Lens Drive System; Movement Of The Lens; Outline - Canon NP6330 Service Manual

CHAPTER 3 EXPOSURE SYSTEM
II. LENS DRIVE SYSTEM
A. Movement of the Lens

1. Outline

The lens assembly is driven by the lens motor (M3).
The machine uses center reference, in which copy paper is centered along the
feeding path for pick-up and feeding. Figure 3-201 shows the spatial relationship
between copy paper and original.
When the power switch is turned on, the lens motor (M3) starts to rotate, moving the
lens in the direction of the lens home position sensor (PS19). The lens motor starts to
rotate in reverse when the signal plate blocks the lens home position sensor, and stops
when the lens is at Direct position.
The microprocessor on the DC controller remembers the Direct position of the lens.
When the ratio is changed, drive pulses corresponding in number to the selected ratio
will be applied to the lens motor to promptly change the position of the lens.
When moving in Enlarge direction (as from Reduce to Direct), the lens is first moved
past the position for the selected ratio; it is then moved back to the appropriate position
by rotating the lens motor in reverse, thereby ensuring correct positioning of the lens.
3-2
Copyboard glass
Original
Figure 3-201
COPYRIGHT © 1997 CANON INC.
Copier
Reference
Copy paper
CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)