Slashdot Mirror

← Back to Stories (view on slashdot.org)

Sony Projector Gets Bright Images From Black Screen

Posted by timothy on from the paradoxically dept.

da_foz writes "Sony has developed a new projector that can give a bright, unfaded picture without the need to eliminate ambient light. The secret is that they project onto a black screen instead of a white one. Their screen uses species filters so that white ambient light is absorbed, but the red, green, and blue light from the projector is reflected. Sony sees a possible use in home entertainment systems because of the ability to have a much bigger picture than conventional TVs as well as businesses adopting the projectors for presentations."

4 of 357 comments (clear)

  1. Now if only... by Insomnia · · Score: 4, Interesting

    ...they could come up with a lamp that would actually last. I've gone through at least 6 InFocus projectors in the last 1.5 years due mainly to bulb failure.

    This technique sounds really cool though, perhaps I won't need to have all my windows boarded up anymore. ...hey, what's that bright thing in the sky outside?

    1. Re:Now if only... by Lumpy · · Score: 4, Interesting

      yes bulb on and going strong....

      turning that bulb on and off does more to it's life than leaving it on... now leaving it on 24/7 will get you to the diminished light output and dead point far faster, but you can easily triple your bulb's typical life by leaving it on when you are not going to be watching it for short peroids of time.

      also don't even be tempted to enclose the projector. it must have free air flow from all sides and NOT be located near a AC/heat vent.

      --
      Do not look at laser with remaining good eye.
  2. Are three colors protected by patents? by ironring · · Score: 5, Interesting
    This appears to be a very cool technology. I have wanted to put a front projection system into my home, but have no way to control ambient light during the day. When this screen becomes available, it will probably push me over the edge.

    I assume the three frequencies that are reflected are fairly well tuned. I wonder if this means I will be stuck purchasing a Sony projector to match these? I also wonder if Sony may be able to stop others from making matching projectors since they probably own some Patents around this technology?

  3. Re:Black? by baxissimo · · Score: 4, Interesting

    The red green and blue of projectors or monitors or whatever are not a single frequency of light. LEDs don't give you pure frequencies either. Lasers are the only thing that give you light at a pure, single frequency I think. On the other hand, this page seems to indicate that DLP light consists of sharper spectral peaks than either LCD or CRT (3rd paragraph).

    But still I suspect that their filters probably filter out some of the visible light coming out of the projectors, making this black screen not quite as bright as a comparable white reflective screen. After all it has to be easier to make a material with close to 100% diffuse reflectance across the whole spectrum than to create something that's near 0% everywhere except for three narrow notches which are near 100%. But I'm no expert on light

    So I'm thinking it's highly unlikely that the the filters come anywhere near 100% black in the non-reflected parts of the spectrum. No doubt this is the blackest projection screen you've ever seen, but I really doubt it will be the blackest thing you've ever seen. Especially if you've seen Undercover Brother

    Still it's a pretty neat trick. Anyone know how they make passive filters with such sharp tuning to specific frequencies. Is it some kind of diffraction thing?