Canon FAX-L1000 - Manual (Page 451)

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FAX-L1000 Chapter 5: Appendix
3.5.3 Operation
a) Function
a-1) Reversing function
When the duplexing unit receives the duplexing unit command from the fax, it turns ON
the duplexing unit solenoid, moves the face-up deflector and feeds the paper to the
duplexing unit. It also rotates the reversing motor in the reverse direction for about 1
second, and feeds the paper remaining in the reversing unit to the duplexing unit pick-up
sensor.
About 0.3 seconds (about 0.5 seconds for 1200dpi print) after the paper reaches the
reversed paper sensor, the duplexing unit driver rotates the reversing motor in the normal
direction, and feeds the paper to the reversing wait position (where the paper reaches
about 0.2 seconds after the leading edge of the paper passes the reversed paper sensor).
If the duplexing unit pick-up sensor does not detect the preceding paper, the duplexing
unit driver rotates the reversing motor in the reverse direction and the duplex feed motor
in the normal direction in order to feed the paper to the duplex pick-up wait position
(where the paper reaches about 0.4 seconds after the leading edge of the paper passes the
duplexing unit pick-up sensor) at high speed.
If the duplexing unit pick-up sensor detects the preceding paper, the duplexing unit holds
the paper at the duplexing unit pick-up wait position until the preceding paper passes the
sensor.
a-2) Duplexing unit pick-up function
When the /PRNT signal is sent to the ECNT board from the video controller, the main
motor of the printer starts rotation. When the main motor rotation reaches its prescribed
speed, the engine controller turns ON the feed roller clutch of the printer and sends the
duplexing unit pick-up command to the duplexing unit driver.
When the duplexing unit driver receives the duplexing unit pick-up command from the
fax, it rotates the duplex feed motor in the reverse direction to feed the paper from the
duplexing unit pick-up wait position to the pre-feeder sensor of the printer at the same
speed as the print speed of the fax.
The ECNT board detects the conditions of the pre-feed sensor for a prescribed period of
time after the duplexing unit pick-up starts. If the pre-feed sensor does not detect no paper
within the prescribed period of time, the ECNT board turns OFF the feed roller clutch and
sends the feed stop command to the duplexing unit driver to stop feeding the paper in the
prescribed period of time after the top of page sensor detects the paper present condition
of the preceding paper. When the top of page sensor detects the trailing edge of the
preceding paper, the CPU resumes feeding the stopped paper. By this, the between-page
distance appropriate for the continuous printing is achieved.
The paper then reaches the registration arm where its skew is corrected, goes through
transfer, separation, fixing and delivery unit and is delivered to the tray.