| 摘要 |
PURPOSE:To improve the mountability of an ink ribbon cassette and contrive a smaller solenoid, by providing a stroke-controlling means by which the stroke of a solenoid in a thermal head pressing mechanism is set to be small in the condition wherein printing can be started, and the stroke is set to be large in non-printing time. CONSTITUTION:The stroke-controlling mechanism comprises a lever 27, a projection 28 provided on the lever 27, a reversing sprint 29, and a projection 36 provided on a base 34. The lever 27 can be titled to the side of a platen 18 after the ribbon cassette 7 is mounted. A pressing lever 25 is pushed out toward the platen 18 by the projection 28 of the lever 27, whereby the spacing L1 between the head and the platen is changed to L2 (<L1), and the stroke l1 of the solenoid 22 is changed to l2 (<l1). In this case, the load on the solenoid 22 is as indicated by a load curve D, and a solenoid attracting force characteristic necessary for the load curve D is indicated by curve B, while the attracting force characteristic necessary for a load curve C is indicated by curve A. Accordingly, a smaller solenoid 22 can be contrived. |
