| 摘要 |
PROBLEM TO BE SOLVED: To start the feeding of a succeeding transfer material, after the ejection of a preceding transfer material is confirmed, in order to avoid trouble in carrying the transfer material, at the time of consecutively forming images on both front and rear sides of the transfer material. SOLUTION: Photosensors S1 and S2 are installed in the downstream position of a timing roller 15c and the upstream position of a fixing device 17 respectively. When the feeding of a preceding recording paper is started by the timing roller 15c, the preceding recording paper is detected by the photosensor S1, has a transfer for a front-side image on a photoreceptor drum 10 in a transfer unit 14c, while being carried by a toner image receptor 14a and further, for a rear-side image on the toner image receptor 14a, in a rear-side transfer unit 14g and then, is detected by the photosensor S2, to be fed to the fixing device 17. At this Lime, it is judged whether the recording paper is smoothly carried or not by the time difference between the signals of the detections by the respective photosensors S1 and S2. In the former case, the feeding of a succeeding recording paper can be attained and in the latter case, an image forming process is stopped and the rear-side image of a succeeding original which has already been formed on the toner image receptor 14a is erased by cleaning. |
