All about SED.

1. Surface Conduction Electron
Emitter Display (SED)

2. INTRODUCTION
The SED technology has been developing since
1987. The flat panel display technology that
employs surface conduction electron emitters for
every individual display pixel can be referred to as
The Surface-conduction Electron-emitter Display
(SED). Though the technology differs, the basic
theory that the emitted electrons can excite a
phosphor coating on the display panel seems to be
the bottom line for both the SED display
technology and the traditional cathode ray tube
(CRT) Televisions.

3. Current display technologies
CRT


Highest image quality.
Costlier than most others.
LCD
Motion blur.
 Low power consumption.
PLASMA
 Grey levels are high.
 High power consumption.


4. Manufacture of SED TV
SED is a display device includes an electronemitting device which is a laminate of an
insulating layer and a pair of opposing
electrodes formed on a planar substrate.
 First the anode and cathode plates are
fabricated separately.
 Assembled with the other components.
 Sealed using glass frit or other novel
materials and then evacuated.

5. Block diagram

7. WORKING
CREATING THE PICTURE


Electrons are emitted from the electron
emission region by applying a voltage to the
electrodes, thereby stimulating a phosphorous to
emit light .
It's a flat-panel television that uses millions of
miniature CRTs are called Surface Conducting
Electron emitters (SCEs). A set has three SCEs for
every pixel -- one each for Red, Green and Blue.

8. A widescreen, high-definition set can have more
than 6 million SCEs.


An SED-TV has millions of these SCEs arranged
in a matrix, and each one controls the Red,
Green or Blue aspect of one pixel of the picture.
The inside of an SED-TV is a vacuum. All of the
SCEs are on one side of the vacuum, and the
phosphor- coated screen is on the other. The
screen has a positive electrical charge, so it
attracts the electrons from the SCEs.

9. 
When bombarded by moderate voltages (tens of
volts), the electrons tunnel across a thin slit in
the surface conduction electron emitter
apparatus.

Some of these electrons are then scattered at the
receiving pole and are accelerated towards the
display surface. These emitted electrons can then
excite the phosphor coating on the display panel.

When they reach the screen, the electrons pass
through a very thin layer of aluminum. They hit
the phosphors, which then emit red, green or
blue light.

10. 
Our eyes and brain combine these glowing dots
to create a picture. Any part of the screen that's
not used to create pixels is black, which gives the
picture better contrast.

There's also a color filter between the phosphors
and the glass to improve color accuracy and cut
down on reflected light.

11. To tie it all together, when the SED-TV
receives a signal, it:



Decodes the signal
Decides what to do with the red, green and blue
aspect of each pixel
Activates the necessary SCEs, which generate
electrons that fly through the vacuum to the
screen.
The set can create a picture sixty times per second.
It creates the entire picture every time unlike CRT.

14. FABRICATION OF NANO GAPS
Nanogaps are the electron guns of SED.A
nanometer scale gap (nanogap) structure in
palladium strip fabricated by hydrogen
absorption under high-pressure treatment.
It is found that the edge roughness of the nanogap
improves the electron emission characteristics.
The electron emission current is dependent upon
the angle of inclination of surface.

15. Hydrogen plasma treatment is used to increase
the edge roughness of the nanogap and thereby
dramatically improve the electron emission
characteristics. For the nanogap with a separation
of 90 nm, the turn-on voltage significantly reduces
from 60 to 20 V after the hydrogen plasma
treatment.

17. Electrons are supplied to the anode
in 2 steps

Step 1: The electron source operates by first
emitting electrons laterally across a very
narrow gap formed between two electrodes.
The electrons tunnel through the vaccum gap
from one electrode to the other electrode.

19. 
Step 2: The electrons that tunnel across the
gap and strike the counter-electrode are either
absorbed into the counter electrode or they are
scattered, captured by the electric field created
by the anode potential and accelerated to a
particular phosphor dot, thus creating a spot of
red, green or blue light. Multiple scattering
events may take place before the electron is
captured by the anode field.

21. SED TV Compared to CRT
CRT


They are as deep as they
are wide and they are
heavy too.
Have image challenges
around the far edges of
the picture tube.
SED
 They’re slim and light
weight.

CRTs can be made as
large as the
manufacturer dares.

22. SED TV Compared to Plasma TV
Plasma TV



SED
Grey levels in plasma TVs
are high. The black is
actually dark grey.
Consumes more power.

Perfect black.

Suffers from black level
issues and solarization.

SEDs consumes half the
power that the plasma does
at the given screen size.
SEDs don’t have such
issues.

23. SED TV Compared to LCD
LCD




LCD suffers from motion
blur.
It has limited angle of view
and tends to become too dim
to view off axis.
Outdoor scenes in bright
light block up blacks and
bleach out whites.
Suffers from black level
issues and solarization.
SED




There is no motion blur in
SED.
This will not be an issue for
SED’s self illuminated
phosphors.
SED shows the peak
brightness.
SEDs don’t have such
issues.

26. ADVANTAGES








Slim
Superior contrast ratios
Exceptional response time
Better picture quality
More brightness
Color performance
Viewing angles
Consumes very less power.

27. FEATURES








Contrast ratio 100,000:1.
Response time 0.2 milliseconds.
Brightness of 450 cd/m2.
180º Viewing angle.
Viewable in Bright room.
It can be used in Mobile device display.
Low power consumption.
Longer life expectancy.

28. CONCLUSION
SED will be the next generation display technology
in the near by future though patent controversy
and the lack of cheaper manufacturing techniques
are slowing down the commercial viability of
SED TV.

29. REFERENCE

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www.canon.com
www.thoshiba.com
www.electronics.howstuffworks.com
www.howstuffworks.com
www.wikipedia.com
www.patentstorm.us
www.freepatentsonline.com
www.googlepatents.com

30. THANK YOU…