E Ink Corp. has demonstrated a range of prototype "electronic paper" display screens with a thickness of just 0.3 millimeters -- half the thickness of a credit card, the company said Thursday.
The display is built on a steel foil substrate and is therefore flexible as well as thin, making it suitable for rugged portable displays, E Ink said in a statement.
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 thickness.
The first prototype features a 1.6-inch (40-millimeter) diagonal screen with a resolution of 100 pixels by 80 pixels. This display is aimed at small mobile devices such as smart cards and cell phones, E Ink said in its statement.
A larger prototype aimed at handheld devices such as PDAs (personal digital assistants) has a 3-inch (75-millimeter) diagonal screen and a resolution of 240 pixels by 160 pixels.
E Ink displays use different technology to LCDs used in existing notebook computer screens.
An E Ink display consists of a thin plastic film, which contains millions of tiny microcapsules filled with dark and light particles which carry opposite electric charges. This sheet is bonded to the steel foil substrate. Depending on the direction of an electric field from the steel foil transistor substrate, either the dark or the light particles are drawn to the surface, generating a pixel of that color.
The displays are expected to be launched commercially in 2004, the Cambridge, Massachusetts, company said.