Paper Loading/Feeding Mechanism - Epson Stylus C87 Service Manual

EPSON Stylus C87/C88/D88

2.2.3 Paper Loading/Feeding Mechanism

Paper loading/feeding mechanism consist of switching lever inside the ink system,
holder shaft unit (including clutch mechanism), and ASF unit.
Switching lever and clutch mechanism play an important role in paper loading
mechanism. Refer to 2.2.3.2 Drive Process (p26)
2.2.3.1 PF Motor Specifications (For both ASF and Pump motor)
Table 2-2. PF Motor Specification
Item
Type 4-phase, 200-pole HB stepping motor
Drive voltage +42 V
Wire wound
3.0 Ω
resistance
Inductance
Drive method
2-2 phase, 1-2 phase, W1-2, 2W1-2, 4W1-2 phase constant-current drive
Drive IC
OPERATING PRINCIPLES
for details.
Specification
±
5 % (applied voltage to the driver)
±
10% (per one phase at 25 °C)
±
3.5 mH 20% (1KH, 1Vrms)
Bipolar drive
A6628
2.2.3.2 Drive Process
1. Drive of the PF motor is transmitted to the paper eject roller and the PF roller via
the PF timing belt, however, it is not transmitted to the LD roller and the retard
roller owing to the clutch of the holder shaft unit.
2. The carriage unit moves to the ASF trigger position once the paper loading
command is received.
3. PF motor is rotated counter clockwise, and the clutch is released by the change
lever.
4. After the clutch is released, the PF motor rotates clockwise. Drive is transmitted to
the LD roller and the paper loading operation begins.
5. During paper loading operation, papers are fed from the ASF unit to inside the
printer by the rotating movement of the two cams of the LD roller.
Cam, large: releases hopper
Cam, small:releases paper back lever
6. Once a sheet of paper is fed, the hopper and the paper back lever bring back rest of
the papers to the position in readiness by the rotating movement of the two cams
mentioned above.
7. When the LD roller is turned a full circle, the change lever release the clutch and
the drive to the LD roller is interfered.
Printer Mechanism
Revision A
26