Future Projections: Cell Phone Market Poised for Projectors

Melinda Rose, Senior Editor, melinda.rose@photonics.com

The market for tiny handheld projectors, known as pico projectors, began in earnest a few years ago, with companies like Microvision Inc., Explay and 3M introducing prototypes at industry events such as the 2008 Consumer Electronics Show (CES). Shortly after, industry wags began writing that consumers would soon be able to buy cell phones and other electronic devices containing embedded projectors, but that has yet to happen in a significant way.

Samsung’s Galaxy Beam smart phone is the first phone on the market to feature an embedded projector. It hit the marketplace in July, but it is currently available only in Singapore. Courtesy of Samsung.

A number of those early products, although garnering a fair share of press, were considered by some in the industry to be more like beta launches than actual market-ready product debuts because of the amount of power they used and their unsatisfactory image quality, to name but a couple of their drawbacks.

The pocket projector market surged from 10 models in 2008 to more than 130 in 2009, but “most of the designs are still quite boring,” said Dr. Jennifer Colegrove, director of display technologies for DisplaySearch, who presented a market overview in May 2010 during the Society for Information Display (SID)’s Display Week in Seattle.

Perhaps in a rush to take advantage of industry buzz, some took off-the-shelf technology, added memory and put it into a small package and called it a pico projector, but they hadn’t yet solved issues such as connectivity to a host device, resulting in a “spaghetti factory” of wires and cables to achieve a projected image, said Matt Nichols, director of communications for Redmond, Wash.-based Microvision, which markets its own laser-based pico projector, the SHOWWX.

“What the market didn’t take into consideration is that just because you can project, it doesn’t mean you should,” Nichols said.

By the time CES was held in January 2010, several companies demonstrated prototypes of cell phones with projectors, although not necessarily embedded ones.

“Everybody was kind of chasing the accessory space because of price, performance, size and power requirements. No one had a solution for a mobile phone,” he said.

The pico projector on LG Electronics’ eXpo – which contains Texas Instruments’ (TI) digital light processing (DLP) chip – clips onto the back of the phone and is sold separately for a retail price of about $180. The eXpo was announced in December 2009 and featured at CES 2010 but soon began shipping without the projector. A number of technology websites reported in March that the projector accessory was delayed by production problems, while the company attributed the dearth of units to “strong demand.”

“LG created a full-blown ad campaign, and nobody on the planet could buy it,” Nichols said.

At press time, the handset was listed as “out of stock” on provider AT&T’s website.

Samsung’s Galaxy Beam, the first smart phone with an embedded projector (also courtesy of TI’s DLP chip), was officially unveiled at the February 2010 Mobile World Congress in Barcelona, Spain, and hit the marketplace in July, but it is currently available only in Singapore, through mobile service provider StarHub.

So what is hampering industry efforts to embed pico projectors into phones? One key drawback is the lack of a true green (515- to 535-nm) laser diode that can cost-effectively be produced in the vast quantities needed for the cell phone market. Shrinking light sources in such electronics is critical because today’s mass market consumer expects the latest cell phone to be thin, sleek and fashionable and not look “like it resembles one from 1995,” Nichols said.

With direct-diode green lasers, “not only does size get smaller, but performance increases, the price goes down, and you can push resolution to HD-ready 720p levels,” he added.

Closing the green gap

Lasers are seen as an ideal light-emitting device for pico projectors because of their wide color gamut, brightness and focus-free operation, although speckle noise – black dots that make the image appear grainy – is a problem, as is cost. Laser beam steering or microdisplay spatial light modulators are the two options that pico projectors have for using laser light.

Red and blue lasers have been commercially available for years and are produced in vast quantities on a monthly basis for applications such as Blu-ray and CD players, but while red diodes, as the most mature, are extremely cheap, blue diodes are still seen as fairly expensive, and green, even more so.

Although several companies say they have demonstrated direct-diode green lasers in the lab, there currently are none available for the pico projector market. Synthetic green lasers used today in portable electronic devices convert infrared light from red lasers into green light via a frequency-doubling crystal, a process that makes the laser more bulky and less efficient than direct-emitting lasers.

Kaai Inc. of Goleta, Calif., created a buzz when it announced in January that it had demonstrated a 523-nm continuous-wave green laser diode. Kaai’s lasers are based on InGaN (indium gallium nitride) semiconductor technology and fabricated on nonpolar and semipolar GaN substrates.

GaN semiconductors are available on the market for blue LEDs and are a key material for pushing light-emitting devices into the green wavelength. A big drawback to using the material in light emission is that luminance efficiency drops quickly as the wavelength increases.

Courtesy of Corning Inc.

Sumitomo Electric Industries Ltd. of Osaka, Japan, announced in July 2009 that it had solved that problem by developing a GaN crystal that inhibits the efficiency drop, resulting in room-temperature pulse operation of a laser diode emitting in the pure-green region of 531 nm.

Another hitch in the road to market for embedded projectors is that, although frequency-doubled synthetic green lasers are more mature, supplies have been far from plentiful. Microvision had to delay market rollout of the SHOWWX because of laser supply constraints. The company has multiyear deals with Corning Inc. of Corning, N.Y., and Osram Opto Semiconductors GmbH of Regensburg, Germany, to supply their green and blue laser diodes, and says deliveries have improved.

Top right: Lasers, such as Corning’s G-2000, are seen as ideal light-emitting devices for pico projectors because of their ability to provide a wide color gamut, high brightness and focus-free operation. Courtesy of Corning Inc. Bottom right: With its direct-emitting green laser achievement in the lab, Osram Opto Semiconductors said it has set an important new milestone in mobile laser projection. Courtesy of Osram.

“For the short term, we’re now satisfied. A year ago or six months ago, I would have said no,” Nichols said.

Corning promoted its latest green laser for microprojection, the G-2000, at SID’s Display Week. The laser uses a 1060-nm distributed Bragg reflector laser source to produce a green wavelength of 530 nm via a periodically poled lithium niobate crystal waveguide.

The 720-pixel higher-brightness (15-lm output) prototype pico projector that Microvision demonstrated at SID Display Week features the G-2000 and is scheduled to hit the market as a commercial product in the second half of 2011. The package size of this second-generation module is 25 percent smaller than the first generation, Nichols said.

Corning’s G-2000 green laser is a high-quality, compact and efficient green light source for use in embedded microprojectors.

“The module in the SHOWWX is a physical size that’s acceptable to handset manufacturers. What isn’t acceptable is the price and power performance,” he said. Manufacturers are now developing prototypes with the current module.

Market requirements for green

The green laser is responsible for more than half of the projected light from a red-green-blue (RGB) optical engine, so it must have enough optical power to project displays at more than 15 lm. It also must have a high enough modulation speed to project high-resolution (WVGA and above) images. Power efficiency, thermal stability and size are other factors. Corning says that the G-2000 meets those requirements by providing 80 mW of power, a wall-plug efficiency of 8 percent, modulation speeds up to 150 MHz, an operating temperature range of 10 to 60 °C and a footprint of less than 5 mm.

Other alternatives on the market to TI’s DLP chip, which has an RGB LED as its light source, are pico projectors that use field-sequential liquid crystal on silicon (LCoS) technology, and still others that use microelectromechanical systems. In most of these systems, the technology can use either RGB LEDs or lasers as their light source. (For more on pocket projectors and their light sources, see “Pico Boom,” Photonics Spectra, September 2009, p. 76).

Because they are significantly less costly and more safe than lasers, LEDs are serious competitors for pico and embedded projector applications, although they remain hampered by their limited focusing ability. Over the past two years, LED makers have concentrated their efforts on providing better and smaller light sources that can be embedded into portable devices. LED-based systems haven’t yet met the market’s desired specifications for size, resolution and brightness, but that is changing as manufacturers release high-brightness LEDs that demonstrate greater efficiencies.

One such company is Osram Opto Semiconductors, which announced in June that its new Ostar Compact high-current LED, a 2 mm² chip modified by improved epitaxial processes, can be pulsed up to 6 A instead of the typical 4 A. Thermal resistance has been reduced from 6 K/W to 3 K/W, allowing heat to dissipate more efficiently. The light output boost that the chip gets from these improvements makes it a viable choice for pico and pocket projectors, according to Osram.

Osram Opto Semiconductors said its new high-performance Ostar Compact is ideal for miniprojectors. Courtesy of Osram.

“We are prepared for the embedded projector market ramp-up with products and production equipment. But the real ramp-up will be decided by consumers,” said Wolfgang Schnabel, marketing manager of projection at Osram.

The company also is pursuing a green laser solution.

“We are working on solving the green gap, and we are positive [we will] introduce a solution quite soon,” Schnabel said. “We are also working on direct green lasers and introduced an R&D prototype last year about a direct-emitting green InGaN laser with 50 mW.”

That prototype was announced in August 2009 and was developed under the German Ministry for Education and Research’s MOLAS project, which involves developing technologies for ultracompact and mobile laser projection systems.

Projector market forecast

Half a million pocket projectors – both stand-alone and embedded – worth $117 million were shipped in 2009, DisplaySearch’s Colegrove said, but the number of stand-alone units was more than double that of embedded types, a situation she said is expected to continue over the next couple of years.

For manufacturers who want to bring the next generation of mobile devices to market, Microvision provides the PicoP display engine for high-volume embedded laser projection applications. Courtesy of Microvision.

“So why are they only selling 500,000 units? The image quality is not exciting for consumers,” said Mark Harward, CEO of Syndiant Inc., at the DisplaySearch business conference during Display Week. “To go mass-market, pico projectors must meet the consumer’s minimum performance threshold. The product must ‘wow.’”

Dallas-based Syndiant says its VueG8, which uses the LCoS light modulation process, benefits from its ability to use high-volume digital CMOS manufacturing techniques to build hundreds of microdisplays on a single silicon wafer.

Syndiant announced at Projection Summit 2010 in Las Vegas in June that it had developed a pico projector smaller than 4 cc with partners Foryou Multimedia Electronics Co. Ltd. of Huizhou City, China, and Hong Kong’s Applied Science and Technology Research Institute Co. Ltd. for embedding into handheld devices. It is expected to ship before the end of this year.

The smaller-than-4-cc pico projector engine developed by Hong Kong’s Applied Science and Technology Research Institute Co. Ltd. and Foryou Multimedia of China features Syndiant’s VueG8 technology. Courtesy of Business Wire.

DisplaySearch forecasts that the total pocket projector market will reach 142 million units and $13.9 billion in revenue in 2018, with 45 million units being stand-alone projectors and 97 million the embedded type.

The green laser market is expected to drive that growth. According to Yole Développement sarl of Lyon, France, the green laser market is expected to reach revenue of about $500 million by 2016 (see “Microprojectors spur development of green lasers,” Photonics Spectra, July 2010, p. 23).

“The next-generation synthetic green lasers are expected to be more efficient and less expensive than their first-generation cousins,” said Tiffany Bradford, an investor relations specialist at Microvision, in an early August blog post on the company’s website.

“We also anticipate that the direct green lasers targeted for introduction in the second half of next year may not reach desired performance and cost targets immediately. For these reasons, we believe that synthetic lasers could continue to remain a competitive alternative to direct green lasers for at least the first four to five years after diodes are introduced,” she said.