Purge Unit; Functions Of Purge Unit - Canon WS8400 Service Manual

Chapter 2
b) Nozzle structure
Ink is supplied from the ink tank, passes through by a mesh ink filter, and is sent to the nozzles.
Ink is supplied from the shared ink chamber to the nozzles. When the head driving current is applied to the nozzle heater, this causes the ink to boil and
form bubbles so that ink droplets are discharged from the nozzles.

2.3.2.5 Purge Unit

2.3.2.5.1 Functions of purge unit

To maintain high print quality, the purge unit performs maintenance of the nozzles in the printhead.
The functions of the purge unit include capping, cleaning, and ink supply.
a) Capping
Capping prevents nozzle drying and dust adhesion by pressing the cap of the purge unit to the face plate on the nozzle section of the printhead.
Capping is performed when printing is completed, at the start of the suction operation, and when switching to the standby state due to an error.
The capping operation also connects the ink passage between the printhead and purge unit.
b) Cleaning
Cleaning includes a wiping operation for removing paper fibers and dried ink deposits adhering to the nozzle face plates of the printhead, a suction
operation for removing ink from the nozzles and drawing new ink to refresh the nozzles, and a maintenance jet operation where ink is sprayed from the
nozzles to the cap or maintenance jet tray to remove bubbles in the nozzles and dust and other foreign particles near the nozzles. The combination of these
three maintenance operations improves nozzle discharge performance.
Details of the cleaning function are shown in the table below.
2-14
0 0 0
1 1
2 2 2
3 3
1276 1276 1276
1277 1277
1278 1278 1278
1279 1279
Bk PC C
Heater
0 0
1 1 1
2 2
3 3 3
1276 1276
1277 1277 1277
1278 1278
1279 1279 1279
PM M
F-2-13
Resin
Heater
Shared ink chamber
F-2-14
5/600inch
1/1200inch
0
1
2
3
1276
1277
1278
1279
Y
82/600inch
Silicon plate
0009-1514