US Patent 9257677 Organic light emitting diode display having low refraction protrusions

An organic light emitting diode display is provided. The organic light emitting diode display includes a flexible substrate, an organic light emitting diode disposed on the flexible substrate, a thin film encapsulator disposed on the organic light emitting diode, a plurality of low refraction protrusions disposed on at least one of a surface of the flexible substrate and the thin film encapsulator, wherein each of the low refraction protrusions is formed having an isosceles trapezoid shape, and a high refraction layer disposed covering the plurality of low refraction protrusions.