ICIECA 2014 Paper

1. Nandha Engineering college
-by
Kiruthika.J
Sivasakthi.K
3rd year ECE-B
Mail id: kiruthika.lingam95@gmail.com
sivasakthijana@gmail.com

2. Introduction:
 Day by day the advancement in mobile
is increasing.
 In the evolution of mobile technology,
along with power consumption, displays
and size of the phones are also focused.
 In the generation of mobiles now OLEDs
are being used for screen displays.

3. Different types of TouchScreen:
TFT LCD
 Better image quality
and high resolution.
 Narrow viewing
angle so poor
visibility in sunlight.
 Consume more
power.
 But manufacturing
process is cheaper.
IPS/RETINA-LCD
 Superior to TFT due
to wider viewing
angle.
 Low power
consumption and
higher resolution.
 Cost is high. Used in
iPhone 4.

4. Resistive LCD
 Small gap between
two conductors.
 When touched they
meet at the point of
their touch.
 Information is sent to
chip thereby triggering
an action at that point
of touch.
 Often require stylus to
identify touch.
Capacitive LCD
 Layer of glass coated
with transparent
conductor.
 When touched an
interruption in the
electrostatic field is
created.
 This is detected by
chip and an action is
triggered.

5. What is an OLED?
 OLED is a flat light emitting technology,
made by placing organic thin films
between two conductors.
 OLEDs can have either two layers or
three layers of organic material.
 Like an LED, an OLED is a solid-state
semiconductor device that is 100 to 500
nanometers thick or about 200 times
smaller than a human hair.

6. How do OLEDs
Emit Light?
 The battery or
power supply
voltage is applied
across the OLED.

7.  An electrical current flows from the cathode
to the anode through the organic layers
 The cathode gives electrons to the emissive
layer of organic molecules. The anode
removes electrons from the conductive layer
of organic molecules
 At the boundary when an electron finds an
electron hole, the electron fills the hole and
the energy in the form of a photon of light is
given up

8. Passive-matrix OLED
(PMOLED)
 PMOLEDs have strips of cathode, organic
layers and strips of anode.
 The intersections of the cathode and anode
make up the pixels where light is emitted.
 External circuitry applies current to
selected strips of anode and cathode,
determining which pixels get turned on and
which pixels remain off.
 The brightness of each pixel is
proportional to the amount of applied
current.

9. Active-matrix OLED
(AMOLED)
 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.
 AMOLEDs consume less
power than PMOLEDs
because the TFT array
requires less power than
external circuitry, so they
are efficient for large
displays.

10. Transparent OLED
 Transparent OLEDs have
only transparent
components (substrate,
cathode and anode)
 when turned off, are up to
85 percent as transparent
as their substrate.
 A transparent OLED display
can be either active- or
passive-matrix.

11. Foldable OLED:
 Foldable OLEDs have substrates made
of very flexible metallic foils.
 Foldable OLEDs are very lightweight
and durable.
 Potentially, foldable OLED displays can
be attached to fabrics to create "smart"
clothing, such as outdoor survival
clothing with an integrated computer
chip, cell phone, GPS receiver and
OLED display sewn into it.

12. OLED Advantages:
 Light-emitting layers of an OLED are
lighter, the substrate of an OLED can be
flexible instead of rigid.
 OLEDs are brighter than LEDs.
 OLEDs do not require backlighting.
 OLEDs are easier to produce and can
be made to larger sizes.

13. Disadvantages:
 Lifetime - While red and green OLED
films have longer lifetimes (46,000 to
230,000 hours), blue organics currently
have much shorter lifetimes
 Manufacturing - Manufacturing
processes are expensive right now.
 Water - Water can easily damage
OLEDs.

14. AMOLED Display Mobiles

15. Prototype of Flexible Displays
for mobiles

16. Usage of transparent Display
OLED in Future