surface-conduction electron emitter display (SED)
The SED display, developed by Toshiba and Cannon, combines the advantages of two technologies, those of the cathode ray tube with those of semiconductor flat panel displays. The SED (Surface-Conduction Electron Emitter Display) technology uses electron emissions to excite colored phosphors to emit light, similar to the way the cathode-ray tube( CRT) works. The essential difference is that the SED display does not work with three cathodes, but that each pixel represents its own emission system.
In terms of construction, each pixel consists of the emission electrodes and the light-generating color phosphors. The electron emitters have a planar structure and an emission surface consisting of ultra-thin palladium oxide deposited on a glass substrate. The free electrons are generated via a differential voltage in a slot only a few nanometers wide, called a nano-slit, which is located between two emission electrodes. These free electrons are accelerated toward the color phosphors and release photons from them, which emit visible light via microfilters.
An accelerating voltage of about 10 kV is used to accelerate the emission electrons. This voltage is applied between the emission electrode and an extremely thin metal electrode onto which the phosphors are vapor-deposited. The metal electrode allows the electrons to pass through, but provides light reflection so that the full light output is available to the viewer and does not compromise the contrast ratio due to internal illumination. Each color triple consists of the primary colorsred, green and blue( RGB).
Flat screens using SED technology are characterized by high contrast, with a contrast ratio of 9,000 :1, and the high resolution with which HDTV with 1,920 x 1,080 pixels can be displayed. Further advantages lie in the extremely short response time of the individually controllable color triplets, resulting in excellent picture quality without annoying trailing effects.