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Project Goals
Gain a better understanding of the origins of Television– where we are now– what we see for future developments
Overview
Project Plan Nipkow’s Disk Cathode Ray Tube
(CRT) Color Television High Definition
Television (HDTV)
Projection Television The four new
television evolutions Price Ranges Enhanced Television Conclusion
Project Plan
Kin– Research on High Definition TV
– Research on new technologies
– Projection television
Mario– Research on mechanic and electronic television, including
color television
– Research on enhanced television and future developments
– Interactive TV
Cathode-Ray Tube
First introduced in 1897 by German scientist, Karl Ferdinand Braun
In 1905, first demonstratedBeing used in most televisions todayCalled tube television or electronic
television
Electronic Television
Hindered television sales:– Great Depression– World War II
Post WWII, Golden Age of Television– Black and white
Color Television
Trichromatic color mixing theory CBS color system incompatible with black and
white sets at home – Field Sequential method, sandwiched wheel
RCA’s system worked on monochrome monitors– Dot sequential method, sampling using time-division
multiplexing
Aspect ratio
“This film has been modified from its original version. It has been formatted to fit your screen”
Fitting the picture from widescreen to home television
High Definition TV (HDTV)
Motivated by Hollywood to boost ticket sales Uses our field of vision, which is more rectangular
than square – stronger visual impact
HDTV
Higher resolution and quality audio More pixels per inch creating a smoother picture
– 1 NTSC pixel = 4.5 HDTV pixels Is becoming more and more important to consumers
Projection Television
No different from regular television sets, just bigger
Most consider 40” plus as projection TVSupported by both tube and fixed pixel
display television
Front or Transmissive Projection
Screen is located across the roomLight passes through the image-forming
display panel and is then projected onto the screen
Rear or Reflective Projection
Screen is located within the TV boxLight is reflected off the projection display
panel and is then projected onto the screen
New Technologies
Fixed-Pixel Displays:– Liquid-Crystal Display (LCD)– Plasma– Digital Light Processing (DLP)– Liquid Crystal on Silicon (LCoS)
Liquid Crystal Display (LCD)
Liquid crystals coated with phosphors
Voltage applied by thin-film transistor (TFT)
The cells “untwist” to an exact degree to filter light beams
(Courtesy of Sound & Vision Magazine)
LCD
Pro:– Bright colors– Only a few inches deep
Con:– Worst fixed-pixel display for true black– Low resolution (not enough for HDTV)– Narrow viewing angle
Plasma
(Courtesy of Sound & Vision Magazine)
Gas-filled sub-pixels coated with red, green, and blue phosphors
Voltage applied by electrode
Exciting the gas to stimulate the phosphors to emit color light beams
Plasma
Pro:– Wide viewing angle– Bright pictures– High enough resolution for HDTV
Con:– Also does not produce true black– Potential for “burn-in”
Digital Light Processing (DLP)
(Courtesy of Sound & Vision Magazine)
Digital Micromirror Device (DMD) made up of tiny mirrors
Reflect the light from the lamp onto the screen
Liquid Crystal on Silicon (LCoS)
(Courtesy of Sound & Vision Magazine)
Gas-filled sub-pixels coated with red, green, and blue phosphors
Voltage applied Exciting the gas to
stimulate the phosphors to emit color light beams
Light is then reflected of the mirrors to the screen
LCoS
Pro:– Highest resolution compared to LCD and DLP
and obviously supports HDTV– Pixel spacing in close, creating
smoother pictures
Con:– Not explored extensively yet
Television Price Ranges
CRT– $500 ~ $2000
LCD– $2500 ~ $8000
Plasma– $3000 ~ $15000
DLP– $4000 ~ $15000
LCoS– $15000 and up
Enhanced Television
Interactive TV– Watch TV, but customize it and make it your own
– Example: show Demo
Experiments by TCI and Timer Warner 1980’s– Shop online, play games, etc..
– Testers found the service very useful
– Failed due to inability to cover cost of operating the service and keep the prices reasonable for consumer
Conclusion
LCoS is most likely to becoming the wave of the future television market– Combines both technology of LCD and DLP
– Eliminates the rainbow effect by using a prism instead of a spinning color wheel
Expensive but may become economically affordable within the next few years
HDTV supported by LCoS– HDTV preferred by consumers
Conclusion (cnt’d)
Things to see in the future– Convergence of TV and computers– Cheaper Interactive Television– Embedding the interactivity inside the
broadcast signal
Reference
http://www.tvhistory.tv/ http://www.novia.net/~ereitan/ http://www.acmi.net.au/AIC/NIPKOW%5FDISK.html http://www.howstuffworks.com/tv2.htm http://inventors.about.com/gi/dynamic/offsite.htm?
site=http://ieee.cincinnati.fuse.net/reiman/10%5F1994.html
http://www.museum.tv/archives/etv/C/htmlC/colortelevis/colortelevis.htm
http://www.civilization.ca/hist/tv/tv02eng.html http://www.pbs.org/opb/crashcourse/enhanced_tv/