Technical / Research - Page 41

Guangzhou New Vision Optoelectronics (NVO) developed a flexible 4.8" AMOLED display. This full-color panel is only 100 microns thick and weighs just one gram. This panel uses an Ln-IZO backplane and a Polyimide substrate.

NVO developed their own Ln-IZO (Lithium-Niobate Indium-Zinc-Oxide) technology and they say that that it performs better than IGZO as it has higher electron mobility and stability and it is easier to process.

Rolic and Roth & Rau agreed to jointly develop system solutions for the organic electronics and display market. The partnership will bring together Rolic’s competences in materials and device fabrication and Roth & Rau’s expertise in integrated process equipment.

In the first stage of this agreement, the two companies will offer barrier and encapsulation technologies. for flexible OLEDs, OPVs and other flexible organic electronics. Roth & Roe's R&D facility is close by to Rolic's newly established OLED-focused technical center in Eindhoven and they both hope that this will enable to quickly bring their joint solutions to the market.

Cynora is a German startup established in 2003 that developed copper-based OLED emitter systems. In October 2012 the company unveiled a mostly-solution-based flexible OLED prototype, developed in collaboration with InnovationLab. Last month Germany’s BMBF launched the cyCESH project which aims to develop soluble (printable) materials for low-cost high efficiency OLED lighting devices. Cynora is the leader of the consortium in this €6 million project, together with Novaled and the University of Regensburg.

Cynora's technology is interesting and the company's CEO Dr. Tobias Grab and the company's Business Development manager, Dr. Mathias Mydlak, were kind enough to provide the information for this article explaining the company's technology.

The US Department of Energy (DoE) announced the eligble topics for the FY 2014 SBIR and STTR funding. There are two topics involving OLED lighting efficiency. The first is the development of OLED materials and structures that will lead to the production and commercialization of a highly efficient, stable white OLED device. The DOE specifically mentions the development of highly efficient, blue emitter materials and hosts.

The second topic is the development of methods of manufacturing either OLED pixels or panels or devices. The DoE is also interested in system level integration solutions that would accelerate OLED devices into niche markets. If you want to apply, you will have to send the application by October 15. The DoE will formally announce the opportunities on August 12.

The US PTO published a new patent from Apple (filed in 2012) that describes how to use sensors to compensate for ambient lighting (see DisplayMate's related recent article) and lifetime brightness degradation in OLED displays. The patent describes that photo-diodes can be placed inside the OLED array or above and below it.

Putting photo-diodes inside the display will enable them to more accurately measure light levels. So if a part of the screen is dimmer than the rest of the screen (for example because only a part of the display is under direct light) - the photodiode will detect it and then the display brightness in that area can be increased. This is something that cannot be achieved with a single sensor. Those photodiodes can also be used to learn whether certain OLED pixels (or pixel groups) have lowered brightness due to aging. Then the display can compensate and drive these pixels higher.

My friend Raymond Soneira from DisplayMate wrote an interesting article for the SID Information Display magazine on Tablet displays technologies in real world ambient light. The displays obviously progressively degrades as ambient light is increased, and Raymond then shows how you can compensate and correct images by by dynamically modifying the color gamut and intensity scale.

The article points out the importance of using a managed wide color gamut in displays. Here OLEDs (and also LCDs with Quantum Dots) have an advantage obviously over regular LCDs. This basically means that by having a wider color gamut, a display can be made to look better under ambient light.

Researchers from the University of Tokyo developed a highly-flexible OLED lighting device that can work even after being completely bent and crumpled. They hope that this device can be used for medical and healthcare sensors.

The flexible panel uses a metal electrode (LiF/Al), a transparent PEDOT:PSS transparent electrode and a polymer substrate. The minimum bending radius is 10 micrometer and the brightness of the panel is 100 cd/m².

Researchers from Germany's TU Darmstadt University developed new glowing fibers by coating them with white OLED emitters. They call their technology reproducible rotational coating and they envision all sorts of possibilities in the area of smart textiles, as in the future it'll be possible to coat all sorts of semiconductor components (such as transistors or solar cells) on fibers.

The researchers use vacuum deposition and small-molecule OLEDs for this process. They deposit seven different layers but the whole OLED is just 200 nanometers thick. OLEDs require a very smooth substrate and so currently they use glass fibers - which aren't really useful in wearable applications as they are too brittle to be woven into textiles. They are now starting to experiment with polymer-coated glass fibers that may be flexible enough to be used in textiles.

NVIDIA unveiled a new research project that developed a near-eye light field display. A prototype unit was shown that uses two Sony ECX332A OLED microdisplays (1280x720 each). The microdisplays are covered with a micro-lens array which creates the light field.

The basic idea is that users can focus at multiple depth and create a field of view of about 70 degrees. If you wear glasses, this display can account for your glasses using software algorithms. Check out the video above for more info.

Researchers from the University of California, Berkeley developed a new "electronic-skin" consisting of touch sensors and small OLED lighting 'pixels". The e-skin reacts to touch and the more intense the pressure, the brighter the light. This technology can be used to enable applications such as smart automobile dashboards or wallpaper that double as touchscreen displays.

The e-skin is based on plastic and has several OLED "pixels". Each pixel consists of a tiny transistor (made using nanowires), an OLED and a pressure sensor. To produce this they cured a polymer layer on top of a silicon wafer, ran a regular process to deposit the electronics and then de-laminated the silicon. The first prototype the researchers made has 16x16 pixels (see above and in the video below).