My 3rd Generation Scanner Build Thread

[daniel_reetz]

I got a few stray minutes in the shop tonight and I moved the slides to the back of the platen -- not all the way to the back, but close enough. The video is at this link:

http://vimeo.com/5723950 (might still be encoding, should be up in 20 minutes or less)

A few things became evident.

* Some bracing is necessary. You can't just attach the thing to the drawer slides. Cross bracing of some kind is a must .
* The slides need to be firmly anchored. In this setup, they are mounted to aluminum blocks and clamped to a 1 1/2" solid table.
* Drawer slides suck. They suck because they extend in two stages. The 19" rack slides that I posted earlier in this thread are much better. Having 2 stages is just another source of instability.
* This probably requires a heavy base. Hence it will probably not work with a portable scanner, but it should be alright for other stuff.

[you1]

Thank you for the posting.

I'm going to try it on my setup this weekend, and put the rails all the way in the back.
I plan to add a counter weight; hopefully, I wont need cross bracing.

[daniel_reetz]

I think with a counterweight, it shouldn't need any help. If my platen weren't made out of cheap cardboard stuff (just for testing!) it would probably work even better.

[Turtle]

You can see that the folks that makes commercial scanners had spent time and money trying to simplify things. You can copy their designs for your own use. Like in this image attachment example, the loads put the slides on the sides helps in various ways. They eliminate the need to stabilize the cradle. The cradle could be made out of thin flimsy materials, becoming portable... and what ever is holding the slide will hold your camera mount as well.

atizstylescanner.gif (31.22 KiB) Viewed 2319 times

Like the commercial scanner, I would put the slide posts near the user and closer to the platen. Just like the one seen the video in this thread http://vimeo.com/5723950 except that the user is suppose to be on the other side.

[you1]

Hi Turtle,

My platen is mostly glass http://www.diybookscanner.org/forum/viewtopic.php?f=1&t=47. To employ your suggestion, I would have to frame the platen such that no pressure is applied on the glass. In my case this would mean heavy wood working.
Alternatively, I can create a large handle that only connects to the rails; so that the platen is not the entity responsible for the rise.

I actually fiddled with, and prefer the idea of putting the rails in the center. One issue I noticed immediately is that at times one side of platen wants to rise more than the other, there by causing a sticking point. You can see this "sticking" point in Daniel's video. I am "assuming" that by putting the rails in the rear center, this will be less of an issue.
Perhaps putting the counter weight would also address this issue! Bingo!

A closer inspection http://www.youtube.com/watch?v=KPpGLvpEVCI reveals that they are countering the weight with springs (something that we've only discussed).

Additionally, I don't know the difference in quality of our rails in comparison to their gliding mechanism.


And another thing! How is the high-end camera able to focus at pages that have little text (end of chapters). I'm planning on attaching my cameras on the raise mechanism in order to lock focus for taking pictures.

[daniel_reetz]

You can copy their designs for your own use.

I *really* appreciate the thoughts you posted here, so I hope this doesn't come off the wrong way -- but I feel I should say something.

While it's true that anyone could easily copy a commercial product, it would not be something that we can share freely. Our community has already developed quite a diverse set of designs, and that's strength. Sure, in the long run, I hope we converge on some solutions for some things -- the "best" ways of doing stuff... and the best ways may even resemble the commercial way. But for the sake of our community, the existence of this website, and even the future of DIY book scanning, if is important that we don't baldly copy their work, because it could easily lead to an ugly legal end to this project and community.

And besides, I don't think their designs are all that great.

As for myself, I've been iterating through all these ideas and documenting them online not only because it generates valuable knowledge for all of us (which I feel I owe, given everyone else's contributions here), but because it also generates proof that at least my folding design will be a "clean room" implementation -- I haven't read their patents, seen any of their engineering documents, or done anything other than watching some of their marketing stuff. That leaves room for the design to be free and freely available.

[daniel_reetz]

And another thing! How is the high-end camera able to focus at pages that have little text (end of chapters). I'm planning on attaching my cameras on the raise mechanism in order to lock focus for taking pictures.

With SLRs it is possible to get a huge depth of focus -- so that autofocus becomes totally unnecessary. I am certain theirs are fixed focus. And Spamsickle has been using manual focus with good results for a while now...

[Karyudo]

I haven't read their patents, seen any of their engineering documents, or done anything other than watching some of their marketing stuff. That leaves room for the design to be free and freely available.

IANAL, but I think there are a few issues here, and I don't think any of them is a huge stumbling block:

1) I don't think anyone can stop us from discussing technical solutions to a problem, even if it's a discussion of a patented process. I don't think anyone could even stop us from reproducing the patent itself -- part of the point of a patent is that the entity holding the patent gives up the knowledge in exchange for a monopoly on the idea. Though if we were to publish copyrighted drawings from a patented design, then I think there'd be trouble,

2) I don't think there is much remedy for a disgruntled patent holder against a community that is building its own equipment, even if said patent holder feels the designs being generated infringe. I don't believe there are any statutory damages available, which mean each infringement claim would have to be brought to suit and litigated -- which is hugely expensive.

3) I don't think ignorance of existing patents and prior art prevents legal action by a patent holder. It's irrelevant that an idea is generated independently; pretty sure it's the final embodiment that matters. If an independently-generated design is marketed and later deemed to have infringed, then I don't think it's important whether the infringement was willful or accidental.

4) It is quite all right to make an improvement to a patent that is not your own, and be able to patent your improvement.

Finally, I'm guessing the interesting part of commercial scanning systems is either the page-turning mechanism (which we mostly don't care about, sinc we're generally not trying to scan books non-stop all day, every day), and the proprietary software (which we're already doing without). So I would find it quite a stretch for any legal action to be raised over drawer slides and camera mounts.

[daniel_reetz]

At this point, I don't know enough about patent law to be anything but paranoid -- that's probably obvious.

Just a policy note, not about patents: for the purposes of this forum, we should be careful about what gets copied into the forum software. From the news page: "Please don’t post copyrighted information unless (a) you are the owner, (b) you have explicit permission from the owner, or (c) it conforms to United States fair use law. ". In this case, the modifications to the above Atiz image probably constitute fair use. But it would be much better to simply link to an external image or draw up a new image.

[Karyudo]

In general, I think you're being smart about IP issues. But you may have more rights than you're exercising. Patents and copyright don't have as much power as the IP industry would lead you to believe. I think in many cases, they count on the "chilling effect" created by FUD (fear, uncertainty, and doubt) over exactly what rights the various IP protections afford. And it's also true that ignorance is not always a defense. You may wish to browse through some stuff at the USPTO...?