US Patent No. 9,322,973

LIGHTING DEVICE WITH LIGHT SOURCES POSITIONED NEAR THE BOTTOM SURFACE OF A WAVEGUIDE


Patent No. 9,322,973
Issue Date April 26, 2016
Title Lighting Device With Light Sources Positioned Near The Bottom Surface Of A Waveguide
Inventorship Serge J. Bierhuizen, Santa Rosa, CA (US)
Assignee Koninklijke Philips N.V., Eindhoven (NL) Lumileds LLC, San Jose, CA (US)

Claim of US Patent No. 9,322,973

1. A device comprising:
a waveguide comprising a first section of transparent material;
a light source disposed proximate a bottom surface of the waveguide, the light source comprising:
a base element upon which at least one semiconductor light emitting diode is situated;
sidewalls that extend from the base element to the waveguide and form a cavity between the semiconductor light emitting device
and the light guide; and

a second section of transparent material disposed within the cavity; and
a surface to be illuminated proximate a top surface of the waveguide;
wherein:
the sidewalls are reflective, and
the semiconductor light emitting diode includes a photonic crystal configured such that at least half of energy emitted by
the semiconductor light emitting diode is emitted at angles >45° relative to a normal to a top surface of the semiconductor
light emitting diode.