Canon 1000 Service Manual page 194

3. OPERATION AND TIMING
Moving the Lifter Down
• The paper deck cover must be open, i.e., the cover open signal (STDO) is '1'.
• The lifter lower limit switch (SW11) must be off, i.e., the lifter lower limit signal (LFLM) is '1'.
As a result of the above conditions, the output signals from the combination circuit will be as follows:
• The lifter up signal (STMUP) will be '0'.
• The lifter down signal (STMDN) will be '1'.
whereupon the lifter starts to move down.
In Response to a Jam
When a jam occurs, the lifter up/down control signal by the CPU changes from '0' to '1'.
The condition causes the lifter up signal (STMUP) to go '0' and the lifter down signal to go '1', thereby
lowering the lifter. At this time, the lifter will not move down to its lowest position but will stop when the top
surface of paper lowers a maximum of about 12 mm.
Motor ON
control signal
Lifter up/down
CPU
control signal
DC controller PCB
3-150
COPYRIGHT © 2001 CANON INC.
Lifter up signal (STMUP)
Lifter down signal (STMDN)
Over current
detection
circuit
Combination
circuit
Motor drive IC
Lifter position signal (LTP)
Lifter lower limit signal (LFLM)
Cover open signal (STDO)
Figure 3-619
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
J2223A
-4
M8001
-5
Paper deck motor
+5V
-8
Paper deck lifter
SW8001 upper limit switch
Paper deck lifter
position sensor
PS8002
+5V
-9 Paper deck lifter
SW8002
lower limit switch
+5V
Paper deck cover
-10
SW8003 open/closed
detection switch