Canon iPF825, Service Manual

Page: 96 / 316

Chapter 2
2-26
2.3.2.5 Purge Unit
2.3.2.5.1 Functions of Purge Unit
0020-5700
To maintain high print quality, the purge unit performs maintenance of the nozzles of the printhead.
The purge unit supports a capping function, cleaning function, and ink supply function.
a) Capping function
The capping function presses the cap of the purge unit against the face plate on the nozzle section of the printhead to prevent nozzle drying and dust adhesion.
Capping is performed when printing is complete, at the start of the suction operation, and when switching to the standby state due to an error.
The capping function also establishes the ink passage between the printhead and purge unit.
b) Cleaning function
The cleaning function restores the printhead to the state where ink can be easily discharged from nozzles. This function includes the following three types of oper-
ations.
- Wiping operation
This operation is performed to remove paper fibers and dried ink from the face plate.
- Pumping operation
This operation is performed to remove ink from the nozzles and fill the nozzles with fresh ink.
- Maintenance jet operation
This operation is performed to spray ink from the nozzles to the cap, the HP maintenance jet tray, the BP maintenace jet tray, the maintenance jet ink groove of the
platen to remove bubbles in the nozzles and dust and other foreign particles.
c) Ink supply function
The suction pump of the purge unit operates together with the ink supply valve to supply ink to the printhead during the initial filling and ink level adjustment.
Details of the cleaning function are shown in the table below.
Cleaning mode
Name of Service mode or
PRINT INF
(Name of Main Menu)
Operation Description of cleaning
Cleaning 1 CLN-A-1/CLN-M-1
(Head Cleaning A) Normal cleaning Removes dried ink from nozzles, thick ink accumulated on the
face, and paper particles.
Cleaning 2 CLN-A-2 Ink level adjustment and cleaning Adjust the ink level in the head by suction, and then performs
normal cleaning.
Cleaning 3 CLN-A-3 Initial filling ink Fills the empty tube (during initial installation) with ink, and
then performs normal cleaning.
Cleaning 4 CLN-M-4
(Replace P.head) Ink drainage for head replacement Drains ink to replace the head (drains only the ink in the head).
Cleaning 5 CLN-M-5
(Move Printer) Ink drainage for secondary transport Drains ink from the head and tube for secondary transport.
Cleaning 6 CLN-A-6/CLN-M-6
(Head Cleaning B) Normal (strong) cleaning Performs suction stronger than when adjusting the ink filling
amount in the head or normal cleaning to unclog nozzles.
Cleaning 7 CLN-A-7 Aging Performs idle ejection after replacement of the head.
Cleaning 10 CLN-A-10
(Move Printer) Ink filling after secondary transport Fills the empty tube (during installation after secondary
transport) with ink, and performs normal cleaning.
Cleaning 11 CLN-A-11 Ink filling after head replacement Performs normal cleaning after head replacement and ink
filling.
Cleaning 15 CLN-A-15 Dot count suction Performs suction to remove ink adhered to dried nozzles and
thick ink accumulated on the face when the dot count reaches
the prescribed value.
Cleaning 16 CLN-A-16 Precipitated ink agitation Performs the agitation (ink supply valve open/close) operation
to prevent the ink ingredient from precipitating.
Cleaning 17 CLN-A-17 Cleaning (weak) Performs cleaning weaker than normal cleaning to unclog
nozzles.