Stamped Metallic Optical Reflectors for Ultraviolet Light Emitting Diodes

Germicidal irradiation with a dose of UV-C light is an effective method for disinfecting surfaces, water, and air. New commercial devices are abandoning mercury gas-arc lamps in favor of UV-C LEDs, but UV-C LEDs are less efficient. This requires optical designs that use lenses to deliver UV-C light with high irradiance values to the target. This paper presents metallic optical reflectors (MORs), made with stamping processes, as a new lens for UV-C LEDs. Designs are described, tested, and validated for applications in SMD packages and chip-on-board (COB) modules. Aspherical mirror surface in MORs narrow the beam and achieve viewing angles as small as 15 degrees FWHM with high efficiency. Simulations and tests conducted with a gonio-spectroradiometer agree sufficiently well so that the optical model can be used to design germicidal irradiation systems for surfaces or air in upper-room applications.