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Tiny volumetric display

mitxela.com

51–60 of 180 posts

Re: Tiny volumetric display

#51

holy hell is this guy productive. it is worth scrolling through the various one-off projects he has completed and documented: https://mitxela.com/projects

I thought so too but look at the dates and the scope of the projects. They're just good at managing their time :) I probably have just as many projects accumulated over the years.

Re: Tiny volumetric display

#52
post #35

Earlier quoted context omitted.

The fundamental problem is refresh rate. If you have two phones that refresh at 240Hz (the fastest I know of), and you want your frame rate to be 12 Hz, you’ll still only be getting 20 refreshes per 180 degree rotation. So your angular resolution will only be 9 degrees. Assuming you use portrait mode, that will make your outermost voxels ~5 mm arcs. And even there, 12 Hz is probably pushing it in terms of flicker.

Yeah, well, that's not going to work. Interesting problem all the same. For a 1 meter diameter and height cylinder at 60Hz voxel refresh and say 1mm resolution at the edge one would need the plane rotating at obviously 3600 rpm, and edge pixels switching at about 380KHz. Since rgb is nice to have that's 10 gigabit for a somewhat coarse display. Nothing impossible, but not a DIY territory yet. I think one'd want the L…

Note that in your hypothetical 1m 60Hz display, the edge of the cylinder is moving at 422 miles per hour. I'm going to recommend an evacuated transparent bell jar for safety, at a minimum...

Re: Tiny volumetric display

#53
A couple ideas for improvement. If you have extra identical motors and disassemble two, you can fashion a rotating power transmission system from the brushes in two assemblies. You sacrifice two motors for each unit, but it's a perfect fit and very reliable (with a cap and rectifier), and you don't have to worry about batteries anymore.

The rectifier also provides a signal that the assembly has completed a rotation, so you can maintain image stability based on actual position, rather than guessing how long a cycle is.

Transmitting power via induction might work, but I was never able to deliver it efficiently enough, so to make it work I had to turn up the source voltage so high that I worried about fires.

This advice comes from my 2001 Burning Man art project. A very sad early prototype is pictured here: https://github.com/sowbug/tqw/blob/master/photos/side.jpg. The final installation worked great.

Re: Tiny volumetric display

#57
post #4

The centering issue could be solved by putting two led boards on top, back to back.Perhaps one board could shift the leds over by half to create an interlacing effect while doubling resolution.

Or just ... don't center, and change the math to acknowledge that the LEDs aren't centered?
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