EPSON Stylus Color 900 Revision C
Operating Principles Printer Mechanism Operating Principles 51
2.2.4 Paper Feed Mechanism
The paper feed mechanism manages constant paper feeding during
printing through to paper ejection. Unlike previous models, the PF motor
of this printer only drives the paper feed mechanism, having no
connection with the carriage lock mechanism nor the pump mechanism.
See Figure 2-5 and Table 2-11 for the cross section of the paper feed
mechanism and the PF motor specifications, respectively.
Table 2-11. PF Motor Specifications
For the printer-specific feature, the PF motor pinion transfers torque to
the PF drive gear without any transmission gear in between. The gears
used for the PF motor pinion and the PF drive gear are very precise.
Therefore, note the points below when handling them:
1. Do not touch the gear surface with your bare hands.
2. Keep other parts or tools for servicing such as screw drivers away
from the gears.
The PE sensor in the paper feed mechanism is used to check the
following:
1. During paper loading, checks if the leading edge of the paper from
the ASF is correctly transported.
2. Checks if the paper loaded meets the specifications.
3. Checks if the paper is properly ejected after printing is over.
4. Checks if paper is jamming.
See Table 2-12 and Table 2-13 for the PE sensor specifications and the
PE sensor switch mode, respectively.
Table 2-12. PE Sensor Specifications
Table 2-13. PE Sensor Switch Mode
Figure 2-5. Paper Feed Mechanism
No. Items Specifications
1 Type 4-phase / 200-pole / HB-type stepping motor
2 Drive voltage 42 VDC
±
5% (Applied to the driver)
3 Coil resistance 8.1
Ω
±
10%
4 Drive mode Bipolar constant current drive mode
No.
Item Specifications
1Type
Transmission-type photoelectric transfer
system
2 Drive voltage 5 VDC
±
5% (Applied to the driver)
3 Collector resistance 30 VDC or less
Paper
installation
Switch mode Output voltage
Not installed Open 0.7 VDC or less
Installed Closed 2.4 VDC or more
PF m otor pinion
PF drive gear
Sub roller
Actuator
PE sensor
Paper
PF (pow dery-coated)
ro lle r
Paper ejection
ro lle r
Notched roller
