Transcript Underwater Welding - University of Waterloo

The future of display technology?
Prepared By:
Ryan Michaud
Adam Neale
Andrei Iakimtchik
Date: March 27th, 2007.
Presentation Outline
 History of display technology
 Current display alternatives
 How FEDs work
 Companies working on FED
 Difficulties with FED
 Future of FED displays
History of Display Technology
Cathode Ray Tube
1950’s
Liquid Crystal Displays
1970’s
Field Emission Displays
1980’s
Cathode Ray Tubes (CRT)
 Geissler Tubes (1855)
 First CRT oscilloscope invented
40 years later
 Commercially practical CRT
made by Allen DuMont (1931)
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)
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)
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
Technology Comparison cont’d
CRT
Advantages
Shortcomings
 Good color representation
 Large and bulky (2 kg/in)
 Large viewing angle
 Flicker causes eye strain
 Fast response time (50 µs)
 High power (11 W/in)
 Low price
 Multiple resolutions
Technology Comparison cont’d
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
Technology Comparison cont’d
LCD
Advantages
Shortcomings
 Light weight (0.6 kg/in)
 Small viewing angle
 Low power (5 W/in)
 Slow response time (8 ms)
 Less eye strain
 Weaker contrast & color
 High brightness (500 Cd/m2)
Technology Comparison cont’d
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 phosphorcoated layer of glass to
generate light
Technology Comparison cont’d
PDP
Advantages
Shortcomings
 High brightness (1000 Cd/m2)
 More power vs LCD (8 W/in)
 High contrast (10000:1)
 Burn-in effect
 Large viewing angle
 Size limitation (>40”)
 Slow response time
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
How FED Works?
 Array of mini-CRTs
Technology Options - SED
 “Surface-conduction
electron emitter display”
 Joint venture between
Toshiba and Canon
Technlogy Options - Spindt
 Spindt emitters are tiny
cones that create a very high
charge density
 Alignment of the cone and
gate is critical
Technology Options - CNT
 Carbon nanotubes as
electron source
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
Challenges: Technical Problems
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Fluctuations in emission current
Low cost manufacturing methods
Developing for large areas
Tip damage
High vacuum levels required
Dropping LCD prices
 LCD panels are dropping in cost while increasing
in quality
Hope for FED Displays
 The success of FEDs depends on:
 Cost
 Quality
 Timing
Technologically advantageous product suffers
from poor timing
Questions?