JP3290084B2 - Method and apparatus for ejecting ink droplets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for ejecting ink droplets.

[0002]

2. Description of the Related Art The non-impact type printing apparatus which has been replacing the conventional impact type printing apparatus and is now expanding its market greatly is the simplest in principle and has a multi-gradation and color printing. An easy-to-use printing apparatus is an ink jet printing apparatus. Above all, a drop that ejects only ink drops used for printing
The on-demand type is rapidly spreading due to its good injection efficiency and low running cost.

[0003] As a drop-on-demand type, there is a shear mode type utilizing a piezoelectric material disclosed in Japanese Patent Application Laid-Open No. 63-247051. As shown in FIG. 6, this type of ink droplet ejecting apparatus 600 includes a bottom wall 601 and a top wall 6.
02 and shear mode actuator wall 60 therebetween
Consists of three. The actuator wall 603 is connected to the bottom wall 60.
1 and a lower wall 607 made of a piezoelectric material polarized in the direction of arrow 611 and an upper wall 605 made of a piezoelectric material bonded to the top wall 602 and polarized in the direction of arrow 609. The actuator walls 603 are paired to form an ink chamber 613 therebetween, and an ink chamber 613 is formed between a pair of adjacent actuator walls 603.
A narrower space 615 is formed.

[0004] One end of each ink chamber 613 has a nozzle 61
A nozzle plate 617 having a nozzle 8 is fixedly connected to an ink supply source (not shown) at the other end. Electrodes 619 and 621 are provided on both sides of each actuator wall 603 as a metallized layer. Specifically, the ink chamber 6
An electrode 619 is provided on the actuator wall 603 on the thirteenth side, and an electrode 621 is provided on the actuator wall 603 on the space 615 side. Note that the surface of the electrode 619 is covered with an insulating layer 630 for insulating the ink. The electrode 621 facing the space 615 is connected to the ground 62.
3 is connected to an electrode 619 provided in the ink chamber 613.
5 is connected.

[0005] When the controller 625 applies a voltage to the electrode 619 of each ink chamber 613, each actuator wall 603 undergoes a piezoelectric thickness-shear deformation in a direction to increase the volume of the ink chamber 613. For example, as shown in FIG. 7, when a voltage E (V) is applied to the electrode 619c of the ink chamber 613c, electric fields in the directions of arrows 631 and 632 are generated on the actuator walls 603e and 603f, respectively, and the actuator walls 603e and 603f are generated. Is the ink chamber 613c
In the direction of increasing the volume of the piezoelectric element. At this time, the pressure in the ink chamber 613c including the vicinity of the nozzle 618c decreases. The application state of the voltage E (V) is maintained for the one-way propagation time T of the pressure wave in the ink chamber 613. Then, ink is supplied from an ink supply source (not shown) during that time. The one-way propagation time T is a time required for the pressure wave in the ink chamber 613 to propagate in the longitudinal direction of the ink chamber 613, and the length L of the ink chamber 613 and the amount of ink in the ink chamber 613 T = L / a depending on the sound speed a at
Is determined.

According to the pressure wave propagation theory, the pressure in the ink chamber 613 reverses and changes to a positive pressure after a lapse of T time from the application of the voltage, but the electrode 621c of the ink chamber 613c is synchronized with this timing. Is returned to 0 (V). Then, the actuator wall 603e,
603f returns to the state before deformation (FIG. 6), and pressure is applied to the ink. At this time, the pressure that has turned positive and the pressure generated by the actuator walls 603e and 603f returning to the state before deformation are added, and a relatively high pressure is generated near the nozzle 618c of the ink chamber 613c. , An ink droplet is ejected from the nozzle 618c.

[0007]

Conventionally, in this type of ink droplet ejecting apparatus 600, since the volume of ejected ink droplets is determined by the shape of the ink chamber 613, the driving voltage, and the like, good print quality is obtained. Therefore, when a larger amount of ink is required, the shape of the ink chamber needs to be changed. In addition, even when a required amount of ink is obtained, there is a disadvantage that the driving frequency must be reduced because the stability during ejection is reduced.

Further, as shown in FIG. 9A, by continuously generating a plurality of ejection pulses in response to a one-dot printing command, ink droplets ejected by the preceding ejection pulse are discharged from the ink chamber. It is known that, prior to separation from ink, a subsequent ejection pulse ejects an ink droplet to combine the two ink droplets in flight to form a relatively large volume ink droplet. However, in such a case, FIG.
As shown in (b), the pressure in the vicinity of the nozzle 618 becomes extremely high by the second ejection pulse and does not easily attenuate. Since the stability at the time decreases, the driving frequency must be reduced.

On the other hand, for example, Japanese Patent Application Laid-Open No. 62-2993
As disclosed in JP-A-43-43 and the like, it has been considered to reduce the residual pressure wave vibration in the ink chamber by applying a cancel pulse subsequent to a print pulse for ejecting ink droplets. In other words, the pressure wave that ejected the ink rebounds at the front end and the rear end of the ink chamber, and vibrates the meniscus of the nozzle 4T time after the start of the ejection. Counteract. However, 4 hours after the start of injection
In the case where the cancel pulse is generated after the time T, it cannot cope with the case where a plurality of ejection pulses are continuous as described above. Further, in addition to a positive power supply for generating an injection pulse, a negative power supply for generating a cancel pulse having an opposite phase is required, which causes a problem that a control device becomes complicated and costs increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not require a change in the shape of the ink chamber, provides an ink amount required for printing, and stably operates even at a high driving frequency. It is an object of the present invention to provide a low-cost ink droplet ejecting method and apparatus capable of obtaining good printing quality for printing.

[0011]

According to the present invention, there is provided an ink-filled ink chamber having an ejection pulse signal for changing the volume of the ink chamber. by applying, to increase the volume of the ink chamber to generate a pressure wave in the ink chamber, after Lee time T ink chamber pressure waves are one-way propagation or T odd number times time, the volume from increasing state A method of ejecting ink droplets by applying pressure to the ink in the ink chamber by reducing to a natural state, applying a plurality of pulse signals including the ejection pulse signal to a print command of one dot, After the ejection of the plurality of ink droplets , the wave width becomes 0 . 3T-0.
7T or 1 . A non-ejection pulse signal that does not cause an ink droplet to be ejected at 3T to 1.8T is defined as an intermediate timing (HM) between a rising timing (HS) and a falling timing (HE) of the non-ejection pulse signal, and the plurality of non-ejection pulse signals. The time difference from the falling timing (BE) of the ejection pulse signal applied last in the pulse signal is 2.35.
An ink droplet ejecting method characterized in that application is performed so as to be T to 2.65T.

According to a third aspect of the present invention, there is provided an ink chamber filled with ink, an actuator for changing a volume of the ink chamber, a driving power supply for applying an electric signal to the actuator, and the actuator. wherein by applying an injection pulse signal from the driving power source, the ink chamber volume increases of to generate a pressure wave in the ink chamber, before Symbol ink time chamber the pressure wave is one-way propagation T or T odd, the After a lapse of several times, the control device reduces the volume from the increased state to the natural state, applies pressure to the ink in the ink chamber, and ejects the ink droplets. In response to the print command, after applying a plurality of pulse signals including the ejection pulse signal to the actuator , the wave width ,
0 . 3T to 0.7T or 1 . A non-ejection pulse signal that does not cause an ink droplet to be ejected in 3T to 1.8T is defined as an intermediate timing (H) between the rising timing (HS) and the falling timing (HE) of the non-ejection pulse signal.
M) and the drive power supply to the actuator so that the time difference between the falling timing (BE) of the last applied ejection pulse signal of the plurality of pulse signals is 2.35T to 2.65T. The present invention provides an ink droplet ejecting apparatus.

As described above, a plurality of pulse signals are applied to the ink chamber in response to a one-dot printing command, whereby a plurality of ink droplets are ejected, and the amount of ink required for printing is obtained. After ejection of the ink, the wave width relative to the injection pulse signal,
0 . 3T to 0.7T or 1 . A non-ejection pulse signal that does not cause an ink droplet to be ejected in 3T to 1.8T is defined as an intermediate timing (H) between the rising timing (HS) and the falling timing (HE) of the non-ejection pulse signal.
M) is applied to the ink chamber so that the time difference between the falling timing (BE) of the last applied ejection pulse signal of the plurality of ejection pulse signals is 2.35T to 2.65T. Residual pressure wave vibration in the ink chamber after droplet ejection can be suppressed, and stable ejection can be performed even at high frequency printing.

Preferably, the peak value of the injection pulse and the peak value of the non-injection pulse are the same, so that a single power supply is required for the driving power supply. A stable injection can be realized at low cost without requiring a driving power supply.

[0015] More preferably, the actuator is at least one wall constituting the ink chamber, and at least a part of the wall is formed of a piezoelectric material. Ink droplets can be ejected without applying heat to the ink, and high-frequency printing can be stably realized.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

The structure of the mechanical part of the ink droplet ejecting apparatus 600 according to the present embodiment is the same as that of the conventional one shown in FIG.

An example of specific dimensions of the ink droplet ejection device 600 will be described. The length L of the ink chamber 613 is 7.5 mm
It is. The nozzle 618 has a diameter of 40 μm on the ink droplet ejection side, a diameter of 72 μm on the ink chamber 613 side, and a length of 1 μm.
00 μm. The viscosity at 25 ° C. of the ink used in the experiment was about 2 mPa · s, and the surface tension was 30 mN / m.
It is. The ratio L / a (= T) between the sound velocity a and the above L in the ink in the ink chamber 613 was 8 μsec.

Next, an ink chamber 61 according to an embodiment of the present invention will be described.
FIG. 1 shows a drive waveform 10 applied to the electrode 619 in 3.

The driving waveform 10 includes ejection pulse signals A and B for ejecting ink droplets and a non-ejection pulse signal C for reducing the residual pressure wave vibration in the ink chamber 613. , B and the non-ejection pulse signal C both have a peak value (voltage value) of E (V) (for example, 20).
(V)). The widths Wa and Wb of the ejection pulse signals A and B correspond to the one-way propagation time T (= L / a) of the pressure wave in the ink chamber 613, that is, 8 μsec.
The time d1 from the falling timing AE of the ejection pulse signal A to the rising timing BS of the ejection pulse signal B also matches the one-way propagation time T (= L / a) of the pressure wave in the ink chamber 613, that is, 8 μsec. It is.
The width Wc of the non-ejection pulse signal C is 0.5 times the one-way propagation time T (= L / a) of the pressure wave in the ink chamber 613, that is, 4 μsec. The non-ejection pulse signal C does not lead to ejecting ink droplets at this wave width. The time d2 from the falling timing BE of the ejection pulse signal B to the intermediate timing HM between the rising timing HS and the falling timing HE of the non-ejection pulse signal C is 2 times the one-way propagation time T of the pressure wave in the ink chamber 613. 0.5 times, that is, 20 μsec.

Next, an embodiment of a control device for realizing the drive waveform 10 will be described with reference to FIGS. 2, 3 and 4. FIG.

The control device 625 shown in FIG.
2 and a discharge circuit 184 and a pulse control circuit 186. The piezoelectric material and the electrodes 619, 621 of the actuator wall 603 are represented by a capacitor 191. 191A and 191B are the terminals.

The input terminals 181 and 182 apply voltages applied to the electrodes 619 in the ink chamber 613 to E (V) and 0, respectively.
This is an input terminal for inputting a pulse signal for setting to (V). The charging circuit 182 includes resistors R101, R102, R1
03, R104, R105, transistor TR101,
It is composed of TR102.

When an ON signal (+5 V) is input to the input terminal 181, the transistor TR is input via the resistor R 101.
101 conducts, and a current flows from the positive power supply 187 via the resistor R103 in the direction from the collector to the emitter of the transistor TR101. Therefore, the voltage division of the voltage applied to resistors R104 and R105 connected to positive power supply 187 increases, the current flowing to the base of transistor TR102 increases, and the transistor TR102 conducts between the emitter and collector. 20 from positive power supply 187
The voltage (V) is applied to the terminal 191A of the capacitor 191 via the collector and the emitter of the transistor TR102 and the resistor R120. This timing is the timing of the timing charts T1, T3 and T5 shown in FIG. The timing chart shown in FIG. 3 is a timing chart showing input signals to input terminals 181 and 182 of control device 625 and outputs from capacitor 191.

Next, the discharge circuit 184 will be described. The discharging circuit 184 includes resistors R106 and R107 and a transistor TR103. When an ON signal (+5 V) is input to the input terminal 182, the transistor TR103 conducts via the resistor R106, and the terminal 191A of the capacitor 191 is grounded via the resistor R120.
Therefore, the electric charge applied to the actuator wall 603 of the ink chamber 613 shown in FIGS. 6 and 7 is discharged. This timing is the timing of T2, T4 and T6 in the timing chart shown in FIG.

The input signal 11 of the drive waveform 10 input to the input terminal 181 of the charging circuit 182 is normally off as shown in the timing chart (A) of FIG.
It is turned on at a predetermined timing T1 for injection and turned off at a timing T2. Subsequent timing T3
At timing T4, turn off at timing T5, and turn off at timing T6.

Next, the input terminal 182 of the discharging circuit 184
The input signal 12 is turned off when the input signal 11 is on (T1, T3, T5) as shown in the timing chart (A) shown in FIG.
When 1 is off (T2, T4, T6), it is turned on.

As shown in FIG. 3B, normally, the output waveform 13 at the electrode 191A of the capacitor 191 is maintained at 0 (V).
1, that is, a charge is charged to the actuator wall 603,
After the charging time Ta determined by the transistor TR102, the resistor R120, and the capacitance of the actuator wall 603 formed of the shear mode type piezoelectric element, the voltage becomes E (V) (for example, 20 (V)). At timing T2, the discharge time T determined by the capacitance of the actuator wall 603 is determined.
It becomes 0 (V) after b.

As described above, since the actual drive waveform 13 has a delay of Ta and Tb at the rise and fall, respectively, the ejection pulse of the drive waveform 10 when the voltage is 1 / 2E (V) (for example, 10 (V)) Each of the above-mentioned timings T3, T4, T5, T6 so that the time d2 between the falling timing BE of the signal B and the intermediate timing between the rising timing HS and the falling timing HE of the non-ejection pulse signal C becomes the value shown in FIG. Set.

Next, a description will be given of a pulse control circuit 186 for generating a pulse signal having the above-mentioned timings T1 to T6 input to the input terminal 181 of the charging circuit 182 and the input terminal 182 of the discharging circuit 184.

The pulse control circuit 186 is provided with a CPU 110 for performing various arithmetic processing.
An RA 110 stores print data and various data.
M112, a ROM storing a control program of the pulse control circuit 186 and sequence data for generating an ON / OFF signal at the timings T1 to T6.
114 are connected. Here, in the ROM 114,
As shown in FIG. 4, an ink droplet ejection control program storage area 114A and a drive waveform data storage area 114B are provided. Therefore, the sequence data of the drive waveform 10 is stored in the drive waveform data storage area 114B.

Further, the CPU 110 is connected to an I / O bus 116 for exchanging various data, and a print data receiving circuit 118 and pulse generators 120 and 122 are connected to the I / O bus 116. The output of the pulse generator 120 is connected to the input terminal 181 of the charging circuit 182, and the output of the pulse generator 122 is connected to the input terminal 182 of the discharging circuit 184.

The CPU 110 operates in accordance with the sequence data stored in the drive waveform data storage area 114B of the ROM 114 according to the pulse generators 120 and 1.
22 is controlled. Therefore, the timings T1 to T
By storing in advance the various patterns 6 in the drive waveform data storage area 114B in the ROM 114,
The drive waveform 10 shown in FIG.
Can be applied to the actuator wall 603.

The pulse generators 120 and 1
22 and the same number of charging circuits 182 and discharging circuits 184 as the number of nozzles of the inkjet head. In the present embodiment, control of one nozzle is described as a representative, but control of other nozzles is similar.

The results of the ink droplet ejection test when driven by the driving method of the present embodiment will be described.

In the driving method of this experiment, when driven at 20 (V), two ink droplets are ejected corresponding to the ejection pulse signals A and B, and the ejection speed is 5.5 m / s and the two ink droplets are ejected. The total drop volume was 55 pl. As a comparative experiment, when the ejection pulse signal A of the driving waveform 10 is eliminated and the ejection pulse signal B and the non-ejection pulse signal C are driven alone, one ink droplet is ejected, the ejection speed is 5 m / s,
The ink droplet volume was 30 pl. From this result, it can be seen that the volume of the ejected ink droplet is increased by doubling the number of ejection pulses with respect to the 1-dot printing command according to the driving method of the present embodiment.

Next, the time difference d2 between the width Wc of the non-ejection pulse signal C, the intermediate timing HM between the rising timing HS and the falling timing HE of the non-ejection pulse signal C, and the falling timing BE of the ejection pulse signal B
The following describes the results of an experiment conducted to determine the appropriate range of.

The table shown in FIG. 5 shows that the width Wc of the non-ejection pulse signal C is changed from 0.2T to 2.0T,
Rise timing HS and fall timing H
E and the time difference d2 between the falling timing BE of the ejection pulse signal B and the intermediate timing HM between 2.3T and 2.3T.
The evaluation result when changing to 7T is shown. As an evaluation method, a change in the injection speed when continuously driven at a voltage E = 20 (V) and a drive frequency of 15 kHz was measured, and when the injection was unstable, accompanied by splashing, or when injection was stopped, the evaluation was evaluated as x.

From this result, the width Wc of the non-ejection pulse signal C is obtained.
In the range of 0.3T to 0.7T or 1.3T to 1.7T, and the intermediate timing HM between the rising timing HS and the falling timing HE of the non-ejection pulse signal C and the rising timing of the ejection pulse signal B. Fall timing B
When the time difference d2 from E is 2.35T to 2.65T, the change in the ink droplet ejection speed is stable within a range of ± 0.5 m / s even when driving at a high frequency of 15 kHz. Therefore, it is possible to perform ink droplet ejection with good print quality.

The embodiment has been described in detail above.
The present invention is not limited to this. In the above embodiment, the fall timing AE of the ejection pulse signal A
Although the time d1 from the time t to the rising timing BS of the ejection pulse signal B is set to be equal to T, it may be an odd multiple of T, for example, 3T.

In the above-described embodiment, two ejection pulse signals are provided for one dot printing command. However, there are cases where three or more ejection pulse signals are provided for one dot printing command. Also, the time difference between the rising timing HS of the non-ejection pulse signal C and the intermediate timing HM between the falling timing HE and the falling timing of the last ejection pulse signal is set to 2.35T to 2.65T,
And the width Wc of the non-ejection pulse signal C is set to 0.3T to 0.7.
Experiments have confirmed that stable injection can be obtained even at the time of high-frequency driving when T or the range of 1.3T to 1.7T. As the number of ejection pulse signals for one dot printing command increases, the volume of ink droplets obtained increases, and the required amount of ink droplets can be obtained by changing the number of ejection pulse signals as required for print density. At this time, the plurality of ejection pulse signals corresponding to the one-dot printing command can be variously changed in pulse width and pulse interval based on the knowledge of those skilled in the art. For example, the first ejection pulse signal The pulse width may be changed for each ejection pulse signal, such as 0.5T, and the second and subsequent ejection pulse signals are 1T or 3T. In addition, the plurality of ejection pulse signals are generated by continuously generating a plurality of independent ink droplets, and before the ink droplet ejected by the previous ejection pulse is separated from the ink in the ink chamber, the ink droplet is generated by the subsequent ejection pulse. May be ejected to unite the two ink droplets during flight to form ink droplets of a relatively large volume.

Further, in the above embodiment, the positive power supply 1
Although 87 is used, a negative power supply may be used by reversing the polarization direction of 609 and 611 in FIG.

As shown in FIG. 8, the polarization direction is reversed, the electrodes 719 on the ink chamber 713 side are connected to the ground, and each electrode facing the space 715 is divided into two. As the electrodes 721 and 722, one electrode 721 may be connected to the resistor R120 shown in FIG. 2 and the other electrode 722 may be connected to the same resistor of another injection charging circuit (not shown).

In this embodiment, the ink is ejected by deforming the volume of the ink chamber 613 by deforming both the lower wall 607 and the upper wall 605 of the actuator wall 603. Ink may be ejected such that one is formed of a material that does not undergo piezoelectric deformation and the other is deformed along with the piezoelectric deformation.

In this embodiment, the ink chamber 613 is used.
Space 615 was provided on both sides of the
The ink chambers may be adjacent. Furthermore, in the present embodiment, the shear mode type actuator is used, but a configuration in which a piezoelectric material is laminated and a pressure wave is generated by deformation in the laminating direction may be used. In addition, the present invention can be carried out in various modified and improved forms based on the knowledge of those skilled in the art as long as pressure waves are generated in the ink chambers, not limited to piezoelectric materials.

[0046]

As described above, according to the ink droplet ejection method and apparatus of the present invention, a plurality of ejection pulse signals are applied in response to a one-dot print command to eject a plurality of ink droplets. The droplet volume can be increased as compared with the case of a single ejection pulse signal. At this time, it is not necessary to change the shape of the ink chamber of the ink droplet ejecting apparatus, and the amount of ink required for printing can be obtained at low cost. In addition, since a non-ejection pulse signal is applied at a predetermined timing and wave width after a plurality of ejection pulse signals, residual pressure wave vibration in the ink chamber after ejection of ink droplets can be suppressed, and stable even at high frequency printing. Can be sprayed.

The driving power source has the same peak value of the ejection pulse and the non-ejection pulse, so that the driving power source may be a single power source. Unlike the conventional driving power source, a special driving power source is used to suppress the residual vibration. , And stable injection can be realized at low cost.

Further, the actuator has at least one wall constituting the ink chamber, and at least a part of the wall is formed of a piezoelectric material. In addition to being able to eject ink droplets without applying heat to ink, high-frequency printing can be stably realized.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a driving waveform of an ink droplet ejecting apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a drive circuit of the ink droplet ejection device.

FIG. 3 is a diagram showing a timing chart for driving the ink droplet ejecting apparatus.

FIG. 4 is a diagram showing a storage area of a ROM of a control device of the ink droplet ejection device.

FIG. 5 is a diagram illustrating the results of an experiment performed to determine an appropriate range of a pulse signal width of a driving waveform of the ink droplet ejecting apparatus.

FIG. 6 is a cross-sectional view showing a conventional example and an ink droplet ejecting apparatus according to an embodiment of the present invention.

FIG. 7 is a horizontal sectional view of FIG. 6;

FIG. 8 is a diagram illustrating an ink droplet ejecting apparatus according to another embodiment of the present invention.

FIG. 9 is a diagram showing a conventional drive waveform and a pressure change near a nozzle.

[Explanation of symbols]

 10 Drive Waveform 187 Positive Power Supply 600 Ink Droplet Ejector 603 Actuator Wall 613 Ink Chamber 625 Controller

Claims (5)

(57) [Claims] 1. A pressure wave is generated in an ink chamber by increasing a volume of the ink chamber by applying an ejection pulse signal for changing the volume of the ink chamber to the ink chamber filled with ink . time T the pressure wave Lee ink chamber is one-way propagation or after odd number multiple time T, in reducing the increasing state volume natural state method for ejecting ink droplets by applying pressure to the ink in the ink chamber, After applying a plurality of pulse signals including the ejection pulse signal in response to a 1-dot printing command to eject a plurality of ink droplets, the wave width becomes 0 . 3T to 0.7T or 1 . 3T to 1.8
The non-ejection pulse signal that does not lead to the ejection of the ink droplet at T is determined by the rising timing (H) of the non-ejection pulse signal.
S) and an intermediate timing (HM) between the falling timing (HE) and a falling timing (B) of the last applied injection pulse signal of the plurality of pulse signals.
An ink droplet ejection method, wherein the application is performed so that the time difference from E) is 2.35T to 2.65T. 2. The peak value of each of the ejection pulse and the non-ejection pulse is the same.
3. The method for ejecting ink droplets according to item 1. 3. An ink chamber filled with ink, and an actuator for changing a volume of the ink chamber.
If, by applying the pulse signal morphism injection to the actuator, the ink chamber volume increase of by generating a pressure wave in the ink chamber, before Symbol pressure wave of the ink chamber time T for one-way propagation or T, after several times longer odd, the drop ejection device provided by reducing the increased state volume natural state to the ink in the ink chamber and a control device for ejecting ink droplets by applying a pressure, the control device 1 After applying a plurality of pulse signals including the ejection pulse signal to the actuator in response to the dot printing command, the wave width becomes 0 . 3T to 0.7T or 1 . 3T to 1.8
The non-ejection pulse signal that does not lead to the ejection of the ink droplet at T is determined by the rising timing (H) of the non-ejection pulse signal.
S) and an intermediate timing (HM) between the falling timing (HE) and a falling timing (B) of the last applied injection pulse signal of the plurality of pulse signals.
Drop ejection device time difference between E) is characterized by indicia pressure to the actuator so as to 2.35T ~2.65T. Peak value of 4. The front Ki噴 elevation pulses and non-ejection pulse claim 3, characterized in that each identical
3. The ink droplet ejecting apparatus according to claim 1. 5. The actuator according to claim 3, wherein the actuator is at least one wall constituting the ink chamber, and at least a part of the wall is formed of a piezoelectric material. 3. The ink droplet ejecting apparatus according to claim 1.