Technology Assistant: E Ink Technology

Earlier, the launch of Amazon's Kindle that is an e-book reader and now demonstration of Paper Phone's prototype blows the expectations. The E-ink (electronic ink) technology could replace paper and might soon begin to compete with LCD displays.

E-Ink is a specific type of ink that is used in Electronic Paper Displays (EPD) developed by E Ink Corporation, based on research started at the MIT Media Lab. A straightforward fusion of chemistry, physics and electronics to create electronic paper that will change our way of reading, writing and interacting with gadgets.

About the technology and how it works?

E ink is made of a bunch of tiny microcapsules that are about the diameter of human hair. These microcapsules contained in a layer of liquid polymer and each micro capsules contains white and black particles that are charged positive and negative respectively. Another layer consists of circuitry to control the display.

For the negative side of electric field, the black particles move to the top of the microcapsule to become visible to the reader. This makes the surface appear dark at that location for the positive cycle of the electric field. As the white particles are charged positive, the opposite electric field pulls them to the bottom of the microcapsules where they are hidden. For the positive cycle of the electric field white particle becomes visible on top of the capsule and black particles get hidden. This pattern of white and black can then be created to form words and sentences.

Benefits of E Ink technology

Less Power Consumption : As it requires no backlight, the power consumption in an E Ink display is low as compared to traditional LCD or TFT display. It also does not require power to hold a page of text or an image on screen, the power is required only to change the page.

Performance : E ink does not emits its own light, in fact it reflects external light that makes it easier to read even in direct sunlight.

Disadvantages of E Ink technology

As all the technology has some pitfalls so E ink have:

It has very low refresh rate that restricts producers from implementing more interactive applications.
Ghosting is another limitation of the technology. This refers that a shadow of the image may be visible even we turn on to the next page.
As it does not emit its own light and reflects only external light, it is hard to read and work on it in dark.

Major Products on E-Ink technology