Purge Unit Structure - Canon BJC-1000 Service Manual

Part 4: Technical Reference

3.3.2 Purge unit structure

1) Purge drive gear
The purge drive gear which is driven by the transmission gear activates the cam
controlling the pumping operation. The transmission gear is rotated by the paper
feed roller which is driven by the paper feed motor.
The cam's position is detected by the home position sensor via the sensor arm.
2) Wiper unit
When the carriage moves from left to right, the wiper retracts so that it does not
touch the head. However, when the carriage moves from right to left, the wiper
wipes off the ink from the BJ cartridge's face plate at the following times:
when the printer is turned on, once every 60 seconds (or after a set dot count is
reached) during printing, when the paper feed operation ends, when the pumping
operation ends, and when the cap is opened or closed.
3) Cap unit
The cap unit has a rubber cap. When the carriage moves to the home position, the
cap unit is pressed against the print head's face plate to cap it.
Also, since the cap is connected to a pump, the cap sucks ink out of the BJ cartridge
during the pumping operation. The ink which has been sucked out is sent to the
bottom cover unit's waste ink absorber.
4) Maintenance jet absorber
The maintenance jet absorber at the home position absorbs the ink ejected from the
nozzles for a test to adjust the nozzles in the following cases: when the printer is
turned on, during printing, when wiping occurs during printing, when paper feeding
ends, when the pumping operation ends, and when the cap opens.
5) Slide lock pin
The slide lock pin moves the cap when the carriage moves from left to right and reaches
the capping position. Capping is thereby executed and the slide arm is unlocked.
When the slide arm is unlocked, the feed roller's rotation is transmitted to the purge
drive gear and sheet feeder.
Maintenance Jet Absorber
Slide Lock Pin
Purge Drive Gear
Figure 4-17 Purge Unit
4-18
BJC-1000
Cap Unit
Wiper Unit