Television Development Mario Vargas Kin Piu Lam

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

Nipkow’s Disk  Paul Nipkow’s Disk

Mechanical Television  Before 1930’s  Uses Nipkow’s Disk Front view Inside View

Cathode-Ray Tube  First introduced in 1897 by German scientist, Karl Ferdinand Braun  In 1905, first demonstrated  Being used in most televisions today  Called tube television or electronic television

How the CRT works?

CRT (internal view)

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

RCA’s Color TV System

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 TV  Supported by both tube and fixed pixel display television

Projection Television  Examples:

Front or Transmissive Projection  Screen is located across the room  Light passes through the image-forming display panel and is then projected onto the screen

Rear or Reflective Projection  Screen is located within the TV box  Light 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

DLP  Pro: –Best fixed-pixel display at producing true black  Con: –Prone to “rainbow” effect

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      p://ieee.cincinnati.fuse.net/reiman/10%5F1994.html  olortelevis.htm  