title: Energy feedback freeform lenses for uniform illumination of extended light source LEDs.
abstract: Using freeform lenses to construct uniform illumination systems is important in light-emitting diode (LED) devices. In this paper, the energy feedback design is used for freeform lens (EFFL) constructions by solving a set of partial differential equations that describe the mapping relationships between the source and the illumination pattern. The simulation results show that the method can overcome the illumination deviation caused by the extended light source (ELS) problem. Furthermore, a uniformity of 95.6% is obtained for chip-on-board (COB) compact LED devices. As such, prototype LEDs manufactured with the proposed freeform lenses demonstrate significant improvements in luminous efficiency and emission uniformity.
authors.forename: Zongtao
authors.initials: Z
authors.lastname: Li
authors.forename: Shudong
authors.initials: S
authors.lastname: Yu
authors.forename: Liwei
authors.initials: L
authors.lastname: Lin
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
authors.forename: Xinrui
authors.initials: X
authors.lastname: Ding
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.forename: Binhai
authors.initials: B
authors.lastname: Yu