Abstract: A method and apparatus for detecting an abnormal paper feed such as a paper jam in a printing press which can reduce the work load for an operator and prevent productivity and printing quality from being lowered by detecting the elapsed time of travel of a first sheet of paper from a paper feeder to a register, with the time corresponding to the number of sheets reaching the register. This number is compared to a number of paper sheets stored in a memory. When there is an agreement between the compared sheet numbers, normal paper feeding is indicated. When the detected number of sheets is more or less than the number stored in memory, abnormal paper feeding is indicated and further paper feeding is interrupted. A number less than the required number is indicative of paper remaining on a feeder board from a previous printing operation. A number larger than the required number is indicative of a paper jam.

Abstract: The apparatus includes a print switch, the remaining paper detection apparatus, and a controller and a remaining paper detection controller. The print switch sets a printing press to a printing operation mode. The remaining paper detection apparatus detects remaining paper sheets on a convey board. The controller and remaining paper detection controller inhibit the print switch from setting the printing operation mode when a remaining paper sheet is detected by the remaining paper detection apparatus.