Researchers from the Fraunhofer FEP announced a new development that can reduce the power consumption of OLED microdisplays. The power reduction is enabled by new chip and control electronics, that now only handles pixel changes and does not refresh the entire display all at once.
The researchers say that this development enabled a drastic reduction in power consumption - which is somewhat surprising. The new microdisplays (which are monochrome - green) use 1 to 4 mW, which they say is a fraction of the power consumed by the Fraunhofer's previous generation display - a color (WOLED+CF) bi-directional OLED (so this is not a fair comparison of course).
The brochure of this new display is available here. The display itself is a 0.2" 304x256 panel (2,100 PPI) with a 4-bit static pixel cell (16 gray levels). Maximum brightness is 7,000 nits.
The Fraunhofer FEP is also developing bi-directional OLED microdisplays - which include photo-detectors in between the OLED pixels.