Ricoh J001 Service Manual page 496

Ink Supply System
M/Y compartment (for Magenta, Yellow Ink cartridges)
K/C compartment (For Black, Cyan Ink cartridges)
Each compartment contains:
1 pump motor.
2 pumps (one for each ink cartridge)
2 cams
When a print head tank needs ink:
The printer switches on one ink pump motor. The motor and its worm gear are rotated
forward or reverse (depending on which type of ink is requested). Only one pump
operates at a time.
One or the other pump is operated, depending on whether the ink pump motor rotates
forward or reverse. (Two pumps that share a motor cannot operate together at the
same time.)
A cam striking a plunger vibrates the plunger to form the vacuum in the line that sucks
ink from the cartridge.
The supply motor operates long enough to pump the prescribed amount of ink to the
tank. Then it switches off.
⇒
Explanation of "air release filling":
In order to eject the ink properly from the print head, it is necessary to maintain
negative pressure (with respect to the surrounding air) inside the head tank. If
negative pressure is lost, the ink can leak out from the nozzle and adversely affect the
image quality. If this occurs, the negative pressure must be re-established. This
process is known as "air release filling".
When the surface of the liquid dips below the detection pins (see diagram below), the
machine will perform air release filling. This is because if this happens, negative
pressure may have been lost. To perform air release filling, the air release valve is
opened (which re-calibrates the internal pressure), ink is poured into the ink head, and
suction the ink by suction cap with air release valve is closed. Therefore, to perform
this process, the machine consumes ink.
Air Detection Pin
J007/J010/J011
CÓPIA NÃO CONTROLADA
Ink level decreases when air enters from
the air release valve or ink tube. It also
decreases when the amount of ink
supplied is less than the ink consumed.
6-16
CÓPIA NÃO CONTROLADA
Rev. 11/2008
Air is detected
SM