| 摘要 |
PURPOSE:To easily detect the life of a printing head, and to perform a printing head life detecting in which its printing quality can be easily maintained and its maintenance can be easily conducted by providing a counter for counting the driving number of a printing pin having a high using-frequency, and providing displaying function for displaying the life in the counter. CONSTITUTION:A counter 2 has a rotatable ratchet 2-2 supported to a shaft 2-1 and a ratchet pawl 2-3 for rotating the ratchet. The pawl 2-3 is secured to a plate 2-5, and one end of the plate 2-5 supported to a shaft 2-5 is disposed oppositely to a magnet 2-7. When a carry signal of a counter 3-1 is input to the magnet, the plate 2-5 is attracted to the magnet 2-7, and the pawl 2-3 allows the ratchet 2-2 to rotate at a predetermined angle. A scale plate 2-4 secured to the ratchet 2-2 is rotated by the carry signal. Then, a red is displayed at a position corresponding to the number of driving pulses of presumed life, such as at 10 stepping position of the plate 2-4. When the red is detected from a display window, an operator conducts a countermeasure as the life of a printing head is over. |
