Patent ID: 8628255

Claim:
A lighting panel comprising: a substantially planar waveguide having at least one light emitting face, wherein at least one edge of the waveguide comprises a light reflective layer; a plurality of light emitting diodes that are located on the at least one edge or one or more other edges of the waveguide and are operable to generate blue excitation light having a peak emission wavelength greater than 450 nm; a heat sink around at least a part of a surface of the at least one edge of the waveguide, the heat sink being in thermal communication with the plurality of light emitting diodes; and at least one phosphor provided adjacent to the at least one light emitting face of the waveguide, wherein the lighting panel being configured such that excitation light is coupled into the at least one edge of the waveguide such that it propagates through the waveguide and is then emitted through the light emitting face, at least a part of the excitation radiation excites the at least one phosphor which in response emits light of a different color, and an illumination product of the system comprises a combination of the blue excitation light and photo luminescent light emitted by the at least one phosphor.