| 摘要 |
PROBLEM TO BE SOLVED: To improve productivity of both-side printing by minimizing the reduction of fixing speed for an image on a second side of a recording material at the both-side printing time. SOLUTION: The fixing performance of the image on the second side of a recording material is deteriorated when the toner spread quantity on the image of the second side is >=0.4 g/A4 in the case fixing speed is 200 mm/sec, and remains in good conditions until the quantity is <=0.5 g/A4 in the case when the fixing speed is 150 mm/sec. The surface potential on a photosensitive drum after forming the latent image becomes for instance, 500 V by an absolute value, on a section that the maximum quantity toner is mounted, and 0 V on the section that the toner is not mounted, and moreover the proportional relation is present between the total surface potential by integrating surface potential data of the image on the second side in the respective image element for four colors and the toner spread amount of the image on the second side. On determining the whole surface potential based on the surface potential data of the image on the second surface, the fixing speed is kept to 200 mm/sec when the data is <=150 V, and slowed to 150 mm/sec when the data is >150 V. |
