Display manufacturer eMagin Corp. of Hopewell Junction, N.Y., has received a U.S. patent for a new OLED design. The patent, "Laterally Structured High Resolution Multicolor Organic Electroluminescence Display Device," pertains to an OLED architecture named the pillar-and-channel structure that promises to improve display performance.
Pillar-and-channel differs from the structure of the conventional OLED. Display elements are vertically stacked in conventional OLEDs, and the light-emitting OLED material is sandwiched between a transparent cathode layer and an anode layer. With pillar-and-channel, electrodes are positioned upright on either side of the OLED material so neither electrode is in the path of the light (see the figure).
The primary benefit is that it permits use of a field electrode to increase charge density in the film. Higher levels of drive current may then be applied to each pixel. Also with the new structure, OLED pixels can be more tightly packed together. Greater light output—in the range of 30,000 to 50,000 nits—is possible as a result.
While a conventional structure can provide those luminances in microdisplays, pillar-and-channel makes it easier to obtain them in larger displays. The new structure also allows OLEDs to be efficiently encapsulated and potentially made less susceptible to heat, shock, and moisture, which are hazards in outdoor display applications.
For details, go to www.emagin.com.