| 摘要 |
PURPOSE:To enable to maintain printing quality for a long period of time, by a method wherein a printing starting timing after reversing an ink ribbon is generated at random so that printing after the reversion is not conducted at a fixed part, in a line printer. CONSTITUTION:When the trailing end of the ink ribbon is detected by a detecting mechanism 109, a flip-flop circuit 201 is reset, and the ribbon is reversed by a lower-side motor 107. In addition, an output 11 from the circuit 201 is inputted into one-shot multivibrators 303, 304 to trigger the multivibrator 304, and a printing inhibiting flip-flop circuit 306 is set, resulting in a stand-by condition for printing. Meanwhile, the ink ribbon is taken up to the lower side, and the circuit 306 is reset by an output from a pulse-generating circuit 301 to restart printing. In this case, an output pulse from the circuit 301 is non-synchronously outputted independently of the ribbon-driving system, so that the printing after the reversion can be started at a random position. Accordingly, printing quality and the useful life of the ink ribbon can be enhanced. |
