Marco Angelici, MЕMS Micro Actuаtors Business Unit director at STMicroelectronics, says that in the not-so-distant future AR glasses will replace mobile phones.
According to Angelici, the lack of smartphone innovation will eventually lead to the transition from phones to AR smart glasses. The ability to project information directly at eye level enabling you to perceive the data and interact with the environment at the same time is the main advantage of AR glasses technology. Therefore, augmented reality is likely to become the next computing platform in the long run. As stated by Angelici and ST, laser-beam scanning (LBS) and laser scanning mirror are the main enabling technologies for the shift.
The execution of the first AR smart glasses concept was lacking, as the strange design of Google Glass along with its price of $1,500 didn’t meet users’ expectations. However, those failed attempts served as a lesson to developers, Angelici said. All-day wearable AR glasses must offer fashionable design, functionality, and a comfortable using experience at a reasonable price.
Developing an ecosystem
In October 2020, STMicroelectronics, Dispelix, Applied Materials, Osram, and Mega1 formed the LaSAR (Laser Scаnning for Augmented Reality) Alliance aimed at building an ecosystem that will catalyze the development and production of AR wearable devices.
Designing a compact, lightweight pair of smart glasses for mass manufacturing in 2022 is the main task of the collaboration. The main device features are going to include low power consumption (under 500mW), a high brightness level of more than 1,000 nits, and compact dimensions. As the device won’t be a gaming solution, a 30° FoV is suitable for convenient interaction with the glasses, according to Angelici.
MEMS micromirrors optimization
MEMS micromirrors are utilized in LBS systems for projecting infrared patterns or visible images. Laser diodes emit laser beams that are subsequently deflected by MEMS micromirrors that provide image projection onto the required FoV.
Angelici is sure that LBS is a high-potential technology, due to its brightness and energy efficiency benefits. He mentions that LBS provides the opportunity to illuminate only those pixels of the frame where the content is displayed. In addition, Angelici points out that ST aims at developing lasers with zero power consumption when the pixel is not illuminated.
Over the last few months, ST has proved its commitment to LBS technology through strategic collaborations such as the partnership with Intel based on the incorporation of MEMS micromirror into RealSense LiDAR Camera L515.
ST experts have concluded that piezoelectric is the best solution for AR when it comes to power efficiency, performance, and dimensions. Thus, the improvement of piezoelectric MEMS requires ST’s cooperation with A*Star Institute of Microelectronics in Singapore and ULVAC (Japanese vacuum technology leader).
Initiating and planning
ST designed Star0, a first reference design for AR glasses that contains the MEMS ScanAR components, Osram’s RGB module, and Dispelix’s lens. Then it proceeded to develop a 2nd generation, Star1, featuring a 65° FoV, 1,280×720-pixel resolution, and 50% less power consumption in comparison with Star0 (781 mW for a full white display).
ST has determined a piezoelectric process plan and anticipates reducing the power consumption by 50% and the size by 30%, as well as implementing FHD resolution or a 90° FoV during the next couple of years.
Angelici says that the 50% actuation efficiency improvement is expected to be achieved in 2023–2024 when AR technology presumably becomes mainstream.
