MIT Technology Review

Monday, May 13, 2013

New Kind of LED Could Mean Better Google-Glass-Like Displays

Micro-display LED tech could light up the next generation of face-wearable gadgets.


Blue chip: Lumiode tests out a blue LED.

A tiny head-mounted display, like the one in Google Glass, will only be useful if you can see on-screen alerts and information clearly. And that’s tricky to achieve, especially without draining battery life—as Google notes, it can be hard to use Glass’s projected display in bright sunlight.

A Brooklyn-based startup called Lumiode is working on one possible solution. Unlike most displays, which have a light-emitting backplane and use filters to make the individual color pixels that collectively form images, Lumiode’s technology uses the light-emitting diodes as the pixels. They are more efficient because no light is lost through filtering. The result, says founder and CEO Vincent Lee, will be tinier, brighter, more energy-efficient head-mounted displays and projectors. And while it will be some time before the company’s technology is ready for a Google Glass-like product, growing interest in ever-smaller electronic displays that fit in with our daily lives could spur demand.

Most displays—such as LCD monitors or smartphone screens—use LEDs for the light source at the back of the screen. In such screens, images are created as light passes through filters. The drawback is that this reduces overall brightness and means that the LEDs are always on, which wastes energy.

Lumiode, which spun out of Lee’s graduate work at Columbia University’s Columbia Laboratory for Unconventional Electronics, takes a different tack. The company patterns LED into arrays, adding a layer of silicon on top of each individual LED that controls the amount of light it emits. In this way the LED itself serves as the component that forms an image. “What we’re doing is, we’re patterning LED wafers directly, and making the image component directly in the LED material, rather than using it as a backlight,” Lee says.

Lee says the Lumiode display isn’t very expensive to make, since it uses standard components and processing techniques. The company believes its technology is 30 times brighter and 10 times more efficient than other display technologies.

Officially formed in September, Lumiode is still in the early stages—the company’s latest prototype is about one millimeter square and contains 50 by 50 LEDs of a single color; additional colors will likely be created by adding a special layer on top of the chip. But Lee expects to make a 320-by-240-pixel prototype in about a year, and hopes to then partner with electronics makers to incorporate the technology into future devices. In addition to head-mounted displays, he can envision Lumiode’s technology being used to project information onto the windshield of a car.

Lumiode is exploring other potential uses for its technology. Combining Lumiode with infrared or ultraviolet LEDs, for example, could lead to improved 3-D scanning and printing.