At the Frontiers in Optics and Laser Science conference, OQmented gave a paper on how to save power and improve the image quality of a LBS system. They have developed a dual-axis Aluminum Nitride-based MEMS scanner but have added a vacuum encapsulation dome over the device to improve reliability and lower power consumption. They prefer AlN to PZT material for the MEMS device because of improved reliability, better linearity with no hysteresis, CMOS compatibility and bipolar actuation.
Bipolar actuation is the key to lower power consumption via their LC-resonance drive circuit. This allows scanning from 20 kHz up to 40 kHz. Power consumption for the MEMS scanner drive ASIC, Sense ASIC and microcontroller for a 30-degree FOV is a mere 22 mW. For a 70-degree FOV the power only increases to 31 mW. RGB laser power is in addition, but here, they suggest PWM over amplitude modulation.
They then described coherent scanning, which is different than raster scanning and interlaced Lissajous scanning. Coherent scanning requires a number of system elements to eliminate flicker artifacts – precisely the solution that OQmented has put together. They also showed text projected on a wall from the scanner which illustrated exceptional detail clarity.
Coherent Scanning can Eliminate Flicker and Provide Crisp Images
The company has a first generation LBS engine available today with a volume of 1.3 cc3, with plans to shrink to less than 0.4 cc3.
