Field Emission Displays

A Field emission display is a flat screen monitor/television technology that takes the original cathode ray tube design to the next level. FEDs use an array of cathode ray tubes as a matrix of sub-pixels. Each sub pixel consists of red, green, and blue pixels and each pixel is controlled by a single CRT. Field emission displays are also known as nano-emissive displays and are related to another similar technology known as surface-conduction electron-emitter displays (SED).

Monitors and televisions of old used a single CRT bombarded by electrons from an internal electron gun. The FED, instead, uses multiple micro-electron guns using carbon nanotubes as an electron source. The brightness of each sub-pixel can no longer be controlled with varying voltage as was done with CRTs. Brightness of the FED is controlled by a process called pulse-width modulation which regulates how many electrons are released and reach the screen.

One problem with the FED technology is the number of electron guns and cathode ray tubes required to all be working in conjunction. Dead pixels are a common problem of new FEDs. All new FEDs must be thoroughly examined for dead pixels and sent to a repair shop for recalibration when any are found. Often, this problem is not fixed by repairing the malfunctioning CRT but by adjusting the pulse-width so neighboring pixels can power the dead one.

FED technology was first developed in the early 1990s but never reached maturity until 2005 when a prototype was released in May 2005 by Motorola. Motorola and several other companies abandoned FED development, mostly for financial reasons. In 2007, Carbon Nanotechnologies, Inc. picked up the technology, promising to release working models in 2009 through a subsidiary, Field Emission Technologies. In early, 2009, however, Field Emission Technologies abandoned production when it could not raise the capital required to operate the production facility. It is currently unknown if or when FED technology will be picked up again and be available for consumer use.

As the green movement continues to grow, FED technology may yet resurge. Tests done by Sony of 36 inch screens show FED as using only 14 watts compared to the 100 watts of an LCD. It only the reliability of the system that is holding it back. FED screens are cheaper to produce and weigh less than LCDs. FEDs face the challenge of being extremely difficult to produce on a mass scale which is causing manufacturers to explore OLED and SED technology instead.