Laser Projected QR Code?

Discussion in 'Digital Video' started by HalfOnWhole, Nov 30, 2011.

  1. HalfOnWhole macrumors member

    May 23, 2011
    Hey guys,

    I know this isn't exactly related to digital video, but I didn't know where else to go. I'm trying to figure out if it's possible to project a QR code related to my company from a laser projector. I haven't been able to locate any useful info on this yet. Of course it would have to be something that a smartphone qr reader could pickup.

  2. jtara macrumors 65816

    Mar 23, 2009
    Why wouldn't it be possible? You feed the projector a video signal in the format it expects (HDMI, DVI, VGA, whatever it accepts), it displays it. It doesn't know what it's displaying. So, generate a QR code on your computer/tablet/smartphone display, and connect whatever compatible external output you have to the projector.

    Maybe because it's obvious?

    Again, why wouldn't it? You point the camera at the screen. It takes a picture. You see the picture on your smartphone display? The QR software should be able to decode it. Again, the software doesn't know whether it's looking at the projector screen or hardcopy. It just interprets the pattern in the image.

    Am I missing something here?
  3. HalfOnWhole thread starter macrumors member

    May 23, 2011
    Well, I understand the concept is simple. I'd rather not have to attach a computer, as this is something I'd ideally have left alone as a sort of advert. A slide projection comes to mind. It wouldn't be shining onto a screen, but rather a large building wall, window, ceiling, etc.
  4. Erendiox macrumors 6502a


    Oct 15, 2004
    Brooklyn NY
    Connecting a cheap computer is going to be the easiest way to produce the image you want. Making a custom slide with your desired image sounds like a hassle to me (and who actually uses slide projectors anymore?). Find yourself a junk laptop that has enough life in it to boot up and spit out a VGA signal. That way you can create your QR image digitally, and you can even change it later if you want.
  5. jtara macrumors 65816

    Mar 23, 2009
    Maybe I misunderstood you. I thought you meant a video projector. Do you mean something else? Like a laser pattern generator as might be used in a dance club?

    It's all done with motors and mirrors. (Literally!)

    These generally project pretty patterns, though, not dot matrices. There are actually laser video projectors, but these are very costly, and probably much higher resolution than you need.

    There might in fact be an issue with a camera being able to record it, because frame rate is likely to be low and the shutter might not be open long enough to get a full image.

    I think this would require quite a powerful laser, perhaps too powerful to be safe. The problem is the large "filled in" areas. The projectors used in clubs display outlines. You need a raster scan, and the brightness will have to be way more than to display a simple outline.

    Get a slide projector. A big, industrial one. ;)

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