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DIY Retinal Projection

20 points by bcjordan 14y ago

daniel-cussen 14y ago
I'm surprised how useful 3D printing turns out to be for this kind of application.
- robbiep 14y ago
  It's turning up everywhere now for the DIY crowd. Might be stating the obvious but really seems like personal 3d printing is hitting a high saturation amongst those serious enough to blog. The upside for me - So many interesting projects to read about!
jonmrodriguez 14y ago
Awesome stuff! The cool thing about a laser projector is that unlike with a lens-based projector, there is infinite depth of field: http://www.amazon.com/review/R1S9P57VXN5LSH/ http://www.amazon.com/review/R1S9P57VXN5LSH/ But I think there should be some regulation on legal maximum instantaneous brightness. Per the review I linked, the projector used in this project has a 848 x 480 pixel framebuffer. But the laser bounces off a scanning mirror, so at any given time, only one pixel is bright as day and the rest of the pixels are black. This means that the actual power being zapped into your retina is about 400 thousand times brighter than what you perceive. Have there been experiments over the long term to make sure these don't cause retinal sunburn?
- jacquesm 14y ago
  As long as that mirror is moving there is no problem, but if it should ever stop you're in immediate trouble.
logn 14y ago
I generally don't tackle projects that have the words "DIY", "retinal", and "laser" in the description. Granted, the author addresses safety issues.
jacquesm 14y ago
Seen on the outside of the casing of a laser projector: "Do not look into laser with remaining eye". That one was a bit more powerful than this one but the point is still valid. The problem with a setup like this is that in case of deflection failure if you're not projecting into someone's eye that results in an annoyingly bright line but not much else. If you are projecting into the eye then you could quite possibly do a lot of damage, in an eyeblink (to use a bad pun) at that. So it's not just enough to deal with reducing the amount of light put out on average to be safe. You also need to deal with failure modes to get the laser to shut down immediately if anything puts the actuators out of order.

20 points by bcjordan 14y ago

daniel-cussen 14y ago

I'm surprised how useful 3D printing turns out to be for this kind of application.

robbiep 14y ago
It's turning up everywhere now for the DIY crowd. Might be stating the obvious but really seems like personal 3d printing is hitting a high saturation amongst those serious enough to blog. The upside for me - So many interesting projects to read about!

jonmrodriguez 14y ago

Awesome stuff! The cool thing about a laser projector is that unlike with a lens-based projector, there is infinite depth of field: http://www.amazon.com/review/R1S9P57VXN5LSH/ http://www.amazon.com/review/R1S9P57VXN5LSH/ But I think there should be some regulation on legal maximum instantaneous brightness. Per the review I linked, the projector used in this project has a 848 x 480 pixel framebuffer. But the laser bounces off a scanning mirror, so at any given time, only one pixel is bright as day and the rest of the pixels are black. This means that the actual power being zapped into your retina is about 400 thousand times brighter than what you perceive. Have there been experiments over the long term to make sure these don't cause retinal sunburn?

jacquesm 14y ago
As long as that mirror is moving there is no problem, but if it should ever stop you're in immediate trouble.

logn 14y ago

I generally don't tackle projects that have the words "DIY", "retinal", and "laser" in the description. Granted, the author addresses safety issues.

jacquesm 14y ago

Seen on the outside of the casing of a laser projector: "Do not look into laser with remaining eye". That one was a bit more powerful than this one but the point is still valid. The problem with a setup like this is that in case of deflection failure if you're not projecting into someone's eye that results in an annoyingly bright line but not much else. If you are projecting into the eye then you could quite possibly do a lot of damage, in an eyeblink (to use a bad pun) at that. So it's not just enough to deal with reducing the amount of light put out on average to be safe. You also need to deal with failure modes to get the laser to shut down immediately if anything puts the actuators out of order.