We missed [iliasam’s] laser text projector when it first appeared, perhaps because the original article was in Russian. However, he recently reposted in English and it really caught our eye. You can see a short video of it in operation, below.
The projector uses raster scanning where the beam goes over each spot in a grid pattern. The design uses one laser from a cheap laser pointer and a salvaged mirror module from an old laser printer. The laser pointer diode turned out to be a bit weak, so a DVD laser was eventually put into service. A DVD motor also provides the vertical scan which is just a slight wobble of a mirror. A Blue Pill CPU provides all the smarts. You can find the code on GitHub.
The projector is fairly limited in size with a maximum resolution of 32×14. Some displays use a vector scheme that draws with the laser. This is brighter and more capable, but also more difficult to arrange since the laser has to move rapidly in a complex motion. The raster scanning is much easier to accomplish.
A light sensor tells the CPU when the laser is about to start hitting the vertical scan mirror. Obviously, there are other ways you could arrange for the mirrors to move, but the logic would be the same.
We’ve seen [illiasam] has a lot of interest in lasers. He’s hacked rangefinders and even 3D scanners that we’ve looked at before.
i wont be happy until i see someone use this as an ssh terminal.
Definitely… my 1st thought was something vt100ish… or better a later variant with sixels… :-D
cool, reminds me of a fictional book I read 10+ years back where a tech startup gave out laser pointers at a conference that could transcribe and translate then project conversations near it.
Makers by Cory Doctorow, right at the beginning (https://craphound.com/makers/Cory_Doctorow_-_Makers.html#Part1)
The horizontal resolution is not specified, but it’s obviously much more than 32. I believe that 32 is the maximum number of lines that could be displayed, but he’s only using 14 since he doesn’t have a good vsync.
Yes, the real horizontal resolution defined in my code is 256 pixels per line.
And the height is defined as 24 lines, but only 14 of them can be normally used. This is done for maximum hardware simplification.
P.S. This project has its own page at the hackaday.io more than year: https://hackaday.io/project/28338-lasertext
Good start for a laser TV.
I work for the JMGO ( http://en.jmgo.com ) which develops and produces laser TV’s (i.e. the ultra-short throw laser projector), what should i say? projectors using the laser illumination source are the future but currently the projected image quality still cannot be as good as the TV’s, and the price is still high it is declining though.
I would love to mount such a projector on a drone and project text on walls with it. May that be possible?