Paper Jam Detection - Canon CLBR 460ps Service Manual

CHAPTER 2
C. Paper Jam Detection
To detect presence of the paper and whether the paper has been correctly fed, the following
paper sensors are provided:
• Duplex pick-up paper sensor (PS3104)
• Reversing unit paper sensor (PS3101)
• Reversing unit stationary paper sensor (PS3103)
The microcomputer (M-CPU) on the duplex driver PCB determines if paper jam has occurred by
checking for the presence of paper in the sensor at the timing stored in the CPU.
If it detects a jam, the CPU immediately stops the duplex unit operation and reports the jam
to the engine controller.
1. Reversing unit delay jam
The CPU assesses an reversing unit delay jam if the reversing unit paper sensor (PS3101) can-
not detect paper within the prescribed period of time after the duplex deflector drive solenoid is
turned ON.
2. Reversed unit stationary jam 1
The CPU assesses a reversing unit stationary jam 1, if the paper does not passes through the
PS3101 within the specified period of time after the delivery deflector drive solenoid (SL3102) is
turned ON.
3. Reversing unit delay jam 2
The CPU assesses a reversing unit delay jam 2, if the paper does not reach the PS3103 within
the specified period of time after the reversing motor (M3102) starts rotating clockwise.
4. Duplexing unit pick-up delay jam
The CPU assesses a duplexing unit pick-up delay jam, if the paper does not reach the PS3104
within the specified period of time after the reversing motor (M3102) starts rotating clockwise.
5. Duplexing unit pick-up stationary jam
The CPU assesses a duplexing unit pick-up stationary jam, if the paper does not pass through
the PS3104 within the specified period of time after the duplex feed motor (M3101) starts run-
ning for duplexing unit pick-up.
6. Residual paper jam
a. The CPU assesses a reversing unit residual paper jam and stops the printer immediately if
the PS3103 detects paper during the wait period of the duplexing unit.
b. The CPU assesses a duplex feed unit residual paper jam and stops the printer if the PS3103
and the PS3104 detect paper after completion of automatic delivery (note) during the wait
period of the duplexing unit.
c. The CPU assesses a duplex feed unit residual paper jam and stops the printer if the PS3101,
PS3103, and PS3104 detect no paper first and then any of the sensors detects paper during
the wait period of the duplexing unit.
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