Design of Diffuse Reflection Freeform Surface for Uniform Illumination

Indirect illumination with light-emitting diodes (LEDs) and diffusers is widely applied in various fields that require uniform illumination. In this paper, a design of diffuse reflection freeform surface is proposed. Based on the Lambertian characteristic of LEDs and ideal diffuse surface, a mathematical model is developed. Nonlinear algebraic equations are established by redistributing the energy emitted from LEDs to the illuminated scene for uniform illumination. Solving these equations numerically, the outline of the diffuse surface is obtained. Finally, by using ray tracing software TracePro, the simulation result shows that the irradiance uniformity of the detection plane is above 95% with high accepted tolerance.