JP3249719B2 - Ink ejecting apparatus and driving method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet apparatus and an ink jet apparatus.
It relates method of driving it.

[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.

The Kaiser type disclosed in Japanese Patent Publication No. 53-12138 as a drop-on-demand type,
Alternatively, a thermal jet type disclosed in Japanese Patent Publication No. 61-59914 is a typical method.
Among them, the former is difficult to miniaturize, and the latter requires a heat resistance of the ink in order to apply high heat to the ink, and each has a very difficult problem.

A new method for simultaneously solving the above-mentioned defects has been proposed in Japanese Patent Application Laid-Open No. 63-247051.
No. 6,098,045, which utilizes shear mode deformation of a piezoelectric ceramic disclosed in Japanese Patent Application Laid-Open Publication No. H10-209,878.

[0005] As shown in FIG. 6, the above-described shear mode type ink ejecting apparatus 600 includes a bottom wall 601, a top wall 602, and a shear mode actuator wall 603 therebetween. The actuator wall 603 is bonded to the bottom wall 601 and is polarized in the direction of the arrow 611 in the lower wall 607.
And an upper wall 605 bonded to the top wall 602 and polarized in the direction of the arrow 609. The actuator walls 603 are paired to form an ink flow path 613 therebetween, and a space 615 smaller than the ink flow path 613 is formed between the next pair of actuator walls 603.

A nozzle 6 is provided at one end of each ink flow path 613.
A nozzle plate 617 having an 18 is fixed, and electrodes 619 and 621 are provided as metal layers on both side surfaces of each actuator wall 603. Each of the electrodes 619 and 621 is covered with an insulating layer (not shown) for insulating the ink. The electrode 621 facing the space 615 is connected to the ground 623, and the electrode 619 provided in the ink flow path 613 is connected to a silicon chip 625 that supplies an actuator drive signal.

Next, a method for manufacturing the ink ejecting apparatus 600 will be described. First, the piezoelectric ceramic layer polarized in the direction of the arrow 611 is bonded to the bottom wall 601, and the piezoelectric ceramic layer polarized in the direction of the arrow 609 is bonded to the top wall 602. The thickness of each piezoelectric ceramic layer is equal to the height of the lower wall 607 and the upper wall 605. Next, a parallel groove is formed in the piezoelectric ceramic layer by rotation of a diamond cutting disk or the like to form a lower wall 607 and an upper wall 605. Then, the electrode 61 is formed on the side surface of the lower wall 607 by vacuum evaporation.
9, 621 are formed, and the insulating layer is provided on the electrodes 619, 621. Similarly, electrodes 619 and 621 and the insulating layer are provided on the side surface of the upper wall 605.

The ink channel 613 and the space 615 are formed by bonding the zenith of the upper wall 605 and the zenith of the lower wall 607. Next, the nozzle plate 617 in which the nozzle 618 is formed is adhered to one end of the ink flow path 613 and the space 615 so that the nozzle 618 corresponds to the ink flow path 613, and The other end is electrically connected to silicon chip 625 and ground 623.

The electrodes 619 of each ink flow path 613
When the voltage is applied by the recon chip 625, the piezoelectric thickness shear deformation of each actuator wall 603 occurs in the direction of increasing the volume of the ink flow path 613. For example, as shown in FIG. 7, when a voltage V is applied to the ink flow path 613c, electric fields in the directions of arrows 627 and 629 are generated on the actuator walls 603e and 603f, respectively, and the actuator walls 603d and 603e change the volume of the ink flow path 613c. In the direction of increasing the piezoelectric thickness. At this time, the pressure in the ink flow path 613c including the vicinity of the nozzle 618c decreases. This state is maintained for a time T during which the pressure wave propagates in the ink flow path 613 one way. Then, ink is supplied from a manifold (not shown) during that time. The one-way propagation time T is a time required for the pressure wave in the ink flow path 613 to propagate in the longitudinal direction of the ink flow path 613, and the length L of the ink flow path 613 and this ink flow path 613
T = L / a is determined by the sound speed a in the ink inside. According to the pressure wave propagation theory, the pressure in the ink flow path 613 reverses and changes to a positive pressure just after T time has elapsed from the application of the voltage, but the electrode 619c of the ink flow path 613c is synchronized with this timing. Is returned to 0.

Then, the actuator walls 603e, 60
3f 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 when the actuator walls 603e and 603f return to the state before deformation are added, and a relatively high pressure is generated in a portion of the ink flow path 613c near the nozzle 618c. Thus, ink is ejected from the nozzle 618c.

After the ink is ejected, if the ink flow path 6
Unless a new voltage pulse is applied to the electrodes 619e and 619f of the ink flow path 13c, the pressure in the ink flow path 613c becomes 2
It keeps changing for a while with T as the cycle. This is the residual pressure fluctuation. When the frequency of the voltage pulse is changed due to the fluctuation of the residual pressure, the ink jetting speed fluctuates, and the landing position shifts, so that the printing quality is impaired or the jetting becomes impossible.

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 fluctuation in the ink flow path 613 by applying a cancel pulse following a print pulse for performing ink ejection. In other words, a cancel pulse for generating a pressure wave having a phase opposite to that of the residual pressure fluctuation in the ink flow path 613 is applied after a predetermined time from the ink ejection. As shown in FIG.
A cancel pulse G having a width T and a phase opposite to that of the ejection pulse is applied to the thirteen electrodes 619 after T from the fall of the ejection pulse F. Further, the voltage value is set according to the amplitude of the residual pressure fluctuation so as to just cancel the fluctuation (for example, 0.6 times the injection pulse). By giving this cancel pulse, the actuator wall 603 deforms in the opposite direction to that at the time of ink ejection, and gives a pressure wave whose phase is opposite to that of the residual pressure fluctuation, thereby canceling the residual pressure fluctuation. This eliminates fluctuations in the ink ejection speed when the frequency of the voltage pulse is changed, and improves print quality.

Next, a drive circuit for realizing the cancellation of the residual pressure fluctuation will be described. The output signals X, Y, and Z shown in FIG.
Is a signal for setting the voltage applied to V, 0, and -0.6 × V. When the output signal X is turned on, a voltage pulse (F in FIG. 8) for ejecting ink is generated. Also,
When the output signal Z is turned on, a voltage pulse (G in FIG. 8) for causing a pressure fluctuation for cancellation is generated.
In other cases, the output signal Y is turned on, and the output voltage is set to zero. The capacitor 91 includes an actuator wall 603 of the ink flow path 613 and electrodes 6 formed on both sides thereof.
15, 619.

The driving circuit is composed of three blocks surrounded by broken lines, each of which is an injection charging circuit 82, a discharging circuit 84, and a cancel pressure generating circuit 86.
When the input signal X is turned on, the transistor Tc
Is conducted, and a voltage of V is applied from the positive power supply 87 to the electrode E of the capacitor 91 via the resistor R12. Input signal Y
Is turned on, the transistor Tg is turned on and the resistor R1 is turned on.
2, the electrode E of the condenser 91 is grounded. When the input signal Z is turned on, the transistor Ts conducts, and a voltage of −0.6 × V is applied from the negative power supply 88 to the electrode E of the capacitor 91 via the resistor R12.

As shown in FIG. 10, the width T and the phase of the injection pulse F are the same after 2T from the fall of the injection pulse F, and the voltage value (for example, 0.5% of the injection pulse F) corresponds to the amplitude of the residual pressure fluctuation. By applying the (×) cancel pulse H, the residual pressure fluctuation can also be canceled. In this case, the drive circuit does not need the negative power supply 88 as shown in FIG. 9, but has a voltage V × 0.
5 to provide a second positive power supply (not shown)
What is necessary is just to switch and use it with the positive power supply 87.

Here, when switching the print density, for example, when lowering the print density, it is necessary to increase the volume of the ink droplets in order to maintain the print quality. A method of increasing the driving voltage and increasing the volume of the ink droplet is disclosed in
99450.

[0017]

However, in the method of driving the ink ejecting apparatus having the above-described structure, when increasing the ink droplet volume, two or more types of power supplies having different voltage values are required to increase the driving voltage. However, there is a problem that the cost increases. Japanese Patent Application Laid-Open No. 62-199450 discloses that the volume of an ink droplet is changed by changing the voltage width, but the specific width is not disclosed.

After the ejection pulse F having a positive voltage V is applied to suppress the residual pressure oscillation, the pressure wave propagates in the ink flow path 613 and makes one reciprocation. In order to cancel the fluctuation, a cancel pulse G that is a negative voltage or a cancel pulse H that is a positive voltage but different in voltage value must be given. Therefore, a positive power supply and a negative power supply, or two types of positive power supplies having different voltages are required, and the driving circuit becomes complicated,
There was a problem that costs increased.

[0019] The present invention includes a switching the ink drop volume corresponding to the print resolution <br/> degree only by a single driving power source, the pulse
Suppressing variation in the ejection speed of the ink when changing the frequency of the signal, and an object thereof is to provide a method of driving a good printing obtained quality low-cost ink-jet apparatus and its.

[0020]

In order to achieve this object, according to the first aspect of the present invention, there is provided an ink jet printer in which ink is filled.
A road, and an actuator for changing the volume of the ink passage, by applying a pulse signal to the actuator, and control means for ejecting ink droplets by changing the volume of the ink flow path there <br/> ink jet equipment, wherein, when printing in the first resolution,
Pal for pulse width to inject 3 times or more and odd multiples of the ink one-way propagation time T of a pressure wave in the ink flow path
A first drive waveform signal including a scan signal, and indicia pressure to the actuator, to eject ink droplets of the first volume, when printing at the second resolution is a high resolution than said first resolution
Come, 0.6 and 0.9 times or 1.1 to 1.4 times big one first drive waveform signal and the peak value of the one-way propagation time T of the pulse width pressure wave of the ink flow path is the same Eject ink
A second drive signal including a pulse signal for, and marked pressure before Symbol actuator, characterized in that ejects ink droplets of the first volume is smaller than the second volume.

According to a second aspect of the present invention, the first and second drive waveform signals compensate for a pulse signal for ejecting the ink and a residual pressure fluctuation in the ink flow path after the ejection.
Characterized that you made of a pulse signal for amortization.

In the third aspect, the first drive waveform signal is
Pulse signal to compensate for residual pressure fluctuations
The same peak value as the pulse signal for firing the ink
And the pulse width is 0.3T to 1.7T, and
The falling of the pulse signal for ejecting the ink
From the timing Tp.
The center tie between the timing Ts and the fall timing Te
The delay time Td before the mining Tm is 2.25T to 2.75.
T.

According to the fourth aspect, the second drive waveform signal is
Pulse signal to compensate for residual pressure fluctuations
Have the same peak value and the pulse signals for ejecting the serial ink, a and pulse width 0.3T～1.7T, and the falling timing Tp of the pulse signal for ejecting the ink, The delay time Td between the rising timing Ts and the falling timing Te of the pulse signal until the center timing Tm is 2.25T to 2.75.
T.

According to the fifth aspect, the ink to be filled with the ink
A flow path and an actuator for changing the volume of the ink flow path.
An ink ejecting apparatus including a tutor;
By applying a pulse signal to the actuator,
A drive that ejects ink droplets by changing the volume of the ink flow path
Pulse width when printing at the first resolution
Is at least three times the one-way propagation time T of the pressure wave in the ink flow path.
Pulse signal for ejecting an odd number of times
Applying a first drive waveform signal including
And ejecting a first volume of ink droplets, the first resolution
When printing at a higher resolution, the second resolution, the pulse
The width is 0.6 of the one-way propagation time T of the pressure wave in the ink flow path.
0.9 times or 1.1 to 1.4 times and the first drive wave
Pal for ejecting ink with the same crest value as the shape signal
A second drive signal including a drive signal to the actuator.
To eject a second volume ink droplet smaller than the first volume.
It is characterized by firing .

[0025]

[Action] In the driving method of ink jet apparatus and their according to the present invention having the above configuration, when printing at the first resolution
A pulse width of at least three times the one-way propagation time T of the pressure wave in the ink flow path and an odd number of times .
A first drive waveform signal including a pulse signal, and indicia pressure to the actuator, thereby ejecting ink droplets of the first volume.
And a second resolution that is higher than the first resolution
In when printing, the pulse width is one-way propagation time T of a pressure wave in the ink channel 0.6-0.9 fold or 1.1-1.
It is four times, and the first drive waveform signal and the peak value identical
A second drive signal including a pulse signal for ejecting ink, and marked pressure to the actuator, thereby ejecting ink droplets of a first volume smaller than the first volume. First resolution,
Ink droplets of a volume corresponding to each of the second resolutions are ejected.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 shows an ink jetting apparatus 600 according to this embodiment.
As in the conventional ink ejecting apparatus 600 shown in FIG.
1, a ceiling wall 602 and a shear mode actuator wall 603 therebetween. The actuator wall 603 is
A lower wall 607 bonded to the bottom wall 601 and polarized in the direction of arrow 611;
It consists of an upper wall 605 polarized in the 09 direction. The actuator walls 603 are paired to form an ink flow path 613 therebetween, and a space 61 narrower than the ink flow path 613 is provided between the next pair of actuator walls 603.
5 are formed.

At one end of each ink channel 613, a nozzle 6
A nozzle plate 617 having an 18 is fixed, and electrodes 619 and 621 are provided as metal layers on both side surfaces of each actuator wall 603. Each of the electrodes 619 and 621 is covered with an insulating layer (not shown) for insulating the ink. The electrode 621 facing the space 615 is connected to the ground 623, and the electrode 619 provided in the ink flow path 613 is connected to a silicon chip 625 that supplies an actuator drive signal.

An example of specific dimensions of the ink ejecting apparatus according to the present embodiment will be described. The length L of the ink flow path 613 is 7.5.
mm. The dimensions of the nozzle 618 are such that the diameter on the ink ejection side is 40 μm, the diameter on the ink flow path 613 side is 72 μm, and the length is 100 μm. The viscosity of the ink used in the experiment was 2 mPa / s, and the surface tension was 30 mN / m. Then, the sound velocity in the ink in the ink flow path 613 is represented by a ratio L / a of a to L (= one-way propagation time T of the pressure wave).
Is 8 μsec.

Next, the driving waveforms 10 and 20 applied to the electrode 619 in the ink flow path 613 of this embodiment are shown in FIG. The first drive waveform 10 is a waveform for obtaining a large volume of the first ink droplet, and the second drive waveform 20 is a waveform for obtaining a small volume of the second ink droplet. Can select the drive waveform 10 and, if the resolution is high, select the drive waveform 20 to select the volume of the ink droplet that matches the resolution.

The first drive waveform 10 includes a first pulse signal A for ejecting ink and an ink flow path 6 after ejection.
13 includes a second pulse signal B for compensating for the residual pressure fluctuation, and both the first pulse signal A and the second pulse signal B have the same peak value (voltage value) (for example, 22).
v). The width Wa of the first pulse signal A is equal to three times the one-way propagation time T (L / a) of the pressure wave in the ink flow path 613, that is, 24 μsec. The width Wb of the second pulse signal B is equal to 1.5 times the one-way propagation time T of the pressure wave in the ink flow path 613, that is, 12 μsec. Fall timing Tp of the first pulse signal A
1 to the rising timing T of the second pulse signal B
The delay time Td1 up to the intermediate timing Tm1 between s1 and the falling timing Te1 is equal to the ink flow path 61.
3 corresponds to 2.5 times the one-way propagation time T of the pressure wave, that is, 20 μsec.

The second drive waveform 20 includes a first pulse signal C for ejecting ink and an ink flow path 6 after ejection.
13 includes a second pulse signal D for compensating for residual pressure fluctuations, and both the first pulse signal C and the second pulse signal D have the same peak value (voltage value) (for example, 22).
v). The width Wc of the first pulse signal C is equal to 0. 1 of the one-way propagation time T (L / a) of the pressure wave in the ink flow path 613.
625 times, that is, 5 μsec, and the width Wd of the second pulse signal D corresponds to 0.5 times the one-way propagation time T of the pressure wave in the ink flow path 613, ie, 4 μsec.
c.

By setting the width Wc of the first pulse signal C to 5 μs, which is 0.625 times the one-way propagation time T, the same ink droplet ejection speed as the ink droplet ejection speed by the first drive waveform 10 is used. Can be obtained. With the change of the type of ink, the shape of the ink flow path, the shape of the nozzle, etc., the width Wc of the first pulse signal C is set to 0.6 to less than the one-way propagation time T of the pressure wave.
It may be changed to 0.9 times, or 1.1 to 1.4 times, and adjusted so as to obtain the same ink droplet ejection speed as the first drive waveform 10. The delay time Td2 from the fall timing Tp2 of the first pulse signal C to the intermediate timing Tm2 between the rise timing Ts2 and the fall timing Te2 of the second pulse signal D is the same as the delay time Td2 of the first drive waveform 10. It corresponds to 2.5 times the one-way propagation time T of the pressure wave which is the same as the delay time Td1, that is, 20 μm.
sec.

An embodiment of a drive circuit for realizing the drive waveforms 10 and 20 will be described with reference to FIGS. FIG.
Are signals for setting the voltage applied to the electrode 619 in the ink flow path 613 to V and 0, respectively. When the output signal X is turned on, a voltage V is generated, and when the output signal Y is turned on, the voltage becomes zero. Capacitor 1
Reference numeral 91 denotes an actuator wall 603 of the ink flow path 613 and electrodes 619 and 621 formed on both sides thereof.

The driving circuit is composed of two blocks surrounded by broken lines, each of which is an injection charging circuit 182 and a discharging circuit 184. When the input signal X is turned on, the transistor Tc is turned on, and a voltage of V, for example, 22 V is applied from the positive power supply 187 to the electrode E of the capacitor 191 via the resistor R120. When the input signal Y is turned on, the transistor Tg is turned on, and the voltage E of the capacitor 191 is grounded via the resistor R120.

FIG. 3A shows the timing charts 11 and 12 of the input signals X and Y of the first drive waveform 10 and the output voltage waveform 13 of the electrode E. Second drive waveform 20
Of input signals X and Y of FIG.
4 and 15 and the output voltage waveform 16 of the electrode E are shown in FIG.

As shown in the timing chart 11 of the input signal X, the input signal X is normally in an off state, and is turned on at a predetermined timing T1 for injection and turned off at a timing T2. It turns on at the subsequent timing T3 and turns off at the timing T4. The second drive waveform 20 is turned on at timing T5 and turned off at timing T6. It is turned on at the subsequent timing T7 and turned off at the timing T8. The timing chart 12 of the input signal Y is turned off when the input signal X is on, and turned on when the input signal X is off.

Output waveforms 13 and 16 at the electrode E at that time
Is normally 0 V, but the charge to the capacitor 191 is charged at timings T1 and T5, and the charging time T determined by the transistor Tc, the resistor R120, and the capacitor 191.
After a, the voltage becomes V (for example, 22 V). At timings T2 and T6, the charge of the capacitor 191 is discharged, and becomes 0 V after a discharging time Tb determined by the transistor Tg, the resistor R120, and the capacitor 191. Subsequently, at timings T3 and T7, the charge to the capacitor 191 is charged.
After the charging time Ta determined by the transistor Tc, the resistor R120, and the capacitor 191, the voltage becomes V (for example, 22V). Further, the charge of the capacitor 191 is discharged at timings T4 and T8, and becomes 0v after a discharge time Tb determined by the transistor Tg, the resistor R120, and the capacitor 191.

As described above, since the actual drive waveforms 13 and 16 have delays of Ta and Tb at the rise and fall, respectively, the first and second drive waveforms 10 and 20 at the voltage of 1/2 × V (for example, 11 V) are used. 1 pulse signal A,
The widths Wa and Wc of C and the width W of the second pulse signals B and D
The timings T1, T2, T3, T4, T5, and T are set so that b, Wd, and the delay time Td have the values shown in FIG.
6, T7 and T8 are set.

An ink ejection test was conducted when the ink was driven by the driving method of the present embodiment. The drive voltage was 22 V, at which the ink ejection speed was 5 m / s at a very low drive frequency, for example, 60 Hz. When the drive frequency is changed from 5 kHz to 15 kHz, the ink ejection speed can be stably ejected between 4.5 and 5.3 m / s in both the first drive waveform 10 and the second drive waveform 20. Was. As a comparative experiment, when driving is performed only with the first pulse signal A of the first driving waveform 10 of the present embodiment, the ink ejection speed varies between 4.5 and 6.5 m / s, and the driving frequency is 8 kHz. In the case described above, the injection becomes impossible, and when only the first pulse signal C of the second drive waveform 20 is driven,
The ink jetting speed varied between 4 and 7 m / s, and it became impossible to jet at a driving frequency of 6 kHz or more. The result is shown in FIG. From this result, it can be seen that the driving method of the present embodiment suppresses the fluctuation of the ink ejection speed when the frequency of the voltage pulse is changed. Further, the ink droplet volume is about 40 pl when driven by the first drive waveform 10 irrespective of the frequency, is about 25 pl in the case of the second drive waveform 20, and the second in the case of the first drive waveform 10. Drive waveform 2
The ink droplet volume was increased by about 60% from the case of 0.

If the first drive waveform 10 is used for printing at a resolution of, for example, 360 dpi, and the second drive waveform 20 is used for printing at a resolution of, for example, 720 dpi, good print quality can be obtained at each resolution. be able to.

Further, in the driving method of the ink ejecting apparatus of this embodiment, the first pulse signal A, the second pulse signal B, and the second driving waveform of the first driving waveform 10 are applied to the electrode 619 of the ink flow path 613. Since the same positive voltage V is applied to both the first pulse signal C and the second pulse signal D in 20, only a positive power supply 187 is required as a driving power supply, and a positive power supply and a negative power supply are required as in the related art. Alternatively, the control circuit is simpler than when two types of positive power supplies having different voltages are used, and cost can be reduced.

Next, the widths Wb and Wd of the second pulse signals B and D in the respective drive waveforms 10 and 20, and the fall timings Tp1 and Tp2 of the first pulse signals A and C are shown.
From the intermediate timing Tm1 of the second pulse signals B and D,
The result of an experiment performed to determine an appropriate range with the delay time Td up to Tm2 will be described.

FIG. 5 shows the width W of the second pulse signals B and D.
The evaluation results when b and Wd are changed from 0.3T to 2.0T and the delay time Td is changed from 2.0T to 3.0T are shown. The left side shows the results for the first drive waveform 10 and the right side shows the results for the second drive waveform 20. Evaluation method is 5kHz ~
The change in the ink ejection speed was examined by changing the drive frequency to 15 kHz. The drive voltage was 22 V, which is a very low drive frequency, for example, 60 Hz, and the ink ejection speed is 5 m / s.

Here, the double circle in the evaluation indicates that the speed fluctuation is 1 m.
/ S, less than 1.0 m / s
less than s, triangles indicate speed fluctuation of 2.0 or more and less than 3 m / s, ×
Indicates that injection became impossible at a certain frequency. From this result, the delay time Td is in the range of 2.25T to 2.75T, and the widths Wb and Wd of the second pulse signals B and D are set to 0.
When 3T to 1.7T is set, the speed fluctuation is small, and the width Wb of the second pulse signal B is set to 0.5T or 1.3 to 1.3T.
If 1.7T and the width Wd of the second pulse signal D are 0.5T or 1.5T, ink ejection with better print quality can be performed.

Although one embodiment has been described in detail, the present invention is not limited to this embodiment. For example, in the above embodiment, the positive power supply 187 is used, but a negative power supply may be used by reversing the polarization directions of 609 and 611 in FIG. The present invention can be implemented in other configurations with various changes and improvements based on the knowledge of those skilled in the art without departing from the scope of the claims.

In this embodiment, the actuator wall 60
3, the ink was ejected by deforming the volume of the ink flow path 613 by the piezoelectric deformation of the lower wall 607 and the upper wall 605. The ink may be ejected such that the ink is deformed along with the deformation.

In this embodiment, the air chambers 615 are provided on both sides of the ink flow path 613. However, the air flow paths may be adjacent to each other without providing the air chamber.

[0049]

[Effect of the Invention] As described above, according to the driving method of the ink ejection device and its the present invention, is printed at a first resolution
When, the first driving waveform signal to said actuator
And indicia pressure, when printing at the second resolution, the second drive signal to mark pressure to the actuator, first resolution, the first ink droplet volume corresponding to the second resolution, respectively, the second ink droplet Since the jetting is performed, the printing quality of both the first resolution and the second resolution is good. Further, the peak values of the pulse signals are the same.
By being the same, it is possible to drive with a single drive power supply, so that the drive circuit becomes simpler and the cost is reduced as compared with the conventional case.

[Brief description of the drawings]

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

FIG. 2 is a diagram illustrating a drive circuit of the ink ejecting apparatus.

FIG. 3 is a timing chart of a driving method of the ink ejecting apparatus.

FIG. 4 is a diagram illustrating the results of an experiment in which the frequency of the driving method of the ink ejecting apparatus was changed.

FIG. 5 is a diagram illustrating a result of an experiment in which the width and application timing of a second pulse signal in the method of the ink ejecting apparatus are changed.

FIG. 6 is a diagram illustrating a conventional example and an ink ejecting apparatus according to the present invention.

FIG. 7 is a diagram illustrating an operation of a conventional example and an ink ejecting apparatus according to the present invention.

FIG. 8 is a diagram showing a driving method of a conventional example.

FIG. 9 is a diagram showing a conventional driving circuit.

FIG. 10 is a diagram showing another example of the driving method of the conventional example.

[Explanation of symbols]

 10 First drive waveform 20 Second drive waveform 187 Positive power supply 600 Ink ejecting device 603 Actuator wall 613 Ink flow path 619 Electrode 621 Electrode

Claims (5)

(57) [Claims] An ink flow path 1. A ink is filled, an actuator for changing the volume of the ink passage, by applying a pulse signal to the actuator to vary the volume of the ink flow path an ink jet equipment and control means for ejecting ink droplets Te, wherein, when printing in the first resolution, the pulse width of the pressure wave of the ink flow path <br/> one-way propagation more than three times the time T in and an odd multiple of Lee
A first drive waveform signal including a pulse signal for ejecting ink, and marked pressure to the actuator, to eject ink droplets of the first volume, printed at a second resolution which is higher resolution than said first resolution You
Rutoki, a 0.6 to 0.9-fold or 1.1 to 1.4 times big <br/> one first drive waveform signal one-way propagation time T of the pulse width is a pressure wave in the ink flow path Ink with the same peak value is ejected
A second drive signal including a pulse signal for causing, in marked pressure before Symbol actuator, ink ejection instrumentation, characterized in that for ejecting ink droplets of the first volume is smaller than the second volume
Place. 2. The first and second driving waveform signals are:
A pulse signal for ejecting the ink ,
To compensate for residual pressure fluctuations in the ink flow path after ejection
Ink jet equipment according to claim 1, wherein the this composed of a pulse signal. 3. The residual pressure in the first drive waveform signal .
The pulse signal for compensating for the force fluctuation
The same peak value as the pulse signal to be emitted, and
A pulse width of 0.3T to 1.7T;
Of falling edge of pulse signal for jetting
From Tp, the rising timing Ts of the pulse signal
And the fall timing Te to the center timing Tm.
Ink jet equipment according to claim 2, the delay time Td is characterized in that it is a 2.25T~2.75T in. 4. A residual pressure in the second drive waveform signal .
The pulse signal for compensating for the force fluctuation
It has the same peak value and the pulse signal for causing Isa, and the pulse width is 0.3T～1.7T, and the ink
From the fall timing Tp of the pulse signal for ejecting, rising timing Ts of the pulse signal
Ink jet equipment according to claim 2, start delay time Td to the center timing Tm and edge timing Te is characterized in that it is a 2.25T~2.75T with. 5. An ink flow path filled with ink,
An actuator for changing the volume of the ink flow path;
A pulse signal applied to the actuator.
Ejecting ink droplets by changing the volume of the ink flow path
A driving method, wherein when printing at the first resolution, the pulse width is
Of one-way propagation time T of pressure wave at
Drive wave including a pulse signal for injecting ink
A shape signal is applied to the actuator to produce a first volume
Ink droplets are ejected , and printing is performed at a second resolution higher than the first resolution.
When the pulse width is one-way propagation of the pressure wave in the ink flow path
0.6 to 0.9 times or 1.1 to 1.4 times the time T
Ink is ejected with the same peak value as the first drive waveform signal.
A second drive signal including a pulse signal for causing
A second volume, smaller than the first volume, applied to the actuator
Ink jetting device, which jets a plurality of ink droplets
Driving method.