Realization of specific illuminance distributions of OLED lightings using inverted microlens films

The illuminance distribution of flat organic-light-emitting diode (OLED) lightings combined with inverted microlens arrays was investigated through both an experiment and simulation. Two inverted prism films on the OLED surface produced a fourfold symmetry in the illuminance distribution caused by the refraction at the lower and the upper interfaces with air. A simple simulation model could reliably reproduce the experimental distribution. Other specific illuminance distributions, such as the ring-shaped one, were formed in terms of inverted ellipsoidal and pyramid microlens arrays. These results suggest that specific illuminance distributions can be realized by combining inverted microlens arrays with flat OLED lightings, which may be useful for special lightings such as decoration or exhibition lightings.