The transfer roller cleaning is performed during WAIT period, INTR period, LSTR period and after forming the image for the front side of page when duplex printing. Figure 1-23 Transfer roller cleaning Cleaning blade Photosensitive drum Toner collection box Transfer roller Environment change control The environment change control calibrates each high-voltage bias to obtain an appropriate image according to the environment changes. The DC controller determines the environment, where the product is installed, based on the surrounding temperature and humidity data from the environment sensor. It adjusts the high-voltage biases to accommodate environmental changes.
The DC controller determines an environment sensor abnormality and notifies the formatter when it detects out of specified range data from the environment sensor. 30 Chapter 1 Theory of operation ENWW Reverse tr ansfer bias