100% of the overall thickness of the wavelength converter of Examples 3, 18-20, the ratio of the thickness of the high-concentration layer is in the range of 60% to 95%, and the ratio of the thickness of the low-concentration layer is in the range of 5% to 40%. For the wavelength converters of Examples 18-20 that use a solvent-containing wavelength converter composition, the ratio of the thickness of the high-concentration layer is less than that of the wavelength converter of Example 3 that uses a solvent-free wavelength converter composition. The high-concentration layer contains a high filling rate of the first and second phosphors, and a high density of the first and second phosphors in the high-concentration layer.

[0285] Figure 18 This is an SEM image of a cross-section of a sample of the wavelength conversion component of Example 18. Figure 19 This is an SEM image of a cross-section of a sample of the wavelength conversion component of Example 3. Figure 18 and Figure 19 The white solid lines shown are for illustrative purposes and represent the overall thickness (height) of the wavelength converter 41. Figure 18 and Figure 19The white dashed lines shown are for illustrative purposes and represent the boundary between the high-concentration layer 41a and the low-concentration layer 41b of the wavelength converter 41. In the cross-section of the samples of the wavelength conversion components of Examples 3 and 18, the wavelength conversion component 40 includes a wavelength converter 41 and a light-transmitting element 42. The wavelength converter 41 includes a high-concentration layer 41a with a high filling rate of the first phosphor 71 and the second phosphor 72, and a low-concentration layer 41b with a low filling rate of the first phosphor 71 and the second phosphor 72. For the wavelength converter 41 of Example 18, which uses a wavelength converter composition containing a solvent, the ratio of the thickness of the high-concentration layer 41a is less than that of the wavelength converter 41 of Example 3, which uses a wavelength converter composition without a solvent. The high-concentration layer 41 contains a high filling rate of the first phosphor and the second phosphor, and the high-concentration layer 41 contains a high density of the first phosphor and the second phosphor. For the wavelength converter 41 of Example 18, the ratio of the thickness of the low-concentration layer 41b is greater than the ratio of the thickness of the low-concentration layer 41b of the wavelength converter 41 of Example 3.

[0286] Industrial applicability

[0287] The light-emitting device of the embodiments of this disclosure can be used as a headlight. Headlights equipped with the light-emitting device based on the embodiments of this disclosure can be used in vehicles such as road transport vehicles (motorized two-wheelers, motorized four-wheelers, etc.), railway vehicles, tractors (such as land preparation / handling / loading machinery), or excavators (such as excavating machinery).

Claims

1. A light-emitting device, comprising: Light-emitting elements having a peak emission wavelength in the range of 400nm to 490nm, and Wavelength conversion component, The wavelength conversion component includes a first phosphor having a peak emission wavelength in the range of 480 nm to less than 580 nm, and a second phosphor having a peak emission wavelength in the range of 580 nm to less than 680 nm and having a composition different from that of the first phosphor. The light-emitting device emits light with a first luminance ratio Ls / L of 0.9 or less, derived from the following formula (1). The first luminance ratio Ls / L is the ratio of the first effective radiant luminance Ls of the light emitted by the light-emitting device in the range of 380 nm to 780 nm to the luminance L of the light emitted by the light-emitting device in the same range. The first effective radiant luminance Ls takes into account the relative visibility curve of human photopic vision as defined by the CIE (International Commission on Illumination) and the spectral sensitivity of the human S-cone. The luminance L takes into account the relative visibility curve of human photopic vision. In equation (1), S(λ) is the spectral radiance of the light emitted by the light-emitting device, V(λ) is the relative visibility curve of human photopic vision as specified by CIE (International Commission on Illumination), and Gs(λ) is the spectroscopic sensitivity of the human S-cone when the wavelength λnm is above 380nm and below 550nm.

2. The light-emitting device according to claim 1, wherein it emits light with a correlated color temperature of 1800K or higher and 5000K or lower.

3. The light-emitting device according to claim 1 or 2, wherein, The emission spectrum of the first phosphor has a half-width of 90 nm or more and 125 nm or less.

4. The light-emitting device according to claim 1 or 2, wherein, The emission spectrum of the second phosphor has a half-width of 3 nm or more and 15 nm or less, or a half-width of 60 nm or more and 120 nm or less.

5. The light-emitting device according to any one of claims 1 to 4, wherein, The first phosphor comprises at least one selected from rare earth aluminate phosphors having a composition included in the composition expressed by formula (1A) below, and a first nitride phosphor having a composition included in the composition expressed by formula (1B) below. Ln 1 3(Al 1-a Ga a )5O 12 :Ce (1A) In equation (1A), Ln 1 Let a be at least one element selected from Y, Gd, Tb, and Lu, and let a satisfy 0 ≤ a ≤ 0.

5. to w In 2 x Si6N y :What z (1B) In equation (1B), Ln 2 It must contain at least one selected from Y and Gd, and optionally at least one selected from Sc and Lu, with 1 mole of Ln contained in the composition. 2 When the element is set to 100 mol%, Ln 2 The total amount of Y and Gd contained therein is more than 90 mol%, and w, x, y and z satisfy 1.2≤w≤2.2, 0.5≤x≤1.2, 10≤y≤12, 0.5≤z≤1.2, 1.80<w+x<2.40, 2.9≤w+x+z≤3.

1.

6. The light-emitting device according to any one of claims 1 to 5, wherein, The second phosphor comprises at least one selected from the following: The following are examples of phosphors: a second nitride phosphor having a composition included in a composition expressed in formula (2A); a third nitride phosphor having a composition included in a composition expressed in formula (2B); a fluoride phosphor having a composition included in a composition expressed in formula (2C); a fluoride phosphor having a composition different from that expressed in formula (2C) and having a composition included in a composition expressed in formula (2C'); and an α-silicon phosphor having a composition included in a composition expressed in formula (2G). M 1 2Si5N8:Eu (2A) In equation (2A), M 1 It contains at least one alkaline earth metal element selected from Ca, Sr, and Ba. Sr. q That s the t And u N v :I (2B) In equation (2B), q, s, t, u, and v satisfy 0 ≤ q < 1, 0 < s ≤ 1, q + s ≤ 1, 0.9 ≤ t ≤ 1.1, 0.9 ≤ u ≤ 1.1, and 2.5 ≤ v ≤ 3.5, respectively. A c [M 2 1-b Mn 4+ b F d ] (2C) In equation (2C), A contains elements selected from K. + Li + Na + 、Rb + Cs + and NH4 + At least one of them, M 2 It contains at least one element selected from Group 4 and Group 14, b satisfies 0 < b < 0.2, and c is [M]. 2 1-b Mn 4+ b F d The absolute value of the charge of an ion, d, satisfies 5 < d < 7. A’ c’ [M 2 ’ 1-b’ Mn 4+ b’ F d’ ] (2C’) In equation (2C'), A' contains elements selected from K. + Li + Na + 、Rb + Cs + and NH4 + At least one of them, M 2 'Contains at least one element selected from Group 4, Group 13, and Group 14, b' satisfies 0 < b' < 0.2, and c' is [M 2 ' 1-b’ Mn 4+ b’ F d’ The absolute value of the charge of an ion, d', satisfies 5 < d' < 7. M 8 v3 And 12-(w3+x3) the w3+x3 A x3 N 16-x3 :I (2G) In equation (2G), M 8 It contains at least one element selected from Li, Mg, Ca, Sr, Y and the lanthanides (but excluding La and Ce), and v3, w3 and x3 satisfy 0 < v3 ≤ 2.0, 2.0 ≤ w3 ≤ 6.0 and 0 ≤ x3 ≤ 1.0, respectively.

7. The light-emitting device according to any one of claims 1 to 4, wherein, The first phosphor is a rare-earth aluminate phosphor having a composition contained in the composition expressed by the following formula (1A). The second phosphor comprises at least one selected from the following: a second nitride phosphor having a composition included in a composition represented by formula (2A), a third nitride phosphor having a composition included in a composition represented by formula (2B), and an α-silicon phosphor having a composition included in a composition represented by formula (2G). Ln 1 3(Al 1-a Ga a )5O 12 :Ce (1A) In equation (1A), Ln 1 Let a be at least one element selected from Y, Gd, Tb, and Lu, and let a satisfy 0 ≤ a ≤ 0.

5. M 1 2Si5N8:Eu (2A) In equation (2A), M 1 It contains at least one alkaline earth metal element selected from Ca, Sr, and Ba. Sr. q That s the t And u N v :I (2B) In equation (2B), q, s, t, u, and v satisfy 0 ≤ q < 1, 0 < s ≤ 1, q + s ≤ 1, 0.9 ≤ t ≤ 1.1, 0.9 ≤ u ≤ 1.1, and 2.5 ≤ v ≤ 3.5, respectively. M 8 v3 And 12-(w3+x3) the w3+x3 A x3 N 16-x3 :I (2G) In equation (2G), M 8 It contains at least one element selected from Li, Mg, Ca, Sr, Y and the lanthanides (but excluding La and Ce), and v3, w3 and x3 satisfy 0 < v3 ≤ 2.0, 2.0 ≤ w3 ≤ 6.0 and 0 ≤ x3 ≤ 1.0, respectively.

8. The light-emitting device according to any one of claims 1 to 7, wherein, The wavelength conversion component comprises an organosilicon resin with a Shore A hardness of 30 or higher and 80 or lower.

9. The light-emitting device according to any one of claims 1 to 8, wherein the emitted light has a correlated color temperature of 1800K or more and less than 3500K, and the content of the first phosphor is in the range of 5% by mass or more and 93% by mass or less relative to the total amount of the first phosphor and the second phosphor.

10. The light-emitting device according to any one of claims 1 to 8, wherein, The light-emitting device emits light with a correlated color temperature of 3500K or higher and less than 4000K, and the content of the first phosphor is in the range of 20% by mass or higher and 95% by mass relative to the total amount of the first phosphor and the second phosphor.

11. The light-emitting device according to any one of claims 1 to 8, wherein the emitted light has a correlated color temperature of 4000K or more and 5000K or less, and the content of the first phosphor is in the range of 50% by mass or more and 99% by mass or less relative to the total amount of the first phosphor and the second phosphor.

12. The light-emitting device according to any one of claims 1 to 11, wherein, The wavelength conversion component includes a wavelength converter, which comprises the first phosphor, the second phosphor, and a light-transmitting material. The wavelength converter comprises a high-concentration layer with a high filling rate of the first phosphor and the second phosphor, and a low-concentration layer with a low filling rate of the first phosphor and the second phosphor. The high-concentration layer is disposed on the side of the light-emitting element.

13. A headlight comprising the light-emitting device according to any one of claims 1 to 12.

14. The headlight according to claim 13, wherein it comprises two or more light-emitting devices, each having a different value of the first brightness ratio Ls / L.

15. A headlight comprising two or more light-emitting devices, namely a first light-emitting device and a second light-emitting device. The first light-emitting device comprises the light-emitting device according to any one of claims 1 to 12. The second light-emitting device emits light with a first luminance ratio Ls / L exceeding 0.9, derived from the following formula (1). The first luminance ratio Ls / L is the ratio of the first effective radiant luminance Ls of the light emitted by the light-emitting device above 380 nm and below 780 nm to the luminance L of the light emitted by the light-emitting device above 380 nm and below 780 nm. The first effective radiant luminance takes into account the relative visibility curve of human photopic vision as defined by the CIE (International Commission on Illumination) and the spectroscopic sensitivity of the human S-cone. The luminance L takes into account the relative visibility curve of human photopic vision. In equation (1), S(λ) is the spectral radiance of the light emitted by the light-emitting device, V(λ) is the relative visibility curve of human photopic vision as specified by CIE (International Commission on Illumination), and Gs(λ) is the spectroscopic sensitivity of the human S-cone when the wavelength λnm is above 380nm and below 550nm.

16. A light-emitting device comprising: Light-emitting elements having a peak emission wavelength in the range of 400nm to 490nm, and Wavelength conversion component, The wavelength conversion component includes a first phosphor having a peak emission wavelength in the range of 480 nm to less than 580 nm, and a second phosphor having a peak emission wavelength in the range of 580 nm to less than 680 nm and having a composition different from that of the first phosphor. The light-emitting device emits light with a second luminance ratio B / A of 0.104 or less, derived from the following equation (2). The second luminance ratio B / A is the ratio of the second effective radiance B of the light emitted by the light-emitting device in the range of 300 nm to 800 nm to the radiance A of the light emitted by the light-emitting device in the range of 300 nm to 800 nm. The second effective radiance B takes into account the scattering intensity curve relative to wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1. In equation (2), S(λ) is the spectral radiance of the light emitted by the light-emitting device, and Dc(λ) is the scattering intensity curve relative to the wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.

17. The light-emitting device according to claim 16, wherein it emits light with a correlated color temperature of 1800K or higher and 5000K or lower.

18. The light-emitting device according to claim 16 or 17, wherein, The emission spectrum of the first phosphor has a half-width of 90 nm or more and 125 nm or less.

19. The light-emitting device according to claim 16 or 17, wherein, The emission spectrum of the second phosphor has a half-width of 3 nm or more and 15 nm or less, or a half-width of 60 nm or more and 120 nm or less.

20. The light-emitting device according to any one of claims 16 to 19, wherein, The first phosphor comprises at least one selected from rare earth aluminate phosphors having a composition included in the composition expressed by formula (1A) below, and a first nitride phosphor having a composition included in the composition expressed by formula (1B) below. Ln 1 3(Al 1-a Ga a )5O 12 :Ce(1A) In formula (I), Ln 1 Let a be at least one element selected from Y, Gd, Tb, and Lu, and let a satisfy 0 ≤ a ≤ 0.

5. to w In 2 x Si6N y :What z (1B) In equation (II), Ln 2 It must contain at least one selected from Y and Gd, and optionally at least one selected from Sc and Lu, with 1 mole of Ln contained in the composition. 2 When the element is set to 100 mol%, Ln 2 The total amount of Y and Gd contained therein is more than 90 mol%, and w, x, y and z satisfy 1.2≤w≤2.2, 0.5≤x≤1.2, 10≤y≤12, 0.5≤z≤1.2, 1.80<w+x<2.40, 2.9≤w+x+z≤3.

1.

21. The light-emitting device according to any one of claims 16 to 20, wherein, The second phosphor comprises at least one selected from the following: The following are examples of phosphors: a second nitride phosphor having a composition included in a composition expressed in formula (2A); a third nitride phosphor having a composition included in a composition expressed in formula (2B); a fluoride phosphor having a composition included in a composition expressed in formula (2C); a fluoride phosphor having a composition different from that expressed in formula (2C) and having a composition included in a composition expressed in formula (2C'); and an α-silicon phosphor having a composition included in a composition expressed in formula (2G). M 1 2Si5N8:Eu(2A) In equation (2A), M 1 It contains at least one alkaline earth metal element selected from Ca, Sr, and Ba. Sr. q That s the t And u N v :I(2B) In equation (2B), q, s, t, u, and v satisfy 0 ≤ q < 1, 0 < s ≤ 1, q + s ≤ 1, 0.9 ≤ t ≤ 1.1, 0.9 ≤ u ≤ 1.1, and 2.5 ≤ v ≤ 3.5, respectively. A c [M 2 1-b Mn 4+ b F d ](2C) In equation (2C), A contains elements selected from K. + Li + Na + 、Rb + Cs + and NH4 + At least one of them, M 2 It contains at least one element selected from Group 4 and Group 14, b satisfies 0 < b < 0.2, and c is [M]. 2 1-b Mn 4+ b F d The absolute value of the charge of an ion, d, satisfies 5 < d < 7. A’ c’ [M 2 ’ 1-b’ Mn 4+ b’ F d’ ] (2C’) In equation (2C'), A' contains elements selected from K. + Li + Na + 、Rb + Cs + and NH4 + At least one of them, M 2 'Contains at least one element selected from Group 4, Group 13, and Group 14, b' satisfies 0 < b' < 0.2, and c' is [M 2 ' 1-b’ Mn 4+ b’ F d’ The absolute value of the charge of an ion, d', satisfies 5 < d' < 7. M 8 v3 And 12-(w3+x3) the w3+x3 A x3 N 16-x3 :I (2G) In equation (2G), M 8 It contains at least one element selected from Li, Mg, Ca, Sr, Y and the lanthanides (but excluding La and Ce), and v3, w3 and x3 satisfy 0 < v3 ≤ 2.0, 2.0 ≤ w3 ≤ 6.0 and 0 ≤ x3 ≤ 1.0, respectively.

22. The light-emitting device according to any one of claims 16 to 19, wherein, The first phosphor is a rare-earth aluminate phosphor having a composition contained in the composition expressed by the following formula (1A). The second phosphor comprises at least one selected from the following: a second nitride phosphor having a composition included in a composition represented by formula (2A), a third nitride phosphor having a composition included in a composition represented by formula (2B), and an α-silicon phosphor having a composition included in a composition represented by formula (2G). Ln 1 3(Al 1-a Ga a )5O 12 :Ce (1A) In equation (1A), Ln 1 Let a be at least one element selected from Y, Gd, Tb, and Lu, and let a satisfy 0 ≤ a ≤ 0.

5. M 1 2Si5N8:Eu (2A) In equation (2A), M 1 It contains at least one alkaline earth metal element selected from Ca, Sr, and Ba. Sr. q That s the t And u N v :I (2B) In equation (2B), q, s, t, u, and v satisfy 0 ≤ q < 1, 0 < s ≤ 1, q + s ≤ 1, 0.9 ≤ t ≤ 1.1, 0.9 ≤ u ≤ 1.1, and 2.5 ≤ v ≤ 3.5, respectively. M 8 v3 And 12-(w3+x3) the w3+x3 A x3 N 16-x3 :I (2G) In equation (2G), M 8 It contains at least one element selected from Li, Mg, Ca, Sr, Y and the lanthanides (but excluding La and Ce), and v3, w3 and x3 satisfy 0 < v3 ≤ 2.0, 2.0 ≤ w3 ≤ 6.0 and 0 ≤ x3 ≤ 1.0, respectively.

23. The light-emitting device according to any one of claims 16 to 22, wherein, The wavelength conversion component comprises an organosilicon resin with a Shore A hardness of 30 or higher and 80 or lower.

24. The light-emitting device according to any one of claims 16 to 23, wherein, The light-emitting device emits light with a correlated color temperature of 1800K or higher and less than 3500K, and the content of the first phosphor is in the range of 5% by mass or higher and 93% by mass relative to the total amount of the first phosphor and the second phosphor.

25. The light-emitting device according to any one of claims 16 to 23, wherein, The light-emitting device emits light with a correlated color temperature of 3500K or higher and less than 4000K, and the content of the first phosphor is in the range of 20% by mass or higher and 95% by mass relative to the total amount of the first phosphor and the second phosphor.

26. The light-emitting device according to any one of claims 16 to 23, wherein the emitted light has a correlated color temperature of 4000K or more and 5000K or less, and the content of the first phosphor is in the range of 50% by mass or more and 99% by mass or less relative to the total amount of the first phosphor and the second phosphor.

27. The light-emitting device according to any one of claims 16 to 26, wherein, The wavelength conversion component includes a wavelength converter, which comprises the first phosphor, the second phosphor, and a light-transmitting material. The wavelength converter comprises a high-concentration layer with a high filling rate of the first phosphor and the second phosphor, and a low-concentration layer with a low filling rate of the first phosphor and the second phosphor. The high-concentration layer is disposed on the side of the light-emitting element.

28. A headlight comprising the light-emitting device according to any one of claims 16 to 27.

29. The headlight according to claim 28, wherein it comprises two or more light-emitting devices, each having a different value of the second brightness ratio B / A.

30. A headlight comprising two or more light-emitting devices, namely a first light-emitting device and a second light-emitting device. The first light-emitting device comprises the light-emitting device according to any one of claims 16 to 27. The second light-emitting device emits light with a second luminance ratio B / A exceeding 0.104, derived from the following equation (2). The second luminance ratio B / A is the ratio of the second effective radiance B of the light emitted by the light-emitting device in the range of 300 nm to 800 nm to the radiance A of the light emitted by the light-emitting device in the range of 300 nm to 800 nm. The second effective radiance B takes into account the scattering intensity curve relative to wavelength when the Rayleigh scattering intensity at a wavelength of 300 nm is set to 1. In equation (2), S(λ) is the spectral radiance of the light emitted by the light-emitting device, and Dc(λ) is the scattering intensity curve relative to the wavelength when the scattering intensity of Rayleigh scattering at a wavelength of 300 nm is set to 1.

31. A vehicle comprising a light-emitting device according to any one of claims 1 to 12, 16 to 27.

32. A vehicle having the headlights according to any one of claims 13-15 and 28-30.

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