JP2002337333A - Ink jet recorder and method for driving ink jet recording head for use therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent erroneous ejection of an ink drop when the oscillator voltage is recovered by a voltage recovering means. SOLUTION: A drive signal being fed to a piezoelectric oscillator includes expansion waveform elements P1, P2 and P3 for expanding a pressure generation chamber, a contraction waveform element P5 for contracting the pressure generation chamber expanded by the expansion waveform elements to eject an ink drop from a nozzle opening, and a damping waveform element P7 varying from the end voltage VL of the contraction waveform element P5 to a damping voltage VM in order to damp the residual oscillation of meniscus in the pressure generation chamber after ejecting an ink drop. Start voltage and end voltage of the drive signal are equal to each other and correspond to a waiting voltage VL being set as the voltage of the piezoelectric oscillator, when the drive signal is not fed and the damping voltage VM is set between the waiting voltage VL and the highest voltage of the drive signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for printing on a recording paper or the like by ejecting ink droplets from nozzle openings by vibration of a piezoelectric vibrator, and a method of driving an ink jet recording head used in the apparatus. is there.

[0002]

2. Description of the Related Art Generally, an ink jet recording apparatus is
It has a recording head provided with a large number of nozzle openings in the sub-scanning direction (recording paper feed direction), and moves the recording head in the main scanning direction (recording paper width direction) by a carriage mechanism to perform a predetermined paper feed. Thus, a desired print result is obtained. Then, based on the dot pattern data obtained by developing the print data input from the host computer, ink droplets are respectively ejected from the nozzle openings of the recording head at a predetermined timing, and these ink droplets are recorded on the recording paper. A dot is formed by landing and adhering to a print recording medium such as, and printing is performed.

In general, the recording head transmits the deformation of the piezoelectric vibrator to the diaphragm, contracts the pressure generating chamber to increase the internal pressure, and discharges ink droplets from the nozzle openings. The deformation of the piezoelectric vibrator is performed by changing a driving voltage input to the piezoelectric vibrator. Therefore, the ejection of the ink droplet is performed by expanding and contracting the pressure generating chamber.

Each piezoelectric vibrator used in the recording head of the ink jet recording apparatus is regarded as an ideal capacitor in design. That is, it is considered that the voltage (segment voltage) of the piezoelectric vibrator keeps maintaining the voltage at the time when the supply of the drive signal is stopped.
Based on this idea, the drive signal has its start and end voltages set to the same level.

However, it has been found that an actual piezoelectric vibrator has insulation resistance, and if left without supplying a drive signal, the vibrator voltage gradually drops due to natural discharge.
This drop in the transducer voltage occurs due to, for example, non-uniformity of the piezoelectric material in the piezoelectric layer. Also, when the electrodes are short-circuited due to foreign matter interposed between the electrodes of the piezoelectric vibrator, a drop in the vibrator voltage is caused.

Therefore, the piezoelectric vibrator which is in a standby state with no drive signal applied thereto is restored so that the vibrator voltage reduced by the discharge is restored to an intermediate voltage which is a standby voltage of the piezoelectric vibrator. Means for applying a voltage to the element (hereinafter referred to as “voltage recovery means”) have been proposed. For example, Japanese Patent No. 3097155 (JP-A-4-310748)
Japanese Patent Application No. 3-77718) discloses that a charge voltage for charging a piezoelectric element is applied to the piezoelectric element at a timing different from the printing timing of the piezoelectric element, thereby compensating for a decrease in charge due to discharge of the piezoelectric element. A piezoelectric element charging means is described.

[0007]

By the way, the amount of drop of the oscillator voltage increases as the time from the end of the supply of the previous drive signal to the start of the supply of the subsequent drive signal, that is, as the non-supply period of the drive signal becomes longer. Become. Further, as the film thickness of the piezoelectric vibrator becomes thinner (as the electric field intensity becomes higher), the drop of the vibrator voltage becomes remarkable. For this reason, in a piezoelectric vibrator having a small volume (thin film thickness) demanded recently, even if the non-supply period of the drive signal is extremely short, the vibrator voltage dropped by the discharge and the subsequent waveform element , The difference from the starting voltage increases.

Further, in recent years, there has been a tendency to set an intermediate voltage, which is a standby voltage, high in order to increase a difference in vibration control waveform applied to a piezoelectric vibrator after an ink droplet is ejected. Then, since the drop amount of the oscillator voltage increases as the oscillator voltage increases, the drop amount of the oscillator voltage eventually increases as the intermediate voltage is set higher.

As described above, in recent years, the drop amount of the oscillator voltage tends to increase. When the oscillator voltage is recovered by the voltage recovery means in a state where the oscillator voltage is greatly reduced, the ink is simultaneously discharged from the nozzle opening. There is a problem that the droplet is ejected by mistake.

In the above-described conventional ink jet recording apparatus, the driving signal for one printing cycle (one driving cycle) includes a driving waveform for medium dots and a driving waveform for minute dots. It was extremely difficult to do so. This is because the standby voltage suitable for the driving waveform for medium dots and the standby voltage suitable for the driving waveform for minute dots generally do not match. When the standby voltage of the drive waveform for the medium dot is adjusted to the standby voltage of the drive waveform for the minute dot, the height difference of the drive waveform for the medium dot becomes too large. There is a problem that air bubbles are easily taken in the inside. In this way, when air bubbles are taken into the nozzle opening, the pressure in the pressure generating chamber is not normally increased, and the ink droplets are not normally ejected, which causes an ejection failure.

In the above-described conventional ink jet recording apparatus, even if the viscosity of ink changes due to a change in the ambient temperature around the apparatus, the same drive signal can be used regardless of the change in the environment. Done. For this reason,
For example, if the viscosity of the ink decreases in a high temperature environment,
The meniscus is likely to be unstable, and air bubbles are easily taken into the nozzle opening as described above. Furthermore, when the use environment of the apparatus changes and the viscosity of the ink changes, the ejection characteristics also change, and there is a problem that it is difficult to obtain a constant print quality.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an ink jet recording apparatus capable of reliably preventing erroneous ejection of ink droplets when voltage of a vibrator is recovered by voltage recovery means. It is an object of the present invention to provide a method of driving an ink jet recording head used for the same.

It is another object of the present invention to provide an ink jet recording apparatus capable of ejecting ink droplets without taking air bubbles into a nozzle opening, and a method of driving an ink jet recording head used therefor.

It is another object of the present invention to provide an ink jet recording apparatus capable of preventing air bubbles from being taken into a nozzle opening even when environmental conditions around the apparatus change, and a method of driving an ink jet recording head used therefor. Aim.

[0015]

In order to solve the above-mentioned problems, the present invention provides a recording head having a piezoelectric vibrator for expanding and contracting a pressure generating chamber communicating with a nozzle opening, and a recording head comprising the piezoelectric vibrator. A drive signal generating means for generating a drive signal applied to the piezoelectric vibrator for driving, the drive signal includes an expansion waveform element whose voltage changes so as to expand the pressure generation chamber; and A contraction waveform element in which the voltage changes so as to cause the pressure generation chamber expanded by the expansion waveform element to contract to discharge ink droplets from the nozzle opening, and a residual vibration of the meniscus of the pressure generation chamber after ink droplet discharge. A damping waveform element whose voltage changes from a terminal voltage of the contraction waveform element to a damping voltage so as to expand the pressure generating chamber contracted by the contraction waveform element, Wherein the start voltage and the end voltage of the drive signal are equal and correspond to a standby voltage set as the voltage of the piezoelectric vibrator when the drive signal is not supplied, and the vibration damping voltage is the standby voltage And the highest voltage in the drive signal.

Preferably, the expansion corrugated element comprises:
A waveform element front part, a waveform element rear part located after the waveform element front part, and a waveform element connection part connecting an end of the waveform element front part and a start end of the waveform element rear part, wherein the waveform element The connection is located at an intermediate voltage between the standby voltage and the highest voltage, and the slope of the front of the waveform element is smaller than the slope of the rear of the waveform element.

[0017] Preferably, a voltage difference between the standby voltage and the intermediate voltage is reduced in accordance with an increase in environmental temperature.

Preferably, the duration of the front part of the waveform element is set longer than the natural oscillation period of the pressure generating chamber.

Preferably, the drive signal includes a return waveform element located after the vibration suppression waveform element and changing from the vibration suppression voltage to the standby voltage.

Preferably, the slope of the return waveform element is smaller than the slope of the contraction waveform element.

Preferably, the duration of the return waveform element is set longer than the natural oscillation period of the pressure generating chamber.

[0022] Preferably, the standby voltage is a minimum voltage in the drive signal.

Preferably, the duration of the rear part of the waveform element is set to be equal to or longer than the natural oscillation cycle of the piezoelectric vibrator and equal to or shorter than the natural oscillation cycle of the pressure generating chamber.

Preferably, the duration of the contraction waveform element is set to be equal to or longer than the natural vibration period of the piezoelectric vibrator.

Preferably, the duration of the vibration-damping waveform element is set to be equal to or longer than the natural vibration period of the piezoelectric vibrator.

Preferably, a contraction holding waveform element for maintaining a contracted state of the pressure generating chamber contracted by the contraction waveform element follows the contraction waveform element, and the contraction waveform element and the contraction holding waveform The total duration of the elements is set to be substantially equal to an integral multiple of the natural oscillation period of the pressure generating chamber.

Preferably, the total duration of the contraction waveform element and the contraction holding waveform element is set to be substantially equal to the natural oscillation period of the pressure generating chamber.

Preferably, the voltage difference of the contraction waveform element itself is reduced in accordance with an increase in environmental temperature.

[0029] Preferably, the voltage difference between the vibration suppression waveform elements themselves is increased in accordance with the rise in the environmental temperature.

[0030] Preferably, an expansion holding waveform element for maintaining an expansion state of the pressure generating chamber expanded by the expansion waveform element follows the expansion waveform element, and the expansion holding element expands in response to an increase in environmental temperature. Increase the duration of the holding waveform element.

In order to solve the above problems, the present invention provides a method of driving an ink jet recording head having a piezoelectric vibrator for expanding and contracting a pressure generating chamber communicating with a nozzle opening. Generating a drive signal to be applied to the piezoelectric vibrator for driving; anddriving the piezoelectric vibrator by applying the drive signal to the piezoelectric vibrator, wherein the drive signal comprises:
An expansion waveform element in which the voltage changes so as to expand the pressure generation chamber; and a contraction in which the voltage changes so as to discharge the ink droplet from the nozzle opening by contracting the pressure generation chamber expanded by the expansion waveform element. In order to suppress the residual vibration of the waveform element and the meniscus of the pressure generation chamber after ink droplet ejection, the vibration is controlled from the terminal voltage of the contraction waveform element so as to expand the pressure generation chamber contracted by the contraction waveform element. A damping waveform element whose voltage changes to a voltage, wherein the start voltage and the end voltage of the drive signal are equal and the standby voltage set as the voltage of the piezoelectric vibrator when the drive signal is not supplied. Correspondingly, the damping voltage is between the standby voltage and the highest voltage in the drive signal.

Preferably, the expansion waveform element is
A waveform element front part, a waveform element rear part located after the waveform element front part, and a waveform element connection part connecting an end of the waveform element front part and a start end of the waveform element rear part, wherein the waveform element The connection is located at an intermediate voltage between the standby voltage and the highest voltage, and the slope of the front of the waveform element is smaller than the slope of the rear of the waveform element.

Preferably, the voltage difference between the standby voltage and the intermediate voltage is reduced in accordance with an increase in the environmental temperature.

Preferably, the duration of the front part of the waveform element is set longer than the natural oscillation period of the pressure generating chamber.

Preferably, the drive signal includes a return waveform element located after the vibration suppression waveform element and changing from the vibration suppression voltage to the standby voltage.

Preferably, the slope of the return waveform element is smaller than the slope of the contraction waveform element.

[0037] Preferably, the duration of the return waveform element is set longer than the natural oscillation period of the pressure generating chamber.

Preferably, the standby voltage is a minimum voltage in the drive signal.

Preferably, the duration of the rear part of the waveform element is set to be equal to or longer than the natural oscillation cycle of the piezoelectric vibrator and equal to or shorter than the natural oscillation cycle of the pressure generating chamber.

Preferably, the duration of the contraction waveform element is set to be equal to or longer than the natural vibration period of the piezoelectric vibrator.

Preferably, the duration of the vibration-damping waveform element is set to be equal to or longer than the natural vibration period of the piezoelectric vibrator.

Preferably, a contraction holding waveform element for maintaining a contracted state of the pressure generating chamber contracted by the contraction waveform element follows the contraction waveform element, and the contraction waveform element and the contraction holding waveform The total duration of the elements is set to be substantially equal to an integral multiple of the natural oscillation period of the pressure generating chamber.

Preferably, the total duration of the contraction waveform element and the contraction holding waveform element is set to be substantially equal to the natural oscillation period of the pressure generating chamber.

Preferably, the voltage difference of the contraction waveform element itself is reduced in accordance with an increase in environmental temperature.

Preferably, the voltage difference between the damping waveform elements themselves is increased in accordance with an increase in environmental temperature.

Preferably, an expansion holding waveform element following the expansion waveform element for holding the expansion state of the pressure generating chamber expanded by the expansion waveform element follows the expansion waveform element. Increase the duration of the holding waveform element.

[0047]

FIG. 1 is a diagram showing a peripheral structure of an ink jet recording apparatus according to a first embodiment of the present invention. This device has an ink cartridge 101
And a carriage 102 having a recording head 10 attached to the lower surface.

The carriage 102 is connected to a stepping motor 104 via a timing belt 103, and is guided by a guide bar 105 to reciprocate in the paper width direction (main scanning direction) of the recording paper 106.
The recording head 10 is attached to the surface of the carriage 102 facing the recording paper 106 (the lower surface in this example). Then, ink is supplied from the ink cartridge 101 to the recording head 10 and the carriage 1
The image and the characters are printed on the recording paper 106 in a dot matrix by ejecting ink droplets on the upper surface of the recording paper 106 while moving 02.

In FIG. 1, reference numeral 107 denotes a cap which seals the nozzle opening of the recording head 10 during printing suspension or the like to prevent the nozzle opening from drying as much as possible, and reference numeral 108 denotes a paper feed roller for feeding the recording paper.

FIG. 2 is a functional block diagram of the ink jet recording apparatus according to the first embodiment of the present invention. This ink jet recording apparatus includes a printer controller 1 and a print engine 2. The printer controller 1 has an interface (hereinafter, referred to as “I / F”) 3 for receiving print data and the like from a host computer (not shown) and an R for storing various data.
AM4, a ROM 5 storing routines for various data processing, a control unit 6 including a CPU, an oscillation circuit 7, and a drive signal generation circuit (drive signal (Generating means) 8 and an I / F 9 for transmitting print data, drive signals, and the like developed into dot pattern data (bitmap data) to the print engine 2.

The I / F 3 receives, for example, any one of character code, graphic function, and image data or print data including a plurality of data from a host computer or the like. Also, this I / F3
Is a busy signal (BUS) to the host computer.
Y) and an acknowledgment signal (ACK) can be output.

The RAM 4 is used as a receiving buffer 4a, an intermediate buffer 4b, an output buffer 4c, a work memory (not shown), and the like. The print data from the host computer received by the I / F 3 is temporarily stored in the reception buffer 4a. The intermediate buffer 4b stores the intermediate code data converted into the intermediate code by the control unit 6. In the output buffer 4c,
The dot pattern data after the gradation data is decoded is developed. The ROM 5 stores various control routines executed by the control unit 6, font data, graphic functions, various procedures, and the like.

The control section 6 reads out the print data in the reception buffer 4a, converts it into an intermediate code, and stores the intermediate code data in the intermediate buffer 4b. Next, the control unit 6 analyzes the intermediate code data read from the intermediate buffer 4b, and develops the intermediate code data into dot pattern data with reference to font data and graphic functions in the ROM 5. The developed dot pattern data is stored in the output buffer 4c after necessary decoration processing is performed.

When dot pattern data corresponding to one line of the recording head 10 is obtained, the dot pattern data for one line is serially transmitted to the recording head 10 via the I / F 9. When one line of dot pattern data is output from the output buffer 4c, the contents of the intermediate buffer 4b are erased and the next intermediate code conversion is performed.

The print engine 2 includes a recording head 1
0, a paper feed mechanism 11, and a carriage mechanism 12. The paper feed mechanism 11 includes a paper feed motor, a paper feed roller, and the like, and sequentially feeds a print storage medium such as a recording paper to perform sub-scanning. The carriage mechanism 12 includes a carriage on which the recording head 10 is mounted, a carriage motor for moving the carriage via a timing belt or the like, and causes the recording head 10 to perform main scanning.

The recording head 10 has a large number (for example, 96) of nozzle openings in the sub-scanning direction, and discharges ink droplets from each nozzle opening at a predetermined timing. Print data expanded to dot pattern data
In synchronization with the clock signal (CK) from the oscillation circuit 7, I
/ F9 is serially transmitted to the shift register 13.
The serially transferred print data (SI) is temporarily
Latched by the latch circuit 14. The latched print data is boosted by the level shifter 15 as a voltage amplifier to a voltage that can drive the switch circuit 16, for example, a predetermined voltage value of about several tens of volts. The print data boosted to a predetermined voltage value is given to the switch circuit 16. A drive signal (COM) from the drive signal generation circuit 8 is applied to an input side of the switch circuit 16, and a piezoelectric vibrator 17 is connected to an output side of the switch circuit 16.

The print data controls the operation of the switch circuit 16. For example, while the print data applied to the switch circuit 16 is “1”, the drive signal is
The piezoelectric vibrator 17 expands and contracts according to the drive signal. On the other hand, while the print data applied to the switch circuit 16 is “0”, the supply of the drive signal to the piezoelectric vibrator 17 is cut off, and the piezoelectric vibrator 17 retains the previous electric charge and the previous displacement state is changed. Will be retained.

Here, when the drive signal is not applied to the piezoelectric vibrator 17, the voltage of the piezoelectric vibrator 17 gradually decreases due to the discharge as shown by the broken line in FIG. 4 described later. Therefore, in the present embodiment, the voltage recovery means 30 (FIG. 2) for recovering the voltage of the piezoelectric vibrator 17 reduced by the discharge to the standby voltage set as the voltage of the piezoelectric vibrator when the drive signal is not supplied. ) Is provided.

Next, the recording head 10 will be described in detail.

As the recording head 10, for example, a recording head 10 to which a piezoelectric vibrator 17 in a longitudinal vibration mode is attached is used. As shown in FIG. 3, the recording head 10 includes a base 21 made of a synthetic resin, and a flow path unit 22 attached to a front surface (left side in the figure) of the base 21. The flow path unit 22 includes a nozzle plate 25 having a nozzle opening 28 formed therein and a diaphragm 26.
And a flow path forming plate 27.

The base 21 is a block-shaped member provided with a housing space 24 opened at the front and back. The housing space 24 houses the piezoelectric vibrator 17 fixed to the fixed substrate 20.

The nozzle plate 25 is a thin plate-like member having a large number of nozzle openings 28 formed in the sub-scanning direction. Each nozzle opening 28 is opened at a predetermined pitch corresponding to the dot formation density. The vibration plate 26 is a plate-shaped member including a thick island portion 29 with which the piezoelectric vibrator 17 contacts, and an elastic thin portion 30 provided so as to surround the periphery of the island portion 29. The island portions 29 are provided in large numbers at a predetermined pitch so that one nozzle portion 28 corresponds to one island portion 29.

The flow path forming plate 27 is provided with an opening for forming a pressure generating chamber 31, an ink chamber 32, and an ink supply path 33 for communicating the pressure generating chamber 31 with the ink chamber 32. Then, the nozzle plate 25 is connected to the flow path forming plate 27.
The vibration plate 26 is disposed on the back side, and the flow path unit 22 is integrated by bonding or the like with the nozzle plate 25 and the vibration plate 26 sandwiching the flow path forming plate 27. Are formed.

In the flow channel unit 22, the nozzle opening 2
The pressure generating chamber 31 is formed on the back side of the pressure generating chamber 8, and the island portion 29 of the diaphragm 26 is located on the back side of the pressure generating chamber 31. The pressure generating chamber 31 and the ink chamber 32 communicate with each other through an ink supply path 33.

The front end of the piezoelectric vibrator 17 is in contact with the island portion 29 from the back side, and the piezoelectric vibrator 17 is fixed to the base 21 in this contact state. The piezoelectric vibrator 17 is supplied with a drive signal (COM), print data (SI), and the like via a flexible cable 23.

Here, the piezoelectric vibrator 17 contracts when charged, and expands when discharged. Therefore, in the recording head 10 having the above-described configuration, the piezoelectric vibrator 17 is contracted by being charged, and the island portion 29 is pulled back along with the contraction, and the contracted pressure generating chamber 31 is expanded. With this expansion, the ink in the ink chamber 32 flows into the pressure generating chamber 31 through the ink supply path 33. On the other hand, the discharge causes the piezoelectric vibrator 17 to extend forward, the island portion 29 of the elastic plate being pushed forward, and the pressure generating chamber 31 contracting. With this contraction, the ink pressure in the pressure generating chamber 31 increases, and ink droplets are ejected from the nozzle openings 28.

Next, control of the recording head 10 will be described.

FIG. 4 is a circuit diagram showing a case where the drive signal generation circuit 8 generates
FIG. 4 is a diagram illustrating a driving signal of a printing cycle (one driving cycle) T. In this drive signal, the start voltage at the signal start point (P0) and the end voltage at the signal end point (P10) are both the minimum drive voltage V
L, the minimum drive voltage VL and the maximum drive voltage V
A voltage level is switched between H and H to form a waveform.

The above drive signal is calculated from the lowest drive voltage VL.
The pressure generating chamber 31 is slightly expanded by increasing the voltage to an intermediate voltage (intermediate driving voltage) VM between the highest driving voltage VH and the lowest driving voltage VL, and maintaining the intermediate driving voltage VM to keep the pressure generating chamber 31 constant. The signal (P1,
P2; preparation signal), the voltage is increased from the intermediate drive voltage VM to the maximum drive voltage VH, the meniscus is drawn by expanding the pressure generation chamber 31, and the pressure generation chamber 31 is kept at the maximum drive voltage VH for a certain period of time. The signal held in the state (P
3, P4; expansion signal), and the voltage is reduced to the minimum drive voltage VL to contract the pressure generating chamber 31, and the minimum drive voltage V
A signal for ejecting ink droplets by maintaining the pressure generating chamber 31 while maintaining L for a certain period of time (P5, P6; ejection signal)
And Here, P1, P2, and P3 constitute an expansion waveform element in the present invention.

The driving signal is a signal (P7) constituting a vibration-damping waveform element for damping the residual vibration of the meniscus by increasing the voltage again to the intermediate driving voltage VM after the ejection and expanding the pressure generating chamber 31. After the vibration of the meniscus is maintained, the voltage is maintained at the intermediate drive voltage VM for a certain period of time, then lowered relatively slowly to the minimum drive voltage VL to contract the pressure generation chamber 31 and stand by in the pressure generation chamber 31 Signal (P8, P) including return waveform element (P9) for returning to the state
9; return signal). Here, the meniscus refers to a curved free surface of the ink exposed at the nozzle opening 28.

In the present embodiment, the voltage of the waveform element connection portion (P2) of the preparation signal (P1, P2) is changed to the damping voltage (voltage of P8) which is the terminal voltage of the damping waveform element (P7). Although it is set to be equal to, the voltage of the waveform element connection part (P2) can be set higher or lower than the damping voltage.

The driving waveform is input to the piezoelectric vibrator 17 so that the piezoelectric vibrator 17 contracts and expands.
The pressure generating chamber 31 is expanded and contracted to discharge ink droplets. That is, first, in the standby state (P0), FIG.
As shown in (a), the meniscus 50 is located at the nozzle opening 2.
8 at the position of the opening edge. In this standby state (P
0), when the preparation signals (P1, P2) are input, the piezoelectric vibrator 17 contracts and the pressure generating chamber 31 slightly expands,
As shown in FIG. 5B, the meniscus 50 is slightly drawn from the nozzle opening 28. Next, by holding the pressure generating chamber 31 for a certain period of time, the drawn meniscus 50 slightly returns forward as shown in FIG. 5C.

Next, when the expansion signals (P3, P4) are input, the piezoelectric vibrator 17 contracts and the pressure generating chamber 31 further expands, and as shown in FIG.
Is drawn. At this time, since the pressure generating chamber 31 has been expanded to some extent by the preparation signals (P1 and P2), the meniscus 50 is not drawn too much. Then, the ejection signal (P) including the contraction waveform element (P5)
When (5, P6) is input, the piezoelectric vibrator 17 expands and the pressure generating chamber 31 contracts rapidly. This pressure generating chamber 31
Due to the contraction, the pressure in the pressure generating chamber 31 is increased, and the ink near the nozzle opening 28 jumps out and is ejected as an ink droplet. At this time, since the meniscus 50 before ejection is less drawn in, the incorporation of bubbles into the nozzle opening 28 is prevented.

Next, when the vibration damping waveform element (P7) is input, the piezoelectric vibrator 17 contracts, the pressure generating chamber 31 expands, and the meniscus 5 that is about to fly forward by ejection is discharged.
By returning 0, the residual vibration of the meniscus 50 is damped. As a result, the residual vibration of the meniscus is suppressed, and when the ink droplets are continuously ejected, the next ejection operation can be performed after the meniscus vibration is converged, and the variation in the volume of the ink droplets is reduced, and the stable operation is achieved. Quality print quality can be ensured.

When the return signal (P8, P9) including the return waveform element (P9) is input, the piezoelectric vibrator 17 expands, and the pressure generating chamber 31 is relatively slow enough not to eject ink droplets. It contracts at the speed until it has the same volume as the standby state (P0). Thus, the vibration suppression waveform element (P
By providing return signals (P8, P9) for returning the pressure generating chamber 31 to the standby state after the output of 7), the voltages at the start point and the end point of the drive signal become equal. There is no need to add an unnecessary signal for returning the voltage.

In the above drive signal, the preparation signal (P1,
It is preferable that the duration (t1) of the waveform element front part (P1) constituting a part of P2) is set to be equal to or longer than the natural oscillation period Tc of the pressure generating chamber 31. By doing this,
The vibration of the meniscus 50 generated when the pressure generating chamber 31 expands due to the input of the waveform element front part (P1) is suppressed to a low level, and when the pressure generating chamber 31 expands due to the subsequent input of the waveform element rear part (P3). This is because air bubbles are prevented from being taken into the nozzle openings 28.

In the drive signal, the duration (t 2) of the rear part (P 3) of the waveform element is equal to or longer than the natural vibration cycle Ta of the piezoelectric vibrator 17 and the natural vibration cycle T of the pressure generating chamber 31.
It is preferable to set c or less. By doing so, without increasing the maximum drive voltage VH so much,
This is because ink droplets having an appropriate ejection speed and ink weight can be ejected.

In the drive signal, the duration (t 3) of the contraction waveform element (P 5) for contracting the pressure generating chamber 31 in the ejection signal (P 5, P 6) is determined by the natural oscillation period of the piezoelectric vibrator 17. It is preferable to set Ta or more. By doing so, occurrence of residual vibration of the diaphragm 29 after ejection is prevented, and unnecessary ejection of ink irrelevant to the print signal is prevented.

In the drive signal, it is preferable that the duration (t5) of the damping waveform element (P7) is set to be equal to or longer than the natural vibration period Ta of the piezoelectric vibrator 17. Further, it is preferable that the duration (t4) of the ejection signals (P5, P6) is set to be substantially equal to an integral multiple of the natural oscillation period Tc of the pressure generating chamber 31. Further, the duration (t4) of the ejection signals (P5, P6) is determined by the pressure generation chamber 31.
Is preferably set so as to be substantially equal to the natural vibration period Tc. By doing so, the timing at which the pressure generating chamber 31 is expanded by the vibration damping waveform element (P7) becomes close to the opposite phase to the residual vibration of the meniscus 50 after ejection, so that the residual vibration of the meniscus 50 is more effectively reduced. It is because it can be suppressed to. Therefore, when continuously ejecting ink droplets, the next ejection operation can be performed after the meniscus vibration is sufficiently converged, and the variation in the volume of ink droplets is reduced, and stable print quality can be secured.

In the drive signal, the duration (t) of the return waveform element (P9) of the return signal (P8, P9)
6) is preferably set to be equal to or longer than the natural vibration period Tc of the pressure generating chamber 31. By doing so, after the residual vibration of the meniscus 50 is damped by the damping waveform element (P7), the pressure generating chamber 31 can be returned to the standby state with almost no oscillation of the meniscus 50. . Therefore, when continuously ejecting ink droplets, the next ejection operation can be performed without vibrating the meniscus, and a stable print quality can be secured without causing a variation in the volume of the ink droplets.

Here, the natural vibration period T of the piezoelectric vibrator 17
a can be represented by the following equation (1).

1 / Ta = 1 / (2πL) √ (E / ρ) (1) L: Free end length of piezoelectric vibrator E: Young's modulus of piezoelectric vibrator ρ: Specific gravity of piezoelectric vibrator The natural vibration period Tc of the generation chamber 31 can be expressed by the following equation (2).

Tc = 2π√ (Cc · Mn · Ms / (Mn + Ms)) (2) Mn: inertance of nozzle opening Ms: inertance of ink supply path Cc: compliance of pressure generating chamber As described above, the present embodiment is implemented. According to the embodiment, the piezoelectric vibrator 1
7, the start voltage and the end voltage (VL) of the drive signal corresponding to the standby voltage are set lower than the standby voltage (start / end voltage) of the conventional drive waveform. The voltage difference at the time of recovery to the standby voltage by the means 30 becomes smaller than before. Therefore, it is possible to reliably prevent ink droplets from being erroneously ejected when the oscillator voltage is restored to the standby voltage.

Further, in this embodiment, before the output of the expansion signals (P3, P4) including the rear part (P3) of the waveform element, the pressure generating chamber 31 in the standby state is reset by the expansion signals (P3, P4).
By providing the preparatory signals (P1, P2) including the waveform element front part (P1) to be expanded in a range smaller than the expansion amount caused by air bubbles, the incorporation of bubbles into the nozzle opening 28 is prevented, and the occurrence of ejection failure is also prevented Is done. In addition, after the ejection signals (P5, P6) including the ejection waveform element (P5) are output, the vibration suppression waveform element (P7) having the timing and the duration that effectively suppresses the residual vibration of the meniscus 50 exists. When suppressing the residual vibration of the ink droplets 50 and continuously ejecting the ink droplets, the next ejection operation can be performed after the vibration of the meniscus 50 is sufficiently converged, and the variation in the volume of the ink droplets is reduced, and the stable operation is achieved. Printing quality can be ensured.

Further, since the return signals (P8, P9) including the return waveform element (P9) for returning the pressure generating chamber 31 to the standby state after the output of the vibration suppression waveform element (P7) are provided.
Since the voltages at the start point and the end point of the drive signal become equal, it is not necessary to add an unnecessary signal for returning the voltage when the drive signal is continuously generated. Moreover, since the voltage in the standby state (standby voltage) is the minimum drive voltage VL, the minimum drive voltage V
L can be set to ground voltage to facilitate control.

FIG. 6A is a diagram showing drive signals according to the second embodiment of the present invention. In the driving signal of this embodiment, two driving waveforms S1 and S2 are present in one printing cycle (one driving cycle) T in addition to the driving waveform S3 having the same waveform shape as the driving signal shown in FIG. Then, the three drive waveforms S1 to S3 are selectively driven.

The drive waveform S1 is a micro-vibration drive waveform that increases the voltage from the minimum drive voltage VL to a voltage at which no ink droplet is ejected and returns the voltage to the minimum drive voltage VL again.
By inputting the micro-vibration drive waveform S1, the meniscus 50 of the nozzle opening 28 in the standby state vibrates microscopically without discharging ink droplets, and diffuses the thickened ink near the nozzle opening 28 to lower the viscosity. It has become.

The drive waveform S2 is obtained by increasing the voltage from the lowest drive voltage VL to the highest drive voltage VH, holding the voltage for a predetermined period, drawing the meniscus 50 greatly, and increasing the voltage from the highest drive voltage VH to a voltage approximately halfway between VL and VH. This is a driving waveform for a minute dot that causes the ink droplet to be ejected while being lowered, held for a predetermined time, and returned to the minimum drive voltage VL again to eject a minute ink droplet.

In this recording apparatus, for example, when performing the micro-vibration operation, the switch circuit 16 is connected only for the period T1 to generate only the drive signal S1, and the micro-vibration operation is performed. In the case of forming minute dots, the period T2
Only the switch circuit 16 is connected, and only the drive signal S2 is generated to eject ink droplets for minute dots.
To form a medium dot relatively larger than the minute dot, the switch circuit 16 is connected for only the period T3 to generate only the drive signal S3, thereby ejecting a medium dot ink droplet. Further, when forming a large dot relatively larger than the medium dot, the switch circuit 16 is connected in the periods T2 and T3 to generate a drive signal S2 + S3, thereby forming a large dot with two ink droplets. .

In this manner, as shown in FIG. 6B, three types of dots having different sizes are formed by one type of drive signal, and a certain degree of clogging is eliminated by the fine vibration operation. It can be performed. Otherwise, the third embodiment is the same as the first embodiment, and has the same functions and effects.

Next, an ink jet recording apparatus and a method of driving the recording head according to a third embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 7, the ink jet recording apparatus according to the present embodiment has a temperature sensor 115 for measuring a temperature environment around the apparatus, and a driving signal corresponding to the environmental temperature measured by the temperature sensor 115. And a drive signal generating means 113 for generating a drive signal having a waveform shape calculated by the waveform shape calculating means 114. In the recording apparatus, the waveform of the drive signal is changed according to the environmental temperature around the apparatus.
In FIG. 7, reference numeral 112 denotes a print control unit that creates bitmap data based on a print signal from a host, and reference numeral 111 denotes a carriage control unit that controls reciprocal scanning of the carriage 102.

FIG. 8 shows a drive signal used in the present embodiment. Among the waveforms of the drive signal shown in FIG. 8, the voltage difference (P5) of the contraction waveform element (P5) of the ejection signals (P5, P6) is shown. Vhm), the voltage difference (Vcp) at the waveform element front part (P1) of the preparation signal (P1, P2), the voltage difference (Vsp) at the vibration suppression waveform element (P7), and the expansion signal (P3, P
4) Voltage holding time (P) in expansion holding waveform element (P4)
w) are changed in accordance with the respective environmental temperatures.

More specifically, the contraction waveform element (P
For example, as shown in Table 1 below, it is preferable that the voltage difference (Vhm) of (5) decreases as the environmental temperature T increases. In this manner, when the environmental temperature T increases and the viscosity of the ink decreases, the meniscus 50 (FIG. 5)
Since (a)) becomes unstable and air bubbles are easily taken in, the air bubbles can be prevented from being taken in by reducing the voltage difference (Vhm) in the contraction waveform element (P5). Also,
When the environmental temperature T becomes low and the viscosity of the ink becomes high, the meniscus 50 becomes difficult to fly out. You will be able to maintain quality. In Table 1, Vhm25
Is Vhm when the environmental temperature T is 25 ° C., and is set to 23 V in this example.

[0095]

[Table 1] Also, the waveform element front part (P1) of the preparation signal (P1, P2)
Is preferably smaller as the environmental temperature T becomes higher, as shown in Table 2 below, for example. In this manner, when the environmental temperature T increases and the viscosity of the ink decreases, the meniscus 50 is easily pulled in and bubbles are easily taken in. Therefore, the voltage difference (Vcp) at the front part (P1) of the waveform element is obtained. By reducing the size, it is possible to prevent air bubbles from being taken up. Further, when the environmental temperature T decreases and the viscosity of the ink increases, the meniscus 50 becomes difficult to be drawn in.
By increasing the voltage difference (Vcp) in 1) and pulling in the meniscus 50 to some extent, a certain printing quality can be maintained.

[0096]

[Table 2] When changing the voltage difference (Vcp) at the front part (P1) of the waveform element, the voltage at the waveform element connection part (P2) may be changed, or the voltage (starting voltage) in the standby state (P0). May be changed. When changing the voltage (start voltage) in the standby state (P0), the voltage (end voltage) at the end point (P10) of the drive signal is changed in the same manner so that the start voltage and the end voltage become equal.

Further, it is preferable that the voltage difference (Vsp) at the vibration suppression waveform element (P7) increases as the environmental temperature T increases, as shown in Table 3 below, for example. By doing so, when the environmental temperature T increases and the viscosity of the ink decreases, the meniscus 50 tends to vibrate and the residual vibration increases, so that the voltage difference (Vsp) at the vibration damping waveform element (P7). The residual vibration can be effectively damped by increasing. Further, when the environmental temperature T decreases and the viscosity of the ink increases, the meniscus 50 becomes less likely to vibrate, so that the voltage difference (Vsp) at the damping waveform element (P7) is reduced.
Is reduced, the residual vibration is effectively damped, and oscillation of the meniscus 50 is reduced.

[0098]

[Table 3] The voltage holding time (Pw) of the expansion signal (P3, P4) in the expansion holding waveform element (P4) is preferably made longer as the environmental temperature T becomes higher, as shown in Table 4 below, for example. In this way, when the voltage difference (Vhm) in the contraction waveform element (P5) of the ejection signal (P5, P6) is changed according to the environmental condition T, the ejection speed of the ink droplet also changes, and the dot landing Although the position is shifted, by changing the voltage holding time (Pw) of the expansion signal (P3, P4) in the expansion holding waveform element (P4), the shift of the landing position of the dot is eliminated, and a constant print quality is obtained. Can be kept. In addition, the contraction waveform element (P5) according to the environmental temperature T
, It is necessary to increase the voltage difference (Vhm) on the low temperature side, but the expansion holding waveform element (P4) of the expansion signal (P3, P4) in the range where the environmental temperature T is low. , The voltage difference (Vcp) at the waveform element connection part (P2) does not need to be too large, and the maximum drive voltage V
H can be kept low so that the design of the apparatus can be made more relaxed.

[0099]

[Table 4] As described above, in the present embodiment, by changing the waveform shape of the drive signal in accordance with the environmental temperature around the device, under conditions where the viscosity of the ink is reduced under high temperature or the like and the meniscus is likely to be unstable, By making the waveform shape according to the temperature change, such as changing the waveform shape so as to reduce the movement of the meniscus, it is possible to effectively prevent the incorporation of bubbles into the nozzle opening, and to maintain the discharge characteristics constant and maintain a constant Printing quality can be obtained.

FIG. 9 is a sectional view showing a recording head 10a used in the fourth embodiment of the present invention. This embodiment is different from the above-described first to third embodiments in that
Instead of the recording head 10 having a longitudinal vibration mode piezoelectric vibrator, a recording head 10a having a flexural vibration mode piezoelectric vibrator is used.

The recording head 10a has an actuator unit 51 in which a plurality of pressure generating chambers 52 are formed, a flow path unit 55 in which a nozzle opening 53 and an ink chamber 54 are formed and which is adhered to the lower surface of the actuator unit 51. A piezoelectric vibrator 17 attached to the upper surface of the actuator unit 51, whereby the pressure of the pressure generating chamber 52 is generated by the vibration of the piezoelectric vibrator 17, and the ink droplet is ejected from the nozzle opening 53. ing.

The actuator unit 51 includes a pressure generating chamber forming substrate 60 in which a space for forming the pressure generating chamber 52 is formed, and a vibration which is located on the upper surface of the pressure generating chamber forming substrate 60 and closes the upper opening of the space. It comprises a plate 61 and a lid member 64 located on the lower surface of the pressure generating chamber forming substrate 60. The lid member 64 is formed with a first ink flow path 62 for communicating the ink chamber 54 with the pressure generation chamber 52 and a second ink flow path 63 for communicating the pressure generation chamber 52 with the nozzle opening 53.

The flow path unit 55 includes a storage chamber forming substrate 66 in which a space for forming the ink chamber 54 is formed, and a nozzle plate 67 having a nozzle opening 53 formed therein and located on the lower surface of the storage chamber forming substrate 66. And a supply port forming plate 68 located on the upper surface of the storage chamber forming substrate 66. In the storage chamber forming substrate 66, the nozzle opening 53 is provided.
Is formed with a nozzle communication port 59 communicating with the nozzle. Also,
The supply port forming plate 68 is provided with an ink supply port 65 for supplying ink from the ink chamber 54 to the pressure generation chamber 52 via the first ink flow path 62, and the pressure generation chamber 5.
A communication port 58 for communicating the second and second ink channels 63 with the nozzle communication port 59 and the nozzle opening 53 is formed.

The piezoelectric vibrator 17 is formed in a plate shape at a portion corresponding to the pressure generating chamber 52 on the upper surface of the vibration plate 61. A lower electrode 69 is formed on the lower surface of the piezoelectric vibrator 17, and an upper electrode 70 is formed on the upper surface so as to cover the piezoelectric vibrator 17. The piezoelectric vibrators 1 are provided at both ends of the upper surface of the actuator unit 51.
A terminal 71 is formed to be electrically connected to the upper electrode 70 of FIG. The upper surface of the terminal 71 is formed higher than the upper surface of the piezoelectric vibrator 17. Then, on the upper surface of the terminal 71,
A flexible circuit board 72 is stretched, and a drive signal is input to the piezoelectric vibrator 17 via the terminal 71 and the upper electrode 70. Although only two pressure generating chambers 52, two piezoelectric vibrators 17, and two terminals 71 are shown in the figure, a large number of rows are provided in a direction perpendicular to the plane of the drawing.

In the recording head 10a, when a driving waveform is input to the piezoelectric vibrator 17 and the piezoelectric vibrator 17 is charged, the piezoelectric vibrator 17 contracts in the horizontal direction. At this time, the lower surface side of the piezoelectric vibrator 17 fixed to the vibration plate 61 does not shrink, and only the upper surface side shrinks.
In addition, the vibration plate 61 bends downward, causing the pressure generating chamber 52 to contract. When the pressure in the pressure generating chamber 52 rises, the ink in the pressure generating chamber 52 is ejected from the nozzle openings 53 as ink droplets, and printing is performed on recording paper or the like. Next, when the piezoelectric vibrator 17 is discharged, the piezoelectric vibrator 17 is discharged.
Then, the diaphragm 61 returns to the original state, the inside of the pressure generating chamber 52 expands, and new ink is supplied from the ink chamber 54 to the pressure generating chamber 52 through the ink supply port 65.

As described above, in the recording head 10a,
The relationship between the voltage level due to charging and discharging of the piezoelectric vibrator 17 and the direction in which the pressure generating chamber 52 expands and contracts is basically opposite to that in the first to third embodiments.

In the recording head 10a, FIG.
A drive signal as shown in FIG. That is, in the first to third embodiments, the expansion of the pressure generating chamber 31 increases the voltage, and the ejection of the ink droplet uses the drive signal having the waveform of decreasing the voltage. The expansion of the pressure generating chamber 52 lowers the voltage, and the contraction of the pressure generating chamber 52 uses a drive signal having a waveform that raises the voltage. Also in this case, the same operation and effect as those of the above embodiments can be obtained.

[0108]

As described above, according to the present invention, the starting voltage and the ending voltage of the drive signal corresponding to the standby voltage of the piezoelectric vibrator are set lower than the standby voltage of the conventional drive signal. Therefore, the voltage difference when the oscillator voltage lowered by the voltage recovery means is recovered to the standby voltage by the voltage recovery means becomes smaller than before. Therefore, it is possible to reliably prevent ink droplets from being erroneously ejected when the oscillator voltage is restored to the standby voltage.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration explanatory view showing an overall configuration of the ink jet recording apparatus according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a mechanical structure of a recording head of the ink jet recording apparatus according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram showing drive signals for a recording head used in the first embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating a behavior of a meniscus according to the print head driving method according to the first embodiment of the present invention.

FIGS. 6A and 6B are diagrams for explaining a second embodiment of the present invention, wherein FIG. 6A is an explanatory diagram showing a drive signal, and FIG.
FIG. 4 is a diagram showing dots to be formed.

FIG. 7 is a system configuration diagram of an ink jet recording apparatus according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram showing a drive signal used in a third embodiment of the present invention.

FIG. 9 is a sectional view showing a recording head used in a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram showing drive signals used in a fourth embodiment of the present invention.

Claims (32)

[Claims] 1. A recording head having a piezoelectric vibrator for expanding and contracting a pressure generating chamber communicating with a nozzle opening, and generating a drive signal applied to the piezoelectric vibrator for driving the piezoelectric vibrator. And a drive signal generating means, wherein the drive signal comprises an expansion waveform element whose voltage changes so as to expand the pressure generation chamber, and the pressure generation chamber expanded by the expansion waveform element to contract the pressure generation chamber. A contraction waveform element whose voltage changes so as to eject an ink droplet from a nozzle opening; and the pressure generation chamber contracted by the contraction waveform element in order to suppress residual vibration of a meniscus of the pressure generation chamber after ink droplet ejection. A damping waveform element whose voltage changes from the end voltage of the contraction waveform element to the damping voltage so as to cause the expansion of the drive signal, and the start voltage and the end voltage of the drive signal are equal. In addition, it corresponds to a standby voltage set as a voltage of the piezoelectric vibrator when the drive signal is not supplied, and the damping voltage is between the standby voltage and the highest voltage in the drive signal. Ink jet recording apparatus. 2. The expansion waveform element includes a waveform element front part, a waveform element rear part located after the waveform element front part, and a waveform connecting an end of the waveform element front part and a start end of the waveform element rear part. Element connection part, wherein the waveform element connection part is located at an intermediate voltage between the standby voltage and the maximum voltage, and a slope of the waveform element front part is smaller than a slope of the waveform element rear part. 2. An ink jet recording apparatus according to claim 1, wherein: 3. An ink jet recording apparatus according to claim 2, wherein a voltage difference between said standby voltage and said intermediate voltage is reduced in accordance with an increase in environmental temperature. 4. The ink jet recording apparatus according to claim 2, wherein a duration of the front part of the waveform element is set longer than a natural oscillation period of the pressure generating chamber. 5. The drive signal according to claim 1, wherein the drive signal includes a return waveform element located after the vibration suppression waveform element and changing from the vibration suppression voltage to the standby voltage. Item 8. An ink jet recording apparatus according to item 1. 6. The ink jet recording apparatus according to claim 5, wherein the slope of the return waveform element is smaller than the slope of the contraction waveform element. 7. The ink jet recording apparatus according to claim 5, wherein a duration of the return waveform element is set longer than a natural oscillation period of the pressure generating chamber. 8. The ink jet recording apparatus according to claim 1, wherein said standby voltage is a minimum voltage of said drive signal. 9. The ink jet type according to claim 2, wherein the duration of the rear part of the waveform element is set to be equal to or longer than the natural oscillation cycle of the piezoelectric vibrator and equal to or shorter than the natural oscillation cycle of the pressure generating chamber. Recording device. 10. The ink jet recording apparatus according to claim 1, wherein a duration of the contraction waveform element is set to be equal to or longer than a natural oscillation period of the piezoelectric vibrator. 11. The ink jet recording according to claim 1, wherein the duration of said vibration damping waveform element is set to be equal to or longer than the natural vibration period of said piezoelectric vibrator. apparatus. 12. A contraction holding waveform element for maintaining a contracted state of the pressure generating chamber contracted by the contraction waveform element follows the contraction waveform element, and a total of the contraction waveform element and the contraction holding waveform element. The ink jet recording apparatus according to any one of claims 1 to 11, wherein a duration of the ink jet recording apparatus is set to be substantially equal to an integral multiple of a natural oscillation period of the pressure generating chamber. 13. The pressure generating chamber according to claim 12, wherein the total duration of the contraction waveform element and the contraction holding waveform element is set to be substantially equal to the natural oscillation period of the pressure generating chamber. Inkjet recording device. 14. The ink jet recording apparatus according to claim 1, wherein a voltage difference between the contraction waveform elements is reduced according to an increase in environmental temperature. 15. The ink jet recording apparatus according to claim 1, wherein a voltage difference between said vibration damping waveform elements is increased in accordance with an increase in environmental temperature. 16. An expansion holding waveform element following the expansion waveform element for maintaining an expansion state of the pressure generating chamber expanded by the expansion waveform element, and the expansion holding waveform element responds to an increase in environmental temperature. The ink jet recording apparatus according to any one of claims 1 to 15, wherein a continuation time is extended. 17. A method for driving an ink jet recording head having a piezoelectric vibrator for expanding and contracting a pressure generating chamber communicating with a nozzle opening, comprising applying a voltage to the piezoelectric vibrator to drive the piezoelectric vibrator. Generating a drive signal to be applied, and applying the drive signal to the piezoelectric vibrator to drive the piezoelectric vibrator, wherein the drive signal has a voltage to expand the pressure generating chamber. An expansion waveform element that changes, a contraction waveform element that changes the voltage so as to cause the pressure generating chamber expanded by the expansion waveform element to discharge an ink droplet from the nozzle opening, In order to suppress the residual vibration of the meniscus of the pressure generation chamber, the end of the contraction waveform element is expanded so that the pressure generation chamber contracted by the contraction waveform element is expanded. A damping waveform element whose voltage changes from a voltage to a damping voltage, wherein the starting voltage and the ending voltage of the driving signal are equal and set as the voltage of the piezoelectric vibrator when the driving signal is not supplied. Wherein the vibration damping voltage is between the standby voltage and the highest voltage of the drive signal. 18. An inflatable corrugated element comprising: a corrugated element front portion;
A waveform element rear portion located after the waveform element front portion, and a waveform element connection portion connecting an end of the waveform element front portion and a start end of the waveform element rear portion, wherein the waveform element connection portion includes the standby voltage. 18. The method according to claim 17, wherein the waveform element is located at an intermediate voltage between the waveform element and the maximum voltage, and the slope of the front part of the waveform element is smaller than the slope of the rear part of the waveform element. . 19. The method according to claim 18, wherein a voltage difference between said standby voltage and said intermediate voltage is reduced in accordance with an increase in environmental temperature. 20. The method according to claim 18, wherein the duration of the front part of the waveform element is set longer than the natural oscillation period of the pressure generating chamber. . 21. The drive signal according to claim 17, wherein the drive signal includes a return waveform element located after the vibration suppression waveform element and changing from the vibration suppression voltage to the standby voltage.
0. The driving method of the ink jet recording head according to any one of 0. 22. The method according to claim 21, wherein the slope of the return waveform element is smaller than the slope of the contraction waveform element. 23. The method according to claim 21, wherein a duration of the return waveform element is set longer than a natural oscillation period of the pressure generating chamber. 24. The method according to claim 17, wherein the standby voltage is a minimum voltage of the drive signal. 25. The continuation time of the rear part of the waveform element is set to be equal to or longer than the natural oscillation cycle of the piezoelectric vibrator and equal to or shorter than the natural oscillation cycle of the pressure generating chamber.
9. The method for driving an ink jet recording head according to item 8. 26. The ink jet recording head according to claim 17, wherein a duration of the contraction waveform element is set to be equal to or longer than a natural oscillation period of the piezoelectric vibrator. Drive method. 27. An ink-jet recording method according to claim 17, wherein a duration of said vibration damping waveform element is set to be equal to or longer than a natural vibration period of said piezoelectric vibrator. Head driving method. 28. A contraction holding waveform element following the contraction waveform element for maintaining a contracted state of the pressure generating chamber contracted by the contraction waveform element, and the sum of the contraction waveform element and the contraction holding waveform element. 28. The duration of the pressure generation chamber is set to be substantially equal to an integral multiple of the natural vibration period of the pressure generating chamber.
The driving method of the ink jet recording head according to any one of the above. 29. The system according to claim 28, wherein the total duration of the contraction waveform element and the contraction holding waveform element is set to be substantially equal to the natural oscillation period of the pressure generating chamber. Driving method for an ink jet recording head. 30. The ink jet recording head according to claim 17, wherein a voltage difference between the contraction waveform elements themselves is reduced in accordance with an increase in environmental temperature. Method. 31. The ink jet recording head according to claim 17, wherein a voltage difference between said vibration damping waveform elements themselves is increased in accordance with an increase in environmental temperature. Drive method. 32. An expansion holding waveform element following the expansion waveform element for maintaining an expansion state of the pressure generating chamber expanded by the expansion waveform element, and the expansion holding waveform element responds to an increase in environmental temperature. The method according to any one of claims 17 to 31, wherein the continuation time of the ink jet recording head is increased.