STMicroelectronics' LBS technology is enabling fashionable designs of smart AR glasses.
Smart augmented reality (AR) glasses are seeing increasing adoption in sectors such as field service, logistics, manufacturing, operation, and inspection. According to market analyst Global Industry Analysts, the global market for smart AR glasses—estimated at 255.6 thousand units in 2020—is projected to reach 8.8 million units by 2026, growing at a compound annual growth rate (CAGR) of 80.3% over the forecast period, amid developments in machine vision and AI technologies, as well as analytics and big data.
According to GIA, organizations adopting AR wearable electronics are showing applications that result in improvements in productivity, efficiency, and compliance. In fact, Allied Market Research noted that 93% of large industrial companies are already using smart AR glasses for their operations, especially with the advent of Industry 4.0.
But to push AR glasses to the mass consumer market, innovation is key.
And that’s where STMicroelectronics comes in.
“The main feature of the glass is that it must be all-day-wearable,” said Davide Bruno, Regional Vice President of AMS MEMS Marketing & Application and Smartphone Competence Center, Asia Pacific, for STMicroelectronics. “The glass we are looking for is something that is very similar to the eyeglasses that many of us are wearing in our daily lives. It has to be very fashionable and light, with a very nice design.”
Key parameters for this include very light design, less than 60g in weight; fashionable, therefore, form factor is important, which implies that the hardware, the battery, and all the other systems must be very compact with a very small footprint; and then power consumption—smart glasses should last for all day.
And the technology to enable all of these is ST’s laser beam scanning (LBS) technology.
LBS is not a new technology. “It is a mature technology that you have already had in the market,” explains Bruno. “For example, LBS is used by Microsoft, North, and Intel. It is also used in lidar applications. Something that is a little bit newer in terms of application is in medical, to discover veins in arms of patients. So, LBS is not new; it is a mature, proven technology in the market.”
ST’s success with LBS started with the first Pico projector. “Then we moved to other applications like laptop with Intel Realsense. We had a very long cooperation with Microvision with several products introduced in the market,” explains Bruno. “We introduced the first smart glass ‘North’ two years ago. Today, we are talking about the first optical engine for AR glasses that is very small.”
Compared with competing technologies like µLED, LCoS and DLP, ST’s LBS features low persistency. It has a 10ns laser response time compared with the millisecond range of other technologies; low latency; as well as high luminosity. As for power efficiency, because of ST’s scanning characteristics, the line buffering cost less power consumption compared with competing technologies’ frame buffering.
“We also have the energy recovery drivers for piezo mirrors, which can cost less power consumption,” says Johnny Yang, Optoelectronics Technologist, AMS MEMS, Asia Pacific for ST. “In a laser driver, we even have look-ahead logic for fast on/off transitions when few consecutive pixels are off. For volume occupation, we can have very compact module size and light weight. The most specialty is our MEMS mirror because it has great scalability for field of view [FOV] and resolution.”
Another key parameter enabled by ST’s LBS is the optical engine volume occupation. Davide notes that LBS’s optical engine volume is much, much lower than the other three technologies.
“Our STAR0 is currently in mass production with our partners. The optical engine for STAR0 has a FOV for 56° in diagonal, and output brightness from 1.5 to 10lumen. Its resolution is 600p and engine size is less than 1cc (0.75cc). We use electrostatic MEMS mirror,” explains Yang.
ST has also improved its optical engine STAR1 with its new thin-film piezo MEMS mirror, thanks to the PεTRA high efficiency thin-film piezo process technology. “For example, we improved the FoV to up to 65°, which is larger than the current 56°. For resolution, we increased it from 600p to 720p. And the most important thing is that we can even reduce the optical engine size to less than 0.7cc, which is not easy because we can have larger FoV and higher resolution at the same time. Last but not least, for STAR1 optical engine design, with the thin-film piezo MEMS mirror, we can even have 15% less power consumption than our original STAR0 solution,” says Yang.
Nowadays, one critical factor that determines the success or failure of a product is the time to market. In line with this, STMicroelectronics, together with Applied Materials, Dispelix, Mega1, and Osram, established the Laser Scanning for Augmented Reality (LaSAR) Alliance last year to create an ecosystem that will enable and accelerate the design and manufacture of AR wearable devices such as smart glasses and head-mounted displays.
“For the MEMS mirrors, mirror drivers, and other key components, ST is working with our partners closely in the LaSAR Alliance to make MEMS ScanAR a one-stop shop for LBS,” says Bruno.
In November 2020, ST signed a cooperation agreement with Quanta to have a final reference design for the AR smart glasses. Its collaboration with OQmented announced in March this year, meanwhile, enhanced its technology for AR and 3D sensing markets.
ST and its partners in the LaSAR Alliance are fully focusing on providing the best reference design to the end-customer so that they can speed up the development and focus more on the content that will be overlaid onto the world seen through the glasses every day.
The View Forward
From a practical, “daily life” perspective, AR glasses still need to have compelling use cases for mass adoption to really happen with consumers. But for ST, it is the fashionability of the glasses, in addition to the AR technology it offers, that will push the all-day-wearable to consumers.
And ST’s LBS is the technology that will enable the form factor needed to make the fashionable glasses consumers would want to wear.
Stephen Las Marias is the editor of EE Times Asia. You may reach him at firstname.lastname@example.org.