Canon PC980 Service Manual - Page 212

CHAPTER 8 ADF D. Detecting an Original 1. Outline The ADF's original detection mechanism has the following two functions: 1. Detecting the Presence/Absence of an Original Checks whether there is an original on the original tray. 2. Identifying the Length of the Original Checks the length of the original placed on the original tray. 3. Detecting the Presence/Absence of an Original The original placement sensor (PI3) is used to check the presence/absence of an original. When an original is placed on the original tray, the original placement sensor (PI3) sends the original detection signal (PDP3) to the ADF controller PCB in response to the movement of the detecting lever away from the sensor. Original Original tray Detecting lever PI3 ADF controller PCB Figure 8-106 Original detection signal (PDP3) 8-6 COPYRIGHT © 1999 CANON INC. CANON PC800s/900s REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)