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.
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!
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?
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.
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.
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.
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:
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.
(Hopefully someone can visualize what I mean.)