hexa_storm

Open-hardware laser scanner uses PCB motor to rotate polygon

Thanks for posting this I am currently building a prism scanner and quickly drafted some prior art in this field and did a quick patent analysis see https://hackaday.io/project/21933-open-hardware-fast-high-re...

claim 1 in US7892474B2... by means of mask exposure ... so prisms brings you around it.

do you have a link?

DLP projection has a lot of advantages, the area projection is one of those. For large area beamers are moved; see moving light technology by prodways https://youtu.be/1AQJaqdrzzE . There is no longer a real difference then. Lasers can go below 200 nm using dual photon (nanoscribe) or sted lithography.

you can also combine it with optical coherence tomography and use it for detecting eye diseases or laser surgery...

rotating mirrors are too fast for laser industry, it requires a very fast switchable laser, like the one developed by european union https://www.razipol.eu/

the rotating reflective polygon patent is this one US9079355 I think it is even more relevant but somehow it did not get posted. https://patents.google.com/patent/US9079355B2/en

You have to specify application in a patent. Riken desribed it for 3D printing in 1997 see https://sffsymposium.engr.utexas.edu/Manuscripts/1997/1997-2.... but did not specify the use of laser diode as it was quite new at the time. It got only invented in 1996 by https://en.wikipedia.org/wiki/Shuji_Nakamura who got a patent for the laserdiode but little rewards and fought with his employer over it.

they use glass lenses and infrared, cross scan error must be quite significant due to long separation distance between polygon and substrate.

You have to specify application in a patent. Riken desribed it for 3D printing in 1997 see https://sffsymposium.engr.utexas.edu/Manuscripts/1997/1997-2... but did not specify the use of laser diode as it was quite new at the time. It got only invented in 1996 by https://en.wikipedia.org/wiki/Shuji_Nakamura who got a patent for the laserdiode but little rewards and fought with his employer over it.

the rotating reflective polygon patent is this one https://patentimages.storage.googleapis.com/29/68/46/da50635... I think it is even more relevant but somehow it did not get posted.

true it is a nice machine.. but laser bundles have advantages. You can direct other wavelengths, sinter powders and get to much smaller features. All these LCD printer, do show a pixel size but not a real spec or accuracy. If you go really high end even for mask projection with UV led you need expensive lights see https://www.idonus.com/activities/products/mems-products/uv-... ... costs around 20K i believe.

It's true... if I wasn't forced to avoid the IP.. It would have been unlikely I would have made such an effort or this thing build.

This is how it prints on UV paper, https://cdn.hackaday.io/images/1013221548797737200.jpg . This is the calibration data recorded by imaging with the camera directly on a CMOS chip. You can count pixels.. this is what an expert needs to determine the quality. https://cdn.hackaday.io/files/21933938381472/calib_data.zip

More data is here https://cdn.hackaday.io/files/21933938381472/21measurements.... pixel 4.65 microns. You can use opencv to do the trick. I added a little script in this one.

expensive is a matter of taste. The envisiontec 3SP costs well over 5K euros and can go up to 100K. You can only get a a price if you ask for a quote. Carbon 3D does not sell their printers you have to lease them. Formlabs does sell you a printer at 3.5K but you can't use third party resins, so you decide. I actually know some open-hardware printers which sell for 5K.

That is indeed.. how i decided to brand it and this seems working. In reality both systems have different optical properties; this does matter if you push them to the limits. Galvanometers are slow, require more calibration. Rotating devices don't stand still at the end of a sweep and are much faster (10 times).

Of course, what’s worse than a weak start is simply not starting at all. Moreover, if you’ve publicly disclosed your invention, then you have only a one-year grace period to apply for a patent. You forfeit your patent rights if you fail to file within the 1-year grace period. http://www.patenttrademarkblog.com/first-to-file-patent-rule...

In the EU.. you destroy immediately.. there is no grace period.

patents are expensive and you don't know the results.. Patent in my name is here https://patentimages.storage.googleapis.com/43/72/4e/1ee7792... .. but is for a plurality of sources. So I avoid my patent, I am author of :P

should have named it differently; I use a laser scanner with a prism instead of a mirror. A detailed description is here; https://reprap.org/wiki/Transparent_Polygon_Scanning

There is a blog here https://hackaday.io/project/21933-open-hardware-transparent-... also provides all the link to github files. Design are made in Freecad, Kicad, C++ and Python. My main focus is on developing prior art. This needs to be done to prevent IP and "liberate" the technology from patent trolls.