Oki IP-6620 Maintenance Manual page 540

Principle of operation
Electrodes are attached to both sides of the walls in the PZT groove. The electric potential of
electrodes on both sides of the grooves with a nozzle is 0 V. Electrodes on the opposite side of
the walls are connected in order for the voltage to be applied to eject the ink.
When the voltage is applied to the electrodes of nozzles from which you want ink to be ejected,
the walls are distorted outward and the cubic capacity of the actuator is increased. When the
voltage returns to 0 V, the distortion of the walls is recovered, as is the cubic capacity of the
actuator. Ink is ejected due to this change in the cubic capacity of the actuator.
(2) Driving waveforms
The first waveform is used to eject one ink droplet, the second is used for two droplets, and the
third for three droplets.
For the tickling operation, the waveform's time width is shorter than for the ejection operation.
1 droplet/dot
2 droplet/dot
3 droplet/dot
Tickling
OKI Data Infotech Corporation CONFIDENTIAL
Chapter 8 Operation Mechanism
8-19