The Propeller UV Green_Board Laser System

Gareth

I present here the driving force behind a Parallax Propeller project i started early September with a blog here Mystery Autumn .

The idea came after buying a Blue Laser at the start of 2011, i noticed when i shined it onto a white surface it gave off a florescence, it did not take me long to test all surfaces and per chance it hit some UV Glow material ............... that's was the beginnings of what i present here.
A while back i was in Technorama (a science exhibition) where they had a huge wall covered in UV sensitive material.... i knew then that i needed a big sheet to play around with ....

UV Sensitive Paint is not very easy to apply and streaky/blotchy ..... so i plumped for a 500mm square sheet of.... i must say long glow persistence UV sensitive Vinyl.
Normally Glow walls are activated with high power "Zenon Flash" lights.
Seems that "Blue Lasers" just dip into the UV light emission range and do a much better Job ..... oh Yehhhh.

Warning :-

1. UltraViolet lasers emit UV light and should be treated with care particulaly when attached to 2D servo systems.
2. Contain the laser inside (its so easy for it to stray out of the windows and attract Aliens) .
3. Wear Protective UV Sun-glasses tuned to block the light frequency you are using for your own safety.
4. Using this device is very addictive and will burn most of your time bringing many experiential Green in-sights.

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The UV Green_Board Laser System ingredients :-

1. UV laser - (mine is <5mw).
2. 500mmx500mm Phosphorescent UV sensitive sticky-backed vinyl stuck onto plexiglass base, from kilabitzzz
3. Two fast Servos - (mine are digital "Full Metal Geared").
4. RBBB Propeller board. available from M44D40
5. PPPB Servo Driver & H-Bridge for laser, available from CTC Mini Prop Undershield
6. Two Lipo batteries for the propeller and servos.
7. Two AA batteries to supply the UV Laser

I aligned the Laser as close as i could to the XY pivot point to remove any rotation error whilst scanning.

The two servos are arranged to allow the Servo to move in 2 dimensions.


Here you can see CTCs Propeller power driver shield. Driving the servos and the UV Laser.

Above the PPPB and Below the RBBB propeller chipped board.

Just for scale and an idea on distance to UV Phosphorescent Sheet.


The system is capable of producing not only XY Graphics.

[video=youtube_share;RojnUp1iFCc]

Or extract ascii letters and graphics direct from the Propeller chip its_self.
Yes the Whole Alphanumeric and graphic set is siting awaiting inside the propeller chip....Big YAY
This is a Coil......

[video=youtube_share;McVACA5g2TA]

But also Vector Graphics..


Here i have some trouble calculating the Set...ServoRamp time_ings (its on list of ToDo )


And Bitmap......

[video=youtube_share;q06OPeHHXxs]

And most fun and revealing the Mandelbrot Graphic series....with Calculations done in Real-Time..
I controlled the intensity of the laser using PWM, this allowed me to create a Green Scale (aka greyscale) graphics.




Thats the system .... if you want to know more then please feel free to comment in the blank boxes below ......

Duane Degn

Another very cool project Gareth!

Who needs a CRT when you have a laser a couple of servos? The servo noise between lines gives a new meaning to "horizontal sync."

Thanks for taking time to document this.

ElectricAye

Very cool.

Does this laser appear blue or is it actually invisible to your eyes? If you can see it and it's blue, it's probably not causing fluorescence via UV activation. Instead, some materials are made to fluoresce in blue light. I think a true laser only emits in a single wavelength, although there are some that use one wavelength to activate another color (a lot of cheap green lasers, for example, use that technique), so I doubt you could have a blue laser that "spills over" into the UV. I doubt it would have a spectrum spread out like that. But, in any case, you've achieved a totally cool effect. Congratulations.

VIRAND

A 405nm laser pointer may make a blue looking spot on a wall because its slightly fluorescent but the beam itself looks purple like a blacklight in the fog.

Gareth

Duane Degn wrote: »

Another very cool project Gareth!

Who needs a CRT when you have a laser a couple of servos? The servo noise between lines gives a new meaning to "horizontal sync."

Thanks for taking time to document this.

Yes the servos are metal geared so the characteristic "Carriage Return" bonus noise shows through.
My latest software does not CR .... it reverses the bitmap pattern and plots it backwards... meaning i also gain some time from eliminating the "flyback time"

Gareth

ElectricAye wrote: »

Very cool.

Does this laser appear blue or is it actually invisible to your eyes? If you can see it and it's blue, it's probably not causing fluorescence via UV activation. Instead, some materials are made to fluoresce in blue light. I think a true laser only emits in a single wavelength, although there are some that use one wavelength to activate another color (a lot of cheap green lasers, for example, use that technique), so I doubt you could have a blue laser that "spills over" into the UV. I doubt it would have a spectrum spread out like that. But, in any case, you've achieved a totally cool effect. Congratulations.

The laser is for sure blue on a pure white background, any other colour and it leans into the violet.
When you observe the laser it give off a weird reflection -- a bit like its there but really the eye cannot focus or accept its there - i cant explain it really , you have to see it to believe it.....
The colour of the laser is really dependent on the surface material, some materials absorb it completely and some glow like "Hell", it is very much different to a red or green laser.
When you shine a red or Green laser at the UV sensitive vinyl it has absolutely no effect...nada not even a faint glow.

Gareth

VIRAND wrote: »

A 405nm laser pointer may make a blue looking spot on a wall because its slightly fluorescent but the beam itself looks purple like a blacklight in the fog.

I like your analogy with the fog ..... (trying to describe the glow off this type of laser if frankly......foggy....fuzzy)
There are indeed different shades of blue - and cheap blue ones lean into the blue-violet range.
I am more than happy that my 405nm laser causes havoc and "excite"-ment to the UV sensitive sheet.

Duane Degn

Gareth wrote: »

and some glow like "Hell"

I was very startled when I first pointed my violet laser at a tennis ball. It was kind of eery how bright it was.

My wife embroiders with glow in the dark thread sometimes. If the thread color closely matches the material color, she'll borrow the violet laser so she can better see the needle work. (The embroidery is done on a machine, she only checks it at the end.)

She often includes hidden messages (usnig the glow in the dark thread) on gifts she embroiders.

Crazyrabbit

Very nice. Surprised theaccuricy of the servos at thatdistance.