| 摘要 |
PURPOSE:To prevent the generation of defective printing by installing a ribbon setting state sensing means at the end of a printing head wire and providing a control means for stopping the operation of a printer when an abnormal state is sensed. CONSTITUTION:A reflective type photosensor 20 and a reflecting plate 21 are disposed across an ink ribbon 1, and in the case the ink ribbon 1 is set normal, the sensing point of the reflective type photosensor 20 is set inwardly by the distance (n) from the ink ribbon 1 and outwardly by the distance (m) from a printing wire 13 at the extreme end. Because of the above arrangement, in the case the ink ribbon 1 is set normal, reflecting rays come from the black ink ribbon 1 and the output from the reflective photosensor 20 is dark. In the case the setting of the ink ribbon 1 is slipped off, reflecting rays are white coming from a white reflective plate 21 and the output from the reflective photosensor 20 is light. |
