Sharp FO-3150 Service Manual page 86

FO-3150U/C
2) Unit control
a. Main motor drive circuit
This machine uses the 4-phase pulse motor, and is driven by the follow-
ing pulses and the circuit
24V
VBB
CNMMT
MA 1
OUT1
MA- 2
OUT2
MM
MB 3
OUT3
MB- 4
OUT4
( Printer PWB)
(Drive waveform)
Stop Rotation
MCA
MCB
MEN-
Fig. 10
b. Paper feed controller
Basically, the feed roller is rotated 1.5 times.
If interval between PUS and PIN is within 0.5 sec., it is rotated 1 time.
The procedure of clutch control
1 Timer is cleared by PUS ON according to clutch control demand.
2 PUS OFF 100 ms after PUS ON
3 PUS ON again 450 ms after the procedure 1 above.
4 If paper is remained in PIN 500 ms after the procedure 1, the third
PUS ON is stopped.
5 PUS OFF 1.25s after the procedure 1. Clutch control demand OFF if
additional control is cancelled.
6 PUS ON again 1.534s after the procedure 1.
7 Clutch control demend OFF 3.366s after the procedure1.
If the paper is not fed normally and the paper in detector signal (PIN_) is
not outputted even with the above operation, the PCU judges it as a
paper jam display is made.
The paper in detector signal (PIN_) is used for the top margin control
signal in addition to jam detection.
The diagram below shows timings of clutch operation.
PUS
0.8
0.1
0.45
0.5
PIN
0.5 0.991 1.25 1.534 2.334
Fig. 11
5V
IC2
14
ENABLE1
7
ENABLE2
IC9
13 MA 62
IN1
MEN- 60
8 MB 61
IN2
( Control PWB)
0.8
1.534
3.366
c. Electrical connection
In the paper feed and transportation system, drive parts and sensors
are connected as shown in the figure below.
CONTROL PWB
PRINTER PWB
8bit
CPU
(IC9)
62 MA 13
60 MEN- 7,14
61 MB 8
ASIC
126 PUS
(IC8)
52 PIN- 3
8bit CPU
4
(IC9)
51 POUT- 3
4
CNPRT
• The main motor, which is the drive source for the paper feed and trans-
portation system, is a 4-phase stepping motor in 2-phase excitement
bipolar system, The step angle is 7.5 .
• The pick-up solenoid operates on 24V to turn on/off paper feed.
• There are following kinds of sensors.
Paper in sensor: (Transmission photo transistor):
This sensor is used to detect the paper feed timing of the next paper
(in prefeed) and to make synchronization between paper transport and
image forming on the drum. This sensor is also used to detect paper
jams.
Paper out sensor: (Transmission photo transistor):
This sensor senses paper exit, and paper jam.
5 – 13
CNMMT
1
1 MA
IC2 17
2 MA-
Motor
4
3 MB
driver
2
4 MB-
MAIN MOTOR
+24V
CNPL
1 +24V
4 IC1 13
2 PUS-
+5V
1
PAPER
PAPER IN PICK-UP SOLENOID
SENSOR
PI2
2
+5V
1
PAPER OUT
SENSOR
PI1
2
Fig. 12