JP7426829B2 - Printing system, printing method, and printing device - Google Patents

Description

The present invention relates to a printing system, a printing method, and a printing device.

Conventionally, inkjet printers, which are printing devices that perform printing using inkjet heads, have been widely used. When printing using an inkjet head, in order to print with high quality, it is required to reduce the influence of variations in the characteristics of nozzles in the inkjet head.

In contrast, conventional methods for reducing the effects of individual differences in inkjet heads include adjusting the voltage of the drive signal waveform (head drive waveform) used to drive the inkjet head and the temperature at which the ink is heated (ink heating waveform). Methods of stabilizing the temperature by adjusting the temperature are known. When such a method is used, for example, by reducing the influence of individual differences among inkjet heads on the diameter of formed ink dots, unevenness in print density can be reduced. Conventionally, regarding the method of controlling inkjet heads, recovery processing is also known in which another nozzle is used in place of an abnormal nozzle (defective nozzle) whose ejection characteristics are out of the normal range (for example, see Patent Document 1). ).

JP2014-172260A

When trying to reduce the effects of individual differences in inkjet heads by stabilizing the voltage of the head drive waveform and the ink heating temperature, a configuration for adjusting the voltage and heating temperature is required, which reduces the cost of the device. is likely to increase. Furthermore, depending on the model of the printing device, it may be difficult to use these configurations.

In addition, when printing using another nozzle instead of the abnormal nozzle, for example, the timing at which the ink lands on the printing target medium (media) may differ from normal times, resulting in recovery processing being performed on the print result. The areas where this has been done may become more noticeable. In particular, when recovery processing is performed on a plurality of nozzles located close to each other, there is a risk that the print quality will be greatly affected. Therefore, it has conventionally been desired to reduce the influence of variations in nozzle characteristics in an inkjet head by a more appropriate method. Therefore, an object of the present invention is to provide a printing system, a printing method, and a printing device that can solve the above problems.

The inventor of the present application has conducted extensive research on methods for reducing the effects of abnormal nozzles on inkjet heads. If there is an abnormal nozzle whose ejected amount of ink is outside a predetermined normal range, when generating data (ejection designation data) indicating the ejection position etc. at which the inkjet head is to eject ink, the characteristics of the abnormal nozzle are determined. I thought about taking it into consideration. With this configuration, for example, by generating ejection designation data adjusted to compensate for the characteristics of the abnormal nozzle, the influence of the abnormal nozzle can be appropriately reduced.

In addition, the inventor of the present application further conducted extensive research and discovered the features necessary to obtain such effects, leading to the present invention. In order to solve the above problems, the present invention provides a printing system that performs printing using an inkjet method, which includes an inkjet head that ejects ink from a plurality of nozzles, and a plurality of ejection positions that are set according to the printing resolution. an ejection data generation unit that generates ejection designation data indicating at least a position at which ink should be ejected; and an ejection control unit that causes each of the plurality of nozzles in the inkjet head to eject ink based on the ejection designation data. If the nozzle whose amount of ejected ink is outside a predetermined normal range is defined as an abnormal nozzle, the ejection data generation unit determines whether the abnormal nozzle exists among the plurality of nozzles in the inkjet head. The ejection specification data to be generated is different depending on whether or not the abnormal nozzle exists, and when the abnormal nozzle does not exist among the plurality of nozzles, the ejection specification data is generated without considering the characteristics of the abnormal nozzle. When the abnormal nozzle exists among the plurality of nozzles, the characteristics of the abnormal nozzle are considered based on abnormal nozzle information that is information indicating the abnormal nozzle. the ejection designation data for abnormal times that is at least partially different from the ejection designation data for normal times, and when the abnormal nozzle exists among the plurality of nozzles; The ejection control unit causes each of the plurality of nozzles in the inkjet head to eject ink based on the abnormality ejection designation data, and controls at least some of the ejections based on the abnormality ejection designation data. The abnormal nozzle is caused to eject ink to the position.

In this configuration, for example, information indicating the position and characteristics of the abnormal nozzle may be used as the abnormal nozzle information. In this case, the position of the abnormal nozzle can be considered, for example, as the position of the abnormal nozzle within the inkjet head. More specifically, the inkjet head has, for example, a nozzle row in which a plurality of nozzles are lined up in a predetermined nozzle row direction. In this case, the position of the abnormal nozzle can be considered, for example, as the position of the abnormal nozzle within the nozzle array. Further, in the abnormal nozzle information, as the characteristic of the abnormal nozzle, for example, information indicating the magnitude relationship or difference between the amount of ink ejected by the abnormal nozzle and a predetermined reference amount may be used.

When configured in this way, for example, by using abnormal ejection specification data that is generated taking into account the characteristics of the abnormal nozzle, ink can be ejected to multiple nozzles in the inkjet head while taking into account the characteristics of the abnormal nozzle. can be done. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced. In this case, by printing using the abnormal nozzle as well, for example, compared to using another nozzle instead of the abnormal nozzle, the impact of the abnormal nozzle is reduced while suppressing the impact on printing quality. can do. Therefore, with this configuration, for example, even if an abnormal nozzle exists among a plurality of nozzles in the inkjet head, the influence of the abnormal nozzle can be appropriately reduced.

In addition, in this configuration, if the amount of ink ejected from one nozzle with respect to a unit area is defined as the unit ejection amount, the ejection control section may, for example, inject ink to the abnormal nozzle based on the abnormal ejection specification data. By ejecting, the unit ejection amount of the abnormal nozzle is made different from that when normal ejection designation data is used. With this configuration, for example, it is possible to cause the plurality of nozzles in the inkjet head to appropriately eject ink in consideration of the characteristics of the abnormal nozzle.

Note that the case where the normal-time ejection designation data is used can be considered as, for example, the case where an inkjet head in which an abnormal nozzle exists is caused to eject ink using the normal-time ejection designation data. In addition, regarding the unit discharge amount of an abnormal nozzle when using the discharge specification data for normal times, for example, if the discharge specification data for normal times is used as is without using the discharge specification data for abnormal times, it is possible to It can be considered as the unit discharge amount, etc. Further, the unit ejection amount can be considered as, for example, the average amount of ink ejected to a unit area by one nozzle. Further, in this case, the average ejection amount can be considered to be, for example, the average ejection amount during a series of printing operations.

In addition, when generating the ejection specification data for abnormal times, the ejection data generation unit, for example, based on the abnormal nozzle information, sets the At least a part of the normal ejection designation data is made different from the normal ejection designation data. In this case, the ejection control unit may, for example, cause each of the plurality of nozzles in the inkjet head to eject ink based on the abnormality ejection specification data, so that the position at which ink is ejected by the abnormal nozzle is determined by the normal ejection specification data. Ink is ejected from each of a plurality of nozzles in an inkjet head so that it is less noticeable than when using an inkjet head. With this configuration, for example, the influence of an abnormal nozzle can be more appropriately reduced.

In addition, in this configuration, the printing system includes, for example, a main scanning drive section that causes the inkjet head to perform a main scanning operation of ejecting ink while moving relative to the medium to be printed in a preset main scanning direction. and a sub-scanning drive unit that causes the inkjet head to perform a sub-scanning operation that moves relative to the medium in a sub-scanning direction perpendicular to the main-scanning direction. Further, in this case, as the ejection designation data, for example, data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation may be used. With this configuration, for example, ink can be appropriately ejected from each of the plurality of nozzles in the inkjet head.

Further, in this configuration, printing on the medium may be performed using, for example, a multi-pass method. In this case, the multi-pass method can be considered, for example, as a method in which a main scanning operation is performed multiple times for each position on the medium. More specifically, regarding the arrangement of ejection positions set according to the printing resolution, if the arrangement of ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line, then In the pass type operation, for example, the inkjet head forms ink dots at some ejection positions in the main scanning direction line in one main scanning operation according to the control of the ejection control unit, and The main scanning operation and the sub-scanning operation are performed so that dots can be formed at all ejection positions in the main scanning direction line by performing the main scanning operation a plurality of times.

In addition, in this case, if we define the number of times ink is ejected by any nozzle in multiple main scanning operations to the ejection position included per unit length in one main scanning direction line as the unit ejection number, then For example, if the unit ejection count in the main scanning direction line corresponding to the abnormal nozzle is different from the case where normal ejection specification data is used, and the normal ejection specification data is used, Ejection designation data for abnormal conditions is generated such that the influence of abnormal nozzles is reduced. With this configuration, for example, it is possible to appropriately generate abnormal discharge specification data that takes into account the characteristics of the abnormal nozzle. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced. The line in the main scanning direction corresponding to the abnormal nozzle can be considered, for example, as a line in the main scanning direction that includes the ejection position where ink is ejected by the abnormal nozzle. Further, the unit number of ejections can be considered as, for example, the number of ejections per unit length, which is determined depending on the print density.

In addition, the ejection data generation unit compensates for the deviation in the amount of ink ejected from the abnormal nozzle by, for example, changing the unit ejection number in the main scanning direction line corresponding to the abnormal nozzle from that when using the normal ejection designation data. The ejection specification data for abnormal situations is generated. In this case, compensation for the deviation in the amount of ink ejected by the abnormal nozzle is not limited to strictly compensating for the deviation, but it is considered that the influence of the abnormal nozzle is further reduced. be able to. With this configuration, for example, the influence of an abnormal nozzle can be appropriately reduced.

In addition, in this configuration, the ejection data generation section uses, for example, a mask that selects some ejection positions on the main scanning direction line, and in which main scanning operation is applied to each ejection position on the main scanning direction line. Decide whether to form dots. In this case, the ejection data generating section generates the ejection designation data for abnormal times using, for example, a mask that is at least partially different from the mask used when generating the ejection designation data for normal times. With this configuration, for example, it is possible to appropriately generate abnormal-time ejection designation data that is different from normal-time ejection designation data. In this case, for example, by selecting a mask to be used when generating the abnormality discharge specification data according to the characteristics of the abnormal nozzle, abnormality discharge specification data can be generated according to the characteristics of the abnormal nozzle. It also becomes possible.

Furthermore, the influence of abnormal nozzles may be reduced by, for example, changing the volume of ink ejected from the nozzles. In this case, it is conceivable to use an inkjet head that can change the volume of ink ejected from each nozzle in multiple stages, for example. Further, as the ejection designation data, for example, data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation and the volume of ink ejected to each ejection position may be used. In this case, the ejection data generation unit may generate an abnormal nozzle in which the volume of ink to be ejected to at least some ejection positions in the main scanning direction line corresponding to the abnormal nozzle is different from the case where the normal ejection designation data is used. Generate discharge specification data. Even with this configuration, for example, the influence of an abnormal nozzle can be appropriately reduced.

Further, in this configuration, it is possible to use information obtained by printing a predetermined test pattern using a plurality of nozzles in an inkjet head, for example, as the abnormal nozzle information. With this configuration, for example, the characteristics of an abnormal nozzle can be appropriately detected. Moreover, thereby, for example, abnormal nozzle information used to reduce the influence of abnormal nozzles can be appropriately created.

Further, as a configuration of the present invention, it is also possible to use a printing method and a printing apparatus having the same characteristics as described above. Also in this case, for example, the same effects as above can be obtained.

According to the present invention, for example, the influence of abnormal nozzles in an inkjet head can be appropriately reduced.

1 is a diagram illustrating an example of the configuration of a printing system 10 according to an embodiment of the present invention. FIG. 1A shows an example of the configuration of the printing system 10. As shown in FIG. FIG. 1B shows an example of the configuration of the print execution unit 12 in the printing system 10. 3 is a flowchart illustrating an example of how to generate RIP data for abnormal times. FIG. 6 is a diagram illustrating operations of dot size correction and mask pattern correction. FIG. 3(a) shows an example of the operation of dot size correction. FIG. 3(b) shows an example of the operation of mask pattern correction. FIG. 3 is a diagram illustrating the arrangement of ink dots 302 formed on a medium. FIG. 4A shows an example of the arrangement of ink dots 302 formed on a medium when printing is executed in the print execution unit 12. FIGS. 4B and 4C show an example of an operation in which ink is ejected in multiple main scanning operations with respect to an ejection position in one main scanning direction line regarding a multi-pass printing operation. FIG. 7 is a diagram illustrating an example of operation of mask pattern correction. FIGS. 5A to 5C show examples of mask pattern correction operations when there is an abnormal nozzle whose amount of ink ejected is smaller than the normal range. FIG. 7 is a diagram illustrating an example of operation of mask pattern correction. FIGS. 6A to 6C show examples of mask pattern correction operations when there is an abnormal nozzle ejecting an amount of ink greater than the normal range. FIG. 7 is a diagram illustrating dot size correction in more detail. FIG. 7A shows an example of the arrangement of ink dots 302 formed in one line in the main scanning direction when normal RIP data is used. FIGS. 7B and 7C show examples of dot size correction operations.

Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the configuration of a printing system 10 according to an embodiment of the present invention. FIG. 1A shows an example of the configuration of the printing system 10. As shown in FIG. FIG. 1B shows an example of the configuration of the print execution unit 12 in the printing system 10. Further, except for the points described below, the printing system 10 of this example may be the same as or have characteristics of known printing systems.

In this example, the printing system 10 is a printing system that prints on a printing target medium 50 using an inkjet method, and includes a printing execution section 12 and a RIP processing section 14. The printing execution section 12 is a section that executes a printing operation of ejecting ink onto the medium 50. The print execution unit 12 can be considered, for example, as a part of the printing system 10 that functions as a printing device. Further, the print execution unit 12 can be considered as, for example, a main body part of an inkjet printer.

In this example, the print execution unit 12 receives RIP generation data, which is data generated by performing RIP (Raster Image Processor) processing, from the RIP processing unit 14 and ejects ink according to the RIP generation data. A printing operation is executed on the medium 50. Further, the printing execution unit 12 includes a plurality of inkjet heads 102 , a platen 104 , a main scanning drive unit 106 , a sub-scanning drive unit 108 , and a control unit 110 .

Each of the plurality of inkjet heads 102 is an ejection head that ejects ink using an inkjet method, and ejects ink of each color used for printing. In this case, it is conceivable that each of the plurality of inkjet heads 102 ejects ink of a mutually different color. More specifically, each of the plurality of inkjet heads 102 ejects ink of each process color, which is a basic color in color printing, for example. As the process color inks, for example, cyan (C), magenta (M), yellow (Y), and black (K) inks may be used. Further, each inkjet head 102 has a nozzle row in which a plurality of nozzles are lined up in a predetermined nozzle row direction, and ink is ejected from each nozzle in the nozzle row. More specifically, in this example, the nozzle row direction is a direction parallel to the sub-scanning direction (X direction in the figure) set in advance in the printing execution unit 12.

Furthermore, in this example, each inkjet head 102 is an inkjet head that can change the volume of ink ejected from each nozzle in multiple stages. In this case, for example, there is a capacity for forming large (L) size ink dots, a capacity for forming medium (M) size ink dots, and a capacity for forming small (S) size ink dots. An inkjet head 102 or the like capable of ejecting ink at three different capacities can be suitably used. Further, such an inkjet head 102 can be considered, for example, as a variable head in which the volume of ink to be ejected is variable.

The platen 104 is a table-like member on which the medium 50 is placed, and holds the medium 50 in a state facing the plurality of inkjet heads 102 . The main scanning drive unit 106 is a drive unit that causes the plurality of inkjet heads 102 to perform a main scanning operation. In this case, the main scanning operation is an operation of ejecting ink while moving relative to the medium 50 in a preset main scanning direction. Further, in this example, the main scanning direction is a direction perpendicular to the sub-scanning direction (Y direction in the figure). Further, during the main scanning operation, the main scanning drive unit 106 controls each nozzle in each of the plurality of inkjet heads 102 with respect to the ejection position set according to the printing resolution according to the control of the control unit 110. Discharge ink. The sub-scanning drive unit 108 is a drive unit that causes the plurality of inkjet heads 102 to perform a sub-scanning operation. In this case, the sub-scanning operation is an operation of moving in the sub-scanning direction relative to the medium 50. Further, the sub-scanning operation can be considered as, for example, an operation of feeding the medium 50 in the sub-scanning direction between main scanning operations.

The control unit 110 is a part that includes, for example, a CPU in the print execution unit 12, and controls the operation of each unit of the print execution unit 12. Further, as explained above, in this example, the main scanning drive unit 106 causes each nozzle in each of the plurality of inkjet heads 102 to eject ink under the control of the control unit 110. In this case, the control unit 110 can be considered to control the ejection of ink from each nozzle. More specifically, in this example, the control unit 110 is an example of an ejection control unit, and causes each nozzle in each inkjet head 102 to eject ink based on RIP generated data. Further, thereby, the control unit 110 causes each nozzle in each inkjet head 102 to eject ink to an ejection position determined depending on the image to be printed, for example. With this configuration, for example, printing operations based on RIP generated data can be appropriately executed.

Further, as explained above, in this example, the print execution section 12 receives RIP generation data from the RIP processing section 14. In this case, the RIP processing unit 14 generates RIP generation data by performing RIP processing in accordance with, for example, the configuration of the print execution unit 12 and the settings of the printing operation to be executed in the print execution unit 12. More specifically, in this example, the RIP processing unit 14 generates, as RIP generation data, data indicating at least a position at which ink should be ejected among a plurality of ejection positions set according to the printing resolution. In this case, the RIP generated data can be considered as an example of ejection designation data, for example. Furthermore, as explained above, in this example, each of the plurality of inkjet heads 102 in the printing execution unit 12 is an inkjet head that can change the volume of ink ejected from the nozzle in multiple stages. Therefore, in this example, data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation and the volume of ink ejected to each ejection position is used as the RIP generation data.

Further, in this example, the RIP processing section 14 is an example of an ejection data generation section. As the RIP processing unit 14, for example, a computer that executes software for RIP processing can be suitably used. The RIP processing section 14 can be considered, for example, as a computer that controls the operation of the printing execution section 12. Further, as explained above, in this example, the plurality of inkjet heads 102 in the print execution section 12 eject ink onto the medium 50 by performing a main scanning operation. In this case, the RIP processing unit 14 generates, as RIP generation data, data indicating at least the ejection position at which ink is ejected from each nozzle of each inkjet head 102 in each main scanning operation.

Further, in this example, the RIP processing unit 14 generates RIP generation data by further considering the ejection characteristics of each nozzle in each inkjet head 102. More specifically, when a nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the RIP processing unit 14 determines whether an abnormal nozzle exists among the plurality of nozzles in the inkjet head 102. The RIP generation data to be generated differs depending on whether or not the RIP generation data is generated. In this case, the presence of an abnormal nozzle among the plurality of nozzles in the inkjet head 102 can be considered as, for example, the presence of an abnormal nozzle in one of the inkjet heads 102 in the printing execution unit 12.

In addition, in this case, if we differentiate the RIP generated data generated when there is no abnormal nozzle as RIP data for normal times, and the RIP generated data generated when an abnormal nozzle exists as RIP data for abnormal times, Regarding the operation of the RIP processing unit 14, for example, it can be considered that when there is no abnormal nozzle, RIP data for normal times is generated, and when there is an abnormal nozzle, RIP data for abnormal times is generated. Furthermore, in this case, the normal RIP data is an example of normal ejection designation data that is ejection designation data that is generated without considering the characteristics of the abnormal nozzle. The abnormality RIP data is an example of abnormality ejection specification data that is generated taking into consideration the characteristics of the abnormal nozzle. The RIP data for abnormal times can be considered, for example, as RIP generated data that is at least partially different from the RIP data for normal times.

Furthermore, in this example, if an abnormal nozzle exists, the RIP processing unit 14 generates RIP data for abnormal times based on abnormal nozzle information created in advance. In this case, the abnormal nozzle information is information indicating an abnormal nozzle. As the abnormal nozzle information, for example, information indicating the position and characteristics of the abnormal nozzle may be used. In this case, the position of the abnormal nozzle can be considered, for example, as the position of the abnormal nozzle within the inkjet head. Furthermore, the position of the abnormal nozzle can be considered, for example, as the position of the abnormal nozzle within the nozzle row of each inkjet head 102. Further, in the abnormal nozzle information, as the characteristic of the abnormal nozzle, for example, information indicating the magnitude relationship or difference between the amount of ink ejected by the abnormal nozzle and a predetermined reference amount may be used.

More specifically, in this example, as the abnormal nozzle information, for example, information obtained by printing a predetermined test pattern (adjustment pattern) using a plurality of nozzles in each inkjet head 102 is used. It is possible that With this configuration, for example, the characteristics of an abnormal nozzle can be appropriately detected. Further, thereby, for example, abnormal nozzle information indicating the position and characteristics of the abnormal nozzle can be appropriately created.

Further, as described above, as the RIP processing section 14, for example, a computer or the like that executes software for RIP processing can be suitably used. In this case, it is conceivable that the abnormal nozzle information is stored in advance in the storage device (eg, HDD, etc.) of the RIP processing unit 14, and used when generating the RIP data for abnormal situations. Further, when there is no abnormal nozzle in the print execution section 12, the RIP processing section 14 generates normal RIP data using the same or similar method as, for example, a known computer for RIP processing. Furthermore, when an abnormal nozzle exists in the printing execution unit 12, the RIP processing unit 14 generates abnormality RIP data that is at least partially different from the normality RIP data, as described above, based on the abnormal nozzle information. .

According to this example, for example, by using the RIP data for an abnormality as described above, the method of ejecting ink onto the medium 50 when an abnormal nozzle exists is determined according to the characteristics of the abnormal nozzle. can be made different from the case where does not exist. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately suppressed. In addition, in this example, when there is an abnormal nozzle, instead of using another nozzle in place of the abnormal nozzle, the abnormal nozzle itself is used and correction is made to suppress the influence of the abnormal nozzle. (correction of ejection characteristics). More specifically, if an abnormal nozzle exists among the plurality of nozzles in any of the inkjet heads 102, the control unit 110 in the print execution unit 12 controls the number of nozzles in the inkjet head 102 based on the abnormal RIP data. and causes the abnormal nozzles to eject ink from at least some of the ejection positions based on the abnormality RIP data.

According to this example, for example, by using the abnormality RIP data generated in consideration of the characteristics of the abnormal nozzle, ink is applied to a plurality of nozzles in each inkjet head 102 in consideration of the characteristics of the abnormal nozzle. It can be discharged. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced. In addition, in this case, by printing using the abnormal nozzle, for example, compared to using another nozzle instead of the abnormal nozzle, the influence of the abnormal nozzle can be reduced while suppressing the impact on printing quality. can be reduced. Therefore, according to this example, even if an abnormal nozzle exists among a plurality of nozzles in the inkjet head 102, the influence of the abnormal nozzle can be appropriately reduced.

Next, the operation when using the abnormality RIP data will be explained in more detail. FIG. 2 is a flowchart showing an example of how to generate RIP data for abnormal times. As explained above, in this example, abnormal nozzle information is obtained by printing a predetermined test pattern using a plurality of nozzles in each inkjet head 102 (see FIG. 1) of the printing execution unit 12. get. In this case, the test pattern can be considered, for example, as an adjustment pattern used to make adjustments according to the characteristics of the abnormal nozzle.

In this case, first, a plurality of test patterns (adjustment patterns) are printed using the print execution unit 12 (S102). In this case, it is conceivable to print a test pattern for each of the plurality of inkjet heads 102 in the print execution unit 12. Further, in this case, it is conceivable that each nozzle in each inkjet head 102 is caused to eject ink under the same conditions, thereby causing the inkjet head 102 to draw a test pattern that reflects the state of the nozzle. For each nozzle to eject ink under the same conditions, it can be considered that the conditions are substantially the same depending on the purpose of checking the state of the nozzle, for example.

More specifically, in this case, a plurality of test patterns corresponding to each of the plurality of inkjet heads 102 are printed so that one test pattern is drawn in one main scanning operation by one inkjet head 102. It is possible to do so. Further, in this case, it is possible to draw a test pattern corresponding to one inkjet head 102 using all the nozzles in that inkjet head 102. Further, as the test pattern, it is possible to use, for example, a pattern that is the same as or similar to a known test pattern for checking the state of the nozzle. With this configuration, for example, the states of the plurality of nozzles in each inkjet head 102 can be appropriately confirmed.

Furthermore, after printing the test pattern, the state of the nozzle used to print the test pattern is checked based on the printed test pattern. Also, thereby, for example, the range of abnormal nozzles that require correction of the ejection characteristics (range of correction target nozzles) is confirmed (S104). In this case, for example, it is conceivable to check the state of each nozzle based on the state of the portion drawn by each nozzle in the test pattern. More specifically, in this case, for example, by checking where the diameter of the ink dots that make up the test pattern (print dot diameter) is large or small, you can determine whether the test pattern was drawn by an abnormal nozzle. It is conceivable to identify the location where the Further, in this case, the diameter of the dots may be checked visually by the operator or automatically using a camera or the like.

Further, in this case, it is conceivable to determine the state of the nozzle for a location where the diameter of the dot is large or small, and to associate it with the position of the nozzle that ejected ink to that location. Furthermore, in this example, abnormal nozzle information is created based on the results of the association. In this case, the state of the nozzle may be determined, for example, by determining whether the amount of ink being ejected is too large or too small. It is also conceivable to determine which of a plurality of preset levels the amount of ink is.

Here, in order to confirm the characteristics of each nozzle with higher accuracy, it is conceivable to identify the nozzles that have drawn each position of the test pattern on a nozzle-by-nozzle basis (one nozzle at a time). However, in this case, it is necessary to check the test pattern in detail, which may increase the number of man-hours required to check the test pattern. Furthermore, in order to enable confirmation on a nozzle-by-nozzle basis, it is necessary to use, for example, a pattern in which lines are lined up at larger intervals, which may result in an increase in the size of the test pattern.

Therefore, it is conceivable to check the nozzle status not on a nozzle-by-nozzle basis, but on a region-by-region basis that includes a plurality of nozzles. In this case, for example, it may be possible to check the state of each part of the test pattern for each range (region) drawn by a predetermined number of nozzles located close to each other in the nozzle row. Further, in this case, it is conceivable that the correction to the ejection characteristics of the nozzle is also performed on a region-by-region basis. In this case, it is not necessary to specify the position of the abnormal nozzle on a nozzle-by-nozzle basis, but it is sufficient to determine which region the abnormal nozzle is included in on a region-by-region basis to be corrected. Therefore, with this configuration, for example, it is possible to more easily and appropriately determine the nozzle to be corrected. Further, thereby, for example, it is possible to appropriately correct the ejection characteristics of an abnormal nozzle without specifying which nozzle in the inkjet head 102 is an abnormal nozzle on a nozzle-by-nozzle basis. Further, in this case, regarding the correction of the ejection characteristics of the abnormal nozzle, for example, it may be considered that the shading caused by the influence of the abnormal nozzle is macroscopically grasped for each region, and the shading is corrected for each region.

Further, among the operations shown in the figure, the operations in step S102 and step S104 can be considered as operations that are performed in advance before performing the RIP processing in the RIP processing section 14, for example. In addition, in this case, in the operations after step S106 described below, the abnormal nozzle information created by performing the operations in step S102 and step S104 is used to correct the ejection characteristics of the abnormal nozzle.

Furthermore, in this example, the method of correction differs depending on whether or not printing on the medium 50 is performed using a multi-pass method. In this case, the multi-pass method can be considered, for example, as a method in which a main scanning operation is performed multiple times for each position on the medium 50. In addition, in the print execution unit 12 of this example, the multi-pass operation is an operation in which the number of main scanning operations that makes it possible to eject ink to each ejection position set according to the printing resolution is two or more. Execute. In addition, the print execution unit 12 switches between a one-pass printing operation and a multi-pass printing operation in accordance with set printing conditions and the like. In this case, the printing operation in one pass can be considered, for example, as a printing operation in which the inkjet head 102 passes only once at a position opposite to each position on the medium. Further, in this example, the RIP processing section 14 generates RIP generation data in accordance with the conditions of printing executed by the printing execution section 12. As explained above, if an abnormal nozzle exists in any inkjet head 102 in the print execution section 12, the RIP processing section 14 generates abnormality RIP data as RIP generation data.

Furthermore, in this case, the RIP processing unit 14 changes the way the abnormality RIP data is generated depending on whether or not the printing execution unit 12 performs a multi-pass printing operation (S106). More specifically, when the print execution unit 12 performs a multi-pass printing operation (S106: Yes), the RIP processing unit 14 performs a multi-pass printing operation in order to determine the ejection position at which ink is ejected in each main scanning operation. The ejection characteristics of the abnormal nozzle are corrected by mask pattern correction, which is a method of making the mask pattern used different from the mask pattern used when generating the normal RIP data (S108). Mask pattern correction can be considered as, for example, an operation in which the ejection characteristics of an abnormal nozzle are corrected by using a mask with a pattern that is thicker or thinner. The operation of mask pattern correction will be explained in more detail later.

Further, when the printing execution unit 12 performs a printing operation in one pass (S106: No), the RIP processing unit 14 performs a dot printing process, which is a method of changing the size of ink dots formed at some ejection positions. The ejection characteristics of the abnormal nozzle are corrected by size correction (S110). Dot size correction can be considered as an operation that corrects the ejection characteristics of an abnormal nozzle by increasing or reducing the size of ink dots formed at at least some ejection positions, for example. The operation of dot size correction will also be explained in more detail later.

In this case, by supplying the abnormality RIP data generated by performing mask pattern correction or dot size correction to the printing execution section 12 and causing the printing execution section 12 to perform the printing operation, mask pattern correction or dot size correction can be performed. The result of the size correction is reflected in the control of the printing operation (S112). With this configuration, for example, it is possible to cause the printing execution unit 12 to appropriately execute a printing operation that reduces the influence of an abnormal nozzle.

Next, the operations of dot size correction and mask pattern correction will be explained in more detail. FIG. 3 is a diagram illustrating the operations of dot size correction and mask pattern correction. FIG. 3(a) is a diagram showing an example of the dot size correction operation. Regarding the density of the pattern drawn in , the results when dot size correction is not performed and the results when dot size correction is performed are shown in comparison. In this case, printing with a print density of 100% means, for example, ejecting a predetermined amount of ink once at each ejection position that is set according to the printing resolution. You can think about it.

More specifically, in FIG. 3A, the diagram on the left shows an example of the density distribution of a pattern drawn on the medium when one main scanning operation is performed without dot size correction. The diagram on the left can be considered, for example, as a diagram showing the printing results when printing is performed in one pass without performing correction for the ejection characteristics of the abnormal nozzle. Furthermore, the diagram on the right shows an example of the density distribution of a pattern drawn on the medium when one main scanning operation is performed with dot size correction.

If dot size correction is not performed, as shown in the figure on the left, there will be a difference in density between the area drawn by the abnormal nozzle and the other areas. More specifically, in the case shown in the figure, in the left-hand figure, a thin spot has occurred in a part of the pattern due to the influence of the ejection characteristics of the abnormal nozzle. On the other hand, when performing dot size correction, for at least some of the ink dots formed by the abnormal nozzle, the volume of ink ejected from the nozzle is changed when that dot is formed. This changes the size of the dots. In this case, by changing the size of the dots to compensate for the characteristics of the abnormal nozzle, the density of the part drawn by the abnormal nozzle can be corrected, for example, as shown in the right diagram in FIG. 3(a). Reduce the effects of abnormal nozzles.

FIG. 3(b) is a diagram illustrating an example of the operation of mask pattern correction, in which printing is performed using a multi-pass method with a print density of 100% using one inkjet head 102 in which an abnormal nozzle exists. Regarding the density of a pattern drawn on a medium, the results when mask pattern correction is not performed and the results when mask pattern correction is performed are compared and shown. Further, in FIG. 3(b), the above-mentioned matters are illustrated for the case where the number of passes in the multipath method is set to two.

More specifically, in FIG. 3(b), the diagram on the left shows the image drawn on the medium in each main scanning operation when two main scanning operations are performed for the number of passes without performing mask pattern correction. An example of pattern density distribution is shown. The diagram on the left can be considered, for example, to be a diagram showing the printing results when printing is performed using the multipass method without correcting the ejection characteristics of the abnormal nozzle. Furthermore, the diagram on the right shows an example of the density distribution of a pattern drawn on the medium in each main scanning operation when dot size correction is performed.

If mask pattern correction is not performed, as shown in the figure on the left, a difference in density will occur between the portion drawn by the abnormal nozzle and the other portions in each main scanning operation. More specifically, in the case shown in the figure, in the left-hand figure, a thin spot has occurred in a part of the pattern due to the influence of the ejection characteristics of the abnormal nozzle. On the other hand, when performing mask pattern correction, the mask pattern used to determine the ejection position at which ink is ejected in each main scanning operation is made different from the mask pattern used when generating the normal RIP data. , change the density of the area drawn with the abnormal nozzle. In addition, in this case, by using a mask that compensates for the characteristics of the abnormal nozzle, the density of the part drawn by the abnormal nozzle can be corrected and the influence of the abnormal nozzle is Reduce.

Next, a more specific example of the dot size correction and mask pattern correction operations performed in this example will be explained. First, in relation to the dot size correction and mask pattern correction operations, the RIP processing operations performed in the RIP processing section 14 of this example will be explained in more detail.

FIG. 4 is a diagram illustrating the arrangement of ink dots 302 formed on a medium. FIG. 4(a) is a diagram showing an example of the arrangement of ink dots 302 formed on a medium when printing is executed in the print execution unit 12 (see FIG. 1), and is printed with a print density of 100%. An example of the arrangement of ink dots formed on a part of the medium by one inkjet head 102 (see FIG. 1) is shown below. In this case, for example, as shown in the figure, one ink dot 302 of a predetermined size is formed at each ejection position set according to the printing resolution. In addition, in the following, regarding the arrangement of ejection positions set according to the printing resolution, the arrangement of ejection positions arranged in the main scanning direction (Y direction) with the positions aligned in the sub-scanning direction (X direction) will be explained. It is called a direction line. Further, in this example, the printing execution unit 12 forms a row of ink dots 302 on the medium by ejecting ink to each ejection position in each main scanning direction line.

Regarding this point, as explained above, in this example, the print execution unit 12 performs one-pass printing operation or multi-pass printing operation depending on the set printing conditions etc. perform an action. When performing a printing operation in one pass, the printing execution unit 12 ejects ink to an ejection position in one main scanning direction line in any one main scanning operation. In addition, in this example, when performing a printing operation using the multi-pass method, the printing execution unit 12 is configured to perform printing at a discharge position in one main scanning direction line, as shown in FIGS. 4(b) and 4(c), for example. On the other hand, ink is ejected in any one of a plurality of main scanning operations.

FIGS. 4B and 4C show an example of an operation in which ink is ejected in multiple main scanning operations with respect to an ejection position in one main scanning direction line regarding a multi-pass printing operation. More specifically, in FIG. 4B, regarding a plurality of ink dots 302a and 302b formed at ejection positions in one main scanning direction line, the number of dots formed in the same main scanning operation is The dots are illustrated with the same hatching pattern, but with different hatching patterns of dots formed in different main scanning operations.

More specifically, in the case shown in FIG. 4(b), the printing execution unit 12 forms a plurality of dots 302a shown in the same hatching pattern in any one main scanning operation, and forms the plurality of dots 302a shown in the same hatching pattern in any one of the main scanning operations. By forming the plurality of dots 302b shown in any other one main scanning operation, ink can be applied to the plurality of ejection positions forming one main scanning direction line in two main scanning operations. Exhale. Furthermore, in this example, the print execution unit 12 performs at least one sub-scanning operation while performing these two main-scanning operations. In this case, ink is ejected from one nozzle of the inkjet head 102 to a part of the ejection position in one main scanning direction line, and ink is ejected to the other part of the ejection position in the main scanning direction line. On the other hand, ink is ejected from one of the other nozzles in the inkjet head 102. More specifically, in this case, for example, as shown in FIG. 4C, the plurality of dots 302a in FIG. 4B are formed by any nozzle A in the inkjet head 102, and the plurality of dots 302b It can be considered that the nozzle B is formed by any nozzle B other than the nozzle A.

Here, the method of determining the ejection position at which ink is ejected in each main scanning operation will be explained in more detail. As explained above, in this example, the inkjet head 102 in the print execution unit 12 discharges ink to the discharge position under the control of the control unit 110 (see FIG. 1). Further, in the multi-pass operation, the inkjet head 102 forms ink dots at some ejection positions in the main scanning direction line in one main scanning operation according to the control of the control unit 110, and The main scanning operation and the sub-scanning operation are performed so that dots can be formed at all ejection positions in the main scanning direction line by performing the main scanning operation a preset plurality of times. In this case, the control unit 110 causes each nozzle in each inkjet head 102 to eject ink based on the RIP generation data received from the RIP processing unit 14 (see FIG. 1).

Further, in this example, the RIP processing unit 14 generates RIP generation data by performing RIP processing based on print image data that is image data indicating an image to be printed. More specifically, the RIP processing unit 14 performs, for example, resolution conversion processing, color conversion processing, color separation processing, quantization processing, pass division processing, etc. as RIP processing for print image data. If there is no abnormal nozzle, resolution conversion processing, color conversion processing, color separation processing, quantization processing, pass division processing, etc. may be performed the same as or similar to each processing in known RIP processing. . Further, in this case, the resolution conversion process is, for example, a process of converting the resolution of print image data in accordance with the resolution of printing executed by the print execution unit 12. The color conversion process is, for example, a process of converting a color to match the color of ink used in the print execution unit 12. In the color conversion process, the RIP processing unit 14 performs color conversion according to, for example, a profile (for example, an ICC profile) created in accordance with the color of ink used in the print execution unit 12. The separation process is a process in which print image data after color conversion in the color conversion process is divided into separation data that is data for each ink color. In this case, the separation data can be considered, for example, as data indicating an image to be drawn with one color of ink. As the separation data corresponding to each ink color, it is possible to use a grayscale image (for example, an 8-bit grayscale image).

The quantization process is, for example, a process of converting separation data into halftone image data that can be drawn using an inkjet head. The quantization process can be considered, for example, as a process of converting into the number of gradations that can be expressed using an inkjet head. More specifically, in this example, the RIP processing unit 14 generates binary image data corresponding to separation data corresponding to each color of ink through quantization processing. In this case, the binary image can be considered to be, for example, an image in which a value of 0 or 1 is set at each ejection position that is set depending on the resolution. Furthermore, the binary image can be considered, for example, as an image indicating the ejection position at which ink should be ejected. Furthermore, as described above, in this example, the inkjet head 102 is an inkjet head that can change the volume of ink ejected from each nozzle in multiple stages. In this case, in the quantization process, for example, a binary image may be generated for each capacity. The binary image corresponding to each capacity can be considered, for example, as an image indicating the ejection position at which ink should be ejected at each capacity.

Further, the pass division process is, for example, a process of determining the ejection position at which ink should be ejected in each main scanning operation. In the pass division process, the RIP processing unit 14 determines which ejection positions are set with values for ejecting ink in the binary image generated by the quantization process, based on printing conditions such as the number of passes, for example. It is determined whether ink is ejected during the main scanning operation. Further, the RIP processing section 14 thereby generates RIP generation data in accordance with the printing conditions executed by the printing execution section 12. Further, in this example, the RIP processing unit 14 uses a mask to select some ejection positions on the main scanning direction line, and injects dots at each ejection position on the main scanning direction line in which main scanning operation. Decide what to form.

According to this example, for example, the ejection position at which ink is ejected in each main scanning operation can be appropriately determined, and, for example, RIP generation data corresponding to an image to be printed can be appropriately generated. Furthermore, by performing the printing operation in accordance with the RIP generated data in the print execution unit 12, it is possible to appropriately perform the printing operation on the medium.

Furthermore, as explained above, in this example, the RIP processing section 14 generates different RIP generation data depending on whether or not there is an abnormal nozzle in the inkjet head 102 in the printing execution section 12. . Furthermore, when printing is performed using a multi-pass method, the ejection characteristics of the abnormal nozzle are corrected by mask pattern correction. Therefore, the mask pattern correction performed in this example will be explained in more detail below.

FIGS. 5 and 6 are diagrams showing examples of mask pattern correction operations. If we classify the case where there is an abnormal nozzle whose ink ejection amount is outside the normal range as an abnormal nozzle presence, and the case where all nozzles are normal as all nozzles normal, for example, when an abnormal nozzle exists, all nozzles are normal. If ink is ejected in the same manner as when the nozzle is normal, it is conceivable that the amount of ink actually ejected onto the medium will differ from the intended state.

More specifically, as explained above, in this example, the RIP processing unit 14 generates normal-time RIP data as RIP-generated data for when all nozzles are normal. If the printing operation in the print execution unit 12 when an abnormal nozzle exists is performed according to the RIP generated data for normal times, there will be no shortage or excess of ink in the main scanning direction line corresponding to the abnormal nozzle. Conceivable. Therefore, as explained above, when an abnormal nozzle exists, the RIP processing unit 14 of this example takes into consideration the characteristics of the abnormal nozzle and generates abnormal RIP data that is different from normal RIP data. .

Furthermore, as explained above, in the mask pattern correction performed in this example, the RIP processing unit 14 changes the mask pattern used to determine the ejection position at which ink is ejected in each main scanning operation to the normal state. The ejection characteristics of the abnormal nozzle are corrected by making the mask pattern different from that used when generating the RIP data. Furthermore, in this case, the RIP processing unit 14 generates the RIP data for abnormal times in the path division process using a mask that is at least partially different from the mask used when generating the RIP data for normal times. With this configuration, for example, it is possible to appropriately generate RIP data for abnormal times that is different from RIP data for normal times. In this case, for example, by selecting a mask to be used when generating RIP data for abnormal situations based on abnormal nozzle information according to the characteristics of the abnormal nozzle, RIP data for abnormal situations can be generated according to the characteristics of the abnormal nozzle. can be generated.

Furthermore, if we define the number of times ink is ejected by any nozzle in multiple main scanning operations to the ejection position included per unit length in one main scanning direction line as the unit ejection number, then the RIP processing unit 14 The operation of generating RIP data for abnormal times can be considered as the operation of generating RIP data for abnormal times in which the unit ejection number changes compared to the case where RIP data for normal times is used. More specifically, in this example, the RIP processing unit 14 determines, based on the abnormal nozzle information, that the number of unit ejections in the main scanning direction line corresponding to the abnormal nozzle is different from that when normal RIP data is used, and that The abnormality RIP data is generated such that the influence of an abnormal nozzle is reduced compared to when using normal RIP data. With this configuration, for example, it is possible to appropriately generate RIP data for abnormal situations in consideration of the characteristics of the abnormal nozzle. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced.

Regarding the case of using the normal RIP data, consider, for example, the case where the normal RIP constant data is used to eject ink to the inkjet head 102 (see FIG. 1) in which an abnormal nozzle exists. be able to. Regarding the unit ejection number, for example, the number of times ink is ejected to an ejection position within one main scanning line in multiple main scanning operations in a multi-pass method is calculated by calculating the length of the main scanning line (the length in the main scanning direction). ) can also be thought of as the value divided by Further, the unit number of ejections can be considered as, for example, the number of ejections per unit length, which is determined depending on the print density. The line in the main scanning direction corresponding to the abnormal nozzle can be considered, for example, as a line in the main scanning direction that includes the ejection position where ink is ejected by the abnormal nozzle.

Next, an example of the mask pattern correction operation will be described in more detail. First, an example of the mask pattern correction operation when there is an abnormal nozzle whose amount of ink ejected is less than the normal range will be described in more detail with reference to FIGS. 5(a) to 5(c). FIGS. 5A to 5C show examples of mask pattern correction operations when there is an abnormal nozzle whose amount of ink ejected is smaller than the normal range.

For example, when printing an image in which ink is ejected to the ejection position in one main scanning direction line in two main scanning operations as shown in FIGS. 4(b) and 4(c) when all nozzles are normal, the main scanning If the amount of ink ejected by any of the nozzles that ejects ink toward the direction line is less than the normal range, the position at which ink is ejected in each main scanning operation is set to one of the positions shown in FIGS. 5(a) to (c). It is conceivable to change it as shown in the figure below. In FIGS. 5A to 5C, the amount of ink ejected by nozzle A is normal among the plurality of nozzles A and B that eject ink to one line in the main scanning direction in different main scanning operations. In the case where the number is less than the range, an example of the ejection positions at which ink is ejected in each of nozzles A and B according to the abnormality RIP data is shown. Further, in FIGS. 5(a) to 5(c), arrows are attached to ejection positions where ink is not ejected when all nozzles are normal.

Furthermore, among these, FIG. 5A is an example in which the number of positions where ink is ejected by the abnormal nozzle itself (nozzle A) is increased. In this case, for example, as a mask for determining the position at which ink is ejected by the nozzle A in the pass division process, a mask is used in which more ejection positions are selected than when generating the normal RIP data. Further, FIG. 5B is an example in which the number of positions where ink is ejected by the abnormal nozzle and other nozzles (nozzles A and B) is increased. In this case, for example, as a mask for determining the positions at which ink is ejected by the nozzles A and B in the pass division process, a mask is used in which more ejection positions are selected than when generating the normal RIP data. The example shown in FIG. 5B can also be considered as an example in which the position at which ink is ejected by a normal nozzle other than the abnormal nozzle is further changed. Further, FIG. 5C is an example in which the number of positions from which ink is ejected is increased by another nozzle (nozzle B) that ejects ink to the line in the main scanning direction corresponding to the abnormal nozzle. In this case, for example, as a mask for determining the position at which ink is ejected by the nozzle B in the pass division process, a mask is used in which more ejection positions are selected than when generating the normal RIP data. The example shown in FIG. 5(c) can also be considered as an example in which the position at which ink is ejected by a normal nozzle other than the abnormal nozzle is changed without changing the position at which ink is ejected by the abnormal nozzle. .

With these configurations, for example, when there is an abnormal nozzle whose amount of ink ejected is less than the normal range, it is possible to generate RIP data for abnormal times in which the number of ejection positions from which ink is ejected increases. Therefore, for example, even if the amount of ink ejected in one ejection operation by an abnormal nozzle is small, there is no abnormal nozzle regarding the amount of ink per unit length in the main scanning direction line. The amount of ink can be approximated. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced.

Next, an example of the mask pattern correction operation when there is an abnormal nozzle ejecting an amount of ink larger than the normal range will be explained in more detail using FIGS. 6(a) to 6(c). . If there is an abnormal nozzle that ejects an amount of ink that is larger than the normal range, it is conceivable to generate abnormal RIP data in which the number of ejection positions from which ink is ejected is reduced, contrary to the above. FIGS. 6A to 6C show examples of mask pattern correction operations when there is an abnormal nozzle ejecting an amount of ink greater than the normal range. In FIGS. 6(a) to (c), among the plurality of nozzles A and B that eject ink to one line in the main scanning direction in different main scanning operations, the amount of ink ejected by nozzle A is normal. In the case where the number of inks exceeds the range, an example of the ejection positions at which each of nozzles A and B ejects ink according to the abnormality RIP data is shown. In addition, in FIGS. 6(a) to (c), arrows are attached to the ejection positions where ink is ejected when all nozzles are normal, but where ink is not ejected in the operations of FIGS. 6(a) to (c). .

Furthermore, among these, FIG. 6A is an example in which the number of positions from which ink is ejected by the abnormal nozzle itself (nozzle A) is reduced. In this case, for example, as a mask for determining the position at which ink is ejected by the nozzle A in the pass division process, a mask is used in which fewer ejection positions are selected than when generating the normal RIP data. Further, FIG. 6(b) is an example in which the number of positions where ink is ejected by the abnormal nozzle and other nozzles (nozzles A and B) is reduced. In this case, for example, as a mask for determining the positions at which ink is ejected by the nozzles A and B in the pass division process, a mask is used in which fewer ejection positions are selected than when generating the normal RIP data. The example shown in FIG. 6(b) can also be considered as an example in which the position at which ink is ejected by a normal nozzle other than the abnormal nozzle is further changed. Further, FIG. 6C is an example in which the number of positions from which ink is ejected is reduced by another nozzle (nozzle B) that ejects ink to the line in the main scanning direction corresponding to the abnormal nozzle. In this case, for example, as a mask for determining the position at which ink is ejected by the nozzle B in the pass division process, a mask is used in which fewer ejection positions are selected than when generating the normal RIP data. The example shown in FIG. 6(c) can also be considered as an example in which the position at which ink is ejected by a normal nozzle other than the abnormal nozzle is changed without changing the position at which ink is ejected by the abnormal nozzle. .

With these configurations, for example, even if the amount of ink ejected in one ejection operation by an abnormal nozzle is large, the amount of ink per unit length in the main scanning direction line can be adjusted. , the amount of ink can be brought close to the amount that would be achieved if no abnormal nozzle existed. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced.

Here, the operation of mask pattern correction as described above can be considered as, for example, an operation of changing the amount of ink ejected from one nozzle with respect to a unit area. More specifically, for example, if the amount of ink ejected from one nozzle with respect to a unit area is defined as the unit ejection amount, regarding the operation of the control section 110 in the print execution section 12, for example, the RIP data for abnormality may be By causing the abnormal nozzle to eject ink based on the abnormal nozzle, the unit ejection amount of one of the nozzles used to form the line in the main scanning direction corresponding to the abnormal nozzle is considered to be different from when normal RIP data is used. be able to. More specifically, when changing the position from which ink is ejected from an abnormal nozzle, as in the case shown in FIGS. 5(a), (b) and 6(a), (b), It can be considered that the unit discharge amount of the nozzle is different from that when normal RIP data is used.

In addition, in this case, regarding the unit discharge amount of the abnormal nozzle when using the normal RIP data, for example, if the normal RIP data is used as is without using the abnormal RIP data, an abnormality may occur. It can be considered as the unit discharge amount, etc. Further, the unit ejection amount can be considered as, for example, the average amount of ink ejected to a unit area by one nozzle. Further, in this case, the average ejection amount can be considered to be, for example, the average ejection amount during a series of printing operations.

In addition, regarding the operation of the RIP processing unit 14 that generates RIP data for abnormal times, for example, based on abnormal nozzle information, abnormal This can also be considered as an operation that makes at least part of the RIP data for normal times different from the RIP data for normal times. By generating the abnormality RIP data in this manner, for example, it is possible to cause the plurality of nozzles in the inkjet head 102 of the print execution unit 12 to appropriately eject ink in consideration of the characteristics of the abnormal nozzle. Further, in this case, the control unit 110 in the print execution unit 12 controls the position at which ink is to be ejected by the abnormal nozzle by, for example, causing each of the plurality of nozzles in the inkjet head 102 to eject ink based on the abnormality RIP data. Ink is ejected from each of the plurality of nozzles in the inkjet head 102 so that the ink is less noticeable than when normal RIP data is used. With this configuration, for example, the influence of an abnormal nozzle can be appropriately reduced.

Regarding the relationship between the characteristics of the abnormal nozzle and the RIP data for abnormal times, as described above, if there is an abnormal nozzle that ejects an amount of ink smaller than the normal range, the RIP processing unit 14, for example, Generates RIP data for abnormal situations where the number of ejection positions increases. Furthermore, if there is an abnormal nozzle that ejects an amount of ink that is larger than the normal range, the RIP processing unit 14 generates RIP data for abnormal times in which the number of ejection positions for ejecting ink is reduced, for example. In this case, the generated abnormality RIP data can be considered as data that compensates for deviations in the amount of ink ejected from the abnormal nozzle, for example.

In this case, compensation for the deviation in the amount of ink ejected by the abnormal nozzle is not limited to strictly compensating for the deviation, but it is considered that the influence of the abnormal nozzle is further reduced. be able to. In addition, for such compensation, for example, the density at each position of a test pattern (adjustment pattern) used to make adjustments according to the characteristics of the abnormal nozzle is measured, and from the measurement results it is possible to determine the density of ink ejected from the abnormal nozzle. It is conceivable that by detecting the magnitude of the shift in quantity, compensation is performed according to the magnitude of the detected shift. In addition, in this case, when considering the RIP data for abnormal times, focusing on the number of unit ejections, for example, the number of unit ejections in the main scanning direction line corresponding to the abnormal nozzle is different from that when using the RIP data for normal times. It can also be considered as data that compensates for deviations in the amount of ink ejected from the abnormal nozzle.

Further, as explained above, in the printing system 10 of this example (see FIG. 1), when the printing execution unit 12 performs a printing operation in one pass, as a correction for the ejection characteristics of the abnormal nozzle, Perform dot size correction. FIG. 7 is a diagram illustrating dot size correction in more detail. FIG. 7A shows an example of the arrangement of ink dots 302 formed in one line in the main scanning direction when normal RIP data is used (dot size correction is not performed). FIGS. 7B and 7C show examples of dot size correction operations.

As explained above, as the inkjet head 102 (see FIG. 1) in the printing execution unit 12 of this example, an inkjet head that can change the volume of ink ejected from each nozzle in multiple stages is used. Further, in this case, the inkjet head 102 has a capacity for forming large (L) size ink dots, a capacity for forming medium (M) size ink dots, and a capacity for forming small (M) size ink dots from each nozzle. S) Ink is ejected at three different capacities to form ink dots of size S). Therefore, during actual printing, ink dots 302 of various sizes are mixed and lined up on the main scanning direction line, as shown in FIG. 7A, for example, depending on the image to be printed. In this case, if there is an abnormal nozzle whose ejected amount of ink is outside the normal range, the size of the ink dot 302 formed by the abnormal nozzle will be different from the original size when the nozzle is normal. There will be a discrepancy between the sizes.

In contrast, in dot size correction, the influence of the abnormal nozzle is reduced by changing the volume of ink ejected from the abnormal nozzle to at least some of the ejection positions. More specifically, in this case, the RIP processing unit 14 detects an abnormality in which the volume of ink ejected to at least some ejection positions in the main scanning direction line corresponding to the abnormal nozzle is different from that when normal RIP data is used. Generate time RIP data.

More specifically, if there is an abnormal nozzle whose amount of ink ejected is smaller than the normal range, the main scanning direction corresponding to the abnormal nozzle, for example, as in the ejection position indicated with an arrow in FIG. The volume of ink ejected to some ejection positions on the direction line is made larger than when normal RIP data is used. In addition, if there is an abnormal nozzle that ejects more ink than the normal range, the main scanning direction line corresponding to the abnormal nozzle may be The volume of ink ejected to some ejection positions is made smaller than when normal RIP data is used. With this configuration, for example, the total amount of ink ejected to the main scanning direction line corresponding to the abnormal nozzle can be appropriately brought close to the amount when the nozzle is normal. Moreover, thereby, for example, the influence of an abnormal nozzle can be appropriately reduced.

Next, supplementary explanations regarding each of the configurations explained above, explanations of modifications, etc. will be given. As explained above, according to this example, by performing mask pattern correction, dot size correction, etc., it is possible to appropriately correct the ejection characteristics of the abnormal nozzle. Furthermore, even if there is an abnormal nozzle in one of the inkjet heads 102, this can appropriately prevent unevenness in printing density at the position where ink is ejected in that inkjet head 102. Printing can be performed with appropriate quality. In this case, as can be understood from the above explanation, in this example, correction for the ejection characteristics of the abnormal nozzle can be achieved without adjusting the voltage of the head drive waveform or adjusting the ink heating temperature. can do. Therefore, there are no restrictions on the model of the inkjet head or the device configuration of the print execution unit, and the ejection characteristics of the abnormal nozzle can be corrected in various configurations.

Further, as explained above, in this example, the printing system 10 includes the print execution unit 12 and the RIP processing unit 14. In this case, as the print execution section 12 and the RIP processing section 14, it is conceivable to use separate devices as explained above using, for example, FIG. 1 and the like. Further, in this case, the printing system 10 can be considered to be composed of a plurality of devices, for example.

On the other hand, in a modification of the configuration of the printing system 10, for example, the printing system 10 may be configured with one device. In this case, for example, the printing system 10 may be configured with one inkjet printer having the functions of the print execution section 12 and the RIP processing section 14. Further, in this case, the inkjet printer constituting the printing system 10 can be considered, for example, as a printing device corresponding to the print execution section 12 in which the control section 110 has the function of the RIP processing section 14. Further, in a further modification of the configuration of the printing system 10, it is conceivable that the printing system 10 is configured with three or more devices. In this case, for example, the printing system 10 may be configured by a plurality of print execution units 12 and RIP processing units 14. Furthermore, for example, it is also conceivable to configure the printing system 10 with three or more devices by further using another device having a part of the function of the print execution section 12 or the RIP processing section 14.

In addition, in the above, regarding correction of the ejection characteristics of abnormal nozzles, dot size correction is mainly performed when printing in one pass, and mask pattern correction is performed when printing in multi-pass method. I explained the operation in this case. In this case, the operation of the printing system 10 can be considered as, for example, an operation of performing either dot size correction or mask pattern correction depending on the number of passes. In addition, in a modification of the operation of the printing system 10, for example, when performing multi-pass printing, it is also possible to perform both dot size correction and mask pattern correction. With this configuration, for example, the ejection characteristics of the abnormal nozzle can be corrected with higher accuracy. In addition, in a modification of the operation of the printing system 10, for example, when performing multi-pass printing, only dot size correction may be performed without performing mask pattern correction. In addition, if the printing system 10 is capable of performing multi-pass operation using multiple types of passes, for example, only dot size correction may be performed during multi-pass operation using a certain number of passes. It is also possible to do this.

Furthermore, as explained above, in this example, the correction for the ejection characteristics of the abnormal nozzle is not performed by alternative processing, which is a method of using another normal nozzle in place of the abnormal nozzle, but by the correction of the abnormal nozzle itself. Correction is also performed by ejecting ink. In this case, even when there are a large number of abnormal nozzles, correction can be made more appropriately than with respect to the ejection characteristics of the abnormal nozzles. More specifically, for example, when performing alternative processing for an abnormal nozzle, the timing at which ink is ejected to some ejection positions may change, making the positions where the alternative processing has been performed more noticeable. Therefore, for example, when there are a large number of abnormal nozzles, if alternative processing is performed, the position where the alternative processing has been performed becomes conspicuous, and there is a risk that the quality of printing may deteriorate. In particular, when a plurality of abnormal nozzles exist in close positions, it is thought that the position where alternative processing has been performed becomes particularly noticeable. In contrast, in this example, by performing the printing operation while also using the abnormal nozzle, it is possible, for example, to make the position targeted for correction less noticeable. Further, as a result, even when there are a large number of abnormal nozzles, for example, correction can be made more appropriately than with respect to the ejection characteristics of the abnormal nozzles.

Further, as explained above, mask pattern correction and dot size correction may be performed not in units of one nozzle but in units of areas including a plurality of nozzles. On the other hand, when mask pattern correction or dot size correction is performed as in this example, even if correction is performed on a plurality of adjacent nozzles, the position targeted for correction can be made less noticeable. Therefore, according to this example, even if correction is performed in units of regions including a plurality of nozzles, it is possible to appropriately perform printing with high quality.

In addition, the above description mainly describes the operation of checking the status of each nozzle in the inkjet head 102 by printing a test pattern (adjustment pattern) used to make adjustments according to the characteristics of the abnormal nozzle. Did. In this case, as explained above, the diameter of the ink dots constituting the test pattern is confirmed, for example, by visual inspection by the operator or automatic operation using a camera or the like. Further, the operation of automatically checking the dot diameter can be considered as, for example, an operation of scanning a test pattern and automatically correcting it. Further, mask pattern correction and dot size correction may be performed using a configuration other than the configuration in which abnormal nozzles are confirmed by printing a test pattern, for example. For example, mask pattern correction or dot size correction may be performed depending on the duty in image data indicating an image to be printed. It is also conceivable, for example, to measure the temperature of each part of the inkjet head and perform mask pattern correction or dot size correction in accordance with temperature unevenness occurring within the inkjet head.

Furthermore, in the above description, the configuration of the printing system 10 has been mainly described in the case where ink is ejected onto a medium. In this case, the print execution unit 12 in the printing system 10 can be considered as an inkjet printer or the like that draws a two-dimensional image on a medium. Further, in a modification of the printing system 10, it is also possible to use a 3D printer (3D printing device) or the like that forms a three-dimensional object as the printing execution unit 12. Even in such a case, the influence of the abnormal nozzle can be appropriately reduced by, for example, performing mask pattern correction, dot size correction, etc. in the same or similar manner as described above.

INDUSTRIAL APPLICATION This invention can be conveniently utilized for a printing system, for example.

DESCRIPTION OF SYMBOLS 10... Printing system, 12... Print execution unit, 14... RIP processing unit, 50... Medium, 102... Inkjet head, 104... Platen, 106... Main scanning drive unit , 108... Sub-scanning drive unit, 110... Control unit, 302... Dot

Claims (12)

A printing system that prints using an inkjet method,
An inkjet head that ejects ink from multiple nozzles,
an ejection data generation unit that generates ejection designation data indicating at least a position at which ink should be ejected among a plurality of ejection positions set according to printing resolution;
a main scanning drive unit that causes the inkjet head to perform a main scanning operation of ejecting ink while moving relative to a printing target medium in a preset main scanning direction;
a sub-scanning drive unit that causes the inkjet head to perform a sub-scanning operation that moves relative to the medium in a sub-scanning direction perpendicular to the main-scanning direction;
an ejection control unit that causes each of the plurality of nozzles in the inkjet head to eject ink based on the ejection designation data,
Performing multi-pass printing in which the main scanning operation is performed a plurality of times for each position on the medium,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the ejection data generation section determines whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. If the abnormal nozzle does not exist among the plurality of nozzles, the ejection specification data is generated without considering the characteristics of the abnormal nozzle. When certain normal discharge designation data is generated and the abnormal nozzle exists among the plurality of nozzles, the characteristics of the abnormal nozzle are considered based on abnormal nozzle information that is information indicating the abnormal nozzle. generating abnormality discharge specification data that is at least partially different from the normality discharge specification data;
If the abnormal nozzle exists among the plurality of nozzles, the ejection control unit causes each of the plurality of nozzles in the inkjet head to eject ink based on the abnormal ejection designation data,
and causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data ,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
The inkjet head is configured to form ink dots at some of the ejection positions in the main scanning direction line in one main scanning operation under the control of the ejection control unit, and to form a preset plurality of ink dots at some of the ejection positions in the main scanning direction line. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line by performing the main scanning operation twice;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
The ejection data generation unit is configured to determine, based on the abnormal nozzle information, the ejection position where ink is ejected by a nozzle other than the abnormal nozzle among the nozzles that eject ink to the main scanning direction line corresponding to the abnormal nozzle. By changing the number of ejections in the main scanning direction line corresponding to the abnormal nozzle, the number of unit ejections in the main scanning direction line corresponding to the abnormal nozzle is different from that when using the ejection designation data for normal times, and more than when using the ejection designation data for normal times. A printing system characterized in that the abnormality ejection designation data is generated such that the influence of the abnormal nozzle is reduced . A printing system that prints using an inkjet method,
An inkjet head that ejects ink from multiple nozzles,
an ejection data generation unit that generates ejection designation data indicating at least a position at which ink should be ejected among a plurality of ejection positions set according to printing resolution;
a main scanning drive unit that causes the inkjet head to perform a main scanning operation of ejecting ink while moving relative to a printing target medium in a preset main scanning direction;
a sub-scanning drive unit that causes the inkjet head to perform a sub-scanning operation that moves relative to the medium in a sub-scanning direction perpendicular to the main-scanning direction;
an ejection control unit that ejects ink to each of the plurality of nozzles in the inkjet head based on the ejection designation data;
Equipped with
Performing multi-pass printing in which the main scanning operation is performed a plurality of times for each position on the medium,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the ejection data generation section determines whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. If the abnormal nozzle does not exist among the plurality of nozzles, the ejection specification data is generated without considering the characteristics of the abnormal nozzle. When certain normal discharge designation data is generated and the abnormal nozzle exists among the plurality of nozzles, the characteristics of the abnormal nozzle are considered based on abnormal nozzle information that is information indicating the abnormal nozzle. generating abnormality discharge specification data that is at least partially different from the normality discharge specification data;
If the abnormal nozzle exists among the plurality of nozzles, the ejection control unit causes each of the plurality of nozzles in the inkjet head to eject ink based on the abnormal ejection designation data,
and causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
The inkjet head is configured to form ink dots at some of the ejection positions in the main scanning direction line in one main scanning operation under the control of the ejection control unit, and to form a preset plurality of ink dots at some of the ejection positions in the main scanning direction line. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line by performing the main scanning operation twice;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
The ejection data generation unit responds to the abnormal nozzle while causing other nozzles other than the abnormal nozzle to eject ink to the main scanning direction line corresponding to the abnormal nozzle based on the abnormal nozzle information. By changing only the ejection position at which ink is ejected to the abnormal nozzle without changing the ejection position at which ink is ejected by the other nozzle with respect to the main scanning direction line, the abnormal nozzle is The number of unit ejections in the corresponding line in the main scanning direction is different from the case where the normal ejection designation data is used, and the influence of the abnormal nozzle is reduced compared to the case where the normal ejection designation data is used. A printing system characterized in that the printing system generates the abnormality ejection designation data. When the amount of ink ejected from one nozzle with respect to a unit area is defined as a unit ejection amount, the ejection control unit may cause the abnormal nozzle to eject ink based on the abnormal ejection designation data. 3. The printing system according to claim 1 , wherein the unit ejection amount of the abnormal nozzle is different from that when the normal ejection designation data is used. When generating the ejection designation data for abnormal times, the ejection data generation section generates the ejection data based on the abnormal nozzle information so that the influence of the abnormal nozzle is smaller than when using the ejection designation data for normal times. At least a part of the abnormal discharge specification data is different from the normal discharge specification data,
The ejection control unit causes each of the plurality of nozzles in the inkjet head to eject ink based on the abnormality ejection designation data, so that the position where ink is ejected by the abnormal nozzle is set to the normal ejection designation data. 4. The printing system according to claim 1, wherein the ink is ejected from each of the plurality of nozzles in the inkjet head so as to be less noticeable than when data is used. The ejection data generation unit is configured to determine how the amount of ink ejected from the abnormal nozzle is different because the unit ejection number in the main scanning direction line corresponding to the abnormal nozzle is different from the case where the normal ejection designation data is used. 5. The printing system according to claim 1, wherein the printing system generates the abnormal ejection designation data in which the abnormality is compensated for. The ejection data generation section includes:
Using a mask that selects some of the ejection positions in the main scanning direction line, it is determined in which main scanning operation the dots are to be formed at each of the ejection positions in the main scanning direction line. ,
6. The ejection designation data for abnormal times is generated using the mask that is at least partially different from the mask used when generating the ejection designation data for normal times. The printing system described in The inkjet head is capable of changing the volume of ink ejected from each nozzle in multiple stages,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each of the nozzles in each main scanning operation, and the volume of ink ejected to each of the ejection positions;
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line,
The ejection data generation unit is configured to generate the abnormal ejection in which the volume of ink ejected to at least some of the ejection positions in the main scanning direction line corresponding to the abnormal nozzle is different from that in the case where the normal ejection designation data is used. 7. The printing system according to claim 1, wherein the printing system generates specification data. 8. The printing system according to claim 1, wherein the abnormal nozzle information is information obtained by printing a predetermined test pattern using the plurality of nozzles in the inkjet head. A printing method that prints using an inkjet method,
Generating ejection designation data indicating at least a position at which ink should be ejected among a plurality of ejection positions set according to printing resolution,
Using an inkjet head that ejects ink from multiple nozzles,
A main scanning operation in which ink is ejected while moving relative to a medium to be printed in a preset main scanning direction, and a movement relative to the medium in a sub-scanning direction orthogonal to the main scanning direction. By causing the inkjet head to perform a sub-scanning operation to perform a sub-scanning operation, printing is performed in a multi-pass method in which the main-scanning operation is performed a plurality of times for each position on the medium,
causing each of the plurality of nozzles in the inkjet head to eject ink based on the ejection designation data;
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the nozzle is generated depending on whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. When the ejection specification data is different and the abnormal nozzle does not exist among the plurality of nozzles, the ejection specification data for normal times is the ejection specification data that is generated without considering the characteristics of the abnormal nozzle. and when the abnormal nozzle exists among the plurality of nozzles, the ejection designation is generated based on abnormal nozzle information that is information indicating the abnormal nozzle, taking into consideration the characteristics of the abnormal nozzle. data, and generates abnormal discharge specification data that is at least partially different from the normal discharge specification data;
If the abnormal nozzle exists among the plurality of nozzles, causing each of the plurality of nozzles in the inkjet head to eject ink based on the abnormal ejection designation data,
and causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data ,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
By forming ink dots at some of the ejection positions in the main scanning direction line in the inkjet head in one main scanning operation, and performing the main scanning operation a preset plurality of times. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
Based on the abnormal nozzle information, changing the ejection position where ink is ejected by a nozzle other than the abnormal nozzle among the nozzles that eject ink to the main scanning direction line corresponding to the abnormal nozzle, The number of unit ejections in the main scanning direction line corresponding to the abnormal nozzle is different from that when the normal ejection designation data is used, and the influence of the abnormal nozzle is lower than when the normal ejection designation data is used. A printing method characterized in that the abnormality ejection designation data is generated such that the ejection designation data is ejected during an abnormality . A printing method that prints using an inkjet method,
Generating ejection designation data indicating at least a position at which ink should be ejected among a plurality of ejection positions set according to printing resolution,
Using an inkjet head that ejects ink from multiple nozzles,
A main scanning operation in which ink is ejected while moving relative to a medium to be printed in a preset main scanning direction, and a movement relative to the medium in a sub-scanning direction orthogonal to the main scanning direction. By causing the inkjet head to perform a sub-scanning operation to perform a sub-scanning operation, printing is performed in a multi-pass method in which the main-scanning operation is performed a plurality of times for each position on the medium,
of the plurality of nozzles in the inkjet head based on the ejection designation data.
Let each ink be ejected,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the nozzle is generated depending on whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. When the ejection specification data is different and the abnormal nozzle does not exist among the plurality of nozzles, the ejection specification data for normal times is the ejection specification data that is generated without considering the characteristics of the abnormal nozzle. and when the abnormal nozzle exists among the plurality of nozzles, the ejection designation is generated based on abnormal nozzle information that is information indicating the abnormal nozzle, taking into consideration the characteristics of the abnormal nozzle. data, and generates abnormal discharge specification data that is at least partially different from the normal discharge specification data;
If the abnormal nozzle exists among the plurality of nozzles, causing each of the plurality of nozzles in the inkjet head to eject ink based on the abnormal ejection designation data,
and causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
By forming ink dots at some of the ejection positions in the main scanning direction line in the inkjet head in one main scanning operation, and performing the main scanning operation a preset plurality of times. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
Based on the abnormal nozzle information, while causing other nozzles other than the abnormal nozzle to eject ink with respect to the main scanning direction line corresponding to the abnormal nozzle, By changing only the ejection position at which ink is ejected to the abnormal nozzle without changing the ejection position at which ink is ejected by the other nozzle, the main scanning direction line corresponding to the abnormal nozzle is The abnormality discharge designation is such that the unit discharge number is different from the case where the normal discharge designation data is used, and the influence of the abnormal nozzle is reduced compared to the case where the normal discharge designation data is used. A printing method characterized by generating data. A printing device that prints using an inkjet method,
An inkjet head that ejects ink from multiple nozzles,
a main scanning drive unit that causes the inkjet head to perform a main scanning operation of ejecting ink while moving relative to a printing target medium in a preset main scanning direction;
a sub-scanning drive unit that causes the inkjet head to perform a sub-scanning operation that moves relative to the medium in a sub-scanning direction perpendicular to the main-scanning direction;
an ejection control unit that causes each of the plurality of nozzles in the inkjet head to eject ink based on ejection designation data indicating at least a position at which ink should be ejected at a plurality of ejection positions set according to printing resolution; ,
Performing multi-pass printing in which the main scanning operation is performed a plurality of times for each position on the medium,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the ejection control unit determines whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. The control for ejecting ink from each of the plurality of nozzles in the inkjet head is controlled differently depending on the
If the abnormal nozzle does not exist among the plurality of nozzles, the inkjet head is adjusted based on the normal ejection specification data, which is the ejection specification data generated without considering the characteristics of the abnormal nozzle. Ink is ejected from each of the multiple nozzles,
When the abnormal nozzle exists among the plurality of nozzles, the ejection designation data is generated based on abnormal nozzle information that is information indicating the abnormal nozzle, taking into consideration the characteristics of the abnormal nozzle. , causing each of the plurality of nozzles in the inkjet head to eject ink based on abnormal ejection specification data that is at least partially different from the normal ejection specification data;
and when the abnormal nozzle exists among the plurality of nozzles, causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data ,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
The inkjet head is configured to form ink dots at some of the ejection positions in the main scanning direction line in one main scanning operation under the control of the ejection control unit, and to form a preset plurality of ink dots at some of the ejection positions in the main scanning direction line. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line by performing the main scanning operation twice;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
The abnormality ejection designation data is configured to change the ejection position at which ink is ejected by a nozzle other than the abnormal nozzle among the nozzles that eject ink to the main scanning direction line corresponding to the abnormal nozzle. , the number of unit ejections in the main scanning direction line corresponding to the abnormal nozzle is different from that when using the normal ejection designation data, and the influence of the abnormal nozzle is greater than when the normal ejection designation data is used. A printing device characterized in that the data is such that the amount of data is reduced . A printing device that prints using an inkjet method,
An inkjet head that ejects ink from multiple nozzles,
a main scanning drive unit that causes the inkjet head to perform a main scanning operation of ejecting ink while moving relative to a printing target medium in a preset main scanning direction;
a sub-scanning drive unit that causes the inkjet head to perform a sub-scanning operation that moves relative to the medium in a sub-scanning direction perpendicular to the main-scanning direction;
an ejection control unit that ejects ink to each of the plurality of nozzles in the inkjet head based on ejection designation data indicating at least a position at which ink should be ejected at a plurality of ejection positions set according to printing resolution;
Equipped with
Performing multi-pass printing in which the main scanning operation is performed a plurality of times for each position on the medium,
The ejection designation data is data indicating at least the ejection position at which ink is ejected from each nozzle in each main scanning operation,
When the nozzle whose ejected amount of ink is outside a predetermined normal range is defined as an abnormal nozzle, the ejection control unit determines whether or not the abnormal nozzle exists among the plurality of nozzles in the inkjet head. The control for ejecting ink from each of the plurality of nozzles in the inkjet head is controlled differently depending on the
If the abnormal nozzle does not exist among the plurality of nozzles, the inkjet head is adjusted based on the normal ejection specification data, which is the ejection specification data generated without considering the characteristics of the abnormal nozzle. Ink is ejected from each of the multiple nozzles,
When the abnormal nozzle exists among the plurality of nozzles, the ejection designation data is generated based on abnormal nozzle information that is information indicating the abnormal nozzle, taking into consideration the characteristics of the abnormal nozzle. , causing each of the plurality of nozzles in the inkjet head to eject ink based on abnormal ejection specification data that is at least partially different from the normal ejection specification data;
and when the abnormal nozzle exists among the plurality of nozzles, causing the abnormal nozzle to eject ink to at least some of the ejection positions based on the abnormal ejection designation data,
Regarding the arrangement of the ejection positions set according to the printing resolution, if the arrangement of the ejection positions lined up in the main scanning direction with their positions aligned in the sub-scanning direction is defined as a main scanning direction line.
If,
The inkjet head is configured to form ink dots at some of the ejection positions in the main scanning direction line in one main scanning operation under the control of the ejection control unit, and to form a preset plurality of ink dots at some of the ejection positions in the main scanning direction line. performing the main scanning operation and the sub-scanning operation so that the dots can be formed at all the ejection positions in the main scanning direction line by performing the main scanning operation twice;
When the number of times ink is ejected by any of the nozzles in the plurality of main scanning operations with respect to the ejection position included per unit length in one main scanning direction line is defined as the unit ejection number,
The ejection designation data for abnormality includes ejecting ink to the main scanning direction line corresponding to the abnormal nozzle while causing other nozzles other than the abnormal nozzle to eject ink. By changing only the ejection position at which ink is ejected to the abnormal nozzle without changing the ejection position at which ink is ejected by the other nozzle, the main scanning direction corresponding to the abnormal nozzle is changed. The number of unit discharges in the direction line is different from the case where the normal discharge designation data is used, and the data is such that the influence of the abnormal nozzle is reduced compared to the case where the normal discharge designation data is used. A printing device featuring:

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