the future of display tech

8/6/2019 The Future of Display Tech.

http://slidepdf.com/reader/full/the-future-of-display-tech 1/23

The future of display technology?

Prepared By:



Presentation Outliney History of display technology

y Current display alternatives

y How FEDs work

y Companies working on FED

y Difficulties with FED

y Future of FED displays



History of Display Technology

Cathode Ray Tube

1950¶s

Liquid Crystal Displays

1970¶s

Field Emission Displays

1980¶s



Cathode Ray Tubes (CRT)y Geissler Tubes (1855)

y First CRT oscilloscope invented40 years later

y Commercially practical CRT

made by Allen DuMont (1931)



Liquid Crystal Display

y Liquid Crystalline materials

discovered (1880s)

y James Fergason produced first

practical LCD display (1967)

y Epson introduced first color LCD

TV 2´ in diagonal (1985)



Plasma Display Panel

y Plasma identified by William

Crookes (1879s)

y Prototype for PDP introduced at

University of Illinois (1964)

y Fujitsu introduced first 42´ color

PDP (1997)



y Vacuum tube with phosphor-

coated screen

y Cathode emits electrons to be

accelerated by the anode

y Deflectors guide the electron

beams

y Electrons excite phosphor

molecules to produce light

CRT

Technology Comparison



Advantages Shortcomings

y Good color representation

y Large viewing angle

y Fast response time (50 µs)

y Low price

y Multiple resolutions

y Large and bulky (2 kg/in)

y Flicker causes eye strain

y High power (11 W/in)

CRT

Technology Comparison cont¶d




LCD

y A layer of liquid crystalline

sandwiched between 2 glass

layers with polarizer

y Light generated behind the

screen, passed through

y Applied voltage controls the

crystalline orientation





y Light weight (0.6 kg/in)

y Low power (5 W/in)

y Less eye strain

y High brightness (500 Cd/m2)

y Small viewing angle

y Slow response time (8 ms)

y Weaker contrast & color

LCD




PDP

y Two layers of glass with pixel

array in between

y Each pixel contains a mix of

neon and xenon gas

y Current is passed through a

pixel to ionize gas, and emitUV radiation

y UV rays excites phosphor-

coated layer of glass to

generate light





y High brightness (1000 Cd/m2)

y High contrast (10000:1)

y Large viewing angle

y More power vs LCD (8 W/in)

y Burn-in effect

y Size limitation (>40´)

y Slow response time

PDP



FED: The Best of Both WorldsPromised Advantages

y

Very light (100 g/in)y Large Viewing angle (178o)

y Extremely fast (20 ns)

y Low power (0.2 W/in)

y High contrast (10x PDP)

y No flicker

y No dead pixels



How FED Works?y Array of mini-CRTs



Technology Options - SEDy Surface-conduction

electron emitter display

y Joint venture betweenToshiba and Canon



Technlogy Options - Spindty Spindt emitters are tiny

cones that create a very high

charge density y Alignment of the cone and

gate is critical



Technology Options - CNT

y Carbon nanotubes aselectron source



Companies Researching FEDy Canon and Toshiba joint venture in SED

y Sony promises Spindt-type FED display in 2009

y Samsung is researching CNTs, Applied Nanotech Inc.have made a 25´ display



Challenges: Technical Problemsy Fluctuations in emission current

y Low cost manufacturing methods

y Developing for large areasy Tip damage

y High vacuum levels required



Dropping LCD pricesy LCD panels are dropping in cost while increasing

in quality



Hope for FED Displays

y The success of FEDs depends on:

y Costy Quality

y Timing

Technologically advantageous product suffersfrom poor timing



Questions?

the future of display tech

Documents