Single lamp illumination system for a dual plane flat-bed scanner

A flat-bed scanner for scanning an original document to obtain a digitized representation of said original document, said flat-bed scanner comprising:

• a stationary reflective object focal plane for supporting a reflective original document;
• a stationary transmissive object focal plane disposed substantially parallel to and at a vertical distance below said stationary reflective object focal plane, for supporting a transmissive original document;
• a scan carriage movably disposed for linear motion along a scanning axis;
• and
• an illumination system for illuminating a scan line of said original document in said reflective or transmissive object focal plane, said scan line being substantially perpendicular to said scanning axis, said illumination system being enclosed within said scan carriage and comprising an illumination source having a single lamp, said lamp disposed along a lamp axis substantially parallel to said scan line of said original document, said illumination system further comprising a single switch mirror for selectively redirecting an illumination output of said lamp to illuminate said scan line in said reflective or transmissive object focal plane.