Future Trends of Televisions

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Future Trends of Televisions

• By Rion Núñez
• Team 11

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Types of Televisions

• CRT (cathode ray tube)
• Plasma
• LCD (liquid crystal display)
• DLP (digital light processing)
• OLED (organic light emitting diode)
• SED (surface-conduction electron-emitter display)

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CRT (cathode ray tube)

• Invented in 1897 by Karl Ferdinand Braun
• Standard for televisions until recent years

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How CRT works

• Acathode
• Bconductive coating
• Canode
• Dphosphor-coated screen
• Eelectron beams
• Fshadow mask
• Uses R,G,and B phosphors
• The three beams are accelerated and focused by
  the anode

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CRT Advantages

• High color fidelity and contrast
• Better resolution with moving images

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CRT Disadvantages

• susceptible to phosphor burn-in
• Bulky and heavy sets
• Consume a lot of energy
• Old technology

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Plasma Displays

• invented at the University of Illinois at
  Urbana-Champaign in 1964 for the PLATO Computer
  System
• 1983 IBM introduced 19 orange on black
  monochrome
• Gas made up of free flowing ions and electrons

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How Plasmas work

• 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

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Plasma Advantages

• Brighter than CRTs
• Flat panel
• Lowering in cost

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Plasma Disadvantages

• Susceptible to phosphor burn-in
• Not well used in bright rooms

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LCD (liquid crystal display)

• Liquid crystals were first discovered in 1888, by
  Austrian botanist Friedrich Reinitzer
• First experimental LCD by RCA in 1968
• Based on properties of polarized light

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How LCD works

• 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

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LCD Advantages

• More efficient use of electricity than CRT
• Produce little glare compared to plasmas
• Largest screen sizes than other flat panels

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LCD Disadvantages

• Manufacturers often reject about 40 of the
  panels that come off the assembly line
• Color contrast is not the best

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DLP (digital light processing)

• Developed by Texas instruments
• Created by Dr. Larry Hornbeck in 1987

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How DLP works

• 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

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DLP Advantages

• Insusceptible to phosphor burn-in
• More affordable than plasmas and LCDs

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DLP Disadvantages

• Not as thin as other high definition displays

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OLED (organic light emitting diode)

• Developed by Eastman-Kodak
• Competing against LCD and plasma television
  displays

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How OLED works

• 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

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OLED Advantages

• Thinner, lighter, more flexible
• Can be plastic instead of glass
• Does not require backlighting
• Brighter than traditional LEDs
• Consume less power than LEDs
• Large field of view around 170 degrees

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OLED Disadvantages

• Easily damaged by water
• High manufacturing costs
• Blue OLED films have shorter lifespan than Red
  and Green

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SED (surface-conduction electron-emitter display)

• 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

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How SED works

• 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

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SED Advantages

• Lower power consumption
• Fast video response
• High contrast of color
• 3cm thick
• Better picture than LCD and Plasma

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SED Disadvantages

• Cost
• Availability

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Extra

• http//www.youtube.com/watch?vhxv7mmKHRhs

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Sources

• http//electronics.howstuffworks.com/lcd.htm
• http//electronics.howstuffworks.com/oled1.htm
• http//electronics.howstuffworks.com/plasma-displa
  y.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.htm
  l?tagtxt
• http//reviews.cnet.com/8301-12760_7-9674057-5.htm
  l?tagtxt