e-paper

ASHISH KUMAR SAHOO [12012011003]

ABSTRACT

E-paper is a revolutionary material that can be used to make next generation electronic displays.

It is portable reusable storage and display medium that look like paper but can be repeatedly

written one thousands of times. These displays make the beginning of a new area for battery

power information applications such as cell phones, pagers, watches and hand-held computers

etc.

Two companies are carrying our pioneering works in the field of development of electronic ink

and both have developed ingenious methods to produce electronic ink. One is E-ink, a company

based at Cambridge, in U.S.A. The other company is Xerox doing research work at the Xerox's

Palo Alto Research Centre. Both technologies being developed commercially for electronically

configurable paper like displays rely on microscopic beads that change color in response to the

charges on nearby electrodes.

To build e-paper, several different technologies exist, some using plastic substrate and

electronics so that the display is flexible. E-paper or electronics ink display technology designed

to mimic the appearance of ordinary ink on paper. Unlike a conventional flat panel display, which

uses a back light to illuminate its pixels, electronic paper reflects light like ordinary paper and is

capable of holding text and images indefinitely without drawing electricity, while allowing the

image to be change later.

Like traditional paper, E-paper must be lightweight, flexible, glare free and low cost. Research

found that in just few years this technology could replace paper in many situations and leading

us ink a truly paperless world.

TABLE OF CONTENTS

1. INTRODUCTION 1

1.1 History 2

2. TECHNOLOGY USED 3 2.1 Gyricon 3

2.2 Electrophoretic 3

2.3 Electrowetting 6

2.4 Electrofluidic 7

3. KEY BENIFITS 9

3.1 Paper-like Readability 9

3.2 Ultra-Low Power Consumption 10

3.3 Thin, Light Form Factor 10

3.4 The Ultimate Mobile Display Solution 10

3.5 Twistable 11

3.6 Simple manufacturing process 11

4. HIGHLIGHTS OF ELECTRONIC INK 12

5. DISADVANTAGES 13

6. APPLICATIONS 14

6.1 Electronic Shelf Label 14

6.2 Electronic Watch and Clock 15

6.3 e-Book 15

6.3 Smart Card Display 16

6.4 Newspapers 16

6.5 Other products 17

7. THE FUTURE SCENARIO 18

8. CONCLUSION 19

BIBLIOGRAPHY

20

E-Paper Technology 1

Ashish Kumar Sahoo

1. INTRODUCTION

Today's electronic displays have ever more evolved to be more lightweight, efficient and clear.

Yet the importance of the paper has not diminished. We still prefer it to others for a variety of

reasons including its readability, high contrast, convenient handling, minimum power

requirement cost and strain less reading it offers. At the same time, an electronic display offers

us a paperless environment and relieves us from carrying loads of paper for referring to

information when required.

Electronic ink is a pioneering invention that combines all the desired features of a modern

electronic display and the sheer convenience and physical versatility of sheet of paper. E-paper

or electronic paper is sometimes called radio paper or smart paper. Paper would be perfect

except for one obvious thing: printed words can't change. The effort is to create a dynamic high-

resolution electronic display that's thin and flexible enough to become the next generation of

paper.

The technology has been identified and developed is well under way. Within five years, it is

envisioned electronic books that can display volumes of information as easily as flipping a page

and permanent newspapers that update themselves daily via wireless broadcast. They deliver

the readability of paper under virtually any condition, without backlighting. And electronic ink

displays are persistent without power, drawing current only when they change, which means

batteries can be smaller and last longer.


Ashish Kumar Sahoo

1.1 History

Electronic paper was first developed in the 1970s by Nick Sheridon at Xeroxs Palo Alto

Research center. The first electronic paper, called Gyricon, consisted of tiny, statically charged

balls that were black on one side and white on the other. The "text" of the paper was altered by

the presence of an electric field, which turned the balls up or down.

In the 1990s another type of electronic paper was invented by Joseph Jacobson, who later co-

founded the corporation E Ink which formed a partnership with Philips Components two years

later to develop and market the technology


Ashish Kumar Sahoo

2. TECHNOLOGY USED

2.1 Gyricon

Electronic paper was first developed in the 1970s by Nick Sheridon at Xerox's Palo Alto

Research Center. The first electronic paper, called Gyricon, consisted of polyethylene spheres

between 75 and 106 micrometers across. Each sphere is a Janus particle composed of negatively

charged black plastic on one side and positively charged white plastic on the other(each bead

is thus a dipole). The spheres are embedded in a transparent silicone sheet, with each sphere

suspended in a bubble of oil so that they can rotate freely. The polarity of the voltage applied

to each pair of electrodes then determines whether the white or black side is face-up, thus giving

the pixel a white or black appearance. At the FPD 2008 exhibition, Japanese company Soken

has demonstrated a wall with electronic wall-paper using this technology

2.2 Electrophoretic

An electrophoretic display forms visible images by rearranging charged pigment particles using

an applied electric field.

Fig-2.1: Basic Scheme of an Electrophoretic Display


Ashish Kumar Sahoo

In the simplest implementation of an electrophoretic display, titanium dioxide particles

approximately one micrometer in diameter are dispersed in a hydrocarbon oil. A dark-colored

dye is also added to the oil, along with surfactants and charging agents that cause the particles

to take on an electric charge. This mixture is placed between two parallel, conductive plates

separated by a gap of 10 to 100 micrometers. When a voltage is applied across the two plates,

the particles will migrate electrophoretically to the plate bearing the opposite charge from that

on the particles. When the particles are located at the front (viewing) side of the display, it

appears white, because light is scattered back to the viewer by the high-index titanium particles.

When the particles are located at the rear side of the display, it appears dark, because the

incident light is absorbed by the colored dye. If the rear electrode is divided into a number of

small picture elements (pixels), then an image can be formed by applying the appropriate

voltage to each region of the display to create a pattern of reflecting and absorbing regions.

Electrophoretic displays are considered prime examples of the electronic paper category,

because of their paper-like appearance and low power consumption.

Electrophoretic displays can be manufactured using the Electronics on Plastic by Laser Release

(EPLaR) process developed by Philips Research to enable existing AM-LCD (Active matrix

liquid crystal display) manufacturing plants to create flexible plastic displays.

2.2.1. Electronics on Plastic by Laser Release (EPLaR) :

Electronics on Plastic by Laser Release (EPLaR) is a method for manufacturing flexible

electrophoretic display using conventional AM-LCD manufacturing equipment avoiding the

need to build new factories. The technology can also be used to manufacture flexible OLED

(Organic LED) displays using standard OLED fabrication facilities.

The technology was developed by Philips Research and uses standard display glass as used in

TFT-LCD processing plants. It is coated with a layer of polyimide using a standard spin-coating

procedure used in the production of AM-LCD displays. This polymide coating can now have a

regular TFT matrix formed on top of it in a standard TFT processing plant to form the plastic


Ashish Kumar Sahoo

display, which can then be removed using a laser to finish the display and the glass reused thus

lowering the total cost of manufacture.

2.2.2. Development in Electrophoretic Display:

In the 1990s another type of electronic paper was invented by Joseph Jacobson, who later

co-founded the E Ink Corporation which formed a partnership with Philips Components two

years later to develop and market the technology. In 2005, Philips sold the electronic paper

business as well as its related patents to Prime View International. This used tiny microcapsules

filled with electrically charged white particles suspended in colored oil. In early versions, the

underlying circuitry controlled whether the white particles were at the top of the capsule (so it

looked white to the viewer) or at the bottom of the capsule (so the viewer saw the color of the

oil). This was essentially a reintroduction of the wellknown electrophoretic display technology,

but the use of microcapsules allowed the display to be used on flexible plastic sheets instead of

glass.

Fig-2.2: Basic Scheme of an Electrophoretic Display using color filters

One early version of electronic paper consists of a sheet of very small transparent capsules,

each about 40 micrometers across. Each capsule contains an oily solution containing black dye

(the electronic ink), with numerous white titanium dioxide particles suspended within.

The particles are slightly negatively charged, and each one is naturally white. The

microcapsules are held in a layer of liquid polymer, sandwiched between two arrays of


Ashish Kumar Sahoo

electrodes, the upper of which is made transparent. The two arrays are aligned so that the sheet

is divided into pixels, which each pixel corresponding to a pair of electrodes situated either side

of the sheet. The sheet is laminated with transparent plastic for protection, resulting in an overall

thickness of 80 micrometers, or twice that of ordinary paper. The network of electrodes is

connected to display circuitry, which turns the electronic ink 'on' and 'off' at specific pixels by

applying a voltage to specific pairs of electrodes. Applying a negative charge to the surface

electrode repels the particles to the bottom of local capsules, forcing the black dye to the surface

and giving the pixel a black appearance. Reversing the voltage has the opposite effect - the

particles are forced from the surface, giving the pixel a white appearance. A more recent

incarnation of this concept requires only one layer of electrodes beneath the microcapsules.

2.3 Electrowetting

Electro-wetting display (EWD) is based on controlling the shape of a confined

water/oil interface by an applied voltage. With no voltage applied, the (coloured) oil forms a

flat film between the water and a hydrophobic (water-repellent), insulating coating of an

electrode, resulting in a coloured pixel.

Fig-2.3: Appearance of pixels seen from transparent electrode layer


Ashish Kumar Sahoo

When a voltage is applied between the electrode and the water, the interfacial tension

between the water and the coating changes. As a result the stacked state is no longer stable,

causing the water to move the oil aside.

This results in a partly transparent pixel, or, in case a reflective white surface is used

under the switchable element, a white pixel. Because of the small size of the pixel, the user only

experiences the average reflection, which means that a high-brightness, high-contrast

switchable element is obtained, which forms the basis of the reflective display.

Displays based on electro-wetting have several attractive features. The switching between

white and coloured reflection is fast enough to display video content.

It is a low-power and low-voltage technology, and displays based on the effect can be

made flat and thin. The reflectivity and contrast are better or equal to those of other reflective

display types and are approaching those of paper. In addition, the technology offers a unique

path toward high-brightness full-colour displays, leading to displays that are four times brighter

than reflective LCDs and twice as bright as other emerging technologies.

Instead of using red, green and blue (RGB) filters or alternating segments of the three

primary colours, which effectively result in only one third of the display reflecting light in the

desired colour, electro-wetting allows for a system in which one sub-pixel is able to switch two

different colours independently. This results in the availability of two thirds of the display area

to reflect light in any desired colour. This is achieved by building up a pixel with a stack of two

independently controllable coloured oil films plus a colour filter.

2.4 Electrofluidic

Electrofluidic displays are a variation of an electrowetting display. Electrofluidic displays

place an aqueous pigment dispersion inside a tiny reservoir. The reservoir comprises


Ashish Kumar Sahoo

in the May 2009 Issue of Nature Photonics, the technology can potentially provide >85% white

state reflectance for electronic paper.


Ashish Kumar Sahoo

3. KEY BENEFITS

E-Paper has numerous benefits. The reader does not need to get used to a new format - reading

an E-Paper equals reading a printed newspaper. However, E-Paper guarantees independency

regarding room and time. E-Paper can be read everywhere in the world, at every hour, and since

digital editions can also be received on PDAs and smart phones, mobility is almost limitless.

Additionally, E-Paper saves resources. On the one hand, paper and space are saved - because

E-Paper does not pile up anywhere - on the other hand, valuable time is saved. Since the

complete pages are displayed on the PC monitor, one instantly gets an overview over all

headlines and thus gets to the relevant articles a lot faster

Unlike conventional LCD's and other kinds of reflective displays, an electronic ink display is

exceptionally bright and is ready viewable under both bright and dim lighting conditions. To

be more assertive we could compare electronic ink display with the latest liquid crystal displays.

Table 3.1: Comparison of E-ink & LCD

Electronic ink display Liquid Crystal Displays

Wide viewing angle Best image only from one position

Black on paper white Gray on gray

Readable in sunlight Can be difficult to see

Holds image without power drain Required power to hold images

Legible under most lighting conditions Often requires backlight

Plastic or glass Glass only

Light Weight Power supply and glass make LCDs

relatively heavy

Thin (~1 mm) Thick (~7 mm)


Ashish Kumar Sahoo

3.1 Paper-like Readability

Paper is easily readable over wide variations in lighting conditions and viewing angle. E Ink's

electronic ink technology approaches printed paper in performance by incorporating the same

coloring pigments often used to make paper white and ink black.

When reading text, both reflectance and contrast are important factors in determining the

readability of a display. In fact, the contrast of E Ink is nearly twice that of printed newspaper.

As can be seen from its high reflectance and contrast the E Ink display is much more readable

than LCD.

The bright paper-white background of electronic ink eliminates the need for a backlight is most

conditions.

3.2 Ultra-Low Power Consumption

Electronic ink displays offer greatly reduced power consumption. Lower power

consumption translates to longer battery life, and perhaps more importantly, the ability to use

smaller batteries in electronic ink devices- reducing device weight and cost. The reason for

the reduced power consumption offered by electronic ink displays is two-fold: (1) they are

completely reflective requiring no backlight and (2) they are inherently bi-stable for extended

periods of time. Once an image is written on an electronic ink display, it will be retained

without additional power input until the next image is written. Hence the power consumption

of an electronic ink display will ultimately depend upon the frequency at which the displayed

image is changed. However, in both cases, a reduction in power consumption by several

orders of magnitude can be achieved by using electronic ink with its bi-stable imaging.

3.3 Thin, Light Form Factor

An electronic ink display module is thinner, lighter weight, and more robust than conventional

LCD's. These benefits are especially important in smart handheld applications where portability

is paramount. First generation, electronic ink displays will be but by laminating electronic ink

to a conventional glass TFT substrate In addition, no polarizes are required for electronic ink

displays. The resulting electronic ink display cell is also about half that of a typical LCD cell.


Ashish Kumar Sahoo

Elimination of the glass top sheet means that displays made with an electronic ink display

module should be inherently more robust.

3.4 The Ultimate Mobile Display Solution

Paper-like viewing characteristics and appearance, combined with ultra-low power

consumption and thin light form factors, make E ink's electronic ink display material the ideal

technology solution for information intensive, handheld devices such as PDAs, mobile

phones and electronic readers; or any applications requiring a high degree of display

legibility.

3.5 Twistable

Electronic Paper is made using soft plastic containing small particles and fluid. As there is no

hard material, Electronic Paper is highly flexible and it is able to be twisted or bended into

different curvatures. The Electronic Paper can be applied to different shapes of products,

without being limited to being bonded to flat display panels. The end product becomes more

imaginative in shape and style.

3.6 Simple Manufacturing Process

The manufacturing process is carried out using a roll-to-roll method, similar to

printing paper, by injecting dielectric fluid and charged particles into the layer of capsules,

and then sealing the top layer. The production is performed continuously at high speed. The

Electronic Paper can be produced in a large form and then cut into any desired size and shape

for different application requirements.


Ashish Kumar Sahoo


Ashish Kumar Sahoo

4. HIGHLIGHTS OF ELECTRONIC INK

Electronic ink moves information display to a new dynamic level, with dramatic

benefits over traditional media.

Superior Look - Because it's made from the same basic materials as regular ink and

paper, electronic ink retains the superior viewing characteristics of paper, including

high contrast, wide viewing angle, and bright paper-white background.

Versatile - Electronic ink can be printed on almost any surface, from plastic to metal to

paper. And it can be coated over large areas cheaply.

Low Power - Electronic ink is a real power miser. It displays an image even when the

power is turned off and it's even legible in low light reducing the need for a backlight.

This can significantly extend battery life for portable devices.

Scalable - E Ink's electronic ink process is highly scalable, which makes it competitive

against today's older technologies.


Ashish Kumar Sahoo

5. DISADVANTAGES

Electronic paper technologies have a very low refresh rate comparing with other lowpower

display technologies, such as LCD. This prevents producers from implementing sophisticated

interactive applications (using fast moving menus, mouse pointers or scrolling) like those which

are possible on handheld computers. An example of this limitation is that a document cannot

be smoothly zoomed without either extreme blurring during the transition or a very slow zoom.

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.


Ashish Kumar Sahoo

6. APPLICATIONS

Electronic Paper behaves similarly to conventional paper, allowing high readability under low

or high light conditions, and being thin and lightweight and fully pliable. In addition, Electronic

Paper has the advantage of allowing the content to be changed easily at any time via the

Electronic Paper driver IC. Electronic Paper will provide a viable substitute to paper in certain

areas. Some examples of Electronic Paper applications are described below.

6.1 Electronic Shelf Label

In a large department store or supermarket, there are many price tag labels on the shelves

indicating product price. Whenever there is a change of price information, it is very tedious to

change the price tags individually. By replacing the paper price tag with Electronic Paper, the

price information can be easily updated once the Electronic Paper price tags are connected via

a wireless network.

Fig-6.1: Electronic Paper used in Price Tag Application

The Electronic Paper price tag requires no battery power to maintain display and prices can be

updated using the energy from the RF wave to change the image content.


Ashish Kumar Sahoo

6.2 Electronic Watch and Clock

Watch and clock designs can become more imaginative using Electronic Paper.

Fig-6.2: Electronic Paper Watch and Bendable Module

For example, a watch using Electronic Paper will allow time and image to be displayed on the

wrist strap of the watch.

6.3 e-Books

In 2004 Sony released Libri EBR-1000EP in Japan, the first e-book reader with an

electronic paper display. In November 2006, the iRex iLiad was ready for the consumer

market. In November 2009 Barnes and Noble launched the Barnes & Noble Nook, based on

the Android operating system.

In late 2007, Amazon began producing and marketing the Amazon Kindle, an e-book

reader with an e-paper display.


Ashish Kumar Sahoo

Fig-6.3: Sony e-Book reader

6.4 Smart Card Display

Today, many credit cards contain a smart card to store information such as accumulated credit

and money expenses etc. Since Electronic Paper has the advantage of lower power consumption

and is as flexible as the card, it offers a good solution to displaying this type of information on

the card.

6.5 Newspapers

In February 2006, the Flemish daily De Tijd distributed an electronic version of the paper to

select subscribers in a limited marketing study, using a pre-release version of the iRex iLiad.

This was the first recorded application of electronic ink to newspaper publishing.

In September 2007, the French daily Les chos announced the official launch of an electronic

version of the paper on a subscription basis.

Since January 2008, the Dutch daily NRC Handelsblad is distributed for the iRex iLiad reader.


Ashish Kumar Sahoo

Fig-6.4: Electronic newspaper

6.6 Other Products

E- Ink unveiled its first product using electronic ink-immediate large-area displays- in 1999.

These large signs draw only 0.1 watts of power, which means that the same power required

running a single 100-watt light bulb, could power 1,000 immediate signs. E Ink said that in

electronic devices, electronic ink would use 50 to 100 times power than liquid crystal displays

because electronic ink only needs power when changing its display. Electronic ink can be

printed on any surface, including walls, billboards, product labels and T-shirts. Homeowners

could soon be able to instantly change their digital wallpaper by sending a signal to the

electronic ink painted on their walls.


Ashish Kumar Sahoo

7. THE FUTURE SCENARIO

The Holy Grail of electronic ink technology is a digital book that can typeset itself and

that readers could leaf through just as if it were made of regular paper. Such a book could be

programmed to display the text from a literary work and once you've finished that tale, you

could automatically replace it by wirelessly downloading the latest book from a computer

database. Xerox had introduced plants to insert a memory device into the spine of the book,

which would allow users to alternate between up to 10 books stored on the device. Just as

electronic ink could radically change the way we read books, it could change the way you

receive your daily newspaper. It could very well bring an end to newspaper delivery, as we

know it. Instead of delivery people tossing the paper from their bike or out their car window, a

new high-tech breed of paper deliverers who simply press a button on their computer that would

simultaneously update thousands of electronic newspapers each morning. Sure, it would look

and feel like your old paper, but you wouldn't have to worry about the newsprint getting

smudged on your fingers, and it would also eliminate the piles of old newspapers that need

recycling. Prior to developing digital books and newspapers E-Ink will be developing a

marketable electronic display screen for cell phones, PDA's, pagers and digital watches.


Ashish Kumar Sahoo

8. CONCLUSION

Electronic ink is not intended to diminish or do away with traditional displays. Instead

electronic ink will initially co-exist with traditional paper and other display technologies. In the

long run, electronic ink may have a multibillion-dollar impact on the publishing industry.

Ultimately electronic ink will permit almost any surface to become a display, bringing

information out of the confines of traditional devices and into the world around us.

.


Ashish Kumar Sahoo

BIBLIOGRAPHY

[1] Crowley, J. M.; Sheridon, N. K.; Romano, L. "Dipole moments of gyricon balls" Journal of

Electrostatics 2002, 55, (3-4), 247.

[2] Comiskey, B.; Albert, J. D.; Yoshizawa, H.; Jacobson, J. "An electrophoretic ink for

allprinted reflective electronic displays" Nature 1998, 394, (6690), 253-255.

[3] http://en.wikipedia.org/wiki/Electronic_paper.

[4] Blankenbach K, Schmoll A, Bitman A, Bartels F and Jerosch D 2008 Novel highly

reflective and bistable electrowetting displays SID J. 16 23744.

[5] Andersson, P.; Nilsson, D.; Svensson, P. O.; Chen, M.; Malmstrm, A.; Remonen, T.;

Kugler, T.; Berggren, M. "Active Matrix Displays Based on All-Organic Electrochemical

Smart Pixels Printed on Paper" Adv Mater 2002, 14, (20), 1460-1464.

[6] Huitema, H. E. A.; Gelinck, G. H.; van der Putten, J. B. P. H.; Kuijk, K. E.; Hart, C. M.;

Cantatore, E.; Herwig, P. T.; van Breemen, A. J. J. M.; de Leeuw, D. M. "Plastic transistors

in active-matrix displays" Nature 2001, 414, (6864), 599.

e-paper

Documents

electronic paper

smart paper

ordinary paper

radio paper

configurable paper

loads of paper

traditional paper

epaper technology