Philips is trying two routes to solve the dilemma of how to display video on mobile handsets, seen as the killer application for broadband mobile services.

One route is the roll-up or fold-up display, the other is installing a mini-projector in the handset to project an image onto a wall or screen.

Both routes need to solve the limited size of displays on handsets, which could make video-on-the-handset unattractive.

Although Philips is a leader in the development of flexible, potentially roll-up, displays, it believes that they are a decade away.

"There are two bottlenecks," Johan van de Ven, CTO of Philips Mobile Display Systems, told Electronics Weekly. "One is finding a barrier layer robust enough to stop all the dangerous gases we breathe from degrading the display. The other is that the substrate materials available are not mechanically reliable enough and robust enough -- just imagine what people do with their mobile phones."

The second route to larger displays for handsets is projection. "The other option is to build a low power, low cost projection system into the mobile handset," said van de Ven. "It may be possible to project an A3 or A4 size display on a wall. That's still a couple of years away."

In the meantime, to cope with video, mobile phone displays will move from passive matrix to active matrix, from one and a half inch on the diagonal to two and a half inch, and to increasing the number of on-screen pixels.

Philips currently commands 25 percent of the market for displays in mobile phones. The firm recently shipped its billionth mobile phone display. Ten years ago it had shipped 100 million displays and, in six years' time, it expects have shipped two billion.