Inside the "World's Smallest" Projector - Gearlog

Inside the "World's Smallest" Projector - Gearlog

OK, Microvision's SHOW pico projector may not necessarily be the world's smallest projector. There are tiny competitors from 3M, Toshiba, and Explay, using technologies as varied as DLP, LCOS and, as in the SHOW, lasers. Yet none are as thin as the SHOW. In fact, most of these competitors appear no thinner than an inch (at least from images we've found on the Web, since none of these companies have yet shown us these products in person). The latest Microvision SHOW projector is just 14 mm thick and is primed to get even thinner.

I last saw this iPod-size marvel at CES 2008. Back then, company reps were all but certain that commercial Microvision mobile projectors would be out before the end of this year. Now, however, the company tells us that we won't see these devices on the market until spring of next year.

The good news is that in the intervening months, Microvision has refined its technology, making the custom ASIC chip even smaller and rewriting algorithms to better control the 60-Hz refresh rate (getting rid of an up-to 4-Hz variance), remove some of the banding and shimmer I saw in the first prototype, and add a new, extended color mode that makes the image more vibrant and appear brighter.

When I met with Microvision late last year and at CES in January, I got a high-level primer on how the SHOW produces infinite-focus color images up to 3 meters wide--and on almost any surface-- without a lens. However, on recent visit, company executives went deeper, showing me the chip that drives the image and explaining, in some detail, how this tiny projector works.

At the heart of the SHOW is a tiny ASIC (or Application Specific Integrated Circuit). [Editor's Note: The following describes the Integrated Photonics Module (IPM), which is the optomechanical component of the PicoP -- the IPM is controlled by ASIC chips but is not itself an ASIC.] This 7-mm-thick, 5cc chip is a silicon MEMS (micro electro-mechanical system). At the center of the chip is a tiny mirror. The three color (RGB) lasers hit the mirror, which uses magnets, coils, and harmonics to oscillate from side to side and up and down. In this way it draws a 60-Hz raster pattern or image that is roughly 480p (WVGA 848 by 480 pixels). (See photos below).

Microvision execs told me that the technology offers their company some benefits over competitors. One of the biggest might be the unbelievably short "throw"--this is the amount of distance the projector needs from the screen to display a reasonably sized picture. A Microvision projector held a foot away from the projection surface will display a 1-foot-diagonal image. When I projected it onto my office ceiling from a distance of about 8 feet, I got a roughly 8-foot diagonal image. According to Microvision, competing mini-projectors have about half the throw ability. At virtually any distance, the SHOW image remains in focus.

Even though Microvision has been promising projector-equipped mobile phones since last year (and has managed to build a functioning prototype), the first Microvision products will be two standalone projectors, One will work with mobile media devices such as iPods, and the other will be a mobile media device that can play photos and videos on its own. The products will be officially unveiled at CES 2009 in Las Vegas and could retail for around $400.

Microvision partner Motorola reportedly is still working on an in-phone projector based on Microvision's technology; and Microvision is still working on making the projector even smaller. In fact, execs said that future SHOW devices could support higher resolutions without getting any bigger.


Here's a close-up of the tiny, 5CCs MEMS.


The Microvision MEMS with the magnets split open.


A side view of the Microvision MEMS.


The prototype case for the Microvision SHOW sits under an iPod.