Outline; No. 4/5 Mirror Drive System - Canon NP6317 Service Manual

CHAPTER 3 EXPOSURE SYSTEM
IV. No. 4/5 MIRROR DRIVE SYSTEM
1.

Outline

The copier changes the reproduction ratio by varying the position of the No. 4/5 mirror and
moving the lens. Figure 3-401 shows the positions of the mirror and the lens according to different
reproduction ratios.
The mirror is driven by the mirror motor (M3), and its position is monitored by the mirror
home position sensor (Q4). The mirror is positioned with reference to the number of motor pulses
counted from the mirror home position.
When the power is turned on, the mirror motor (M3) continues to rotate clockwise until the
mirror home position sensor (Q4) turns on. Thereafter, it rotates counterclockwise for a specific
number of pulses to stop the No. 4/5 mirror at Direct position.
When a non-Direct ratio is selected during standby, both mirror and lens are driven accord-
ingly.
Mirror
home position
sensor (Q4)
Direct
3-8
Mirror
motor (M3)
Figure 3-401
COPYRIGHT © 1999 CANON INC.
Enlargement /
Reduction
CANON NP6317 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)