| 摘要 |
<p>A serial impact printer of the type utilizing a dot matrix print head is specifically adaptable for use as a calculator or adding machine and is characterized by utilizing a common drive source to advance the print head across the paper, advance the paper between printing operations, and selectively advance the print ribbon between the ribbon supply spool and takeup spool. An improved paper-advancing means has been devised which operates in close correlation with the print head drive member to provide a relatively high speed, simplified and inexpensive printer unit; and the ribbon supply spools are so constructed and arranged as to be interchangeable and to permit direct drive through a spoolengaging member on the print head whereby to advance the ribbon in direct response to print head travel.</p> |
