0 to 360 degree camera and MORE!

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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Fri Sep 09, 2016 12:28 am

The forum seems a bit dead at present and probably there is little interest in this laser
project anyway.
However, I have made some discoveries.

Firstly, the 45 degree angle of the fast rotating 1/4 inch mirror is absolutely critical to give
straight line scanning. Even a few thou error leads to inches of error in line linearity.
(the scanning line rises and falls)

Secondly, although it will scan up to 180 degrees, any image wider that this leads to inversion !!
For example, as one scans down, the laser over 180 degrees, is rising up and vica verca.
This will always happen even if not using any rotating mirror.

So a 360 degree scan image will have the first 1/2 correct and as one goes over 180 degrees
the second part slowly reverses. Interesting eh? :lol: This could probably be overcome
by plotting the 180 to 360 degree of the image in reverse in the software program.

The laser width is too big for very big close ups (less than about 3 feet), so I must see
if I can focus it smaller.

All 3 sections of construction are now underway......

The circuits for ADC and PWM etc. The mechanical construction and the laptop program I am working on.
“One small step for a man,"......because he has Arthritis.
Albert.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Fri Sep 09, 2016 2:25 pm

Viewmaster wrote:The forum seems a bit dead at present and probably there is little interest in this laser
project anyway.


I am interested Albert i am sure others are !

I am keen to see the mechanical side of it ,Your type of wide scanning is something i have not tried .

So your going to try 180 now ? 360 perhaps 2 lasers either side of the rotating mirror then you have a full scan but i bet lining them up would be touchy but not impossible .
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Fri Sep 09, 2016 5:57 pm

Although the rack and pinion for frame is working OK it's now in the melting pot !!!

I think I have a better idea using one tiny mirror as at present for line scan
but a second tall slim rotating mirror for frame. The laser reflection from the first
mirror 'running up and down' the second mirror !

The tiny one does the line scan and the vert one frame.

Although the scan width might be limited to just under 180 degrees
the frame speed of the system could run very fast if required,
unlike the present rack and pinion.

Unlike my rack and pinion there is no fly back return required. Nor is there
any non linearity either. Another bonus is the rig would be very small in size.
Just two tiny (no need for power to drive a rack) PWM motors and tiny mirrors
and one laser. No micro switches etc either.

Software much the same as before.

We shall see............. I do luv melting pots ! :lol:
“One small step for a man,"......because he has Arthritis.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Fri Sep 09, 2016 9:00 pm

Viewmaster wrote:Although the rack and pinion for frame is working OK it's now in the melting pot !!!


Arrr this happens all the time funny what happens when you make something and work out a better way

I think I have a better idea using one tiny mirror as at present for line scan
but a second tall slim rotating mirror for frame. The laser reflection from the first
mirror 'running up and down' the second mirror !


Yes this will work !
viewtopic.php?f=1&t=1557&hilit=octagon

The tiny one does the line scan and the vert one frame.

Pretty much done this a while back sure works ...works much better a mirror with more sides for the line scan

Although the scan width might be limited to just under 180 degrees
the frame speed of the system could run very fast if required,
unlike the present rack and pinion.


Yes with a polygon or more sided mirror from a laser scanner i got up to 60 lines easy had no video signal to test above that at the time ,i would not be surprised if it could do double that ,so yes well worth trying !

Unlike my rack and pinion there is no fly back return required. Nor is there
any non linearity either. Another bonus is the rig would be very small in size.
Just two tiny (no need for power to drive a rack) PWM motors and tiny mirrors
and one laser. No micro switches etc either.


Yes again that will work ,i would go will at least a 4 sided one for the frame ...never tried just one but you would need speed //i like stepper motors for the frame and DC PWM yes for the line ...that in the line was all manual control .

Software much the same as before.

We shall see............. I do luv melting pots ! :lol:

[/quote]

Good luck Albert on the reboot
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Sat Sep 10, 2016 12:53 am

Harry, you seem to have done it all before, on your own, years ago!!

Why do I bother except I will not have any varying motor speed rotational sync
problem to overcome and its near 180 degrees............

As the the old cockney song of old said, "My old man said follow the van........."

In my case it's, " My old laptop will follow the scan." :lol:

Have you ever made a matching laser camera and recorded
its output for future playback ?

I do hope now that my bloody melting pot gives it a rest as it gets
expensive to keep it melted :lol:
“One small step for a man,"......because he has Arthritis.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Sat Sep 10, 2016 12:47 pm

Viewmaster wrote:Harry, you seem to have done it all before, on your own, years ago!!


Not the same design as yours and your project is a camera ,the dual mirror scanning has been done before i more than likely was inspired by Allan shorts many mirror projects just changed it a bit for what i had handy and could construct best could ,not to pretty but it was a proof of concept ...i don't know how this ended up but much better at constructing stuff than me ....
viewtopic.php?f=1&t=2090&start=30

Why do I bother except I will not have any varying motor speed rotational sync
problem to overcome and its near 180 degrees............


I was thinking at the time to try a flying spot idea to as a second use but never got around to it and being all in manual control i would of had trouble any way ...so yours is different Albert we think alike we all do on the same problem !

As the the old cockney song of old said, "My old man said follow the van........."

Well i followed to so was not me who thought of the idea we all hold hands as we match though time :lol:

In my case it's, " My old laptop will follow the scan." :lol:


Yes this is some thing i would like to see i have no idea how to work that out ...so seeing you do it is interesting to me .

Have you ever made a matching laser camera and recorded
its output for future playback ?


For a short time ........in a different way when Gary pointed me to the way of a flying spot camera i started off using a defocused green laser pointed at the back of the Nipkow and then lens focused it to the subject ...worked fine till i broke the laser wiring it up to the main supply instead of its current limiting supply :roll: i then replaced the laser with one luxeon Led with that i mixed the video with the sync and recored the result....it would of been a laser if not for my lack of attention ....viewtopic.php?f=1&t=1523&hilit=question&start=135

I do hope now that my bloody melting pot gives it a rest as it gets
expensive to keep it melted :lol:

[/quote]

The dual mirror side of things i found only the line scan is critical the frame is easy may be harder in your system ? analog is so much easer !
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Sat Sep 10, 2016 8:06 pm

Harry, I am not interested at present in getting moving pictures.
Just to experiment in software processing various lines/frames speeds, scan widths
and heights on the laptop.

So keeping it simple with single mirrors for line and frame. They will be quite OK for what
I wish to do and keeps construction time down.

In any case, even at a lowest 1 frame per second there will be nil flicker on this system as
the next incoming image can just easily overwrite the previous one on screen. So a
constant picture is presented.

It was the Cambridge rig that demonstrated to us that by using a PC one could generate
large pictures from a simple scanning system.

I have 'bit' the' byte' bug now. :lol:
“One small step for a man,"......because he has Arthritis.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Sun Sep 11, 2016 12:24 am

Viewmaster wrote:Harry, I am not interested at present in getting moving pictures.
Just to experiment in software processing various lines/frames speeds, scan widths
and heights on the laptop.


Still pictures are easier the frame rate can be slow and get more lines ....you can invent the Albert system and whos to say any different .!

So keeping it simple with single mirrors for line and frame. They will be quite OK for what
I wish to do and keeps construction time down.


Sure i understand no problems then a single mirror you can do all that for sure !

In any case, even at a lowest 1 frame per second there will be nil flicker on this system as
the next incoming image can just easily overwrite the previous one on screen. So a
constant picture is presented.


So it will be a type of modern and old mechanical facsimile in a way ,i like this idea it tends to be forgotten it was invented before even voice transmissions and all electric before electronics which is amazing to me .

It was the Cambridge rig that demonstrated to us that by using a PC one could generate
large pictures from a simple scanning system.


Very neat idea too.

I have 'bit' the' byte' bug now. :lol:
[/quote]

The software your writing would be pretty unique....

I suppose would not be to hard at those speeds to do colour if you wanted ?
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Sun Sep 11, 2016 2:28 am

Harry,as you are into so many NBTV things I daresay you may have
meddled with this non opto pulse generation.

For the frame mirror (and maybe line) instead of using opto to get pulses
I am going to use a tiny home made commutator. It might be intermittent but I like to
try new things I haven't yet done. Frame revs are very low .
Maybe you have experimented with this system in the past?

In parallel with the frame shaft I have tapped a 6 BA hole into a nylon section and put in a brass screw.

Then turned down the nylon diameter until the screw is partly exposed.

TWO, very small silver looking brushes, (with 3 forks on each), taken from
a tiny high speed brushed mini motor and mounted side by side, will contact
this exposed brass each rev and so be shorted to each other, thereby giving a pulse.

As there are 3 mini forks to each brush there's a good chance that at least one will do the shorting out
at each rev. To do this on the very high speed line shaft might be a trifle risky though.
“One small step for a man,"......because he has Arthritis.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Sun Sep 11, 2016 11:49 am

Viewmaster wrote:Harry,as you are into so many NBTV things I daresay you may have
meddled with this non opto pulse generation.


Yes have tried some thing else Hall effect sensor with tiny magnets ,that worked just as well.
I think they can pick up ferromagnetic metals but i was trying it on a plastic drum and the magnets gave a nice pulse BTW should be able to pick up those plastic fridge magnets easy.

For the frame mirror (and maybe line) instead of using opto to get pulses
I am going to use a tiny home made commutator. It might be intermittent but I like to
try new things I haven't yet done. Frame revs are very low .
Maybe you have experimented with this system in the past?


I am a little bit iffy as they are noisy as you say but slow i don't think it would matter.
... but your idea being slow might just be able to use those tiny position switches in printers or reed switch with a little magnet ....they are pretty good at some higher speeds ...never tried a home made commutator but looked into it and i ended up going with an induction idea .

In parallel with the frame shaft I have tapped a 6 BA hole into a nylon section and put in a brass screw.

Then turned down the nylon diameter until the screw is partly exposed.


I don't think you would have problems slow and it is more satisfying making this especially when it works.

TWO, very small silver looking brushes, (with 3 forks on each), taken from
a tiny high speed brushed mini motor and mounted side by side, will contact
this exposed brass each rev and so be shorted to each other, thereby giving a pulse.


Yes again it sounds good and would work ,,i would look on a scope and see what speed it starts to look ruff if at all ?

As there are 3 mini forks to each brush there's a good chance that at least one will do the shorting out
at each rev. To do this on the very high speed line shaft might be a trifle risky though.


I think you will be right Albert lots of ways to do the same thing as we know and does not hurt giving it a try and see its always fun trying !
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Wed Sep 14, 2016 6:34 pm

Here's the experimental scanner. Shows worm drive to frame mirror and 45 degree 1/4 inch high speed line mirror
(it's the one held by a jubilee clip!)

Laser shines straight onto tiny rotating line mirror which in turn shines onto slower speed long frame mirror thereby
getting nearly 180 degree max width scan. ( width can be controlled on laptop)

Sorry, there is no Lego anymore. :D


Image
“One small step for a man,"......because he has Arthritis.
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Wed Sep 14, 2016 7:50 pm

Viewmaster wrote:Here's the experimental scanner. Shows worm drive to frame mirror and 45 degree 1/4 inch high speed line mirror
(it's the one held by a jubilee clip!)

Laser shines straight onto tiny rotating line mirror which in turn shines onto slower speed long frame mirror thereby
getting nearly 180 degree max width scan. ( width can be controlled on laptop)

Sorry, there is no Lego anymore. :D






Arrrrr i have been keen to see the build Albert .
I have always found the frame mirror hard to drive slow by a DC motor but you must be wanting it running faster always gone with a stepper motor here ...

I think i have only tried once a one mirror line mirror but i didn't understand enough about modulating a luxeon around 2008 .

That looks like a mighty laser Albert what did you end up getting ?
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Wed Sep 14, 2016 8:14 pm

It's just a standard cheap green laser pen bought in eBay, Harry, for a few quid.
I may have to get higher power..........wearing my laser safety googles.

No stepper motors used. Just two PWM's.
The worm gear (8/1 reduction at present) gives me a frame rate from about 1 per sec up to about 12 per sec.
Small brake will be put on that frame mirror shaft to prevent any back lash.

Don't forget Harry, as I said, the motor speed can fluctuate anyway and the running laptop
program will draw new lines and frames auto locked to the positions of both
line and frame mirrors. As I vary the line/frame speed for experimentation, the laptop
will auto follow ..........that is my dream anyway. :lol:

Line pulse creation to use the laser light at start of each line and at end, so I will get plenty
of oomph from that !
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Re: 0 to 360 degree camera and MORE!

Postby Harry Dalek » Wed Sep 14, 2016 8:49 pm

I would love to see it in action at a safe distance Australia is safe enough... :wink:
Well adjustable it is Albert multi system only limited by the motor speed of your line and frame mirror.
I like the scanner its nice and small and having mucked about with this stuff pretty hard get to work accurately and smaller must be harder ..
Look forward to seeing more
The electromagnetic spectrum has no theoretical limit at either end. If all the mass/energy in the Universe is considered a 'limit', then that would be the only real theoretical limit to the maximum frequency attainable.
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Re: 0 to 360 degree camera and MORE!

Postby Viewmaster » Wed Sep 14, 2016 10:31 pm

Harry Dalek wrote: small and having mucked about with this stuff pretty hard get to work accurately and smaller


Yes, Harry, accuracy is king. The 45 degree mirror angle has to be spot on.
The line mirror axis has to be exactly 90 degree from frame mirror axis.
Unless both of these are correct then scanning lines will not be straight.

This first rig may not be up to that but it will work, albeit with some image distortion.

That in itself might lead me to play around with large deliberate distortion ........
.....but I don't want Paul Nipkow to turn in his grave.......... at 12.5 revs. :D
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