Chapter 22-12The machine uses an on-demand method, which requires a low thermal capacity. The method enables the machine to start up quickly and its heater to use littlepower while the machine is in a standby state. The machine may therefore be characterized by a short wait time and low energy consumption.The machine applies a positive DC bias to its pressure roller for the purpose of reinforcing the retention of toner on print paper, consequently preventing stray toner.Moreover, to prevent offset from the fixing film, the film surface is given a fluorine coating. The sleeve of the fixing film is made of rubber.F-2-222.3.1.7 ITB Cleaning Block 0007-4982The ITB and drum are cleaned in this block by returning residual toner on the ITB into the waste toner case through the drum, as a preparation for the next printoperation.This block comprises the following four steps:Residual tonerIn the secondary transfer step, not all the toner on the ITB is transferred onto paper. Some toner remains on the ITB. This toner is called the residual toner.Step 9: Auxiliary ITB cleaning roller chargingIn this step, the holding force of the residual toner on the ITB is strengthened to prevent the toner from falling from the ITB and scattering in the printer.A DC positive bias is applied to the auxiliary ITB cleaning roller to charge the residual toner on the ITB positively. Then the residual toner is pressed to the ITB.F-2-23Step 10: ITB cleaning roller chargingThe residual toner on the ITB is charged uniformly positively in this step.A DC positive bias and AC bias are applied to the ITB cleaning roller in order to apply positive charges to the residual toner. This will make the next step, ITBcleaning, easier.F-2-24Step 11: ITB cleaningThe positively charged residual toner on the ITB is returned to the drum in this step. A potential difference is produced between the drum and the ITB by applyingFixing film Fixing heaterPaperTonerPressure rollerDC biasChargedresidual tonerITBDC bias Residual tonerAuxiliary ITBcleaning rollerITBITB cleaning rollerDC biasChargedresidual tonerResidual tonerAC bias
