JP2016036994A - Liquid ejection device, control method for liquid ejection device and control program for liquid ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate remaining amounts of ink.SOLUTION: There is provided a liquid ejection device comprising: a driving signal generating part that generates a driving signal; a piezoelectric element that is displaced according to the driving signal; a storage part that stores liquid; a pressure chamber, into which liquid supplied from the storage part is filled, whose inner pressure is increased and decreased by displacement of the piezoelectric element; a nozzle that can eject the liquid filled into the pressure chamber; a detecting part that detects residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the driving signal; a remaining amount estimating part that estimates remaining amounts of the liquid stored in the storage part; and a remaining amount memorizing part that memorizes estimated values of the remaining amounts of the liquid estimated by the remaining amount estimating part. The remaining amount estimating part comprises: an ejection amount estimating part that estimates, on the basis of a result of detection performed by the detecting part, ejection amounts of the liquid ejected from the nozzle; and a remaining amount renewing part that subtracts estimated values of the ejection amounts estimated by the ejection amount estimating part from the estimated values of the remaining amounts of the liquid memorized by the remaining amount memorizing part and causes the remaining amount memorizing part to memorize the subtraction result as estimated values of the remaining amounts of the liquid.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid ejection apparatus, a method for controlling the liquid ejection apparatus, and a control program for the liquid ejection apparatus.

  Liquid ejecting apparatuses such as ink jet printers that print an image on a medium by driving a piezoelectric element to eject ink filled in a cavity of an ejecting section from a nozzle are widely used. In such a liquid ejecting apparatus, ink is usually supplied from an ink cartridge that stores ink to the cavity. When the ink stored in the ink cartridge is exhausted during the printing process and the supply of ink to the cavity is interrupted, the printing process is interrupted. Therefore, in order to execute the printing process smoothly, it is necessary to prevent the ink from running out that the ink stored in the ink cartridge during the printing process is exhausted. In order to prevent the ink from running out, it is preferable to accurately grasp the remaining amount of ink stored in the ink cartridge and to notify the user when the remaining amount of ink has decreased.

By the way, there may be a so-called ejection abnormality in which ink cannot be ejected accurately from the nozzle of the ejection section due to thickening of the ink inside the ejection section or mixing of bubbles. When an ejection abnormality occurs, the amount of ink ejected from the ejection unit also changes, and it may become impossible to grasp the remaining amount of ink stored in the ink cartridge.
Therefore, in order to make it possible to grasp the remaining amount of ink even in the case of such an ejection abnormality, the ink ejection amount is estimated based on the number of ejection units that cannot eject ink. The technique which performs is proposed (for example, patent document 1).

JP 2010-201879 A

  However, for ejection abnormalities where ink cannot be ejected normally from the nozzles of the ejection section, in addition to the case where ink cannot simply be ejected from the nozzle, the amount of ink ejected from the nozzle decreases, or conversely, the ink from the nozzle In some cases, the amount of discharge increases. Therefore, as in the technique described in Patent Document 1, it is not possible to accurately grasp the remaining ink amount even if the remaining ink amount is estimated by grasping whether ink is ejected from the ejection unit or not. Existed.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a technique that makes it possible to accurately estimate the remaining amount of ink.

  In order to solve the above problems, a liquid ejection device according to the present invention includes a drive signal generation unit that generates a drive signal, a piezoelectric element that is displaced according to the drive signal, a storage unit that stores liquid, The liquid supplied from the storage unit is filled inside, a pressure chamber in which the internal pressure is increased or decreased by displacement of the piezoelectric element, and the pressure chamber communicates with the pressure chamber according to the increase or decrease of the pressure in the pressure chamber. A nozzle capable of discharging the liquid filled in the pressure chamber, a detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal, and the storage unit A remaining amount estimating unit that estimates the remaining amount of liquid, and a remaining amount storing unit that stores an estimated value of the remaining amount of liquid estimated by the remaining amount estimating unit, wherein the remaining amount estimating unit includes: Based on the detection result of the detection unit, The estimated discharge amount estimated by the discharge amount estimation unit is subtracted from the estimated value of the remaining amount of liquid stored in the remaining amount storage unit and the discharge amount estimation unit that estimates the discharged amount of liquid. And a remaining amount updating unit that stores the result of the subtraction in the remaining amount storage unit as an estimated value of the remaining amount of the liquid.

According to this invention, the discharge amount of the liquid discharged from the nozzle is estimated based on the detection result of the residual vibration generated in the pressure chamber. The waveform of the residual vibration changes according to the discharge state of the liquid from the nozzle. That is, the discharge state of the liquid from the nozzle can be classified based on the residual vibration.
For this reason, even if the liquid discharge amount from the nozzle increases or decreases according to the liquid discharge state from the nozzle, the liquid discharge amount from the nozzle is estimated based on the detection result of the residual vibration. It is possible to estimate an accurate discharge amount according to the discharge state of the liquid from the nozzle. In other words, even if the amount of liquid discharged from the nozzle increases or decreases depending on the state of liquid discharged from the nozzle, the remaining amount of liquid stored in the storage unit is determined by the state of liquid discharged from the nozzle. Can be estimated accurately according to

  Moreover, in the liquid ejection apparatus described above, the ejection amount estimation unit is based on a determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit, and a determination result of the determination unit. An estimation execution unit that estimates a discharge amount of the liquid discharged from the nozzle, and when the determination unit determines that the liquid cannot be discharged from the nozzle, from the nozzle It is also possible to estimate that the discharge amount of the liquid is “0”.

  According to this aspect, when the liquid cannot be ejected from the nozzle, it is estimated that the liquid ejection amount from the nozzle is “0”. Therefore, the remaining amount of the liquid stored in the storage unit can be accurately estimated. it can.

  Moreover, in the liquid ejection apparatus described above, the ejection amount estimation unit is based on a determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit, and a determination result of the determination unit. An estimation execution unit configured to estimate a discharge amount of the liquid discharged from the nozzle, and the estimation execution unit is configured so that the liquid oozes out of the pressure chamber from the nozzle. When it is determined that the discharge state is abnormal, it is estimated that the discharge amount of the liquid from the nozzle is small compared to a case where the discharge state is determined to be normal. .

  According to this aspect, when the liquid oozes out from the nozzle and the liquid oozed out from the nozzle prevents the liquid from being ejected from the nozzle, the liquid is ejected from the nozzle in comparison with the normal state. Therefore, the remaining amount of liquid stored in the storage unit can be accurately estimated.

Moreover, in the liquid ejection apparatus described above, the ejection amount estimation unit is based on a determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit, and a determination result of the determination unit. An estimation execution unit configured to estimate a discharge amount of the liquid discharged from the nozzle, and the estimation execution unit includes the determination unit configured to discharge the liquid because the liquid in the pressure chamber is thickened. When it is determined that the state is abnormal, compared to the case where it is determined that the discharge state is normal,
It may be characterized that it is estimated that the discharge amount of the liquid from the nozzle is small.

  According to this aspect, when the liquid in the pressure chamber is thickened and the liquid discharge from the nozzle is hindered by the thickened liquid, the liquid discharge state from the nozzle is normal compared to the case Since the amount of liquid discharged from the nozzle is estimated to be small, the remaining amount of liquid stored in the storage unit can be accurately estimated.

  Moreover, in the liquid ejection apparatus described above, the ejection amount estimation unit is based on a determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit, and a determination result of the determination unit. An estimation execution unit that estimates an ejection amount of the liquid ejected from the nozzle, and the estimation execution unit has an abnormality in the ejection state because the determination unit is separated from a partition wall of the pressure chamber When it is determined that the discharge state is normal, it may be estimated that the discharge amount of the liquid from the nozzle is small compared to the case where the discharge state is determined to be normal.

  According to this aspect, since the partition wall of the pressure chamber is peeled off, the pressure in the pressure chamber cannot be increased or decreased sufficiently even if the piezoelectric element is displaced. For example, when the amount of liquid discharged from the nozzle is normal, it is estimated that the amount of liquid discharged from the nozzle is small compared to the case where the amount of liquid discharged from the nozzle is normal. Can be estimated accurately.

  The liquid ejection apparatus control method according to the present invention includes a drive signal generation unit that generates a drive signal, a piezoelectric element that is displaced according to the drive signal, a storage unit that stores liquid, and a supply from the storage unit. A pressure chamber in which the liquid is filled, and the pressure inside the pressure chamber is increased or decreased by displacement of the piezoelectric element, and the pressure chamber communicates with the pressure chamber according to the pressure increase or decrease in the pressure chamber. A nozzle capable of discharging the liquid filled in the liquid, a detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal, and a residual liquid stored in the storage unit. A remaining amount storage unit that stores an estimated value of the amount, and a method for controlling the liquid ejection device, based on the detection result of the detection unit, estimating the ejection amount of the liquid ejected from the nozzle, The estimated liquid discharge rate The remaining amount storing portion is subtracted from the estimated value of the remaining amount of the liquid storing, the result of the subtraction to be stored in the remaining amount storage unit as the estimated value of the remaining amount of the liquid, it is characterized.

  According to this invention, since the discharge amount of the liquid discharged from the nozzle is estimated based on the detection result of the residual vibration generated in the pressure chamber, the liquid discharge from the nozzle is performed according to the liquid discharge state from the nozzle. Even when the amount increases or decreases, it is possible to estimate an accurate discharge amount according to the discharge state of the liquid from the nozzle. Thereby, the remaining amount of the liquid stored in the storage unit can be accurately estimated.

  A control program for a liquid ejection apparatus according to the present invention is supplied from a drive signal generation unit that generates a drive signal, a piezoelectric element that is displaced according to the drive signal, a storage unit that stores liquid, and the storage unit. A pressure chamber in which the liquid is filled, and the pressure inside the pressure chamber is increased or decreased by displacement of the piezoelectric element, and the pressure chamber communicates with the pressure chamber according to the pressure increase or decrease in the pressure chamber. A nozzle capable of discharging the liquid filled in the liquid, a detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal, and a residual liquid stored in the storage unit. A control program for a liquid ejection apparatus comprising a remaining amount storage unit that stores an estimated value of an amount and a computer, wherein the computer estimates the remaining amount of the liquid stored in the storage unit And The remaining amount estimating unit stores the discharge amount estimating unit for estimating the discharge amount of the liquid discharged from the nozzle based on the detection result of the detecting unit, and the remaining amount storing unit. Subtract the estimated value of the discharge amount estimated by the discharge amount estimation unit from the estimated value of the remaining amount of liquid, and store the result of the subtraction in the remaining amount storage unit as the estimated value of the remaining amount of liquid. A quantity updating unit.

  According to this invention, since the discharge amount of the liquid discharged from the nozzle is estimated based on the detection result of the residual vibration generated in the pressure chamber, the liquid discharge from the nozzle is performed according to the liquid discharge state from the nozzle. Even when the amount increases or decreases, it is possible to estimate an accurate discharge amount according to the discharge state of the liquid from the nozzle. Thereby, the remaining amount of the liquid stored in the storage unit can be accurately estimated.

1 is a block diagram illustrating an outline of a configuration of an inkjet printer 1 according to an embodiment of the present invention. 1 is a schematic partial cross-sectional view of an inkjet printer 1. 2 is a schematic cross-sectional view of a recording head 30. FIG. 3 is a plan view illustrating an example of arrangement of nozzles N in the recording head 30. FIG. It is explanatory drawing which shows the change of the cross-sectional shape of the discharge part D when the drive signal Vin is supplied. 3 is a circuit diagram showing a simple vibration model representing residual vibration in a discharge section D. FIG. It is a graph which shows the relationship between the experimental value of residual vibration in case the discharge state in the discharge part D is normal, and a calculated value. It is explanatory drawing which shows the state of the discharge part D when a bubble mixes in the discharge part D inside. It is a graph which shows the experimental value and calculated value of a residual vibration in the state in which the bubble to the inside of the discharge part D was mixed. FIG. 6 is an explanatory diagram illustrating a state of a discharge unit D when ink near a nozzle N is fixed. It is a graph which shows the experimental value and calculated value of a residual vibration in the state which became unable to discharge ink by adhesion of the ink of nozzle N vicinity. It is explanatory drawing which shows the state of the discharge part D when paper dust adheres to the nozzle N vicinity. It is a graph which shows the experimental value and calculation value of a residual vibration in the state which cannot discharge ink by adhesion of the paper dust to the nozzle N vicinity. 3 is a block diagram illustrating a configuration of a drive signal generation unit 51. FIG. It is explanatory drawing which shows the decoding content of decoder DC. 5 is a timing chart showing the operation of a drive signal generation unit 51. 5 is a timing chart showing the operation of a drive signal generation unit 51. 3 is a timing chart showing a waveform of a drive signal Vin. 3 is a block diagram illustrating configurations of a residual vibration detection unit 52 and a switching unit 53. FIG. 5 is a timing chart showing the operation of a residual vibration detection unit 52. It is explanatory drawing for demonstrating determination information RS. It is explanatory drawing which shows an example of the data structure of discharge state management table TBL1. 6 is an explanatory diagram for explaining a failure of a discharge unit D. FIG. It is explanatory drawing which shows an example of the data structure of discharge amount information table TBL2. It is explanatory drawing which shows an example of the data structure of the discharge amount information table TBL2A which concerns on the modification 3 of this invention.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each figure, the size and scale of each part are appropriately changed from the actual ones. Further, since the embodiments described below are preferable specific examples of the present invention, various technically preferable limitations are attached thereto. However, the scope of the present invention is particularly limited in the following description. Unless otherwise stated, the present invention is not limited to these forms.

<A. Embodiment>
In the present embodiment, the liquid ejecting apparatus will be described by exemplifying an ink jet printer that ejects ink (an example of “liquid”) to form an image on a recording paper P (an example of “medium”).

<1. Overview of inkjet printers>
The configuration of the inkjet printer 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

FIG. 1 is a functional block diagram showing the configuration of the ink jet printer 1.
The inkjet printer 1 includes print data Img indicating an image to be formed (printed) in the inkjet printer 1 and the number of copies of the image to be formed by the inkjet printer 1 from a host computer (not shown) such as a personal computer or a digital camera. Copies information CP indicating Wcp is supplied. Then, the ink jet printer 1 executes a printing process in which an image indicated by the print data Img is formed on the recording paper P by the number of copies Wcp indicated by the copy number information CP. In the following, a series of processes from when the inkjet printer 1 receives the print data Img and the number of copies information CP to when the execution of the print processing for forming the image indicated by the print data Img by the number of copies Wcp indicated by the number of copies information CP is completed. This process may be referred to as a print job. In the present embodiment, it is assumed that the inkjet printer 1 is a line printer.

  As shown in FIG. 1, the inkjet printer 1 includes a head unit 5 provided with a plurality of ejection units D that eject ink, and four ink cartridges 31 (an example of a “storage unit”) that stores ink. ), A remaining amount estimating unit 20 that estimates the remaining amount of ink stored in each ink cartridge 31, a transport mechanism 7 for changing the relative position of the recording paper P with respect to the head unit 5, and each unit of the inkjet printer 1. A control unit 6 that controls the operation, a control program for the ink jet printer 1, a storage unit 60 that stores an estimated value of the remaining amount of ink that is an estimation result by the remaining amount estimation unit 20, and various other information, and an ejection unit D Maintenance processing for recovering the ink ejection state in the ejection section D to normal when it is detected that an ejection abnormality has occurred. It comprises a row restoring mechanism (not shown), a display unit 81 for displaying an error message or the like is constituted by a liquid crystal display or LED lamp, a.

Here, the ejection abnormality is a general term for a state in which the ink ejection state in the ejection unit D becomes abnormal, in other words, a state in which ink cannot be ejected accurately from the nozzle N provided in the ejection unit D ( For the nozzle N, refer to FIGS. 3 and 4 described later).
More specifically, the ejection abnormality means that the image indicated by the print data Img is formed because the amount of ink ejected is small even when the ejection unit D cannot eject ink, and even when ink can be ejected from the ejection unit D. In a state where the ejection unit D cannot eject an amount of ink necessary to perform, a state where an amount of ink more than that necessary for forming the image indicated by the print data Img is ejected from the ejection unit D, an ejection from the ejection unit D This includes a state in which the ink to be landed at a position different from the landing position planned for forming the image indicated by the print data Img.

  The maintenance process includes a wiping process for wiping off foreign matters such as paper dust adhering to the vicinity of the nozzle N of the discharge unit D with a wiper (not shown), a flushing process for preliminarily discharging ink from the discharge unit D, and the discharge unit D. This is a general term for processes for returning the ink ejection state of the ejection part D to normal, such as a suction process for sucking the thickened ink and bubbles by a tube pump (not shown).

FIG. 2 is a partial cross-sectional view illustrating the outline of the internal configuration of the inkjet printer 1.
As shown in FIG. 2, the inkjet printer 1 includes a carriage 32 on which the head unit 5 is mounted. In addition to the head unit 5, four ink cartridges 31 are mounted on the carriage 32.
The four ink cartridges 31 are provided in one-to-one correspondence with four colors (CMYK) of black (BK), cyan (CY), magenta (MG), and yellow (YL). Each ink cartridge 31 is filled with ink of a color corresponding to the ink cartridge 31. Each ink cartridge 31 may be provided in another place of the ink jet printer 1 instead of being mounted on the carriage 32.

As shown in FIG. 1, the transport mechanism 7 includes a transport motor 71 serving as a drive source for transporting the recording paper P, and a motor driver 72 for driving the transport motor 71.
2, the transport mechanism 7 includes a platen 74 provided on the lower side of the carriage 32 (in the −Z direction in FIG. 2), a transport roller 73 that rotates by the operation of the transport motor 71, and A guide roller 75 provided to be rotatable around the Y axis and a storage unit 76 for storing the recording paper P in a rolled state are provided.
When the inkjet printer 1 executes a printing process, the transport mechanism 7 feeds the recording paper P from the storage unit 76 and follows a transport path defined by the guide roller 75, the platen 74, and the transport roller 73. In the figure, the sheet is conveyed at a conveyance speed Mv in the + X direction (the direction from the upstream side to the downstream side).

The control unit 6 shown in FIG. 1 includes, for example, a CPU (Central Processing Unit) or an FPGA (field-programmable gate array), and the CPU operates according to a control program stored in the storage unit 60. Thus, the operation of each part of the inkjet printer 1 is controlled.
Specifically, the control unit 6 forms an image corresponding to the print data Img on the recording paper P by controlling the head unit 5 and the transport mechanism 7 based on the print data Img supplied from the host computer. Controls execution of print processing.
In the printing process, the control unit 6 first stores the print data Img supplied from the host computer in the storage unit 60. Next, the control unit 6 controls the operation of the head unit 5 based on various data stored in the storage unit 60 such as the print data Img, and the print signal SI and the drive waveform for driving the ejection unit D. A signal such as the signal Com is generated. Further, the control unit 6 generates a signal for controlling the operation of the motor driver 72 based on the print signal SI and various data stored in the storage unit 60, and outputs the generated various signals. Then, the control unit 6 drives the transport motor 71 so as to transport the recording paper P in the + X direction through the control of the motor driver 72, and the control unit 6 controls the head unit 5 from the discharge unit D. The presence / absence of ink ejection, the amount of ink ejection, and the ink ejection timing are controlled. Thereby, the control unit 6 adjusts the dot size and the dot arrangement formed by the ink ejected on the recording paper P, and controls the execution of the printing process for forming the image corresponding to the print data Img on the recording paper P. . Although details will be described later, the drive waveform signal Com according to the present embodiment includes drive waveform signals Com-A and Com-B.

As shown in FIG. 1, the head unit 5 includes a recording head 30 including M ejection units D and a head driver 50 that drives each ejection unit D included in the recording head 30 (this embodiment). M is a natural number of 4 or more).
Hereinafter, in order to distinguish each of the M ejection portions D, they may be referred to as “first stage, second stage,..., M stage” in order. In the following description, the m stages of ejection units D may be expressed as ejection units D [m] (the variable m is a natural number that satisfies 1 ≦ m ≦ M).

  Each of the M ejection portions D receives ink supplied from any one of the four ink cartridges 31. Each ejection part D can be filled with ink supplied from the ink cartridge 31 and eject the filled ink from a nozzle N included in the ejection part D. Each ejection unit D forms an image on the recording paper P by ejecting ink onto the recording paper P at a timing when the transport mechanism 7 transports the recording paper P onto the platen 74. As a result, the four CMYK inks can be ejected from the M ejection portions D as a whole, and full color printing is realized.

As shown in FIG. 1, the head driver 50 includes a drive signal generation unit 51, a residual vibration detection unit 52, and a switching unit 53.
The drive signal generation unit 51 determines each of the M ejection units D included in the recording head 30 based on various signals supplied from the control unit 6 such as the print signal SI and the drive waveform signal Com output from the control unit 6. A drive signal Vin for driving is generated, and the generated drive signal Vin is supplied to the ejection unit D via the switching unit 53 described later. When the drive signal Vin is supplied, each discharge unit D is driven based on the supplied drive signal Vin, and can discharge the ink filled therein onto the recording paper P.
The residual vibration detection unit 52 (an example of a “detection unit”) detects residual vibration generated in the discharge unit D after the discharge unit D is driven by the drive signal Vin as a residual vibration signal Vout. Then, the residual vibration detection unit 52 generates a shaped waveform signal Vd by performing processing such as removing a noise component or amplifying the signal level on the detected residual vibration signal Vout, and generates the shaped waveform. The waveform signal Vd is output as the detection result of the residual vibration in the discharge part D.
The switching unit 53 electrically connects each ejection unit D to either the drive signal generation unit 51 or the residual vibration detection unit 52 based on the switching control signal Sw supplied from the control unit 6. Details of the head driver 50 will be described later.

As shown in FIG. 1, the remaining amount estimation unit 20 estimates the ejection amount of ink from each ejection unit D based on the shaped waveform signal Vd output from the residual vibration detection unit 52, and indicates the estimation result. A discharge amount estimation unit 21 that outputs a value W, and an estimated value Q of the remaining amount of ink in each ink cartridge 31 based on the estimated value W of the ink discharge amount output from the discharge amount estimation unit 21; A remaining amount updating unit 22 that updates the estimated value Q obtained by calculating the estimated value of the remaining amount of ink stored in the storage unit 60.
Among these, the ejection amount estimation unit 21 determines the ink ejection state in the ejection unit D [m] based on the shaped waveform signal Vd indicating the residual vibration generated in the ejection unit D [m], and indicates the result of the determination. An ejection value determination unit 23 that generates the determination information RS (an example of a “determination unit”) and an estimated value of the amount of ink discharged from the discharge unit D [m] based on the determination information RS generated by the discharge state determination unit 23 And an estimation execution unit 24 that calculates W and outputs the estimated value W.
Based on the shaped waveform signal Vd output from the residual vibration detection unit 52, the discharge state determination unit 23 measures the time length of one cycle of the residual vibration generated in the discharge unit D [m] and indicates the result of the measurement. Based on the measurement unit 25 that generates the detection signal Tc and outputs the generated detection signal Tc, and the detection signal Tc that the measurement unit 25 outputs, the ink ejection state in the ejection unit D [m] is determined, and the determination is made. And a determination execution unit 26 for generating determination information RS indicating the result of the above.

  The storage unit 60 temporarily stores EEPROM (Electrically Erasable Programmable Read-Only Memory) and data necessary for executing various processing such as printing processing, or for executing various processing such as printing processing. A RAM (Random Access Memory) that temporarily develops a control program and the like and a PROM (Programmable read only memory) that stores the control program and the like are provided.

As illustrated in FIG. 1, the storage unit 60 stores a discharge state management table TBL1, a discharge amount information table TBL2, and a remaining amount management table TBL3 (an example of a “remaining amount storage unit”).
Although the details will be described later, the discharge state management table TBL1 stores determination information RS generated by the determination execution unit 26 and the number m of stages of the discharge unit D corresponding to the determination information RS (FIG. 22). reference). The ejection amount information table TBL2 stores an estimated value W of the ejection amount of ink ejected from the ejection unit D when the ejection unit D is in the ejection state indicated by the determination information RS (FIG. 24). reference). Further, the remaining amount management table TBL3 stores an estimated value Q of the remaining amount of ink in each ink cartridge 31 output from the remaining amount update unit 22.
In addition to these various tables, the storage unit 60 executes a control program for executing various processes such as a print process, print data Img supplied from a host computer, and various processes such as a print process. Data necessary for storage is stored.

In addition to controlling the execution of the printing process described above, the control unit 6 controls the execution of the ejection state determination process, which is a process for determining the ink ejection state in the ejection unit D, and sets the estimated value Q of the remaining amount of ink. Controls execution of a remaining amount estimation process that is a process to be generated. That is, the inkjet printer 1 performs various processes such as a printing process and a remaining amount estimation process by the control unit 6 operating according to the control program and controlling the operation of each unit of the inkjet printer 1.
Although the details will be described later, the discharge state determination process is a process that is a premise of the remaining amount estimation process.

<2. Configuration of recording head>
With reference to FIGS. 3 and 4, the recording head 30 and the ejection unit D provided in the recording head 30 will be described.

  FIG. 3 is an example of a schematic partial sectional view of the recording head 30. In this figure, for convenience of illustration, among the recording heads 30, one ejection unit D among the M ejection units D included in the recording head 30 and ink supply to the one ejection unit D. A reservoir 350 communicating with the nozzle 360 and an ink intake port 370 for supplying ink from the ink cartridge 31 to the reservoir 350 are shown.

  As shown in FIG. 3, the ejection unit D includes a piezoelectric element 300, a cavity 320 (an example of a “pressure chamber”) filled with ink, a nozzle N communicating with the cavity 320, a vibration plate 310, and the like. . The ejection unit D ejects ink in the cavity 320 from the nozzles N when the piezoelectric element 300 is driven by the drive signal Vin. The cavity 320 of the discharge part D is a space defined by a cavity plate 340 formed into a predetermined shape having a recess, a nozzle plate 330 on which a nozzle N is formed, and a vibration plate 310. The cavity 320 communicates with the reservoir 350 via the ink supply port 360. The reservoir 350 communicates with one ink cartridge 31 through the ink intake port 370.

In the present embodiment, for example, a unimorph (monomorph) type as shown in FIG. Note that the piezoelectric element 300 is not limited to a unimorph type, and may be a bimorph type or a laminated type that can deform the piezoelectric element 300 and discharge a liquid such as ink.
The piezoelectric element 300 includes a lower electrode 301, an upper electrode 302, and a piezoelectric body 303 provided between the lower electrode 301 and the upper electrode 302. When the lower electrode 301 is set to a predetermined reference potential VSS and the drive signal Vin is supplied to the upper electrode 302, a voltage is applied between the lower electrode 301 and the upper electrode 302. The piezoelectric element 300 bends in the vertical direction in the drawing in accordance with the voltage, and as a result, the piezoelectric element 300 vibrates.

  A diaphragm 310 is installed in the upper surface opening of the cavity plate 340, and the lower electrode 301 is joined to the diaphragm 310. For this reason, when the piezoelectric element 300 vibrates by the drive signal Vin, the vibration plate 310 also vibrates. Then, the volume of the cavity 320 (pressure in the cavity 320) is changed by the vibration of the vibration plate 310, and the ink filled in the cavity 320 is ejected from the nozzle N. Ink is supplied from the reservoir 350 when the ink in the cavity 320 decreases due to ink ejection. Ink is supplied to the reservoir 350 from the ink cartridge 31 through the ink intake 370.

FIG. 4 is an explanatory diagram for explaining an example of the arrangement of M nozzles N provided in the recording head 30 when the inkjet printer 1 is viewed in plan from the + Z direction or the −Z direction.
As shown in FIG. 4, the recording head 30 includes a nozzle row Ln-BK composed of a plurality of nozzles N, a nozzle row Ln-CY composed of a plurality of nozzles N, and a nozzle row Ln-MG composed of a plurality of nozzles N. And four nozzle rows Ln consisting of nozzle rows Ln-YL consisting of a plurality of nozzles N are provided. Each of the plurality of nozzles N belonging to the nozzle row Ln-BK is a nozzle N provided in the ejection unit D that ejects black (BK) ink, and each of the plurality of nozzles N belonging to the nozzle row Ln-CY. Is a nozzle N provided in the discharge section D that discharges cyan (CY) ink, and each of the plurality of nozzles N belonging to the nozzle row Ln-MG is provided in the discharge section D that discharges magenta (MG) ink. Each of the plurality of nozzles N belonging to the nozzle row Ln-YL is a nozzle N provided in the discharge section D that discharges yellow (YL) ink. Each of the four nozzle rows Ln is provided so as to extend in the Y-axis direction when viewed in plan. A range YNL in which each nozzle row Ln extends in the Y-axis direction is a recording sheet P (more precisely, the recording sheet P has a maximum width that can be printed by the inkjet printer 1 in the Y-axis direction). When printing the paper P), the recording paper P has a range YP or more in the Y-axis direction.

  As shown in FIG. 4, in the plurality of nozzles N constituting each nozzle row Ln, the positions of the even-numbered nozzles N and the odd-numbered nozzles N in the X-axis direction are different from each other from the left side (−Y side). In addition, they are arranged in a so-called staggered pattern. In each nozzle row Ln, the interval (pitch) between the nozzles N in the Y-axis direction can be appropriately set according to the printing resolution (dpi: dot per inch).

  Further, in the printing process according to the present embodiment, one long image that extends over the entire area of the recording paper P is not formed, but the recording paper P is printed on a plurality of print areas (for example, as shown in FIG. 4). In addition, when an A4 size image is printed on the recording paper P, the A4 size rectangular area or a label on the label paper is divided into a blank area for dividing each of the plurality of print areas. Thus, a case is assumed where a plurality of images corresponding to a plurality of print areas are formed on a one-to-one basis.

<3. Discharge unit operation and residual vibration>
Next, the ink ejection operation from the ejection unit D and the residual vibration generated in the ejection unit D will be described with reference to FIGS.

FIG. 5 is an explanatory diagram for explaining an ink ejection operation from the ejection unit D. FIG.
In the state shown in FIG. 5A, when the drive signal Vin is supplied from the head driver 50 to the piezoelectric element 300 included in the ejection unit D, the piezoelectric element 300 responds to the electric field applied between the electrodes. Distortion occurs, and the diaphragm 310 of the discharge part D bends upward in the drawing. Thereby, compared with the initial state shown in FIG. 5A, as shown in FIG. 5B, the volume of the cavity 320 of the discharge section D is enlarged. In the state shown in FIG. 5B, when the potential indicated by the drive signal Vin is changed, the diaphragm 310 is restored by its elastic restoring force, and goes downward in the figure beyond the position of the diaphragm 310 in the initial state. As a result, the volume of the cavity 320 rapidly contracts as shown in FIG. At this time, due to the compression pressure generated in the cavity 320, a part of the ink filling the cavity 320 is ejected as an ink droplet from the nozzle N communicating with the cavity 320.

  The vibration plate 310 of each discharge section D undergoes damped vibration, that is, residual vibration until a next ink discharge operation is started after a series of ink discharge operations are completed. The residual vibration generated in the vibration plate 310 of the discharge unit D includes acoustic resistance Res due to the shape of the nozzle N and the ink supply port 360 or the viscosity of the ink, inertance Int due to the ink weight in the flow path, and compliance Cm of the vibration plate 310. It is assumed that it has a natural vibration frequency determined by

A calculation model of residual vibration generated in the discharge unit D based on the above assumption will be described.
FIG. 6 is a circuit diagram showing a calculation model of simple vibration assuming residual vibration of the discharge section D. Thus, the calculation model of the residual vibration of the discharge part D can be expressed by the sound pressure Prs, the inertance Int, the compliance Cm, and the acoustic resistance Res described above. When the step response when the sound pressure Prs is applied to the circuit of FIG. 6 is calculated for the volume velocity Uv, the following equation is obtained.
Uv = {Prs / (ω · Int)} e ^−σt · sin (ωt)
ω = {1 / (Int · Cm) −α ² } ^1/2
σ = Res / (2 · Int)

The calculation result (calculated value) obtained from this equation is compared with the experimental result (experimental value) in the residual vibration experiment of the discharge section D performed separately. The residual vibration experiment is an experiment in which residual vibration generated in the discharge section D is detected after the ink is discharged from the discharge section D in which the ink discharge state is normal.
FIG. 7 is a graph showing the relationship between experimental values and calculated values of residual vibration. As can be seen from the graph shown in FIG. 7, when the ink ejection state in the ejection part D is normal, the two waveforms of the experimental value and the calculated value are almost the same.

  Now, in spite of the ejection part D performing the ink ejection operation, the ink ejection state in the ejection part D is abnormal and the ink droplets are not ejected normally from the nozzles N of the ejection part D, that is, ejection Abnormalities may occur. The cause of this ejection abnormality is (1) mixing of bubbles into the cavity 320, (2) thickening or fixing of ink in the cavity 320 due to drying of the ink in the cavity 320, and (3). Examples include adhesion of foreign matters such as paper dust near the outlet of the nozzle N, (4) failure of the discharge section D, and the like.

  As described above, the ejection abnormality typically means that ink cannot be ejected from the nozzle N, that is, a non-ejection phenomenon of ink appears. In this case, pixel missing in the image printed on the recording paper P is lost. Arise. Further, as described above, in the case of abnormal ejection, even if ink is ejected from the nozzle N, the amount of ink is too small, or the flight direction (ballistic) of the ejected ink droplets is deviated. It will appear as a missing dot in the pixel.

  In the following, based on the comparison result shown in FIG. 7, at least one of the acoustic resistance Res and inertance Int is set so that the calculated value of the residual vibration and the experimental value are substantially matched for each cause of the discharge abnormality occurring in the discharge portion D. Adjust the value of.

First, (1) the mixing of bubbles into the cavity 320, which is one of the causes of ejection abnormalities, will be examined. FIG. 8 is a conceptual diagram for explaining a case where bubbles are mixed in the cavity 320. As shown in FIG. 8, when bubbles are mixed in the cavity 320, it is considered that the total weight of the ink filling the cavity 320 is reduced and the inertance Int is reduced. Further, as illustrated in FIG. 8, when bubbles are attached in the vicinity of the nozzle N, it is considered that the diameter of the nozzle N is increased by the size of the diameter, and the acoustic resistance Res is reduced. It is thought to do.
Accordingly, the acoustic resistance Res and the inertance Int are set to be small compared with the case where the ink ejection state as shown in FIG. 7 is normal, and matched with the experimental value of the residual vibration when the bubbles are mixed. A result (graph) like 9 was obtained. As shown in FIGS. 7 and 9, when a discharge abnormality occurs due to bubbles mixed in the cavity 320, the frequency of residual vibration is higher than when the discharge state is normal. In addition, the attenuation rate of the amplitude of the residual vibration is reduced due to the decrease in the acoustic resistance Res, and it can be confirmed that the residual vibration is slowly decreasing the amplitude.

Next, (2) thickening or fixing of ink in the cavity 320, which is one of the causes of ejection abnormalities, will be examined. FIG. 10 is a conceptual diagram for explaining a case where ink near the nozzle N of the cavity 320 is fixed by drying. As shown in FIG. 10, when the ink near the nozzle N is dried and fixed, the ink in the cavity 320 is confined in the cavity 320. In such a case, it is considered that the acoustic resistance Res increases.
Therefore, compared with the case where the ink ejection state as shown in FIG. 7 is normal, the acoustic resistance Res is set to be large, and the experimental value of the residual vibration when the ink near the nozzle N is fixed or thickened. By matching, a result (graph) as shown in FIG. 11 was obtained. The experimental values shown in FIG. 11 indicate the residual vibration of the diaphragm 310 provided in the ejection unit D in a state where the ejection unit D is left without the cap (not shown) attached for several days and the ink near the nozzle N is fixed. It is measured. As shown in FIGS. 7 and 11, when the ink in the vicinity of the nozzle N in the cavity 320 is fixed, the residual vibration frequency is extremely low and the residual vibration is lower than when the ejection state is normal. A characteristic waveform in which is overdamped is obtained. This is because, when the vibration plate 310 is drawn in the + Z direction (upward) to discharge ink, the vibration plate 310 moves in the −Z direction (downward) after ink flows from the reservoir into the cavity 320. In addition, since there is no escape path for ink in the cavity 320, the vibration plate 310 cannot vibrate rapidly (because it is overdamped).

Next, (3) adhesion of foreign matters such as paper dust near the outlet of the nozzle N, which is one of the causes of ejection abnormalities, will be examined. FIG. 12 is a conceptual diagram for explaining the case where paper dust adheres to the vicinity of the nozzle N outlet. As shown in FIG. 12, when paper dust adheres to the vicinity of the outlet of the nozzle N, the ink oozes out from the cavity 320 through the paper dust, and ink cannot be ejected from the nozzle N. When paper dust adheres to the vicinity of the outlet of the nozzle N and the ink oozes out from the nozzle N, the amount of ink that oozes out from the cavity 320 when viewed from the diaphragm 310 is greater than when the ejection state is normal. The increase in inertance is thought to increase the inertance Int. Further, it is considered that the acoustic resistance Res is increased by the fiber of the paper powder attached near the outlet of the nozzle N.
Therefore, compared with the case where the ink ejection state as shown in FIG. 7 is normal, the inertance Int and the acoustic resistance Res are set to be large, and the residual vibration when the paper dust adheres to the vicinity of the nozzle N outlet By matching the values, results (graphs) as shown in FIG. 13 were obtained. As can be seen from the graphs of FIGS. 7 and 13, when paper dust adheres near the outlet of the nozzle N, the frequency of residual vibration is lower than when the ejection state is normal.
From the graphs shown in FIGS. 11 and 13, (3) the case where foreign matter such as paper dust adheres to the vicinity of the outlet of the nozzle N is compared with the case of (2) the thickening of the ink in the cavity 320. It can be seen that the frequency of the residual vibration is high.

Here, in both (2) the case of ink thickening and (3) the case of paper dust adhering to the vicinity of the nozzle N outlet, the residual vibration is higher than that in the case where the ink discharge state is normal. The frequency is low. The causes of these two ejection abnormalities can be distinguished by comparing the residual vibration waveform, specifically, the frequency or period of the residual vibration with a predetermined threshold.
Note that (4) the failure of the discharge section D will be described later.

As is clear from the above description, the discharge state of each discharge unit D can be determined based on the waveform of residual vibration generated when each discharge unit D is driven, particularly the frequency or cycle of the residual vibration. More specifically, based on the frequency or period of the residual vibration, whether or not the discharge state in each discharge unit D is normal, and if the discharge state in each discharge unit D is abnormal, the discharge abnormality It can be determined which of the above (1) to (3) corresponds to the cause of the above.
The ink jet printer 1 according to the present embodiment executes a discharge state determination process for analyzing a residual vibration and determining a discharge state.

<4. Configuration and operation of the head driver>
Next, the configuration and operation of the head driver 50 (the drive signal generation unit 51, the residual vibration detection unit 52, and the switching unit 53) will be described with reference to FIGS.

<4.1. Drive signal generator>
FIG. 14 is a block diagram illustrating a configuration of the drive signal generation unit 51 in the head driver 50.
As shown in FIG. 14, the drive signal generation unit 51 has a one-to-one correspondence with a set of the shift register SR, the latch circuit LT, the decoder DC, and the transmission gates TGa and TGb to the M ejection units D. So that it has M. Hereinafter, each element constituting the M sets may be referred to as a first stage, a second stage,...

The drive signal generator 51 is supplied with a clock signal CL, a print signal SI, a latch signal LAT, a change signal CH, and a drive waveform signal Com (Com-A, Com-B) from the controller 6.
Here, the print signal SI is a digital signal that defines the amount of ink ejected from each ejection part D (each nozzle N) when forming one dot of an image. More specifically, the print signal SI according to the present embodiment defines the amount of ink ejected by each ejection unit D with two bits, the upper bit b1 and the lower bit b2, and is supplied from the control unit 6 to the clock signal CL. The drive signal generator 51 is supplied serially, for example. By controlling the amount of ink ejected from each ejection section D according to the print signal SI, each dot of the recording paper P represents four gradations of non-recording, small dots, medium dots, and large dots. Is possible.

  Each of the shift registers SR temporarily holds the print signal SI for every 2 bits corresponding to each ejection unit D. Specifically, M shift registers SR of 1 stage, 2 stages,..., M stages corresponding to M ejection sections D on a one-to-one basis are connected in cascade with each other and serially supplied print signals. SI is sequentially transferred to the subsequent stage according to the clock signal CL. When the print signal SI is transferred to all of the M shift registers SR, each of the M shift registers SR maintains a state in which data for 2 bits corresponding to itself is held in the print signal SI. .

  Each of the M latch circuits LT simultaneously latches the print signals SI for 2 bits corresponding to the respective stages held in the M shift registers SR at the timing when the latch signal LAT rises. In FIG. 14, SI [1], SI [2],..., SI [M] are respectively latched by the latch circuits LT corresponding to the 1-stage, 2-stage,. A 2-bit print signal SI is shown.

Incidentally, the operation period during which the head driver 50 drives the ejection part D is composed of a plurality of unit operation periods Tu. In the present embodiment, each unit operation period Tu is composed of a control period Ts1 and a control period Ts2 subsequent thereto, and the control periods Ts1 and Ts2 have the same time length.
In the present embodiment, the unit operation period Tu includes a unit printing operation period Tu-P (see FIG. 16), which is a unit operation period Tu in which the printing process is executed, and a discharge state determination process in the remaining amount estimation process. The unit operation period Tu is a unit determination operation period Tu-T (see FIG. 17) which is a unit operation period Tu to be executed.

As described above, the inkjet printer 1 according to the present embodiment divides the long recording paper P into a plurality of printing regions and a margin region for partitioning each of the plurality of printing regions, One image is formed for the print area.
Specifically, the control unit 6 is a period in which at least a part of the print area of the recording paper P is located below the recording head 30 (−Z side) among the plurality of unit operation periods Tu constituting the operation period. Are classified into unit printing operation periods Tu-P, and the operation of each part of the ink jet printer 1 is controlled so that the printing process is executed in the unit printing operation periods Tu-P.
On the other hand, the control unit 6 determines a period in which only the margin area of the recording paper P is located below the recording head 30 (−Z side) out of the plurality of unit operation periods Tu constituting the operation period. It classifies into period Tu-T, and controls the operation of each part of ink jet printer 1 so that the discharge state determination process is executed in the unit determination operation period Tu-T.

  The control unit 6 supplies the print signal SI to the drive signal generation unit 51 for each unit operation period Tu (unit print operation period Tu-P, unit determination operation period Tu-T) and for each unit operation period Tu. The latch circuit LT supplies a latch signal LAT that latches the print signals SI [1], SI [2],..., SI [M]. That is, the control unit 6 controls the drive signal generation unit 51 so that the drive signal Vin is supplied to the M ejection units D every unit operation period Tu.

More specifically, the control unit 6 performs printing processing for each of the M ejection units D in the unit printing operation period Tu-P in which printing processing is executed among the plurality of unit operation periods Tu. The drive signal generation unit 51 is controlled so that the drive signal Vin is supplied. As a result, during the unit printing operation period Tu-P, the M ejection portions D eject an amount of ink corresponding to the print data Img onto the recording paper P, and an image corresponding to the print data Img is formed on the recording paper P. The printing process is executed.
In addition, the control unit 6 determines a driving signal for determination processing for each of the M ejection units D in the unit determination operation period Tu-T in which the discharge state determination process is executed among the plurality of unit operation periods Tu. The drive signal generation unit 51 is controlled so that Vin is supplied. Thereby, in the unit determination operation period Tu-T, a discharge state determination process for determining whether or not a discharge abnormality has occurred in the discharge portion D is executed.

The decoder DC decodes the 2-bit print signal SI [m] latched by the latch circuit LT, and outputs selection signals Sa and Sb in the control periods Ts1 and Ts2, respectively.
FIG. 15 is an explanatory diagram showing the contents of decoding performed by the decoder DC in each unit operation period Tu. 15A shows the contents of decoding performed by the decoder DC in the unit printing operation period Tu-P in which the printing process is executed, and FIG. 15B shows the unit in which the ejection state determination process is executed. The contents of decoding performed by the decoder DC in the determination operation period Tu-T are shown.
As shown in this figure, when the content indicated by the print signal SI [m] corresponding to m stages is, for example, (b1, b2) = (1, 0), the m-stage decoder DC is in the control period Ts1. The selection signal Sa is set to the high level H and the selection signal Sb is set to the low level L. In the control period Ts2, the selection signal Sb is set to the high level H and the selection signal Sa is set to the low level L.

  As shown in FIG. 14, the drive signal generator 51 includes M sets of transmission gates TGa and TGb. The transmission gate TGa is turned on when the selection signal Sa is at the H level and turned off when the selection signal Sa is at the L level. The transmission gate TGb is turned on when the selection signal Sb is at the H level and turned off when the selection signal Sb is at the L level. For example, in the m-th stage, when the content indicated by the print signal SI [m] is (b1, b2) = (1, 0), the transmission gate TGa is turned on and the transmission gate TGb is turned off in the control period Ts1. In the control period Ts2, the transmission gate TGb is turned on and the transmission gate TGa is turned off.

As shown in FIG. 14, the drive waveform signal Com-A is supplied to one end of the transmission gate TGa, and the drive waveform signal Com-B is supplied to one end of the transmission gate TGb. The other ends of the transmission gates TGa and TGb are commonly connected to the output end OTN to the switching unit 53.
The transmission gates TGa and TGb are exclusively turned on, and the drive waveform signal Com-A or Com-B selected for each of the control periods Ts1 and Ts2 is output to the m-stage output terminal OTN as the drive signal Vin [m]. This is supplied to the m-stage ejection unit D via the switching unit 53.

<4.2. Drive waveform signal>
16 and 17 are timing charts for explaining the drive waveform signal Com output from the control unit 6 in each unit operation period Tu.
Among these, FIG. 16 shows an example of the drive waveform signal Com output by the control unit 6 in the unit printing operation period Tu-P in which the printing process is executed, and FIG. 17 shows the unit determination in which the ejection state determination process is executed. An example of the drive waveform signal Com output from the control unit 6 during the operation period Tu-T is shown.

In the present embodiment, the waveform of the drive waveform signal Com-A output from the control unit 6 differs between the unit printing operation period Tu-P and the unit determination operation period Tu-T. The control unit 6 selects a waveform of the drive waveform signal Com-A by referring to a setting parameter (not shown) stored in the storage unit 60.
Hereinafter, of the drive waveform signal Com-A, a signal output by the control unit 6 in the unit printing operation period Tu-P is referred to as a printing drive waveform signal Com-AP (see FIG. 16), and the unit determination operation period Tu. A signal output by the control unit 6 at -T is referred to as a determination drive waveform signal Com-AT (see FIG. 17).

As illustrated in FIG. 16, the printing drive waveform signal Com-AP output by the control unit 6 in the unit printing operation period Tu-P is provided in the waveform PA1 provided in the control period Ts1 and in the control period Ts2. A signal having a waveform PA2.
The waveform PA1 is a waveform such that when the signal of the waveform PA1 is supplied as the drive signal Vin to the ejection unit D, a medium amount of ink corresponding to a medium dot is ejected from the ejection unit D.
The waveform PA2 is a waveform such that when the signal of the waveform PA2 is supplied to the ejection unit D as the drive signal Vin, a small amount of ink corresponding to a small dot is ejected from the ejection unit D.
For example, the potential difference between the lowest potential Va11 and the highest potential Va12 of the waveform PA1 is determined to be larger than the potential difference between the lowest potential Va21 and the highest potential Va22 of the waveform PA2.

As illustrated in FIG. 17, the determination drive waveform signal Com-AT output by the control unit 6 during the unit determination operation period Tu-T is a signal having a waveform PT provided so as to straddle the control periods Ts1 and Ts2. is there.
The waveform PT is a waveform for determining the ink ejection state in the ejection section D based on the residual vibration generated in the ejection section D when the signal of the waveform PT is supplied to the ejection section D as the drive signal Vin. is there. The waveform PT is a waveform that does not cause ink to be ejected from the ejection unit D even when the signal of the waveform PT is supplied to the ejection unit D as the drive signal Vin. For example, the potential difference between the lowest potential VcL and the highest potential VcH of the waveform PT is determined to be smaller than the potential difference between the lowest potential Va21 and the highest potential Va22 of the waveform PA2. That is, the discharge state determination process according to the present embodiment determines the ink discharge state in the discharge unit D based on the residual vibration generated in the discharge unit D when the discharge unit D is driven so as not to discharge ink. A case of so-called “non-ejection inspection” is assumed.
However, the waveform PT may be a waveform such that ink is ejected from the ejection section D when the drive signal Vin having the waveform PT is supplied to the ejection section D. That is, the ejection state determination process may be executed as “ejection inspection”.

As illustrated in FIGS. 16 and 17, the drive waveform signal Com-B output by the control unit 6 during the unit operation period Tu (unit print operation period Tu-P and unit determination operation period Tu-T) is the control period Ts1. Is a signal having two waveforms PB, that is, a waveform PB provided in the waveform PB and a waveform PB provided in the control period Ts2.
The waveform PB is a waveform such that ink is not ejected from the ejection part D even when the signal of the waveform PB is supplied to the ejection part D as the drive signal Vin. For example, the potential difference between the lowest potential Vb and the highest potential (reference potential V0 in this figure) of the waveform PB is determined to be smaller than the potential difference between the lowest potential Va21 and the highest potential Va22 of the waveform PA2.

16 and 17, the unit operation period Tu is defined by a latch signal LAT output from the control unit 6. The control periods Ts1 and Ts2 included in the unit operation period Tu are defined by the latch signal LAT and the change signal CH output from the control unit 6.
As shown in FIGS. 16 and 17, the m-stage latch circuit LT outputs the print signal SI [m] at the timing when the latch signal LAT rises and the unit operation period Tu is started. The m-stage decoder DC outputs selection signals Sa and Sb in the control periods Ts1 and Ts2 based on the print signal SI [m] output from the m-stage latch circuit LT. The m-stage transmission gates TGa and TGb are driven by the drive waveform signal Com-A or Com-B based on the selection signals Sa and Sb output from the m-stage decoder DC in each control period Ts (Ts1, Ts2). Any one of them is selected, and the selected drive waveform signal Com is output as the drive signal Vin [m].
Note that the detection period designation signal Tsig shown in FIG. 17 is a signal that defines a detection period Td for detecting residual vibration generated in the discharge section D. The detection period designation signal Tsig and the detection period Td will be described later.

<4.3. Drive signal>
Next, the waveform of the drive signal Vin output from the drive signal generation unit 51 in the unit printing operation period Tu-P in the unit operation period Tu will be described with reference to FIG.
When the printing signal SI [m] supplied in the unit printing operation period Tu-P is (b1, b2) = (1, 1), the selection signal Sa becomes H level in the control period Ts1, and the transmission gate TGa is turned on. Then, the drive waveform signal Com-A is selected, and the waveform PA1 is output as the drive signal Vin [m]. Similarly, during the control period Ts2, the drive waveform signal Com-A is selected, and the waveform PA2 is output as the drive signal Vin [m]. Therefore, when the print signal SI [m] is (b1, b2) = (1, 1), the drive signal Vin for print processing supplied to the discharge section D [m] in the unit print operation period Tu-P. [M] includes the waveform PA1 and the waveform PA2. As a result, the ejection unit D [m] ejects a medium amount of ink based on the waveform PA1 and a small amount of ink based on the waveform PA2, and the inks ejected twice are combined. Thus, large dots are formed on the recording paper P.

  When the print signal SI [m] supplied in the unit printing operation period Tu-P is (b1, b2) = (1, 0), the drive waveform signal Com-A is selected in the control period Ts1, and the control period Ts2 Since the drive waveform signal Com-B is selected in step S1, the print processing drive signal Vin [m] supplied to the discharge section D [m] includes a waveform PA1 and a waveform PB. As a result, the discharge unit D [m] discharges a medium amount of ink based on the waveform PA1 to form medium dots on the recording paper P.

  When the print signal SI [m] supplied in the unit print operation period Tu-P is (b1, b2) = (0, 1), the drive waveform signal Com-B is selected in the control period Ts1, and the control period Ts2 Since the drive waveform signal Com-A is selected in FIG. 5, the print processing drive signal Vin [m] supplied to the discharge section D [m] includes a waveform PB and a waveform PA2. As a result, the ejection unit D [m] ejects a small amount of ink based on the waveform PA2 to form small dots on the recording paper P.

  When the print signal SI [m] supplied in the unit printing operation period Tu-P is (b1, b2) = (0, 0), the drive waveform signal Com-B is selected in the control periods Ts1 and Ts2, and the ejection is performed. The drive signal Vin [m] for print processing supplied to the section D [m] includes two waveforms PB. As a result, no ink is ejected from the ejection part D [m], and no dots are formed on the recording paper P (non-recording).

In the present embodiment, as shown in FIG. 15B, the print signal SI [m] that the control unit 6 outputs in the unit determination operation period Tu-T is (b1, b2) = (1, 1). Or (0, 0).
More specifically, the control unit 6 sets the print signal SI [m] to (1, 1) when the discharge unit D [m] is the target of the discharge state determination process in the unit determination operation period Tu-T. If the discharge state determination process is not to be performed, the print signal SI [m] is set to (0, 0).
Accordingly, the drive signal Vin [m] supplied to the discharge unit D [m] in the unit determination operation period Tu-T is the target of the discharge state determination process by the discharge unit D [m] in the unit determination operation period Tu-T. In this case, the drive waveform signal for determination is Com-AT, and when it is not the target of the discharge state determination process, the drive waveform signal is Com-B.

In the following description, among the ejection units D, the ejection unit D that is the target of the ejection state determination process, that is, the ejection unit D that determines the ejection state of the ink may be referred to as a determination target ejection unit DJ. . Further, in order to determine the ink ejection state in the determination target ejection unit DJ, the ejection unit D to which the determination drive waveform signal Com-AT is supplied as the drive signal Vin by the drive signal generation unit 51 is used as the drive target ejection. It may be called part D-R.
For example, in the ejection state determination process, in order to determine the ink ejection state in the ejection unit D [m], the drive signal generation unit 51 sends a determination drive waveform signal to the ejection unit D [m] as the drive signal Vin. When supplying Com-AT, the discharge unit D [m] corresponds to the determination target discharge unit DJ and also corresponds to the drive target discharge unit DR.

<4.4. Switching part>
FIG. 19 is a block diagram illustrating an example of the configuration of the residual vibration detection unit 52 and the switching unit 53 provided in the head driver 50.
As illustrated in FIG. 19, the switching unit 53 includes one to M stages of M switching circuits Ux (Ux [1], Ux [2],... Corresponding to the M ejection units D on a one-to-one basis. , Ux [M]). The m-stage switching circuit Ux [m] includes the upper electrode 302 of the piezoelectric element 300 of the ejection section D [m], the m-stage output end OTN provided in the drive signal generation section 51, or the residual vibration detection section 52. Electrically connect to one of them.
Hereinafter, the state in which the switching circuit Ux [m] electrically connects the ejection unit D [m] and the m-stage output end OTN of the drive signal generation unit 51 is referred to as a first connection state. The state in which the switching circuit Ux [m] electrically connects the discharge unit D [m] and the residual vibration detection unit 52 is referred to as a second connection state.

The control unit 6 outputs a switching control signal Sw for controlling the connection state of each switching circuit Ux to each switching circuit Ux.
Specifically, in the unit printing operation period Tu-P in which the printing process is performed, the control unit 6 causes the switching circuit Ux [m] to be in the first connection state over the entire period of the unit printing operation period Tu-P. Is supplied to the switching circuit Ux [m]. For this reason, the drive signal Vin [m] is supplied from the drive signal generation unit 51 to the ejection unit D [m] over the entire unit printing operation period Tu-P.

In addition, in the unit determination operation period Tu-T in which the discharge state determination process is performed, the control unit 6 is configured such that the discharge unit D [m] is the determination target discharge unit DJ that is the determination target of the discharge state determination process. , The switching control signal Sw [such that the switching circuit Ux [m] enters the first connection state in the unit determination operation period Tu-T other than the detection period Td and enters the second connection state in the detection period Td. m] is supplied to the switching circuit Ux [m] (see FIG. 17 for the detection period Td).
Therefore, when the discharge unit D [m] is the determination target discharge unit DJ in the unit determination operation period Tu-T, drive signal generation is performed in a period other than the detection period Td in the unit determination operation period Tu-T. The drive signal Vin [m] is supplied from the unit 51 to the discharge unit D [m], and from the discharge unit D [m] to the residual vibration detection unit 52 in the detection period Td in the unit determination operation period Tu-T. On the other hand, the residual vibration signal Vout is supplied.

On the other hand, when the discharge unit D [m] is not the determination target discharge unit DJ in the unit determination operation period Tu-T, the control unit 6 causes the switching circuit Ux [m] to perform the unit determination operation period Tu-T. The switching control signal Sw [m] that maintains the first connection state over the entire period is supplied to the switching circuit Ux [m].
For this reason, in the unit determination operation period Tu-T, when the discharge unit D [m] is not the determination target discharge unit DJ, the discharge unit D [m] includes the entire unit determination operation period Tu-T. The drive signal Vin [m] is supplied from the drive signal generation unit 51.

In the present embodiment, as shown in FIG. 19, the inkjet printer 1 includes one residual vibration detection unit 52 for the M ejection units D, and the residual vibration detection unit 52 includes 1 A case is assumed in which residual vibration generated in one discharge section D can be detected in one unit operation period Tu.
For this reason, in the discharge state determination process according to the present embodiment, the control unit 6 selects one discharge unit D from among the M discharge units D during each unit determination operation period Tu-T. Select as -J. Then, in each unit determination operation period Tu-T, the control unit 6 sets one discharge unit D selected as the determination target discharge unit DJ to the second connection state in the detection period Td, and otherwise ( M-1) The switching control signal Sw is generated so that the number of ejection units D is in the first connection state.

As described above, the detection period Td is a period for detecting residual vibration generated in the determination target discharge unit DJ that is the discharge unit D that is the target of the discharge state determination process.
In the present embodiment, as shown in FIG. 17, the detection period Td is a period after the potential of the determination drive waveform signal Com-AT changes from the lowest potential VcL to the highest potential VcH, and the highest potential VcH is maintained. It shall be part or all of the period. In the detection period Td, the residual vibration detection unit 52 detects a change in electromotive force of the piezoelectric element 300 of the determination target discharge unit DJ as a residual vibration signal Vout.
As shown in FIG. 17, the control unit 6 according to this embodiment sets the potential of the detection period designation signal Tsig to a predetermined detection period designation potential VHigh in the detection period Td and the potential VLow in periods other than the detection period Td. Thus, the detection period Td is defined.

<4.5. Residual vibration detector>
The residual vibration detection unit 52 detects residual vibration generated in the discharge unit D selected as the determination target discharge unit DJ in the unit determination operation period Tu-T as the residual vibration signal Vout, and based on the residual vibration signal Vout. To generate the shaped waveform signal Vd. Then, the residual vibration detection unit 52 outputs the generated shaped waveform signal Vd as a detection result of the residual vibration in the determination target discharge unit DJ. As described above, the shaped waveform signal Vd is an amplitude suitable for processing in the residual amount estimation unit 20 by removing the noise component from the residual vibration signal Vout and further converting the amplitude of the residual vibration signal Vout from which the noise component has been removed. It is a signal adjusted to.

  The residual vibration detection unit 52 includes, for example, a configuration that includes a high-pass filter, a low-pass filter, and the like, and that can output a shaped waveform signal Vd in which the frequency range of the residual vibration signal Vout is limited and noise components are removed. The residual vibration detection unit 52 is a negative feedback amplifier for adjusting the amplitude of the residual vibration signal Vout, or a voltage for converting the impedance of the residual vibration signal Vout and outputting a low impedance shaped waveform signal Vd. A configuration including a follower may be used.

<5. Remaining amount estimation unit>
Next, the remaining amount estimation unit 20, the discharge state management table TBL1, the discharge amount information table TBL2, and the remaining amount management table TBL3 included in the storage unit 60 will be described with reference to FIGS. .

<5.1. Discharge state determination unit>
As described above, the remaining amount estimation unit 20 includes the discharge amount estimation unit 21 and the remaining amount update unit 22. The discharge amount estimation unit 21 includes a discharge state determination unit 23 and an estimation execution unit 24. In the following, first, the discharge state determination unit 23 in the remaining amount estimation unit 20 will be described.

As described above, the discharge state determination unit 23 includes the measurement unit 25 and the determination execution unit 26.
As shown in FIG. 19, the measurement unit 25 determines the shaped waveform signal Vd output from the residual vibration detection unit 52, the mask signal Msk generated by the control unit 6, and the potential at the amplitude center level of the shaped waveform signal Vd. The threshold potential Vth-C, the threshold potential Vth-O determined to be higher than the threshold potential Vth-C, and the threshold potential Vth-U determined to be lower than the threshold potential Vth-C. Supplied. Based on these signals and the like, the measuring unit 25 outputs a detection signal Tc and a validity flag Flag indicating whether or not the detection signal Tc is a valid value.

FIG. 20 is a timing chart showing the operation of the measurement unit 25.
As shown in this figure, the measuring unit 25 compares the potential indicated by the shaped waveform signal Vd with the threshold potential Vth-C, and when the potential indicated by the shaped waveform signal Vd is equal to or higher than the threshold potential Vth-C, When the potential indicated by the shaped waveform signal Vd is less than the threshold potential Vth-C, the comparison signal Cmp1 is generated which is at a low level.
In addition, the measurement unit 25 compares the potential indicated by the shaped waveform signal Vd with the threshold potential Vth-O. When the potential indicated by the shaped waveform signal Vd is equal to or higher than the threshold potential Vth-O, the measuring unit 25 becomes high level. When the potential indicated by the signal Vd is less than the threshold potential Vth-O, the comparison signal Cmp2 that is at a low level is generated.
The measuring unit 25 compares the potential indicated by the shaped waveform signal Vd with the threshold potential Vth-U. When the potential indicated by the shaped waveform signal Vd is less than the threshold potential Vth-U, the measuring unit 25 becomes high level. When the potential indicated by the signal Vd is equal to or higher than the threshold potential Vth-U, the comparison signal Cmp3 that is at a high level is generated.

  The mask signal Msk is a signal that becomes a high level only for a predetermined period Tmsk after the supply of the shaped waveform signal Vd from the residual vibration detection unit 52 is started. In the present embodiment, the detection signal Tc is generated only for the shaped waveform signal Vd after the lapse of the period Tmsk in the shaped waveform signal Vd, so that the noise component superimposed immediately after the start of the residual vibration is removed. A high detection signal Tc can be obtained.

The measuring unit 25 includes a counter (not shown). The counter counts a clock signal (not shown) at time t1, which is the timing when the potential indicated by the shaped waveform signal Vd is first equal to the threshold potential Vth-C after the mask signal Msk falls to a low level. Start. That is, the counter is the earlier of the timing at which the comparison signal Cmp1 first rises to the high level after the mask signal Msk falls to the low level, or the timing at which the comparison signal Cmp1 first falls to the low level. Counting starts at time t1, which is the timing.
Then, after starting the counting, the counter is obtained by terminating the counting of the clock signal at time t2, which is the timing at which the potential indicated by the shaped waveform signal Vd becomes the threshold potential Vth-C for the second time. The count value is output as the detection signal Tc. That is, the counter is earlier of the timing at which the comparison signal Cmp1 rises to the high level for the second time after the mask signal Msk falls to the low level, or the timing at which the comparison signal Cmp1 falls to the low level for the second time. At time t2, which is the other timing, the counting is finished. Thus, the measuring unit 25 generates the detection signal Tc by measuring the time length from time t1 to time t2 as the time length for one cycle of the shaped waveform signal Vd.

Incidentally, when the amplitude of the shaped waveform signal Vd is small as indicated by a broken line in FIG. 20, there is a high possibility that the detection signal Tc cannot be measured accurately. In addition, when the amplitude of the shaped waveform signal Vd is small, even if it is determined that the discharge state of the discharge portion D is normal based only on the result of the detection signal Tc, the discharge abnormality actually occurs. There is a possibility that has occurred. For example, when the amplitude of the shaped waveform signal Vd is small, it can be considered that ink cannot be ejected because ink is not injected into the cavity 320.
Therefore, in the present embodiment, it is determined whether or not the amplitude of the shaped waveform signal Vd has a sufficient magnitude for measurement of the detection signal Tc, and the result of the determination is output as the validity flag Flag. .
Specifically, the measuring unit 25 determines that the potential indicated by the shaped waveform signal Vd exceeds the threshold potential Vth-O in the period in which the counting is performed by the counter, that is, the period from time t1 to time t2. The value of the validity flag Flag is set to a value “1” indicating that the detection signal Tc is valid when it is below the threshold potential Vth−U, and is set to “0” otherwise. Then, the validity flag Flag is output. More specifically, in the period from time t1 to time t2, the measuring unit 25 falls again from the low level to the high level after the comparison signal Cmp2 rises to the low level, and the comparison signal Cmp3 goes from the low level to the high level. The value of the validity flag Flag is set to “1” when falling to the low level again after rising to the level, and the value of the validity flag Flag is set to “0” in other cases.

  As described above, the measurement unit 25 according to the present embodiment generates the detection signal Tc indicating the time length of one cycle of the shaped waveform signal Vd, and the shaped waveform signal Vd is used for measuring the detection signal Tc. A validity flag Flag indicating whether or not the amplitude is sufficiently large is generated.

  Next, the determination execution unit 26 included in the discharge state determination unit 23 and the discharge state determination process will be described.

The ejection state determination process according to the present embodiment includes a first determination process and a second determination process. In the discharge state determination process for the determination target discharge unit DJ, the inkjet printer 1 first executes a first determination process for the determination target discharge unit DJ.
Here, the first determination process is based on the residual vibration generated in the determination target discharge unit DJ when only the determination target discharge unit DJ is driven as the drive target discharge unit DR. This is a process for determining the ink ejection state in the ejection section DJ. By executing the first determination process, it is possible to determine whether or not the ink discharge state in the determination target discharge portion DJ is normal. However, even if the first determination process is executed and the determination result that a discharge abnormality has occurred in the determination target discharge unit DJ is obtained, the cause of the discharge abnormality can be recovered by the maintenance process. There is a possibility that it is not possible to distinguish whether the ink viscosity is a thickening of the ink or the failure of the determination target ejection unit DJ that cannot be recovered by the maintenance process. Therefore, when the inkjet printer 1 obtains a determination result that a discharge abnormality has occurred in the determination target discharge unit DJ when the first determination process is executed, the determination target discharge unit D- A second determination process is performed to determine whether J is out of order.

  The second determination process is a determination target when the determination target discharge part DJ and the adjacent discharge part D-Nb of the determination target discharge part DJ are simultaneously driven as the drive target discharge part DR. This is a process of determining the ink ejection state in the determination target ejection unit DJ based on the residual vibration generated in the ejection unit DJ. By executing the second determination process, it is possible to determine whether or not the determination target ejection unit DJ is out of order. The details of the adjacent discharge part D-Nb will be described later.

In the first determination process, the control unit 6 is supplied with the determination drive waveform signal Com-AT only for the determination target discharge unit DJ, and for the discharge units D other than the determination target discharge unit DJ. The drive waveform signal Com and the print signal SI that are supplied with the drive waveform signal Com-B are output to the drive signal generation unit 51.
In the first determination process, the determination execution unit 26 determines whether the determination target discharge is based on the detection signal Tc and the validity flag Flag generated by the measurement unit 25 according to the residual vibration generated in the determination target discharge unit DJ. The ink ejection state in the section DJ is determined, and first determination information RS1 indicating the result of the determination is generated.
In the following, the detection signal Tc and the validity flag Flag output from the measurement unit 25 in the first determination process are referred to as the detection signal Tc1 and the validity flag Flag1, respectively, and the measurement unit 25 in the second determination process The detection signal Tc and the validity flag Flag to be output are referred to as a detection signal Tc2 and a validity flag Flag2, respectively.

In the second determination process, the control unit 6 supplies the determination drive waveform signal Com-AT to the determination target discharge unit DJ and the adjacent discharge unit D-Nb of the determination target discharge unit DJ. The drive signal generation unit 51 generates the drive waveform signal Com and the print signal SI so that the drive waveform signal Com-B is supplied to the discharge units D other than the determination target discharge unit DJ and the adjacent discharge unit D-Nb. Output to.
In the second determination process, the determination execution unit 26 determines whether the determination target discharge is based on the detection signal Tc2 and the validity flag Flag2 generated by the measurement unit 25 according to the residual vibration generated in the determination target discharge unit DJ. The ink ejection state in the section DJ is determined, and second determination information RS2 indicating the result of the determination is generated.

Note that, as described above, in the first determination process for the determination target discharge unit DJ, the inkjet printer 1 according to the present embodiment indicates that the discharge state of the determination target discharge unit DJ is abnormal. Only when the determination result is obtained, the second determination process for the determination target discharge portion DJ is executed.
When only the first determination process is executed in the discharge state determination process for each discharge unit D, the determination execution unit 26 sets the first determination information RS1 as the determination information RS corresponding to the discharge unit D. .
On the other hand, when both the first determination process and the second determination process are executed in the discharge state determination process for each discharge unit D, the determination execution unit 26 uses the first determination information RS1 and the second determination information. Determination information RS is generated based on RS2.

Hereinafter, the process which produces | generates 1st determination information RS1 among 1st determination processes is demonstrated.
FIG. 21 is an explanatory diagram for explaining a process in which the determination execution unit 26 generates the first determination information RS1.
As shown in this figure, the determination execution unit 26 sets the time length indicated by the detection signal Tc1 to the threshold value Tth1, the threshold value Tth2 indicating a time length longer than the threshold value Tth1, the threshold value Tth3 indicating a time length longer than the threshold value Tth2, And it compares with four threshold values of threshold value Tth4 (or some threshold values of these four threshold values) showing the time length longer than threshold value Tth3.
Here, the threshold value Tth1 is the time length of one period of residual vibration when bubbles are generated in the cavity 320 and the frequency of residual vibration is high, and one period of residual vibration when the discharge state is normal. It is a value for indicating the boundary with the time length of.
Further, the threshold value Tth2 is the time length of one period of residual vibration when foreign matter such as paper dust adheres to the vicinity of the nozzle N outlet and the frequency of residual vibration becomes low, and the residual vibration when the discharge state is normal. It is a value for indicating the boundary with the time length of one cycle.
Further, the threshold value Tth3 is a time length corresponding to one period of the residual vibration when the frequency of the residual vibration becomes lower than the case where foreign matter such as paper dust adheres due to thickening of ink near the nozzle N, and the nozzle N This is a value for indicating a boundary with the time length of one cycle of residual vibration when foreign matter such as paper dust adheres to the vicinity of the exit.
Further, the threshold value Tth4 has a residual vibration more than that in the case where the ink cannot be ejected from the nozzle N due to the fixing of the ink near the nozzle N, and the ink near the nozzle N is thickened so that it is difficult to eject the ink from the nozzle N. This is a value indicating the boundary between the time length of one cycle of residual vibration when the frequency is low and the time length of one cycle of residual vibration when the ink in the vicinity of the nozzle N is thickened.

As shown in FIG. 21, when the value of the validity flag Flag1 is “1” and the detection signal Tc1 satisfies “TTH1 ≦ Tc1 ≦ TTH2”, the determination execution unit 26 performs ink in the ejection unit D. The discharge state is determined to be normal, and a value “1” indicating that the discharge state is normal is set in the first determination information RS1.
In addition, when the value of the validity flag Flag1 is “1” and the detection signal Tc1 satisfies “Tc1 <TTH1”, the determination execution unit 26 generates a discharge abnormality due to bubbles generated in the cavity 320. And a value “2” indicating that a discharge abnormality due to bubbles has occurred is set in the first determination information RS1.
Further, the judgment execution unit 26 determines that the value of the validity flag Flag1 is “1” and the detection signal Tc1 satisfies “TTH2 <Tc1 ≦ TTH3”. It is determined that a discharge abnormality has occurred due to the foreign matter, and a value “3” indicating that a discharge abnormality has occurred due to adhesion of foreign matter such as paper dust is set in the first determination information RS1.
In addition, the determination execution unit 26 discharges the ink by increasing the viscosity of the ink in the cavity 320 when the value of the validity flag Flag1 is “1” and the detection signal Tc1 satisfies “TTH3 <Tc1 ≦ TTH4”. It is determined that an abnormality has occurred, and a value “4” indicating that an abnormal discharge has occurred due to ink thickening is set in the first determination information RS1.
Further, when the value of the validity flag Flag1 is “1” and the detection signal Tc1 satisfies “TTH4 <Tc1”, the determination execution unit 26 causes ink from the nozzle N to adhere to the ink in the cavity 320. It is determined that a discharge abnormality that makes it impossible to discharge the ink has occurred, and a value “5” indicating that a discharge abnormality due to ink sticking has occurred is set in the first determination information RS1.
Further, when the value of the validity flag Flag1 is “0”, the determination execution unit 26 indicates that an ejection abnormality has occurred in the first determination information RS1 due to some cause such as ink not being injected. Is set to a value “6”.

As described above, the determination execution unit 26 is generated according to the residual vibration generated in the discharge unit D [m] in the first determination process in which the discharge unit D [m] is the determination target discharge unit DJ. Based on the detection signal Tc1 and the validity flag Flag1, the discharge state in the discharge unit D [m] is determined, and first determination information RS1 corresponding to the discharge unit D [m] is generated.
Then, the determination execution unit 26 stores the first determination information RS1 corresponding to the discharge unit D [m] in the discharge state management table TBL1 illustrated in FIG. 22 in association with the stage number m of the discharge unit D [m]. .

FIG. 22 is a diagram illustrating an example of a data structure of the discharge state management table TBL1. As shown in this figure, the discharge state management table TBL1 includes a stage number m of the discharge unit D [m], information indicating the possibility of failure in the discharge unit D [m], first determination information RS1, Second determination information RS2 and determination information RS are stored in association with each other.
In this figure, for convenience of explanation, the discharge state management table TBL1 shows a case where information indicating the possibility of failure in the discharge unit D [m] is stored, but the discharge state management table TBL1 is Information indicating the possibility of failure may not be stored. Further, the discharge state management table TBL1 may store the detection signal Tc and the validity flag Flag in association with the number of stages m of the discharge unit D [m].

Although details will be described later, as shown in FIG. 22, when the first determination information RS1 indicates “3”, “4”, “5”, or “6”, it corresponds to the first determination information RS1. There is a possibility that the discharge unit D [m] to be broken has failed.
Therefore, the control unit 6 refers to the discharge state management table TBL1, and the first determination information RS1 corresponding to the discharge unit D [m] is “3”, “4”, “5”, or “6”. , It is determined that the discharge abnormality occurring in the discharge part D [m] may be caused by the failure of the discharge part D [m]. Each part of the inkjet printer 1 is controlled so that the determination process is executed.
Hereinafter, the failure of the discharge unit D will be described.

FIG. 23 is an explanatory diagram for explaining a failure of the discharge unit D. FIG.
As described above, the recording head 30 is provided with a plurality of cavities 320 corresponding to the plurality of ejection portions D, and the plurality of cavities 320 are separated from each other by the cavity plate 340 (see FIGS. 3 and 4). . Hereinafter, a portion of the cavity plate 340 that divides the cavity 320 is referred to as a partition wall 340A.
As shown in FIG. 23A, in the discharge section D, the partition 340A may peel from the nozzle plate 330 (hereinafter simply referred to as “peeling of the partition 340A”) due to deterioration over time. In FIG. 23A, the cavity 320 of the discharge part D [m] and the cavity 320 of the discharge part D [m-1] are separated by a partition 340A-1, and the cavity 320 of the discharge part D [m] The case where the cavity 320 of the discharge part D [m + 1] is partitioned by the partition 340A-2 and the partition 340A-1 and the partition 340A-2 are separated is illustrated.
In addition, when the cavity 320 of the one discharge part D and the cavity 320 of the other discharge part D adjoin via the partition 340A, the other discharge part D is made into the adjacent discharge part of the one discharge part D. This is called D-Nb. FIG. 23 illustrates a case where the discharge unit D [m−1] and the discharge unit D [m + 1] are adjacent discharge units D-Nb of the discharge unit D [m].

As shown in FIG. 23A, when the partition wall 340A (340A-1, 340A-2) of the discharge part D [m] is peeled off, the diaphragm 310 is bent by the drive signal Vin and the cavity 320 is contracted. Thus, even if pressure is applied to the inside of the cavity 320 of the discharge part D [m], the pressure escapes to the cavity 320 of the adjacent discharge part D-Nb via the partition wall 340A. In this case, it is considered that the compliance Cm increases in the residual vibration calculation model shown in FIG.
For this reason, when the partition 340A of the discharge part D [m] is peeled off, the amplitude of the residual vibration generated in the discharge part D [m] as compared with the case where the discharge state of the discharge part D [m] is normal. And the frequency of residual vibration generated in the discharge part D [m] is reduced. Therefore, when the partition wall 340A of the discharge part D [m] is peeled off, the residual vibration generated in the discharge part D [m] causes foreign matters such as paper dust to adhere to the vicinity of the nozzle N of the discharge part D [m]. Ink remaining in the cavity 320 of the ejection part D [m], or residual ink when the ink in the cavity 320 of the ejection part D [m] is thickened and fixed, or ink is injected into the cavity 320 of the ejection part D [m]. The waveform is close to the residual vibration in the absence. In other words, when the partition wall 340A of the discharge part D [m] is peeled off, the discharge part D [m] is set as the drive target discharge part DR and the discharge part D [m] is set as the determination target discharge part. When the first determination process is performed as DJ, the first determination information RS1 obtained from the discharge unit D [m] is a value of “3”, “4”, “5”, or “6”. Is likely to indicate.

  On the other hand, as shown in FIG. 23B, the discharge part D [m] and the discharge part D-Nb adjacent to the discharge part D [m] (in the example shown in this figure, the discharge part D [m-1] and D [m + 1]) are simultaneously driven, pressure is applied to the inside of the cavity 320 of the discharge part D [m], and pressure is applied to the inside of the cavity 320 of the adjacent discharge part D-Nb. Therefore, in this case, even if the partition 340A of the discharge part D [m] is peeled off, the pressure applied to the inside of the cavity 320 of the discharge part D [m] is applied to the adjacent discharge part D-Nb via the partition 340A. Escape can be kept small. For example, in this case, the discharge unit D [m] behaves as if the discharge state is normal.

As described above, when a failure occurs in the discharge unit D [m] (separation of the partition wall 340A), the discharge unit D [m] is in the first determination process in which the discharge unit D [m] is driven alone. There is a high possibility that the residual vibration that occurs and the residual vibration that occurs in the discharge section D [m] in the second determination process for simultaneously driving the discharge section D [m] and the adjacent discharge section D-Nb have different waveforms.
Therefore, the first determination information RS1 obtained by driving the discharge unit D [m] alone, and the second determination obtained by simultaneously driving the discharge unit D [m] and the adjacent discharge unit D-Nb. By comparing the information RS2, the ejection abnormality occurring in the ejection section D [m] is the increase in the viscosity of ink that can be recovered by the maintenance process, or the ejection section D [ m] can be distinguished.

The determination execution unit 26 sets the discharge unit D [m] and the adjacent discharge unit D-Nb of the discharge unit D [m] as the drive target discharge unit DR, and sets the discharge unit D [m] as the determination target discharge unit D-. In the second determination process of J, the discharge state in the discharge unit D [m] is determined based on the detection signal Tc2 and the validity flag Flag2 generated according to the residual vibration generated in the discharge unit D [m]. The second determination information RS2 corresponding to the discharge unit D [m] is generated. Then, the determination execution unit 26 stores the second determination information RS2 corresponding to the discharge unit D [m] in the discharge state management table TBL1 illustrated in FIG. 22 in association with the stage number m of the discharge unit D [m]. .
In the second determination process, the process in which the determination execution unit 26 generates the second determination information RS2 is the same process as the process of generating the first determination information RS1, and the first determination information RS1 shown in FIG. In the description of the processing for generating the detection signal Tc1, the detection signal Tc1 may be read as the detection signal Tc2, the validity flag Flag1 as the validity flag Flag2, and the first determination information RS1 as the second determination information RS2.

The determination execution unit 26 records the first determination information RS1 corresponding to the discharge unit D [m] in the discharge state management table TBL1 shown in FIG. 22, and the second determination information corresponding to the discharge unit D [m]. When RS2 is not recorded (indicated as “-” in FIG. 22), that is, when only the first determination process is executed in the discharge state determination process for the discharge unit D [m], the discharge is performed. A value indicated by the first determination information RS1 is set in the determination information RS corresponding to the part D [m].
On the other hand, the determination execution unit 26 records both the first determination information RS1 and the second determination information RS2 corresponding to the discharge unit D [m] in the discharge state management table TBL1, that is, the discharge unit D. In the ejection state determination process for [m], when both the first determination process and the second determination process are executed, first, the value indicated by the first determination information RS1 and the second determination information RS2 Compare the value indicated by. When the first determination information RS1 and the second determination information RS2 corresponding to the discharge unit D [m] indicate the same value, the determination execution unit 26 indicates that the discharge abnormality occurring in the discharge unit D [m] is the first. Considering that the cause is indicated by the determination information RS1 and the second determination information RS2, the determination information RS corresponding to the discharge unit D [m] includes the first determination information RS1 and the second determination information RS2. Set the value shown. Further, when the first determination information RS1 and the second determination information RS2 corresponding to the discharge unit D [m] indicate different values, the determination execution unit 26 adds the determination information RS corresponding to the discharge unit D [m] to the determination information RS. A value “9” indicating that a failure (separation of the partition wall 340A) has occurred in the discharge section D [m] is set.
The determination execution unit 26 stores the determination information RS generated corresponding to the discharge unit D [m] in the discharge state management table TBL1 in association with the stage number m of the discharge unit D [m].

<5.2. Estimating execution unit>
Next, the estimation execution unit 24 included in the remaining amount estimation unit 20 and the remaining amount estimation process will be described.

As described above, the remaining amount estimation process is a process of generating an estimated value Q of the remaining amount of ink for each color ink, and is controlled by the estimation execution unit 24 and the remaining amount update unit 22 under the control of the control unit 6. It is a process to be executed.
Hereinafter, a process of generating the estimated value W of the ink ejection amount executed by the estimation execution unit 24 in the remaining amount estimation process will be described.

The estimation execution unit 24 estimates the ejection amount W of the ink ejected from each ejection unit D based on the determination information RS stored in the ejection state management table TBL1 and the print signal SI generated by the control unit 6. Ask for.
Specifically, when the estimation execution unit 24 obtains the estimated value W of the ejection amount of ink ejected from the ejection unit D [m], first, the ejection unit D [m] is referred to the ejection state management table TBL1. ] Is obtained. Next, the estimation execution unit 24 acquires the print signal SI [m] output from the control unit 6. Then, the estimation execution unit 24 refers to the ejection amount information table TBL2 to obtain the estimated value W of the ink ejection amount corresponding to the obtained determination information RS and the print signal SI [m].

  FIG. 24 is a diagram illustrating an example of a data structure of the ejection amount information table TBL2. The ejection amount information table TBL2 includes a value indicated by the determination information RS and an estimated value W of the ink amount ejected from the ejection unit D [m] when forming a dot having a size specified by the print signal SI [m]. Are stored in association with each other. The estimated value W of the ink ejection amount stored in the ejection amount information table TBL2 is a value calculated in advance.

As shown in FIG. 24, when the value indicated by the determination information RS is “2”, that is, when a discharge abnormality occurs due to the bubble generated in the cavity 320, the diameter of the nozzle N is increased by the amount of the bubble. Therefore, the amount of ink ejected from the ejection part D [m] increases as compared with the case where the ejection state is normal.
Further, when the value indicated by the determination information RS is “3”, that is, when a discharge abnormality occurs due to a foreign matter such as paper dust adhering to the vicinity of the nozzle N outlet, the discharge of ink from the nozzle N is hindered by the foreign matter. Therefore, the amount of ink ejected from the ejection part D [m] is reduced as compared with the case where the ejection state is normal.
In addition, when the value indicated by the determination information RS is “4”, that is, when an abnormal discharge occurs due to the increased viscosity of the ink in the cavity 320, the increased viscosity of the ink prevents the discharge of ink from the nozzle N. Therefore, the amount of ink ejected from the ejection unit D [m] is reduced as compared with the case where the ejection state is normal.
In addition, when the value indicated by the determination information RS is “5”, that is, when the ejection abnormality occurs due to the fixation of the ink in the cavity 320 and the ink cannot be ejected from the nozzle, the ink ejected from the ejection unit D [m] The amount is “0”.
In addition, when the value indicated by the determination information RS is “6”, that is, when the ejection abnormality occurs due to reasons such as ink not being injected and the amplitude of the residual vibration is small, sufficient pressure is applied to the cavity 320. Therefore, the amount of ink ejected from the ejection unit D [m] is reduced as compared with the case where the ejection state is normal.
In addition, when the value indicated by the determination information RS is “9”, that is, when a discharge abnormality occurs because the discharge unit D [m] is out of order, sufficient pressure is applied to the cavity 320. Since this is not possible, the amount of ink ejected from the ejection part D [m] is reduced as compared with the case where the ejection state is normal.

  As described above, the estimation execution unit 24 according to the present embodiment generates the estimated value W of the ink ejection amount from the ejection unit D [m] according to the ink ejection state in the ejection unit D [m]. For this reason, even when the ejection abnormality occurs in the ejection part D [m], the amount of ink ejected from the ejection part D [m] can be accurately estimated according to the cause of the ejection abnormality. It becomes possible.

  The estimation execution unit 24 according to the present embodiment generates the estimated value W at a timing when the print data Img is supplied from the host computer and the control unit 6 generates the print signal SI. However, the estimation execution unit 24 may generate the estimated value W, for example, for each unit printing operation period Tu-P in which the printing process is executed, or one image indicated by the print data Img in the print job. You may do this every time you print.

<5.3. Remaining amount update section>
Next, the remaining amount update unit 22 in the remaining amount estimation unit 20 will be described.
The remaining amount update unit 22 sums up the estimated value W generated by the estimation execution unit 24 for each ink color, and calculates a total estimated ejection amount Wtotal that is a total value of the estimated value W of the ejection amount of ink of each color. .
Further, the remaining amount update unit 22 acquires the estimated value Q of the remaining amount of ink in each ink cartridge 31 stored in the remaining amount management table TBL3 as the estimated remaining amount Qold before update.

Then, the remaining amount update unit 22 subtracts the calculated total estimated discharge amount Wtotal from the acquired estimated remaining amount Qold for each ink color, and the subtracted value remains as the estimated value Q of the remaining amount of ink. It is stored in the quantity management table TBL3. Thereby, the remaining amount update unit 22 updates the estimated value Q of the remaining amount of ink stored in the remaining amount management table TBL3.
When the ink cartridge 31 is newly installed, the remaining amount update unit 22 fills the reservoir 350 and the cavity 320 corresponding to the ink cartridge 31 from the amount of ink initially stored in the ink cartridge 31. By subtracting the amount of ink to be generated, an estimated value Q of the remaining amount of ink is generated.
As described above, the remaining amount update unit 22 and the estimation execution unit 24 execute the remaining amount estimation process for generating the estimated value Q of the remaining amount of ink based on the determination information RS and the print signal SI.

  The update of the estimated value Q of the remaining amount of ink executed by the remaining amount update unit 22 is performed at the timing when the print job is finished, the timing when the formation of one image in the print job is completed, and the ink from each ejection unit D. What is necessary is just to perform suitably at the timing etc. which ejected the estimated value Q of the residual amount of ink with the operation part (illustration omitted) with which the user of the inkjet printer 1 was provided in the inkjet printer 1, etc ..

  As described above, the remaining amount update unit 22 according to the present embodiment is a total estimation that is a total value of the estimated values W of the ejection amount of ink from each ejection unit D after the ejection unit D ejects ink. Since the discharge amount Wtotal is calculated and the estimated value Q of the ink remaining amount is generated based on the total estimated discharge amount Wtotal, the ink remaining amount remaining after the ink jet printer 1 executes the printing process is accurately grasped. can do.

<6. Conclusion of Embodiment>
As described above, the ink jet printer 1 according to the present embodiment generates the determination information RS indicating the ink discharge state in the discharge unit D based on the residual vibration generated in the discharge unit D, and the determination information RS Based on this, the estimated value W of the ink remaining amount is generated by generating the estimated value W of the ink ejection amount from the ejection unit D.
For this reason, the ink jet printer 1 according to the present embodiment can accurately estimate the remaining amount of ink even when ejection abnormality occurs in the ejection part D.

The remaining amount estimation unit 20 described above may be implemented as an electronic circuit, or may be a functional block realized by a CPU or the like operating according to a control program.
In addition, a part of the remaining amount estimation unit 20 may be mounted as an electronic circuit, and the remaining part may be mounted as a functional block realized by a CPU.
For example, among the remaining amount estimation unit 20, only the measurement unit 25 suitable for processing by analog signals is mounted as an electronic circuit, and the remaining amount update unit 22, estimation execution unit 24, and determination execution unit 26 suitable for digital processing. May be implemented as a function by the CPU.

<B. Modification>
Each of the above forms can be variously modified. Specific modifications are exemplified below. Two or more aspects arbitrarily selected from the following examples can be appropriately combined within a range that does not contradict each other.
In addition, about the element which an effect | action and a function are equivalent to embodiment in the modification illustrated below, the code | symbol referred by the above description is diverted and each detailed description is abbreviate | omitted suitably.

<Modification 1>
In the above-described embodiment, it is determined whether or not the discharge unit D [m] is out of order by comparing the first determination information RS1 and the second determination information RS2, but the present invention is in such an aspect. It is not limited, and whether or not the residual vibration generated in the discharge part D [m] in the first determination process and the residual vibration generated in the discharge part D [m] in the second determination process have different waveforms. It is sufficient to determine whether or not the discharge unit D [m] is out of order.
Specifically, the first comparison for comparing the first determination information RS1 and the second determination information RS2, the second comparison for comparing the detection signal Tc1 and the detection signal Tc2, the validity flag Flag1 and the validity flag Flag2 By performing a part or all of the third comparison, and the residual vibration generated in the discharge part D [m] in the first determination process and the discharge part D [m in the second determination process. It may be determined whether or not the residual vibration generated in the waveform has a different waveform.

<Modification 2>
The ink jet printer 1 according to the embodiment and the modification described above performs the first determination process and the second determination process in the discharge state determination process, but the present invention is limited to such an aspect. In the ejection state determination process, only the first determination process may be executed without executing the second determination process.
The detection signal Tc when a failure has occurred in the discharge section D often shows a value close to the detection signal Tc when the value indicated by the determination information RS is “3” to “6”. Therefore, the ejection amount of ink from the ejection unit D when a failure occurs in the ejection unit D is close to the ejection amount when the value indicated by the determination information RS is “3” to “6”. There are many. For this reason, even if it is a case where the failure in the discharge part D is not detected without performing the 2nd determination process, it is possible to estimate the discharge amount of the ink from the discharge part D.

<Modification 3>
In the embodiment and the modification described above, the estimation execution unit 24 generates the estimated value W of the ink ejection amount based on the determination information RS, but the present invention is not limited to such an aspect and is detected. The estimated value W of the ink ejection amount may be generated based on the signal Tc.
For example, the ejection amount estimation unit 21 is configured without the determination execution unit 26, and the estimation execution unit 24 generates an estimated value W of the ink ejection amount based on the detection signal Tc1 generated by the measurement unit 25. May be. That is, the discharge amount estimation unit 21 may not generate the determination information RS.
In this case, the storage unit 60 stores the discharge amount information table TBL2A illustrated in FIG. 25 instead of the discharge amount information table TBL2, and the number of stages of the discharge unit D [m] instead of the discharge state management table TBL1 It is only necessary to store a table for managing m and the detection signal Tc1 indicating the period of residual vibration in the discharge section D [m] in association with each other.
As shown in FIG. 25, the ejection amount information table TBL2A includes ink that is ejected from the ejection unit D [m] when forming a range of the detection signal Tc1 and a dot having a size specified by the print signal SI [m]. The quantity estimated value W is stored in association with each other. The estimation execution unit 24 according to the present modification refers to the ejection amount information table TBL2A, so that the estimated value W of the ejection amount of ink corresponding to the detection signal Tc1 indicating the period of residual vibration occurring in the ejection unit D [m]. Can be obtained.

<Modification 4>
In the embodiment and the modification described above, the remaining amount estimation unit 20 estimates the remaining amount of ink stored in each ink cartridge 31, but the present invention is not limited to such an aspect, and the ink cartridge 31 is not limited thereto. The remaining amount of the sum of the ink stored in the ink, the ink filled in the reservoir 350, and the ink filled in the cavity 320 may be estimated.
In other words, in the above-described embodiment and modification, the ink cartridge 31 is defined as the “storage unit”, but the entire ink cartridge 31, the reservoir 350, and the cavity 320 are defined as the “storage unit”. Also good.
In this case, when the ink cartridge 31 is newly installed, the remaining amount update unit 22 does not consider the ink amount filled in the reservoir 350 or the cavity 320, and the ink amount stored in the ink cartridge 31 first. From this, the estimated value Q of the remaining amount of ink in the storage unit may be calculated by simply subtracting the estimated value W of the ink ejection amount in the ejection unit D.

<Modification 5>
In the embodiment and the modification described above, the remaining amount update unit 22 estimates the remaining amount of ink (that is, the current remaining amount of ink) at the time of execution of the remaining amount estimation process in the remaining amount estimation process. The invention is not limited to such an embodiment, and may be capable of estimating the remaining amount of ink in the future.
For example, when the print data Img and the copy number information CP are supplied from the host computer and the print job is started, the remaining amount update unit 22 determines the ink discharged in the print job before the start of the print job. By calculating the total estimated ejection amount Wtotal in advance, the estimated value Q of the remaining amount of ink at the end of the print job may be calculated. In this case, when the number of copies Wcp indicated by the number of copies information CP is large, it is possible to prevent the print job from being interrupted due to the ink being exhausted before the completion of the print job.

<Modification 6>
The inkjet printer 1 according to the embodiment and the modification described above is a line printer in which the nozzle row Ln is provided so that the range YNL includes the range YP, but the present invention is not limited to such an aspect. The ink jet printer 1 may be a serial printer in which the recording head 30 reciprocates in the Y-axis direction to execute print processing.

<Modification 7>
In the inkjet printer 1 according to the embodiment and the modification described above, when performing a printing process, for example, one long recording sheet P is divided into Wcp print areas and a margin for separating the print areas. However, the present invention is not limited to such an embodiment, and one recording paper P is formed on the entire recording paper P. An image may be formed.
In this case, for example, the recording paper P may have a rectangular shape like an A4 size paper. In this case, in the printing process, the transport mechanism 7 intermittently supplies the plurality of recording papers P onto the platen 74, and one image for one recording paper P supplied on the platen 74. May be formed. In this case, the discharge state determination process is performed from the time when one recording sheet P is unloaded from the platen 74 to the time when another recording sheet P is first supplied onto the platen 74 after the one recording sheet P. It may be executed in a period (that is, a period in which the recording paper P does not exist on the platen 74).

<Modification 8>
The inkjet printer 1 according to the embodiment and the modification described above can eject four colors of CMYK ink, but the present invention is not limited to such an aspect, and the inkjet printer 1 has at least one color. It is sufficient that the above ink can be ejected, and the ink color may be a color other than CMYK.
Further, the inkjet printer 1 according to the embodiment and the modification described above includes at least four ejection portions D in the recording head 30 (that is, M ≧ 4), but the present invention is limited to such an aspect. However, it is sufficient that at least one discharge section D is provided (that is, M ≧ 1).

<Modification 9>
In the embodiment and the modification described above, the drive waveform signal Com includes the drive waveform signals Com-A and Com-B, but the present invention is not limited to such an aspect, and the drive waveform signal Com is It may be a signal including only one signal (for example, drive waveform signal Com-A) or a signal including three or more signals (for example, drive waveform signals Com-A, Com-B, Com-C).
In the embodiment and the modification described above, the print signal SI is a 2-bit signal, but the number of bits of the print signal SI is the number of gradations to be displayed and the number of control periods Ts included in the unit operation period Tu. What is necessary is just to determine suitably according to the number etc. of the signal contained in the drive waveform signal Com.

<Modification 10>
In the embodiment and the modification described above, the head driver 50 includes one drive signal generation unit 51, and the drive signal generation unit 51 is supplied with a single type of drive waveform signal Com. The present invention is not limited to such an embodiment, and the head driver 50 includes, for example, a plurality of drive signal generation units 51 provided for each ink color ejected by the ejection unit D, and the control unit 6 The head driver 50 may be supplied with a plurality of types of drive waveform signals Com corresponding to the plurality of drive signal generation units 51 on a one-to-one basis.
In the embodiment and the modification described above, the head driver 50 includes one residual vibration detection unit 52. However, the present invention is not limited to such an aspect, and the head driver 50 includes a plurality of head drivers 50. The residual vibration detector 52 may be provided. In this case, the residual vibration signals Vout from the plurality of ejection units D can be detected simultaneously in each unit determination operation period Tu-T.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 5 ... Head unit, 6 ... Control part, 7 ... Conveyance mechanism, 20 ... Remaining quantity estimation part, 21 ... Discharge amount estimation part, 22 ... Remaining amount update unit, 23 ... discharge state determination unit, 24 ... estimation execution unit, 25 ... measurement unit, 26 ... determination execution unit, 30 ... recording head, 31 ... ink cartridge , 50... Head driver, 51... Drive signal generation unit, 52... Residual vibration detection unit, 53... Switching unit, 60. Motor driver, D ... discharge unit, N ... nozzle, TBL1 ... discharge state management table, TBL2 ... discharge amount information table, TBL3 ... remaining amount management table.

Claims (7)

A drive signal generator for generating a drive signal;
A piezoelectric element that is displaced in response to the drive signal;
A reservoir for storing the liquid;
A pressure chamber in which the liquid supplied from the storage unit is filled, and the internal pressure is increased or decreased by displacement of the piezoelectric element;
A nozzle communicating with the pressure chamber and capable of discharging a liquid filled in the pressure chamber in accordance with an increase or decrease in pressure in the pressure chamber;
A detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal;
A remaining amount estimating unit for estimating the remaining amount of the liquid stored in the storage unit;
A remaining amount storage unit that stores an estimated value of the remaining amount of the liquid estimated by the remaining amount estimation unit;
With
The remaining amount estimating unit
A discharge amount estimation unit that estimates a discharge amount of the liquid discharged from the nozzle based on a detection result of the detection unit;
The estimated value of the discharge amount estimated by the discharge amount estimation unit is subtracted from the estimated value of the remaining amount of the liquid stored in the remaining amount storage unit, and the result of the subtraction is used as the estimated value of the remaining amount of the liquid. A remaining amount update unit to be stored in the remaining amount storage unit;
Comprising
A liquid discharge apparatus characterized by that. The discharge amount estimating unit
A determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit;
An estimation execution unit that estimates a discharge amount of the liquid discharged from the nozzle based on a determination result of the determination unit;
With
The estimation execution unit
When the determination unit determines that the liquid cannot be discharged from the nozzle,
Estimating that the discharge amount of the liquid from the nozzle is “0”;
The liquid ejection apparatus according to claim 1, wherein The discharge amount estimating unit
A determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit;
An estimation execution unit that estimates a discharge amount of the liquid discharged from the nozzle based on a determination result of the determination unit;
With
The estimation execution unit
When the determination unit determines that the discharge state is abnormal because the liquid oozes out of the pressure chamber from the nozzle,
Compared to the case where it is determined that the discharge state is normal,
Estimating that the discharge amount of the liquid from the nozzle is small,
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The discharge amount estimating unit
A determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit;
An estimation execution unit that estimates a discharge amount of the liquid discharged from the nozzle based on a determination result of the determination unit;
With
The estimation execution unit
When the determination unit determines that the discharge state is abnormal because the liquid in the pressure chamber is thickened,
Compared to the case where it is determined that the discharge state is normal,
Estimating that the discharge amount of the liquid from the nozzle is small,
The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus according to claim 1. The discharge amount estimating unit
A determination unit that determines a discharge state of the liquid from the nozzle based on a detection result of the detection unit;
An estimation execution unit that estimates a discharge amount of the liquid discharged from the nozzle based on a determination result of the determination unit;
With
The estimation execution unit
When the determination unit determines that the discharge state is abnormal because the partition of the pressure chamber is peeled off,
Compared to the case where it is determined that the discharge state is normal,
Estimating that the discharge amount of the liquid from the nozzle is small,
The liquid ejection apparatus according to claim 1, wherein the liquid ejection apparatus is a liquid ejection apparatus according to claim 1. A drive signal generator for generating a drive signal;
A piezoelectric element that is displaced in response to the drive signal;
A reservoir for storing the liquid;
A pressure chamber in which the liquid supplied from the storage unit is filled, and the internal pressure is increased or decreased by displacement of the piezoelectric element;
A nozzle communicating with the pressure chamber and capable of discharging a liquid filled in the pressure chamber in accordance with an increase or decrease in pressure in the pressure chamber;
A detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal;
A remaining amount storage unit that stores an estimated value of the remaining amount of the liquid stored in the storage unit;
A method for controlling a liquid ejection apparatus comprising:
Based on the detection result of the detection unit, estimate the discharge amount of the liquid discharged from the nozzle,
Subtracting the estimated discharge amount of the liquid from the estimated value of the remaining amount of the liquid stored in the remaining amount storage unit,
The result of the subtraction is stored in the remaining amount storage unit as an estimated value of the remaining amount of liquid.
A control method for a liquid ejection apparatus. A drive signal generator for generating a drive signal;
A piezoelectric element that is displaced in response to the drive signal;
A reservoir for storing the liquid;
A pressure chamber in which the liquid supplied from the storage unit is filled, and the internal pressure is increased or decreased by displacement of the piezoelectric element;
A nozzle communicating with the pressure chamber and capable of discharging a liquid filled in the pressure chamber in accordance with an increase or decrease in pressure in the pressure chamber;
A detection unit for detecting residual vibration generated in the pressure chamber after the piezoelectric element is displaced according to the drive signal;
A remaining amount storage unit that stores an estimated value of the remaining amount of the liquid stored in the storage unit;
A computer,
A control program for a liquid ejection device comprising:
The computer,
A remaining amount estimating unit for estimating the remaining amount of the liquid stored in the storage unit;
Function as
The remaining amount estimating unit
A discharge amount estimation unit that estimates a discharge amount of the liquid discharged from the nozzle based on a detection result of the detection unit;
The estimated value of the discharge amount estimated by the discharge amount estimation unit is subtracted from the estimated value of the remaining amount of the liquid stored in the remaining amount storage unit, and the result of the subtraction is used as the estimated value of the remaining amount of the liquid. A remaining amount update unit to be stored in the remaining amount storage unit;
Comprising
A control program for a liquid ejecting apparatus.

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