| 摘要 |
PURPOSE:To make a pin mesh with a guide slot by providing a Geneva stop wherein a driving gear is equipped with a notch corresponding to a rotational path of a driven gear as a means for transferring a torque of a motor to a platen. CONSTITUTION:A motor 4 rotates and a circular arc of a driving gear 7 contacts with a fin 8a, so that positions of the driving gear 7 and a driven gear 8 are corrected to positions where a pin 7b meshes with a guide slot 8b. The pin 7b of the driving gear 7 meshes with the guide slot 8b of the driven gear 8, the driven gear 8 begins to rotate so as to drive a platen 2. The driven gear 8 further rotates and stops when the mesh of the pin 7b with the guide slot 8b is completed. A position of the platen 2 at this time is kept by a mesh of a ratchet gear 10 with an arm 11. At this time, an optical sensor 13 outputs a detecting signal so that the motor 4 is stopped. Since the positions of the driving gear 7 and the driven gear 8 are corrected to the positions where the pin 7b meshes with the guide slot 8b, the driving gear 7 and the driving gear 8 can well mesh with each other even if the positional relation between the meshing position of the ratchet mechanism and the pin 7b and the guide slot 8b is not good. |
