ece434 fed presentation - copy

7/29/2019 ECE434 FED Presentation - Copy

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The future of display technology?

Prepared By:Sajith . B

E6

CAS Mallappally


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Presentation Outline Introduction

History of display technology

FED technology

FED packaging

How FEDs work

Comparison

Advantages Disadvantages

Applications

Companies working on FED

Conclusion


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Introduction Displays are devices by which we can view moving

objects

Used in television and computers

They also have wide use in laboratories and in

medical applications.


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History of Display Technology

C R T

1950s

L C D

1960s

F E D

1980s

PLASMA

DISPLAY

1970s


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FED Technology The FED screen mainly contains three parts:

Low-voltage phosphorous plate

A field emission cathode using a thin carbon sheet asan edge emitter

FED packaging, including sealing and vacuum

processing


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Structure of FED


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Low voltage phosphor The low voltage phosphors are the screens in which

the images are displayed

In the display technology the phosphor screens actas anode, which receives the electrons emitted from

the cathode

The phosphors are made up of layers of three

primary colours -green, red and blue


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Field Emission Cathode In the field emission display screen the cathode are

electron guns which emit electrons

Electron guns are called micro tips

The emission of electrons is called cold cathode

emission


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Structure of micro tip


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Micro tip - Different types Wedge type emitter using silicon.

Silicon tips with continuous coating of diamond

particles.

Single-crystal diamond particle on silicon tips.

Planar diode emitter.

Metal-insulator-semiconductor type planar emitter


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Wedge type emitter using

silicon


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Silicon tips with continuous

coating of diamond particles


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Single crystal diamond

particle on silicon tips


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Planar diode emitter


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Metal insulator

semiconductor type planar

emitter


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FED packaging


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FED - Working

This emission of electron occurs from the coldcathode when a voltage is applied between the

cathode and anode

These electrons propagate from cathode to anode


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Working contd. They bombard with the phosphor, which is the anode and

causes it to glow

This reproduces the image on the screen by the mixing of

colours present in the screen


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Two ways of working Low voltage anode

High voltage anode


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Advantages Shortcomings

Good color representation

Large viewing angle

Fast response time (50 s)

Low price

Multiple resolutions

Large and bulky (2 kg/in)

Flicker causes eye strain

High power (11 W/in)

CRT

Comparison with other

displays


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Comparison contd

Advantages Shortcomings

Light weight (0.6 kg/in)

Low power (5 W/in)

Less eye strain

High brightness (500 Cd/m2)

Small viewing angle

Slow response time (8 ms)

Weaker contrast & color

LCD


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FED: The Best of Both WorldsPromised Advantages

Very light (100 g/in)

Large Viewing angle (178o)

Extremely fast (20 ns)

Low power (0.2 W/in)

High contrast (10x PDP)

No flicker

No dead pixels


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Challenges: Technical Problems Fluctuations in emission current

Low cost manufacturing methods

Developing for large areas Tip damage

High vacuum levels required

Vacuum tubes do require maintenance.


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FED Applications Sonograms

X-ray imaging

Heart-rate monitors

Laptop computers

Hang-on-the-wall televisions

Big screen and PC monitors High-definition TV


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Companies Researching FED Canon and Toshiba joint venture in SED

Sony promises Spindt-type FED display in 2009

Samsung is researching CNTs, Applied Nanotech Inc.have made a 25 display


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Conclusion CRT technology has already reached its

technological and marketing limits and will likely be

replaced in 10 years. The modern world needs substances that are small in

size.

This shows that the cathode ray tube do not have

much to do anything in the market in future. And itwould die already, ifField Emission Display (FED)

technology or any other displays would bring

anything to the market.


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References

BOOKS

ELECTRONICS FOR YOU, JUNE 2002 ELECTRONICS FOR YOU, JULY 2002

WEB

WWW.SHARPWORLD.COM

WWW.WTEC.ORG

WWW.VIRTUALVISION.COM


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THANKYOU

ece434 fed presentation - copy

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