PORTLAND, Ore. — Structured light illumination (SLI) can automatically build a three-dimensional model of any object, replacing the tedious process of measurement that is usually required. Stripes of light are projected onto objects as a digital camera records their deformation, letting algorithms automatically deduce the size, shape and subtlest contours of even moving objects.
Now microelectromechanical system startup Seikowave (Lexington, Ky.), in cooperation with the Center for Visualization and Virtual Environments at the University of Kentucky, is harnessing MEMS picoprojectors to bring SLI to the mass market.
"We've been using $30,000 DLP [digital light processor] hardware in the research lab; over 90 percent of the cost of our system is in the projector right now," said Seikowave chief technology officer Daniel Lau, who pioneered SLI as a professor at the University of Kentucky. "Where Seikowave comes in is using MEMS to bring the projector cost down to $40, changing the economics to a mass-market technology."
Structured light illumination automatically builds a 3-D model of any object by projecting stripes of light an measuring their distortion with a digital camera.
Source: University of Kentucky.
SLI applications that have already been pioneered in Lau's university lab include contactless fingerprint scanning, intelligent surveillance and automatic profilometry (creation of 3-D models). Even videogame makers could profit from SLI, using it to generate 3-D models automatically with textures from real-world setups created for the game.
From projector to creator
MEMS picoprojectors were invented to enable small electronic devices to control large displays. Seikowave now plans to turn the picoprojector into a low-cost automatic 3-D model generator by writing SLI algorithms for the computer housing the MEMS device.
SLI works by projecting a series of light stripes on an object while observing their distortions with a digital camera. The process has been perfected in the lab for still images, but Seikowave and the University of Kentucky are pioneering SLI-based modeling using live video feeds. At high frame rates (up to 250 frames/second), Seikowave's algorithms use a proprietary lookup table to generate 3-D models in real-time from the observed distortions in the striped patterns.
The company is negotiating with MEMS picoprojector makers to create special high-frame-rate units suitable for SLI. "Picoprojectors are a little short on illumination—we use a laser light source in the lab—and they also need to be running at 120 to 150 frames per second," said Lau.
Seikowave president Matt Bellis described the challenges of moving from a startup's proof-of-concept demonstration to delivering marketable products in a talk at last month's MEMS CTO Meeting, sponsored by Yole Development in Anaheim, Calif. Bellis recently moved to Japan, where Seikowave has opened an office and hired Minoru Niimura as chief operating officer. Niimura is a 25-year veteran from Epson who worked with Bellis at their previous MEMS startup, Miradia, which was acquired by Walsin Lihwa Corp. (Taiwan).