| 摘要 |
PURPOSE:To prevent the inspection surface of a detection sensor from being stained and facilitate work for insertion of sheet by moving a detection sensor from an inspection position to an inspection release position when monitoring of printing surface is not required and controlling a movement means and cleaning means so as to clean the inspection surface of the detection sensor. CONSTITUTION:Arms 13, 14, for example, are fixed to a detection sensor 4 for detecting stain on the printing surface of a printing web 1 to make it possible to move the sensor between an inspection position T and an inspection release position R by extending a rod of an air cylinder 17. A cleaning means B is made up of an air nozzle 20 and a plurality of nozzles 21. The time it takes for an inferior part such as a connected part of the printing web to pass the sensor 4 and the movement time of the sensor 4 are obtained by means of a delay device to control the action of the cylinder 17 and means B so that the sensor 4 is moved to blow air against the inspection surface of the sensor 4. Since the gap between the sensor 4 and a transfer roller 2 increases, sheet insertion work can be carried out more easily. |
