| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect the position of a recording medium without being restricted in mounting positions. <P>SOLUTION: A current/voltage supply section 221 supplies a current to a transfer roller that transfers developer on a photoreceptor drum to a conveyed paper sheet by electrostatic force. A voltage detecting section 222 detects a voltage value produced in the transfer roller. When the paper sheet is not present on the transfer roller, a storage section 223b samples the voltage value detected by the voltage detecting section 222 in a fixed cycle, and stores this voltage value. From the sampled voltage value stored in the storage section 223b, a threshold setting section 224 calculates a threshold value for detecting the paper sheet. A medium detecting section 225 compares the threshold calculated by the threshold setting section 224 with the voltage value detected by the voltage detecting section 222, and detects presence/no presence of the paper sheet on the transfer roller. <P>COPYRIGHT: (C)2008,JPO&INPIT |
