| 摘要 |
PURPOSE:To eliminate running trouble of ink ribbons and to prevent degradation of printing quality, by releasing the ink ribbon if power source of printer is interrupted or printing is not started within a predetermined period of time, thereby preventing dispersion of ink. CONSTITUTION:A drive control section 92 drives a ratchet mechanism 91 respectively upon elapse of predetermined time after start and end of required printing operation, so as to rotate a cam 8 by half revolutions in the direction of an arrow. It is set such that a roller opening lever 7 causes pressure contact of B feed roller 2 with A feed roller 1 during printing operation, while a projection 72 being pushed by a spring 93 on the roller opening lever 7 fits in a recess 81 in the cam 8 when printing operation is not carried out. Upon fitting of the projection 72 in the recess 81 of the cam 8, B feed roller 2 moves in the direction of an arrow C and separates from A feed roller 1. Consequently, an ink ribbon 4 is released from a pair on rollers, and attraction of the ink ribbon 4 due to feed roller can be prevented. |
