LIGHT EXTRACTION APPARATUS AND METHODS FOR OLED DISPLAYS AND OLED DISPLAYS USING SAME

摘要

Apparatus and methods for improved light extraction from top-emitting OLEDs used to form displays include an array of light-emitting apparatus (60) each having the OLED (32) and a light-extraction apparatus (64) that includes an index-matching layer (70) and a tapered reflector (51). The tapered reflector (51) has the form of an inverted truncated pyramid, with the narrow end (58) interfacing with the OLED (32) through the index-matching layer (70). Light from the OLED undergoes total internal reflection within the tapered reflector (51) at the tapered reflector side surfaces (56) and is directed toward the top surface (54) of the tapered reflector (51). This light falls within the escape cone (59) of the top surface (54) and so exits the top surface (54). The OLED display (30) has a substrate that supports an array of OLEDs (32) and also includes an array of the tapered reflectors (51) operably arranged with respect to the OLEDs (32), and an encapsulation layer (100) atop the tapered reflector array.