Side-emitting rod for use with an LED-based light engine
AssigneeKoninklijke Philips Electronics N.V.
InventorsMichael D. Pashley, Thomas M. Marshall, Frank J. P. Schuurmans
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Abstract
According to this invention, a side-emitting illumination device for uniformly distributing light is composed of an LED light source, a light-transmitting rod which permits total internal reflection, and outcoupling material affixed to an outer surface of the rod. Light enters the rod at one end and travels along the rod by total internal reflection. Light that hits the outcoupling material is angularly distributed based on the width of the outcoupling material.
Claims19
A side-emitting illumination device for uniformly distributing light comprising:
- an LED light source,
- a light-transmitting rod which permits total internal reflection, and
- outcoupling material affixed to an outer surface of the rod, wherein the width of the outcoupling material affixed to an outer surface of the rod controls the angular distribution of light leaving the side of the rod.
A method of controlling the angular distribution of light leaving the side of a side-emitting illumination device for uniformly distributing light comprising:
- providing a light-transmitting rod which permits total internal reflection with an outcoupling material along its side;
- controlling the width of the outcoupling material to achieve a desired angular distribution of light leaving the side of the rod;
- and
- illuminating the light-transmitting rod with an LED light source.
Dependencies are inferred from the claim text.