Ink jet recording head drive method and ink jet recording apparatus

An ink jet recording head drive method comprising:

• applying a drive voltage to an electro-mechanical converter which changes a pressure within a pressure generation chamber filled with ink, so that an ink droplet is ejected from a nozzle opening communicating with the pressure generation chamber, wherein
• the drive voltage has a voltage waveform including a first voltage change process for increasing a volume of the pressure generation chamber so as to pull the ink meniscus from the nozzle opening toward the pressure generation chamber and a second voltage change process for decreasing the volume of the pressure generation chamber so as to eject the ink droplet;
• the first voltage change process is preceded by a preparatory voltage change process for slightly pulling the ink meniscus from the nozzle opening toward the pressure generation chamber;
• said preparatory voltage change process increasing the volume of the pressure generation chamber and having a voltage change speed less than a voltage change speed of the first voltage change process;
• and
• the voltage change speed of the first voltage change process for increasing the volume of the pressure generation chamber is set greater than a natural period of a pressure wave generated in the pressure generation chamber.

An ink jet recording head drive method comprising:

• applying a drive voltage to an electro-mechanical converter which changes a pressure within a pressure generation chamber filled with ink, so that an ink droplet is ejected from a nozzle opening communicating with the pressure generation chamber, wherein
• the drive voltage has a voltage waveform including a first voltage change process for increasing a volume of the pressure generation chamber so as to pull the ink meniscus from the nozzle opening toward the pressure generation chamber and a second voltage change process for decreasing the volume of the pressure generation chamber so as to eject the ink droplet;
• the first voltage change process is preceded by a preparatory voltage change process for slightly pulling the ink meniscus from the nozzle opening toward the pressure generation chamber, said preparatory voltage change process including a third voltage change process for decreasing the volume of the pressure generation chamber and a voltage maintaining process for maintaining a voltage for a predetermined period of time;
• and
• the third voltage change process for decreasing the volume of the pressure generation chamber having a voltage change time set greater than a natural period of a pressure wave generated in the pressure generation chamber.

An ink jet recording head drive method comprising:

• applying a drive voltage to an electro-mechanical converter which changes a pressure within a pressure generation chamber filled with ink, so that an ink droplet is ejected from a nozzle opening communicating with the pressure generation chamber, wherein
• the drive voltage has a voltage waveform including a first voltage change process for increasing a volume of the pressure generation chamber so as to pull the ink meniscus from the nozzle opening toward the pressure generation chamber and a second voltage change process for decreasing the volume of the pressure generation chamber so as to eject the ink droplet;
• the first voltage change process is preceded by a preparatory voltage change process for slightly pulling the ink meniscus from the nozzle opening toward the pressure generation chamber, said preparatory voltage change process including a third voltage change process for decreasing the volume of the pressure generation chamber and a voltage maintaining process for maintaining a voltage for a predetermined period of time;
• and
• the predetermined period of time of the voltage maintaining process is set to ⅓ to ⅔ of a natural period of the vibration of the ink droplet at the nozzle opening.

An ink jet recording apparatus comprising:

• an ink jet recording head for applying a drive voltage to an electro-mechanical converter which changes a pressure within a pressure generation chamber filled with ink, so that an ink droplet is ejected from a nozzle opening communicating with the pressure generation chamber;
• and at least one waveform generation unit for generating a drive voltage to be applied to the electro-mechanical converter, wherein
• the drive voltage generated by the at least one waveform generation unit includes a first voltage change process for increasing the volume of the pressure generation chamber so as to pull the ink meniscus from the nozzle opening toward the pressure generation chamber and a second voltage change process for decreasing the volume of the pressure generation chamber to eject the ink droplet;
• and
• the first voltage change process is preceded by a preparatory voltage change process for pulling the ink meniscus from the nozzle opening toward the pressure generation chamber to a lesser degree than that of the first voltage change process.

An ink jet recording head drive method for an ink jet recording head comprising:

• a plurality of pressure generation chambers filled with ink;
• nozzles provided in the pressure generation chambers for discharging the ink;
• and vibration generation unit provided for each of the pressure generation chambers for causing a pressure change in the pressure generation chambers, wherein
• drive voltage waveforms to be applied to the vibration generation unit are prepared according to a diameter of ink droplet to be ejected, so that the drive voltage waveforms corresponding to different ink droplet diameters are applied at predetermined different timings and the drive voltage waveforms are set so that a smaller diameter ink droplet is ejected earlier.

An ink jet recording head drive method for an ink jet recording head that includes a pressure generation chamber filled with ink, a pressure generation chamber filled with ink, a pressure generation unit for generating a pressure in the pressure generation chamber, and a nozzle opening communicating with the pressure generation chamber, the drive method comprising:

• applying a drive waveform signal to the pressure generation unit so as to change the volume of the pressure generation chamber so that an ink droplet is ejected from the nozzle, the drive waveform signal having a waveform including:
• a first voltage change process for applying a voltage to increase the volume of the pressure generation chamber;
• and
• a second voltage change process for applying a voltage to decrease the volume of the pressure generation chamber,
• wherein the first voltage change process has a voltage change time set within a range of about ⅓ to ⅔ of a natural period Tc of a pressure wave generated in the pressure generation chamber, and the second voltage change process has a start time set after completion of the first voltage change process.

An ink jet recording head drive circuit for an ink jet recording head having a pressure generation chamber filled with ink, a pressure generation unit for generating a pressure in the pressure generation chamber, and a nozzle communicating with the pressure generation chamber, wherein a drive waveform signal is applied to the pressure generation unit so as to change the volume of the pressure generation chamber so that an ink droplet is ejected from the nozzle, the circuit comprising:

• a waveform generation unit operating according to the drive waveform signal, the drive waveform signal having a waveform including:
• a first voltage change process for applying a voltage to increase the volume of the pressure generation chamber;
• and
• a second voltage change process for applying a voltage to decrease the volume of the pressure generation chamber,
• wherein the first voltage change process has a voltage change time set within a range of about ⅓ to ⅔ of a natural period Tc of a pressure wave generated in the pressure generation chamber, and the second voltage change process has a start time set after completion of the first voltage change process.