Abstract: A system that permits the plotting of any combination of several colors in one pass. Three differently colored light sources are provided, and thus one, two or three colors may be plotted at the same time. An apparatus is provided for causing relative movement between the scanning head and the substrate along each of the two axes of the substrate. Preferably, the first axis is disposed circumferentially about a cylinder, on which the substrate is situated, the cylinder having a central axis, and the second axis is disposed approximately parallel to the central axis. The system includes deflection means, preferably acousto-optical modulators, for deflecting along a path a portion of each beam of light by an amount dependent upon the frequency of a signal that is present at the deflection means' input.

Abstract: A system for scanning or plotting a graphic image. The system deflects (10) a portion of the beam of light (18) by an amount dependent upon the value of a characteristic of a signal (12). A plurality of signals is generated (12), each having a different value of the characteristic. Portions of the beam are deflected along paths (15), such that the pixels created by one portion are disposed along one scan line, while pixels of the other portion are disposed along a successive scan line.

Abstract: A method and apparatus for producing a time advanced pulse train from an input pulse train using a phase locked loop with time delayed feedback. The apparatus is used to generate clock signals that occur at a precise relationship to the position of a scanning or writing laser beam.

Abstract: A frequency synthesizer and method for producing an output pulse based upon a mathematical calculation with the output pulse synchronized to an input pulse train on a pulse-by-pulse basis.