Compact plotter for generation of accurate plotted images of long length

A method of reproducing a pattern on paper, comprising the steps of:

• storing data bits in a data base corresponding to the pattern to be printed on the paper;
• arranging a plurality of rows of data bits from said data base for printing in a corresponding plurality of rows on the paper, the first row of data being associated with a first location at the top of the paper, and the last row of data being associated with a second location at the bottom of the paper, said first and second paper locations corresponding to the upper and lower parts of the pattern;
• advancing the paper in incremental lengths which vary about a predefined length;
• and
• printing each row of data on the paper in a manner corresponding to length of paper advancement such that the first row of data is printed at the first location and the last row of data is printed at the second location.

A method of reproducing a pattern or design on paper from data stored in a data base;

• comprising the steps of:
• scanning a printer across the surface of the paper in a rectilinear path corresponding to a plurality of rows on the paper;
• advancing the paper in increments alternately between scans in a direction transverse to the rectilinear path;
• measuring the advancement of the paper;
• timing the printing of data by the printer in each scan so as to segment the scanned paper rows into areas corresponding to paper columns;
• arranging data bits from the data base in a plurality of rows corresponding to the paper rows and in a plurality of columns corresponding to the paper columns;
• and
• correlating the actual length of the measured paper advancement with the number of rows of data bits to be printed so that the number of rows used from the data base is different than the number of paper rows printed when the measured paper advancement differs from a predefined length.

A plotter for reproducing a pattern on paper, comprising:

• a data processor including;
• a data base for storing a plurality of bits of data representative of the pattern to be plotted on the paper;
• means for arranging the stored data wherein the data can be accessed in a serial manner;
• a printer mounted for scanning movement laterally adjacent the paper, each said movement defining a scan, said printer being adapted for printing N impressions defining a column, each said impression being associated with one said data bit;
• paper advancement means for incrementally advancing paper from a continuous roll in approximate equal predetermined standard increments in a direction transverse to the scanning movements of said printer;
• measurement means for measuring the actual incremental advancement of the paper;
• comparator means for comparing the measured actual incremental advancement of the paper with said predetermined standard increments and for generating an output indicating a paper advancement greater or less than said standard increments;
• and
• means responsive to said output of said comparator means for allocating a selected number of bits from said data base for printing in a selected scan in dependence upon said comparator means output.

A plotter for reproducing a pattern on paper comprising:

• a paper carriage for moving paper from a continuous roll;
• a plurality of print heads mounted for simultaneous movement adjacent said paper, each said print head being adapted for simultaneously printing a plurality of impressions on the paper and each said print head being movable along a different portion of a line transverse to the movement of the paper;
• a data base for storing data corresponding to the pattern;
• and
• a controller for coordinating the movement of the paper with the movement of each said print head, and for transferring said data to each said print head to cause the simultaneous printing of data by each said print head and thereby reproduce the stored pattern, said controller further including means for transferring a variable amount of data from said data base to be printed based upon the amount of movement of the paper.