Minolta Di551 Service Manual page 117

ADU
1. Operation
a. ADU conveyance control
The paper fed from the ADU paper reversal sec-
tion is fed to ADU pre-registration rollers at a high
speed by transmitting the drive force of M5 (con-
veyance) to ADU conveyance rollers 1 to 4. ADU
conveyance rollers 1 and 2 are turned ON/OFF
by MC13 (ADU conveyance) and ADU convey-
ance rollers 3 and 4 are controlled by MC2 (ADU
deceleration). After a lapse of the specified time
from turning ON of PS49 (ADU deceleration),
MC2 and MC13 are turned OFF to press the
paper against the ADU pre-registration roller,
forming a paper loop.
MC13 is turned ON/OFF only when the paper
length is 325 mm or longer. If the paper length is
less than 325 mm, it stays ON during copying.
b. ADU feed control
M6 (loop roller) starts rotating at a high speed
after a lapse of the specified time from detection
of the leading edge of paper by PS50 (ADU pre-
registration). Thus, the ADU pre-registration
roller starts rotating to feed paper to the second
paper feed section. At this time, MC2 (ADU
deceleration) and MC13 (ADU conveyance) are
turned OFF so that the drive force of M5 (con-
veyance) which is also used to drive the second
paper feed section is not transmitted to ADU con-
veyance rollers 1, 2, 3, and 4. MC2 and MC13
are turned ON after a lapse of the specified time
from detection of the trailing edge of paper by
PS49 (ADU deceleration), proceeding to feed
the next sheet of paper.
After a lapse of the specified time from detection
of the leading edge of paper by PS44 (registra-
tion), M6 starts rotating at a low speed. MC1
(registration) is turned ON after formation of a
paper loop by the registration roller, thus writing
the image on the back side.
c. ADU lock control
The ADU handle is locked by SD9 (ADU lock).
PS47 (ADU handle) detects the handle position
to determine whether the handle is locked or
released.
2. Signals
a. Input signals
(1) ADU_JAM (PS41 to ADUSDB)
Detection signal of paper passage from exit of
ADU conveyance roller 1
[L]: Detected.
[H]: Not detected.
(2) HD_PS (PS47 to ADUDB)
ADU handle position detection signal
[H]: Handle is released.
(3) ADUCR_PS (PS48 to ADUDB)
Detection signal of paper passage from exit of
ADU conveyance roller 2
[L]: Detected.
[H]: Not detected.
(4) ADUDN_PS (PS49 to ADUDB)
Detection signal of paper passage from exit of
ADU conveyance roller 3
[L]: Detected.
[H]: Not detected.
b. Output signals
(1) LOCK_SD (ADUDB to SD9)
SD9 (ADU lock) drive signal
[L]: SD9 ON
[H]: SD9 OFF
(2) ADUDN_MC (ADUDB to MC2)
MC2 (ADU deceleration) drive signal
[L]: MC2 ON
[H]: MC2 OFF
(3) ADUCR_MC (ADUDB to MC13)
MC13 (ADU conveyance) drive signal
[L]: MC13 ON
[H]: MC13 OFF
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