SYSTEM AND METHOD FOR PROVIDING COLOR LIGHT SOURCES IN PROXIMITY TO PREDETERMINED WAVELENGTH CONVERSION STRUCTURES
An optical device includes a light source with at least two radiation sources, and at least two layers of wavelength-modifying materials excited by the radiation sources that emit radiation in at least two predetermined wavelengths. Embodiments include a first plurality of n radiation sources configured to emit radiation at a first wavelength. The first plurality of radiation sources are in proximity to a second plurality of m of radiation sources configured to emit radiation at a second wavelength, the second wavelength being shorter than the first wavelength. The ratio between m and n is predetermined. The disclosed optical device also comprises at least two wavelength converting layers such that a first wavelength converting layer is configured to absorb a portion of radiation emitted by the second radiation sources, and a second wavelength converting layer configured to absorb a portion of radiation emitted by the second radiation sources.
1 . A light-emitting system comprising:
at least one first light-emitting source configured to emit a first radiation, said first radiation being blue light having a first wavelength;
at least one second light-emitting source configured to emit a second radiation, said second radiation being violet light having a second wavelength shorter than said first wavelength;
one or more wavelength-converting materials disposed to absorb at least a portion of said first or second radiations, and configured to emit a converted radiation having one or more wavelengths longer than said first or second wavelengths such that said system emits emitted light comprising a blend of two or more of said first, second and converted radiations; and
at least one driving circuit for selectively powering said at least one first and second light-emitting sources to adjust said blend of said emitted light.
2 . The system of claim 1 , wherein said at least one driving circuit is configured to be controlled to vary power to said at least one first light-emitting source and said at least one second light-emitting source, respectively.
3 . The system of claim 1 , wherein said at least one driving circuit is configured to selectively brighten, dim, or turn off at least one of said at least one first light-emitting source or said at least one second light-emitting source based on a selected output of said emitted light.
4 . The system of claim 1 , wherein said at least one driving circuit is configured to vary power to one of said at least one first light-emitting source or said at least one second light-emitting source, while maintaining power to the other of said at least one first light-emitting source or said at least one second light-emitting source.
5 . The system of claim 1 wherein said at least one driving circuit is configured to power said at least one first light-emitting source or said at least one second light-emitting source based on a ratio of power being delivered to said at least one first light-emitting source to power being delivered to said at least one second light-emitting source.
6 . The system of claim 1 , wherein said at least one driving circuit is configured to power said at least one first light-emitting source and said at least one second light-emitting source such that said emitted light has essentially a constant luminance.
7 . The system of claim 1 , wherein said at least one driving circuit is configured to power said at least one first light-emitting source and said at least one second light-emitting source such that said emitted light has a color rendering index which is maintained above a predetermined value.
8 . The system of claim 1 , wherein said at least one driving circuit is configured to power said at least one first light-emitting source and said at least one second light-emitting source such that said emitted light has a color rendering index and a luminance which are varied according to predetermined values.
9 . The system of claim 1 , wherein said at least one driving circuit is configured to power, selectively, said at least one first light-emitting source and said at least one second light-emitting source at predetermined times.
10 . The system of claim 1 wherein said emitted light comprises a blend of only said first and converted radiations or a blend of only said second and converted radiations.
11 . The system of claim 1 wherein said wavelength-converting material is disposed in patterned shapes.
12 . The system of claim 11 , further comprising more than one patterned shapes, wherein said patterned shapes are optically isolated from each other.
13 . The system of claim 12 , where said optical isolation is provided by optical elements.
14 . The system of claim 13 , wherein said optical elements are reflective elements disposed between said patterned shapes.
15 . The system of claim 1 , wherein said wavelength-converting materials include a first material substantially emitting light in a range of about 500 nm to about 600 nm and a second material substantially emitting light in a range of about 600 nm to about 700 nm.
16 . The system of claim 15 , wherein said at least one first light-emitting source comprises a plurality of said first light-emitting sources, or said at least one second light-emitting source comprises a plurality of second light-emitting sources, said first and second light-emitting sources being configured with said first and second materials in at least one of a first pattern or a second pattern, in said first pattern, a first portion of said first light-emitting sources is patterned with said first material and a second portion of said first light-emitting sources is patterned with said second material, said first and second portions being different, and, in said second pattern, a third portion of said second light-emitting sources is patterned with said first material and a fourth portion of said second light-emitting sources is patterned with said second material, said third and fourth portions being different.
17 . The system of claim 1 further comprising at least one third light-emitting source configured to emit light having a third wavelength within a range of about 600 nm to 660 nm.
18 . The system of claim 1 , wherein said at least one first light-emitting source has a wavelength of 430 nm to about 490; and wherein said at least one second light-emitting source has a wavelength of greater than 405 nm.
19 . The system of claim 1 , further comprising an optical element configured to suppress a fraction of said emitted light in a predetermined wavelength range.
20 . The system of claim 19 , wherein said optical element is one or more of a light-absorbing element, a light-reflecting element, or a wavelength-converting element.
21 . The system of claim 19 , wherein said optical element is positioned to selectively suppress a fraction of said emitted light.
22 . A light-emitting system comprising:
at least one blue light-emitting source;
at least one violet light-emitting source;
one or more phosphors to absorb at least a portion of light from at least one of said blue or violet light-emitting sources, and emit light of one or more different wavelengths; and
one or more drivers for selectively driving said at least one blue and violet light-emitting sources, said one or more drivers being configured to brighten or dim said at least one blue light-emitting source relative to said at least one violet light-emitting source, or to turn off said at least one blue light-emitting source while powering said at least one violet light-emitting source.
23 . The system of claim 22 , wherein said blue light-emitting source has a wavelength of 420 nm to about 490; and wherein said violet light-emitting source has a wavelength of 380 nm to about 430 nm.
24 . A method of using a light-emitting device, said device comprising at least one blue light-emitting source, at least one violet light-emitting source, one or more phosphors to absorb at least a portion of light from at least one of said blue or violet light-emitting sources and emit light of one or more different wavelengths, and one or more drivers for selectively driving a first electrical power into said blue light-emitting source, and a second electrical power into said violet light-emitting sources, said method comprising:
selectively driving said blue and said violet light-emitting sources during a first period according to a first ratio of said first power to said second power; and
selectively driving said blue and said violet light-emitting source during a second period according to a second ratio of said first power to said second power;
wherein said first ratio is larger than said second ratio.
25 . The method of claim 24 , wherein said device emits essentially white light during said first and second periods.
26 . The method of claim 24 , wherein selectively driving said blue and said violet light-emitting sources during said second period comprises decreasing said first power relative to said second power to obtain said second ratio.
27 . The method of claim 26 , wherein said second power remains essentially the same for said first and second ratios.
28 . A method of varying light output using a light-emitting device, said device comprising at least one blue light-emitting source, at least one violet light-emitting source, one or more phosphors, said device emitting light having an emitted spectral power distribution (SPD), said method comprising:
operating said light-emitting device during a first period such that a first fraction of said SPD is in a wavelength range of about 430 nm to 490 nm; and
operating said light-emitting device during a second period such that a second fraction of said SPD is in said wavelength range,
wherein said second fraction is less than said first fraction.
29 . The method of claim 28 , wherein said light-emitting device comprises one or more drivers for selectively driving said blue and violet light-emitting sources, and wherein operating said light-emitting device during said second period comprises diming said at least one blue emitting source relative to said at least one violet light-emitting source, or turning off said at least one blue light-emitting source while powering said at least one violet light-emitting source.
30 . The method of claim 28 , wherein said light-emitting device further comprises an optical element configured to suppress a fraction of said first wavelength, and wherein operating said light-emitting device during said second period comprises using said optical element to block a portion of said first wavelength.