Ink Ejection Device; Ink Near End - Ricoh J012 Service Manual

6.4.4

INK EJECTION DEVICE

Each print head uses a piezo-electric element (PZT) . This forces ink from the ink reservoirs
out of the ink nozzles and onto the paper.
This is done with pressure. At the prescribed time, an electric charge is applied to the PZT.
This makes the PZT expand. The expansion of the PZT puts pressure on the ink below. This
makes the ink move in both directions. The ink on the right is forced out the ejection port.
This device is unique. Other printers on the market use small heaters that form bubbles to
eject ink from the ports.
6.4.5

INK NEAR END

The printer detects ink near-end in two ways:
The printer software maintains a count of how much ink is consumed from each
cartridge and signals near-end when a cartridge is nearly empty.
As a backup method, the ink level sensor monitors the positions of the ink level levers
on the sides of the ink tanks. This is described below.
Each print head in the ink tank unit [1] has a ink level lever This lever presses against a
spring loaded bellows in the center of the print head tank. The right side of each tank is
constructed of flexible plastic:
As ink enters the tank, the pressure of the ink pushes against the side of the tank and
moves the lever away from the side of the print head tank.
SM
CÓPIA NÃO CONTROLADA
6-31
CÓPIA NÃO CONTROLADA
Print Heads
J012/J013/J014