4. Turning On and Off the Grid BiasA voltage is applied to the grid wire while the primary corona current is beinggenerated to ensure even placement of charges on the drum.The grid bias is controlled by the grid potential control command (GRCONT)generated by the DC controller: a grid bias of about -800 V is applied when the DCcontroller generates the GRCONT command (analog, about 5 V).As shown in Figure 4-106, the machine keeps the grid bias at 0 V between sheetsof copy paper (A), and exerts control so that charges will not be placed on the drum bysending primary charging corona current through the grid wire (GND).Figure 4-1064-8CHAPTER 4 IMAGE FORMATION SYSTEMCOPYRIGHT © 1997 CANON INC. CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)PhotosensitivedrumGridPrimary corona wireAATo HVTCOPY PAPERPAPER FEED DIRECTIONNon-chargeCharge
