| 摘要 |
PURPOSE:To prevent a malfunction, and to stabilize a detecting operation by providing an initial pressure applying means between a sensor main frame and a supporting member, in a sensor whose electric resistance is varied by being pressed by a body to be detected. CONSTITUTION:A platen 12 for supporting a printing form 11 is extended and provided between right and left side walls 10a, 10b of a frame 10 of a printing device, and when a motor 11 rotates forward and backward, a guide shaft 18 approaches and is separated from the platen 12 by an action of eccentric bodies 16, 17. A printing head 30 is placed on a carriage which has been inserted, fitted and supported so as to be movable into the guide shaft 18, and a bracket 31 is fitted and fixed to the upper part. A sensor main frame 35 whose electric resistance is varied by pressure, and an adjusting screw 33 and a plate spring 37 functioning as an initial pressure applying means are installed to the bracket 31. By applying an initial pressure to the sensor main frame 35, no malfunction is generated even if the sensor contacts the platen 12, and the paper thickness of the printing form 11 is detected. |
