Pangolins New Beam Brush Hardware ! & audiance scan !

[Lasermad]

theres an elephant in the room and no one seems to want to talk about it

[drlava]

Bill, sounds good! and you're right I said 'convergence' and was thinking 'divergence' no wonder there was no response.

Here's a question - will the controller for this have features that will help ensure audience scanning safety, or will a PASS/Scanfail system still be needed? For example will the controller read the x-axis galvo position output, will it be able to automatically widen the beam, will it have a blanking/shutter passthrough to shut the lasers down in case of failure?

[Banthai]

Paul Said

theres an elephant in the room and no one seems to want to talk about it

are you refering to me then mate ..... cos ... i did put on a few pounds over the weekend

chuck us a bun ....


But i think ( going back to your first post ) you said ...

imagine not having to worry about audiance scanning ! you simply set a zone where the audiance is and increase the beam size ! ..increasing beam size reduceses amount of laser peower entering your eyes therefore makes it safer etc ......... now the reason why i am hesitant about this is i am sure its not that simple ..or is it ..i also dont think it was directly mentioned at the presentation but everything i know about laser safety and increasing safety the easiest way to resolve is to increase divergence

The problem is ... that yes this can make laser shows safer and make audience scanning safer ( thats the number one reason why i want one desperately )

But you can not lable the device as a LASER SAFETY UNIT as its not failsafe .... for instance a scan fail detector will shut the projector down if a scanner has failed .... full stop ... but this requires the end user ( laserist ) to set parameters and to designate safe zones etc... which means that if the user fits this to the projector and claims the projector is now audience safe ... but in reality has not set the correct divergance for the audience areas .... How safe is it ?

I think it will certainly assist the laserist in making safer shows but the responsibility must go to the end user not this device

all ther best .... Karl

PS : one of the things that Bill did mention about this device ( to make it even safer ) is that because the device (like a G120 scanner ) has a sprung centre return position ... so if the power is removed the lens always returns to the start position ...

this makes it possible to offset the beam diameter .... have a wider ( safer ) beam at the start then focus to a standard beam diameter .... meaning that if used in conjuction with other safety devices ... it would return to a safe position on power failure or scanner failure for instance


Karl

[aijii]

i think i want the fourth one

[Pangolin]

Bill, sounds good! and you're right I said 'convergence' and was thinking 'divergence' no wonder there was no response.

Here's a question - will the controller for this have features that will help ensure audience scanning safety, or will a PASS/Scanfail system still be needed? For example will the controller read the x-axis galvo position output, will it be able to automatically widen the beam, will it have a blanking/shutter passthrough to shut the lasers down in case of failure?

So far, our thinking is that this will be a servo input, similar to the servo input everyone is using for X and Y. It does provide a position signal which can be used as another input to a scan-fail safeguard.

I don't think it would be right to have the servo itself automatically and unconditionally widen the beam based on the Y position (you wrote X but I think you meant Y) because, for graphics applications, this would not be the right thing to do.

Bill

[drlava]

I don't think it would be right to have the servo itself automatically and unconditionally widen the beam based on the Y position (you wrote X but I think you meant Y) because, for graphics applications, this would not be the right thing to do.
Bill

Yes, I wouldn't suggest this. Just trying to flesh out exactly what is required for a safe, approved setup. Whether it's just this, or if a scansafe device is required on top.

It's conceivable that the beambrush controller could be sophisticated enough to be fault tolerant and have the ability to monitor itself and (at least) the galvo that might be able to direct the beam toward the crowd (with some disabling setting for non-crowd scanning situations I.E. graphics shows of course) and blank/shutter/spread the lasers in a fault situation. If done with linear circuits the added expense would be minimal, but the engineering time/design product overlap (PASS) decisions are up to you.

[White-Light]

If the beam brush is mounted pre scanners doesn't this then raise the question of power of loss through partial loss of the beam due to it being wider than the scanner mirrors?

Also, don't the scanner mirrors then act as a limiting factor on the thickness of the beam as you're then limited to a maximium thickness equivolent to the mirror size as anything larger is lost in the projector and not reflected?

[Pangolin]

Yes, I wouldn't suggest this. Just trying to flesh out exactly what is required for a safe, approved setup. Whether it's just this, or if a scansafe device is required on top.

It's conceivable that the beambrush controller could be sophisticated enough to be fault tolerant and have the ability to monitor itself and (at least) the galvo that might be able to direct the beam toward the crowd (with some disabling setting for non-crowd scanning situations I.E. graphics shows of course) and blank/shutter/spread the lasers in a fault situation. If done with linear circuits the added expense would be minimal, but the engineering time/design product overlap (PASS) decisions are up to you.

Maybe it's the fact that I came home to over 600 emails, but somehow I can't really follow your discussion.

But anyway, everyone knows that Pangolin has a good reputation for laser safety and we invented PASS so whatever we do, it will be safe.

If the beam brush is mounted pre scanners doesn't this then raise the question of power of loss through partial loss of the beam due to it being wider than the scanner mirrors?

Also, don't the scanner mirrors then act as a limiting factor on the thickness of the beam as you're then limited to a maximium thickness equivolent to the mirror size as anything larger is lost in the projector and not reflected?

Generally the increase in spot size would not be observed by the scanner mirrors themselves, because the increase is so small considering that the beam brush device is very close to the scanners.

Bill

[White-Light]

Generally the increase in spot size would not be observed by the scanner mirrors themselves, because the increase is so small considering that the beam brush device is very close to the scanners.

Bill

So is it correct to say that what it effectively does is increase the divergence rather than the beam width so the beam width occurs after the scanners?

[DixiScan]

I think I know how this brush-invention works !!

Here can you find the theory with lenses: http://www.ultravires.net/holo2.htm

And a small demo video of it: http://ultravires.net/cube4web.WMV

(of course the LED's are replaced be lasers)

Is it?


Gr,
Dixi