Future Trends of
Televisions
By: Rion Núñez
Team 11
Types of Televisions
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CRT (cathode ray tube)
Plasma
LCD (liquid crystal display)
DLP (digital light processing)
OLED (organic light emitting diode)
SED (surface-conduction electron-emitter
display)
CRT (cathode ray tube)
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Invented in 1897 by Karl
Ferdinand Braun
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Standard for televisions
until recent years
How CRT works
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A=cathode
B=conductive coating
C=anode
D=phosphor-coated screen
E=electron beams
F=shadow mask
Uses R,G,and B phosphors
The three beams are
accelerated and focused by the
anode
CRT Advantages
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High color fidelity and contrast
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Better resolution with moving images
CRT Disadvantages
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susceptible to phosphor burn-in
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Bulky and heavy sets
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Consume a lot of energy
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Old technology
Plasma Displays
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invented at the University
of Illinois at UrbanaChampaign in 1964 for the
PLATO Computer System
1983 IBM introduced 19”
orange on black
monochrome
Gas made up of free
flowing ions and electrons
How Plasmas work
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Made up of tiny fluorescent lights
Each pixel contains a red, green,
and blue light
xenon and neon gas is contained in
hundreds of thousands of cells
positioned between two plates of
glass along with electrodes
When charged, it releases
ultraviolet photons which act with
the phosphors
This brings their energy level up,
when it goes back down it is
released as visible light photons
Plasma Advantages
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Brighter than CRTs
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Flat panel
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Lowering in cost
Plasma Disadvantages
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Susceptible to phosphor burn-in
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Not well used in bright rooms
LCD (liquid crystal display)
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Liquid crystals were first
discovered in 1888, by
Austrian botanist Friedrich
Reinitzer
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First experimental LCD by
RCA in 1968
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Based on properties of
polarized light
How LCD works
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Formed by two glass layers called
substrates
One is in charge of columns, and the
other is in charge of rows
Liquid crystals are sandwiched in
between these two layers
Uses a grid to charge specific pixels
When this happens the crystals
untwist and allow light to pass through
LCD Advantages
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More efficient use of electricity than CRT
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Produce little glare compared to plasmas
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Largest screen sizes than other flat panels
LCD Disadvantages
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Manufacturers often reject about 40 % of the
panels that come off the assembly line
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Color contrast is not the best
DLP (digital light processing)
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Developed by Texas
instruments
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Created by Dr. Larry
Hornbeck in 1987
How DLP works
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One DLP chip contains more than 2 million
mirrors
Each mirror made of aluminum represents
one pixel on the screen
The chip will rapidly decode a bit-streamed
image code that enters through the
semiconductor
It changes the data from interlaced to
progressive scanning and adjusts the
picture
The mirrors then tilt off and on to allow light
to pass and can do it up to 5,000 times per
second
The is then sent through a transparent,
spinning color wheel that is synchronized
with the chip into red, green, and blue, light,
and can produce 16.7 million colors
DLP Advantages
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Insusceptible to phosphor burn-in
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More affordable than plasmas and LCDs
DLP Disadvantages
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Not as thin as other high definition displays
OLED (organic light emitting
diode)
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Developed by EastmanKodak
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Competing against LCD
and plasma television
displays
How OLED works
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Has two to three layers of organic material
the emissive and conductive layer
These these are sandwiched in between
the cathode and anode
When an electrical current is sent through
the LED, it moves from the cathode to
anode (negative to positive)
The cathode gives electrons to the
emissive layer, and the anode takes away
electrons from the conductive layer
When they recombine, the extra energy is
given off as light which corresponds to the
type of organic molecule
The voltage also depends on how much
light is given off
OLED Advantages
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Thinner, lighter, more flexible
Can be plastic instead of glass
Does not require backlighting
Brighter than traditional LED’s
Consume less power than LED’s
Large field of view around 170 degrees
OLED Disadvantages
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Easily damaged by water
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High manufacturing costs
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Blue OLED films have shorter lifespan than
Red and Green
SED (surface-conduction
electron-emitter display)
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Formed in 2004 between
Toshiba and Canon
Created SED Co. LTD for
developing and producing
SED technology
Canon for electron source
technology
Toshiba for the display
How SED works
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Uses millions of cathode ray tubes
called SCEs (surface-conduction
electron emitters)
They have a layer of carbon with a gap
down the center
Half of the carbon layer is connected
to a negative electrode, the other to a
positive
Activates SCEs all at once instead of
CRT going one row at a time
Does not use interlacing
SED Advantages
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Lower power consumption
Fast video response
High contrast of color
3cm thick
Better picture than LCD and Plasma
SED Disadvantages
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Cost
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Availability
Extra
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http://www.youtube.com/watch?v=hxv7mmK
HRhs
Sources
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http://electronics.howstuffworks.com/lcd.htm
http://electronics.howstuffworks.com/oled1.htm
http://electronics.howstuffworks.com/plasma-display.htm
http://entertainment.howstuffworks.com/sed-tv.htm
http://www.howstuffworks.com/tv.htm
http://www.howstuffworks.com/tv3.htm
http://electronics.howstuffworks.com/dlp.htm
http://reviews.cnet.com/8301-12760_7-9673322-5.html?tag=txt
http://reviews.cnet.com/8301-12760_7-9674057-5.html?tag=txt