| 摘要 |
<p>A printing apparatus (10, 110) for printing on a substrate (24), the apparatus (10, 110) including a base (11) mounting a storage spool (15) to store printing ribbon (16) of the kind including a web carrying marking medium, and the base (11) mounting a ribbon take-up spool (20) for taking up ribbon (16), and there being a ribbon path from the storage spool (15) to the take-up spool (20) through a printing station (22) where there is a print head (25), printing being effected at the printing station (22) when relatively moving the print head (25) and the substrate (24) with the ribbon (16) interposed between the substrate (24) and the print head (25) so that marking medium is transferred from the ribbon web to the substrate (24), characterised in that the apparatus (10, 110) includes a movable ribbon guide member (36; 36a, 36b) about which the ribbon (16) is entrained along the ribbon path, a ribbon guide member drive device (40; 40a, 40b) moving the movable ribbon guide member (36; 36a, 36b), and there being a controller (28) which, during or inbetween at least some printing operations, controls drive of at least the take-up spool (20) to advance ribbon (16) through the printing station (22), and the controller (28) controlling the movable ribbon guide member (36; 36a, 36b) in response to an input signal representative of the ribbon tension along the ribbon path to adjust the ribbon tension in the ribbon path between predetermined tension limits.</p> |
