[sane-devel] Art project

[m. allan noah]

As I said before, this is not a physical limitation. The motor itself
does not care how long the belt or track is. It is the brains of the
scanner that care. Most of them use a single register to store the
scan length, and if you wish to scan a length that will not fit in the
register, the scanner cannot do it.

I have two suggestions-

1. if you do not need high resolution along the length of the scan,
you might be able to add a gear train, or change the stepper motor to
one with larger steps. Thus, when the scanner chip moves the motor by
one step, it does not move 1mm, but rather, moves 3mm. If you then
scan at the highest resolution the scanner can manage, it will
actually make non-square pixels, but it will cover the distance. You
will have to move the motor slowly, and you might have to add an
amplifier.

2. Investigate one of the home-made 'player piano' scanners. Those
guys are archiving very long pieces of paper.

allan

On Wed, Aug 4, 2010 at 11:01 AM, karim moreau <karimmoreau at gmail.com> wrote:
> Hi,
>
>
>
> I've been trying another way of looking at things and was wondering whether
> it would be possible to remove the motor from a scanner but still keep it
> functional. I know that I can manually start the scanner and place its head
> into zero position.
>
> Is it possible to tell the scanner to scan a 2 meters long surface and
> therefore to remain on/in scanning position long enough? And then, from the
> drivers, to obtain a 21,7cm x 200cm jpg ?
>
> In most of the scanning software, you can set the exact size of the surface
> you want to the scanner to scan, by defining a surface that is less than the
> maximum scanning surface: would the opposite be possible, and tell the
> scanner to scan more than 21,7 x 29?
>
> If that is the case, I could very well use an independently operated motor
> that I would control to move the scanner head along the surface, at a speed
> matching the constructor specification.
>
> I suppose for instance that when a scanner is scanning a document in a
> 300dpi resolution, it's speed is constant.
>
> Thanks very much for all your insight.
>
>
> 2010/7/14 Ulrich Deiters <ulrich.deiters at gmx.de>
>>
>> Is it really necessary to remodel the scanner? Alternatively,
>> you might use a lens/mirror system to project an image of your
>> large object onto a standard A4 flatbed scanner. You would have to
>> provide additional lighting for the object, and you would have
>> to to something to protect your scanner from stray light, but
>> it should be possible.
>>
>> You will, of course, not achieve a greater image resolution.
>>
>> Best regards,
>>
>> Ulrich Deiters
>>
>> --
>> sane-devel mailing list: sane-devel at lists.alioth.debian.org
>> http://lists.alioth.debian.org/mailman/listinfo/sane-devel
>> Unsubscribe: Send mail with subject "unsubscribe your_password"
>>             to sane-devel-request at lists.alioth.debian.org
>
>
>
> --
> Karim Moreau
> 76 rue de la jonquiere
> 75017 paris
> 06 22 18 91 55
> karimmoreau at gmail.com
>
> --
> sane-devel mailing list: sane-devel at lists.alioth.debian.org
> http://lists.alioth.debian.org/mailman/listinfo/sane-devel
> Unsubscribe: Send mail with subject "unsubscribe your_password"
>             to sane-devel-request at lists.alioth.debian.org
>



-- 
"The truth is an offense, but not a sin"