Printing control device, printing control method, program, and printing system

Abstract

Provided are a printing control device, a printing control method, a program, and a printing system in which the amount of liquid ejected from each nozzle in one ejection period is optimized with respect to each of the case where a pre-processing liquid is provided and the case where a pre-processing liquid is not provided. The printing control device: determines whether the printing mode is a first printing mode in which a pre-processing liquid is provided to a medium, or a second printing mode in which the pre-processing liquid is not provided to the medium; sets a first drive waveform as a drive waveform for an inkjet head if in the first printing mode, and sets a second drive waveform as the drive waveform for the inkjet head if in the second printing mode; and, if the second drive waveform is applied, decreases the maximum amount of liquid ejected from one nozzle in one period, compared to if the first drive waveform is applied.

Description

Print control device, print control method, program, and print system

[0001] The present invention relates to a print control device, a print control method, a program, and a print system.

[0002] Known inks used in inkjet printing devices include two-component inks to which a pretreatment liquid is applied before forming an image, and one-component inks to which a pretreatment liquid is not applied before forming an image.

[0003] In printing using two-component ink, the ink ejected from the inkjet head reacts with the pretreatment liquid, suppressing the flow of the ink on the paper and preventing uneven drying of the paper on which an image has been printed. On the other hand, in printing using two-component ink, the volume of the liquid applied to the paper increases due to the use of the pretreatment liquid, and the energy required for the drying process increases compared to when one-component ink is used.

[0004] When printing using two-component ink, paper deformation such as cockle caused by a lack of energy required for the drying process becomes relatively large, which may lead to paper lifting when printing on the back side of double-sided printing.

[0005] When printing using one-component ink, the quality of the printed image is inferior compared to when two-component ink is used, but less energy is required for the drying process compared to when two-component ink is used, resulting in less paper deformation and excellent paper transportability.

[0006] Japanese Patent Application Laid-Open No. 2006-103664 (Patent Document 1) describes an inkjet printing apparatus equipped with a pretreatment section that applies a pretreatment liquid to a sheet material. The apparatus described in this document stores a table of the relationship between the type, basis weight, or thickness of the sheet material, including the relationship between whether or not the treatment liquid is applied, and the air volume of the air blower. The apparatus determines whether or not the treatment liquid is applied, and if the treatment liquid is not applied, determines whether or not the sheet material is thin coated paper.

[0007] In this device, when the sheet material is thin coated paper, the air volume of the air blower is increased, and when a treatment liquid is applied or when the sheet material is not thin coated paper, the air volume of the air blower is decreased.

[0008] Japanese Patent Application Laid-Open No. 2021-054623

[0009] However, there are advantages and disadvantages to using one-liquid ink and two-liquid ink. A printing device preferably has a configuration that allows selection between a mode using one-liquid ink and a mode using two-liquid ink depending on the application. To achieve a high level of selectability, it is preferable to set the optimal process for each mode.

[0010] Since one-liquid ink and two-liquid ink have different wetting and spreading rates, it is preferable to switch to an optimal ejection waveform that can change the ink ejection amount for one dot depending on whether the ink used is one-liquid ink or two-liquid ink.

[0011] In Patent Document 1, the air volume of the air blower is switched depending on whether or not treatment liquid is being applied, but the ink ejection volume is not optimized depending on whether treatment liquid is being applied or not.

[0012] The present invention has been made in consideration of these circumstances, and aims to provide a print control device, a print control method, a program, and a printing system that optimizes the amount of liquid ejected from each nozzle in one ejection cycle, both when pretreatment liquid is applied and when pretreatment liquid is not applied.

[0013] A print control device according to the present disclosure is a print control device that controls a printing device equipped with an inkjet head having one or more nozzles, and includes one or more processors and one or more memories that store programs to be executed by the one or more processors. The one or more processors execute the programs to determine whether the printing mode is a first printing mode in which a pretreatment liquid that reacts with liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which the pretreatment liquid is not applied to the medium. If it is determined that the printing mode is the first printing mode, the print control device sets a first drive waveform as the drive waveform to be applied to the inkjet head. If it is determined that the printing mode is the second printing mode, the print control device sets a second drive waveform as the drive waveform to be applied to the inkjet head. When the second drive waveform is applied, the print control device reduces the maximum amount of liquid ejected from one nozzle in one ejection cycle compared to when the first drive waveform is applied.

[0014] According to the printing control device of the present disclosure, the amount of liquid ejected from each nozzle in one ejection cycle is optimized for each of the first printing mode in which pretreatment liquid is applied and the second printing mode in which pretreatment liquid is not applied.

[0015] The nozzle includes a nozzle opening for ejecting a liquid, and may include a flow path and a pressure generating element that communicate with the nozzle opening.

[0016] The liquid includes color ink containing color materials, coloring agents, etc. A first ink that has the property of thickening upon reacting with the pretreatment liquid may be applied in the first printing mode. A second ink that does not contain a component that reacts with the pretreatment liquid may be applied in the second printing mode.

[0017] In the print control device according to another aspect, the second drive waveform may have a smaller amplitude than the first drive waveform.

[0018] According to this aspect, when the second drive waveform is applied, the amount of liquid ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform is applied.

[0019] In another aspect of the printing control device, the first drive waveform and the second drive waveform each may include a plurality of pulse waveforms, and the second drive waveform may include a smaller number of pulse waveforms than the first drive waveform.

[0020] According to this aspect, when the second drive waveform is applied, the amount of liquid ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform is applied.

[0021] In a print control device according to another aspect, the second drive waveform may have a smaller change in amplitude per unit time than the first drive waveform.

[0022] According to this aspect, when the second drive waveform is applied, the amount of liquid ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform is applied.

[0023] In another aspect of the printing control device, one or more processors may apply a second printing mode when liquid is applied to both one side and the other side of the medium, and may apply a first printing mode when liquid is applied to only one side of the medium.

[0024] According to this aspect, compared to the first printing mode in which pretreatment liquid is applied, in the second printing mode in which pretreatment liquid is not applied, the liquid on the medium is more likely to wet and spread, and dots of the specified size can be formed using a relatively small amount of liquid.

[0025] In another aspect of the printing control device, the one or more processors are a drying device provided in the printing device, and when controlling the drying device that performs a drying process on a medium to which liquid ejected from an inkjet head has been applied, a first drying intensity is applied as the drying intensity when it is determined that the printing mode is the first, and a second drying intensity is applied as the drying intensity when it is determined that the printing mode is the second, and the second drying intensity may be a drying intensity lower than the first drying intensity.

[0026] According to this aspect, in the second printing mode, deformation of the medium caused by the drying process is suppressed, and medium transport is optimized.

[0027] In another aspect of the printing control device, one or more processors may read a first drying condition table in which a first drying intensity is defined when a first printing mode is applied, and read a second drying condition table in which a second drying intensity is defined when a second printing mode is applied.

[0028] According to this aspect, the drying intensity that is optimized in advance for each print mode can be applied in the first print mode and the second print mode.

[0029] A print control method according to the present disclosure is a print control method for controlling a printing device that includes an inkjet head with one or more nozzles, and determines whether the printing mode is a first printing mode in which a pretreatment liquid that reacts with liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which the pretreatment liquid is not applied to the medium, and if it is determined that the printing mode is the first printing mode, sets a first drive waveform as the drive waveform to be applied to the inkjet head, and if it is determined that the printing mode is the second printing mode, sets a second drive waveform as the drive waveform to be applied to the inkjet head, and when the second drive waveform is applied, reduces the maximum amount of liquid ejected from one nozzle in one ejection cycle compared to when the first drive waveform is applied.

[0030] According to the print control method of the present disclosure, it is possible to obtain the same effects as the print control device of the present disclosure. The constituent elements of the print control device of other aspects can be applied to the constituent elements of the print control method of other aspects.

[0031] The program according to the present disclosure is a program for controlling a printing device equipped with an inkjet head having one or more nozzles, and causes a computer to realize a function for determining whether the printing mode is a first printing mode in which a pretreatment liquid that reacts with liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which pretreatment liquid is not applied to the medium, and a function for setting a first drive waveform as the drive waveform to be applied to the inkjet head when it is determined that the printing mode is the first printing mode, and a function for setting a second drive waveform as the drive waveform to be applied to the inkjet head when it is determined that the printing mode is the second printing mode, and the program reduces the maximum amount of liquid ejected from one nozzle in one ejection cycle when the second drive waveform is applied compared to when the first drive waveform is applied.

[0032] According to the program of the present disclosure, it is possible to obtain the same effects as the print control device of the present disclosure. The constituent elements of the print control device of other aspects can be applied to the constituent elements of the program of other aspects.

[0033] A printing system according to the present disclosure includes an inkjet head having one or more nozzles, a pretreatment liquid application device that applies a pretreatment liquid to a medium, one or more processors, and one or more memories that store programs to be executed by the one or more processors, wherein the one or more processors execute the programs to determine whether a first printing mode is in which a pretreatment liquid that reacts with liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which the pretreatment liquid is not applied to the medium, and when it is determined that the first printing mode is in which a first drive waveform is set as the drive waveform to be applied to the inkjet head, and when it is determined that the second printing mode is in which a second drive waveform is set as the drive waveform to be applied to the inkjet head, and when the second drive waveform is applied, the maximum amount of liquid ejected from one nozzle in one ejection cycle is reduced compared to when the first drive waveform is applied.

[0034] According to the printing system of the present disclosure, it is possible to obtain the same effects as the printing control of the present disclosure. The components of the printing control of other aspects can be applied to the components of the printing system of other aspects.

[0035] According to the present invention, the amount of liquid ejected from each nozzle in one ejection cycle is optimized for both the first printing mode in which pretreatment liquid is applied and the second printing mode in which pretreatment liquid is not applied.

[0036] FIG. 1 is a perspective view showing the overall configuration of a printing system according to a first embodiment. FIG. 2 is a functional block diagram showing the electrical configuration of the printing system shown in FIG. 1. FIG. 3 is a block diagram showing an example of the hardware configuration of the electrical configuration shown in FIG. 2. FIG. 4 is a perspective view showing an example of the configuration of an inkjet head. FIG. 5 is a perspective view of a head module, including a partial cross-sectional view. FIG. 6 is a plan view showing an example of the nozzle arrangement of the inkjet head shown in FIG. 4. FIG. 7 is a cross-sectional view showing the internal structure of the head module. FIG. 8 is a flowchart showing the steps of a print control method according to a first embodiment. FIG. 9 is a table showing parameter settings for each print mode applied to the printing system according to the first embodiment. FIG. 10 is a schematic diagram showing a first drive waveform applied to a first print mode. FIG. 11 is a schematic diagram showing a first example of a second drive waveform applied to a second print mode. FIG. 12 is a schematic diagram showing a second example of a second drive waveform applied to the second print mode. FIG. 13 is a schematic diagram showing a third example of a second drive waveform applied to the second print mode. FIG. 14 is a functional block diagram showing the electrical configuration of a printing system according to a second embodiment. Fig. 15 is a block diagram showing an example of a hardware configuration of the electrical configuration shown in Fig. 14. Fig. 16 is a flowchart showing the procedure of a print control method according to a second embodiment. Fig. 17 is a table showing parameter settings for each print mode applied to a print system according to the second embodiment.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this specification, the same components are designated by the same reference numerals, and redundant explanations will be omitted where appropriate.

[0038] [Configuration Example of Printing System According to First Embodiment] [Outline of Printing System] Fig. 1 is a perspective view showing the overall configuration of a printing system according to an embodiment. The printing system 10 achieves a first printing mode with excellent image quality and a second printing mode with excellent paper transportability using a single printing system. In other words, the printing system 10 has a first printing mode that emphasizes high image quality and a second printing mode that emphasizes paper transportability, and is configured to be freely switchable between the first printing mode and the second printing mode. The printing mode can be switched for each print job.

[0039] In the printing system 10, from the viewpoint of prioritizing paper transportability, the first printing mode in which a precoat liquid is used is recommended for single-sided printing in which an image is printed on only one side of the paper, while the second printing mode in which a precoat liquid is not used is recommended for double-sided printing in which images are printed on both sides of the paper.

[0040] The printing system 10 uses a different drive waveform in the first print mode than in the second print mode. Specifically, the drive waveform used in the second print mode is a waveform that reduces the amount of ink ejected from one nozzle in one ejection cycle compared to the drive waveform used in the first print mode.

[0041] The reason for this is as follows: In the second printing mode, the ink does not use precoat liquid, so the ink spreads more easily on the paper, and it is possible to form an image without missing pixels using a smaller amount of ink than in the first printing mode, which uses precoat liquid.

[0042] The comparison between the ink ejection amount applied in the first print mode and the ink ejection amount applied in the second print mode may be based on the maximum ink ejection amount ejected from one nozzle in one ejection cycle. If multiple types of droplet sizes, such as large droplets, medium droplets, and small droplets, are used as the ink ejection amount ejected from one nozzle in one ejection cycle, the ink ejection amount is adjusted for each droplet size depending on the print mode. Details of the adjustment of the ink ejection amount will be described later.

[0043] The precoat liquid described in the embodiments is an example of a pretreatment liquid. The first printing mode described in the embodiments is an example of a first printing mode in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium. The second printing mode described in the embodiments is an example of a second printing mode in which the pretreatment liquid is not applied to the medium. The ejection volume of large droplets described in the embodiments is an example of the maximum liquid ejection volume ejected from one nozzle in one ejection cycle.

[0044] [Overall Configuration] The printing system 10 is equipped with a digital printing device 16 that prints color images on paper using single-pass printing.

[0045] The paper may be a paper medium such as a sheet or continuous paper, a sheet-like metal medium, or a cloth medium such as fabric. The paper may be a soft packaging such as a plastic film. The paper may be a single layer or multiple layers may be overlapped. The paper may be in a continuous roll-to-roll form or in the form of sheets cut to a specified length. The paper may be called a medium, media, sheet, film, substrate, etc. The paper is illustrated.

[0046] The printing system 10 includes a paper feeder 12 , a precoater 14 , a printing device 16 , a drying device 18 , an inspection device 20 and a stacking device 22 .

[0047] 1 indicate the paper transport direction of each part in the printing system 10. The paper transport direction is the direction in which the paper moves from the paper feeder 12, through the precoater 14, the printer 16, the dryer 18, and the inspector 20, to the stacker 22.

[0048] The direction perpendicular to the paper transport direction and parallel to the plane parallel to the printing surface of the paper is the paper width direction. Each component of the printing system 10 will now be described in detail.

[0049] [Paper Feeder] When the paper is in sheet form, the paper feeder 12 has a tray that stores the paper. When the paper is in continuous form, the paper feeder 12 has a roll storage section that stores a roll of paper. The paper feeder 12 supplies the paper to the precoat device 14 in accordance with the printing control of the printing device 16. The paper feeder 12 may have a correction mechanism that corrects the attitude of the paper.

[0050] [Precoat Device] The precoat device 14 applies a precoat liquid to paper, which aggregates or insolubilizes colorant components contained in the aqueous ink. In the paper transport direction in the printing system 10, the precoat device 14 is located downstream of the paper feed device 12 and upstream of the printing device 16.

[0051] The precoat device 14 is provided with an application roller, and employs a roller application method in which the application roller is brought into contact with the printing surface of the paper, and the precoat liquid applied to the surface of the application roller is transferred to the printing surface of the paper.

[0052] The precoat device 14 may include a metering roller that transfers the measured precoat liquid to the surface of the application roller and a precoat liquid storage unit that stores the precoat liquid. Note that the precoat device 14 may also use other application methods, such as a spray method or an inkjet method.

[0053] The precoat liquid contains a flocculant as a component for flocculating the coloring material components contained in the aqueous ink. Examples of the flocculant include polyvalent metal compounds, organic acids, metal complexes, and aqueous cationic polymers. The flocculant may contain an organic acid.

[0054] From the viewpoint of the aggregation speed of the ink, the content of the aggregating agent relative to the total amount of the precoat liquid is preferably 0.1 mass percent or more and 40 mass percent or less, and more preferably 1 mass percent or more and 10 mass percent or less.

[0055] The precoat liquid preferably contains water. The water content of the precoat liquid is preferably 50 mass percent or more, more preferably 60 mass percent or more, relative to the total amount of the precoat liquid. The upper limit of the water content of the precoat liquid is preferably 90 mass percent, more preferably 80 mass percent.

[0056] The precoat liquid may contain resin particles, a water-soluble solvent, and a surfactant. The precoat liquid may also contain a solid wetting agent, colloidal silica, an inorganic salt, a discoloration inhibitor, an emulsion stabilizer, a penetration enhancer, an ultraviolet absorber, an antiseptic, an antifungal agent, a pH adjuster, a viscosity adjuster, a rust inhibitor, a chelating agent, and a water-soluble polymer compound other than the water-soluble cationic polymer.

[0057] From the viewpoint of the ink aggregation speed, the pH value of the precoat liquid at 25° C. is preferably 0.1 or more and less than 3.5. Furthermore, from the viewpoint of the ink aggregation speed, the viscosity of the precoat liquid when it contains an aggregating agent is preferably 0.5 mPa-second or more and 10 mPa-second or less, and more preferably 1 mPa-second or more and 5 mPa-second or less.

[0058] The surface tension of the precoat liquid at 25° C. is preferably 60 millinewtons per meter or less, more preferably 20 to 50 millinewtons per meter, and even more preferably 3 to 45 millinewtons per meter.

[0059] The printing system 10 may include a precoat drying device that dries the precoat liquid applied to the printing surface of the paper. The precoat drying device may be configured integrally with the precoat device 14, or may be configured as an external device of the precoat device 14.

[0060] The precoat drying device may heat the paper using a heater or the like, or may blow air onto the paper using a fan motor or the like, or may use a combination of heating and blowing air to blow heated gas onto the paper.

[0061] The precoat device 14 includes a precoat transport device that transports paper through the precoat device 14. The precoat transport device may be a roller transport, drum transport, or belt transport. The precoat transport device is not shown in the figure. Paper whose printing surface has been coated with precoat liquid using the precoat device 14 is sent to the printing device 16. The precoat device 14 described in the embodiment is an example of a pretreatment liquid application device that applies pretreatment liquid to a medium.

[0062] [Printing Device] The printing device 16 is equipped with inkjet head 30K, inkjet head 30C, inkjet head 30M, and inkjet head 30Y. Inkjet head 30K, inkjet head 30C, inkjet head 30M, and inkjet head 30Y are arranged in the above-described order from the upstream side along the paper transport direction in the printing device 16. The arrow line attached to the print drum 32 indicates the paper transport direction in the printing device 16.

[0063] The inkjet head 30K ejects black ink, the inkjet head 30C ejects cyan ink, the inkjet head 30M ejects magenta ink, and the inkjet head 30Y ejects yellow ink.

[0064] The printing device 16 forms a color image on paper using color inks such as black ink. The printing device 16 may also include an inkjet head that ejects special color inks other than black or other process inks, such as an inkjet head that uses white ink to form a white image that serves as a background image for the color image.

[0065] Inkjet head 30K, inkjet head 30C, inkjet head 30M, and inkjet head 30Y are each oriented such that the normal to the nozzle surface intersects the vertical direction. Hereinafter, inkjet head 30K and the like may be referred to as inkjet head 30 when there is no need to distinguish between them.

[0066] The printing device 16 includes a print drum 32 as a paper transport device in the printing device 16. The print drum 32 has a cylindrical shape and is supported so as to be rotatable about its central axis. The print drum 32 includes a paper support area on its circumferential surface that supports paper.

[0067] The rotation shaft of the print drum 32 is connected via a drive mechanism to a motor, which serves as the drive source for the drive mechanism. When the motor is rotated, the print drum 32 rotates in the direction indicated by the arrow. When the print drum 32 is rotated, the paper supported on the circumferential surface of the print drum 32 is transported in the direction of rotation of the print drum 32.

[0068] The paper support area has a plurality of suction holes formed therein. The plurality of suction holes are arranged based on a predetermined pattern. The plurality of suction holes communicate with a gas flow path. The gas flow path is connected to a suction pump. The suction pump is operated to generate negative pressure in the plurality of suction holes, thereby securing the paper to the paper support area of ​​the print drum 32.

[0069] The paper transport mode in the printing device 16 is not limited to a transport mode using the print drum 32. For example, a transport mode using a transport belt or a transport mode using a plurality of rollers can be applied.

[0070] The rotation shaft of the print drum 32, the drive mechanism of the print drum 32, the motor connected to the drive mechanism, the paper support area of ​​the print drum 32, the suction holes in the paper support area, the gas flow path, and the suction pump are not shown.

[0071] The printing device 16 includes an in-line sensor 34. The in-line sensor 34 is disposed downstream of the inkjet head 30Y in the paper transport direction of the printing device 16. The in-line sensor 34 reads a test pattern printed on the paper and outputs a read signal of the test pattern. The printing device 16 detects an abnormality in the nozzles of the inkjet head 30Y based on the read signal of the test pattern.

[0072] The inline sensor 34 includes an image sensor that reads an image printed on paper. The image sensor may be a CCD image sensor, a CMOS image sensor, or the like. The inline sensor 34 has a capturing area that corresponds to the entire width of the paper in the paper width direction. The inline sensor 34 may also include an optical component such as a condenser lens. Note that CCD is an abbreviation for Charge Coupled Device. CMOS is an abbreviation for Complementary Metal Oxide Semiconductor.

[0073] [Drying Device] The drying device 18 performs a drying process on the paper that has been handed over from the printing drum 32 and has a color image printed on its printing surface using the printing device 16. The drying device 18 may be equipped with a heater and a fan, and may be configured to blow warm air onto the printed paper. The drying device 18 also includes a drying conveying device that conveys the paper through the drying device 18.

[0074] The drying conveying device may be applied to a paper conveying system using rollers, drums, grippers, belts, or other conveying systems. The drying conveying device may also be applied to a combination of several conveying systems. For example, the drying conveying device may be applied to a conveying system that combines grippers and belts to support the leading edge of the paper using a gripper and a suction belt to support the trailing edge of the paper. The arrows shown on the drying device 18 indicate the paper conveying direction in the drying device 18.

[0075] [Inspection Device] The inspection device 20 includes a photographing device that photographs the print image printed on paper and a lighting device that illuminates the print image. The inspection device 20 outputs scanned data of the print image. The inspection device 20 can detect defects in the print image based on the scanned data of the print image. The arrows shown on the inspection device 20 indicate the paper transport direction in the inspection device 20.

[0076] The inspection device 20 includes an inspection transport device that transports paper in the inspection device 20. The inspection transport device may have a configuration similar to that of the drying transport device. The arrows shown on the inspection device 20 indicate the paper transport direction in the inspection device 20.

[0077] [Stacking Device] The stacking device 22 stores the paper sheets handed over from the inspection device 20. When the paper sheets are in the form of sheets, the stacking device 22 includes a tray for storing the paper sheets. When the paper sheets are in the form of a continuous sheet, the stacking device 22 includes a roll storage section for storing a roll on which the paper sheets are wound.

[0078] The stacking device 22 may sort and store the printed sheets of paper in accordance with the inspection results of the inspection device 20. For example, the stacking device 22 may include a non-defective product image storage section that stores non-defective product images and a defective product image storage section that stores defective product images.

[0079] The printing system 10 may also include a maintenance device that performs maintenance processes such as wiping, purging, and suction of the inkjet head 30. The maintenance device may include a head moving device that moves the inkjet head 30, a wiping device that wipes the inkjet head 30, and a capping device that caps the inkjet head 30. The maintenance device is not shown in the drawings.

[0080] [Electrical Configuration of Printing System] Figure 2 is a functional block diagram showing the electrical configuration of the printing system shown in Figure 1. The printing system 10 includes a system control unit 100, a transport control unit 102, a precoat control unit 104, a print control unit 106, an inline sensor control unit 107, a drying control unit 108, and an inspection control unit 109. The printing system 10 also includes a memory 120 and a sensor 130.

[0081] The system control unit 100 comprehensively controls the overall operation of the printing system 10. The system control unit 100 sends command signals to various control units. The system control unit 100 functions as a memory controller that controls the storage of data in the memory 120 and the reading of data from the memory 120.

[0082] The memory 120 includes a drive waveform storage unit 122 and a data storage unit 124. The drive waveform storage unit 122 stores a drive waveform that is applied to the drive voltage supplied to the inkjet head 30.

[0083] The data storage unit 124 stores various data applied to the printing system 10. The memory 120 may include a program storage unit in which various programs applied to the printing system 10 are stored and a parameter storage unit in which various parameters applied to the printing system 10 are stored.

[0084] The system control unit 100 acquires sensor signals transmitted from the sensors 130 and transmits command signals based on the sensor signals to various control units. The sensors 130 include position detection sensors and temperature sensors provided in various parts of the printing system 10.

[0085] The printing system 10 includes a print mode setting unit 140. The print mode setting unit 140 switches between a first print mode in which a precoat liquid is used and a second print mode in which a precoat liquid is not used.

[0086] The print mode setting unit 140 also switches between a single-sided print mode in which printing is performed on only one side of the paper, and a double-sided print mode in which printing is performed on both sides of the paper.

[0087] That is, the system control unit 100 sends command signals to each unit according to the print mode set using the print mode setting unit 140. For example, when the first print mode, in which precoat liquid is used, is set, the system control unit 100 sends an operation command signal to the precoat control unit 104. Details of the control of each unit for each print mode will be described later.

[0088] The transport control unit 102 sets transport conditions based on command signals sent from the system control unit 100, and controls the operation of the transport device 24 based on the set transport conditions. The transport conditions include the transport speed of the paper.

[0089] 2 includes the precoat conveying device provided in the precoat device 14, the print drum 32, the drying conveying device provided in the drying device 18, and the inspection conveying device provided in the inspection device 20, all of which are shown in FIG. 1. The conveying device 24 may also include the paper feeding device 12 and the stacking device 22.

[0090] The precoat control unit 104 sets precoat conditions based on command signals sent from the system control unit 100, and controls the operation of the precoat device 14 based on the set precoat conditions. Examples of the precoat conditions include the amount of precoat liquid applied per unit area of ​​paper and the amount of precoat liquid applied per unit time.

[0091] The precoat control unit 104 operates the precoat device 14 to apply precoat liquid to the paper when the first printing mode in which precoat liquid is used is set, and stops the operation of the precoat device 14 when the second printing mode in which precoat liquid is not used is set.

[0092] In the roller application method, when the first print mode is set, the application roller repeatedly contacts and separates from the paper for each sheet, and a specified amount of precoat liquid applied to the application roller is transferred to the paper. On the other hand, when the second print mode is set, the application roller is separated from the paper, and precoat liquid is not applied to the paper.

[0093] The print control unit 106 sets print conditions based on command signals sent from the system control unit 100, and controls the operation of the printing device 16 based on the set print conditions. That is, the print control unit 106 controls the ejection of ink from the inkjet head 30 provided in the printing device 16. The print conditions include a print mode.

[0094] The print control unit 106 includes an image processing unit 110, a drive voltage generation unit 112, and a drive waveform setting unit 114. The image processing unit 110 performs color separation processing, color conversion processing, correction processing for each processing, and halftone processing on the print data to generate halftone data for each color.

[0095] The drive voltage generation unit 112 generates a drive voltage to be supplied to the inkjet head 30 of each color based on the halftone data for each color, and supplies the drive voltage to the inkjet head 30 .

[0096] The drive voltage generation unit 112 generates ejection timing signals representing the ejection timing for each nozzle provided in the inkjet head 30 of each color based on the halftone data for each color, and supplies the ejection timing signals to the inkjet head 30. That is, the drive voltage generation unit 112 includes an electric circuit that outputs a drive voltage and an electric circuit that outputs an ejection timing signal.

[0097] The drive waveform setting unit 114 reads out the drive waveform stored in the drive waveform storage unit 122 in accordance with the printing conditions, etc., and sets the drive waveform to be applied to the drive voltage. The drive waveform setting unit 114 may have a function to adjust the drive waveform.

[0098] The print control unit 106 performs ejection correction on the inkjet head 30 for abnormal nozzles identified based on the read data of the test pattern sent from the inline sensor 34. Examples of ejection correction include masking the non-ejecting nozzles and substituting ejection using nozzles near the non-ejecting nozzles at the printing position of the non-ejecting nozzles.

[0099] The inline sensor control unit 107 sets the reading conditions of the inline sensor 34 based on a command signal sent from the system control unit 100, and controls the reading of the test pattern using the inline sensor 34.

[0100] The inline sensor control unit 107 acquires the read data of the test pattern transmitted from the inline sensor 34. The printing system 10 identifies abnormal nozzles based on the read data of the test pattern acquired via the inline sensor control unit 107. Information about the abnormal nozzles is transmitted to the print control unit 106.

[0101] The drying control unit 108 sets processing conditions such as drying intensity in the drying process based on a command signal sent from the system control unit 100, and controls the operation of the drying device 18 based on the set processing conditions.

[0102] The inspection control unit 109 sets inspection conditions based on command signals transmitted from the system control unit 100, and controls the operation of the inspection device 20 based on the set inspection conditions. The inspection control unit 109 acquires inspection results of the printed image, which indicate whether the printed image is good or bad, from the inspection device 20.

[0103] Based on the inspection results of the print images obtained from the inspection device 20, the system control unit 100 sorts the print images into non-defective and defective print images in the stacking device 22 shown in FIG.

[0104] [Example of Hardware Configuration of Control Device Applied to Printing System] Fig. 3 is a block diagram that schematically shows an example of the hardware configuration of the electrical configuration shown in Fig. 2. The control device 200 provided in the printing system 10 includes a processor 202, a computer-readable medium 204 that is a non-transitory tangible entity, a communication interface 206, and an input / output interface 208.

[0105] A computer is applied to the control device 200. The computer may be in the form of a server, a personal computer, a workstation, a tablet terminal, or the like.

[0106] The processor 202 includes a central processing unit (CPU) and may include a graphics processing unit (GPU). The processor 202 is connected to a computer-readable medium 204, a communication interface 206, and an input / output interface 208 via a bus 210. An input device 214 and a display device 216 are connected to the bus 210 via the input / output interface 208.

[0107] The computer-readable medium 204 includes a memory serving as a main storage device and a storage serving as an auxiliary storage device. The computer-readable medium 204 may be a semiconductor memory, a hard disk drive, a solid-state drive, or the like. The computer-readable medium 204 may be any combination of multiple devices.

[0108] A hard disk drive may be referred to as an HDD, which is an abbreviation of the English term Hard Disk Drive, and a solid state drive may be referred to as an SSD, which is an abbreviation of the English term Solid State Drive.

[0109] The control device 200 is connected to a network via a communication interface 206, and is communicably connected to external devices. The network may be a local area network (LAN), etc. The network is not shown in the figure.

[0110] The computer-readable medium 204 stores a transport control program 220 , a pre-coat control program 222 , a print control program 224 , an in-line sensor control program 226 , a drying control program 228 , and an inspection control program 230 .

[0111] The transport control program 220 is applied to the transport control unit 102 shown in Fig. 2 to realize the function of transporting paper. The precoat control program 222 is applied to the precoat control unit 104 to realize the function of applying precoat liquid.

[0112] The print control program 224 is applied to the print control unit 106 to realize the print function. The print control program 224 includes an image processing program 232, a drive waveform setting program 234, and a drive voltage generation program 236.

[0113] The image processing program 232 is applied to the image processing unit 110 to realize the image processing function. The drive waveform setting program 234 is applied to the drive waveform setting unit 114 to realize the drive waveform setting function. The drive voltage generation program 236 is applied to the drive voltage generation unit 112 to realize the drive voltage generation function in cooperation with the image processing program 232 and the drive waveform setting program 234.

[0114] The inline sensor control program 226 is applied to the inline sensor control unit 107 and realizes the reading function of the inline sensor 34. The drying control program 228 is applied to the drying control unit 108 and realizes the function of drying paper using the drying device 18. The inspection control program 230 is applied to the inspection control unit 109 and realizes the function of inspecting images printed on paper using the inspection device 20.

[0115] The various programs stored in the computer-readable medium 204 include one or more instructions. Various data, various parameters, etc. are stored in the computer-readable medium 204. Note that the memory 120 including the drive waveform storage unit 122 and the data storage unit 124 shown in FIG. 2 may be included in the computer-readable medium 204 shown in FIG. 3.

[0116] In the printing system 10, the processor 202 executes various programs stored in the computer-readable medium 204 to realize various functions of the printing system 10. Note that the term "program" is synonymous with the term "software."

[0117] The control device 200 performs data communication with an external device via a communication interface 206. The communication interface 206 may be compliant with various standards such as USB (Universal Serial Bus). The communication form of the communication interface 206 may be either wired communication or wireless communication.

[0118] The control device 200 is connected to an input device 214 and a display device 216 via an input / output interface 208. The input device 214 is implemented by input devices such as a keyboard and a mouse. The display device 216 displays various types of information applied to the control device 200.

[0119] The display device 216 may be a liquid crystal display, an organic EL display, a projector, or any combination of multiple devices. The "EL" in the organic EL display is an abbreviation for "Electro-Luminescence."

[0120] Examples of the hardware structure of the processor 202 include a CPU, a GPU, a programmable logic device (PLD), and an application specific integrated circuit (ASIC). The CPU is a general-purpose processor that executes programs and functions as various functional units. The GPU is a processor specialized for image processing.

[0121] A PLD is a processor whose electrical circuit configuration can be changed after the device is manufactured. An example of a PLD is an FPGA (Field Programmable Gate Array). An ASIC is a processor with dedicated electrical circuitry designed specifically to perform a specific process.

[0122] A processing unit may be configured with one of these various processors, or may be configured with two or more processors of the same or different types. Examples of combinations of various processors include a combination of one or more FPGAs and one or more CPUs, and a combination of one or more FPGAs and one or more GPUs. Another example of a combination of various processors is a combination of one or more CPUs and one or more GPUs.

[0123] A single processor may be used to configure multiple functional units. An example of using a single processor to configure multiple functional units is a configuration in which a single processor is configured by applying a combination of one or more CPUs and software, such as a SoC (System On a Chip) that is typified by a computer such as a client or server, and this processor operates as multiple functional units.

[0124] Another example of using one processor to configure multiple functional units is to use a processor that uses one IC chip to realize the functions of an entire system including multiple functional units. Note that IC is an abbreviation for Integrated Circuit.

[0125] In this way, the various functional units are configured as hardware structures using one or more of the various processors described above.More specifically, the hardware structures of the various processors described above are electric circuits (circuitry) that combine circuit elements such as semiconductor elements.

[0126] The computer-readable medium 204 may include semiconductor devices such as read-only memory (ROM), random access memory (RAM), and solid-state drives (SSD). The computer-readable medium 204 may include magnetic storage media such as hard disks. The computer-readable medium 204 may comprise multiple types of storage media.

[0127] [Configuration example of inkjet head] Fig. 4 is a perspective view showing a configuration example of an inkjet head. The inkjet head 30 shown in the figure has a structure in which a plurality of head modules 40 are connected in a row along the longitudinal direction of the inkjet head 30. The plurality of head modules 40 are integrated and supported by a head frame 42.

[0128] The inkjet head 30 is a line head in which a plurality of nozzles are arranged across a length corresponding to the entire width of the paper in the paper width direction. The nozzles are not shown in Fig. 4. The nozzles are indicated by the reference numeral 62 in Fig. 6.

[0129] The nozzle surface 44 of the head module 40 has a planar shape that is a parallelogram. Dummy plates 46 are attached to both ends of the head frame 42. The planar shape of the nozzle surface 44 of the inkjet head 30, including the head module 40 and the dummy plates 46, is rectangular as a whole.

[0130] A flexible substrate 48 is attached to the head module 40. The flexible substrate 48 is a wiring member that transmits a drive voltage supplied to the head module 40. One end of the flexible substrate 48 is electrically connected to the head module 40, and the other end is electrically connected to a drive voltage supply circuit. The drive voltage supply circuit is not shown in the figure. The drive voltage supply circuit is a component of the drive voltage generation unit 112 shown in FIG. 2.

[0131] Each of the multiple head modules 40 provided in the inkjet head 30 can be associated with a module number that indicates the position of the head module 40, starting from the head module 40 arranged at one end of the inkjet head 30.

[0132] 5 is a perspective view of the head module 40, including a partial cross-sectional view. The head module 40 has an ink supply unit made up of an ink supply chamber 52, an ink circulation chamber 54, etc., on the top surface side in FIG. 5, which is the side opposite to the nozzle surface 44 of the nozzle plate 50.

[0133] The ink supply chamber 52 is connected to a buffer tank via a supply-side individual flow path 56. The ink circulation chamber 54 is connected to a buffer tank via a recovery-side individual flow path 58.

[0134] Fig. 6 is a plan view showing an example of the nozzle arrangement of the inkjet head shown in Fig. 4. The central portion of the nozzle surface 44 of the head module 40 is provided with a strip-shaped nozzle arrangement portion 60. The nozzle arrangement portion 60 essentially functions as the nozzle surface 44.

[0135] A plurality of nozzles 62 are arranged in the nozzle arrangement section 60. The nozzles 62 include nozzle openings 64 formed in the nozzle surface 44. In the following description, the arrangement of the nozzles 62 may be read as the arrangement of the nozzle openings 64.

[0136] The head module 40 has a planar shape of a parallelogram having a long side end face along the V direction inclined at an angle β with respect to the paper width direction, indicated by the symbol X, and a short side end face along the W direction inclined at an angle α with respect to the paper transport direction, indicated by the symbol Y.

[0137] In the head module 40, a plurality of nozzles 62 are arranged in a matrix with rows extending along the V direction and columns extending along the W direction. The nozzles 62 may also be arranged in rows extending along the paper width direction and in columns diagonally intersecting the paper width direction.

[0138] In the case of an inkjet head 30 in which a plurality of nozzles 62 are arranged in a matrix, a projected nozzle array obtained by projecting each of the nozzles 62 in the matrix arrangement along the nozzle array direction can be considered equivalent to a single nozzle array in which the nozzles 62 are arranged at approximately equal intervals at a density that achieves the maximum recording resolution in the nozzle array direction. The projected nozzle array is a nozzle array obtained by orthogonally projecting each of the nozzles 62 in the matrix arrangement along the nozzle array direction.

[0139] "Approximately equal intervals" means that the droplet ejection points are substantially equal intervals as recordable droplet ejection points in a printing device. For example, the concept of equal intervals also includes cases where the intervals are slightly different to account for manufacturing errors and / or droplet movement on the paper due to impact interference. The projected nozzle array essentially corresponds to the nozzle array. When the projected nozzle array is taken into consideration, a nozzle number indicating the nozzle position can be assigned to each nozzle 62 in the order in which the projected nozzles are aligned along the nozzle array direction.

[0140] Although FIG. 6 illustrates an inkjet head 30 in which a plurality of nozzles are arranged in a matrix, the nozzles may be arranged in a single row or in a zigzag pattern in two rows.

[0141] The effective density of the nozzles 62 in the paper width direction corresponds to the print resolution in the paper width direction. An example of the print resolution in the paper width direction is 1200 dots per inch. Dots per inch, which represents the number of dots per inch, can be referred to as dpi, an abbreviation of Dots Per Inch.

[0142] 7 is a cross-sectional view showing the internal structure of the head module 40. The head module 40 includes ink supply channels 70, individual supply channels 72, pressure chambers 74, nozzle communication channels 76, individual circulation channels 78, a common circulation channel 80, piezoelectric elements 82, and a vibration plate 84.

[0143] The ink supply paths 70, individual supply paths 72, pressure chambers 74, nozzle connecting paths 76, individual circulation paths 78, and common circulation path 80 are formed in a flow path structure 86. The nozzle 62 includes a nozzle opening 64 and a nozzle connecting path 76. The nozzle connecting path 76 is a flow path that constitutes the ejection element, and corresponds to the flow path that communicates with the nozzle opening 64.

[0144] The individual supply channels 72 are channels that connect the pressure chambers 74 and the ink supply channels 70. The nozzle communication channels 76 are channels that connect the pressure chambers 74 and the nozzle openings 64. The individual circulation channels 78 are channels that connect the nozzle communication channels 76 and the common circulation channel 80.

[0145] A vibration plate 84 is disposed on the flow path structure 86. A piezoelectric element 82 is disposed on the vibration plate 84 via an adhesive layer 88. The piezoelectric element 82 has a layered structure of a lower electrode 90, a piezoelectric layer 92, and an upper electrode 94. The lower electrode 90 is sometimes called a common electrode, and the upper electrode 94 is sometimes called an individual electrode.

[0146] The upper electrode 94 is an individual electrode patterned to correspond to the shape of each pressure chamber 74, and each pressure chamber 74 is provided with a piezoelectric element 82. The piezoelectric element 82 corresponds to an energy generating element that constitutes an ejection element.

[0147] 5. Ink is supplied from the ink supply channel 70 to the pressure chamber 74 via the individual supply channel 72. A drive voltage is applied to the upper electrode 94 of the piezoelectric element 82 to be operated in accordance with image data, causing the piezoelectric element 82 and the diaphragm 84 to deform, changing the volume of the pressure chamber 74.

[0148] The head module 40 ejects ink droplets from the nozzle openings 64 via the nozzle communication passages 76 in response to pressure changes that accompany changes in the volume of the pressure chambers 74. Note that image data may also be referred to as print data or original print data.

[0149] The pressure chambers 74 corresponding to the respective nozzle openings 64 have a roughly square planar shape, with an outlet to the nozzle opening 64 located at one of the diagonal corners and an individual supply path 72 serving as an ink inlet located at the other. The shape of the pressure chamber is not limited to a square. The planar shape of the pressure chamber can be a variety of shapes, such as a rhombus, a quadrangle such as a rectangle, a pentagon, a hexagon, other polygons, a circle, or an ellipse.

[0150] A circulation outlet 96 is formed in the nozzle communication path 76. The nozzle communication path 76 is connected to the individual circulation flow path 78 via the circulation outlet 96. Of the ink held in the nozzles 62, ink that is not used for ejection is collected into the common circulation flow path 80 via the individual circulation flow path 78.

[0151] 5. The ink is collected into the common circulation flow path 80 via the individual circulation flow paths 78. This prevents the ink held in the nozzles 62 from becoming thicker during non-ejection periods.

[0152] 7 illustrates an example of a piezoelectric element 82 having a structure in which the piezoelectric element 82 is separated into individual elements corresponding to the plurality of nozzles 62. Of course, a structure in which a piezoelectric layer 92 is integrally formed for the plurality of nozzles 62, an individual electrode is formed for each of the plurality of nozzles 62, and an active region is formed for each nozzle 62 may also be applied.

[0153] [Flowchart of print control method according to first embodiment] Figure 8 is a flowchart showing the steps of the print control method according to the first embodiment. In the print mode setting step S10, the print mode setting unit 140 shown in Figure 2 sets the first print mode or the second print mode. The print mode setting unit 140 may obtain print mode information input by the user using the input device 214 shown in Figure 3, and set the print mode based on the obtained print mode information.

[0154] The print mode setting unit 140 may set the first print mode when a single-sided print mode in which an image is printed on only one side of the paper is set, and may set the second print mode when a double-sided print mode in which an image is printed on both one side and the other side of the paper is set. Once a print mode is set in the print mode setting step S10, the process proceeds to a print mode determination step S12.

[0155] In the print mode determination step S12, the drive waveform setting unit 114 determines whether the first print mode or the second print mode is set. If the drive waveform setting unit 114 determines that the second print mode is set in the print mode determination step S12, the determination is No. If the determination is No, the process proceeds to the second print mode ejection rate setting step S14.

[0156] In the second print mode ejection volume setting step S14, the drive waveform setting unit 114 sets the ejection volume of the single-liquid ink to be applied to the second print mode. Once the ejection volume of the single-liquid ink has been set in the second print mode ejection volume setting step S14, the process proceeds to the drive waveform setting step S18. Note that the single-liquid ink described in the embodiment is an example of a second ink that does not contain a component that reacts with the pretreatment liquid.

[0157] On the other hand, if the drive waveform setting unit 114 determines that the first print mode is set in the print mode determination step S12, the determination is Yes. If the determination is Yes, the process proceeds to the first print mode ejection rate setting step S16.

[0158] In the first-printing-mode ejection-volume setting step S16, the drive waveform setting unit 114 sets the ejection volumes of the two-liquid inks to be applied to the first printing mode. Once the ejection volumes of the two-liquid inks have been set in the first-printing-mode ejection-volume setting step S16, the process proceeds to the drive waveform setting step S18. The two-liquid ink described in the embodiment is an example of a first ink that has the property of thickening upon reaction with the pretreatment liquid.

[0159] In the drive waveform setting step S18, the drive waveform setting unit 114 sets a drive waveform based on the ink ejection amount set in the second print mode ejection amount setting step S14 or the ink ejection amount set in the first print mode ejection amount setting step S16. Once the drive waveform has been set in the drive waveform setting step S18, the process proceeds to the print execution step S20.

[0160] In the print execution step S20, the drive voltage generation unit 112 applies the dot size for each print pixel and the ejection timing for each nozzle that are specified based on the print data, and applies the drive waveform set in the drive waveform setting step S18 to supply a drive voltage to each nozzle to execute printing. When printing starts in the print execution step S20, the process proceeds to the print completion determination step S22.

[0161] In the print end determination step S22, the print control unit 106 determines whether a predetermined print end condition is met during printing. Examples of the predetermined print end condition include completion of a predetermined number of prints, completion of a predetermined print job, and acquisition of a print end command.

[0162] In the print end determination step S22, if the print control unit 106 determines that the specified print end condition is not satisfied, the determination is No. If the determination is No, the determination of the print end condition continues until the determination is Yes in the print end determination step S22.

[0163] On the other hand, if the print control unit 106 determines that the specified print end condition is met in the print end determination step S22, the result is Yes. If the determination is Yes, the print control unit 106 executes the specified print end process and ends printing.

[0164] [Detailed Description of Printing Condition Settings for Each Print Mode] Figure 9 is a table showing parameter settings for each print mode applied to the printing system according to the first embodiment. The table shown in the figure includes an image quality evaluation and a conveyance evaluation for each print mode. In the table, dip is the unit of print resolution, i.e., dots per inch. Furthermore, sph is the unit of conveyance speed, i.e., sheets per hour, which represents the number of sheets printed per hour. In the Maximum Ink Ejection Applicable column, "type" and "less than type" indicate that the amount of ink ejected from one nozzle in one ejection cycle is less in the second print mode than in the first print mode.

[0165] The A and B in the image quality column represent the relative difference in image quality. The image quality was evaluated under the conditions of a resolution of 1200 x 1200 dots per inch and a conveying speed of 3600 sheets per hour.

[0166] Image quality evaluation A indicates that the image quality is better than image quality evaluation B. Also, A and B in the transportability column in the table in the same figure indicate relative differences in transportability. Transportability evaluation A indicates that the transportability is better than transportability evaluation B.

[0167] [Specific Example of Drive Waveform] Figure 10 is a schematic diagram showing the first drive waveform applied to the first print mode. Figure 10 shows the drive waveform in a graphical format. The horizontal axis of the graph shown in the figure represents time in seconds. The vertical axis represents voltage in volts. The voltage of the drive waveform is synonymous with the amplitude of the drive waveform.

[0168] V0 represents the reference potential. The reference potential V0 is the potential of the drive waveform that realizes a static meniscus. V p1 , V p2 and V p3 and represent the peak potentials. p1 , peak potential V p2 and peak potential V p3 Collectively, the peak potential V p It is sometimes referred to as.

[0169] The first drive waveform 300 draws the static meniscus into the nozzle, and maintains the state in which the meniscus is drawn into the nozzle for a certain period of time, thereby operating the piezoelectric element to push ink out of the nozzle and eject the ink.

[0170] The first drive waveform 300 includes a plurality of pulse waveforms, namely, a first pulse 302, a second pulse 304, a third pulse 306, a fourth pulse 308, a fifth pulse 310, and a sixth pulse 312. The first drive waveform 300 also includes a settling pulse 314 that sets the meniscus in a static state.

[0171] The first drive waveform 300 realizes ejection volumes corresponding to three types of droplet sizes called large droplets, medium droplets, and small droplets. Large droplets have a larger ejection volume than medium and small droplets. Medium droplets have a smaller ejection volume than large droplets and a larger ejection volume than small droplets. Small droplets have a smaller ejection volume than large and medium droplets.

[0172] If small droplets are formed, the sixth pulse 312 is applied. If medium droplets are formed, the third pulse 306, the fourth pulse 308, the fifth pulse 310, and the sixth pulse 312 are applied. If large droplets are formed, all pulses from the first pulse 302 through the sixth pulse 312 are applied. The settling pulse 314 is applied to large, medium, and small droplets.

[0173] That is, the enable signal that defines the ejection timing for each nozzle selects the sixth pulse 312 and the settling pulse 314 when small droplets are formed. Similarly, the enable signal that selects the third pulse 306, the fourth pulse 308, the fifth pulse 310, the sixth pulse 312, and the settling pulse 314 when medium droplets are formed. The enable signal that selects the first pulse 302 through the settling pulse 314 when large droplets are formed.

[0174] 11 is a schematic diagram showing a first example of a second drive waveform 320 applied to the second print mode. The second drive waveform 320 according to the first example includes an eleventh pulse 322, a twelfth pulse 324, a thirteenth pulse 326, a fourteenth pulse 328, a fifteenth pulse 330, a sixteenth pulse 332, and a settling pulse 314.

[0175] The eleventh pulse 322 has a reference potential V0 to a peak potential V p11 The voltage from the reference potential V to the peak potential V in the first pulse 302 shown in FIG. p1 The voltage of the 12th pulse 324 from the reference potential V to the peak potential V p11 The voltage from the reference potential V to the peak potential V p1 This is 25 percent lower than the voltage up to

[0176] The 13th pulse 326 has a reference potential V0 to a peak potential V p12 The voltage from the reference potential V to the peak potential V p2 The peak potential V of the fourteenth pulse 328 from the reference potential V is reduced by 25 percent compared to the voltage up to the reference potential V. p13 The voltage from the reference potential V to the peak potential V p3 This is 25 percent lower than the voltage up to

[0177] The peak potential V of the 15th pulse 330 from the reference potential V p13 The voltage from the reference potential V to the peak potential V p3 The peak potential V of the 16th pulse 332 from the reference potential V is 25 percent smaller than the voltage up to the p14 The voltage from the reference potential V to the peak potential V p3 This is 25 percent lower than the voltage up to

[0178] The selection of pulses corresponding to large, medium, and small droplets in the second drive waveform 320 is the same as that in the first drive waveform 300 shown in Figure 10. Also, the settling pulse 314 in the second drive waveform 320 is the same as the settling pulse 314 in the first drive waveform 300. In Figure 11, the first pulse 302 to the sixth pulse 312 are each illustrated using dashed lines.

[0179] When the second drive waveform 320 shown in Fig. 11 is applied, the ink ejection volume is reduced by 25 percent for each of large droplets, medium droplets, and small droplets compared to when the first drive waveform 300 is applied. The reduction ratio of the ink ejection volume described above can be calculated from the area ratio between the first drive waveform 300 in Fig. 10 and the second drive waveform 320 shown in Fig. 11. The reduction ratio of the ink ejection volume can be determined as appropriate within a range that does not change the droplet size.

[0180] 12 is a schematic diagram showing a second example of the second drive waveform applied to the second print mode. In the second example, the second pulse 304 and the fourth pulse 308 are omitted in the second drive waveform 340 compared to the first drive waveform 300 shown in FIG. 10, and the number of pulses when medium and large droplets are formed is reduced compared to the first print mode.

[0181] That is, when large droplets are formed, the first pulse 302, the third pulse 306, the fifth pulse 310, the sixth pulse 312, and the settling pulse 314 are applied, when medium droplets are formed, the third pulse 306, the fifth pulse 310, the sixth pulse 312, and the settling pulse 314 are applied, and when small droplets are formed, the sixth pulse 312 and the settling pulse 314 are applied.

[0182] When the second drive waveform 340 shown in FIG. 12 is applied, the ink ejection volume is reduced by approximately 33 percent when large droplets are formed and by approximately 25 percent when medium droplets are formed, compared to when the first drive waveform 300 is applied.

[0183] The ink ejection volume when small droplets are formed by applying the second drive waveform 340 is the same as the ink ejection volume when small droplets are formed by applying the first drive waveform 300. Even when small droplets are formed by reducing the voltage of the sixth pulse 312, as with the sixteenth pulse 332 shown in FIG. 11 , the ink ejection volume may be reduced compared to the first print mode. In FIG. 12 , the second pulse 304 and the fourth pulse 308 are illustrated using dashed lines. The reduction in the number of pulses in the second drive waveform 340 can be determined as appropriate, as long as the droplet size is not changed.

[0184] 13 is a schematic diagram showing a third example of a second drive waveform applied to the second print mode. Compared to the first drive waveform 300 shown in FIG. 10 , the second drive waveform 360 according to the third example includes a 22nd pulse 364 instead of the 2nd pulse 304, and a 24th pulse 368 instead of the 4th pulse 308. The second drive waveform 360 also includes a 25th pulse 370 instead of the 5th pulse 310, and a 26th pulse 372 instead of the 6th pulse 312.

[0185] The 22nd pulse 364 changes from the reference potential V0 to the peak potential V p1 The slope representing the change in voltage from the reference potential V to the peak potential V is made smaller. p1 The slope and peak potential V p1 The gradient of the change from the first pulse 304 to the reference potential V0 is made smaller than that of the second pulse 304.

[0186] The 24th pulse 368 is a pulse that changes from the reference potential V to the peak potential V p2 The slope of the change to the fourth pulse 308 is the same as that of the fourth pulse 308, and the peak potential V p2 The gradient of the change from the fourth pulse 308 to the reference potential V0 is made smaller than that of the fourth pulse 308.

[0187] The 25th pulse 370 is a pulse that changes from the reference potential V to the peak potential V p3 The slope of the change to the peak potential V p3 The gradient of the change from the potential V to the reference potential V is the same as that of the fifth pulse 310.

[0188] The 26th pulse 372 is a pulse that changes from the reference potential V to the peak potential V p3 The slope of the change to the peak potential V p3 The gradient of the change from the sixth pulse 312 to the reference potential V0 is smaller than that of the sixth pulse 312.

[0189] That is, when the gradient of the first drive waveform 300 is reduced from the first pulse 302 to the sixth pulse 312, the potential V is reduced from the reference potential V to the peak potential V. p The slope and peak potential V pAt least one of the gradients of the change from the potential V0 to the reference potential V0 is reduced.

[0190] 13 is applied, the ink ejection volume is reduced by approximately 20 percent when large droplets are formed, approximately 27 percent when medium droplets are formed, and approximately 17 percent when small droplets are formed, compared to when the first drive waveform 300 is applied. Note that in Figure 13, the second pulse 304, fourth pulse 308, fifth pulse 310, and sixth pulse 312 are illustrated using dashed lines. The slope of the second drive waveform 360 can be changed as appropriate, as long as the droplet size is not changed.

[0191] [Example of Application to a Print Control Device] A print control device may be configured using some of the components of the printing system 10 shown in Figures 2 and 3. For example, a computer may be applied as hardware using some of the components of the printing system 10 to configure a print control device including the system control unit 100, print control unit 106, memory 120, print mode setting unit 140, etc. shown in Figure 2.

[0192] [Operational Effects of First Embodiment] The printing system 10 and the printing control method according to the first embodiment can achieve the following operational effects.

[0193] [1] In the first printing mode, in which a precoat liquid is used, the first driving waveform 300 is applied, and in the second printing mode, in which a precoat liquid is not used, the second driving waveform 320, etc. is applied. When the second driving waveform 320 is applied, the maximum ejection amount of ink ejected from one nozzle in one ejection cycle is reduced compared to when the first driving waveform 300 is applied.

[0194] This allows optimization of the ink ejection amount in the first printing mode and the second printing mode. Furthermore, as a result of optimizing the ink ejection amount, a consistent quality of the printed image is ensured, which can contribute to cost reduction.

[0195] [2] The second driving waveform 320 has a potential difference from the reference potential V to the peak potential V compared to the first driving waveform 300. pAs a result, when the second drive waveform 320 is applied, the maximum ejection amount of ink ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform 300 is applied.

[0196] [3] The second drive waveform 340 lacks the second pulse 304 and fourth pulse 308 that constitute the first drive waveform 300, and a smaller number of pulses is applied compared to the first drive waveform 300. As a result, when the second drive waveform 340 is applied, the maximum amount of ink ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform 300 is applied.

[0197] [4] The second driving waveform 360 has a lower reference potential V0 and a lower peak potential V1 per unit time than the first driving waveform 300. p As a result, when the second drive waveform 340 is applied, the maximum amount of ink ejected from one nozzle in one ejection cycle can be reduced compared to when the first drive waveform 300 is applied.

[0198] [5] When multiple droplet sizes are used as droplet sizes to be ejected from one nozzle in one ejection cycle, the ejection volume of each droplet size is reduced in the second print mode compared to the first print mode, thereby optimizing the ink ejection volume for each droplet size.

[0199] [Configuration example of printing system according to second embodiment] [Problem] The drying strength required to dry paper on which an image has been printed differs between a first printing mode in which a precoat liquid is used and a second printing mode in which a precoat liquid is not used. When switching between the first printing mode and the second printing mode, it is necessary to switch the drying performance of the drying device without delaying the timing of the print mode switch.

[0200] The image forming apparatus described in Japanese Patent No. 4655697 reduces the amount of treatment liquid ejected onto the front side compared to the amount of treatment liquid ejected onto the back side in double-sided printing mode, but does not optimize drying strength.

[0201] The inkjet printing device described in Japanese Patent Laid-Open No. 2021-054623, cited as Patent Document 1, reduces the amount of cooling air when applying treatment liquid compared to when applying treatment liquid to thin coated paper. This allows the inkjet printing device described in this document to reduce power consumption. However, with the inkjet printing device described in this document, deformation of the paper due to insufficient drying can hinder paper transport.

[0202] The printing system according to the second embodiment realizes an optimal drying process in both the first printing mode in which a precoat liquid is used and the second printing mode in which a precoat liquid is not used.

[0203] [Overview] The printing system according to the second embodiment has the same overall configuration as the printing system 10 according to the first embodiment shown in Fig. 1. In the printing system according to the second embodiment, the drying performance of the drying device 18 is switched depending on the printing mode. Details are described below.

[0204] [Electrical configuration of printing system] Figure 14 is a functional block diagram showing the electrical configuration of a printing system according to the second embodiment. The printing system 10A shown in the figure is equipped with a memory 120A instead of the memory 120 in the printing system 10 shown in Figure 2. The memory 120A includes a drying condition table storage unit 126 in which a plurality of drying condition tables 126A are stored.

[0205] In the second printing mode, in which precoat liquid is not used, the amount of liquid applied to the paper is reduced by the amount of precoat liquid applied compared to the first printing mode, in which precoat liquid is used. Also, in the second printing mode, the amount of ink ejected is reduced compared to the first printing mode. As a result, less energy is required to dry the paper in the second printing mode compared to the first printing mode.

[0206] Therefore, when the second printing mode is set, the printing system 10A applies a second drying intensity that is lower than the first drying intensity of the first printing mode.

[0207] Specifically, the drying temperature applied in the second printing mode is lowered relative to the drying temperature applied in the first printing mode. It has been found that even if the drying temperature applied in the second printing mode is lowered by 20°C from the drying temperature applied in the first printing mode, images printed on paper can have sufficient image quality. For example, if the drying temperature corresponding to the first drying intensity is 100°C, the drying temperature corresponding to the second drying intensity may be 80°C. In other words, the reduction ratio of the second drying intensity relative to the first drying intensity may be 20 percent.

[0208] In the second printing mode, the drying temperature is lowered compared to the first printing mode, which suppresses deformation of the paper and reduces paper transport problems caused by paper deformation, improving paper transportability. The printing conditions applied to both the first and second printing modes are a paper transport speed of 3600 sheets per hour and a print resolution of 1200 x 1200 dots per inch. Sheets of paper are used.

[0209] The switching of drying conditions, including the drying intensity, is performed by switching the drying condition table 126A stored in memory 120A. That is, the drying control unit 108 acquires information about the printing mode set using the printing mode setting unit 140, and when the first printing mode is performed, it reads out the drying condition table 126A for the first printing mode from the drying condition table storage unit 126. On the other hand, when the second printing mode is performed, the drying control unit 108 reads out the drying condition table 126A for the second printing mode from the drying condition table storage unit 126.

[0210] The drying strength according to the thickness of the paper is applied to the drying device 18. The drying control unit 108 reads from the memory 120A a drying condition table 126A that defines drying conditions for each thickness of the paper.

[0211] The drying condition table 126A for the first printing mode described in the embodiment is an example of a first drying condition table, and the drying condition table 126A for the second printing mode described in the embodiment is an example of a second drying condition table.

[0212] [Example of Hardware Configuration of Control Device Applied to Printing System] Fig. 15 is a block diagram that schematically shows an example of the hardware configuration of the electrical configuration shown in Fig. 14. The control device 200A shown in Fig. 15 includes a computer-readable medium 204A that stores a drying condition table 126A for each print mode.

[0213] The drying control program 228 reads out the drying condition table 126A corresponding to the print mode, and applies the drying conditions defined in the drying condition table 126A to the drying device 18 shown in FIG. 14 to control the operation of the drying device 18.

[0214] [Flowchart of print control method according to second embodiment] Fig. 16 is a flowchart showing the procedure of the print control method according to second embodiment. The flowchart shown in Fig. 16 adds a second print mode drying condition setting step S15 and a first print mode drying condition setting step S17 to the flowchart shown in Fig. 8.

[0215] Once the ejection volume of the single-liquid ink to be applied to the second print mode has been set in the second print mode ejection volume setting step S14, the process proceeds to the second print mode drying condition setting step S15. In the second print mode drying condition setting step S15, the drying control unit 108 shown in Fig. 15 reads out the drying condition table 126A, which specifies the drying intensity to be applied to the second print mode, from the drying condition table storage unit 126. Once the drying conditions have been set in the second print mode drying condition setting step S15, the process proceeds to the drive waveform setting step S18.

[0216] Furthermore, once the ejection volumes of the two-liquid inks to be applied to the first printing mode have been set in the first printing mode ejection volume setting step S16, the process proceeds to the first printing mode drying condition setting step S17. In the first printing mode drying condition setting step S17, the drying control unit 108 shown in Fig. 15 reads out the drying condition table 126A, which specifies the drying intensity to be applied to the first printing mode, from the drying condition table storage unit 126. Once the drying conditions have been set in the first printing mode drying condition setting step S17, the process proceeds to the drive waveform setting step S18.

[0217] The second print mode drying condition setting step S15 may be performed before the second print mode ejection amount setting step S14, or may be performed after the drive waveform setting step S18 and before the print execution step S20.

[0218] Similarly, the first printing mode drying condition setting process S17 may be performed before the first printing mode ejection volume setting process S16, or may be performed after the drive waveform setting process S18 and before the print execution process S20.

[0219] [Detailed Description of Printing Condition Settings for Each Print Mode] Fig. 17 is a table showing parameter settings for each print mode applied to the printing system according to the second embodiment. The table shown in Fig. 17 has a drying strength column added to the table shown in Fig. 9.

[0220] The drying strength column describes the relative relationship between the drying strength applied to the first printing mode and the drying strength applied to the second printing mode. That is, a relatively strong drying strength is applied to the first printing mode, while a relatively weak drying strength is applied to the second printing mode. In this embodiment, a 20% reduction ratio of the second drying strength relative to the first drying strength is illustrated, but the reduction ratio of the drying strength can be appropriately specified based on printing conditions such as the type of paper and the type of ink. For example, the reduction ratio of the drying strength can be greater than 0% and less than 50%.

[0221] [Operational Effects of Second Embodiment] The printing system 10A and the printing control method according to the second embodiment can achieve the following operational effects.

[0222] [1] In the second printing mode, which does not use precoat liquid, a lower drying intensity is applied compared to the first printing mode, which uses precoat liquid, and drying processes appropriate for each of the first and second printing modes are performed. This achieves a specified dry state for the paper and achieves favorable paper transport due to suppression of paper deformation. It also ensures consistent quality in printed images and can contribute to cost reduction.

[0223] [2] The drying intensity in the first printing mode and the drying intensity in the second printing mode are switched by switching the drying condition table in which the drying intensity is defined, thereby optimizing the drying process based on the predetermined drying intensity.

[0224] [Terminology] The term printing device is synonymous with terms such as printing press, printer, printing device, image recording device, image forming device, image output device, and drawing device. The term image should be interpreted in a broad sense, and also includes color images, black and white images, single color images, gradation images, and uniform density images.

[0225] The term printing includes concepts of terms such as image recording, image formation, printing, drawing, and printing. The term apparatus may include concepts of a system.

[0226] The term "image" is used as a comprehensive term that includes not only photographic images but also designs, characters, symbols, line drawings, mosaic patterns, colored patterns, and various other patterns, as well as appropriate combinations of these. The term "image" may also include the meaning of image signals and image data that represent an image.

[0227] The above-described embodiments of the present invention may be modified, added, or deleted as appropriate without departing from the spirit of the present invention. The present invention is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present invention by those skilled in the art.

[0228] REFERENCE SIGNS LIST 10 Printing system 10A Printing system 12 Paper feeder 14 Precoater 16 Printing device 18 Drying device 20 Inspection device 22 Stacking device 24 Conveying device 30 Inkjet head 30C Inkjet head 30K Inkjet head 30M Inkjet head 30Y Inkjet head 32 Printing drum 34 Inline sensor 40 Head module 42 Head frame 44 Nozzle surface 46 Dummy plate 48 Flexible substrate 50 Nozzle plate 52 Ink supply chamber 54 Ink circulation chamber 56 Supply-side individual flow path 58 Recovery-side individual flow path 60 Nozzle arrangement section 62 Nozzle 64 Nozzle opening 70 Ink supply path 72 Individual supply path 74 Pressure chamber 76 Nozzle communication path 78 Circulation individual flow path 80 Circulation common flow path 82 Piezoelectric element 84 Vibration plate 86 Flow path structure 88 Adhesive layer 90 Lower electrode 92 Piezoelectric layer 94 Upper electrode 96 Circulation outlet 100 System control unit 102 Transport control unit 104 Precoat control unit 106 Print control unit 108 Drying control unit 109 Inspection control unit 110 Image processing unit 112 Drive voltage generation unit 114 Drive waveform setting unit 120 Memory 120A Memory 122 Drive waveform storage unit 124 Data storage unit 126 Drying condition table storage unit 126A Drying condition table 130 Sensor 140 Print mode setting unit 200 Control device 200A Control device 202 Processor 204 Computer readable medium 204A Computer readable medium 206 Communication interface 208 Input / output interface 210 Bus 214 Input device 216 Display device 220 Transport control program 222 Pre-coat control program 224 Print control program 226 In-line sensor control program 228 Drying control program 230 Inspection control program 232 Image processing program 234 Drive waveform setting program 236 Drive voltage generation program 300 First drive waveform 302 First pulse 304 Second pulse 306 Third pulse 308 Fourth pulse 310 Fifth pulse 312 Sixth pulse 314 Settling pulse 320 Second drive waveform 322 Eleventh pulse 324 Twelfth pulse326 13th pulse 328 14th pulse 330 15th pulse 332 16th pulse 340 Second drive waveform 360 Second drive waveform 364 22nd pulse 368 24th pulse 370 25th pulse 372 26th pulse Steps from S10 to S22 Steps of print control method

Claims

1. A print control device that controls a printing device having an inkjet head with one or more nozzles, one or more processors; One or more memories in which programs to be executed by the one or more processors are stored; Equipped with The one or more processors execute the program, determining whether a first printing mode is in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or whether a second printing mode is in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The droplets in the second driving waveform are ejected in a smaller amount than the droplets in the first driving waveform. Print control device.

2. A print control device that controls a printing device having an inkjet head with one or more nozzles, one or more processors; One or more memories in which programs to be executed by the one or more processors are stored; Equipped with The one or more processors execute the program, determining whether a first printing mode is in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or whether a second printing mode is in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The ejection amount of the droplet in the second driving waveform is set to be equal to the ejection amount of the droplet in the first driving waveform. Print control device.

3. The print control device according to claim 1 , wherein the second drive waveform has a smaller amplitude than the first drive waveform.

4. each of the first driving waveform and the second driving waveform includes a plurality of pulse waveforms; The print control device according to claim 1 , wherein the second drive waveform includes a smaller number of pulse waveforms than the first drive waveform.

5. 3 . The print control device according to claim 1 , wherein the second drive waveform has a smaller change in amplitude per unit time than the first drive waveform.

6. The one or more processors: When applying liquid to both sides of the medium, the second printing mode is applied; The print control device according to claim 1 , wherein the first print mode is applied when the liquid is applied to only one surface of the medium.

7. The one or more processors: a drying device provided in the printing device, wherein when controlling the drying device that performs a drying process on a medium onto which liquid ejected from the inkjet head is applied, a first drying intensity is applied as a drying intensity when it is determined that the printing mode is the first printing mode, and a second drying intensity is applied as a drying intensity when it is determined that the printing mode is the second printing mode; The print control device according to claim 1 , wherein the second drying strength is lower than the first drying strength.

8. The one or more processors: When the first printing mode is applied, a first drying condition table in which the first drying intensity is defined is read out; The print control device according to claim 7 , wherein when the second print mode is applied, a second drying condition table in which the second drying intensity is defined is read out.

9. A printing control method for controlling a printing device having an inkjet head with one or more nozzles, comprising: determining whether a first printing mode is in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or whether a second printing mode is in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The droplets in the second driving waveform are ejected in a smaller amount than the droplets in the first driving waveform. Printing control method.

10. A printing control method for controlling a printing device having an inkjet head with one or more nozzles, comprising: determining whether a first printing mode is in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or whether a second printing mode is in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The ejection amount of the droplet in the second driving waveform is set to be equal to the ejection amount of the droplet in the first driving waveform. Printing control method.

11. A program for controlling a printing device having an inkjet head with one or more nozzles, On the computer, a function of determining whether the printing mode is a first printing mode in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which the pretreatment liquid is not applied to the medium; a function of setting a first driving waveform as a driving waveform to be applied to the inkjet head when it is determined that the printing mode is the first printing mode, and setting a second driving waveform as a driving waveform to be applied to the inkjet head when it is determined that the printing mode is the second printing mode; and a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set, compared to when the first drive waveform is set; As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The small droplets in the second driving waveform realize a function of performing print control in which an ejection amount of the small droplets is reduced compared to an ejection amount of the small droplets in the first driving waveform. program.

12. A program for controlling a printing device having an inkjet head with one or more nozzles, comprising: On the computer, a function of determining whether the printing mode is a first printing mode in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or a second printing mode in which the pretreatment liquid is not applied to the medium; a function of setting a first driving waveform as a driving waveform to be applied to the inkjet head when it is determined that the printing mode is the first printing mode, and setting a second driving waveform as a driving waveform to be applied to the inkjet head when it is determined that the printing mode is the second printing mode; and a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set, compared to when the first drive waveform is set; As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The droplets in the second driving waveform realize a function of performing print control in which the ejection amount of the droplets is the same as that of the droplets in the first driving waveform. program.

13. A non-transitory computer-readable recording medium having the program according to claim 11 or 12 recorded thereon.

14. an inkjet head having one or more nozzles; a pretreatment liquid application device that applies a pretreatment liquid to a medium; one or more processors; One or more memories in which a program to be executed by the one or more processors is stored; Equipped with The one or more processors execute the program, determining whether the printing mode is a first printing mode in which the pretreatment liquid, which reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid, is applied to the medium, or whether the printing mode is a second printing mode in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The droplets in the second driving waveform are ejected in a smaller amount than the droplets in the first driving waveform. Printing system.

15. An inkjet head having one or more nozzles; a pretreatment liquid application device that applies a pretreatment liquid to a medium; one or more processors; One or more memories in which programs to be executed by the one or more processors are stored; Equipped with The one or more processors execute the program, determining whether a first printing mode is in which a pretreatment liquid that reacts with the liquid ejected from the inkjet head to relatively increase the viscosity of the liquid is applied to the medium, or whether a second printing mode is in which the pretreatment liquid is not applied to the medium; when it is determined that the printing mode is the first printing mode, a first driving waveform is set as a driving waveform to be applied to the inkjet head, and when it is determined that the printing mode is the second printing mode, a second driving waveform is set as a driving waveform to be applied to the inkjet head; In a print control in which a maximum liquid ejection amount ejected from one nozzle in one ejection cycle is reduced when the second drive waveform is set compared to when the first drive waveform is set, As the liquid to be discharged from one nozzle, a large droplet, a medium droplet having a smaller discharge amount than the large droplet, or a small droplet having a smaller discharge amount than the medium droplet is selected, The large droplet in the second driving waveform is ejected in a smaller amount than the large droplet in the first driving waveform, The medium droplet in the second driving waveform is ejected in a smaller amount than the medium droplet in the first driving waveform, The ejection amount of the droplet in the second driving waveform is set to be equal to the ejection amount of the droplet in the first driving waveform. Printing system.