Optical Fibers for Scanning Digitizers

The surface condition alters the light that is reflected to the photoelectric detector during the scanning. Documents are scanned electronically, mechanically, or in combination, with the portion of the document being scanned mounted flat or in a circular arc. The physical dimensions of scanning assemblies are controlled by the size of the document and the light paths required to scan the surface. In most assemblies, lenses and mirrors are combined with rotating or translating document holders. In more recent assemblies, stationary copy is scanned by a flying spot from a cathode-ray tube, a charge-coupled photodiode array, or an acousto-optically modulated laser. Optical fibers are also used to pipe light from the document to a rotary scan head or solid state image sensor. In this paper, we describe the performance characteristics of a flying-spot type of optical fiber scanner that has inherent advantages for digitizing large documents. This paper gives special attention to glass fiber characteristics required to construct this new potentially low-cost scanning digitizer. 1 1 2 3,4 5