Canon BJ-W9000 Service Manual page 169

BJ-W9000 Part 4: Technical Reference
3.6.2 Construction of Purge Unit
a) Caps
The nozzle arrays on the BJ print heads are capped during the capping and cleaning
operations. The rubber portion of the cap touches the face plate of the nozzle array.
Each of the twelve nozzle arrays of the BJ print heads (three nozzle arrays x four BJ
print heads) is capped with its own cap.
Of the four caps from left to right seen from the front, the 1st, 4th, 7th and 10th are
suction caps that are connected to the suction pumps.
Of the 8 caps from left to right seen from the front, the 2nd, 3rd, 5th, 6th, 8th, 9th,
11th and 12th are preventive caps, all of which are dedicated to the capping
operation.
Not only the preventive caps but also the suction caps cover the nozzle arrays during
the capping operation. The caps are raised by the cap cams operated by the purge
motor to cover the arrays when the carriage has moved to the home position.
The suction caps cover the arrays during the cleaning operation and the suction
pump vacuums the ink from the BJ print heads.
Depending on the cleaning mode, one of the three combinations of suction caps, that
is, 1st, 4th, 7th and 10th, 1st and 10th, or 4th and 7th is selected. The selected
suction caps are raised by the cap cams operated by the purge motor for the nozzle
capping action.
Suction cap
Supply cap
Wiper blade
Wiper motor
Purge motor
Figure 4-19 Cap Unit
4-31