Epson DFX-9000 - Page 76

Epson DFX-9000 Revision B
Operating Principles Printer mechanism 69
2.2.4.4 Paper path switching mechanism
The switch between front-feed and rear-feed is made automatically by
the Host-computer Control Paper Path (HCPP) motor drive. The drive
force is transmitted to the HCPP motor gears and HCPP slide cams, and
moves the Shift gear. The Shift gear slides to switch the paper paths,
which is recognized by the Paper Path Shift sensor (PPSS) installed on
the left side frame. The HCPP motor drive system is unipolar and
constant current.
Figure 2-12. Paper path switching mechanism
Paper path switching mechanism error detection
Paper path switching mechanism errors are detected by the HCPP motor
driver. The error (Fatal error: HPCC driver error) is detected when a
single phase of the HCPP motor is energized for longer than the allowed
period of time. The +42 V power supply is shut off by hardware when
this error is detected.
A HCPP motor out-of-step error cannot be detected; the mechanism
does not include a circuit to detect rotations of the motor.
HCPP
Slid
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Shift Gear
HCPP Gear
HCPP Motor Gear
HCPP Motor
PPSS
Sensor
Left Side Frame
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