A highly durable and foldable AMOLED display with a symmetric panel stacking (SPS) design and touch functionality was demonstrated to surpass 1 million folding cycles with no damage to the TFT , OLED and TFE layers. The S/N ratio of the touch function was improved using a metal mesh touch sensor.

A 5" plastic-based AMOLED panel with optimal structure and optical design was fabricated. The panel is designed to coincide the OLED/TFT layer with the neutral plane and limit the largest strain of the outmost part to be less than 1%. Its performance remained prominent after repeated rolled at 3mm radius. Author KeywordsFlexible; rollable; foldable; AMOLED; plastic; neutal plane; symmetric panel stack Objective and BackgroundThe advancement of thin, light and flexible displays has been receiving great attention over the past decades. Due to high temperature requirement during the fabrication process, most of flexible panels demonstrated were fabricated on plastic substrates such as polyimide and PEN, etc. In recent years, we have also successfully demonstrated our capability to produce plastic-based EPD and AMOLED displays with fixed curve and down to certain bending conditions [1][2]. In addition to thinner feature compared to EPD, AMOLED's, intrinsic property including self-emission ability and high color production range as well as fast response time allows easy video viewing, providing a very wide range of its application possibilities in the near future. The plastic-based AMOLED panels have been commercialized on smartphones; however, the fixed curve appearance is far from satisfying customers' desire for a truly flexible device. Based on the marketing research, demand of truly flexible panels become desirous with rapid requirement of hand-on electronics like smartphones, tablets and wearable devices…etc.Currently, the commercial fixed-curve smartphones or watches were made of top-emission AMOLED combined with a layer of circular polarizer (CPL). The most common types of CPL is mainly composed of stretched PVA and retardation films with the overall thickness usually larger 140m. Therefore, the mechanical property of a CPL such as minimum bending radius is large and its rolling feasibility is limited. Meanwhile, the light efficiency is reduced to less than 50% and light leaking phenomena is found while panel is bent to curve. Therefore, we propose a new structure-symmetrical panel stack (SPS)-that allows us to produce a much thinner, softer plastic-based AMOLED panel without the employment of CPL in this study.Unlike the previous report which demonstrated multi-foldable display with AMOLED [3], plastic substrates are adopted on both sides in this work. Color Filter (CF) part is fabricated using a transparent plastic substrate and AMOLED part is fabricated on the high-temperature-resistance plastic substrate. The thickness and young's modules of each layer is carefully designed to achieve the most optimized mechanical properties. In addition, optical performance comparable to conventional AMOLED is obtained by employing full color RGB with anti-reflection layer (ARL) designed on the CF side. Because the SPS structure provides optimal mechanical properties, the proposed structure is expected to have little difficulty of achieving large-scale production in the future. Panel structure design and fabricat...

We demonstrated a HD+ resolution (1600 x 900) full color AMOLED display panel by applying optical cavity design on white OLED and combined with high transparency color filter. This panel achieved a record-high real pixel density as 413 ppi for mobile apparatus and should be suitable for applications pursuing high-quality display.

A foldable active‐matrix organic light‐emitting diode display capable of enduring very severe folding and environmental impact was obtained using symmetric panel stacking with an innovative design of color filter structure. The display was subjected to in situ folding cycle under an ambient test condition of 60°C/90% relative humidity, and no performance degradation was found for the display and the touch function during and after the test. In addition, 95% coverage of BT.2020 color space was obtained without additional power consumption compared with that of the panel with National Television System Committee (NTSC) color space.

We demonstrated a pixel density of 413ppi for active-matrix OLED (AMOLED) by using one-FMM-solution developed based on real stripe-RGB pixel rendering. The panel achieved a high NTSC ratio of 101% and low reflectivity of ambient light less than 6% without utilization of circular polarizer as well as low power consumption of 190mW with high aperture ratio of 33% for each sup-pixel and under 30% image loading. Author KeywordsAMOLED; pixel density; FMM; RGB side-by-side; WOLED+CF Objective and BackgroundDue to continuous demand of superior picture quality, activematrix organic light emitting device (AMOLED) has emerged as a strong candidate for display technology in portable device recently. To become a high-end product, besides producing an excellent color performance, a display panel must also provide high resolution and high pixel density. White OLED (WOLED) with color filter is a simple way to achieve high pixel density AMOLED because it does not require the use of fine metal mask (FMM) in the fabrication process. However, in comparison with RGB side-by-side (SBS) technology, WOLED requires higher power consumption, but produce lower color purity. A complicated hybrid tandem white OLED device structure is thus essential to achieve high efficiency [1].