BY MELINDA ROSESENIOR EDITOR
Tiny projectors, known as pico or pocket projectors, are on the cusp of becoming the next big thing asthey shrink to sizes practical for embedding into ever-smaller cell phones andother mobile devices as well as head-updisplays for the military and auto industries. As these projectors continue toshrink, a battle is growing between LEDsand lasers to become the pre-eminent picolight source.
The lamps first used as light sources fortabletop projectors or rear-projection televisions are large and power hungry, andthey generate enormous amounts of heat,so manufacturers have turned increasinglyto LEDs and, more recently, to lasers asbetter choices.
Pico projectors are driven by threemajor technologies: digital light processing (DLP), liquid crystal on silicon(LCoS) and laser beam steering (LBS).
Texas Instruments (TI) of Dallas pioneered the DLP projection system in 1987.DLP technology is driven by a small chipcontaining up to 2 million hinge-mountedmicromirrors. The chip switches each mirror on and off several thousand times persecond, generating light or dark pixels.
“DLP can work with lasers or LEDs and
is poised to take advantage of either LED
or laser technology,” said Frank J. Moizio,
DLP emerging markets manager at TI.
“DLP products today ship with lasers.”
One such product is the 65-in. laser TV,
LaserVue, from Mitsubishi Electric of
Tokyo, which appeared on the market in
October 2008 for $7000. Mitsubishi said
the lasers give the TV about twice the
color range of other high-definition TVs,
while consuming as much as 75 percent
less power than LCD and plasma
LCoS uses liquidcrystal instead ofmirrors to control the amountof light eachpixel receives.
Its light source
has shifted in recent
years from high-intensity lamps to LEDs,
but lasers also can be used.
LBS systems use optics to combineRGB (red, green, blue) laser beams andthen guide them with a mirror to create animage.
Show me the market
With the worldwide economy in aslump, diode makers are looking to selltheir product however they can. Theworldwide mobile phone market, with onebillion units sold last year, is an attractiveone: Even a 2 percent slice translates tosales of 20 million to 30 million diodes.
Pico projector prototypes with a resolution similar to a DVD were featured at theConsumer Electronics Show in Las Vegasin 2008 and 2009 and have been tricklingonto the market.
The MPro110 from 3M of St. Paul,Minn., has an LED light source and LCoSimager. The Pico, a handheld projectormade by Optoma Technology of Milpitas,Calif., and featuring TI’s DLP, began shipping at the end of 2008.
Samsung Electronics Co. Ltd. of Seoul,South Korea, unveiled its Show, the firstsmart phone to include a pico projector, atthe Consumer Electronics Show in January. Show also features TI’s DLP and iscurrently available only in South Korea.
According to industry analyst iSuppliCorp. of El Segundo, Calif., the market forpico projectors will explode by nearly6000 percent over the next four years,growing from fewer than 50,000 units this
76 Photonics Spectra September 2009Pocket projectors are poised to explode, but will lasers or LEDs be the pre-eminent light source?
This diagram shows theinternal components thatmake up Microvision’sPicoP engine, includinglaser diodes and amicroelectromechanicalsystems chip. Courtesyof Microvision Inc.
The Show, thefirst smart phone toinclude a pico projector,currently is sold only in SouthKorea. Courtesy of SamsungElectronics Co. Ltd.