| 摘要 |
PURPOSE:To reduce the number of parts, and enable rotation of a platen roller with a little drive torque by positioning a printing head through fitting of a positioning guide to the periphery of a bearing and setting an escape groove which permits the contact length of a bearing with the shaft of a platen to be reduced compared to the total length of the bearing, in the bearing. CONSTITUTION:A bearing 24 has an escape groove 25 for reducing the contact length B of a platen shaft 20a, compared to the total length of the bearing 24. Therefore, a friction resistance between the bearing and the platen shaft can be decreased in spite of the large length of the bearing. Further, a pair of right and left bearings 24 support the platen shaft 20a in freely rotating manner, and a positioning guide 26 is fitted to the periphery of the bearing. For this reason, the separate provision of a bearing for support of a platen roller 20 and a bearing into which the positioning guide 26 for positioning a printing head 21 to the platen roller 20 is fitted is not required. Consequently, the number of parts can be reduced and at the same time, the assembly be simply performed. Further, the device can be fabricated at low cost, accordingly. |
