Contents
1 Introduction 1
1.1 Organization Of the Report . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Basic Working 3
3 Technology 5
3.1 Gyricon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.2 Electrophoretic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.3 Electrowetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.4 Displaying Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4 Advantages and Disadvantages 9
4.1 Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.2 Disadvantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Commercial Applications 10
6 Conclusion and Future Work 12
References 12

Abstract
An Electronic Paper Display is a display that possess a paper-like high contrast ap-
pearance, ultra-low power consumption, and a thin, light form. It gives the viewer the
experience of reading from paper, while having the power of updatable information.
Electronic paper display is similar to normal paper in that it uses ambient light
to display images and that it can hold the image indenitely without drawing power.
This is contradictory to the current display techniques which uses backlight for illu-
minating pixels and also uses power for maintaining the display.

Chapter 1
Introduction
With a world full of monitors and electronic displays made with liquid crystals, light-
emitting diodes and gas plasma, we probably don't think of paper as being a revo-
lutionary display technology, but the Chinese invention of paper in 105 A.D. forever
changed the way the world communicates. Without it, books might still be printed
on silk scrolls that only the wealthy could aord, making literacy a rare skill.
For nearly 2,000 years, ink on paper was the only way to display words and images,
and it still beats computer displays when it comes to portability and price. Paper
also doesn't require an external power supply. Yet it does have some limitations:
Once you've printed words on paper, those words cannot be changed without at least
leaving some marks, and it is also dicult to carry around a large number of books.
In this era of modern computing, a lot of books are present in digital form. The
sales record of Amazon in the past few months shows that ebook sales has surpassed
the sales of hard copies. This could point to a revolution in the change of reading
habits of the public. Reading ebooks using conventional display technologies like
LCD, CRT etc poses these problems :
 Strain to the eye
 Poor contrast in sunlight
 Power is required to maintain the display
Scientists have come up with a revolutionary new technology for displaying text
and images. This technology has been named Electronic Paper Display.

Chapter 2
Basic Working
Consider a beach ball lled with a blue colored dye. Let it be lled with some white
ping pong balls whose position can be controlled using say, a set of electrodes. If the
white balls are at the top(viewing side) of the beach ball, it will appear white. If they
are at the bottom, it will appear blue. This is the basic concept behind the working
of electronic ink.
An electronic paper display typically consists of these components :
 Millions of tiny micro-capsules or cavities.
 An ink or oily substance lling the micro-capsules or cavities.
 Pigmented chips or balls with a negative charge
oating inside the micro-capsule.
When an electrical charge is applied to the micro-capsules, the chips will either
rise to the top or be pulled to the bottom. When pushed to the top, the chips make
the capsules look white; when they are pulled to the bottom, the viewer only sees the
dark ink. Patterns of white and dark can then be created to form words and sentences.
In reality, these micro-capsules are only 100 microns wide, and roughly 100,000
micro-capsules can t into a square inch of paper. In each of those micro-capsules there
are hundreds of smaller pigmented chips. Using this, a suciently high resolution can
be obtained.