SED Panel Contrast Ratio Boosted to 100,000:1

[erdega79]

http://techon.nikkeibp.co.jp/english...050421/104026/

At the Display 2005 event held in Tokyo on April 20, 2005, SED (Surface-conduction Electron-emitter Display) Inc., a joint venture formed by Canon Inc. and Toshiba Corp., unveiled a SED panel with the contrast ratio boosted to approximately 100,000:1. The company's first SED panel revealed at CEATEC JAPAN 2004 only achieved a contrast ratio of 8,600:1.

The key factor behind the sharp rise in contrast ratio is a broad reduction in black luminance. Black luminance has been reduced to 0.003 cd/m2, from the previous prototypes' 0.04 cd/m2. "We have achieved the sharp cut in black luminance by improving the electron-emitting source property," said a Toshiba spokesperson. Many display engineers have been interested in SED panels, appraising them as "capable of showing a completely different 'black' compared to conventional displays." The SED panel seems to have marked even higher specifications in "black" display capability.

Canon and Toshiba have also succeeded in boosting peak luminance that they had previously described as an issue in mass-producing the 400 cd/m2 model.

SED panel with boosted contrast ratio

[Rob]

I wonder if they have sorted out the problem with the pixels spacers being visible. A grid like structure that prevenmts the screen from imploding.

[erdega79]

Originally Posted by Rob

I wonder if they have sorted out the problem with the pixels spacers being visible. A grid like structure that prevenmts the screen from imploding.

I wouldn't know but I do know that sed panel is superior to lcd and plasma in contrast ration obviously, response times and power consumption. They should start shipping them in 2006

[Rob]

If they can sort out the spacer problem, SED looks promising. kind of like a cross between the benefits of crt with the benefits of a digital screen.

[philip2005]

erm i'm new to this whats SED?! Will it solve the problems of blotchy pastel colors on LCD and Plasma tv's?

[DaDane]

This page, which is in Danish, claims that Toshiba are building a factory for the sum of 11.5 billon kr (1.85 billion $) that is expected to start mass production in 2007.

It is expected that the first models will be 50" and with a resolution on 1920 by 1080.

They link to this page, but it doesn't really tell as much.

Sounds very interesting!

But others have 1080p panels coming as well!

• Sharp Introduces 45-inch, 1080p LCD Panel PC Mag (2004-09-01)
• Samsung Does 1080p in a Big Way (70" flat plasma) PC Mag (2004-09-01)
• Mitsubishi Bows 1080p DLP with DVR at Dealer Line Show - Due september (62" @ 5799$ SRP, 73" @ $7499, they also have more expensive sets with bulild in harddrive and cheaper 1080p but with rear projection
• Mitsubishi Digital Electronics America Introduces Two LCD Flat Panel HDTVs "line-up is highlighted by a new 37-inch HDTV with true high definition 1920 x 1080p panel resolution"

And here you can actually buy a 37" 1080p LCD TV for $2.499, 56" DLP Projection TV for $3.999 or a 62" DLP Projection TV for $3.999

[erdega79]

SED Ready to Enter Volume Production

SED Ready to Enter Volume Production

Canon Inc of Japan and Toshiba Corp of Japan exhibited the new surface-conduction electron emitter display (SED) panel they jointly developed, at the Display 2005 show held from April 20 to 22, 2005. This was the second public exhibition of the panel since CEATEC Japan 2004 in October 2004, but even so the booth was packed with people wanting to verify its image expression capabilities with their own eyes.

The performance of the SED panel exhibited by the two firms this time was significantly higher than that of the panel shown in October 2004. The contrast ratio (dim environment), for example, has been improved from 8600:1 to 100k:1, and peak luminance from 300cd/m2 to 400cd/m2. As a member of Toshiba's staff explained, "We will not begin volume production with the display performance of this panel. Display performance will be improved even further by that time. We expect to begin volume production as planned in August 2005." The developers are clearly confident that panel performance will be improved and volume production launched on schedule (see Fig).



Refining Black Rendering

One of the key attractions of the SED panel is how well it can display black, a capability that leaves many display engineers in awe. The specifications indicate that this performance has been further improved. The current prototype from the pair exhibits a black luminance (an indicator of black display performance) of 0.003cd/m2, a marked improvement from the 0.04cd/m2 level of October 2004.

Normally liquid crystal display (LCD) panels show degraded blacks due to light leakage from the backlight, and plasma display panels (PDP) from pre-discharge emission, making it difficult to reduce black luminance even as low as 0.1cd/m2. A member of Toshiba's staff described the difference: "The black displayed on LCD and PDP panels is a moonlit night, and the black that an SED panel gives is a moonless, starry night."

SED panels adjust luminance by controlling the number of electrons discharged from the electron source. The characteristics of electron discharge have been modified to make response to source drive voltage more abrupt, allowing a further reduction in luminance. Another result of this change was the improvement in contrast ratio (dim environment) from 8400:1 in October 2004 to 100k:1 at the latest show.

In addition to the improved black luminance, the new prototype also offers an improvement in peak luminance from 300cd/m2 to 400cd/m2. Peak luminance has been cited as a major issue with the SED panel. At the exhibition in October 2004 a number of observing engineers commented that the relatively low luminance would make it difficult to see clearly in a bright room, according to one PDP development engineer. As a result, Canon and Toshiba intend to continue improvement through the start of volume production. The firms explained that they expect to boost peak luminance to 500cd/m2 in volume production models.

Color Reproduction

Kazunori Fukuma, coordinator for display and component materials and the person directing SED panel development at Toshiba, explained for the very first time some of the characteristics of the SED panel. Concerning the ability to express motion clearly, for example, which they proudly describe as "more than sufficient," he disclosed residual emission characteristics for red, blue and green phosphors, and explained that the use of microfilters made it possible to broaden the color reproduction gamut to 94% of National Television System Committee (NTSC) standards.

The microfilters are one of Toshiba's cathode ray tube (CRT) technologies, boosting color reproduction performance and helping prevent reflection of incident light. Toshiba's Fukuma added, "We use the same phosphors as the CRT, improved for use in the SED panel." Concretely, the red phosphor is Y2O2S:Eu, the green is ZnS:Cu,Al and the blue is ZnS:Ag,Al.

Fukuma also mentioned the high gradation display performance of the SED. While gradation display has been controlled by varying the pulse width modulation until now, he indicated that this technique could be combined with pulse voltage modulation. The prototype is a 10-bit design (1,024 gradations), but the firm claims success in 12- to 13-bit designs.

Most PDP and LCD TVs offer 8- to 10-bit gradation performance, with any colors above this range requiring dithering or approximation with signal processing. In contrast, the SED panel may be able to display color signals with this color range without any problem.

[Rob]

Sony also has 1080p sets coming in their 'Qualia' range. The first is a 45" LED tv that renmoves the need for a back light improving colour range, contrast etc. Then there's their 50-70" SXRD rear pro. Apparantly provides a far better PQ than lcd or plasma. Based on LCOS technology. Finally, they have a £25k projection unit capabale of 1080p on a 10 foot screen. Also based on SXRD technology.