eMagin Corporation has been notified by the U.S. Patent and Trademark Office of patent issuance for an invention of a device incorporating a new class of organic light emitting diode (OLED) materials which enables higher resolution flat panel displays with lower power consumption and increased operating temperature range.
Hole transport layers have historically been the weakest link in the parameters of temperature stability, forward voltage, and power efficiency of single molecule-based OLEDs. The invention describes a new thermally stable class of hole transport compounds integrated into multi-layered organic light emitting diodes. These materials (i.e., thermostable aryl amine compounds) are prepared as nanostructure layers approximately 10 nm to 50 nm thick as part of a multi-layered OLED device allowing for a more gradual (or staircase) change in the energy of holes and electrons, resulting in a lower operating voltage and a high quantum yield of luminescence for each current level.
The benefits of this new "staircase" class of light emitting device include increased power efficiency, increased quantum injection efficiency, and a lower forward organic diode voltage for use with lower voltage integrated circuits. The staircase device uses materials designed to provide operation at temperatures well above 284 degrees F). "Higher temperature stability provides for more flexibility in packaging techniques and color filter processing, as well as providing usability in ever more environmentally rugged applications," said Susan Jones, eMagin's executive vice president. "Lower forward voltages should permit even lower power consumption on our current types of displays and allow smaller, higher density transistor cells to be designed. These two combined characteristics open the door for higher pixel densities, increased luminance, and higher resolution OLED displays in the future, which are of interest to both military and consumer customers."
eMagin's OLEDs already operate over a far larger temperature range than liquid crystal display (LCD) materials, and this invention is expected to further enhance this already significant advantage.
The staircase device will be able to be implemented in eMagin's standard production equipment without redesign of the manufacturing systems or the supporting integrated circuit chips, once sufficient quantities of the new hole transport materials can be produced. Jones added, "Many of our patents have the potential to enhance OLED performance and cost for a broad range of applications beyond near-to-eye microdisplays. The staircase patent will be considered for licensing to other manufacturers for applications which are not competitive to our near-to-eye microdisplay business."
The new device is potentially applicable for near-to-eye displays used in applications such as virtual reality, camera viewfinders, handheld phones with large virtual screens, head mounted wearable computer and virtual reality displays, and could also be used as part of a technology base for larger direct view OLED flat panel display applications such as notebooks, large screen televisions, and many other electronic products.
In addition to developing its own intellectual property portfolio, eMagin is a licensee of Eastman Kodak's small molecule OLED technology. Industry research analysts, such as iSuppli/Stanford Resources and DisplaySearch predict that the OLED display market could grow to $3 billion by 2007.
The world leader in organic light emitting diode (OLED)-on-silicon microdisplay technology, eMagin combines integrated circuits, microdisplays, and optics to create a virtual image similar to the real image of a computer monitor or large screen TV. eMagin invented the award-winning SVGA+ and SVGA-3D OLED microdisplays, the world's first single-chip color video OLED microdisplay and embedded controller for advanced virtual imaging. eMagin's microdisplay systems are expected to enable new mass markets for wearable personal computers, wireless Internet appliances, portable DVD-viewers, digital cameras, and other emerging applications for consumer, industrial, and military applications. eMagin has developed its own technology to create high performance OLEDon- silicon microdisplays and related optical systems, and is a licensee of Eastman Kodak's OLED technology.
eMagin sells full-color active matrix OLED-on-silicon microdisplays.