1-26CHAPTER 1 GENERAL DESCRIPTIONCOPYRIGHT © 1997 CANON INC. CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)Figure 1-610During copying, toner is attracted to the photosensitive drum by the work of the drumsurface potential and the developing bias (at time of positive component), turning thestatic latent image into a visible image. Excess toner is drawn back from thephotosensitive drum by the work of the drum surface potential and the developing bias(at time of negative component).AC bias (frequency, in particular) mainly affects gradation, i.e., the lower thefrequency, the better the gradation; however, such tends to cause fogging. DC biasmainly affects copy density and fogging; a higher bias, i.e., closer to 0 V, increasesimage density but tends to cause fogging.G. Transfer (step 5)Figure 1-611A negative corona charge is applied to the back of the copy paper, causing the toneron the drum to move to the copy paper.The transfer guide and vertical pass upper guide is grounded through a varistor toprevent soiling of the back of the copy paper and to prevent poor transfer.Reference:If the transfer guide and the vertical path were grounded, the charges which shouldbe on the back of paper would escape through the paper, causing transfer faults. Ifthey were fully separated, on the other hand, the transfer guide would be charged,ultimately soling the back of the transfer guide with toner.DC biasPositivecomponent0 VNegativecomponentTransferguide platesCopypaper
