CHAPTER 3 EXPOSURE SYSTEMCOPYRIGHT © 1999 CANON INC. CANON NP6320 REV.0 DEC. 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. It ismoved by the lens drive system. The reproduction ratio around the drum is varied by changing thespeed of the scanner. Figure 3-101 shows how the position of the lens is varied to change thereproduction 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 is mirror 1 plusthe scanning lamp.)The mirror speed is faster than the drum peripheral speed for reduction and slower for enlarge-ment.Note:1. The relative position of the mirrors is not changed to vary the reproduction ratio.2. For Direct copying, the speed of the mirror is the same as the peripheral speed of the drum.DIRECTFF1F2F'F1'F2'REDUCTIONENLARGEMENT
