Specifications

REV.-A
< Printing >
This section describes how ink is injected through the nozzles.
(1) Normal condition
---Piezoelectric Element is electrically charged and bent inward.
/
Piezoelectric Element
)
(
Figure 2-4. Printing Principle (1)
(2) Charging operation --When the electric charge of the
piezoelectric element is gradually discharged,
the element is bent outward to let ink into the pressure chamber.
Pressure Chamber
1
I
Figure 2-5. Printing Principles (2)
(3) Injecting operation --The ink in the pressure chamber is injected when the
piezoelectric element
is quickly charged and bent inward.
1
1
Figure 2-6. Printing Principles (3)
When charging ink or cleaning the
printhead, the ink in the pressure chamber is vacuumed out by the
pump. When printing, on the other hand, the ink is simultaneously injected and supplied according to
the change of volume of the pressure chamber.
This printer is provided with the function to change the
printhead drive voltage corresponding to the
ink temperature, because the viscosity of the ink is subject to change depending on the ink temperature.
A thermistor is attached on the carriage to detect the ink temperature. When the ink temperature is
low (i.e. the viscosity is high), the
printhead drive voltage is increased, or vice versa.
The temperature signal is fed back to the
printhead drive voltage control circuit to adjust the voltage
to a proper level.
2-3