Information processing apparatus, ink circulation system, information processing method, and program

Abstract

To provide an information processing apparatus, an ink circulation system, an information processing method, and a program capable of making it easier to input appropriate pressure setting values.SOLUTION: An information processing apparatus performs an operation setting of a circulation device that circulates ink by controlling such that ink pressure at an inlet becomes a first setting value and ink pressure at an outlet becomes a second setting value in a circulation flow path passing through an ink jet head having the inlet into which ink flows and the outlet from which ink flows out. The information processing apparatus comprises a control unit. The control unit receives input of the first setting value by a user and executes an input assisting process for prompting input of a value within a reference range for the first setting value when the input value of the first setting value is outside a reference range corresponding to the ink jet head and usage conditions thereof.SELECTED DRAWING: Figure 12

Description

[Technical Field]

[0001] The present invention relates to an information processing device, an ink circulation system, an information processing method, and a program. [Background technology]

[0002] Conventionally, there are inkjet recording devices that form images on a recording medium by ejecting ink onto the recording medium from multiple nozzles provided in an inkjet head. Some such inkjet recording devices are equipped with an ink circulation system that circulates ink that is not ejected from the nozzles of the inkjet head in a circulation flow path. This ink circulation system includes a circulation device that circulates the ink by generating a pressure difference between an inlet into which the ink flows and an outlet from which the ink flows out of the inkjet head. The set value of the pressure that the circulation device generates in the circulation flow path to circulate the ink is input and set by the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-68431 Summary of the Invention [Problem to be solved by the invention]

[0004] The pressure setting value can usually be freely set within a range that can be controlled by the circulation device. However, this settable pressure range does not take into account the inkjet head connected to the circulation device or its operating conditions (e.g., ink physical properties, driving conditions, etc.). Therefore, depending on the inkjet head used and its operating conditions, problems can occur if the pressure setting value is too high or too low. For example, if the inlet pressure setting value is too high, the inkjet head may be damaged or ink may leak from the nozzles. Furthermore, if the inlet pressure setting value is too low, the ink back pressure at the nozzles may become too low, causing meniscus break and entraining air bubbles. It is not easy for users to accurately determine the pressure range that will not cause such problems. Therefore, the above-mentioned conventional technology has the problem that the pressure setting value in the circulation device is easily inappropriate.

[0005] An object of the present invention is to provide an information processing device, an ink circulation system, an information processing method, and a program that can easily input an appropriate pressure setting value. [Means for solving the problem]

[0006] In order to achieve the above object, the invention of the information processing device described in claim 1 is as follows: An information processing device that performs operation settings of a circulation device that circulates ink in a circulation flow path that passes through an inkjet head having an inlet through which ink flows in and an outlet through which ink flows out, by controlling the ink pressure at the inlet to be a first set value and the ink pressure at the outlet to be a second set value, A control unit is provided, The control unit accepting an input of the first setting value by a user; If the input value of the first setting value is outside a standard range corresponding to the inkjet head and its usage conditions, an input assistance process is executed to prompt the user to input a value for the first setting value that is within the standard range.

[0007] The invention described in claim 2 is the information processing device described in claim 1, The control unit executes the input assisting process when the input value of the first setting value is outside the first reference range within which the inkjet head can eject ink normally.

[0008] The invention described in claim 3 is the information processing device described in claim 2, an upper limit value of the first reference range is set to a value that prevents ink from leaking from the nozzles of the inkjet head when ink is not being ejected from the nozzles, The lower limit of the first reference range is set to a value at which meniscus break of the ink in the nozzle does not occur when the ejection flow rate per unit time according to the ink ejection from the nozzle is at its highest.

[0009] The invention described in claim 4 is the information processing device described in claim 1, The control unit executes the input assisting process when the input value of the first setting value is outside the second reference range that corresponds to a pressure resistance range of the inkjet head.

[0010] The invention described in claim 5 is the information processing device described in claim 1, The input assist process is a process of causing a notification unit to issue a predetermined notification.

[0011] The invention described in claim 6 is the information processing device described in claim 1, The input assistance process is a process for invalidating the input value.

[0012] The invention described in claim 7 is the information processing device described in claim 1, The control unit Accepting an input of the model of the inkjet head by the user; The reference range is determined based on the input model.

[0013] The invention described in claim 8 is the information processing device described in claim 1, the use conditions are driving conditions of the inkjet head, and include the driving conditions that affect a maximum value of an ejection flow rate per unit time according to the ejection of ink from nozzles of the inkjet head, The control unit accepting an input of the operating conditions by the user; The reference range is determined based on the input driving conditions.

[0014] The invention described in claim 9 is the information processing device described in claim 1, the usage conditions include physical property values ​​of the ink, The control unit receiving input of ink information by the user that can identify physical property values ​​of the ink; The reference range is determined based on the physical property values ​​of the ink specified based on the ink information.

[0015] The invention described in claim 10 is the information processing device described in claim 1, the use conditions include a differential pressure between the first set value and the second set value, The control unit accepting an input of the second setting value by the user; The reference range is determined based on the differential pressure between the input first set value and the input second set value.

[0016] The invention described in claim 11 is the information processing device described in claim 2, When the control unit receives an input of the first setting value, the control unit sets an initial value of the first setting value within the first reference range and causes a predetermined display unit to display the initial value.

[0017] In order to achieve the above object, the invention of the ink circulation system described in claim 12 is as follows: An information processing device according to any one of claims 1 to 11; the inkjet head; The circulation device; Equipped with.

[0018] In order to achieve the above object, the invention of the information processing device described in claim 13 is as follows: An information processing method executed by a computer for setting the operation of a circulation device that circulates ink in a circulation flow path that passes through an inkjet head having an inlet for ink inflow and an outlet for ink outflow, by controlling the ink pressure at the inlet to be a first set value and the ink pressure at the outlet to be a second set value, receiving an input of the first setting value from a user; a step of executing an input assistance process for prompting an input of a value within the standard range for the first setting value when the input value of the first setting value is outside the standard range according to the inkjet head and its usage conditions; Includes.

[0019] In order to achieve the above object, the invention of the program described in claim 14 is as follows: A program that causes a computer to function as a control means, the program configuring an operation of a circulation device that circulates ink by controlling an ink pressure at an ink inlet to be a first set value and an ink pressure at an ink outlet to be a second set value in a circulation flow path that passes through an inkjet head having an inlet for ink inflow and an outlet for ink outflow, The control means accepting an input of the first setting value by a user; If the input value of the first setting value is outside a standard range corresponding to the inkjet head and its usage conditions, an input assistance process is executed to prompt the user to input a value within the standard range for the first setting value. [Effects of the Invention]

[0020] According to the present invention, it is possible to easily input an appropriate pressure setting value. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an inkjet recording apparatus. [Figure 2] FIG. 2 is a schematic diagram of a head unit as viewed from the conveyor belt side. [Figure 3] FIG. 2 is a perspective view of an inkjet head. [Figure 4] FIG. 2 is a schematic cross-sectional view showing the internal configuration of an injection head unit. [Figure 5] FIG. 2 is a diagram illustrating a configuration of an ink circulation system. [Figure 6] FIG. 2 is a block diagram showing the main functional configuration of the inkjet printing apparatus. [Figure 7] FIG. 10 is a diagram showing the change in the usable range Rp according to the injection flow rate, and the first reference range R1. [Figure 8] FIG. 10 is a diagram showing how the shape of region r changes when the viscosity of ink is changed. [Figure 9] FIG. 10 is a diagram showing how the shape of region r changes when the surface tension of the ink is changed. [Figure 10] FIG. 10 is a diagram showing changes in the shape of region r when drive conditions are changed. [Figure 11] FIG. 2 is a diagram showing a first reference range R1 and a second reference range R2. [Figure 12] 10 is a flowchart showing a control procedure for a setting process. [Figure 13] FIG. 10 is a diagram illustrating a setting screen. [Figure 14] FIG. 10 is a diagram showing a warning screen. [Figure 15] FIG. 10 is a diagram showing a warning screen. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the scope of the invention is not limited to the illustrated examples.

[0023] (Configuration of Inkjet Recording Apparatus) Fig. 1 is a diagram showing a schematic configuration of an inkjet recording apparatus 1. The inkjet recording apparatus 1 includes a conveying section 20, a head unit 30, and a control device 10 (information processing device) (see Fig. 6) that controls the operation of each of these sections. The inkjet recording apparatus 1 also includes an ink circulation system 100 (see Figs. 5 and 6) for circulating ink in a predetermined circulation flow path 101.

[0024] The transport unit 20 includes two transport rollers 21 and 22 that rotate around a rotation axis extending in the X direction in Fig. 1, and a ring-shaped transport belt 23 whose inner side is supported by the transport rollers 21 and 22. The transport roller 21 rotates in response to the operation of a transport motor (not shown), causing the transport belt 23 to move in a circular motion around the transport rollers 21 and 22. The transport unit 20 transports the recording medium M in the movement direction of the transport belt 23 (transport direction; Y direction in Fig. 1) as the transport belt 23 moves in a circular motion with the recording medium M placed on the transport surface of the transport belt 23.

[0025] The recording medium M may be, for example, a sheet of paper cut to a certain size. The recording medium M is supplied onto a conveyor belt 23 by a paper feeder (not shown), and ink is ejected (discharged) from a head unit 30 to record an image. The recording medium M is then discharged from the conveyor belt 23 to a predetermined paper discharge section. Note that a long medium such as roll paper may also be used as the recording medium M. In addition to paper such as plain paper or coated paper, various media that can fix ink that has landed on their surfaces, such as fabric or sheet-like resin, may be used as the recording medium M.

[0026] The head units 30 eject ink at appropriate timing based on image data onto the recording medium M transported by the transport unit 20 to record an image. The inkjet recording apparatus 1 of this embodiment is equipped with four head units 30, each corresponding to one of four colors of ink: yellow (Y), magenta (M), cyan (C), and black (K). The four head units 30 are arranged at predetermined intervals in the order of Y, M, C, and K from the upstream side in the transport direction of the recording medium M. The number of head units 30 can be changed depending on the number of colors used, and may be three or less or five or more.

[0027] FIG. 2 is a schematic diagram of the head unit 30 as viewed from the conveyor belt 23 side. The head unit 30 has a plurality of inkjet heads 40 (eight in this embodiment) attached to a mounting member 30a. Each inkjet head 40 has a plurality of nozzles N. In this embodiment, each inkjet head 40 has four nozzle rows. Each nozzle row is made up of nozzles N linearly arranged at equal intervals in the X direction. The four nozzle rows of the inkjet head 40 are arranged such that their positions in the X direction are shifted from each other so that the positions of the nozzles N do not overlap in the X direction. Note that the number of nozzle rows of the inkjet head 40 is not limited to four, and may be three or less, or five or more.

[0028] In the head unit 30, the eight inkjet heads 40 are arranged in a staggered pattern so that the arrangement range of the nozzles N in the X direction is continuous. The arrangement range of the nozzles N included in the head unit 30 in the X direction covers the width in the X direction of an area of ​​the recording medium M on which an image can be recorded. The head unit 30 is used in a fixed position when forming an image. The head unit 30 forms an image by a single pass method by ejecting ink from the nozzles N to each position at a predetermined interval in the transport direction as the recording medium M is transported.

[0029] The ink ejected from the nozzles N of the inkjet head 40 is a phase-change ink that changes phase between a gel state and a sol (liquid) state depending on the temperature. The head unit 30 has an ink heating unit (not shown) that heats the ink to a temperature at which the ink becomes in the sol state. The inkjet head 40 ejects the ink in the sol state from the nozzles N. The ink ejected from the nozzles N and landing on the recording medium M quickly changes phase to the gel state when cooled to room temperature. Note that the composition of the ink is not limited to the above. For example, an ultraviolet curing agent may be added to the ink to make it an ultraviolet curable ink that hardens when exposed to ultraviolet light.

[0030] 3 is a perspective view of the inkjet head 40. The inkjet head 40 includes an inlet 41 into which ink flows, an ejection head unit 43 that ejects the ink that has flowed in from the inlet 41 from the nozzles N, and an outlet 42 through which a portion of the ink that has not been ejected from the nozzles N flows out.

[0031] FIG. 4 is a schematic cross-sectional view showing the internal configuration of the ejection head unit 43. The ejection head unit 43 has a structure in which a nozzle plate 431 in which nozzles N are provided, a flow path substrate 432 in which ink flow paths communicating with the nozzles N are formed, and an ink manifold 433 in which ink to be supplied to each nozzle N is stored are stacked in this order. The nozzle plate 431 is formed with a plurality of nozzles N penetrating the nozzle plate 431. By setting the back pressure of the ink in the nozzles N to an appropriate negative pressure, the surface of the ink at the opening of the nozzle N, i.e., the meniscus m, is slightly retracted toward the interior of the nozzle N. The flow path substrate 432 is formed with an ink channel 45 and an individual discharge flow path 46 for each nozzle N. The ink manifold 433 is formed with a common ink chamber 44 communicating with the inlet 41 and a common discharge flow path 47 communicating with the outlet 42. The common ink chamber 44 is connected to the ink channel 45 corresponding to each nozzle N. The common discharge flow path 47 is connected to the individual discharge flow paths 46 corresponding to the nozzles N.

[0032] The ink channel 45 of the flow path substrate 432 penetrates the flow path substrate 432 and guides the ink stored in the common ink chamber 44 to the nozzle N. The wall surface of the ink channel 45 is a piezoelectric element that deforms in response to the application of a voltage. When a predetermined drive signal is applied to an electrode (not shown), the wall surface of the ink channel 45 deforms in response to this drive signal, and the pressure inside the ink channel 45 changes. In response to this change in pressure, ink is ejected from the nozzle N that communicates with the ink channel 45.

[0033] The individual discharge flow paths 46 branch off from the ink channels 45 at a position near the nozzles N and communicate with a common discharge flow path 47 of the ink manifold 433. A portion of the ink in the ink channels 45 that has not been ejected from the nozzles N flows through the individual discharge flow paths 46 and the common discharge flow path 47 and flows out of the inkjet head 40 from the outlet 42. In addition to the individual discharge flow paths 46, the ink manifold 433 may also be provided with a flow path for guiding the ink that has flowed in from the inlets 41 to the outlet 42, i.e., a flow path connecting the common ink chamber 44 and the common discharge flow path 47.

[0034] FIG. 5 is a diagram showing the configuration of an ink circulation system 100. The ink circulation system 100 includes a circulation flow path 101 that passes through an inkjet head 40, a circulation device 50, two pressure sensors 61 and 62, two flow rate sensors 71 and 72, and a control device 10. The circulation device 50, the pressure sensors 61 and 62, and the flow rate sensors 71 and 72 are provided midway along the circulation flow path 101. The circulation flow path 101 is provided, for example, inside the inkjet head 40. Ink flowing out from the outlet 42 of the inkjet head 40 circulates through the circulation flow path 101 and then flows back into the inlet 41. The circulation device 50 controls the pressure of the ink in the circulation flow path 101 to circulate the ink through the circulation flow path 101. Note that, although one inkjet head 40 is connected to one circulation device 50 in FIG. 5, two or more inkjet heads 40 may be connected to one circulation device 50. That is, the circulation device 50 may circulate ink in two or more circulation channels 101 corresponding to two or more inkjet heads 40, respectively.

[0035] The pressure sensors 61 and 62 are provided in the circulation flow path 101 near the inlet 41 and the outlet 42, respectively. The pressure sensor 61 detects the pressure of ink at the inlet 41 and outputs the detected value to the circulation device 50. The pressure sensor 62 detects the pressure of ink at the outlet 42 and outputs the detected value to the circulation device 50. The flow rate sensor 71 is provided in the circulation flow path 101 midway from the circulation device 50 to the inlet 41. The flow rate sensor 72 is provided in the circulation flow path 101 midway from the outlet 42 to the circulation device 50. The flow rate sensors 71 and 72 detect the amount (volume) of ink flowing through the circulation flow path 101 per unit time and output the detected value to the circulation device 50.

[0036] The circulation device 50 controls the pressure of ink in the circulation channel 101 based on the detection values ​​of the two pressure sensors 61, 62 so that the pressure of ink at the inlet 41 becomes a predetermined first set value and the pressure of ink at the outlet 42 becomes a predetermined second set value. For this control, the circulation device 50 may further refer to the detection values ​​of the flow rate sensors 71, 72. The first set value and the second set value are set by the control device 10 connected to the circulation device 50. The first set value and the second set value are input to the control device 10 by the user. The first set value is set to a value higher than the second set value. Therefore, the circulation device 50 controls the pressure of ink at the inlet 41 so that it is higher than the pressure of ink at the outlet 42. This pressure difference between the inlet 41 and the outlet 42 circulates ink in the circulation channel 101.

[0037] A main tank (not shown) that stores ink is connected to the circulation device 50. When ink is ejected from the nozzles N of the inkjet head 40 and the ink in the circulation flow path 101 decreases, ink is supplied from the main tank to the circulation device 50.

[0038] The configuration of the circulation device 50 is not particularly limited as long as it can control the pressure of ink at the inlet 41 and the outlet 42. The circulation device 50 may include, for example, at least one sub-tank that temporarily stores ink within the circulation device 50, and a pressure control means that controls the pressure of ink within the sub-tank. The pressure control means may include, for example, a liquid feed pump that sends ink to the sub-tank, or an exhaust pump that exhausts air from the sub-tank. The circulation device 50 may be, for example, a CIMS (Compact Ink Modular System) manufactured by Megnajet.

[0039] FIG. 6 is a block diagram showing the main functional configuration of the inkjet recording apparatus 1. The transport section 20 includes a transport drive section 24. The head unit 30 includes a head control section 31, the inkjet head 40 described above, a circulation device 50, pressure sensors 61 and 62, and flow rate sensors 71 and 72. The control device 10 includes a control section 11 (control means), an operation display section 12 (notification section, display section), and a communication section 13. The various sections of the inkjet recording apparatus 1 are connected via a signal transmission path such as a bus. In the following, the configurations described with reference to FIGS. 1 to 5 will not be described again.

[0040] The transport driver 24 of the transport unit 20 supplies a drive signal to the transport motor of the transport roller 21 based on a control signal sent from the control unit 11, and moves the transport belt 23 in a circular motion at a predetermined speed and timing.

[0041] The head control section 31 of the head unit 30 outputs various control signals and image data to the ejection head section 43 provided in the inkjet head 40 at timings according to control signals sent from the control section 11. The control signals include signals that specify drive waveforms related to the drive signals. The ejection head section 43 supplies drive signals to the electrodes of the inkjet head 40 in accordance with the control signals and image data input from the head control section 31. This causes the piezoelectric elements to deform, causing ink to be ejected from the nozzles N.

[0042] The control unit 11 of the control device 10 is a hardware processor having a CPU 111 (Central Processing Unit), RAM 112 (Random Access Memory), and storage unit 113. The CPU 111 reads various control programs 1131 and setting data stored in the storage unit 113, and executes the programs 1131 to perform various arithmetic processing. In this way, the CPU 111 comprehensively controls the overall operation of the inkjet recording apparatus 1 and the ink circulation system 100. The RAM 112 provides the CPU 111 with working memory space and stores temporary data. The storage unit 113 has non-volatile memory and stores the programs 1131, print jobs (image recording commands) input via the communication unit 13, image data related to the print jobs, various setting data, and the like. The storage unit 113 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0043] The operation display unit 12 includes a display device such as a liquid crystal display, and an input device such as operation keys and a touch panel overlaid on the screen of the display device. The operation display unit 12 displays, on the display device, status information of the inkjet recording apparatus 1, information related to notifications (notifications, warnings, etc.) to the user, and the like. In this way, the operation display unit 12 functions as a notification unit. The operation display unit 12 also converts the user's input operation on the input device into an operation signal and outputs the operation signal to the control unit 11.

[0044] The communication unit 13 is a communication interface that controls communication operations with external devices. The communication unit 13 acquires data related to print jobs from external devices under the control of the control unit 11, and also transmits status information to external devices.

[0045] (Circulation device operation settings) Next, the operation settings of the circulation device 50 will be described. As described above, the circulation device 50 controls the ink pressure at the inlet 41 and the outlet 42 to be the first set value and the second set value, respectively, and circulates ink through the circulation channel 101 by maintaining a constant differential pressure. Here, the first set value of the pressure at the inlet 41 has a pressure range (hereinafter referred to as the "usable range Rp") within which ink can be normally ejected from the nozzle N. The state in which ink can be normally ejected from the nozzle N is a state in which the ink back pressure in the nozzle N is a negative pressure within a predetermined appropriate range, causing ink to be slightly drawn toward the inside of the nozzle N. This state prevents ink from leaking from the nozzle N when not ejecting, while allowing an appropriate amount of ink droplets to be ejected from the nozzle N in accordance with pressure fluctuations in the ink channel 45 when ejecting. Pressure loss occurs in the ink path from the inlet 41 to the nozzle N depending on the shape of the path. The first set value of the inlet 41 is determined so that the pressure obtained by subtracting this pressure loss from the pressure of the ink at the inlet 41 is a negative pressure within the above-mentioned predetermined range. In other words, if the pressure of the ink at the inlet 41 (first set value) is a value within the above-mentioned usable range Rp, the pressure (negative pressure) applied to the meniscus m of the ink in the nozzle N will be within the appropriate range, enabling normal ink ejection.

[0046] On the other hand, if the first set value is greater than the usable range Rp, the pressure applied to the meniscus m becomes positive, causing ink to leak from the nozzle N when not ejecting. Also, if the first set value is equal to or greater than the withstand pressure upper limit, which is even greater than the usable range Rp, the ink pressure inside the inkjet head 40 becomes too high, damaging the inkjet head 40. On the other hand, if the first set value is less than the usable range Rp, the absolute value of the negative pressure applied to the meniscus m becomes too large, causing a "meniscus break" in which the ink meniscus m is destroyed. When a meniscus break occurs, air bubbles continue to be drawn into the nozzle N from the meniscus m, preventing normal ink ejection.

[0047] As shown in Figure 7, the usable range Rp changes depending on the ejection flow rate. Here, the ejection flow rate is the total amount (volume) of ink ejected per unit time from all nozzles N of the inkjet head 40. Figure 7 shows the results of calculations for each ejection flow rate of the usable range Rp of the pressure of the inlet 41 that does not cause ink leakage or meniscus break when ink is ejected from the nozzle N under the following conditions: Number of nozzles: 1024 Injection volume 79pl (3dpd) Drive frequency 11.4kHz Injection flow rate / nozzle 0.0009 mL / s Of the above, "ejected liquid volume" represents the volume of ink ejected from nozzle N per dot. "3 dpd" represents the drive condition for ejecting three drops of ink per dot. Therefore, under the above conditions, three drops of ink are ejected per dot, with a total volume of 79 pl. Furthermore, drive frequency represents the repetition frequency of the drive signal that ejects three drops of ink.

[0048] As can be seen from FIG. 7, the width of the usable range Rp is constant at approximately 3 kPa for all ejection flow rates. Meanwhile, as the ejection flow rate increases, the upper limit of the usable range Rp gradually increases, as indicated by line La, and the lower limit of the usable range Rp gradually increases, as indicated by line Lb. This is because, as the ink flow rate increases in the path from the inlet 41 to the nozzle N, the pressure loss in that path increases, and the usable range Rp shifts upward by the amount of this increased pressure loss. Specifically, when the ejection flow rate is minimum (0 mL / s), i.e., when all nozzles are not ejecting, the usable range Rp is -1.2 to 1.8 kPa. Furthermore, when the ejection flow rate is maximum (approximately 0.9 mL / s), i.e., when ink is ejected from all nozzles, the usable range Rp is -0.5 to 2.5 kPa. Therefore, to ensure proper ink ejection over the entire range of ejection flow rates, the pressure of the inlet 41, i.e., the first set value, must be set within the range of -0.5 to 1.8 kPa. Hereinafter, this range will be referred to as the "first reference range R1." The upper and lower limits of the first reference range R1 will be referred to as "P1a" and "P1b," respectively. As can be seen from FIG. 7, the upper limit P1a of the first reference range R1 is set to a value that prevents ink leakage from the nozzles N when ink is not being ejected from all nozzles N. The lower limit P1b of the first reference range R1 is set to a value that prevents ink meniscus break in the nozzles N when the ejection flow rate is at its highest.

[0049] The upper limit P1a and lower limit P1b of the first reference range R1 are determined by the shape of the parallelogram region r that the usable range Rp forms when the ejection flow rate is changed in Figure 7. Even when the same model of inkjet head 40 is used, the shape of the region r changes depending on the usage conditions. Here, the usage conditions include, for example, the physical properties of the ink used and / or the driving conditions of the inkjet head 40.

[0050] FIG. 8 shows how the shape of region r changes when the viscosity of the ink is changed. The region r on the left side of FIG. 8 represents the same region r as in FIG. 7 (the same applies to FIGS. 9 and 10 below). In contrast, the right side of FIG. 8 represents region r when ink with a higher viscosity than that on the left side is used. The higher the viscosity of the ink, the greater the pressure loss in the flow path, and therefore the greater the upward shift of the usable range Rp associated with an increase in the ejection flow rate. That is, as shown on the right side of FIG. 8, the slopes of lines La and Lb, which represent the upper and lower limits of the usable range Rp, become steeper. As a result, the upper limit P1a of the first reference range R1 remains unchanged, while the lower limit P1b increases. Therefore, as the viscosity of the ink used increases, the width of the first reference range R1 becomes narrower.

[0051] Figure 9 shows how the shape of region r changes when the surface tension of the ink is changed. The smaller the surface tension of the ink, the lower the meniscus resistance. In other words, the smaller the surface tension of the ink, the more likely it is that a meniscus break will occur due to a negative pressure with a smaller absolute value. Therefore, as shown on the right side of Figure 9, line Lb, which represents the lower limit of the usable range Rp, shifts upward. As a result, the upper limit P1a of the first reference range R1 remains unchanged, while the lower limit P1b increases. Therefore, as the surface tension of the ink used decreases, the width of the first reference range R1 becomes smaller.

[0052] FIG. 10 shows how the shape of region r changes when the drive conditions are changed. Here, we illustrate the case where the amount of liquid ejected from nozzle N per unit time is increased. In this case, the maximum value of the ejection flow rate increases, so as shown on the right side of FIG. 9, region r becomes a parallelogram, with lines La and Lb extended to the right. As a result, the upper limit P1a of the first reference range R1 remains unchanged, while the lower limit P1b increases. Therefore, increasing the amount of liquid ejected from nozzle N per unit time narrows the width of the first reference range R1. Note that region r also changes in the same way as in FIG. 10 when other drive conditions, such as the drive frequency, that affect the maximum value of the ejection flow rate per unit time (in other words, the range of fluctuation of the ejection flow rate) are changed.

[0053] In addition to the above, the shape of region r and first reference range R1 also change depending on the differential pressure between inlet 41 and outlet 42, the model (structure) of inkjet head 40, etc. For example, increasing the differential pressure increases the circulating flow rate of ink, which in turn increases pressure loss and the slope of lines La and Lb. When using ink containing components that are prone to settling, the differential pressure may be increased to increase the circulating flow rate of ink.

[0054] As illustrated in FIGS. 8 to 10, when inkjet heads 40 of the same model are used, the lower limit P1b of the first reference range R1 is likely to fluctuate depending on the operating conditions, while the upper limit P1a is less likely to fluctuate. For this reason, the initial value Pi of the first reference value may be set to a value close to the upper limit P1a, for example, the upper limit P1a minus a predetermined value D. The predetermined value D is set based on the fluctuation range of the pressure at the inlet 41 during operation of the inkjet head 40, so that the pressure at the inlet 41 set to the initial value Pi does not exceed the upper limit P1a. For example, the predetermined value D may be set to a value greater than half the fluctuation range. Fluctuations in the pressure at the inlet 41 can be caused, for example, by ink pulsation in the circulation flow path 101 or momentary pressure fluctuations when ink is ejected from the nozzle N.

[0055] As described above, if the first set value of the pressure at the inlet 41 falls outside the first reference range R1, normal ink ejection becomes impossible. Furthermore, if the first set value falls outside the second reference range R2, which corresponds to the pressure resistance range of the inkjet head 40, the inkjet head 40 may be damaged. As shown in FIG. 11 , the second reference range R2 includes the first reference range R1. The upper limit P2a of the second reference range R2 is greater than the upper limit P1a of the first reference range R1, and the lower limit P2b of the second reference range R2 is smaller than the lower limit P1b of the first reference range R1. To prevent damage to the inkjet head 40, the first set value of the pressure at the inlet 41 must be set at least within the second reference range R2.

[0056] The upper limit value P1a and lower limit value P1b of the first reference range R1 described above, and the upper limit value P2a and lower limit value P2b of the second reference range R2 can be calculated by theoretical calculation based on the physical properties of the ink, driving conditions, and the model of the inkjet head 40, etc.

[0057] (Control device operation) The first set value of the pressure at the inlet 41 and the second set value of the pressure at the outlet 42 are set by a user's input operation to the control device 10 and registered in the circulation device 50. If the first set value input by the user is outside the first reference range R1, normal ink ejection will not be possible, as described above. If the first set value input by the user is outside the second reference range R2, the inkjet head 40 may be damaged. However, it is not always easy for a user to accurately determine and input a pressure range that will not cause such problems. Conventional control devices allow the user to freely input the first and second set values ​​within the range that the circulation device 50 can control. Therefore, if the user inputs inappropriate values, normal ink ejection may not be possible or the inkjet head 40 may be damaged.

[0058] Therefore, when the input value of the first setting value is outside the reference range, the control unit 11 of the control device 10 of this embodiment executes an input assistance process to prompt the user to input a value within the reference range for the first setting value. For example, when the input value of the first setting value is outside the first reference range R1, the control unit 11 executes the input assistance process of displaying a warning screen 90 (see FIGS. 14 and 15 ) on the operation display unit 12 to warn that the value is out of range. Furthermore, when the input value of the first setting value is outside the second reference range R2, the control unit 11 executes the input assistance process of invalidating the input value of the first setting value. In other words, the control unit 11 executes an input restriction to prevent the user from entering a value outside the second reference range R2. Note that the input assistance process corresponding to each reference range is not limited to the above. For example, an input restriction may be executed when the value is outside the first reference range R1, or a warning may be issued when the value is outside the second reference range R2.

[0059] The setting process executed by the control unit 11 of the control device 10 to appropriately set the first set value and the second set value will be described below. Fig. 12 is a flowchart showing the control procedure of the setting process. This setting process is executed, for example, when an operation is performed on the operation display unit 12 to instruct the start of setting of the circulation device 50. When the setting process is started, the control unit 11 causes the operation display unit 12 to display a predetermined setting screen 80 (step S101).

[0060] FIG. 13 is a diagram showing a setting screen 80. The setting screen 80 displays drop-down lists 81, 84 to 86, text boxes 82 and 83, and a confirm button 87. The drop-down list 81 is used to select the model of the inkjet head 40. The text boxes 82 and 83 are used to input a first set value for the pressure of the inlet 41 and a second set value for the pressure of the outlet 42, respectively. The drop-down list 84 is used to select, among the driving conditions, the amount of ink ejected from the nozzle N, in this case, the number of droplets ejected per dot (dpd). The drop-down list 85 is used to select, among the driving conditions, the driving frequency. The drop-down list 86 is used to select the type of ink to be used. The contents listed in the drop-down lists 81, 84 to 86 are pre-registered in the storage unit 113. Furthermore, the types of ink are associated with physical properties such as the viscosity and surface tension of the ink and are registered in the storage unit 113. Therefore, the type of ink corresponds to ink information capable of identifying the physical properties of the ink. The user can enter the first and second setting values ​​in the text boxes 82 and 83, and select the desired settings in the drop-down lists 81, 84 to 86, and then select the enter button 87 to confirm the input contents.

[0061] Note that the control unit 11 may display in a text box 82 on the setting screen 80 an initial value Pi (see FIGS. 8 to 10) of the first reference value of the inlet 41 that corresponds to the model of the inkjet head 40 that is being selected using a drop-down list 81. Similarly, the control unit 11 may display in a text box 83 an initial value of the second reference value of the outlet 42 that corresponds to the model of the inkjet head 40 that is being selected.

[0062] Alternatively, the text box 83 may be configured to input the differential pressure between the inlet 41 and the outlet 42 instead of the second set value. In this case, the second set value of the pressure at the outlet 42 is automatically determined based on the first set value input in the text box 82 and the differential pressure input in the text box 83. Alternatively, input of the differential pressure may be omitted, and the differential pressure may be automatically set to a predetermined value (for example, 15 kPa).

[0063] Returning to FIG. 12 , the control unit 11 repeatedly determines whether or not the operation to select the decision button 87 has been performed (step S102). If it determines that the operation to select the decision button 87 has been performed ("YES" in step S102), the control unit 11 determines a first reference range R1 and a second reference range R2 for the pressure of the inlet 41 based on the input content on the setting screen 80 (step S103). For example, the control unit 11 calculates the first reference range R1 and the second reference range R2 based on the input information on the model of the inkjet head 40, the driving conditions, the ink type, and the physical property values ​​of the ink, which are identified from the input information, and the differential pressure between the first and second reference values. Alternatively, the control unit 11 may determine the first reference range R1 and the second reference range R2 by referring to predetermined table data. In this case, table data in which the first reference range R1 and the second reference range R2 are associated with each combination of the model of the inkjet head 40, the driving conditions, the ink type, and the differential pressure may be stored in advance in the storage unit 113.

[0064] The control unit 11 determines whether the input value of the first setting value related to the pressure of the inlet 41 is outside the second reference range R2 (step S104). If it is determined that the input value of the first setting value is outside the second reference range R2 (step S104: YES), the control unit 11 invalidates the input value of the first setting value (step S105). Here, the control unit 11 erases the input value of the first setting value input in the text box 82, moves the cursor into the text box 82, and prompts the user to re-input it. The control unit 11 may also erase the input value of the second setting value input in the text box 83 and prompt the user to re-input it. The control unit 11 may further cause the operation / display unit 12 to display a warning that the input value of the first setting value is outside the second reference range R2 and may damage the inkjet head 40. After step S105 is completed, the control unit 11 returns the process to step S102.

[0065] If the control unit 11 determines that the input value of the first setting value is within the second reference range R2 ("NO" in step S104), it determines whether the input value of the first setting value is greater than the upper limit value P1a of the first reference range R1 (step S106). If the control unit 11 determines that the input value of the first setting value is greater than the upper limit value P1a of the first reference range R1 ("YES" in step S106), it causes the operation display unit 12 to display a warning screen 90 shown in FIG. 14, which warns that the first setting value is too large (step S107). This warning screen 90 displays a message that the first setting value of the pressure of the inlet 41 is too high, which may result in ink leakage. The warning screen 90 also displays the first reference range R1 (here, -0.5 to 1.8 kPa) as the recommended range for the first setting value of the inlet 41 under the current operating conditions. The warning screen 90 also displays a message inquiring whether or not to modify the setting value, a YES button 91, and a NO button 92. When the YES button 91 is selected, the control unit 11 returns the process to step S102 as shown in FIG. 12 and accepts re-input of the first setting value. Although not shown in FIG. 12, when the NO button 92 is selected, the control unit 11 transitions the process to step S110. Note that, since it is not recommended to operate the inkjet recording apparatus 1 in a state where the first setting value is greater than the upper limit value P1a of the first reference range R1, the NO button 92 may not be displayed on the warning screen 90, and the process may always return to step S102 when the YES button 91 is pressed.

[0066] If the control unit 11 determines that the input value of the first setting value is equal to or less than the upper limit P1a of the first reference range R1 ("NO" in step S106), it determines whether the input value of the first setting value is less than the lower limit P1b of the first reference range R1 (step S108). If the control unit 11 determines that the input value of the first setting value is less than the lower limit P1b of the first reference range R1 ("YES" in step S108), it causes the operation display unit 12 to display a warning screen 90 of FIG. 15 warning that the first setting value is too small (step S109). This warning screen 90 displays a message that a meniscus break may occur because the first setting value of the pressure of the inlet 41 is too small. Other display contents and processing when the YES button 91 or the NO button 92 is selected are the same as those in FIG. 14 and step S107.

[0067] If the input value of the first setting value is equal to or greater than the lower limit P1b of the first reference range R1, that is, if it is determined that the input value of the first setting value is within the first reference range R1 ("NO" in step S108), the control unit 11 registers the first setting value and the second setting value input on the setting screen 80 in the circulation device 50 (step S110). When step S110 is completed, the control unit 11 ends the setting process. Thereafter, the circulation device 50 starts circulating the ink based on the registered first setting value and second setting value.

[0068] In the setting process of FIG. 12, steps S104 to S109 are executed after the decision button 87 is selected on the setting screen 80. Alternatively, steps S104 to S109 may be executed based on the input content at the time when the first setting value is entered into the text box 82 on the setting screen 80.

[0069] As described above, the control device 10 according to this embodiment performs operational settings for the circulation device 50. The circulation device 50 circulates ink by controlling the ink pressure at the inlet 41 and the ink pressure at the outlet 42 in the circulation flow path 101 passing through the inkjet head 40 so that the ink pressure at the inlet 41 is a first set value and the ink pressure at the outlet 42 is a second set value. The control device 10 includes a control unit 11. The control unit 11 accepts input of a first set value by a user. If the input first set value is outside the first reference range R1 and / or the second reference range R2 corresponding to the inkjet head 40 and its usage conditions, the control unit 11 executes an input assistance process to prompt the user to input a value for the first set value that falls within the reference range. This makes it easier to input an appropriate first set value corresponding to the inkjet head 40 and its usage conditions. In other words, even if the user does not know the appropriate range of the first set value, they can easily input an appropriate first set value by correcting the input value according to the input assistance process. This makes it possible to prevent problems such as damage to the inkjet head 40, leakage of ink from the nozzles N, and meniscus break of the ink, which are caused by inputting an inappropriate first setting value.

[0070] Furthermore, the control unit 11 executes input assistance processing when the input value of the first setting value is outside the first reference range R1 that allows normal ink ejection by the inkjet head 40. This allows the user to correct the input value in accordance with the input assistance processing, thereby inputting an appropriate first setting value that allows normal ink ejection.

[0071] Furthermore, the upper limit value P1a of the first reference range R1 is set to a value that prevents ink leakage from the nozzle N when ink is not being ejected from the nozzle N of the inkjet head 40. The lower limit value P1b of the first reference range R1 is set to a value that prevents ink meniscus break from the nozzle N when the ink ejection flow rate per unit time from the nozzle N is at its highest. This makes it possible to prevent problems such as ink leakage caused by a first set value that is too large and meniscus break caused by a first set value that is too small.

[0072] Furthermore, the control unit 11 executes input assistance processing when the input value of the first setting value is outside the second reference range R2, which corresponds to the pressure resistance range of the inkjet head 40. This allows the user to correct the input value in accordance with the input assistance processing, thereby preventing the user from entering an inappropriate first setting value that may damage the inkjet head 40.

[0073] The input assistance process for the first reference range R1 is a process in which the operation display unit 12 as a notification unit displays a warning screen 90 as a notification. This allows the user to recognize that the input value of the first setting value is inappropriate, and allows the user to appropriately correct the input value.

[0074] Furthermore, the input assistance process for the second reference range R2 is a process for invalidating the input value, thereby reliably preventing the input of an inappropriate first setting value that may damage the inkjet head 40.

[0075] The control unit 11 also receives input of the model of the inkjet head 40 from the user and determines the first reference range R1 and the second reference range R2 based on the input model. This allows the input assistance process to be performed based on the first reference range R1 and the second reference range R2 appropriate for the model of the inkjet head 40.

[0076] The above-mentioned usage conditions may also be drive conditions of the inkjet head 40, including drive conditions that affect the maximum value of the ejection flow rate from the nozzles N. In this case, the control unit 11 accepts input of the drive conditions by the user and determines the first reference range R1 and the second reference range R2 based on the input drive conditions. This allows the input assistance process to be performed based on the first reference range R1 and the second reference range R2 appropriate for the drive conditions.

[0077] The usage conditions may also include ink physical property values. In this case, the control unit 11 receives input from the user of the type of ink (ink information) that can identify the ink physical property values, and determines the first reference range R1 and the second reference range R2 based on the ink physical property values ​​identified based on the ink type. This allows the input assist process to be performed based on the first reference range R1 and the second reference range R2 appropriate for the ink physical property values.

[0078] The use conditions may also include the differential pressure between the first set value and the second set value. In this case, the control unit 11 accepts the user's input of the second set value and determines the first reference range R1 and the second reference range R2 based on the differential pressure between the input first set value and the second set value. This allows the input assistance process to be performed based on the first reference range R1 and the second reference range R2 appropriate for the differential pressure.

[0079] Furthermore, when accepting input of the first setting value, the control unit 11 may set an initial value Pi of the first setting value within the first reference range R1 and display the initial value on the operation display unit 12. This allows the user to enter an appropriate first setting value without performing any special input operation. Furthermore, the initial value Pi allows the user to know the approximate value of the appropriate first setting value.

[0080] The ink circulation system 100 according to this embodiment includes the above-described control device 10, the inkjet head 40, and the circulation device 50.

[0081] The information processing method according to the present embodiment also includes a step of accepting input of a first setting value by a user. The information processing method also includes a step of executing an input assistance process to prompt the user to input a value for the first setting value that falls within the reference range when the input value for the first setting value is outside the first reference range R1 and / or the second reference range R2. This makes it easier to input an appropriate first setting value, and prevents problems caused by inputting an inappropriate first setting value.

[0082] Furthermore, the program 1131 according to this embodiment causes the control unit 11 to function as a control unit. The control unit accepts input of a first setting value by the user. If the input first setting value is outside the first reference range R1 and / or second reference range R2 according to the inkjet head 40 and its usage conditions, the control unit executes an input assistance process to prompt the user to input a value for the first setting value that falls within the reference range. This makes it easier to input an appropriate first setting value, and prevents problems caused by inputting an inappropriate first setting value.

[0083] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above embodiment, the "nozzle circulation method" in which ink is circulated using the individual discharge flow paths 46 near the nozzles N is exemplified, but the ink circulation method is not limited to this. For example, the individual discharge flow paths 46 may be omitted, and a "manifold circulation method" in which ink is circulated using a flow path connecting the inlet 41 and the outlet 42 provided in the ink manifold 433 may be used.

[0084] In addition, in the above embodiment, an example has been given in which the control device 10 that controls the overall operation of the inkjet recording apparatus 1 also serves as an information processing device that performs the setting operation of the circulation device 50, but the present invention is not limited to this. That is, the information processing device that performs the setting operation of the circulation device 50 may be provided separately from the control device that controls the overall operation of the inkjet recording apparatus 1. Furthermore, the circulation device 50 and the information processing device may be provided integrally.

[0085] Furthermore, although examples of the input assistance process include a notification using the warning screen 90 and input restriction, the process is not limited to these. The input assistance process may be any process that prompts the user to enter a value within a reference range for the first setting value. For example, the input assistance process may be a process that automatically corrects the first setting value entered by the user so that it falls within the reference range.

[0086] In the above embodiment, the recording medium M is transported by the transport unit 20 including the transport belt 23, but the present invention is not limited to this. The transport unit 20 may transport the recording medium M by holding it on the outer circumferential surface of a rotating transport drum, for example.

[0087] Furthermore, in the above embodiment, the inkjet recording apparatus 1 of a single pass type has been described as an example, but the present invention may also be applied to an inkjet recording apparatus that records an image while scanning the recording head.

[0088] Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0089] 1. Inkjet recording device 10 Control device (information processing device) 11 Control unit (control means) 40 Inkjet head 41 Inlet 42 Outlet 43 Injection head 44 Common ink chamber 45 ink channels 46 Individual discharge flow path 47 Common discharge flow path 50 Circulation device 61, 62 Pressure sensor 71, 72 Flow sensor 80 Settings screen 90 Warning Screen 100 Ink Circulation System 101 Circulation flow path m Meniscus M Recording medium N nozzle R1 First reference range R2 Second reference range Rp usable range

Claims

1. An information processing device for setting the operation of a circulation device that circulates ink in a circulation flow path that passes through an inkjet head having an inlet for ink flow in and an outlet for ink flow out, by controlling the ink pressure at the inlet to be a first set value and the ink pressure at the outlet to be a second set value, A control unit is provided, The control unit accepting an input of the first setting value by a user; an information processing device that, when the input value of the first setting value is outside a standard range corresponding to the inkjet head and its usage conditions, executes an input assistance process to prompt the user to input a value for the first setting value that is within the standard range.

2. the control unit executes the input assist process when the input value of the first setting value is outside the first reference range within which the inkjet head can normally eject ink. The information processing device according to claim 1 .

3. an upper limit value of the first reference range is set to a value that prevents ink from leaking from the nozzles of the inkjet head when ink is not being ejected from the nozzles, the lower limit of the first reference range is set to a value that does not cause meniscus break of the ink in the nozzle when the ejection flow rate per unit time according to the ink ejection from the nozzle is at its highest; The information processing device according to claim 2 .

4. the control unit executes the input assist process when the input value of the first setting value is outside the second reference range corresponding to a pressure resistance range of the inkjet head. The information processing device according to claim 1 .

5. The input assistance process is a process of causing a notification unit to issue a predetermined notification. The information processing device according to claim 1 .

6. The input assistance process is a process for invalidating the input value. The information processing device according to claim 1 .

7. The control unit Accepting an input of the model of the inkjet head by the user; determining the reference range based on the input model; The information processing device according to claim 1 .

8. the use conditions are driving conditions of the inkjet head, and include the driving conditions that affect a maximum value of an ejection flow rate per unit time according to the ejection of ink from nozzles of the inkjet head, The control unit accepting an input of the operating conditions by the user; determining the reference range based on the input driving conditions; The information processing device according to claim 1 .

9. the usage conditions include physical property values ​​of the ink, The control unit receiving input of ink information by the user that can identify physical property values ​​of the ink; determining the reference range based on the physical property value of the ink identified based on the ink information; The information processing device according to claim 1 .

10. the use conditions include a differential pressure between the first set value and the second set value, The control unit accepting an input of the second setting value by the user; determining the reference range based on the input differential pressure between the first set value and the second set value; The information processing device according to claim 1 .

11. When the control unit receives the input of the first setting value, the control unit sets an initial value of the first setting value within the first reference range and causes a predetermined display unit to display the initial value. The information processing device according to claim 2 .

12. An information processing device according to any one of claims 1 to 11; the inkjet head; The circulation device; An ink circulation system comprising:

13. 1. An information processing method executed by a computer for setting the operation of a circulation device that circulates ink in a circulation flow path that passes through an inkjet head having an inlet for ink inflow and an outlet for ink outflow, by controlling the ink pressure at the inlet to be a first set value and the ink pressure at the outlet to be a second set value, receiving an input of the first setting value from a user; a step of executing an input assistance process for prompting an input of a value within the standard range for the first setting value when the input value of the first setting value is outside the standard range according to the inkjet head and its usage conditions; An information processing method including:

14. A program that causes a computer to function as a control means, the program configuring an operation of a circulation device that circulates ink by controlling an ink pressure at an ink inlet to be a first set value and an ink pressure at an ink outlet to be a second set value in a circulation flow path that passes through an inkjet head having an inlet for ink inflow and an outlet for ink outflow, The control means accepting an input of the first setting value by a user; a program that, when the input value of the first setting value is outside a standard range according to the inkjet head and its usage conditions, executes an input assistance process to prompt the user to input a value within the standard range for the first setting value.

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