Wednesday, May 10, 2006

The next generation of TV

I just ran across this article from Canon (see above link.)

All TV technologies have some key problems with them:

  • CRTs are heavy, use a lot of electricity, and have a practical size limit. The largest widescreen CRTs I know of are 34". The largest 4:3 aspect CRTs I know of are 40". This is a nice size, but is small compared to what other technologies can provide.
  • Internal projection systems (CRT, DLP or LCD) can go to huge sizes, but there are brightness problems. Images tend to dim-out if you watch the screen from an odd angle. CRT-based projectors often suffer from burn-in, so they create problems for video games and those TV channels (like news channels) that have tickers and static images on-screen for extended periods of time. Replacement projector bulbs (for DLP and LCD units) can be expensive.
  • External projection systems (LCD and DLP) can be projected to humongous sizes, but you need a place to put the screen, and the projector needs an unobstructed view of that screen. Lenticular screens (that give you maximal brightness) tend to dim-out when seen from odd angles. And replacement projector bulbs can be expensive.
  • Plasma screens look great, but they can suffer from burn-in. They also tend to lose their brightness and/or focus after a few years. Considering how expensive these screens are, I can't see myself ever buying one. (But if you want to give me one for my birthday, I won't refuse to use it.
  • LCD screens look great (and modern units don't have the off-angle fading and color distortions that were a problem in the past), but they can be very expensive. Especially at very large sizes.
Well, canon has solved these problems with their SED technology.

SED can be thought of as the successor to CRT technology. A traditional CRT has a screen coated with phosphors that glow when hit by an electron beam. An electron gun at the back of the tube beams electrons at the phosphors to light them up. Deflector magnets bend the beam so it can hit more than just the phosphors directly in front of the beam. Circuitry manipulates the deflectors so the beam scans over the entire phosphor-surface 60 times per second (or faster, depending on the refresh rate), producing the image.

This is the reason CRTs can't get much larger than they are now. When the screen gets larger, you need more distance between the electron gun and the screen, since the deflectors can only bend an electron beam so far before it loses focus. Increasing the distance from the gun means you need more electricity (since the beam has a longer distance to travel), and it means the TV will get larger.

With SED, they eliminate this problem. Instead of a single electron gun, producing a beam, there are millions of micro-size electron-emitters. One for each pixel. Since each one beams its electrons straight ahead, there is no need for deflector magnets, and no need for a great distance between the emitters and the phosphors. The result is a screen with all the brightness, color definition, and off-angle quality of a CRT, but completely flat, and with lower power consumption. And there is no technical reason why SED panels can't be made as large as plasma screens - which means pretty much any size the public will be willing to buy.

I can also see these replacing LCDs as the display of choice for computers. Especially for graphic professionals. Large flat screens without all the contrast and color issues that professionals have with LCDs.

This tech is still experimental, so I don't know when we'll see commercial products, but hopefully it will be soon. This seems to me that it will end up being the best of all worlds (unless you want the wall-filling image size of an external projector, of course.)


MuyCaliente said...

The other problem with CRT's that the new tech won't fix (and may make worse) is the retina burning radition emitted. I'm a big fan of Sony's new SXRD tech.

Shamino said...

Radiation from CRTs is hype and hysteria. See this article for more details.

While older sets (especially from the 70's and earlier) had poor shielding, modern sets have been shielded for over 20 years.

Back in the 80's some European nations started passing strict laws about emissions from CRTs. All manufacturers modified their designs in order to comply with these standards. Today, it would be hard to find a new set that doesn't comply. The result of all this shielding is that (as the above-linked IBM article points out), the amount of radiation from a modern CRT is virtually undetectable, and orders of magnitude smaller than many forms of radiation that nobody cares about.

As for the TV you linked to, it looks nice, but it's a projector. Which means it will fade/dim if you aren't sitting in the sweet-spot in front of it. But maybe you don't care about that - I seem to be more annoyed by this than most people.

The bigger problem with it is that it is a Sony. My personal experience with Sony products is that they are all garbage. They all have failed within 2-4 years after purchase, always just outside of the warrantee period, and repair costs are usually higher than replacement costs. This includes computers, tape drives (including 4mm, 8mm and VHS), CD players, cameras and TVs. The only Sony products I've used that haven't failed prematurely are professional computer monitors - and they are extremely expensive. (No, I didn't personally buy all of these devices, but most of them.)

When combined with the fact that Sony equipment is usually among the most expensive brands, it's just adding insult to injury.

I've been burned enough with Sony's poor reliability that I will only buy a Sony product if there is absolutely no other choice. (Like when I needed to buy an audio CD player - Sony is the only brand you can get that isn't complete trash or insanely expensive.)

If this same TV was sold with a Panasonic brand, I would be far more interested.