Surface Conduction Electron emitter Display (SED)

The SED technology has been developing since 1987. The flat panel display technology that employs surface conduction electron emitters for every individual display pixel can be referred to as the Surface-conduction Electron-emitter Display (SED). Though the technology differs, the basic theory that the emitted electrons can excite a phosphor coating on the display panel seems to be the bottom line for both the SED display technology and the traditional cathode ray tube (CRT) televisions. When bombarded by moderate voltages (tens of volts), the electrons tunnel across a thin slit in the surface conduction electron emitter apparatus. Some of these electrons are then scattered at the receiving pole and are accelerated towards the display surface, between the display panel and the surface conduction electron emitter apparatus, by a large voltage gradient (tens of kV) as these electrons pass the electric poles across the thin slit. These emitted electrons can then excite the phosphor coating on the display panel and the image follows.

SED TVs were supposed to have been the next big thing in the flat panel TVs. We were promised the slim convenience of LCD and plasma TVs,  and the amazing colour definition and response times found in CRT displays. The main advantage of SED’s compared with LCD’s and CRT’s is that it can provide with a best mix of both the technologies. The SED can combine the slim form factor of LCD’s with the superior contrast ratios, exceptional response time and can give the better picture quality of the CRT’s. The SED’s also provides with more brightness, color performance, viewing angles and also consumes very less power. More over, the SED’s do not require a deflection system for the electron beam, which has in turn helped the manufacturer to create a display design, that is only few inches thick but still light enough to be hung from the wall. All the above properties has consequently helped the manufacturer to enlarge the size of the display panel just by increasing the number of electron emitters relative to the necessary number of pixels required. Thus they seemed to be cheaper.

There is a significant increase in the SED market because of the various advantages associated with the technology such as cathode ray tubes-matching black levels, contrast potential and excellent color, comparatively low-cost production and wide viewing angle. The surface-conduction electron-emitter display market can be segmented by end-use applications into television, cameras (digital and video), mobile and healthcare devices display screen. The market can also be segmented geographically into North America, APAC, Europe and RoW regions. Some of the key players in the embedded system market are Canon Corporation, Toshiba Corporation and Sony Corporation among others.