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

My implementation of the Book shooter MK-V design

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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zbgns
Posts: 33
Joined: 22 Dec 2016, 06:07
E-book readers owned: Tolino, Kindle
Number of books owned: 600
Country: Poland

My implementation of the Book shooter MK-V design

Post by zbgns » 18 Oct 2018, 20:27

Inspired by the project presented in the following thread: viewtopic.php?f=14&t=3501, I built my clone of the Book shooter MK-V originally designed by Hiroshi Yanagisawa. Dimensions are pretty the same, however I did not follow all build instructions, using some different materials. I was captivated by simplicity of the design and I wanted to make it even more compact, with no moving parts and no necessity for calibration each time before use. I would like to thank Hiroshi Yanagisawa for the project and the inspiration.

I have presented short description of my implementation here: viewtopic.php?f=14&t=3501#p21419. However, it was not finished work, so I did not decided to present it in more detail there. From this time I adopt some improvements. At current stage it satisfies my needs, and I was able to digitize several books from my private library mainly (old books that are not available in electronic form, usually not in very good shape).

There is still room for improvements. Nevertheless, as I find it fully operational, I would like to present, what I was able to obtain so far.

It looks like this:
1.png
Materials used:
1. High Impact Polystyrene Sheet (HIPS), 3 mm thick.
2. Anti-glare glass 24 x 24 cm.
3. Plastic angles of two types to reinforce the construction,
4. Bolts and nuts,
5. Magnet rubber to hold the phone in place,
6. Duct tape.

No any power tools were necessary except a driller to drill holes used to mount the construction with bolts and nuts. I used only a break-off blade knife for cutting all plastic elements, sand paper to polish up edges, a glue, a duct tape and a screwdriver.

I regard the lighting used as my original input to this project. I used LED tape 5V as the light source easy to be powered with e.g. a power bank or any laptop by its USB slots. The lighting is located inside the scanner, in the bottom part, near to the glass.
4.jpg
Even distribution of the light was a big challenge. Upper part of a page photographed is higher distance from the light source than the bottom part, so light was uneven. At the beginning I painted black interior side of the device as I was convinced it may help avoid reflections. However, it turned out that it was mistake. Repainting it white helped in much better light distribution. I originally used “warm white” LEDs (2700 – 3000K), but it does not work with the camera white balance algorithms. So I replaced it “neutral white” (4600K) and now colors are reproduced definitely better, in more natural way.
sample.JPG
It was also necessary to work on the holding of the camera. The scanner is designed to work with iPhone 7, however it may be adopted to any other phone model. Alternatively I used HTC 10. There was huge problem with mounting HTC 10 as it is relatively heavy and has rounded back so is prone to change its position what leads to geometric distortions of photographed objects. iPhone 7 has flat back what makes it better adjusted to such scanner's element role. At the beginning I followed the original project and affixed a plastic bumper (case) as the phone holder. But it turned out that it does not hold the camera in sufficiently stable position and before every use it is necessary to re-calibrate it. So I started looking for better solution. I affixed magnet in form of elastic magnetic rubber. The magnet is weak enough to not interfere with electronics of the phone but holds the phone firmly. Moreover there are brackets stabilizing position of the phone. There is a support from the bottom and a stopper at one side so it is very easy to place the phone immediately in the right position, with no any further calibration or adjustments needs. Of course, I had to equip the phone in an iron plate at the back that allow for such magnetic connection.
2.jpg
I worked also on positioning of the camera to have geometric distortion as small as possible. It is not ideal yet. I suspect that part of distortions result from lenses (barrel distortions) that may be difficult to correct without involving some advanced software processing.

The iPhone 7 has 12 mega pixel camera (3024 x 4032 pixels), so the “optical” density is approx. 470 DPI at the distance of 18 cm.
5.jpg
Finally, I would like to answer the question, how efficient the scanner is in terms of number of pages it is able to capture in given time. So I decided to calculate this in natural conditions and scanned a book, 352 pictures from the front cover to the back cover.
6.jpg
I did it with no special hurry, as I tried to take good picture of each page. So it was not like a test of maximal speed I’m able to reach, but rather measuring of my natural pace. It took me 40 minutes, 51 second, what means 516 pages per one hour.

The below chart presents how much time took to capture each individual page.
chart.png
There is a peak at page 274. The Bluetooth trigger stopped working, so I had to reconnect it. This is why there was 34 seconds brake between pages 273 and 274.

If someone has any improvements in mind, that may be adopted to my project, I would be really grateful for sharing this with me.

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