Epson Stylus 1500 - Paper Feed Mechanism

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 Description
Motor type 4-phase, 96-pole, HB-type
Drive voltage
+42 VDC ± 5%
Coil resistance
10 Ω ± 10%
Drive frequency 300 - 2160 Hz
Excitation mode
❑ Constant current bipolar drive
❑ Paper feed / pump drive: 2-2 phase, W1-2 phase
Minimum step 1/720" (2-2 phase)
Table 2-4. Drive Terms (Paper Feed Mechanism)
Mode
Frequency
(Hz)
Current Value (A / Phase)
Acceleration
W1-2 / 2-2
Phase
Constant
Deceleration
W1-2 / 2-2
Phase
Rush
(before
/ after)
Paper loading (ASF) 2160 0.9 / 0.9 0.9 0.75 / 0.75 0.6 / 0.6
Paper feed 2160 0.9 / 0.9 0.9 0.75 / 0.75 0.6 / 0.6
Pump drive 700 — / 0.9 0.9 0.9 / — 0.75 / 0.75
Pump drive
(lower speed)
300 — / — 0.9 — / — 0.75 / 0.75
Note: Hold current is 0.6 A.
Operating Principles
EPSON Stylus 1500 Service Manual 2-7