<title>Large-Format Precision Film Recorder</title>

Abstract

A line of large-format raster-type film recorders, utilizing Argon ion laser and rotating-drum techniques, is described. Image formats of up to 40" x 72" are available. The recorders are characterized by high absolute accuracy (down to 20 microns) high incre-mental accuracy (2.5 microns), continuously variable line-spacing and fairly high speed (up to 1 million points per second). Input is coded digital data from any source. Although developed for graphic arts applications, as part of a series of digital color image processing systems, these recorders can be readily adapted to other applications, including many that now use X-Y film plotters. One present version of the recorder enables exposing most common lithographic films with binary ("line") images as well as with half-tone images of any mesh number and angle. This version is already being applied to decorative printing preparation, to computer-aided cartography and to seismographic and remotely-sensed (aerial and satellite) data recording. Another version enables recording of variable-density (continuous-tone) films. Future plans include adaptation to the exposure of offset plates, further increase in accuracy and a five-fold increase in speed.