Quote:
Originally Posted by EdKozk2
Harry,
Do I understand this right:
Do you have a laser inside of a scannning drum?
Does the scanning beam scan the back side of a
veiwing screen that is coated with glow paint ?
Same idea as storing an image on the old P7 crt's.
Is the image decay rate a problem ?
Cool project 
Ed |
Well the whole project is on the NBTV forum
http://www.taswegian.com/NBTV/forum/...318&hilit=sstv
I am not sure if you can view the pictures and odd video if your not a member but this is the link to my project.
How its done and how i came to getting it to work was a long process the idea was right but i needed to get my head around the correct scanning and how to modulate the laser .
Ok the drum is painted in Glow paint i found the type shown in the last few posts was much better than what i started with as its finer the first type i used was grainy so not great for fine detail.
I used a Uv laser to charge the glow paint the amount of time the paint is charged will glow depends on the intensity of the laser ,think i used a 20mw but all that power is not needed.
Now the glow drums rotation is the vertical line speed stepper motor controlling and the horizontal i used a 6 sided polygon mirror from a broken laser printer stuck on a old floppy drive stepper motor but a 4 sided mirror would do too.
Both the vertical and line speed are manual control so just a pot controlling the stepper motors clock speed .
NO on the decay of the light you can control this with the laser modulation intensity control also by the time the drum rotates around whats left of the last image can be over written with a new image .
The idea was to make a mechanical P7 mechanical monitor copying the P7 CRT results i think infact it can out do it i never tried but i am sure it could do 12 sec at least .
I do plan on making another bit smaller .the screen does not have to be a drum i just went with that idea if you read my posts on the project and see the picture one design was a stationary screen.
I documented by photos and video a fair bit of the project i could just about to a cd or dvd of it any case i have lots ,i tried to put a few videos up but this forum doesn't take them.
Ok the pictures below first is the original drum painted in the first grainy glow paint the little picture of john logie baird its a little grainy close up ,the new glow paint drum its the second picture gives a finer image the last image is the line mirror i used with its stepper motor .