I thought I would share my first design with you. It's very basic and was really intended to demonstrate proof of concept more than anything else.
As this works reasonably well I can now go on to improve the design.
What do you need:
1 - A camera. I decided to go for the Canon Sureshot A480 as this can be modified with the CHDK firmware to enable remote operation
2 - A piece of perspex. I found that the perspex cover of an A4 clip-frame to be perfectly adequate.
3 - Some bits of wood 2" x 0.5" & cardboard. Odds and ends I had lying around.
4 - A 5V power supply (for the camera). This was something I made many years ago as an electronics project. I may replace this later.
5 - A usb cable and a switch (+ a soldering iron)
Here is the finished result: (Note that the single page is there just to show where the book goes! An actual book would be held open against the perspex with one hand while taking a picture with the other).
and here is a "scanned" page:
Construction details:
a) Construct a basic 3-sided A4-sized frame from the pieces of wood and attach the sheet of perspex.
My wood-working skills are almost non-existent and it took me quite some time to get the ends flat enough to be perpendicular. I would recommend deciding on the dimensions and going to a woodwork store and get them cut to shape - perhaps even using mitred joints for a more aesthetic look.
The perspex is attached to the frame with panel pins. It works but the perspex tends to split. It may have been better to pre-drill some small holes first.
b) Set up the camera for remote operation. Download the CHDK firmware and follow the installation instructions (these are fairly straightforward). It took me a while, however, to figure out how to set the camera up for remote control. It turns out that you need to enter the <alt> menu (you'll know how to do this from the installation instruction) and go to:
Main menu
Miscellaneous stuff
Remote parameters
Enable remote [ ]
and "check" the [ ] box.
c) Set up the camera remote switch. Strip one end of a camera usb cable (the bit which plugs into a computer). Basically, the usb cable to the camera needs to have a 5V "signal" on the red wire and the black wire is "negative". The other two wires are not needed.
I attached a switch between the 5V power supply and the camera. The first operation of the switch focuses the camera and the next takes the shot.
d) Set up for a scan. I held the frame on a workbench (later, it will be attached to a platform). The correct camera position was found (by trial and arror!) and a piece of cardboard fitted to eliminate reflections. I originally had a tripod but this refected in the perspex and the legs got in the way. Note: don't forget a hole for the autofocus!
And you're ready to go!
