Many hackers have experimented with the persistence of vision effect. Whip around a bunch of LEDs, flash them at just the right times, and it’s possible to make images to appear to hang in the air. There’s plenty of ways to do this, whether by manually shaking the LEDs by hand, spinning them around, or even putting them on your bike wheels. [Carl Bugeja] went a different route, taking advantage of the possibilities created by flex PCBs.
[Carl]’s project goes by the name FlexLED. This aptly describes the build, which, in prototype form, mounts a single LED on the end of a flex PCB. The PCB itself has a pattern of traces creating a coil, which enable it to interact with magnetic fields more strongly. By passing the right current through the coil, the flexible PCB can be made to flap up and down, moving the LED on the end at a rapid rate. By then controlling the flashing of the LED, it’s possible to create a persistence of vision effect.
Currently fitted with only one LED, capable of 3 colors, the visual display of the FlexLED is somewhat limited. However, [Carl] reports the effect is more impressive in person than on camera, and is already working on plans to scale up the project to a multi-LED diplay.
POV technology can do some pretty impressive things – even volumetric displays are possible. If you’re working on something yourself, be sure to let us know. Video after the break.
For those that haven’t heard of [Carl] before, I highly encourage you to watch/subscribe to his channel. Interesting content, educational, and astonishingly high video quality/production values for a ~10k subscriber channel!
So seems like he could easily do two directions like x and y, maybe with a little mirrors instead and then thereby make sort of a laser light show galvos out of it? Maybe even a cheap 3d resin printer ala the defunct peachy printer only hopefully without the defunct part?
This reminds me of an eyeglasses-mounted head-up display based on vibrating a set of fiber-optic tips in the form of the end of a vibrating ribbon, making a POV display with 128 LEDs remotely-located at the other end of the ribbon.
From 1982… http://wearcam.org/computing/HUD-paper/HUD.html (Thanks to Steve Mann for archiving all this stuff from back in the early days.)
Wow impressive, thanks for the link!
Do you know how the vibration can be correctly transmitted from one end to the other of the fiberoptic ribbon?
They do not explain this and it seem to me to be the most complex and limiting part of the idea haha
In case it’s not clear, only the very tip (a few millimeters) of the fiberoptic ribbon oscillates (vibrates). Without going back to look at the original material, my recollection (from 3+ decades ago!) is that there is a tiny magnet glued near that tip. The tip oscillates at the resonant frequency of the fiber, like a tuning fork, and the magnet nudges it at that resonant frequency, driven by a small (stationary) coil: just about the reverse of how [Carl] does it here. I’m not sure how they get the phase correct and stable. That’s the part I found difficult when building things like this.
There was a product, I believe back in the late 80’s called The Cube. It seems to me PC magazine did a review of it back then. It was one of the first in-front-of-eye retail products I think. But I could never find it when I went back and looked in the last few years. I don’t think it ever made headway in the market – likely too many years ahead of it’s time. It may have been at Vegas in 90′ – can’t remember for sure. I do remember that was the year video toaster was shown, along with a mouse shaped like a pen (only square body) – I actually won one in a give away. Likely based on the patent. As I recall the reviewer said the cube hummed/vibrated slightly in use – almost like Piezo unit with an LED on both axis. Does that ring a bell?
Sounds like the Private Eye http://www.loper-os.org/vintage/paralleleye/eye.html
I had one of those mouse pens — one of my many attempts to find something that didn’t aggravate my RSI. It was worthless.
Worthless is right. The mouse ball was too small and too close to the square body making it difficult to control. And the buttons sucked. And no – I don’t believe that was it – however, I liked the article. It bears mentioning we were still using 56k modems and BBS for comm, and if you were lucky you had an FTP connection to the college paper network your were on cloud 9. Before Netscape, hell – I didn’t even use a CDrom until 92. 720 and 1.4 meg diskettes were killer, and Windows came on like 14 diskettes. Still, those days were a lot of fun if you were Developer (Programmer/Analyst back then).
Nice project Try to put 8 or16 smd led to make a 2d display
Looks like a good start on what’s needed for a super high speed LASER deflector for light shows. LASER vector arcade games without having the corners rounded off due to galvanometers being unable to move quite fast enough.
There use to be paddle-mounted LED displays that could be programmed to display a message as the paddle was swung. I saw them in use by parking attendants. There was only a single row of LEDs. The trick was using an accelerometer to change the LEDs at just the right speed, so that persistence of vision made the message appear to hang in the air.
this is neat just as a way to visualize a magnetic field
The design is an equivalent of a regular speaker sans the cone. It is a neat idea, but it is not a breakthrough in galvo scanning, nor it is a novel way of looking at magnetic fields.