Pocket-Size Roll-Up Displays

Nancy D. Lamontagne, Managing Editor

Displays are becoming tiny, but the smaller they get, the harder it is to see a lot of information at once. Although devices such as the iPhone include ways to zoom in on information in an e-mail or on a Web page, this gets tiring if you’re trying to read a newspaper or a novel. Those who want to read books and other publications electronically now turn to their computers or to e-readers such as Amazon’s “Kindle” and Sony’s “Reader.” The latter devices are about the size of a book but are thinner and weigh a little less than 300 grams. However, rollable displays are making a much smaller option viable. The Koninklijke Philips Electronics NV spin-off Polymer Vision of Eindhoven, the Netherlands, is releasing its “Readius” e-reader with a rollable display in some European countries later this year. Launches in other countries, including the US, will follow.

Image courtesy of Polymer Vision.

The gray-scale device’s 5-in. display can roll up for storage, with the entire device going from 115 × 160 × 21 mm when open to 115 × 57 × 21 when closed (fitting in the hand of most people). At just 115 g, it is less than half the weight of the Amazon and Sony products.

The display consists of a 25-μm-thick plastic substrate and active-matrix layers (4 μm thick in total) that drive E Ink’s Vizplex electrophoretic imaging film (40 μm thick). The film forms the image from oppositely charged black-and-white particles in capsules filled with a clear fluid. The rollable display is about the same thickness as paper (0.1 mm). The displays are created using methods similar to those that produce LCD flat screens. However, unlike those flat screens, only flexible organic layers and ductile metals are used so that the displays are rollable. Interested in seeing color pictures while you’re reading? You’re in luck. The company showed a prototype of a full-color rollable display at the Society for Information Display (SID) Exhibition in Los Angeles in May. This 65K color prototype has a roll radius of only 6 mm and a resolution of 127 ppi.