WO2015001919A1

WO2015001919A1 - Inkjet recording device

Info

Publication number: WO2015001919A1
Application number: PCT/JP2014/065283
Authority: WO
Inventors: 裕子栗原; 河野　貴
Original assignee: 株式会社日立産機システム
Priority date: 2013-07-03
Filing date: 2014-06-10
Publication date: 2015-01-08
Also published as: CN105339174A; JP6114125B2; JP2015013385A; CN105339174B

Abstract

In a device with two or more nozzles which are retained within a print head, and which are operated to carry out printing of a single item of printed material, a situation may occur in which, despite a given nozzle becoming unable to continue printing due to the occurrence of a malfunction, the other nozzles are fine. In such a case, particularly when the customer is printing a printed material that does not permit the conveyor line to be quickly halted, considerable printing wastage is produced, despite the presence of nozzles which are able to print, resulting in the problem that the product production schedule is affected. To solve the aforementioned problem, when printing by operating two or more nozzles, in the event that a given nozzle is unable to continue printing due to the occurrence of a malfunction, control is carried out in such a way that printed content that should have been printed by the nozzle that is unable to continue printing is printed by other, normal nozzles. Through the use of the present invention, printing can continue without quickly halting the conveyor line, even when a malfunction has occurred in a given nozzle.

Description

Inkjet recording device

The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus corresponding to a nozzle abnormality in an ink jet recording apparatus having two or more nozzles.

As a background art in this technical field, there is JP 2010-137528 (Patent Document 1). This document describes control that “in an inkjet recording apparatus having two nozzles, provides a technique for making it possible to adjust the vertical spacing of characters printed by each nozzle”.

JP 2010-137528 A

In an ink jet recording apparatus that performs printing on one printed matter using two or more nozzles, the ink jet recording apparatus performs printing by ejecting ink for each nozzle. Therefore, the ink jet recording apparatus controls each nozzle. There is a need. However, the state of all nozzles is not necessarily the same, and even when printing cannot be continued due to an abnormality in a certain nozzle, it is possible that other nozzles are normal. In this case, especially for customers who print on printed matter (cables, pipes, etc.) that cannot immediately stop the conveyance line, a lot of printing waste is generated due to the influence of abnormal nozzles even though there are nozzles that can print. There was a problem of ending up.
Patent Document 1 does not consider this point.

When printing by operating two or more nozzles, if it becomes impossible to continue printing due to an abnormality in one nozzle, the other nozzles that cannot continue printing with other normal nozzles will be Control to print.

Even if an abnormality occurs in a certain nozzle, printing can be continued without immediately stopping the transport line.

1 is an overall configuration and functional block diagram of a general inkjet recording apparatus. It is the structural example and printing example of a print head at the time of a twin nozzle. It is an example of the various printing parameters required for an inkjet recording device when printing with a twin nozzle. It is a figure which shows the printing parameter allocation at the time of nozzle vertical arrangement | positioning, and a printing result. It is a figure which shows the printing parameter allocation at the time of nozzle horizontal arrangement | positioning, and a printing result. It is the example of a screen for setting the execution control of relief control at the time of nozzle abnormality, and a nozzle control flowchart. It is a figure which shows the example of ink particle flight at the time of nozzle vertical direction arrangement | positioning. It is a figure which shows the example of ink particle flight at the time of nozzle horizontal arrangement | positioning. It is a relief control flowchart at the time of nozzle abnormality. It is a processing flowchart when nozzle abnormality is canceled. 5 is a diagram showing a nozzle printing range at normal time and abnormal time, and a table showing the number of ink particles flying from the nozzle when printing one vertical line in the printing range.

In the following embodiments, for simplicity of explanation, the print head has two nozzles (hereinafter, this print head is referred to as a twin nozzle), and these are operated to print on one printed matter. An apparatus for executing the above will be described.

FIG. 1A is an overall view of a general ink jet recording apparatus. Reference numeral 1 denotes an ink jet recording apparatus, 18 denotes a display, and 21 denotes a print head. FIG. 1B shows a functional block diagram of the inkjet recording apparatus 1. The ink jet recording apparatus 1 is roughly composed of a controller A and a printing apparatus B, and performs printing on a product 7 that is a printing object on the transport line 6.

The ink jet recording apparatus 1 needs to analyze the information obtained from the input unit 2 in the control unit 3 having the control unit 8 and the storage unit 4 having the memory 9 and the program storage unit 10 so as to obtain an optimum printing result. The control signal is corrected and the output signal is transmitted from the output unit 5. Further, the printing object detection device 12 that receives a signal from the printing material sensor 11 at the input unit 2 of the controller A, the conveyance speed detection device 14 that receives a signal from the encoder 13, and an input device that receives an input signal from an operator. 15, information on the printing apparatus B and the product is input, and calculation processing is performed by the control unit 3, and an output signal is transmitted from the output unit 5 to the printing apparatus B.

When setting and changing the print data and various printing conditions for printing, the setting value input to the input device 15 of the controller A from the touch panel 16 as the input means of the printing device B is stored in the memory 9 of the storage unit 4. The information is stored and processed by the control device 8 of the control unit 3 and displayed on the display 18 via the display device 17.

When printing on the product 7 on the transport line 6 is started, the position of the product 7 is specified by the printed material detection device 12 and the transport speed detection device 14. Next, the ink supplied from the ink container 19 by the pump 20 is excited by the excitation voltage generator 23 at the nozzle 22 in the print head 21 to form ink particles 24, and the charging voltage is adjusted in accordance with the print data on the memory 9. The generator 25 applies a charging voltage to the charging electrode 26. The charged ink particles 24 are deflected when passing through the deflection electrode 28 to which the voltage of the deflection voltage generator 27 is applied, and a printing dot is formed on the product 7 to perform printing. At this time, the charging electrode 26 always applies the same direction of charge to the ink particles 24, and the deflection electrode 28 always applies the same voltage, so that the deflection direction of the print dots is always deflected upward. The ink particles 24 that are not charged are not used for printing but are collected by the gutter 59 and returned to the ink container 19. Further, the state of the print head 21 is constantly monitored by a control signal 29 which is an output of a detection unit including a sensor (not shown), and each element (nozzle 22, charging electrode 26, deflection electrode 28) of the print head 21 is abnormal. If there is, the ink jet recording apparatus 1 immediately performs an abnormality handling process.

In addition, the state of the device power supply 30 is managed by the power supply device 31, and the state of the external connection terminal 32 is managed by the connection device 33.

FIG. 2 shows a configuration example and a print example of the print head 21 at the time of twin nozzles. 2A and 2B, the print head 21 includes a nozzle 22a (hereinafter referred to as nozzle α) and a nozzle 22b (hereinafter referred to as nozzle β). The nozzle α includes a charging electrode 26a and a heel deflection. Printing is performed using the electrode 28a and the gutter 59a, and the nozzle β using the charging electrode 26b, the deflection electrode 28b and the gutter 59b. Here, for convenience of explanation, a nozzle, a charging electrode, a deflection electrode, and a gutter are collectively referred to as a sub print head.

The ink jet recording apparatus controls the nozzle α and the nozzle β independently, and the print contents and print set values of the nozzle α and the nozzle β are different from each other. Here, the arrangement of the nozzle α and the nozzle β may be a vertical arrangement method or a horizontal arrangement method. In the method of arranging in the vertical direction, as shown in FIG. 2A, since the

deflection electrodes

28a and 28b are arranged in the vertical direction, characters in the vertical direction are displayed as shown in the printing example 7A. You can print at the same time. Further, in the method of arranging in the horizontal direction, as shown in FIG. 2B, the

deflection electrodes

28a and 28b are arranged in the horizontal direction, so that they are in the horizontal direction as shown in the printing example 7B. Characters can be printed simultaneously.

FIG. 3 is a diagram showing an example of various printing parameters required by the ink jet recording apparatus when printing with twin nozzles.

In this embodiment, when one nozzle becomes abnormal in the twin nozzle, control is performed so that the remaining nozzles print the content to be printed by the abnormal nozzle. FIG. 6 is a diagram illustrating a relationship of necessary print parameters at that time.

Here, the nozzle abnormality means that the sub print head including the charging electrode, deflection electrode, and gutter including the nozzle is abnormal, and the ink particles emitted from the nozzle due to the abnormality are included in the target product. A state in which printing is not performed accurately. Hereinafter, the abnormality of the sub print head will be described as nozzle abnormality. Causes of the abnormality include clogging of the nozzle and a case where the charged charge amount at the charging electrode is different from a specified value. Further, as described in FIG. 1, as a method for detecting an abnormality, whether or not each element (nozzle 22, charging electrode 26, deflection electrode 28) of the print head 21 is abnormal is a control signal that is a sensor output. It is detected by constantly monitoring using 29.

3A is a diagram showing the print contents 34 and the print range when the nozzle α and the nozzle β are arranged in the vertical direction, and FIG. 3B is a diagram showing the nozzle α and the nozzle β in the horizontal direction. FIG. 6 is a diagram showing the print contents 38 and the print range when they are arranged. FIG. 3C shows a configuration example of print parameters, and FIG. 3D shows a print parameter setting screen example.

In FIG. 3A, the print range (parameter L1) 35 printed by the nozzle α and the print range (parameter M1) 36 printed by the nozzle β are different in the vertical direction. The print range (parameter N1) 37 for printing the whole is a combination of the print range (parameter L1) 35 and the print range (parameter M1) 36. That is, when one nozzle becomes abnormal, when printing contents to be printed by the abnormal nozzles with the remaining normal nozzles, printing control is performed using the printing range (parameter N1) 37. Accordingly, the print content 34 is set so that printing can be performed using either a combination of the print range (parameter L1) 35 and the print range (parameter M1) 36 or a print range (parameter N1) 37.

3B, the printing range (parameter L2) 39 printed by the nozzle α and the printing range (parameter M2) 40 printed by the nozzle β are different in the horizontal direction. The print range (parameter N2) 41 for printing the whole is a combination of the print range (parameter L2) 39 and the print range (parameter M2) 40. In other words, when one nozzle becomes abnormal and the remaining normal nozzle prints the print contents to be printed by the abnormal nozzle, the print range (parameter N2) 41 is used to perform print control. Accordingly, the print content 38 is set so that printing can be performed using either a combination of the print range (parameter L2) 39 and the print range (parameter M2) 40 or a print range (parameter N2) 41.

The print parameters 42 shown in FIG. 3C include types such as a character size 43, a character height 44, and an ink particle usage rate 45. These parameters are input from the touch panel 16 and displayed on the display 18 as shown in the setting screen 46 shown in FIG. In FIG. 3D, when inputting from the touch panel 16, for example, items for each parameter and buttons for increasing / decreasing their set values may be set.

When using the print parameter 42 for the

print contents

34 and 38, the use range is distinguished for each print range. In the print contents 34, when the print ranges are 35, 36, and 37, the print parameters 42 are distinguished by parameters L1, M1, and N1, respectively. In the print contents 38, when the print ranges are 39, 40, and 41, the print parameters 42 are distinguished by parameters L2, M2, and N2. The print parameters are stored in the memory 9, and are read out and used as necessary. In the ink jet recording apparatus 1, these print parameters 42 are appropriately managed and used for printing.

FIG. 4 shows the assignment of print parameters and the print results when the nozzles are vertically arranged with twin nozzles according to the present embodiment and both nozzles are normal and when either nozzle is abnormal. FIG.

4A, in normal printing, the nozzle α prints the print range 35 with the parameter L1, and the nozzle β prints the print range 36 with the parameter M1. The printing result at this time is normal printing 47 in FIG. When the nozzle α is abnormal, the printing result is incorrect as in the abnormal printing 48. Similarly, when the nozzle β becomes abnormal, the printing result is incorrect as in the abnormal printing 49. In order to solve this, in this embodiment, as shown in FIG. 4A, when some of the nozzles become abnormal, the normal nozzles are switched to the process of printing the print range 37 with the parameter N1. . As a result, the print result 50 shown in FIG. 4B is obtained, and even if an abnormality occurs, the print result is the same as that in the normal state.

FIG. 5 shows the print parameter allocation and the print results when the nozzles are arranged in the horizontal direction in the twin nozzles according to the present embodiment, when both nozzles are normal and when either nozzle is abnormal. FIG.

5A, in normal printing, the nozzle α prints the print range 39 with the parameter L2, and the nozzle β prints the print range 40 with the parameter M2. The printing result at this time is normal printing 51 in FIG. When the nozzle α is abnormal, the printing result is incorrect as in the abnormal printing 52. Similarly, when the nozzle β becomes abnormal, the print result becomes incorrect as in the abnormal print 53. In order to solve this, in this embodiment, as shown in FIG. 5A, when some of the nozzles become abnormal, the normal nozzles are switched to the process of printing the print range 41 with the parameter N2. . As a result, the print result 54 shown in FIG. 5B is obtained, and the same print result as that in the normal state is obtained even if an abnormality occurs.

As described above, when a nozzle becomes abnormal, conventionally, a part of the printing result is not printed, and thus printing is wasted. To prevent this, processing is performed to continue printing even with a normal nozzle. The printing parameters (N1, N2) for the printing range (37, 41) for printing the whole are created in advance, and the control is switched to printing control with only normal nozzles when an abnormality occurs. According to this embodiment, even if an abnormality occurs, the same printing result as that at the normal time is obtained, and the problem of wasteful printing can be solved.

In addition, when switching to printing control with only normal nozzles when an abnormality occurs, the state is stored in the memory, and the state is notified to the outside of the ink jet recording apparatus, so that external correspondence associated with switching of printing control can be performed. Can be easily. In addition, since printing can be continued urgently after the occurrence of an abnormality, the period during which printing cannot be completed until repair is completed is shortened. Therefore, there is an effect that generation of printing waste can be reduced and the influence on the customer's product development schedule can be suppressed.

As described above, the present embodiment has been described assuming the case of twin nozzles. However, the case of having a plurality of nozzles can be expressed in a general form as follows. For parameters required for printing, one parameter (parameter X) for printing one printing result with a plurality of nozzles and one parameter (parameter Y) for printing one printing result with a nozzle other than the nozzle that caused the abnormality (Nozzle number -1) are prepared. Normally, when all the nozzles operate normally, printing is executed using the prepared parameter X for each nozzle. When printing cannot be continued due to an abnormality in a certain nozzle, this can be realized by switching to a process in which other normal nozzles perform printing using the parameter Y.

FIG. 6A shows an example of a screen 55 for making it possible to select whether or not to perform printing control using only normal nozzles when an abnormality occurs. FIG. 6B shows a nozzle control flowchart.
Assuming that the process of performing printing control with only normal nozzles when an abnormality occurs is the relief control process when the nozzle is abnormal, the item 56 “Relief control when nozzle is abnormal” in the screen example 55 is an option of “do not / do” The relief control processing based on the present embodiment is performed only when “Yes” is held.

In the flowchart shown in FIG. 6B, first, a nozzle abnormal portion is determined at a branch 57. Nozzle abnormality is determined by monitoring the nozzle state using the control signal 29. When both of the two nozzles are abnormal, the process moves to normal abnormality processing in processing 58. In normal abnormality processing, printing of the nozzle that has become abnormal is interrupted, and a message is displayed on the display 18 that the nozzle is in an abnormal state. When there is an abnormality in only one of the nozzles, the setting of the item 56 “rescue control when the nozzle is abnormal” is checked in processing 59. When the setting is “NO”, the process proceeds to a normal abnormality process in process 58. When “Yes”, the relief control process f2 is executed. Details of the relief control process f2 will be described later. When there is no abnormality, the method of controlling the two nozzles is left in the process 60, and the print parameters L (L1, L2) and M (M1, M2) which are the print ranges of the nozzles α and β in the process 61, respectively. Continue printing using.

According to this embodiment, since it is possible to input a setting as to whether or not the relief control process is performed when the nozzle is abnormal, it is possible to automatically stop the conveyance line or automatically when setting in the test mode. When the relief control process does not need to be performed, the relief control process can be set to OFF.

FIG. 7 is an example of ink particle flight in normal printing and abnormal printing in this embodiment when the nozzles are arranged in the vertical direction with twin nozzles. Of these, FIG. 7A shows an ink particle flight example 62 for normal printing 47 when both nozzle α and nozzle β operate normally, and FIG. 7B shows printing 50 when nozzle α is abnormal. Ink particle flight example 63-α is shown for -α, and FIG. 7C shows ink particle flight example 63-β for print 50-β when nozzle β is abnormal. Here, the ink particle flight example shows the vertical direction of the character.

First, at the time of normal printing 47, as shown in FIG. 7A, the ink particle flight example 62 normally flies in accordance with the printing contents. Further, when the nozzle α is abnormal, as shown in FIG. 7B, printing is performed only with the nozzle β, so the range in which the nozzle β prints compared to the normal printing 47 as in the ink particle flight example 63-α. Although spread in the vertical direction of the character, the landing position of the ink particles 24 is the same place as the ink particle flight example 62 of the normal print 47.

Similarly, when the nozzle β is abnormal, as shown in FIG. 7C, printing is performed only with the nozzle α, so the range in which the nozzle α prints compared to the normal printing 47 as in the ink particle flying example 63-β. Expands vertically. However, since the deflection direction of the ink particles 24 is always deflected upward, the landing position of the ink particles 24 is different from the ink particle flight example 62 of the normal printing 47, and there is a problem that it moves upward in the character vertical direction.

FIG. 8 is an example of ink particle flight in normal printing and abnormal printing in this embodiment when the nozzles are arranged in a horizontal direction with twin nozzles. Of these, FIG. 8A shows an ink particle flight example 64 for normal printing 51 when both nozzle α and nozzle β operate normally, and FIG. 8B shows printing 54 when nozzle α is abnormal. The ink particle flight example 65-α is shown for -α, and FIG. 8C shows the ink particle flight example 65-β for the print 54-β when the nozzle β is abnormal. Here, unlike the example of FIG. 7, the ink particle flight example shows the direction of the transport line.

First, in the case of normal printing 51, as shown in FIG. 8A, the ink particle flight example 64 normally flies in accordance with the printing content. Further, when the nozzle α is abnormal, as shown in FIG. 8B, printing is performed only with the nozzle β, so the range in which the nozzle β prints compared to the normal printing 51 as in the ink particle flying example 65-α. Although spreading in the transport line direction, the landing position of the ink particles is the same place as the ink particle flight example 64 of the normal print 51.

Similarly, when the nozzle β is abnormal, as shown in FIG. 8C, printing is performed only with the nozzle α, so the range in which the nozzle α is printed compared to the normal printing 51 as in the ink particle flying example 65-β. Spreads in the direction of the transport line. In addition, because the arrangement of the nozzles α and β does not change the vertical range of characters printed by normal nozzles, the ink particle landing position is the same location as the ink particle flight example 64 of the normal print 51.

As described above, when printing control is performed using only normal nozzles when an abnormality occurs, the printing position may move depending on the position of the normal nozzles, and it is necessary to change the printing control. The relief control process f2 for solving this will be described below.

FIG. 9 shows the relief executed when the item 56 “Relief Control at Nozzle Abnormality” shown in FIG. 6A is “Yes” when the nozzle control flowchart shown in FIG. It is a flowchart f2 of a control process. In FIG. 9, first, at branch 66, it is checked whether the abnormal nozzle is nozzle α or nozzle β.

When the nozzle α is abnormal, it is set in the “relief control mode” in which the inkjet recording apparatus performs the relief control in the process r1, and the outside is notified in the process r2 that it is in the relief control mode. At this time, the notification means is a screen display on the display 18 or a communication / signal on the connection device 33. Thereafter, in a process 67, only the nozzle β is controlled, printing is performed using the print parameter N in a process 68, and printing is continued in a process 69.

When the nozzle β is abnormal, the printing of the nozzle β is interrupted in a process 70, and a message is displayed on the display 18 that the nozzle β is in an abnormal state in a process 71. Thereafter, in a process 72, guidance for prompting the change of the print head position is displayed. This guidance is a display for allowing the customer to select whether or not to change the print head position. As described with reference to FIG. 7, this is a countermeasure for a case where the print position moves. When the print head position is changed at branch 73, a relief is performed in which print control is performed using only normal nozzles when an abnormality occurs. Control becomes possible. In process 74, the print head position is physically moved, the guidance is deleted in process 75, and the process shifts to a printable state in process 76. Thereafter, after the processes r1 and r2 described above are performed, only the nozzle α is controlled in process 77, printing using the print parameter N is performed in process 68, and printing is continued in process 69.

If the print head position is not changed at branch 73, the relief control for performing the print control with only normal nozzles when an abnormality occurs cannot be performed. Therefore, the guidance display is minimized in process 78 and the process is terminated. At this time, the “relief control mode” is not executed in spite of the nozzle abnormality, and the normal printing control is performed. If it is desired to set the “relief control mode” in this state, it is possible to change to the “relief control mode” by maximizing the guidance display again and then changing the print head position in step 73.

FIG. 10 is a processing flowchart when the nozzle abnormality is canceled by the relief control in which the printing control is performed only with the normal nozzle when the abnormality occurs. It is determined whether or not the abnormality has been canceled at branch 79, and if it is canceled, it is checked at branch 80 whether printing has been performed in the repair control mode. If it is in the relief control mode, the nozzle that has been abnormally released is checked at branch 81.

When the nozzle α is released abnormally, the relief control mode is released in the process n1, and the release of the relief control mode is notified to the outside in the process n2. At this time, the notification means is a screen display on the display 18 or a communication / signal on the connection device 33. Thereafter, in a process 82, two nozzles are controlled, and in a process 83, printing using the print parameters L (L1, L2) and M (M1, M2), which are the print ranges of the nozzles α and β, respectively. In step 84, printing is continued.

When the nozzle β is released abnormally, a guidance for prompting a change of the print head position is displayed in processing 85. This guidance is a display for allowing the customer to select whether or not to change the print head position. When the print head position is changed at the branch 86, the normal print control can be returned. At this time, the print head position is changed in process 87, and the guidance is erased in process 88. Thereafter, the process proceeds to the processes n1 and n2.

If the print head position is not changed at branch 86, it is not possible to return to normal print control. At this time, the guidance display is minimized in process 89 and the process is terminated. In this case, even if the nozzle abnormality is canceled, the operation is performed in the “relief control mode” instead of the normal print control. If normal print control is desired in this state, the guidance display can be maximized again and then the print head position can be changed at branch 86 to change to normal print control.

As described above, in this embodiment, when printing control is performed with only normal nozzles when an abnormality occurs, it is possible to cope with the case where the printing position moves according to the position of the normal nozzle, and an abnormality occurs. Even in this case, the same printing result as that in the normal state can be obtained, and printing waste can be reduced.

FIG. 11A shows the printing range of the nozzle β in the normal printing 47 when the nozzles α and β are both normal and the abnormal printing 50 when the nozzle α is abnormal in the present embodiment. FIG. 11B is a table showing the number of ink particles flying from the nozzle β necessary for printing one vertical line 90 in the printing range of FIG.

The number of ink flights when printing one vertical line 90 varies depending on the value of the ink particle usage rate 45 in the printing parameters. Here, the ink particle usage rate 45 is a parameter for designating a ratio of thinning out ink particles actually used for printing out of the ink particles output from the nozzle, and the number of ink particles used for printing is output from the nozzle. When it is desired to set one of N ink particles to be used, 1 / N is designated and used. For example, when one of the two is used, it becomes 1/2. The ink particle usage rate 45 varies depending on the print quality and the conveyance line speed. In general, increasing the thinning ratio can suppress the influence between inks, so that it is possible to improve the printing quality, but it is difficult to cope with an increase in the conveyance line speed. .

Here, in Table 91 in FIG. 11B, the number of ink particles used for printing in the normal printing 47 and the abnormal printing 50 when the ink particle usage rate 45 is the same will be described. When the ink particle usage rate 45 is 1/1, the number 92 of ink particles used for printing in the normal time printing 47 is 8, and the number 93 of ink particles used for printing in the abnormal time printing 50 is 16. Similarly, when the ink particle usage rate 45 is 1/2, the number 94 of ink particles used for printing in the normal printing 47 is 16, and the number 95 of ink particles used for printing in the abnormal printing 50 is 32. . Since the ink particles are output from the nozzles at a constant speed, the number of ink particles used for printing is equal to the time required for printing one vertical line 90. In other words, when there is no change in the transport line speed and the ink particle usage rate 45, when the abnormal print 50 is printed in the relief control mode, the number of ink particles used for printing and the time required for printing are twice the normal print 47. Is required. For this reason, in order to obtain a printing result similar to the normal printing 47 when printing the abnormal printing 50 in the relief control mode, it is necessary to perform a correction process in addition to the parameter correction.

There are two types of correction processing methods. One is a method in which the conveyance line speed is also slowed at the time of abnormal printing 50. This correction process has an advantage that printing can be performed without changing the printing parameters internally. In this case, it is necessary to notify the outside whether or not it is in the relief control mode, and this can be realized by the process r2 in the flowchart f2 in FIG. 9 or the process n2 in the flowchart in FIG.

The other is a method in which the ink particle usage rate 45 that can be set is limited in advance, and when printing 50 is performed in an abnormal state, the ink particle usage rate 45 is corrected to perform printing. Specifically, when the ink particle usage rate 45 of the nozzles α and β is set to 1 / N, N is set in advance as an equal value with an even value. When normal printing 47 is performed in this state, the nozzles α and β print with the ink particle usage rate 45 set. In addition, when the abnormal printing 50 is performed in the relief control mode, the number of ink particles used for printing by a normal nozzle is doubled. Therefore, a value twice the set ink particle usage rate 45 (that is, N is halved). Is automatically corrected to a new ink particle usage rate 45 and printing is performed. The reason why N is set in advance as an even value is that it is easier to handle a divisible value because it must be halved in the relief control mode, and the reason for setting the same value is that each nozzle print control is easy. It is to make it.

In the example of Table 91 in FIG. 11B, as described in the column with correction, in the case of normal printing 47, the ink particle usage rate of the nozzles α and β is 1/1. First, it is set as 1/2, and the number of ink particles 96 at this time is 16. After that, when the abnormal printing 50 is obtained in the relief control mode, the ink particle usage rate is doubled, so the ink particle usage rate is doubled to a value set to 1/1. Correction is made, and the number of ink particles 97 at this time is also 16. This correction process has the advantage that it is not necessary to change the transport line speed.

As described above, in this embodiment, when performing relief control in the event of nozzle abnormality, the print quality in normal printing and abnormal printing is made the same by correcting a predetermined ink particle usage rate. There is an effect that can be done.

In the above-described embodiment, the case where there are two nozzles has been described, but a case where there are three or more nozzles will be considered. In this case, since the control method using twin nozzles is synthesized, the problem can be solved in the same manner by using the above-described embodiment for any two of the three or more nozzles. it can.

As shown in FIG. 7C, when the nozzles are arranged vertically, if the contents to be printed by the abnormal nozzles are to be printed by the normal nozzles arranged on the upper side, the upper side in the character longitudinal direction is displayed. Therefore, if there is a normal nozzle below the abnormal nozzle, it is desirable to support it with the normal nozzle arranged on the lower side.

In addition, by printing the content to be printed by the abnormal nozzle with the normal nozzle adjacent to the abnormal nozzle, the print range of the normal nozzle can be minimized.
The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiment has been described in detail for easy understanding of the present invention.For example, in the above-described embodiment, the arrangement of the twin nozzles has been described for the vertical and horizontal cases. For example, it is conceivable to arrange the nozzles α and β in an oblique direction. In this case, since the diagonal direction is considered to be a combination of the vertical and horizontal arrangements, by using the vertical and horizontal controls simultaneously or in combination in the above-described embodiment, the same applies. Can solve the problem.
Moreover, it is not necessarily limited to what has all the structures demonstrated. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is also possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

1: Inkjet recording apparatus 21: Print head 22a: Nozzle α with twin nozzles
22b: Nozzle β with twin nozzle
37: Print range (parameter N1)
41: Print range (parameter N2)
42: Print parameter 56: Item “Relief control when nozzle is abnormal”
f2: Relief control flowchart

Claims

Sub-printing consisting of a nozzle that ejects ink into particles, a charging electrode that charges ink particles by applying a charging voltage, a deflection electrode that deflects charged ink particles, and a gutter that collects ink particles that are not used for printing In an inkjet recording apparatus having a plurality of heads,
A detection unit for detecting whether or not the sub print head is abnormal;
A control unit for controlling printing by independently controlling the plurality of sub print heads;
When the control unit detects that one sub print head is abnormal, the control unit switches the print control so that the print content to be printed by the abnormal sub print head is printed by another normal sub print head. An ink jet recording apparatus.
The inkjet recording apparatus according to claim 1,
A storage unit for storing control parameters for each nozzle;
The storage unit stores control parameters for printing one print result with a plurality of sub print heads and for printing one print result with a sub print head other than the sub print head in which an abnormality has occurred. And
The ink jet recording apparatus, wherein the control unit performs print control using any of the control parameters according to a state of a nozzle.
The inkjet recording apparatus according to any one of claims 1 and 2,
In the case where the abnormal sub print head has an input unit that can input a setting for whether or not to perform relief control for printing the content to be printed by another normal sub print head, and the input result is a setting for performing relief control In addition, when one of the sub print heads is detected to be abnormal by the detecting means, the use of the abnormal sub print head is stopped and the ink jet recording apparatus is switched to the relief control.
The inkjet recording apparatus according to any one of claims 1 to 3, wherein when the print content to be printed by the abnormal sub print head is switched to print control for printing by another normal sub print head, An ink jet recording apparatus comprising: a recording unit that stores a state; and an output unit that outputs the state to the outside of the apparatus.
The inkjet recording apparatus according to any one of claims 1 to 4,
The plurality of sub print heads are arranged vertically,
When the other normal sub print head is disposed above the abnormal sub print head, the print contents to be printed by the abnormal sub print head are printed by the other normal sub print head. Before switching control,
An inkjet recording apparatus, wherein the position of the normal sub print head is moved in the vertical direction.
Sub-printing consisting of a nozzle that ejects ink into particles, a charging electrode that charges ink particles by applying a charging voltage, a deflection electrode that deflects charged ink particles, and a gutter that collects ink particles that are not used for printing In an inkjet recording apparatus having a plurality of heads,
A detection unit for detecting whether or not the sub print head is abnormal;
A control unit for controlling printing by independently controlling the plurality of sub print heads;
When the detection unit detects that one of the sub print heads is abnormal, the control unit stops using the abnormal sub print head and changes the print contents to be printed by the abnormal sub print head to another normal sub print head. The print control is switched so as to perform the relief control for printing with the print head, and the ink particle usage rate, which is a predetermined ratio of thinning out the ink particles used for printing out of the ink particles emitted from the nozzles, is corrected. An ink jet recording apparatus.
The ink jet recording apparatus according to any one of claims 1 to 6,
The detection unit is a sensor that monitors a state of the sub print head, and detects an abnormality by monitoring a state of a nozzle, a charging electrode, and a deflection electrode in the sub print head. .