# US 11,114,594 B2 · Light emitting device packages using light scattering particles of different size > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,114,594 B2 - Document ID: US11114594B2 - Status: Granted - Kind: B2 - Application number: 11/895,573 - Filed: 2007-08-24 - Published: 2009-02-26 - Granted: 2021-09-07 - Earliest claimed: 2007-08-24 - Assignees: CreeLED, Inc. - Applicants: Arpan Chakraborty - Inventors: Arpan Chakraborty - Web page: https://patentgrep.com/patent/US11114594B2 ## CPC - H10H 20/854: characterised by their material, e.g. epoxy or silicone resins - H10H 20/8513: {having two or more wavelength conversion materials} - H10H 20/853: characterised by their shape - H10H 20/855: Optical field-shaping means, e.g. lenses - H10H 20/882: {Scattering means (H10H20/82 takes precedence)} - H10W 90/00: Package configurations - Y10T 428/2991: Coated - H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A radiation emitting device comprising light scattering particles of different sizes that at least partially surround an emitter, improving the spatial color mixing and color uniformity of the device. Multiple sizes of light scattering particles are dispersed in a medium to at least partially surround a single- or multiple-chip polychromatic emitter package. The different sizes of light scattering particles interact with corresponding wavelength ranges of emitted radiation. Thus, radiation emitted over multiple wavelength ranges or sub-ranges can be efficiently scattered to eliminate (or intentionally create) spatially non-uniform color patterns in the output beam. ## Claims ### Claim 1 An emitting device, comprising: multiple emitters spaced apart on a common flat surface, wherein each of said multiple emitters emit a spectrum of radiation and at least two of said emitters emit spectrums having different wavelength ranges; an encapsulant over said multiple emitters and on said common flat surface, each of said emitters disposed off-center on said common flat surface with respect to said encapsulant; a first plurality of scattering particles comprising a diameter greater than 1 micrometer at least partially surrounding at least one emitter of said multiple emitters, wherein said first plurality of scattering particles scatters light at wavelengths within a first sub-spectrum of said spectrums; and a second plurality of scattering particles comprising a diameter less than 1 micrometer at least partially surrounding at least one emitter of said multiple emitters, wherein said second plurality of scattering particles scatters light at wavelengths within a second sub-spectrum of said spectrums; wherein said first plurality of scattering particles interacts with said wavelengths within said first sub-spectrum more than said wavelengths within said second sub-spectrum, and said second plurality of scattering particles interacts with said wavelengths within said second sub-spectrum more than said wavelengths within said first sub-spectrum; wherein said first and second pluralities of scattering particles are mixed together in and are dispersed throughout a common medium and said first and second pluralities of scattering particles contain indices of refraction different than the index of refraction of said common medium; wherein radiation emitted from said multiple emitters interacts with said first and second pluralities of scattering particles, such that said diameters of said first and second pluralities of scattering particles and the index of refraction differential between said common medium and said first and second pluralities of scattering particles create a substantially forward or sideways scattering effect over said first sub-spectrum and said second sub-spectrum. ### Claim 2 (depends on 1) The emitting device of claim 1, wherein said emitted spectrum comprises visible light. ### Claim 3 (depends on 1) The emitting device of claim 1, further comprising additional pluralities of scattering particles such that said emitting device comprises scattering particles of at least three different sizes. ### Claim 4 (depends on 1) The emitting device of claim 1, wherein said first and second pluralities of light scattering particles in said encapsulant are configured such that said emitted radiation passes through said encapsulant. ### Claim 5 (depends on 1) The emitting device of claim 1, wherein said first and second pluralities of light scattering particles are positioned in a wavelength conversion layer that at least partially surrounds said at least one emitter. ### Claim 6 (depends on 1) The emitting device of claim 1, wherein said first and second pluralities of light scattering particles are positioned in a lens element that interacts with said emitted radiation. ### Claim 7 (depends on 1) The emitting device of claim 1, wherein said first plurality of light scattering particles comprises alumina (Al2O3). ### Claim 8 (depends on 1) The emitting device of claim 1, wherein said first and second pluralities of light scattering particles are homogeneously mixed. ### Claim 9 (depends on 1) The emitting device of claim 1, wherein said first plurality of scattering particles at least partially surrounds said emitter according to a first particle density. ### Claim 10 (depends on 1) The emitting device of claim 1, wherein said second plurality of scattering particles at least partially surrounds said emitter according to a second particle density. ### Claim 11 (depends on 1) The emitting device of claim 1, wherein the density of said first plurality of particles and the density of said second plurality of particles are related according to a density ratio. ### Claim 12 (depends on 1) The emitting device of claim 1, wherein said first plurality of scattering particles comprises alumina particles, said alumina particles comprising diameters ranging from approximately 1-2 micrometers and distributed at approximately 0.08% per volume in a medium surrounding said at least one emitter. ### Claim 13 (depends on 12) The emitting device of claim 12, wherein said second plurality of scattering particles comprises submicron alumina particles, said submicron alumina particles comprising diameters less than approximately 1 micrometer and distributed at approximately 0.14% per volume in said medium. ### Claim 14 (depends on 1) The emitting device of claim 1, wherein the scattering particles are concentrated in the common space based on a loss figure due to absorption. ### Claim 15 (depends on 1) The emitting device of claim 1, wherein said first plurality of scattering particles and said second plurality of scattering particles comprise at least one material that is selected according to characteristics of said spectrum of radiation from said at least one emitter. ### Claim 16 (depends on 1) The emitting device of claim 1, wherein said first plurality of scattering particles and said second plurality of scattering particles comprise various combinations of materials that are used to achieve a particular scattering effect. ### Claim 17 (depends on 1) The emitting device of claim 1, wherein said first plurality of scattering particles and said second plurality of scattering particles comprise various combinations of different forms of a same material that are used to achieve a particular scattering effect. ### Claim 18 A light emitting device package, comprising: multiple emitter chips within said package, each of which is on a common surface and surrounded by a respective separate encapsulant, each of said separate encapsulants surrounding a single emitter chip, wherein each of said multiple emitter chips emits a different spectrum; said encapsulants configured such that light emitted from said multiple emitter chips passes through said encapsulants; and a plurality of scattering particles dispersed throughout each of said encapsulants, wherein said plurality of scattering particles in each encapsulant is selected to scatter the spectrum emitted by said single emitter chip surrounded by that particular encapsulant, wherein at least two of said encapsulants comprise scattering particles having different characteristics. ### Claim 19 (depends on 18) The light emitting device package of claim 18, wherein said multiple emitter chips emit at least two different colors. ### Claim 20 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles in at least one of said encapsulants are homogeneously mixed within said encapsulants. ### Claim 21 (depends on 18) The light emitting device package of claim 18, wherein said multiple emitter chips comprise at least one red light emitter and at least one white light emitter. ### Claim 22 (depends on 18) The light emitting device package of claim 18, wherein said encapsulants comprise beam-shaping properties. ### Claim 23 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles comprises alumina (Al2O3). ### Claim 24 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles are positioned in said encapsulants according to respective particle densities, each size of scattering particle corresponding to a respective particle density. ### Claim 25 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles in at least one of said multiple emitter chips comprises a first and a second size of alumina particles, said first size comprising diameters ranging from approximately 1-2 micrometers and distributed at approximately 0.08% per volume in said encapsulants, and said second size comprising diameters less than approximately 1 micrometer and distributed at approximately 0.14% per volume in said encapsulants. ### Claim 26 (depends on 18) The light emitting device package of claim 18, wherein the scattering particles are concentrated in said encapsulants based on a loss figure due to absorption. ### Claim 27 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles comprise various combinations of materials that are used to achieve a particular scattering effect. ### Claim 28 (depends on 18) The light emitting device package of claim 18, wherein said plurality of scattering particles comprise various combinations of different forms of a same material that are used to achieve a particular scattering effect. ### Claim 29 (depends on 18) The light emitting device package of claim 18, further comprising a wavelength conversion layer.