Paper Up Drive Control - Konica Minolta 7085/FORCE 85 Service Manual

TRAY 3 PAPER FEED UNIT

[4] Paper Up Drive Control

3
PS16
PS22
PS40
M21
24VDC
SD7
SD7 CONT
For 7085
Papers stacked in the tray are pushed up by
3
transmitting the drive force of M21 (up drive 3) to the
paper up/down plate in the tray via up/down wires.
MC21 is controlled by PRCB (printer control board)
via DCDB (DC drive board) (for 7075), or directly by
PRCB (for 7085). The related signals are PS22 (tray
upper limit 3) and PS40 (remaining paper detection
3). To prevent pull-out of tray during copying operation
that cause paper jamming, a tray lock mechanism is
implemented by PS16 (handle release 3) and SD7
(lock SD3).
1. Operation
a. Paper up drive control
When tray 3 is loaded, M21 goes ON for a fixed
time, raising the paper up/down plate in the tray.
When PS22 detects the upper limit of paper as
the paper up/down plate in the tray goes up, it
goes ON and consequently M21 goes OFF, stop-
ping raising the paper up/down plate. When
PS22 goes OFF after a paper is fed, M21 goes
ON again, moving the paper up/down plate up-
ward. The paper up/down plate in the tray is low-
ered mechanically by its own weight.
b. Paper up drive timing
(1) ON timing
M21 is turned ON when loading of a tray is de-
tected (by shorting wires at both ends of the
drawer connector) or when no paper is detected.
(2) OFF timing
M21 is turned OFF when PS22 is turned ON.
MODEL
7075/7085
SERVICE HANDBOOK
5VDC
5VDC
SGND
PS16
SGND
DCPS1
24VDC
PS22
PGND
24VDC
PGND
DCPS2
PS40
24VDC
M21 CONT
M21 CONT
M21 EM
M21 FEM
24VDC
SD7 CONT SD7 CONT
DCDB
24VDC
M21 CONT
For 7075
PRCB
MANUAL
c. Remaining Paper Detection
The level of paper remaining in the tray is de-
tected according to the time that M21 requires to
lift up the paper up/down plate when the tray is
set. This lift-up time (operation time of M21) is
recorded in the PRCB. Subsequently, remain-
ing paper is detected by the paper feed counter.
The detected remaining paper level is displayed
on the operation panel in 5 steps. PS40 is used
M21
to detect the remaining paper level when it drops
below about 10%.
SD7
d. Tray lock control
When the tray handle is gripped, PS16 is turned
ON. This signal then causes SD7 to go ON,
releasing the lock.
2. Signals
3
a. PRCB input signals
(1) PS16 (PS16 to PRCB)
Tray drawer handle detection signal
[L]: Detected
[H]: Not detected
(2) PS22 (PS22 to PRCB)
Paper upper limit detection signal
[L]: Not detected
[H]: Detected
(3) PS40 (PS40 to PRCB)
Remaining paper detection signal
[L]: Detected
[H]: Not detected
(4) M21 EM (DCDB to PRCB: 7075 only)
M21 fault (excessive current) detection signal
[L]: Normal
[H]: Abnormal
(5) M21 FEM (DCDB to PRCB: 7075 only)
Signal indicating if M21's 24V fuse is blown
[L]: Not detected
[H]: Detected
b. PRCB output signals
(1) M21 CONT (PRCB to DCDB to M21: 7075)
M21 ON/OFF control signal
[L]: M21 ON
[H]: M21 OFF
(2) SD7 CONT (PRCB to DCDB to SD7: 7075)
SD7 drive control signal
[L]: SD7 ON
[H]: SD7 OFF
REVISED EDITION
2 - K - 4
Jan. 2002
3
(PRCB to M21: 7085)
(PRCB to SD7: 7085)
DATE PAGE
2-K-4 REPLACEMENT
METHOD