A laser scanner for the densitometric analysis of radiographs

An instrument is described which can scan radiographs and collect densitometric readings for subsequent computer analysis. A laser beam is focused onto the film. Raster scan of the beam is provided by two orthogonal mirror galvanometers. The light, attenuated by the radiograph, is gathered by a lens in such a way that it is directed into a small detector regardless of the scan position. Beam position signals and density readings are stored and analyzed in a minicomputer.