Outline; Operation; Suction - Canon BJ-W3000 Service Manual

CHAPTER 2. BASIC OPERATION
b. Timing
Ink is ejected into the caps in the order of
the heads (Bk, C, M and Y) under the follow-
ing conditions.
[1] When printing is to be started
Just before printing is started,
maintenance jet is performed.
[2] During printing
The timing of the maintenance jet during
printing is based on the internal tempera-
ture detected by the thermister in the
media sensor.
The maintenance jet timer is reset after
the maintenance jet is conducted.
[3] After wiping
After wiping, ink is pre-discharged into
the caps. However, when the drive
frequency is 14.4kHz, it is not con-
ducted.
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4. Suction

a. Outline
The cap is pressed against the head and
the thickened ink and air bubbles in the
nozzles are removed by suction.
The cap is connected to the waste ink
absorber unit by the waste ink carriage tube.
Removed ink is carried to the waste ink
absorber unit by vacuum. Each application
of suction removes, about 0.2g of ink.
b. Operation
Suction operation is classified into all-
color suction, color suction and black suc-
tion.
Suction is effected by rotating the guide
roller, which is driven by the purge motor
(M3) in the purge unit.
The guide roller position is detected by
the pump home position sensor (PS1). The
position where the guide roller has rotated 40
degrees from the pump home position is
considered to be the guide roller stand- by
position.
When the guide roller is rotated for cap-
ping, the cam starts to squeeze the waste ink
carriage tube at a point 43 degrees from the
pump home position.