Canon BJC-55 Service Bulletin page 137

BJC-50
b) Purging
Purging is performed to correct/prevent the non-ejection of ink, which is caused by
unnecessary bubbles and dust on the head faceplate.
The cap and pump in the purge section are used for purging operation.
c) Capping
Capping operation is performed to correct/prevent the non-ejection of ink, which is
caused by the dried-up of ink inside nozzles.
Cap is pressed against the head faceplate when the carriage moves to the home
position.
When the cap moves away from the faceplate, waste ink in the cap is sucked by
purging operation. The sucked ink is absorbed by the absorber in the pump and
finally absorbed by the waste ink absorber.
Capping is performed in the following cases:
1. When the printer is turned off with the POWER button
2. When the printer receives no data or commands for 1 minute while paper is set
in the paper feeder.
d) Wiping
Wiping operation is performed to correct/prevent the non-ejection of ink, which is
caused by paper-powder on the head faceplate or by the foreign materials in ink.
The wiper is set and released by wiping hooks on the carriage. When the carriage
moves from the home position, the wiper touches the aluminum plate of the head,
removes the stain from the wiper and then wipes off the ink from the faceplate.
Wiping operation is performed in the following cases:
1. When the number of dots printed or the print time exceeds the preset value
during printing
2. After purging
3. Before capping
Hooks
Wiper Lever
1. Wiper is set.
e) Maintenance jet
The maintenance jet is performed during cleaning to remove bubbles inside nozzles
and the dust near ink ejection apertures.
In this operation, the ink is ejected from the head into the cap and sucked into the
waste ink absorber through the pump section.
Carriage
Latch Lever
Wiper
Figure 4-20 Wiping Function
BJ Head
2. Wiper is released.
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Part 4: Technical Reference