Fraunhofer IAP - Page 12

Fraunhofer IPMS are showing an OLED based pico projector at SID. The projector is based on an OLED microdisplay by the Hypoled project.

The prototype projector is 25mm long, 18mm diameter, quite small (although not the smallest pico projector module). The OLED is currently monochrome only. The brightness is 10,000 candelas per square meter (a color OLED will be about half).

The Fraunhofer institute shows their "Interactive Data Eyeglasses". These glasses include an OLED microdisplay on a CMOS chip that also includes an eye tracker .

The chips (which is 19.3 by 17 mm) is fitted behind the hinge on the temple. The image is then projected onto the retina of the user. The OLED have been chosen because they needed high luminance.

Several German companies are collaborating on a project called CARO (CAR-OLED). CARO is an R&D project which aims to develop OLEDs for automotive applications (displays and signage).

OLED steering wheel prototype

Two of the companies (Fraunhofer IPMS and Optrex) have developed a steering wheel with an integrated white circula OLED signage display. It shows car-manufacturer neutral functions. Because the OLED is so thin, the basic design of the steering wheel is not changed, including the embedded airbag. The OLED displays was made at the Fraunhofer IPMS pilot lines.

Novaled, Fraunhofer IPMS and Optrex Europe developed a new, unique PMOLED driver. They have implemented an innovative MLA scheme called SELA (Summed Equiline Addressing). Basically, instead of driving using a single-line addressing scheme, the SELA allows parallel driving of multiple rows, thus preventing high current amplitudes.

Basically this means that we get higher lifetime, better resolution and better efficiency in the OLED display. The driver is specified for operations between -40°C and +125°C, exhibits an OLED drive voltage up to 25 V, and a column source current up to 2 mA. In particular the latter can currently not be fulfilled by any commercial available PM OLED driver.

In addition to the innovative addressing concept and the new OLED MLA driver, a high temperature stable and long-living orange emitting PIN OLED layer stack was developed by Novaled AG. In automotive applications high reliability at 85°C
operational temperature and highly stable brightness (often only 20% reduction over lifetime is allowed) is required. The newly developed OLED stack offers an operating lifetime of currently 5.300 hours at 85°C and 20% brightness drop at an initial brightness of 600 cd/m².

The Fraunhofer IPMS is one of the leading OLED research centers, mostly focused on OLED lighting. I've had the good chance to interview Prof. Karl Leo, the Director of the Institute.

Large Area OLED lighting panel,Fraunhofer

Karl talks about COMEDD (their new OLED research/production center), his views on OLED lighting and Europe's plans for this market, their transparent OLED research program, OLED Television, and even an OLED based pico-projector. I think this is a very interesting interview!

Link to interview

I recently had the chance to talk with the nice guys over the Fraunhofer IPMS in Germany, and the Institute Director (Prof Karl Leo) have agreed to do a short interview and talk about their OLED program.

These guys have been working on OLED since 2000, now organized under the name Center for Organic Materials and Electronics Devices Dresden (COMEDD). COMEDD's aim is to do not only research, but also pilot fabrication. More on COMEDD here.

Prof. Dr. Karl Leo, since 1993, is full professor of optoelectronics at the Technische Universität Dresden and starting 2007 institute director of the Fraunhofer IPMS. Additionally he is one of the founders of the Spin-Off Novaled AG.

During the Photonics West 2009 the Fraunhofer IPMS will present the prototype of a bi-directional OLED microdisplay with an imaging CMOS photo diode matrix interlaced in a QVGA display (12 x 9 mm²), both are integrated and work at the CMOS chip.

Furthermore, an optical flux sensor will be presented, which includes the required light source on the CMOS-sensor chip. A CMOS photo diode line allows the detection of the speed of a particle flow and an embedded OLED light source in the form of stripes in parallel to the photo diode line provides the illumination of the medium.

Due to the achieved reduction of the expenditure regarding the construction and circuit technology numerous applications of those devices are enabled. Fields of application vary from chemistry, medicine to life science. Other applications of OLED-on-CMOS include light barriers, opto-couplers and optical communications.

The new Center for Organic Materials and Electronic Devices Dresden (COMEDD) facility is now open in Dresden, Germany. COMEDD is owned and operated by the Fraunhofer IPMS and it will be used to make OLED displays and lighting products, and also OPV panels.

Fraunhofer hopes that COMEDD will become a production center for OLEDs and not just a research center with pilot lines. The researchers at COMEDD will focus on OLED displays on glass, Microdisplays on silicon (in partnership with MED) and flexible displays on plastic. They will also make OLED lighting on glass or flexible substrates.

A research group of the Dresden Technical University (together with Novaled) has achieved record energy consumption for OLEDs. The achievement brings the organic LED technology closer to industrial volume production, and these OLEDs are prototyped at the Fraunhofer ITMS.

The research team achieved an efficiency of 26, 22 and 3.1 percent for red, green and blue organic LEDs which combined form a white light source. The low efficiency for blue results of physical differences — while red and green OLEDs are phosphorescent light sources, their blue counterpart is a fluorescent one, resulting in lower light emission. The difference, however, can be compensated for by increasing the active size of the blue light emitter as well as sending a higher current through it, explained research group member Rico Meerheim.

OLEDs are a 'cold' flat light source - they emit no heat - and thus are safe to touch. This means that it's possible to use them as a touch-light-controller. The Fraunhofer IPMS institute showed (at the Plastic electronics 2008 conference) the world's such device

The touch function generate a completely new feeling of light. It´s
like magic: turn on the light simply by a hand movement, noted Jörg
Amelung, head of business unit of organic materials and systems at the
Fraunhofer IPMS.

Read more here (Science daily)