TECHNOLOGY FOR CHANGE

Pico-Projectors Downsized for Cheaper Smartphones

R. Colin Johnson | Date: 02-16-11 | Comments

The world�s largest maker of micro-electro-mechanical systems (MEMS) chips announced it has teamed with pico-projector pioneer bTendo to develop the world�s smallest, lowest-power pico-projector for smartphones and other portable consumer electronics devices.

Pico-projectors promise to enable even the smallest-screen smartphones to project 50- to 100-inch displays onto any flat, white surface. Texas Instruments (TI, Dallas, Texas) currently leads with its digital-light processor (DLP), but now STMicroelectronics (Geneva, Switzerland), the world's largest MEMS chip maker, has thrown its weight behind a relatively unknown startup with a novel, two-mirror design.

Today, the most popular pico-projectors use the time-proven DLP technology from TI, which employs millions of tiny MEMS micromirrors on a chip that projects all the pixels in an image simultaneously by dedicating a mirror to each, then illuminating the whole array with a single light source. Kfar Saba, Israel-based startup bTendo, on the other hand, uses just two mirrors to perform the same task by scanning the pixels onto the screen one at a time.

Israel's bTendo marries lasers with beam-steering using micromirrors that combine the illumination from three lasers (red, green, blue) then deflect it to the proper pixel by steering the laser beams in two dimensions�fast horizontal and slow vertical.

The lower manufacturing and materials costs of bTendo's approach give it the potential to bring ultracheap pico-projectors to even the least expensive smartphones. In today�s market, only a few high-end units can afford to include a DLP.

Several other contenders are also racing to release cheap alternatives to DLP, including Microvision (Redmond, Wash.), which announced the world's first laser-based pico-projector using its single MEMS micromirror technique, and Maradin Technologies (Caesarea, Israel), which offers a solution similar to Microvision's. In addition, TI itself continues to downsize and reduce the cost of its DLP to remain competitive.

STMicroelectronics and bTendo, on the other hand, aim to leapfrog all these competitors by developing what they claim will be the world's smallest, least-expensive MEMS module for pico-projectors. The unit, like all laser-based solutions, will be focus-free, by virtue of using three lasers�one each for red, blue, and green�to illuminate each pixel, rather than using lenses with LEDs that must be focused on the plane of the projection screen. Lasers maintain focus regardless of how far away the screen is, or even whether it is flat or curved.

The bTendo's unique approach uses two uniaxial mirror mechanisms, rather than a conventional biaxial mirror, to simplify the requirements for its actuation engine.

STMicroelectronics and bTendo are planning to release a complete pico-projector module that is less than 6 millimeters high and consumes no more than 2.5 cubic centimeters in volume. By using the Mobile Industry Processor Interface (MIPI), the team hopes to bring to market the least-expensive, lowest-power solution that nevertheless projects focus-free images that are sharper and more vivid than those of its competitors.

A prototype of the new pico-projector module will be shown this week at Mobile World Congress in Barcelona.