LIQUID EJECTION DRIVE DEVICE

1 . A liquid ejection drive device, comprising:

a drive circuit configured to apply a drive signal to an actuator for driving an ejection of a liquid from a pressure chamber connected to a nozzle, wherein

the drive signal includes a multidrop waveform with a plurality of drop waveforms for causing one droplet to be ejected, each drop waveform having an expansion phase, a normal phase, and a contraction phase, and

at least one drop waveform in the plurality of drop waveforms is an adjustment drop waveform having an auxiliary contraction phase in which contraction of the pressure chamber is less than in the contraction phase, the auxiliary contraction phase after the expansion phase and before the contraction phase.

2 . The liquid ejection drive device according to claim 1 , wherein the adjustment drop waveform is the first drop waveform in the plurality of drop waveforms of the multidrop waveform.

3 . The liquid ejection drive device according to claim 1 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

the plurality of adjustment drop waveforms is before at least one reference drop waveform in the plurality of drop waveforms in the multidrop waveform.

4 . The liquid ejection drive device according to claim 1 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a contraction amount in the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than a contraction amount in the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

5 . The liquid ejection drive device according to claim 1 , wherein a voltage level in the auxiliary contraction phase is higher than a voltage level in the normal phase but lower than or equal to a voltage level in the contraction phase.

6 . The liquid ejection drive device according to claim 5 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a total pulse width of the auxiliary contraction phase and the normal phase in the plurality of adjustment drop waveforms is fixed.

7 . The liquid ejection drive device according to claim 1 , wherein,

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a total pulse width of the auxiliary contraction phase and the normal phase in the plurality of adjustment drop waveforms is fixed.

8 . The liquid ejection drive device according to claim 7 , wherein a contraction amount in the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than a contraction amount in the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

9 . The liquid ejection drive device according to claim 1 , wherein

the plurality of drop waveforms includes at least three drop waveforms in sequence,

the first drop waveform in the sequence is the adjustment drop waveform, and

the second and third drop waveforms in the sequence are standard drop waveforms without the auxiliary contraction phase.

10 . The liquid ejection drive device according to claim 1 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a pulse width of the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than a pulse width of the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

11 . The liquid ejection drive device according to claim 1 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

an amplitude of the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than an amplitude of the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

12 . A liquid ejection drive device, comprising:

a drive circuit configured to apply a drive signal to an actuator for driving an ejection of a liquid from a pressure chamber connected to a nozzle, wherein

the drive signal is a multidrop waveform with a plurality of drop waveforms for causing one droplet to be ejected, each drop waveform having an expansion phase, a normal phase, and a contraction phase,

at least a first drop waveform in the plurality of drop waveforms is an adjustment drop waveform having an auxiliary contraction phase in which contraction of the pressure chamber is less than in the contraction phase, the auxiliary contraction phase after the expansion phase and before the contraction phase, and

at least a last drop waveform in the plurality of drop waveforms is a standard drop waveform without the auxiliary contraction phase.

13 . The liquid ejection drive device according to claim 12 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms in consecutive sequence from the first drop waveform, and

a contraction amount in the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than a contraction amount in the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

14 . The liquid ejection drive device according to claim 1 , wherein a voltage level in the auxiliary contraction phase is higher than a voltage level in the normal phase but lower than or equal to a voltage level in the contraction phase.

15 . A liquid ejection device, comprising:

an actuator;

a pressure chamber adjacent to the actuator;

a nozzle connected to the pressure chamber; and

a drive circuit configured to apply a drive signal to the actuator for driving an ejection of a liquid from the pressure chamber, wherein

the drive signal includes a multidrop waveform with a plurality of drop waveforms for causing one droplet to be ejected, each drop waveform having an expansion phase, a normal phase, and a contraction phase, and

at least one drop waveform in the plurality of drop waveforms is an adjustment drop waveform having an auxiliary contraction phase in which contraction of the pressure chamber is less than in the contraction phase, the auxiliary contraction phase after the expansion phase and before the contraction phase.

16 . The liquid ejection device according to claim 15 , wherein the adjustment drop waveform is the first drop waveform in the plurality of drop waveforms of the multidrop waveform.

17 . The liquid ejection device according to claim 15 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

the plurality of adjustment drop waveforms is before at least one reference drop waveform in the plurality of drop waveforms in the multidrop waveform.

18 . The liquid ejection device according to claim 15 , wherein

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a contraction amount in the auxiliary contraction phase of an adjustment drop waveform later in the multidrop waveform is less than a contraction amount in the auxiliary contraction phase of an adjustment drop waveform earlier in the multidrop waveform.

19 . The liquid ejection device according to claim 15 , wherein a voltage level in the auxiliary contraction phase is higher than a voltage level in the normal phase but lower than or equal to a voltage level in the contraction phase.

20 . The liquid ejection device according to claim 15 , wherein,

the plurality of drop waveforms includes a plurality of adjustment drop waveforms, and

a total pulse width of the auxiliary contraction phase and the normal phase in the plurality of adjustment drop waveforms is fixed.