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 demonstratedBeing used in most televisions todayCalled tube television or electronic

television

How the CRT works?

http://www.howstuffworks.com/tv2.htm

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 TVSupported by both tube and fixed pixel

display television

Projection Television

Examples:

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

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

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/