No assignee for this patent application has been made.
Reporters obtained the following quote from the background information supplied by the inventors: "This invention relates to a lighting luminaire, and particularly to a solid state lighting luminaire with remote phosphor.
"Light emitting diodes (LEDs) are solid state lighting devices that convert electric energy to light, and generally comprise one or plural active layers of semiconductor material sandwiched between oppositely doped layers. When a bias voltage is applied across the doped layers, holes and electrons are injected into the active layer where they recombine to generate light.
"To use an LED chip in lighting devices, it is known to enclose an LED chip in a package to provide environmental and mechanical protection, color selection, light focusing and the like. An LED package can also include electrical leads, contacts or traces for electrically connecting the LED package to an external power source. In a typical LED package 10 illustrated in FIG. 1, a single LED chip 12 is mounted on a cup reflector 14 by means of a solder bond or conductive epoxy, and the bonding wires 15 are used to connect the contacts of the LED chip 12 to traces (not shown). The reflective cup may be filled with an encapsulated structure 16 which may contain a wavelength conversion material such as a phosphor. The entire assembly may be further encapsulated in a clear protective resin, which may be molded in the shape of a lens to shape the light emitted from the LED chip, if needed.
"LED packages 10 can generate white light by having a blue emitting LED chip 12 covered by a phosphor that absorbs blue light and re-emits yellow light. Some of the blue light passes through the conversion material without being converted such that the LED package 10 emits a white light combination of blue and yellow light.
"Generally, the approach for forming the phosphor structure over the LED package utilized a typical two-step method. The first step is to dispense the transparent encapsulant filled up to certain portion of the package and then bake in a chamber to harden the encapsulant, so that the phosphor particles were kept in a certain distance from the blue LED chip. However, during the process, the outside surface of the encapsulant is generally a concave surface because of the capillary phenomena, which would cause the inhomogeneous phosphor thickness in the package. Since a longer excitation optical paths in larger angle may cause more down-conversion yellow rays, extra yellow light would be generated in the perimeter of the LED package to degrade lighting quality. This is understood as the yellow ring effect."
In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventors' summary information for this patent application: "it is an object of the present invention to provide a solid state lighting luminaire with remote phosphors to reduce the angular dependent CCT deviation as well as the yellow ring effect.
"The present invention provide a solid state lighting luminaire, which comprises a solid state light source, an encapsulated structure, and a first phosphor. The encapsulated structure encapsulates the solid state light source and has an outside illuminating surface. The first phosphor is patterned to cover a portion of the outside illuminating surface for down-converting the illumination from the solid state light source.
"A method of fabricating the above mentioned solid state lighting luminaire is provided in the present invention. The method comprises the steps of: a) providing a solid state light source; b) forming an encapsulated structure to encapsulate the solid state light source; and c) spraying a patterned first phosphor, which is utilized for down-converting the illumination from the solid state light source, on a predetermined portion of the outside illuminating surface.
BRIEF DESCRIPTION OF THE DRAWINGS
"FIG. 1 is a typical white light LED package with remote phosphor structure.
"FIG. 2 is a schematic view of a white-light LED package in accordance with an embodiment of the present invention.
"FIG. 3 is a diagram showing the experimental result of angular dependent CCT regarding the typical LED package with remote phosphor, the LED package with patterned phosphor as described in FIG. 2, and the typical LED package with phosphor mixed in the encapsulated structure.
"FIG. 4 is a schematic view showing a fabrication method of the white-light LED package of FIG. 2 in accordance with an embodiment of the present invention.
"FIG. 5 is a schematic view of a white-light LED package in accordance with another embodiment of the present invention.
"FIG. 6 is a schematic view of a white-light LED package in accordance with still another embodiment of the present invention.
"FIG. 7 is a schematic view showing a fabrication method of the white-light LED package of FIG. 5 in accordance with an embodiment of the present invention.
"FIG. 8 is a schematic view showing a fabrication method of the white-light LED package of FIG. 6 in accordance with an embodiment of the present invention."
For more information, see this patent application: WANG, Shing-Chung; KUO, Hao-Chung; CHEN, Hsin-Chu; CHEN, Kuo-Ju. Solid State Lighting Luminaire and a Fabrication Method Thereof. Filed
Keywords for this news article include: Patents.
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