CPC F21K 9/61 (2016.08) [F21K 9/232 (2016.08); G02B 6/0045 (2013.01); F21V 2200/20 (2015.01); F21Y 2115/10 (2016.08)] | 14 Claims |
1. A light emitting device comprising:
at least one LED light source adapted for, in operation, emitting light source light, and
an elongated light guide comprising a height direction a width direction, a depth direction and a central longitudinal axis extending in the height direction, wherein the elongated light guide further comprises:
a first major surface and a second major surface arranged extending opposite to the first major surface in the depth direction of the elongated light guide,
a first minor surface and a second minor surface arranged extending opposite to the first minor surface in the width direction of the elongated light guide, and
a first end and a second end arranged extending opposite to the first end in the height direction of the elongated light guide,
wherein the elongated light guide further comprises at least one light in-coupling element configured to couple the light source light into the elongated light guide and at least one light out-coupling element configured to couple the light source light out of the elongated light guide, the elongated light guide being configured to guide at least a portion of the light source light which is coupled into the light guide at the light in-coupling element via total internal reflection to the light out-coupling element,
wherein the elongated light guide is twisted around the central longitudinal axis of the light guide,
wherein the at least one light out-coupling is elongated, and
wherein the at least one light in-coupling element comprises a LED filament extending in the height direction of the light guide throughout a part or all of the light guide.
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