Paper Feed Mechanism - Epson Stylus COLOR 1520 Service Manual

EPSON Stylus &2/25 1520

2.2.4 Paper Feed Mechanism

The paper feed mechanism of this printer consists of the integrated ASF (Auto Sheet Feeder) mechanism,
tractor mechanism, PF (Paper Feed) motor, front/rear PE (Paper End) sensors, PF roller, paper guide
mechanism, paper eject unit, and PF motor drive disengage mechanism. The torque from the PF motor
drives the paper load mechanism, paper feed mechanism and paper eject mechanism. While the printer
is not printing, the PF motor drive disengage mechanism switches the torque from the PF motor to the
pump mechanism, which depends on the CR position. While the paper feed mechanism is driven, the
torque from the PF motor is transmitted via PF motor pinion gear and disengage gear to the PF roller.,
where the torque is then divided into 2 directions. One is transmitted to the paper eject mechanism via the
gear train in the paper guide assembly. The other is transmitted to the ASF mechanism via the
transmission gear.
The tractor drive gear train is set at the left end of the PF roller. Table 2-4 and Table 2-5 shows the
specification for the PF motor and PF motor drive terms, respectively. Figure 2-5 illustrates the paper feed
mechanism.
Item
Motor type
Drive voltage
Coil resistance
Connection
Excitation mode
Minimum step
Operation
mode
Paper feed
ASF Feed
Pump driven
Pump driven
(slow)
Note) Double 1-2 phase drive / 2-2 phase drive
2-6
Table 2-4 PF Motor Specification
4-phases / 96-pole / HB type stepping motor
42 VDC 5% (The voltage applied to the driver)
10 10% (at 25 C per 1 phase)
Bipolar
2-2 phase, 1-2 phase, W1-2 phase constant current drive
1/720 inch / step (2-2 phase drive)
Table 2-5 PF Motor Drive Terms
Acceleration Constant
0.9/0.9
0.9/0.9
/0.9
/
Figure 2-5. Paper Feeding Mechanism
Description
Deceleration
0.9 0.75/0.75
0.9 0.75/0.75
0.9 0.9
0.9
/
Stand-by
0.6
0.6
0.6
0.6
Rev. A