LED LIGHTING ARRANGEMENT INCLUDING LIGHT EMITTING PHOSPHOR
A lighting arrangement comprises: a light transmissive substantially spherical shell; at least one LED located within the shell and operable to generate light of a first wavelength range and at least one phosphor operable to absorb at least a portion of the light emitted by the LED(s) and to emit light of a different wavelength range, wherein light generated by the arrangement comprises the combined light emitted by the LED(s) and the phosphor(s). The phosphor(s) can be provided as a layer on at least a part of the inner and/or outer surfaces of the shell or incorporated within the shell.
1 . A lighting arrangement comprising: a light transmissive substantially spherical shell; at least one LED located within the shell and operable to generate light of a first wavelength range and at least one phosphor operable to absorb at least a portion of the light emitted by the LED and to emit light of a different wavelength range, wherein light generated by the arrangement comprises the combined light emitted by the LED and the phosphor and wherein the at least one phosphor is selected from the group consisting of: being provided as a layer on at least a part of an inner surface of the shell; being provided as a layer on at least a part of an outer surface of the shell; being incorporated within the shell and combinations thereof.
2 . The lighting arrangement of claim 1 , and further comprising a second phosphor selected from the group consisting of: being provided as respective layer on at least a part of an inner surface of the shell; being provided as a respective layer on at least a part of an outer surface of the shell; being provided as a mixture with the first phosphor as a layer on at least a part of an inner surface of the shell; being provided as a mixture with the first phosphor as a layer on at least a part of an outer surface of the shell; being incorporated as a mixture with the first phosphor within at least a part of the shell and combinations thereof.
3 . The lighting arrangement according to claim 1 , in which the phosphor layer is of thickness in a range 20 to 500 μm.
4 . The lighting arrangement according to claim 1 , in which the shell is selected from the group consisting of: a plastics material, a polycarbonate, a glass and a silica glass.
5 . The lighting arrangement according to claim 1 , in which the at least one phosphor has a general formula A 2 SiO 4 :Eu 2+ D where A is a divalent metal selected from the group consisting of Sr, Ca, Ba, Mg, Zn and Cd and D is a dopant selected from the group consisting of F, Cl, Br, I, P, S and N.
6 . The lighting arrangement according to claim 1 , in which the at least one phosphor has a formula (YA) 3 (AlB) 5 (OC) 12 :Ce 3+ where A is a trivalent metal selected from the group consisting of Gd, Tb, La, Sm or divalent metal ions such as Sr, Ca, Ba, Mg, Zn and Cd; B is selected from the group consisting of Si, B, P, and Ga; and C is a dopant selected from the group consisting of F, Cl, Br, I, P, S and N.
7 . The lighting arrangement according to claim 1 , in which the at least one phosphor comprises an orange-red silicate-based phosphor having a formula (SrM1) 3 Si(OD) 5 :Eu where M1 is selected from the group consisting of Ba, Ca, Mg, Zn; and D is selected from the group consisting of F, Cl, S, and N.
8 . The lighting arrangement according to claim 1 , in which the phosphor comprises a red silicon nitride based phosphor having a formula (SrM1)Si 5 N 8 where M1 is selected from the group consisting Sr, Ca, Mg, and Zn.
9 . The lighting arrangement according to claim 1 , in which the phosphor comprises a red sulfate based phosphor having a formula (SrM1)S where M1 is selected from the group consisting of Ca, Ba, and Mg.
10 . The lighting arrangement according to claim 1 , in which the phosphor comprises a green sulfate based phosphor having a formula (SrM1)(GaM2) 2 S 4 :Eu where M1 is selected from the group consisting of Ca, Ba, and Mg, and M2 is selected from the group consisting of Al and In.
11 . The lighting arrangement according to claim 1 , in which the at least one phosphor comprises a powder which is incorporated within one of a light transmissive epoxy resin, a silicone material and a polymer material.
12 . The lighting arrangement according to claim 11 , and further comprising incorporating a light diffusing material with the phosphor.
13 . The lighting arrangement according to claim 12 , in which the light diffusing material is selected from the group consisting of: titanium oxide, silica and alumina
14 . The lighting arrangement according to claim 1 , in which the at least one LED comprises gallium nitride based LED.
15 . The lighting arrangement according to claim 1 , in which the LED is operable to emit light having a wavelength in a range of 300 nm to 500 nm.
16 . The lighting arrangement according to claim 1 , in which the phosphor is configured to emit light having a wavelength ranging from 450 nm to 700 nm.
17 . The lighting arrangement according to claim 1 , in which the arrangement is configured to generate white light.
18 . A lighting arrangement comprising: a light transmissive substantially spherical shell; at least one LED located within the shell and operable to generate excitation light having a wavelength ranging from 300 nm to 500 nm and at least one phosphor operable to absorb at least a portion of the LED light and to emit light having a wavelength ranging from 450 to 700 nm, wherein light generated by the arrangement comprises the combined light emitted by the LED and the phosphor and is configured to appear white in color and wherein the at least one phosphor is selected from the group consisting of: being provided as a layer on at least a part of the inner curved surface of the shell; being provided as a layer on at least a part of the outer curved surface of the shell; being incorporated within the shell and combinations thereof.
19 . An optical component for a lighting arrangement comprising at least one LED operable to generate excitation light of a first wavelength range; at least one phosphor operable to absorb at least a portion of the light generated by the LED and to emit light of a second wavelength range, wherein light generated by the arrangement comprises the combined light of the first and second wavelength ranges; the optical component comprising a light transmissive substantially spherical shell configured such that the LED is locatable within the shell and wherein the phosphor is selected from the group consisting of: being provided as a layer on at least a part of the inner curved surface of the shell; being provided as a layer on at least a part of the outer curved surface of the shell; being incorporated within the shell and combinations thereof.