New display tech combines e-ink and LCD

AUTHOR: Inavate

Seven years of research at the University of Cincinnati has given birth to a “zero power” display technology. The University has published details of a display that it claims takes the best attributes from e-Reader and LCD technologies to create a revolutionary breakthrough. The screen offers high readability in bright sunlight and the ability to display high-speed colour content with “zero electrical power usage”.

The research, published in journal Applied Physics Letters, details the new electrofluidics design developed by the University and start-up company Gamma Dynamics. Lead researcher, Jason Heikenfel, UC associate professor of electrical and computer engineering in the college of Engineering & Applied Science, and John Rudolph, president of Gamma Dynamics, claim to be first to the table with a solution to a problem that has baffled other research teams for the last ten years.

Rudolph believes the technology will be seen as in-store supermarket shelf labels and advertising displays in as little as three years time.

Perhaps most importantly, the display can be manufactured with existing equipment and technology, a significant point when a new LCD plant costs approximately $2 billion (€1.4 billion) to build.

Heikenfeld said: “What we’ve developed breaks down a significant barrier to bright electronic displays that don’t require a heavy battery to power them.”

He explained that, currently, electronic devices fall into two basic camps. The first includes those devices that offer limited function and slow speed but require little power to operate. These would include e-readers like the Kindle.

In the second camp, devices like cell phones, laptops and the iPad provide high colour saturation and high-speed capability for video and other functions but at a cost of high-power usage.

Heikenfeld said: “Conventional wisdom says you can’t have it all with electronic devices: speed, brightness and low-cost manufacturing. That’s going to change with the introduction of this new discovery into the market. This idea has been in the works for a while, but we did not start really pushing the project until we thought we could make it manufacturable.”

The new “zero-power” design combines the features of both e-readers and LCD displays. It requires low power because it makes use of ambient light vs. a strong, internal light source within the device.

Two layers of liquid, oil and a pigment dispersion fluid (like an inkjet fluid), sit behind the display screen. Between the two layers are reflected electrodes that act like a reflective mirror.

Ambient light enters through the display screen through the first layer of liquid, hits the reflective electrodes and bounces back out to the viewer’s eye. That creates the perception of a bright, colour-saturated image, text or video.

A small electric charge powers the movement of these oil and pigment-dispersion liquids. The movement occurs between a bottom layer behind the reflective electrodes and a top layer in front of the reflective electrodes.

When the pigmented substance is positioned in the “top” layer (sandwiched between the ambient light and reflective electrodes), it creates a ray of coloured light, which combines with millions of ambient light rays to produce a full-colour display.

Dupont and Sun Chemical were involved in the research and partial support was provided by grants from the National Science Foundation, the Army Research Laboratory and the Air Force Research Laboratory.

[via University of Cincinnati]