FLEXIBLEELECTRONIC DISPLAY

Presented By:

Vinesh C.H

1AY11EC122

BEEC,AIT

Guided By:

Prof Sujatha B.M

Associate Professor

Dept. of E&C,AIT

Department of Electronics & Communication,Acharya Institute Of Technology

1

WHAT’S IN IT FOR YOU TODAY ???2

OBVIOUSLY!!!

NOTHING BUT ,ALL ABOUT

FLEXIBLE e-DISPLAY

3

WHY? WHY? WHY? 4

DO YOU EVER WISH TO SEE YOUR CELL PHONE IN THIS STATE ???

5

PRESENTATION ROAD MAP

6

PRESENTATION ROAD MAP

7

HISTORY

8

HISTORY

• Nicholas K. Sheridon invented Gyricon at

Xerox Palo Alto Research Center

(Xerox PARC), In the 1970’s

• Eventually became the basis of the

e-paper.

• Cost-inefficient.

• Gyricon and E-paper never had much

success, but was on the right track.

9

PRESENTATION ROAD MAP

10

PRE-REQUISITES

11

PRE-REQUISITES

1.Flexible Substrates

2.Encapsulation

3.Organic and Inorganic Conducting Layers

4.Electro-optic Materials

5.Thin Film Transistors

12

1.Flexible Substrates

• The primary flexible substratecandidates are plastics and thin glass.

• Plastic substrates are inexpensive, roll-to roll processable and can belaminated to multi-layers.

• Thin glass substrates exhibit betterthermal stability and have higher visualtransparency than plastics, but cannotfully bend.

13

2.Encapsulation

• Since flexible displays utilize organic materials, a barrier

layer is essential in protecting and enclosing the

functional materials and layers from oxygen and degraded

water.

• Since organic materials tend to oxidize and hydrolyze,

oxygen and water permeation through a flexible substrate

is of particular importance flexible electronics.

14

3.Organic and Inorganic Conducting Layers

• Indium tin oxide (ITO) is the typical conducting layer used in

display technology because of its excellent optical clarity.

• When ITO is deposited on a polymeric substrate, it can crack

under tensile strain and cause catastrophic failure.

• Conducting polymers are also being considered for flexible display

applications.

• There is a new conducting substrate technology based on

nanotechnology. 15

4.Electro-optic Materials

• The various types of electro-optic materials for flexible display fall

into three categories – emissive, reflective, and transmissive.

• In order to have a truly low power display, a reflection mode of

operation will have to be implemented on flexible substrates.

• Polymer-dispersed liquid crystals, encapsulated electrophoretics,

gyricon, and bi chromic ball composites all operate in the

reflective mode.

16

5.Thin Film Transistors

• A thin-film transistor (TFT) is a special

kind of field-effect transistor.

• Made by depositing thin films of an

active semiconductor layer as well as

the dielectric layer and metallic contacts

over a supporting substrate.

• A common substrate is flexible glass.

• This differs from the

conventional transistor, where the

semiconductor material typically is the

substrate, such as a silicon wafer.17

PRESENTATION ROAD MAP

18

TYPES OF FLEX-DISPLAY

19

TYPES OF FLEX-DISPLAY

1.F-OLED DISPLAY

2.GYRICON DISPLAY

3.FLEXIBLE LCD DISPLAY

4.ELECTROPHORETIC DISPLAY

5.E PAPER

20

1. F-OLED DISPLAY

• Organic light emitting diodes

(OLED) display is another

promising technology for flexible

flat panel displays.

• Works on the principle of

ELECTROPHOSPHORESCENCE

• Flexible OLEDs are very

lightweight and durable. Their use

in devices such as cell phones and

PDAs can reduce breakage.21

F-OLED DISPLAY STRUCTURE

22

F-OLED DISPLAY

HOW IT EMITS LIGHT ??

1. Electrical current flows from the cathode to

the anode through the organic layers,giving

electrons to the emissive layer and

removing electrons from the conductive

layer.

2. Removing electrons from the conductive

layer leaves holes that need to be filled

with the electrons in the emissive layer.

3. The holes jump to the emissive layer and

recombine with the electrons. As the

electrons drop into the holes, they release

their extra energy as light.23

F-OLED DISPLAY TYPES

• PM-FOLEDs have strips of

cathode, organic layers and strips

of anode. The anode strips are

arranged perpendicular to the

cathode strips

• The intersections of the cathode

and anode make up the pixels

where light is emitted.

• The brightness of each pixel is

proportional to the amount of

applied current.

PASSIVE MATRIX OLED

24

F-OLED DISPLAY TYPES

• AM-FOLEDs have full layers of

cathode, organic molecules and

anode, but the anode layer

overlays a thin film transistor

(TFT) array that forms a matrix.

• The TFT array itself is the

circuitry that determines which

pixels get turned on to form an

image.

• AM-FOLEDs consume less power

than PMOLEDs because the TFT

array requires less power than

external circuitry, so they are

efficient for large displays.

ACTIVE MATRIX OLED

25

2. GYRICON DISPLAY

STRUCTURE

• Gyricon are spherical beads with

one black and one white

hemisphere.

• The spheres are only 100um in

diameter and make a display that is

only 200um thick.

• In the display, the beads are

dispersed in a transparent rubber

sheet and suspended in oil, allowing

it to rotate in response to an electric

field.

• The electric field is applied by the

transparent electrode

26

GYRICON DISPLAY WORKING• When voltage is applied to the surface of the sheet, the

beads rotate to present one colored side to the viewer.

• Voltages can be applied to the surface to create images

such as text and pictures.

• The image will persist until new voltage patterns are

applied.

27

PRESENTATION ROAD MAP

28

COMPARISION

29

COMPARISION

Comparison of Flexible Screens (F-OLED's) vs. LCD Screens (LED)

Cost Durability Weight Speed Applications

Flex Screens

(F-OLED)

High: Cannot

mass produce.

Low cost

technology isn't

available yet.

Durable: Mostly

made of flexible

plastic. Hence it

doesn’t shatter.

Lighter: Potential

to be just a thin

sheet of plastic.

Faster: More

responsive to

touch.

Unlimited: Can be

applied to curved

or round services.

LCD Screens

(LED)

Low: Ability to

mass produce.

Fragile: Screen is

made of glass and

will shatter

Heavier: Requires

glass and more

support layers.

Slower: Older

technology

Limited: Requires

a flat, straight

surface.30

PRESENTATION ROAD MAP

31

VIDEO

32

33

REFERENCES

• Cashmore, Peter. "Why Your next Phone Might Be Bendable." CNN. Turner BroacastingSystem, Inc., n.d. Web. 15 Apr. 2013. <http://www.cnn.com/2011/10/31/tech/innovation/flexible-screens-cashmore/index.html?iref=allsearch>.

• Genuth, Iddo. "The Future of Electronic Paper." The Future of Electronic Paper. The Future of Things, 2013. Web. 15 Apr. 2013. <http://thefutureofthings.com/articles/1000/the-future-of-electronic-paper.html>.

• Grose, Thomas K. "OLEDs: The Light Idea." Time. Time, 2013. Web. 15 Apr. 2013. <http://www.time.com/time/magazine/article/0,9171,2005725,00.html>.

• Nikamahjan. "OLED Advantages and Disadvantages." OLED Advantages and Disadvantages. Expertscolumn, 2013. Web. 15 Apr. 2013. <http://expertscolumn.com/content/oled-advantages-and-disadvantages>.

• OLED-Info. "Flexible OLED Displays." Flexible OLED Displays. Metalgrass Software, 2013. Web. 15 Apr. 2013. <http://www.oled-info.com/flexible-oled>.

34