Surface-conduction Electron-emitter Display
Surface - conduction Electron - emitter Display ( approximately of surface-conduction electron -emitter display, SED ) refers to the field emission display (FED ) Related screen technology of conductive electron emitters.
It was originally developed by Canon and Toshiba SED Inc. in a joint venture, but was sold in 2007 January 29, Toshiba 50 - % stake in SED Inc. for patent disputes with the Nano - Proprietary Inc. Canon.
Because of these patent disputes, the marketing of screens was moved to SED based on Canon mid-2007 for an indefinite period. The end of May, 2010, Canon the development of SED TVs for home use by its own account completely on ice.
The display works much like a CRT. But instead of using a single electron emitter an SED works with one emitter for each subpixel.
An electron emitter has a planar structure and an emitter region composed of an ultra-thin layer of palladium oxide ( PdO ), an electrode layer and a glass substrate. The palladium oxide layer has a few nanometers wide slot. Substituting the electrodes under tension, it shall in this tiny slit to a tunnel effect. This then emits electrons accelerated in the electric field of an externally applied high voltage and are shot on an opposite phosphor coated glass substrate.
Unlike CRTs, the SED technology does not require electron beam deflection. This large displays are also suitable for wall mounting.
It was originally planned to leave the production of 55 -inch displays in SED technology in July 2007, calling on the conventional manufacturing plant in Hiratsuka City.
In 2008, Canon wanted to bring together the new technology with Toshiba in Japan and the United States to the mass market, but this failed due to patent disputes. Meanwhile, Canon has won this battle against Applied Nanotech, so that appropriate products can be sold now. By now also market-ready OLED TV has become another technology has become established, however, which now represents an additional competition for the market launch of the SED technology.
The efficiency of the SE displays should be at about 5 lumens per watt and therefore be significantly higher than the 1 to 2 lumens per watt at plasma screens. Compared with LC display shall consist according to the manufacturer an advantage of 30 percent. This results in a significantly lower power consumption: Comparison of LCD requires an SED only half and against a CRT, only a third of its performance.
The achievable contrast of SED is also higher, around 100,000: 1 resulted primarily from the elimination of a backlight, as is necessary in LC displays. The color black is represented as a true black as plasma screens.
Another advantage over current flat panel displays is the very fast response time ( less than one millisecond ) - similar to the classic CRT monitors. It is also stated by the manufacturers to higher color fidelity and larger viewing angles.
Thus, an SED combines almost exclusively the advantages of both technologies CRT and LCD: Low power consumption, high contrast, fast response time, deep black and flat construction. Disadvantages, which divides the SED with other flat panel displays, are support only a single resolution and the possibility of the emergence of pixel defects and the need to introduce a completely new manufacturing technology. As with all screen technologies in which phosphorus-containing phosphors are used, there is also in SE displays the risk of burn-in static images. Moreover occurs as with all cathode ray screens from X-rays. This does not exist on LCD and plasma screens.