| 摘要 |
PURPOSE:To obtain the sufficient contact state of a thermal head and a recording medium and to reduce the thickness of the thermal head, by adjusting the tension of a tension spring when said spring is provided under tension and allowing the thermal head to take linear motion toward a platen. CONSTITUTION:When a recording medium 17 is introduced, a thermal head 10 moves upwardly to be set to a retracted position. When a drive arm 15 begins to move at the start time of printing operation, a head holding member 11 and a thermal head 10 follow the drive arm 15 by the action of a tension spring 14. However, after the thermal head 10 moves to a position where the recording medium 17 is pressed to a platen 13, only the drive arm 15 is displaced to a predetermined position. Therefore, at the time of printing operation, the pressing force corresponding to the tension of the tension spring 14 is applied to the recording medium 17. Since the tension spring 14 is set in a stretched state, large pressing force can be generated in spite of a small stroke. Further, because of constitution such that the thermal head 10 falls from the part directly above the platen 13, the width of a thermal head holding mechanism in the lateral direction thereof can be reduced. |
