CHAPTER 3 EXPOSURE SYSTEMCOPYRIGHT © 1999 CANON INC. CANON NP6317 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON) 3-1I. BASIC OPERATIONA. Changing the Reproduction RatioThe reproduction ratio across the drum is varied by changing the position of the lens and theposition of No. 4 and No. 5 mirrors. It is moved by the lens drive system. The reproduction ratioaround the drum is varied by changing the speed of the scanner. Figure 3-101 shows how theposition of the lens and mirror is varied to change the reproduction ratio across the drum.Figure 3-101The scanner drive system changes the reproduction ratio around the drum by varying the speedat which mirror 1 moves relative to the peripheral speed of the drum. (The scanner consists ofmirror 1 and the scanning lamp.)The mirror speed is higher than the drum peripheral speed for REDUCTION and lower forENLARGEMENT.Note:For DIRECT copying, the speed of the mirror is the same as the peripheral speed of thedrum.100%50%200%No. 4/5 mirrorLens
