Relationship Between The Scanner Sensors And The Signals - Canon NP6251 Service Manual

The scanner is slowed down as soon as the signal plate has reached the scanner
original leading edge 1 sensor (PS3); brakes are applied when it reaches the scanner
home position sensor (PS1) so that it stops at its home position.
When stream reading mode is selected with the RDF in use, the scanner original
leading edge 2 sensor (PS4) is used to find out whether the No. 1 mirror mount of the
scanner has reached a specific position.
The distance over which the scanner travels varies according to the size of the copy
paper and the selected reproduction ratio.

2. Relationship between the Scanner Sensors and the Signals

Sensor
Scanner home
position sensor
(PS1)
Original leading
edge 1 sensor
(PS3)
Scanner leading
edge 2 sensor
(PS4)
COPYRIGHT © 1997 CANON INC.
Signal
Forward
SCHP
SCDP1
SCDP2
Table 3-301
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
Scanner
Reverse
• Indicates that the scanner is at
• Indicates that the scanner has
• Indicates that the registration
• Indicates the scanner forward
• Indicates that the scanner
• Indicates that the scanner has
CHAPTER 3 EXPOSURE SYSTEM
Description
home position.
reached a point in home
position.
clutch has turned on.
distance reference.
brakes have turned on.
reached stream reading
position.
3-7