Close Encounters of the Third Kind: SED

Written by Vincent Alzieu

Published on October 5, 2005


The three kinds: Plasma, LCD and SED

Every four years, Canon travels around the world and organises three products exposition, one in Tokyo, one in New-York and the third one in Paris. One of them is currently held in la Défense, Paris and it is impossible not to see them.

They have rented the CNIT, a part of the esplanade and the Arch basements. Canon presents current and upcoming technologies in a several thousands of square meters exposition open to the public.

Standard products are exposed such as printers and digital cameras, but there are other products more unusual such as this virtual control by hand of a data bank image projected on a big screen (like in Minority Report!), a camera capable of taking pictures by itself when the user is smiling, hydrogen batteries for digital cameras, transparent digital camera bodies, or even this mobile scanner to see patients’ organs in real time at home. But the high point of this exposition is without any contest the SED monitor!

It has been three years since the first time we heard about this technology. Three years that we have been waiting for an alternative technology, other than the OLED to replace LCD and Plasma monitors. A few figures are enough for everyone to understand why this monitor is so much awaited:

  • Response time : inferior to 1 ms
  • Contrast ratio : 100,000:1 (brightness is of 400 cd/m²)
  • Viewing angles : complete, 180° in each directions.

    In fact, SED seems to be the natural son of TFT and CRT monitors. It combines the thinness of the first and the qualities of the second and improves them. Like cathode-ray tube TVs, SED technology is based on the collision of electrons and phosphoric monitor to emit light. Still, unlike cathode-ray tubes, there isn’t a single gun for the monitor, but a mini electron gun behind each sub-pixel! 1920 x 1080 x 3 = 6.2 million of guns.

    If we take a closer look, each sub-pixel is made of a small glass panel portion covered with phosphor which connects to a conductor. In the rear there is first an empty space, then a transmitter which frees electrons if an electric voltage is applied between 16 an 18 Volts. Electrons emitted are then accelerated by a second Voltage close to 10,000 Volts applied this time between the panel conductor and another one located under the transmitter. They hit the panel phosphor and produces light.

  • First easy point to check: viewing angles. As seen in this image, they really are total. You will notice that the panel has been treated with a process close to Sony’s X-Black. This is the supposedly anti reflection filter which in fact produces the opposite effect. It reinforces contrast but tends to reflect objects. In fact it only does that when a light source is placed in front of the monitor. Usually, in the dark for example or if lighting repartition is good we don’t see our reflection.

    To really emphasize the monitor advantages, Canon organised a test room with the SED placed between a plasma and a LCD TV. All of them where in full HD (1920x1080 pixels) and had 36” diagonal. The LCD almost certainly included an IPS panel, and not one of the best… This is huge. Even if we have to be careful with our judgement (the entire room has been designed to show the SED greatness) we still have a couple of visual tests. We have to admit that we have never seen something like that. Here are a few pictures:

    Shutter speed is one second for the first picture with the sensitivity adjusted to 400 ISO. The camera receives a maximum of light and exaggerates objects’ brightness. Just to give you an idea, the room was dark and it was impossible to see with our naked eye the technology indications.
    On the monitor, the image displayed was supposedly black for all three monitors.

    Ok, competing monitor’s adjustment probably weren’t optimum. Still, by looking at images displayed next, Canon seemed to have used accurate parameters for the plasma TV. Image displayed was superb. The LCD’s was a little bit less nice. Still, we already said that many time, IPS monitors’ black level is far from being as good as competing technologies and in particular VA LCDs. It is also true that we have never been really convinced by big LCDs: washed away black level, twinkling effect etc. But here, it really gets a good trashing for all “tests”.

    We haven’t unfortunately any pictures to illustrate the last test, reaction time. One of the video sequences shows a streetcar moving from right to left. This second test really is impressive: with the LCD the result is disastrous with huge ghosting effect and with the plasma, sharpness is reduced. Video displayed by the SED it is magnificent. I have never seen something like that, even with a CRT. The object lines move without any blurred effect. It is just like a picture of the streetcar moved by hand. Impressive!

    Now we have to step back a little and reduce our enthusiasm. We remind you that this room was designed to show the advantages of this monitor. But still… if you have a TFT monitor at home, display a black image, shut down all light sources to have the same environment as this presentation. Look at your monitor. It is really black? Even better, take a photo in 400 ISO with 1 second shutter speed (we used the PowerShot A620).

    Next question: when will this monitor be released at what will be its price?

    UPdate 10/19/05:The first monitors of this type might be released by Toshiba in 2007. Canon speaks of computer monitors end of 2006, early 2007. Their price? In principle the same than LCD and plasmas for the same diagonal. We can’t wait to test them.