The scanner is slowed down as soon as the signal plate has reached the scanneroriginal leading edge 1 sensor (PS3); brakes are applied when it reaches the scannerhome position sensor (PS1) so that it stops at its home position.When stream reading mode is selected with the RDF in use, the scanner originalleading edge 2 sensor (PS4) is used to find out whether the No. 1 mirror mount of thescanner has reached a specific position.The distance over which the scanner travels varies according to the size of the copypaper and the selected reproduction ratio.2. Relationship between the Scanner Sensors and the SignalsTable 3-301COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 3 EXPOSURE SYSTEM3-7SensorScanner homeposition sensor(PS1)Original leadingedge 1 sensor(PS3)Scanner leadingedge 2 sensor(PS4)SignalSCHPSCDP1SCDP2Description• Indicates that the scanner is athome position.• Indicates that the scanner hasreached a point in homeposition.• Indicates that the registrationclutch has turned on.• Indicates the scanner forwarddistance reference.• Indicates that the scannerbrakes have turned on.• Indicates that the scanner hasreached stream readingposition.ScannerForward Reverse
