| 摘要 |
<p>PURPOSE:To reliably recognize the presence of a sheet by a method wherein, in a duplicator, according to the output voltage value of a paper sensor situated between a feed roller and a feeding position on the body side, the presence of a sheet is discriminated. CONSTITUTION:When, during installation of a sheet feeding device 27, a service man switch 42 is turned ON and a sheet is placed on a conveyance passage 34, a first voltage V1 is inputted to a CPU 40 from a paper sensor 38 formed with an infrared ray light emitting diode 38a and a photo sensor 38b, and when the sheet is taken out, a second voltage V2 is inputted. The CPU 40 determines an average voltage thereof to store it in a memory 44. When the service man switch 42 is turned OFF, a sheet feeding device 27, completing regulation of a control part 41, is set to a body 28, and during the starting of a copy, the sheet on an elevator tray 31 is fed to the separation roller 36 side through rotation of a feed roller 33 with the aid of a DC motor 37, the second voltage V2 is outputted from the sensor 38, and in the case of V2>(V1+V2)/2, it is discriminated that the sheet is present.</p> |
