Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Exploring concepts: glassless, sliding frames as platen?

Built a scanner? Started to build a scanner? Record your progress here. Doesn't need to be a whole scanner - triggers and other parts are fine. Commercial scanners are fine too.
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mrwarper
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Exploring concepts: glassless, sliding frames as platen?

Post by mrwarper » 03 Jul 2015, 08:47

Hi, long time no-scan!

While I try to catch up with what I've been missing since my last visit, I'd like to get some comments on several ideas I've been considering. In the end, they all could be integrated in some kind of modular scanner support or easel, which would have different interchangeable parts and would be quickly reassembled depending on the kind of book that's to be scanned. First things first, though, and the first thing I've been pondering about is a 'glassless platen'.

The platen does two things: it flattens pages, while letting light through. But it can give problems too: reflections, keeping it spotlessly clean (unless you don't mind fixed motes on all pages of your scan), etc.

I think a hollow frame applied to the borders of the open book, say from 1cm inwards of its borders, would keep the pages as flat while avoiding any of the problems. Two such frames at an angle would form a 'regular platen', and to deal with different book sizes, the upper inner angle of each frame would be solid, and its other two sides would slide, so as to be fixed at the right position (i.e. matching the page size) before scanning.

Your thoughts? Also, please don't hesitate to ask anything if I haven't been clear enough.

Note: of course the glassless platen wouldn't work for books or pages which don't have a margin by all their borders. Since I feel the lack of reflections is still a huge improvement, this would fit very well with the bigger 'interchangeable parts' concept.

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jck57
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Re: Exploring concepts: glassless, sliding frames as platen?

Post by jck57 » 03 Jul 2015, 08:58

This one has an adjustable, glassless frame for scanning one page at a time:

http://www.diybookscanner.org/forum/vie ... ?f=1&t=422

dpc
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Re: Exploring concepts: glassless, sliding frames as platen?

Post by dpc » 03 Jul 2015, 18:08

Why not just hold the pages flat with your thumbs and scrap the entire platen/cradle mechanism entirely?

So much of the complication involved with a DIY book scanner are the v-shaped platen and the cradle and the movement necessary to keep the pages flat. Get rid of it all and hold the pages down with your thumbs and remove the thumb images during post processing. There's less chance of artifacts like reflections and specks on the platen glass and certainly less toil on the operator. You also don't have to worry about designing a cradle/platen for odd book sizes and your thumbs can handle anything from the largest coffee table book to the naturally-closed paperbacks.

duerig
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Re: Exploring concepts: glassless, sliding frames as platen?

Post by duerig » 03 Jul 2015, 19:38

That is true. A further advantage of using your thumbs is that it is then very easy to use them as a guide for cropping. Instead of error prone algorithms that try to detect content, this lets you just crop to the page with pretty consistent margins. I have been using this technique for the laser scanner prototype and it works quite well.

-D

mrwarper
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Re: Exploring concepts: glassless, sliding frames as platen?

Post by mrwarper » 20 May 2016, 06:16

jck57 wrote:This one has an adjustable, glassless frame for scanning one page at a time:

Monson's Sticks: Cheap Single Camera Rig with Remote
Sorry for having gone AWOL, this just blew up my mind, and then I got busy with other stuff. W-O-W. This is almost as good as the ghetto ass scanner in its simplicity, and quite in line with the concepts I'd like to explore.

I take it as long as the book spine and maybe the cover are rigid, the pages don't bulge up between the sticks, do they?

mrwarper
Posts: 18
Joined: 29 Dec 2012, 21:50
E-book readers owned: 10x iRex DR1000, 15x iRex DR800
Number of books owned: 10000
Country: Spain
Contact:

Re: Exploring concepts: glassless, sliding frames as platen?

Post by mrwarper » 20 May 2016, 06:36

dpc wrote:Why not just hold the pages flat with your thumbs and scrap the entire platen/cradle mechanism entirely?

So much of the complication involved with a DIY book scanner are the v-shaped platen and the cradle and the movement necessary to keep the pages flat. Get rid of it all and hold the pages down with your thumbs and remove the thumb images during post processing. There's less chance of artifacts like reflections and specks on the platen glass and certainly less toil on the operator. You also don't have to worry about designing a cradle/platen for odd book sizes and your thumbs can handle anything from the largest coffee table book to the naturally-closed paperbacks.
The problem with thumbs is, they're just not as good at keeping pages completely flat as a platen, and you need both hands. I am interested in the "hollow frame" concept as a compromise attempting to still get pages flat, and get rid of specks, reflections, etc. at the same time. while keeping at least one hand free.

I think it wouldn't be too hard to adapt adapt this concept to something in between Monson's sticks and the ghetto ass scanner to make it adjustable (no two books are ever the same size), I just wanted to know if something similar has been tried, and with what results.

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