Ricoh C211 Service Manual page 430

7-2.
Sub-scanning Reduction
r
E Phase
r I 1 1
CN605-7 OD
C Phase
CN605-8
CN605-9
— OE 4E
1
J
ERG
1
Original Transport Motor
-10
Transport Motor
Drive Circuit
b
A/D Converter
CN40:
-17
CN40:
-18
:1~40:
CN40:
-20
c2y40:
5V
)RF@i
)RFqB
Motor
)RF9C Drive
Timing
)RFf@
Pulse c~
Generator
)RF@E
I
I
Timing
Pulse
Genera-
1- tor
Master Processing Control PCB
Note: The SS830 Sub-scanning Reduction operates in a similar fashion as that of the SS950. The SS830 uses
a
4-phase motor as opposed to a 5-phase motor in the SS950. This is due to the difference in scanning
resolutions of the two machines; the 5-phase motor allows for more precise motor movement.
0123456 78910111213
A
Phase
B Phase
C Phase
D Phase
E
Phase
(CN605-1)
(CN403-17)
(CN605-3)
(CN403-18)
(CN605-5)
(CN403-19)
(CN605-7)
(CN403-20)
— — — — -
(CN605-9)
(CN403-21)
10-1 line+
(1/16 mm)
Note: The reduction ratio change is performed by changing the pulse width (t).
Reduction
Original Transportation
Command Sheet Transportation
I
Ratio
Pulse Width PPS
100%0 1.484ms
674
930/o 1.378ms 726
820/o 1.214ms
824
759'0
1.l12ms
899
7170 1.060ms
944
64% 0.950ms 1053
Pulse Width PPS
0.742ms
1348
~ =0.928
0.689ms 1451
~ =0.928
g =0.818
0.607ms
1648
& =0.818
674
— =0.74
0.556ms
1348
1798 —.
899
~ 798 '0.749
When the reduction command is
sent
from
the main board, the frequency of the pulses
from the pulse generator increases. The drive pulse generator then increases the
frequency of the motor drive pulses to increase the motor rotation speed.
2-18