Service manual

READ SECTION
2-C-3
2 UNIT EXPLANATION
f. ADF copy operation
g. Platen copy operation
2. Signals
a. PRCB input signals
(1) PS5 (PS5 to SCDB to PRCB)
Scanner home position detection signal.
The reference position for the home position of
the exposure unit is detected.
[L]: The exposure unit is detected.
[H]:The exposure unit is not detected.
(2) PS6 (PS6 to SCDB to PRCB)
Original home position detection signal.
In the platen mode, the reference position for the
original’s leading edge is detected.
[L]: The exposure unit is detected.
[H]:The exposure unit is not detected.
(3) PS7 (PS7 to SCDB to PRCB)
ADF brake detection signal.
In the DF mode, the exposure reference position
is detected.
[L]: The exposure unit is detected.
[H]:The exposure unit is not detected.
b. PRCB output signals
(1) M13 CLK (PRCB to SCDB)
Clock signal for M13.
(2) M13 F/R (PRCB to SCDB)
M13 rotational direction switchover signal.
[L]: The exposure unit is moved toward the paper
exit side.
[H]:The exposure unit is moved toward the paper
feed side.
(3) M13 CSEL (PRCB to SCDB)
M13 excitation switchover signal.
[L]: 2-/3-phase excitation
[H]:W2-/3-phase excitation
(4) M13 V0 to V2 (PRCB to SCDB)
M13 excitation current switchover signal.
c. SCDB output signals
(1) M13 DRIVE, U, V, W (SCDB to M13)
M13 drive control signals.
These signals are used to control rotation of
M13. By supplying and stopping clock pulses,
the motor is turned ON/OFF and the rotational
direction is switched.
PS7 PS5
Original
read
position
Scanner
HP
ADF
break
Second white correction
First white correction
PS5 PS6PS7
AE scan
Original area justment
Home position search
Exposure scan
ADF
brake
Scanner
return
Original HP
Scanner
HP
Second white correction
First white correction
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