By Barry Fox

THE long-promised roll-up displays that can be peeled out like a roller blind from hand-held gadgets will be arriving in the shops in March 2007, according to Philips.

Working with US-based electronic paper pioneer E-Ink, Philips has developed a paper-white, 13 centimetre-wide screen which is only 0.1 millimetres thick and can be pulled from a tight roll just 15 millimetres in diameter. It can display a monochrome image with four shades of grey as well as black and white, and needs no battery-draining backlight, like LCDs.

A backing layer of plastic film is covered with a matrix of transistors and topped with a liquid suspension of transparent "electronic ink" microcapsules. Each capsule is about 50 micrometres in diameter and contains black and white particles. The liquid suspension is then covered with a clear sheet of plastic.

The black and white particles in the capsules are polarised, so using the transistors to apply a pattern of positive and negative charges choreographs the particles to form monochrome images with what Philips says is "paper-like contrast".

The firm hopes to license the technology to makers of in-car satellite navigation equipment, mobile web browsers and smart phones. Philips expects mass production to begin in two years.