Ink ribbon feed
AssigneeAlcatel Business Systems
InventorsRaymond J. Herbert, Thomas D. Williams
Life of this patent
Estimating the term…
Abstract
A ribbon feed for a thermal ink transfer ribbon (14) is disclosed in which the ribbon is drawn from a supply spool (15) and, together with an article (17) such a mail item on which printing is to be effected, is fed past a thermal print head (12). A tachometer (45) is coupled to the feed to generate pulses as the item is fed. A sensor (33, 34) generates pulses as the spool (15) rotates due to drawing of the ribbon therefrom. The number of sensor pulses occurring in periods determined by the tachometer pulses is compared with a predetermined value to provide to enable detection of occurrence of a fault in the ribbon feed from the spool.
Claims11
A ribbon feed mechanism including means for drawing an ink ribbon from a spool of wound ribbon past a print head first means responsive to movement of the ribbon past the print head to produce first signals representing increments of movement of the ribbon;
- second means responsive to rotation of the spool to produce second signals representing increments of angular rotation of the spool and control means operative to count the number of first signals occurring during an interval defined by said second signals and to compare said count with a predetermined reference value.
A ribbon feed mechanism including means for feeding a print receiving medium past a print head and for effecting drawing of a thermal transfer ink ribbon from a spool of wound ribbon into ink transfer relationship with said print receiving medium during passage of said print receiving medium past said print head;
- first means responsive to movement of said print receiving medium past the print head to produce a succession of first signals representing successive increments of movement of said medium;
- second means responsive to rotation of the spool to produce a pair of second signals spaced by an interval and representing an increment of angular rotation of the spool during said interval;
- and control means operative during said interval to count the number of first signals occurring during said interval and to compare said count of first signals with a predetermined reference value to provide a ribbon feed indication.
Dependencies are inferred from the claim text.