Liquid discharge device and method for detecting the same

Abstract

To reduce ink consumption during classification of a plurality of discharge parts into a plurality of ranks.SOLUTION: A liquid discharge device comprises: a plurality of discharge parts capable of being filled with liquid and discharging the filled liquid; a generation part that generates first rank information on the basis of detection results of vibration caused in a first discharge part while the first discharge part is filled with a first liquid among the plurality of discharge parts; and an inspection part that inspects the first discharge part on the basis of the first rank information and the detection results of vibration caused in the first discharge part, while the first discharge part is filled with a second liquid. The first rank information indicates the rank to which the first discharge part belongs when the plurality of discharge parts is classified into the plurality of ranks on the basis of the characteristics of vibration of each discharge part.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection device and a method for inspecting a liquid ejection device. [Background technology]

[0002] A liquid ejection device such as an inkjet printer drives each of a plurality of ejection sections to eject a liquid such as ink filled in each of the ejection sections, thereby forming an image on a medium (hereinafter, the liquid such as ink used to form an image on a medium is referred to as the "printing liquid" and is an example of the "second liquid"). However, in liquid ejection devices, ejection abnormalities can occur, preventing the printing liquid from being ejected normally from the ejection sections. As a result, techniques for inspecting the ejection sections have been proposed. For example, Patent Document 1 discloses a technique in which a plurality of ejection sections are classified into a plurality of ranks based on the vibration characteristics of each ejection section, and each ejection section is inspected based on criteria corresponding to the rank to which each ejection section belongs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-179873 Summary of the Invention [Problem to be solved by the invention]

[0004] However, according to the conventional technology, when classifying a plurality of ejection sections into a plurality of ranks, it is necessary to fill the plurality of ejection sections with printing liquid, and it is also sometimes necessary to eject printing liquid from the plurality of ejection sections. Therefore, according to the conventional technology, for example, if the task of classifying a plurality of ejection sections into a plurality of ranks is performed before shipping the liquid ejection device, it is necessary to fill the plurality of ejection sections with printing liquid before shipping the liquid ejection device. Furthermore, according to the conventional technology, for example, if the task of classifying a plurality of ejection sections into a plurality of ranks is performed at a timing other than the timing when the liquid ejection device performs the process of forming an image on a medium, it is necessary to consume printing liquid for purposes other than forming an image on the medium. In these cases, the consumption of printing liquid can increase. [Means for solving the problem]

[0005] In order to solve the above problems, the liquid ejection device of the present invention comprises a plurality of ejection sections that can be filled with liquid and eject the filled liquid, a generation section that generates first rank information based on a detection result of vibrations that occur in a first ejection section among the plurality of ejection sections when the first ejection section is filled with a first liquid, and an inspection section that inspects the first ejection section based on a detection result of vibrations that occur in the first ejection section when the first ejection section is filled with a second liquid and the first rank information, and is characterized in that the first rank information indicates the rank to which the first ejection section belongs when the plurality of ejection sections are classified into a plurality of ranks based on the vibration characteristics of each ejection section.

[0006] Furthermore, the method for inspecting a liquid ejection device according to the present invention is a method for inspecting a liquid ejection device that is filled with liquid and has a plurality of ejection sections that can eject the filled liquid, and is characterized in that first rank information is generated based on detection results of vibrations that occur in a first ejection section of the plurality of ejection sections when the first ejection section is filled with a first liquid, and the first ejection section is inspected based on detection results of vibrations that occur in the first ejection section when the first ejection section is filled with a second liquid and the first rank information, and the first rank information indicates the rank to which the first ejection section belongs when the plurality of ejection sections are classified into a plurality of ranks based on the vibration characteristics of each ejection section. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a block diagram showing an example of the configuration of an inkjet printer 1 according to an embodiment of the invention. [Figure 2] FIG. 1 is a perspective view showing an example of the general structure of an inkjet printer 1. [Figure 3] FIG. 10 is a cross-sectional view illustrating an example of the structure of a discharge section D[m]. [Figure 4] FIG. 2 is a block diagram showing an example of the configuration of a head unit 3. [Figure 5] 10 is a timing chart for explaining an example of a signal supplied to the head unit 3. [Figure 6] FIG. 10 is an explanatory diagram illustrating an example of an individual designation signal Sd[m]. [Figure 7] FIG. 10 is an explanatory diagram illustrating an example of an individual designation signal Sd[m]. [Figure 8] 10 is a timing chart for explaining an example of a detection signal SK[m]. [Figure 9] FIG. 10 is an explanatory diagram for explaining an example of assignment rank information QR. [Figure 10] FIG. 10 is an explanatory diagram for explaining an example of appropriate vibration information QP during storage. [Figure 11] 10 is an explanatory diagram for explaining an example of appropriate in-use vibration information QS. FIG. [Figure 12]It is an explanatory diagram for explaining an example of the relationship between the appropriate range information QPP at the time of saving and the appropriate range information QSS at the time of use. [Figure 13] It is a flowchart for explaining an example of the rank information generation process. [Figure 14] It is a flowchart for explaining an example of the ejection state inspection process. [Figure 15] It is a block diagram showing an example of the configuration of the inkjet printer 1B according to Modification 1 of the present invention.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, in each figure, the dimensions and scales of each part are appropriately different from the actual ones. In addition, the embodiments described below are preferred specific examples of the present invention, and thus various technically preferable limitations are imposed. However, the scope of the present invention is not limited to these embodiments unless there is a description specifically limiting the present invention in the following description.

[0009] <<A. Embodiment>> In the present embodiment, a liquid ejection device will be described by exemplifying an inkjet printer that ejects ink to form an image on a recording paper PP.

[0010] <<1. Outline of Inkjet Printer>> Hereinafter, an example of the configuration of the inkjet printer 1 according to the present embodiment will be described while referring to FIGS. 1 to 3.

[0011] FIG. 1 is a functional block diagram showing an example of the configuration of the inkjet printer 1.

[0012] 1, print data Img indicating the image to be formed by the inkjet printer 1 is supplied from a host computer such as a personal computer or digital camera to the inkjet printer 1. The inkjet printer 1 executes a printing process to form the image indicated by the print data Img supplied from the host computer on recording paper PP.

[0013] As shown in Figure 1, the inkjet printer 1 includes a control unit 2 that controls each part of the inkjet printer 1, a head unit 3 that is provided with an ejection section D that ejects ink, a drive signal generation unit 4 that generates a drive signal Com for driving the ejection section D, an analysis unit 5 that analyzes the detection results of vibrations occurring in the ejection section D, a memory unit 6 that stores various information, and a transport unit 7 that changes the relative position of the recording paper PP with respect to the head unit 3. In this embodiment, the inkjet printer 1 is an example of a "liquid ejection device."

[0014] In this embodiment, it is assumed that the inkjet printer 1 includes one or more head units 3, one or more drive signal generation units 4 that correspond one-to-one to the one or more head units 3, and one or more analysis units 5 that correspond one-to-one to the one or more head units 3. Specifically, in this embodiment, it is assumed that the inkjet printer 1 includes four head units 3, four drive signal generation units 4 that correspond one-to-one to the four head units 3, and four analysis units 5 that correspond one-to-one to the four head units 3. However, for convenience of explanation, the following description will focus on one of the four head units 3, one drive signal generation unit 4 that corresponds to one of the head units 3 out of the four drive signal generation units 4, and one analysis unit 5 that corresponds to one of the head units 3 out of the four analysis units 5, as shown in FIG.

[0015] The control unit 2 includes one or more central processing units (CPUs). However, the control unit 2 may include a programmable logic device such as a field-programmable gate array (FPGA) instead of or in addition to a CPU.

[0016] The storage unit 6 includes one or both of a volatile memory such as RAM (Random Access Memory) and a non-volatile memory such as ROM (Read Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), or PROM (Programmable ROM). The storage unit 6 stores the control program PG for the inkjet printer 1, assigned rank information QR, optimum storage vibration information QP, and optimum usage vibration information QS. The assigned rank information QR, optimum storage vibration information QP, and optimum usage vibration information QS will be described later. In this embodiment, the optimum storage vibration information QP is an example of "first reference information," and the optimum usage vibration information QS is an example of "second reference information."

[0017] The control unit 2 executes the control program PG stored in the storage unit 6 and operates in accordance with the control program PG, thereby functioning as a discharge control unit 21, a rank information generating unit 22, and a discharge state inspecting unit 23. In this embodiment, the rank information generating unit 22 is an example of a "generating unit," and the ejection state inspecting unit 23 is an example of an "inspecting unit."

[0018] The discharge control unit 21 generates a waveform designation signal dCom and supplies the generated waveform designation signal dCom to the drive signal generation unit 4. Here, the waveform designation signal dCom is a digital signal that defines the waveform of the drive signal Com. The drive signal Com is an analog signal for driving the discharge units D. The drive signal generation unit 4 generates a drive signal Com having a waveform defined by the waveform designation signal dCom and supplies the generated drive signal Com to the head unit 3.

[0019] The discharge control unit 21 generates a designation signal SI and supplies the generated designation signal SI to the head unit 3. Here, the designation signal SI is a digital signal that designates the type of operation of the discharge unit D. Specifically, the designation signal SI is a signal that designates whether or not to supply the drive signal Com to the discharge unit D, thereby designating the type of operation of the discharge unit D.

[0020] The rank information generating unit 22 generates the belonging rank information QR based on the appropriate vibration information at the time of storage QP. Hereinafter, a series of processes related to the generation of the belonging rank information QR by the rank information generating unit 22 will be referred to as a rank information generating process. The ejection state inspection unit 23 inspects the ink ejection state in the ejection unit D based on the in-use appropriate vibration information QS. Hereinafter, a series of processes related to the inspection of the ink ejection state in the ejection unit D by the ejection state inspection unit 23 will be referred to as the ejection state inspection process.

[0021] The head unit 3 includes a supply circuit 31 , a recording head 32 , and a detection circuit 33 .

[0022] The recording head 32 has M discharge sections D. Here, the value M is a natural number that satisfies "M≧2." Note that, hereinafter, the mth discharge section D of the M discharge sections D provided in the recording head 32 may be referred to as discharge section D[m]. Here, the variable m is a natural number that satisfies "1≦m≦M." Furthermore, hereinafter, when a component or signal of the inkjet printer 1 corresponds to a discharge section D[m] among the M discharge sections D, the subscript [m] may be added to the symbol representing the component or signal.

[0023] The supply circuit 31 switches whether to supply the drive signal Com to the discharge section D[m] based on the designation signal SI. Hereinafter, the drive signal Com supplied to the discharge section D[m] may be referred to as the supply drive signal Vin[m].

[0024] Based on the designation signal SI, the supply circuit 31 switches whether to supply a vibration signal VX[m] indicating the potential of the upper electrode Zu[m] provided on the piezo element PZ[m] of the discharge section D[m] to the detection circuit 33. Hereinafter, when the vibration signal VX[m] is supplied from the discharge section D[m] to the detection circuit 33, the discharge section D[m] may be referred to as the discharge section DK to be inspected. The piezo element PZ[m] and the upper electrode Zu[m] will be described later with reference to FIG.

[0025] The detection circuit 33 generates a detection signal SK[m] based on the vibration signal VX[m] supplied from the discharge section D[m] that is set as the test target discharge section DK via the supply circuit 31. Specifically, the detection circuit 33 generates the detection signal SK[m] by amplifying the vibration signal VX[m].

[0026] The analysis unit 5 analyzes the waveform of vibrations occurring in the discharge section D[m] driven as the discharge section DK to be inspected based on the detection signal SK[m] output from the detection circuit 33, and extracts information indicating the characteristics of the vibrations. In this embodiment, as an example, it is assumed that the analysis unit 5 generates period information NTC[m] indicating the period TC[m] of vibrations occurring in the discharge section D[m] driven as the discharge section DK to be inspected based on the detection signal SK[m]. However, the present invention is not limited to this example. The analysis unit 5 may also generate information including some or all of the period TC[m], amplitude, and phase of vibrations occurring in the discharge section D[m] driven as the discharge section DK to be inspected based on the detection signal SK[m].

[0027] As described above, in this embodiment, the inkjet printer 1 executes a printing process, a rank information generation process, and a discharge state inspection process. This embodiment assumes that the printing process and the discharge state inspection process are executed after the inkjet printer 1 has been shipped, when the discharge units D have been filled with ink and are ready to discharge ink from the discharge units D. This embodiment also assumes that the rank information generation process is executed before the inkjet printer 1 has been shipped, when the discharge units D have been filled with preservation liquid. In this case, the preservation liquid may be a liquid that is not used to form images in the printing process by the inkjet printer 1. The preservation liquid may also be a liquid that is used to protect the discharge units D of the inkjet printer 1 before shipping. The preservation liquid may also be an antifreeze liquid that is used to prevent the discharge units D of the inkjet printer 1 from freezing before shipping. However, the present invention is not limited to this embodiment. The rank information generation process may be executed after the inkjet printer 1 has been shipped, when the ejection unit D has been filled with preservation liquid. Even in this case, the preservation liquid may be a liquid that is not used by the inkjet printer 1 to form images in the printing process. The preservation liquid may also be a liquid for cleaning the flow path that communicates with the ejection unit D of the inkjet printer 1.

[0028] When the printing process is executed, the ejection control unit 21 generates signals for controlling the head unit 3, such as a specification signal SI, based on the print data Img. The ejection control unit 21 also generates signals for controlling the drive signal generation unit 4, such as a waveform specification signal dCom. The control unit 2 also generates a transport control signal MH for controlling the transport unit 7. In this way, during the printing process, the control unit 2 controls the transport unit 7 to change the relative position of the recording paper PP with respect to the head unit 3, while adjusting the presence or absence of ink ejection from the ejection unit D[m], the amount of ink ejection, the timing of ink ejection, and the like, and controls each part of the inkjet printer 1 so that an image corresponding to the print data Img is formed on the recording paper PP.

[0029] When the rank information generation process is executed, the discharge control unit 21 supplies a designation signal SI to the head unit 3 to drive the discharge unit D[m] as the test-target discharge unit DK. The head unit 3 then outputs a detection signal SK[m] indicating vibrations that occur in the discharge unit D[m] as a result of the discharge unit D[m] being driven as the test-target discharge unit DK. Next, the analysis unit 5 generates period information NTC[m] indicating the period TC[m] of the vibrations that occur in the discharge unit D[m] based on the detection signal SK[m]. The rank information generation unit 22 then generates assigned rank information QR based on the period information NTC[m] and the appropriate-for-storage vibration information QP.

[0030] Here, the rank information QR indicates the rank to which each of the M ejection units D[1] to D[M] included in the head unit 3 belongs when classifying the M ejection units D[1] to D[M] into a plurality of ranks based on the period TC[m] of the vibration generated in each ejection unit D[m]. Hereinafter, among the ranks of the M ejection units D[1] to D[M] indicated by the rank information QR, the rank to which the ejection unit D[m] belongs is referred to as rank RK[m]. In the present embodiment, it is assumed that the M ejection units D[1] to D[M] included in the head unit 3 are classified into R ranks. Here, the value R is a natural number that satisfies "2 ≤ R < M".

[0031] Also, the proper vibration information QP during storage indicates the proper range of the period TC[m] of the vibration generated in the ejection unit D[m] driven as the inspection target ejection unit DK in a state where the ejection unit D[m] belonging to each rank r is filled with the storage liquid. Here, the variable r is a natural number that satisfies "1 ≤ r ≤ R".

[0032] When the ejection state inspection process is executed, the ejection control unit 21 supplies a designation signal SI for driving the ejection unit D[m] as the inspection target ejection unit DK to the head unit 3. Then, the head unit 3 outputs a detection signal SK[m] indicating the vibration generated in the ejection unit D[m] as a result of driving the ejection unit D[m] as the inspection target ejection unit DK. Next, the analysis unit 5 generates period information NTC[m] indicating the period TC[m] of the vibration generated in the ejection unit D[m] based on the detection signal SK[m]. Then, the ejection state inspection unit 23 inspects the ejection state of the ink in the ejection unit D based on the period information NTC[m] and the proper vibration information QS during use. In other words, the ejection state inspection unit 23 inspects whether or not ejection abnormality has occurred in the ejection unit D[m] based on the period information NTC[m] and the proper vibration information QS during use.

[0033] Here, ejection abnormality is a general term for a state in which ink cannot be ejected normally from the nozzle N of the ejection unit D[m]. For example, ejection abnormality includes a state in which ink cannot be ejected from the ejection unit D[m], a state in which the ejection unit D[m] ejects an amount of ink different from the ink ejection amount specified by the drive signal Com, and a state in which the ejection unit D[m] ejects ink at a speed different from the ink ejection speed specified by the drive signal Com.

[0034] In addition, the appropriate vibration information QS during use is information that indicates the appropriate range of the period TC[m] of the vibration that occurs in the ejection section D[m] that is driven as the ejection section DK to be tested when the ejection section D[m] belonging to each rank r is filled with ink.

[0035] In the following, the period TC[m] of the detection signal SK[m] detected from the discharge section D[m] driven as the discharge section DK to be tested when the discharge section D[m] is filled with storage liquid may be referred to as the period TC-P[m], and the period information NTC[m] indicating the period TC-P[m] may be referred to as the period information NTC-P[m]. In the following, the period TC[m] of the detection signal SK[m] detected from the discharge section D[m] driven as the discharge section DK to be tested when the discharge section D[m] is filled with ink may be referred to as the period TC-S[m], and the period information NTC[m] indicating the period TC-S[m] may be referred to as the period information NTC-S[m]. In this embodiment, the storage liquid is an example of the "first liquid," and the ink is an example of the "second liquid."

[0036] FIG. 2 is a perspective view showing an example of the general internal structure of the inkjet printer 1. As shown in FIG.

[0037] 2, this embodiment assumes that the inkjet printer 1 is a serial printer. Specifically, when performing a printing process, the inkjet printer 1 transports the recording paper PP in the X1 direction, while reciprocating the head unit 3 in the Y1 direction, which intersects with the X1 direction, and in the Y2 direction, which is the opposite direction to the Y1 direction, to eject ink from the ejection units D[m], thereby forming dots on the recording paper PP according to the print data Img.

[0038] Hereinafter, the X1 direction and its opposite X2 direction will be collectively referred to as the "X-axis direction," the Y1 direction intersecting the X-axis direction and its opposite Y2 direction will be collectively referred to as the "Y-axis direction," and the Z1 direction intersecting the X-axis and Y-axis directions and its opposite Z2 direction will be collectively referred to as the "Z-axis direction." In this embodiment, as an example, a description will be given assuming that the X-axis direction, Y-axis direction, and Z-axis direction are mutually orthogonal. However, the present invention is not limited to this aspect. The X-axis direction, Y-axis direction, and Z-axis direction may intersect with each other. In this embodiment, the Z1 direction is the direction in which ink is ejected from the ejection section D[m].

[0039] As shown in FIG. 2, the inkjet printer 1 according to this embodiment includes a housing 100, and a carriage 110 that is capable of reciprocating within the housing 100 in the Y-axis direction and that has four head units 3 mounted thereon.

[0040] In this embodiment, as shown in FIG. 2, it is assumed that the carriage 110 stores four ink cartridges 120, each corresponding to one of the four colors of ink: cyan, magenta, yellow, and black. Furthermore, as described above, it is assumed in this embodiment that the inkjet printer 1 includes four head units 3, each corresponding to one of the four ink cartridges 120. Each ejection section D[m] receives a supply of ink from the ink cartridge 120 corresponding to the head unit 3 in which the ejection section D[m] is provided. This allows each ejection section D[m] to fill itself with the supplied ink and eject the filled ink from the nozzles N. Note that the ink cartridges 120 may also be provided outside the carriage 110.

[0041] In this embodiment, it is assumed that the carriage 110 does not have the ink cartridge 120 mounted thereon before the inkjet printer 1 is shipped. In addition, in this embodiment, it is assumed that the ejection section D[m] is filled with preservative liquid before the inkjet printer 1 is shipped.

[0042] As described above, the inkjet printer 1 according to this embodiment also includes a transport unit 7. The transport unit 7 includes a carriage transport mechanism 71 for reciprocating the carriage 110 in the Y-axis direction, a carriage guide shaft 76 that supports the carriage 110 so that it can reciprocate in the Y-axis direction, a medium transport mechanism 73 for transporting the recording paper PP, and a platen 75 that is provided in the Z1 direction of the carriage 110. When a printing process is performed, the transport unit 7 uses the carriage transport mechanism 71 to reciprocate the head unit 3 together with the carriage 110 along the carriage guide shaft 76 in the Y-axis direction, and the medium transport mechanism 73 to transport the recording paper PP on the platen 75 in the X1 direction, thereby changing the relative position of the recording paper PP with respect to the head unit 3 and enabling ink to land on the entire recording paper PP.

[0043] FIG. 3 is a schematic partial cross-sectional view of the recording head 32, in which the recording head 32 is cut so as to include the ejection portion D[m].

[0044] As shown in FIG. 3, the ejection section D[m] includes a piezoelectric element PZ[m], a cavity CV[m] filled with ink or a storage liquid, a nozzle N[m] communicating with the cavity CV[m], and a vibration plate 321. The ejection section D[m] ejects ink from the cavity CV[m] through the nozzle N[m] when the piezoelectric element PZ[m] is driven by the supply drive signal Vin[m]. The cavity CV[m] is a space defined by a cavity plate 324, a nozzle plate 323 in which the nozzle N[m] is formed, and a vibration plate 321. The cavity CV[m] is connected to a reservoir 325 through an ink supply port 326. The reservoir 325 is connected to the ink cartridge 120 corresponding to the ejection section D[m] through an ink intake port 327. The piezoelectric element PZ[m] has an upper electrode Zu[m], a lower electrode Zd[m], and a piezoelectric body Zm[m] disposed between the upper electrode Zu[m] and the lower electrode Zd[m]. The lower electrode Zd[m] is electrically connected to a power supply line Lv set to a predetermined potential VBS. When a supply drive signal Vin[m] is supplied to the upper electrode Zu[m] and a voltage is applied between the upper electrode Zu[m] and the lower electrode Zd[m], the piezo element PZ[m] is displaced in the Z1 or Z2 direction in accordance with the applied voltage, causing the piezo element PZ[m] to vibrate. The lower electrode Zd[m] is joined to the diaphragm 321. Therefore, when the piezo element PZ[m] is driven to vibrate by the supply drive signal Vin[m], the diaphragm 321 also vibrates. The vibration of the diaphragm 321 changes the volume of the cavity CV[m] and the pressure within the cavity CV[m], causing the ink filled in the cavity CV[m] to be ejected from the nozzle N[m].

[0045] <<2. Head Unit Overview>> The head unit 3 will be outlined below with reference to FIGS.

[0046] FIG. 4 is a block diagram showing an example of the configuration of the head unit 3.

[0047] 4, the head unit 3 includes a supply circuit 31, a recording head 32, and a detection circuit 33. The head unit 3 also includes a wiring Lc to which the drive signal Com is supplied from the drive signal generation unit 4, and a wiring Ls for supplying the vibration signal VX[m] to the detection circuit 33.

[0048] The supply circuit 31 includes M switches Wc[1] to Wc[M] that correspond one-to-one to the M discharge sections D[1] to D[M], M switches Ws[1] to Ws[M] that correspond one-to-one to the M discharge sections D[1] to D[M], and a connection state designation circuit 34 that designates the connection state of each switch.

[0049] The connection state designation circuit 34 generates a connection state designation signal Rc[m] that designates the on / off state of the switch Wc[m] and a connection state designation signal Rs[m] that designates the on / off state of the switch Ws[m] based on the designation signal SI, latch signal LAT, change signal CH, and period designation signal Tsig supplied from the control unit 2.

[0050] The switch Wc[m] switches between conduction and non-conduction between the wiring Lc and the upper electrode Zu[m] of the piezo element PZ[m] based on the connection state designation signal Rc[m]. In this embodiment, the switch Wc[m] is turned on when the connection state designation signal Rc[m] is at a high level, and turned off when the connection state designation signal Rc[m] is at a low level. When the switch Wc[m] is turned on, the drive signal Com supplied to the wiring Lc is supplied to the upper electrode Zu[m] of the discharge section D[m] as the supply drive signal Vin[m]. The switch Ws[m] switches between conduction and non-conduction between the wiring Ls and the upper electrode Zu[m] of the piezo element PZ[m] based on the connection state designation signal Rs[m]. In this embodiment, the switch Ws[m] is turned on when the connection state designation signal Rs[m] is at a high level and turned off when the connection state designation signal Rs[m] is at a low level. When the switch Ws[m] is turned on, a vibration signal VX[m] indicating the potential of the upper electrode Zu[m] provided in the discharge section D[m] is supplied from the upper electrode Zu[m] to the detection circuit 33 via the wiring Ls.

[0051] The detection circuit 33 generates a detection signal SK[m] having a waveform corresponding to the waveform of the vibration signal VX[m] based on the vibration signal VX[m] supplied from the wiring Ls. Specifically, the detection circuit 33 generates the detection signal SK[m] by amplifying the vibration signal VX[m].

[0052] FIG. 5 is a timing chart showing an example of various signals such as the drive signal Com supplied to the head unit 3. In FIG.

[0053] 5, in this embodiment, when the inkjet printer 1 executes a printing process, a rank information generation process, or a discharge state inspection process, one or more unit periods TP are set as the operating period of the inkjet printer 1. During each unit period TP, the inkjet printer 1 can drive each discharge section D[m].

[0054] 5, the control unit 2 outputs a latch signal LAT having a pulse PLL, thereby defining a unit period TP as the period from the rising edge of the pulse PLL to the rising edge of the next pulse PLL. Furthermore, the control unit 2 outputs a change signal CH having a pulse PLC in a unit period TP, and divides the unit period TP into a drive period TQ1 from the rising edge of the pulse PLL to the rising edge of the pulse PLC, and a drive period TQ2 from the rising edge of the pulse PLC to the rising edge of the pulse PLL.

[0055] Furthermore, the control unit 2 outputs a period designation signal Tsig having a pulse PLT1 and a pulse PLT2 in a unit period TP. The control unit 2 then divides the unit period TP into a control period TS1 from the rising edge of the pulse PLL to the rising edge of the pulse PLT1, a control period TS2 from the rising edge of the pulse PLT1 to the rising edge of the pulse PLT2, and a control period TS3 from the rising edge of the pulse PLT2 to the rising edge of the pulse PLL.

[0056] As shown in FIG. 5, the designation signal SI includes M individual designation signals Sd[1] to Sd[M] that correspond one-to-one to the M discharge sections D[1] to D[M]. The individual designation signal Sd[m] designates the drive mode of the discharge section D[m] during each unit period TP when the inkjet printer 1 executes a printing process, a rank information generation process, or a discharge state inspection process. Prior to each unit period TP, the control unit 2 synchronizes the designation signal SI, including the M individual designation signals Sd[1] to Sd[M], with the clock signal CL and supplies it to the connection state designation circuit 34. The connection state designation circuit 34 then generates a connection state designation signal Rc[m] and a connection state designation signal Rs[m] during that unit period TP based on the individual designation signal Sd[m].

[0057] In this embodiment, when the inkjet printer 1 executes a printing process, it is assumed that the ejection section D[m] is capable of forming either a large dot made of ink with an ink amount ξ1, or a small dot made of ink with an ink amount ξ2 that is less than the ink amount ξ1.

[0058] 6 and 7 are explanatory diagrams for explaining an example of the individual designation signal Sd[m].

[0059] As shown in Figures 6 and 7, in this embodiment, the individual designation signal Sd[m] indicates one of four values ​​during the unit period TP: a value "1" that designates the discharge section D[m] as a large dot-forming discharge section DP-1; a value "2" that designates the discharge section D[m] as a small dot-forming discharge section DP-2; a value "3" that designates the discharge section D[m] as a non-driven discharge section DP-3; and a value "4" that designates the discharge section D[m] as a test target discharge section DK.

[0060] Here, the large-dot-forming discharge unit DP-1 is a discharge unit D that forms large dots in the unit period TP. The small-dot-forming discharge unit DP-2 is a discharge unit D that forms small dots in the unit period TP. The non-driven discharge unit DP-3 is a discharge unit D that is not driven by the drive signal Com in the unit period TP. The test-target discharge unit DK is a discharge unit D that is the target of the rank information generation process or the discharge state inspection process in the unit period TP.

[0061] Returning to the explanation of Figure 5. As shown in FIG. 5, in this embodiment, the drive signal Com has a waveform PA1 provided in the drive period TQ1 and a waveform PA2 provided in the drive period TQ2.

[0062] Of these, waveform PA1 is a waveform that, during control period TS1 of drive period TQ1, rises from reference potential V0 to potential VL1, which is lower than reference potential V0, and potential VH1, which is higher than reference potential V0, before returning to reference potential V0, and then maintains reference potential V0 during control periods TS2 and TS3 of drive period TQ1. Waveform PA1 is determined so that when a supply drive signal Vin[m] having waveform PA1 is supplied to ejection section D[m], ink equivalent to ink amount ξ1 is ejected from ejection section D[m].

[0063] Furthermore, the waveform PA2 is a waveform that, during the drive period TQ2, goes from the reference potential V0 to a potential VL2 that is lower than the reference potential V0, passes through a potential VH2 that is higher than the reference potential V0, and then returns to the reference potential V0. The waveform PA2 is determined so that when a supply drive signal Vin[m] having the waveform PA2 is supplied to the ejection section D[m], ink equivalent to the ink amount ξ2 is ejected from the ejection section D[m].

[0064] In this embodiment, as an example, it is assumed that when the potential of the supply drive signal Vin[m] supplied to the ejection section D[m] is high, the volume of the cavity CV[m] provided in the ejection section D[m] is smaller than when the potential is low. Therefore, when the ejection section D[m] is driven by the supply drive signal Vin[m] having a waveform PA1 or the like, the potential of the supply drive signal Vin[m] changes from low to high, causing the ink in the ejection section D[m] to be ejected from the nozzle N[m].

[0065] Next, the operation of the discharge section D[m] designated by the individual designation signal Sd[m] will be described with reference to FIGS.

[0066] 6, when the individual designation signal Sd[m] indicates a value of "1" that designates the discharge section D[m] as the large-dot-forming discharge section DP-1 during the unit period TP, the connection state designation circuit 34 sets the connection state designation signal Rc[m] to a high level during the drive period TQ1. In this case, the switch Wc[m] is turned on during the drive period TQ1. Therefore, during the unit period TP, the discharge section D[m] is driven by the supply drive signal Vin[m] having the waveform PA1, and discharges ink of an ink amount ξ1 corresponding to a large dot.

[0067] Furthermore, if the individual designation signal Sd[m] indicates a value of "2" that designates the discharge section D[m] as the small-dot-forming discharge section DP-2 during the unit period TP, the connection state designation circuit 34 sets the connection state designation signal Rc[m] to a high level during the drive period TQ2. In this case, the switch Wc[m] is turned on during the drive period TQ2. Therefore, during the unit period TP, the discharge section D[m] is driven by the supply drive signal Vin[m] having the waveform PA2, and discharges ink of an ink amount ξ2 corresponding to a small dot.

[0068] Furthermore, when the individual designation signal Sd[m] indicates a value of "3" that designates the ejector D[m] as the non-driven ejector DP-3 during the unit period TP, the connection state designation circuit 34 sets the connection state designation signals Rc[m] and Rs[m] to a low level during the unit period TP. In this case, the switches Wc[m] and Ws[m] are turned off during the unit period TP. Therefore, the ejector D[m] is not driven by the drive signal Com during the unit period TP and does not eject ink.

[0069] As shown in FIG. 7, when the individual designation signal Sd[m] indicates a value of "4" during the unit period TP, which designates the discharge section D[m] as the discharge section DK to be inspected, the connection state designation circuit 34 sets the connection state designation signal Rc[m] to a high level during the control period TS1 and sets the connection state designation signal Rs[m] to a high level during the control period TS2. In this case, the switch Wc[m] is turned on during the control period TS1, and the switch Ws[m] is turned on during the control period TS2. Therefore, the discharge section D[m] designated as the discharge section DK to be inspected is driven by the supply drive signal Vin[m] having the waveform PA1 during the control period TS1. As a result, vibrations generated in the discharge section D[m] remain during the control period TS2. Then, during the control period TS2, the potential of the upper electrode Zu[m] provided on the discharge section D[m] changes in response to the vibrations remaining in the discharge section D[m]. The detection circuit 33 detects the potential of the upper electrode Zu[m], which changes in response to the vibration remaining in the discharge section D[m], as a vibration signal VX[m] via the switch Ws[m] during the control period TS2. That is, the waveform of the vibration signal VX[m] detected from the discharge section D[m] during the control period TS2 represents the waveform of the vibration remaining in the discharge section D[m] during the control period TS2. The waveform of the detection signal SK[m] generated based on the vibration signal VX[m] detected from the discharge section D[m] during the control period TS2 represents the waveform of the vibration remaining in the discharge section D[m] during the control period TS2.

[0070] <<3. Overview of Analysis Unit 5>> The analysis unit 5 will be outlined below with reference to FIG.

[0071] As described above, the analysis unit 5 generates period information NTC[m] indicating the period TC[m] of the vibration occurring in the ejection section D[m] driven as the ejection section DK to be inspected based on the detection signal SK[m] supplied from the detection circuit 33.

[0072] 8 is a timing chart for explaining an example of the detection signal SK[m] that the detection circuit 33 supplies to the analysis unit 5. The detection signal SK[m] that the detection circuit 33 outputs during the control period TS2 indicates a waveform based on the vibration remaining in the discharge section D[m] during the control period TS2.

[0073] 8, during the control period TS2, the analysis unit 5 measures a period TC[m], which is the length of time from when the potential of the detection signal SK[m] matches a reference potential VK0 set near the center of the amplitude of the detection signal SK[m] to when the potential next matches the reference potential VK0, and generates period information NTC[m] indicating the period TC[m]. As described above, the rank information generation unit 22 generates assigned rank information QR based on the period information NTC[m]. Also, as described above, the ejection state inspection unit 23 inspects the ink ejection state of the ejection section D[m] driven as the ejection section DK to be inspected, based on the period information NTC[m].

[0074] <<4. Various Information Stored in Storage Unit 6>> Hereinafter, various types of information stored in the storage unit 6 will be described with reference to FIGS.

[0075] <<4.1. Rank Information QR Code>> FIG. 9 is an explanatory diagram illustrating an example of the data configuration of the assignment rank information QR.

[0076] 9, the assigned rank information QR has M records that correspond one-to-one to the M discharge sections D[1] to D[M] included in the head unit 3. Each record in the assigned rank information QR includes discharge section identification information Im and individual rank information QRR[m].

[0077] The discharge section identification information Im is information for identifying each discharge section D[m] from among the M discharge sections D[1] to D[M] included in the head unit 3. Specifically, the discharge section identification information Im indicates the value m. The individual rank information QRR[m] indicates the rank RK[m] to which the discharge section D[m] belongs. In this embodiment, the discharge section D[m] is an example of a "first discharge section," and the individual rank information QRR[m] is an example of "first rank information."

[0078] <<4.2. Appropriate Vibration Information QP During Storage>> FIG. 10 is an explanatory diagram for explaining an example of the data configuration of the appropriate-for-storage vibration information QP.

[0079] 10, the optimum vibration information QP during storage has R records corresponding one-to-one to the R ranks into which the M discharge sections D[1] to D[M] are classified. Each record in the optimum vibration information QP during storage includes rank identification information Ir and optimum period information QPT[r].

[0080] The rank identification information Ir is information for identifying each rank among the R ranks into which the M discharge sections D[1] to D[M] are classified. Specifically, the rank identification information Ir indicates the value r.

[0081] The appropriate cycle information QPT[r] is information indicating an appropriate range of the cycle TC[m] of the detection signal SK[m] detected from the discharge unit D[m] driven as the inspection target discharge unit DK in a state where the discharge unit D[m] belonging to the rank r is filled with the preservation liquid. Here, the appropriate range of the cycle TC[m] is a range in which the cycle TC[m] of the detection signal SK[m] detected from the discharge unit D[m] driven as the inspection target discharge unit DK can be obtained when no discharge abnormality occurs in the discharge unit D[m].

[0082] In the present embodiment, the appropriate cycle information QPT[r] includes cycle lower limit information QPL[r] and cycle upper limit information QPH[r]. The cycle lower limit information QPL[r] indicates a cycle TPL[r] that is the minimum value that the cycle TC[m] (i.e., cycle TC-P[m]) of the detection signal SK[m] detected from the discharge unit D[m] driven as the inspection target discharge unit DK can take in a state where the discharge unit D[m] belonging to the rank r is filled with the preservation liquid when no discharge abnormality occurs in the discharge unit D[m]. The cycle upper limit information QPH[r] indicates a cycle TPH[r] that is the maximum value that the cycle TC[m] (i.e., cycle TC-P[m]) of the detection signal SK[m] detected from the discharge unit D[m] driven as the inspection target discharge unit DK can take in a state where the discharge unit D[m] belonging to the rank r is filled with the preservation liquid when no discharge abnormality occurs in the discharge unit D[m]. Note that the cycle TPL[r] and the cycle TPH[r] satisfy 'TPL[r]<TPH[r]'.

[0083] In the following, the R rank identification information Ir included in the appropriate vibration information QP during storage is referred to as rank information QIR. Also, in the following, the R appropriate cycle information QPT[1] to QPT[R] included in the appropriate vibration information QP during storage is referred to as appropriate range information QPP during storage. In the present embodiment, the appropriate range information QPP during storage is an example of "first range information".

[0084] <<4.3. Appropriate Vibration Information QS during Use>> FIG. 11 is an explanatory diagram for explaining an example of the data configuration of the appropriate vibration information QS during use.

[0085] As shown in FIG. 11, the proper vibration information QS during use has R records corresponding one-to-one with R ranks into which M ejection units D[1] to D[M] are classified. Each record included in the proper vibration information QS during use includes rank identification information Ir and proper cycle information QST[r].

[0086] The proper cycle information QST[r] is information indicating an appropriate range of the cycle TC[m] of a detection signal SK[m] detected from the ejection unit D[m] driven as the inspection target ejection unit DK in a state where the ejection unit D[m] belonging to rank r is filled with ink.

[0087] In the present embodiment, the proper cycle information QST[r] includes cycle lower limit information QSL[r] and cycle upper limit information QSH[r]. The cycle lower limit information QSL[r] indicates a cycle TSL[r], which is the minimum value that the cycle TC[m] (that is, cycle TC - S[m]) of the detection signal SK[m] detected from the ejection unit D[m] driven as the inspection target ejection unit DK in a state where the ejection unit D[m] belonging to rank r is filled with ink can take when no ejection abnormality occurs in the ejection unit D[m] belonging to rank r. The cycle upper limit information QSH[r] indicates a cycle TSH[r], which is the maximum value that the cycle TC[m] (that is, cycle TC - S[m]) of the detection signal SK[m] detected from the ejection unit D[m] driven as the inspection target ejection unit DK in a state where the ejection unit D[m] belonging to rank r is filled with ink can take when no ejection abnormality occurs in the ejection unit D[m] belonging to rank r. Note that the cycle TSL[r] and the cycle TSH[r] satisfy “TSL[r] < TSH[r]”.

[0088] Incidentally, hereinafter, the R pieces of proper cycle information QST[1] to QST[R] included in the proper vibration information QS during use are referred to as proper range information QSS during use. In the present embodiment, the proper range information QSS during use is an example of “second range information”.

[0089] <<Relationship between the appropriate range information QPP at the time of storage and the appropriate range information QSS at the time of use>> FIG. 12 is a diagram showing an example of the relationship between the periods TPL[r] and TPH[r] indicated by the appropriate range information QPP at the time of storage and the periods TSL[r] and TSH[r] indicated by the appropriate range information QSS at the time of use.

[0090] In the present embodiment, as an example, it is assumed that the period TC-S[m] when the discharge unit D[m] is filled with ink is longer than the period TC-P[m] when the storage liquid of the discharge unit D[m] is filled. Therefore, in the present embodiment, as an example, as shown in FIG. 12, the periods TPL[r], TPH[r], TSL[r], and TSH[r] are determined in advance so that the relationship of 'TPL[r]<TPH[r]<TSL[r]<TSH[r]' is established.

[0091] Further, in the present embodiment, as an example, it is assumed that the period TC[m1] of the discharge unit D[m1] belonging to rank r1 is shorter than the period TC[m2] of the discharge unit D[m2] belonging to rank r2, that is, the case where 'TC[m1]<TC[m2]' holds. Here, the values r1 and r2 are natural numbers satisfying '1≦r1<r2≦R' and 'r2 = 1 + r1', the value m1 is a natural number satisfying '1≦m1≦M', and the value m2 is a natural number satisfying '1≦m2≦M' and'm2≠m1'. Therefore, in the present embodiment, as an example, as shown in FIG. 11, the periods TSH[r1] and TSH[r2] are determined in advance so that the relationship of 'TSH[r1]<TSH[r2]' is established, the periods TSL[r1] and TSL[r2] are determined in advance so that the relationship of 'TSL[r1]<TSL[r2]' is established, the periods TPH[r1] and TPH[r2] are determined in advance so that the relationship of 'TPH[r1]<TPH[r2]' is established, and the periods TPL[r1] and TPL[r2] are determined in advance so that the relationship of 'TPL[r1]<TPL[r2]' is established.

[0092] In this embodiment, as an example, it is assumed that the rank information generation unit 22 determines the rank r among the ranks 1 to R that has the largest difference value dPP[m][r] as the rank r to which the ejection section D[m] belongs. Here, the difference value dPP[m][r] is the smaller of the difference values ​​dPH[m][r] and dPL[m][r]. The difference value dPH[m][r] is the absolute value of the difference between the period TPH[r] and the period TC-P[m]. The difference value dPL[m][r] is the absolute value of the difference between the period TPL[r] and the period TC-P[m]. In other words, the difference value dPP[m][r] is the shortest distance between the period TC-P[m] and the boundaries (upper and lower limits) of the appropriate range of the period TC-P[m] corresponding to the rank r defined by the appropriate period information QPT[r]. In other words, in this embodiment, the rank information generation unit 22, as an example, determines the rank r to which the discharge section D[m] belongs so as to maximize the shortest distance between the boundary (upper and lower limits) of the appropriate range of the period TC-P[m] of rank r defined by the appropriate period information QPT[r] and the period TC-P[m].

[0093] <<5. Inkjet Printer 1 Operation>> An example of the operation of the inkjet printer 1 will be described below with reference to FIGS.

[0094] <<5.1. Rank Information Generation Process>> 13 is a flowchart showing an example of the operation of the control unit 2 when the rank information generation process is executed. As described above, the rank information generation process is executed before the inkjet printer 1 is shipped and in a state where the ejection section D[m] is filled with preservative liquid.

[0095] As shown in FIG. 13, when the rank information generation process is started, the control unit 2 sets a variable m to "1" (S101).

[0096] Next, the discharge control unit 21 drives the discharge unit D[m] as the discharge unit DK to be inspected (S103). Specifically, in step S103, the discharge control unit 21 drives the discharge section D[m] as the discharge section DK to be tested by supplying to the head unit 3 a designation signal SI including an individual designation signal Sd[m] that designates that the discharge section D[m] is to be driven as the discharge section DK to be tested.

[0097] Next, the rank information generating unit 22 acquires period information NTC-P[m] indicating the period TC-P[m] of the detection signal SK[m] detected from the discharge section D[m] driven as the discharge section DK to be inspected (S105). Next, the rank information generating unit 22 acquires the appropriate vibration information QP at the time of storage from the storage unit 6 (S107).

[0098] Thereafter, the rank information generating unit 22 generates individual rank information QRR[m] based on the period information NTC-P[m] acquired in step S105 and the optimum vibration information during storage QP acquired in step S107 (S109). Specifically, the rank information generation unit 22 identifies the rank r at which the difference value dPP[m][r] is maximum, based on the period TC-P[m] indicated by the period information NTC-P[m] acquired in step S105 and the periods TPL[1] to TPL[R] and the periods TPH[1] to TPH[R] indicated by the appropriate storage range information QPP of the appropriate storage vibration information QP acquired in step S107. Next, the rank information generation unit 22 sets the identified rank r as the rank RK[m] to which the discharge section D[m] belongs, thereby generating individual rank information QRR[m].

[0099] Next, the rank information generating unit 22 determines whether the value m is "M" (S111). If the result of the determination in step S111 is negative, the rank information generating unit 22 adds "1" to the value m (S113), and the process proceeds to step S103. If the result of the determination in step S111 is positive, the rank information generating unit 22 ends the rank information generating process.

[0100] <<5.2. Discharge Status Inspection Process>> 14 is a flowchart showing an example of the operation of the control unit 2 when the ejection state inspection process is executed. As described above, the ejection state inspection process is executed after the inkjet printer 1 is shipped and the ejection section D[m] is filled with ink.

[0101] As shown in FIG. 14, when the ejection state inspection process is started, the control unit 2 sets the variable m to "1" (S201).

[0102] Next, the discharge control unit 21 drives the discharge unit D[m] as the discharge unit DK to be inspected (S203). Specifically, in step S203, the discharge control unit 21 drives the discharge section D[m] as the discharge section DK to be tested by supplying to the head unit 3 a designation signal SI including an individual designation signal Sd[m] that designates that the discharge section D[m] is to be driven as the discharge section DK to be tested.

[0103] Next, the ejection state inspection unit 23 acquires period information NTC-S[m] indicating the period TC-S[m] of the detection signal SK[m] detected from the ejection unit D[m] driven as the ejection unit DK to be inspected (S205). Next, the ejection state inspection unit 23 acquires the appropriate vibration information QS for use from the storage unit 6 (S207). Furthermore, the discharge state inspection section 23 acquires the individual rank information QRR[m] corresponding to the discharge section D[m] from the storage unit 6 (S209).

[0104] Thereafter, the ejection state inspection unit 23 inspects the ejection unit D[m] based on the period information NTC-S[m] acquired in step S205, the appropriate vibration information during use QS acquired in step S207, and the individual rank information QRR[m] acquired in step S209 (S211). Specifically, the ejection state inspection unit 23 first selects the appropriate period information QST[r] corresponding to the rank RK[m] indicated by the individual rank information QRR[m] acquired in step S209 from among the R pieces of appropriate period information QST[1] to QST[R] included in the appropriate in-use vibration information QS acquired in step S207. Next, the ejection state inspection unit 23 determines whether or not "TSL[r]≦TC-S[m]≦TSH[r]" is satisfied based on the period TSL[r] and period TSH[r] indicated by the selected appropriate period information QST[r] and the period TC-S[m] indicated by the period information NTC-S[m] acquired in step S205. If the determination is affirmative, the ejection state inspection unit 23 generates information indicating an inspection result that the ink ejection state of the ejection section D[m] is normal and stores the generated information in the storage unit 6. On the other hand, if the result of the determination is negative, the discharge state inspection section 23 generates information indicating the inspection result that a discharge abnormality has occurred in the discharge section D[m], and stores the generated information in the storage unit 6.

[0105] Next, the ejection state inspection unit 23 determines whether the value m is "M" (S213). If the result of the determination in step S213 is negative, the ejection state inspection unit 23 adds "1" to the value m (S215), and the process proceeds to step S203. If the result of the determination in step S213 is positive, the ejection state inspection unit 23 ends the ejection state inspection process.

[0106] <<6. Conclusion of this embodiment>> As described above, in this embodiment, the inkjet printer 1 executes the rank information generation process with the discharge section D[m] filled with storage liquid, and executes the printing process and rank information generation process with the discharge section D[m] filled with ink. Therefore, according to this embodiment, it is possible to reduce the amount of ink used compared to conventional methods in which the rank information generation process is executed with the discharge section D[m] filled with ink.

[0107] Also, when it is necessary to execute the rank information generation process with the discharge unit D[m] filled with ink as in the conventional mode, for example, before the inkjet printer 1 is shipped, after changing the liquid filled in the discharge unit D[m] from the storage liquid to ink, the rank information generation process is executed, and then, after the rank information generation process is completed, it is necessary to change the liquid filled in the discharge unit D[m] back from ink to the storage liquid. In contrast, in the present embodiment, the rank information generation process can be executed without changing the liquid filled in the discharge unit D[m] before the inkjet printer 1 is shipped. That is, in the present embodiment, compared with the mode in which it is necessary to execute the rank information generation process with the discharge unit D[m] filled with ink, it is possible to reduce the load related to the preparatory work for executing the rank information generation process, and it is also possible to reduce the load related to the post-work from after the execution of the rank information generation process until the inkjet printer 1 is shipped.

[0108] <<B. Variation Example>> Each of the above embodiments can be variously modified. Specific modification modes are exemplified below. Two or more modes arbitrarily selected from the following examples can be appropriately combined within a range that does not conflict with each other. In the variation examples exemplified below, for elements whose actions and functions are equivalent to those of the embodiment, the reference numerals referred to in the above description are used, and the detailed description of each is appropriately omitted.

[0109] <<B.1. Variation Example 1>> In the above-described embodiment, the mode in which the control unit 2 generates the affiliated rank information QR and the control unit 2 inspects the ink discharge state in the discharge unit D has been exemplified and described, but the present invention is not limited to such a mode. Generation of the affiliated rank information QR and / or inspection of the ink discharge state in the discharge unit D may be executed by a component different from the control unit 2.

[0110] FIG. 15 is a functional block diagram showing an example of the configuration of the inkjet printer 1B according to Variation Example 1.

[0111] As shown in FIG. 15, the inkjet printer 1B is configured in the same manner as the inkjet printer 1 according to the embodiment described above, except that it has a control unit 2B instead of the control unit 2, a rank information generation unit 81, and an ejection state inspection unit 82.

[0112] The rank information generating unit 81, like the rank information generating section 22, generates the belonging rank information QR based on the optimum vibration information QP during storage and the period information NTC[m]. The ejection state inspection unit 82, like the ejection state inspection section 23, inspects the ink ejection state in the ejection section D based on the individual rank information QRR[m], the appropriate vibration information during use QS, and the period information NTC[m]. In this modified example, the rank information generating unit 81 is an example of a "generating section," and the ejection state inspecting unit 82 is an example of an "inspecting section."

[0113] The control unit 2B is configured in the same manner as the control unit 2 according to the above-described embodiment, except that it includes an information linking unit 24, does not include a rank information generating unit 22, and does not include an ejection state inspection unit 23. The information linking unit 24 supplies the rank information generation unit 81 with the appropriate vibration information QP during storage acquired from the memory unit 6, supplies the ejection state inspection unit 82 with the appropriate vibration information QS during use and individual rank information QRR[m] acquired from the memory unit 6, stores the assigned rank information QR generated by the rank information generation unit 81 in the memory unit 6, and also stores the results of the inspection of the ink ejection state in the ejection section D performed by the ejection state inspection unit 82 in the memory unit 6.

[0114] Also in this modification example, the inkjet printer 1B can execute the rank information generation process with the storage liquid filled in the ejection unit D[m]. Therefore, compared with the conventional mode of executing the rank information generation process with ink filled in the ejection unit D[m], it is possible to reduce the amount of ink used, and it is also possible to reduce the load related to the preparation work for executing the rank information generation process.

[0115] In this modification example, the analysis unit 5, the rank information generation unit 81, and the ejection state inspection unit 82 may be mounted on the head unit 3.

[0116] <<B.2. Modification Example 2>> In the above-described embodiment and modification example 1, the case where the inkjet printer 1 includes four head units 3 and four analysis units 5 is assumed. However, the present invention is not limited to such a mode. The inkjet printer 1 may include one or more and three or less head units 3 and analysis units 5, or may include five or more head units 3 and analysis units 5.

[0117] <<B.3. Modification Example 3>> In the above-described embodiment, modification example 1, and modification example 2, the case where the inkjet printer 1 is a serial printer is illustrated. However, the present invention is not limited to such a mode. The inkjet printer 1 may be a so-called line printer in which a plurality of nozzles N are provided in the head unit 3 so as to extend wider than the width of the recording paper PP.

[0118] <<C. Supplementary Note>> Aspects related to the above description are appended below. For the sake of easy understanding of each aspect, hereinafter, the reference numerals in the drawings are appended in parentheses for convenience, but the present invention is not intended to be limited to the illustrated aspects.

[0119] <<C.1. Supplementary Note 1>> The inkjet printer 1 according to Supplementary Note 1 includes M ejection units D[1] to D[M] that are filled with a liquid and can eject the filled liquid, and a rank information generation unit 22 that generates individual rank information QRR[m] based on the detection result of vibrations generated in the ejection unit D[m] when the ejection unit D[m] is filled with a preservation liquid among the M ejection units D[1] to D[M], and a ejection state inspection unit 23 that inspects the ejection state of the ink in the ejection unit D[m] based on the detection result of vibrations generated in the ejection unit D[m] when the ejection unit D[m] is filled with ink and the individual rank information QRR[m]. The individual rank information QRR[m] indicates the rank RK[m] to which the ejection unit D[m] belongs when classifying the M ejection units D[1] to D[M] into R ranks based on the period TC[m] of vibrations generated in each ejection unit D.

[0120] According to Supplementary Note 1, since the inkjet printer 1 can generate the individual rank information QRR[m] in a state where the ejection unit D[m] is filled with the preservation liquid, it is possible to reduce the amount of ink used and to reduce the load related to the preparation work for generating the individual rank information QRR[m], as compared with the mode of generating the individual rank information QRR[m] in a state where the ejection unit D[m] is filled with ink.

[0121] <<C.2. Supplementary Note 2>> The inkjet printer 1 according to Supplementary Note 2 is the inkjet printer 1 according to Supplementary Note 1, wherein the ink is a liquid used in the printing process of forming an image on the recording paper PP, and the preservation liquid is a liquid not used in the printing process.

[0122] According to Supplementary Note 2, it is possible to suppress the amount of ink used, as compared with the mode of generating the individual rank information QRR[m] in a state where the ejection unit D[m] is filled with ink.

[0123] <<C.3. Supplementary Note 3>> The inkjet printer 1 according to Supplementary Note 3 is the inkjet printer 1 according to Supplementary Note 1 or Supplementary Note 2, wherein the ink is a liquid used in the printing process of forming an image on the recording paper PP, and the storage liquid is a liquid for cleaning the flow path communicating with the ejection unit D[m].

[0124] According to Supplementary Note 3, during the process of cleaning the flow path communicating with the ejection unit D[m] before the shipment of the inkjet printer 1 or the like, the individual rank information QRR[m] can be generated. Therefore, compared with the mode of generating the individual rank information QRR[m] in a state where the ejection unit D[m] is filled with ink, it is possible to reduce the load related to the generation of the individual rank information QRR[m].

[0125] <<C.4. Supplementary Note 4>> The inkjet printer 1 according to Supplementary Note 4 is the inkjet printer 1 according to Supplementary Notes 1 to 3, wherein the ink is a liquid used in the printing process of forming an image on the recording paper PP, and the storage liquid is an antifreeze liquid.

[0126] According to Supplementary Note 4, before the shipment of the inkjet printer 1 or the like, the individual rank information QRR[m] can be generated in a state where the ejection unit D[m] is filled with the antifreeze liquid. Therefore, compared with the mode of generating the individual rank information QRR[m] in a state where the ejection unit D[m] is filled with ink, it is possible to reduce the load related to the generation of the individual rank information QRR[m].

[0127] <<C.5. Supplementary Note 5>> The inkjet printer 1 according to Supplementary Note 5 is the inkjet printer 1 according to Supplementary Notes 1 to 4, wherein the rank information generation unit 22 generates individual rank information QRR[m] based on the detection result of the vibration generated in the discharge unit D[m] when the discharge unit D[m] is filled with the storage liquid and the proper vibration information QP during storage. The proper vibration information QP during storage includes proper range information QPP indicating a proper range of the vibration period TC[m] generated in the discharge unit D[m] when the discharge unit D[m] belonging to rank r among the R ranks is filled with the storage liquid when the M discharge units D[1] to D[M] are classified into R ranks based on the vibration period TC[m] generated in each discharge unit D. <{0000487}><{0000488}><{0000489}><<C.6. Supplementary Note 6>><{0000490}>The inkjet printer 1 according to Supplementary Note 6 is the inkjet printer 1 according to Supplementary Notes 1 to 5, wherein the discharge state inspection unit 23 inspects the discharge unit D[m] based on the detection result of the vibration generated in the discharge unit D[m] when the discharge unit D[m] is filled with ink and the proper vibration information QS during use. The proper vibration information QS during use includes proper range information QSS indicating a proper range of the vibration period TC[m] generated in the discharge unit D[m] when the discharge unit D[m] belonging to rank r among the R ranks is filled with ink. <{0000491}>

Explanation of Reference Signs

Claims

1. a plurality of discharge units that are filled with liquid and that are capable of discharging the filled liquid; a generating unit that generates first rank information based on a detection result of vibration occurring in a first discharging unit among the plurality of discharging units when the first discharging unit is filled with a first liquid; an inspection unit that inspects the first discharge unit based on a detection result of vibration generated in the first discharge unit when the first discharge unit is filled with the second liquid and the first rank information; Equipped with the first rank information indicates a rank to which the first ejection unit belongs when the plurality of ejection units are classified into a plurality of ranks based on vibration characteristics of each ejection unit; A liquid ejection device characterized by:

2. the second liquid is a liquid used in a printing process for forming an image on a medium, the first liquid is a liquid that is not used in the printing process; The liquid ejection device according to claim 1 .

3. the second liquid is a liquid used in a printing process for forming an image on a medium, the first liquid is a liquid for cleaning a flow path communicating with the first discharge portion; The liquid ejection device according to claim 1 .

4. the second liquid is a liquid used in a printing process for forming an image on a medium, The first liquid is an antifreeze liquid. The liquid ejection device according to claim 1 .

5. The generation unit generating the first rank information based on a detection result of vibrations occurring in the first discharge section when the first discharge section is filled with the first liquid and first reference information; The first reference information is When the plurality of ejection sections are classified into a plurality of ranks based on the vibration characteristics of each ejection section, the first range information indicates an appropriate range of the vibration characteristics generated in one ejection section belonging to one of the plurality of ranks when the one ejection section is filled with the first liquid, The liquid ejection device according to claim 1 .

6. The inspection unit inspecting the first discharge portion based on a detection result of vibrations occurring in the first discharge portion when the first discharge portion is filled with the second liquid and second reference information; The second reference information is and second range information indicating an appropriate range of characteristics of vibration generated in one discharge portion belonging to one rank among the plurality of ranks when the one discharge portion is filled with the second liquid. The liquid ejection device according to claim 5 .

7. 1. A method for inspecting a liquid ejection device that is filled with liquid and has a plurality of ejection units that can eject the filled liquid, comprising: generating first rank information based on a detection result of vibration occurring in a first discharge portion among the plurality of discharge portions when the first discharge portion is filled with a first liquid; inspecting the first discharge portion based on a detection result of vibration occurring in the first discharge portion when the first discharge portion is filled with the second liquid and the first rank information; the first rank information indicates a rank to which the first ejection unit belongs when the plurality of ejection units are classified into a plurality of ranks based on vibration characteristics of each ejection unit; A method for inspecting a liquid ejection device.

8. the second liquid is a liquid used in a printing process for forming an image on a medium, the first liquid is a liquid that is not used in the printing process; 8. The method for inspecting a liquid ejection device according to claim 7.

9. the second liquid is a liquid used in a printing process for forming an image on a medium, the first liquid is a liquid for cleaning a flow path communicating with the first discharge portion; 8. The method for inspecting a liquid ejection device according to claim 7.

10. the second liquid is a liquid used in a printing process for forming an image on a medium, The first liquid is an antifreeze liquid.

8. The method for inspecting a liquid ejection device according to claim 7.

11. generating the first rank information based on a detection result of vibrations occurring in the first discharge section when the first discharge section is filled with the first liquid and first reference information; the first reference information includes first range information indicating an appropriate range of vibration characteristics generated in one discharge part belonging to one of the plurality of ranks when the plurality of discharge parts are classified into a plurality of ranks based on vibration characteristics of each discharge part, in a state where the one discharge part is filled with the first liquid, 8. The method for inspecting a liquid ejection device according to claim 7.

12. inspecting the first discharge portion based on a detection result of vibrations occurring in the first discharge portion when the first discharge portion is filled with the second liquid and second reference information; the second reference information includes second range information indicating an appropriate range of characteristics of vibration generated in one ejection portion belonging to one rank among the plurality of ranks in a state in which the one ejection portion is filled with the second liquid, 12. The method for inspecting a liquid ejection device according to claim 11.

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