M13 (Scanner Drive) Control - Minolta Di850 Service Manual

READ SECTION

[3] M13 (Scanner Drive) Control

M13 CLK M13 DRIVE U
M13 F/R M13 DRIVE V
M13 CSEL M13 DRIVE W
M13 V0
M13 V1
M13 V2
PS5
PS7
PS6
PS4
PRCB SCDB
M13 (scanner drive) is driven by the SCDB (scanner
drive board) and is controlled by the PRCB (printer
control board).
Related signals are PS5 (scanner HP), PS6 (original
HP), and PS7 (ADF brake).
1. Operation
a. Operation of M13
M13 is a 3-phase stepping motor driven using
the 3-phase bipolar constant-current drive
method. The motor is turned ON/OFF by supply-
ing/stopping clock pulses.
b. Movement speed of the exposure unit
Scanning speed
Operation mode
Scan 400 mm/sec (600 dpi, 1:1)
Forward 615.38 mm/sec
Home position 205.1 mm/sec
search
c. Positions of sensors
Paper exit side
PS7 PS5
M13
5VDC
PS5
PS5
SGND
PS7 PS7
5VDC
PS6 PS6
SGND
24VDC
PGND
DCPS2
5VDC
SGND
DCPS1
Movement speed
Paper feed side
PS6
2-C-2
d. Exposure unit home position search
If the exposure unit is not at the home position
when the main switch is turned ON or when the
START PRINT button is pressed, the home posi-
tion is searched for in the following manner:
(1) When the exposure unit is on the paper exit side
with respect to the home position
When the exposure unit is at PS7 (ADF brake)
(PS7 is ON), it moves forward at a low speed.
And it moves until PS5 (scanner HP) turns ON
and OFF again, then stops. It moves backward
until PS5 turns ON again.
When the exposure unit is between PS7 and
PS5, it moves backward until PS7 turns ON
before moving forward as mentioned above.
(2) When the exposure unit is on the paper feed side
When the exposure unit is at PS5 (PS5 is ON), it
moves forward at a low speed until PS5 turns
OFF before moving as discussed in (1) above.
When the exposure unit is located on the paper
feed side with respect to PS5, it moves backward
then stops for a short while after PS5 turns ON.
Then it moves forward and performs operations
as described in (1) above.
e. Read with shading correction
L1 is turned ON, when black correction has been
completed after the home position search oper-
ation, thus reading the light reflected by the white
reference plate installed underneath the glass
stopper plate and performing the first white cor-
rection. Then, the exposure unit moves to the
paper exit side, performs the second white cor-
rection while stopping at the preset position, then
returns to the home position to turn OFF L1.
ADF Scanner
break HP
PS7 PS5
First white correction
Second white correction