| « Multitouch Display: a plexiglas case for the LCD FTIR multitouch (part two) |
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)
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)
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| « Multitouch Display: a plexiglas case for the LCD FTIR multitouch (part two) |
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Ciao!
anche io ho letto il post MOLTO interessante di alexP e volevo testare la sua configurazione. Il problema come dici te � cercare il laser e la lente. Sono 3gg che cerco in rete la soluzione e fin ora ho trovato solo la lente e il diodo, tuttavia mi manca il package per racchiudere il tutto. Hai notato quello in foto di alexP? Sai mica dove trovarlo?
grazie
Pole
Ciao Pole,
credo che, alla fine, il package sia il problema più facilmente risolvibile, si potrebbe usare anche uno spezzone di tubo di alluminio o simile. Io invece quel che non riesco a trovare è sicuramente la lente (per il laser forse uso quello del masterizzatore). Tu dove hai trovato laser e lente? Mi passeresti i link? Mi faresti un grosso favore! Se vuoi rispondimi via mail, trovi l'indirizzo nella pagina "about". Grazie! Fabio
Hi,
Hows your work going with the infrared laser, im very eager to finish my exams and get my hands onto a cdrom drive :), i have plans to use linux as the base OS, waiting for your updates :)
Regards
Sharath Patali
@Sharath
Hi, the IR laser is on hold actually as another reader of this blog suggested me some good places to find such kind of lasers at a reasonable price. Actually he's investigating to find also the cylindrical lens, stay tuned!
You can use the base of a (good) wineglass as a simple cylindrical lens, just for testing. :-) Seems to work pretty well.
@Emiel
Thanks Emiel, you're absolutely right. This time, with the LCD multitouch I promised myself to prepare a more stable setup because I would try to use it daily, so I'm trying to go from pure testing to stable and proper methods, the setup may be too unstable with my wife claiming the glass! :o)