P‐75: Improved Optical Characteristics of a Front‐Light System Using Fine‐Pitch Patterned OLED

Abstract

We have been developing a front-light system that uses an OLED light source patterned with a fine pitch. This system can be used in reflective LCDs, electrophoretic displays (EPD), microelectromechanical systems (MEMS) and other applications. In this paper, we present a new structural design for an OLED frontlight system. In the new system, the space between a pair of glass substrates is filled with resin, and a pattern of black resin is formed on the counter-substrate such that it corresponds to a pattern of Al cathodes. The new system has excellent characteristics as a front-light. Light is used more efficiently than in the conventional design, and the reflection of ambient light can be avoided.

66.4: High Contrast Edgelit Frontlight Solution for Reflective Displays

“…This has limited the expansion of reflective LCD applications, and stimulated a number of investigations for developing better FL. A notable example of an alternative solution with high contrast capabilities is the OLED based frontlight reported by Norio Koma et al [5], where a sparse array of white light emitting OLED pixels was fabricated on a glass substrate to create a FL with uniform emission independent of the stack configuration (with or without air gap).…”

“…The use of opaque, unidirectionally reflective light turning microstructures allowed us to avoid the view cone limiting, light leakage issues typical of TIR turning based lightguides [1,5] (caused by light travelling inside the guide and incident on the turning structures at angles that do not TIR but rather transmit across the material interface). The choices of the shape, size, and distribution of the reflective microstructures are made after defining a desired optical module architecture in order to meet the final product requirements for brightness, uniformity and view cone.…”

Front‐of‐Screen Display Components and Technologies

“…The integration of a FL in the FOS stack enhances the display brightness in environments with insufficient ambient illumination, and thus introduces a hybrid reflective-emissive usage model that eliminates the traditional usability limitations of purely reflective e-Paper applications. 15,16 18 Information Display 9 /12 Making Displays Work for You (continued from page 15)…”

“…As reflective displays are increasingly used in mobile devices, frontlights (FLs) become a key enabler for optimizing the user experience across applications. The integration of a FL in the FOS stack enhances the display brightness in environments with insufficient ambient illumination, and thus introduces a hybrid reflective‐emissive usage model that eliminates the traditional usability limitations of purely reflective e‐Paper applications 15 , 16 …”

“…As a result of the stringent reflective‐display FOS requirements, the emerging FL optomechanical system designs and manufacturing and integration strategies show a departure from traditional BL solutions in order to enable high emissive as well as reflective FOS performance 16,17 …”