Multiple-chip excitation systems for white light emitting diodes (LEDs)
First Claim
1. A white light illumination system comprising a multi-chip excitation source and a phosphor package, the multi-chip excitation source comprising:
- a first radiation source for providing UV co-excitation radiation to the phosphor package, the first radiation source emitting in wavelengths ranging from about 250 nm to about 410 nm;
a second radiation source for providing blue co-excitation radiation to the phosphor package, the second radiation source emitting in wavelengths ranging from about 410 nm to about 480 nm; and
a phosphor package configured to emit photoluminescence in wavelengths ranging from about 440 nm to about 700 nm upon co-excitation from the first and second radiation sources, wherein the phosphor package includes a green emitting aluminate-based phosphor;
wherein the phosphor package further including a red emitting phosphor, the red emitting phosphor comprises a nitride-based red phosphor; and
the nitride-based red phosphor is of a general formula MmMaMb(N,D)n;
Zz, where Mm is a divalent element;
Ma is a trivalent element;
Mb is a tetravalent element;
N is nitrogen;
Z is an activator; and
D is a halogen; and
where stiochiometry of constituent elements (m+z);
a;
b;
n is about 1;
1;
1;
3.
2 Assignments
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Accused Products
Abstract
Embodiments of the present invention are directed toward white light illumination systems (so called “white LEDs”) that comprise a multi-chip excitation source and a phosphor package. In a two-chip source, the two LEDs may be UV-emitting and blue emitting, or blue-emitting and green-emitting. The phosphor package is configured to emit photoluminescence in wavelengths ranging from about 440 nm to about 700 nm upon co-excitation from the first and second radiation sources. The photoluminescence emitted by the phosphors is at least 40 percent of the total power in the white light illumination, and the portion of the total power in the white light illumination contributed by the first and second radiation sources (LEDs) is less than about 60 percent. This ratio can vary in alternative embodiments, and includes 50/50, 60/40, 70/30, and 80/20, respectively. The white light illumination emitted by the system has in one embodiment a color rendering index (CRI) greater than about 90.
119 Citations
20 Claims
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1. A white light illumination system comprising a multi-chip excitation source and a phosphor package, the multi-chip excitation source comprising:
-
a first radiation source for providing UV co-excitation radiation to the phosphor package, the first radiation source emitting in wavelengths ranging from about 250 nm to about 410 nm; a second radiation source for providing blue co-excitation radiation to the phosphor package, the second radiation source emitting in wavelengths ranging from about 410 nm to about 480 nm; and a phosphor package configured to emit photoluminescence in wavelengths ranging from about 440 nm to about 700 nm upon co-excitation from the first and second radiation sources, wherein the phosphor package includes a green emitting aluminate-based phosphor; wherein the phosphor package further including a red emitting phosphor, the red emitting phosphor comprises a nitride-based red phosphor; and
the nitride-based red phosphor is of a general formula MmMaMb(N,D)n;
Zz, where Mm is a divalent element;
Ma is a trivalent element;
Mb is a tetravalent element;
N is nitrogen;
Z is an activator; and
D is a halogen; and
where stiochiometry of constituent elements (m+z);
a;
b;
n is about 1;
1;
1;
3. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A white light illumination system comprising a multi-chip excitation source and a phosphor package, the multi-chip excitation source comprising:
-
a first radiation source for providing UV co-excitation radiation to the phosphor package, the first radiation source emitting in wavelengths ranging from about 250 nm to about 410 nm; a second radiation source for providing blue co-excitation radiation to the phosphor package, the second radiation source emitting in wavelengths ranging from about 410 nm to about 480 nm; and a phosphor package configured to emit photoluminescence in wavelengths ranging from about 440 nm to about 700 nm upon co-excitation from the first and second radiation sources, wherein the phosphor package includes a green emitting aluminate-based phosphor; wherein the phosphor package further including a red emitting phosphor, the red emitting phosphor comprises a nitride-based red phosphor; and
the nitride-based red phosphor is of a general formula MmMaMbD3wN[(2/3)m+z+a+(4/3)b−
w]Zz, where Mm is a divalent element selected from the group consisting of Be, Mg, Ca, Sr, Ba, Zn, Cd, and Hg;
Ma is a trivalent element selected from the group consisting of B, Al, Ga, In, Y, Sc, P, As, La, Sm, Sb, and Bi;
Mb is a tetravalent element selected from the group consisting of C, Si, Ge, Sn, Ni, Hf, Mo, W, Cr, Pb, Ti, and Zr;
D is a halogen selected from the group consisting of F, Cl, Br, and I;
Z is an activator selected from the group consisting of Eu, Ce, Mn, Tb, and Sm;
N is nitrogen and wherein 0.01≦
m≦
1.5;
0.01≦
a≦
1.5;
0.01≦
b≦
1.5;
0.0001≦
w≦
0.6, and 0.0001≦
z≦
0.5. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification