JP6950568B2 - How to drive the liquid injection device and the liquid injection device - Google Patents

Description

The present invention relates to a method for driving a liquid injection device such as an inkjet recording device, and a liquid injection device.

The liquid injection device is a device that includes a liquid injection head capable of injecting liquid as droplets from a nozzle, and injects various liquids from the liquid injection head. As a typical example of this liquid injection device, for example, an inkjet recording head (hereinafter referred to as a recording head) is provided, and liquid ink is ejected as ink droplets from a nozzle of the recording head to record an image or the like. An image recording device such as an inkjet recording device (printer) can be mentioned. In addition, a liquid injection device for injecting various types of liquids such as color materials used for color filters such as liquid crystal displays, organic materials used for organic EL (Electro Luminescence) displays, and electrode materials used for electrode formation. Is used. Then, the recording head for the image recording apparatus injects liquid ink, and the color material injecting head for the display manufacturing apparatus injects a solution of each color material of R (Red), G (Green), and B (Blue). Further, the electrode material injection head for the electrode forming apparatus injects a liquid electrode material, and the bioorganic material injection head for the chip manufacturing apparatus injects a solution of the bioorganic substance.

The above liquid injection head includes a piezoelectric element as a pressure generating element that generates pressure in the liquid in the pressure chamber, and the piezoelectric element vibrates due to the supply of a drive signal (that is, a drive waveform) to inject the liquid in the pressure chamber from a nozzle. do. By the way, by repeatedly driving the piezoelectric element, there is a possibility that the piezoelectric element deteriorates and the displacement amount of the piezoelectric element decreases. As a result, the amount of droplets ejected from the nozzle is reduced, and there is a risk that the image quality and the like may be deteriorated. In order to suppress such a problem, there is known a technique of measuring the number of times a droplet is ejected from a nozzle (the number of times of ejection) and correcting the voltage of a drive signal according to the number of times of injection (see Patent Document 1). ).

JP-A-2009-666948

However, it has been found by the inventor's experiment that the degree of deterioration of the piezoelectric element tends to change depending on the supply time of the drive signal to the piezoelectric element rather than the number of times the droplets are ejected. Since the supply time of the drive signal to the piezoelectric element may change depending on the type of drive waveform, even if the voltage of the drive signal is corrected according to the number of droplet injections, the drive signal cannot be sufficiently corrected. There was a risk. As a result, there is a risk that deterioration of printed image quality and the like cannot be sufficiently suppressed.

The present invention has been made in view of such circumstances, and an object of the present invention is a method for driving a liquid injection device capable of appropriately correcting a drive signal supplied to a pressure generating element and suppressing deterioration of image quality, and a method for driving the liquid injection device. , To provide a liquid injection device.

The method for driving the liquid injection device of the present invention has been proposed in order to achieve the above object, and includes a nozzle for injecting a liquid and a nozzle for injecting a liquid.
A pressure chamber communicating with the nozzle and
A pressure generating element that causes a pressure change in the liquid in the pressure chamber,
A drive waveform generator that generates a plurality of types of drive waveforms supplied to the pressure generating element,
It is a driving method of a liquid injection device including
A step of measuring the count value of the number of times the drive waveform is supplied to the pressure generating element for each type of the drive waveform, and
A step of multiplying the count value by a coefficient based on at least one of a reference potential or a period that serves as a reference for a change in the potential of the drive waveform to obtain an aging value that is an index of the degree of deterioration of the pressure generating element.
The step of correcting the drive waveform according to the aging value and
It is characterized by including.

According to the present invention, since the degree of deterioration of the pressure generating element is determined based on at least one of the reference potential and the period, the aging value which is an index of the degree of deterioration of the pressure generating element can be obtained more accurately. As a result, the drive waveform can be appropriately corrected according to the aging value, and deterioration of the printed image quality can be suppressed.

Further, in the above driving method, it is desirable that the coefficient is set for each type of the driving waveform.

According to this driving method, more accurate correction can be performed according to the type of driving waveform.

Further, in any of the above driving methods, it is desirable to correct the driving waveform when the correction value of the driving waveform calculated based on the aging value is equal to or more than a predetermined value.

Further, in any of the above driving methods, the nozzle, the pressure chamber, and the pressure generating element are provided, and a liquid injection head that injects liquid from the nozzle while moving in the main scanning direction is provided.
It is desirable to obtain the aging value and correct the drive waveform each time the liquid injection head scans once or a plurality of times.

According to this driving method, since the aging value is obtained and the driving waveform is corrected every time the scanning is performed once or a plurality of times, it is possible to perform more appropriate correction for the driving waveform and deteriorate the printed image quality. It can be further suppressed.

Further, in any of the above driving methods, it is desirable to obtain the aging value after turning on the power of the liquid injection device and correct the driving waveform.

According to this driving method, deterioration of image quality after the power of the liquid injection device is turned on can be suppressed.

Further, in any of the above driving methods, it is desirable to obtain the aging value and correct the driving waveform before starting the printing operation of injecting the liquid from the nozzle toward the landing target.

According to this driving method, deterioration of image quality can be suppressed for each printing operation.

Further, in any of the above-mentioned driving methods, the plurality of types of driving waveforms may be waveforms in which at least one of the reference potential and the period is different from each other.

According to this driving method, even when the reference potential and the period of each driving waveform are different from each other, the correction can be performed according to the type of the driving waveform.

Further, in any of the above-mentioned driving methods, the plurality of types of driving waveforms may be waveforms in which at least one of the number of pulses or the shape of the pulses included in the driving waveform is different from each other.

According to this driving method, even if the number of pulses and the shape of the pulses of each driving waveform are different from each other, the correction can be performed according to the type of the driving waveform.

The liquid injection device of the present invention includes a nozzle for injecting a liquid and a nozzle for injecting a liquid.
A pressure chamber communicating with the nozzle and
A pressure generating element that causes a pressure change in the liquid in the pressure chamber,
A drive waveform generator that generates a plurality of types of drive waveforms supplied to the pressure generating element,
It is a liquid injection device equipped with
A count value relating to the number of times the drive waveform is supplied to the pressure generating element is measured for each type of the drive waveform.
The count value is multiplied by a coefficient based on at least one of a reference potential or a period that serves as a reference for a change in the potential of the drive waveform to obtain an aging value that is an index of the degree of deterioration of the pressure generating element.
It is characterized in that the drive waveform is corrected according to the aging value.

It is a perspective view explaining the structure of one form of a liquid injection device (printer). It is a block diagram explaining the electrical structure of a liquid injection device. It is a partial cross-sectional view of a liquid injection head (recording head). It is a waveform diagram explaining an example of the 1st drive signal. It is a waveform diagram explaining an example of the 1st drive pulse. It is a waveform diagram explaining an example of a 2nd drive signal. It is a waveform diagram explaining an example of the 2nd drive pulse. It is a waveform diagram explaining each waveform selected when forming small dot, medium dot, and large dot respectively. It is a graph explaining the relationship between the energization time in each waveform and the rate of change of the injection amount of ink. It is a table explaining an example of a correction coefficient table. It is a flowchart explaining the correction of a drive waveform. It is a graph explaining the correction of the drive waveform in other embodiments. It is a table explaining an example of the correction coefficient table in another embodiment. It is a table explaining an example of the correction coefficient table in another embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are given as suitable specific examples of the present invention, but the scope of the present invention is the scope of the present invention unless otherwise specified in the following description to limit the present invention. It is not limited to these aspects. Further, in the following, as the liquid injection device of the present invention, an inkjet recording device (hereinafter, printer) 1 will be described as an example.

FIG. 1 is a perspective view illustrating a configuration of one form of the printer 1, and FIG. 2 is a block diagram illustrating an electrical configuration of the printer 1. The printer 1 in the present embodiment includes a print engine 2 having a paper feed mechanism 3, a carriage moving mechanism 4, a linear encoder 5, and a recording head 6, and a printer controller 7 that controls each part of the print engine 2.

The printer controller 7 is a control unit that controls each part of the printer. The printer controller 7 in the present embodiment includes a control circuit 9 and a drive signal generation circuit 10 (corresponding to a drive waveform generation unit in the present invention) and the like. The control circuit 9 is an arithmetic processing device for controlling the entire printer, and is composed of a CPU, a storage device, and the like (not shown). The control circuit 9 controls each unit according to a program or the like stored in the storage device. Further, the control circuit 9 in the present embodiment has a size at which timing from the nozzle 21 (see FIG. 3) of the recording head 6 during a printing operation (liquid injection operation) based on print data received from an external device or the like. The injection data indicating whether to inject the ink droplets (droplets) of the above ink is generated, and the injection data is transmitted to the head controller 12 of the recording head 6.

Further, as will be described later, the control circuit 9 has a timing signal (timing pulse) PTS (see FIGS. 4 and 6) from an encoder signal (encoder pulse) output from the linear encoder 5 as the carriage 16 moves (main scan). ) Functions as a timing pulse generation means. This timing signal PTS is a signal that determines the generation start timing of the drive signal generated by the drive signal generation circuit 10. That is, the drive signal generation circuit 10 outputs a predetermined drive waveform each time the timing signal PTS is received. In other words, the drive signal generation circuit 10 repeatedly generates various drive waveforms in a cycle based on the timing signal PTS (hereinafter, referred to as a unit cycle T). The generation frequency of the drive waveform based on the timing signal PTS of the printer 1 in the present embodiment is set to, for example, about 8 [kHz] in the printing operation. In the period when the carriage 16 is not moved other than the printing operation, the timing signal PTS is generated at regular intervals by a timer or the like according to the type of the driving waveform (for example, the micro-vibration waveform or the inspection waveform). Further, the control circuit 9 outputs a latch signal LAT that defines the latch timing of the print data and a change signal CH that defines the selection timing of each drive pulse included in the drive signal. Further, the control circuit 9 in the present embodiment counts a value related to the number of times the drive waveform is supplied to the piezoelectric element 24 (timing signal PTS in the present embodiment), and based on this, an index of the degree of deterioration of the piezoelectric element 24 is used. calculate. Then, the voltage value of the drive waveform (difference between the maximum potential and the minimum potential, the reference potential (intermediate potential), etc.) applied to the piezoelectric element 24 is corrected according to the index of the degree of deterioration. The correction of this drive waveform will be described later.

The drive signal generation circuit 10 generates an analog voltage signal based on waveform data related to the waveform of the drive signal, and amplifies this by an amplifier circuit (not shown) to generate a drive signal COM. Further, the voltage of the drive signal COM is corrected according to the degree of deterioration of the piezoelectric element 24 by the signal from the control circuit 9. That is, the drive signal generation circuit 10 generates a voltage-corrected drive signal COM. The drive signal generation circuit 10 in the present embodiment repeatedly generates the first drive signal COM1 shown in FIG. 4 and the second drive signal COM2 shown in FIG. 6, respectively, in the unit cycle T described above. Further, the first drive signal COM1 is divided into two drive pulses (also simply referred to as pulses) by the change signal CH generated in response to the latch signal LAT, and each drive pulse is selectively output. That is, the drive signal generation circuit 10 generates two types of drive waveforms having different numbers of drive pulses from the first drive signal COM1. The details of these first drive signal COM1 and second drive signal COM2 will be described later. Further, the drive signal generation circuit 10 in the present embodiment generates various drive waveforms in addition to the drive waveform (that is, the discharge waveform) used for the printing operation including the first drive signal COM1 and the second drive signal COM2. Generate. For example, a defective nozzle is generated based on the flushing waveform used for the flushing operation of ejecting ink from the nozzle 21 outside the printing area and the back electromotive force signal of the piezoelectric element 24 caused by the residual vibration when the piezoelectric element 24 is driven. The inspection waveform used for the nozzle inspection operation to be detected, the micro-vibration waveform used for the micro-vibration operation that slightly vibrates the meniscus in the nozzle 21 to the extent that ink droplets are not ejected, and the high frequency in the ink in the pressure chamber 26. Generates ultrasonic micro-vibration waveforms used for recovery operation to restore defective nozzles by applying micro-vibration. These drive waveforms are generated by the drive signal generation circuit 10 and transmitted to the head controller 12 of the recording head 6. Then, the drive waveform sent from the drive signal generation circuit 10 side is selectively applied to the piezoelectric element 24 based on the injection data or the like sent from the control circuit 9.

Next, the print engine 2 will be described. As shown in FIG. 1, the print engine 2 includes a paper feed mechanism 3, a carriage moving mechanism 4, a linear encoder 5, a recording head 6, and the like. The carriage moving mechanism 4 includes a carriage 16 to which a recording head 6 which is a kind of a liquid injection head is attached, a drive motor (for example, a DC motor) or the like for running the carriage 16 via a timing belt or the like (FIG. FIG. (Not shown), the recording head 6 mounted on the carriage 16 is moved along the guide rod 18 in the main scanning direction. The paper feed mechanism 3 includes a paper feed motor, a paper feed roller, and the like, and sequentially feeds the recording medium S (a type of droplet landing target) onto the platen to perform sub-scanning. Further, the linear encoder 5 outputs an encoder signal corresponding to the scanning position of the recording head 6 mounted on the carriage 16 to the control circuit 9 of the printer controller 7 as position information in the main scanning direction. The control circuit 9 can grasp the scanning position (current position) of the recording head 6 based on the encoder signal received from the linear encoder 5 side.

The printer 1 configured in this way sequentially conveys the recording medium S by the paper feed mechanism 3, and while moving the recording head 6 relative to the recording medium S in the main scanning direction, the nozzle 21 of the recording head 6 is used. An image or the like is recorded by injecting (discharging) ink (ink droplets), which is a kind of liquid, from (see FIG. 3) and landing the ink on the recording medium S. It is also possible to adopt a configuration in which the ink cartridge 17 is arranged on the main body side of the printer and the ink of the ink cartridge 17 is sent to the recording head 6 side through the supply tube.

FIG. 3 is a cross-sectional view of a main part for explaining the internal configuration of the recording head 6. The recording head 6 in the present embodiment is configured by laminating a nozzle plate 22, a flow path substrate 23, a piezoelectric element 24 (corresponding to a pressure generating element in the present invention), a case 20, and the like. The nozzle plate 22 is a plate-shaped member in which a plurality of nozzles 21 are opened in a row at a pitch corresponding to the dot formation density, and is made of, for example, a silicon single crystal substrate or a metal plate such as stainless steel. In the present embodiment, two rows of nozzle rows (a type of nozzle group) composed of a plurality of nozzles 21 are arranged side by side on the nozzle plate 22. The nozzle row in this embodiment is composed of, for example, a total of 400 nozzles 21.

A pressure chamber 26 communicating with the nozzle 21 of the nozzle plate 22 is formed on the flow path substrate 23. A plurality of pressure chambers 26 are formed corresponding to each nozzle 21. A common liquid chamber 25 is formed outside the row of pressure chambers 26 in the flow path substrate 23. The common liquid chamber 25 communicates with each pressure chamber 26 individually via a supply port 27. Further, ink from the ink cartridge 17 side is introduced into the common liquid chamber 25 through the ink introduction path 28 of the case 20. A piezoelectric element 24 is formed on the upper surface of the flow path substrate 23 on the side opposite to the nozzle plate 22 side via an elastic film 30.

The piezoelectric element 24 is formed by sequentially laminating a metal lower electrode film, a piezoelectric layer made of, for example, lead zirconate titanate, and an upper electrode film made of metal (none of which are shown). There is. The piezoelectric element 24 is a so-called bending mode piezoelectric element, and is formed so as to cover the upper part of the pressure chamber 26. In the present embodiment, two rows of piezoelectric element rows are arranged side by side corresponding to two rows of nozzle rows. A wiring board 31 such as a COF (Chip On Film), which forms a part of a signal path and is a kind of wiring member, is electrically connected to the terminal portion of each piezoelectric element 24. The wiring board 31 applies a drive signal sent from the printer controller 7 to the piezoelectric element 24. In the present embodiment, the head controller 12 (see FIG. 2) is provided on the wiring board 31, but the present invention is not limited to this, and the head controller 12 is arranged on a separate board that functions as an interposer. You can also do it. The drive waveform sent from the drive signal generation circuit 10 side through the wiring board 31 is selectively applied to the piezoelectric element 24 based on the injection data sent from the control circuit 9. When the drive pulse included in the drive waveform is applied to the piezoelectric element 24, the piezoelectric element 24 is deformed according to the voltage waveform of the drive pulse. As a result, pressure fluctuation occurs in the ink in the pressure chamber 26 corresponding to the piezoelectric element 24, and the ink is ejected (discharged) from the nozzle 21 due to the pressure fluctuation of the ink.

Next, the ejection waveform used in the printing operation will be described. FIG. 4 is a waveform diagram illustrating an example of the configuration of the first drive signal COM1 in the initial state in the present embodiment. Further, FIG. 5 is a waveform diagram of the first drive pulse P1 included in the first drive signal COM1 in the initial state. In each figure, the horizontal axis represents time and the vertical axis represents voltage (potential). The first drive signal COM1 of the present embodiment is repeatedly generated from the drive signal generation circuit 10 in the unit cycle T defined by the timing signal PTS and the latch signal LAT as described above. This unit cycle T is divided into a first cycle T1 in the first half portion and a second cycle T2 in the second half portion by a change signal CH generated in response to the latch signal LAT. In the present embodiment, the first drive pulse P1 (a type of pulse in the present invention) is generated in the first half (first cycle T1) and the second half (second cycle T2), respectively.

As shown in FIG. 5, the first drive pulse P1 includes a first pre-expansion element p1, a first expansion hold element p2, a first contraction element p3, a first contraction hold element p4, and a first return expansion. It has an element p5 and. The first pre-expansion element p1 is lower than the first reference potential VB1 from the first reference potential VB1 (intermediate potential in the first drive signal COM1) which is the potential of the start point and the end point of the potential change in the first drive signal COM1. It is a waveform element whose potential changes up to 1 expansion potential VL1 (minimum potential in the first drive signal COM1). The first expansion hold element p2 is a waveform element that maintains the first expansion potential VL1 which is the terminal potential of the first preliminary expansion element p1 for a certain period of time. The first contraction element p3 has a relatively steep potential gradient (potential change per unit time) from the first expansion potential VL1 to the first contraction potential VH1 (maximum potential in the first drive signal COM1) higher than the first reference potential VB1. It is a waveform element that changes with rate). The first contraction hold element p4 is a waveform element that maintains the first contraction potential VH1 for a predetermined time. The first return expansion element p5 is a waveform element in which the potential returns from the first contraction potential VH1 to the first reference potential VB1. The potential of the first reference potential VB1 in the present embodiment is set to a potential (that is, an intermediate potential) between the first expansion potential VL1 and the first contraction potential VH1.

Immediately before the first drive pulse P1 is applied to the piezoelectric element 24 (before the ink is ejected), the first reference potential VB1 is continuously applied to the piezoelectric element 24, and the first reference potential VB1 is continuously applied to the pressure chamber 26. Does not cause a pressure change (pressure vibration) due to the drive of the piezoelectric element 24. When the drive pulse P1 is applied to the piezoelectric element 24 from this state, the piezoelectric element 24 is first bent toward the outside of the pressure chamber 26 (the side away from the nozzle 21) by the first pre-expansion element p1 to this. Along with this, the pressure chamber 26 expands from the reference volume corresponding to the first reference potential VB1 to the first expansion volume corresponding to the first expansion potential VL1. Due to this expansion, the meniscus in the nozzle 21 is largely drawn toward the pressure chamber 26 side. Then, the expanded state of the pressure chamber 26 is maintained for a predetermined time by the first expansion hold element p2, and then the piezoelectric element 24 is directed toward the inside of the pressure chamber 26 (the side approaching the nozzle 21) by the first contraction element p3. And bend. Along with this, the pressure chamber 26 is rapidly contracted from the first expansion volume to the first contraction volume corresponding to the first contraction potential VH1. As a result, the ink in the pressure chamber 26 is pressurized, and the meniscus in the nozzle 21 is pushed out to the injection side (the recording medium S side on the platen). Subsequently, the first contraction hold element p4 is supplied, and the contracted state of the pressure chamber 26 is maintained for a predetermined time. During this time, the ink is pushed out of the opening of the nozzle 21 on the nozzle forming surface by inertia, and the amount corresponding to the medium dot, which is the middle size of the ink droplets that can be ejected by the recording head 6. Ink droplets are ejected from the nozzle 21. After that, the first return expansion element p5 is applied to the piezoelectric element 24, and the piezoelectric element 24 is displaced to the first reference potential VB1. As a result, the pressure chamber 26 expands from the contraction volume to the reference volume corresponding to the first reference potential VB1.

FIG. 6 is a waveform diagram illustrating an example of the configuration of the second drive signal COM2 in the initial state in the present embodiment. Further, FIG. 7 is a waveform diagram of the second drive pulse P2 included in the second drive signal COM2 in the initial state. The second drive signal COM2 in the present embodiment is repeatedly generated from the drive signal generation circuit 10 in the unit cycle T defined by the timing signal PTS and the latch signal LAT, similarly to the first drive signal COM1. In this second drive signal COM2, only the second drive pulse P2 is generated in the unit period T. The second drive pulse P2 in the present embodiment is a drive pulse for ejecting the smallest ink droplet (small dot) among the ink droplet sizes that can be ejected from the nozzle 21 of the recording head 6. As shown in FIG. 7, the second drive pulse P2 in the present embodiment includes the second pre-expansion element p11, the second expansion hold element p12, the second contraction element p13, the first intermediate hold element p14, and the like. It is composed of a re-expansion element p15, a second intermediate hold element p16, a re-contraction element p17, a re-contraction hold element p18, and a second return expansion element p19.

The second pre-expansion element p11 is different from the first reference potential VB1 of the first drive pulse P1 (in this embodiment, higher than the first reference potential VB1), and the second reference potential VB2 (in the second drive signal COM2). It is a waveform element whose potential changes with a constant gradient from the intermediate potential) to the second expansion potential VL2 (minimum potential in the second drive signal COM2) lower than the second reference potential VB2. The second expansion hold element p12 is a waveform element that maintains the second expansion potential VL2, which is the terminal potential of the second preliminary expansion element p11, for a certain period of time. The second contraction element p13 is a waveform element whose potential changes from the second expansion potential VL2 to the first intermediate contraction potential VM1 which is higher than the second expansion potential VL2 and lower than the second contraction potential VH2 described later. The first intermediate hold element p14 is a waveform element that maintains the first intermediate contraction potential VM1 for a certain period of time. The re-expansion element p15 is a waveform element whose potential drops from the first intermediate contraction potential VM1 to the second intermediate expansion potential VM2 which is lower than the first intermediate contraction potential VM1 and higher than the second expansion potential VL2. The second intermediate hold element p16 is a waveform element that maintains the second intermediate expansion potential VM2 for a certain period of time. The recontraction element p17 is a waveform element whose potential changes from the second intermediate expansion potential VM2 to the second contraction potential VH2 (maximum potential in the second drive signal COM2) higher than the first intermediate contraction potential VM1. The re-contraction hold element p18 is a waveform element that maintains the second contraction potential VH2 for a certain period of time. The second return expansion element p19 is a waveform element in which the potential returns from the second contraction potential VH2 to the second reference potential VB2. The potential of the second reference potential VB2 in the present embodiment is set to a potential (that is, an intermediate potential) between the second expansion potential VL2 and the second contraction potential VH2.

When the second drive pulse P2 is applied to the piezoelectric element 24, first, the piezoelectric element 24 is bent toward the outside of the pressure chamber 26 by the second pre-expansion element p11, and the pressure chamber 26 is seconded accordingly. It expands from the reference volume corresponding to the reference potential VB2 to the second expansion volume corresponding to the second expansion potential VL2, and the meniscus in the nozzle 21 is largely drawn toward the pressure chamber 26 side. The expanded state of the pressure chamber 26 is maintained for a predetermined time by the second expansion hold element p12. After being held by the second expansion hold element p12, the piezoelectric element 24 is rapidly bent toward the inside of the pressure chamber 26 by the second contraction element p13. Along with this, the pressure chamber 26 is contracted from the second expansion volume to the intermediate contraction volume corresponding to the first intermediate contraction potential VM1. As a result, the ink in the pressure chamber 26 is pressurized, and the meniscus is pushed out to the injection side. After that, the first intermediate hold element p14 is applied to the piezoelectric element 24, and the state in which the pressure chamber 26 is contracted is maintained for a predetermined time.

Subsequently, when the re-expansion element p15 is applied to the piezoelectric element 24, the piezoelectric element 24 suddenly bends toward the outside of the pressure chamber 26. Along with this, the pressure chamber 26 expands again from the intermediate contraction volume to the intermediate expansion volume corresponding to the second intermediate expansion potential VM2. Here, inside the nozzle 21, the ink in the central portion (the portion closer to the virtual central axis of the nozzle 21) is more likely to move following the pressure change in the pressure chamber 26, while the portion closer to the inner wall surface of the nozzle is more likely to move. Since it is difficult to follow the pressure change due to the influence of viscosity, the moving speed becomes slow. Therefore, when the pressure chamber 26 is rapidly expanded, the central portion of the meniscus is mainly pulled back to the pressure chamber 26 side, while the portion of the meniscus near the inner wall surface of the nozzle 21 is located closer to the injection side than the central portion. do. The expanded state of the pressure chamber 26 is maintained for a predetermined time by the second intermediate hold element p16.

After the second intermediate hold element p16, the re-shrinkage element p17 causes the piezoelectric element 24 to flex more toward the inside of the pressure chamber 26. Along with this, the pressure chamber 26 is rapidly contracted from the intermediate expansion volume to the second contraction volume corresponding to the second contraction potential VH2. As a result, the ink in the pressure chamber 26 is pressurized, and the central portion of the meniscus, which easily follows the pressure change, is pushed out to the injection side. The contracted state of the pressure chamber 26 is maintained for a predetermined time by the re-contracted hold element p18. After the re-contraction hold element p18, the second return expansion element p19 is applied to the piezoelectric element 24, and the piezoelectric element 24 is displaced to the reference position corresponding to the second reference potential VB2. As a result, the pressure chamber 26 expands from the second contraction volume to the reference volume corresponding to the second reference potential VB2. Since the ink in the nozzle 21 is drawn in the direction opposite to this direction while the central portion of the meniscus is mainly extending in the injection direction due to the inertial force due to the re-shrinkage element p17, the ink in the nozzle 21 is drawn into the injection side of the central portion of the meniscus. The extruded portion is separated from the ink in the nozzle 21, and this separated portion flies toward the recording medium S as ink droplets corresponding to small dots smaller than the ink droplets ejected by the first drive pulse P1. do.

FIG. 8 is a waveform diagram illustrating a drive waveform according to the recording gradation. More specifically, waveform 1 in FIG. 8 is a drive pulse selection pattern when recording small dots, waveform 2 in FIG. 8 is a drive pulse selection pattern when recording medium dots, and waveform 3 in FIG. 8 is. The selection patterns of the drive pulses when recording large dots are shown. In the present embodiment, a total of four gradations can be expressed in the formation region of one pixel (constituent unit such as an image) in the recording medium S, including non-recording in which dots are not formed. That is, by changing the number and types of drive pulses applied to the piezoelectric element 24 within the unit period T, the size of dots recorded for one pixel region (virtual pixel formation region in the recording medium S) can be changed. Can be different. For example, when forming small dots in the pixel region in the unit cycle T, the waveform 1 in which only the second drive pulse P2 in the unit cycle T of the second drive signal COM2 is selected is applied to the piezoelectric element 24. Further, when forming a middle dot in the pixel region in the unit cycle T, the waveform 2 in which one first drive pulse P1 in the unit cycle T of the first drive signal COM1 is selected is applied to the piezoelectric element 24. Further, when forming a large dot in the pixel region in the unit cycle T, the waveform 3 in which two first drive pulses P1 in the unit cycle T of the first drive signal COM1 are selected is applied to the piezoelectric element 24.

By the way, it is known that when the above-mentioned drive waveform is applied to the piezoelectric element 24 and the piezoelectric element 24 is continuously driven, the deformation characteristics of the piezoelectric element 24 deteriorate and the ink injection amount (ejection amount) decreases. Has been done. FIG. 9 is a graph for explaining the relationship between the energization time in the waveforms 1, waveforms 2 and waveforms 3 and the rate of change in the ink injection amount (Iw). The vertical axis in FIG. 9 is the rate of change in the injection amount (Iw) of the ink droplets ejected when the drive waveform is applied to the piezoelectric element 24 (specifically, when the piezoelectric element 24 is not deteriorated (in other words, in other words). (When the energization time is 0), the rate of change based on the injection amount of ink droplets according to the drive waveform). In short, the vertical axis in FIG. 9 represents the degree of deterioration of the piezoelectric element 24. Further, the horizontal axis in FIG. 9 is the energization time to the piezoelectric element 24, that is, the cumulative time (integrated time) when the drive waveform is applied to the piezoelectric element 24.

As shown in the graph of FIG. 9, it can be seen that as the energization time becomes longer, the amount of ink ejected decreases, that is, the piezoelectric element 24 deteriorates. Here, as described above, the waveform 2 and the waveform 3 are drive waveforms composed of the first drive pulse P1 and changing with reference to the first reference potential VB1, whereas the waveform 1 is the second drive pulse P2. It is a drive waveform that changes with reference to a second reference potential VB2 that is higher than the first reference potential VB1. That is, the waveform 1 has a higher reference potential as a reference for the change in potential than the waveforms 2 and 3. In short, the potential of waveform 1 is higher than the potentials of waveform 2 and waveform 3 for most of the period during which the drive waveform is applied. As can be seen from the graph of FIG. 9, since the reference potentials of the waveform 2 and the waveform 3 are aligned to the same potential, the degree of deterioration of the piezoelectric element 24 when the waveform 2 is continuously applied and the waveform 3 are applied. The degree of deterioration in the case of the piezoelectric element 24 when the continuation is continued is substantially the same. On the other hand, since the reference potential of the waveform 1 is set higher than that of the waveform 2 and the waveform 3, the degree of deterioration of the piezoelectric element 24 when the waveform 1 is continuously applied is such that the waveform 2 or the waveform 3 is continuously applied. It is faster than the degree of deterioration in the case of the piezoelectric element 24 in the case. Therefore, in the present invention, the potential difference Vh1 and Vh2 (hereinafter referred to as the voltage value of the drive waveform) between the maximum potential and the minimum potential of the drive waveform is corrected to be large according to the degree of this deterioration.

The correction of the drive waveform in this embodiment will be described. FIG. 10 is a table for explaining an example of the correction coefficient table. FIG. 11 is a flowchart illustrating a flow of a driving waveform correction method. First, the number of times of the timing signal PTS of the drive waveform is set as a count value (corresponding to the count value regarding the number of times of supply of the drive waveform in the present invention), and is measured for each type of drive waveform (step S1). That is, the timing signals PTS of all the drive waveforms supplied to the piezoelectric element 24 are counted, and the number of times is stored as a count value. As shown in FIG. 10, the printer 1 in the present embodiment has waveforms 1 to 3 which are discharge waveforms, waveforms 4 to 7 which are flushing waveforms, waveforms 8 to 10 which are inspection waveforms, and fine waveforms. It has waveforms 11 to 13 which are vibration waveforms, and waveforms 14 and 15 which are ultrasonic waveforms. That is, it has a total of 15 types of drive waveforms, that is, waveforms 1 to 15. These waveforms 1 to 15 differ in the reference potential, the unit period T, the number of drive pulses included in the waveform, or at least one or more of the shapes of the drive pulses. For example, the reference potential and the shape of the drive pulse are different between the waveform 1 and the waveform 2, and the number of drive pulses is different between the waveform 2 and the waveform 3.

Next, the count value of the timing signal PTS is multiplied by a coefficient based on at least one of the reference potential and the period to obtain an aging value that is an index of the degree of deterioration of the piezoelectric element 24 (step S2). In this embodiment, the aging value is obtained by multiplying both the coefficient a based on the period and the coefficient b based on the reference potential. Specifically, the aging value A can be obtained by, for example, the following equation (1).
A = (PTS1 x a1 x b1) + (PTS2 x a2 x b2) + ...
+ (PTS14 x a14 x b14) + (PTS15 x a15 x b15) ... (1)
Here, PTS1 to PTS15 are count values of the respective timing signals PTS of waveforms 1 to 15. Further, the coefficients a1 to a15 are coefficients related to each period of the waveforms 1 to 15, and the coefficients b1 to b15 are coefficients related to each reference potential of the waveforms 1 to 15. These coefficients a1 to a15 and b1 to b15 are stored as a table in a storage device (not shown) of the control circuit 9.

More specifically, the coefficients a1 to a15 represent the interval of the timing signal PTS, and for example, the length of the unit cycle T or the ratio of the length of the unit cycle T to the reference time (which can be arbitrarily set) is used. Be done. As shown in the above equation (1), by multiplying the coefficients a1 to a15 by PTS1 to PTS15, an index (or the length of the energization time itself) relating to each energization time of the waveforms 1 to 15 can be obtained. can. On the other hand, the coefficients b1 to b15 are coefficients for correcting an index related to the energization time (or the length of the energization time itself), and are determined according to the value of the current reference potential. The coefficients b1 to b15 are set to higher values as the driving waveform has a higher reference potential, and are set to lower values as the driving waveform has a lower reference potential. That is, the higher the reference potential of the drive waveform, the more easily the piezoelectric element 24 deteriorates when it is supplied to the piezoelectric element 24, so that the aging value is set to be large. In short, in the graph of FIG. 9, when the horizontal axis is the aging value, the drive waveform with a higher reference potential tends to move to the right side of the graph, and the ink injection amount tends to decrease due to deterioration of the piezoelectric element 24. The coefficients b1 to b15 correct the count of the aging value accordingly. On the other hand, the lower the reference potential is, the less likely it is that the piezoelectric element 24 will deteriorate when it is supplied to the piezoelectric element 24. Therefore, the aging value is set to be smaller. In short, in the graph of FIG. 9, the lower the reference potential of the drive waveform, the more difficult it is to move to the right side of the graph, and the more difficult it is to reduce the amount of ink ejected. Therefore, the coefficients b1 to b15 correct the count of the aging value accordingly. do. As described above, the coefficients b1 to b15 are correction coefficients for finely adjusting the aging value according to the reference potential. When the reference potential is reset to a potential different from the initial setting by the correction, the coefficient value can be changed based on the corrected reference potential. Further, when the discharge waveform is corrected according to the temperature, even if the reference potential is reset to a potential different from the initial setting by the temperature correction, the coefficient value is changed based on the reference potential after the temperature correction. You can also do it. In short, the coefficients b1 to b15 can be reset based on the reference potential by calculation, table, or the like.

After obtaining the aging value, the correction value of the drive waveform is calculated based on the aging value (step S3). Here, the correction value is a voltage value of the drive waveform (difference between the maximum potential and the minimum potential in the drive waveform) in consideration of the degree of deterioration of the piezoelectric element 24, and is calculated by, for example, the following equation (2).
Vhn = Vhn0 + (A × cn)… (2)
Here, Vhn is a correction value in the waveform n, and Vhn0 is a voltage value of the waveform n in the initial state (initial setting). cn is a coefficient obtained by multiplying the aging value A by a voltage value (A × cn) for supplementing the initial voltage value Vhn0 of the waveform n. This coefficient cn is obtained for each type of drive waveform. The coefficient cn can be calculated by an experiment, a simulation, or the like. Specifically, for example, a linear approximation equation can be obtained from the graph corresponding to each waveform shown in FIG. 9, and a value corresponding to the reciprocal of the slope of the equation can be used as the coefficient cn. Further, the value of the coefficient cn is not limited to this, and can be arbitrarily set according to the deterioration method of the piezoelectric element 24. In short, the amount of ink ejected by the drive waveform to which the correction value Vhn is applied compensates for the decrease in the amount of ink ejected due to the deterioration of the piezoelectric element 24, and the ink is equivalent to the initial (state in which the piezoelectric element 24 is not deteriorated). The coefficient cn may be any value as long as it can be corrected so as to have the injection amount of. As shown in FIG. 10, such a coefficient cn (coefficient 1 to coefficient c15 of each waveform 1 to 15) is stored as a table in a storage device (not shown) of the control circuit 9.

In the above equation (2), the correction value Vhn is expressed by a linear equation of the aging value A, but the present invention is not limited to this. The correction value Vhn can also be obtained by a higher-order equation. Further, in the above equation (2), the voltage value (A × cn) is added to the correction value Vhn, but the method is not limited to this. For example, the correction value Vhn may be obtained as in the following equation (3).
Vhn = Vhn0 × (A × cn ′)… (3)
In this case, (A × cn ′) is a correction magnification multiplied by the voltage value Vhn0 of the waveform n in the initial state (initial setting). Even in this case, the coefficient cn'is stored as a table in the storage device (not shown) of the control circuit 9.

The above-mentioned correction value is calculated at least in the discharge waveform (waveform 1 to waveform 3), and is applied as a voltage value of the corrected discharge waveform. That is, the voltage value of the drive waveform is corrected based on the correction value (step S4). In the present embodiment, each time the recording head 6 performs one main scan (unit scan), a correction value based on the aging value is calculated, and the voltage value of the drive waveform is corrected according to the correction value. Here, the correction value of the drive waveform is applied to the drive waveform each time one main scan (unit scan) is performed, and the correction value (difference between the voltage value before correction and the voltage value after correction). If does not exceed the minimum variable width of the voltage value of the drive waveform that can be generated by the drive signal generation circuit 10, it is not reflected in the actual drive waveform. For example, when the initial voltage value of the drive waveform is 20 V and the variable width of the voltage value of the drive waveform that can be generated by the drive signal generation circuit 10 is set in 0.1 V increments, the correction value is 20 V or more. If it is less than 1V, 20V is applied as the voltage value of the drive waveform, and if the correction value is 20.1V or more and less than 20.2V, 20.1V is applied as the voltage value of the drive waveform. That is, it is set to correct the actual drive waveform when the calculated correction value of the drive waveform is equal to or more than a predetermined value (in the present embodiment, the value set for each minimum unit of the variable width).

As described above, in the correction of the drive waveform in the present embodiment, the aging value as an index of the degree of deterioration is obtained based on the reference potential and the period of the drive waveform, so that a more accurate aging value can be obtained. .. As a result, the drive waveform can be appropriately corrected according to the aging value, and deterioration of the printed image quality can be suppressed. Further, since each coefficient is set for each type of drive waveform, more accurate correction can be performed according to the type of drive waveform. Further, in the present embodiment, since the aging value is obtained and the drive waveform is corrected each time the recording head 6 scans once, the drive waveform can be corrected more appropriately, and the image quality to be printed can be improved. Deterioration can be further suppressed. Then, as described above, even when the reference potential or the unit period T of each drive waveform is different from each other, the correction can be performed according to the type of the drive waveform. Further, even when the number of drive pulses and the shape of the drive pulses of each drive waveform are different from each other, the correction can be performed according to the type of the drive waveform.

In the above-described embodiment, the drive waveform is corrected each time the main scan is performed, but the present invention is not limited to this. For example, the drive waveform may be corrected each time the main scan is performed a plurality of times. In short, the aging value may be obtained and the drive waveform may be corrected each time the recording head 6 scans once or a plurality of times. Further, after the power of the printer 1 is turned on, the aging value may be obtained at the timing before the printing operation (job) is started, or during the printing operation (between jobs), and the drive waveform may be corrected. By doing so, it is possible to suppress the deterioration of the image quality after the power is turned on and the deterioration of the image quality in each printing operation. Further, at a predetermined timing (for example, every time the recording head 6 scans once or a plurality of times, after the power of the printer 1 is turned on, before the printing operation (job) is started, or during the printing operation (between jobs). Etc.), the aging value is obtained, and if the aging value is equal to or greater than the predetermined value, the correction value of the drive waveform is calculated to correct the drive waveform, and if the aging value is equal to or less than the predetermined value. The current drive waveform may be applied without calculating the correction value of the drive waveform. In other words, at a predetermined timing, it is determined from the calculated aging value whether or not correction is necessary, and if correction is necessary, the correction value of the drive waveform is calculated to correct the drive waveform, and the correction is performed. If it is not necessary, the current drive waveform may be applied without calculating the correction value of the drive waveform. Further, in the above-described embodiment, the aging value is based on the count value of the timing signal PTS, the coefficients a1 to a15 relating to the period of the waveforms 1 to 15, and the coefficients b1 to b15 relating to the reference potential of the waveforms 1 to 15. , And by extension, the correction value was calculated, but it is not limited to this. The aging value and the correction value can be calculated based only on the count value of the timing signal PTS and the coefficients a1 to a15 relating to the period of the waveforms 1 to 15. In that case, in the above equation (1), an equation in which all the values of the coefficients b1 to b15 are set to 1 may be used. Further, the aging value and the correction value can be calculated only based on the count value of the timing signal PTS and the coefficients b1 to b15 relating to the reference potential of the waveforms 1 to 15. In that case, in the above equation (1), an equation in which all the values of the coefficients a1 to a15 are set to 1 may be used.

Further, the coefficient cn in the above-described embodiment has one value for one waveform (for example, a linear approximation formula is obtained from a graph showing the degree of deterioration of the piezoelectric element 24 as shown in FIG. 9, and the slope thereof is calculated. (Value according to the reciprocal) was used, but it is not limited to this. For example, the value of the coefficient cn may be changed according to the interval of the aging value. Specifically, the correction in the case of the waveform 1 will be described. FIG. 12 is a graph showing the relationship between the energization time in the waveform 1 described above and the rate of change in the ink injection amount (Iw). FIG. 13 is a table relating to the coefficient c1 of the waveform 1. As shown in the graph of FIG. 12, for example, a section T1 in which the aging value is 0 or more and less than t1, a section T2 in which the aging value is t1 or more and less than t2, and a section T3 in which the aging value is t2 or more and less than t3. It is divided into five sections, a section T4 in which the aging value is t3 or more and less than t4, and a section T5 in which the aging value is t5 or more, and the coefficient is obtained from the graph in each section. Then, these coefficients are stored as a table in a storage device (not shown) of the control circuit 9. For example, as shown in FIG. 13, the coefficient c11 of the waveform 1 in the section T1, the coefficient c12 of the waveform 1 in the section T2, the coefficient c13 of the waveform 1 in the section T3, the coefficient c14 of the waveform 1 in the section T4, and the coefficient c5 in the section T5. The coefficient c15 of the waveform 1 is stored as a table. Although not shown, the coefficients corresponding to each of the sections T1 to T5 are also stored in the other waveforms 2 to 15.

Then, the correction value Vhn of the drive waveform is obtained by, for example, the following equation (4).
Vhn = Vhn'+ A'x cnx ... (4)
Here, Vhn'is the current voltage value (setting voltage value) of the waveform n, and A'is the increase in the aging value from the time when the correction value was calculated last time. cnx is a coefficient of the Tx interval in the waveform n. By making the value of the coefficient cnx different according to the interval of the aging value and obtaining the correction value of the drive waveform in this way, the drive waveform can be corrected more accurately. The method for calculating the aging value A is obtained from the equation (1) in the same manner as in the above-described embodiment. Although omitted in the table shown in FIG. 13, the coefficients a1 to a15 and b1 to b15 for obtaining the aging value A are stored as a table in the storage device (not shown) of the control circuit 9. .. Further, since other configurations and a method for correcting the drive waveform are the same as those in the above-described embodiment, the description thereof will be omitted.

By the way, in each of the above-described embodiments, the number of times of the timing signal PTS of the drive waveform is used as a count value, and the aging value is obtained by measuring each type of the drive waveform, but the present invention is not limited to this. Not limited to the timing signal PTS, a signal related to another period such as a latch signal LAT may be measured as a count value, and an aging value may be obtained based on this.

It is also possible to measure the number of times the drive pulse is applied to the piezoelectric element as a count value to obtain the aging value. In this case, for example, the aging value A can be obtained by the following equation (5).
A = (PC1 x a1'x b1 x d1) + (PC2 x a2'x b2 x d2)
+ ... + (PC15 x a15'x b15 x d15) ... (5)
Here, PC1 to PC15 are count values of drive pulses (corresponding to count values related to the number of times the drive waveform is supplied in the present invention). The drive pulse to be counted is not limited to the drive pulse for ejecting ink from the nozzle 21, and also includes the drive pulse for vibrating the meniscus in the nozzle 21 to the extent that the ink is not ejected from the nozzle 21. Further, the coefficients a1'to a15' are coefficients for deriving an index regarding the energization time from the count value based on the number of drive pulses included in the unit period T of the waveforms 1 to 15. For example, since only one drive pulse is included in the unit period T of the waveform 1 and the waveform 2, the values of the coefficients a1'and the coefficient a2' corresponding to these waveforms 1 and 2 correspond to the unit period T. Value. On the other hand, since two drive pulses are included in the unit cycle T of the waveform 3, the value of the coefficient a3'corresponding to this is a value corresponding to a value halved of the unit cycle T.

Further, the coefficients b1 to b15 are the same coefficients as the coefficients b1 to b15 of the above-described embodiment, and are coefficients related to the reference potential of the waveforms 1 to 15. That is, the coefficients b1 to b15 are correction coefficients for finely adjusting the aging value according to the reference potential. Further, the coefficients d1 to d15 are correction coefficients for finely adjusting the aging value according to the shape of the drive pulse (for example, the value of the maximum voltage of the drive pulse, the application time of the maximum voltage, etc.). The coefficients d1 to d15 are set according to the degree of deterioration of the piezoelectric element 24 due to the drive pulse, not the degree of deterioration of the piezoelectric element 24 due to the reference potential. For example, since the second drive pulse P2 included in the waveform 1 and the first drive pulse P1 included in the waveform 2 or the waveform 3 have different waveform shapes, the piezoelectric element 24 is applied when applied to the piezoelectric element 24. Deterioration may vary. In such a case, the coefficient d1 corresponding to the waveform 1, the coefficient d2 corresponding to the waveform 2, and the coefficient d3 corresponding to the waveform 3 are set to different values according to the degree of deterioration thereof. On the other hand, since the first drive pulse P1 included in the waveform 2 and the first drive pulse P1 included in the waveform 3 have the same waveform shape, the piezoelectric element 24 deteriorates when applied to the piezoelectric element 24. The degree of is almost the same. Therefore, the coefficient d2 corresponding to the waveform 2 and the coefficient d3 corresponding to the waveform 3 are set to the same value. If the degree of deterioration of the piezoelectric element 24 is approximately the same or negligible for each type of drive pulse included in each waveform, the values of the coefficients d1 to d15 in the above equation (5) are set to 1. You can do it. Further, these coefficients a1'to a15', b1 to b15, and d1 to d15 are stored as a table in a storage device (not shown) of the control circuit 9 (see, for example, FIG. 14).

Then, when the aging value is obtained as described above, the correction value of the drive waveform is calculated based on the aging value in the same manner as in the above-described embodiment. That is, the correction value Vhn in the waveform n is calculated from the above equation (2). Since the coefficient cn in this embodiment is the same as the coefficient cn in the first embodiment described above, the description thereof will be omitted. Further, the coefficients c1 to c15 are stored as a table in a storage device (not shown) of the control circuit 9 together with the coefficients a1'to a15', b1 to b15, and d1 to d15 (see, for example, FIG. 14). Since the other configurations and the method for correcting the drive waveform are the same as those in the above-described embodiment, the description thereof will be omitted. Then, by calculating the aging value in consideration of the shape of the drive pulse in this way, the aging value, that is, the degree of deterioration of the piezoelectric element 24 can be obtained more accurately. As a result, the drive waveform can be corrected more accurately according to the degree of deterioration of the piezoelectric element 24, and the deterioration of the image quality can be further suppressed.

The above equation for correcting the drive waveform and the coefficients used in the equation can be derived in advance from the experimental results and simulation results. Further, instead of using such an equation, the energization time or the voltage value (correction value) of the drive waveform corresponding to the aging value may be stored in the storage device as a table. In this case, the energization time or the aging value is counted, and the voltage value of the drive waveform corresponding to the count value is acquired by referring to the table.

Further, in each of the above-described embodiments, a so-called bending vibration type piezoelectric element has been exemplified as the pressure generating element, but the pressure generating element is not limited to this. For example, the present invention can be applied to a configuration in which a so-called longitudinal vibration type piezoelectric element is used as a pressure generating element. In this case, the polarity of the waveform of each of the above drive pulses is inverted.

The present invention is not limited to printers, as long as it is a liquid injection device having a configuration in which droplets are ejected from a nozzle by driving a pressure generating element, and various inkjet recording devices such as plotters, facsimile devices, copiers, etc. It can also be applied to a device and a liquid injection device other than a recording device, for example, a display manufacturing device, an electrode manufacturing device, a chip manufacturing device, and the like.

1 ... Printer, 2 ... Print engine, 3 ... Paper feed mechanism, 4 ... Carriage movement mechanism, 5 ... Linear encoder, 6 ... Recording head, 7 ... Printer controller, 9 ... Control circuit, 10 ... Drive signal generation circuit, 12 ... Head controller, 16 ... carriage, 17 ... ink cartridge, 18 ... guide rod, 20 ... case, 21 ... nozzle, 22 ... nozzle plate, 23 ... flow path substrate, 24 ... piezoelectric element, 25 ... common liquid chamber, 26 ... pressure Room, 27 ... Supply port, 28 ... Ink introduction path

Claims (9)

A nozzle that injects liquid and
A pressure chamber communicating with the nozzle and
A pressure generating element that causes a pressure change in the liquid in the pressure chamber,
A drive waveform generator that generates a plurality of types of drive waveforms supplied to the pressure generating element,
It is a driving method of a liquid injection device including
A step of measuring the count value related to the number of times the drive waveform is supplied to the pressure generating element for each type of the drive waveform, and
A step of multiplying the count value by a coefficient based on at least one of a reference potential or a period that serves as a reference for a change in the potential of the drive waveform to obtain an aging value that is an index of the degree of deterioration of the pressure generating element.
The step of correcting the drive waveform according to the aging value and
A method for driving a liquid injection device, which comprises. The method for driving a liquid injection device according to claim 1, wherein the coefficient is set for each type of the drive waveform. The method for driving a liquid injection device according to claim 1 or 2, wherein the drive waveform is corrected when the correction value of the drive waveform calculated based on the aging value is equal to or greater than a predetermined value. It has the nozzle, the pressure chamber, and the pressure generating element, and includes a liquid injection head that injects liquid from the nozzle while moving in the main scanning direction.
The drive of the liquid injection device according to any one of claims 1 to 3, wherein the aging value is obtained and the drive waveform is corrected each time the liquid injection head scans once or a plurality of times. Method. The method for driving a liquid injection device according to any one of claims 1 to 4, wherein the aging value is obtained and the drive waveform is corrected after the power of the liquid injection device is turned on. According to any one of claims 1 to 5, the driving waveform is corrected by obtaining the aging value before starting the printing operation of injecting the liquid from the nozzle toward the landing target. The method for driving a liquid injection device according to the description. The method for driving a liquid injection device according to any one of claims 1 to 6, wherein at least one of the reference potential and the period is different from each other in the plurality of types of drive waveforms. The liquid injection according to any one of claims 1 to 7, wherein at least one of the number of pulses and the shape of the pulses included in the drive waveform is different from each other in the plurality of types of drive waveforms. How to drive the device. A nozzle that injects liquid and
A pressure chamber communicating with the nozzle and
A pressure generating element that causes a pressure change in the liquid in the pressure chamber,
A drive waveform generator that generates a plurality of types of drive waveforms supplied to the pressure generating element,
It is a liquid injection device equipped with
A count value relating to the number of times the drive waveform is supplied to the pressure generating element is measured for each type of the drive waveform.
The count value is multiplied by a coefficient based on at least one of a reference potential or a period that serves as a reference for a change in the potential of the drive waveform to obtain an aging value that is an index of the degree of deterioration of the pressure generating element.
A liquid injection device characterized in that the drive waveform is corrected according to the aging value.

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