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The sad part of this whole article is this method of scanning a laser beam had to be devised to side step a patent that uses common galvanometers instead. So th
by MisterTea 7y ago
The sad part of this whole article is this method of scanning a laser beam had to be devised to side step a patent that uses common galvanometers instead. So there isn't any new 3d printing technology here. Only a clever method to circumvent a silly patent.
- hexa_storm 7y agoThat 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).
- sydd 7y agothe concept is really cool, congrats! Can the prototype actually print? Do you have some photos of the printed stuff?
- hexa_storm 7y agoThis is how it prints on UV paper, https://cdn.hackaday.io/images/1013221548797737200.jpg 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 https://cdn.hackaday.io/files/21933938381472/calib_data.zip More data is here https://cdn.hackaday.io/files/21933938381472/21measurements.rar 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.
- thawkins 7y agoGalvanometer based systems often suffer from acceleration issues at the start and end of the swing which limits the usable spread.
- mensetmanusman 7y agoI work in the area of new intellectual property generation, and you (as was I) would be surprised to learn this is not actually a sad feature of the system. There have been countless advancements in the sciences when people have been forced to work around existing IP and have uncovered hidden benefits when working through the actual implementation. It is a hidden benefit of the western system of IP that China et al. have not yet caught on to.
- hexa_storm 7y agoIt'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.
- kevin_thibedeau 7y agoThe problem is that, in 2019, most obvious methods of scanning a laser with moving mirrors should be covered by expired patents from 40-30 years ago.
- hexa_storm 7y agoYou have to specify application in a patent. Riken desribed it for 3D printing in 1997 see https://sffsymposium.engr.utexas.edu/Manuscripts/1997/1997-25-Yamazawa.pdf 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 https://en.wikipedia.org/wiki/Shuji_Nakamura who got a patent for the laserdiode but little rewards and fought with his employer over it.
- kevin_thibedeau 7y agohow is "obvious thing ... with a laser diode" any different than "obvious thing ... with a computer"?
- mikekchar 7y ago
- rasz 7y agolaser printers use rotating mirror instead of galvanometers
- hexa_storm 7y agothey use glass lenses and infrared, cross scan error must be quite significant due to long separation distance between polygon and substrate.
- antisemiotic 7y agoI was to a couple additive manufacturing exhibitions and conferences, and generally the people from the metal 3d printing industry seem to call all laser pointing devices "galvanoscanners", regardless of actual construction.
- hexa_storm 7y agorotating 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/ https://www.razipol.eu/
- antisemiotic 7y agoRotating mirrors here means continuously rotating, not precise rotation to some particular point? I misunderstood then, yeah, that kind of mirrors aren't used there (I think).
- Someone 7y agoThe patent (https://patents.google.com/patent/US7892474B2/en https://patents.google.com/patent/US7892474B2/en) doesn’t seem to mention galvanometers at all. It uses the phrase ”digital light processing/digital micromirror device”. I don’t know how that slash should be interpreted. If it’s “aka”, the patent doesn’t cover using prisms. I wouldn’t bet on that, though, noting that the patent is careful to avoid the term “light”, using the broader “electromagnetic radiation” instead.
- hexa_storm 7y agothe 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 https://patents.google.com/patent/US9079355B2/en
- hexa_storm 7y agoclaim 1 in US7892474B2... by means of mask exposure ... so prisms brings you around it.
- xvilka 7y agoOnly proves that patents are a hindrance to the progress, not a solution to speed it up.
- The_rationalist 7y agoWhy people are so greedy? Let's say X make an innovation that necessitate the use an older patent from inventor Y. Three things: 1) X has not to pay anything to conceptualize his innovation. 2) X can make a nested patent. 3) a user of the innovation of x must pay a royaltie (why is that an issue?) to Y. If X made a nested patent, the user must pay X and Y. Is this right? BTW who fixe the amount of royalties?
- Damogran6 7y agoPresumably each chunk of royalty makes it that much harder to sell a successful product. Often these fess are significantly higher than nearly any other component on the device (think Qualcomm for cellphones and Fraunhofer for mp3 decoding) Nobody's going to buy the $100 item if it provides $15 amount of value, and nobody's going to make it for $15 if $9 of it is going to licensing.
- The_rationalist 7y agoYes, but I observe on the net what seems to be an aversion to pay all patents even if it only cost a few cents. The price per unit of the concerned patent is never talked about and this irrational aversion is an issue. Websites displaying patent content should display price too. I don't know if patents are generally overpriced but patent owner have an incentive to maximize their benefits which means they probably want to maximize the number of users of the patents by making it cheap.
- AstralStorm 7y agoIn which case licensing fees should be explicitly capped. E.g. to a percentage of revenue you make off the device. That'd stop patent trolls and silly patent holdings dead. You don't use it, you can't charge others. If someone starts using it, you would charge a percentage royalty.