CPC F21K 9/232 (2016.08) [F21K 9/235 (2016.08); F21K 9/64 (2016.08); F21K 9/90 (2013.01); F21Y 2115/10 (2016.08)] | 15 Claims |
1. A lighting device comprising:
a transmissive housing;
a filament within said transmissive housing, said filament comprising a transmissive substrate carrying a plurality of solid state lighting elements; and
a phosphor containing resin coating enveloping said filament, said resin coating including at least one region, with a reduced thickness, leaking light produced by said solid state lighting elements that is unconverted by said phosphor;
wherein the transmissive housing carries a further phosphor layer covering a part of the transmissive housing and being optically aligned with each of said regions of the resin coating with the reduced thickness, each of said further phosphor layers being arranged to receive said unconverted light leaking from at least one of said regions, whilst other part of the housing remains transmissive.
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