Patent ID: 7513669

Claim:
An apparatus comprising: a light pipe comprising a layer of transparent material having a top surface, a bottom surface, and an edge surface, said light pipe being positioned to receive said light within a cone of angles through said edge surface such that said light within said predetermined cone of angles is totally reflected from said top surface, said light pipe comprising features that redirect some of said light within said cone of angles at angles such that some of said redirected light exits through said top surface; a light source comprising a plurality of LED dies arranged in an array on a substrate, said substrate being coplanar with said light pipe, each LED emitting light having an excitation wavelength, said light source emitting light within a cone of angles, said light source further comprising a reflector adjacent said plurality of LED dies to reflect light from said LED dies into said edge surface of said light pipe; an index matching compound between said light source and said light pipe edge surface; and a light conversion layer overlying said top surface, said light conversion layer converting light of said excitation wavelength to light in an output spectrum having wavelengths different from said excitation wavelength; wherein said light conversion layer comprises soluble phosphor compounds dissolved in a transparent medium; wherein a portion of said light of said excitation wavelength exits from said light conversion layer, said portion being greater than 10 percent of said light of said excitation wavelength that enters said light conversion layer.