JP3324949B2 - Method and apparatus for ejecting ink droplets - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ink Shizuku噴picolinimidate location.

[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 that is polarized in the direction of arrow 611 and an upper wall 605 made of a piezoelectric material that is 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 a space 6 smaller than the ink chamber 613 is provided between the next pair of actuator walls 603.
15 are 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 6
The electrode 619 connected to the control unit 23 and provided in the ink chamber 613 is a control device 6 for supplying an actuator drive signal.
25.

[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 the ink supply source during that time.

The one-way propagation time T is equal to the ink chamber 61.
3 is the time required for the pressure wave in the ink chamber 613 to propagate in the longitudinal direction of the ink chamber 613, and T = L according to the length L of the ink chamber 613 and the sound speed a in the ink inside the ink chamber 613.
/ A.

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.

[0008]

Conventionally, in the case of this type of ink droplet ejecting apparatus 600, when the viscosity of the ink is lowered, such as at high temperature, after one or a plurality of ink droplets are ejected, the ink remaining in the ink chamber is left. There was a disadvantage that an accidental drop, that is, an unexpected ink drop was ejected due to the pressure wave vibration, and good printing quality could not be obtained.

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, in the case where a cancel pulse is generated after 4T time for each ejection of an ink droplet as described above, if a plurality of ejection pulses are continuous, the cancellation pulse is inserted by extending the interval between each ejection pulse. Therefore, there is a disadvantage that the driving frequency must be reduced. 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. Even when the viscosity of the ink is reduced, for example, at a high temperature, good printing quality without accidental drop can be obtained. and an object thereof is to provide an ink Shizuku噴picolinimidate location that can be printed at high speed without lowering the frequency.

[0012]

According to the present invention, there is provided an ink chamber filled with ink , an actuator for changing a volume of the ink chamber , issued at a predetermined cycle timing
Depending on the print command , one or more injection pulse signals
A control device for generating a pressure wave in the ink chamber by applying a voltage to the actuator to apply pressure to the ink and ejecting one or more ink droplets.
In the ink drop ejecting apparatus, the control device is configured to control the predetermined
It is determined whether there is a print command at the next print command cycle timing corresponding to the print command cycle timing .
Have a means that, if there is no print command in the periodic timing of the next print command, after the one or more injection pulse signal, the non-ejection pulse signal does not lead to ejects ink droplets, to the actuator Apply and next mark
There the non-ejection pulse signal when there is a print command in the periodic timing of the letter command to the drop ejection apparatus characterized by not applying to the actuator.

[0013]

According to the printing command of a single dot or a plurality of continuous dots as described above, one or a plurality of ejection pulse signals are applied to the actuator at a periodic timing of a predetermined printing command, and a single or a plurality of ink droplets are applied. after injection, when there is no print command in the periodic timing of the next printing instructions corresponding to the cycle timing of the predetermined printing instruction, a non-ejection pulse signal does not lead to ejects ink droplets, to be applied to the actuator Therefore, the residual pressure wave vibration in the ink chamber after the ink droplet ejection can be suppressed, and at a high temperature, even when the viscosity of the ink is reduced,
Good printing quality without accidental drop is obtained. In addition, after the ink droplet is ejected, if there is a print command at the next cycle timing corresponding to the predetermined cycle timing, that is, if a plurality of ejection pulses are continuous, a non-ejection pulse is inserted between each ejection pulse. And printing can be performed at high speed.

Preferably, the ejection pulse signal is applied to an actuator to increase the volume of the ink chamber to generate a pressure wave in the ink chamber, and a time T, during which the pressure wave propagates one way in the ink chamber, Alternatively, after elapse of an odd multiple of T, the non-ejection pulse signal has a wave width that reduces the volume from the increased state to the natural state, and the non-ejection pulse signal has a wave width of 0.3T to .7T, or 1.3T to 1.8T, and the rising timing (HS) and falling timing (H) of the non-ejection pulse signal.
By setting the time difference between the intermediate timing (HM) to E) and the falling timing of the last applied ejection pulse signal to be 2.35 to 2.65T, the residual pressure wave in the ink chamber after the ink droplet ejection is performed. Vibration can be effectively suppressed, and good printing without accidental drop can be realized at high speed as described above.

More preferably, the peak value of the ejection pulse and the peak value of the non-ejection pulse are made equal to each other, so that a single drive power supply is required. , And the above-described printing can be realized at low cost.

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-speed printing can be stably realized.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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.

FIG. 1 shows a drive waveform 10 applied to an electrode 619 in an ink chamber 613 according to an embodiment of the present invention.

The drive waveform 10 represents the case of continuous printing of three dots, and reduces the ejection pulse signals A1, A2, and A3 for ejecting ink droplets and the residual pressure wave vibration in the ink chamber 613. And a non-ejection pulse signal B. The peak value (voltage value) of each of the ejection pulse signals A1, A2, A3 and the non-ejection pulse signal B is E (V) (for example, 20 (V)). The injection pulse signals A1, A2,
The wave width Wa of A3 coincides with the ratio L / a (= T) of the sound velocity a in the ink in the ink chamber 613 and the above L, that is, 8 μsec, and the period d1 (for example, the period When the timing is 10 kHz, they are continuous with a time difference of 100 μsec). Thereafter, when there is no print command at the next cycle timing of the third ejection pulse signal A3 (for example, after 100 μsec in the above example), the non-ejection pulse signal B is applied.

The width Wb of the non-ejection pulse signal B is equal to 0. 1 of the one-way propagation time T (= L / a) of the pressure wave in the ink chamber 613.
5 times, that is, 4 μsec. Non-injection pulse signal B
With this wave width Wb, ink drops are not ejected.

The time d2 from the falling timing A3E of the third ejection pulse signal A3 to the intermediate timing HM between the rising timing HS and the falling timing HE of the non-ejection pulse signal B is determined by the pressure wave in the ink chamber 613. 2.5 times the one-way propagation time T, that is, 20 μs
c.

Next, an embodiment of a control device for realizing the driving 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 a voltage applied to the electrode 619 in the ink chamber 613 to E (V), 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 connected via the resistor R101.
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, T5 and T7 shown in FIG. FIG. 3 shows the input terminal 1 of the control device 625.
9 is a timing chart showing input signals to the input devices 81 and 182 and outputs from the 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 through the resistor R106, and the resistor R120 side terminal 191A of the capacitor 191 passes through the resistor R120.
Ground. 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, T6 and T8 in the timing chart shown in FIG.

The input signal 11 input to the input terminal 181 of the charging circuit 182 is normally off, as shown in the timing chart (A) of FIG. 3, and is turned on at a predetermined timing T1 for injection. And the timing T2
Turned off at It is turned on at the subsequent timing T3, turned off at the timing T4, and further turned on at the timing T
5, and is turned off at timing T6, then turned on at timing T7, and turned off at timing T8.

As shown in the timing chart (A) of FIG. 3, the input signal 12 input to the input terminal 182 of the discharge circuit 184 is turned on when the input signal 11 is on (T1, T2).
(3, T5, T7), it is turned off, and when the input signal 11 is off (T2, T4, T6, T8), it is turned on.

Normally, as shown in FIG.
The output waveform 13 at A is maintained at 0 (V),
At timing T1, a charge is charged to the capacitor 191 or the actuator wall 603, and the transistor TR
Voltage E (V) after a charging time Ta determined by the voltage 102, the resistance R120, and the capacitance of the actuator wall 603.
(For example, 20 (V)). At timing T2, the voltage becomes 0 (V) after a discharge time Tb determined by the capacitance of the actuator wall 603.

As described above, the actual drive waveform 13 has a delay of Ta and Tb at the rise and fall, respectively. Therefore, the third waveform of the drive waveform 10 when the voltage is 1 / 2E (V) (for example, 10 (V)). Each of the above-described timings T6, T7, T4, T4, T4, T4, T4, T4, T5, T5, T6, T7, T7, T7, T7, T9, T9, T9, T9, T9, T9, T9, T9 Set T8.

Next, a pulse control circuit 186 for generating a pulse signal having the above-mentioned timings T1 to T8, which is input to the input terminal 181 of the charging circuit 182 and the input terminal 182 of the discharging circuit 184, will be described.

The pulse control circuit 186 is provided with a CPU 110 for performing various arithmetic processing.
0 is a RAM 1 for storing print data and various data.
ROM 114 which stores a control program for the T.12 and pulse control circuit 186 and sequence data for generating ON / OFF signals at the timings T1 to T8.
Is connected. Here, in the ROM 114, as shown in FIG.
14A and a drive waveform data storage area 114B. Therefore, the sequence data of the drive waveform 10 is stored in the drive waveform data storage area 114B.

In the control program storage area 114A,
Further, as shown in FIG. 10, the CPU 110 determines whether or not there is a print command at the next cycle timing of the ejection pulse signal (S1), and based on the determination result, determines whether the ejection command is stored in the waveform data storage area 114B. Whether the non-ejection pulse signal B is added to the pulse signal (S2, S
A program for determining 3) is stored.

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.

CPU 110 operates in accordance with the sequence data stored in drive waveform data storage area 114B of ROM 114 to generate pulse generators 120 and 1 according to the sequence data.
22 is controlled. Therefore, the timings T1 to T1
By storing the various patterns of T8 in the drive waveform data storage area 114B in the ROM 114 in advance, the drive pulse of the drive waveform 10 shown in FIG.

The pulse generators 120 and 122
In addition, the same number of charging circuits 182 and discharging circuits 184 as the number of nozzles are provided. In the present embodiment, control of one nozzle is described as a representative, but control of other nozzles is similar.

The result 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 a driving frequency of 10 kHz at 20 (V) in an environment of 25 ° C., three ink droplets are ejected corresponding to the ejection pulse signals A1, A2, and A3. The ejection speed was 5.0 m / s, and the volume of each ink droplet was 35 pl. At a high temperature at which the viscosity of the ink decreases, for example, in an environment of 40 ° C. (the viscosity of the ink used in this experiment is about 1 mPa · s), when the ink is driven at 17 (V), the ejection pulse signal A
Three ink droplets are ejected corresponding to 1, A2 and A3,
The ejection speed was 5.0 m / s, and the volume of each ink droplet was 42 pl. However, there was no subsequent accidental drop, and stable ejection was possible.

As a comparative experiment, drive waveform 1 of the present embodiment
The non-ejection pulse signal B of 0 is eliminated and the ejection pulse signal A
When driven by only 1, A2, and A3, when driven at a driving frequency of 10 kHz at 20 (V) in an environment of 25 ° C., three ink droplets corresponding to the ejection pulse signals A1, A2, and A3 Was ejected, the ejection speed was 5.0 m / s, and the volume of each ink droplet was 35 pl, which was the same as in the case of the non-ejection pulse signal B described above. But,
At a high temperature at which the viscosity of the ink decreases, for example, in an environment of 40 ° C. (the viscosity of the ink used in this experiment is about 1 mPa · s), when driven at 17 (V), the ejection pulse signals A1, A2 , A3 were ejected, the ejection speed was 5.0 m / s, and the volume of each ink droplet was 42 pl. However, there was an accidental drop, and good printing was not obtained. . From this result, it can be seen that the printing method of the present embodiment can provide good printing without accidental drop even for ink whose viscosity at high temperature has decreased.

Next, the width Wb of the non-ejection pulse signal B, the intermediate timing HM between the rising timing HS and the falling timing HE of the non-ejection pulse signal B, and the falling timing A3E of the third ejection pulse signal A3 are shown. The result of an experiment performed to determine the appropriate range of the time difference d2 will be described.

The table shown in FIG. 5 shows that the width Wb of the non-ejection pulse signal B is changed from 0.2T to 2.0T,
Rise timing HS and fall timing H
E and the third injection pulse signal A
3. The time difference d2 from the falling timing A3E of (3) is 2.
The evaluation result when changing to 3T-2.7T is shown. As an evaluation method, when an ink droplet is ejected when driven at a driving frequency of 10 kHz at 20 (V) in an environment of 40 ° C.,
The case where an accidental drop occurred was evaluated as x.

From this result, the width Wb of the non-ejection pulse signal B 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 B, and the third ejection pulse signal A3 It can be understood that no accidental drop occurs when the time difference d2 from the falling timing A3E of the second signal is 2.35 to 2.65T. Therefore, ink droplet ejection with good print quality can be performed.

The embodiment has been described in detail above.
The present invention is not limited to this. For example, in the above-described embodiment, the case of printing three consecutive dots has been described. However, if there is no print command at the next cycle timing, the printing of a single dot is not limited to two or more dots. Even in this case, the time difference between the rising timing HS of the non-ejection pulse signal B and the intermediate timing HM between the falling timing HE and the falling timing of the last ejection pulse signal is 2.35 to 2. 65T and the non-injection pulse signal B
Of 0.3T to 0.7T, or 1.3T to 1.T.
A similar result can be obtained if the range is 7T.

The number of pulses, the pulse width, the pulse interval, and the drive frequency of the ejection pulse signal can be variously changed based on the knowledge of those skilled in the art. For example, as shown in FIG. 8A, the wave width Wc of the ejection pulse signal is
The ratio L / a of the sound velocity a to the above-mentioned L in the ink in No. 3
An injection pulse signal C having an odd multiple of (= T), for example, 3T or 5T may be used. Further, as shown in FIG. 8B, two ejection pulse signals D and E may be used for a one-dot printing command. At this time, the wave widths Wd and We of the ejection pulse signals D and E are both T or an odd multiple of T, the pulse interval d3 is T or an odd multiple of T, or the wave width Wd of the ejection pulse signals D and E is , We are set to 0.5T or an odd multiple of T, the same result is obtained. Further, FIG.
As shown in (d), for one dot print command, 3
Similar results can be obtained by using one or more ejection pulse signals FL. In the above embodiment, the driving frequency, that is, the driving cycle timing is set to 10 kHz. However, the oscillation frequency of the meniscus of the ink in the nozzle hole 618 appears later than the cycle in which the pressure wave propagates. Similar results can be obtained even if the size is smaller or larger than in the embodiment.

In the above embodiment, the positive power supply 18
7, the polarization direction may be reversed from 609 and 611 in FIG. 1, and a negative power supply may be used. Further, the polarization direction is reversed as shown in FIG.
19 is connected to the ground, each electrode facing the space 715 is divided into two, and one electrode 721 is connected to the resistor R120 shown in FIG. 2 as the electrodes 721 and 722, and the other electrode 722 is shown. Alternatively, it may be connected to a similar resistor of another injection charging circuit. In addition,
In the present embodiment, the lower wall 6 of the actuator wall 603
07 and the ink chamber 61 due to piezoelectric deformation of the upper wall 605.
Although the ink was ejected by deforming the volume of 3, the ink was ejected by forming one of the lower wall and the upper wall with a material that does not undergo piezoelectric deformation, and deformed along with the other piezoelectric deformation. Is also good.

In this embodiment, the ink chamber 613 is used.
Although the air chambers 615 are provided on both sides of the printer, the ink chambers may be arranged adjacent to each other without providing the air chambers. 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, if it generates a pressure wave in the ink chamber as well as the piezoelectric material,
The present invention can be implemented in various modified and improved embodiments based on the knowledge of those skilled in the art.

[0050]

As described above, according to the present invention, after a single or a plurality of ink droplets are ejected, a predetermined print command is issued.
Of if there is no print command in the periodic timing of the next printing instructions corresponding to the cycle timing, the non-ejection pulse signal does not lead to ejects ink droplets, to be applied to the actuator, the ink chamber after drop ejection Residual pressure wave vibration can be suppressed, and good print quality without accidental drops can be obtained even when the viscosity of the ink decreases, such as at high temperatures. In addition, after the ink droplet is ejected, when there is a print command at the next print command cycle timing corresponding to the predetermined print command cycle timing, that is, when a plurality of ejection pulses are continuous, each ejection There is no need to insert a non-ejection pulse between pulses, and printing can be performed at high speed.

When the ejection pulse signal is applied to the actuator, the volume of the ink chamber is increased to generate a pressure wave in the ink chamber, and the time T during which the pressure wave propagates in the ink chamber in one way or an odd multiple of T. After a lapse of time, the non-ejection pulse signal has a wave width that reduces the volume from the increasing state to the natural state,
T to 0.7T or 1.3T to 1.8T, and an intermediate timing (HM) between the rising timing (HS) and the falling timing (HE) of the non-ejection pulse signal
And the time difference between the falling timing of the last applied ejection pulse signal and 2.35 to 2.65 T, it is possible to effectively suppress the residual pressure wave vibration in the ink chamber after the ink droplet ejection. As described above, good printing without accidental drop can be realized at high speed.

Further, by setting the peak values of the ejection pulse and the non-ejection pulse to be the same, a single power source is required for the drive power source, and a special power source is required to suppress the residual pressure wave vibration as in the conventional case. The above-described printing can be realized at low cost without any need.

Further, the actuator has at least one wall constituting an ink chamber, and at least a part of the wall is formed of a piezoelectric material.
As with the thermal jet type, ink droplets can be ejected without applying heat to the ink, and high-speed 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 a driving waveform of an ink droplet ejecting apparatus according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view illustrating an ink droplet ejecting apparatus according to another embodiment of the present invention.

FIG. 10 shows an RO of the control device of the ink droplet ejection device according to the present invention.
9 is a flowchart illustrating the control contents of M.

[Explanation of symbols]

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

Claims (4)

(57) [Claims] 1. An ink chamber filled with ink, an actuator for changing the volume of the ink chamber, and one or more ejection pulse signals applied to the actuator by a print command issued at a predetermined cycle timing. by, the ink chamber to generate a pressure wave ink pressure to be, in the ink droplet ejection device and a control device for ejecting one or more ink droplets, wherein the control device, the predetermined printing and means for determining whether there is a print command in the periodic timing of the next printing instructions corresponding to the period timing of the instruction, the next print life
If there is no print command at the cycle timing of the command, after the one or more ejection pulse signals, a non-ejection pulse signal that does not lead to ejection of ink droplets is applied to the actuator, and the cycle of the next print command An ink droplet ejecting apparatus, wherein the non-ejection pulse signal is not applied to the actuator when a print command is issued at a timing. 2. The control device applies the ejection pulse signal to an actuator to increase the volume of the ink chamber to generate a pressure wave in the ink chamber, and the pressure wave propagates one way in the ink chamber. After a lapse of time T or an odd multiple of T, the volume is reduced from the increased state to the natural state, and the control device outputs the non-ejection pulse signal with a pulse width of 0.3T to 0. 7T or 1.3T to 1.8T, and an intermediate timing (HM) between a rising timing (HS) and a falling timing (HE) of the non-ejection pulse signal, and a falling edge of the injection pulse signal applied last. The time difference from the timing is 2.35 to 2.65T.
2. The ink droplet ejection device according to 1. 3. A peak value of the injection pulse, and non-ejection pulse claim 2, characterized in that each identical
3. The ink droplet ejecting apparatus according to claim 1. Wherein said actuator is at least one wall constituting the ink chamber, claims 1 to 3, wherein at least a portion of the wall portion is formed of a piezoelectric material An ink droplet ejection device according to any one of the above.