DETECTOR FOR SHEETLIKE OBJECT

PURPOSE:To detect a sheetlike object having general purposes without being influence by the physical properties of the object by installing a pneumatic change detector provided with conveyor rollers in front and rear sides near a sheetlike article passing position. CONSTITUTION:Conveyor rollers 1, 1', 2, 2' are provided in front and rear sides, and a sheet guide 5 having an opening 4 in which a pneumatic change detector 3 can be charged is provide at its lower surface. The detector 3 is so mounted that a detection port 6 is the opening 4 and disposed near a lower surface of a sheetlike object 7 to pass. At the time of using an apparatus, the object 7 is held by the rollers 1, 1', passes near the guide 5, and is delivered by the rollers 2, 2'. In this case, the object 7 passes near the top of the port 6, and hence a variation in pneumatic pressure is generated in a upper space of the port 6, detected by the detector 3 to be output as an electric signal. Thus, since physical properties of the object are not used, the object having general purposes can be detected.