Epson 1400 - Stylus Photo Color Inkjet Printer, Service Manual, Page: 27 / 168

EPSON Stylus Photo 1390/1400/1410 Revision B
OPERATING PRINCIPLES Printer Mechanism 27
2.2.3.1 ASF Paper Feeding Mechanism
The following shows the specifications of the stepping motor that drives the ASF Assy.
Driven by the ASF Motor, the ASF Assy performs the following feeding operation.
1. When a paper feeding command is issued from the PC or the Paper button of the
panel is pressed after power-on, the driving force of the ASF Motor begins to be
transmitted to the LD Roller following the route shown below.
2. When the LD Roller starts rotating, the flag of the ASF Sensor Wheel comes free
from the notch on the ASF Sensor. At the same time, the Paper Back Lever
becomes free from the Cams located at the left and right ends of the LD Roller,
then the Paper Holder on the Paper Back Lever inclines downward by tensile force
of the Paper Back Lever Torsion Spring.
3. By the LD Roller's rotation, the Hopper is released from the Hopper Cams located
on the left and right ends of the LD Roller, and the Hopper pops up by tensile force
of the Hopper Compression Spring.
4. When the next sheet of paper is fed by the LD Roller and the Retard Roller, the
Hopper is pressed against the Frame again by the Hopper Cams, and the Paper
Holder of the Paper Back Lever rises by the Cams on the left and right ends of the
LD Roller to prevent the next sheet from being fed with the previous sheet.
5. The LD Roller stops to rotate when it makes one revolution and the flag of the
ASF Sensor Wheel returns to the ASF Sensor.
Figure 2-5. ASF Paper Feeding Mechanism
Table 2-5. ASF Motor Specifications
Item Specifications
Type
4-phase, 48-pole PM type stepping motor
Drive voltage
+42V ± 5% (voltage applied to driver)
Winding resistance
7.0
Ω
± 10% (per phase at 25°C)
Inductance
10.2mH ± 20% (1kH, 1Vrms, at 25°C)
Drive method
Bipolar drive/constant-current drive
Drive IC
A6628
ASF Motor
Combination Gear 29, 11
LD Shaft Spur Gear
LD Roller
ASF Motor
ASF
Sensor
Combination
Gear 29.11
LD Shaft
Spur Gear
Relay Board
ASF Sensor
Wheel
Standby State Feeding Paper
LD Roller
Hopper
Hopper
Compression
Spring
Retard
Roller
Paper
Paper Back Lever
LD
Roller
Cam
Paper Back Lever
Torsion Spring