Field Emission Displays

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Field Emission Displays

• The future of display technology?

Prepared By Ryan Michaud Adam Neale Andrei
Iakimtchik Date March 27th, 2007.
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Presentation Outline

• History of display technology
• Current display alternatives
• How FEDs work
• Companies working on FED
• Difficulties with FED
• Future of FED displays

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History of Display Technology

• Cathode Ray Tube
• 1950s

Liquid Crystal Displays 1970s
Field Emission Displays 1980s
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Cathode Ray Tubes (CRT)

• Geissler Tubes (1855)
• First CRT oscilloscope invented 40 years later
• Commercially practical CRT made by Allen DuMont
  (1931)

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Liquid Crystal Display

• Liquid Crystalline materials discovered (1880s)
• James Fergason produced first practical LCD
  display (1967)
• Epson introduced first color LCD TV 2 in
  diagonal (1985)

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Plasma Display Panel

• Plasma identified by William Crookes (1879s)
• Prototype for PDP introduced at University of
  Illinois (1964)
• Fujitsu introduced first 42 color PDP (1997)

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Technology Comparison
CRT

• Vacuum tube with phosphor-coated screen
• Cathode emits electrons to be accelerated by the
  anode
• Deflectors guide the electron beams
• Electrons excite phosphor molecules to produce
  light

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Technology Comparison contd
CRT

• Advantages

• Shortcomings

• Good color representation
• Large viewing angle
• Fast response time (50 µs)
• Low price
• Multiple resolutions

• Large and bulky (2 kg/in)
• Flicker causes eye strain
• High power (11 W/in)

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Technology Comparison contd
LCD

• A layer of liquid crystalline sandwiched between
  2 glass layers with polarizer
• Light generated behind the screen, passed
  through
• Applied voltage controls the crystalline
  orientation

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Technology Comparison contd
LCD

• 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

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Technology Comparison contd
PDP

• Two layers of glass with pixel array in between
• Each pixel contains a mix of neon and xenon gas
• Current is passed through a pixel to ionize gas,
  and emit UV radiation
• UV rays excites phosphor-coated layer of glass to
  generate light

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Technology Comparison contd
PDP

• Advantages

• Shortcomings

• High brightness (1000 Cd/m2)
• High contrast (100001)
• Large viewing angle

• More power vs LCD (8 W/in)
• Burn-in effect
• Size limitation (gt40)
• Slow response time

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FED The Best of Both Worlds

• Promised 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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How FED Works?

• Array of mini-CRTs

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Technology Options - SED

• Surface-conduction electron emitter display
• Joint venture between Toshiba and Canon

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Technlogy Options - Spindt

• Spindt emitters are tiny cones that create a very
  high charge density
• Alignment of the cone and gate is critical

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Technology Options - CNT

• Carbon nanotubes as electron source

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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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Challenges Technical Problems

• Fluctuations in emission current
• Low cost manufacturing methods
• Developing for large areas
• Tip damage
• High vacuum levels required

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Dropping LCD prices

• LCD panels are dropping in cost while increasing
  in quality

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Hope for FED Displays

• The success of FEDs depends on
• Cost
• Quality
• Timing

• Technologically advantageous product suffers
  from poor timing

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Questions?
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