Canon LBP-860, Service Manual

Page: 70 / 219

E Paper Jam Detection
To detect the presence of paper and whether or not the paper has been fed correctly, the
following paper sensors are provided:
. paper sensor
. Delivery paper sensor
The microprocessor (CPU) determines if a paper jam has occurred by checking whether paper is
present at the sensor within the amount of time specified in the memory.
it detects a jam. the microprocessor stops printing, and sends a signal to the
video controller to notify it.
1.
Pick-up unit delay jam
The microprocessor detects a pick-up unit delay jam if the paper does not reach the resist
paper sensor within the required time after the paper is picked
Seconds)
Cassette pnk-up roller clutch
PRINT
M? tray roller clutch
solenoid
command
Jam check
n
+-
I
paper
Normal
Main motor (Ml)
3.76 2.85 seconds tray).
Figure 2-38
2.
Pick-up unit stationary jam
The microprocessor detects a pick-up unit stationary jam when the resist paper sensor
detects the sheet of paper within the required time after the VERTICAL SYNC signal
has
been received.
(Unit: Seconds)
PRINT
VERTICAL SYNC REQUEST
signal
Jam check
paper sensor
Normal
motor (Ml)
7.24 seconds 6 39 seconds 6.87 seconds (Letter). 8.49 seconds (Legal)
6.6 seconds 8.49 seconds [Universal). 6.39 seconds (Envelope feeder)
Figure 2-39