The directional out-coupling efficiency enhancement of an organic light-emitting device(OLED) is discussed,which can be realized by using microlens array(MLA) film attached to OLED.The ray tracing method is used to simulate the directional enhancement effects of the out-coupling efficiency by elliptical MLA with different major-minor axis ratios.The microlens array mold is fabricated by digital micro-mirror device(DMD) based parallel photolithography and the thermal reflow method.The MLA film is finally obt...