Paper Feed Control - Konica Minolta 7020 Service Manual

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PAPER FEED UNIT
[3]

Paper Feed Control

24VDC
24VDC
PGND
PGND
SGND
DCPS
M9 (paper feed motor) drive power is transmitted to the
various rollers by means of SD1 (first paper feed SD (upper
tray)), SD2 (first paper feed SD (lower tray)), and SD3
(bypass SD). When M9 first comes ON, no rollers are in
contact with paper; accordingly, SD1, SD2, or SD3 operate
to raise or lower the feed rollers or bypass plate so as to
make contact with paper and initiate feeding.
When SD1 (first paper feed SD) comes ON, MC2 (loop
clutch) also comes ON at the same time, conveying the
paper up to the registration rollers. PS1 (registration PS)
detects the leading edge of the paper, MC2 goes OFF,
and the paper is formed into a loop. When the drum
charge stabilizes, MC1 (registration) and MC2 both come
ON to drive the second paper feed.
Paper feed operations are controlled by the PRDB (printer
drive board).
24VDC
24VDC
PGND
PGND
M9 CLK
M9 CONT
5VDC
SGND
SGND
PS1
5VDC
MC1 DRIVE
24VDC
24VDC
MC2 DRIVE
5VDC
SD1 DRIVE
24VDC
24VDC
SD2 DRIVE
SD3 DRIVE
24VDC
PRDB
1. Operation
a. Timing for first paper feed (bypass)
(1) Start for first sheet
At a predetermined time interval after START button
ON.
M9
(2) Start for second sheet
At a predetermined time interval after first sheet SD3
ON.
PS1
(3) OFF timing
At a predetermined time interval after SD3 ON.
MC1
MC2
b. Timing for first paper feed (upper tray)
(1) Start for first sheet
SD1
At a predetermined time interval after START button
ON.
SD2
(2) Start for second sheet
SD3
At a predetermined time interval after first sheet SD1
ON.
(3) OFF timing
At a predetermined time interval after SD1 ON.
c. Timing for first paper feed (lower tray)
(1) Start for first sheet
At a predetermined time interval after START button
ON.
(2) Start for second sheet
At a predetermined time interval after first sheet SD2
ON.
(3) OFF timing
At a predetermined time interval after SD2 ON.
d. Control for second paper feed (MC1)
(1) ON timing
At a predetermined time interval after PS1 ON.
(2) OFF timing
At a predetermined time interval after PS1 OFF.
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