Image illumination and capture in a scanning device

A scanning device comprising:

• a target bed;
• an imaging unit operative to capture an image of a document placed on the target bed;
• a light source operative to illuminate the document placed on the target bed;
• a tapered first slab waveguide configured to receive the image of the document into a first tapered face of the first slab, the image propagating through the waveguide from the first tapered face to a first thick end of the first slab after internal reflection within the first slab, the imaging unit disposed to receive the image as it emerges from the first thick end of the first slab;
• and
• a tapered second slab waveguide configured to receive light from the light source into a second thick end of the second slab, the light propagating through the waveguide from the second thick end of the second slab and emerging from a second tapered face of the second slab after internal reflection within the second slab, light from the light source transversely passing through the first slab to illuminate the document placed on the target bed.