Looking for some advise as I want to start a project that uses a laser projector, like a clock projector/keyboard projector.
Anyone know if there is some kind of standard component available like this?
Thx in advance
Joost
A complete module is expensive, 300 dollars and more. Making it yourself is dangerous.
Using a led with a lcd is safe. You could buy a few on Ebay and open them to see how they do that.
think they use mems mirrors (IC with mirros) that can be switched very fast..
You could use an old-school galvanometer movement.
AWOL:
You could use an old-school galvanometer movement.
This could actually be more expensive and/or more difficult than anything else.
If you try to do anything like this without proper positional feedback (on professional galvos, this is usually done via capacitive or optical sensing) - you'll get a mess on the output.
More expensive if you decide to go with actual galvos - those aren't cheap (even used unless you get really lucky), and you need two of them; you also need proper driver boards (with feedback sensing), supplies, etc.
More difficult if you attempt to build your own galvos - which can be done (a few people have done so), but it requires a lot of time, effort, and money to build one, then duplicate it. Lots of fiddling with parts placement, etc (coils, magnets, positional sensing devices and more); then you still need to build custom drivers and feedback electronics to control the parts. Once you have something working, then you're back to tuning, etc. You'll be spending an equal - or likely longer - amount of time building the galvo system than you will on your primary project.
Again - open loop isn't the way to go here, but it can be done if you don't expect quality results (the output will look like a serial killer's scrawl at best). Basically, you want your positioning system to have low mass and high speed, with little "ringing" (settlement at stopping points). Feedback is used to achieve this in actual galvos; with homebrew open-loop "galvos" the problem is that the system usually has high-mass and no way to counteract this (because it is open loop).
One possibility (which will work ok - but still won't be ideal) would be to use bipolar stepper motors for the galvos (with a mirror mounted on the shaft); you energize one set of coils to "hold" the rotor, then you drive the other set of coils to work against the first set. The stepper will "vibrate" as you "position" (based on the voltage polarity, amount, etc). There's a bit on the internet on how to do this - again, it isn't the best method, but it works ok compared to other open-loop designs.