Ink-jet printing apparatus having printed head driven by ink viscosity dependent drive pulse

An ink-jet printing apparatus comprising:

• a printing head having an ink channel, an actuator for changing a volume of the ink channel and a nozzle connected with the ink channel to eject the ink from the ink channel onto a print media;
• and
• a drive circuit connected to the printing head for applying a first drive pulse signal to the actuator so that the ink channel is expanded a volume thereof to generate a pressure wave in the ink channel and, after a lapse of an approximate odd-numbered multiple of one-way propagation time T of the pressure wave in the ink channel, an expanded volume of the ink channel is decreased to normal state thereof to apply pressure to the ink in the ink channel for ejecting the ink from the ink channel through the nozzle,
• wherein the drive circuit, after applying the first drive pulse signal to the actuator, applies to the actuator a second drive pulse signal which has a magnitude substantially equal to that of the first drive pulse signal and a pulse width equal to approximately 1.6 to 1.8 times the one-way propagation time T so that a center of the second drive pulse signal is provided in a range of approximately 2.25 to 2.75 times the one-way propagation time T from an end time of the first drive pulse signal.

An ink-jet printing apparatus comprising:

• a printing head including an ink channel, an actuator driven by a drive signal for changing pressure in the ink channel and a nozzle connected with the ink channel so that ink is ejected from the ink channel onto print media by changes in pressure in the ink channel;
• temperature detecting device for detecting an ambient temperature around the printer head;
• and
• a drive circuit connected between the temperature detecting device and the actuator for applying the drive signal to the actuator, the drive circuit including a reference voltage setting part for setting a drive voltage of the drive signal according to printing head characteristics and the detected ambient temperature so that a rate of ink droplet ejection from the nozzle is adjusted to a predetermined ink droplet ejection rate, wherein the reference voltage setting part has a data table defining a relationship of the drive voltage relative to the printing head characteristics and the ambient temperature so that the drive voltage is set with reference to the data table.

An ink-jet printing apparatus comprising:

• a printing head including an ink channel, an actuator driven by a drive signal for changing pressure in the ink channel and a nozzle connected with the ink channel so that ink is ejected from the ink channel onto print media by changes in pressure in the ink channel;
• detecting circuit for detecting a parameter variable with a viscosity of the ink to be ejected;
• a memory defined in a form of a data table which defines a relationship of a drive voltage of the drive signal relative to the operation characteristics of the printing head and the parameter;
• and
• a drive circuit for applying the drive signal to the actuator, the drive circuit being for variably setting the drive voltage of the drive signal in dependence on the detected parameter and the operation characteristics with reference to the data table in the memory.