| 摘要 |
PURPOSE:To fix the distance between the printing surface of a printing paper sheet and a printing head by providing a pressing means pressing a platen toward the printing head and a unidirectional movement checking means checking the movement of the platen in the direction toward the printing head. CONSTITUTION:When a printing paper sheet 22 is put in at a printing position, a printing head carrier 2 carrying the printing head 1 is guided by a carrier guiding member 3 to move in the printing direction while pressing the sheet 22 and the platen 4 downward by means of a roller, and the platen 4 put together with platen guide parts 5 and 5' is guided by platen guiding members 6 and 6' to move downward. Link levers 8 and 8' engaging with the guide parts 5 and 5' through the intermediary of a shaft 16 rotate around a shaft 17, and ratchet levers 9 and 9' engaged with these levers 8 and 8' through the intermediary of a shaft 18 are thereby rotated around a shaft 19, move to positions ahead by the thickness of the sheet 22, following the movement of the platen 4 in the direction of the printing head, and are fixed there by lock levers 10 and 10'. Accordingly, the position of the platen 4 is also fixed. |
