4 ms·

Print an Arduino-powered color mechanical television

96 points by sohkamyung 4y ago

mLuby 4y ago
Any reason a belt with holes couldn't replace the disk with holes for a more compact and rectangular viewing surface? Should be easy enough to test with a belt sander. The closest thing from the time was mirror drums but those don't sound too similar, and they had mirrors for some reason.
guerrilla 4y ago
Hmmm, it's tiny... but what about a bigger matrix of LEDs that can be moved around just a little bit. The idea I guess is time-multiplexing lights in space... So if you have a big board with a grid of LEDs and shake it around a bit, you can do the same thing but with less movement and more lights... You get more pixels for the same number of lights. (Hopefully someone can visualize what I mean.)
- deleted 4y ago
  [deleted]
- tyingq 4y ago
  There are little toy fans with 8 or so leds on the blades that do this...show a word while the fan spins.
  - samstave 4y ago
    Ans SUPER expensive ones that appear to make a 3D hologram in the air. However, wouldnt it make sense to change the shape from a square to a wedge/arc that more accurately follows the arc of its orbit and resulting in a tighter pitch between scan line?
  - Animats 4y ago
    There used to be cheap LED wand displays you could wave in the air to display messages. Once popular with ravers.[1] [1] http://www.houseofrave.com/skyliner_message_writer.html http://www.houseofrave.com/skyliner_message_writer.html
- mgdlbp 4y ago
  Better yet, move the matrix in the normal axis to put your pixels in 3D space. https://www.google.com/search?q=swept+volume+display https://www.google.com/search?q=swept+volume+display For something less cutting edge, you can spin a bar with individual LEDs instead of a disk full of holes. Also makes for a good DIY project now that we have the microcontrollers to do it without specialized slip rings. But contrary to popular use, neither of these is a 'holographic display' as they don't use holography!
- cjsawyer 4y ago
  check out the suspected new displays in the next oculus headset https://www.androidcentral.com/gaming/virtual-reality/quest-pro-t-rex-super-resolution https://www.androidcentral.com/gaming/virtual-reality/quest-...
- uggabuggar 4y ago
- zimpenfish 4y ago
  I worked for a company (2009-10) that made big spinny ones for outdoor advertising (they got a few deployed in the UK) and were working on a 8'x5' billboard-style one which had 8 huge rotors, each with 4 arms, coated in (of the time huge) LEDs. When it span up, it sounded like a steam-powered 747 trying to take off. Thankfully (because the potential for catastrophic disintegration was huge) the company went bust before any of these got deployed anywhere near the public.
JKCalhoun 4y ago
I was surprised it looks as good as it does. Amazing.
Animats 4y ago
That's cute. I considered doing that back when I was doing steampunk props. I'd like to see someone revive Scophony.[1] That was the best of the mechanical television systems. It's a much brighter system, because a whole line is illuminated once, not just one pixel at a time. 9' x 12' projectors were built, at 405 lines. The "super-sonic light valve" is the only hard part. That's a long, narrow liquid tank with a transducer at one end. You could probably use a prism from an old laser printer for the fast scanning direction, and 3-phase drone motors to drive the mirrors. Keeping the mechanics in sync would not be hard with modern motor controllers. [1] https://en.wikipedia.org/wiki/Scophony https://en.wikipedia.org/wiki/Scophony
rkagerer 4y ago
https://youtu.be/LmISP_fAAws?t=15 https://youtu.be/LmISP_fAAws?t=15 I find the images gorgeous and could watch this for longer. Anyone know if there's more footage anywhere? Also how big could one theoretically / practically scale this up? How big a wheel would you need for a public display?
UncleSlacky 4y ago
This reminds me of the recovery of original Baird recordings (made on phonograph-style discs) which couldn't be played back at the time, but modern technology came to the rescue: http://www.tvdawn.com http://www.tvdawn.com
linker3000 4y ago
There was a project in the 1980s in one of the electronics mags to make a mechanical TV. I didn't build a unit, but the bit I remember was the need to sacrifice a 12" LP for the disc and drilling a spiral of holes in it.

96 points by sohkamyung 4y ago

Any reason a belt with holes couldn't replace the disk with holes for a more compact and rectangular viewing surface? Should be easy enough to test with a belt sander. The closest thing from the time was mirror drums but those don't sound too similar, and they had mirrors for some reason.

guerrilla 4y ago

Hmmm, it's tiny... but what about a bigger matrix of LEDs that can be moved around just a little bit. The idea I guess is time-multiplexing lights in space... So if you have a big board with a grid of LEDs and shake it around a bit, you can do the same thing but with less movement and more lights... You get more pixels for the same number of lights. (Hopefully someone can visualize what I mean.)

deleted 4y ago
[deleted]
tyingq 4y ago
There are little toy fans with 8 or so leds on the blades that do this...show a word while the fan spins.
- samstave 4y ago
  Ans SUPER expensive ones that appear to make a 3D hologram in the air. However, wouldnt it make sense to change the shape from a square to a wedge/arc that more accurately follows the arc of its orbit and resulting in a tighter pitch between scan line?
- Animats 4y ago
  There used to be cheap LED wand displays you could wave in the air to display messages. Once popular with ravers.[1] [1] http://www.houseofrave.com/skyliner_message_writer.html http://www.houseofrave.com/skyliner_message_writer.html
mgdlbp 4y ago
Better yet, move the matrix in the normal axis to put your pixels in 3D space. https://www.google.com/search?q=swept+volume+display https://www.google.com/search?q=swept+volume+display For something less cutting edge, you can spin a bar with individual LEDs instead of a disk full of holes. Also makes for a good DIY project now that we have the microcontrollers to do it without specialized slip rings. But contrary to popular use, neither of these is a 'holographic display' as they don't use holography!
cjsawyer 4y ago
check out the suspected new displays in the next oculus headset https://www.androidcentral.com/gaming/virtual-reality/quest-pro-t-rex-super-resolution https://www.androidcentral.com/gaming/virtual-reality/quest-...
uggabuggar 4y ago
zimpenfish 4y ago
I worked for a company (2009-10) that made big spinny ones for outdoor advertising (they got a few deployed in the UK) and were working on a 8'x5' billboard-style one which had 8 huge rotors, each with 4 arms, coated in (of the time huge) LEDs. When it span up, it sounded like a steam-powered 747 trying to take off. Thankfully (because the potential for catastrophic disintegration was huge) the company went bust before any of these got deployed anywhere near the public.

JKCalhoun 4y ago

I was surprised it looks as good as it does. Amazing.

Animats 4y ago

That's cute. I considered doing that back when I was doing steampunk props. I'd like to see someone revive Scophony.[1] That was the best of the mechanical television systems. It's a much brighter system, because a whole line is illuminated once, not just one pixel at a time. 9' x 12' projectors were built, at 405 lines. The "super-sonic light valve" is the only hard part. That's a long, narrow liquid tank with a transducer at one end. You could probably use a prism from an old laser printer for the fast scanning direction, and 3-phase drone motors to drive the mirrors. Keeping the mechanics in sync would not be hard with modern motor controllers. [1] https://en.wikipedia.org/wiki/Scophony https://en.wikipedia.org/wiki/Scophony

rkagerer 4y ago

https://youtu.be/LmISP_fAAws?t=15 https://youtu.be/LmISP_fAAws?t=15 I find the images gorgeous and could watch this for longer. Anyone know if there's more footage anywhere? Also how big could one theoretically / practically scale this up? How big a wheel would you need for a public display?

UncleSlacky 4y ago

This reminds me of the recovery of original Baird recordings (made on phonograph-style discs) which couldn't be played back at the time, but modern technology came to the rescue: http://www.tvdawn.com http://www.tvdawn.com

linker3000 4y ago

There was a project in the 1980s in one of the electronics mags to make a mechanical TV. I didn't build a unit, but the bit I remember was the need to sacrifice a 12" LP for the disc and drilling a spiral of holes in it.