Field emission display
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This article contains information about a scheduled or expected future product. It may contain preliminary or speculative information, and may not reflect the final version of the 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.
Like LCDs, 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. Carbon Nanotechnologies claimed production would start in late 2006. [3]
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[edit] Potential advantages
- For gamers, game consoles with light guns may be able to react to the object that emits the sufficient lighting dynamics on the screen like on conventional CRTs which emit a flexible range of light dynamics; whereas, an LCD flat-panel monitor will only produce color and illuminate it with a backlight.
- Unlike LCD displays, the FED may have flexible handling of non-standard resolutions that LCDs will emulate poorly due to their native resolutions.
[edit] 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]
[edit] See also
[edit] References
- ^ FED. Meko, Ltd. (2006-11-22). Retrieved on 2006-11-27.
- ^ SED. Meko, Ltd. (2006-11-22). Retrieved on 2006-11-27.
- ^ January 2000 archive of Candescent web site
- ^ Light emitting principle of an FED system by SHARP
[edit] External links
- News and infos about FED-Displays
- How field emission displays work
- Carbon TVs to edge out liquid crystal, plasma?, article from CNET news.com
- Candescent and Sony to Jointly Develop FED Technology
| Display Technology | |
|---|---|
| Non-video | Split-flap display | Flip-dot display | Electronic paper |
| Video | Vacuum fluorescent display | Cathode ray tube | Plasma display (Organic) Light-emitting diode | Laser TV | Liquid crystal display |
| 3D | Stereoscopic | Volumetric | Laser beam |
| Static media | Movie projector | Slide projector | Hologram | Neon sign |
