Microlens array diffuser for a light-emitting diode backlight system

Microlens array (MLA) diffusers for light-emitting diode (LED) backlight systems have been developed. A high fill-factor photoresist mold for the MLA was fabricated using three-dimensional diffuser lithography, and the patterns were transferred to a nickel master mold for UV-curable polymer replication. The fabricated microlens had various paraboloidal profiles, and its aspect ratio was controlled from 1.0 to 2.1. The MLA diffuser showed a batwing radiation pattern with a radiation angle of 150 degrees. The fabricated MLA diffuser may greatly enhance the color-mixing characteristics of LED backlight systems and help reduce the number of LEDs required. (c) 2006 Optical Society of America.