Mirror deflectors

[Sceadwian]

Not sure if this topic has been covered in here before, but what methods would anyone recommend for deflecting a mirror for controlling a laser? I'm looking for a working area of 5 square feet at a distance of 12 feet with a frequency responce in the mid to high audio range (10-20khz maybe) higher if it's practical. I'm thinking a 45 degree mirror used as the control but I haven't a clue where to look for or ideas on how to construct acutators that would be appropriate. The only thing that comes to mind are small voice coils but I have a feeling that would be a nightmare to implement any kind of accurate control of.

The whole idea is basically for a home brew lissajouse generator, although it'd be nice to try some vector graphics as well. I've seen refrences to piezo deflectors, but I'm not sure if something like that would be possible to make at home.

 

[3v0]

Would the voice coil drives from hard disk drives work? Use the existing drive electronics.

Just Googled for it found **broken link removed**

Hacked Gadgets has a follow up to to the hard drive laser oscilloscope, here's how to make one - "A hard drive voice coil circuit is hacked to allow it to be directly connected to a stereo output. This allows audio to move the hard drive read write head. Mirrors are positioned on the center of the platter and hinged on the side to allow a way for the laser to be moved in two axis. The read write head is connected to the hinged mirror so that they move together. And finally a laser is mounted to the hard drive pointing at the hinged mirror. Crank up the tunes and have fun!"

EDIT: The above is driven with a stereo. This link uses a computer to drive a laser scanner but should be of help.

 

[Sceadwian]

A voice coil is going to have bad over/under shoot problems with anything besides a sine wave unless it's heavily damped, I want to try to avoid that.

 

[jbeng]

Look at this link on that big on-line auction site. This sounds like it will (mostly) do what you want. You'll be limited to low frequencies and can do low-quality graphics, but they're still fun to play with.
If you're eventually looking to do hi-res graphics/animations, the price goes up quickly. General Scanning makes hi-speed, closed-loop scanners that a lot of folks use.
You'll also need a servo amp to drive them. And a D/A interface card for your computer. And animation software. And a big, powerful Argon/Krypton white-light laser. And a water cooler (chiller) for the laser. And a whole slew of other mirrors and beamsplitters and stuff on the optical table. Oh, sorry, went a little overboard there...
Jeff

 

[jbeng]

Sorry, I just re-read your original post and the link I sent you to probably won't do what you want. If you want to do graphics at higher speeds like that, you'll probably have to go with the expensive stuff. Apparently, it's quite a science to build scanners that will run at high speeds like that. That it, judging from the prices at least...
Jeff

 

[3v0]

A voice coil is going to have bad over/under shoot problems with anything besides a sine wave unless it's heavily damped, I want to try to avoid that.

The disk drive electronics are designed to handle these problems. I was not suggesting you use a naked voice coil.