Canon iR4570 Series Service Manual page 177

Start key
ON
SREADY
STBY
Reader motor
(M501)
LED
CIS HP sensor
(PS503)
Shading
position
F-5-8
Stream reading
start position
1.CIS position check
2.Original scan
F-5-9
Only if 1 min or more
passed since previous
rotation
Shading correction
SCRW
Shading
Stream reading
position
start position
CIS HP
sensor
Original glass
read start position HP
*1:Only if 1 min or more has passed since previous rotation
SCFW
Shading
Shading
Original
position
position
trailing edge
Shading
position
*1
*1
STBY
forward
reverse