E Ink has demonstrated a range of prototype ‘electronic paper’ display screens just 0.3mm thick — half that of a credit card.

The display is built on a steel foil substrate and is therefore flexible as well as thin, making it suitable for rugged portable displays.

Traditional active-matrix LCDs (liquid crystal displays) are built using two separate sheets of fragile glass and cannot be reduced to less than two millimeters in thickness.

The first prototype features a 1.6in diagonal screen with a resolution of 100x80 pixels. This display is aimed at small mobile devices such as smartcards and cell phones.

A larger prototype aimed at handheld devices such as PDAs (personal digital assistants) has a 3in diagonal screen and a resolution of 240x160 pixels.

E Ink
displays use different technology to the LCDs used in existing notebook computer screens. The displays consist of a thin plastic film containing millions of tiny microcapsules. These are filled with dark and light particles and carry opposite electrical charges. This sheet is bonded to the steel foil substrate and dark or light particles are drawn to its surface depending on the direction of its electrical field. This generates a pixel of that colour.

E Ink displays are expected to be launched commercially in 2004.