Canon multipass c3000 Service Manual (en)

BJ head protection
In order to always maintain good print quality, this model performs cleaning of
the BJ head at appropriate times.
There are three types of cleaning operations: pump suction, wiping, and
maintenance jet.  Also, the print head is capped after printing, to preserve the
Cleaning operation (pump suction)
Cleaning operation is performed using the cap and pump of the purge unit.
The cleaning operation is performed at the following times:
• When the user initiates a cleaning operation
• At power-on
• When the BJ cartridge is changed
• At the start of a print operation when at least 72 hours has passed since 
the last cleaning
(However, when using the BC-21/BC-22, the first cleaning after changing
the BJ cartridge/ink cartridge will occur when a print operation begins after
24 hours or more.)
Wiping operation
When the carriage passes by from left to right, the wiper blade drops down so
that it does not touch the print head.  When the carriage passes by from right
to left, the blade rises to contact the print head and wipe away paper fibers
and ink residue.
The wiping operation is performed at the following times:
• At the start of printing when less than 72 hours has passed since the last 
cleaning operation
• Every 60 seconds during printing (or after a fixed number of dots have been
• During a capping operation
Maintenance jet
The maintenance jet operation prepares the nozzle spray orifice ink surface
shape by performing an ink test, firing at the maintenance jet absorber.
The maintenance jet operation is performed during a cleaning operation, after
a wiping operation, and after a fixed time (BC-20: 12 seconds; BC-21/BC-22:
variable, between 5 and 20 seconds) while printing.
Capping after print completion
The capping operation is performed at the following times:
• When a fixed amount of time passes after the completion of printing without
new print data being received by the Printer Section
• During printing, after the second wiping operation (i.e. after 120 seconds)
with no print data received by the Printer Section
• After changing the BJ cartridge
Part 1: Facsimile