| 摘要 |
PURPOSE:To always perform the stable and excellent image forming with regard to a recording material having a different substrate color. CONSTITUTION:The substrate color density of the recording material is measured by disposing the density sensor in the feeding path of the recording material for detecting the density of the substrate color of the recording material of the image forming subject (S1). On comparing the measured level with the prescribed reference level, the developing bias of the developing time is changed corresponding to the level being high or low. As the developing bias, the reference bias is applied when the measured level is almost the same as the reference level (S3) and it is made lower than the reference bias when the measured level is higher, on the contrary, it is made higher than the reference bias when the measured level is lower. |
