Lens Drive System; Outline - Canon NP6317 Service Manual

CHAPTER 3 EXPOSURE SYSTEM
II. LENS DRIVE SYSTEM
A.

Outline

The lens is moved by the scanner motor (M2). Normally, the coupling gear is in its upper
position, and connects the scanner motor to the scanner drive capstan. To move the lens, the lens
solenoid (SL2) goes ON, causing the coupling gear to disengage from the scanner capstan gear and
engage with the lens capstan gear. The lens is a "floating element" type. In operation, the relative
position of lens elements (individual lenses) changes, and the focal length changes as a result, but
the changes are intended to optimize lens sharpness for each reproduction ratio, not to make the
lens function as a zoom lens. (The lens should not be dismantled.)
When the scanner motor rotates (CW), the lens will be moved to the left (for ENLARGE-
MENT) by the capstan and cable.
When the paper size is changed or when the copier is in the REDUCE mode, the blank expo-
sure shutter moves in relation to the distance over which the lens travels, thereby blanking out the
width corresponding to the reproduction ratio.
The DC controller indicates 'E210' on the control panel in response to an error in the lens drive
system.
Couping gear
Lens drive cable
DC contoroller PCB
3-2
Solenoid "ON"
SL2
Idler gear
Q4
ENLARGEMENT direction
Figure 3-201
COPYRIGHT © 1999 CANON INC.
Scanner drive capstan
Scanner motor (M2)
Lens
CANON NP6317 REV.0 APR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)