Development of SED (surface-condition electron-emitter display) screens began in 1986 at Canon and was joined in 1999 by Toshiba.

SEDs combine elements of both CRT (cathode ray tube) and LCD (liquid crystal display) technologies. As with CRTs, electrons hit a phosphor-coated screen to emit light. But instead of being shot from an electron gun, electrons are drawn out of an emitter through a slit that is only a few nanometers wide. The result is a picture that is as bright as a CRT and does not suffer a time lag sometimes seen on LCD panels with rapidly moving images.

In addition to the superior picture, the panels also consumed half the power or less of competing screens of the time, so both companies expected success. In 2004 they established SED Inc. to commercialize the technology.

So confident was Toshiba that it began running down its plasma TV operations in preparation for a full-scale launch of SED. By 2010, the company said at the time, it was expecting to command a third of the global market for 40-inch or larger TVs.

A US$1.7 billion investment followed in a factory and screens were promised in 2005, but they never came. Citing difficulties getting down production costs, the companies delayed the launch of SED until 2007.