Figure 2-4. Principles Of The Printing Operation; Figure 2-5. Principles Of The Printing Operation - Epson Stylus 800 Service Manual

Stylus S00+ service Manual
Principles of the Printing Operstion
The printhead performs the following operations to eject ink from each nozzle:
1. Normal state
No electrical charge is applied to the MLP (Multi-Layer Piezoelectric) element attached to the back
of the cavity, and pressure in the cavity is kept at a constant level.
Nozzle

Figure 2-4. Principles of the Printing Operation 1

2. Ejection
The head data signal is applied to the control line of a nozzle to select the active nozzle for printin~
and the MLP element is gradually charged with the drive voltage. Charging the MLP element
bends the vibration plate to compress the cavity. Then, ink is ejected from the nozzle.
Nozzle

Figure 2-5. Principles of the Printing Operation 2

When the ink charge or printhead cleaning operation is performed, ink in the cavity is vacuumed
out with the pump mechanism. During printin~ on the other hand, ink is simultaneously supplied
from the ink cartridge and ejected from the nozzle, according to the change in the volume of the
cavity.
A thermistor is attached to the printhead drive board to monitor the temperature, because the
viscosity of the ink varies, depending on the temperature. The dew temperature level is fed
back to the printhead drive voltage control circuit to regulate the drive voltage to a proper level.
Rev. A
Cavity
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