PORTLAND, Ore. -- Pico-projectors allow iPod-size devices to project a 12- to 30-inch display on the wall, but they are not yet available in consumer products. So far, most OEMs showing pico-projector prototypes at the Consumer Electronics Show, earlier this month, were using liquid-crystal-on-silicon (LCOS) panels from Displaytech Inc. (Longmont, Colo.). Displaytech's microdisplay technology dovetails well with the emerging pico-projector market, giving original equipment manufacturers (OEMs) a proven technology alternative to more experimental micromirror subsystems that use micro-electro-mechanical system (MEMS) chips--at least in the short term; the final verdict is not yet in.
During 2008, most pico-projector OEMs will be choosing between LCOS panels from Displaytech and the half-dozen other microdisplay makers, and micromirror chips from both Texas Instruments Inc. (Austin, Texas), with its digital light processor (DLP) using millions of micromirrors, and Microvision Inc. (Redmond, Wash.), with its single micromirror MEMS chip. No pico-projector design-wins have been announced so far, but by CES 2009 there will likely be more than a dozen OEMs that have finally chosen between these three alternatives, according to Bill Coggshall, founder of Pacific Media Associates (Menlo Park, Calif.)
"The microdisplay vendors like Displaytech, and the MEMS micromirror companies like Texas Instrument and Microvision, are headed in two different directions," said Coggshall, who helped found legendary Dataquest before leaving in 1992 to found his own market-analysis company, Pacific Media Associates. "Displaytech's solution uses cheap and readily available LEDs and a low-cost liquid-crystal-on-silicon panel, but companies have been manufacturing LCOS panels for years--their solution will look comparatively power hungry and expensive as time goes by. Whereas, both Texas Instrument's and Microvision's MEMS micromirror chips will become smaller, cheaper and lower power in the future, but might not look as attractive to OEMs today. Of the micromirror solutions, Microvision's MEMS solution will probably end up being the smallest, lowest power and cheapest approach, because it uses a single MEMS micromirror, but today it depends on relatively expensive laser. Texas Instruments DLP, on the other hand, is a little bigger, more expensive and higher power today, since it uses millions of micromirrors, but it produces the best images and is readily available."
Of the LCOS panel makers, Displaytech claims the best looking images by virtue of its patented ferroelectric version, FLCOS, which has been sold as a microdisplay for camera viewfinders for six year, chalking up over 18 million unit sales for battery-powered handheld devices. Now Displaytech has repurposed the FLCOS technology--which it calls LightView--for pico-projectors, claiming that 16 OEMs have working prototypes--four of which are confirmed design-wins for pico-projectors that Displaytech showed off in its suite at CES, but which have yet to be formally unveiled by the OEMs.
FLCOS microdisplays, like the other LCOS makers' panels, use time-division multiplexing to switch a low-cost monochrome microdisplay--measuring only half an inch diagonally--between red, green and blue at up to 360 times per second, twice per video frame. LCOS displays are brighter and faster than normal thin-film transistor (TFT) panels, which use filters for red, green and blue subpixels against a black background.
Instead of filters for each color, the FLCOS depends on low-power high-intensity red, green and blue LEDs, which it synchronizes with its monochrome display's time-division multiplexing scheme, thus lowering the cost of FLCOS displays, over full-color displays that must pack subpixels.
"We are using a proven technology--FLCOS--that we have been manufacturing for over six years," said chief technical officer at Displaytech, Mark Handschy. "We have already solved all our manufacturing, reliability and packaging issues, which gives us an advantage over our competitors."
Displaytech has been shipping samples of its 800-by-600 pixel LightView panel to pico-projector OEMs since 2007, and was showing a half dozen prototypes from its OEMs at CES. Production units of the LightView panel for pico-projectors will be delivered to OEMs starting in April 2008, according to Displaytech, which claims that a complete pico-projector subsystem, including the FLCOS panel, red-, green- and blue-LEDs, optical lenses and packaging, has a bill of material of less than $100.