| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can prevent a damage to a fixing means by including a mechanism to carry out an emergency stop of a main body operation by detecting attachment of a large quantity of toner to transfer material caused by lowering of high voltage output voltage occurring when exceeding resonance frequency in the image forming apparatus with a piezoelectric transformer high voltage power source unit. <P>SOLUTION: The image forming apparatus includes a piezoelectric transformer, a piezoelectric transformer driving means, a piezoelectric transformer frequency control means, an output voltage detecting means, an output voltage setting means, an output control means controlling output voltage by a signal from the output voltage detecting means and a signal from the output voltage setting means, and an optical sensor for measuring surface reflectivity installed on an electrostatic attraction conveyance belt or an intermediate transfer body. The image forming apparatus is constituted so that abnormality is reported to a user by carrying out the emergency stop of the main body when a toner image is detected by measuring the surface reflectivity on the electrostatic attraction conveyance belt or outside of a printing region in the intermediate transfer body. <P>COPYRIGHT: (C)2007,JPO&INPIT |
