Developments in Displays
Lots of tweaking going on: every technology is being improved
I’ll go through at least some of these; there are too many to cover
completely.
Then I’ll talk about some of the newer technologies
The major players:
CRTs (they’re still around)
LCDs
PDPs
Projectors
LEDs
Some of the newer entries:
OLEDs
FEDs
Flexible displays; electronic books
3D (if we have time and patience)
CRTs
Still the best all-around image quality
Brightness, moving images, viewing angle
New, thinner designs
But they’re still bulky and heavy
LCDs
Speed is improving
Materials, driving techniques, new geometries
Viewing angle
Backlights
Improved color gamut and contrast; LED backlights
Gray scale and contrast
Transitions between gray levels, not just black to white
Cost and prices
New plants, new entrants
PDPs
Excellent brightness, color, viewing angle
Cost is still high, but lower than LCDs in large sizes
Efficiency still a problem
New geometries, driving waveforms, gas mixtures
Motional artifacts have been essentially eliminated
So has burn-in, allegedly
Projectors
Four flavors: CRT, LCD transmissive, LCD reflective (LCoS), DLP
CRTs are still around, but obsolescent
LCD transmissive: one panel or three panels
One panel with color wheel is inexpensive, but motion problems
LCoS can be compact, but light engine is difficult to make
DLP only from TI; can be very good. One or three panels
Another MEMs device, grating, is still somewhat experimental
Light sources are expensive, have limited life
New optical designs can produce very compact projectors
Problems with ambient light; new screen designs
Front vs rear projection
LEDs
Extremes: small displays and spectaculars
The really big displays are now almost all LEDs
The key was getting blue; now full color is available
Bright, high contrast, easier to install than the previous
Jumbotron CRTs
Ubiquitous: Las Vegas, Times Square, stadia
OLEDs
Rapid progress; some commercial products now
All LCD manufacturers are exploring
Attractions: printing techniques, low cost
Organic TFTs to drive
The possibilities for flexible displays
Also possible for other technologies: LCD, particles
Life and color gamut are improving
Plastic substrates or metal plus plastic
There will be intense competition with LCDs and PDPs
FEDs
New approaches have brought this back to life
Major problem was life due to outgasing, cathode poisoning
New cathodes have alleviated these problems
Carbon nanotubes (CNTs), surface electron conduction
Both seem to be resistant to ion bombardment
Impressive demonstrations, but no products yet
If they work, they have most of the advantages of CRTs
Flexible displays
Can be OLED, electrophoretic, LCD, other
Attractive for extreme portability
Electronic books
Need not be flexible, but that’s a possible added advantage
Even possibilities for very large, roll-up displays
What do you look for in a display
What’s it used for: entertainment TV, PC applications?
The requirements are different
TV wants brightness, motion reproduction
PC or other analytic uses need lower B but high resolution
Motion less important
What’s the viewing distance?
How important are color, gray-scale rendition?
High definition?
Viewing angle
Ambient light. Reflections
3D
A lot of interest, but not much real progress
Multiple images via barrier layers; autostereoscopic
Limited “sweet spot”
Stimulate peripheral vision; IMAX, Cinemascope
Two images and eyeglasses
Head-mounted displays
No breakthroughs yet, despite the hype
But almost 200 companies are interested
Summary
Multiple technologies available now
New ones have an uphill fight, but there are still new entries
The current majors--LCD, PDP, CRT—will not be displaced soon
It takes 10+ years for a new technology to be real in the market
place
Lots that I haven’t discussed: simulators, digital cinema, the
importance of small displays (cell phones, cameras, …)
Stay tuned