As Reported By Richard Babyak In Appliance Design Magazine - Paper Bright Display Permits Seamless Integration (Ntera)

The monochromatic look for major home appliances has been popular for a long time and shows no sign of fading. However, for white or light-colored appliances, complete implementation of the design concept is often thwarted by a dark display area. Whether it’s the black window for LEDs or the grey box of an LCD, the location serves as a stark interruption of the otherwise uniform look. To address that issue, NTERA, Dublin, Ireland, has developed a paper-white display that can be more seamlessly integrated into a white appliance. The display, which is designed to be every bit as readable as ink on paper, provides designers with a new way to use a display to differentiate their products. In addition to white, the display can also feature a translucent background.

The company says its NanoChromics technology gives its display four times the contrast and reflectivity of other display technologies, and that a NanoChromics display can also be produced at lower cost than other displays.

The new display is bistable, meaning it draws power only when the image is changed, and it only requires 1 VDC to drive it. These features make the portable electronics segment another good target market for the technology. NTERA says that its display can be driven 10 times longer than other display technologies in a battery operated device.

In addition to the appliance demonstrator display pictured above, NTERA has also exhibited a demonstration prototype embedded in an Apple iPod music player.

NanoChromics displays are based on the well-established theory of electrochromism, a phenomenon where a material’s absorption of light is affected by an electrical charge. In the most common implementation, materials known as viologens, normally transparent, turn blue when an electric charge is applied. This concept is already widely used in the automotive industry to dim sideview and rearview mirrors in cars.

One of the longstanding barriers to the use of electrochromic materials in displays has been their slow switching speed. Traditional viologen systems are referred to as solution-based devices because they involve the charging of parallel-spaced electrodes that exchange electrons with solution-phase viologens. The slow diffusion of viologen in solution acts to inhibit switching speed.

NTERA solved this problem by developing nanomaterials with high-surface area electrodes to which hundreds of viologen monolayers could be directly attached, thereby permitting a speedier exchange of electrons. Pixels are patterned directly by printing the high-surface area electrode material directly into the pixel areas.

In the charged state, the viologen molecules exhibit a deep blue color. Contrast is achieved through use of white reflective background made from titanium dioxide. Testing of the display’s optical performance by the British Standards Institute has shown that levels of diffuse reflectivity exceed 50 percent and that contrast ratios have been observed up to 15:1. BSI tests have also shown that the contrast ratio remains above 12:1 in luminance intensities up to 60,000 lux. In addition, NTERA say its displays can achieve resolution up to 200 dpi.

NTERA expects that a low-power, high-definition, “paper-like” display can find a home in many applications where designers can use the displays to distinguish their products from the competition