Light emitting device

Abstract

Provided is a light emitting device that is bright in both scotopic vision and photopic vision, and that can evoke an image of a specific state. A light emitting device provided with a light emitting element having a main wavelength in the range of 400 nm or more and 500 nm or less, and a wavelength conversion member disposed on the light emission side of the light emitting element, the wavelength conversion member including a rare earth aluminate phosphor having a composition represented by the following formula (I), the light emitting device emitting light having a main wavelength in the range of 475 nm or more and 500 nm or less, and the ratio of luminous flux in scotopic vision to luminous flux in photopic vision, i.e., the S / P ratio derived from formula (1), being 6.5 or less.(Lu 1－p－ n Ln p Ce n )3(Al 1－m Ga m ) 5k O 12 (I) (in formula (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and k, m, n, and p each satisfy 0.95 ≤ k ≤ 1.05, 0.05 ≤ m ≤ 0.70, 0.002 ≤ n ≤ 0.050, and 0 ≤ p ≤ 0.30).

Description

Technical Field

[0001] This invention relates to light-emitting devices. Background Technology

[0002] As a light-emitting device using a light-emitting element such as a light-emitting diode (LED), there are known light-emitting devices that use a light-emitting element that emits blue light and a phosphor that emits light when excited by light from the light-emitting element, thereby emitting mixed-color light. Such light-emitting devices can be used in a wide range of fields, such as general lighting, automotive lighting, displays, and backlighting for liquid crystal displays.

[0003] In recent years, light-emitting devices that take into account their impact on humans have attracted attention. For example, when humans perceive light, it is known that the visual acuity of the human eye changes between dark and bright environments. In photopic vision in bright environments, colors can be perceived due to the function of cone cells, which are the photoreceptor cells of the human eye. In scotopic vision in dark environments, many colors cannot be perceived because cone cells are inactive, but visual acuity is enhanced due to the function of rod cells.

[0004] It is known that the peak wavelength of visual acuity of cone cells, which are active in bright light, is 555 nm, while the peak wavelength of visual acuity of rod cells, which are active in dark light, is 507 nm. The peak values ​​of visual acuity differ between light and dark conditions. This phenomenon is known as the twilight phenomenon (Purkinje Phenomenon), where colors on the longer wavelength side are clearly visible in bright light, and colors on the shorter wavelength side are clearly visible in dark light.

[0005] For example, Patent Document 1 proposes a streetlight that, as a lighting device utilizing the twilight phenomenon, emits white light that, in a twilight visual environment with intermediate brightness between darkness and light, provides high visibility for drivers on the sidewalk side, high visibility for pedestrians, and makes it difficult to perceive color spots on the lane side and sidewalk side. Patent Document 1 argues that the higher the scotopic vision to photopic vision ratio (S / P ratio), the higher the visibility in a twilight visual environment.

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-220312

[0009] However, if the S / P ratio is too high, the human eye may perceive it as dark under photopic vision and bright under scotopic vision. Additionally, there are requirements for light-emitting devices to emit a specific color that evokes a charging state in humans; the impact of such light emission on human perception must also be considered. Summary of the Invention

[0010] One aspect of the present invention aims to provide a light-emitting device that can emit a bright light-emitting color that evokes images such as specific states, regardless of whether the person is dark-vision or light-vision, while also taking into account the impact on the person.

[0011] One aspect of the present invention is a light-emitting device comprising a light-emitting element and a wavelength conversion component, wherein the light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm, and the wavelength conversion component comprises a rare-earth aluminate phosphor having a composition represented by the following formula (I) disposed on the light-emitting side of the light-emitting element.

[0012] (Lu 1－p－n Ln p Ce n )3(Al 1－m Ga m ) 5k O 12 (I)

[0013] (In formula (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd and Tb, and k, m, n and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050 and 0≤p≤0.30, respectively.)

[0014] The light-emitting device emits light with a dominant wavelength in the range of 475nm to 500nm.

[0015] The ratio of luminous flux under scotopic vision to luminous flux under photopic vision, i.e., the S / P ratio derived from the following formula (1), is 6.5 or less.

[0016]

Equation 1

[0017]

[0018] In equation (1), the constant K is 6831 (lm / W), the constant K' is 1700 (lm / W), the wavelength λnm is in the range of 360nm to 830nm, V(λ) is the spectral luminous efficiency of human photopic vision, V'(λ) is the spectral luminous efficiency of human scotopic vision, and Φ e (λ) represents the total spectral radiant flux of light emitted from the light-emitting device.

[0019] Another aspect of the present invention is a light-emitting device comprising a light-emitting element and a wavelength conversion component, wherein the light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm, and the wavelength conversion component comprises a rare-earth aluminate phosphor having a composition represented by the following formula (I) disposed on the light-emitting side of the light-emitting element.

[0020] (Lu 1－p－n Ln p Ce n )3(Al 1－m Ga m ) 5k O 12 (I)

[0021] (In formula (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd and Tb, and k, m, n and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050 and 0≤p≤0.30, respectively.)

[0022] The light-emitting device emits light with a dominant wavelength in the range of 475nm to 500nm.

[0023] The melatonin illuminance ratio derived from the following formula (2) is below 3.4.

[0024]

Equation 2

[0025]

[0026] (In formula (2), the wavelength is in the range of 380nm above and 730nm below. "Lamp×Circadian" is the circadian rhythm response contained in the spectral distribution of the light-emitting device, "Lamp×Visual" is the visual acuity response contained in the spectral distribution of the light-emitting device, "Lamp" is the spectral distribution of the light-emitting device, "Circadian" is the sensitivity curve of the photoreceptor in the retina of mammals, i.e., the intrinsic photosensitive retinal ganglion cells, "Visual" is the visual acuity curve under human photopic vision, and "1.218" is a constant (lux factor).)

[0027] According to the present invention, it is possible to provide a light-emitting device that emits a bright light-emitting color that evokes images of specific states, such as charging, regardless of whether the view is dark or light, and also takes into account the effect on people. Attached Figure Description

[0028] Figure 1 This is a graph showing the photopic spectral luminous efficiency V(λ) and the scotopic spectral luminous efficiency V'(λ).

[0029] Figure 2 It is a graph that shows the sensitivity curve of the photoreceptors on the retina of mammals, namely the intrinsic photosensitive retinal ganglion cells, and the visual acuity curve under human photopic vision.

[0030] Figure 3 It is a diagram representing region A1 in the xy chromaticity coordinate system of the CIE1931 chromaticity diagram.

[0031] Figure 4 It is a diagram representing region A2 in the xy chromaticity coordinate system of the CIE1931 chromaticity diagram.

[0032] Figure 5 It is a diagram representing region A3 in the xy chromaticity coordinate system of the CIE1931 chromaticity diagram.

[0033] Figure 6A This is a schematic top view of the light-emitting device in the first embodiment.

[0034] Figure 6B This is a schematic cross-sectional view of the light-emitting device in the first embodiment.

[0035] Figure 7 This is a schematic cross-sectional view of the light-emitting device in the second configuration example.

[0036] Figure 8 This is a schematic cross-sectional view of the light-emitting device in the third embodiment.

[0037] Symbol Explanation

[0038] 10, 11: Light-emitting element; 21: Phosphor; 30, 33: Wavelength conversion component; 31: Wavelength converter; 32: Light-transmitting body; 41: Molded body; 42: Resin part; 50: Semiconductor element; 51: First lead; 52: Second lead; 60: Conductive component; 63: Wire; 70: Substrate; 80: Adhesive layer; 90: Coated component; 100, 200, 300: Light-emitting device. Detailed Implementation

[0039] The light-emitting device of the present invention will now be described based on embodiments. However, the embodiments shown below are merely examples to embody the technical concept of the present invention, and the present invention is not limited to the light-emitting device described below. Furthermore, the relationship between color names and chromaticity coordinates, and the relationship between the wavelength range of light and the color names of monochromatic light, are based on JIS Z8110. Additionally, the content of each component in the composition means, unless otherwise specified, the total amount of the multiple substances present in the composition when multiple substances corresponding to each component are present in the composition.

[0040] Light-emitting device

[0041] One type of light-emitting device is a light-emitting device having a light-emitting element and a wavelength conversion component, wherein the light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm, and the wavelength conversion component includes a rare earth aluminate phosphor having a composition represented by formula (I) described later, disposed on the light-emitting side of the light-emitting element, and the light-emitting device emits light having a dominant wavelength in the range of 475 nm to 500 nm, and the ratio of luminous flux under photopic vision to luminous flux under scotopic vision, i.e., the S / P ratio derived from formula (1) described later, is 6.5 or less.

[0042] The dominant wavelength of a light-emitting element refers to the chromaticity coordinates (x = 0.3333, y = 0.3333) of white light in the CIE 1931 chromaticity diagram as defined by the CIE (International Commission on Illumination) and the chromaticity coordinates (x, y) of the emitted color of the light-emitting element, connected by a straight line. E y E The dominant wavelength of a light-emitting device is the wavelength at the point where its extension intersects the spectral locus. The spectral locus is the curve obtained by connecting the chromaticity points of monochromatic (simple) light on a chromaticity diagram. The dominant wavelength of a light-emitting device is the wavelength at the point where the extension of a straight line connecting the chromaticity coordinates (x = 0.3333, y = 0.3333) of white light on the CIE 1931 chromaticity diagram to the chromaticity coordinates (x, y) of the emitted color of the light-emitting device intersects the spectral locus.

[0043] The light-emitting device includes: a light-emitting element having a dominant wavelength in the wavelength range from blue to blue-green, and a phosphor having a peak emission wavelength in the green wavelength range, emitting light with a dominant wavelength in the wavelength range from blue to green, including blue-green. It is known that the higher the ratio of luminous flux under dark vision to luminous flux under light vision, i.e., the higher the S / P ratio, the higher the human visual perception. Figure 1 This is a graph representing the photopic spectral luminous efficiency V(λ) and the scotopic spectral luminous efficiency V'(λ). The photopic spectral luminous efficiency V(λ) and the scotopic spectral luminous efficiency V'(λ) are defined by the CIE. For example... Figure 1As shown, the peak wavelength of the photopic spectral luminous efficiency V(λ) is 555 nm, and the peak wavelength of the scotopic spectral luminous efficiency V'(λ) is 507 nm. The peak values ​​of visual acuity differ between light and dark environments. Because the peak wavelengths of visual acuity differ between light and dark environments, it is known that, due to the twilight phenomenon, colors on the longer wavelength side appear vivid in light, while colors on the shorter wavelength side appear vivid in dark environments. For light-emitting devices emitting light with a dominant wavelength range from violet to green, if the S / P ratio is increased to improve visibility, colors on the shorter wavelength side appear overly vivid and perceived as too bright in the dark. The light-emitting device of this invention, when emitting light with a dominant wavelength range from blue to green (including blue-green), also has an S / P ratio of 6.5 or less. This is considered to reduce the difference in luminous flux between dark and bright environments, resulting in a bright appearance for both photopic and scotopic vision, maintaining excellent visibility.

[0044] The S / P ratio, which is the ratio of luminous flux in the dark to luminous flux in the bright, can be derived from the following equation (1).

[0045]

Equation 3

[0046]

[0047] In equation (1), the constant K is 6831 (lm / W), the constant K' is 1700 (lm / W), the wavelength λnm is in the range of 360nm to 830nm, V(λ) is the spectral luminous efficiency of human photopic vision, V'(λ) is the spectral luminous efficiency of human scotopic vision, and Φ e (λ) is the total spectral radiant flux of light emitted from the light-emitting device.

[0048] The ratio of luminous flux under scotopic vision to luminous flux under photopic vision, i.e., the S / P ratio, emitted from the light-emitting device, is 6.5 or less, preferably 6.0 or less, more preferably 2.0 or more, and even more preferably 3.0 or more. With an S / P ratio of 6.5 or less, by reducing the difference between luminous flux under scotopic vision and luminous flux under photopic vision, it is believed that even in light-emitting devices emitting light with dominant wavelengths in the blue to green wavelength range (including blue-green), light can be emitted that maintains excellent visibility under both scotopic and photopic vision while reducing the perceived brightness difference under both conditions. The dominant wavelength, luminous flux, chromaticity coordinates (x, y) in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram (described later), and total spectral radiant flux of light emitted from the light-emitting device or light-emitting element can be measured using a spectrophotometer (e.g., PMA-11, manufactured by Hamamatsu Hotniks Co., Ltd.) and a photometer system incorporating an integrating sphere.

[0049] Another type of light-emitting device includes: a light-emitting element having a dominant wavelength in the range of 400 nm to 500 nm; and a wavelength conversion member having a rare earth aluminate phosphor composed of a composition represented by formula (I) described later, disposed on the light-emitting side of the light-emitting element, the light-emitting device emitting light having a dominant wavelength in the range of 475 nm to 500 nm, and a melatonin illuminance ratio derived from formula (2) being 3.4 or less.

[0050]

Equation 4

[0051]

[0052] In equation (2), within the wavelength range of 380 nm to 730 nm, "Lamp × Circadian" is the diurnal rhythm response included in the spectral distribution of the light-emitting device, "Lamp × Visual" is the visual acuity response included in the spectral distribution of the light-emitting device, "Lamp" is the spectral distribution of the light-emitting device, "Circadian" is the sensitivity curve of the photoreceptor in the retina of mammals, namely the intrinsically photosensitive retinal ganglion cell (ipRGC), "Visual" is the visual acuity curve under human photopic vision, and "1.218" is a constant (lux factor). The spectral distribution (emission spectrum) of the light-emitting device can be measured using a spectrophotometer (e.g., PMA-11, manufactured by Hamamatsu Hotniks Co., Ltd.) and a photometer system combined with an integrating sphere. "Visual" can be measured using the spectral luminous efficiency V(λ) of human photopic vision as specified by CIE (Visual = V(λ)).

[0053] In addition to cones and rods, intrinsically photosensitive retinal ganglion cells (ipRGCs) containing melanopsin, a visual pigment, have been found in the photoreceptor cells (receptor cells) of the human retina. These ipRGCs, even as individuals, exhibit neural responses to light stimuli. They also receive input from cones and rods and demonstrate neural responses to light stimuli, thus influencing the human circadian rhythm. Figure 2This graph represents the sensitivity curve (circadian rhythm effect curve) of the ipRGC and the visual acuity curve of human photopic vision. The peak wavelength in the human photopic visual acuity curve is 555 nm, while the melanopsin emitted by the ipRGC has its sensitivity peak wavelength around 480 nm to 500 nm. Melanoopsin also participates in the secretion and inhibition of melatonin, a sleep-promoting hormone. Furthermore, the melanopsin emitted by the ipRGC projects onto the imaging system pathway from the lateral geniculate nucleus (the part of the eye that transmits visual information) to the visual cortex, potentially affecting visual perception and other aspects of the visual system. For example, the melatonin illuminance ratio is a value derived from the spectral distribution of the light-emitting device, the sensitivity curve (absorbance) of the ipRGC, and the visual acuity curve under human photopic vision. A higher melatonin illuminance ratio indicates a stronger stimulation of the human circadian rhythm. If the melatonin illuminance ratio of the light emitted from the light-emitting device is below 3.4, it is considered that it will not have a significant impact on a person's circadian rhythm. For example, it can be used as a signal color to indicate that the device is in a specific state, such as when it is charging, and can evoke specific images in a person.

[0054] The melatonin illuminance ratio of the light emitted from the light-emitting device can be 3.3 or less, or 3.2 or less, preferably 1.4 or more, and more preferably 1.5 or more. If the melatonin illuminance ratio of the light emitted from the light-emitting device is in the range of 1.4 or more and 3.4 or less, it is considered that it will not have a significant impact on a person's circadian rhythm, and as a light emitting a signal color indicating a particular state such as charging, it can evoke a specific image in a person.

[0055] The preferred light-emitting device emits light within region A1, which is located in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. Based on the chromaticity coordinates (x, y), let (x = 0.0082, y = 0.5384) be the first point, (x = 0.1096, y = 0.0868) be the second point, (x = 0.210, y = 0.190) be the third point, and (x = 0.260, y = 0.380) be the fourth point. The region is defined by a first straight line connecting the first point and the second point, a second straight line connecting the second point and the third point, a third straight line connecting the third point and the fourth point, and a fourth straight line connecting the fourth point and the first point. Figure 3 Region A1 is represented in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. A preferred light-emitting device emits light within region A1, which is a region connecting... Figure 3 The area enclosed by the lines connecting the first and second points, the second and third points, the third and fourth points, and the fourth and first points. The light-emitting device emits... Figure 3The light within region A1 has a dominant wavelength in the range of 475nm to 500nm, exhibiting a range of luminous colors from blue, including blue-green.

[0056] The preferred light-emitting device emits light within region A2, which is the region defined by the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram, based on the chromaticity coordinates (x, y). Let (x = 0.0350, y = 0.4127) be the first point, (x = 0.0800, y = 0.2149) be the second point, (x = 0.2150, y = 0.2106) be the third point, and (x = 0.2550, y = 0.3550) be the fourth point. The region is defined by a first straight line connecting the first point and the second point, a second straight line connecting the second point and the third point, a third straight line connecting the third point and the fourth point, and a fourth straight line connecting the fourth point and the first point. Figure 4 Region A2 is represented in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. Preferably, the light-emitting device emits light within region A2, which is... Figure 4 The area enclosed by the straight lines connecting the first and second points, the second and third points, the third and fourth points, and the fourth and first points. The light-emitting device emits... Figure 4 The light within region A2 has a dominant wavelength in the range of 475nm to 500nm, exhibiting a color ranging from blue to blue-green.

[0057] More preferably, the light-emitting device emits light within region A3, which is the region defined by the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram, based on the chromaticity coordinates (x, y), where (x = 0.1825, y = 0.3252) is the first point, (x = 0.1550, y = 0.2149) is the second point, (x = 0.1930, y = 0.2106) is the third point, and (x = 0.2205, y = 0.3209) is the fourth point, and is defined by the first straight line connecting the first point and the second point, the second straight line connecting the second point and the third point, the third straight line connecting the third point and the fourth point, and the fourth straight line connecting the fourth point and the first point. Figure 5 Region A3 is represented in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. Preferably, the light-emitting device emits light within region A3, which is... Figure 5 The area enclosed by the straight lines connecting the first and second points, the second and third points, the third and fourth points, and the fourth and first points. The light-emitting device emits... Figure 5 The light within region A3 has a dominant wavelength in the range of 475nm to 500nm, exhibiting a color ranging from blue to blue-green.

[0058] In the emission spectrum of the light-emitting device, the ratio Ib / Ia of the integral value Ib in the wavelength range of 380 nm to 531 nm to the integral value Ia in the wavelength range of 380 nm to 780 nm is preferably in the range of 0.6 to 0.95, more preferably in the range of 0.65 to 0.94, even more preferably in the range of 0.70 to 0.93, and particularly preferably in the range of 0.75 to 0.92. If the ratio Ib / Ia of the integral values ​​in the emission spectrum of the light-emitting device is in the range of 0.6 to 0.95, then the light-emitting device is considered to emit light with a dominant wavelength in the wavelength range from blue to green, including blue-green. The emitted light can maintain excellent visibility under both scotopic and photopic vision, while reducing the perceived difference in brightness under both scotopic and photopic vision. The emission spectrum of the light-emitting device, the integral value Ia of the measured emission spectrum in the wavelength range of 380 nm to 780 nm, and the integral value Ib of the measured emission spectrum in the wavelength range of 380 nm to 531 nm can be measured using a spectrophotometer (e.g., PMA-11, manufactured by Hamamatsu Hotniks Co., Ltd.) and a photometer system equipped with an integrating sphere. The ratio of the integral values ​​Ib / Ia can be obtained from the measured integral values ​​Ia and Ib.

[0059] Light-emitting element

[0060] Light-emitting elements can be used as components, for example, composed of In X Al Y Ga 1－X－Y The light-emitting diode (LED) chip or laser diode (LD) chip, which is a semiconductor light-emitting element of nitride-based semiconductor represented by N (0≤X, 0≤Y, X+Y≤1), is preferably an LED chip.

[0061] The light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm. The dominant wavelength of the light emitted from the light-emitting element is preferably in the range of 420 nm to 495 nm, and more preferably in the range of 430 nm to 490 nm.

[0062] The light-emitting element preferably has a peak emission wavelength in the range of 380nm to 500nm, more preferably in the range of 390nm to 495nm, even more preferably in the range of 400nm to 490nm, and particularly preferably in the range of 420nm to 490nm.

[0063] The light-emitting element has p-electrodes and n-electrodes. The p-electrodes and n-electrodes of the light-emitting element can be formed on the same side of the light-emitting element or on different sides of the light-emitting element. The light-emitting element can be assembled using flip-chip technology.

[0064] Rare earth aluminate phosphors

[0065] The rare-earth aluminate phosphor contained in the light-emitting device has a composition represented by the following formula (I).

[0066] (Lu 1－p－n Ln p Ce n )3(Al 1－m Ga m ) 5k O 12 (I)

[0067] (In formula (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd and Tb, and k, m, n and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050 and 0≤p≤0.30, respectively.)

[0068] A rare earth aluminate having a composition represented by formula (I) is excited by light from a light-emitting element having a dominant wavelength in the range of 400 nm to 500 nm, and performs wavelength conversion on the light emitted from the light-emitting element to emit light with a dominant wavelength in the range of 475 nm to 500 nm from the light-emitting device.

[0069] In equation (I), the molar ratio of Ce is the product of the variable n and 3. The variable n can be greater than or equal to 0.002, greater than or equal to 0.003, greater than or equal to 0.004, greater than or equal to 0.005, less than or equal to 0.050, less than or equal to 0.045, less than or equal to 0.040, less than or equal to 0.035, or less than or equal to 0.030. Ce acts as an activator for rare earth aluminate phosphors. In formula (I), the variable n can be in the range of 0.002 or higher and 0.045 or lower (0.002 ≤ n ≤ 0.045), in the range of 0.002 or higher and 0.040 or lower (0.002 ≤ n ≤ 0.040), in the range of 0.003 or higher and 0.040 or lower (0.003 ≤ n ≤ 0.040), or in the range of 0.003 or higher and 0.035 or lower (0.003 ≤ n ≤ 0.035). The molar ratio of Ce in 1 mole of a rare-earth aluminate phosphor having the composition represented by formula (I) is preferably in the range of 0.006 or higher and 0.15 or lower. If the molar ratio of Ce is in the range of 0.006 or higher and 0.15 or lower, the luminous brightness is high, and the desired luminous color can be obtained.

[0070] In formula (I), the molar ratio of Ga is the product of variable m and variables k and 5, which are in the range of 0.95 to 1.05. Variable m is in the range of 0.05 to 0.70 (0.05 ≤ m ≤ 0.70), or in the range of 0.10 to 0.70 (0.10 ≤ m ≤ 0.70), or in the range of 0.10 to 0.60 (0.10 ≤ m ≤ 0.60). Variable m can be 0.20 or higher, or 0.30 or higher, or 0.55 or lower, or 0.50 or lower. The molar ratio of Ga in 1 mole of a rare-earth aluminate phosphor having the composition represented by formula (I) is preferably in the range of 0.2375 to 3.15. In the formula (I), together with Al, in the molar ratio of Ga represented by the product of variables k and m and 5, the variable m is adjusted in the range of 0.05 and 0.70, thereby changing the emission peak wavelength of the phosphor, so that when used in a light-emitting device, the desired emission color can be obtained.

[0071] In formula (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb. The rare earth element Ln, together with Ce as an activator, acts as a co-activator. Ln can also be at least one rare earth element selected from the group consisting of Y, La, and Gd, and Ln can also be Y. In formula (I), the molar ratio of at least one rare earth element Ln selected from the group consisting of Y, La, Gd, and Tb is the product of the variable p and 3. Formula (I) may also not include the rare earth element Ln. In formula (I), the variable p can be in the range of 0 or higher and 0.20 or lower (0 ≤ p ≤ 0.20). In formula (I), the variable p can also be in the range of 0.001 or higher and 0.20 or lower (0.001 ≤ p ≤ 0.20).

[0072] In formula (I), m, n, and p preferably satisfy 0.10≤m≤0.70, 0.002≤n≤0.040, and 0≤p≤0.20, respectively. By adjusting the molar ratio of Ce (which acts as an activator) and Ga, and by adjusting the molar ratio of the rare earth element Ln as needed, the desired emission color can be obtained when used in a light-emitting device.

[0073] Method for manufacturing rare earth aluminate phosphors

[0074] Rare earth aluminate phosphors can be manufactured by heat-treating a mixture of raw materials containing oxides of each element (Lu, Ce, Al, Ga, and at least one rare earth element Ln selected from the group consisting of Y, La, Gd, and Tb) or compounds that have undergone thermal decomposition to become oxides. A mixture of raw materials containing each element may be referred to as a first raw material mixture, consisting only of the raw materials before heat treatment. Alternatively, a coprecipitate containing all or part of the elements constituting the rare earth aluminate phosphor can be used. For example, by adding an aqueous solution containing Lu, Ce, Al, Ga, and at least one rare earth element selected from the group consisting of Ln, an aqueous solution containing an alkali or carbonate, a coprecipitate containing these elements can be obtained. Drying and heat-treating this coprecipitate can also produce a rare earth aluminate phosphor. Rare earth aluminate phosphors can also be manufactured using a flux; preferably, the flux contains a fluoride containing the elements constituting the rare earth aluminate phosphor. As a flux, at least one selected from the group consisting of BaF2, AlF3, and CeF3 can be listed. The flux is preferably used in an amount ranging from 0.1 parts by weight to 10 parts by weight relative to 100 parts by weight of the raw material mixture (or the first raw material mixture), and may also be used in an amount ranging from 0.5 parts by weight to 8.0 parts by weight. There are cases where the mixture containing the raw material mixture (or the first raw material mixture) and the flux is referred to as the first mixture.

[0075] The heat treatment temperature is preferably in the range of 1000℃ to 1800℃, or it can be in the range of 1100℃ to 1750℃, 1200℃ to 1700℃, 1300℃ to 1650℃, or 1400℃ to 1600℃. The heat treatment can be performed using, for example, an electric furnace or a gas furnace.

[0076] A reducing atmosphere is preferred for heat treatment. Heat treatment can be carried out in a reducing atmosphere containing at least one of nitrogen, hydrogen, a reducing compound, and ammonia. In an atmosphere with high reducing power, the reactivity of the raw material mixture improves, and calcination at atmospheric pressure without pressurization can yield a calcined product. Furthermore, by heat treating the raw material mixture in an atmosphere with high reducing power, the tetravalent Ce(Ce) 4+ Ce is reduced to trivalent Ce(Ce) 3+ This allows for the production of sintered products with an increased proportion of trivalent Ce, which contributes to luminescence.

[0077] The heat treatment time varies depending on the heating rate, heat treatment atmosphere, etc., and is preferably 1 hour or more, more preferably 2 hours or more, even more preferably 3 hours or more, preferably within 20 hours, more preferably within 18 hours, and even more preferably within 15 hours after reaching the heat treatment temperature.

[0078] In the manufacturing method of rare earth aluminate phosphors, rare earth aluminate phosphors can also be obtained in the following manner: A calcined product obtained by heat-treating a raw material mixture is used as a first calcined product; the first calcined product, a Lu-containing compound, a Ce-containing compound, an Al-containing compound, a Ga-containing compound, and a compound containing the rare earth element Ln as needed are mixed and subjected to a second heat treatment to obtain a second calcined product; the obtained second calcined product is used as a rare earth aluminate phosphor. Alternatively, a mixture that does not contain a first calcined product but is obtained by mixing a Lu-containing compound, a Ce-containing compound, an Al-containing compound, a Ga-containing compound, and a compound containing the rare earth element Ln as needed is called a first raw material mixture, and heat-treating the first raw material mixture is called a first heat treatment. A mixture in which a flux is mixed is also called a first mixture. A raw material mixture that is mixed with the first calcined product and contains a Lu-containing compound other than the first calcined product, a Ce-containing compound, an Al-containing compound, a Ga-containing compound, and a compound containing the rare earth element Ln as needed is also called a second raw material mixture. The content of the first calcined material in the total mass of the second calcined material and the second raw material mixture is preferably in the range of 10% by mass or more and 90% by mass or less, and may also be in the range of 20% by mass or more and 80% by mass or less. A flux may also be included in the mixture of the first calcined material and the second raw material mixture. A mixture containing the first calcined material, the second raw material mixture, and a flux as needed is also referred to as the second mixture. When a flux is included, it is preferably used in the range of 0.1 parts by mass or more and 10 parts by mass or less relative to 100 parts by mass of the second raw material mixture, and may also be used in the range of 0.5 parts by mass or more and 8.0 parts by mass or less.

[0079] The first and second heat treatments can be performed at the same heat treatment temperature, heat treatment atmosphere, and heat treatment time as described above. The fired product obtained after the first heat treatment is also called the first fired product. The fired product obtained after the second heat treatment is also called the second fired product.

[0080] The first and second calcined products can also be dispersed through processes such as wet dispersion, wet sieving, dehydration, drying, and dry sieving. Deionized water can be used as a solvent for wet dispersion. The duration of wet dispersion varies depending on the solid dispersion medium and solvent used, but is preferably 30 minutes or more, more preferably 60 minutes or more, further preferably 90 minutes or more, even more preferably 120 minutes or more, and preferably within 420 minutes. This dispersion process ensures good dispersibility of the rare-earth aluminate phosphor during the manufacturing process of the light-emitting device.

[0081] Acid treatment, in which the first or second calcined product after dispersion treatment is contacted with an acidic solution, or alkali treatment, in which the first or second calcined product is contacted with an alkaline solution, can be performed. By contacting the first or second calcined product with the acidic or alkaline solution, decomposition products contained in the first or second calcined product that are decomposed during heat treatment can be removed. The acidic substance contained in the acidic solution can be an inorganic acid such as hydrofluoric acid, nitric acid, or hydrochloric acid, or hydrogen peroxide. The alkaline substance contained in the alkaline solution can be an alkali metal hydroxide or ammonia. The contact time between the first or second calcined product and the acidic or alkaline solution is, for example, 10 minutes or more and 30 hours or less, preferably 30 minutes or more and 25 hours or less, and more preferably 1 hour or more and 25 hours or less, in order to remove the thermal decomposition products contained in the first or second calcined product. Furthermore, the temperature at which the acidic or alkaline solution contacts the first or second fired product is preferably between room temperature (approximately 20°C) and 300°C or lower, more preferably between 30°C and 200°C or lower, and even more preferably between 40°C and 150°C or lower, in order to efficiently remove decomposition products contained in the first or second fired product. After acid or alkaline treatment, a step of cleaning the first or second fired product with a liquid medium may also be included.

[0082] The first and second sintered products obtained are rare earth aluminate phosphors having a composition represented by the formula (I).

[0083] The preferred light-emitting device, in addition to having a rare-earth aluminate phosphor with the composition represented by formula (I), also contains at least one phosphor selected from the group consisting of: a halosilicate phosphor with the composition represented by formula (II); a β-Sialon phosphor with the composition represented by formula (III); an oxynitride phosphor with the composition represented by formula (IV); an alkaline earth metal aluminate phosphor with the composition represented by formula (V); an alkaline earth metal sulfide phosphor with the composition represented by formula (VI); a first silicate phosphor with the composition represented by formula (VII); a second silicate phosphor with the composition represented by formula (VIII); a third silicate phosphor or germanate phosphor with the composition represented by formula (IX); and a fourth silicate phosphor with the composition represented by formula (X).

[0084] (Ca,Sr,Ba)8MgSi4O 16 (F,Cl,Br)2:Eu (Ⅱ)

[0085] Si 6－z Al z O z N 8－z Eu(0<z≤4.2) (Ⅲ)

[0086] BaSi2O2N2:Eu (Ⅳ)

[0087] Sr4Al 14 O 25 Eu (V)

[0088] (Sr, Ca, Ba) Ga2S4: Eu (VI)

[0089] (Ba, Sr, Ca)2SiO4: Eu (VII)

[0090] (Ba,Sr)ZrSi3O9:Eu (VIII)

[0091] Ca3Sc2(Si,Ge)3O 12 :Ce (Ⅸ)

[0092] (ALi3SiO4)n: Eu (A is at least one element chosen from the group consisting of Li, Na, K, Rb, and Cs, and n is an integer from 1 to 8.) (X)

[0093] In this specification, the compositional formula of a fluorophore is separated by commas (,), indicating that the composition contains at least one of the multiple elements, or a combination of two or more elements. Furthermore, in the compositional formula of a fluorophore, the part before the colon (:) indicates the elements constituting the parent crystal and their molar ratio, and the part after the colon (:) indicates the activating element. It can be understood that the molar amount of the activating element after the colon (:) does not necessarily need to be the same as the molar amount of the element before the colon. "Molar ratio" indicates the molar amount of the element in one mole of the fluorophore composition.

[0094] A halosilicate phosphor having the composition represented by formula (II), a β-silicon phosphor having the composition represented by formula (III), an oxynitride phosphor having the composition represented by formula (IV), an alkaline earth metal aluminate phosphor having the composition represented by formula (V), an alkaline earth metal sulfide phosphor having the composition represented by formula (VI), a first silicate phosphor having the composition represented by formula (VII), a second silicate phosphor having the composition represented by formula (VIII), a third silicate phosphor having the composition represented by formula (IX), or a germanate phosphor, and a phosphor having the composition represented by formula (II). At least one phosphor selected from the group consisting of the fourth silicate phosphor represented by formula (X) can be excited by light from a light-emitting element having a dominant wavelength in the range of 400 nm to 500 nm. Together with a rare earth aluminate phosphor having the composition represented by formula (I), it performs wavelength conversion on the light from the light-emitting element and emits light from the light-emitting device having a dominant wavelength in the range of 475 nm to 500 nm, with an S / P ratio of 6.5 or less represented by formula (1), or a melatonin illuminance ratio of 3.4 or less represented by formula (2).

[0095] Wavelength conversion component

[0096] The wavelength conversion member preferably comprises a wavelength conversion body containing a phosphor and a light-transmitting material, and more preferably further comprises a light-transmitting body in which the wavelength conversion body is disposed. The wavelength conversion body preferably contains a phosphor and the light-transmitting material described later. The wavelength conversion body can be formed in a plate-like, sheet-like, or layered form. The wavelength conversion member may also have wavelength conversion bodies in other forms than plate-like, sheet-like, or layered forms. The wavelength conversion member may also use a plate-like sintered wavelength conversion body. For example, the plate-like sintered wavelength conversion body can be obtained using a mixture of phosphor and inorganic oxide as raw material by the method disclosed in Japanese Patent Application Publication No. 2018-172628. For example, alumina (Al2O3) can be used as the inorganic oxide.

[0097] In the light-emitting device, a rare-earth aluminate phosphor with the composition represented by formula (I) is preferably included, along with other phosphors besides the rare-earth aluminate phosphor, which, together with a light-transmitting material, constitute a wavelength converter. The wavelength converter may also constitute a wavelength conversion component together with the light-transmitting material. Preferably, the wavelength converter includes a rare-earth aluminate phosphor with the composition represented by formula (I) in a range of 1 part by mass to 800 parts by mass relative to 100 parts by mass of the light-transmitting material; more preferably, it includes a range of 10 parts by mass to 750 parts by mass; and even more preferably, it includes a range of 15 parts by mass to 700 parts by mass. The light-emitting device includes a wavelength conversion component, which is a wavelength converter containing a rare-earth aluminate phosphor represented by the formula (I) that is excited by the light emission of the light-emitting element. By arranging the wavelength conversion component on the light emission side of the light-emitting element, the light from the light-emitting element can be converted with high efficiency using the rare-earth aluminate phosphor containing the composition represented by the formula (I) in the wavelength converter.

[0098] In a rare earth aluminate phosphor having the composition represented by formula (I), when the molar ratio of Ce, expressed as the product of variable n and 3, is in the range of 0.018 or more and 0.150 or less, and when variable n is 0.006 ≤ n ≤ 0.050, the content of rare earth aluminate phosphor contained in the wavelength converter, relative to 100 parts by mass of the light-transmitting material, can be 10 parts by mass or more and 800 parts by mass, 20 parts by mass or more and 780 parts by mass, 30 parts by mass or more and 750 parts by mass, or 40 parts by mass or more and 700 parts by mass.

[0099] The wavelength converter may contain two or more rare earth aluminate phosphors having different compositions as rare earth aluminate phosphors having the composition represented by the formula (I). For each rare earth aluminate phosphor having a different composition, in the composition represented by the product of variables n and 3, the molar ratio of Ce is in the range of 0.018 to 0.150, and when the variable n is 0.006 ≤ n ≤ 0.050. The total content of the two or more rare earth aluminate phosphors contained in the wavelength converter, relative to 100 parts by mass of the light-transmitting material, can be in the range of 10 parts by mass to 800 parts by mass, 20 parts by mass to 780 parts by mass, 30 parts by mass to 750 parts by mass, or 40 parts by mass to 700 parts by mass.

[0100] In a rare-earth aluminate phosphor having the composition represented by formula (I), when the molar ratio of Ga is 0.5 or more and 3.0 or less, and the molar ratio of Ce is 0.015 or more and 0.040 or less, the content of rare-earth aluminate phosphor contained in the wavelength converter, relative to 100 parts by mass of the light-transmitting material, can be in the range of 20 parts by mass or more and 700 parts by mass, 40 parts by mass or more and 650 parts by mass, 60 parts by mass or more and 600 parts by mass, or 80 parts by mass or more and 560 parts by mass. In a rare-earth aluminate phosphor having the composition represented by formula (I), the molar ratio of Ga is 0.5 or more and 3.0 or less, the variable k is 0.95 or more and 1.05 or less (0.95 ≤ k ≤ 1.05), and the variable m is 0.095 or more and 0.631 or less (0.095 ≤ m ≤ 0.631). In a rare-earth aluminate phosphor having the composition represented by formula (I), the molar ratio of Ce is 0.015 or more and 0.040 or less, and the variable n is 0.005 or more and 0.013 or less (0.005 ≤ n ≤ 0.013).

[0101] In a rare-earth aluminate phosphor having the composition represented by formula (I), when the molar ratio of Ga is 0.5 or more and 2.0 or less, and the molar ratio of Ce is 0.018 or more and 0.040 or less, the content of the rare-earth aluminate phosphor contained in the wavelength converter, relative to 100 parts by mass of the light-transmitting material, can be in the range of 20 parts by mass to 500 parts by mass, 30 parts by mass to 400 parts by mass, or 40 parts by mass to 300 parts by mass. In a rare-earth aluminate phosphor having the composition represented by formula (I), when the molar ratio of Ga is 0.5 or more and 2.0 or less, when the variable k is 0.95 or more and 1.05 or less (0.95 ≤ k ≤ 1.05), and when the variable m is 0.095 or more and 0.421 or less (0.095 ≤ m ≤ 0.421), the content of the rare-earth aluminate phosphor in the wavelength converter can be in the range of 0.095 to 0.421 (0.095 ≤ m ≤ 0.421). In a rare earth aluminate phosphor having a composition represented by the formula (I), the molar ratio of Ce is in the range of 0.018 or more and 0.040 or less, and the variable n is in the range of 0.006 or more and 0.013 or less (0.006≤n≤0.013).

[0102] In addition to the rare-earth aluminate fluorophore represented by formula (I), the wavelength converter may also include at least one fluorophore selected from the group consisting of: a halosilicate salt fluorophore having the composition represented by formula (II); a β-silicon fluorophore having the composition represented by formula (III); an oxynitride fluorophore having the composition represented by formula (IV); an alkaline earth metal aluminate fluorophore having the composition represented by formula (V); an alkaline earth metal sulfide fluorophore having the composition represented by formula (VI); a first silicate fluorophore having the composition represented by formula (VII); a second silicate fluorophore having the composition represented by formula (VIII); a third silicate fluorophore or germanate fluorophore having the composition represented by formula (IX); and a fourth silicate fluorophore having the composition represented by formula (X). The wavelength converter may contain phosphors in a total amount ranging from 1 part to 900 parts by mass relative to 100 parts by mass of the light-transmitting material, or in a total amount ranging from 10 parts to 850 parts by mass, or in a total amount ranging from 15 parts to 800 parts by mass.

[0103] Translucent materials

[0104] The light-transmitting material may include at least one selected from the group consisting of resins, glass, and inorganic materials. The resin is preferably at least one selected from the group consisting of epoxy resins, silicone resins, phenolic resins, and polyimide resins. The inorganic material may include at least one selected from the group consisting of alumina and aluminum nitride. In addition to the phosphor and the light-transmitting material, the wavelength converter may also include, as needed, fillers, colorants, and light-diffusing materials. Examples of fillers include, for example, silicon dioxide, barium titanate, titanium dioxide, and alumina. The content of the components other than the phosphor and the light-transmitting material in the wavelength converter, based on the total content of the other components, may be in the range of 0.01 parts by mass or more and 100 parts by mass or less, or in the range of 0.1 parts by mass or more and 80 parts by mass or less, or in the range of 0.5 parts by mass or more and 75 parts by mass or less, relative to 100 parts by mass of the light-transmitting material.

[0105] Transparent body

[0106] Wavelength conversion components can also include light-transmitting elements. These elements can be plate-shaped bodies made of light-transmitting materials such as glass and 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 element should be sufficient to support the wavelength conversion component without reducing its mechanical strength during manufacturing.

[0107] Light-emitting device—first configuration example

[0108] Example of the configuration of a display light-emitting device. Figure 6A A schematic top view showing the light-emitting device 100 of the first configuration example. Figure 6B yes Figure 6A The diagram shows a schematic cross-sectional view of the light-emitting device 100 along line VI-VI'. The light-emitting device 100 includes: a light-emitting element 10 having a dominant wavelength in the range of 400 nm to 500 nm; and a wavelength conversion member 30 comprising: a wavelength conversion element 31 containing at least one phosphor that emits light upon excitation from the light-emitting element 10; and a light-transmitting element 32 disposed thereon. The light-emitting element 10 is flip-chip mounted on a substrate 70 via bumps serving as conductive members 60. The wavelength conversion element 31 of the wavelength conversion member 30 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 30 are covered by a light-reflecting coating member 90. The wavelength conversion element 31 contains a phosphor that has at least one emission peak wavelength in a specific wavelength range upon excitation from the light-emitting element 10. The wavelength conversion element 31 may also contain two or more phosphors with different wavelength ranges of emission peak wavelengths. The light-emitting element 10 can receive power from the outside of the light-emitting device 100 via wiring and conductive members 60 formed on the substrate 70, thereby causing the light-emitting device 100 to emit light. The light-emitting device 100 may also include a semiconductor element 50, such as a protective element to prevent damage caused by excessive voltage applied to the light-emitting element 10. The covering member 90 is provided, for example, to cover the semiconductor element 50. Hereinafter, the components used in the light-emitting device will be described. For further details, please refer to the disclosure of Japanese Patent Application Publication No. 2014-112635.

[0109] substrate

[0110] The preferred substrate is an insulating material, made of a material that makes it difficult for light from the light-emitting element and external light to pass through. Examples of substrate materials include: ceramics such as alumina and aluminum nitride; and resins such as phenolic resin, epoxy resin, polyimide resin, bismaleimide-triazine resin (BT resin), and polyphthalamide (PPA) resin. Because ceramics have high heat resistance, they are preferred as substrate materials.

[0111] Adhesive layer

[0112] An adhesive layer is placed between the light-emitting element and the wavelength conversion component, fixing the light-emitting element and the wavelength conversion component in place. The adhesive constituting the adhesive layer is preferably made of a material capable of optically bonding the light-emitting element and the wavelength conversion component. Preferably, the material constituting the adhesive layer is at least one resin selected from the group consisting of epoxy resin, silicone resin, phenolic resin, and polyimide resin.

[0113] semiconductor components

[0114] Semiconductor components included in a light-emitting device as needed include, for example, transistors for controlling the light-emitting element and protective components for preventing damage and performance degradation of the light-emitting element caused by excessive applied voltage. Zener diodes are an example of such protective components.

[0115] Covered components

[0116] Insulating materials are preferred as the materials used for the coated components. More specifically, examples include phenolic resins, epoxy resins, bismaleimide-triazine resins (BT resins), polyphthalamide (PPA) resins, and silicone resins. Colorants, phosphors, and fillers may also be added to the coated components as needed.

[0117] conductive components

[0118] Bumps can be used as conductive components, and Au or its alloys can be used as materials for bumps. Eutectic solder (Au-Sn), Pb-Sn, lead-free solder, etc. can be used as other conductive components.

[0119] Manufacturing method of light-emitting device - first configuration example

[0120] This describes an example of a method for manufacturing a light-emitting device. Further details can be found in, for example, Japanese Patent Application Publication No. 2014-112635 or Japanese Patent Application Publication No. 2017-117912. A 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 containing a wavelength converter; a process for bonding the light-emitting elements and the wavelength conversion member; and a process for forming a coated member.

[0121] The process of assembling light-emitting elements

[0122] In the configuration process of light-emitting elements, light-emitting elements are configured and assembled on a substrate. Light-emitting elements and semiconductor elements, such as flip chips, are assembled on the substrate.

[0123] Forming process of wavelength conversion component containing wavelength converter

[0124] In the process of forming a wavelength conversion component containing a wavelength converter, the wavelength converter can be obtained by forming a plate-like, sheet-like, or layered wavelength converter on one side of a light-transmitting body through printing, bonding, compression molding, or electrodeposition. For example, in the printing method, a wavelength conversion component containing a wavelength converter, which contains a phosphor and a resin as a binder or solvent, can be printed onto one side of a light-transmitting body to form a wavelength conversion component containing a wavelength converter.

[0125] Bonding process between light-emitting element and wavelength conversion component

[0126] In the bonding process between the light-emitting element and the wavelength conversion component, the light-emitting surface of the wavelength conversion component and the light-emitting element are facing each other, and the wavelength conversion component is bonded to the light-emitting element via an adhesive layer.

[0127] Forming process of coated components

[0128] In the process of forming the coated component, except for the light-emitting surface, the sides of the light-emitting element and the wavelength conversion component are covered by the coated component with the composition, and the coated component is formed on the sides of the light-emitting element and the wavelength conversion component except for the light-emitting surface. This coated component is used to reflect the light emitted from the light-emitting element, covers the sides without covering the light-emitting surface of the wavelength conversion component, and is formed in a manner that embeds semiconductor elements.

[0129] As described above, it is possible to manufacture Figure 6A and Figure 6B The light-emitting device shown.

[0130] Light-emitting device—Second configuration example

[0131] Figure 7 This is a schematic cross-sectional view showing the light-emitting device 200 of the second configuration example. The light-emitting device 200 is identical to the light-emitting device 100, except that it includes a wavelength conversion member 30 composed of a wavelength conversion element 31 containing at least one phosphor that emits light upon excitation from the light-emitting element 10. Figure 7 In this context, components identical to those in the light-emitting device 100 are given the same designation. The wavelength conversion component 30 may also be composed of a wavelength conversion element 31 instead of a light-transmitting element 32.

[0132] Manufacturing method of light-emitting device—Second configuration example

[0133] The manufacturing method of the light-emitting device of the second embodiment, in the wavelength conversion member forming step, can be the same as the manufacturing method of the light-emitting device of the first embodiment, except that a wavelength conversion member composed of a wavelength conversion body is formed. The wavelength conversion body is prepared by hardening a wavelength conversion body containing a phosphor and a light-transmitting material with a composition, pre-forming it into a plate-like, sheet-like, or layered shape, so that it can be monolithically sized and disposed on the light-emitting element, thus preparing a wavelength conversion member composed of a plate-like, sheet-like, or layered wavelength conversion body. As described above, the light-emitting device of the second embodiment can be manufactured. Furthermore, as described above, a plate-like wavelength conversion sintered body can also be used for the wavelength conversion member.

[0134] Light-emitting device—Third configuration example

[0135] Figure 8This is a schematic cross-sectional view of a light-emitting device 200 according to a third configuration example. The light-emitting device 300 includes, for example, a molded body 41, a light-emitting element 11, and a wavelength conversion member 33. The molded body 41 is integrally formed of a first lead 51, a second lead 52, and a resin portion 42 comprising thermoplastic resin and thermosetting resin. The molded body 41 forms a recess having a bottom surface and side surfaces, and the light-emitting element 11 is mounted on the bottom surface of the recess. The light-emitting element 11 has a pair of positive and negative electrodes, which are electrically connected to the first lead 51 and the second lead 52 respectively via wires 63. The light-emitting element 11 is covered by the wavelength conversion member 33. The wavelength conversion member 33 includes a phosphor 21 that performs wavelength conversion on the light from the light-emitting element 11 and a light-transmitting material. The phosphor 21 may also contain two or more phosphors that are excited by light from the light-emitting element and have at least one emission peak wavelength within a specific wavelength range, with different wavelength ranges for the emission peak wavelengths. The first lead 51 and the second lead 52, which are connected to the positive and negative electrodes of the light-emitting element 11, face outwards from the package constituting the light-emitting device 300, with a portion of the first lead 51 and the second lead 52 exposed. Power is supplied from the outside through these first leads 51 and the second leads 52, causing the light-emitting device 300 to emit light.

[0136] The light-transmitting material used for the wavelength conversion member can be the same as the light-transmitting material used in the wavelength conversion member of the first or second embodiment. Alternatively, the wavelength conversion member can also be the same as the wavelength conversion member of the first and second embodiments, and may include fillers, colorants, and light-diffusing materials as needed.

[0137] Manufacturing method of light-emitting device—Third configuration example

[0138] The manufacturing method of the light-emitting device according to the third embodiment will be described. Further details can be found in, for example, the disclosure in Japanese Patent Application Publication No. 2010-062272. The manufacturing method of the light-emitting device preferably includes a preparation step of a molded body, a configuration step of light-emitting elements, a configuration step of components for wavelength conversion members, and a resin encapsulation forming step. When using an aggregate molded body with multiple recesses, a single-piece encapsulation step can also be included after the resin encapsulation step, separating the resin encapsulation into individual unit areas.

[0139] In the preparation process of the molded body, multiple leads are integrally molded using thermosetting or thermoplastic resin to prepare a molded body having recesses with side and bottom surfaces. The molded body can be formed from an aggregate matrix containing multiple recesses.

[0140] In the process of assembling the light-emitting element, the light-emitting element is arranged on the bottom surface of the recess of the molded body, and the positive and negative electrodes of the light-emitting element are connected to the first lead and the second lead through wires.

[0141] In the process of assembling the component for wavelength conversion, the component for wavelength conversion is disposed in the recess of the molded body.

[0142] In the resin encapsulation forming process, the wavelength conversion member disposed in the recess of the molded body is cured with the composition to form a resin encapsulation, thereby manufacturing a light-emitting device. When using a molded body formed from an assembly substrate containing multiple recesses, after the resin encapsulation forming process, in a single-piece forming process, resin encapsulations are separated into individual unit regions of the assembly substrate each having multiple recesses, thereby manufacturing individual light-emitting devices. As described above, it is possible to manufacture... Figure 8 The light-emitting device shown is a third example of its configuration.

[0143] Example

[0144] The present invention will now be described in detail through examples. However, the present invention is not limited to these examples.

[0145] Rare earth aluminate phosphor A

[0146] Prepare raw materials

[0147] Using lutetium oxide (Lu₂O₃), cerium oxide (CeO₂), aluminum oxide (Al₂O₃), and gallium oxide (Ga₂O₃) as raw materials, a raw material mixture was prepared by adjusting the Lu, Ce, Al, and Ga elements contained in each compound to satisfy the composition described below. 7.0% by mass of barium fluoride (BaF₂) was added as a flux relative to 100% of the total mass, and the raw materials were mixed using a ball mill to obtain a mixture. The raw materials were prepared in the pre-formulated composition as (Lu₂O₃, CeO₂, AlO₃, and GaO₃). 0.987 Ce 0.012 )3(Al 0.9 Ga 0.1 )5O 12 Modulation in a certain way.

[0148] Heat treatment

[0149] The resulting mixture was placed in an alumina crucible and heat-treated at 1600°C for 10 hours in a reducing atmosphere to obtain a calcined product.

[0150] Dispersed processing

[0151] The obtained calcined material, alumina spheres as the dispersion medium, and deionized water were placed in a container and dispersed for 4 hours while rotating. Afterward, the mixture was passed through a wet sieve to remove coarse particles. Next, sedimentation classification was performed to remove fine particles.

[0152] pickling treatment

[0153] The calcined material obtained after sedimentation and classification was acid-washed with a 17% by mass hydrochloric acid aqueous solution, followed by water washing, separation and drying, and the acid-washed calcined material was used as rare earth aluminate phosphor A.

[0154] Rare earth aluminate phosphor B

[0155] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the process was the same as for rare-earth aluminate phosphor A, to obtain rare-earth aluminate phosphor B. The raw materials were prepared such that (Lu...) in the pre-formulated composition... 0.987 Ce 0.013 )3(Al 0.8 Ga 0.2 )5O 12 Modulation in a certain way.

[0156] Rare earth aluminate phosphor C

[0157] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the process was the same as for rare-earth aluminate phosphor A, resulting in rare-earth aluminate phosphor C. The raw materials were prepared such that (Lu...) in the pre-formulated composition... 0.987 Ce 0.013 )3(Al 0.7 Ga 0.3 )5O 12 Modulation in a certain way.

[0158] Rare earth aluminate phosphor D

[0159] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the process was the same as for rare-earth aluminate phosphor A, to obtain rare-earth aluminate phosphor D. The raw materials were prepared such that (Lu...) in the pre-formulated composition... 0.987 Ce 0.013 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0160] Rare earth aluminate phosphor E

[0161] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following composition. The rare earth aluminate phosphor E was obtained by heat treatment at 1500°C for 10 hours, except otherwise performed similarly to rare earth aluminate phosphor A. The raw materials were prepared in a manner that resulted in (Lu...) 0.995 Ce 0.005 )3(Al 0.6 Ga 0.4 )5O12 Modulation in a certain way.

[0162] Rare earth aluminate phosphor F

[0163] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the rare-earth aluminate phosphor F was obtained in the same manner as rare-earth aluminate phosphor E. The raw materials were prepared such that (Lu...) 0.995 Ce 0.005 )3(Al 0.5 Ga 0.5 )5O 12 Modulation in a certain way.

[0164] Rare earth aluminate phosphor G

[0165] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the rare-earth aluminate phosphor G was obtained in the same manner as rare-earth aluminate phosphor E. The raw materials were prepared such that (Lu...) 0.995 Ce 0.005 )3(Al 0.4 Ga 0.6 )5O 12 Modulation in a certain way.

[0166] Rare earth aluminate phosphors H

[0167] Under atmospheric conditions, a heat treatment at 1500℃ for 10 hours was performed, otherwise identical to that of rare-earth aluminate phosphor E, to obtain rare-earth aluminate phosphor H. The raw material was prepared as (Lu) in the pre-formulation. 0.995 Ce 0.005 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0168] Rare earth aluminate phosphor I

[0169] Prepare the raw materials (first mixture).

[0170] Using lutetium oxide (Lu₂O₃), cerium oxide (CeO₂), aluminum oxide (Al₂O₃), and gallium oxide (Ga₂O₃) as raw materials, the raw materials composed of each compound were prepared in a manner that ensured the Lu, Ce, Al, and Ga elements contained in each compound met the composition requirements described below. 7.0% by mass of barium fluoride (BaF₂) was added as a flux relative to 100% of the total mass, and the raw materials were mixed using a ball mill to obtain a first mixture. The raw materials were prepared such that (Lu₂O₃, Ce, Al, and Ga) were present in the preparative composition. 0.995 Ce 0.005 )3(Al0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0171] First heat treatment

[0172] The first mixture was placed in an alumina crucible and heat-treated at 1500°C for 10 hours in a reducing atmosphere to obtain the first calcined product.

[0173] Second mixture

[0174] Using the obtained first calcined product and lutetium oxide (Lu₂O₃), cerium oxide (CeO₂), aluminum oxide (Al₂O₃), and gallium oxide (Ga₂O₃) as raw materials, the raw materials composed of each compound were prepared in such a manner that the Lu, Ce, Al, and Ga elements contained in the first calcined product and each compound met the aforementioned composition. 7.0% by mass of barium fluoride (BaF₂) was added as a flux relative to 100% of the total mass to obtain a second raw material mixture. The first calcined product and the second raw material mixture were then mixed using a ball mill at a mass ratio of 7:3 to obtain the second mixture.

[0175] Second heat treatment

[0176] The obtained second mixture was placed in an alumina crucible and heat-treated at 1500°C for 10 hours in a reducing atmosphere to obtain a second calcined product. Similar to rare earth aluminate A, the second calcined product was subjected to dispersion and acid washing treatment to obtain rare earth aluminate phosphor I.

[0177] Rare earth aluminate phosphors J

[0178] The raw materials composed of each compound were prepared in such a manner that the elements Lu, Ce, Al, and Ga each met the following composition, and all other rare earth aluminate phosphors were prepared in the same manner as rare earth aluminate phosphor A to obtain rare earth aluminate phosphor J. The raw materials were prepared such that (Lu...) in the pre-formulated composition... 0.993 Ce 0.007 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0179] Rare earth aluminate phosphors K

[0180] The raw materials composed of each compound were prepared in such a manner that the elements Lu, Ce, Al, and Ga each met the following composition, and all other elements were prepared in the same manner as rare earth aluminate phosphor A to obtain rare earth aluminate phosphor K. The raw materials were prepared such that they were in the pre-formulated composition (Lu...). 0.992 Ce 0.008 )3(Al 0.6 Ga0.4 )5O 12 Modulation in a certain way.

[0181] Rare earth aluminate phosphors L

[0182] The raw materials composed of each compound were prepared in such a manner that the elements Lu, Ce, Al, and Ga each satisfy the following composition, and in the same manner as rare earth aluminate phosphor A, rare earth aluminate phosphor L was obtained. The raw materials were prepared such that (Lu...) in the pre-formulated composition... 0.990 Ce 0.010 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0183] Rare earth aluminate phosphor M

[0184] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the rare-earth aluminate phosphor M was obtained in the same manner as rare-earth aluminate phosphor A. The raw materials were prepared such that (Lu...) 0.988 Ce 0.012 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0185] Rare earth aluminate phosphors N

[0186] The raw materials composed of each compound were prepared in a manner that ensured that the elements Lu, Ce, Al, and Ga met the following compositional requirements. Otherwise, the process was the same as for rare-earth aluminate phosphor A, to obtain rare-earth aluminate phosphor N. The raw materials were prepared such that (Lu...) in the pre-formulation... 0.987 Ce 0.013 )3(Al 0.6 Ga 0.4 )5O 12 Modulation in a certain way.

[0187] Evaluation of rare earth aluminate phosphors

[0188] The obtained rare-earth aluminate phosphors were evaluated as follows. The evaluation results are shown in Table 1. In Table 1, Ga (molar ratio) and Ce (molar ratio) are the molar ratios of each element in the prepared composition.

[0189] Luminous properties

[0190] The luminescence properties of each phosphor were measured. The luminescence properties of the phosphors were measured using a quantum efficiency measurement device (QE-2000, manufactured by Otsuka Electronics Co., Ltd.). The emission spectrum of each phosphor was measured at room temperature (25℃±5℃) under excitation light of 420nm. Based on the emission spectrum of each phosphor, the chromaticity coordinates (x, y) and luminance (%) in the chromaticity coordinate system of the CIE chromaticity diagram were determined for each phosphor.

[0191] Table 1

[0192]

[0193] Examples 1-1 to 1-3

[0194] A light-emitting device is manufactured using rare-earth aluminate A. The manufacturing method of the light-emitting device can be found in Japanese Patent Application Publication No. 2010-062272. Specifically, a molded body is prepared having a first lead, a second lead, and recesses with a bottom surface and side surfaces. A light-emitting element using a nitride semiconductor with a main wavelength of 455 nm is prepared, the light-emitting element is disposed on the bottom surface of the recess, and connected to the first and second leads via wires. As a light-transmitting material, a wavelength conversion composition containing rare-earth aluminate phosphor A in the amounts shown in Table 2 (Example 1-1: 20 parts by mass, Example 1-2: 40 parts by mass, Example 1-3: 60 parts by mass) relative to 100 parts by mass of silicone resin is prepared, and the wavelength conversion composition is filled into the recess of the molded body. The wavelength conversion composition is hardened by heating at 150°C for 4 hours to form a wavelength conversion member made of a wavelength conversion element covering the light-emitting element, and then resin encapsulation is performed to manufacture the light-emitting device.

[0195] Examples 2-1 to 2-3

[0196] A light-emitting device was manufactured using rare-earth aluminate phosphor B. A wavelength conversion composition containing the amounts shown in Table 2 (Example 2-1: 20 parts by mass, Example 2-2: 40 parts by mass, Example 2-3: 60 parts by mass) of rare-earth aluminate phosphor B was prepared. Except for using the wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0197] Examples 3-1 to 3-3

[0198] A light-emitting device was manufactured using rare-earth aluminate phosphor C. A wavelength conversion composition containing the amounts shown in Table 2 (Example 3-1: 40 parts by mass, Example 3-2: 60 parts by mass, Example 3-3: 80 parts by mass) of rare-earth aluminate phosphor C was prepared. Except for using the wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0199] Comparative Example 4-1, Examples 4-2 to 4-5

[0200] A light-emitting device was manufactured using rare-earth aluminate phosphor D. A wavelength conversion composition containing the amounts shown in Table 2 (Comparative Example 4-1: 20 parts by mass, Example 4-2: 40 parts by mass, Example 4-3: 60 parts by mass, Example 4-4: 90 parts by mass, Example 4-5: 120 parts by mass) of rare-earth aluminate phosphor D was prepared. Except for using this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0201] Comparative Example 1

[0202] A light-emitting element using a nitride semiconductor with a main wavelength of 454 nm was prepared, without using a phosphor. Otherwise, the light-emitting device of the first embodiment was manufactured in the same manner as in Example 1-1.

[0203] Comparative Example 2

[0204] A light-emitting element using a nitride semiconductor with a main wavelength of 484nm was prepared, without using a phosphor. Otherwise, the light-emitting device of the first embodiment was manufactured in the same manner as in Examples 1-1.

[0205] Comparative Example 3

[0206] A light-emitting element using a nitride semiconductor with a main wavelength of 495nm was prepared, without using a phosphor. Otherwise, the light-emitting device of the first embodiment was manufactured in the same manner as in Example 1-1.

[0207] The following evaluations were conducted on each light-emitting element and each light-emitting device. The evaluation results for each light-emitting device are described in Table 2.

[0208] Evaluation of light-emitting elements (dominant wavelength of the light-emitting element)

[0209] For each light-emitting element used in the embodiments and comparative examples, a spectrophotometer (PMA-11, Hamamatsu Hotnik Co., Ltd.) and a photometer system equipped with an integrating sphere were used to measure the chromaticity coordinates (x, y) in the chromaticity coordinate system of the CIE 1931 chromaticity diagram. A straight line was drawn connecting the chromaticity coordinates (x = 0.3333, y = 0.3333) of white light in the CIE 1931 chromaticity diagram to the chromaticity coordinates (x, y) of the emitted color of each light-emitting element. E y E The wavelength of the point where its extension intersects the spectral trajectory is obtained by taking the wavelength of the dominant wavelength.

[0210] Evaluation of light-emitting devices

[0211] Luminous flux, luminous flux ratio, radiant flux (total spectral radiant flux), and chromaticity coordinates (x, y) of the light-emitting device.

[0212] For each light-emitting device, a spectrophotometer (PMA-11, Hamamatsu Hotnik Co., Ltd.) and a photometer system with an integrating sphere were used to obtain the luminous flux, radiant flux (total spectral radiant flux: mW), and chromaticity coordinates (x, y) in the chromaticity coordinate system of the CIE 1931 chromaticity diagram.

[0213] The dominant wavelength λd of the light-emitting device

[0214] The dominant wavelength of each light-emitting device is obtained by connecting the chromaticity coordinates (x = 0.3333, y = 0.3333) of white light in the CIE1931 chromaticity diagram with the chromaticity coordinates (x, y) of the emitted color of each light-emitting device, and taking the wavelength of the point where the extension of the line intersects the spectral trajectory as the dominant wavelength.

[0215] S / P ratio

[0216] Regarding each light-emitting device, based on the above formula (1), the ratio of luminous flux under dark vision to luminous flux under photovision, i.e., the S / P ratio, is calculated.

[0217] Emission spectrum of light-emitting device

[0218] For each light-emitting device, the emission spectrum at room temperature (25℃±5℃) was measured using a spectrophotometer (PMA-11, Hamamatsu Hotniks Co., Ltd.) and a photometer system equipped with an integrating sphere. For each light-emitting device, the relative emission spectrum was obtained by taking the maximum luminous intensity in the emission spectrum of each device as 1.

[0219] Melatonin Illumination Ratio

[0220] Based on the spectral distribution of each light-emitting device, the sensitivity curve (absorbance) of ipRGC, and the visual acuity curve under human photopic vision, the melatonin illuminance ratio is calculated based on the above formula (2).

[0221] The ratio of the integral values ​​of the emission spectrum Ib / Ia

[0222] In the relative emission spectra of each light-emitting device, the ratio Ib / Ia of the integral value Ib in the wavelength range of 380 nm to 531 nm to the integral value Ia in the wavelength range of 380 nm to 780 nm is obtained.

[0223] Table 2

[0224]

[0225] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the S / P ratio, which is the ratio of luminous flux under scotopic vision to luminous flux under photopic vision, is 6.5 or less. It can be considered that the light-emitting devices of each embodiment can reduce the difference between luminous flux in the dark and luminous flux in the bright even when emitting light with a dominant wavelength in the range of blue to green, including blue-green, and can maintain excellent visibility that appears bright under both scotopic and photopic vision.

[0226] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the melatonin illuminance ratio is 3.4 or less. It is believed that the light-emitting devices of each embodiment are unlikely to have a significant impact on human circadian rhythms. For example, as a signal color indicating a specific state of a machine, such as charging time, they can emit light with a dominant wavelength in the blue to green wavelength range, including blue-green, that can evoke specific images.

[0227] Light emitted from the light-emitting devices of each embodiment, having a dominant wavelength in the range of 475 nm to 500 nm, exhibits the following characteristics in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram: Figure 3 The area A1 shown is Figure 4 The luminous color within region A2 is shown. The luminous devices of Examples 3-2, 4-2, 4-3, 4-4, and 4-5 also exhibit the same luminous color within regions A1 and A2. Figure 5 The area A3 shown has a blue to blue-green luminous color.

[0228] The light-emitting devices of each embodiment are considered to emit light that is in the range of 0.6 or higher and 0.95 or lower, with the integral ratio Ib / Ia being 0.6 or higher. This light is capable of maintaining excellent visibility that appears bright under both scotopic and photopic vision, while reducing the difference in brightness perceived by humans under both scotopic and photopic vision.

[0229] The light-emitting device of Comparative Example 1 emits light with a dominant wavelength below 475 nm, and its S / P ratio is higher than 6.5. When viewed in the dark, it is conceivable that the light might appear excessively bright. Furthermore, the light-emitting device of Comparative Example 1, emitting light with a dominant wavelength below 475 nm, has a melatonin illuminance ratio higher than 3.4, which is considered potentially disruptive to human circadian rhythms. Additionally, the light-emitting device of Comparative Example 1, emitting light with a dominant wavelength below 475 nm, does not exhibit... Figure 3 The emitted color within region A1 is shown. Furthermore, the light-emitting device of Comparative Example 1 has an integral value ratio Ib / Ia higher than 0.95, which suggests that it might appear too bright in the dark.

[0230] The light-emitting device of Comparative Example 2 emits light with a dominant wavelength in the range of 475 nm to 500 nm, but its S / P ratio is higher than 6.5, which could be considered excessively bright when viewed in the dark. Furthermore, the light-emitting device of Comparative Example 2 emits light with a dominant wavelength in the range of 475 nm to 500 nm, and its melatonin illuminance ratio is higher than 3.4, which is considered potentially to affect human circadian rhythms. Additionally, the light-emitting device of Comparative Example 2 emits light with a dominant wavelength in the range of 475 nm to 500 nm, presenting... Figure 3 The luminous color is shown in area A1, but it is not displayed. Figure 4 Within the area A2 shown and Figure 5 The emitted color within area A3 is shown. Furthermore, the light-emitting device of Comparative Example 2 has an integral value ratio Ib / Ia higher than 0.95, which suggests that it might appear too bright in the dark.

[0231] The light-emitting device of Comparative Example 3 emits light with a dominant wavelength in the range of 475 nm to 500 nm, but its S / P ratio is higher than 6.5, which may result in an overly bright appearance when viewed in the dark. Furthermore, the light-emitting device of Comparative Example 3 emits light with a dominant wavelength in the range of 475 nm to 500 nm, and its melatonin illuminance ratio is higher than 3.4, which is considered potentially to affect human circadian rhythms. Additionally, the light-emitting device of Comparative Example 3 emits light with a dominant wavelength in the range of 475 nm to 500 nm, and this light exhibits… Figure 3 Within the area A1 shown and Figure 4 The area A2 shown is emitting a light color, but it does not exhibit any light emission. Figure 5 The emitted color within area A3 is shown. Furthermore, the light-emitting device of Comparative Example 3 has an integral value ratio Ib / Ia higher than 0.95, which suggests that it might appear too bright in the dark.

[0232] In the light-emitting device of Comparative Example 4-1, the composition of the rare earth aluminate phosphor D contained in the wavelength conversion component has a higher molar content of Ga and a higher molar content of Ce. Therefore, compared with phosphors with a lower molar content of Ga, the emission peak wavelength of rare earth aluminate phosphor D changes. If the content of rare earth aluminate phosphor D is low, it is impossible to emit light with a dominant wavelength in the range of 475 nm to 500 nm.

[0233] Comparative Examples 5-1 to 5-2, Examples 5-3 to 5-7

[0234] A light-emitting device was manufactured using rare-earth aluminate phosphor E. A wavelength conversion composition containing the amounts shown in Table 3 (Comparative Example 5-1: 20 parts by mass, Comparative Example 5-2: 40 parts by mass, Example 5-3: 60 parts by mass, Example 5-4: 90 parts by mass, Example 5-5: 120 parts by mass, Example 5-6: 200 parts by mass, Example 5-7: 280 parts by mass) of rare-earth aluminate phosphor E was prepared. Except for using this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0235] Comparative Examples 6-1 to 6-4, Examples 6-5 to 6-9

[0236] A light-emitting device was manufactured using rare-earth aluminate phosphor F. A wavelength conversion composition containing the amounts shown in Table 3 (Comparative Example 6-1: 20 parts by mass, Comparative Example 6-2: 40 parts by mass, Comparative Example 6-3: 60 parts by mass, Comparative Example 6-4: 100 parts by mass, Example 6-5: 200 parts by mass, Example 6-6: 300 parts by mass, Example 6-7: 400 parts by mass, Example 6-8: 450 parts by mass, Example 6-9: 550 parts by mass) of rare-earth aluminate phosphor F was prepared. Except for the use of this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0237] Comparative Examples 7-1 to 7-4, Examples 7-5 to 7-11

[0238] A light-emitting device was manufactured using rare-earth aluminate phosphor G. A wavelength conversion composition containing the amounts shown in Table 3 (Comparative Example 7-1: 20 parts by mass, Comparative Example 7-2: 40 parts by mass, Comparative Example 7-3: 60 parts by mass, Comparative Example 7-4: 150 parts by mass, Example 7-5: 250 parts by mass, Example 7-6: 350 parts by mass, Example 7-7: 450 parts by mass, Example 7-8: 560 parts by mass, Example 7-9: 600 parts by mass, Example 7-10: 650 parts by mass, Example 7-11: 700 parts by mass) of rare-earth aluminate phosphor G was prepared. Except for using this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0239] Comparative Examples 8-1 to 8-4, Examples 8-5 to 8-8

[0240] A light-emitting device was manufactured using rare-earth aluminate phosphor H. A wavelength conversion composition containing the amounts shown in Table 3 (Comparative Example 8-1: 20 parts by mass, Comparative Example 8-2: 40 parts by mass, Comparative Example 8-3: 60 parts by mass, Comparative Example 8-4: 100 parts by mass, Example 8-5: 200 parts by mass, Example 8-6: 300 parts by mass, Example 8-7: 400 parts by mass, Example 8-8: 450 parts by mass) of rare-earth aluminate phosphor H was prepared. Except for using this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0241] Comparative Examples 9-1 to 9-2, Examples 9-3 to 9-6

[0242] A light-emitting device was manufactured using rare-earth aluminate phosphor I. A wavelength conversion composition containing the amounts shown in Table 3 (Comparative Example 9-1: 20 parts by mass, Comparative Example 9-2: 40 parts by mass, Example 9-3: 60 parts by mass, Example 9-4: 120 parts by mass, Example 9-5: 200 parts by mass, Example 9-6: 300 parts by mass) of rare-earth aluminate phosphor I was prepared. Except for using this wavelength conversion composition, the light-emitting device was manufactured in the same manner as in Example 1-1.

[0243] For each light-emitting device, the evaluation was performed in the same manner as in Examples 1-1. The results are shown in Table 3.

[0244] Table 3

[0245]

[0246] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the S / P ratio (luminous flux under scotopic vision to luminous flux under photopic vision) is 6.5 or less. It is believed that the light-emitting devices of each embodiment, even when emitting light with a dominant wavelength in the blue to green wavelength range including blue-green, can reduce the difference between luminous flux in dark areas and luminous flux in bright areas, maintaining excellent visibility that appears bright under both scotopic and photopic vision, and reducing the perceived difference in brightness.

[0247] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the melatonin illuminance ratio is 3.4 or less. It is believed that the light-emitting devices of each embodiment will not have a significant impact on human circadian rhythms. For example, as a signal color indicating a specific state of a machine, such as charging time, they can emit light with a dominant wavelength in the blue to green wavelength range, including blue-green, that can evoke specific images.

[0248] Light emitted from the light-emitting devices of each embodiment, having a dominant wavelength in the range of 475 nm to 500 nm, appears in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram as follows: Figure 3 Within the area A1 shown and Figure 4 The luminous color within region A2 is shown. The luminous devices of Examples 5-5, 5-6, 6-6 to 6-9, 7-7 to 7-11, 8-5 to 8-8, and 9-5 also exhibit the luminous color within regions A1 and A2. Figure 5 The area A3 shown has a blue to blue-green luminous color.

[0249] The light-emitting devices of each embodiment are considered to emit light in a range where the ratio of the integral value Ib / Ia is 0.6 or higher and 0.95 or lower, such that they can maintain excellent visibility that appears bright under both scotopic and photopic vision, while reducing the difference in brightness perceived by humans under both scotopic and photopic vision.

[0250] In Comparative Examples 5-1 to 5-2, 6-1 to 6-4, 7-1 to 7-4, 8-1 to 8-3, and 9-1, the light-emitting devices have low brightness because Ga has a higher molar content and Ce a lower molar content in the rare-earth aluminate phosphors E to I contained in the wavelength conversion component. If the content of rare-earth aluminate phosphors E to I is low, light with a dominant wavelength below 475 nm is emitted, and the S / P ratio is higher than 6.5. When viewed in the dark, it is conceivable that the light will be perceived as too bright. In addition, the light-emitting devices in Comparative Examples 5-1 to 5-2, 6-1 to 6-4, 7-1 to 7-4, 8-1 to 8-3, and 9-1 emit light with a dominant wavelength below 475 nm, and the melatonin illuminance ratio is higher than 3.4, which may affect human circadian rhythms. In the light-emitting devices of Comparative Examples 8-4 and 9-2, in each component of the rare earth aluminate phosphor H or I contained in the wavelength conversion component, because Ga has a higher molar content, the emission peak wavelength of the rare earth aluminate phosphor H or I changes compared to phosphors with a lower molar content of Ga. If the content of rare earth aluminate phosphor H or I is low, it is impossible to emit light with a dominant wavelength in the range of 475 nm or higher and 500 nm or lower.

[0251] Example 10-1, Comparative Examples 10-2 to 10-3

[0252] manufacture Figure 6A and Figure 6B The light-emitting device is as shown.

[0253] In the configuration process of the light-emitting element, a ceramic substrate made of aluminum nitride is used as the substrate. The light-emitting element is a nitride-based semiconductor layer with a dominant wavelength of 450 nm stacked on top. The size of the light-emitting element is approximately square, with a planar shape of about 1.0 mm square and a thickness of about 0.11 mm. The light-emitting element is configured such that the light-emitting surface is located on the substrate side, and flip-chip assembly is performed using bumps made of Au conductive members. Additionally, gaps are left between the light-emitting element and the semiconductor element, and flip-chip assembly is performed using bumps made of Au conductive members.

[0254] In the process of forming a wavelength converter containing a wavelength conversion element, a rare-earth aluminate phosphor A is used. A composition for the wavelength converter is prepared, wherein, as a light-transmitting material, rare-earth aluminate phosphor A is contained in the amounts shown in Table 4 (Example 10-1: 100 parts by mass, Comparative Example 10-2: 150 parts by mass, Comparative Example 10-3: 200 parts by mass) relative to 100 parts by mass of silicone resin, and 15 parts by mass of alumina is contained as a filler. As a light-transmitting material, a light-transmitting material is prepared as follows: it is made of borosilicate glass, approximately 0.15 mm larger in length and width than the planar shape of the light-emitting element, approximately 1.15 mm square in planar shape, and approximately 0.10 mm thick. On one roughly square side of the light-transmitting body, a wavelength conversion element is printed using a printing method. The wavelength conversion element is then heated at 180°C for 2 hours to harden, forming a layered wavelength conversion element with a thickness of approximately 80 μm. This results in a wavelength conversion component that integrates the layered or plate-shaped wavelength conversion element with the light-transmitting body.

[0255] In the bonding process of the light-emitting element and the wavelength conversion component, a silicone resin-containing adhesive is used to bond one side of the wavelength conversion component (approximately 1.15 mm square) to the other side of the light-emitting element (approximately 1.0 mm square), forming an adhesive layer between the light-emitting element and the wavelength conversion component.

[0256] In the process of forming the coated component, a composition for the coated component is prepared, containing dimethyl silicone resin and titanium dioxide particles with an average particle size (catalog value) of 0.28 μm, wherein the titanium dioxide particles comprise 30 parts by mass relative to 100 parts by mass of dimethyl silicone resin. The composition for the coated component is used to cover the sides of a light-emitting element and a wavelength conversion element including a wavelength converter and a light-transmitting element disposed on a substrate. The composition for the coated component is filled in such a way that the semiconductor element is completely embedded within it. The composition for the coated component is then hardened to form the coated component, forming a resin encapsulation and manufacturing a light-emitting device.

[0257] Examples 11-1 to 11-2, Comparative Example 11-3

[0258] A light-emitting device was manufactured by mixing rare-earth aluminate phosphor A and rare-earth aluminate phosphor H in a weight ratio of 50:50. A wavelength converter composition containing a mixture of rare-earth aluminate phosphor A and rare-earth aluminate phosphor H was prepared in the amounts shown in Table 4 (Example 11-1: 200 parts by mass, Example 11-2: 300 parts by mass, Comparative Example 11-3: 500 parts by mass). Except for using the wavelength converter composition, the light-emitting device was manufactured in the same manner as in Example 10-1.

[0259] Examples 12-1 to 12-3

[0260] A light-emitting device was manufactured using rare-earth aluminate phosphor H. A wavelength converter composition containing rare-earth aluminate phosphor H was prepared in the amounts shown in Table 4 (Example 12-1: 400 parts by mass, Example 12-2: 500 parts by mass, Example 12-3: 600 parts by mass). Except for the use of this wavelength converter composition, the light-emitting device was manufactured in the same manner as in Example 10-1.

[0261] Table 4

[0262]

[0263] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the S / P ratio (luminous flux under scotopic vision to luminous flux under photopic vision) is 6.5 or less. It is believed that even when emitting light with a dominant wavelength in the blue to green wavelength range, including blue-green, the light-emitting devices of each embodiment can reduce the difference between luminous flux in dark areas and luminous flux in bright areas, maintain excellent visibility that appears bright under both scotopic and photopic vision, and reduce the perceived difference in brightness.

[0264] The light-emitting devices of each embodiment emit light with a dominant wavelength in the range of 475 nm to 500 nm, and the melatonin illuminance ratio is 3.4 or less. The light-emitting devices of each embodiment are unlikely to have a significant impact on human circadian rhythms. For example, they emit light with a dominant wavelength in the blue to green wavelength range, including blue-green, that can give a specific image to a person, serving as a signal color for a specific state of a machine, such as when it is charging.

[0265] Light emitted from the light-emitting devices of each embodiment, having a dominant wavelength in the range of 475 nm to 500 nm, appears in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram as follows: Figure 3 Within the area A1 shown and Figure 4 The luminous color is shown in region A2. The luminous device of Examples 12-3 also exhibits the same luminous color in regions A1 and A2. Figure 5The area A3 shown has a blue to blue-green luminous color.

[0266] The light-emitting devices of each embodiment are considered to emit light that maintains excellent visibility under both scotopic and photopic vision while reducing the difference in perceived brightness under both scotopic and photopic vision.

[0267] In Comparative Examples 10-2 to 10-3 and Comparative Example 11-3, the rare earth aluminate phosphor A contained in the wavelength converter has high brightness. If the content of rare earth aluminate phosphor is high, light with a main wavelength higher than 500 nm is emitted, but light with a main wavelength in the range of 475 nm to 500 nm cannot be emitted.

[0268] [Industry Applicability]

[0269] One aspect of the light-emitting device of the present invention can be used as a light-emitting device for general lighting, a light-emitting device for vehicles, a display device, a lighting fixture, a display, etc.

Claims

1. A light-emitting device comprising a light-emitting element and a wavelength conversion component, wherein the light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm, and the wavelength conversion component comprises a rare-earth aluminate phosphor disposed on the light-emitting side of the light-emitting element, having a composition represented by the following formula (I). (Lu 1－p－n Ln p Ce n )3 (Al 1－m Ga m ) 5k O 12 (I) In equation (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and k, m, n, and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050, and 0≤p≤0.30, respectively. The light-emitting device emits light with a dominant wavelength in the range of 475nm to 500nm. The ratio of luminous flux under scotopic vision to luminous flux under photopic vision, i.e., the S / P ratio derived from the following formula (1), is below 6.

5. Light is emitted within region A2, which is defined in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. Based on the chromaticity coordinates (x, y), let (x = 0.0350, y = 0.4127) be the first point, (x = 0.0800, y = 0.2149) be the second point, (x = 0.2150, y = 0.2106) be the third point, and (x = 0.2550, y = 0.3550) be the fourth point. The region is defined by a first straight line connecting the first and second points, a second straight line connecting the second and third points, a third straight line connecting the third and fourth points, and a fourth straight line connecting the fourth point and the first point. In equation (1), the constant K is 6831 lm / W, the constant K' is 1700 lm / W, the wavelength λnm is in the range of 360nm to 830nm, V(λ) is the spectral luminous efficiency of human photopic vision, V'(λ) is the spectral luminous efficiency of human scotopic vision, and Φ e (λ) is the total spectral radiant flux of light emitted from the light-emitting device.

2. A light-emitting device comprising a light-emitting element and a wavelength conversion component, wherein the light-emitting element has a dominant wavelength in the range of 400 nm to 500 nm, and the wavelength conversion component comprises a rare-earth aluminate phosphor disposed on the light-emitting side of the light-emitting element, having a composition represented by the following formula (I). (Lu 1－p－n Ln p Ce n )3 (Al 1－m Ga m ) 5k O 12 (I) In equation (I), Ln is at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and k, m, n, and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050, and 0≤p≤0.30, respectively. The light-emitting device emits light with a dominant wavelength in the range of 475nm to 500nm. The melatonin illuminance ratio derived from the following formula (2) is below 3.

4. Light is emitted within region A2, which is defined in the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram. Based on the chromaticity coordinates (x, y), let (x = 0.0350, y = 0.4127) be the first point, (x = 0.0800, y = 0.2149) be the second point, (x = 0.2150, y = 0.2106) be the third point, and (x = 0.2550, y = 0.3550) be the fourth point. The region is defined by a first straight line connecting the first and second points, a second straight line connecting the second and third points, a third straight line connecting the third and fourth points, and a fourth straight line connecting the fourth point and the first point. In Equation (2), the wavelength is in the range of 380nm and below 730nm. "Lamp×Circadian" is the circadian rhythm response contained in the spectral distribution of the light-emitting device, "Lamp×Visual" is the visual acuity response contained in the spectral distribution of the light-emitting device, "Lamp" is the spectral distribution of the light-emitting device, "Circadian" is the sensitivity curve of the photoreceptor in the retina of mammals, i.e., the intrinsic photosensitive retinal ganglion cell, "Visual" is the visual acuity curve under human photopic vision, and "1.218" is a constant, i.e., the illuminance factor.

3. The light-emitting device according to claim 1, wherein, The S / P ratio is below 6.

0.

4. The light-emitting device according to claim 1, wherein, The S / P ratio is 3.0 or higher.

5. The light-emitting device according to claim 2, wherein, The melatonin illuminance ratio is 1.4 or higher.

6. The light-emitting device according to any one of claims 1 to 5, wherein, In the emission spectrum of the light-emitting device, the ratio Ib / Ia of the integral value of the emission spectrum in the wavelength range of 380 nm to 531 nm to the integral value of the emission spectrum in the wavelength range of 380 nm to 780 nm is in the range of 0.6 to 0.

95.

7. The light-emitting device according to any one of claims 1 to 5, wherein, Light is emitted within region A3, which is the region defined by the xy chromaticity coordinate system of the CIE 1931 chromaticity diagram, based on the chromaticity coordinates (x, y). Let (x = 0.1825, y = 0.3252) be the first point, (x = 0.1550, y = 0.2149) be the second point, (x = 0.1930, y = 0.2106) be the third point, and (x = 0.2205, y = 0.3209) be the fourth point. The region is defined by the first straight line connecting the first point and the second point, the second straight line connecting the second point and the third point, the third straight line connecting the third point and the fourth point, and the fourth straight line connecting the fourth point and the first point.

8. The light-emitting device according to any one of claims 1 to 5, wherein, The fluorophore comprises a rare earth aluminate fluorophore having a composition represented by formula (I), and at least one fluorophore selected from the group consisting of: a halosilicate fluorophore having a composition represented by formula (II); a β-silicon fluorophore having a composition represented by formula (III); an oxynitride fluorophore having a composition represented by formula (IV); an alkaline earth metal aluminate fluorophore having a composition represented by formula (V); an alkaline earth metal sulfide fluorophore having a composition represented by formula (VI); a first silicate fluorophore having a composition represented by formula (VII); a second silicate fluorophore having a composition represented by formula (VIII); a third silicate fluorophore or germanate fluorophore having a composition represented by formula (IX); and a fourth silicate fluorophore having a composition represented by formula (X). (Ca, Sr, Ba) 8MgSi4O 16 (F, Cl, Br) 2: Eu (II) And 6－z the z A z N 8－z :Eu(0<z≤4.2) (Ⅲ) BaSi2O2N2:Eu (Ⅳ) Sr4Al 14 THE 25 I (V) (Sr, Ca, Ba) Ga2S4: Eu (VI) (Ba, Sr, Ca) 2SiO4: Eu (VII) (Ba, Sr) ZrSi3O9: Eu (VIII) Ca3Sc2 (Si, Ge)3O 12 :What (Ⅸ) (ALi3SiO4)n:Eu(X), where A is at least one element selected from the group consisting of Li, Na, K, Rb and Cs, and n is an integer from 1 to 8.

9. The light-emitting device according to any one of claims 1 to 5, wherein, In the formula (I), k, m, n, and p satisfy 0.95≤k≤1.05, 0.3≤m≤0.5, 0.002≤n≤0.04, and 0≤p≤0.20, respectively.

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