The Next Generation of Flat Panel TVs: OLED, SED and TDEL

The general public has finally caught the flat panel wave. We’re not exaggerating. As unfortunate as it is, because at the top-end CRT still delivers the picture quality that plasma and LCD strive for, the death knell has sounded. Most major electronics manufacturers have drastically slashed their CRT product lines. Some have altogether stopped making CRT TVs.

The performance of LCDs and plasmas has been improving substantially with each new generation. Not only have the displays gotten bigger but the prices have gotten smaller. Now that they have positioned themselves as the technologies of choice when purchasing a new television set, we’re here to tell you about display technologies of the future.

Don’t fret. None of these technologies will make your sexy new flat panel display obsolete any time soon, but they have high hopes and big plans just over the horizon.

OLED (Organic Light Emitting Diode) displays

This technology may already be in your hands, as it is replacing LCD displays on many MP3 players, cell phones, and car radios. Producers claim it is faster, provides higher contrast, broader colour, and a larger viewing angle.

Kodak has held the patent on organic light emitting materials since the 1980’s when a researcher discovered that putting an electric current through organic material makes it glow green.

Today’s OLED displays squish thin carbon-based films between two charged electrodes, one a metallic cathode, and one a transparent anode, which is usually glass. But the material can also be printed on malleable, wafer-thin substances like plastic. This brings the potential for bendable screens that can be rolled up and tucked away. Organic compounds themselves emit light, therefore needing less power compared to LCDs, which need a backlight. This does away with the display aperture factor, so there are no natural limits on pixel count or resolution, or the size of the display. It is also said to be less costly to produce than current technology.

There are a couple kinks to work out though. Organic molecules have a short lifetime, typically 1,000 hours, which is dramatically less than LCD and plasma. The displays are also sensitive to small traces of water. Problems may be worked out by the arrival of active matrix (AM) OLED technology. AM-OLED displays are brighter and more defined than their passive matrix counterparts. Last summer, Samsung showcased a 40-inch TV that uses AM-OLED. The company says it will mass produce AM-OLED displays on high-end mobile TV phones in January 2007 or earlier. Sony also plans to start production of large screen displays in 2007. OLED is expected to be the dominant big screen technology by 2010.

SED (Surface-conduction Electron-emitter Display)

SED technology was designed specifically for large screen flat panel TVs. SED came to the plate when Canon’s electron-emitting technology, under development since the late 80s, joined Toshiba’s CRT technology in the late 90’s. Just like in CRTs, SED electrons are emitted to excite a phosphor film on the display panel. But instead of one electron gun dispersing electrons through a deep vacuum, each pixel in an SED has its own electron emitters which filter electrons into an array of slits only nanometers wide.

SED displays are thinner than CRT TVs (comparable to the thickness of LCD), but hold similar life expectancy and the same picture quality benefits, like high contrast ratios, gradation levels and dynamic colour. Also, they have faster refresh rates or video response than LCDs and PDPs, which does away with the ghosting phenomenon (great for competitive gamers). This may be what everyone is looking for: the picture quality of the old cathode ray tube without the thickness or heaviness.

SED technology has a better viewing angle than LCDs. The makers also claim it uses two thirds less the energy required for LCDs, and less than PDP and CRT. According to experts, it more aptly handles the display of black but does not yet measure up to the overall brightness of a PDP or LCD.

Toshiba/Canon promised SED production was to start last year, the first product being a 55-inch high-end TV. Delays have occurred mainly due to pricing pressures, as the price of current flat panel displays has plummeted in the last few years, but at this year’s CES in Las Vegas, Toshiba wowed the crowds with their pre-production models and said production would start in late 2006.

TDEL (Thick-film Dielectric Electroluminescent) displays

This technology was conceived by Toronto-based iFire Technology Corp. in the early 90s. TDEL uses the same form of inorganic electroluminescence (IEL) as TFEL (thin-film electroluminescence) which is commercially available and has been developed since the 70s. Former TFEL technology had difficulty properly displaying full colour, blue in particular. This is not the case for TDEL which uses iFire’s patented ‘color by blue’ technology.

The TDEL structure is made on a glass or other inexpensive substrate consisting of a thick-film dielectric layer and a thin-film phosphor layer squished between two sets of electrodes to make a matrix of pixels. It seems complex, but basically it works when phosphors emit light in the presence of an electric field. And because TDEL uses solid-state phosphors instead of liquids (like LCDs) or gases (like PDP), it is probably the most sturdy new technology, less prone to shock and breakage during shipping.

Besides its durability, TDEL’s claim to fame is its low cost of production. The thick-film dielectric layer can be manufactured by simple printing techniques, which gives TDEL a cost advantage. According to the makers, TDEL has the potential for a 50 per cent manufacturing cost advantage over LCDs which require extra costly precautions to prevent cleanroom contamination. So we are looking at costs similar to CRT TVs.

iFire claims TDEL also has picture quality similar to CRT TVs. They say their displays are brighter, more efficient, more resistant to contamination during manufacturing, and more resistant to electrical breakdown than TFEL, but with less dark contrast and contrast in bright lighting.

Although the technology is scaleable up to 50-inches, iFire’s plan is to start with mid-30-inch flat panel TVs only. Pilot production is scheduled for this year, and mass production next year.

We toured iFire’s facilities in the spring and were thoroughly impressed, not only by the colour saturation of their prototypes but by the relative simplicity of their production techniques.

After decades of CRT dominance we now have a variety of choice for a variety of applications. As the industry evolves, we’ll keep you up to speed.


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