JP7740962B2 - Color adjustment device and method, information processing device, program, printing system, and method for manufacturing printed matter - Google Patents

Description

This disclosure relates to color adjustment devices and methods, information processing devices, programs, printing systems, and methods for producing printed materials, and in particular to color adjustment and print control technologies applicable to printing using roll media.

Patent Document 1 describes a method for reproducing the target color by generating a chart on which patches consisting of the device signal value of the color to be adjusted and its surrounding signal values are arranged, printing the chart using a printer, selecting the target color of the color to be adjusted from the printed chart, and replacing the device signal value of the color to be adjusted with the selected digital signal value.

Patent No. 5462756

Color adjustment is required to match the color of printed materials to a color sample. During color adjustment, a color matching chart is printed and the amount of adjustment is determined by measuring or visually inspecting the chart. Typically, a few sheets of such color adjustment charts are sufficient, so printing the chart on a printing device that uses roll paper results in a much larger amount of paper waste than the printed chart. In particular, when printing a small number of copies on roll paper using a large printing device with a long paper transport path from the unwinding section to the winding section, the amount of paper waste can be greater than the number of printed copies, and the challenge is how to reduce this paper waste.

This disclosure has been made in light of these circumstances, and aims to provide a color adjustment device and method, an information processing device, a program, a printing system, and a method for manufacturing printed matter that can reduce paper waste resulting from printing a color adjustment chart when printing on roll media.

A color adjustment device according to one aspect of the present disclosure includes a processor and a storage device storing instructions executed by the processor. When printing images to be printed for multiple print jobs on roll media, the processor generates a color adjustment chart used for adjustments to reproduce a specific target color specified in the image data of a second print job that is printed later than a first print job among the multiple print jobs, merges the chart image data of the color adjustment chart with the image data of the first print job, prints the images to be printed for the first print job and the color adjustment chart by executing the first print job, and sets an image signal value corresponding to the target color based on the colorimetric results obtained by measuring the printout of the color adjustment chart.

With this color adjustment device, the color adjustment chart used to adjust the reproduction of specific target colors when printing the image to be printed for the second print job is combined with the image data of the first print job, which precedes the second print job by one or more print jobs, and is printed as part of the image data for the first print job. This allows for continuous printing (continuous printing) as a series of printing operations that includes printing the image to be printed for the first print job and printing the color adjustment chart for the second print job, thereby reducing paper waste associated with printing the color adjustment chart.

In a color adjustment device according to another aspect of the present disclosure, the color adjustment chart may include color patches for multiple image signal values, including a first image signal value that is a candidate image signal value corresponding to the target color, and a second image signal value that is another candidate that indicates a color surrounding the first image signal value.

In a color adjustment device according to another aspect of the present disclosure, the color adjustment chart may include a chart pattern in which multiple color patches are arranged two-dimensionally.

In a color adjustment device according to another aspect of the present disclosure, the second print job may be printed next after the first print job.

In a color adjustment device according to another aspect of the present disclosure, the chart image data may be printed immediately following the image data to be last printed in the first print job.

In a color adjustment device according to another aspect of the present disclosure, the color adjustment chart may include single-color color patches of colorants used in the printing device, and the processor may be configured to check the color reproducibility of the printing device based on the color measurement results of the single-color color patches.

The phrase "check color reproducibility" includes the concepts of evaluating color reproducibility and judging color reproducibility. "Monochrome" includes the concept of primary colors.

In a color adjustment device according to another aspect of the present disclosure, multiple color patches of the same color may be arranged at different positions on the surface of a color adjustment chart, and the processor may be configured to check the color uniformity within the printing area of the printing device based on the color measurement results of the multiple color patches of the same color.

"Color patches of the same color" means color patches in which the image signal values defining the color of the color patches are the same.

In a color adjustment device according to another aspect of the present disclosure, when two or more second print jobs are combined into one continuous print run to print the images to be printed for two or more second print jobs, the processor may be configured to combine chart image data of multiple color adjustment charts used to adjust the reproduction of each of the multiple target colors used in the two or more second print jobs into the image data of the first print job.

A color adjustment device according to another aspect of the present disclosure may be configured to include a spot color information database that stores data on image signal values corresponding to target colors, and the processor may be configured to modify the data in the spot color information database based on the color measurement results of the color adjustment chart.

In a color adjustment device according to another aspect of the present disclosure, the processor may be configured to print the image to be printed in the second print job using image signal values set based on the color measurement results of the color adjustment chart.

In a color adjustment device according to another aspect of the present disclosure, the image signal value corresponding to the target color may be a combination of signal values for each of multiple colors, including cyan, magenta, and yellow, used in the printing device.

A color adjustment method according to another aspect of the present disclosure is a color adjustment method executed by a processor when printing images to be printed for multiple print jobs on roll media, and includes the steps of: generating a color adjustment chart used for adjustments to reproduce a specific target color specified in the image data of a second print job, which is printed later than a first print job among the multiple print jobs; merging the chart image data of the color adjustment chart with the image data of the first print job; executing the first print job to cause a printing device to print the chart image data by including it in the image data to be printed for the first print job; and setting an image signal value corresponding to the target color based on the colorimetric results obtained by measuring the printout of the color adjustment chart.

An information processing device according to another aspect of the present disclosure is an information processing device that controls a printing device that prints on roll media, and includes a processor and a storage device that stores instructions executed by the processor. The processor accepts multiple print jobs, sets the printing order for the multiple print jobs, generates a color adjustment chart used to adjust the reproduction of a specific target color specified in the image data of a second print job that is printed later than a first print job among the multiple print jobs, merges the chart image data of the color adjustment chart with the image data of the first print job, prints the image to be printed for the first print job and the color adjustment chart by executing the first print job, measures the printout of the color adjustment chart to obtain colorimetric results, sets image signal values corresponding to the target color based on the colorimetric results, and prints the image to be printed for the second print job using the image signal values set for the target color based on the colorimetric results.

A printing system according to another aspect of the present disclosure includes a printing device that prints on roll media and an information processing device that controls the printing device. The information processing device has a processor and a storage device that stores instructions executed by the processor. The processor accepts multiple print jobs, sets the printing order for the multiple print jobs, generates a color adjustment chart used to adjust the reproduction of a specific target color specified in the image data of a second print job that is printed later than a first print job among the multiple print jobs, merges the chart image data of the color adjustment chart with the image data of the first print job, executes the first print job, causes the printing device to print the image to be printed for the first print job and the color adjustment chart, measures the printout of the color adjustment chart to obtain colorimetric results, sets image signal values corresponding to the target color based on the colorimetric results, and causes the printing device to print the image to be printed for the second print job using the image signal values set for the target color based on the colorimetric results.

A printing system according to another aspect of the present disclosure may be configured to include a colorimeter that measures the color of a printed copy of the color adjustment chart.

A printing system according to another aspect of the present disclosure may be configured to include a movement mechanism for moving the colorimeter, and the processor may control the movement mechanism to move the color measurement position of the colorimeter based on position information of the color patches included in the color adjustment chart, and automatically obtain color measurement results for each color patch on the color adjustment chart.

In a printing system according to another aspect of the present disclosure, the printing device may be an inkjet printer equipped with inkjet heads that eject inks of the colors cyan, magenta, yellow, and black.

A program according to another aspect of the present disclosure is a program that causes a computer to implement color adjustment functions for a printing device. When printing images to be printed for multiple print jobs on roll media, the program causes the computer to implement the following functions: generate a color adjustment chart used to adjust the reproduction of a specific target color specified in the image data of a second print job that is printed later than a first print job among the multiple print jobs; merge the chart image data of the color adjustment chart with the image data of the first print job; print the images to be printed for the first print job and the color adjustment chart by executing the first print job; and set image signal values corresponding to the target color based on the colorimetric results obtained by measuring the printout of the color adjustment chart.

A method for producing printed matter according to another aspect of the present disclosure is a method for producing printed matter using a printing device that prints on roll media, and includes the steps of: an information processing device accepting multiple print jobs and setting a printing order for the multiple print jobs; the information processing device generating a color adjustment chart used to adjust the reproduction of a specific target color specified in the image data of a second print job that is printed later than a first print job among the multiple print jobs; the information processing device merging chart image data of the color adjustment chart with the image data of the first print job; executing the first print job, causing the printing device to print the image to be printed for the first print job and the color adjustment chart; measuring the printout of the color adjustment chart using a colorimeter; the information processing device acquiring the colorimetric results of the printout of the color adjustment chart and setting image signal values corresponding to the target color based on the colorimetric results; and printing the image to be printed for the second print job using the image signal values set for the target color based on the colorimetric results.

This disclosure makes it possible to reduce paper waste resulting from printing color adjustment charts when printing on roll media.

FIG. 1 is a diagram showing the overall configuration of an example of a roll-type inkjet printer. FIG. 2 is an explanatory diagram that schematically shows the order of printing including color adjustment when a color adjustment method according to a comparative example is applied. FIG. 3 is an explanatory diagram that schematically shows the order of printing including color adjustment when the color adjustment method according to the embodiment is applied. FIG. 4 is an explanatory diagram showing an example of the contents of a PDF (Portable Document Format) file as image data to be printed. FIG. 5 is an explanatory diagram showing an example of spot color data in a PDF file. FIG. 6 is an explanatory diagram showing an example of color profile data. FIG. 7 shows an example of a screen for checking the status of a registered job, which is displayed on the screen of a printer controller connected to an inkjet printing machine. FIG. 8 is a functional block diagram showing the functional configuration of an information processing apparatus functioning as a printer controller. FIG. 9 is an explanatory diagram showing the flow of the spot color adjustment chart pattern generation and printing process. FIG. 10 is a conceptual diagram of the spot color adjustment chart pattern generation process. FIG. 11 is an explanatory diagram showing the flow of the spot color adjustment chart measurement and spot color information correction process. FIG. 12 is a schematic diagram showing an outline of an automatic color measurement system provided in an inkjet printing machine. FIG. 13 is a conceptual diagram of the cubic interpolation calculation. FIG. 14 is an explanatory diagram showing the flow of printing processing of image data after spot color information correction. FIG. 15 is a block diagram showing an example of the hardware configuration of an information processing device that functions as a printer controller for an inkjet printing machine. FIG. 16 is a flowchart showing an example of a print job registration process in the printing system according to the embodiment. FIG. 17 is a flowchart showing an example of a printing process in the printing system according to the embodiment. FIG. 18 is a flowchart showing an example of chart measurement and spot color information correction processing in the printing system according to this embodiment. FIG. 19 is a flowchart showing an example of printing processing for a job image after spot color information correction in the printing system according to this embodiment. FIG. 20 is a functional block diagram showing the configuration of a control system of a printing system according to an embodiment. FIG. 21 is a flowchart of a method for producing a printed matter using the printing system according to the embodiment.

A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

<<Outline of printing methods using roll paper>>
Paper used in printing devices comes in two forms: sheet paper and roll paper. Sheet paper is paper cut to a specified size and is also called sheet paper. Roll paper is paper that is very long in one direction and is rolled up into a roll, also called continuous paper. Printing machines that use roll paper are relatively large. The roll paper is loaded into the paper loading slot, fed through the machine's paper transport path, and then wound around the roll at the discharge end, transporting the roll paper as it is printed. This roll-to-roll transport system offers the advantage of allowing for flexible print size adjustments, since the cut size in the paper feed direction can be freely changed. However, because paper must continue to be fed into the machine until the printed product is discharged, the paper in the section of the paper transport path between the imaging unit and the discharge outlet is wasted (waste paper).

Note that although "paper" is used here, the material of the recording medium used for printing is not limited to paper, and can be a variety of materials other than paper, such as resin film, cloth, or nonwoven fabric. It is clear that the terms "paper" or "paper" can be understood as a term that broadly encompasses the concept of "medium," such as recording media or substrate, regardless of material. The same applies to the term "waste paper," which includes the concept of substrate (medium) that is wasted. Furthermore, the roll-to-roll transport method is synonymous with the web transport method, and roll-type medium is synonymous with web-type medium.

<<Inkjet printer configuration example>>
FIG. 1 is an overall configuration diagram showing an example of a roll-type inkjet printer 10. The inkjet printer 10 is a digital printing device that prints an image on a web-like substrate 1 using a single-pass method. The substrate 1 may be an impermeable medium, such as a transparent resin film substrate used in flexible packaging. Examples of substrates 1 suitable for flexible packaging include ONY (oriented nylon), OPP (oriented polypropylene), and PET (polyethylene terephthalate). The substrate 1 is an example of a "roll medium" in this disclosure. The inkjet printer 10 shown in FIG. 1 produces reverse-printed printed matter in which the printing target is visible from the side opposite the printed surface of the substrate 1.

Note that "impermeable" means that the material is impermeable to the water-based primer and water-based ink described below. "Flexible packaging" refers to packaging made of a material that deforms depending on the shape of the packaged item. "Transparent" means that the visible light transmittance is between 30% and 100%, preferably between 70% and 100%.

The inkjet printing machine 10 includes a conveying section 20, an unwinding section 30, a precoating section 50, a jetting section 80, a main drying section 100, and a winding section 120.

[Transportation section]
The conveying section 20 conveys the substrate 1 along a conveying path from the unwinding section 30 to the winding section 120 .

The unwinding unit 30 includes an unwinding roll 32. The unwinding roll 32 includes a rotatably supported reel (not shown). The substrate 1 before an image is printed is wound in a roll around the reel. On the other hand, the winding unit 120 includes a winding roll 122. The winding roll 122 includes a rotatably supported reel (not shown). One end of the substrate 1 is connected to the reel. The winding roll 122 includes a winding motor (not shown) that rotates the reel.

The conveying section 20 is equipped with a plurality of pass rollers 22 that function as guide rollers. The conveying section 20 conveys the substrate 1 using the plurality of pass rollers 22, a first suction drum 84 that corresponds to the main feed roller, first drive rollers 34 that correspond to the sub-feed rollers, an application roller 54, a second suction drum 86, a third drive roller 106, a fourth drive roller 130, and a take-up roll 122.

Furthermore, the conveying unit 20 detects the conveying tension of the substrate 1 using the first tension pickup roller 23, the second tension pickup roller 24, the third tension pickup roller 25, the fourth tension pickup roller 26, the fifth tension pickup roller 27, and the sixth tension pickup roller 28. The conveying tension is the tensile force that the substrate 1 receives in the direction of travel of the substrate 1.

The conveying unit 20 rotates the first suction drum 84 using a motor (not shown), causing the substrate 1 to unwind from the unwinding roll 32. The conveying unit 20 also rotates the reel of the winding roll 122 using a winding motor, causing the printed substrate 1 to be wound onto the winding roll 122.

The conveying section 20 guides the substrate 1 unwound from the unwinding roll 32 using multiple pass rollers 22, transporting it through the unwinding section 30, pre-coating section 50, jetting section 80, main drying section 100, and winding section 120 in that order.

In this way, the substrate 1 is transported by the transport unit 20 along the transport path from the unwind roll 32 to the take-up roll 122 in a roll-to-roll manner. Note that in this specification, the transport path of the substrate 1 may be simply referred to as the "transport path." Furthermore, the length of the printed surface of the substrate 1 in a direction perpendicular to the direction in which the substrate 1 travels is referred to as the width of the substrate 1. The length of the substrate 1 in a direction perpendicular to the printed surface is referred to as the thickness of the substrate 1.

[Unwinding section]
The unwinding section 30 includes an unwinding roll 32, a first drive roller 34, a second drive roller 36, and a corona treatment section 38. A plurality of pass rollers 22 are arranged on the conveyance path of the unwinding section 30. The substrate 1 unwound from the unwinding roll 32 is guided by the arrangement of the plurality of pass rollers 22 and conveyed to the first drive roller 34.

The first drive roller 34 is rotated by a motor (not shown) and comes into contact with the substrate 1 to transport it. The substrate 1 transported by the first drive roller 34 is then transported to the second drive roller 36. The second drive roller 36 is rotated by a motor (not shown) and comes into contact with the substrate 1 to transport it.

The substrate 1 transported by the second drive roller 36 is transported to a position opposite the corona treatment section 38.

The corona treatment unit 38 is located upstream of the precoat unit 50 on the transport path. The corona treatment unit 38 applies corona discharge treatment to the printing surface of the substrate 1, improving adhesion between the water-repellent printing surface and the water-based primer and water-based ink.

The substrate 1, whose printing surface has been modified by the corona treatment unit 38, is guided by multiple pass rollers 22 and transported to the first tension pickup roller 23. The substrate 1, whose transport tension has been detected by the first tension pickup roller 23, is guided by the pass rollers 22 and transported from the unwinding unit 30 to the pre-coating unit 50.

[Precoat section]
The precoat unit 50 is disposed upstream of the jetting unit 80 in the transport path. The precoat unit 50 applies an aqueous primer to the printing surface of the substrate 1. The aqueous primer is a liquid containing water and a component that aggregates, insolubilizes, or thickens the colorant components in the aqueous ink, and thickens by reacting with the aqueous color ink and aqueous white ink. The amount of aqueous primer applied is approximately 1/10 of the amount of aqueous ink applied by the jetting unit 80. The viscosity of the aqueous primer is, for example, 0.5 cP or more and 5.0 cP or less. 1 cP is equal to 0.001 Pa·s.

The precoat unit 50 includes a coater 52 and a precoat drying unit 58. A plurality of pass rollers 22 are arranged on the conveying path of the precoat unit 50. The substrate 1 conveyed from the unwinding unit 30 is guided by the plurality of pass rollers 22 and conveyed to a position opposite the coater 52.

The coater 52 is a chamber doctor type coater. It comprises an application roller 54, a chamber 55, an opposing roller 56, and a blade (not shown). The application roller 54 is rotated by a motor (not shown). The chamber 55 stores an aqueous primer. The coater 52 supplies the aqueous primer from the chamber 55 to the surface of the rotating application roller 54. The blade scrapes off excess aqueous primer from the surface of the rotating application roller 54. The application roller 54 sandwiches the substrate 1 between itself and the opposing roller 56, and the surface to which the aqueous primer has been supplied is brought into contact with the printed surface of the substrate 1, applying the aqueous primer supplied to the surface to the printed surface of the substrate 1.

The coater 52 is not limited to a chamber doctor type coater, and a direct gravure coater or a kiss reverse coater may also be used.

The substrate 1 coated with the aqueous primer is guided by multiple pass rollers 22 and transported to a position opposite the precoat drying section 58.

The precoat drying unit 58 corresponds to a precoat drying means that dries the aqueous primer applied to the printed surface of the substrate 1 by the precoat unit 50. The precoat drying unit 58 is equipped with a hot air heater (not shown). The hot air heater has two slit nozzles (not shown) that span the entire width of the substrate 1. The precoat drying unit 58 blows hot air from the slit nozzles of the hot air heater toward the printed surface of the substrate 1 to dry the aqueous primer.

The substrate 1 on which the aqueous primer has dried is transported from the precoat section 50 to the jetting section 80.

[Jetting section]
The jetting unit 80 prints an image on the printing surface of the substrate 1. From the viewpoint of maintaining print quality, the jetting unit 80 controls the temperature of the substrate 1 to be between 23° C. and 30° C. The jetting unit 80 includes a first non-contact turn unit 60, a first suction drum 84, a second suction drum 86, a color printing unit 88, a white printing unit 90, and a second non-contact turn unit 92.

The substrate 1 transported from the precoat section 50 is transported to the second tension pickup roller 24. Once the transport tension of the substrate 1 is detected by the second tension pickup roller 24, it is guided by the pass rollers 22 and transported to the first non-contact turn section 60.

The first non-contact turn section 60 changes the direction of the transport path (the direction of travel of the substrate 1) from downward to upward without contacting the printing surface of the substrate 1. In other words, the substrate 1 guided downward by the pass roller 22 is guided upward by the first non-contact turn section 60.

In this specification, "downward" does not necessarily mean a direction directly below, but refers to a direction moving downward from the horizontal. Similarly, "upward" does not necessarily mean a direction directly above, but refers to a direction moving upward from the horizontal.

The first non-contact turn section 60 is constructed using a turn bar that floats the substrate 1 by blowing air. For example, the turn bar may be an air turn bar TBA or TBE manufactured by BELLMATIC Corporation. The air blown out from the turn bar's outlet causes the substrate 1 to float from the turn bar's conveying plate, and the substrate 1 is floated and conveyed without contact with the turn bar. Note that "floating conveying" is synonymous with "floating conveying," "non-contact conveying," and "air float conveying."

The first non-contact turning section 60 lifts the substrate 1 from the conveying plate by a predetermined lift amount (a predetermined distance from the blowing surface), turning the direction of the conveying path of the substrate 1 180 degrees from downward to upward. In this embodiment, the first non-contact turning section 60 turns the direction of the conveying path 180 degrees, but the change in direction of the conveying path is not limited to 180 degrees, as long as the direction of travel before and after the turn is changed from downward to upward.

The substrate 1 turned by the first non-contact turning section 60 is transported to the first suction drum 84.

The first suction drum 84 is positioned upstream of the color printing unit 88 and the white printing unit 90 on the conveying path.

The first suction drum 84 is rotated by a motor (not shown) and transports the substrate 1 by adsorbing it to its outer circumferential surface. The first suction drum 84 has multiple suction holes (not shown) on its outer circumferential surface. The first suction drum 84 adsorbs the substrate 1 to its outer circumferential surface by suctioning the suction holes with a pump (not shown).

The substrate 1 transported by the first suction drum 84 is supported and guided by path rollers 22, 22, ... arranged at regular intervals along the transport path, and is transported to the third tension pickup roller 25. The substrate 1, whose transport tension has been detected by the third tension pickup roller 25, is transported to the second suction drum 86.

The second suction drum 86 is positioned downstream of the color printing unit 88 and the white printing unit 90 on the transport path and upstream of the main drying unit 100 on the transport path. The second suction drum 86 is rotated by a motor (not shown) and transports the substrate 1 by suction onto its outer circumferential surface. The configuration of the second suction drum 86 is similar to that of the first suction drum 84.

A color printing unit 88, a white printing unit 90, and an inspection unit 97 are located on the transport path between the first suction drum 84 and the second suction drum 86. That is, the first suction drum 84 and the second suction drum 86 are located before and after the color printing unit 88, the white printing unit 90, and the inspection unit 97. The reason the first suction drum 84 and the second suction drum 86 are located before and after the color printing unit 88, the white printing unit 90, and the inspection unit 97 is to set transport tension on the substrate 1 without contacting the printed surface of the substrate 1.

The substrate 1 transported from the first suction drum 84 is transported to a position facing the color printing unit 88. The color printing unit 88 applies water-based color ink to the printing surface of the substrate 1 to print a color image. The color printing unit 88 is equipped with inkjet heads 96K, 96C, 96M, and 96Y.

Inkjet heads 96K, 96C, 96M, and 96Y eject water-based inks of black (K), cyan (C), magenta (M), and yellow (Y), respectively. Water-based ink refers to ink in which coloring materials such as dyes and pigments are dissolved or dispersed in water and a water-soluble solvent. Organic pigments are used as the pigments for each water-based ink. The viscosity of each water-based ink is 0.5 cP or more and 5.0 cP or less. Water-based ink is supplied to each of inkjet heads 96K, 96C, 96M, and 96Y from an ink tank of the corresponding color (not shown) via a piping path (not shown).

Inkjet heads 96K, 96C, 96M, and 96Y are each composed of a line-type recording head capable of printing in a single scan on substrate 1 transported by transport unit 20. Inkjet heads 96K, 96C, 96M, and 96Y are each arranged so that their nozzle surfaces (not shown) face path rollers 22, 22, ... In other words, inkjet heads 96K, 96C, 96M, and 96Y are arranged at regular intervals along the transport path.

The nozzle surface of each of the inkjet heads 96K, 96C, 96M, and 96Y has a two-dimensional array of nozzles, which are ejection ports for aqueous ink. The nozzle surface refers to the ejection surface on which the nozzles are formed. A water-repellent film is formed on the nozzle surface of each of the inkjet heads 96K, 96C, 96M, and 96Y.

Each of the inkjet heads 96K, 96C, 96M, and 96Y can be constructed by connecting multiple head modules in the substrate width direction. The substrate width here refers to the substrate width in a direction perpendicular to the transport direction of the substrate 1. The transport direction of the substrate 1 is referred to as the Y direction. The substrate width direction perpendicular to the Y direction is referred to as the X direction.

Each of the inkjet heads 96K, 96C, 96M, and 96Y is a line-type recording head with a nozzle row that can record an image at a specified printing resolution over the entire recording area of the substrate 1 in the X direction in a single scan. Such recording heads are also called "full-line-type recording heads" or "page-wide heads."

The specified print resolution may be a print resolution predetermined by the inkjet printer 10, or may be a print resolution selected by the user or automatically selected by a program depending on the print mode. For example, the print resolution may be 1200 dpi (dots per inch) in the X direction and 1200 dpi in the Y direction.

In the case of an inkjet head with a two-dimensional nozzle array, the projected nozzle array, in which each nozzle in the two-dimensional nozzle array is projected (orthogonally projected) so that it is aligned along the nozzle array direction, can be considered equivalent to a single nozzle array in which each nozzle is aligned at approximately equal intervals in the nozzle array direction at a nozzle density that achieves maximum printing resolution. "Approximately equal intervals" means that the nozzles are essentially aligned at equal intervals in terms of droplet ejection points that can be recorded by an inkjet printing device. For example, the concept of "equal intervals" also includes cases in which the intervals are slightly different to account for manufacturing errors and/or droplet movement on the medium due to impact interference. The projected nozzle array is equivalent to the actual nozzle array. When considering the projected nozzle array, a nozzle number indicating the nozzle position can be assigned to each nozzle in the order in which the projected nozzles are aligned along the nozzle array direction. The nozzle array direction is synonymous with the nozzle alignment direction.

The nozzle arrangement in each of the inkjet heads 96K, 96C, 96M, and 96Y is not limited, and various nozzle arrangements can be adopted.

Droplets of water-based ink are ejected from at least one of the inkjet heads 96K, 96C, 96M, and 96Y toward the printing surface of the substrate 1 being transported by the transport unit 20, and the ejected droplets adhere to the substrate 1, thereby printing an image on the printing surface of the substrate 1.

The transport unit 20 functions as a relative movement mechanism that moves the inkjet heads 96K, 96C, 96M, and 96Y relative to the substrate 1. Note that while a configuration using four colored water-based inks is shown here, the ink colors and number of colors are not limited to this embodiment. Furthermore, the arrangement order of the inkjet heads for each color is not limited.

The substrate 1 on which the color image has been printed by the color printing unit 88 is transported to a position opposite the white printing unit 90.

The white printing unit 90 is located downstream of the color printing unit 88 on the transport path. The white printing unit 90 applies water-based white ink to the printing surface of the substrate 1 to print a white background image. The water-based white ink uses titanium oxide as a pigment, which has a relatively higher specific gravity than the organic pigments in the color inks, making the ink liquid relatively heavy overall. The white printing unit 90 is equipped with inkjet heads 96W1 and 96W2.

The configuration of inkjet heads 96W1 and 96W2 is the same as that of inkjet heads 96K, 96C, 96M, and 96Y. White water-based ink is supplied to inkjet heads 96W1 and 96W2 from an ink tank (not shown) via a piping path (not shown). Inkjet heads 96W1 and 96W2 are positioned so that their nozzle surfaces face the path rollers 22, 22, respectively.

Droplets of water-based white ink are ejected from at least one of the inkjet heads 96W1 and 96W2 toward the printing surface of the substrate 1 being transported by the transport unit 20, and the ejected droplets adhere to the substrate 1, printing a white background image on the printing surface of the substrate 1.

Note that while a configuration using two inkjet heads 96W1 and 96W2 is shown here, it is also possible to use only one inkjet head, or three or more inkjet heads.

The water-based color ink and water-based white ink applied to the printing surface of the substrate 1 in the jetting unit 80 undergo a condensation and thickening reaction with the water-based primer applied to the printing surface of the substrate 1 in the precoat unit 50.

The substrate 1, on which a white background image has been printed by the white printing unit 90, is guided by the pass rollers 22 and transported to a position opposite the inspection unit 97.

The inspection unit 97 inspects test pattern images, such as nozzle check patterns, printed on the substrate 1 by inkjet heads 96K, 96C, 96M, 96Y, 96W1, and 96W2. The inspection unit 97 includes a first scanner 98 and a second scanner 99. The first scanner 98 and the second scanner 99 each include an imaging device that captures the test pattern image printed on the printing surface of the substrate 1 and converts it into an electrical signal. A color CCD (Charge Coupled Device) linear image sensor can be used as the imaging device. Note that a color CMOS (Complementary Metal Oxide Semiconductor) linear image sensor can also be used instead of a color CCD linear image sensor.

The first scanner 98 and the second scanner 99 are each positioned on the printing surface side of the substrate 1, and read the test pattern image printed on the printing surface of the substrate 1 from the printing surface side. The test pattern images read by the first scanner 98 and the second scanner 99 are evaluated by a judgment unit (not shown), and defective nozzles are identified, etc.

The substrate 1, whose test pattern image has been inspected by the inspection unit 97, is guided downward by the second suction drum 86 and transported to the second non-contact turning unit 92.

The second non-contact turn unit 92 (an example of a non-contact conveying unit) is positioned between the second suction drum 86 and the main drying unit 100 on the conveying path, and is particularly positioned immediately after the white printing unit 90 on the conveying path. The second non-contact turn unit 92 changes the orientation of the conveying path from downward to upward without contacting the printed surface of the substrate 1. The configuration of the second non-contact turn unit 92 is similar to that of the first non-contact turn unit 60. The second non-contact turn unit 92 lifts the substrate 1 by a predetermined lift amount and turns it 180 degrees. The second non-contact turn unit 92 may be equipped with a drying function that blows air. The second non-contact turn unit 92 does not contact the printed surface and therefore does not affect the image printed on the printed surface.

The substrate 1 turned by the second non-contact turning section 92 is guided by multiple pass rollers 22 and transported to the fourth tension pickup roller 26.

The substrate 1, whose transport tension has been detected by the fourth tension pickup roller 26, is transported from the jetting unit 80 to the main drying unit 100. In this way, the inkjet printer 10 turns the substrate 1 without contact between printing and drying. By changing the direction of the transport path from downward to upward using the second non-contact turning unit 92, the transport path can be made straight, allowing for a lower profile and lower costs for the inkjet printer 10.

A preheating unit (not shown) may be provided between the second suction drum 86 and the second non-contact turning section 92 on the transport path to preheat the substrate 1 in order to increase the viscosity of the aqueous color ink and aqueous white ink. The preheating unit may be, for example, an infrared (IR) heating unit, a hot air heating unit, or an electromagnetic wave (microwave) heating unit. Because the substrate 1 deforms at approximately 60°C, an electromagnetic wave heating unit that uses electromagnetic waves of a wavelength selectively absorbed by the aqueous color ink and aqueous white ink is preferred.

[Main drying section]
The main drying section 100 is disposed downstream of the jetting section 80 on the transport path. The main drying section 100 dries the aqueous ink applied to the printing surface of the substrate 1. The main drying section 100 includes a plurality of hot air heaters 104 and a third drive roller 106. A plurality of pass rollers 22 are disposed on the transport path of the main drying section 100. The substrate 1 transported from the jetting section 80 is guided by the plurality of pass rollers 22 and transported to the third drive roller 106.

Multiple hot air heaters 104 are arranged on the transport path up to the third drive roller 106 of the main drying section 100. Each hot air heater 104 is arranged with its air blowing surface facing the printed surface of the substrate 1. Each hot air heater 104A blows hot air from a round nozzle toward the printed surface of the substrate 1 to dry the water-based ink.

The substrate 1, on which the water-based ink has been dried by the hot air heater 104, is transported to the third drive roller 106. The third drive roller 106 is rotated by a motor (not shown), and comes into contact with the substrate 1 to transport it.

The substrate 1 transported by the third drive roller 106 is guided by pass rollers 22, 22, ... and transported from the main drying section 100 to the winding section 120.

[Winding section]
The winding section 120 includes a winding roll 122, an inspection section 124, a fourth drive roller 130, a fifth drive roller 132, and a pressure roller 136. A plurality of pass rollers 22 are arranged on the transport path of the winding section 120. The substrate 1 transported from the main drying section 100 is guided by the pass rollers 22 and transported to a fifth tension pickup roller 27. The substrate 1, whose transport tension has been detected by the fifth tension pickup roller 27, is guided by the pass rollers 22 and transported to a position facing the inspection section 124.

The inspection unit 124 inspects the image printed on the printing surface of the substrate 1. The inspection unit 124 is equipped with a third scanner 126 and a fourth scanner 128. The configurations of the third scanner 126 and the fourth scanner 128 are similar to those of the first scanner 98 and the second scanner 99.

The third scanner 126 and the fourth scanner 128 are each positioned on the opposite side of the printed surface of the substrate 1, and read the image printed on the printed surface of the substrate 1 from the opposite side of the printed surface. The images read by the third scanner 126 and the fourth scanner 128 are judged as good or bad by a judging unit (not shown).

The substrate 1, whose image has been inspected by the inspection unit 124, is guided by the pass roller 22 and transported to the fourth drive roller 130. The fourth drive roller 130 is rotated by a motor (not shown) and comes into contact with the substrate 1 to transport it. The substrate 1 transported by the fourth drive roller 130 is then transported to the fifth drive roller 132. The fifth drive roller 132 is rotated by a motor (not shown) and comes into contact with the substrate 1 to transport it.

The substrate 1 transported by the fifth drive roller 132 is guided by multiple pass rollers 22 and transported to the sixth tension pickup roller 28. The substrate 1, whose transport tension has been detected by the sixth tension pickup roller 28, is guided by the pass rollers 22 and wound onto the winding roll 122.

A pressure roller 136 is positioned opposite the winding roll 122. The pressure roller 136 is provided at the tip of a swing arm 138. The swing arm 138 presses the pressure roller 136 against the substrate 1 wound around the winding roll 122 using a pressing means (not shown).

Furthermore, near the winding roll 122 on the transport path of the winding unit 120, for example in the area surrounded by the rectangular frame indicated by the dashed lines in the figure, a measurement unit 150 is provided for measuring the color of the printed color adjustment chart to obtain measurement data. Note that the printed color adjustment chart is sometimes referred to as the "printed chart."

<<Explanation of technical issues>>
When printing using a digital printing press such as the inkjet printing press 10, a printer controller is connected to the printing press, and a print job is registered in the printer controller along with image data to be printed. In this specification, a print job may be simply referred to as a "job." After registering one or more jobs, typically multiple jobs, the printing order is determined, and the jobs are executed in that order for printing. For example, when printing the (N-1)th job, where N is an integer greater than or equal to 2, color matching for the (N-1)th job is performed, and then printing for the (N-1)th job is executed. Then, after the (N-1)th job is completed, color matching for the (N)th job is performed, and then printing for the (N-1)th job is executed. In this printing process, the printing operation is interrupted at the following times [1] to [3] during the period from printing the color adjustment chart for (N-1)th color matching to printing the (N-1)th job, and each of these three interruptions results in wasted paper.

[1] Between "printing a color adjustment chart for the N-1th color matching" and "printing the N-1th job." [2] Between "printing the N-1th color matching" and "printing a color adjustment chart for the Nth color matching." [3] Between "printing a color adjustment chart for the Nth color matching" and "printing the Nth job." FIG. 2 is an explanatory diagram schematically showing the order of printing, including color adjustment, when a color adjustment method according to a comparative example is applied. In FIG. 2, an "x" mark indicates that a paper waste occurs due to an interruption of the printing operation. In the printing process shown in FIG. 2, first, a color adjustment chart for the N-1th color matching is printed, and after the color adjustment, the N-1th job is printed. Then, when printing the Nth job, first, a color adjustment chart for the Nth color matching is printed, and after the color adjustment, the Nth job is printed.

As explained in [1], [2], and [3] above, this method results in wasted paper due to interruptions in the printing operation, indicated by the "x" marks. In particular, in the case of a large inkjet printing press 10 in which the substrate transport path from the unwinding section 30 to the winding section 120 is several tens of meters long, a significant amount of wasted paper can occur when printing a color adjustment chart.

<<Summary of solutions to reduce paper waste>>
3 is an explanatory diagram schematically illustrating the order of printing including color adjustment when the color adjustment method according to the embodiment is applied. In this embodiment, printing is performed continuously without interruption between printing the (N-1)th job and printing the color adjustment chart for the Nth color adjustment. Specifically, the chart image data of the color adjustment chart used for the Nth color adjustment can be linked and printed during the final printing of the (N-1)th job.

With this configuration, the number of interruptions resulting in paper waste during the period from printing the color adjustment chart for the N-1th color matching to printing the Nth job will be two, as shown below.

<1> Between "printing a color adjustment chart for the N-1th color matching" and "printing the N-1th job + printing a color adjustment chart for the Nth color matching"<2> Between "printing the N-1th job + printing a color adjustment chart for the Nth color matching" and "printing the Nth job" According to the method shown in FIG. 3, the interruption that occurred between "printing a job" and "printing a color adjustment chart for the color matching of the next job" is eliminated, and compared to the three interruptions described in the comparative example, there are only two interruptions, which reduces one paper waste. According to this embodiment, it is possible to reduce paper waste by substantially half compared to the method of the comparative example. The N-1th job is an example of a "first print job" in the present disclosure. The Nth job is an example of a "second print job" in the present disclosure.

<<Explanation of image data and special color data>>
Image data used for printing is, for example, in a format such as a Portable Document Format (PDF) file that includes character codes representing CMYK process colors and spot colors. Figure 4 shows an example of the contents of a PDF file. A PDF file is a script file in XML (eXtensible Markup Language) format, and the file contains various printing conditions and image data of the actual print target. Figure 5 shows an example of spot color data written in a PDF file.

As shown in Figures 4 and 5, the PDF file has a structure that includes character codes. When spot colors are used, the spot color name, device signal value, or Lab value is described inside the PDF file. Spot colors may be, for example, Pantone (registered trademark) colors. The printing press's control device uses this information to convert the data using a RIP (Raster Image Processor) so that the image information defined by the spot colors becomes a bitmap image with signal values that can be reproduced in the specified colors.

<<How to convert spot color data>>
Image data containing character codes, such as PDF files, is converted into bitmap image data using a raster image processor (RIP). The RIP is equipped with a spot color information database. The spot color information database contains spot color names, device signal values that reproduce those colors, and chromaticity value information such as Lab values. During raster processing, the RIP references the spot color names in the spot color image area, extracts the device signal values corresponding to the spot color names in the spot color information database, and converts them into bitmap image data.

Note that PDF files may also contain device signal values or chromaticity value information, and the RIP may refer to the data in the PDF file rather than the spot color information database.

The need for color adjustment of spot color data in digital printing presses
When printing spot colors using an analog printing machine such as an offset press, the ink colors can be freely changed, so the ink that will produce the specified spot color is created using an ink toning machine and then set on the printing machine to print. Therefore, the color of the spot color is determined by the color of the ink itself. The color reproduction accuracy of the ink toning machine improves color inspection accuracy, allowing the specified color to be reproduced with high precision.

In contrast, in the case of digital printing machines, for example inkjet printing machines, the ink colors that can be used are predetermined for the machine, and ink colors cannot be freely selected. Instead, spot colors are created using process colors by mixing ink colors (e.g., CMYK) that can be used in the inkjet printing machine 10. Therefore, it is necessary to appropriately assign device signal values so that the target spot color can be reproduced.

The general method is to define spot colors using chromaticity values such as Lab values, and then use a color profile to convert those Lab values to device signal values. Lab values represent coordinates in the L*a*b* color space defined by the International Commission on Illumination (CIE).

Figure 6 shows an example of a color profile. A color profile is a set of parameters that describe the relationship between chromaticity values, such as Lab values, and device signal values. Combinations of device signal values at regular intervals are created into a chart pattern, and the chart is printed and the colors are measured (colorimetry) to determine the relationship between chromaticity values and device signal values. The numerical range of the L* value in Lab values is 0 to 100. The numerical ranges of the a* and b* values are -128 to +127. Device signal values include signal values for each of the multiple colors C, M, Y, and K, and a color is specified by the combination of these signal values. Since the color profile determines device signal values through interpolation after matching data at regular intervals, there may be errors in the relationship between the chromaticity values on the actual print and the device signal values, which can result in colors not matching with high precision. Therefore, color adjustment of the spot color data is required to accurately match the color to the target color.

Overview of Color Adjustment Method According to Embodiment
In an inkjet printer 10 according to an embodiment, when a spot color such as a Pantone® color is specified in image data to be printed, the printer controller generates chart image data of a color adjustment chart (color chart) that includes multiple candidate combinations of CMYK signal values (device signal values) for reproducing the spot color using the CMYK process colors, in order to reproduce a color that is as close as possible to the specified spot color. The printer controller prints the generated color adjustment chart in the image data of a preceding job that is one or more jobs before the target job in which the spot color is to be matched, and then, based on the colorimetric results of the printed color adjustment chart, determines the combination of process colors to be used to reproduce the spot color of the target print, and then prints the image of the target job that includes the spot color.

<<Specific examples of data processing>>
FIG. 7 shows an example of a status confirmation screen for a registered job displayed on the screen of a printer controller connected to the inkjet printing machine 10 according to this embodiment.

A printer controller is configured, for example, using a combination of computer hardware and software. For example, print control software is stored in the storage device of a personal computer (PC), and multiple image sets to be printed are registered in this software, and the printing order is set.

Each print job registered in the printer controller is assigned a job ID (Identification) as job identification information, and a list of registered jobs is displayed on the registered job status confirmation screen shown in Figure 7. The example screen shown in Figure 7 shows a job list 4 that is ordered so that printing will occur in ascending order of job ID numbers. A print execution button 6 and a cancel button 7 are displayed below the job list 4 display on this screen. The print execution button 6 is a GUI (Graphical User Interface) button used to input instructions to execute printing. When the print execution button 6 is pressed, printing will occur in ascending order of job ID numbers.

Figure 8 is a functional block diagram showing the functional configuration of an information processing device 200 that functions as a printer controller. The information processing device 200 includes a print job management unit 202, a chart generation unit 204, an image data combination unit 206, a RIP processing unit 208, and a printer control unit 210. The information processing device 200 also includes a spot color information database 220, a chart information database 222, a measurement data management unit 223, a spot color data correction unit 226, and an image database 228. Note that the abbreviation "DB" in Figure 8 stands for "database."

The print job management unit 202 manages the registration and execution of jobs. The print job management unit 202 manages the job list 4 described in Figure 7. The image database 228 stores image data for printing linked to each job ID. The chart generation unit 204 generates image data for a chart pattern of a color adjustment chart used to adjust the color of spot colors based on spot color information included in the image data to be printed specified for each job. The chart information database 222 stores position information and CMYK signal value information for each patch in the chart pattern generated by the chart generation unit 204 linked to the job ID.

The image data combining unit 206 combines the chart image data of the Nth chart pattern at the end of the image data of the N-1th job. The RIP processing unit 208 includes a color conversion processing unit 209. The color conversion processing unit 209 performs color management processing on the image data to be printed. The color conversion processing unit 209 performs color conversion for spot colors in the image by referencing a spot color information database 220, and for process colors other than spot colors, performs color conversion using a color profile such as Japan Color.

The RIP processor 208 receives image transfers from the print job manager 202 and performs color conversion and rasterization. The RIP processor 208 may create raster data for all images to be printed within a job in advance, or may generate raster data on the fly. The RIP processor 208 may also link the raster data for the job image and the raster data for the chart image.

The printer control unit 210 controls the ink ejection operation of each of the inkjet heads 96K, 96C, 96M, and 96Y based on the raster data for each ink color generated by the RIP processing unit 208. In other words, the printer control unit 210 controls the drawing operation of the inkjet heads 96K, 96C, 96M, and 96Y.

The spot color information database 220 stores spot color information that associates the target chromaticity values of spot colors with the device signal values required to reproduce those target chromaticity values. When printing image data that includes spot colors, the color conversion processing unit 209 references the spot color information stored in the spot color information database 220 to determine the device signal values corresponding to the spot colors. The device signal values expressed as CMYK signal values are an example of "image signal values" in this disclosure.

The measurement data management unit 223 acquires measurement data of each color patch measured using the colorimeter 250 and stores the measurement data in the measurement data management database 224. The spot color data correction unit 226 uses the measurement data stored in the measurement data management database 224 to correct the information in the spot color information database 220. When printing image data including spot colors, the color conversion processing unit 209 references the spot color information stored in the spot color information database 220 to determine the device signal value corresponding to the spot color. The information processing device 200 is an example of a "color adjustment device" in this disclosure. The information processing device 200 incorporates the functions of a color adjustment device.

The data processing performed by the information processing device 200 can be broadly divided into the following three processes (processes 1 to 3).

[Process 1] The first process is the generation of a chart pattern for a color adjustment chart for adjusting spot colors and the printing of that chart. That is, the information processing device 200 generates image data for the color adjustment chart to be linked to the end of the image to be printed for the N-1th job (hereinafter referred to as the N-1th image), links the image data of the N-1th image and the color adjustment chart, and performs processing to print the color adjustment chart together with the N-1th image.

[Process 2] The second process is to measure the print result of the color adjustment chart linked to the rear end of the N-1th image using the colorimeter 250, determine the device signal values capable of reproducing the spot color target color, and update the spot color information database 220.

[Process 3] The third process is to convert the spot color image material into specified device signal values using updated data from the spot color information database 220 for the image data to be printed, and then execute printing.

Processes 1, 2, and 3 will be explained in more detail below.

[Process 1: Generation and printing of spot color adjustment chart pattern] Fig. 9 is an explanatory diagram showing the flow of generation and printing of spot color adjustment chart pattern. The arrows shown by solid lines in the information processing device 200 in Fig. 9 indicate the flow of active data in the data processing process of process 1. On the other hand, the arrows shown by dashed lines indicate paths that are not directly involved in process 1.

<Generation of special color adjustment chart pattern>
When the Nth job is registered, the print job management unit 202 extracts the paper size information and spot color name information contained in the PDF file, and causes the chart generation unit 204 to start a chart image generation process for spot color adjustment.

The chart generation unit 204 acquires device signal values (CMYK values in this example) corresponding to the extracted spot color name information from the spot color information database 220. The chart generation unit 204 generates a chart consisting of a group of color patches with (2*k+1)3 combinations of signal values of each color, C-k*ΔC to C+k*ΔC, M-k*ΔM to M+k*ΔM, and Y-k*ΔY, centered on the device signal values (CMYK values) acquired corresponding to ^{the spot} color name information, and arranges the chart pattern so that it fits on the paper size specified in the PDF file.

Figure 10 is a conceptual diagram of the process for generating a spot color adjustment chart pattern. In this example, for the spot color device signal values CMY, the C signal is divided into five levels: C-2*ΔC, C-ΔC, C, C+ΔC, and C+2*ΔC; the M signal is divided into five levels: M-2*ΔM, M-ΔM, M, M+ΔM, and M+2*ΔM; and the Y signal is divided into five levels: Y-2*ΔY, Y-ΔY, Y, Y+ΔY, and Y+2*ΔY. 125 color patches combining the levels of these three colors are created, and these are then used to create a chart pattern. Color patches are sometimes simply referred to as "patches."

In the figure, the notations "c-2," "c-1," "c," "c+1," and "c+2" represent the signal values of "C-2*ΔC," "C-ΔC," "C," "C+ΔC," and "C+2*ΔC," respectively, for the C signal. Similarly, the notations "m-2," "m-1," "m," "m+1," and "m+2" represent the signal values of "M-2*ΔM," "M-ΔM," "M," "M+ΔM," and "M+2*ΔM," respectively, for the M signal. The notations "y-2," "y-1," "y," "y+1," and "y+2" represent the signal values of "Y-2*ΔY," "Y-ΔY," "Y," "Y+ΔY," and "Y+2*ΔY," respectively, for the Y signal.

By arranging and linking five types of 5x5 color patch groups shown in the upper part of Figure 10, the chart pattern shown in the lower part of Figure 10 is obtained. The signal value of (c, m, y) in Figure 10 is an example of a "first image signal value" in this disclosure. Furthermore, the signal values of the other patches surrounding (c, m, y) shown in Figure 10 are examples of "second image signal values" in this disclosure.

Chart information, including layout information for the color adjustment chart generated by the chart generation unit 204, is registered in the chart information database 222. The chart information registered in the chart information database 222 includes the job ID of the print job that includes the spot color to be adjusted by the color adjustment chart, the CMYK signal values of each patch used during measurement, and position coordinate information for each patch.

It is preferable to insert single-color patches (primary color patches for each of the CMYK colors) corresponding to the ink colors along with this color adjustment chart so that the color reproducibility of the inkjet printing machine 10 can be confirmed. The chart generation unit 204 may generate a color adjustment chart that includes a chart pattern for adjusting spot colors and single-color patches for confirming color reproducibility, or may generate a chart pattern for adjusting spot colors and a chart pattern of single-color patches for confirming color reproducibility as separate chart image data. Furthermore, in addition to single-color patches, gray color patches created by mixing colors may also be added.

If the color of the single-color patch or mixed-color patch deviates by more than a certain amount while the printing operation is continuing, the information processing device 200 performs calibration to restore the color reproduction of the inkjet printing device 10.

It is also preferable to arrange patches of the same color at multiple positions within the surface together with this spot color adjustment chart. The information processing device 200 can confirm the uniformity of color within the printing area by evaluating the color measurement results of these multiple patches of the same color arranged at different positions. If the colors of these multiple patches of the same color shift by more than a certain amount while the printing operation is continuing, the information processing device 200 performs in-surface unevenness correction to restore in-surface unevenness of the inkjet printing device 10.

<Processing for combining the image to be printed and the spot color adjustment chart pattern>
The color adjustment chart generated by the chart generation unit 204 is combined with the image data of the (N-1)th job in the image data combination unit 206 as an image to be linked to the last image of the (N-1)th job. For example, if the (N-1)th job is to print 1000 images, the color adjustment chart is combined as the image for printing the 1001st image. In this way, the image data combined by the image data combination unit 206 is stored in the image database 228 via the print job management unit 202.

As an alternative method, instead of linking the job image data and color adjustment chart as images, the image data and color adjustment chart data can be linked using link information or the like to manage them as a set, and then these data can be combined when printing.

<Printing image data>
When the operator issues an instruction to print the N-1th image data, the print job management unit 202 transfers the N-1th image data and the image data of the spot color adjustment chart to be printed at the rear edge to the RIP processing unit 208. The RIP processing unit 208 performs different color conversion processes on the N-1th image data and the image data of the spot color adjustment chart.

For the N-1th image data, color management processing is performed by the color conversion processing unit 209, converting the image data signal values into device signal values so that the image data is printed in the specified target color. At this time, signals designated as spot colors are converted by referencing the device signal values of the designated spot colors optimized for printing the N-1th job from the spot color information database 220.

The image data that has been color converted by the color conversion processing unit 209 is converted into raster image data, then sent to the printer control unit 210 and printed by the inkjet heads 96K, 96C, 96M, and 96Y. The printed image IMG(N-1) in Figure 9 represents a printout of the job image printed on the substrate 1 based on the image data of the N-1th job.

In contrast, the chart image data of the spot color adjustment chart is not color converted by the color conversion processing unit 209, but is instead converted directly into raster image data. This is because color conversion is not necessary, as the correspondence between device signal values and actual colors is desired. The chart image data of the spot color adjustment chart is converted into raster image data by the RIP processing unit 208, then sent to the printer control unit 210 and printed by inkjet heads 96K, 96C, 96M, and 96Y. The color adjustment chart image CP(N) in Figure 9 represents a chart printout printed on the substrate 1 based on the chart image data for color adjustment of spot colors included in the Nth job.

[Process 2: Measurement of Spot Color Adjustment Chart and Correction of Spot Color Information] Fig. 11 is an explanatory diagram showing the flow of measurement of the spot color adjustment chart and correction of spot color information. The solid arrows in the information processing device 200 shown in Fig. 11 indicate the active data flow in the data processing process of Process 2.

<Chart measurement>
Here, an example of automatically measuring the color of a printed color adjustment chart image CP(N) will be described. FIG. 12 is a schematic diagram illustrating an overview of an automatic color measurement system provided in the inkjet printing machine 10. The colorimeter 250 is a measuring device that measures the color of color patches on a printed copy of the color adjustment chart image CP(N). The colorimeter 250 is mounted on an X-direction rail 252 and can move in the X direction. The rail 252 can also be moved in the Y direction by a Y-direction movement mechanism (e.g., a mechanism including a Y-direction rail), not shown. Such a mechanism that allows movement in the X and Y directions allows the colorimeter 250 to be moved in the X and Y directions, thereby changing the color measurement position of the colorimeter 250. Based on positional information of each color patch on a color adjustment chart in which multiple color patches are arranged two-dimensionally, the colorimeter 250 is moved to the position of each color patch to automatically measure the color. By performing color measurement using the colorimeter 250, the chromaticity values (e.g., Lab values) of each color patch can be obtained.

The automatic color measurement system, including the colorimeter 250 and rail 252, is positioned in the measurement section 150 near the downstream take-up roll 122 in the substrate transport path of the inkjet printing machine 10.

When printing of the color adjustment chart image CP(N) is complete, the printed portion of the chart pattern stops at the measurement unit 150 located downstream of the inkjet printing machine 10. When measuring the chart, the roll substrate is not cut, and a measurement table (colorimetry stage) (not shown) used for chart measurement and the colorimeter 250 are automatically positioned at the position of the printed color adjustment chart image CP(N).

The measurement data management unit 223 receives the job ID corresponding to the color adjustment chart image CP(N) to be measured from the print job management unit 202, and then receives the position information and device signal value information of each patch in the color adjustment chart from the chart information database 222.

The measurement data management unit 223 automatically measures the chart print using the received position information, and the obtained measurement data is associated with the device signal values and stored in the measurement data management database 224.

<Correction of device signal values corresponding to spot colors>
The spot color data correction unit 226 extracts the target chromaticity value (target Lab value) of the target spot color from the spot color information database 220, and registers the device signal value corresponding to the color patch from the measurement data management database 224 that is closest to the target chromaticity value in the spot color information database 220 as the corrected device signal value of the target spot color.

If it is not possible to select a patch from the multiple color patches whose color difference from the target chromaticity value is less than a certain level, an interpolation calculation (e.g., cubic interpolation) is performed from the multiple patches to determine a device signal value that reproduces a color that approximates the target chromaticity value (target Lab value), and this is registered in the spot color information database 220 as the modified device signal value of the target spot color.

Figure 13 is a conceptual diagram of cubic interpolation calculations. Figure 13 shows an example of cubic interpolation calculations that estimate measurement values by weighting the values of eight measurement points. This type of interpolation calculation makes it possible to determine device signal values that reproduce colors that approximate the target chromaticity values.

[Process 3: Printing process of image data after spot color information correction] Fig. 14 is an explanatory diagram showing the flow of printing process of image data after spot color information correction. The solid arrows in the information processing device 200 shown in Fig. 14 indicate the active data flow in the data processing process of Process 3.

<Printing image data>
When the operator issues an instruction to print the image data of the Nth job, the print job management unit 202 transfers the Nth image data to the color conversion processing unit 209. At this time, the data of the (N+1)th spot color adjustment chart image is also transferred to the RIP processing unit 208.

The color conversion processing unit 209 performs color management processing on the Nth image data, converting the image data signal values into device signal values so that the image data will be printed in the specified target color. At this time, signal values specified for spot colors are converted by referencing the spot color information database 220 and the modified device signal values of the specified spot color optimized for printing the Nth image. The color-converted Nth image data is printed according to the printer control unit 210. The printing and measurement of the N+1th spot color adjustment chart image are the same as those described in Process 1 and Process 2, so a redundant description will be omitted.

<<Hardware Configuration Example of Information Processing Device 200>>
15 is a block diagram showing an example of the hardware configuration of an information processing device 200 that functions as a printer controller for the inkjet printing machine 10. The information processing device 200 is configured, for example, by a combination of computer hardware and software. The information processing device 200 includes a processor 302, a computer-readable medium 304 that is a non-transitory tangible entity, a communication interface 306, and an input/output interface 308. The processor 302 includes a CPU (Central Processing Unit). The processor 302 may also include a GPU (Graphics Processing Unit). The processor 302 is connected to the computer-readable medium 304, the communication interface 306, and the input/output interface 308 via a bus 310.

The computer-readable medium 304 includes, for example, random access memory (RAM) 312, read-only memory (ROM) 314, and storage 316. RAM 312 is memory that functions as a main storage device. Storage 316 is a secondary storage device. Storage 316 may be, for example, a hard disk drive (HDD) device, a solid state drive (SSD) device, or a combination of these. Part or all of the storage area of the computer-readable medium 304 may be included in the processor 302. RAM 312, ROM 314, and storage 316 are each an example of a "storage device" in this disclosure.

The computer-readable medium 304 stores programs and data that realize the functions of the printer controller. Note that the term "program" includes the concept of a program module. Some of the processing functions of the information processing device 200 may be realized using integrated circuits such as a DSP (Digital Signal Processor) or FPGA (Field Programmable Gate Array).

The information processing device 200 is connected to an input device 322 and a display device 324. The input device 322 is configured, for example, by a keyboard, a mouse, a multi-touch panel, or other pointing device, or a voice input device, or an appropriate combination of these. The display device 324 is configured, for example, by a liquid crystal display, an organic electro-luminescence (OEL) display, or a projector, or an appropriate combination of these. The input device 322 and the display device 324 may be configured integrally, such as a touch panel. The input device 322 and the display device 324 may be included in the information processing device 200, or the information processing device 200, the input device 322, and the display device 324 may be configured integrally.

Figure 16 is a flowchart showing an example of the print job registration process in the printing system according to this embodiment. Here, we will explain an example in which the processor 302 automatically sets the printing order of the jobs according to the order in which the jobs are registered.

In step S21, the processor 302 accepts registration of the Nth job. Next, in step S22, the processor 302 determines whether the Nth job has been registered. If the determination result in step S22 is No, the processor 302 returns to step S21.

If the determination result in step S22 is Yes, the processor 302 proceeds to step S23. In step S23, the processor 302 associates the image data of the job with the job ID and stores it in the image database 228.

Next, in step S24, the processor 302 determines whether a spot color is specified in the image data of the Nth job. If the determination result in step S24 is Yes, the processor 302 proceeds to step S25. In step S25, the processor 302 generates a chart pattern of a color adjustment chart including multiple color patches for adjusting the color reproduction of the spot color used.

Next, in step S26, the processor 302 registers chart information, including the position information and device signal values of each color patch of the generated color adjustment chart, in the chart information database 222.

Next, in step S27, the processor 302 performs a combining process to combine the chart image data of the color adjustment chart with the image data of the (N-1)th job.

Next, in step S28, the processor 302 associates the image data combined with the chart image data with the (N-1)th job and stores the image data in the image database 228. After step S28, the processor 302 ends the flowchart in FIG.
Also, if the determination result in step S23 is a No determination, the processor 302 skips steps S25 to S28 and ends the flowchart of FIG.

The flowchart in FIG. 16 may be repeatedly executed each time a new job is registered. The processor 302 may increment the value of N and execute the flowchart in FIG. 16 each time a new job is added.

The processor 302 may also accept input of an instruction to change the printing order of jobs on the registered job status confirmation screen described in FIG. 7. The processor 302 changes the printing order settings of the jobs in accordance with the accepted instruction. If the printing order settings are changed, the flowchart in FIG. 16 may be executed in accordance with the changed printing order.

In this way, the job is registered along with the image data to be printed, and the printing order is determined, after which the processor 302 receives an instruction to start printing.

Figure 17 is a flowchart showing an example of printing processing in a printing system according to an embodiment. In step S31, the processor 302 accepts a print instruction. The print instruction may be input by a user via an input device, or may be issued automatically according to a program or the like. In step S32, the processor 302 determines whether a print instruction for the (N-1)th job has been received. If no print instruction has been received and the determination result in step S32 is No, the processor 302 returns to step S31.

On the other hand, if a print instruction is received and the judgment result in step S32 is Yes, the processor 302 proceeds to step S33.

In step S33, the processor 302 transfers the image data of the image to be printed (job image) of the N-1th job and the chart image data of the spot color adjustment chart to be printed at the trailing edge to the RIP processing unit 208.

In step S34, the color conversion processing unit 209 of the RIP processing unit 208 performs color conversion processing on the N-1th image data. Then, in step S35, the processor 302 converts the N-1th image data after color conversion processing into raster image data, and prints the job image by controlling the ejection of inkjet heads 96K, 96C, 96M, and 96Y based on the raster image data.

In step S36, the processor 302 determines whether printing of the specified number (quantity) of job images specified for the target job has been completed. If the determination in step S36 is No, the processor 302 returns to step S35 and continues printing the job images.

If the specified number of sheets has been printed and the determination result in step S36 is Yes, the processor 302 proceeds to step S37.

In step S37, the processor 302 prints a spot color adjustment chart based on the chart image data combined with the image data of the N-1th job. As a result, the spot color adjustment chart is printed after the final copy of the multiple copies specified in the job. The printing process of the chart image in step S37 is carried out seamlessly (continuous printing) after the printing process of the job image in step S35, by maintaining continuous transport without stopping the transport of the substrate 1. Note that the chart image may be printed with an appropriate gap between the trailing edge of the final job image and the chart image, taking into account the ease of separating the job image print and the chart print in post-processing after printing.

After step S37, the processor 302 ends the flowchart in FIG. 17. The flowchart in FIG. 17 may be executed repeatedly until all registered jobs have been executed. Each time a job is executed, the processor 302 may increment the value of N and execute the flowchart in FIG. 17.

Figure 18 is a flowchart showing an example of the chart measurement and spot color information correction process in the printing system according to the embodiment. In step S41, the processor 302 determines whether or not a spot color adjustment chart has been printed. If the determination result in step S41 is No, step S41 is looped. If the spot color adjustment chart has been printed in step S37 of Figure 17 and the determination result in step S41 of Figure 18 is Yes, the processor 302 proceeds to step S42.

In step S42, the processor 302 controls the transport mechanism for the substrate 1 to stop the chart print at the position of the measurement unit 150.

Then, in step S43, the processor 302 controls the movement mechanisms of the measurement table and the colorimeter 250 to position the measurement table and the colorimeter 250 at the position of the chart print.

Next, in step S44, the processor 302 obtains chart information for the chart to be measured from the chart information database 222.

Then, in step S45, the processor 302 controls the position of the colorimeter 250 based on the position information of each patch contained in the chart information, automatically measures the color of each patch, and obtains the measurement results.

Next, in step S46, the processor 302 associates the measurement results of each patch with the patch's device signal value and stores them in the measurement data management database 224.

Then, in step S47, the processor 302 determines the device signal value closest to the target chromaticity value of the target spot color based on the measurement results of the spot color adjustment chart, registers the obtained value as a corrected device signal value in the spot color information database, and updates the spot color information database.

After step S47, the processor 302 ends the flowchart in FIG. 18. The flowchart in FIG. 18 may be repeatedly executed each time a spot color adjustment chart is printed.

Figure 19 is a flowchart showing an example of printing processing for a job image after spot color information correction in a printing system according to an embodiment.

In step S51, the processor 302 accepts a print instruction. Then, in step S52, the processor 302 determines whether a print instruction for the Nth job has been received. If there is no print instruction and the determination result in step S52 is No, the processor 302 returns to step S51.

On the other hand, if a print instruction is received and the judgment result in step S52 is Yes, the processor 302 proceeds to step S53.

In step S53, the processor 302 transfers the image data of the Nth job image to the RIP processing unit 208. At this time, if a chart image of the spot color adjustment chart of a job (N+1) or later is combined with the Nth job, the chart image data is also transferred, as in step S33 of Figure 17.

In step S54, the color conversion processing unit 209 of the RIP processing unit 208 performs color conversion processing on the Nth image data. At this time, for image portions of spot colors specified in the image data, the spot color information database 220 is referenced, and the corresponding device signal values are applied.

Then, in step S55, the processor 302 converts the Nth image data after color conversion processing into raster image data, and prints the job image by controlling the ejection of inkjet heads 96K, 96C, 96M, and 96Y based on the raster image data.

In step S56, the processor 302 determines whether printing of the specified number of sheets (quantity) specified for the target job has been completed. If the determination in step S56 is No, the processor 302 returns to step S55 and continues printing the job images.

If the specified number of sheets has been printed and the determination result in step S56 is Yes, the processor 302 ends the flowchart in FIG. 19. Note that if the chart image of the spot color adjustment chart of the (N+1)th or subsequent job has been combined with the Nth job, the spot color adjustment chart is printed based on that chart image data, as in step S37 in FIG. 17, and then the flowchart in FIG. 19 ends.

The flowchart in FIG. 19 may be executed repeatedly until all registered jobs have been executed. Each time a job is executed, the processor 302 may increment the value of N and execute the flowchart in FIG. 19.

If the image data of the target job is combined with the chart image data of a subsequent job, the flowchart in Figure 18 is applied, and if the image data of the target job is not combined with the chart image data of a subsequent job (uncombined), the flowchart in Figure 19 may be applied.

<<Modification: Method of Combining Spot Color Adjustment Chart and Image Data>>
In the above explanation, we have described how the chart image data of the spot color adjustment chart for the Nth job is actually (physically) linked to the image data of the N-1th job as image data, but the linking method is not limited to this, and the following methods are also possible, for example.

[Example 1] The image data of a job registered in the information processing device 200 and the spot color adjustment chart generated by the chart generation unit are not physically combined in the image data combination unit 206, but are managed in the print job management unit 202 as combined information linking them, and may be combined and printed as continuous page data when an actual print instruction is issued. With such a configuration, the burden of data processing can be reduced when the job printing order is changed, and it can be handled easily.

[Example 2] If a user changes the printing order of a job after registering the job in the information processing device 200, the processor 302 is configured to change the binding relationship between the job's image data and the spot color adjustment chart at that time.

[Example 3] When printing multiple jobs one at a time, the printer can operate in the following order: print 1 job → stop → print 1 job → stop. Alternatively, it can also operate in the following order: print 2 jobs consecutively → stop. In the latter case, the spot color adjustment charts for the two jobs are combined and merged with the image data of the job one or more jobs before.

<Printing system control system>
FIG. 20 is a functional block diagram showing the configuration of a control system of a printing system 12 according to an embodiment. The printing system 12 includes an inkjet printing press 10 and an information processing device 200. The information processing device 200 functions as a control device for the inkjet printing press 10. The information processing device 200 includes a user interface 170, a storage unit 172, a communication unit 173, a system control unit 174, a conveyance control unit 176, an unwinding control unit 178, a precoat control unit 180, a jetting control unit 182, a main drying control unit 184, a winding control unit 186, a measurement control unit 188, a spot color adjustment processing unit 190, and an image processing unit 192. The configuration of the inkjet printing press 10 is the same as that described in FIG. 1. Elements of the inkjet printing press 10 that are not shown in FIG. 20 will be described using the reference numerals of FIG. 1.

The user interface 170 includes the input device 322 and display device 324 described in FIG. 15. By operating the user interface 170, the user can cause the inkjet printer 10 to print the desired image.

The memory unit 172 stores programs for controlling the inkjet printer 10 and information necessary for executing the programs. The memory unit 172 is configured from the storage area of the computer-readable medium 304 described in Figure 13.

The communication unit 173 includes a communication interface 306 (see FIG. 15). The information processing device 200 is connected to a host computer (not shown) via the communication unit 173, and can send and receive data to and from the host computer. Note that "connection" includes a wired connection, a wireless connection, or a combination of these. The communication unit 173 may be equipped with a buffer memory to speed up communication processing. The communication unit 173 serves as an image input interface unit for acquiring image data representing an image to be printed. The image data imported via the communication unit 173 is stored in the storage unit 172. Note that, in addition to the communication unit 173, the information processing device 200 may also be equipped with a media interface (not shown) that reads data from an external storage device such as a memory card, as a means for acquiring image data from the outside.

The system control unit 174 performs various processes in accordance with the commands of the programs stored in the memory unit 172, and controls the overall operation of the inkjet printing machine 10. The system control unit 174 also functions as a calculation unit that performs various calculation processes.

The transport control unit 176 controls the transport unit 20. The transport control unit 176 controls the rotation of motors (not shown) and other components, rotating them at predetermined speeds to transport the substrate 1 in a roll-to-roll manner. The transport control unit 176 also controls the first tension pickup roller 23, the second tension pickup roller 24, the third tension pickup roller 25, the fourth tension pickup roller 26, the fifth tension pickup roller 27, and the sixth tension pickup roller 28 to detect the transport tension of the substrate 1.

The unwinding control unit 178 controls the rotation of a motor (not shown) to rotate the first drive roller 34 and the second drive roller 36 at a predetermined speed. The unwinding control unit 178 also controls the corona treatment unit 38 to apply corona discharge treatment to the substrate 1 and modify the printed surface of the substrate 1.

The precoat control unit 180 controls the coater 52. That is, the precoat control unit 180 controls the rotation of the motor (not shown) of the application roller 54, causing the application roller 54 to rotate at a predetermined speed and apply the aqueous primer to the printing surface of the substrate 1 via the application roller 54. The precoat control unit 180 also controls heating by a hot air heater (not shown) in the precoat drying unit 58, causing the hot air heater to dry the aqueous primer applied to the printing surface of the substrate 1.

The jetting control unit 182 controls the jetting unit 80 and the third drive roller 106 of the main drying unit 100. The jetting control unit 182 includes a print control unit, tension control unit, and air volume control unit (not shown). The print control unit controls the color printing unit 88 and the white printing unit 90.

The print control unit controls the ejection of ink from inkjet heads 96K, 96C, 96M, and 96Y based on the RIP-processed image data. That is, the print control unit causes inkjet heads 96K, 96C, 96M, and 96Y to eject droplets of black, cyan, magenta, and yellow water-based ink toward substrate 1 when substrate 1 passes a position facing each nozzle face. This causes a color image to be printed on the printing surface of substrate 1.

The print control unit also controls the ejection of ink from the inkjet heads 96W1 and 96W2 based on the RIP-processed image data. That is, the jetting control unit 182 causes the inkjet heads 96W1 and 96W2 to eject droplets of white water-based ink toward the substrate 1 when the substrate 1 passes a position facing each nozzle face. This causes a white background image to be printed on the printing surface of the substrate 1. The white background image is not limited to an image printed over the entire area of the color image, but may also be an image selectively printed in areas of the color image.

The print control unit also controls imaging by the inspection unit 97, causing the test pattern image printed on the substrate 1 to be read. The print control unit causes the first scanner 98 and the second scanner 99 to read the test pattern image when the test pattern image printed on the substrate 1 passes a position opposite the inspection unit 97. The print control unit may store the images read by the first scanner 98 and the second scanner 99 in the memory unit 172. The print control unit controls a determination unit (not shown) to identify faulty nozzles from the images read by the first scanner 98 and the second scanner 99.

The tension control unit controls the transport tension, which is the tension in the direction of movement of the substrate 1 as it is floated and transported by the second non-contact turn unit 92. The tension control unit controls the rotational speed of the third drive roller 106 relative to the rotational speed of the second suction drum 86, and imparts a rotational speed difference between the second suction drum 86 and the third drive roller 106 so that the transport tension of the substrate 1 detected by the fourth tension pickup roller 26 becomes a preset transport tension. The tension control unit sets a higher transport tension the greater the tensile modulus (Young's modulus) of the substrate 1, and a lower transport tension the smaller the tensile modulus of the substrate 1, thereby making the amount of elongation of the substrate 1 uniform.

The tension control unit may control the rotational speed of the first drive roller 34 relative to the rotational speed of the first suction drum 84 or the application roller 54 so that the transport tension of the substrate 1 detected by the first tension pickup roller 23 is the desired tension. The tension control unit may also control the rotational speed of the application roller 54 relative to the rotational speed of the first suction drum 84 so that the transport tension of the substrate 1 detected by the second tension pickup roller 24 is the desired tension.

The tension control unit may control the rotational speed of the second suction drum 86 relative to the rotational speed of the first suction drum 84 so that the transport tension of the substrate 1 detected by the third tension pickup roller 25 is the desired tension. The tension control unit may also control the rotational speed of the fourth drive roller 130 relative to the rotational speed of the third drive roller 106 so that the transport tension of the substrate 1 detected by the fifth tension pickup roller 27 is the desired tension. The tension control unit may also control the rotational speed of the take-up roll 122 relative to the rotational speed of the fifth drive roller 132 so that the transport tension of the substrate 1 detected by the sixth tension pickup roller 28 is the desired tension.

The air volume control unit controls the second non-contact turn unit 92. The air volume control unit selects and switches the amount of air blown out (air volume) from the outlet of the second non-contact turn unit 92 from at least two set values depending on the type of substrate 1. By controlling the air volume, the air volume control unit ensures that the floating amount of the substrate 1 floated and transported by the second non-contact turn unit 92 is uniform regardless of the transport tension.

The air volume control unit may control the amount of air blown out of the first non-contact turn section 60 as needed.

The main drying control unit 184 controls the main drying unit 100. The main drying control unit 184 controls heating by the hot air heater 104. The main drying control unit 184 controls the temperature and air volume of the hot air heater 104 to dry the water-based ink.

The winding control unit 186 controls the rotation of a motor (not shown) to rotate the fourth drive roller 130 and the fifth drive roller 132 at a predetermined speed. The winding control unit 186 controls the inspection unit 124 to capture images, thereby reading the image printed on the substrate 1. The winding control unit 186 causes the third scanner 126 and the fourth scanner 128 to read the image when the image printed on the substrate 1 passes a position opposite the inspection unit 124. The winding control unit 186 may store the images read by the third scanner 126 and the fourth scanner 128 in the memory unit 172.

The winding control unit 186 also controls a determination unit (not shown) to determine the quality of the image printed on the substrate 1 from the images read by the third scanner 126 and the fourth scanner 128. The determination unit may read data on non-defective images from the memory unit 172 and compare it with the read images to determine the quality of the image. The winding control unit 186 may also control a stamp process to sort out defective images.

The measurement control unit 188 controls the operation of the automatic color measurement system provided in the measurement unit 150. The measurement control unit 188 controls the movement of the measurement table and colorimeter 250, and performs automatic measurement of the color adjustment chart based on the position information of each patch on the color adjustment chart.

The spot color adjustment processing unit 190 acquires the measurement data of each patch measured using the colorimeter 250, performs processing to determine the device signal value corresponding to the target color of the spot color, and corrects (updates) the information in the spot color information database 220.

The image processing unit 192 includes the processing functions of the RIP processing unit 208. The image processing unit 192 performs various conversion processes, correction processes, halftone processes, etc. on the image data to be printed. Conversion processes include pixel count conversion, tone conversion, color conversion, etc. Correction processes include density correction, including unevenness correction to suppress uneven density, and non-ejection correction to suppress the visibility of image defects caused by faulty nozzles.

Halftoning is generally a process in which m-level (m is an integer equal to or greater than 3) multi-level image data is quantized and converted into n-level (n is an integer equal to or greater than 2 and less than m) data. For example, multi-level image data with 8 bits (256 levels) or more per color is essentially understood to be continuous-level image data. The image processing unit 192 converts, on a pixel-by-pixel basis, continuous-level image data for each color of CMYK, for example, into dot data that represents a multi-level dot arrangement of ternary or greater values.

In this example, the inkjet heads 96K, 96C, 96M, and 96Y can eject three different droplet sizes (dot sizes): small, medium, and large. In this case, the image processing unit 192 converts the continuous tone color separation image data into a four-level (n=4) signal: "eject large ink droplets," "eject medium ink droplets," "eject small ink droplets," and "no ejection (no droplets)." This type of halftone processing can be performed using, for example, a dithering method or an error diffusion method. The image processing unit 192 also performs corrections based on the scanned image obtained from the inspection unit 124.

The ejection timing and ink ejection amount for each pixel position are determined based on the dot data generated through processing by the image processing unit 192, and a drive voltage corresponding to the ejection timing and ink ejection amount for each pixel position and a control signal that determines the ejection timing for each pixel are generated. This drive voltage is supplied to inkjet heads 96K, 96C, 96M, and 96Y, and dots are recorded on the substrate 1 using ink ejected from inkjet heads 96K, 96C, 96M, and 96Y.

<<Method for manufacturing printed matter>>
21 is a flowchart showing a method for producing a printed matter using the printing system 12 according to the embodiment. Note that the color adjustment work for spot colors has already been explained, so here, the printing of job images will be mainly explained together with the operation of the inkjet printing machine 10.

In step S101, the information processing device 200 acquires information indicating the type of substrate 1. The user can input the type of substrate 1 to be used for printing via the user interface 170. The type of substrate 1 may also be acquired automatically from an identification code attached to a roll or the like set in the unwinding section 30. Information on the type of substrate 1 may be acquired after the job is registered, or may be acquired after the job is registered.

In step S102, the conveying unit 20 begins conveying the substrate 1. That is, the conveying unit 20 rotates the first suction drum 84 using a motor (not shown), causing the substrate 1 to be unwound from the unwinding roll 32. The conveying unit 20 also rotates the reel of the winding roll 122 using a winding motor (not shown), causing the substrate 1 to be wound onto the winding roll 122. In this way, the conveying unit 20 conveys the substrate 1 from the unwinding roll 32 to the winding roll 122 using a roll-to-roll method.

In step S103, the corona treatment unit 38 applies corona discharge treatment to the printing surface of the substrate 1.

In step S104, the precoat unit 50 applies an aqueous primer to the printing surface of the substrate 1.

In step S105, the precoat drying unit 58 dries the aqueous primer applied to the printing surface of the substrate 1.

In step S106, the jetting unit 80 adsorbs the substrate 1 using the first suction drum 84 and the second suction drum 86.

In step S107, the second non-contact turning section 92 guides the substrate 1, which has been guided to the downward transport path by the second suction drum 86, to the upward transport path without contacting the printing surface.

In step S108, the tension control unit adjusts the conveying tension of the substrate 1, which is floated and conveyed by the second non-contact turn unit 92, to a preset conveying tension by imparting a rotational speed difference between the second suction drum 86 and the third drive roller 106 based on the conveying tension detected by the fourth tension pickup roller 26. The conveying tension is set according to the type of substrate 1 obtained in step S101. The conveying tension may also be set according to the tensile modulus of elasticity of the substrate 1. A table showing the relationship between the type of substrate 1 and the tensile modulus of elasticity may be stored in the memory unit 172.

In step S109, the air volume control unit adjusts the amount of floating of the substrate 1 being floated and transported by the second non-contact turn section 92 by controlling the amount of air blown out from the outlet of the second non-contact turn section 92. The amount of air blown out is set according to the set tension set in step S108. This ensures that the amount of floating of the substrate 1 is uniform regardless of the transport tension.

In step S110, the color printing unit 88 prints a color image on the printing surface of the substrate 1 based on the image data of the target job. In step S111, the white printing unit 90 prints a white background image on the printing surface of the substrate 1.

In step S112, the main drying unit 100 dries the water-based ink applied to the printing surface of the substrate 1.

In step S113, the inspection unit 124 inspects the image printed on the printing surface of the substrate 1. The substrate 1 is then wound onto the winding roll 122. In this way, a printed product is produced, and after step S113, production of the printed product is completed. The printed roll-shaped substrate 1 is then subjected to cutting, bending, weaving, bonding, and other post-processing using an automatic post-processing device (not shown).

<Inkjet head ejection method>
In general, an ejector of an inkjet head includes a nozzle for ejecting ink, a pressure chamber connected to the nozzle, and an ejection energy generating element for applying ejection energy to the liquid in the pressure chamber. Regarding the ejection method for ejecting droplets from the nozzle of the ejector, the means for generating the ejection energy is not limited to a piezoelectric element, and various ejection energy generating elements such as a heating element or an electrostatic actuator can be used. For example, a method can be adopted in which droplets are ejected by utilizing the pressure of film boiling caused by heating the liquid with a heating element. Depending on the ejection method of the inkjet head, a corresponding ejection energy generating element is provided in the flow path structure.

About the programs that run computers
A program that causes a computer to realize some or all of the processing functions of the information processing device 200 can be recorded on a computer-readable medium such as an optical disk, a magnetic disk, a semiconductor memory, or other tangible, non-transitory information storage medium, and the program can be provided through this information storage medium.

Instead of providing the program by storing it on such non-transitory computer-readable media, it is also possible to provide the program signal as a download service using telecommunications lines such as the Internet.

Some or all of the processing functions of the information processing device 200 may be realized by cloud computing, or may be provided as a SasS (Software as a Service) service.

<<Hardware configuration of each processing unit>>
The hardware structure of the processing units in the information processing device 200 that perform various processes, such as the print job management unit 202, chart generation unit 204, image data combination unit 206, RIP processing unit 208, color conversion processing unit 209, printer control unit 210, measurement data management unit 223, spot color data correction unit 226, communication unit 173, system control unit 174, conveyance control unit 176, unwinding control unit 178, precoat control unit 180, jetting control unit 182, main drying control unit 184, winding control unit 186, measurement control unit 188, spot color adjustment processing unit 190, and image processing unit 192, is, for example, various processors as shown below.

Various types of processors include CPUs, which are general-purpose processors that execute programs and function as various processing units; GPUs, which are processors specialized for image processing; programmable logic devices (PLDs), such as FPGAs (Field Programmable Gate Arrays), which are processors whose circuit configuration can be changed after manufacture; and dedicated electrical circuits, such as ASICs (Application Specific Integrated Circuits), which are processors with circuit configurations designed specifically to perform specific processes.

A single processing unit may be composed of one of these various processors, or two or more processors of the same or different types. For example, a single processing unit may be composed of multiple FPGAs, or a combination of a CPU and an FPGA, or a combination of a CPU and a GPU. Multiple processing units may also be composed of a single processor. Examples of multiple processing units composed of a single processor include, first, a configuration in which a single processor is composed of a combination of one or more CPUs and software, as typified by client or server computers, and this processor functions as multiple processing units. Second, a configuration in which a processor is used to realize the functions of an entire system including multiple processing units on a single IC (Integrated Circuit) chip, as typified by a system-on-chip (SoC). In this way, the various processing units are composed of one or more of the various processors listed above as a hardware structure.

Furthermore, the hardware structure of these various processors is, more specifically, an electrical circuit that combines circuit elements such as semiconductor elements.

Effects of this embodiment
According to this embodiment, the following effects can be obtained.

[1] When printing multiple jobs, the system takes advantage of the order in which the jobs are printed, printing the image data of the preceding job followed by a color adjustment chart for adjusting the spot colors of the subsequent job, thereby reducing paper waste when printing the charts.

[2] The area (page) of the printed color adjustment chart on the roll-shaped substrate 1 can be treated as an independent page, just like the printed image to be printed for the job. Therefore, by placing the color adjustment chart only on the final page of multiple copies of printed material, after printing, simply remove the page with the chart image, and then use an automatic post-processing device to perform the required post-processing on the multiple copies of printed material specified for the job. In this way, this embodiment is well-suited for post-processing work using an automatic post-processing device.

<<About recording media>>
In the above embodiment, a transparent resin film substrate 1 is used as an example of the recording medium, but the form of the recording medium is not limited to this and various forms are possible, regardless of the material, such as paper, cloth, or nonwoven fabric. In the case of a printing system that prints on a non-transparent medium such as paper, the inkjet heads 96W1 and 96W2 for white ink described in Figure 1 are not required.

<<Variation 1>>
In the above embodiment, an example in which aqueous ink is used has been described, but ultraviolet-curable ink may be used instead of aqueous ink. When ultraviolet-curable ink is used, the inkjet printer 10 includes an ultraviolet irradiation device instead of or in addition to the ink heating and drying treatment unit.

<<Variation 2>>
In the above embodiment, the inkjet printer 10 using a page-wide full-line head has been described, but the scope of application of the present disclosure is not limited to this, and the technology of the present disclosure can also be applied to printers that perform printing by moving a short recording head, such as a serial head, and performing multiple head scans. Furthermore, the method of forming images is not limited to the inkjet method.

<<Using recording heads other than inkjet type>>
In the above embodiment, an inkjet printer 10 is used as an example of a printing device, but the scope of application of the present disclosure is not limited to this. In addition to inkjet printing, the present disclosure can also be applied to various types of digital printing devices that perform dot recording, such as a thermal transfer printing device equipped with a recording head that uses thermal elements as recording elements, an LED electrophotographic printer equipped with a recording head that uses LED (Light Emitting Diode) elements as recording elements, and a silver halide photographic printer equipped with an LED line exposure head. The "colorant" used for printing is not limited to ink, and may be, for example, toner.

<<Terminology>>
The term "printing device" is synonymous with terms such as printing press, image forming device, printer, printing device, image recording device, image output device, or drawing device. The term "printing" includes concepts of terms such as print, image forming, image recording, printing, and drawing.

"Image" is to be interpreted broadly and includes color images, black and white images, single-color images, gradation images, and uniform density (solid) images. "Image" is used as a comprehensive term that is not limited to photographic images, but also includes designs, letters, symbols, line drawings, mosaic patterns, color-coded patterns, various other patterns, or any combination of these.

"others"
The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the technical idea of the present disclosure.

1 Substrate 4 Job list 6 Print execution button 7 Cancel button 10 Inkjet printing machine 12 Printing system 20 Conveying section 22 Path roller 23 First tension pickup roller 24 Second tension pickup roller 25 Third tension pickup roller 26 Fourth tension pickup roller 27 Fifth tension pickup roller 28 Sixth tension pickup roller 30 Unwinding section 32 Unwinding roll 34 First drive roller 36 Second drive roller 38 Corona treatment section 50 Precoat section 52 Coater 54 Application roller 55 Chamber 56 Opposing roller 58 Precoat drying section 60 First non-contact turning section 80 Jetting section 84 First suction drum 86 Second suction drum 88 Color printing section 90 White printing section 92 Second non-contact turning section 96K Inkjet head 96C Inkjet head 96Y Inkjet head 96M Inkjet head 96W1 Inkjet head 96W2 Inkjet head 97 Inspection section 98 First scanner 99 Second scanner 100 Main drying section 104, 104A Hot air heater 106 Third drive roller 120 Winding section 122 Winding roll 124 Inspection section 126 Third scanner 128 Fourth scanner 130 Fourth drive roller 132 Fifth drive roller 136 Roller 138 Swing arm 150 Measurement section 170 User interface 172 Memory section 173 Communication section 174 System control section 176 Conveyance control section 178 Unwinding control section 180 Precoat control section 182 Jetting control section 184 Main drying control section 186 Winding control section 188 Measurement control section 190 Spot color adjustment processing section 192 Image processing section 200 Information processing device 202 Print job management section 204 Chart generation section 206 Image data combination section 208 RIP processing section 209 Color conversion processing section 210 Printer control section 220 Spot color information database 222, chart information database 223, measurement data management section 224, measurement data management database 226, spot color data correction section 228, image database 250, colorimeter 252, rail 302, processor 304, computer-readable medium 306, communication interface 308, input/output interface 310, bus 312, RAM
314 ROM
316 Storage 322 Input device 324 Display device CP(N) Color adjustment chart image IMG(N-1), IMG(N) Print image S21 to S28 Steps S31 to S37 of print job registration processing Steps S41 to S47 of printing processing Steps S51 to S56 of chart measurement and spot color information correction processing Steps S101 to S113 of printing processing after spot color information correction Steps of method for manufacturing printed matter

Claims (21)

a processor;
a storage device storing instructions to be executed by the processor;
The processor:
When printing images to be printed for a plurality of print jobs on a roll medium, a color adjustment chart is generated to be used for adjustment to reproduce a specific target color specified in image data of a second print job that is printed later in the order of printing than a first print job among the plurality of print jobs;
Merging chart image data of the color adjustment chart with image data of the first print job;
By executing the first print job, the print target image of the first print job and the color adjustment chart are printed;
and setting an image signal value corresponding to the target color based on a color measurement result obtained by measuring the color of a printed matter of the color adjustment chart.
Color adjustment device. the color adjustment chart includes color patches for each of a plurality of image signal values, including a first image signal value that is a candidate for an image signal value corresponding to the target color, and a second image signal value that is another candidate that indicates a color surrounding the first image signal value;
The color adjustment device according to claim 1 . the color adjustment chart includes a chart pattern in which a plurality of the color patches are two-dimensionally arranged;
The color adjustment device according to claim 2 . The second print job is next in the print order to the first print job.
The color adjustment device according to claim 1 . the chart image data is printed following the last image data to be printed in the first print job;
The color adjustment device according to claim 1 . the color adjustment chart includes color patches of single colors of colorants used in the printing device;
the processor confirms the color reproducibility of the printing device based on the color measurement result of the single-color color patch.
The color adjustment device according to claim 1 . a plurality of color patches of the same color are arranged at different positions on the surface of the color adjustment chart;
the processor confirms color uniformity within a printing area printed by a printing device based on color measurement results of the plurality of color patches of the same color;
The color adjustment device according to claim 1 . When two or more second print jobs are grouped together and printed in a single continuous printing, the images to be printed of the two or more second print jobs are printed.
the processor combines the chart image data of the plurality of color adjustment charts used for adjustment to reproduce each of the plurality of target colors used in the two or more second print jobs together with the image data of the first print job;
The color adjustment device according to claim 1 . a characteristic color information database for storing data of image signal values corresponding to the target colors;
the processor corrects data in the spot color information database based on the color measurement result of the color adjustment chart.
The color adjustment device according to any one of claims 1 to 8. the processor causes the image to be printed of the second print job to be printed using image signal values set based on the color measurement result of the color adjustment chart;
The color adjustment device according to any one of claims 1 to 9. The image signal value corresponding to the target color is a combination of signal values of each of a plurality of colors including cyan, magenta, and yellow used in a printing device.
The color adjustment device according to any one of claims 1 to 10. The processor determines whether or not a spot color is specified in the image data of the second print job;
generating the color adjustment chart when it is determined that a spot color is specified in the image data of the second print job;
The color adjustment device according to any one of claims 1 to 11. the processor combines the chart image data with the trailing end of the image data of the first print job;
The color adjustment device according to any one of claims 1 to 12. A color adjustment method executed by a processor when printing images to be printed for a plurality of print jobs on a roll medium, comprising:
the processor:
generating a color adjustment chart to be used for adjustment to reproduce a specific target color specified in the image data of a second print job that is printed later than the first print job among the plurality of print jobs;
Merging chart image data of the color adjustment chart with image data of the first print job;
By executing the first print job, causing a printing device to print the chart image data by including it in image data to be printed by the first print job;
the processor sets an image signal value corresponding to the target color based on a color measurement result obtained by measuring the color of a printed matter of the color adjustment chart;
A color adjustment method, including: An information processing device that controls a printing device that prints on a roll medium,
a processor;
a storage device storing instructions to be executed by the processor;
The processor:
Accepts multiple print jobs,
setting a printing order for the plurality of print jobs;
generating a color adjustment chart to be used for adjustment to reproduce a specific target color designated in the image data of a second print job that is printed later than the first print job among the plurality of print jobs;
Merging chart image data of the color adjustment chart with image data of the first print job;
By executing the first print job, the print target image of the first print job and the color adjustment chart are printed;
obtaining a color measurement result obtained by measuring the color of a printed matter of the color adjustment chart;
Based on the color measurement result, an image signal value corresponding to the target color is set;
printing the image to be printed of the second print job using image signal values set for the target color based on the color measurement results;
Information processing device. a printing device that prints on a roll medium;
an information processing device that controls the printing device,
The information processing device
a processor;
a storage device storing instructions to be executed by the processor;
The processor:
Accepts multiple print jobs,
setting a printing order for the plurality of print jobs;
generating a color adjustment chart to be used for adjustment to reproduce a specific target color designated in the image data of a second print job that is printed later than the first print job among the plurality of print jobs;
Merging chart image data of the color adjustment chart with image data of the first print job;
By executing the first print job, the printing device is caused to print the print target image of the first print job and the color adjustment chart;
obtaining a color measurement result obtained by measuring the color of a printed matter of the color adjustment chart;
Based on the color measurement result, an image signal value corresponding to the target color is set;
causing the printing device to print the image to be printed of the second print job using image signal values set for the target color based on the color measurement results;
Printing system. a colorimeter for measuring the color of a printed matter of the color adjustment chart;
The printing system of claim 16 . a moving mechanism for moving the colorimeter,
the processor controls the movement mechanism to move the color measurement position of the colorimeter based on position information of the color patches included in the color adjustment chart, and automatically obtains the color measurement results for each of the color patches of the color adjustment chart.
The printing system of claim 17 . the printing device is an inkjet printer equipped with inkjet heads that eject ink of each color, cyan, magenta, yellow, and black;
A printing system according to any one of claims 16 to 18 . A program for causing a computer to realize a function of color adjustment of a printing device,
a function of generating a color adjustment chart to be used for adjustments to reproduce a specific target color designated in image data of a second print job that is printed later than a first print job among the plurality of print jobs when printing images to be printed for the plurality of print jobs on a roll medium;
a function of combining chart image data of the color adjustment chart with image data of the first print job;
a function of printing the print target image of the first print job and the color adjustment chart by executing the first print job;
a function of setting an image signal value corresponding to the target color based on a color measurement result obtained by measuring the color of a printed matter of the color adjustment chart;
A program that enables a computer to achieve this. A method for producing a printed matter using a printing device that prints on a roll medium, comprising:
The information processing device
Accepting a plurality of print jobs and setting a printing order for the plurality of print jobs;
The information processing device generates a color adjustment chart to be used for adjustment to reproduce a specific target color specified in image data of a second print job that is printed later than a first print job among the plurality of print jobs;
the information processing device combines chart image data of the color adjustment chart with image data of the first print job;
Execution of the first print job causes the printing device to print the print target image of the first print job and the color adjustment chart;
measuring the color of a printed matter of the color adjustment chart using a colorimeter;
the information processing device acquires a color measurement result of a printout of the color adjustment chart, and sets an image signal value corresponding to the target color based on the color measurement result;
the printing device prints the image to be printed of the second print job using image signal values set for the target color based on the color measurement results;
A method for producing a printed matter, comprising: