DRIVE DEVICE AND LIQUID EJECTION DEVICE
According to one embodiment, a drive device for a liquid ejection device or the like includes a drive circuit configured to output a drive waveform to an actuator of a liquid ejection unit. The actuator has a charge-discharge time constant. The drive waveform during a non-initial portion makes a transition from a first potential higher than an intermediate potential to a second potential lower than the intermediate potential and then a transition from the second potential to the intermediate potential within a time period less than or equal to the charge-discharge time constant.
1 . A drive device, comprising:
a drive circuit configured to output a drive waveform to an actuator of a liquid ejection unit, wherein
the actuator has a charge-discharge time constant, and
the drive waveform in a non-initial portion makes, within a time period less than or equal to the charge-discharge time constant, a transition from a first potential higher than an intermediate potential to a second potential lower than the intermediate potential and then a transition from the second potential to the intermediate potential.
2 . The drive device according to claim 1 , wherein the drive circuit is configured to switch between three voltages for outputting the drive waveform.
3 . The drive device according to claim 1 , wherein the drive waveform in an initial portion before the non-initial portion makes a transition from the intermediate potential to the second potential, and then a transition from the second potential to the first potential.
4 . The drive device according to claim 3 , wherein, in the initial portion of the waveform, the transition from the second potential to the first potential occurs in a step waveform in which the intermediate potential is held for a predetermined time period before transitioning to the first potential.
5 . The drive device according to claim 4 , wherein the time period for the non-initial portion of the waveform is set to compensate for an amount of charge accumulated due to the step waveform.
6 . The drive device according to claim 1 , wherein the intermediate potential is ground potential.
7 . The drive device according to claim 1 , wherein the liquid ejection unit is a inkjet head.
8 . The drive device according to claim 1 , wherein the drive circuit includes two voltage sources and three switches.
9 . The drive device according to claim 1 , wherein the actuator is a piezoelectric actuator.
10 . A liquid ejection device, comprising:
a liquid ejection head including an actuator; and
a drive device including a drive circuit, the drive circuit configured to output a drive waveform to the actuator, wherein
the actuator has a charge-discharge time constant, and
the drive waveform in a non-initial portion makes, within a time period less than or equal to the charge-discharge time constant, a transition from a first potential higher than an intermediate potential to a second potential lower than the intermediate potential and then a transition from the second potential to the intermediate potential.
11 . The liquid ejection device according to claim 10 , wherein the drive circuit is configured to switch between three voltages for outputting the drive waveform.
12 . The liquid ejection device according to claim 10 , wherein the drive waveform in an initial portion before the non-initial portion makes a transition from the intermediate potential to the second potential, and then a transition from the second potential to the first potential.
13 . The liquid ejection device according to claim 12 , wherein, in the initial portion of the waveform, the transition from the second potential to the first potential occurs in a step waveform in which the intermediate potential is held for a predetermined time period before transitioning to the first potential.
14 . The liquid ejection device according to claim 13 , wherein the time period for the non-initial portion of the waveform is set to compensate for an amount of charge accumulated due to the step waveform.
15 . The liquid ejection device according to claim 10 , wherein the intermediate potential is ground potential.
16 . The liquid ejection device according to claim 10 , wherein the liquid ejection head is a inkjet head.
17 . The liquid ejection device according to claim 10 , wherein the drive circuit includes two voltage sources and three switches.
18 . The liquid ejection device according to claim 10 , wherein the actuator is a piezoelectric actuator.
19 . A printer, comprising:
a sheet conveying apparatus;
an inkjet head including an actuator and configured to eject ink towards a sheet conveyed by the sheet conveying apparatus; and
a drive device including a drive circuit, the drive circuit configured to output a drive waveform to the actuator, wherein
the actuator has a charge-discharge time constant, and
the drive waveform in a non-initial portion makes, within a time period less than or equal to the charge-discharge time constant, a transition from a first potential higher than an intermediate potential to a second potential lower than the intermediate potential and then a transition from the second potential to the intermediate potential.
20 . The printer according to claim 19 , wherein, in the initial portion of the waveform, the transition from the second potential to the first potential occurs in a step waveform in which the intermediate potential is held for a predetermined time period before transitioning to the first potential.