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US 6,633,120 B2Granted
LED lamps
AssigneeUnisplay S.A.
InventorHassan P. A. Salam
Life of this patent
Estimating the term…
Abstract
A high power LED lamp has a GaN chip placed over an AlGaInP chip. A reflector is placed between the two chips. Each of the chips has trenches diverting light for output. The chip pair can be arranged to produce white light having a spectral distribution in the red to blue region that is close to that of daylight. Also, the chip pair can be used to provide an RGB lamp or a red-amber-green traffic lamp. The active regions of both chips can be less than 50 microns away from a heat sink.
Claims54
An LED lamp for generating incoherent visible light, comprising:
- first and second inorganic structures stacked one over the other and each comprising a lower inorganic semiconductor layer and an upper inorganic semiconductor layer, the lower and upper semiconductor layers forming a diode and an active region between said layers generating light;
- an imaginary plane generally parallel to said layers defining a reference plane;
- each of said structures as viewed normal to said reference plane having a light generating zone having on outer side perimeter(25) beyond which light generation by the structure ceases;
- wherein
- said second structure comprises at least one semiconductor layer that is nitride of one or more of gallium, indium and aluminum;
- said first structure generates light of a different color from that generated by said second structure;
- and
- said first structure is provided with light-diverting surfaces distant from and within its said perimeter as viewed normal to said reference plane, the light-diverting surfaces being oblique to said reference plane and arranged for diverting light generated in said first structure, the diverted light passing through the said zone of the second structure.
5 more elements
An LED lamp for generating incoherent visible light, comprising:
- first and second inorganic structures stacked one over the other and each comprising a lower inorganic semiconductor layer and an upper inorganic semiconductor layer, the lower and upper semiconductor layers forming a diode and an active region between said layers generating light;
- an imaginary plane generally parallel to said layers defining a reference plane;
- each of said structures as viewed normal to said reference plane having a light generating zone having on outer side perimeter beyond which light generation by the structure ceases;
- wherein said first structure generates light of a different color from that generated by said second structure and wherein said first structure is provided with light-diverting surfaces distant from and within its said perimeter as viewed normal to said reference plane, the light-diverting surfaces being oblique to said reference plane and arranged for diverting light generated in said first structure, the diverted light passing through said second structure.
1 more element
An LED lamp for generating incoherent visible light, comprising:
- a first stack of inorganic semiconductor layers for generating light of a first color, the first stack having a top light-emitting surface, at least one of the layers of the first stack being lattice-matched to a gallium arsenide substrate that has been removed;
- a second stack of inorganic semiconductor layers for generating light of a second color, at least one of the layers of the second stack comprising nitride of one or more of gallium, aluminum and indium, and
- wherein substantially all of the light passing through said top light-emitting surface passes through said second stack.
An LED lamp for generating incoherent visible light, comprising:
- a first stack of inorganic semiconductor layers for generating light of a wavelength greater than 550 nanometers, the first stack having a top light-emitting surface;
- a second stack of inorganic semiconductor layers for generating light of a wavelength less than 550 nanometers, an imaginary plane generally parallel to the layers of second stack defining a reference plane;
- the second stack as viewed normal to said reference plane having a light generating zone having on outer side perimeter beyond which light generation by the structure ceases;
- a heat sink for cooling both of said stacks;
- non-semiconductor light passing material of refractive index greater than one placed between said stacks;
- and
- wherein
- substantially all of the light passing through said top light-emitting surface passes through said second stack;
- said second stack is provided with light-diverting surfaces distant from and within its said boundary as viewed normal to said reference plane, the light-diverting surfaces being inclined to the reference plane and arranged for diverting light generated in the second stack;
- and
- said second stack is less than 50 microns away from said heat sink.
8 more elements
Dependencies are inferred from the claim text.