# US 10,770,628 B2 · Light emitting device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,770,628 B2 - Document ID: US10770628B2 - Status: Granted - Kind: B2 - Application number: 16/426,918 - Filed: 2019-05-30 - Published: 2019-12-05 - Granted: 2020-09-08 - Earliest claimed: 2018-05-31 - Assignees: Nichia Corporation - Applicants: Nichia Corporation - Inventors: Makiko Iwasa; Kazushige Fujio - Web page: https://patentgrep.com/patent/US10770628B2 ## CPC - H10H 20/8513: {having two or more wavelength conversion materials} - A61L 2/084: Visible light - H10H 20/8515: {not being in contact with the bodies} - H10H 20/854: characterised by their material, e.g. epoxy or silicone resins - H10H 20/856: Reflecting means - A61L 2202/11: Apparatus for generating biocidal substances, e.g. vaporisers, UV lamps - H10H 20/825: containing nitrogen, e.g. GaN - H10H 20/8506: {Containers} - H10H 20/8512: {Wavelength conversion materials} - H10H 20/857: Interconnections, e.g. lead-frames, bond wires or solder balls - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) ## Abstract A light emitting device includes a light emitting element having an emission peak wavelength in a range of 380 nm to 420 nm and a fluorescent member including at least one fluorescent material that is excited by light from the light emitting element for light emission, wherein a mixture of light from the light emitting element and light from the fluorescent material has a correlated color temperature in a range of 2000 K to 7500 K as measured according to JIS Z8725, and the light emitting device has a spectral distribution in which, when the integral value over a wavelength range of 380 nm to 780 nm is normalized to 100%, the proportion of an integral value over a wavelength range of 380 nm to 420 nm is 15% or more, and the ratio a as defined by the expression (1) is 0.9 or more and 1.6 or less. ## Claims ### Claim 1 A light emitting device comprising: a light emitting element having an emission peak wavelength in a range of 380 nm to 420 nm; and a fluorescent member including at least one fluorescent material that is excited by light from the light emitting element for light emission, a mixture of light from the light emitting element and light from the fluorescent material having a correlated color temperature of 2000 K to 7500 K as measured according to JIS Z8725, the light emitting device having a spectral distribution in which, when an integral value over a wavelength range of 380 nm to 780 nm is normalized to 100%, the proportion of an integral value over a wavelength range of 380 nm to 420 nm is 15% or more, and the ratio a as defined by the following expression (1) falling within a range of 0.9 to 1.6: Ratio ⁢ ⁢ a = G L / B L G S / B S ( 1 ) wherein BS represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in a spectral distribution of a reference light source at the correlated color temperature of the light emitting device, Gs represents a maximum emission intensity in a wavelength range of 485 nm to 548 nm in the spectral distribution of the reference light source at the correlated color temperature of the light emitting device, and the denominator of the expression (1) is a ratio of Gs to Bs, and wherein BL represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the light emitting device, GL represents a maximum emission intensity in a wavelength range of 485 nm to 548 nm in the spectral distribution of the light emitting device, and the numerator of the expression (1) is a ratio of GL to BL. ### Claim 2 (depends on 1) The light emitting device according to claim 1, wherein the light emitting element has an emission peak wavelength in a range of 400 nm to 410 nm. ### Claim 3 (depends on 1) The light emitting device according to claim 1, wherein the general color rendering index Ra is 80 or more or the specialty color rendering index R12 is 50 or more. ### Claim 4 (depends on 1) The light emitting device according to claim 1, wherein the absolute value A of a value calculated by subtracting the ratio a from 1 is 0.6 or less. ### Claim 5 (depends on 1) The light emitting device according to claim 1, wherein a total of the ratio a, the ratio b and the ratio c defined by the expression (1), and by the following expressions (2) and (3), respectively, is 2.5 or more and 4.5 or less: Ratio ⁢ ⁢ b = Y L / B L Y S / B S ( 2 ) wherein BS represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the reference light source at the correlated color temperature of the light emitting device, YS represents a maximum emission intensity in a wavelength range of 580 nm to less than 610 nm in the spectral distribution of the reference light source at the correlated color temperature of the light emitting device, and the denominator of the expression (2) is a ratio of Ys to Bs, and wherein BL represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the light emitting device, YL represents a maximum emission intensity in a wavelength range of 580 nm to less than 610 nm in the spectral distribution of the light emitting device, and the numerator of the expression (2) is a ratio of YL to BL, Ratio ⁢ ⁢ c = R L / B L R S / B S ( 3 ) wherein BS represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the reference light source at the correlated color temperature of the light emitting device, RS represents a maximum emission intensity in a wavelength range of 610 nm to 780 nm in the spectral distribution of a reference light source at the correlated color temperature of the light emitting device, and the denominator of the expression (3) is a ratio of Rs to Bs, and wherein BL represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the light emitting device, RL represents a maximum emission intensity in a wavelength range of 610 nm to 780 nm in the spectral distribution of the light emitting device, and the numerator of the expression (3) is a ratio of RL to BL. ### Claim 6 (depends on 5) The light emitting device according to claim 5, wherein an absolute value B of a value calculated by subtracting the total of the ratio a, the ratio b and the ratio c from 3 is 1.5 or less. ### Claim 7 (depends on 1) The light emitting device according to claim 1, wherein in the spectral distribution of the light emitting device, the proportion of the integral value over a wavelength range of 380 nm to 420 nm relative to the integral value, 100%, over a wavelength range of 380 nm to 780 nm is 35% or less. ### Claim 8 (depends on 1) The light emitting device according to claim 1, wherein the fluorescent material contains at least one fluorescent material selected from the group consisting of a first fluorescent material having an emission peak wavelength in a range of 430 nm to less than 485 nm, as excited by the light from the light emitting element, a second fluorescent material having an emission peak wavelength in a range of 485 nm to less than 610 nm, as excited by the light from the light emitting element, and a third fluorescent material having an emission peak wavelength in a range of 610 nm to 780 nm, as excited by the light from the light emitting element. ### Claim 9 (depends on 8) The light emitting device according to claim 8, wherein the first fluorescent material contains at least one fluorescent material selected from the group consisting of a fluorescent material containing a halogen-containing alkaline earth metal phosphate containing at least one alkaline earth metal element, and at least one halogen element and Eu, and a fluorescent material containing an alkaline earth metal silicate containing at least one element selected from the group consisting of Ba, Sr and Ca, and Mg and Eu as an activating element. ### Claim 10 (depends on 8) The light emitting device according to claim 8, wherein the second fluorescent material contains at least one fluorescent material selected from the group consisting of a fluorescent material containing a rare earth aluminate containing at least one rare earth element except Ce, and Al and optionally Ga, and Ce as an activating element, a fluorescent material containing a halogen-containing alkaline earth metal silicate containing at least one alkaline earth metal element selected from the group consisting of Ca, Sr and Ba, and at least one halogen element selected from the group consisting of F, Cl and Br, and Eu as an activating element, a fluorescent material containing a β-SiAlON and Eu as an activating element, a fluorescent material containing a rare earth nitride containing at least one rare earth element selected from the group consisting of La, Y and Gd, and Si, in the composition and Ce as an activating element, and a fluorescent material containing an alkaline earth metal silicate and Eu as an activating element. ### Claim 11 (depends on 8) The light emitting device according to claim 8, wherein the third fluorescent material contains at least one fluorescent material selected from the group consisting of a florescent material containing a nitride containing at least one alkaline earth metal element, and Al and Si, and Eu as an activating element, a fluorescent material containing a nitride containing at least one alkaline earth metal element, and Si, and Eu as an activating element, and a fluorescent material containing a nitride containing at least one alkaline earth metal element, and Li and Al, and Eu as an activating element. ### Claim 12 (depends on 8) The light emitting device according to claim 8, wherein the first fluorescent material contains at least one fluorescent material selected from the group consisting of a fluorescent material having a composition represented by the following formula (I) and a fluorescent material having a composition represented by the following formula (II): (Ca,Sr,Ba,Mg)10(PO4)6(F,Cl,Br,I)2:Eu (I) (Ba,Sr,Ca)3MgSi2O8:Eu (II) ### Claim 13 (depends on 8) The light emitting device according to claim 8, wherein the second fluorescent material contains at least one fluorescent material selected from the group consisting of a fluorescent material having a composition represented by the following formula (III), a fluorescent material having a composition represented by the following formula (IV), a fluorescent material having a composition represented by the following formula (V), a fluorescent material having a composition represented by the following formula (VI), and a fluorescent material having a composition represented by the following formula (VII): (Lu,Y,Gd,Tb)3(Al,Ga)5O12:Ce (III) (Ca,Sr,Ba)8MgSi4O16(F,Cl,Br)2:Eu (IV) Si6-zAlzOzN8-z:Eu(0