I. PROCESSESA. Controlling the Drum Surface Potential1. OutlineThe machine uses an electrostatographic method, and is constructed as shown inFigure 4-101.The quality of copy images are mostly affected by the following:q Changes in the sensitivity of the drum.w Changes in the degree of charging by the primary charging assembly.e Changes in the degree of exposure.These changes are in turn brought about by changes in the site environment(temperature, humidity) or deterioration of or dirt on associated parts.The machine is equipped with a drum surface potential control mechanism to ensurestable latent static images in the presence of these factors.Figure 4-101- ----------- - - - - ----Pre-exposurelamp ++++Photosensitive drum LampregulatorPCBPotentialmeasurementPCBScanning lampBlanking exposureBladeCleaning bladeTransferchargingassemblySeparationcharging wireCopy paperCleaning rollerCleaning screwHigh-voltage transformerDC controller PCBDarkareaLight areaOpticalimagePre-transferchargingassembly+++++ +++++++++++++++++++++++PotentialsensorPrimarychargingDeveloping cylinderCOPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 4 IMAGE FORMATION SYSTEM4-1
