Freeform lenses for illumination of specific shapes in (<Emphasis Type="Italic">u</Emphasis>,<Emphasis Type="Italic">v</Emphasis>) coordinate system

Lens for rectangular illumination has been designed in (u,v) coordinate system already. Because of light source in (u,v) coordinate system can be divided into two identical parts, we have found that it is possible to design lenses for illumination of specific shapes. Specific shapes include triangles, as well as quadrangles which can be divided into two equal-area parts by one of the diagonals. We partition two equal-area parts into grids separately with equivalent luminous flux as well as light source, after that we construct freeform lenses by ray mapping method. Simulation results show that lenses for illumination of specific shapes are obtained with a Lambertian point source and favorable efficiency is over 0.86.