Microdisplays based on OLEDs for multimedia applications like video and data display could be available within a couple of years according to Fraunhofer IPMS.
For the first time ever, OLEDs offer the possibility to integrate highly efficient light sources with photo detectors on a CMOS backplane. This enables fully integrated optoelectronic applications based on silicon, which allows micro-scale optical emitters and receivers on the same chip, providing a device that presents and captures images at the same time.
This could be the foundation for a new class of device for personalized information management that presents information to the user, and at the same time optically recognizes a command by the user.
The chip measuring 19.3 by 17 millimeters is fitted on the prototype eyeglasses behind the hinge on the temple. From the temple the image on the microdisplay is projected onto the retina of the user so that it appears to be viewed from a distance of about one meter. The image has to outshine the ambient light to ensure that it can be seen clearly against changing and highly contrasting backgrounds. For this reason the research scientists use OLEDs, organic light-emitting diodes, to produce microdisplays of particularly high luminance.
When a person observes the environment around them normally, additional information is presented via the modified glasses that carry bidirectional microdisplays (Augmented Reality, AR). This visual information can be deliberately and unconsciously activated with just the movement of the eyes, resulting in personalized, mobile, interactive, see-through AR Displays.
Museums and historic centers could hand out the devices to tourists who would be able to activate with their eyes a video, picture or text information about a piece of art or historic building. Industrial applications could provide an interface to equipment and processes enabling information to be monitored in real time.
The future could also be in Military applications. A company called Elbit Systems has already developed a Display and Sight Helmet (DASH) that is used by military pilots to aim their weapons simply by looking at the target. The system measures the pilot's Line of Sight (LOS) relative to the aircraft, and transfers this information to other aircraft systems. Soon we may see microdisplays in military visors with virtual displays projected across the visor, where the pilot can see and interact with information and targeting prompts.
The monochrome display has a resolution of 320 x 240 pixels (QVGA) controlled by a digital video interface. The OLED pixel matrix is interleaved with an array of 320 x 240 photo diodes, which are internally connected to form a miniature imager of 4 x 3 pixels.
Future designs of the bidirectional microdisplay include:
- Brightness: >1000 cd / m²
- OLED efficiency: >15 cd /A
- Display resolution: VGA (640 x 480 pixels)
- Display size: ca. 0.5"
- Camera resolution: 50 x 50 pixels.
OLED microdisplays are already used in the gaming industry and design applications. eMagin manufactures active matrix OLED-on-silicon microdisplays, based on its own patent portfolio as well as its OLED license from Eastman Kodak. Their Z800 3DVisor enables users to "see" their data in full 3D-surround viewing with just a turn of the head. Gamers can immerse themselves "virtually inside" their games, or designers, publishers and engineers can view multiple drawings and renderings as if they were each laid out on an artist's table, even in 3D.
MicroOLED design and develop high-performance microdisplays for near-to-eye applications. The company's core offering consists of highly integrated microdisplays for use in video glasses for mobile HDTV, viewfinders for cameras, and professional applications. Reports suggest they will start mass producing their OLED microdisplay by the end of 2009.