| 摘要 |
PROBLEM TO BE SOLVED: To precisely replace a rotating roller and prevent the measurement failure of carrying speed of a document sheet by measuring the carrying speed of a sheet to be carried by the rotation of a roller member, and displaying the replacement of the roller member when the life of the roller member is judged. SOLUTION: A carrying speed measuring sensor 25 is provided on the upstream side of the carrying direction (arrowed direction B) of a document sheet S and substantially in the vertical center to the carrying direction in order to prevent the oblique traveling of the document sheet by the load of a rotating roller 251 in the carrying of the document sheet S. When the feeding number of the document sheet S is increased, and the life of the rotating roller 251 comes near, a slippage is generated between the rotating roller 251 and the document sheet S by the reduction in frictional coefficient of the rubber surface of the rotating roller 251, and the waveform of an encoder output is not constant. When it can be judged whether such a phenomenon is different from a sudden one, the life of the rotating roller 251 can be judged to replace the rotating roller 251. |
