Field-emission display

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Template:Future product A field emission display (FED) is a type of flat panel display using field emitting cathodes to bombard phosphor coatings as the light emissive medium.

Field emission displays are very similar to cathode ray tubes, however they are only a few millimeters thick. Instead of a single electron gun, a field emission display (FED) uses a large array of fine metal tips or carbon nanotubes (which are the most efficient electron emitters known), with many positioned behind each phosphor dot, to emit electrons through a process known as field emission. Because of emitter redundancy, FEDs do not display dead pixels like LCDs even if 20% of the emitters fail. Sony is researching FED because it is the flat-panel technology that comes closest to matching the picture of a CRT.[citation needed]

FEDs are energy efficient and could provide a flat panel technology that features less power consumption than existing LCD and plasma display technologies. They can also be cheaper to make, as they have fewer total components. As of yet, however, there are no consumer production models available in the United States, although small demo panels have been produced.

A similar technology to be commercialized in 2007 is the SED (surface-conduction electron-emitter) display, a simplified variant of FED technology. Whereas FED uses a 'Spindt tip' semi-conductor or carbon nanotube emitter, with multiple redundant emitters per area of display[1], SED uses a single emitter based on palladium oxide laid down by an inkjet or silk-screen process.[2]. SED is considered the variant of FED that is currently feasible to mass-produce.

In 2001, Candescent had spent $600 million on producing FEDs with non-carbon material, but it was abandoned, with assets sold to Canon in August 2004, two months after filing for voluntary reorganization under Chapter 11. The UK company Advance Nanotech, in collaboration with the University of Bristol, has developed a similar panel that relies on specially doped diamond dust. The first 1000 Carbon Nanotechnologies was set to production in late 2006 by Sony. [3]

Nano-emissive display is the name given by Motorola for field emission display. A prototype model was demonstrated by Motorola in May 2005. Nano-emissive display (NED) is Motorola's term for their Carbon Nanotubes (CNTs)-based display technology.

Potential disadvantages

  • Although physically simple, actual operation of field emitters in a production device are anything but simple. Field emitters depend on high electric field strength to tear electrons from the surface. Instead of very high voltages, FEDs use very small radii – atomic lattice size – and element spacing for cathodes. This small size renders the cathodes susceptible to damage by ion impact. The ions are produced by the high voltages interacting with residual gas molecules inside the device. FEDs require high vacuum levels which are difficult to attain: the vacuum suitable for conventional CRTs and vacuum tubes is not sufficient for long term FED operation. Intense electron bombardment of the phosphor layer will also release gas during use.[4]

See also

References

  1. ^ "FED". Meko, Ltd. 2006-11-22. Retrieved 2006-11-27. {{cite web}}: Check date values in: |date= (help)
  2. ^ "SED". Meko, Ltd. 2006-11-22. Retrieved 2006-11-27. {{cite web}}: Check date values in: |date= (help)
  3. ^ January 2000 archive of Candescent web site
  4. ^ Light emitting principle of an FED system by SHARP

External links

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