Hewlett-Packard Company

Larry Wayne Hennessee

Richard M Kemplin

Richard N Tverdoch

An X-Y plotter is provided having an automatic pen changer comprising a pen repository, a memory for storing data identifying a pen selected by a user, a plot head for automatically fetching pens from and depositing pens into the repository, a processing means having a routine stored in a read-only-memory for providing head-movement coordinates, and a control means for moving the head to said coordinates, the pen-changing action (fetching and depositing) being performed solely by movement of the head to said coordinates. Deposited pens are automatically capped to prevent drying-out, fetched pens are automatically uncapped prior to use.

Plotter with automatic pen-changer

A plotter system is provided having an adaptive velocity means for improving plotted line quality by selectively varying the velocity of the plot head to produce smooth, substantially continuous motions of the plot head between data points, in accordance with changes in the data input rate or changes in the distance between data points. This reduces the time that the plot head remains stationary during plotting, thereby reducing excess deposits such as ink pools that may be applied to a portion of a surface when the plot head becomes stationary waiting for data. The system includes a motor unit, a plot head with a pen, and an adaptive velocity means comprising a random access memory (RAM) unit for storing data values to be plotted, a processor unit, and a read only memory (ROM) unit having a stored routine. The plot head is driven by the motor unit under control of the processor operating in accordance with the stored routine and control and data values stored in the RAM.

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San Diego, CA, United States of America

Larry Wayne Hennessee