| 摘要 |
PURPOSE:To detect the presence or absence of a paper, by providing a platen comprising a conductive part at an outer peripheral part thereof, disposing a paper guide plate formed of a conductive material in contact with the outer peripheral part of the platen, connecting a paper-detecting circuit to the conductive part of the platen and the paper guide plate, and detecting the presence or absence of conduction between the conductive part and the guide plate. CONSTITUTION:When a paper 7 is not inserted and a paper guide plate 9 is in contact with a platen 5, a conductive path extends through a lead wire 13, a first conductive part 10, a platen 5, a second conductive part 11 and a lead wire 14 to a paper-detecting circuit 15, so that the resistance of the assembly as evaluated from the circuit side is low. On the other hand, when the paper 7 is inserted into a guide passage 8 and is passed between the paper guide plate 9 and the platen 5, the conduction between the platen 5 and the paper guide plate 9 is interrupted by the paper 7, so that the resistance of the assembly as evaluated from the circuit side is high. The presence or absence of the paper is judged by reading changes in the resistance by the paper-detecting circuit 13. |
