E-paper

Submitted by:Nagendra Kumar Beniwal10404EN054

Critic:Shardul Goel10404EN003

Introduction

E-paper also known as Electronic Paper or Electronic ink Display.

Electronic paper was first developed in the 1970s by Nick Sheridon at Xerox’s Palo Alto Research center.

Unlike conventional backlit flat panel displays which emit light, E-paper displays reflect light like ordinary paper, theoretically making it more comfortable to read, and giving the surface a wider viewing angle compared to conventional displays. 

extremely light and flexible.

Construction of E-paper

• It has two different parts.• Front plane.• Back plane.

• The front plane consist of E-ink.

• The back plane consist of electronic circuits.

• Back plane is made up of organic thin film transistor arrays which provide voltage needed by the E-Paper.

• To form an E-ink electronic display the ink is printed onto a plastic film that is laminated to a layer of circuitry.

• The front plane consist of E-ink.

• E-ink is made up of millions of tiny microcapsules.

• Microcapsules have diameter of the order of 100 microns.

• Each microcapsule contains positively charged white particles and negatively charged black particles suspended in a clear fluid .

• When a positive or negative electric field is applied, corresponding particles move to the top of the microcapsule where they become visible to the viewer. This makes the surface appear white or black at that spot.

Front plane

E-ink 2-pigment system

Technologies proposed so far:

GyriconElectrophoretic displayElectrowetting

Glyricon

• It was the first electronic paper and was developed in 1970’s.• Consists of polyethylene spheres having diameter between 75-106

micrometers.• 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).

• These spheres are embedded in transparent silicone made 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.

Electrophoretic display

• Each E-ink capsule contains an oily solution containing black dye (the electronic ink), with numerous white titanium dioxide particles suspended within these capsules are dispersed in a hydrocarbon oil in which dark-colored dye and charging agents are also added.

• Capsule diameter is 40 micrometer.

• Gap between the two conducting plates is of the order of 100 micrometers and the mixture is placed between these plates.

• 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 refractive -index titania 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.

Electrowetting

Based on the phenomenon of Electrowetting effect.

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.

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, if a reflective white surface is used under the switchable element, a white pixel.

L-liquidI-insulatorS-substrate

Comparison of e-paper & lcd

Electronic Ink Display Liquid Crystal Display

Wide viewing angle Best image only from one position

Readable in sunlight Can be difficult to see in sunlight

Holds image without power drain Required power to hold images

Plastic or glass Glass only

Light Weight Power supply and glass make LCDs relatively heavy

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

Power consumption

This analysis done for E ink triton.

Mechanical / Dimensional for 6" Display:

Electrical specifications:

Supply Voltage: 2.7—3.3 V DC

Power Consumption:Active update peak: 1800 mWActive update typical: 750 mWStandby typical: 1 mW

Merits of E-paper Paper-like Readability They are persistent without power, drawing current only when

they change, which means low power consumption therefore batteries can be smaller and last longer.

• An electronic ink display module is thinner, lighter weight, and more robust than conventional LCD's.

• 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.

• They are completely reflective requiring no backlight.

• They are inherently bi-stable for extended periods of time.

• 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.

Demerits of E-paper

Electronic paper technologies have a very low refresh rate compared to other low-power display technologies, such as LCD.

An example of this limit is that a document cannot be smoothly zoomed without either extreme blurring during the transition or a very slow zoom. A shadow of an image may be visible after refreshing parts of the

screen. Such shadows are termed "ghost images", and the effect is termed "ghosting“.

Because of ghosting the entire screen white and black when loading a new image.

Applications

• Wristwatches

• e-Book reader

eg: Amazon kindle.

• Electronic Shelf Label

In a large department store or supermarket, e-paper can be used for labelling the shelves and price tagging.

Smart Card DisplaySome credit cards contain a smart card to store information such as accumulated credit and money expenses etc.

Mobile phones E-Newspaper Time Table at Stations

• Electronic Billboards

• Status displays

• Digital Photo Frames

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.

References

Flexible and Roll-able Displays/Electronic Paper A Brief Technology Overview Rong-Chang (R.C.) Liang

Paper Electronics and Electronic Paperby Magnus Berggren*'**, Thomas Kugler*'**, Tommi Remonen*, David

Nilsson**,Miaoxiang Chen**, Petronella Norberg"*The Research Institute ACRE0 AB, Bredgatan 34, SE-602 21 Norrkoping, Sweden **Organic Electronics Group, Campus Norrkoping, SE-601 74, Sweden

E-paper: Clarifying future R&D needs by a fundamental understanding of the maximum performance of current technologies

Author(s): Heikenfeld, J. Novel Devices Lab., Univ. of Cincinnati, Cincinnati, OH, USA 

http://en.wikipedia.org/wiki/Electronic_paper http://spectrum.ieee.org/consumer-electronics/portable-devices/ligh

ter-brighter-displays Image taken from: http://www.eink.com/technology.html

http://www.amazon.in/gp/product/B007RF5F0Q/ref=famstripe_kp3

Thank You