Is it time to say goodbye to the CRT technology? Not really! The growing demand for flat panel display technologies like Liquid Crystal Display (LCD) and Plasma Displays (PDP) has no doubt reduced growth of CRT-based displays in the recent years.

But, CRT is here to stay maybe in a different form probably because of the inherent advantages that it carries. The fact remains that LCD and PDP still cannot match the vivid colors, clarity and faster refresh rate that CRT technology offers.

Source: Canon

It is intriguing to know that despite this inadequacy, the last few years saw LCD and plasma selling like hot cakes, only because customers wanted bigger and slimmer display panels. Moreover, these panels have become a lot more affordable in the recent years.

The need for larger screen displays is also fueled by the need for higher image quality witnessed by the advent of digital broadcast and broadband. The coming of next-generation DVDs, digital cameras and digital video camcorders will only add to the demand for larger screen displays.

Keeping in mind the image quality that CRT offers, enlarging CRT screens would mean making the units significantly heavier and deeper. For years the challenge has been to develop a new kind of display offering the same picture quality of a CRT in a slim yet large unit.

Enter, SED
Canon and Toshiba together have successfully met this challenge through SED (Surface-conduction Electron-emitter Display) technology. Canon began SED research in 1986 and, in 1999, began joint development activities with Toshiba with the aim of commercializing product on this technology.

Comparison of CRT and SED

Source: Canon

The companies showed a prototype of a SED TV set in September 2004. Knowing that the joint development had a definite future, both companies established a joint venture company called SED Inc in October 2004.

Initially, they expected to bring SED televisions to the market in 2005. But due to some manufacturing difficulties, they changed the launch date to Spring 2006, only to push this date further to Q4 of 2007 recently.

Canon and Toshiba are touting SED technology to be historic milestone in the display industry since the introduction of CRT technology. According to industry experts, SED will do to plasma what LCD has done to CRT. Heralded as the new generation of high-quality large flat-screen display, the SED is almost ready for practical application. Its greatest feature is the ability to produce vivid color images that surpass conventional types of display. Also, the SED delivers exceptional overall image quality-fast video-response performance, high contrast, high gradation levels-and low power consumption.

How it works?
SED was created through the merging of Canon's proprietary electron-emission and micro-fabrication technologies coupled with Toshiba's CRT technology and mass-production technologies for LCDs and semiconductors. Like conventional CRTs, SEDs utilize the collision of electrons with a phosphor-coated screen to emit light. Electron emitters, which correspond to an electron gun in a CRT, are distributed in an amount equal to the number of pixels on the display.

In SED, the key to the electron emitters is an extremely narrow slit, several nanometers wide, between two electric poles. Electrons are emitted from one side of the slit when approximately 10V of electricity are applied. Some of these electrons are scattered at the other side of the slit and accelerated by the voltage (approximately 10 kV) applied between the glass substrates; causing light to be emitted when they collide with the phosphor-coated glass plate.

Better than LCD, PDP
LCDs are lighter, but tend to have limited viewing angles, have difficulty producing very dark blacks, and can be a little sluggish when it comes to showing fast action. Since SEDs apply the same light emission theory as CRTs, they provide dynamic color expression, a sharp picture, and faster video-response than LCDs and PDPs.

The brightness of SED is excellent. Blacks are absolutely black, response times are as low as one millisecond, and the viewing angle is essentially 180 degrees. Additionally, SEDs do not require electronic beam deflection, making it possible to have screens of more than 40 inches in size, that are only several centimeters thick.

Low power consumption is another main feature of the new display technology. SEDs convert electrical energy into light with a higher emission efficiency than other display types, resulting in power consumption that is two-thirds that of PDPs, and also surpasses CRTs and LCDs.

In other words, SEDs are highly Earth-friendly, meeting the needs of the times. With the application of inkjet printing technology to develop a high-performance electron-emitter and a screen-printing method to produce matrix wiring, SED Inc is improving production technologies to manufacture large-screen panels at low cost.

Cost Factor
The prices of competing technologies, LCDs and plasma displays, have fallen much more than the companies anticipated in recent years. Moreover, LCD and PDP manufacturers around the world have announced plans to enhance manufacturing capacities in recent months.

This could further lower LCD and plasma prices. Reducing prices of LCD and plasma is sure to give SED a tough time. However, experts feel, since SED is better in its picture quality against LCD or plasma display, it need not compete only on the price factor.

The overall flat-panel television market is expected to see high growth during the 2008 Beijing Olympics, also for the reason that there will be a global shift in the broadcast technology from analogue to digital. The launch of the first SED TV sets won't be until the fourth quarter of 2007, which clearly indicates that SED Inc is looking at putting all its efforts to push SED-based TV sets for the Beijing Olympics in 2008.

NELSON JOHNY

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