2–2COPYING PROCESSCOPYRIGHT © 1998 CANON INC. CANON NP6621 REV.0 FEB. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)The copier forms images through the followingsteps, and each of the steps functions as describedbelow.step 1 pre-exposurestep 2 primary charging (negative DC)step 3 image exposurestep 4 development (AC and negative DC bias)step 5 transfer (negative DC)step 6 separation (curvature + static eliminator)step 7 fixingstep 8 drum cleaningThe photosensitive drum consists of aphotoconducting layer on the outside and an alumi-num base on the inside; the photoconducting layeris made of organic photoconductor (OPC), and thealuminum conductor is a photoconductor.Figure 2-103B. Latent Static ImageFormation BlockThe block consists of three steps; at the end ofthe block, areas of the drum corresponding to theblack areas of the original are left with negativecharges and the areas of the drum corresponding tothe white areas of the original are rid of negativecharges.The images formed on the drum by the pres-ence and absence of negative charges are notvisible to the human eye and, therefore, the termlatent static images.Figure 2-104Surface potential (V)Time (t)Light areaDark area-500-1000 Pre-exposure(step1)Primarycoronacharging(step 2) Image exposure(step 3)Photo conducting layerBase
