LIQUID EJECTION APPARATUS AND METHOD FOR GENERATING CONCENTRATION CORRECTION INFORMATION

Abstract

To complete density calibration processing of a liquid discharge device with small man-hours.SOLUTION: The image density is controlled by generating density correction information corresponding to a reference printing condition on the basis of reference measurement information becoming a measurement result of a patch pattern printed under the reference printing condition. At this time, a storage unit stores difference information being a difference between reference measurement information and measurement information of one or a plurality of printing conditions different from the reference printing condition in advance. A density correction information generation unit generates the density correction information corresponding to the reference printing condition on the basis of the reference measurement information, or generates the density correction information corresponding to the one or the plurality of printing conditions different from the reference printing condition on the basis of the reference measurement information and the difference information stored in the storage unit. With this, by performing printing and measuring of a patch pattern one time, the density correction information corresponding to the other printing condition can be calculated with the calculation based on the difference information and the man-hours of density calibration processing can be significantly reduced.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a liquid ejection apparatus and a method for generating density correction information. [Background technology]

[0002] 2. Description of the Related Art Nowadays, there are known image forming apparatuses using a so-called inkjet method, etc. In such image forming apparatuses, it is preferable to output an image with a desired ink density based on input image information.

[0003] For this reason, in the color image processing method disclosed in Patent Document 1 (JP Patent Publication 01-041375 A), a predetermined pattern is printed for each of the colors cyan, magenta, yellow, and black, and the pattern is read by a scanner, a colorimeter, a densitometer, or the like. Then, the deviation between the read value (colorimetric value) and the expected value is detected, and the density of the output image is corrected based on the detected deviation (density calibration process). This makes it possible to obtain an output image with the desired ink density based on the input image information. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the color image processing method of Patent Document 1, each time printing was performed under different printing conditions, it was necessary to print a specific pattern, measure the color of the printed pattern, and perform a density calibration process to correct the density of the output image based on the color measurement results.

[0005] That is, the above-mentioned density calibration process had to be performed each time the printing conditions were changed, such as when a pretreatment such as application of a bleeding suppressant to prevent printing bleeding to a recording medium is performed or not performed, etc. Similarly, the above-mentioned density calibration process had to be performed each time the printing conditions were changed, such as when printing at a different resolution, when printing at a different printing speed, when printing on different paper, when printing with different ink, etc.

[0006] For this reason, by repeatedly executing the density calibration process for each printing condition, there has been a problem in that the number of steps required for the density calibration process, for example, when installing the image forming apparatus, increases.

[0007] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a liquid ejection device and a method for generating concentration correction information that make it possible to complete concentration calibration processing for each printing condition with a minimal number of steps. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the present invention provides a liquid ejection device that controls image density by generating density correction information corresponding to standard printing conditions based on standard measurement information that is a measurement result of a predetermined patch pattern printed under standard printing conditions that serve as a reference, and has a storage unit that stores difference information that is a difference between the standard measurement information and measurement information of one or more printing conditions different from the standard printing conditions, and a density correction information generation unit that generates density correction information corresponding to the standard printing conditions based on the standard measurement information, and generates density correction information corresponding to the one or more printing conditions different from the standard printing conditions based on the standard measurement information and the difference information stored in the storage unit. The reference printing conditions are printing conditions when a pretreatment is not performed on the recording medium, in which at least a bleeding suppressing agent for preventing printing bleeding is applied to the recording medium, and the printing conditions different from the reference printing conditions are printing conditions when the pretreatment is performed on the recording medium. . Effect of the Invention

[0009] According to the present invention, it is possible to complete the density calibration process for each printing condition with a small number of steps. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing the system configuration of a line engine printer system. [Diagram 2] FIG. 2 is a block diagram showing the hardware configuration of the main parts of the obverse side printing device. [Diagram 3] FIG. 3 is a functional block diagram of each function realized by the control unit executing the print control program. [Figure 4] FIG. 4 is a flowchart showing the printing operation that the control unit of the obverse side printing device performs based on the print control program. [Diagram 5] FIG. 5 is a detailed functional block diagram of the gradation adjustment unit realized based on the print control program. [Figure 6] FIG. 6 is a flowchart showing the flow of the density calibration process. [Figure 7] FIG. 7 is a diagram showing an example of a patch pattern for density calibration. [Figure 8] FIG. 8 is a diagram showing an example of an OD curve. [Figure 9] FIG. 9 is a diagram illustrating an example of a correction curve. [Figure 10] FIG. 10 is a diagram showing OD curves under different printing conditions. [Figure 11] FIG. 11 shows an OD curve obtained by printing and measuring a patch pattern on a recording medium under a first printing condition, and an OD curve calculated based on gradation-density difference information corresponding to a second printing condition. [Figure 12] FIG. 12 is a diagram showing an example of correction curves for different printing conditions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] A line engine printer system according to an embodiment will be described below with reference to the accompanying drawings.

[0012] (System Configuration) Fig. 1 is a diagram showing the system configuration of a line engine printer system. As shown in Fig. 1, the line engine printer system includes an unwinding device 10, a pre-processing device 20, a front side printing device 30, a scanner device 31, a front / back inversion device 40, a back side printing device 50, a scanner device 51, and a winding device 60.

[0013] In such a line engine printer system, a roll-shaped recording medium 1 is wound around an unwinding section 11 of an unwinding device 10. The recording medium 1 is unwound from the unwinding section 11 and supplied to a pre-processing device 20 via a buffer section 12.

[0014] The recording medium 1 supplied to the pretreatment device 20 passes in order through an applicator 22 that applies a pretreatment liquid to the rear surface of the recording medium 1 and an applicator 21 that applies a pretreatment liquid to the front surface. As a result, the recording medium 1 is subjected to a pretreatment in which a bleeding suppressant for preventing printing bleeding is applied to the front and rear surfaces of the recording medium 1, respectively.

[0015] The recording medium 1 that has been subjected to such pre-processing is supplied to the front surface printing device 30. The front surface printing device 30 is a so-called inkjet printer device. The front surface printing device 30 prints desired characters, images, etc. by ejecting ink from a print head onto the front surface of the recording medium 1. The front surface printing device 30 then dries the printed recording medium 1 in a dryer and supplies it to the front surface reversing device 40. The scanner device 31 optically reads the front surface of the recording medium 1 while the recording medium 1 is being supplied from the front surface printing device 30 to the front surface reversing device 40. The image read by the scanner device 31 is used for image inspection of the front surface.

[0016] The front / back inversion device 40 inverts the recording medium 1 and supplies it to the back printing device 50. The back printing device 50 is also an inkjet printer device like the front printing device 30. The back printing device 50 prints desired characters, images, etc. by ejecting ink from a print head onto the back surface of the recording medium 1. The back printing device 50 then dries the printed recording medium 1 in a dryer and supplies it to the winding device 60. The scanner device 51 optically reads the back surface of the recording medium 1 while the recording medium 1 is being supplied from the back printing device 50 to the winding device 60. The image read by the scanner device 51 is used for image inspection of the back surface. The winding device 60 winds up the recording medium 1, on which printing has been performed on the front and back surfaces, by the winding unit 61 via the buffer unit 62.

[0017] (Hardware configuration of the main parts of the surface printing device) Fig. 2 is a block diagram showing the hardware configuration of the main parts of the front-side printing device 30. The rear-side printing device 50 also has the same hardware configuration as that shown in Fig. 2. As shown in Fig. 2, the front-side printing device 30 has a control unit 80, a memory 81, a transport motor driving unit 82, and a print head driving unit 83. A print control program and gradation-density difference information are stored in the memory 81. The control unit 80 operates based on the print control program to control the transport of the recording medium 1 via the transport motor driving unit 82, while driving the print head via the print head driving unit 83, and ejects ink onto the recording medium 1 to print images, characters, and the like.

[0018] The gradation-density difference information is a difference value between the gradation-density characteristic value under one printing condition and the gradation-density characteristic value under the other printing condition. Specifically, for example, the difference value between the gradation-density characteristic value when a pretreatment such as application of a bleeding suppressant for preventing printing bleeding is performed on the recording medium 1 and the gradation-density characteristic value when the pretreatment is not performed is stored in the memory 81 as the gradation-density difference information. Similarly, the difference value between the gradation-density characteristic value at different resolutions, such as the difference value between the gradation-density characteristic value at a resolution of, for example, 600 dpi (dots per inch) and the gradation-density characteristic value at a resolution of 300 dpi, is stored in the memory 81 as the gradation-density difference information.

[0019] Similarly, the difference value of the gradation-density characteristic value between different printing speeds, such as the difference value between the gradation-density characteristic value when the printing speed is, for example, high and the gradation-density characteristic value when the printing speed is low, is stored in the memory 81 as gradation-density difference information. Similarly, the difference value of the gradation-density characteristic value between different papers, such as the difference value between the gradation-density characteristic value when the recording medium 1 is, for example, plain paper and the gradation-density characteristic value when the recording medium 1 is coated paper, is stored in the memory 81 as gradation-density difference information. Similarly, the difference value of the gradation-density characteristic value between different inks, such as the difference value between the gradation-density characteristic value when the ink used for printing is, for example, water-based ink and the gradation-density characteristic value when the ink is ultraviolet curable ink, is stored in the memory 81 as gradation-density difference information.

[0020] As will be explained in detail later, when the control unit 80 detects the gradation-density characteristic value by printing and measuring the color of a predetermined pattern under one printing condition during density calibration processing, it refers to the gradation-density difference information stored in the memory 81 and calculates the gradation-density characteristic value under the other printing condition through calculation processing. This makes it possible to significantly reduce the number of required printing steps and color measurement steps for the predetermined pattern.

[0021] (Print processing function) Fig. 3 is a functional block diagram of each function realized by executing the print control program by the control unit 80. As shown in Fig. 3, the control unit 80 realizes each function of an image acquisition unit 85, an ink combination replacement processing unit 86, a gradation adjustment unit 87, an upper limit amount setting unit 88, a dot conversion processing unit 89, and an ink discharge control unit 90 by executing the print control program.

[0022] The image acquisition unit 85 acquires image information such as an image to be printed from, for example, a personal computer device or an external memory such as a USB (Universal Serial Bus) memory connected to the front-side printing device 30. The ink combination replacement processing unit 86 determines a combination of ink colors that can be used by the front-side printing device 30 based on the acquired image information. The gradation adjustment unit 87 determines an output gradation for an input gradation in order to obtain a desired density in the determined ink color. The upper limit setting unit 88 determines an upper limit of the amount of ink attached to the paper to be printed so as not to exceed the ink drying capacity of the front-side printing device 30. The dot conversion processing unit 89 converts the image information of the image to be printed into dot information that can be expressed by the front-side printing device 30. The ink discharge control unit 90 controls the discharge of the print head based on the dot information obtained by the conversion process.

[0023] (Printing operation) Fig. 4 is a flowchart showing the printing operation performed by the control unit 80 of the obverse side printer 30 based on the print control program. In the flowchart of Fig. 4, first, in step S1, the image acquisition unit 85 acquires image information such as an image to be printed from, for example, a personal computer device or an external memory such as a USB memory connected to the obverse side printer 30.

[0024] In step S2, the ink combination replacement processing unit 86 determines, based on the acquired image information, a combination of ink colors that can be used in the front-side printing device 30. In step S3, the gradation adjustment unit 87 determines an output gradation for an input gradation for each ink color to achieve a desired image density.

[0025] In step S4, the upper limit setting unit 88 determines the upper limit of the amount of ink to be attached to the paper to be printed so as not to exceed the ink drying capacity of the front-side printer 30. In step S5, the dot conversion processing unit 89 converts the image information of the image to be printed into dot information that can be expressed by the front-side printer 30. In step S6, the ink discharge control unit 90 determines the discharge nozzle and the discharge droplet based on the dot information obtained by the conversion process. Then, in step S7, the ink discharge control unit 90 controls the discharge of the print head so that the determined discharge droplet is discharged from the determined discharge nozzle. As a result, an image or characters corresponding to the image information acquired in step S1 is printed on the front side of the recording medium 1.

[0026] The printing operation of the rear side printer 50 is similar to that of the front side printer 30. Please refer to the above description.

[0027] (Details of the tone adjustment section) Next, the process of determining the output gradation for the input gradation described in step S3 of the flowchart in FIG. 4 is executed as a density calibration process, which is one of the initial adjustment items when the line engine printer system is installed.

[0028] Fig. 5 is a detailed functional block diagram of the gradation adjustment unit 87 realized based on the print control program. As shown in Fig. 5, the gradation adjustment unit 87 has a print control unit 95, a density measurement result acquisition unit 96, an approximation curve calculation unit 97, a target optical density curve calculation unit 98, an optical density correction curve calculation unit 99, and a correction curve setting unit 100. The density measurement result acquisition unit 96 to the optical density correction curve calculation unit 99 are an example of a density correction information generation unit.

[0029] The print control unit 95 controls the print head driving unit 83 to print a patch pattern for density calibration. The density measurement result acquisition unit 96 acquires the colorimetric result (reference measurement information) of the patch pattern measured by the scanner device 31. The approximation curve calculation unit 97 calculates a gradation-image density characteristic value, which is a characteristic value indicating the image density for each gradation, based on the colorimetric result of the patch pattern. The approximation curve calculation unit 97 also calculates an OD (Optical Density) curve, which is an approximation curve of each calculated gradation-image density characteristic value.

[0030] A target optical density curve calculation unit 98 sets a target OD to a target image density based on the OD curve, and calculates a target OD curve indicating a gradation-image density characteristic value that changes linearly up to this target OD. An optical density correction curve calculation unit 99 calculates a correction curve for obtaining intermediate gradations with linear image density based on OD curve 1 and the target OD curve. A correction curve setting unit 100 sets the calculated correction curve in the ink ejection control unit 90. This allows the ink ejection control unit 90 to control the ejection amount of each nozzle of the print head based on the correction curve, and obtain an output image with the desired image density.

[0031] (Density calibration process) 6 is a flowchart showing the flow of the density calibration process. In step S11, since it is necessary to perform density calibration in an unadjusted state, the print control unit 95 confirms that the above-mentioned correction curve is not set in the ink ejection control unit 90, or sets it to unset.

[0032] In step S12, the print control unit 95 controls the printing of a patch pattern for density calibration via the print head driving unit 83. Fig. 7 shows an example of a patch pattern for density calibration. As shown in Fig. 7, the print control unit 95 prints a patch pattern consisting of each gradation for each monochromatic color of black (K), cyan (C), magenta (M), and yellow (Y). This patch pattern is read by the scanner device 31.

[0033] In step S13, the density measurement result acquisition unit 96 measures the image density based on the patch pattern read by the scanner device 31. In steps S14 and S15, the approximation curve calculation unit 97 calculates the above-mentioned OD curve based on the image density measurement results.

[0034] Fig. 8 is a diagram showing an example of an OD curve. Fig. 8 is a graph in which the horizontal axis indicates gradation and the vertical axis indicates image density gradation-image density characteristic value. Each black dot indicates a colorimetric value that is a measurement result of a patch pattern. The approximation curve calculation unit 97 calculates an OD curve (an example of measurement information) that is an approximation curve of each colorimetric value, as shown by the solid line graph in Fig. 8.

[0035] Next, in step S16, the target optical density curve calculation unit 98 sets a target OD to the target image density based on the OD curve, and calculates a target OD curve indicating the gradation-image density characteristic value that changes linearly up to this target OD, as shown in Fig. 8. Then, the optical density correction curve calculation unit 99 calculates a correction curve for obtaining intermediate gradations with linear image density, as shown in Fig. 9, based on the OD curve and the target OD curve.

[0036] In step S17, the correction curve setting unit 100 stores output correction information corresponding to the calculated correction curve in the memory 81. When printing begins, the ink ejection control unit 90 controls the ejection amount of each nozzle of the print head based on the output correction information read from the memory 81. This makes it possible to control the ejection of ink corresponding to the correction curve, and to obtain an output image with the desired image density.

[0037] The measurement of the patch pattern in step S13 may be performed at any timing as long as it is an image of the patch pattern after printing and drying. Also, the scanner device 31 and the scanner device 51 may measure the image density based on the image of the patch pattern.

[0038] Furthermore, the measurement of the patch pattern in step S13 may be performed by a scanner device provided in the front side printing device 30 (or in the back side printing device 50).

[0039] (Reduction of man-hours required for density calibration processing) 10 is a diagram showing OD curves under different printing conditions. Examples of printing conditions include a case where pretreatment such as application of a bleeding suppressant to prevent printing bleeding is performed on the recording medium 1 (an example of a reference printing condition) and a case where pretreatment is not performed (an example of another printing condition), or a case where the resolution is, for example, 600 dpi (dots per inch) and a case where the resolution is 300 dpi. Alternatively, printing conditions include a case where the printing speed is high and a case where the paper used as the recording medium 1 is, for example, plain paper and coated paper, or a case where the ink used for printing is, for example, water-based ink and ultraviolet-curable ink, etc.

[0040] If we assume that the printing conditions are, for example, when pre-treatment such as applying a bleeding inhibitor to the recording medium 1 to prevent printing bleeding is performed, and when pre-treatment is not performed, the OD curve for the first printing conditions shown by the solid line in Figure 10 indicates the OD curve when, for example, pre-treatment is performed, and the OD curve for the second printing conditions shown by the dotted line indicates the OD curve when, for example, pre-treatment is not performed.

[0041] In order to obtain an OD curve corresponding to each of these printing conditions, a process is required in which an image of a patch pattern is printed on a pre-treated recording medium 1 and measured, and a process is also required in which an image of a patch pattern is printed on a recording medium 1 that has not been pre-treated and measured.

[0042] Here, as shown in Figure 10, if the difference (difference in gradation-image density characteristic value) between the OD curve under the first printing conditions and the OD curve under the second printing conditions is known in advance, then, for example, by simply calculating the OD curve under the first printing conditions, the OD curve under the second printing conditions can be calculated from this difference. The opposite calculation is also possible, and by simply calculating the OD curve under the second printing conditions, the OD curve under the first printing conditions can also be calculated from this difference.

[0043] For this reason, the line engine printer system of the embodiment pre-measures and stores gradation-density difference information (an example of difference information) indicating the difference between the OD curve under the first printing conditions and the OD curve under the second printing conditions in memory 81 (an example of a storage unit) of the front side printer 30 (and the back side printer 50) shown in Fig. 2. Therefore, when the approximation curve calculation unit 97 calculates the OD curve under the first printing conditions in steps S14 and S15, it calculates the second OD curve based on the gradation-density difference information stored in memory 81.

[0044] 11 is a diagram showing an OD curve obtained by printing and measuring a patch pattern on a recording medium 1 under a first printing condition, and an OD curve calculated based on gradation-density difference information corresponding to a second printing condition. The OD curve shown by the solid line is the OD curve under the first printing condition obtained by printing and measuring a patch pattern. In contrast, the OD curve shown by the dotted line is the OD curve under the second printing condition calculated based on the gradation-density difference information. As an example, the first printing condition is a case where no pretreatment is performed on the recording medium 1, and the second printing condition is a case where pretreatment is performed on the recording medium 1.

[0045] Conversely, the first printing condition may be a case where preprocessing is performed on the recording medium 1, and the second printing condition may be a case where preprocessing is not performed on the recording medium 1. In this case, the approximation curve calculation unit 97 calculates an OD curve corresponding to the case where preprocessing is performed on the recording medium 1 by printing and measuring a patch pattern on the preprocessed recording medium 1. The approximation curve calculation unit 97 also calculates an OD curve corresponding to the case where preprocessing is not performed on the recording medium 1 based on the gradation-density difference information corresponding to the recording medium 1 not subjected to preprocessing.

[0046] In this way, by storing tone-density difference information in advance in memory 81, two OD curves corresponding to different printing conditions can be obtained by printing and measuring a patch pattern once.

[0047] In this example, two OD curves corresponding to different printing conditions are obtained by printing and measuring the patch pattern once, based on the gradation-density difference information indicating the difference between the OD curve under the first printing condition and the OD curve under the second printing condition. However, this is a minimum example, and in addition to the gradation-density difference information indicating the difference between the OD curve under the first printing condition and the OD curve under the second printing condition, gradation-density difference information indicating the difference between the OD curve under the first printing condition and the OD curve under the third printing condition, and gradation-density difference information indicating the difference between the OD curve under the first printing condition and the OD curve under the fourth printing condition are stored in the memory 81. As a result, the OD curve under the second printing condition, the OD curve under the third printing condition, and the OD curve under the fourth printing condition can be calculated by printing and measuring the patch pattern once under the first printing condition.

[0048] Next, in step S16, the target optical density curve calculation unit 98 sets a target OD to the target image density based on the OD curve for the first printing condition and the OD curve for the second printing condition shown in Fig. 11. The target optical density curve calculation unit 98 also calculates a first target OD curve corresponding to the OD curve for the first printing condition, and a second target OD curve corresponding to the OD curve for the second printing condition, which indicate the gradation-image density characteristic value that changes linearly up to this target OD. In Fig. 11, the straight line graph of the dashed dotted line is the second target OD curve, and the straight line graph of the dashed two dotted line is the second target OD curve.

[0049] Next, based on the OD curve of the first printing condition and the first target OD curve, the optical density correction curve calculation unit 99 calculates a correction curve for the first printing condition (first correction curve) for obtaining intermediate gradations with linear image density, as shown by the dotted line graph in Fig. 12. Also, based on the OD curve of the second printing condition and the second target OD curve, the optical density correction curve calculation unit 99 calculates a correction curve for the second printing condition (second correction curve) for obtaining intermediate gradations with linear image density, as shown by the solid line graph in Fig. 12.

[0050] In step S17, the correction curve setting unit 100 stores output correction information corresponding to the calculated correction curve in the memory 81. When printing, the ink ejection control unit 90 reads out output correction information corresponding to printing conditions such as the presence or absence of the above-mentioned pretreatment, the resolution, or the printing speed from the memory 81. Then, the ink ejection control unit 90 controls the ejection amount of each nozzle of the print head based on the read output correction information. This makes it possible to adjust the image density of the input / output images using a correction curve that matches each printing condition, thereby controlling the ejection of ink, and to obtain an output image with a desired image density.

[0051] The operation of the back side printer 50 is similar to that of the front side printer 30. For this reason, for the operation of the back side printer 50, please refer to the explanation of the operation of the front side printer 30 described above.

[0052] (Effects of the embodiment) As is clear from the above description, the line engine printer system of the embodiment stores gradation-density difference information between the reference printing conditions and other printing conditions in memory 81. Then, based on the colorimetric results of printing and measuring a predetermined patch pattern, it calculates gradation-image density characteristic values, which are characteristic values ​​indicating the image density for each gradation. It also calculates OD curves and corrected OD curves (an example of density correction information), which are approximation curves of each calculated gradation-image density characteristic value.

[0053] Furthermore, after calculating the gradation-image density characteristic value, OD curve, and corrected OD curve for one printing condition in this manner, the gradation-image density characteristic value for the other printing condition, which is the difference from the gradation-image density characteristic value for one printing condition, is calculated based on the gradation-density difference information stored in memory 81, and the OD curve and corrected OD curve are also calculated.

[0054] As a result, by performing the patch pattern printing process and color measurement process once each, it is possible to calculate both the corrected OD curve for one printing condition and the corrected OD curve for the other printing condition. Therefore, since the printing process and color measurement process only need to be performed once, the density calibration process for each printing condition can be completed with fewer steps. This also makes it possible to shorten the time required to install the line engine printer system.

[0055] Furthermore, a highly accurate OD curve can be calculated by applying pre-processing to the recording medium 1. Therefore, by using the OD curve calculated by applying pre-processing to the recording medium 1 as reference measurement information, highly accurate gradation-density difference information, which is the difference with the OD curve when pre-processing is not applied, can be calculated, and highly accurate density calibration processing can be performed.

[0056] Finally, the above-described embodiment is presented as an example, and is not intended to limit the scope of the present invention. This novel embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. In addition, the embodiment and modifications of the embodiment are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0057] 1 Recording medium 10 Unwinding device 11 Unwinding section 12 Buffer section 20 Pretreatment device 21 Coating equipment 22 Coating equipment 30 Surface printing device 31 Scanner device 40 Front and back reversing device 50 Backside Printing Device 51 Scanner device 60 Winding device 61 Winding section 62 Buffer section 80 Control section 81 Memory 82 Transport motor drive unit 83 Print head drive unit 85 Image acquisition unit 86 Ink combination replacement processing unit 87 Tone adjustment section 88 Upper limit setting section 89 Dot conversion processing unit 90 Ink discharge control unit 95 Printing control unit 96 Concentration measurement result acquisition section 97 Approximate curve calculation section 98 Target optical density curve calculation section 99 Optical density correction curve calculation section 100 Correction curve setting section [Prior art documents] [Patent documents]

[0058] [Patent Document 1] Japanese Patent Application Publication No. 01-041375

Claims

1. A liquid ejection apparatus that controls image density by generating density correction information corresponding to a reference printing condition based on reference measurement information that is a measurement result of a predetermined patch pattern printed under the reference printing condition, a storage unit that stores difference information that is a difference between measurement information of one or more printing conditions different from the reference measurement information and the reference measurement information; a density correction information generating unit that generates density correction information corresponding to the standard printing conditions based on the standard measurement information, and generates density correction information corresponding to one or more printing conditions different from the standard printing conditions based on the standard measurement information and the difference information stored in the storage unit; having The reference printing conditions are printing conditions in which a pretreatment is not performed on a recording medium, the pretreatment being to apply at least a bleeding suppressing agent for preventing printing bleeding, The printing conditions different from the reference printing conditions are printing conditions when the pre-processing is performed on the recording medium. A liquid ejection device comprising:

2. A liquid ejection device that controls image density by generating density correction information corresponding to a reference printing condition based on reference measurement information that is a measurement result of a predetermined patch pattern printed under the reference printing condition, a storage unit that stores difference information that is a difference between measurement information of one or more printing conditions different from the reference measurement information and the reference measurement information; a density correction information generating unit that generates density correction information corresponding to the standard printing conditions based on the standard measurement information, and generates density correction information corresponding to one or more printing conditions different from the standard printing conditions based on the standard measurement information and the difference information stored in the storage unit; having The reference printing conditions are printing conditions when a pretreatment is performed on a recording medium, in which at least a bleeding suppressing agent for preventing printing bleeding is applied to the recording medium, The printing conditions different from the reference printing conditions are printing conditions when the pre-processing is not performed on the recording medium. A liquid ejection device comprising:

3. A method for generating density correction information for a liquid ejection device, which controls image density by generating density correction information corresponding to a reference printing condition based on reference measurement information that is a measurement result of a predetermined patch pattern printed under the reference printing condition, comprising the steps of: a first density correction information generating step in which a density correction information generating unit generates density correction information corresponding to the standard printing conditions based on the standard measurement information; a second density correction information generating step in which a density correction information generating unit generates density correction information corresponding to one or more printing conditions different from the standard printing conditions based on the standard measurement information and difference information that is a difference between the standard measurement information and measurement information of one or more printing conditions different from the standard printing conditions stored in a storage unit; having The reference printing conditions are printing conditions in which a pretreatment is not performed on a recording medium, the pretreatment being to apply at least a bleeding suppressing agent for preventing printing bleeding, The printing conditions different from the reference printing conditions are printing conditions when the pre-processing is performed on the recording medium. A method for generating density correction information, comprising:

4. A method for generating density correction information for a liquid ejection device, which controls image density by generating density correction information corresponding to a reference printing condition based on reference measurement information which is a measurement result of a predetermined patch pattern printed under the reference printing condition, comprising: a first density correction information generating step in which a density correction information generating unit generates density correction information corresponding to the standard printing conditions based on the standard measurement information; a second density correction information generating step in which a density correction information generating unit generates density correction information corresponding to one or more printing conditions different from the standard printing conditions based on the standard measurement information and difference information that is a difference between the standard measurement information and measurement information of one or more printing conditions different from the standard printing conditions stored in a storage unit; having The reference printing conditions are printing conditions when a pretreatment is performed on a recording medium, in which at least a bleeding suppressing agent for preventing printing bleeding is applied to the recording medium, The printing conditions different from the reference printing conditions are printing conditions when the pre-processing is not performed on the recording medium. A method for generating density correction information, comprising:

Images