Ink jet printing apparatus, ink jet printing method and ink jet print head with control of drive voltage and pulse width

An ink jet printing apparatus comprising:

• a print head having electrothermal transducers in ink ejection nozzles;
• and
• drive control means for generating a drive pulse for controlling activation of said electrothermal transducers in accordance with print data,
• wherein the drive pulse causes said electrothermal transducers to generate thermal energy to eject ink droplets from said nozzles onto a print medium to print an image,
• wherein said drive control means changes a drive voltage and a drive pulse width simultaneously for said print head in accordance with the print data, and
• wherein the print head is formed with voltage supply paths connected to voltage supply sources for supplying a plurality of different drive voltages, and the drive voltage and the drive pulse width for said electrothermal transducers are changed by controlling the disconnection and connection of the voltage supply paths.

An ink jet printing method of performing printing an image by utilizing a print head having electrothermal transducers in ink ejection nozzles, said method comprising the steps of:

• generating a drive pulse for controlling activation of the electrothermal transducers;
• supplying the drive pulse to the electrothermal transducers;
• and
• causing the electrothermal transducers to generate thermal energy to eject ink droplets from the nozzles onto a print medium,
• wherein, when ejecting small droplets, a drive voltage for the electrothermal transducers is relatively increased and a drive pulse width for the electrothermal transducers is relatively shortened and, when ejecting large droplets, the drive voltage is relatively reduced and the drive pulse width is relatively elongated.

An ink jet printing method of performing printing an image by utilizing a print head having electrothermal transducers in ink ejection nozzles, said method comprising the steps of:

• generating a drive pulse for controlling activation of the electrothermal transducers;
• supplying the drive pulse to the electrothermal transducers;
• and
• causing the electrothermal transducers to generate thermal energy to eject ink droplets from the nozzles onto a print medium,
• wherein a drive voltage and a drive pulse width for the print head are simultaneously changed in accordance with print data, and
• wherein the print head is formed with voltage supply paths connected to voltage supply sources for supplying a plurality of different drive voltages, and the drive voltage and the drive pulse width for the electrothermal transducers are changed by controlling the disconnection and connection of the voltage supply paths.