Samsung SF4500, Service Manual

Page: 53 / 130

6-22 Samsung Electronics
6-1-6 Motor Driver
6-1-6-1. GENERAL
This product use 3 stepper motors, i.e. CR(Cartridge
Return) motor and LF(Line Feed) motor, TX
( Transmission) motor.
CR motor moves left and right all-in-one carriage of
inkjet head and shuttle scanner. It helps the printer
print accurately on the paper. LF motor is driven to
feed and eject paper for printing and to feed and eject
documents to read for scanning. Bi-polar CR motor is
c o n t rolled half step with maximum 24ips(inch/sec),
while LF motor half step and
quarter step at maximum 6ips.
6-1-6-2. CR (CARRIAGE RETURN) MOTOR
DRIVING CIRCUIT
CR motor moves the carriage left and right when ink
cartridge prints something on paper.
- Motor Type : Stepper motor, bi-polar
- Driving Voltage : +30V
- Winding Resistance : 6
Ω
± 10%
- Driving IC : TEA3718DP
×
2
As shown in the above table, current in each mode is
adjusted by voltage of driver(U25, U28) CRV R E F
input. If the output of CR_REF signal controlled by
M F P c o n t roller(U16) is “low”, TR(Q12) will be turned
o ff and the voltage put in to CRVREF of
driver (U25, U28) with +5V divided will go up
(+4.5V). It becomes the standard of the driver, resulting in
high current. If CR_REF output is “high”, TR(Q12)
will be turned on and the voltage put in to CRV R E F
will go down (+3.0V), resulting in low current in the
m o t o r.
C R _ R E F
C R I A 1 C R I A 0
C U R R E N T ( m A ) O P E R AT I O N R E M A R K
( C R I B 1 ) ( C R I B 0 )
H L L 4 9 0 Mono LQ is being driven
L L L 6 7 0 Color draft is being driven
L L L 6 7 0 Mono draft is being driven
X H H 0 No current