| 摘要 |
PURPOSE:To prevent multiple printing or the damage of paper of the deterioration of a printing head due to multiple printing, by checking the movement of the pin holes of paper by a light emitting part and a light receiving part and performing printing operation only when the paper is accurately fed. CONSTITUTION:A light emitting part 6 and a light receiving part 7 detecting the pin holes of printing paper 5 are provided at a part where each pin hole of the printing paper passes. The light emitting part 6 emits pulse light when it receives light emitting instruction from a pin tractor control part 8. The light receiving part 7 receives the pulse light emitted from the light emitting part 6 and sends out the signal thereof to the pin tractor control part 8. The pin tractor control part 8 judges whether light is received. That is, the pin tractor control part 8 allows the end of printing paper to pass between the light emitting part 6 and the light receiving part 7 and the light receiving part 7 receives light when there is the pin hole of the printing paper at the position of the light receiving part 7 and does not receive light when there is no pin hole and, therefore, judgement is performed on the basis of the signal showing whether there is the pin hole thereof or not. |
