electronic-paper

INTRODUCTION:

Electronic paper, e-paper or electronic ink display is a display technology designed to mimic the appearance of ordinary ink on paper. Unlike a conventional flat panel display, which uses a backlight to illuminate its pixels, electronic paper reflects light like ordinary paper. It is capable of holding text and images indefinitely without drawing electricity, while allowing the image to be changed later.

To build e-paper, several different technologies exist, some using plastic substrate and electronics so that the display is flexible. E-paper has the potential to be more comfortable to read than conventional displays.This is due to the stable image, which does not need to be refreshed constantly, the wider viewing angle, and the fact that it reflects ambient light rather than emitting its own light. An e-paper display can be read in direct sunlight without the image appearing to fade. The contrast ratio in available displays as of 2008 might be described as similar to that of newspaper, though newly-developed implementations are slightly better.  There is ongoing competition among manufacturers to provide full-color capability.

BENEFITS:

1)    E-paper is a display technology designed to mimic the appearance of ordinary ink on paper - even its flexibility- and according to new research, reading the news on e-paper is more environmentally friendly than viewing via PC.

2)    Developed to overcome the limitations of computer screens, e-paper reflects light like ordinary paper instead of using a backlight to illuminate pixels and is capable of holding text and images indefinitely without drawing electricity. This in turn means energy savings far beyond that of reading online instead of in print.

3)    The greatest burden on the environment for the paper version is the production of the paper, and in electronic format, the power consumption benefits of e-paper over computer screens come to the fore.

SHORTCOMINGS:

1)    Electronic paper technologies have a very low refresh rate comparing with other low-power display technologies, such as LCD.

2)    Another limitation is that an imprint of an image may be visible after refreshing parts of the screen. Those imprints are known as "ghost images", and the effect is known as "ghosting". This effect is reminiscent of screen burn-in,but, unlike it, is solved after the screen is refreshed several times. Turning every pixel white, then black, then white, helps normalize the contrast of the pixels. This is why several devices with this technology "flash" the entire screen white and black when loading a new image, in order to prevent ghosting from happening.