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News | Micro-nanotechnologies
Leti, a CEA Tech institute, won an Innovation Award for its GaN microdisplay at this year's TechConnect World in Washington D.C. The award-winning development—a world first—gives exceptional luminosity to a screen of such small size.
OLED-type microdisplays, used in camera
viewfinders and virtual-reality systems, measure just several square millimeters.
One of the main complaints about the displays is their low luminosity, a
problem especially for augmented reality systems. “This is because the
microdisplay generates images that are going to be superimposed on the real
environment by way of an optical system. Because the real environment is
well-lit, the microdisplay has to offer particularly good luminosity to be
effective,” explained a Leti researcher.
Gallium nitride (GaN) LEDs, already widely
used in lighting and known for their excellent yields, were the ideal
candidates for more luminous microdisplays. To make them work, Leti researchers
first had to make them much, much smaller and find a way to reproduce hundreds
of thousands of the microsources on a very small surface while maintaining the
ability to power them individually.
Leti leveraged know-how in assembly
technologies to couple a GaN micro-LED network with a power circuit. The
resulting prototype, presented at the TechConnect trade show, boasts more than
70,000 LEDs with a 10-micron pitch (the density of a traditional microdisplay)
and is 1,000 times more luminous than current microdisplays. The prototype will
be presented at CES Las Vegas in January 2016. A second prototype, this one
with 500,000 LEDs, is currently being built. This new prototype will be able to
display HD video. In addition to augmented-reality glasses, the technology
could also find its way into head-up displays for cars and planes and
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.