I’m no specialist, so please correct me if I’m wrong. AFAIK, the problem with lasers hitting someone’s eyes is that the light if very focused and concentrated. Once the beam hits an object, provided it’s not mirror-like, it gets diffused and becomes as harmful as any other light source at the same intensity.

Am I missing something or is this line of thought correct?

Yes you’re right, if you are using a line generator or something to diffuse the laser beam you won’t have to wear glasses when you use your multitouch table, but you can’t look right into the beam !

Just to let you know that I posted a new thread about the Airplane controller, our LLP setup for ordinary surfaces:

http://nuigroup.com/forums/viewthread/7504/

Cheers

Alain

does anybody know Aixiz 780nm 10mW laser diode pinout? As I read somewhere on forums, Thorlabs diode and Aixiz diode have different pinout....

This is a noobie question I guess but I am wondering something about wiring the lasers. Do I wire the lasers in a parallel circuit or do I wire them in series?

warmachine - 12 September 2010 11:25 AM

This is a noobie question I guess but I am wondering something about wiring the lasers. Do I wire the lasers in a parallel circuit or do I wire them in series?

It is advised to wire the lasers in series.
You may want to read the group’s book. There is an appendix that thoroughly explains how to use the lasers in an LLP configuration.
http://nuicode.com/projects/wiki-book/files

Just downloaded the book and it says “Lasers are almost never wired up in series, and there is no reason to do this for a project of this kind. We recommend wiring them in parallel...”
but thanks anyways for the info about the book.

warmachine - 13 September 2010 09:21 PM

Just downloaded the book and it says “Lasers are almost never wired up in series, and there is no reason to do this for a project of this kind. We recommend wiring them in parallel...”
but thanks anyways for the info about the book.

Ooops.. I meant parallel

hey, i ordered recently three 30mw 780nm Laser für an 10” monitor.
(two at the top edges and one on the center of them)
but now I’m not sure whether the lasers are too strong?

im looking to swap FTIR for lasers due to never being fully satisfied with it. my screen is 50” (diagonal), how many lasers will i need? im hearing 2 would be ok, but im also hearing as many as 4 per corner are needed.

out of the following which would be best?

780nm 25mW Infrared Laser
850nm 5mW Infrared Laser
850nm 10mW Infrared Laser

cool mr croc - 30 May 2011 11:07 AM

im looking to swap FTIR for lasers due to never being fully satisfied with it.

Sorry to quote you here, but im just about to start a project but its an lcd ftir. Why are you opting for llp, what wasnt so good?

fracmo2000 - 30 May 2011 05:37 PM

cool mr croc - 30 May 2011 11:07 AM

im looking to swap FTIR for lasers due to never being fully satisfied with it.

Sorry to quote you here, but im just about to start a project but its an lcd ftir. Why are you opting for llp, what wasnt so good?

the camera isnt perpendicular to the screen, the top part of the screen is further away than the bottom, blobs registered at the top are smaller than those at the bottom. so when i set up ccv there is a trade off, the threshold for minimum blob needs to be small enough to register those at the top whilst big enough not to recognise the small blobs left when the compliant layer ever so slightly sticks after a touch. the compliant layer was a massive source of grief for me and id love to remove it. im going to try a hot mirror to see if that will help with the ftir first.

i didnt think you could still use ftir whilst using lcd? have you taking a television and hacked it apart? thats what i would like to do for my final stage of the project but i dont know which model would be guaranteed to work.

cool mr croc - 30 May 2011 05:43 PM

fracmo2000 - 30 May 2011 05:37 PM

cool mr croc - 30 May 2011 11:07 AM

im looking to swap FTIR for lasers due to never being fully satisfied with it.

Sorry to quote you here, but im just about to start a project but its an lcd ftir. Why are you opting for llp, what wasnt so good?

the camera isnt perpendicular to the screen, the top part of the screen is further away than the bottom, blobs registered at the top are smaller than those at the bottom. so when i set up ccv there is a trade off, the threshold for minimum blob needs to be small enough to register those at the top whilst big enough not to recognise the small blobs left when the compliant layer ever so slightly sticks after a touch. the compliant layer was a massive source of grief for me and id love to remove it. im going to try a hot mirror to see if that will help with the ftir first.

i didnt think you could still use ftir whilst using lcd? have you taking a television and hacked it apart? thats what i would like to do for my final stage of the project but i dont know which model would be guaranteed to work.

Ah thanks for the explanation mr croc, Im new to all this and see lots of post saying they are going lcd/llp...I just dont know why. Its been making me wonder, have I picked the wrong horse?