Creating Unity with Phosphor
Patent
US9677719
Owner
OSRAM GmbH
Filing Date
June 11, 2013
Priority Date
June 11, 2012
Portfolio
Lighting - OSRAM
Intro
This invention solves the problem of color variance between light emitted from an LED tube in different directions. The invention proposes a cover part surrounding the light source having different phosphor thickness in two different light emitting directions of the light source.
Claims
1.
A light-emitting device, comprising: a substrate; a light source arranged on the substrate; and a cover part spaced a certain distance apart from t...
- A light-emitting device, comprising: a substrate; a light source arranged on the substrate; and a cover part spaced a certain distance apart from the light source and transmitting light emitted from the light source to outside, wherein the cover part comprises a first part, converting wavelengths of a part of light in light emitted from the light source and having different thicknesses at least in two different light-emitting directions of the light source; and a second part, having different thicknesses in the two different light-emitting directions to compensate the thicknesses of the first part, wherein the first part comprises a substrate and phosphors dispersed in the substrate and arranged on the outermost layer of the cover part, the second part made from a material the same as that of the substrate, and the second part is free from phosphor, and a sum of thickness of the first part and thickness of the second part is a fixed value.
- The light-emitting device according to claim 1, wherein the second part is configured upstream from the first part in a light path.
- The light-emitting device according to claim 1, wherein the first part and the second part are in close contact.
- The light-emitting device according to claim 1, wherein the first part has a non-uniform thickness corresponding to a luminous intensity spatial distribution of the light source.
- The light-emitting device according to claim 4, wherein thickness of the second part depends upon the thickness of the first part.
- The light-emitting device according to claim 1, wherein the light source is blue LEDs, and the first part comprises phosphors converting blue light to yellow light such that the light-emitting device emits white light.
- The light-emitting device according to claim 1, wherein the light source is ultraviolet LEDs, and the first part comprises phosphors converting ultraviolet to visible light such that the light-emitting device emits visible light.
- The light-emitting device according to claim 1, wherein a light transmission material is filled between the cover part and the light source.
- The light-emitting device according to claim 1, wherein the cover part partially encloses the light source, and a light incident surface or a light emergent surface of the cover part is a part of a cylindrical surface, a part of a spherical surface or a part of an ellipsoid surface.
- The light-emitting device according to claim 1, wherein a light incident surface or a light emergent surface of the cover part is a plane.
- The light-emitting device according to claim 1, wherein the first part and the second part are made in one piece.
- The light-emitting device according to claim 11, wherein the first part and the second part are made through a bi-material injection process or a bi-material extrusion process.
- Illuminating apparatus comprising a light-emitting device, the light-emitting device comprising: a substrate; a light source arranged on the substrate; and a cover part spaced a certain distance apart from the light source and transmitting light emitted from the light source to outside, wherein the cover part comprises a first part, converting wavelengths of a part of light in light emitted from the light source and having different thicknesses at least in two different light-emitting directions of the light source; and a second part, having different thicknesses in the two different light-emitting directions to compensate the thicknesses of the first part, wherein the first part comprises a substrate and phosphors dispersed in the substrate and arranged on the outermost layer of the cover part, the second part is made from a material the same as that of the substrate, and the second part is free from phosphor, and a sum of thickness of the first part and thickness of the second part is a fixed value.
Abstract
A light-emitting device may include a substrate, a light source arranged on the substrate, and a cover part spaced a certain distance apart from the l...
A light-emitting device may include a substrate, a light source arranged on the substrate, and a cover part spaced a certain distance apart from the light source and transmitting light emitted from the light source to outside. The cover part includes a first part, converting wavelengths of a part of light in light emitted from the light source and having different thicknesses at least in two different light-emitting directions of the light source, and a second part, having different thicknesses in the two different light-emitting directions to compensate the thicknesses of the first part.
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