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 have diameter of the order of
• 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.
E-ink 2-pigment system
Technologies proposed so far:
• It was the first electronic paper and was developed in 1970’s.
• Consists of polyethylene spheres having diameter between 75-106
• 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.
• 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
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.
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
Thin (~1 mm) Thick (~7 mm)
This analysis done for E ink triton.
Mechanical / Dimensional for 6" Display:
Supply Voltage: 2.7—3.3 V DC
Active update peak: 1800 mW
Active update typical: 750 mW
Standby typical: 1 mW
Merits of E-paper
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
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
Because of ghosting the entire screen white and black when
loading a new image.
• 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
Smart Card Display
Some credit cards contain a smart card to
store information such as accumulated
credit and money expenses etc.
Time Table at Stations
• Electronic Billboards
• Status displays
• Digital Photo Frames
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.
Flexible and Roll-able Displays/Electronic Paper A Brief
Technology Overview Rong-Chang (R.C.) Liang
Paper Electronics and Electronic Paper
by 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
Image taken from: http://www.eink.com/technology.html