HP Color LaserJet Enterprise MFP M680 series - Page 39

Table 1-9 High-voltage power supply circuits (continued)
Circuit Description
Primary-transfer-bias generation The primary transfer bias transfers the toner from each photosensitive drum onto the
ITB. The primary transfer bias circuit in the high-voltage power supply generates the
biases for each color.
Secondary-transfer-bias generation The secondary transfer bias transfers the toner image from the ITB onto the paper. The
secondary transfer bias circuit in the high-voltage power supply generates the bias. The
reversed bias transfers residual toner on the secondary transfer roller back to the ITB.
The residual toner on the ITB is deposited in the toner collection box.
ENWW Engine-control system 15