Drive waveform determination method, recording medium, liquid ejection device, and drive waveform determination system

Abstract

The present invention provides a driving waveform determination method, a recording medium, a liquid ejection device, and a driving waveform determination system, which determine the waveform of a driving pulse applied to a driving element of a liquid ejection head while reducing the burden on the user in terms of time and cost. The driving waveform determination method determines the waveform of a driving pulse applied to a driving element provided in a liquid ejection head that ejects liquid, and includes: a first step of determining a candidate waveform of the driving pulse; a second step of notifying a user of candidate information related to the candidate waveform; a third step of receiving an instruction from the user based on the candidate information; and a fourth step of determining the waveform of the driving pulse based on the instruction.

Description

Technical Field

[0001] The present invention relates to a driving waveform determination method, a driving waveform determination program, a liquid ejection device, and a driving waveform determination system. Background Art

[0002] In a liquid ejection device such as an inkjet printer, ink or the like is generally ejected from a nozzle by applying a driving pulse to a driving element such as a piezoelectric element. Here, the waveform of the driving pulse is determined so that the ejection characteristics of the ink from the nozzle become desired characteristics.

[0003] The technique described in Patent Document 1 measures ejection characteristics by changing parameters for determining the waveform of a driving pulse, that is, a driving waveform, a plurality of times, and determines parameters of the driving waveform actually used based on the measurement results.

[0004] In the technique described in Patent Document 1, there is a problem that the burden on the user becomes excessive because the user manually determines the driving waveform. In view of this, in order to reduce the burden on the user, a method of automating the determination of the driving waveform by simulation or automatic measurement is considered.

[0005] However, when only the determination of the driving waveform is automated, even if the user has knowledge related to the determination of the driving waveform, the knowledge cannot be effectively utilized, and as a result, the number of simulations or actual measurements may become excessive. Since the excessive number of times increases the time required for determining the driving waveform or increases the amount of ink consumed by actual measurement, it is not preferable from the viewpoints of time or cost.

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-131910 Summary of the Invention

[0007] In order to solve the above problems, one aspect of the driving waveform determination method of the present invention determines the waveform of a driving pulse applied to a driving element provided in a liquid ejection head that ejects a liquid, and includes: a first step of determining a candidate waveform of the driving pulse; a second step of notifying a user of candidate information related to the candidate waveform; a third step of receiving an instruction from the user based on the candidate information; and a fourth step of determining the waveform of the driving pulse based on the instruction.

[0008] One aspect of the driving waveform determination program of the present invention causes a computer to execute the driving waveform determination method of the above aspect.

[0009] One aspect of the liquid ejection device of the present invention includes: a liquid ejection head having a drive element for ejecting liquid; and a processing circuit that performs processing to determine the waveform of a drive pulse applied to the drive element. The processing circuit executes the following steps: a first step of determining a candidate waveform of the drive pulse; a second step of notifying a user of candidate information related to the candidate waveform; a third step of receiving an instruction from the user based on the candidate information; and a fourth step of determining the waveform of the drive pulse based on the instruction.

[0010] One aspect of the drive waveform determination system of the present invention includes: a liquid ejection head having a drive element for ejecting liquid; and a processing circuit that performs processing to determine the waveform of a drive pulse applied to the drive element. The processing circuit executes the following steps: a first step of determining a candidate waveform of the drive pulse; a second step of notifying a user of candidate information related to the candidate waveform; a third step of receiving an instruction from the user based on the candidate information; and a fourth step of determining the waveform of the drive pulse based on the instruction. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram showing an outline of a structural example of the drive waveform determination system according to the first embodiment.

[0012] Figure 2 A diagram showing an example of the waveform of a drive pulse.

[0013] Figure 3 A diagram for explaining the measurement of ink ejection characteristics.

[0014] Figure 4 A diagram showing an example of a display image for starting the drive waveform determination mode.

[0015] Figure 5 A diagram showing an example of a display image for a candidate waveform and a hint for inferring ejection characteristics.

[0016] Figure 6 A flowchart showing the drive waveform determination method according to the first embodiment.

[0017] Figure 7 A schematic diagram showing an outline of a structural example of the liquid ejection device according to the second embodiment.

[0018] Figure 8 A flowchart showing the drive waveform determination method according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described. In the drawings, the dimensions or scales of each part are appropriately different from the actual ones, and there are also parts schematically shown for ease of understanding. In addition, as long as there is no record with a special intention of limiting the present invention in the following description, the scope of the present invention is not limited to these embodiments.

[0020] 1. First Embodiment

[0021] 1-1. Outline of Driving Waveform Determination System 100

[0022] Figure 1 It is a schematic diagram showing an example of the structure of the driving waveform determination system 100 according to the first embodiment. The driving waveform determination system 100 determines the waveform of the driving pulse PD used when ejecting ink as an example of a liquid. More specifically, the driving waveform determination system 100 appropriately utilizes the results obtained by measuring the ejection characteristics of the ink, notifies one or more candidate waveforms of the driving pulse to the user, and determines the waveform of the driving pulse based on an instruction from the user.

[0023] As Figure 1 shown, the driving waveform determination system 100 includes a liquid ejection device 200, a measurement device 300, and an information processing device 400 as an example of a computer. Hereinafter, based on Figure 1 , these devices will be described in sequence.

[0024] 1-1a. Liquid Ejection Device 200

[0025] The liquid ejection device 200 is a printer that performs printing on a printing medium by an inkjet method. The printing medium is not particularly limited as long as it is a medium that the liquid ejection device 200 can print on, for example, various papers, various cloths, or various films. In addition, the liquid ejection device 200 can be either a serial printer or a line printer.

[0026] As Figure 1 shown, the liquid ejection device 200 includes a liquid ejection head 210, a moving mechanism 220, a power supply circuit 230, a driving signal generation circuit 240, a driving circuit 250, a storage circuit 260, and a processing circuit 270.

[0027] The liquid ejection head 210 ejects ink toward the printing medium. In Figure 1In this case, as a structural element of the liquid ejection head 210, a plurality of piezoelectric elements 211, which are an example of a driving element, are illustrated. Although not shown, the liquid ejection head 210 has, in addition to the piezoelectric elements 211, a cavity for storing ink and a nozzle communicating with the cavity. Here, the piezoelectric elements 211 are provided for each cavity, and ink is ejected from the nozzle corresponding to the cavity by changing the pressure in the cavity. Alternatively, a heater for heating the ink in the cavity may be used as the driving element instead of the piezoelectric elements 211.

[0028] Although in Figure 1 the example shown, the number of liquid ejection heads 210 included in the liquid ejection device 200 is one, but the number may also be two or more. In this case, for example, two or more liquid ejection heads 210 are unitized. In the case where the liquid ejection device 200 is a serial type, the liquid ejection head 210 or a unit including two or more liquid ejection heads 210 is used in such a manner that a plurality of nozzles are distributed across a part of the width direction of the printing medium. In addition, in the case where the liquid ejection device 200 is a line type, a unit including two or more liquid ejection heads 210 is used in such a manner that a plurality of nozzles are distributed across the entire region of the width direction of the printing medium.

[0029] The moving mechanism 220 changes the relative position between the liquid ejection head 210 and the printing medium. More specifically, in the case where the liquid ejection device 200 is a serial type, the moving mechanism 220 has a conveyance mechanism that conveys the printing medium in a predetermined direction and a moving mechanism that repeatedly moves the liquid ejection head 210 along an axis orthogonal to the conveyance direction of the printing medium. In addition, in the case where the liquid ejection device 200 is a line type, the moving mechanism 220 has a conveyance mechanism that conveys the printing medium in a direction intersecting the long side direction of a unit including two or more liquid ejection heads 210.

[0030] The power supply circuit 230 receives power supply from a commercial power supply (not shown) and generates various predetermined potentials. The generated various potentials are appropriately supplied to each part of the liquid ejection device 200. For example, the power supply circuit 230 generates a power supply potential VHV and a bias potential VBS. The bias potential VBS is supplied to the liquid ejection head 210 and the like. In addition, the power supply potential VHV is supplied to the drive signal generation circuit 240 and the like.

[0031] The drive signal generation circuit 240 is a circuit that generates a drive signal Com for driving each piezoelectric element 211 included in the liquid ejection head 210. Specifically, the drive signal generation circuit 240 includes, for example, a DA conversion circuit and an amplification circuit. In the drive signal generation circuit 240, the DA conversion circuit converts a waveform designation signal dCom, which will be described later, from the processing circuit 270, from a digital signal into an analog signal, and the amplification circuit amplifies this analog signal using the power supply potential VHV from the power supply circuit 230, thereby generating the drive signal Com. Here, the signal of the waveform included in the drive signal Com that is actually supplied to the piezoelectric element 211 is a drive pulse PD. In addition, the drive pulse PD will be described in detail later.

[0032] The drive circuit 250 switches, based on a control signal SI, which will be described later, for each of the plurality of piezoelectric elements 211 whether to supply at least a part of the waveform included in the drive signal Com as the drive pulse PD. The drive circuit 250 is an IC (Integrated Circuit) chip that outputs a drive signal for driving each piezoelectric element 211 and a reference voltage.

[0033] The storage circuit 260 stores various programs executed by the processing circuit 270 and various data such as print data Img processed by the processing circuit 270. The storage circuit 260 includes, for example, a semiconductor memory that is one or both of a volatile memory such as a RAM (Random Access Memory) and a non-volatile memory such as a ROM (Read Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a PROM (Programmable ROM). The print data Img is supplied, for example, from the information processing device 400. In addition, the storage circuit 260 may be configured as a part of the processing circuit 270.

[0034] The processing circuit 270 has a function of controlling the operations of the respective parts of the liquid ejection device 200 and a function of processing various data. The processing circuit 270 includes, for example, one or more processors such as a CPU (Central Processing Unit). In addition, the processing circuit 270 may replace the CPU, or may include a programmable logic device such as an FPGA (field-programmable gate array) in addition to including the CPU.

[0035] The processing circuit 270 controls the operations of the respective parts of the liquid ejection device 200 by executing a program stored in the storage circuit 260. Here, as signals for controlling the operations of the respective parts of the liquid ejection device 200, the processing circuit 270 generates signals such as control signals Sk, SI, and a waveform designation signal dCom.

[0036] The control signal Sk is a signal for controlling the drive of the moving mechanism 220. The control signal SI is a signal for controlling the drive of the drive circuit 250. Specifically, the control signal SI designates, for each predetermined unit time, whether the drive circuit 250 supplies the drive signal Com from the drive signal generation circuit 240 as a drive pulse PD to the liquid ejection head 210. By this designation, the amount of ink ejected from the liquid ejection head 210 and the like are designated. The waveform designation signal dCom is a digital signal for prescribing the waveform of the drive signal Com generated in the drive signal generation circuit 240.

[0037] 1-1b. Measuring device 300

[0038] The measuring device 300 is a device for measuring the ejection characteristics of the ink from the liquid ejection head 210 when the drive pulse PD is actually used. As such ejection characteristics, for example, ejection speed, ink amount, the number of satellites, and stability can be cited. In the present embodiment, a case where the ejection speed and the ink amount among these characteristics are used as the ejection characteristics is illustrated.

[0039] The measuring device 300 of the present embodiment is a imaging device that images the state of the ink flying from the liquid ejection head 210. Specifically, the measuring device 300 includes, for example, an imaging optical system and an imaging element. The imaging optical system is an optical system including at least one imaging lens, and may include various optical elements such as a prism, and may also include a zoom lens or a focusing lens. The imaging element is, for example, a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary MOS) image sensor. The measurement of the ejection characteristics using the imaging image obtained by the measuring device 300 will be described in detail later.

[0040] In addition, although in this embodiment, the measurement device 300 images the ink during flight, it is also possible to measure ejection characteristics such as the ejection amount of the ink from the liquid ejection head 210 based on the results obtained by imaging the ink ejected onto a printing medium or the like. Further, the measurement device 300 only needs to be able to obtain a measurement result corresponding to the ejection characteristics of the ink from the liquid ejection head 210, and is not limited to an imaging device. For example, it may be an electronic scale that measures the mass of the ink ejected from the liquid ejection head 210. Moreover, as an information source for measuring the ejection characteristics of the ink from the liquid ejection head 210, in addition to using the information from the measurement device 300, the results obtained by detecting the waveform of the residual vibration generated in the liquid ejection head 210 may also be used. This residual vibration is the vibration remaining in the ink flow path in the liquid ejection head 210 after the driving of the piezoelectric element 211, and is detected, for example, as a voltage signal from the piezoelectric element 211.

[0041] 1-1c. Information processing device 400

[0042] The information processing device 400 is a computer that controls the operations of the liquid ejection device 200 and the measurement device 300. Here, the information processing device 400 is connected to the liquid ejection device 200 and the measurement device 300 via wireless or wired communication so as to be able to communicate with each other. In addition, a communication network including the Internet may be provided in this connection.

[0043] The information processing device 400 of this embodiment is an example of a computer that executes a program P which is an example of a driving waveform determination program. The program P causes the information processing device 400 to execute a driving waveform determination method that determines the waveform of the driving pulse PD applied to the piezoelectric element 211 provided in the liquid ejection head 210 that ejects ink as an example of a liquid.

[0044] As Figure 1 shown, the information processing device 400 includes a display device 410 as an example of a display unit, an input device 420, a storage circuit 430, and a processing circuit 440. These devices are connected to be able to communicate with each other.

[0045] The display device 410 displays various images under the control of the processing circuit 440. Here, the display device 410 has various display panels such as a liquid crystal display panel or an organic EL (electro-luminescence) display panel, for example. In addition, the display device 410 may be provided outside the information processing device 400. Further, the display device 410 may also be a structural element of the liquid ejection device 200.

[0046] The input device 420 is a device that accepts operations from the user. For example, the input device 420 has a pointing device such as a touchpad, a touch panel, or a mouse. Here, when the input device 420 has a touch panel, it can also serve as the display device 410. In addition, the input device 420 can also be provided outside the information processing device 400. Furthermore, the input device 420 can also be a structural element of the liquid ejection device 200.

[0047] The storage circuit 430 is a device that stores various programs executed by the processing circuit 440 and various data processed by the processing circuit 440. The storage circuit 430 has, for example, a hard disk drive or a semiconductor memory. In addition, part or all of the storage circuit 430 can also be provided in an external storage device or server of the information processing device 400.

[0048] In the storage circuit 430 of the present embodiment, a program P, measurement information D1, and waveform history information D2 are stored. The measurement information D1 is information indicating the measurement results of the aforementioned measurement device 300. The waveform history information D2 is various information used when determining the waveform of the drive pulse PD. For example, it is information indicating the relationship between the waveform of the drive pulse PD and the ejection characteristics of the ink ejected from the liquid ejection head 210. In addition, part or all of the program P, measurement information D1, and waveform history information D2 can also be stored in an external storage device or server of the information processing device 400.

[0049] The processing circuit 440 is a device having a function of controlling each part of the information processing device 400, the liquid ejection device 200, and the measurement device 300, and a function of processing various data. The processing circuit 440 has, for example, a processor such as a CPU (Central Processing Unit). In addition, the processing device 440 can be composed of a single processor or multiple processors. Furthermore, part or all of the functions of the processing circuit 440 can also be implemented by hardware such as a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0050] The processing circuit 440 functions as the candidate determination unit 441, the notification control unit 442, the reception unit 443, and the waveform determination unit 444 by reading and executing the program P from the storage circuit 430.

[0051] The candidate determination unit 441 is a functional unit that executes the first process and determines a candidate waveform for the drive pulse PD. This candidate waveform is an example of a waveform for the user to search when determining the waveform of the drive pulse PD. For example, it is the candidate waveforms SC_1, SC_2, and SC_3 shown below. The notification control unit 442 is a functional unit that executes the second process and notifies the user of candidate information related to this candidate waveform. This notification only needs to be able to notify the user of the content of this candidate, so it is not particularly limited. In this embodiment, the display implemented by the aforementioned display device 410 is used. In addition, this candidate information is, for example, the candidate information R_1, R_2, and R_3 shown below. The reception unit 443 is a functional unit that executes the third process and receives an instruction from the user based on this candidate information via the aforementioned input device 420 or the like. The waveform determination unit 444 is a functional unit that executes the fourth process and determines the waveform of the drive pulse PD based on this instruction. Figure 6 The candidate determination unit 441 is a functional unit that executes the first process and determines a candidate waveform for the drive pulse PD. This candidate waveform is an example of a waveform for the user to search when determining the waveform of the drive pulse PD. For example, it is the candidate waveforms SC_1, SC_2, and SC_3 shown below. The notification control unit 442 is a functional unit that executes the second process and notifies the user of candidate information related to this candidate waveform. This notification only needs to be able to notify the user of the content of this candidate, so it is not particularly limited. In this embodiment, the display implemented by the aforementioned display device 410 is used. In addition, this candidate information is, for example, the candidate information R_1, R_2, and R_3 shown below. The reception unit 443 is a functional unit that executes the third process and receives an instruction from the user based on this candidate information via the aforementioned input device 420 or the like. The waveform determination unit 444 is a functional unit that executes the fourth process and determines the waveform of the drive pulse PD based on this instruction. Figure 6 The candidate determination unit 441 is a functional unit that executes the first process and determines a candidate waveform for the drive pulse PD. This candidate waveform is an example of a waveform for the user to search when determining the waveform of the drive pulse PD. For example, it is the candidate waveforms SC_1, SC_2, and SC_3 shown below. The notification control unit 442 is a functional unit that executes the second process and notifies the user of candidate information related to this candidate waveform. This notification only needs to be able to notify the user of the content of this candidate, so it is not particularly limited. In this embodiment, the display implemented by the aforementioned display device 410 is used. In addition, this candidate information is, for example, the candidate information R_1, R_2, and R_3 shown below. The reception unit 443 is a functional unit that executes the third process and receives an instruction from the user based on this candidate information via the aforementioned input device 420 or the like. The waveform determination unit 444 is a functional unit that executes the fourth process and determines the waveform of the drive pulse PD based on this instruction.

[0052] 1-2. Example waveforms of the drive pulse PD

[0053] Figure 2 It is a diagram showing an example of the waveform of the drive pulse PD. In Figure 2 it shows the temporal change of the potential of the drive pulse PD, that is, the voltage waveform of the drive pulse PD. In addition, the waveform of the drive pulse PD is not limited to the example shown in Figure 2 but is arbitrary.

[0054] As shown in Figure 2 the drive pulse PD is included in the drive signal Com for each unit time Tu. The potential E of the drive pulse PD rises from the reference potential E1 to the potential E2 and then drops to a potential E3 lower than the potential E1, and thereafter returns to the potential E1.

[0055] When described more specifically, the potential E of the drive pulse PD is first maintained at the potential E1 during the period from time t0 to time t1, and then rises to the potential E2 during the period from time t1 to time t2. Then, the potential E of the drive pulse PD is maintained at the potential E2 during the period from time t2 to time t3, and then drops to the potential E3 during the period from time t3 to time t4. Thereafter, it is maintained at the potential E3 during the period from time t4 to time t5, and then rises to the potential E1 during the period from time t5 to time t6.

[0056] The driving pulse PD of such a waveform increases the pressure chamber of the liquid ejection head 210 during the period from time t1 to time t2, and rapidly reduces the volume of the pressure chamber during the period from time t3 to time t4. Due to the change in the volume of the pressure chamber, a part of the ink in the pressure chamber is ejected as droplets from the nozzle.

[0057] The waveform of the driving pulse PD as described above can be represented by a function using parameters p1, p2, p3, p4, p5, p6, and p7 corresponding to the respective periods. When the waveform of the driving pulse PD is defined by this function, the waveform of the driving pulse PD can be adjusted by changing each parameter. By adjusting the waveform of the driving pulse PD, the ejection characteristics of the ink ejected from the liquid ejection head 210 can be adjusted.

[0058] 1-3. Measurement of Ink Ejection Characteristics

[0059] Figure 3 FIG. is for explaining the measurement of the ink ejection characteristics. As Figure 3 shown, the measurement device 300 of the present embodiment images the flying states of the droplets DR1, DR2, DR3, and DR4 of the ink ejected from the nozzle N of the liquid ejection head 210 from a direction orthogonal or intersecting with the ejection direction.

[0060] The droplet DR1 is the main droplet. In contrast, the droplets DR2, DR3, and DR4 are droplets called satellite droplets having diameters smaller than that of the droplet DR1. In addition, the presence or absence, number, or size of the droplets DR2, DR3, and DR4 are different depending on the waveform of the driving pulse PD described above.

[0061] The ejection amount of the ink ejected from the liquid ejection head 210 is calculated, for example, using the captured image of the measurement device 300 and based on the diameter LB of the droplet DR1. In addition, the ejection speed of the ink ejected from the liquid ejection head 210 is calculated, for example, by continuously imaging the droplet DR1 and based on the moving distance LC of the droplet DR1 after a predetermined time and the predetermined time. In Figure 3 this, the droplet DR1 after the predetermined time is indicated by a two-dot chain line. In addition, the aspect ratio (LA / LB) of the ink ejected from the liquid ejection head 210 can also be calculated as an ink ejection characteristic.

[0062] 1-4. Flow of Determining the Waveform of the Driving Pulse PD

[0063] In the drive waveform determination system 100, when determining the waveform of the drive pulse PD, first, one or more initial waveforms are set. This setting is automatically set by input by the user using the aforementioned input device 420 or by execution of the program P.

[0064] Figure 4 FIG. is an example of a display image for starting the drive waveform determination mode. When the program P is executed, the information processing device 400 enters the drive waveform determination mode. For example, Figure 4 the image GU1 for the GUI (Graphical User Interface) shown is displayed on the display device 410. In the image GU1, there are included keys BT1, BT2, and BT3 for receiving instructions from the user.

[0065] The key BT1 is a key for various settings of the drive waveform determination mode. Although not shown, when an operation on the key BT1 is performed by the information processing device 400, the display device 410 displays a GUI image including items for various settings of the drive waveform determination mode. Using this GUI image, for example, input of the initial waveform by the user using the input device 420 is performed.

[0066] The key BT2 is a key for starting the process of determining the waveform of the drive pulse PD. When an operation on the key BT2 is performed, the process of determining the waveform of the drive pulse PD is started. The key BT3 is a key for canceling the drive waveform determination mode. When an operation on the key BT3 is performed, along with the end of the display of the image GU1, the drive waveform determination mode is canceled.

[0067] Figure 6 FIG. is a flowchart showing the drive waveform determination method according to the first embodiment. First, in step S110, the candidate determination unit 441 sets an initial waveform. The method of determining the initial waveform at this time is arbitrary. For example, a waveform pre-stored in the storage circuit 430 can be used, a waveform directly input by the user via the input device 420 can be used, or a waveform randomly determined by the processing circuit 440 can be used.

[0068] Next, in step S120, the candidate determination unit 441 uses this initial waveform for the drive pulse PD, thereby driving the liquid ejection head 210. Then, in step S130, the candidate determination unit 441 measures the ejection characteristics of the ink ejected from the liquid ejection head 210 using the measuring device 300 in the aforementioned manner.

[0069] Thereafter, in step S140, the candidate determination unit 441 determines candidate waveforms SC_1, SC_2, and SC_3 using the measurement results of the measurement device 300. Hereinafter, the processing in step S140 will be described.

[0070] The candidate waveforms SC_1, SC_2, and SC_3 are determined based on the results obtained by measuring the ejection characteristics when the above-described initial waveform is used for the driving pulse PD and ink is ejected from the liquid ejection head 210 by the measurement device 300. In this determination, an evaluation function that becomes minimum or maximum when a predetermined ejection characteristic is a desired value or range is used. For example, in the case of using an evaluation function that becomes minimum when a ejection characteristic is a desired value or range, the candidate waveforms SC_1, SC_2, and SC_3 are determined by Bayesian optimization or the Nelder-Mead method (simplex method) that minimizes the evaluation value of this evaluation function based on the measured ejection characteristics. In this evaluation function, a linear sum of terms related to the predetermined ejection characteristic is used. In the evaluation function of the present embodiment, a linear sum of a term related to the ejection speed and a term related to the ink amount is used. Further, the parameters of this evaluation function are parameters p1, p2, p3,... related to the waveform of the driving pulse PD.

[0071] When described more specifically, an example of this evaluation function f(x) is expressed by the following formula:

[0072] f(x) = W1 × (Vm(x) - Vmtarget) 2 + W2 × (Iw(x) - Iwmtarget) 2 .

[0073] Here, in the evaluation function f(x), x is the parameters p1, p2, p3,... Vm(x) is the measured value of the ejection speed. Iw(x) is the measured value of the ink amount. Vmtarget is the target value of the ejection speed. Imtarget is the target value of the ink amount. W1 and W2 are weight coefficients, respectively. In addition, although in an example of this evaluation function f(x), the evaluation is performed based on the ink amount and the ejection speed, in addition to this, the evaluation can also be performed using the ejection stability or the inclination of the ejection direction.

[0074] When Bayesian optimization is used in the determination of candidate waveforms SC_1, SC_2, and SC_3, the acquisition functions such as EI (Expected Improvement), PI (Probability of Improvement), UCB (Upper Confidence Bound), and PES (Predictive Entropy Search) are used to search for parameters p1, p2, p3, ……, and the candidate waveforms SC_1, SC_2, and SC_3 are determined as candidate waveforms (Xn).

[0075] Here, the characteristics of the obtained candidate waveforms SC_1, SC_2, and SC_3 vary depending on the type of acquisition function used. As a general trend, the candidate waveforms SC_1, SC_2, and SC_3 obtained using the acquisition function EI are waveforms with a relatively high expected improvement amount. The candidate waveforms SC_1, SC_2, and SC_3 obtained using the acquisition function PI are waveforms with a relatively high probability of improvement but a relatively small improvement amount. The candidate waveforms SC_1, SC_2, and SC_3 obtained using the acquisition function UCB are waveforms with a relatively large room for improvement but also a relatively large room for deterioration.

[0076] When the Nelder-Mead method is used in the determination of candidate waveforms SC_1, SC_2, and SC_3, the candidate waveforms SC_1, SC_2, and SC_3 are determined as the solutions obtained from the "reflection", "expansion", and "contraction" of the Nelder-Mead method. Here, by changing the reflection rate of "reflection", the expansion rate of "expansion", and the contraction rate of "contraction", multiple candidate waveforms can be determined using various methods. Since the Nelder-Mead method is a local optimization algorithm, it is preferred when an existing waveform is used for the driving pulse PD and the physical properties of the ink or the ejection characteristics as the target are slightly changed.

[0077] In addition, although the candidate waveforms SC_1, SC_2, and SC_3 are determined using the evaluation function f(x) in step S140 here, this is not necessarily the only way. For example, the candidate waveforms SC_1, SC_2, and SC_3 can also be determined by excluding waveforms that are significantly different from the ideal waveform from the initial waveforms. In addition, the candidate waveforms SC_1, SC_2, and SC_3 can be preset only as the initial waveforms, and these waveforms can be directly determined as the candidate waveforms SC_1, SC_2, and SC_3 in the subsequent steps.

[0078] Next, in step S150, the notification control unit 442 generates candidate information R_1, R_2, and R_3 based on the candidate waveforms SC_1, SC_2, and SC_3 as described later, and causes the display device 410 to display the candidate information R_1, R_2, and R_3.

[0079] Next, in step S160, as described later, a user's instruction related to the selection or correction of the candidate waveforms SC_1, SC_2, and SC_3 by the user via the input device 420 is received.

[0080] Next, in step S170, the waveform determination unit 444 determines whether one of the candidate waveforms SC_1, SC_2, and SC_3 has been selected.

[0081] If none of the candidate waveforms SC_1, SC_2, and SC_3 are selected, the process proceeds to step S180 to determine the next waveform to be applied next. Although the method for determining the next waveform in step S180 is arbitrary, it is preferably a waveform different from the candidate waveforms SC_1, SC_2, and SC_3 that were not selected in the user's instruction. For example, in addition to the candidate waveforms SC_1, SC_2, and SC_3, waveforms pre-stored in the storage circuit 430 can be used, waveforms directly input by the user via the input unit 420 can be used, or waveforms randomly determined by the processing circuit 440 can be used. Thereafter, the process returns to the aforementioned step S120, and the liquid ejection head is driven using the next waveform. Hereinafter, the foregoing steps are implemented in the same manner.

[0082] On the other hand, if one of the candidate waveforms SC_1, SC_2, and SC_3 is selected, the waveform determination unit 444 proceeds to step S190, determines the selected candidate waveform as the waveform of the drive pulse PD, and then ends.

[0083] 1-5. Details of the GUI for receiving user instructions

[0084] Figure 5 FIG. showing an example of the display image used in the aforementioned steps S150 and S160. When the candidate waveforms SC_1, SC_2, and SC_3 are determined in step S140, for example Figure 5 the image GU2 for the GUI shown is displayed on the display device 410.

[0085] In the image GU2, candidate information R_1, R_2, and R_3 and buttons BT4, BT5, and BT6 are included. The candidate information R_1, R_2, and R_3 is information related to mutually different candidate waveforms.

[0086] Specifically, the candidate information R_1 is information related to the candidate waveform SC_1. Hereinafter, the candidate information R_1 among the candidate information R_1, R_2, and R_3 will be representatively described. In addition, regarding the candidate information R_2 and R_3, since they are the same as the candidate information R_1 except that different candidate waveforms SC_2 and SC_3 from the candidate waveform SC_1 are used, their descriptions will be appropriately omitted.

[0087] In Figure 5 the example shown, the candidate information R_1 includes information GF, inference information GP1 and GP2, block group BTA, and button BTS.

[0088] The information GF is information representing the shape of the candidate waveform SC_1 obtained based on the aforementioned initial waveform. In the present embodiment, the information GF uses a graph with the vertical axis representing voltage and the horizontal axis representing time to represent the shape of the candidate waveform SC_1. In addition, Figure 5 the shapes of the candidate waveforms SC_1, SC_2, and SC_3 shown are an example and are not limited thereto. Furthermore, although here, the information representing the shape of the candidate waveform SC_1 is used as the information GF in such a way that the user can visually recognize the time and voltage of the candidate waveform SC_1, for example, information directly representing the time value or voltage value of the candidate waveform SC_1 as its numerical value may also be used as the information GF.

[0089] The inference information GP1 and GP2 are respectively information representing the following inference values, which are inference values related to the ejection characteristics of the ink ejected from the liquid ejection head 210 when the candidate waveform SC_1 is used for the driving pulse PD. Specifically, the inference information GP1 represents an inference value related to the ejection speed of the ink. The inference information GP2 represents an inference value related to the ejection amount of the ink. These information in the present embodiment use a graph with the vertical axis representing probability density and the horizontal axis representing the inference value, and characters representing the mean and variance of the probability distribution by numerical values, and represent the inference value through the probability distribution. In addition, Figure 5 the probability distribution shown is an example and is not limited thereto. Furthermore, although the case where the inference information GP1 and GP2 are represented by a graph with the horizontal axis being the inference value and the vertical axis being the probability density has been described here, they may also be represented by a graph representing the probability density by color or concentration for each inference value, or the probability density may be represented by numerical values for each inference value.

[0090] The inference information GP1 and GP2 are generated based on the ejection characteristics of the ink ejected from the liquid ejection head 210 and the posterior distribution of the aforementioned evaluation function (waveform), and are generated using statistical processing such as Gaussian process regression. In this generation, in addition to the waveform and ejection characteristics, for example, data such as the type of the liquid ejection head 210, the type of the ink, and the environmental temperature can also be used. These data are stored in the storage circuit 430 as waveform history information D2 at an appropriate timing such as during the aforementioned measurement.

[0091] Here, when the data required in the statistical processing for generating the inference information GP1 and GP2 is insufficient, instead of this statistical processing, or in combination with this statistical processing, simulation demonstrations are used to generate the inference information GP1 and GP2. Therefore, even when the data required in this statistical processing is insufficient, the accuracy of the inference value can be improved compared to the case of only using this statistical processing.

[0092] The box group BTA is a group of widgets for adjustment instructions for adjusting the waveforms of the candidate waveforms SC_1, SC_2, and SC_3. In Figure 5 the example shown, the box group BTA is composed of a plurality of combo boxes capable of inputting combinations of the time values t2 - t1, t3 - t2, t3 - t2, t4 - t3, t5 - t4, t6 - t5, the voltage values E1 - E2, and E3 - E1. The candidate waveforms SC_1, SC_2, and SC_3 are re - determined according to the input to the box group BTA. Along with this re - determination, the content of the aforementioned information GF is updated, and the content of the inference information GP1 and GP2 is also updated by re - performing the aforementioned statistical processing or simulation demonstration.

[0093] The button BTS is a button for selection instructions for selecting at least one candidate information from the multiple candidate information R_1, R_2, and R_3. In Figure 5 the example shown, the button BTS is a radio button set according to the information of each candidate information R_1, R_2, and R_3.

[0094] The button BT4 is a button for executing the fifth process of re - determining the candidate waveforms SC_1, SC_2, and SC_3. By operating the button BT4, in step S170, it is determined that no waveform is selected, and the process of advancing to step S180 is implemented. Here, the instruction generated by operating the button BT4 is an instruction indicating that the waveform of the drive pulse PD has not been determined in the determination instruction indicating whether to determine the waveform of the drive pulse PD.

[0095] The button BT5 is a button for determining the waveform of the drive pulse PD. By operating the button BT5, it is determined in step S170 that a waveform is selected, and the process proceeds to step S190. One of the candidate waveforms SC_1, SC_2, and SC_3, or a candidate waveform obtained by the user's modification of them, is determined as the waveform of the drive pulse PD. At this time, for example, one candidate waveform selected by the button BTS is determined as the waveform of the drive pulse PD. Here, the instruction generated by operating the button BT5 is an instruction indicating the determination of the waveform of the drive pulse PD in the determination instruction indicating whether to determine the waveform of the drive pulse PD.

[0096] The button BT6 is a button for canceling the drive waveform determination mode. When the button BT6 is operated, the drive waveform determination mode is canceled together with the end of the display of the image GU2.

[0097] As described above, the drive waveform determination system 100 includes the liquid ejection head 210 and the processing circuit 270. As described above, the liquid ejection head 210 has a piezoelectric element 211, which is an example of a drive element for ejecting ink, which is an example of a liquid. The processing circuit 270 performs a process of determining the waveform of the drive pulse PD applied to the piezoelectric element 211.

[0098] As described above, the processing circuit 270 executes a first process of determining the candidate waveforms SC_1, SC_2, and SC_3 of the drive pulse PD, a second process of notifying the user of the candidate information R_1, R_2, and R_3 related to the candidate waveforms SC_1, SC_2, and SC_3, a third process of receiving an instruction from the user based on the candidate information R_1, R_2, and R_3, and a fourth process of determining the waveform of the drive pulse PD based on the instruction. In this way, the processing circuit 270 executes a drive waveform determination method including the first process, the second process, the third process, and the fourth process.

[0099] In the above drive waveform determination system 100, the waveform of the drive pulse PD can be determined using the automatically determined candidate waveforms SC_1, SC_2, and SC_3. Therefore, compared with the case of manually determining the waveform of the drive pulse PD, the burden on the user can be reduced. Here, since the waveform of the drive pulse PD is determined based on the candidate information R_1, R_2, and R_3 related to the candidate waveforms SC_1, SC_2, and SC_3 notified to the user and according to the instruction from the user, the user's knowledge can be effectively utilized in the determination of the drive pulse PD. Therefore, compared with the case where the waveform of the drive pulse PD is determined completely automatically, the time required for determining the waveform of the drive pulse PD can be shortened, and the amount of ink consumed by actual measurement can be reduced.

[0100] In the present embodiment, as described above, the notification to the user in the second process is implemented by displaying the candidate information R_1, R_2, and R_3 on the display device 410 which is an example of the display unit. Therefore, it is possible to visually notify the user of the candidate information R_1, R_2, and R_3. As a result, compared with the case where a method other than vision is used for the notification of the candidate information R_1, R_2, and R_3, there is an advantage that it is easier for the user to grasp the candidate information R_1, R_2, and R_3. In addition, the notification of the candidate information R_1, R_2, and R_3 to the user is not limited to the notification achieved by display. For example, it may also be a notification achieved by voice or the like.

[0101] In addition, as described above, the candidate information R_1, R_2, and R_3 includes the information GF related to the shapes of the candidate waveforms SC_1, SC_2, and SC_3. Therefore, there is an advantage that it is easier for the user to sensually grasp the candidate waveforms SC_1, SC_2, and SC_3. In addition, although in the present embodiment, the shapes of the candidate waveforms SC_1, SC_2, and SC_3 are notified to the user by using a graph with the vertical axis being voltage and the horizontal axis being time, this notification is not limited thereto. For example, it may also be implemented by displaying characters such as the name representing the shape.

[0102] In addition, as described above, the candidate information R_1, R_2, and R_3 includes the information GF related to the time values and voltage values of the candidate waveforms SC_1, SC_2, and SC_3. Therefore, there is an advantage that it is easier for the user to grasp the candidate waveforms SC_1, SC_2, and SC_3 in detail. In addition, although in the present embodiment, the time values and voltage values of the candidate waveforms SC_1, SC_2, and SC_3 are notified to the user by using a graph with the vertical axis being voltage and the horizontal axis being time, this notification is not limited thereto. For example, it may also be implemented by displaying characters such as the numerical values representing the time value and the voltage value.

[0103] Moreover, as described above, the candidate information R_1, R_2, and R_3 includes the inference information GP1 and GP2 representing the inference values related to the ejection characteristics of the ink ejected from the liquid ejection head 210 when the candidate waveforms SC_1, SC_2, and SC_3 are used for the drive pulse PD. Therefore, by the user making an indication such as determining or adjusting the waveform of the drive pulse PD using the inference information GP1 and GP2 as a clue, the accuracy of the indication can be improved compared with the case where the inference information GP1 and GP2 are not used.

[0104] The inference information GP1 and GP2 respectively represent the inference values through probability distributions. Therefore, the user makes an indication such as determining or adjusting the waveform of the drive pulse PD based on this probability distribution, making it easier for the user to make a judgment for this indication compared to the case where the probability distribution is not used. In this embodiment, this probability distribution represents the mean or variance of the inference value. Additionally, in this embodiment, the probability distribution is notified to the user by using a graph with the vertical axis as the probability density and the horizontal axis as the inference value and displaying characters representing the mean and variance of this probability distribution numerically, but either the graph or the characters can be omitted.

[0105] The candidate waveforms SC_1, SC_2, and SC_3 are respectively candidate waveforms of the drive pulse PD. That is, the candidate waveforms SC_1, SC_2, and SC_3 include multiple candidate waveforms of the drive pulse PD. The second process notifies the user of multiple candidate information R_1, R_2, and R_3 corresponding to the multiple candidate waveforms SC_1, SC_2, and SC_3.

[0106] In this embodiment, as described above, the user can select at least one piece of candidate information from the multiple candidate information R_1, R_2, and R_3, and the indication for this selection is an example of the selection indication in the third process. That is, the indication in the third process includes a selection indication of selecting at least one piece of candidate information from the multiple candidate information R_1, R_2, and R_3. Therefore, compared to the case where the number of candidate waveforms of the drive pulse PD is one, the burden on the user for the indication in the third process can be reduced. Additionally, in this embodiment, multiple candidate waveforms SC_1, SC_2, and SC_3 are notified at once, but this is not limited thereto. For example, the candidate waveforms SC_1, SC_2, and SC_3 can also be notified one by one in sequence according to an indication implemented by the user, etc.

[0107] Furthermore, as described above, the user can adjust the candidate waveforms SC_1, SC_2, and SC_3, and the indication for this adjustment is an example of the adjustment indication in the third process. That is, the indication in the third process includes an adjustment indication of adjusting the candidate waveforms SC_1, SC_2, and SC_3. Therefore, even if the notified candidate waveform is not optimal, the candidate waveform can be optimized through the adjustment indication implemented by the user. Additionally, when the user has knowledge related to the waveform of the drive pulse PD, this knowledge can be effectively utilized to adjust the candidate waveforms SC_1, SC_2, and SC_3.

[0108] In addition, as described above, after notifying a plurality of candidate information R_1, R_2, and R_3, the user can indicate whether to determine the waveform of the driving pulse PD, and this indication is an example of the determination indication in the third process. That is, the indication in the third process includes a determination indication indicating whether to determine the waveform of the driving pulse PD. When this determination indication indicates that the waveform of the driving pulse is determined, the fourth process is executed. That is, in this case, the waveform of the driving pulse PD is determined. On the other hand, when this determination indication indicates that the waveform of the driving pulse PD is not determined, the fifth process of re-determining the candidate waveforms SC_1, SC_2, and SC_3 is executed. Therefore, even if the candidate waveforms SC_1, SC_2, and SC_3 are not optimal, the candidate waveforms SC_1, SC_2, and SC_3 can be optimized according to the determination indication implemented by the user. In addition, when the user has knowledge related to the waveform of the driving pulse PD, there is also an advantage that it is easy to effectively utilize this knowledge.

[0109] In the present embodiment, the aforementioned fifth process re-determines the candidate waveforms SC_1, SC_2, and SC_3 based on the indication from the user in the third process. Therefore, the number of unnecessary candidate waveforms included in the re-determined candidate waveforms can be reduced. As a result, even if the initially notified candidate waveforms are not optimal, the determination of the waveform of the driving pulse can be effectively implemented. In addition, this re-determination is not limited to the case where it is implemented based on the indication from the user. For example, it can also be implemented at each preset time.

[0110] In addition, preferably, the aforementioned fifth process changes the candidate waveforms SC_1, SC_2, and SC_3. In this case, the situation where unnecessary candidate waveforms are included in the re-determined candidate waveforms SC_1, SC_2, and SC_3 can be reduced.

[0111] As described above, the candidate waveforms SC_1, SC_2, and SC_3 are determined using simulation demonstrations. That is, the aforementioned first process determines the candidate waveforms SC_1, SC_2, and SC_3 using simulation demonstrations. Therefore, compared with the case where simulation demonstrations are not used, the number of times of ejecting ink for determining the candidate waveforms SC_1, SC_2, and SC_3 can be reduced.

[0112] In addition, as described above, the candidate waveforms SC_1, SC_2, and SC_3 are determined statistically using information related to the ejection characteristics of the ink ejected from the liquid ejection head 210 as needed. That is, the first process described above determines the candidate waveforms SC_1, SC_2, and SC_3 statistically using information related to the ejection characteristics of the ink ejected from the liquid ejection head 210. Therefore, compared with the case where this information is not used, the number of times of actually ejecting ink can be reduced. In addition, by using past measurement results and the like as this information, the knowledge of the user can also be effectively utilized in determining the waveform of the drive pulse PD.

[0113] In addition, as described above, in addition to performing the respective processes described above, the processing circuit 270 also performs a sixth process, which is a process of measuring the ejection characteristics of the ink ejected from the liquid ejection head 210 when the drive pulse PD using the candidate waveforms SC_1, SC_2, and SC_3 as waveforms is actually applied to the piezoelectric element 211. In addition, the second process described above determines the candidate waveforms SC_1, SC_2, and SC_3 using the result of the sixth process, that is, the measurement result of the ejection characteristics. Therefore, compared with the case where this measurement is not performed, the accuracy of the candidate waveforms SC_1, SC_2, and SC_3 with respect to the desired waveform can be improved.

[0114] 2. Second Embodiment

[0115] Figure 7 FIG. is a schematic diagram showing a structural example of the liquid ejection device 200A according to the second embodiment. The liquid ejection device 200A includes a display device 280, an input device 290, and a measurement device 300A, and is the same as the liquid ejection device 200A described above except that it executes the program P.

[0116] The display device 280 is configured in the same manner as the display device 410 in the first embodiment described above. The input device 290 is configured in the same manner as the input device 420 in the first embodiment described above. The measurement device 300A is configured in the same manner as the measurement device 300 in the first embodiment described above. In addition, at least one of the display device 280, the input device 290, and the measurement device 300A may be provided outside the liquid ejection device 200.

[0117] In the storage circuit 260 of the present embodiment, a program P, measurement information D1, and waveform history information D2 are stored. The processing circuit 270 of the present embodiment is an example of a computer, and functions as a candidate determination unit 271, a notification control unit 272, a reception unit 273, and a waveform determination unit 274 by executing the program P.

[0118] The candidate determination unit 271 determines a candidate waveform of the drive pulse PD in the same manner as the candidate determination unit 441 in the aforementioned first embodiment. The notification control unit 272 notifies the user of the candidate information in the same manner as the notification control unit 442 in the aforementioned first embodiment. The reception unit 273 receives an instruction from the user via the aforementioned input device 290 or the like in the same manner as the reception unit 443 in the aforementioned first embodiment. The waveform determination unit 274 determines the waveform of the drive pulse PD based on this instruction in the same manner as the waveform determination unit 444 in the aforementioned first embodiment. In the above-described manner, the processing circuit 270 executes the first process, the second process, the third process, and the fourth process in the same manner as the processing circuit 440 in the aforementioned first embodiment.

[0119] Even according to the above-described second embodiment, it is possible to determine the waveform of the drive pulse PD while similarly reducing the burden on the user in terms of time and cost as in the aforementioned first embodiment.

[0120] 3. Third Embodiment

[0121] Figure 8 FIG. is a flowchart showing a drive waveform determination method according to the third embodiment.

[0122] Here, since steps S110 to S160 in the third embodiment are the same as steps S110 to S160 in the first embodiment, the description thereof is omitted.

[0123] In the third embodiment, after receiving an instruction from the user related to the selection or correction of the candidate waveform SC_1 by the user via the input device 290 in step S160, the process proceeds to step S210.

[0124] In step S210, the storage circuit 430 stores the information GF, information indicating whether the user has selected the candidate waveform SC_1 indicated by the information GF, information indicating whether the user has corrected the candidate waveform SC_1 indicated by the information GF, and information indicating how much the correction has been made in the case of correction. In addition, the storage area may not be the storage circuit 430. For example, it may be stored in an external storage server or the like separately provided from the liquid ejection device 200 or the information processing device 400.

[0125] Next, in step S220, it is determined whether a predetermined condition is satisfied. Here, the predetermined condition refers to, for example, a condition for determining whether the candidate waveform SC_1 shown in the information GF selected by the user among the information GF stored in the storage circuit 430 etc. is close to the ideal waveform. As the information GF selected by the user is stored in the storage circuit 430 etc. multiple times as described later, when there is no change in the candidate waveform SC_1 shown in this information GF, it can be determined that it is close to the ideal waveform and the predetermined condition is satisfied. In addition to this, when the information GF selected by the user stored in the storage circuit 430 etc. exceeds a predetermined number, it can also be determined that the drive pulse PD has been searched a sufficient number of times and the predetermined condition is satisfied.

[0126] In the case where it is determined in step S220 that the predetermined condition is not satisfied, the process proceeds to step S180. Since step S180 in the third embodiment is the same as step S180 in the first embodiment, the description thereof is omitted.

[0127] In the case where it is determined in step S220 that the predetermined condition is satisfied, the process proceeds to step S230. In step S230, based on the information GF selected by the user stored in the storage circuit 430 etc., the waveform of the drive pulse PD is determined. Either the average value of the candidate waveform SC_1 shown in the information GF selected by the user can be determined as the drive pulse PD, or the candidate waveform SC_1 shown in the last stored information GF can be determined as the drive pulse PD.

[0128] 4. Modification Example

[0129] Although the drive waveform determination method, drive waveform determination program, liquid ejection device, and drive waveform determination system of the present invention have been described above based on the illustrated embodiments, the present invention is not limited to these contents. In addition, the structure of each part of the present invention can be replaced with any structure that exhibits the same function as the foregoing embodiments, and any structure can also be added.

[0130] 4-1. Modification Example 1

[0131] Although in the foregoing embodiments, an example is shown in which the program P is executed by the processing circuit provided in the same device as the installed storage circuit, it is not limited to this structure, and it can also be executed by the processing circuit provided in a device different from the installed storage circuit. For example, similar to the first embodiment, the program P stored in the storage circuit 430 of the information processing device 400 can be executed by the processing circuit 270 of the liquid ejection device 200.

[0132] 4-2. Modification Example 2

[0133] In the foregoing embodiments, a structure for displaying information GF, inference information GP1 and GP2, box group BTA, and button BTS as image GU2 is disclosed, but the structure is not limited thereto. For example, as image GU2, only information GF, box group BTA, and button BTS may be displayed, and an image including inference information GP1 and GP2 may be displayed after a selection instruction or adjustment instruction for the image is performed. In this case, it may be set that information GF is not included in the image including inference information GP1 and GP2. Further, as image GU2, only information GF and button BTS may be displayed, and only a selection instruction for information GF may be accepted. In addition, information GF may not be displayed as image GU2. For example, as image GU2, only inference information GP1 and GP2, and button BTS may be displayed, and a selection instruction for inference information GP1 and GP2 may be accepted.

[0134] Symbol Explanation

[0135] 100… Driving waveform determination system; 200… Liquid ejection device; 200A… Liquid ejection device; 210… Liquid ejection head; 211… Piezoelectric element (driving element); 270… Processing circuit; 280… Display device (display unit); 400… Information processing device (computer); 410… Display device (display unit); 430… Storage circuit; 440… Processing circuit; GF… Information; GP1… Inference information; GP2… Inference information; P… Program (driving waveform determination program); PD… Driving pulse; R_1… Candidate information; R_2… Candidate information; R_3… Candidate information; SC_1… Candidate waveform; SC_2… Candidate waveform; SC_3… Candidate waveform.

Claims

1. A driving waveform determination method, characterized in that, it determines the waveform of a driving pulse applied to a driving element disposed in a liquid ejection head that ejects liquid, and the driving waveform determination method includes: a first step of determining a candidate waveform of the driving pulse; a sixth step of measuring the ejection characteristics of the liquid ejected from the liquid ejection head when the driving pulse using the candidate waveform as the waveform is actually applied to the driving element; a second step of generating candidate information related to the candidate waveform using the result of the sixth step and notifying the candidate information to the user; a third step of receiving an instruction from the user based on the candidate information; a fourth step of determining the waveform of the driving pulse based on the instruction.

2. The driving waveform determination method according to claim 1, characterized in that, the candidate information includes information related to the shape of the candidate waveform.

3. The driving waveform determination method according to claim 1 or 2, characterized in that, the candidate information includes information related to the time value and voltage value of the candidate waveform.

4. The driving waveform determination method according to claim 1, characterized in that, the candidate information includes inference information representing an inference value that is an inference value related to the ejection characteristics of the liquid ejected from the liquid ejection head when the candidate waveform is used for the driving pulse.

5. The driving waveform determination method according to claim 4, characterized in that, the inference information represents the inference value by a probability distribution.

6. The driving waveform determination method according to claim 5, characterized in that, the probability distribution represents the mean or variance of the inference value.

7. The driving waveform determination method according to claim 1, characterized in that, the candidate waveform includes a plurality of candidate waveforms of the driving pulse, the second step notifies the user of a plurality of candidate information corresponding to the plurality of candidate waveforms, and the instruction includes a selection instruction for selecting at least one candidate information from the plurality of candidate information.

8. The driving waveform determination method according to claim 1, characterized in that, the instruction includes an adjustment instruction for adjusting the candidate waveform.

9. The driving waveform determination method according to claim 1, characterized in that, the instruction includes a determination instruction indicating whether to determine the waveform of the driving pulse, when the determination instruction indicates to determine the waveform of the driving pulse, the fourth step is implemented, when the determination instruction indicates not to determine the waveform of the driving pulse, a fifth step is implemented, and the fifth step is a step of re-determining the candidate waveform.

10. The driving waveform determination method according to claim 9, characterized in that, the fifth step re-determines the candidate waveform based on the instruction.

11. The driving waveform determination method according to claim 9 or 10, characterized in that, the fifth step changes the candidate waveform.

12. The driving waveform determination method according to claim 1, characterized in that, The second process implements notification to the user by displaying the candidate information on the display unit.

13. The driving waveform determination method according to claim 1, characterized in that the first process determines the candidate waveform using an analog demonstration.

14. The driving waveform determination method according to claim 1, characterized in that the first process statistically uses information related to the ejection characteristics of the liquid ejected from the liquid ejection head to determine the candidate waveform.

15. A recording medium having recorded thereon a driving waveform determination program, characterized in that the driving waveform determination program causes a computer to execute the driving waveform determination method according to any one of claims 1 to 14.

16. A liquid ejection device, characterized in that it has: a liquid ejection head having a driving element for ejecting a liquid; a processing circuit that implements processing for determining the waveform of a driving pulse applied to the driving element, the processing circuit performs the following processes, namely: a first process that determines a candidate waveform of the driving pulse; a sixth process that measures the ejection characteristics of the liquid ejected from the liquid ejection head when the driving pulse using the candidate waveform as the waveform is actually applied to the driving element; a second process that uses the result of the sixth process to generate candidate information related to the candidate waveform and notifies the candidate information to the user; a third process that receives an instruction from the user based on the candidate information; a fourth process that determines the waveform of the driving pulse based on the instruction.

17. A driving waveform determination system, characterized in that it has: a liquid ejection head having a driving element for ejecting a liquid; a processing circuit that implements processing for determining the waveform of a driving pulse applied to the driving element, the processing circuit performs the following processes, namely: a first process that determines a candidate waveform of the driving pulse; a sixth process that measures the ejection characteristics of the liquid ejected from the liquid ejection head when the driving pulse using the candidate waveform as the waveform is actually applied to the driving element; a second process that uses the result of the sixth process to generate candidate information related to the candidate waveform and notifies the candidate information to the user; a third process that receives an instruction from the user based on the candidate information; a fourth process that determines the waveform of the driving pulse based on the instruction.

Images