Abstract: The invention relates to a light source to emit a mixture of primary and secondary light comprising an electroluminescent device like a light emitting diode LED or a laser, to emit the primary light into a light conversion element (3) to convert the primary light into the secondary light, where a first part of the primary light is emitted along a light path with a first conversion factor (11) for the primary light, and a second part of the primary light is emitted along a light path with a second conversion factor (12) for the primary light larger than the first conversion factor.
August 14, 2006
Date of Patent:
January 5, 2010
Koninklijke Philips Electronics N.V.
Gunnar Luettgens, Albrecht Kraus, Benno Spinger
Abstract: A light-emitting diode comprises a chip emitting visible light of a first wavelength, a light-emitting surface and a phosphor layer provided on the light-emitting surface. Said phosphor layer is capable of converting light of the first wavelength to visible light of a second wavelength. According to the invention, a part of the light-emitting surface is not covered with the phosphor layer. Preferably, the size of said surface is chosen to be such that by mixing emitted light of the first and the second wavelength substantially white light is obtained. Preferably, the surface that is not covered with the phosphor layer comprises a plurality of sub-surfaces, preferably arranged in the form of a pattern.
Abstract: A semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is attached to a compound substrate including a host which provides mechanical support to the device and a ceramic layer including a luminescent material. In some embodiments the compound substrate includes a crystalline seed layer on which the semiconductor structure is grown. The ceramic layer is disposed between the seed layer and the host. In some embodiments, the compound substrate is attached to the semiconductor structure compound substrate is spaced apart from the semiconductor structure and does not provide mechanical support to the structure. In some embodiments, the ceramic layer has a thickness less than 500 ?m.
November 29, 2005
Date of Patent:
April 7, 2009
Koninklijke Philips Electronics N.V., Philips Lumiled Lighting, U.S. LLC