Paper Feed Mechanism - Epson Stylus 1500 Service Manual

Paper Feed Mechanism

This printer's paper feed mechanism consists of the built-in auto sheet feeder (ASF), push tractor,
paper feed (PF) motor, front/rear paper end (PE) sensors, PF roller, eject roller unit, and disengage
mechanism. The PF motor is a 4-phase, 48-pole, PM-type stepping motor that directly drives the
paper feed mechanism (for paper advancing and paper pickup). This motor also drives the pump
mechanism, but only when the printer is in the cleaning state. The paper feed mechanism is driven
using a 1-2 phase drive method, except in the paper feed drive sequence (W1-2 phase). The paper
feed mechanism is illustrated in Figure 2-6.
The disengage mechanism switches PF motor torque between the PF drive and pump drive via the
carriage unit stop positions. PF motor torque is transmitted to the PF roller via the PF motor
pinion, disengage mechanism, and gear train. The torque is then separated for each of the two
directions of the PF roller. One direction of torque transmission is used to drive the paper-ejecting
mechanism via the gear train of the upper paper guide assembly. The other direction is used to
drive the push tractor or ASF mechanism.
Table 2-3. Paper Feed Motor Specifications
Item
Motor type
Drive voltage
Coil resistance
Drive frequency
Excitation mode
Minimum step
Table 2-4. Drive Terms (Paper Feed Mechanism)
Mode
Paper loading (ASF)
Paper feed
Pump drive
Pump drive
(lower speed)
Note: Hold current is 0.6 A.
EPSON Stylus 1500 Service Manual
4-phase, 96-pole, HB-type
+42 VDC ± 5%
10 Ω ± 10%
300 - 2160 Hz
Constant current bipolar drive
Paper feed / pump drive: 2-2 phase, W1-2 phase
1/720" (2-2 phase)
Frequency
Acceleration
(Hz)
W1-2 / 2-2
Phase
2160 0.9 / 0.9
2160 0.9 / 0.9
700 — / 0.9
300 — / —
Operating Principles
Description
Current Value (A / Phase)
Deceleration
Constant W1-2 / 2-2
Phase
0.9 0.75 / 0.75
0.9 0.75 / 0.75
0.9 0.9 / —
0.9 — / —
Rush
(before
/ after)
0.6 / 0.6
0.6 / 0.6
0.75 / 0.75
0.75 / 0.75
2-7