Movement Of The Scanner In Page Separation Mode - Canon NP6251 Service Manual

4. Movement of the Scanner in Page Separation Mode

Copy Start key
ON
Scanner home position
sensor (PS1)
Original leading edge 1
sensor (PS3)
Scanner motor (M3)
Scanning lamp (LA1)
In Figure 3-303, all periods I, II, and III are controlled by the microprocessor on the
DC controller PCB with reference to the original leading edge signal 1 (falling edge of
SCDP1) for the 1st page.
The microprocessor determines the distance over which the scanner moves forward
based on the selected reproduction ratio and the size of the original or selected cassette.
I, II: The distance over which the scanner moves forward is determined based on the
selected reproduction ratio and the size of the original or the cassette size.
III: If original size detection has been executed, the microprocessor halves the
measured size and uses the result as the center of the original, and the scanner
moves assuming it to be the leading edge of the 2nd page.
If page separation is selected without original size detection, the control is based on
the size of the selected cassette.
If the forward distance of II in Figure 3-303 is about 220 mm or more, the point about
220 mm is assumed as the leading edge of the 2nd page.
If the 1st and the 2nd pages are reversed using extended mode (Chapter 1), no
change will occur except that the order of SCFW2/SCRV2 and SCFW1/SCRV1 is
reversed.
COPYRIGHT © 1997 CANON INC.
Leading edge
of 1st page
INTR AER SCFW1 SCRV1
I
FD
Figure 3-303
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 3 EXPOSURE SYSTEM
Leading edge Leading edge
of 1st page of 2nd page
SCFW2
II III
RS
SCRV2 LSTR
3-9