User Guide

4. Moving the Lens
a. At Power-On
When the power switch is turned on, the lens X motor (M4) starts to rotate, and the
lens moves in the direction of the lens X home position sensor (PS6). Then the lens Y
motor (M5) rotates to move the lens in the direction of the lens Y home position sensor
(PS7). When the signal plate on the lens housing blocks the lens X home position sensor
(PS6), the X motor starts to rotate in reverse; when the signal plate on the lens stage
blocks the Y home position sensor (PS7), the lens Y motor (M5) starts to rotate in
reverse.
The motors stop to rotate when the lens has reached Direct/A4 width position. (See
period I of Figure 3-204.)
b. While Making Copies
The microprocessor slave (Q140) remembers the location of the lens in Direct/A4
position. When a different ratio is selected, it immediately applies drive pulses to the lens
X motor (M4)/Y motor (M5) to change the position of the lens. (See period II of Figure 3-
204.)
The lens Y motor (M5) starts to rotate to move the lens when the Copy Start key has
been pressed and the sizes of the original and the copy paper have been determined.
(See period III of Figure 3-204.)
• Sequence of Operations
Figure 3-204
Power switch
ON
Lens Y motor (M5)
Lens X motor (M4)
WMUP/WMUPR
Ratio change
(Reduce)
Lens X home
position (PS6)
Lens Y home
position sensor (PS7)
Motor CW/sensor ON
Motor CCW
Motor ON (direction depends on conditions)
STBY
INTR
Ratio change
(Enlarge)
Copy Start key
ON
I II IIIII
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 3 EXPOSURE SYSTEM
3-4
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