Liquid ejection apparatus and liquid ejection method

1 . A liquid ejection apparatus comprising:

an ejection section including a nozzle, a pressure chamber communicating with the nozzle, and a pressure generation unit that is configured to generate a pressure fluctuation in liquid in the pressure chamber;

a drive signal generation section that is configured to repeatedly generate a drive signal including a plurality of pulses including an ejection pulse and a non-ejection pulse; and

a drive control section that is configured to supply a pulse selected from the ejection pulse and the non-ejection pulse included in the drive signal to the pressure generation unit for each of repetitive cycles, wherein

the ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is ejected from the nozzle,

the non-ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is not ejected from the nozzle, and

when the non-ejection pulse is selected in a preceding cycle of two consecutive cycles among the repetitive cycles, and the ejection pulse is selected in a following cycle of the two consecutive cycles,

a pulse interval T 1 between the non-ejection pulse of the preceding cycle and the ejection pulse of the following cycle satisfies any one of following expressions (1) and (2):

1.7

×

Tc

×

n

≤

T

⁢

1

≤

1.9

×

Tc

×

n

(

1

)

1.2

×

Tc

×

n

≤

T

⁢

1

≤

1.4

×

Tc

×

n

(

2

)

where Tc is a natural vibration cycle of the ejection section, and n is a natural number.

2 . The liquid ejection apparatus according to claim 1 , wherein

the non-ejection pulse includes, at beginning, a first expansion drive element that drives the pressure generation unit to expand a volume of the pressure chamber,

the ejection pulse includes, at beginning, a second expansion drive element that drives the pressure generation unit to expand the volume of the pressure chamber,

the pulse interval T 1 is a time interval between a half-value point of a period of the first expansion drive element and a half-value point of a period of the second expansion drive element, and

the pulse interval T 1 satisfies the expression (1).

3 . The liquid ejection apparatus according to claim 1 , wherein

the non-ejection pulse includes, at beginning, a first expansion drive element that drives the pressure generation unit to expand a volume of the pressure chamber,

the ejection pulse includes, at beginning, a preparatory contraction drive element that drives the pressure generation unit to contract the volume of the pressure chamber,

the pulse interval T 1 is a time interval between a half-value point of a period of the first expansion drive element and a half-value point of a period of the preparatory contraction drive element, and

the pulse interval T 1 satisfies the expression (2).

4 . The liquid ejection apparatus according to claim 1 , wherein

the non-ejection pulse includes, at beginning, a first contraction drive element that drives the pressure generation unit to contract a volume of the pressure chamber,

the ejection pulse includes, at beginning, a second expansion drive element that drives the pressure generation unit to expand the volume of the pressure chamber,

the pulse interval T 1 is a time interval between a half-value point of a period of the first contraction drive element and a half-value point of a period of the second expansion drive element, and

the pulse interval T 1 satisfies the expression (2).

5 . The liquid ejection apparatus according to claim 1 , wherein

the non-ejection pulse includes, at beginning, a first contraction drive element that drives the pressure generation unit to contract a volume of the pressure chamber,

the ejection pulse includes, at beginning, a preparatory contraction drive element that drives the pressure generation unit to contract the volume of the pressure chamber,

the pulse interval T 1 is a time interval between a half-value point of a period of the first contraction drive element and a half-value point of a period of the preparatory contraction drive element, and

the pulse interval T 1 satisfies the expression (1).

6 . The liquid ejection apparatus according to claim 1 , wherein

the n is 1.

7 . The liquid ejection apparatus according to claim 1 , wherein

a pulse width T 3 of the non-ejection pulse is 0.5 Tc.

8 . A liquid ejection apparatus comprising:

an ejection section including a nozzle, a pressure chamber communicating with the nozzle, and a pressure generation unit that is configured to generate a pressure fluctuation in liquid in the pressure chamber;

a drive signal generation section that is configured to repeatedly generate a drive signal including a plurality of pulses including an ejection pulse and a non-ejection pulse; and

a drive control section that is configured to supply a pulse selected from the ejection pulse and the non-ejection pulse included in the drive signal to the pressure generation unit for each of repetitive cycles, wherein

the ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is ejected from the nozzle,

the non-ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is not ejected from the nozzle, and

when the non-ejection pulse is selected in a preceding cycle of two consecutive cycles among the repetitive cycles, and the ejection pulse is selected in a following cycle of the two consecutive cycles,

a coupling interval T 2 between the non-ejection pulse of the preceding cycle and the ejection pulse of the following cycle satisfies any one of following expressions (1) and (2):

1.7

×

Tc

×

n

≤

T

⁢

2

≤

1.9

×

Tc

×

n

(

1

)

1.2

×

Tc

×

n

≤

T

⁢

2

≤

1.4

×

Tc

×

n

(

2

)

where Tc is a natural vibration cycle of the ejection section, and n is a natural number.

9 . The liquid ejection apparatus according to claim 8 , wherein

the non-ejection pulse includes, at end, a first contraction drive element that drives the pressure generation unit to contract a volume of the pressure chamber,

the ejection pulse includes, at beginning, a second expansion drive element that drives the pressure generation unit to expand the volume of the pressure chamber,

the coupling interval T 2 is a time interval between a half-value point of a period of the first contraction drive element and a half-value point of a period of the second expansion drive element, and

the coupling interval T 2 satisfies the expression (2).

10 . The liquid ejection apparatus according to claim 8 , wherein

the non-ejection pulse includes, at end, a first contraction drive element that drives the pressure generation unit to contract a volume of the pressure chamber,

the ejection pulse includes, at beginning, a preparatory contraction drive element that drives the pressure generation unit to contract the volume of the pressure chamber,

the coupling interval T 2 is a time interval between a half-value point of a period of the first contraction drive element and a half-value point of a period of the preparatory contraction drive element, and

the coupling interval T 2 satisfies the expression (1).

11 . The liquid ejection apparatus according to claim 8 , wherein

the non-ejection pulse includes, at end, a first expansion drive element that drives the pressure generation unit to expand a volume of the pressure chamber,

the ejection pulse includes, at beginning, a second expansion drive element that drives the pressure generation unit to expand the volume of the pressure chamber,

the coupling interval T 2 is a time interval between a half-value point of a period of the first expansion drive element and a half-value point of a period of the second expansion drive element, and

the coupling interval T 2 satisfies the expression (1).

12 . The liquid ejection apparatus according to claim 8 , wherein

the non-ejection pulse includes, at end, a first expansion drive element that drives the pressure generation unit to expand a volume of the pressure chamber,

the ejection pulse includes, at beginning, a preparatory contraction drive element that drives the pressure generation unit to contract the volume of the pressure chamber,

the coupling interval T 2 is a time interval between a half-value point of a period of the first expansion drive element and a half-value point of a period of the preparatory contraction drive element, and

the coupling interval T 2 satisfies the expression (2).

13 . The liquid ejection apparatus according to claim 8 , wherein

the n is 1.

14 . The liquid ejection apparatus according to claim 8 , wherein

a pulse width T 3 of the non-ejection pulse is 0.5 Tc.

15 . A liquid ejection method of a liquid ejection apparatus configured to eject liquid, wherein

the liquid ejection apparatus includes

an ejection section including a nozzle, a pressure chamber communicating with the nozzle, and a pressure generation unit that is configured to generate a pressure fluctuation in liquid in the pressure chamber,

a drive signal generation section that is configured to repeatedly generate a drive signal including a plurality of pulses including an ejection pulse and a non-ejection pulse, and

a drive control section that is configured to supply a pulse selected from the ejection pulse and the non-ejection pulse included in the drive signal to the pressure generation unit for each of repetitive cycles,

the ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is ejected from the nozzle,

the non-ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is not ejected from the nozzle, and

when the non-ejection pulse is selected in a preceding cycle of two consecutive cycles among the repetitive cycles, and the ejection pulse is selected in a following cycle of the two consecutive cycles,

a pulse interval T 1 between the non-ejection pulse of the preceding cycle and the ejection pulse of the following cycle satisfies any one of following expressions (1) and (2):

1.7

×

Tc

×

n

≤

T

⁢

1

≤

1.9

×

Tc

×

n

(

1

)

1.2

×

Tc

×

n

≤

T

⁢

1

≤

1.4

×

Tc

×

n

(

2

)

where Tc is a natural vibration cycle of the ejection section, and n is a natural number.

16 . A liquid ejection method of a liquid ejection apparatus configured to eject liquid, wherein

the liquid ejection apparatus includes

an ejection section including a nozzle, a pressure chamber communicating with the nozzle, and a pressure generation unit that is configured to generate a pressure fluctuation in liquid in the pressure chamber,

a drive signal generation section that is configured to repeatedly generate a drive signal including a plurality of pulses including an ejection pulse and a non-ejection pulse, and

a drive control section that is configured to supply a pulse selected from the ejection pulse and the non-ejection pulse included in the drive signal to the pressure generation unit for each of repetitive cycles,

the ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is ejected from the nozzle,

the non-ejection pulse is a pulse of which a potential changes to cause the pressure generation unit to generate the pressure fluctuation such that the liquid is not ejected from the nozzle, and

when the non-ejection pulse is selected in a preceding cycle of two consecutive cycles among the repetitive cycles, and the ejection pulse is selected in a following cycle of the two consecutive cycles,

a coupling interval T 2 between the non-ejection pulse of the preceding cycle and the ejection pulse of the following cycle satisfies any one of following expressions (1) and (2)

1.7

×

Tc

×

n

≤

T

⁢

2

≤

1.9

×

Tc

×

n

(

1

)

1.2

×

Tc

×

n

≤

T

⁢

2

≤

1.4

×

Tc

×

n

(

2

)

where Tc is a natural vibration cycle of the ejection section, and n is a natural number.