Multitouch Display: CD burner infrared laser short test
This is a very short post compared to the ones that I write normally.
Anyway, I was looking around to find how I can achieve the great results that AlexP got in his laser multitouch. I really suggest you to read that link, Alex method is really cool!
So, basically I was guessing where I could find a suitable infrared laser to use for generating a very thin flat plane of infrared light just in front of the multitouch screen.
Googlin' around I found that the laser included in the DVD player/burner is not good as it is a visible red laser of about 650 nm of wavelenght. But the CD player/burner has a chance to be ok as it should be around 780 nm which is just below the visible spectrum that ranges from 380 nm (violet) to 750 nm (red).
Luckily I had an "ancient" SCSI CD burner in my drawer so, of course, I embraced my screwdriver and took it apart.
I was very happy to discover that I can't see anything coming out from the laser with my bare eyes but, once I looked at it with the infrared enabled camera that I use for the multitouch I saw a bright, coherent orange light!
I shoot a very short video:
So, it seems that the laser is really an infrared one. Now next steps may be to collect enough informations on it regarding its real frequency and power.
Further steps will be to understand how to drive it correctly, building a small voltage and current limiter circuit that may power it up without burning it.
Last steps, hopefully, may be to understand how I can get a cylindrical lens without dismantling a craftsmen leveler...
:o)
