Light extraction film for organic light emitting diode display and lighting devices

US8179034B2 · kind B2 · utility

Assignee

• 3M INNOVATIVE PROPERTIES COMPANY · US

Inventors

• John E. Potts · Woodbury, US
• Fred B. McCormick · Maplewood, US
• Martin B. Wolk · Woodbury, US
• Jun-Ying Zhang · Perrysburg, US
• Terry L. Smith · Plainfield, US
• James M. Battiato · Austin, US
• Ding Wang · Austin, US
• William A. Tolbert · Woodbury, US
• Mark A. Roehrig · Stillwater, US
• Clark I. Bright · Arcadia, US

Key dates

• Filing date: Jul 13, 2007
• Grant date: May 15, 2012
• Expiry date: Jan 10, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10K2102/331
• WIPO field: Micro-structural and nano-technology
• WIPO sector: Chemistry

Abstract

A multifunctional optical film for enhancing light extraction includes a flexible substrate, a structured layer, and a backfill layer. The structured layer effectively uses microreplicated diffractive or scattering nanostructures located near enough to the light generation region to enable extraction of an evanescent wave from an organic light emitting diode (OLED) device. The backfill layer has a material having an index of refraction different from the index of refraction of the structured layer. The backfill layer also provides a planarizing layer over the structured layer in order to conform the light extraction film to a layer of an OLED lighting device such as solid state lighting devices or backlight units. The film may have additional layers added to or incorporated within it to an emissive surface in order to effect additional functionalities beyond improvement of light extraction efficiency.