3D printed internal cavity lens for illumination applications

With LED lighting technology having matured in the past few years, lighting fixture manufacturers are now looking to add value to LED systems by introducing novel concepts through different sub-components. In conventional refractive optical systems, the lens outer surface geometries are used to shape the output beam distribution. As a result of geometries used on external surfaces, dust and dirt could accumulate on the surface of the secondary optics, decreasing the fixture's efficiency over time. Furthermore, exterior surfaces with complex geometries are difficult to clean and maintain. Hence, this study is focused on developing a 3D printable lens with planar exterior surfaces and internal cavity structures for beam shaping. The authors investigated the feasibility of using internal cavity structures with refractive spherical arrays to achieve prescribed illuminance distribution. The lens design strategy contains an iterative optimization procedure on internal cavity parameters to improve optical efficiency. Also, the study suggests that 3D printing can be used to manufacture internal cavity structures that are challenging to create using conventional methods.