Innovative LED technology made in Plymouth by Plessey Semiconductor is being used for a new generation of virtual reality (VR) and augmented reality (AR) smart glasses to be launched next year.

Vuzix in the US is developing advanced display engines with its waveguide optics for next generation AR Smart Glasses that it says will be the smallest and most power efficient by using Plessey’s microLED light engine.

The proprietary gallium-nitride-on-silicon (GaN-on-Si) technology uses an integrated monolithic array of RGB pixels with advanced micro-optical elements to create a bright, largely collimated and highly uniform light source.  The resulting optical system is half the size and weight of other technologies and highlights the semiconductor manufacturing and design expertise in the region.

The key to the deal is that Vuzix is also working with Qualcomm’s Snapdragon XR1 platform on AR smart glasses in form factors nearly indistinguishable from regular glasses that will be launched in 2019.

“This development with Vuzix, the leading provider of next-generation augmented reality glasses, is a significant endorsement of Plessey’s GaN-on-silicon microLED approach,” said Dr Keith Strickland, Chief Technology Officer at Plessey. “Monolithic microLED technology is fast emerging as the only one that can provide high luminance in a very small form factor with minimal energy consumption, necessary for reducing costs and enabling lightweight battery-powered products for a range of emerging consumer and industrial applications.”

Plessey plans to be the first to manufacture a monolithic display based on microLEDs fabricated using a GaN-on-Silicon approach later this year. “By being the first to market with a monolithic microLED display we will be demonstrating our expertise and the ability to access our proven turn-key solution, enabling manufacturers to ramp up the development and production of microLED displays to address emerging applications,” said Michael LeGoff, CEO, Plessey Semiconductor.

One of the main challenges involved with manufacturing microLED displays using a non-monolithic approach is the placement of LED chips onto a CMOS backplane, currently achieved using pick and place equipment. This involves the individual placement of every LED on a pitch of less than 50μm, requiring new and expensive equipment that is subject to productivity issues. As the pixel density of displays increases and pitch reduces, pick and place becomes less feasible both commercially and technically.

Using a monolithic process as Plessey does removes the need for placing the LED chips and enables smaller and higher resolution displays for VR, AR and head-up displays. This also allows circuits to be added to the silicon substrate to drive the microLED displays, as well as the close integration of high performance graphic processing units (GPUs) for lower power consumption.

Nick Flaherty