Printing system, printing apparatus, and printing method

Abstract

To provide a printing system that can suppress a color of a medium from changing hue of an image, while suppressing white ink from being used.SOLUTION: A printing system comprises a discharge part that discharges color ink and white ink to a medium, and a control part that controls the discharge part. The printing system obtains image data, information on colors of the medium and information on a density of white ink. The control part calculates a masking ratio of the medium on the basis of the information on colors of the medium and the density of the while ink, calculates adhesion amounts of white ink that are necessary for masking the medium on the basis of the calculated masking ratio, reads out an image parameter describe below in the image data, performs threshold determination of the read image parameter, and adjusts the adhesion amounts of white ink on the basis of the determined result. One or more image parameters are selected from adhesion amounts of color ink and color data that can be measured with a measurement instrument.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a printing system, a printing apparatus, and a printing method.

Background Art

[0002] As an example of a printing apparatus, a DTF (Direct To Film) printer is known. A DTF printer forms a transfer image by applying coloring ink to a transfer base material such as a film. For example, an adhesive powder is applied to the transfer image, and the coloring ink on the film is transferred to a transfer material such as clothing.

[0003] In such printers of the DTF method or other methods, a white ink (white ink) is used to form a base or the like, and washing fastness is ensured and the transfer material is concealed.

[0004] Patent Document 1 discloses a printing method that uses an appropriate amount of white ink according to the color of an image while maintaining good washing fastness for the purpose of reducing costs when forming an image on a medium.

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional art, there is a problem that the color tone of the image changes depending on the color of the medium or the transfer material when reducing the ink adhesion amount. On the other hand, in order to prevent the color tone of the image from changing depending on the color of the medium or the transfer material, increasing the amount of white ink or the like not only increases the cost but also causes a problem of insufficient drying. When drying is insufficient, there is a problem that the ink flows and poor quality occurs.

[0006] Therefore, an object of the present invention is to provide a printing system that can suppress the change in the color tone of an image depending on the color of a medium while suppressing the amount of white ink used.

Means for Solving the Problems

[0007] To solve the above problems, the printing system of the present invention is A printing system having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The printing system includes image information and color information of the medium. Information on the concentration of white ink, and Obtain, The control unit uses the color information of the medium and the information on the concentration of the white ink The amount of white ink ejected is adjusted based on the following image parameters in the aforementioned image information. It is characterized by the following: [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a printing system that can suppress changes in the color of an image depending on the color of the medium while reducing the amount of white ink used. [Brief explanation of the drawing]

[0009] [Figure 1] Figures (A) and (B) illustrate an example of the printing system of the present invention. [Figure 2] Figures (A) and (B) illustrate an example of controlling the amount of white ink applied. [Figure 3A] This is a flowchart illustrating an example of the processing of the printing system of the present invention, and is an example of determining a threshold for the amount of color ink deposited. [Figure 3B] This is a flowchart illustrating an example of the processing of the printing system of the present invention, and is an example of performing threshold determination on color data. [Figure 4] This figure illustrates another example of controlling the amount of white ink applied. [Figure 5]This flowchart illustrates another example of the processing of the printing system of the present invention, and is an example of determining the threshold of color ink adhesion and color data. [Figure 6] Figures (A) and (B) illustrate the flow of ink. [Figure 7] This is a diagram illustrating an example of gradient processing. [Figure 8] This is a flowchart illustrating another example of the processing of the printing system of the present invention. [Figure 9] This is a flowchart illustrating another example of the processing of the printing system of the present invention. [Modes for carrying out the invention]

[0010] The printing system, printing apparatus, and printing method according to the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to the embodiments shown below, and other embodiments, additions, modifications, and deletions can be made within the scope of what a person skilled in the art can conceive. Any embodiment that achieves the function and effect of the present invention is included within the scope of the present invention.

[0011] (First Embodiment) An embodiment of the present invention will be described. In this embodiment, ink is ejected onto a medium.

[0012] The printing system of this embodiment is a printing system having a discharge unit that discharges color ink and white ink onto a medium, and a control unit that controls the discharge unit, wherein the printing system obtains image data, color information of the medium, and density information of the white ink, and the control unit calculates the opacity of the medium based on the color information of the medium and the density of the white ink, calculates the amount of white ink to be deposited to opaque the medium based on the calculated opacity, reads the following image parameters in the image data, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink deposited based on the judgment result. [Image parameters] The image parameters are one or more selected from the amount of color ink adhesion and color data measurable by a colorimeter.

[0013] The printing apparatus of the present embodiment is a printing apparatus having a discharge unit that discharges color ink and white ink onto a medium, and a control unit that controls the discharge unit. The printing apparatus obtains image data, information on the color of the medium, and information on the density of the white ink. The control unit calculates the hiding power of the medium based on the information on the color of the medium and the density of the white ink, calculates the amount of white ink adhesion necessary to hide the medium based on the calculated hiding power, reads the following image parameters in the image data, performs a threshold determination on the read image parameters, and adjusts the amount of white ink adhesion based on the determination result. [Image parameters] The image parameters are one or more selected from the amount of color ink adhesion and color data measurable by a colorimeter.

[0014] The printing method of the present embodiment is a printing method including a discharging step of discharging color ink and white ink onto onto a medium by a printing apparatus, and a control step of controlling the discharge of the color ink and the white ink. The printing method obtains image data, information on the color of the medium, and information on the density of the white ink. The control step calculates the hiding power of the medium based on the information on the color of the medium and the density of the white ink, calculates the amount of white ink adhesion necessary to hide the medium based on the calculated hiding power, reads the following image parameters in the image data, performs a threshold determination on the read image parameters, and adjusts the amount of white ink adhesion based on the determination result. [Image parameters] The image parameters are one or more selected from the amount of color ink adhesion and color data measurable by a colorimeter.

[0015] In the following description, the medium, the transfer medium, and the transfer material have the same meaning. Also, "image data" and "image information" have the same meaning. Also, in the image parameters, "color data" and "color information" have the same meaning.

[0016] In this embodiment, the hiding rate of the medium is calculated using the color information of the medium and the density of the white ink, and the amount of white ink adhesion required to hide the medium is calculated using the calculated hiding rate. Further, image parameters are read from the image data, and it is determined whether the read image parameters are below a predetermined threshold value. Based on this determination result, control is performed to adjust the amount of white ink adhesion.

[0017] When calculating the hiding rate of the medium using the color information of the medium and the density of the white ink, the hiding rate of the medium may be calculated by the following method. The calculation formula for defining whiteness in terms of lightness L* is as follows. (L*_white ink adhesion part)-(L*_transfer target medium) / (L*_white ink adhesion part)

[0018] When defining whiteness in terms of K density*, the calculation formula for the hiding rate of the medium is as follows. (K density*_white ink adhesion part)-(K density*_transfer target medium) / (K density*_white ink adhesion part) The K density represents the K density (visual density) of the spectral density. The visual density represents a weighted value with the characteristics of the response of the intermediate wavelength of the common logarithm of the reciprocal of the reflectance.

[0019] Also, the hiding rate may be set as the white difference ΔE as the hiding property. ΔE_{(white as the target value),(white ink adhesion part)} Although the hiding rate is described in this embodiment, it is not important that it is a ratio, and it is sufficient that the threshold value of the hiding property can be specified numerically.

[0020] For example, if the image parameters are below a predetermined threshold, the printing device dispenses white ink using a calculated amount of white ink to be applied. In this way, the necessary amount of white ink can be applied to areas that would be affected by the color of the medium. This allows for consistent color tones of the transferred image regardless of the medium, while minimizing the amount of white ink used.

[0021] Printing may also be referred to as image formation, recording, printing, copying, shaping, etc., all of which are synonymous. When using an inkjet printing device, the printing system may be referred to as an inkjet system.

[0022] The medium can be selected as appropriate and can include paper, thread, fibers, fabrics, leather, metal, plastic, glass, wood, ceramics, building materials such as wallpaper and flooring, textiles for clothing, signage, etc., as long as the liquid can adhere to it, even temporarily.

[0023] The printing system of this embodiment includes a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit. Within the printing system, the dispensing unit and the control unit may be separate, or they may be located in the same device.

[0024] The system configuration can be selected as appropriate. For example, it may have a printing device having an ejection unit and a control unit. Alternatively, the printing system may have a printing device having an ejection unit and another device having a control unit that controls the printing device.

[0025] The printing system of this embodiment may or may not include an information processing device used by the user (e.g., a personal computer, tablet, smartphone, etc.).

[0026] Figure 1 is a diagram illustrating an example of the printing system 10 of this embodiment. The printing system 10 may include an image forming apparatus 2 having an ejection unit and a control unit, as shown in (A). In this case, the image forming apparatus 2 may exchange data with the information processing apparatus 1. The printing system 10 may include an image forming apparatus 2 having an ejection unit and a control device 3 having a control unit, as shown in (B). In this case, the printing system 10 may exchange data with the information processing apparatus 1, or the control device 3 may exchange data with the information processing apparatus 1.

[0027] The information processing apparatus 1, the image forming apparatus 2, and the control device 3 each appropriately include, for example, a CPU, RAM, ROM, HDD, I / F, etc.

[0028] The ejection unit has a liquid ejection head, such as an inkjet head. There may be one liquid ejection head or multiple liquid ejection heads. The ejection unit may be serial or line-based.

[0029] The image forming apparatus 2 may have a transport unit for transporting the medium. The image forming apparatus 2 may also have a heating unit for heating (or drying, etc.) the medium. Examples of heating units include heaters. The image forming apparatus 2 is an example of a printing apparatus according to this embodiment.

[0030] The printing system of this embodiment obtains image data, information about the color of the medium, and information about the density of the white ink. "Obtaining" may also be referred to as "receiving," "collecting," or "accepting." This data and information may be obtained by the image forming apparatus 2, the control device 3, or other devices. For example, this data and information may be obtained from the information processing apparatus 1. This may or may not be done via the internet.

[0031] The printing system of this embodiment may obtain the above data and information from devices other than the information processing device 1. For example, it may obtain information about the color of the medium as a measurement result from a measuring device that measures the color of the medium. Alternatively, for example, it may obtain information about the density of white ink as a measurement result from a measuring device that measures the density of white ink.

[0032] Image data may, for example, be included in the print instructions. Information on the color of the medium and the density of the white ink may be included in the print instructions and transmitted each time, or the system may obtain this information in advance before the print instructions are sent. In this case, the information can be stored in any storage means.

[0033] The control unit calculates the opacity of the medium based on the color information of the medium and the density of the white ink, and also calculates (or may be called determining) the amount of white ink required to opacify the medium. For example, when printing on red polyester fabric, the opacity of the medium is calculated using the red color information and the density of the white ink. From the opacity of the medium calculated in this way, the amount of white ink required to opacify the medium is calculated. The amount of white ink required to conceal the medium is sometimes referred to as the minimum amount of white ink needed.

[0034] The control unit reads predetermined image parameters from the image data. The control unit performs a threshold check on the read image parameters. Based on the check result, the control unit adjusts the amount of white ink applied. In this way, the necessary amount of white ink can be applied to areas that would be affected by the color of the medium. This reduces the amount of white ink used while suppressing changes in the image's color due to the color of the medium.

[0035] In this embodiment, the image parameter is selected from either the amount of color ink deposited or color data measurable by a colorimeter. When these are used as image parameters, it is easy to read from image data, easy to set thresholds, and easy to control the amount of white ink deposited. When the image parameter is selected from any one of these, it becomes easier to set and determine thresholds, and easier to control the amount of white ink deposited. In addition, it is possible to prevent the threshold determination process from becoming complicated. There are no particular restrictions on which image parameter to use, and the optimal image parameter should be selected depending on the application.

[0036] Ink adhesion amount can also be described as the amount of ink ejected, obtained by analyzing the input image data. When we say we are adjusting the amount of white ink adhesion, we are also saying we are adjusting the amount of white ink that is ejected. Ink adhesion amount can be determined, for example, as follows: By creating a profile at a stage before ejection, the relationship between color and color ink adhesion amount is calculated. Based on this, the ink adhesion amount is determined from the image data.

[0037] The unit for ink adhesion is, for example, %, and in this case, it ranges from 0 to 100%. An ink adhesion of 0% represents a state where not a single drop of the color ink is ejected from the ejection unit, for example, the nozzles of the inkjet head. An ink adhesion of 100% represents a state where the color ink is ejected from all nozzles of the inkjet head at the maximum possible ejection rate per drop. The numerical value of ink adhesion is determined, for example, by processing image data with a RIP (Raster Image Processor). The amount of white ink adhesion and the amount of color ink adhesion can be quantified in the same way.

[0038] The aforementioned color data is data obtained from a general-purpose colorimeter. Examples include spectral reflectance, spectral transmittance, and various color values ​​(X, Y, Z, L*, a*, b*, Δa*, Δb*, ΔL*, ΔEab*, YI, etc.). Examples of color data include spectral reflectance, spectral transmittance, lightness, saturation, and density, and it is preferable to select one of these. These are data obtained from a general-purpose colorimeter, making it easier to set thresholds.

[0039] When selecting brightness, saturation, and density as image parameters, you can quantify them as follows, for example: For example, if the image parameter is brightness, the brightest case is set to 0, the darkest case to 100, and the value is quantified by dividing it into several steps between 0 and 100. For example, if the image parameter is saturation, the lowest saturation is set to 0, the highest saturation to 100, and the value is quantified by dividing it into several steps between 0 and 100. For example, if the image parameter is density, the lowest density is set to 0, the highest density to 100, and the values ​​between 0 and 100 are divided into several steps and quantified numerically.

[0040] As described above, quantifying the parameters between 0 and 100 reduces the complexity of threshold determination when multiple items are selected as image parameters. For image parameters, only one optimal item needs to be selected depending on the application, and each item may have its own unique numerical range instead of being quantified between 0 and 100. Furthermore, each item may have its own unique threshold value when performing threshold determination.

[0041] The method for performing threshold judgments on image parameters read from image data, and the control measures taken based on the judgment results, can be selected as appropriate. An example is explained below. For example, if the image parameter is the amount of color ink applied, the control unit determines whether the amount of color ink applied is equal to or greater than a first threshold. If the amount of color ink applied is equal to or greater than the first threshold, the control unit controls the ejection of white ink at a predetermined lower limit of the amount of white ink applied. The predetermined lower limit of the amount of white ink applied could be, for example, the minimum amount of white ink required to ensure quality. In this way, drying defects can be prevented.

[0042] For example, if the image parameter is color data, the control unit determines whether the color data is below a second threshold. If the color data is below the second threshold, it controls the dispensing of white ink according to the calculated amount of white ink to be applied. The calculated amount of white ink to be applied is determined by calculating the opacity of the medium based on the color information of the medium and the concentration of the white ink, as described above, and then calculating the amount of white ink to be applied in order to conceal the medium. In this case, it is possible to prevent the medium from becoming incapable of being concealed.

[0043] By considering the amount of color ink applied and the color data mentioned above separately, it is possible to reliably conceal the medium and prevent insufficient ink drying. In this case, it is also possible to prevent excessive ink application and thus prevent drying failure. Excessive ink application can lead to drying failure, so reducing the amount of white ink applied as much as possible can prevent drying failure. The lower limit of the amount of white ink applied varies depending on the type of white ink, the type of transfer substrate, the type of material to be transferred, and the drying method, so it is necessary to change the conditions in advance, print a chart, and examine it.

[0044] Select the appropriate numerical settings for the color data so that when the color data values ​​are small, the media's colors are more likely to show through, and when the color data values ​​are large, the media's colors are less likely to show through. This makes it easier to set and determine thresholds for the color data.

[0045] The area in which image parameters are read and the amount of white ink applied is controlled may be the entire image, but it is preferable to perform this operation in predetermined areas. In other words, it is preferable that the control unit reads image parameters for each predetermined area, performs threshold determination, and controls the amount of white ink to be dispensed. By performing this process in predetermined areas, the effects of the present invention can be improved. In areas where it is necessary to apply a larger amount of white ink to conceal the transfer material, a larger amount of white ink can be applied. Furthermore, in areas where it is not necessary to apply a large amount of white ink, the amount of white ink used can be reduced. The scope of the designated area is not particularly limited and can be selected as appropriate.

[0046] White ink is used, for example, as a base layer after an image has been formed on the medium. Preferably, the control unit determines the amount of white ink used as the base layer and controls the amount of ink applied based on the image parameters. By determining the amount of white ink used as the base layer and controlling the amount of ink applied based on image parameters, the influence of the media's color can be further reduced.

[0047] The position of the background after the image is formed on the medium is appropriately selected depending on the intended use of the printed material. The white ink layer may be below or above the color ink layer. The position of the background differs depending on which side of the medium the printed material is viewed from. For example, if the side from which the ink is ejected is considered the front, when viewing the printed material from the front, the order is medium, white ink layer, and color ink layer. When viewing the printed material from the back, the order is medium, color ink layer, and white ink layer.

[0048] Figure 2 illustrates examples of adjusting the amount of white ink applied. Figure 2(A) shows an example of adjusting the amount of white ink applied based on the amount of colored ink applied. Figure 2(B) shows an example of adjusting the amount of white ink applied based on color data (labeled parameter A in the figure).

[0049] In Figure 2, the horizontal axis represents grayscale. While not strictly limited, in the illustrated example, the unit of grayscale is used as a percentage (%). A grayscale of 0% means that the density of the corresponding color is 0, and a grayscale of 100% means that the density of the corresponding color is the maximum. However, the maximum density of the corresponding color depends on the system. The range of grayscale from 0 to 100% is divided into steps and used as the horizontal axis in this example. The unit of grayscale can also be a dimensionless value from 0 to 100 instead of a percentage (%). In this example, the grayscale (horizontal axis) can also be considered as the amount of color ink deposited. Generally, a correlation is taken between the amount of ink deposited and the grayscale.

[0050] In Figure 2, the vertical axis represents ink adhesion amount and parameter A. The unit of ink adhesion amount is %. The unit of parameter A is dimensionless. In this example, parameter A is treated as a single item. In the example shown in Figure 2, the vertical axis is labeled "Adhesion Amount, A". Adhesion Amount represents the amount of ink adhered. As in this example, the ink adhesion amount and color data (parameter A) may be on the same scale. In this example, this scale is in the range of 0 to 100. This embodiment is not limited to this, and the ink adhesion amount and color data (parameter A) may be on different scales. In this example, there are no instances where the ink adhesion amount, parameter A, or gradation exceeds 100 (for example, 100%), but for convenience, the figure displays values ​​up to 120.

[0051] In Figure 2(A), plot a plots the amount of color ink applied [%]. In this example, the amount of color ink applied [%] is directly proportional to the gradation (e.g., %). Gradation is known to be a number that represents how many levels of color intensity, brightness, etc., can be expressed. As the gradation increases, the amount of ink applied increases (becomes larger) in order to express the color intensity, brightness, etc. Therefore, in the example shown, there is a proportional relationship between the amount of color ink applied and the gradation. For this reason, in this example, the gradation on the horizontal axis can be considered equivalent to the amount of color ink applied [%]. In this example, the amount of color ink applied may also be simply referred to as the amount of ink applied.

[0052] In Figure 2(A), plot b represents the amount of white ink [%] adjusted based on the amount of color ink applied. As described above, in this embodiment, for example, it is determined whether the amount of color ink applied is equal to or greater than a first threshold, and if it is equal to or greater than the first threshold, white ink is ejected at a predetermined lower limit of the amount of white ink applied. In the example shown in Figure 2(A), 80% is selected as the first threshold and threshold determination is performed. In the region where the amount of color ink applied is 80% or more, the minimum amount of white ink required to ensure quality is applied. In this example, the region where the amount of color ink applied is 80% or more corresponds to the region where the gradation is 80% or more, and is shown as a dashed line.

[0053] In this example, 30% is given as the minimum amount of white ink adhesion necessary to ensure quality. By setting the amount of white ink adhesion to 30% in areas where the amount of color ink adhesion is 80% or more, it is possible to prevent the amount of ink adhesion from becoming excessively small, and thus prevent, for example, difficulty in adhering adhesive powder. Therefore, a decrease in wash fastness and the occurrence of uneven image color can be suppressed, and quality can be ensured.

[0054] In the region where the amount of colored ink applied is below a first threshold, the amount of white ink applied can be adjusted as appropriate. As shown in plot b, for example, the amount of white ink applied can be controlled to decrease as the amount of colored ink applied increases.

[0055] In Figure 2(B), plot c corresponds to color data. In this example, color data is also referred to as parameter A. Plot c represents the change in parameter A with respect to the grayscale (horizontal axis). If we explain using density as an example of color data, in this example, a smaller value of color data indicates a lighter color, and a larger value indicates a darker color. Therefore, when the density value of the color data is small, the color of the medium is more likely to affect the image. For this reason, in the region where the color data value is small in this example, it is necessary to increase the amount of white ink applied to conceal the color of the medium.

[0056] In Figure 2(B), plot d represents the amount of white ink applied [%] adjusted based on the color data. As described above, in this embodiment, for example, it is determined whether the color data is below a second threshold, and if it is below the second threshold, white ink is dispensed with an amount of white ink applied calculated based on the color information of the medium and the density of the white ink. In the example shown in Figure 2(B), 30 is selected as the second threshold and threshold determination is performed. In the region where the color data is 30 or less, the calculated amount of white ink applied is applied. In this example, the region where the color data is 30 or less corresponds to the region where the gradation is approximately 56% or less, and is shown with a normal dashed line.

[0057] In this example, a calculated white ink adhesion amount of 70% is used as an example. By setting the white ink adhesion amount to 70% in areas where the color data is 30 or less, the media can be reliably concealed.

[0058] In regions where the color data is greater than the second threshold, the amount of white ink applied can be adjusted as appropriate. As shown in plot d, for example, where the color data value is large, the amount of white ink applied can be reduced.

[0059] Figures 3A and 3B are flowcharts illustrating an example of this embodiment. Figure 3A is an example flowchart corresponding to the example shown in Figure 2(A), and Figure 3B is an example flowchart corresponding to the example shown in Figure 2(B).

[0060] First, let's explain Figure 3A. S10 reads the color of the media. S11 reads the ink information. The ink information includes the density of the white ink and other information as needed. You can perform S10 and S11 in any order.

[0061] The color and ink information of the media can be included, for example, in the print instructions from the user. When the system receives the print instructions, it can read the color and ink information of the media. Alternatively, the color and ink information of the media can be stored in advance in any storage device, and then read from the storage device when a print instruction is received. The color and ink information of the media may be entered by the user or determined by measurement.

[0062] In S12, the opacity rate is calculated using the color information of the medium and the density of the white ink, and the minimum required amount of white ink to adhere is calculated using the calculated opacity rate.

[0063] In S13, image data is loaded. Image data is included, for example, in a print instruction from the user. Alternatively, the image data may be stored in any storage device and then read from that storage device. When loading image data, the image parameters within the image data are read.

[0064] In S14, the sRGB values ​​of image data are converted to CMYK values. Converting to CMYK values ​​makes it easier to perform tasks such as ejecting CMYK color inks.

[0065] In S15, it is determined whether the amount of color ink applied is equal to or greater than a set threshold. This threshold is the first threshold mentioned above. If the result is YES, S16 is performed. If the result is NO, S16 is not performed, and the process proceeds to S17.

[0066] In S16, the amount of white ink applied is adjusted. If the amount of color ink applied exceeds a set threshold, a predetermined amount of white ink that ensures quality is set. Note that if the judgment in S16 is YES, it corresponds to the region in Figure 2(A) where the amount of color ink applied is 80 or higher (for example, the region where the gradation is greater than around 80).

[0067] In S17, printing is performed on the medium.

[0068] Next, we will explain Figure 3B. We will omit explanations for parts that are common to both Figure 3A and Figure 3B. Here, we will explain the decision-making process after S14.

[0069] In S18, it is determined whether the color data is below a set threshold. This threshold is the second threshold mentioned above. If the result is YES, S19 is performed. If the result is NO, S19 is not performed, and the process proceeds to S17.

[0070] In S19, the amount of white ink applied is adjusted. If the color data is below the set threshold, the amount of white ink applied is set as calculated in S12. Note that if the judgment in S18 is YES, it corresponds to the region where A in Figure 2(B) is 30 or less (the region where the gradation is, for example, 56% or less).

[0071] In S17, printing is performed on the medium.

[0072] According to the printing system, printing apparatus, and printing method of this embodiment, it is possible to reduce the amount of white ink used, prevent the color of the medium from showing through, and prevent the color of the image from changing depending on the color of the medium.

[0073] Next, we will provide supplementary explanations regarding the adjustment of the amount of white ink adhesion shown in plots b and d. Plots b and d show the amount of white ink adhesion [%] adjusted based on the amount of color ink adhesion and color data. In adjusting the amount of white ink adhesion, the following conditions (1) to (4) are used in this example. (1) Minimum amount of white ink required to ensure quality: 30% (2) Amount of color ink adhesion that causes insufficient ink drying: 80% or more (3) Required amount of white ink to adhere, calculated from the opacity of the medium: 70% (4) Conditions for color data (parameter A) that allows the color of the medium to show through: A is 30 or higher

[0074] Condition (1) specifies the minimum amount of white ink required to ensure quality. If the amount of ink is too small, for example, it becomes difficult to adhere powder, which may lead to reduced wash fastness and uneven image color. Therefore, a lower limit is set for the amount of white ink applied, as in condition (1). Since quality such as uneven color varies depending on the combination of ink and medium, it is preferable to print charts with different amounts of ink applied for each ink and medium, and then set condition (1) after reviewing the results.

[0075] Condition (2) specifies the amount of color ink that will result in insufficient drying. When the gradation (e.g., the amount of color ink applied) is large, the amount of color ink on the medium increases, requiring sufficient drying. For this reason, in areas with a large amount of color ink, the amount of white ink applied to prevent occlusion should be reduced. Since the amount of ink that will result in insufficient drying varies depending on the drying method and type of ink, it is preferable to print a chart with different drying times, drying strengths, and ink application amounts for each ink, and then set condition (2) after reviewing the results.

[0076] Condition (3) specifies the required amount of white ink to be applied, calculated from the opacity of the medium. Condition (3) is, for example, the condition defined in S12 in Figures 3A and 3B. The opacity is calculated from the color information of the medium and the density information of the white ink, and this is used to calculate the required amount of white ink to be applied.

[0077] Condition (4) defines the conditions for color data that allow the color of the medium to show through. For example, colors with low brightness (high color data values) do not easily allow the color of the medium to show through, while colors with high brightness (low color data values) easily allow the color of the medium to show through. Since the conditions for color transparency differ depending on the type of color data, the color of the medium, the type of ink, etc., it is preferable to print a chart for each case, examine them, and then set condition (4). In addition to brightness, for example, if the density is high (a large value in the color data), the color of the medium is less likely to show through, while if the density is low (a small value in the color data), the color of the medium is more likely to show through.

[0078] Let's explain a specific example of how to quantify the color data (parameter A) in Figure 2(B). In Figure 2(B), the values ​​of 0 to 100 for the color data are calculated, for example, from the HSV values ​​and RGB values ​​included in the image data.

[0079] As shown in Figures 2(B) and 3B (S18) above, a threshold check is performed to determine whether the color data satisfies condition (4). In other words, it is determined whether the color data is 30 or less. Where the gradation is 56 or less (the area enclosed by the usual dashed line), the color data (plot c) is 30 or less, so it is expected that the color of the medium will show through. Therefore, where the gradation is 56 or less, condition (3), namely the minimum required amount of white ink (70%) calculated from the opacity rate, is applied. Accordingly, plot d (amount of white ink applied) is adjusted to 70% where the gradation is 56 or less (the area enclosed by the usual dashed line). This prevents the color of the medium from showing through.

[0080] As shown in Figures 2(A) and 3A (S15) above, a threshold determination is made, and the region where the amount of color ink adheres is around 80% or more corresponds to condition (2). Since the amount of ink adhered is large, it is desirable to consider drying properties. Therefore, condition (1) is applied to the region where the amount of color ink adheres is around 80% or more. Accordingly, plot b (amount of white ink adhered) is adjusted to 30% where the gradation is around 80 or higher (the region enclosed by the dashed line).

[0081] Generally, when printing on transfer substrates (e.g., film) in DTF, there is a desire to lower the drying temperature of the heating element (also called a heater) for the printed area. Lower drying temperatures improve the wettability of the printed area, resulting in better color development and more stable liquid ejection from the print head. However, if the drying temperature is too low, the color ink may not dry sufficiently in areas with a large amount of ink. In this case, abnormalities such as ink flow, repelling, and bleeding may occur. Simply reducing the amount of ink applied will cause the color of the transfer material to show through.

[0082] In this example, in areas where a large amount of color ink may not dry completely, the amount of white ink is reduced while ensuring a minimum amount of white ink is applied. This prevents the color of the medium from showing through, and by reducing the amount of white ink, it prevents insufficient drying and thus prevents ink bleeding due to poor drying.

[0083] In this embodiment, by adjusting the amount of white ink applied, it is possible to suppress the change in image color due to the color of the medium without excessive use of white ink. Furthermore, even when white ink is used to suppress the transparency of the medium's color, good drying properties can be achieved, ensuring good quality.

[0084] As mentioned above, in this embodiment, it is preferable to perform threshold determination of image parameters and adjustment of the amount of white ink applied for each predetermined area. By adjusting the amount of white ink applied for each area, it is possible to apply the minimum amount of white ink necessary to prevent the medium's color from showing through in each area, and to appropriately control the amount of white ink used for each area. As a result, the amount of white ink used can be reduced, and good results can be obtained from a cost perspective. In addition, by adjusting the amount of white ink applied for each area, it becomes easier to handle ink flow.

[0085] (Second embodiment) Next, other embodiments of the present invention will be described. In the examples described above, the threshold determination of the image parameter was mainly based on either the amount of colored ink deposited or the color data. However, the present invention is not limited to this, and both the amount of colored ink deposited and the color data may be used as image parameters, or the threshold determination of the image parameter may be performed using both the amount of colored ink deposited and the color data.

[0086] Figure 4 illustrates an example of adjusting the amount of white ink deposited in this embodiment. Figure 4 is a plot similar to Figure 2, with the horizontal and vertical axes being the same as in Figure 2. Also, plots a and c in Figure 4 are the same as plots a and c in Figure 2. Plot a represents the amount of color ink deposited, and plot c represents color data. Plot e represents the amount of white ink deposited.

[0087] In this example as well, similar to Figure 2(A), it is preferable to determine whether the amount of color ink adhesion is above a first threshold (e.g., 80 or more), and if it is above the first threshold, to apply the minimum amount of white ink adhesion necessary to ensure quality (e.g., 30%). In the region where the amount of color ink adhesion is around 80% or more (the region where the gradation is around 80% or more, the region enclosed by the dashed line), the color data (plot c) is greater than 30, so it is assumed that the color of the transfer material will not be affected even if condition (3) is not applied.

[0088] Furthermore, in this example as well, similar to Figure 2(B), it is preferable to determine whether the color data is below a second threshold (for example, 30 or less), and if it is below the second threshold, to apply the calculated amount of white ink required for concealment (for example, 70%).

[0089] In this example, both threshold determination for the amount of color ink deposited and threshold determination for the color data are performed. Therefore, as shown in plot e in Figure 4, a white ink deposition rate of 30% is applied in areas where the amount of color ink deposited is above the first threshold (areas with a gradation of 80% or more, areas with a single dashed line), and a white ink deposition rate of 70% is applied in areas where the color data is below the second threshold (areas with a gradation of approximately 56% or less, areas with a normal dashed line).

[0090] Figure 5 is a flowchart illustrating an example of this embodiment. In Figure 5, processes common to Figures 3A and 3B are denoted by the same reference numerals, and the explanation of these processes is omitted here. In the example shown in Figure 5, the threshold determination of the amount of color ink deposited (S15) and the threshold determination of the color data (S18) are performed within the same flowchart. As a result, the amount of white ink deposited is adjusted, as shown in plot e of Figure 4.

[0091] Thus, threshold determination of image parameters may be performed using both the amount of color ink applied and the color data.

[0092] A supplementary explanation will be provided regarding the flow shown in Figure 5. In the example flow above, the S18 and S15 checks are performed, with the S18 check (color data check) performed first and the S15 check (color ink adhesion amount check) performed second. In the example shown in Figure 4, it is assumed that either S18 or S15 will be YES, but this embodiment is not limited to this. Both check results may be YES. In this case, the priority of which check to perform can be determined by whether the S15 check (color ink adhesion amount check) or the S18 check (color data check) is performed first.

[0093] In the example flow shown in Figure 5, the determination of the amount of color ink applied (S15) is performed later, so the processing for cases where the determination of the amount of color ink applied is YES (S16) takes priority. For example, if the determination in S18 (determination of color data) is YES and the amount of white ink applied is adjusted (S19), and the determination in S15 (determination of the amount of color ink applied) is YES and the amount of white ink applied is adjusted (S16), then the adjustment in S16 will be reflected. The order in which the determinations are performed (first or last) can be selected as appropriate, taking into account the intended use of the printed material.

[0094] In the example shown in Figure 4, the amount of white ink applied (plot e) is continuously varied when the gradation is greater than approximately 56% and less than approximately 80%. Specifically, the amount of white ink applied (plot e) is set to 70% when the gradation is around 50%, and as the gradation increases towards approximately 80%, the amount of white ink applied approaches 30%. While it can be said that the influence of the media's color is minimal when the color data is greater than 30 and close to 30, dispensing white ink in an amount close to the required amount of white ink applied (70% of condition (3)) calculated from the media's opacity rate can more reliably prevent the influence of the media's color.

[0095] This point is reiterated. When the color data is greater than the second threshold (30 in this example, condition (4)) and the amount of color ink deposited is less than the first threshold (80 in this example, condition (2)), it is preferable to gradually decrease the amount of white ink deposited from the amount of white ink deposited when the color data is less than or equal to the second threshold (70% in this example, condition (3)) to the amount of white ink deposited when the amount of color ink deposited is greater than or equal to the first threshold (30% in this example, condition (1)).

[0096] (Third embodiment) Next, another embodiment of the present invention will be described. When the amount of ink deposited differs significantly between adjacent areas, ink may flow to areas with less ink. Such ink flow degrades image quality. In this embodiment, adjacent areas are compared, and the amount of ink deposited is adjusted so that the difference in ink deposits between adjacent areas is minimized. This prevents ink flow.

[0097] Figure 6 is a diagram illustrating ink flow. (A) shows the state before ink flow occurs, and (B) shows the state after ink flow occurs. Ink flows from the 100% area (left side of the figure), where the amount of ink adhering is large, to the 30% area (right side of the figure), where the amount of ink adhering is small.

[0098] In this embodiment, the difference in ink adhesion between adjacent areas is minimized. This suppresses ink flow. To minimize the difference in ink adhesion between adjacent areas, for example, one method is to create a gradient in the amount of ink adhesion at the boundary between adjacent areas. Another method is to apply transparent ink. When applying transparent ink, it is preferable to adjust the amount of transparent ink applied.

[0099] In this embodiment, the amount of white ink deposited in the relevant region is kept constant. Therefore, the above-mentioned amount of ink deposited can be considered to be the amount of colored ink deposited. Note that adjacent regions and adjacent regions have the same meaning. For example, the amount of transparent ink deposited can be increased in regions where the amount of ink deposited is small.

[0100] Figure 7 is a schematic diagram illustrating an example of gradient processing. For example, in a region with 30% ink coverage (right side of the figure), the ink coverage at the boundary with the adjacent region (left side of the figure) gradually increases as you approach the adjacent region. In this way, the difference in ink coverage between adjacent regions can be reduced. In addition, in the area with 100% ink adhesion (left side of the figure), the amount of ink adhesion may be gradually reduced at the boundary with the adjacent area (right side of the figure) as it approaches the adjacent area.

[0101] Figure 8 is a flowchart illustrating an example of this embodiment. Sections common to Figures 3A, 3B, and 5 are omitted from the explanation. Note that the example shown in Figure 8, like the example in Figure 5, is an example where the threshold determination of the amount of color ink deposited (S15) and the threshold determination of the color data (S18) are performed within the same flowchart. However, this embodiment is not limited to this; as with Figures 3A and 3B, either the threshold determination of the amount of color ink deposited (S15) or the threshold determination of the color data (S18) may be performed.

[0102] In S20, it is determined whether the total amount of ink deposited in adjacent areas is within a threshold. In other words, in this example, after adjusting the amount of white ink deposited, the total amount of ink deposited is calculated for each predetermined area, and the total amount of ink deposited in adjacent areas is compared. If the total amount of ink deposited in adjacent areas is within the threshold, printing (S17) is performed without performing S21. If the total amount of ink deposited in adjacent areas is above the threshold, S21 is performed for that area and the adjacent areas.

[0103] In S21, a gradient process is applied to adjacent areas. In this example, the amount of color ink applied to one or both of the two adjacent areas is adjusted.

[0104] In S17, printing is performed on the medium. Thus, according to the printing system of this embodiment, by adjusting the amount of ink applied so that the difference in ink application amount does not become too large, in addition to the effects obtained in the above embodiment, it is possible to prevent a decrease in image quality due to ink flow.

[0105] The above flowchart uses gradient processing as an example, but other methods, such as using transparent ink, can also be used for adjustment. By adjusting the amount of transparent ink applied so that the difference in ink adhesion between adjacent areas is below a predetermined threshold, ink flow can be prevented.

[0106] This embodiment will be described again. In this embodiment, the control unit calculates the total ink adhesion amount, which is the sum of the ink adhesion amounts of each ink, for each predetermined region. If the difference in the total ink adhesion amount between adjacent regions is greater than or equal to a predetermined threshold, the control unit adjusts the adhesion amount of the color inks so that the difference in the total ink adhesion amount between adjacent regions becomes less than the predetermined threshold, thereby performing a gradient process.

[0107] In this embodiment, the following may also be used in addition to the above. In this embodiment, the discharge unit is capable of discharging transparent ink, and the control unit calculates the total ink adhesion amount, which is the sum of the ink adhesion amounts of each ink, for each predetermined region, and adjusts the amount of transparent ink adhesion so that the difference in the total ink adhesion amounts in adjacent regions is less than the predetermined threshold when the difference in the total ink adhesion amounts in adjacent regions is greater than or equal to a predetermined threshold.

[0108] (Fourth embodiment) Next, another embodiment of the present invention will be described. In this embodiment, ink is ejected onto a transfer substrate. Matters similar to those described in the above embodiment will be omitted from the description.

[0109] The printing system of this embodiment is a printing system having a discharge unit that discharges color ink and white ink onto a transfer substrate, and a control unit that controls the discharge unit, wherein the color ink and white ink discharged onto the transfer substrate are transferred to a transfer material, and the printing system obtains image data, color information of the transfer material, and density information of the white ink, and the control unit calculates the opacity of the transfer material based on the color information of the transfer material and the density of the white ink, calculates the amount of white ink to be deposited to opacify the transfer material based on the calculated opacity, reads the following image parameters in the image data, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink deposited based on the judgment result. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink applied and color data measurable by a colorimeter.

[0110] The printing apparatus of this embodiment is a printing apparatus having a discharge unit that discharges color ink and white ink onto a transfer substrate, and a control unit that controls the discharge unit, wherein the color ink and white ink discharged onto the transfer substrate are transferred to a transfer material, and the printing apparatus obtains image data, information on the color of the transfer material, and information on the density of the white ink, and the control unit calculates the opacity of the transfer material based on the information on the color of the transfer material and the density of the white ink, calculates the amount of white ink to be deposited to opacify the transfer material based on the calculated opacity, reads the following image parameters in the image data, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink deposited based on the judgment result. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink applied and color data measurable by a colorimeter.

[0111] The printing method of this embodiment is a printing method that includes a discharge step of discharging color ink and white ink onto a transfer substrate using a printing device, and a control step of controlling the discharge of color ink and white ink, wherein the color ink and white ink discharged onto the transfer substrate are transferred to a transfer material, and the printing method obtains image data, color information of the transfer material, and density information of the white ink, and the control step calculates the opacity of the transfer material based on the color information of the transfer material and the density of the white ink, calculates the amount of white ink to be deposited to opacify the transfer material based on the calculated opacity, reads the following image parameters in the image data, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink deposited based on the judgment result. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink applied and color data measurable by a colorimeter.

[0112] In this embodiment, the opacity of the material to be transferred is calculated using the color information of the material to be transferred and the density of the white ink. The amount of white ink required to conceal the material to be transferred is then calculated using the calculated opacity. Image parameters are read from the image data, and it is determined whether the read image parameters are below a predetermined threshold. Based on this determination, control is performed to adjust the amount of white ink applied.

[0113] For example, if the image parameters are below a predetermined threshold, the calculated amount of white ink to be applied is used to dispense the white ink. In this way, the necessary amount of white ink can be applied to areas where the color of the transfer material would have an effect. This allows for a unified color tone of the transferred image, regardless of the transfer material, while keeping the amount of white ink used down.

[0114] The printing system of this embodiment is suitably applied to DTF (Direct To Film) printing.

[0115] The ink dispensed onto the transfer substrate is transferred to the material to be transferred. This can also be described as the image formed on the transfer substrate being transferred to the material to be transferred. The transfer substrate can be selected as appropriate, and for example, a film is preferably used. The transfer material can be selected as appropriate, and examples include fabrics such as T-shirts. Examples of fabrics include polyester fabric. The transfer material may also be referred to as the printed material.

[0116] There are no particular limitations on the method for transferring an image formed on a transfer substrate to a transfer target material, and any method can be selected as appropriate. For example, adhesive powder may be sprinkled onto the image formed on the transfer substrate, the transfer substrate and the transfer target material may be placed on top of each other, and the transfer may be performed by heating or pressurizing as needed.

[0117] The printing system of this embodiment includes a dispensing unit that dispenses color ink and white ink onto a transfer substrate, and a control unit that controls the dispensing unit. The dispensing unit and the control unit may be separate within the printing system, or they may be located in the same device.

[0118] The system configuration can be the same as in the first embodiment described above, so here we will mainly describe the differences from the first embodiment. In the first embodiment, ink was ejected onto a medium, but in this embodiment, ink is ejected onto the substrate to be transferred. In addition, in this embodiment, color information of the material to be transferred is obtained and the opacity of the material to be transferred is calculated.

[0119] The printing system of this embodiment obtains image data, information on the color of the material to be transferred, and information on the density of the white ink. The printing system of this embodiment may also obtain the above data and information from devices other than the information processing device 1. For example, it may obtain information on the color of the material to be transferred as a measurement result from a measuring device that measures the color of the material to be transferred.

[0120] Image data may, for example, be included in the print instructions. Information on the color of the material to be transferred and the density of the white ink may be included in the print instructions and transmitted each time, or the system may obtain this information in advance before the print instructions are sent.

[0121] The control unit calculates the opacity of the material to be transferred and the amount of white ink required to conceal the material, based on the color information of the material to be transferred and the concentration of the white ink. For example, when transferring an image onto a red polyester fabric, the opacity of the transfer target is calculated using the red color information and the concentration of the white ink. From this calculated opacity, the amount of white ink needed to conceal the transfer target is then calculated. The amount of white ink required to conceal the transfer material is sometimes referred to as the minimum amount of white ink to adhere.

[0122] The control unit reads predetermined image parameters from the image data. The control unit performs a threshold determination on the read image parameters. Based on the determination result, the control unit adjusts the amount of white ink applied. In this way, the necessary amount of white ink can be applied to areas where the color of the transfer material would have an effect. This reduces the amount of white ink used while suppressing changes in the image's color due to the color of the transfer material.

[0123] The image parameters in this embodiment can be the same as those in the first embodiment described above, so their explanation will be omitted.

[0124] The method for performing threshold determination on image parameters read from image data can be the same as in the first embodiment described above. For example, the control unit determines whether the amount of colored ink applied is equal to or greater than a first threshold. If the amount of colored ink applied is equal to or greater than the first threshold, it controls the dispensing of white ink at a predetermined lower limit of the amount of white ink applied. The predetermined lower limit of the amount of white ink applied could be, for example, the minimum amount of white ink required to ensure quality. In this way, drying defects can be prevented.

[0125] For example, the control unit determines whether the color data is below a second threshold. If the color data is below the second threshold, it controls the dispensing of white ink based on the calculated amount of white ink to be applied. The calculated amount of white ink to be applied is determined by calculating the opacity of the material to be transferred based on the color information of the material to be transferred and the concentration of the white ink, as described above, and then calculating the amount of white ink to be applied in order to conceal the material to be transferred. In this case, it is possible to suppress the situation in which the material to be transferred cannot be concealed.

[0126] By considering the amount of colored ink applied and the color data mentioned above separately, it is possible to reliably conceal the transfer material and prevent insufficient ink drying.

[0127] Figure 9 is a flowchart illustrating an example of this embodiment. Sections common to Figures 3A, 3B, and 5 are omitted from the explanation. Note that the example shown in Figure 9, like the example in Figure 5, is an example where the threshold determination of the amount of color ink deposited (S15) and the threshold determination of the color data (S18) are performed within the same flowchart. However, this embodiment is not limited to this; as with Figures 3A and 3B, either the threshold determination of the amount of color ink deposited (S15) or the threshold determination of the color data (S18) may be performed.

[0128] In S22, the color of the material to be transferred is read. The color information of the material to be transferred and the ink information are included, for example, in the print instruction from the user, and the system can read the color information of the material to be transferred and the ink information when it receives the print instruction. Alternatively, the color information of the material to be transferred and the ink information may be stored in advance in any storage means and read from the storage means when a print instruction is received. The color information of the material to be transferred and the ink information may be input by the user or obtained by measurement.

[0129] In S12, the opacity rate is calculated using the color information of the transfer material and the concentration of the white ink, and the minimum required amount of white ink to adhere is calculated using the calculated opacity rate. This calculation may also be called a determination.

[0130] Similar to Figures 3A, 3B, and 5, threshold values ​​are determined in S15 and S18, and the amount of white ink applied is adjusted based on the determination result. Thus, in the printing system of this embodiment, it is possible to prevent the color of the material to be transferred from showing through while suppressing the amount of white ink used, and to prevent the color of the image from changing depending on the color of the material to be transferred. To explain using brightness as an image parameter, for example, when the brightness of a color is lower than a certain value, the color of the material to be transferred does not show through easily, so it is possible to prevent the color of the material to show through without increasing the amount of white ink applied. On the other hand, when the brightness of a color is higher than a certain value, the color of the material to be transferred is more likely to show through, so the amount of white ink applied is adjusted to be dispensed at the lower limit of the calculated amount. This prevents the color of the material to be transferred from showing through and prevents the color of the image from changing depending on the color of the material to be transferred. In addition to brightness, for example, if the density is higher than a certain value, the color of the material being transferred will be less likely to show through, and if the density is lower than a certain value, the color of the material being transferred will be more likely to show through.

[0131] Furthermore, in this embodiment as well, the amount of white ink applied can be adjusted as shown in Figure 2 above. In the description of the first embodiment above, the term "medium" should be read as "transfer material" as appropriate. For example, condition (3) should be read as the required amount of white ink applied calculated from the opacity of the transfer material. Also, for example, condition (4) should be read as the image parameter condition that allows the color of the transfer material to show through.

[0132] In describing condition (1), it can be assumed that the quality, such as color unevenness, in this embodiment differs depending on the combination of ink and transfer material. Therefore, the amount of ink applied is changed for each ink and transfer material, and the chart is printed and examined to determine condition (1).

[0133] Similar to the first embodiment described above, this embodiment also illustrates examples of adjusting the amount of white ink applied (plots b, d, and e) with reference to Figures 2 and 5.

[0134] For example, a threshold determination of color data is performed as shown in S18 of Figure 9. In this example, it is determined whether the color data satisfies condition (4). That is, it is determined whether the color data is 30 or less. Where the gradation is around 56 or less (the area enclosed by the usual dashed line), the color data (plot c) is 30 or less, so it is expected that the color of the material to be transferred will show through. Therefore, where the gradation is around 56 or less, condition (3), that is, the minimum required amount of white ink (70%) calculated from the opacity rate, is applied. Accordingly, plot c (amount of white ink applied) is adjusted to 70% where the gradation is around 56 or less (the area enclosed by the usual dashed line). This prevents the color of the material to be transferred from showing through.

[0135] Areas where the amount of colored ink adheres is approximately 80% or more can be said to be areas where the gradation is approximately 80% or more, and these are the areas enclosed by the dashed line. When a threshold judgment of the color data is performed in this area, the color data (plot c) exceeds 30, so it is assumed that the color of the transfer material will not be affected even without applying condition (3).

[0136] On the other hand, areas where the amount of colored ink adheres is around 80% or more fall under condition (2), and since the amount of ink adhered is large, it is desirable to consider drying properties. Therefore, for example, as shown in S15 of Figure 9, a threshold judgment is made for the amount of colored ink adhered, and condition (1) is applied to areas where the amount of colored ink adheres is around 80% or more. Accordingly, plots b and e (amount of white ink adhered) are adjusted to 30% where the gradation is around 80 or higher (areas enclosed by a dashed line).

[0137] Generally, when printing on transfer substrates (e.g., film) in DTF, there is a desire to lower the drying temperature of the heating element (also called a heater) for the printed area. Lower drying temperatures improve the wettability of the printed area, resulting in better color development and more stable liquid ejection from the print head. However, if the drying temperature is too low, the color ink may not dry sufficiently in areas with a large amount of ink. In this case, abnormalities such as ink flow, repelling, and bleeding may occur. Simply reducing the amount of ink applied will cause the color of the transfer material to show through.

[0138] In this example, in areas where a large amount of color ink may not dry completely, the amount of white ink is reduced while ensuring a minimum amount of white ink is applied. This prevents the color of the transfer material from showing through, and by reducing the amount of white ink, it prevents insufficient drying and thus prevents ink flow due to poor drying.

[0139] By adjusting the amount of white ink applied in this way, it is possible to suppress the color change of the image due to the color of the transfer material without using excessive white ink. Furthermore, even when white ink is used to suppress the transparency of the transfer material's color, good drying properties can be achieved, ensuring good quality.

[0140] Similar to the first embodiment described above, in this embodiment, it is preferable to read image parameters for each predetermined area, perform threshold determination, and control the amount of white ink to be dispensed. By adjusting the amount of white ink to be dispensed for each area, it is possible to apply the minimum amount of white ink necessary to prevent the color of the transfer material from showing through in each area, and to appropriately control the amount of white ink used for each area. As a result, the amount of white ink used can be reduced, and good results can be obtained from a cost standpoint. In addition, by adjusting the amount of white ink to be dispensed for each area, it becomes easier to handle ink flow.

[0141] (Fifth embodiment) Next, another embodiment of the present invention will be described. In this embodiment, as in the fourth embodiment described above, adjacent areas are compared, and the amount of ink deposited is adjusted so that the difference in the amount of ink deposited between adjacent areas becomes small. In other words, in this embodiment, as in the fourth embodiment described above, the amount of ink deposited is adjusted as in the second embodiment described above. According to this embodiment, ink flow can be prevented even in the case of the DTF method.

[0142] In this embodiment, the term "medium" is appropriately replaced with "transfer material" in the descriptions of the third and fourth embodiments. In this embodiment, the same method can be used as in the above embodiments, so most of the explanation is omitted, and only a part is described.

[0143] In this embodiment, Figures 7 to 9, etc., can also be applied. To reduce the difference in ink adhesion between adjacent areas, for example, one method is to create a gradient in the ink adhesion at the boundary between adjacent areas. Another method is to apply transparent ink. When applying transparent ink, it is preferable to adjust the amount of transparent ink applied.

[0144] This embodiment will be described again. In this embodiment, the control unit calculates the total ink adhesion amount, which is the sum of the ink adhesion amounts of each ink, for each predetermined region. If the difference in the total ink adhesion amount between adjacent regions is greater than or equal to a predetermined threshold, the control unit adjusts the adhesion amount of the color inks so that the difference in the total ink adhesion amount between adjacent regions becomes less than the predetermined threshold, thereby performing a gradient process.

[0145] In this embodiment, the following may also be used in addition to the above. In this embodiment, the discharge unit is capable of discharging transparent ink, and the control unit calculates the total ink adhesion amount, which is the sum of the ink adhesion amounts of each ink, for each predetermined region, and adjusts the amount of transparent ink adhesion so that the difference in the total ink adhesion amounts in adjacent regions is less than the predetermined threshold when the difference in the total ink adhesion amounts in adjacent regions is greater than or equal to a predetermined threshold.

[0146] Examples of the present invention are as follows: <1> A printing system having a discharge unit that discharges color ink and white ink onto a medium, and a control unit that controls the discharge unit, wherein the printing system obtains image information and information on the color of the medium, the control unit adjusts the discharge amount of white ink based on the information on the color of the medium and the following image parameters in the image information A printing system characterized by the above. [Image parameters] The image parameters are one or more selected from the discharge amount of color ink and color information measurable by a colorimeter. <2> A printing system having a discharge unit that discharges color ink and white ink onto a transfer substrate, and a control unit that controls the discharge unit, wherein the color ink and white ink discharged onto the transfer substrate are transferred to a transfer target material, the printing system obtains image information and information on the color of the transfer target material, the control unit adjusts the discharge amount of white ink based on the information on the color of the transfer target material and the following image parameters in the image information A printing system characterized by the above. [Image parameters] The image parameters are one or more selected from the discharge amount of color ink and color information measurable by a colorimeter. <3> A printing system having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The aforementioned printing system, Image information Then, information on the color of the aforementioned medium and information on the density of the white ink are obtained, The control unit calculates the opacity of the medium based on the color information of the medium and the density of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the medium Discharge amount Calculate the above Image information The following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing system characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. <4> A printing system having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The aforementioned printing system, Image information Then, information on the color of the transfer material and information on the density of the white ink are obtained. The control unit calculates the opacity of the transfer material based on the color information of the transfer material and the density of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the transfer material Discharge amount Calculate the above Image information The following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing system characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. <5> The aforementioned Color informationThis refers to spectral reflectance, spectral transmittance, lightness, saturation, or density. Characterized by Any one of <1> to <4> The printing system described above. <6> The aforementioned image parameters are the color ink Discharge amount And, The control unit controls the color ink Discharge amount Determine whether the value is greater than or equal to the first threshold, and the color ink Discharge amount If the value is above the first threshold, the predetermined white ink Discharge amount The control system is set to dispense white ink at the lower limit. Characterized by Any one of <1> to <4> The printing system described above. <7> The aforementioned image parameters are: Color information And, The control unit is the Color information Determine whether it is below the second threshold, Color information If the value is below the second threshold, the calculated white ink Discharge amount This controls the ejection of white ink. Characterized by Any one of <1> to <4> The printing system described above. <8> The control unit reads the image parameters for each predetermined area, performs threshold determination, and determines the amount of white ink to be ejected. Discharge amount Control Characterized by <1> from <7> A printing system as described in any of the following. <9> The control unit controls the ink of each ink in each predetermined area. Discharge amount The total ink Discharge amount The total ink in the adjacent region is calculated and Discharge amount If the difference is greater than or equal to a predetermined threshold, the total ink in the adjacent region Discharge amount The difference between the two colors of the inks is set to be smaller than a predetermined threshold. Discharge amount Adjust and apply gradient processing Characterized by <1> from <8> A printing system as described in any of the following. <10> The aforementioned dispensing unit is capable of dispensing transparent ink, The control unit controls the ink of each ink in each predetermined area. Discharge amount The total ink Discharge amount The total ink in the adjacent region is calculated and Discharge amount If the difference is greater than or equal to a predetermined threshold, the total ink in the adjacent region [[ID=6,0]]Discharge amount The difference between the transparent inks is made smaller than a predetermined threshold. Discharge amount Adjust Characterized by <1> from <8> A printing system as described in any of the following. <11> The aforementioned white ink is used as a base after an image has been formed on the medium. The control unit provides the white ink that forms the base layer. Discharge amount Regarding the determination of the aforementioned image parameters and Discharge amount Control Characterized by <1> Or <3> The printing system described above. <12> The aforementioned white ink is used as a base coat after the ink has been transferred to the transfer material. The control unit provides the white ink that forms the base layer. Discharge amount Regarding the determination of the aforementioned image parameters and Discharge amount Control Characterized by <2> Or <4> The printing system described above. <13> A printing device having a discharge unit that discharges color ink and white ink onto a medium, and a control unit that controls the discharge unit, wherein the printing device obtains image information and information on the color of the medium, the control unit adjusts the discharge amount of white ink based on the information on the color of the medium and the following image parameters in the image information A printing device characterized by the above. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter. <14> A printing apparatus having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The printing apparatus obtains image information and color information of the material to be transferred. The control unit adjusts the amount of white ink ejected based on the color information of the transfer material and the following image parameters in the image information. A printing apparatus characterized by the following features. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter. <15> A printing method comprising a dispensing step of dispensing color ink and white ink onto a medium using a printing device, and a control step of controlling the dispensing of color ink and white ink, The aforementioned printing method obtains image information and color information of the medium, The control step adjusts the amount of white ink ejected based on the color information of the medium and the following image parameters in the image information. A printing method characterized by the following features. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter. <16> A printing method comprising a dispensing step of dispensing color ink and white ink onto a transfer substrate using a printing device, and a control step of controlling the dispensing of color ink and white ink, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The aforementioned printing method obtains image information and color information of the material to be transferred, The control step adjusts the amount of white ink ejected based on the color information of the transfer material and the following image parameters in the image information. A printing method characterized by the following features. [Image parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter. <17> A printing apparatus having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The aforementioned printing apparatus, Image information Then, information on the color of the aforementioned medium and information on the density of the white ink are obtained, The control unit calculates the opacity of the medium based on the color information of the medium and the density of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the medium Discharge amount Calculate the above Image information The following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing apparatus characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. <18> A printing apparatus having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The aforementioned printing apparatus, Image information Then, information on the color of the transfer material and information on the density of the white ink are obtained. The control unit calculates the opacity of the transfer material based on the color information of the transfer material and the density of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the transfer material Discharge amount Calculate the above Image information The following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing apparatus characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. <19> A printing method comprising a dispensing step of dispensing color ink and white ink onto a medium using a printing device, and a control step of controlling the dispensing of color ink and white ink, The aforementioned printing method is Image information Then, information on the color of the aforementioned medium and information on the density of the white ink are obtained, The control step calculates the opacity of the medium based on the color information of the medium and the density of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the medium Discharge amount Calculate the above Image informationThe following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing method characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. <20> A printing method comprising a dispensing step of dispensing color ink and white ink onto a transfer substrate using a printing device, and a control step of controlling the dispensing of color ink and white ink, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The aforementioned printing method is Image information Then, information on the color of the transfer material and information on the density of the white ink are obtained. The control step calculates the opacity of the transfer material based on the color information of the transfer material and the concentration of the white ink, and based on the calculated opacity, the amount of white ink necessary to conceal the transfer material Discharge amount Calculate the above Image information The following image parameters are read, a threshold determination is performed on the read image parameters, and based on the determination result, the white ink Discharge amount Adjust A printing method characterized by the following features. [Image parameters] The aforementioned image parameters are for the color ink. Discharge amount and measurable with a colorimeter Color information It is one or more selected from the following. [Explanation of symbols]

[0147] 1. Information Processing Device 2 Image forming apparatus 3. Control device 10 Printing Systems [Prior art documents] [Patent Documents]

[0148] [Patent Document 1] Japanese Patent Publication No. 2013-154516

Claims

1. A printing system having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The printing system obtains image information, color information of the medium, and density information of the white ink. The control unit adjusts the amount of white ink dispensed based on the color information of the medium, the density information of the white ink, and the following image parameters in the image information. A printing system characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

2. A printing system having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The printing system obtains image information, color information of the transfer material, and density information of the white ink. The control unit adjusts the amount of white ink dispensed based on the color information of the transfer material, the density information of the white ink, and the following image parameters in the image information. A printing system characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

3. A printing system having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The printing system obtains image information, color information of the medium, and density information of the white ink. The control unit calculates the opacity of the medium based on the color information of the medium and the density of the white ink, calculates the amount of white ink to be dispensed to opacify the medium based on the calculated opacity, reads the following image parameters in the image information, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink to be dispensed based on the judgment result. A printing system characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

4. A printing system having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The printing system obtains image information, color information of the transfer material, and density information of the white ink. The control unit calculates the opacity of the transfer material based on the color information of the transfer material and the density of the white ink, calculates the amount of white ink to be dispensed to opacify the transfer material based on the calculated opacity, reads the following image parameters in the image information, performs a threshold judgment on the read image parameters, and adjusts the amount of white ink dispensed based on the judgment result. A printing system characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

5. The aforementioned color information is spectral reflectance, spectral transmittance, lightness, saturation, or density. A printing system according to any one of features 1 to 4.

6. The aforementioned image parameter is the amount of color ink ejected, The control unit determines whether the amount of color ink ejected is equal to or greater than a first threshold, and if the amount of color ink ejected is equal to or greater than the first threshold, it controls the ejection of white ink at a predetermined lower limit of the amount of white ink ejected. A printing system according to any one of features 1 to 4.

7. The aforementioned image parameter is the aforementioned color information, The control unit determines whether the color information is below a second threshold, and if the color information is below the second threshold, it controls the dispensing of white ink using the calculated amount of white ink to be dispensed. A printing system according to any one of features 1 to 4.

8. The control unit reads the image parameters for each predetermined region, performs threshold determination, and controls the amount of white ink to be ejected. A printing system according to any one of features 1 to 4.

9. The control unit calculates the total ink ejection amount, which is the sum of the ink ejection amounts of each ink, for each predetermined region. If the difference in the total ink ejection amounts in adjacent regions is greater than or equal to a predetermined threshold, the control unit adjusts the ejection amount of the color inks to perform gradient processing so that the difference in the total ink ejection amounts in adjacent regions becomes less than the predetermined threshold. A printing system according to any one of features 1 to 4.

10. The aforementioned dispensing unit is capable of dispensing transparent ink, The control unit calculates the total ink discharge amount, which is the sum of the ink discharge amounts of each ink, for each predetermined region. If the difference in the total ink discharge amounts in adjacent regions is greater than or equal to a predetermined threshold, the control unit adjusts the discharge amount of transparent ink so that the difference in the total ink discharge amounts in adjacent regions becomes less than the predetermined threshold. The printing system according to claim 1 or 3, characterized by the above.

11. The aforementioned white ink is used as a base after an image has been formed on the medium. The control unit determines the image parameters and controls the amount of white ink used as the base layer to be ejected. The printing system according to claim 1 or 3, characterized by the above.

12. The aforementioned white ink is used as a base coat after the ink has been transferred to the transfer material. The control unit determines the image parameters and controls the amount of white ink used as the base layer to be ejected. The printing system according to claim 2 or 4, characterized by the above.

13. A printing apparatus having a dispensing unit that dispenses color ink and white ink onto a medium, and a control unit that controls the dispensing unit, The printing apparatus obtains image information, color information of the medium, and density information of the white ink. The control unit adjusts the amount of white ink dispensed based on the color information of the medium, the density information of the white ink, and the following image parameters in the image information. A printing apparatus characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

14. A printing apparatus having a dispensing unit for dispensing color ink and white ink onto a transfer substrate, and a control unit for controlling the dispensing unit, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The printing apparatus obtains image information, information on the color of the material to be transferred, and information on the density of the white ink. The control unit adjusts the amount of white ink dispensed based on the color information of the transfer material, the density information of the white ink, and the following image parameters in the image information. A printing apparatus characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

15. A printing method comprising a dispensing step of dispensing color ink and white ink onto a medium using a printing device, and a control step of controlling the dispensing of color ink and white ink, The aforementioned printing method obtains image information, color information of the medium, and information on the density of the white ink. The control step adjusts the amount of white ink dispensed based on the color information of the medium, the density information of the white ink, and the following image parameters in the image information. A printing method characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

16. A printing method comprising a dispensing step of dispensing color ink and white ink onto a transfer substrate using a printing device, and a control step of controlling the dispensing of color ink and white ink, The color ink and white ink dispensed onto the transfer substrate are transferred to the material to be transferred. The aforementioned printing method obtains image information, information on the color of the transfer material, and information on the density of the white ink. The control step adjusts the amount of white ink dispensed based on the color information of the transfer material, the density information of the white ink, and the following image parameters in the image information. A printing method characterized by the following features. [Image Parameters] The aforementioned image parameters are one or more selected from the amount of color ink ejected and color information measurable by a colorimeter.

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