JP3241352B2 - Ink jet head and ink jet recording apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ink jet head and an ink jet recording apparatus.

[0002]

2. Description of the Related Art As disclosed in, for example, JP-A-10-81012, a plurality of ink droplets are ejected from each nozzle of an ink jet head during one printing cycle for forming one dot on recording paper. In addition, there has been proposed an ink jet recording apparatus that forms one dot using a plurality of ink droplets.

An ink jet recording apparatus of this type has a head body in which a pressure chamber for accommodating ink and a nozzle communicating with the pressure chamber are formed, and an ink droplet is ejected from the nozzle by the piezoelectric effect of a piezoelectric element. An ink jet head having an actuator for applying pressure to ink in the pressure chamber, a drive signal supply unit for supplying a drive signal to the actuator, and a relative moving unit for relatively moving the ink jet head and the recording paper are provided.
When the ink jet head and the recording paper are relatively moved by the relative movement means, the drive signal supply means supplies a drive signal including one or more drive pulses to the actuator during one printing cycle. And
One or more ink droplets are ejected from the nozzle. The plurality of ink droplets thus ejected land on the recording paper in the order of ejection to form one ink dot. By arranging a plurality of such dots on the recording paper,
A predetermined image is formed on the recording paper. Then, by adjusting the number of ink droplets ejected during one printing cycle,
The density and size of the dots are adjusted, and so-called multi-tone printing can be performed.

On the other hand, as disclosed in US Pat. No. 5,285,215, by making the ink droplet ejected later have a higher ejection speed than the ink droplet ejected earlier, There is also known a technique in which two ink droplets ejected from the same nozzle are combined before landing to form a large ink droplet before landing.

[0005]

As described above, in order to eject one or more ink droplets during one printing cycle, it is necessary to supply the actuator with a number of drive pulses corresponding to the number of ejections. There is. However, it is difficult to form good ink dots on recording paper simply by supplying a number of drive pulses corresponding to the number of ink droplets ejected without any contrivance in a method of supplying a drive signal.

For example, when performing high-speed printing, since the relative movement speed between the ink jet head and the recording paper is high, a plurality of ink droplets ejected from the same nozzle land sequentially on mutually shifted positions on the recording paper. Easier to do. For this reason, the ink dots become elliptical, and the printing quality is likely to deteriorate. Therefore, in such a case, a plurality of ink droplets are continuously ejected so that the ejection interval of the ink droplets is as short as possible, and the ink droplet ejected later is the ink droplet ejected earlier. It is necessary to make the ejection speed faster than that.

If the ink meniscus vibration at the end of one printing cycle remains until the next printing cycle, the ink ejection performance becomes unstable. Therefore, a method of supplying a drive signal that is not easily affected by meniscus vibration has been desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ink jet head for discharging one or more ink droplets from the same nozzle during one printing cycle, and to provide the ink jet head. To improve the ink ejection performance of the ink jet recording apparatus.

[0009]

In order to achieve the above object, an ink jet head according to the present invention has a plurality of pressure chambers for accommodating ink and a plurality of nozzles respectively communicating with the respective pressure chambers. A plurality of actuators each having a head body, a piezoelectric element, and applying pressure to the ink in each of the pressure chambers by a piezoelectric effect of the piezoelectric element; and ink ejection for driving the actuator so as to eject ink droplets from the nozzles. A drive signal generation unit for generating a reference drive signal including N pulse signals (N is a natural number of 2 or more) within a predetermined printing cycle; and P drive signals (P is N or less) included in the reference drive signal. A signal selector for selectively supplying a (natural number) of ink ejection pulse signals to the actuator. Click ejection pulse signals, who ink droplets ejected later are formed so as to discharge speed than the ink droplet ejected first is faster, the signal selection unit,
It is configured to supply the pulse signals for ink ejection of the (N−P + 1) th or later of the reference drive signals.

With this, the drive signal generation unit can output N ink droplets in one printing cycle so that a maximum of N ink droplets can be ejected.
A reference drive signal including a plurality of ink ejection pulse signals is generated. On the other hand, the signal selection unit is configured to output N-P + 1 among the N ink ejection pulse signals so as to eject P ink droplets in one printing cycle according to a predetermined image signal.
A total of P subsequent ink ejection pulse signals are selected and supplied to the actuator. Here, since the P ink ejection pulse signals are pulse signals continuously generated in the reference drive signal, the time interval between each pulse is short. Therefore, the P ink droplets are continuously discharged without a break. Further, since the N ink ejection pulse signals are generated so that the ink droplets ejected later have a higher ejection speed than the ink droplets ejected earlier, the above-described P ink ejection pulse signals are generated. A total of P ink droplets ejected by the pulse signal are ejected so that the ejection speed increases sequentially. Therefore, the displacement of the landing positions of the P ink droplets is small, and it is easy to combine the P ink droplets before landing. As described above, regardless of the number of ejected ink droplets, good ink dots are formed, and the ink ejection performance is improved.

Further, since the drive signal generated by the drive signal generation section is only one type of reference drive signal, it is not necessary to generate as many drive signals as the number of ink discharges. The configuration of the control system is simplified, and the cost is reduced.

The drive signal generation section generates an auxiliary pulse signal for suppressing meniscus vibration of ink in the head body after generating the reference drive signal, and the signal selection section controls the actuator with respect to the actuator. N-
It is preferable to be configured to supply the (P + 1) th or later ink ejection pulse signal and the auxiliary pulse signal.

As a result, the actuator is
An auxiliary pulse signal is supplied after a total of P ink ejection pulse signals of the (N−P + 1) th and subsequent reference drive signals have been supplied. As a result, ink meniscus vibration after the ejection of P ink droplets is suppressed, and the ink ejection performance in the next printing cycle is stabilized.

Another ink jet head according to the present invention has a head body in which a plurality of pressure chambers accommodating ink and a plurality of nozzles communicating with the respective pressure chambers are formed, and a piezoelectric element. A plurality of actuators for applying pressure to the ink in each of the pressure chambers by the piezoelectric effect of the element, and an ink ejection pulse signal for driving the actuator so as to eject ink droplets from the nozzles within a predetermined one printing cycle. A drive signal generation unit for generating a reference drive signal including N (N is a natural number of 2 or more), and P (P is a natural number of N or less) ink ejection pulse signals included in the reference drive signal to the actuator. And a signal selection unit for selectively supplying the reference drive signal, wherein the pulse signal for ink ejection of the reference drive signal is ejected later. The ink droplets are formed such that the ejection speed is higher than the ink droplets ejected earlier, and the drive signal generation unit suppresses meniscus vibration of the ink in the head body after generating the reference drive signal. The signal selection unit supplies the first pulse signal for ink ejection of the reference drive signal to the actuator when P is 1, while the signal selection unit supplies the second pulse signal to the actuator. In the case of, the pulse signal for ink ejection of the (N−P + 1) th and subsequent pulses of the reference drive signal and the auxiliary pulse signal are supplied.

[0015] Thus, one (P)
When the ink droplet of (= 1) is ejected, only the first pulse signal of the N ink ejection pulse signals included in the reference drive signal is supplied to the actuator. The first pulse signal has a more stable waveform than the second and subsequent pulse signals, and is generated at the earliest time in the printing cycle, so that the ink ejection timing becomes accurate and the ink The ejection performance is stable, and the accuracy of the ink landing position is improved. In this case, 1
Since only ink droplets are ejected, the entire ink ejection amount in one printing cycle is small, and the influence of meniscus vibration is small. Therefore, there is no problem even if the auxiliary pulse signal is not supplied. Further, even when two or more (P ≧ 2) ink droplets are ejected during one printing cycle, the reason is as described above.
Good ink dots are formed irrespective of the number of ejected ink droplets, and the ink ejection performance is improved. In this case,
Since the auxiliary pulse signal is supplied to the actuator after the reference drive signal is supplied, a decrease in ejection performance due to the influence of meniscus vibration is suppressed.

It is preferable that an interval between the Nth ink ejection pulse signal of the reference drive signal and the auxiliary pulse signal is set to be 0.5 to 1.5 times a natural period of the actuator. . The natural period of the actuator refers to the natural period of the entire vibration system including the acoustic element (specifically, ink).

Thus, the meniscus vibration of the ink is efficiently suppressed.

If the potential difference of the auxiliary pulse signal is too small, it is difficult to sufficiently suppress meniscus oscillation. If the potential difference is too large, unintended ink discharge may occur. Therefore, it is preferable that the potential difference of the auxiliary pulse signal is set to 0.1 to 0.3 times the minimum potential difference of the ink ejection pulse signal of the reference drive signal.

Thus, an auxiliary pulse signal suitable for efficiently suppressing meniscus vibration without discharging ink can be obtained.

Each of the ink discharge pulse signals of the reference drive signal is a rectangular or trapezoidal pulse signal having a first potential as a reference potential and a second potential different from the first potential. A switching circuit that selectively switches to one of an ON state in which the reference drive signal is supplied to the actuator and an OFF state in which the supply of the reference drive signal to the actuator is stopped; May be configured to switch from the OFF state to the ON state when the potential of the reference drive signal is the first potential.

Accordingly, the pulse signal for ink ejection of the reference drive signal is constituted by a rectangular or trapezoidal pulse signal having only two potentials, the first potential and the second potential. The waveform is simplified.
Accordingly, the configuration of the drive signal generation unit that generates the reference drive signal is simplified.

The pulse signal for ink ejection of the reference drive signal includes a negative pressure potential for driving the actuator on the side for depressurizing the pressure chamber and a positive potential for driving the actuator on the side for pressurizing the pressure chamber. A potential drop waveform that drops from the reference potential between the high voltage potential to the negative pressure potential,
An initial pulse signal composed of a negative voltage potential maintaining waveform for maintaining the negative voltage potential, a potential rising waveform rising from the negative voltage potential to the positive voltage potential, and a predetermined positive voltage potential to each predetermined voltage It is composed of a potential drop waveform falling to a negative potential, a negative potential maintenance waveform for maintaining each negative potential, and a potential rising waveform rising from each negative potential to a predetermined positive potential. Consisting of one or more subsequent pulse signals,
The signal selection unit includes a switching circuit that selectively switches to one of an ON state in which the reference drive signal is supplied to the actuator and an OFF state in which supply of the reference drive signal to the actuator is stopped, The switching circuit elapses a predetermined time from the start of maintaining the negative-voltage potential maintaining waveform of the reference drive signal so that the supply of the reference drive signal starts after the potential of the reference drive signal becomes a negative-pressure potential. It may be configured to switch from the OFF state to the ON state later.

Accordingly, the switching circuit switches after a predetermined time has elapsed from the start of maintaining the waveform of the negative pressure potential maintaining waveform of the reference drive signal so that the switching is performed with a predetermined time delay from the fall of the waveform of the reference drive signal. , From the OFF state to the ON state. Therefore, since the switching circuit does not switch while the potential of the reference drive signal is falling, the actuator may include a sustain waveform of an unintended potential other than the reference potential, the negative pressure potential, and the positive pressure potential. No unstable driving signal is supplied.

Each of the ink discharge pulse signals of the reference drive signal has a potential drop waveform that drops from a reference potential to a negative pressure potential that drives the actuator to reduce the pressure in the pressure chamber, and maintains the negative pressure potential. And a potential rising waveform that rises from the negative pressure potential to the reference potential. The auxiliary pulse signal drives the actuator from the reference potential to a side that reduces the pressure in the pressure chamber. A potential drop waveform falling to the auxiliary negative pressure potential,
A negative-pressure potential maintaining waveform for maintaining the auxiliary negative-pressure potential; and a potential rising waveform rising from the auxiliary negative-pressure potential to the reference potential. The interval between the end of the rising of the potential of the rising waveform and the start of the falling of the potential of the potential drop waveform of the auxiliary pulse signal is 0.5 times the natural period of the actuator.
It may be set to 〜1.

As a result, a reference drive signal having a potential maintenance waveform of two potentials (a reference potential and a negative pressure potential) is used, and an ink ejection action and a meniscus vibration suppression action based on a so-called pull-push operation of the actuator are utilized. As a result, stable ink ejection can be realized.

The ink discharge pulse signal of the reference drive signal is formed by a negative pressure potential for driving the actuator on the side for reducing the pressure in the pressure chamber and a positive pressure potential for driving the actuator on the side for increasing the pressure in the pressure chamber. From a potential drop waveform that falls from the reference potential to the negative potential, a negative potential maintenance waveform that maintains the negative potential, and a potential rising waveform that rises from the negative potential to the positive potential. An initial pulse signal, a potential drop waveform falling from each predetermined positive potential to each predetermined negative potential, a negative potential maintaining waveform for maintaining each negative potential, and each negative potential. And one or more subsequent pulse signals having a potential rising waveform rising to each predetermined positive pressure potential, and the auxiliary pulse signal reduces the pressure of the actuator in the pressure chamber from the reference potential. Potential lowering waveform for driving to the auxiliary negative pressure potential for driving to the negative side, a negative pressure potential maintaining waveform for maintaining the auxiliary negative pressure potential, and a potential rising waveform rising from the auxiliary negative pressure potential to the reference potential The interval from the end of the potential rise of the potential rise waveform of the last subsequent pulse signal of the reference drive signal to the start of the potential fall of the potential fall waveform of the auxiliary pulse signal is 0. 3 of the natural period of the actuator. It may be set to 5 to 1 times.

With this configuration, the reference driving signal having the potential maintaining waveforms of the three potentials (reference potential, negative pressure potential, and positive pressure potential) is used, and the ink ejection action and the meniscus vibration based on the so-called pull-push operation of the actuator are used. By utilizing the suppression effect, stable ink ejection can be realized.

The ink discharge pulse signal of the reference drive signal is formed by a negative pressure potential for driving the actuator on the side for depressurizing the pressure chamber and a positive pressure potential for driving the actuator on the side for pressurizing the pressure chamber. From a potential drop waveform that falls from the reference potential to the negative potential, a negative potential maintenance waveform that maintains the negative potential, and a potential rising waveform that rises from the negative potential to the positive potential. An initial pulse signal, a potential drop waveform falling from each predetermined positive potential to each predetermined negative potential, a negative potential maintaining waveform for maintaining each negative potential, and each negative potential. And one or more subsequent pulse signals comprising a potential rising waveform that rises to each predetermined positive pressure potential, and the auxiliary pulse signal pressurizes the actuator in the pressure chamber from the reference potential. A potential rising waveform rising to an auxiliary pressurizing potential for driving to the side, a positive pressure potential maintaining waveform for maintaining the auxiliary positive pressure potential, and a potential drop waveform falling from the auxiliary positive pressure potential to the reference potential The interval from the end of the potential rise of the potential rise waveform of the last subsequent pulse signal of the reference drive signal to the start of the potential rise of the potential rise waveform of the auxiliary pulse signal is 1 to 1 times the natural period of the actuator. It may be set to 1.5 times.

[0029] Thus, the ink discharge action based on the so-called pull-push operation of the actuator using the reference drive signal having the potential maintaining waveforms of the three potentials (the reference potential, the negative pressure potential, and the positive pressure potential) is achieved. Utilizing the meniscus vibration suppressing action based on the push-pull operation, stable ink ejection can be realized.

By the way, as the interval between the pulse signals for ink ejection supplied to the actuator is closer to the natural period of the actuator, the ink ejection speed increases. Therefore,
The reference drive signal may be formed so that the interval between the N ink ejection pulse signals gradually approaches the natural period of the actuator and gradually increases.

Thus, the ink droplets ejected later have a higher ejection speed than the ink droplets ejected earlier, so that a preferable specific configuration of the reference drive signal can be obtained.

On the other hand, the greater the pulse height (potential difference) of the ink discharge pulse signal supplied to the actuator, the higher the ink discharge speed. Therefore, the reference drive signal may be formed so that the potential difference in the N ink pulse signals gradually increases.

Thus, the ink droplets ejected later have a higher ejection speed than the ink droplets ejected earlier, so that a preferable specific configuration of the reference drive signal can be obtained.

Another ink jet head according to the present invention
Is a plurality of pressure chambers for accommodating ink and
Head body formed with a plurality of nozzles communicating with each other
And a piezoelectric element, and the piezoelectric effect of the piezoelectric element
A plurality of actuators that apply pressure to the ink in each pressure chamber
Eta and ejecting ink droplets from the nozzles
Ink ejection pulse signal for driving the actuator
N (N is a natural number of 2 or more) in one printing cycle
A drive signal generation unit for generating a reference drive signal;
P (P is a natural number less than or equal to N) included in the quasi-drive signal
Pulse signal for ink discharge is selected for the actuator
Inkjet head equipped with a
A pulse signal for ink ejection of the reference drive signal.
No., ink droplets ejected later are ejected first
It is formed so that the ejection speed is faster than that of ink droplets.
The signal selection unit is configured to output N-P + 1 of the reference drive signals.
The second and subsequent ink ejection pulse signals are supplied.
And P ink droplets are combined with each other within one printing cycle.
And eject it to form one ink dot
It is.

Another ink jet head according to the present invention
Is a plurality of pressure chambers for accommodating ink and
Head body formed with a plurality of nozzles communicating with each other
And a piezoelectric element, and the piezoelectric effect of the piezoelectric element
A plurality of actuators that apply pressure to the ink in each pressure chamber
Eta and ejecting ink droplets from the nozzles
Ink ejection pulse signal for driving the actuator
N (N is a natural number of 2 or more) in one printing cycle
A drive signal generator for generating a reference drive signal I, before Kimoto
P (P is a natural number less than or equal to N) included in the quasi-drive signal
Pulse signal for ink discharge is selected for the actuator
Inkjet head equipped with a
A pulse signal for ink ejection of the reference drive signal.
No., ink droplets ejected later are ejected first
It is formed so that the ejection speed is faster than that of ink droplets.
The signal selection unit determines that the number of ink ejections in one printing cycle is one.
In this case, the Nth ink ejection of the reference drive signal
It is configured to supply an outgoing pulse signal.
is there.

Another ink jet head according to the present invention
Is a plurality of pressure chambers for accommodating ink and
Head body formed with a plurality of nozzles communicating with each other
And a piezoelectric element, and the piezoelectric effect of the piezoelectric element
A plurality of actuators that apply pressure to the ink in each pressure chamber
Eta and ejecting ink droplets from the nozzles
Ink ejection pulse signal for driving the actuator
N (N is a natural number of 2 or more) in one printing cycle
A drive signal generation unit for generating a reference drive signal;
P (P is a natural number less than or equal to N) included in the quasi-drive signal
Pulse signal for ink discharge is selected for the actuator
Inkjet head equipped with a
A pulse signal for ink ejection of the reference drive signal.
No., ink droplets ejected later are ejected first
It is formed so that the ejection speed is faster than that of ink droplets.
The signal selection unit is configured to output at least the first and second signals within one printing cycle.
And when the third ink droplet is ejected, the reference drive
N-2, N-1 and N-th of the
It is configured to supply a pulse signal for ink ejection.
Things.

The ink jet head according to the present invention has
And a plurality of pressure chambers accommodating the
A head body with a plurality of nozzles
Each of the pressures is generated by a piezoelectric effect of the piezoelectric element.
Multiple actuators that apply pressure to ink in a room
The nozzle so that ink droplets are ejected from the nozzle.
Predetermined pulse signal for ink ejection to drive actuator
N (N is a natural number of 2 or more) included in one printing cycle
A driving signal generation unit for generating a quasi-drive signal, the criteria drive
P (P is a natural number less than or equal to N) ink ejection included in the signal
An output pulse signal is selectively supplied to the actuator.
An ink jet head having a signal selector for supplying
Thus, the ink ejection pulse signal of the reference drive signal is:
Ink ejected later is the ink ejected earlier
The signal is formed so that the ejection speed is faster than that of the droplet.
The selection unit is an ink ejection pulse on the rear side of the reference drive signal.
And select and supply the number of signals corresponding to the number of ink ejections
It is configured as follows.

An ink jet recording apparatus according to the present invention includes the ink jet head, and relative moving means for relatively moving the ink jet head and a recording medium when the ink jet head discharges ink. .

Thus, an ink jet recording apparatus having excellent ink ejection performance can be obtained.

[0040]

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

<First Embodiment> FIG. 1 shows a schematic configuration of an ink jet recording apparatus according to a first embodiment. The ink jet recording apparatus includes an ink jet head 1 supported and fixed on a carriage 16.
It has. The carriage 16 is provided with a carriage motor 28 (see FIG. 6), not shown in FIG.
The carriage motor 28 guides the inkjet head 1 and the carriage 16 on a carriage shaft 17 extending in the main scanning direction (X direction shown in FIGS. 1 and 2), and reciprocates in that direction. The carriage 16, the carriage shaft 17, and the carriage motor 28 constitute a relative moving unit that relatively moves the inkjet head 1 and the recording paper 41.

The recording paper 41 is sandwiched between two transport rollers 42 which are driven to rotate by a transport motor 26 (not shown in FIG. 1) (see FIG. 6).
Further, the sheet is conveyed by the respective conveying rollers 42 in a sub-scanning direction (Y direction shown in FIGS. 1 and 2) perpendicular to the main scanning direction.

As shown in FIGS. 2 to 5, the ink-jet head 1 includes a head body 40 having a plurality of pressure chambers 4 for accommodating ink and a plurality of nozzles 2 communicating with the respective pressure chambers 4. It has a plurality of actuators 10 that apply pressure to the ink in each pressure chamber 4 to eject ink droplets from each nozzle 2. The actuator 10 uses a so-called flexural vibration type piezoelectric element 13 as described later, and ejects ink droplets from the nozzle 2 by a pressure change in the pressure chamber 4 due to the contraction and expansion of the pressure chamber 4. The pressure chamber 4 is filled with ink.

As shown in FIG. 2, the pressure chambers 4 are formed in a long groove shape inside the ink jet head 1 so as to extend in the main scanning direction X, and are arranged at predetermined intervals in the sub scanning direction. ing. At one end of the pressure chamber 4 (the right end in FIG. 2), the nozzles 2 are provided on the lower surface of the ink jet head 1 so as to open at predetermined intervals in the sub-scanning direction Y. One end of an ink supply path 5 is connected to the other end (the left end in FIG. 2) of the pressure chamber 4, and the other end of each ink supply path 5 is
Ink supply chamber 3 provided to extend in sub scanning direction Y
It is connected to the.

As shown in FIG. 3, the ink jet head 1 has a nozzle plate 6 on which the nozzles 2 are formed.
, A partition wall 7 for partitioning the pressure chamber 4 and the ink supply path 5, and an actuator 10 are sequentially laminated. The nozzle plate 6 is made of a 20 μm thick polyimide plate, and the partition wall 7 is made of a 280 μm thick stainless steel laminate plate.

As shown in exaggerated manner in FIGS. 4 and 5, the actuator 10 has a diaphragm 11
And a thin-film piezoelectric element 13 for vibrating the diaphragm 11 and an individual electrode 14 are sequentially laminated. The vibration plate 11 is made of a chrome plate having a thickness of 2 μm, and also has a function as a common electrode for applying a voltage to each piezoelectric element 13 together with the individual electrodes 14. The piezoelectric element 13 is
PZ having a thickness of 3 μm provided corresponding to the pressure chamber 4
It is an ultra-thin T (lead zirconate titanate). The individual electrode 14 is made of a platinum plate having a thickness of 0.1 μm, and the entire thickness of the actuator 10 is about 5 μm. Note that an insulating plate 15 made of polyimide is provided between the piezoelectric elements 13 (individual electrodes 14) adjacent to each other.

Next, referring to the block diagram of FIG.
The control circuit 20 of the ink jet recording apparatus will be described.
The control circuit 20 includes a main control unit 21 composed of a CPU, and a ROM 22 storing routines for various data processing.
A RAM 23 for storing various data; driver circuits 25 and 27 for driving and controlling a transport motor 26 and a carriage motor 28; and a motor control circuit 2
4, a data receiving circuit 29 for receiving print data, a drive signal generating circuit 30, and a plurality of selecting circuits 31, 31,.
And The actuator 10 is connected to each selection circuit 31. The drive signal generation circuit 30 generates a reference drive signal having N (N is a natural number of 2 or more) ink ejection pulse signals and an auxiliary pulse signal for suppressing ink meniscus vibration during one printing cycle. I do.
The selection circuit 31 is a circuit for selectively inputting one or more pulse signals included in the reference drive signal to the actuator 10 when the inkjet head 1 is moving in the main scanning direction X together with the carriage 16. . Specifically, the selection circuit 31 is configured by a switching circuit that turns ON / OFF the signal supply from the drive signal generation circuit 30 to the actuator 10, and supplies the N actuators included in the reference drive signal to the actuator 10. The pulse signals of (N-P + 1) th and subsequent pulses among the ink ejection pulse signals are supplied.

Next, the operation of the ink jet recording apparatus will be described. First, when the data receiving circuit 29 receives image data, the main control unit 21 controls the transport motor 26 and the carriage motor 28 via the motor control circuit 24 and the driver circuits 25 and 27 based on the processing routine stored in the ROM 22. Each of them is controlled, and the drive signal generation circuit 30 generates a reference drive signal. Further, the main control unit 21
Outputs information on the number of ink droplets to be ejected in one printing cycle to each selection circuit 31 based on the image data. Then, based on the information, the selection circuit 31 selects P (P is a natural number equal to or less than N) pulse signals from the N pulse signals included in the reference drive signal,
It is supplied to the actuator 10. The selection circuit 31
Also supplies an auxiliary pulse signal from the drive signal generation circuit 30. Thereby, the nozzle 2 of the inkjet head 1
Thus, one or two or more ink droplets are ejected within one printing cycle.

Next, as an example, referring to FIGS. 7 to 9, the operation when one ink droplet is ejected from the nozzle 2 during one printing cycle and the operation when two ink droplets are ejected are described. Will be described.

First, the drive signal generated by the drive signal generation circuit 30 will be described with reference to FIG. 7A or FIG. The drive signal generation circuit 30 generates a reference drive signal including five ink ejection pulse signals P1 to P5 and one auxiliary pulse signal S1 within one printing cycle. Each of the pulse signals P1 to P5 has a reference potential (20
V), the actuator 10 is moved to the side for reducing the pressure in the pressure chamber 4.
, A negative-voltage potential waveform that drops to a negative-voltage potential (0 V) for driving the voltage, a negative-voltage potential maintaining waveform that maintains the negative-voltage potential, and a potential-rising waveform that increases from the negative-voltage potential to the reference potential. . The auxiliary pulse signal S1 has a reference potential (20
V) from a potential drop waveform falling from the auxiliary negative pressure potential (15V) to an auxiliary negative pressure potential (15V), an auxiliary negative pressure potential maintaining waveform maintaining the auxiliary negative pressure potential, and a potential rising waveform rising from the auxiliary negative pressure potential to the reference potential. It is configured. That is, the pulse signals P1 to P5 and S1 are signals that cause the actuator 10 to perform a push-pull operation (a so-called pull-push operation). In this example, the pulse signals P1 to P5, S
1 is a square wave, but these signal waveforms may be trapezoidal waves.

The pulse signals P1 to P5 of the reference drive signal are
The time interval between pulses gradually approaches the natural period of the actuator 10 and gradually increases so that the ink droplet ejected later has a higher ejection speed than the ink droplet ejected earlier. Is formed. In particular,
The intervals between the pulse signals P1 to P5 are 7.5 μs and 9 μs, respectively.
s, 9.5 μs, 10 μs, and 12 μs. Here, the natural period of the actuator 10 is the natural period of the entire vibration system including the influence of the ink in the pressure chamber 4, and is 12 μs in this example. Such a natural period is represented by, for example, the reciprocal of the Helmholtz natural vibration frequency f described in US Pat. No. 4,697,193.

Since the time interval between the pulse signals is set as described above, for example, as shown in FIG.
When two ink droplets Q1, Q2, and Q3 are sequentially ejected, the ejection speeds v1 to v3 of the ink droplets Q1 to Q3 are v1
<V2 <v3. The second ink droplet Q2 catches up with the first ink droplet Q1 before landing on the recording paper, and the first ink droplet Q1 and the second ink droplet Q2 are united to form the ink droplet Q2.
It becomes 12. Further, the third ink droplet Q3 is the ink droplet Q1.
2, the third ink droplet Q3 and the ink droplet Q12 are united to form an ink droplet Q123. in this way,
In the present embodiment, a plurality of ink droplets sequentially ejected are united before landing on a recording sheet to form one ink dot and form one ink dot on the recording sheet.

The interval between the fifth pulse signal P5, which is the last pulse signal (Nth pulse signal) of the reference drive signal, and the auxiliary pulse signal S1 is 0.5 to 1.5 times the natural period of the actuator 10. It is set to double. The interval is particularly preferably 0.5 to 1 times the natural period of the actuator 10, and in this example, it is set to 10 μs (about 0.83 times the natural period). The auxiliary negative pressure potential of the auxiliary pulse signal S1 is preferably 0.1 to 0.3 times the negative pressure potential of the pulse signals P1 to P5 of the reference drive signal.
It is set to 0.25 times.

Next, the operation of the selection circuit 31 will be described. When the number of ink ejections is one, as shown in FIG. 7B, the selection circuit 31 determines whether the potential of the reference drive signal is a reference potential between the fourth pulse signal P4 and the fifth pulse signal P5. Then, the state is switched from the OFF state to the ON state. And
When the auxiliary pulse signal S1 ends and the potential is at the reference potential, the state is switched from the ON state to the OFF state. By such ON / OFF operation of the selection circuit 31, FIG.
As shown in (5), the fifth pulse signal P5 and the auxiliary pulse signal S1 are supplied to the actuator 10.

On the other hand, when the number of ink ejections is 2, FIG.
As shown in (b), when the potential of the reference drive signal is the reference potential between the third pulse signal P3 and the fourth pulse signal P4, the selection circuit 31 switches from the OFF state to the ON state. Then, as in the case where the number of ink ejections is 1, the state is switched from the ON state to the OFF state after the auxiliary pulse signal S1. By the ON / OFF operation of the selection circuit 31, the actuator 10 is supplied with the fourth pulse signal P4, the fifth pulse signal P5, and the auxiliary pulse signal S1, as shown in FIG. 8C. Become.

As described above, according to the present embodiment, while the drive signal generation circuit 30 generates only one type of reference drive signal, a part or all of the reference drive signal is generated by the ON / OFF operation of the selection circuit 31. And the number of pulse signals corresponding to the number of ink ejections is supplied to the actuator 10, so that the drive signal generation circuit 30 can be simplified, and the control circuit 20 can be configured simply and inexpensively. Can be.

The pulse signal of the reference drive signal is formed such that the ink droplet ejected later has a higher ejection speed than the ink droplet ejected earlier. The number of pulse signals is selected according to the number of ink ejections, so that a plurality of ink droplets can be united before landing, and even if the number of ink ejections changes, the flying speed of the ink droplets (ink ejection When the number is one, the ejection speed of the ink droplet can be made substantially constant, and when the number of ink ejections is two or more, the flying speed of the ink droplet after uniting can be made substantially constant. Accordingly, high-speed printing becomes possible and the printing quality is improved.

Since the potential of the sustain waveform of the reference drive signal is only the two potentials of the reference potential and the negative voltage potential, the actuator is only switched from the OFF state to the ON state while the potential is at the reference potential. 10 can be supplied with a good pulse signal. In other words, since the reference potential maintaining waveform for a certain time is provided between the pulse signals, even if the switching timing of the selection circuit 31 is slightly shifted, as long as the selection circuit 31 switches between the reference potential maintaining waveforms. Thus, a good pulse signal is supplied to the actuator 10. Therefore, the drive signal is stably supplied to the actuator 10, so that the ink ejection performance is improved.

Second Embodiment A second embodiment is different from the first embodiment in that the reference drive signal and the auxiliary pulse signal generated by the drive signal generation circuit 30 and the switching timing of the selection circuit 31 are changed. It is.

As shown in FIG. 10, the reference drive signal of the second embodiment includes an initial pulse signal R1 and the initial pulse signal R1.
1 and four subsequent pulse signals R2 to R5. The initial pulse signal R1 has a potential drop waveform falling from the reference potential (10V) to the negative pressure potential (0V), a negative voltage potential maintaining waveform for maintaining the negative voltage potential, and a negative voltage potential to the positive voltage potential (20V). And a potential rising waveform rising up to. Each of the subsequent pulse signals R2 to R5 has a potential drop waveform falling from a positive potential to a negative potential, a negative potential maintaining waveform for maintaining a negative potential, and a potential rising from a negative potential to a positive potential. And a rising waveform. The auxiliary pulse signal T1 has a potential drop waveform falling from the reference potential to the auxiliary negative pressure potential (5 V), an auxiliary negative pressure potential maintaining waveform for maintaining the auxiliary negative pressure potential, and rising from the auxiliary negative pressure potential to the reference potential. And a rising potential waveform.

As in the first embodiment, the selection circuit 31 is configured to select the number of pulse signals on the rear side of the reference drive signal according to the number of ink ejections. However, unlike the first embodiment, the selection circuit 31 of the second embodiment switches from the OFF state to the ON state after a lapse of a predetermined time from the start of maintaining the negative voltage potential maintenance waveform of the pulse signal. That is, the selection circuit 31 is configured to switch with a predetermined time delay from the potential drop of the pulse signal.

In the control circuit for supplying the reference drive signal at the same time as the end of the potential drop of the pulse signal, there is no problem if the switching timing is delayed, but if the switching timing is too early, the driving while the potential is falling is performed. A signal will be supplied and the operation of the actuator will be unstable.
However, according to the present embodiment, the switching timing of the selection circuit 31 is set after a lapse of a predetermined time since the potential drops to the negative voltage potential. Reference numeral 31 is always switched while the potential is at the negative pressure potential. Therefore, the operation of the actuator is stabilized. It should be noted that there is a time difference between when the potential becomes the negative pressure potential and when the selection circuit 31 switches, so that the pulse signal supplied first to the actuator 10 is more pulsed than the pulse signal supplied thereafter. It becomes a signal with a small width. However, since the ejection speed of ink droplets ejected later is faster than that of ink droplets ejected first, the flying behavior of ink droplets after coalescence is mainly dominated by the flying behavior of ink droplets ejected later. Is done. Therefore, in the present embodiment, there is no practical problem in ejecting ink, and good ink ejection performance can be exhibited even though the switching timing of the selection circuit 31 is delayed.

Third Embodiment As shown in FIGS. 11 and 12, the third embodiment also differs from the first embodiment in that the signal generated by the drive signal generation circuit 30 and the switching timing of the selection circuit 31 are changed. In addition.

The reference drive signal according to the third embodiment has an initial pulse signal U1 and four subsequent pulse signals U2 to U5 following the initial pulse signal U1. Initial pulse signal U
1 is a potential drop waveform that falls from the reference potential (20 V) to the negative voltage potential (0 V), a negative voltage potential maintaining waveform that maintains the negative voltage potential, and a predetermined positive voltage potential (15 V) from the negative voltage potential. And a potential rising waveform that rises to the maximum. The subsequent pulse signals U2 to U5 respectively have positive potentials (1
5V, 17V, 22V, 26V) to negative voltage potential (0V)
, A negative-voltage potential maintaining waveform for maintaining a negative-voltage potential, and a positive-voltage potential (17
V, 22 V, 26 V, 26 V). The subsequent pulse signals U2 to U5 are formed such that the potential difference (pulse height) gradually increases so that the ejection speed of the ink droplet ejected later is faster than the ejection speed of the ink droplet ejected earlier. I have.
Specifically, the potential difference of the initial pulse signal U1 is set to 20 V in order to improve the ejection performance of the first ink droplet, and the potential differences of the remaining subsequent pulse signals U2 to U5 are set to 15 V, respectively.
It is set to 17V, 22V and 26V.

After the potential rising waveform of the last subsequent pulse signal U5, the potential changes from the positive potential (26 V) to the reference potential (20 V).
V), and an auxiliary potential maintaining waveform for maintaining the reference potential thereafter. In the present embodiment, an auxiliary pulse signal for suppressing meniscus vibration of ink is formed by the auxiliary potential drop waveform and the auxiliary potential maintaining waveform. Note that the interval between the end of the potential rise of the potential rise waveform of the subsequent pulse signal U5 and the start of the potential fall of the auxiliary potential fall waveform of the auxiliary pulse signal is set to 0.5 to 1 times the natural period of the actuator 10. Is preferred.

As shown in FIGS. 11 (b) and 11 (c), in this embodiment, when the number of ejected ink droplets is 1, the selection circuit 31 selects the initial pulse signal U1. That is,
The selection circuit 31 is turned on at the same time as the start of the printing cycle, and is turned off during or after the potential rise waveform of the initial pulse signal U1.

On the other hand, when the number of ejected ink droplets is two or more, the selection circuit 31 selects a pulse signal on the rear side of the reference drive signal according to the number of ejected ink droplets. As shown in FIGS. 12B and 12C, when the ejection number is 2, the selection circuit 31 switches from the OFF state to the ON state at the same time as the end of the potential drop of the subsequent pulse signal U4 or after a lapse of a predetermined time. , Two pulse signals U4 and U5 for the actuator 10.
Supply.

As described above, in this embodiment, when one ink droplet is ejected during one printing cycle, the initial pulse signal U1 is supplied, and two or more ink drops are ejected during one printing cycle. In this case, the pulse signal on the rear side of the reference drive signal is supplied. Therefore, when the number of ejected ink droplets is two or more, the above-described various effects can be obtained. On the other hand, when the number of ejected ink droplets is one, the accuracy of ejection timing and ejection stability can be further improved.

<Other Embodiments> The ink ejection pulse signal of the reference drive signal is not limited to a pulse signal that causes the actuator to perform a pull-push operation, but a pulse signal that causes a so-called push-pull operation to be performed. It may be a signal.

The auxiliary pulse signal is not limited to the auxiliary pulse signals of the first to third embodiments, but may be composed of other pulse signals. For example, in order to cause the actuator 10 to perform a so-called push-pull operation, a potential rising waveform that rises from a reference potential to a positive potential, a positive pressure potential maintaining waveform that maintains the positive potential, and a positive potential potential that rises from the positive potential to the reference potential. And a potential drop waveform falling down to the potential. In this case, the interval from the end of the potential rise of the potential rise waveform of the last pulse signal of the reference drive signal to the start of the potential rise of the potential rise waveform of the auxiliary pulse signal is 1 to 1.5 times the natural period of the actuator 10. Is preferably set to.

[0071]

As described above, according to one aspect of the present invention, when ejecting P ink droplets during one printing cycle, the drive signal generating section generates a reference drive signal including N pulse signals. Since the pulse signals of (N-P + 1) th and subsequent pulses of the reference drive signal are supplied to the actuator, a good ink dot can be formed on the recording medium by using a plurality of ink droplets.

According to another aspect of the present invention, when P is 1, the first pulse signal of the reference drive signal is supplied, and when P is 2 or more, N-pulse of the reference drive signal is supplied.
Since the (P + 1) th pulse signal and the auxiliary pulse signal are supplied, the ejection performance when ejecting one ink droplet can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ink jet recording apparatus.

FIG. 2 is a partial plan view of the inkjet head.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a partial sectional view near an actuator.

FIG. 5 is a sectional view taken along line BB of FIG. 2;

FIG. 6 is a block diagram of a control circuit.

FIGS. 7A and 7B are timing charts when the number of ink ejections is 1 in the first embodiment, where FIG. 7A shows a drive signal generated by a drive signal generation circuit, and FIG.
N / OFF signal and (c) a drive signal supplied to the actuator.

FIG. 8 is a diagram corresponding to FIG. 7 when the number of ink ejections is two in the first embodiment.

FIG. 9 is a schematic diagram illustrating a flying behavior of an ink droplet.

FIG. 10 is a diagram corresponding to FIG. 7 of the second embodiment.

FIG. 11 is a diagram corresponding to FIG. 7 in a case where the number of ink ejections is 1 in the third embodiment.

FIG. 12 is a diagram corresponding to FIG. 7 when the number of ink ejections is two in the third embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet head 2 Nozzle 4 Pressure chamber 10 Actuator 11 Vibration plate 13 Piezoelectric element 14 Individual electrode 16 Carriage (relative moving means) 30 Drive signal generation circuit (Drive signal generation unit) 31 Selection circuit (Signal selection unit) 40 Head main body 41 Recording Paper (recording medium)

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/055

Claims (17)

(57) [Claims] A head body in which a plurality of pressure chambers for accommodating ink and a plurality of nozzles respectively communicating with the pressure chambers are formed; and a piezoelectric element. A plurality of actuators for applying pressure to the ink in the room, and N pulse signals for ink ejection for driving the actuator so as to eject ink droplets from the nozzles within one predetermined printing cycle (N is a natural number of 2 or more) A) a drive signal generation unit that generates a reference drive signal including the signal; and a signal selection unit that selectively supplies P (P is a natural number equal to or less than N) ink ejection pulse signals included in the reference drive signal to the actuator. And an ink ejection pulse signal of the reference drive signal, wherein the ink droplet ejected later is the ink ejected earlier. Is formed so as to discharge speed is faster than the signal selection unit, N-P of said reference driving signal +
An ink jet head configured to supply first and subsequent ink ejection pulse signals. 2. The ink jet head according to claim 1, wherein the drive signal generation unit generates an auxiliary pulse signal for suppressing meniscus vibration of ink in the head body after generating the reference drive signal. The signal selection unit is configured to control the actuator by the N
An inkjet head configured to supply the (P + 1) th and subsequent ink ejection pulse signals and the auxiliary pulse signal; 3. A head body in which a plurality of pressure chambers for accommodating ink and a plurality of nozzles respectively communicating with the respective pressure chambers are formed, and a piezoelectric element is provided. A plurality of actuators for applying pressure to the ink in the room, and N pulse signals for ink ejection for driving the actuator so as to eject ink droplets from the nozzles within one predetermined printing cycle (N is a natural number of 2 or more) A) a drive signal generation unit that generates a reference drive signal including the signal; and a signal selection unit that selectively supplies P (P is a natural number equal to or less than N) ink ejection pulse signals included in the reference drive signal to the actuator. And an ink ejection pulse signal of the reference drive signal, wherein the ink droplet ejected later is the ink ejected earlier. The drive signal generation unit generates an auxiliary pulse signal for suppressing meniscus vibration of ink in the head body after generating the reference drive signal, and the signal selection. The unit supplies the first pulse signal for ink ejection of the reference drive signal when P is 1 to the actuator, and supplies N-P + 1 of the reference drive signal when P is 2 or more. An ink jet head configured to supply the ink discharge pulse signal and the auxiliary pulse signal for the second and subsequent inks. 4. The ink-jet head according to claim 2, wherein an interval between an N-th ink ejection pulse signal of the reference drive signal and the auxiliary pulse signal is the same. An ink jet head set to 0.5 to 1.5 times the natural period of the actuator. 5. The ink jet head according to claim 2, wherein a potential difference of the auxiliary pulse signal is 0.1 to less than a minimum potential difference of an ink ejection pulse signal of the reference drive signal. Inkjet head set to 0.3 times. 6. The ink jet head according to claim 1, wherein each of the ink ejection pulse signals of the reference drive signal includes a first potential as a reference potential and the first potential. A rectangular or trapezoidal pulse signal having a different second potential, wherein the signal selecting unit stops supplying the reference drive signal to the actuator and stops supplying the reference drive signal to the actuator. A switching circuit that selectively switches to any one of an OFF state, wherein the switching circuit is configured to switch from the OFF state to the ON state when the potential of the reference drive signal is the first potential. Inkjet head. 7. The ink jet head according to claim 1, wherein the ink discharge pulse signal of the reference drive signal is used to drive the actuator to reduce the pressure in the pressure chamber. And a potential drop waveform falling from a reference potential between the negative pressure potential and a positive pressure potential for driving the actuator to the side that pressurizes the pressure chamber from the reference potential to the negative pressure potential, and maintaining the negative pressure potential An initial pulse signal composed of a negative voltage potential maintaining waveform, a potential rising waveform rising from the negative voltage potential to the positive voltage potential, and falling from each predetermined positive voltage potential to each predetermined negative voltage potential One or more subsequent pulses comprising a potential drop waveform, a negative pressure potential maintaining waveform for maintaining each negative pressure potential, and a potential rising waveform rising from each negative pressure potential to each predetermined positive potential. Signal and The signal selection unit includes a switching circuit that selectively switches to one of an ON state in which the reference drive signal is supplied to the actuator and an OFF state in which supply of the reference drive signal to the actuator is stopped, The switching circuit elapses a predetermined time from the start of maintaining the negative-voltage potential maintaining waveform of the reference drive signal so that the supply of the reference drive signal starts after the potential of the reference drive signal becomes a negative-pressure potential. Later, from the OFF state to the ON state
An inkjet head that switches to a state. 8. The ink jet head according to claim 2, wherein each of the ink discharge pulse signals of the reference drive signal reduces the pressure of the actuator in the pressure chamber from a reference potential. A potential drop waveform that drops to a negative pressure potential that drives
A negative pressure potential maintaining waveform for maintaining the negative voltage potential, and a potential rising waveform rising from the negative pressure potential to the reference potential, wherein the auxiliary pulse signal causes the actuator to move the actuator from the reference potential through the pressure chamber. A potential drop waveform that drops to an auxiliary negative pressure potential that is driven to the side to be reduced, a negative pressure potential maintaining waveform that maintains the auxiliary negative pressure potential, and a potential rising waveform that rises from the auxiliary negative pressure potential to the reference potential The interval between the end of the potential rise of the potential rise waveform of the Nth ink ejection pulse signal of the reference drive signal and the start of the potential fall of the potential fall waveform of the auxiliary pulse signal is defined as An ink jet head set at 0.5 to 1 times the natural period. 9. The ink jet head according to claim 2, wherein the pulse signal for ink ejection of the reference drive signal is a negative signal for driving the actuator to a side that reduces the pressure in the pressure chamber. A potential drop waveform that falls from a reference potential between the pressure potential and a positive potential that drives the actuator to the side that pressurizes the pressure chamber, to the negative potential, and a negative potential maintenance that maintains the negative potential An initial pulse signal comprising a waveform, a potential rising waveform rising from the negative potential to the positive potential, and a potential drop waveform falling from each predetermined positive potential to each predetermined negative potential. And one or more subsequent pulse signals composed of a negative voltage potential maintaining waveform for maintaining each negative voltage potential and a potential rising waveform rising from each negative voltage potential to each predetermined positive voltage potential. The supplement The pulse signal has a potential drop waveform that falls from the reference potential to an auxiliary negative pressure potential for driving the actuator to a side that reduces the pressure in the pressure chamber, and a negative pressure potential maintaining waveform that maintains the auxiliary negative pressure potential. A potential rising waveform that rises from the auxiliary negative pressure potential to the reference potential, and a potential falling waveform of the auxiliary pulse signal from the end of potential rising of the potential rising waveform in the last subsequent pulse signal of the reference drive signal. An ink jet head wherein the interval until the start of the potential drop is set to 0.5 to 1 times the natural period of the actuator. 10. The ink jet head according to claim 2, wherein the ink discharge pulse signal of the reference drive signal is a negative signal for driving the actuator to a side that reduces the pressure in the pressure chamber. A potential drop waveform that falls from a reference potential between the pressure potential and a positive potential that drives the actuator to the side that pressurizes the pressure chamber, to the negative potential, and a negative potential maintenance that maintains the negative potential An initial pulse signal comprising a waveform, a potential rising waveform rising from the negative potential to the positive potential, and a potential drop waveform falling from each predetermined positive potential to each predetermined negative potential. And one or more subsequent pulse signals composed of a negative voltage potential maintaining waveform for maintaining each negative voltage potential and a potential rising waveform rising from each negative voltage potential to each predetermined positive voltage potential. The said The auxiliary pulse signal has a potential rising waveform that rises from the reference potential to an auxiliary pressurizing potential for driving the actuator to the side that pressurizes the pressure chamber, and a positive pressure potential maintaining waveform that maintains the auxiliary positive pressure potential. And a potential drop waveform that falls from the auxiliary positive voltage potential to the reference potential, and a potential rise waveform of the auxiliary pulse signal from the end of potential rise of the potential rise waveform in the last subsequent pulse signal of the reference drive signal. The interval until the start of the potential rise is set to 1 to 1.5 times the natural period of the actuator. 11. The ink-jet head according to claim 1, wherein the reference drive signal is such that an interval between N ink ejection pulse signals gradually increases in a natural period of the actuator. An inkjet head formed so as to approach and gradually become longer. 12. The ink-jet head according to claim 1, wherein the reference drive signal is such that the potential difference in the N ink ejection pulse signals gradually decreases. An inkjet head that is formed to be large. 13. A plurality of pressure chambers for accommodating ink, and
Multiple nozzles each communicating with the pressure chamber were formed
A head body, and a piezoelectric element, wherein each of the above-described elements is formed by a piezoelectric effect of the piezoelectric element.
Multiple actuators that apply pressure to the ink in the pressure chamber
And the activator so that ink droplets are ejected from the nozzle.
A pulse signal for ink ejection that drives the
A reference drive that contains N (N is a natural number of 2 or more) in the printing cycle
A drive signal generation unit for generating a motion signal; and P (P is a natural number equal to or less than N) included in the reference drive signal.
The pulse signal for ink ejection of
And a signal selection unit for selectively supplying the
An ink ejection pulse signal of the reference drive signal,
The ink droplet ejected is earlier than the ink droplet ejected earlier
And the signal selection unit is configured to increase the ejection speed.
To supply the first and subsequent ink ejection pulse signals
And P ink droplets are united with each other in one printing cycle.
Ink jets ejected to form
Head. 14. A plurality of pressure chambers for accommodating ink, and
Multiple nozzles each communicating with the pressure chamber were formed
A head body, and a piezoelectric element, wherein each of the piezoelectric elements
Multiple actuators that apply pressure to the ink in the pressure chamber
And the activator so that ink droplets are ejected from the nozzle.
A pulse signal for ink ejection that drives the
A reference drive that contains N (N is a natural number of 2 or more) in the printing cycle
A drive signal generation unit for generating a motion signal; and P (P is a natural number equal to or less than N) included in the reference drive signal.
The pulse signal for ink ejection of
And a signal selection unit for selectively supplying the
An ink ejection pulse signal of the reference drive signal,
The ink droplet ejected is earlier than the ink droplet ejected earlier
The signal selecting unit is configured to increase the number of ink ejections in one printing cycle.
In the case of the Nth ink of the reference drive signal
Ins are configured to supply the ink discharge pulse signals
Jet head. 15. A plurality of pressure chambers for accommodating ink, and
Multiple nozzles each communicating with the pressure chamber were formed
A head body, and a piezoelectric element, wherein each of the above-described elements is formed by a piezoelectric effect of the piezoelectric element.
Multiple actuators that apply pressure to the ink in the pressure chamber
And the activator so that ink droplets are ejected from the nozzle.
A pulse signal for ink ejection that drives the
A reference drive that contains N (N is a natural number of 2 or more) in the printing cycle
A drive signal generation unit for generating a motion signal; and P (P is a natural number equal to or less than N) included in the reference drive signal.
The pulse signal for ink ejection of
And a signal selection unit for selectively supplying the
An ink ejection pulse signal of the reference drive signal,
The ink droplet ejected is earlier than the ink droplet ejected earlier
The signal selector is also formed so as to increase the ejection speed, and the signal selection unit is configured to perform at least the first and second
When ejecting the second and third ink droplets, the above-described reference
N-2, N-1 and N-th of drive signals
Is configured to supply a pulse signal for ink ejection of
Inkjet head. 16. A plurality of pressure chambers for accommodating ink, and
Multiple nozzles each communicating with the pressure chamber were formed
A head body, and a piezoelectric element, wherein each of the above-described elements is formed by a piezoelectric effect of the piezoelectric element.
Multiple actuators that apply pressure to the ink in the pressure chamber
And the activator so that ink droplets are ejected from the nozzle.
A pulse signal for ink ejection that drives the
A reference drive that contains N (N is a natural number of 2 or more) in the printing cycle
A drive signal generation unit for generating a motion signal; and P (P is a natural number equal to or less than N) included in the reference drive signal.
The pulse signal for ink ejection of
And a signal selection unit for selectively supplying the
An ink ejection pulse signal of the reference drive signal,
The ink droplet ejected is earlier than the ink droplet ejected earlier
The signal selector is also formed so as to increase the ejection speed, and the signal selection unit is configured to eject the ink on the rear side of the reference drive signal.
Select the number of output pulse signals according to the number of ink ejections.
An inkjet head configured to supply. 17. Claim the inkjet head according to any one of 1-16, an ink jet type and a relative moving means for relatively moving the recording medium with the ink jet head when the ink ejection of the inkjet head Recording device.