| 摘要 |
PURPOSE:To enable the reciprocating use of an ink ribbon without generating wrinkles on the surface of said ink ribbon, by using not only the ink ribbon having a width capable of printing two characters in a lateral direction but also a flat platen having a width equal to or slightly larger than that of the ink ribbon. CONSTITUTION:If it is assumed that an ink ribbon 3 runs to the direction shown by an arrow (x), the ink ribbon 3 receives force Ft from a take-up side and force Bt from a supply side. Further, the ink ribbon receives friction force F from a thermal head 1 in the direction opposite to the running direction of the ribbon 3. Because the width (b) of a flat platen is equal to or slightly larger than the width (a) of the ribbon 3, the pressure acting on the ribbon 3 is uniform over the lateral direction of the ribbon 3. Therefore, the friction force F applied to the ribbon 3 acts on the center line of the ribbon. As a result, because no moment acts on the ribbon 3, the ribbon 3 is not shifted from the running path thereof and the surface thereof is not creased with wrinkles. Further, the contact pressure of the ribbon 3 and paper 4 is sufficiently obtained over the width of a heat generator 2. |
