Investigation of Color-Over-Angle in Multi-Chip Array LEDs

Color-over-Angle (CoA) describes the perceptible color shift that occurs at different emission angles from a light source. Excessive CoA can negatively impact user experience in illumination applications, such as wall washers. This thesis presents an extensive investigation into CoA in chip-on-board (COB) multi-array light-emitting diodes (LEDs), a topic that remains underexplored. Several key factors including brightness, C-plane geometry, and phosphor coatings have yet to be systematically examined using comprehensive methodologies that integrate color perception analysis and psychophysical testing to define practical CoA specifications.