Sharp FO IS125N Service Manual - Page 80

FO-IS125N STEP 5 (Paper separation): The paper is separated from the OPC drum. STEP 6 (Discharge): The drum surface is discharged to facilitate cleaning of the drum surface. (The remaining toner is easily collected by the main charger roller.) OPC drum Aluminum layer (Drum base) CGL CTL Paper Separation sheet Transfer roller Main charger roller (brush) AC760V (P-P) Residual toner DC-950V OPC drum Fig. 16 There is an electrostatic force between the paper which is positively charged in transfer operation and the OPC drum which is negatively charged. The positive charge on the paper is released to the separation electrode, which is the same potential as the aluminum layer of the OPC drum, to reduce the potential difference between the OPC drum and the paper, reducing the electrostatic force. This operation facilitates separation of the paper from the OPC drum. Aluminum layer (Drum base) CGL CTL Fig. 17 STEP 7 (Cleaning): Residual toner on the OPC drum is removed. The main charger is a rotating brush roller. The main charger removes residual toner from the OPC drum by its rotating sweeping action and causes it to stick to the brush. The main charger brush is in close contact with the mesh-type brush cleaning plate which removes toner and paper dust from the main charger brush mechanically. 3 - 10