Future Trends of Televisions

1. Future Trends of Televisions By: Rion Núñez Team 11

2. 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)

3. CRT (cathode ray tube) • Invented in 1897 by Karl Ferdinand Braun • Standard for televisions until recent years

4. How CRT works • 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

5. CRT Advantages • High color fidelity and contrast • Better resolution with moving images

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

7. 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

8. 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

9. Plasma Advantages • Brighter than CRTs • Flat panel • Lowering in cost

10. Plasma Disadvantages • Susceptible to phosphor burn-in • Not well used in bright rooms

11. 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

12. 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

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

14. LCD Disadvantages • Manufacturers often reject about 40 % of the panels that come off the assembly line • Color contrast is not the best

15. DLP (digital light processing) • Developed by Texas instruments • Created by Dr. Larry Hornbeck in 1987

16. 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

17. DLP Advantages • Insusceptible to phosphor burn-in • More affordable than plasmas and LCDs

18. DLP Disadvantages • Not as thin as other high definition displays

19. OLED (organic light emitting diode) • Developed by Eastman-Kodak • Competing against LCD and plasma television displays

20. 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

21. OLED Advantages • 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

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

23. 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

24. 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

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

26. SED Disadvantages • Cost • Availability

27. Extra • http://www.youtube.com/watch?v=hxv7mmKHRhs

28. Sources • 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