Lens Drive System; Driving The Lens; Outline - Canon NP7160 Service Manual

II. LENS DRIVE SYSTEM
A. Driving the Lens

1. Outline

The lens is driven by the lens motor (M3) and the mirror motor (M4).
As shown in Figure 3-201, when the lens motor rotates in normal direction, the lens moves in
the direction of Enlarge by the drive coming through gears and drive belt.
At this time, the No. 4/No. 5 mirror unit moves by the drive coming from the mirror motor in
the direction of Enlarge/Reduce according to how much the lens moves (reproduction ratio),
thereby varying the optical length.
Mirror motor drive command
Mirror home position
detection signal (MRRHP)
DC
controller
PCB
Lens
motor
drive command
CW
Lens home position detection signal (LNSHP)
COPYRIGHT © 1998 CANON INC.
Mirror home position
sensor (PS3)
Enlarge
Reduce
Lens
motor (M3)
CCW
Figure 3-201
CANON NP7161/NP7160 REV.0 AUG. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 3 EXPOSURE SYSTEM
Mirror motor (M4)
Enlarge/Reduce
Direct
Lens home position
sensor (PS2)
3–3