Light-emitting device and illuminating apparatus comprising the light-emitting device
View Patent ↗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.
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 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.
2. The light-emitting device according to claim 1 , wherein the second part is configured upstream from the first part in a light path.
3. The light-emitting device according to claim 1 , wherein the first part and the second part are in close contact.
4. 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.
5. The light-emitting device according to claim 4 , wherein thickness of the second part depends upon the thickness of the first part.
6. 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.
7. 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.
8. The light-emitting device according to claim 1 , wherein a light transmission material is filled between the cover part and the light source.
9. 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.
10. 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.
11. The light-emitting device according to claim 1 , wherein the first part and the second part are made in one piece.
12. 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.
13. 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.