Currently we’re using 4 lasers, 1 for each corner of the screen, so you don’t have to worry about any kind of occlusion. When you put the hand over the screen it draws the contour of the hand, so it’s possible that detects false blobs, but you have had considered this in you’re software because there’s no solution about it. Respect the space between the screen and the laser line it’s a quite difficult to make it uniform to 1mm thick. Always you would have a nice approximation near the laser an a worse one on the other side of the screen, that is because a 1 degree variation near the laser become a big variation as the distance increase. For all of that it almost impossible 1mm uniform distance in all the screen.
We have configured our software how Alexp said in one of his posts, reaching 60fps in 640x480 resolution, you can also reach 120fps. We use FireflyMV.
About wavelenght we first tried with 850nm lasers and a 850+40 bandpass filter, but for the high price we finally used a 780nm lasers with his respective filter.
We could buy more laser with a lower price and a high range line generator.
Im working with mainly 850nm 10mW lasers using a 70 degree line lens
Using 4 fireflymv s’ @ 60fps mono8 @640x480 resolution.
Yeah i know what you mean the hardest thing i’ve found is getting the lasers perfectly alligned parallel to the screen, we just got these brackets machined out and installed the lasers in them, they make a huge difference to ease of alligning the lasers.
Also i noticed that if you play around with the focus lens on the lasers it can really change the beam width, for my setup i’ve got the majority of them around 1~2mm thick just in the past few days.
I wanted to know if you’ve experience this problem… Say you put five fingers on the wall from one hand but your palm doenst touch the screen just the tips of your fingers touch the screen, Does the IR light reflected from your inputs get caught on your palm creating false inputs… (dunno if i explained it correctly)
The laser mounts look very good. Thanks for sharing.
I think it is one of the parts of peoples setup they do not post separate while it is very important to mount the lasers secure while stil able to finetune them.
Most people use modeling past, but i’m looking for a more structural setup that can also be transported. I had some inspiration last sunday and we made a simple 3 axis mount out of scews and metal corners/strips. I’ll put som pictures up next weekend.