CHAPTER 2 NEW FUNCTIONS2-30 COPYRIGHT © 2001 CANON INC. 2000 2000 2000 2000 CANON iR8500 REV.0 MAR. 2001F02-204-022.4.3 Photosensitive drumThe machine’s photosensitive drum has a higher degree of charging ability than that of theGP605 (iR600).2.4.4 Pre-Transfer Exposure LEDThe machine uses processing speed of 450 mm/sec (as opposed to 300 mm/sec of theGP605 (iR600)), to enable the generation of 85 copies per minute (A4, Direct).To make up for the reduction in the strength of charging on the photosensitive drum, themachine uses a photosensitive drum with a higher charging ability. The wave length of thelight emitted by the pre-exposure lamp is 660 nm, made shorter to eliminate residualcharges and to ensure a specific volume of charge.In addition, to make up for the possible decrease in the power of separation caused by ahigher process speed, the following pre-transfer exposure LED is used:CylinderrotationMain motorDrum rotationScanner motorScanning lampPre-exposurePrimary chargingImage exposureDevelopmentPre-transfer chargingPre-transfer chargingTransferSeparationFixingVoltageRoller applicationvoltageRollerrotationMainheaterSubheaterMain powersupplyStart keyONInitial multiplerotationstart EndImageleadingedgeTrailingedgeTrailingedgeLeadingedge Copy endControl panelpowerOFF100msec100msecForward ReverseCylinder (1 cycle)
