Underwater Welding - University of Waterloo
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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
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?