DIY Laser levelling using webcam and laser level

[John McNamara]

Hi All

My Recovering from the holliday's brain has been thinking on line generation.

Having disassembled many laser printers over the years I found in many of them the single point laser was scanned across the page by a (single point) laser beam reflected by a rotating polygon prism and a very nicely ground asymmetric lens.

My first thoughts were that the integral laser fitted to these units may be invisible and possibly dangerous.
So the manufacturers laser diode would have to go and be replaced by a known and safe (BUT YOU SHOULD NEVER LOOK INTO THE BEAM) of any visible laser.

The ground asymmetric lens is an unknown? It may not be of the correct focal length for our application?

This leaves the rotating prism with surface coated mirror facets.
It is driven by a nice control circuit that will be easy to interface.

I have a few modules recovered from scrapped laserjet 3 Any machine with a Canon SX series engine is likely to be similar. I have a couple of laserjet 3 modules kept for an idea like this.

Scanner modules are fairly cheap $20 to $50
Or you may already have one similar? All we are after it the rotating prism.

If this concept proves doable we can generate a nice scanned plane.

Remember in this case the laser itself is not rotated the prism simply reflects the beam as it is rotated through an arc that changes as the reflecting mirror angle changes.
The laser and scanning mirror unit will need to be located far enough away for the beam to cover all the needed measurement points.

It should have three leveling feet.


https://www.google.com/search?q=lase...w=1045&bih=547

Regards
John

[Michael Gilligan]

Hi All

My Recovering from the holliday's brain has been thinking on line generation.

Having disassembled many laser printers over the years I found in many of them the single point laser was scanned across the page by a (single point) laser beam reflected by a rotating polygon prism […]

If this concept proves doable we can generate a nice scanned plane.

An excellent idea, John

Incidentally: More years ago than I care to remember, I did some environmental tests on a scanner for reading bar-codes at the supermarket check-out [the type that generates a criss-cross of lines] : The interesting thing about this one was that they had dispensed with most of the real hardware and optics ... They were spinning a hologram !!

I don’t know if it ever went into full production.

MichaelG.
.

Edit: ... Just found supporting evidence: https://books.google.co.uk/books?id=...canner&f=false