COPYRIGHT © 1999 CANON INC. CANON 660/2100 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)E. ITD (intermediate transfer drum) Cleaning BlockThis block consists of two steps, cleaning the intermediate transfer drum by returningthe residual toner from the intermediate transfer drum to the photosensitive drum.Step 9 (ITD cleaning roller charging)In this step, a bias is applied to the ITD cleaning roller as needed to charge the resid-ual toner on the intermediate transfer drum to a uniform potential.Normally, the ITD cleaning roller is held away from the intermediate transfer drum. Itis brought into contact with the intermediate transfer drum by means of the ITED clean-ing roller cam for ITD cleaning roller charging; at this time, a positive bias is applied tothe ITD cleaning roller to charge the toner on the intermediate transfer drum to a uniformpotential.At the end of charging, the bias is turned off and, at the same time, the cleaning rollercam is driven to move the ITD cleaning roller away from the intermediate transfer drum.At the end of printing, a negative bias is applied to remove the residual toner adher-ing to the ITD cleaning roller.CHAPTER 1 GENERAL DESCRIPTION1-31ITD cleaning rollerITTD cleaning camResidual tonerCharged residual tonerIntermediate transferdrumAC biasDC biasFigure 1-812In the secondary transfer block, the toner on the intermediate transfer drum is trans-ferred to paper, leaving a minute amount of toner behind. At the end of image stabi-lization correction control or after a jam, further, the intermediate transfer drumremains coated with toner. All such toner is referred to as “residual toner.”Note:Download free service manual at http://printer1.blogspot.com
