JP2021053803A - Head module position adjustment method, inkjet recording device, adjustment support device, program, and printed matter manufacturing method - Google Patents

Abstract

To provide a head module position adjustment method that can appropriately adjust relative positions of head modules in an inkjet recording device comprising a plurality of inkjet head bars that record the same colors and are multiply arranged, an inkjet recording device, an adjustment support device, a program, and a printed matter manufacturing method.SOLUTION: In a head module adjustment method according to an embodiment of the present invention, nozzle relative positions representing relative position displacement between dots which are recorded by corresponding nozzles of head modules which record areas where sheets overlap with each other are measured at a plurality of locations in ranges of the head modules, and a position of the head module is adjusted for each inkjet head bar on the basis of representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from the plurality of locations, so that the representative values of the nozzle relative positions are fitted to a target range.SELECTED DRAWING: Figure 18

Description

The present invention relates to a head module position adjusting method, an inkjet recording device, an adjustment support device, a program, and a printed matter manufacturing method, and a technique for adjusting the position of a head module constituting a line head used in a single-pass type inkjet recording device and an inkjet. The present invention relates to an image recording technique using.

In an inkjet recording device, it is generally required to suppress the occurrence of banding such as white streaks or dark streaks due to ejection failure such as nozzle failure or flight bending. In particular, in a single-pass inkjet recording device, streaks are easily generated due to a defect in one nozzle, so that finer streak correction is required. As a technique for streak correction, for example, in the case of a single-pass inkjet recording device, as described in Patent Document 1, a defective nozzle is masked in advance, and a correction process for supplementing the recording is performed using a proximity nozzle. Is common.

On the other hand, as a trend in the field of single-pass industrial inkjet in recent years, higher productivity is required. A method of multiplexing line heads is known in order to greatly improve productivity (see Patent Document 2). An inkjet recording apparatus having a configuration in which a plurality of line heads for recording the same color are arranged in the paper transport direction can share image recording with each line head, so that image recording can be speeded up. In addition, by shifting the dot recording position between a plurality of line heads arranged in multiple layers in the paper width direction orthogonal to the paper transport direction, a recording resolution exceeding the nozzle arrangement density of each line head is realized. obtain.

Japanese Unexamined Patent Publication No. 2008-179092 Japanese Unexamined Patent Publication No. 2005-238556 Japanese Patent No. 5940183 Japanese Unexamined Patent Publication No. 2010-42596

In a single-pass inkjet recording device, when image recording is performed by multiplexing line heads of the same color in the paper transport direction, the dot arrangement pattern recorded by combining multiple line heads is uniformly distributed in the recording area. In order to align, it is necessary to adjust the relative position between the heads with high accuracy.

For example, in the case of a multi-order inkjet recording device in which two inkjet heads having a recording resolution of 1200 dpi are arranged in the paper transport direction, dots can be recorded in a grid pattern in which each head has a dot spacing of 1200 dpi. Therefore, when recording an image using a pixel grid (a grid of drip points where dots can be placed) composed by superimposing the grid patterns of two heads, the dot spacing is at least 1200 dpi, which is 21.2 micron. It is clear that the grid pattern of the 1200dpi × 2 dot arrangement is broken unless the recording position of the dots is controlled within the range of meters [μm]. In addition, "dpi" means dot per inch and is a unit notation which expresses the number of dots (dots) per inch.

On the other hand, the line head used in the single-pass type inkjet recording device is often configured as one inkjet head bar by connecting a plurality of head modules (see Patent Documents 3-4). Each head module has slightly different characteristics such as nozzle-to-nozzle pitch and discharge direction due to the influence of head warpage and / or contraction. In addition, the discharge direction may change locally in one head module.

Therefore, when multiplexing line heads, the relative position between the head modules is adjusted for each line head, and the relative position between the line heads to be multiplexed is adjusted based on the characteristics of each head module. , Which requires extremely complicated and highly accurate adjustment.

Regarding the adjustment of the mounting position of the head module, Patent Document 3 describes that each inkjet head bar has the same recording area width so that the distance between adjacent head modules is within an allowable range and the recording area width of each inkjet head bar is the same. It has been shown to adjust the head module mounting position. Further, Patent Document 3 discloses that the head module mounting position of each inkjet head bar is adjusted so that the registration deviation between the inkjet head bars of each color is minimized. The deviation of registration means the deviation of the relationship between the relative recording positions of dots.

However, the content described in Patent Document 3 is a head module adjustment technique relating to a single inkjet head bar for each color, and Patent Document 3 does not describe a configuration of multiple arrangements that require more accurate adjustment. ..

Patent Document 4 describes a method of recording a line pattern on paper a plurality of times using at least two nozzle rows in a head unit, and adjusting the angle of the head and the amount of deviation of the position based on the recording result. Has been done. The term "head unit" is understood to correspond to the term "head module".

However, the method described in Patent Document 4 is only a general adjustment method, and does not consider the deviation of the local dot recording position in the head module.

The present invention has been made in view of such circumstances, and in an inkjet recording apparatus provided with a plurality of vertically arranged inkjet headbars for recording the same color, in consideration of variations in characteristics of each head module, the present invention has been made in consideration of variations in characteristics of each head module. One of the purposes is to provide a head module position adjusting method, an adjustment support device, and a program capable of appropriately adjusting the relative position of each head module.

The present invention also provides an inkjet recording apparatus capable of recording a high-quality image by adjusting the relative positions of the head modules in and between the bars of a plurality of inkjet head bars with high accuracy. Another object of the present invention is to provide a printed matter manufacturing method for obtaining a printed matter in which a high-quality image is recorded.

In the present specification, for the sake of brevity, the inkjet head bar may be abbreviated as "bar" and the head module may be abbreviated as "module". In addition, "head" may be described as a conceptual term that includes an inkjet head bar and / or a head module.

The present disclosure provides the following aspects of the invention.

In the head module position adjusting method according to the first aspect, an inkjet head bar configured by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged is used, and as a line head for recording the same color. This is a head module position adjustment method for adjusting the position of the head module in a single-pass inkjet recording device in which a plurality of inkjet headbars are arranged in the paper transport direction. The step of measuring the nozzle relative position, which represents the relative position deviation between the dots recorded by the corresponding nozzles of the head modules to be recorded, at multiple points within the range of the head module, and the nozzle measured from multiple points. A head including a step of keeping the representative value of the nozzle relative position within the target range by adjusting the position of the head module for each inkjet head bar based on the representative value of the nozzle relative position calculated based on the relative position. This is a module position adjustment method.

The representative values of the nozzle relative positions measured at a plurality of points in the head module are numerical values that alleviate the variation in local characteristics in the head module. According to the first aspect, the relative position is evaluated in module units using the representative value of the nozzle relative position, and the representative value of the nozzle relative position between the bars in each head module is within the target range in each bar. The position of each head module can be adjusted.

As a result, the deviation of the relative positions of the head modules between the bars can be made uniform over the recording area of the bars without accumulating due to the connection of the head modules. The fact that the relative position deviations of the head modules do not accumulate can be understood as the fact that the relative position deviations are reset for each module.

When an XY coordinate system is introduced in which the paper transport direction is the Y direction and the paper width direction orthogonal to the paper transport direction is the X direction to express the direction and the positional relationship, the nozzle relative position is the nozzle relative position in the X direction. There may be a relative position of the nozzle in the Y direction. The module position in the X direction can be adjusted based on the relative position of the nozzle in the X direction. The module position in the Y direction can be adjusted based on the relative position of the nozzle in the Y direction. The module position may be adjusted in only one of the X direction and the Y direction, or the module position in each of the two directions may be adjusted.

Aspect 2 may have a configuration in which the representative value of the nozzle relative position for each of the plurality of head modules constituting the inkjet head bar is within the target range in the head module position adjusting method of the aspect 1.

According to the second aspect, the variation of the nozzle relative position can be suppressed over the recording area of the inkjet head bar.

Aspect 3 may have a configuration in which the representative value is an average value in the head module position adjusting method of Aspect 1 or Aspect 2.

As the representative value, in addition to the average value, the median value or the mode value of the histogram can be used.

Aspect 4 may have a configuration in which the target value of the target range is 0 in the head module position adjusting method of any one of the aspects 1 to 3.

The ideal position of the nozzle relative position as the adjustment target can be set to "0".

Aspect 5 may have a configuration in which the target range is within one pixel of the recording resolution composed of a single inkjet head bar in the head module position adjusting method of any one of aspects 1 to 4.

For example, when the recording resolution of one inkjet bar alone is 1200 dpi, the size of one pixel is 1200 dpi dot spacing, that is, 21.2 μm.

Aspect 6 is a configuration in which the target range is within 0.5 pixels of a recording resolution composed of a single inkjet head bar in the head module position adjusting method of any one of aspects 1 to 5. Good.

Aspect 7 is a head module position adjusting method according to any one of aspects 1 to 6, wherein the inkjet recording device sets the positions of dots recorded by the nozzles in the paper transport direction and the paper transport direction for each head module. It is provided with at least one position adjusting mechanism for moving in at least one of the paper width directions orthogonal to the nozzle, and is used to keep the representative value of the nozzle relative position within the target range based on the representative value of the nozzle relative position. The structure may be such that the moving direction and the moving amount are determined by the position adjusting mechanism.

In aspect 8, in the head module position adjusting method of any one of aspects 1 to 7, when the paper transport direction is the Y direction and the paper width direction orthogonal to the Y direction is the X direction, the nozzle relative position is , X-direction nozzle relative position by adjusting the X-direction position of the head module based on the representative value of the X-direction nozzle relative position, including the X-direction nozzle relative position representing the deviation of the X-direction relative position. The configuration may be such that the representative value of is within the target range.

In aspect 9, in the head module position adjusting method of any one of aspects 1 to 7, when the paper transport direction is the Y direction and the paper width direction orthogonal to the Y direction is the X direction, the nozzle relative position is , Y-direction nozzle relative position by adjusting the Y-direction position of the head module based on the representative value of the Y-direction nozzle relative position, including the Y-direction nozzle relative position representing the deviation of the Y-direction relative position. The configuration may be such that the representative value of is within the target range.

Aspect 10 is a nozzle relative position with respect to a head module at a reference position among a plurality of head modules constituting an inkjet head bar in the head module position adjusting method according to any one of aspects 1 to 9. The first adjustment step for adjusting the representative value of the nozzle within the target range, and the second adjustment step for adjusting the representative value of the relative position of the nozzle within the target range for the head module other than the reference position. Including, the second adjustment step is a configuration in which the representative values of the nozzle relative positions are within the target range by moving the head modules in the opposite directions by equal amounts between the head modules that record the overlapping areas of the paper. It may be there.

In the head module position adjusting method according to the eleventh aspect, an inkjet head bar configured by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged is used, and as a line head for recording the same color. This is a head module position adjustment method for adjusting the position of the head module in a single-pass inkjet recording device in which a plurality of inkjet headbars are arranged in the paper transport direction. Acquires nozzle relative position information obtained by measuring the nozzle relative position, which represents the relative position deviation between dots recorded by the corresponding nozzles of the head modules to be recorded, at multiple points within the range of the head module. By adjusting the movement direction and movement amount of the head module for each inkjet head bar based on the step to be performed and the representative value of the nozzle relative position calculated based on the nozzle relative position measured from the plurality of locations, the plurality of locations The sum of the representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from is within the target range, and the deviation of the inter-module distance between adjacent head modules for each inkjet head bar from the reference distance. This is a head module position adjustment method including a step of adjusting the total to 0.

The deviation of the inter-module distance from the reference distance can be obtained as the difference obtained by subtracting the reference distance from the inter-module distance between adjacent head modules. In aspect 11, the step of acquiring the information obtained by measuring the deviation of the inter-module distance between the head modules in each inkjet head bar from the reference distance may be included. According to the eleventh aspect, the relative nozzle positions can be uniformly aligned between the bars.

Aspect 12 may have a configuration in which the representative value is an average value in the head module position adjusting method of the aspect 11.

Aspect 13 may have a configuration in which the target value of the target range is 0 in the head module position adjusting method of the aspect 11 or the aspect 12.

Aspect 14 is the head module position adjusting method according to any one of aspects 1 to 13, in a direction in which the recording resolution of the inkjet headbar alone is uniform for each inkjet headbar, within a specified allowable range. , The configuration may include a step of moving the head modules to adjust the distance between the adjacent head modules.

According to the fourteenth aspect, the movement amount of the head module can be limited and the distance between the modules can be adjusted within a predetermined allowable range.

Aspect 15 is a nozzle relative by recording a line pattern using a plurality of inkjet headbars and measuring the line spacing of the line pattern in the head module position adjusting method of any one of aspects 1 to 14. It may be configured to measure the position.

Aspect 16 is a nozzle relative by recording a dot group using a plurality of inkjet headbars and measuring the dot spacing of the dot group in the head module position adjusting method of any one of the aspects 1 to 14. It may be configured to measure the position.

In aspect 17, in the head module position adjusting method of any one of aspects 1 to 14, a line pattern is recorded in the same area of the paper using a plurality of inkjet headbars, and the density of the recorded pattern is measured. By doing so, the configuration may be such that the relative position of the nozzle is measured.

Aspect 18 may have a configuration in which the head module is adjusted to a position where the concentration becomes the maximum or the minimum in the head module position adjusting method of the aspect 17.

Aspect 19 is the head module position adjusting method according to any one of aspects 1 to 18, in which the inkjet recording apparatus has a plurality of inkjet headbars arranged in the paper transport direction for each color of a plurality of colors, and the recording width of each color. In the entire area, the relative position of the nozzle may be contained within one pixel of the recording resolution composed of a single inkjet head bar.

Aspect 20 is the head module position adjusting method according to any one of aspects 1 to 18, wherein the inkjet recording apparatus has a plurality of inkjet headbars arranged in the paper transport direction for each color of the plurality of colors, and the recording width of each color. In the entire area, the relative position of the nozzle may be kept within 0.5 pixels of the recording resolution composed of a single inkjet head bar.

Aspect 21 is the head module position adjusting method according to any one of aspects 1 to 20, in which the inkjet recording apparatus causes a defective nozzle in any one of a plurality of inkjet headbars. , Other inkjet headbar nozzles may be used to make corrections to supplement the recording of defective nozzles.

For example, when a defective nozzle occurs in any one of a plurality of inkjet headbars, the droplet rate or the amount of droplets of neighboring nozzles at overlapping positions in the paper transport direction of the other inkjet headbars. Can be changed to correct defective nozzles.

The head module position adjusting method according to each of the aspects 1 to 21 can be applied to the process of manufacturing the inkjet recording device. That is, the head module position adjusting method of the present disclosure can be interpreted as a manufacturing method of an inkjet recording apparatus.

The inkjet recording apparatus according to aspect 22 is a single-pass type inkjet recording apparatus using an inkjet head bar formed by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged. A plurality of inkjet headbars as line heads for recording colors are arranged in the paper transport direction, and between dots recorded by corresponding nozzles of head modules that record overlapping areas of paper transported in the paper transport direction. This is an inkjet recording device in which the nozzle relative position representing the relative position deviation is within the target range over the recording area.

In aspect 22, it is preferable that the nozzle relative position is within a certain target value range over the entire recording width of the inkjet head bar.

Aspect 23 further includes a control unit for controlling ejection from each nozzle of the inkjet head bar in the inkjet recording device of the aspect 22, and the control unit is in any one of a plurality of inkjet head bars. When a defective nozzle occurs, a nozzle of another inkjet head bar may be used to make a correction to supplement the recording of the defective nozzle.

In the inkjet recording apparatus of Aspect 22 or Aspect 23, the same matters as those specified in Aspects 1 to 21 can be appropriately combined. In that case, the elements of the steps of the processing or operation specified in the head module position adjusting method can be grasped as the elements of the processing unit or the functional unit as means for carrying out the corresponding processing or operation.

The adjustment support device according to the 24th aspect uses an inkjet head bar formed by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged, and an inkjet as a line head for recording the same color. An adjustment support device that supports adjustment of the positional relationship of head modules in a single-pass inkjet recording device in which a plurality of head bars are arranged in the paper transport direction, and records overlapping areas of paper transported in the paper transport direction. Acquires nozzle relative position information obtained by measuring the nozzle relative position, which represents the relative position deviation between dots recorded by the corresponding nozzles of the head modules, at a plurality of points within the range of the head module. Indicates the movement direction and movement amount of the head module for each inkjet head bar required to keep the representative value of the nozzle relative position calculated based on the information acquisition unit and the nozzle relative position measured from multiple points within the target range. It is an adjustment support device including an adjustment target value calculation unit that calculates an adjustment target value and an output unit that outputs an adjustment target value calculated by the adjustment target value calculation unit.

According to the aspect 24, the operator can adjust the position of each head module according to the adjustment target value output from the adjustment support device.

The adjustment support device according to the 25th aspect uses an inkjet head bar formed by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged, and an inkjet as a line head for recording the same color. An adjustment support device that supports adjustment of the positional relationship of head modules in a single-pass inkjet recording device in which a plurality of head bars are arranged in the paper transport direction, and is a distance between adjacent head modules for each inkjet head bar. Relative between the dots recorded by the corresponding nozzles of the head modules that record the overlapping area of the paper transported in the paper transport direction and the inter-module distance information acquisition unit that acquires information on the deviation from the reference distance of. Nozzle relative position information acquisition unit that acquires nozzle relative position information obtained by measuring nozzle relative positions that represent misalignment at multiple points within the range of the head module, and nozzle relative positions measured from multiple points. In order to keep the sum of the representative values of the nozzle relative positions calculated based on the above in the target range and to make the sum of the deviations from the reference distance of the distance between adjacent head modules for each inkjet head bar from the reference distance to 0. An adjustment target value calculation unit that calculates an adjustment target value indicating the movement direction and movement amount of the head module for each required inkjet head bar, and an output unit that outputs the adjustment target value calculated by the adjustment target value calculation unit. It is an adjustment support device to be equipped.

According to the aspect 25, the operator can adjust the position of each head module according to the adjustment target value output from the adjustment support device.

In the adjustment support device of aspect 24 or 25, the same items as those specified in aspects 1 to 21 can be appropriately combined. In that case, the elements of the steps of the processing or operation specified in the head module position adjusting method can be grasped as the elements of the processing unit or the functional unit as means for carrying out the corresponding processing or operation.

In the program according to the 26th aspect, an inkjet head bar configured by connecting a plurality of head modules having nozzle surfaces in which a plurality of nozzles are arranged is used, and an inkjet head bar as a line head for recording the same color is used. Is a program for realizing a function in a computer to support adjustment of the positional relationship of head modules in a single-pass inkjet recording apparatus in which a plurality of nozzles are arranged in the paper conveying direction, and the nozzles are conveyed to the computer in the paper conveying direction. Nozzles obtained by measuring the relative positions of the nozzles, which represent the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules that record the overlapping area of the paper, at multiple points within the range of the head modules. The function to acquire relative position information and the movement direction of the head module for each inkjet head bar required to keep the representative value of the nozzle relative position calculated based on the nozzle relative position measured from multiple points within the target range. It is a program that realizes a function of calculating an adjustment target value indicating a movement amount and a function of outputting the calculated adjustment target value.

In the program according to the 27th aspect, an inkjet head bar configured by connecting a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and an inkjet head bar as a line head for recording the same color is used. Is a program for realizing a function in a computer to support adjustment of the positional relationship of head modules in a single-pass inkjet recording device in which a plurality of inkjet headbars are arranged in the paper transport direction, and the inkjet headbars are adjacent to each other in the computer. The function to acquire information on the deviation of the distance between the head modules from the reference distance and the dot between the dots recorded by the corresponding nozzles of the head modules that record the overlapping area of the paper transported in the paper transport direction. Based on the function to acquire information on the relative position of the nozzle obtained by measuring the relative position of the nozzle, which represents the relative position deviation, at multiple points within the range of the head module, and the relative position of the nozzle measured from multiple points. Inkjet required to keep the sum of the calculated representative values of the relative positions of the nozzles within the target range and to set the sum of the deviations from the reference distance of the inter-module distances between adjacent head modules for each inkjet head bar to 0. It is a program that realizes a function of calculating an adjustment target value indicating the movement direction and movement amount of the head module for each head bar and a function of outputting the calculated adjustment target value.

In the program of Aspect 26 or Aspect 27, the same matters as those specified in Aspects 1 to 21 can be appropriately combined. In that case, the elements of the processing or operation steps specified in the head module position adjustment method can be grasped as the elements of the program that realizes the corresponding processing or operation functions.

The printed matter manufacturing method according to aspect 28 is a printed matter by recording an image on paper using an inkjet recording apparatus in which the position of the head module is adjusted by using the head module position adjusting method of any one of aspects 1 to 21. It is a printed matter manufacturing method for manufacturing.

According to the present invention, the relative position of each head module can be appropriately adjusted in an inkjet recording apparatus including a plurality of inkjet headbars arranged in a plurality of arrangements for recording the same color.

Further, according to the present invention, it is possible to provide an inkjet recording apparatus capable of recording a high-quality image, and it is possible to obtain a printed matter on which a high-quality image is recorded.

FIG. 1 is a side view showing a schematic configuration of an inkjet recording device according to an embodiment of the present invention. FIG. 2 is a plan view of the inkjet recording apparatus shown in FIG. FIG. 3 is a bottom view showing a schematic configuration of the inkjet head bar. FIG. 4 is a diagram schematically showing a configuration example of a nozzle surface of the head module. FIG. 5 is a block diagram showing a schematic configuration of a control system of an inkjet recording device. FIG. 6 is an explanatory diagram showing an example of a grid pattern showing the arrangement of dots recorded by two multi-arranged inkjet headbars. FIG. 7 is a graph showing the results of a simulation analyzing the relationship between the relative positions of dots and graininess. FIG. 8 is an explanatory diagram showing the relative positional relationship of the dots in the dot arrangement used as the condition in the simulation of the graininess analysis shown in FIG. 7. FIG. 9 is a conceptual diagram showing an example of discharge characteristics of the head module. FIG. 10 is a diagram showing an example of a line pattern recorded using the head module shown in FIG. FIG. 11 is an explanatory diagram showing an example in which the line spacing of the line pattern is uniform between the head modules due to each of the two multiplely arranged bars. FIG. 12 is an explanatory diagram showing an example in which the line spacing of the line pattern differs between the head modules depending on each of the two multiplely arranged bars. FIG. 13 is an explanatory diagram for explaining the term definition of the module Δx. FIG. 14 is an explanatory diagram for explaining the term definition of the module Δy. FIG. 15 is a diagram showing an example of a test chart used for measuring the nozzle Δx. FIG. 16 is an enlarged view of a part of FIG. 15. FIG. 17 is a diagram showing an example of a measurement pattern used for measuring the nozzle Δx and the nozzle Δy. FIG. 18 is a flowchart showing a specific example 1 of an adjustment procedure for adjusting the relative positional relationship between the multi-arranged inkjet headbars. FIG. 19 is an explanatory diagram schematically showing the adjustment process shown in the flowchart of FIG. FIG. 20 is a chart showing an example of the transition of the adjustment value when the adjustment is performed in the adjustment sequence described with reference to FIGS. 18 and 19. FIG. 21 is a flowchart showing a specific example 2 of an adjustment procedure for adjusting the relative positional relationship between the multi-arranged inkjet headbars. FIG. 22 is an explanatory diagram schematically showing the adjustment process shown in the flowchart of FIG. 21. FIG. 23 is an explanatory diagram schematically showing the adjustment process in the case of 5 modules. FIG. 24 is a chart showing an example of the transition of the adjustment value in the case of 5 modules. FIG. 25 shows the transition of the adjustment value when the “Step.5” part of the chart shown in FIG. 24 is decomposed into the two-step procedure of “Step.5-1” and “Step.5-2”. It is a chart which shows. FIG. 26 is an explanatory diagram showing an example of measuring the relative position between dots based on the density of the pattern recorded on the paper. FIG. 27 is a block diagram showing a function provided by the adjustment support device according to the embodiment of the present invention. FIG. 28 is a diagram showing an example of an arrangement configuration of an inkjet head bar in an inkjet recording device. FIG. 29 is a plan view showing another embodiment of the head module constituting the inkjet head bar.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<< Configuration example of inkjet recording device >>
FIG. 1 is a side view showing a schematic configuration of an inkjet recording device according to an embodiment of the present invention. FIG. 2 is a plan view of the inkjet recording apparatus shown in FIG. The inkjet recording device 1 is a digital printing device that records a desired image on paper P by a single-pass method.

The inkjet recording device 1 includes a paper transport unit 10 for transporting the paper P, an inkjet recording unit 20 for recording an image on the paper P, and an image reading unit 30 for reading the image recorded on the paper P. Further, the inkjet recording device 1 includes a paper feeding unit 40 that supplies the paper P to the paper conveying unit 10, and a paper discharging unit 50 that discharges the paper P after image recording.

The paper transport unit 10 transports the paper P as a recording medium along a constant transport path. The paper transport unit 10 of this example is a suction belt transport mechanism that sucks the paper P on the surface of the traveling belt 11 and transports the paper P. The belt 11 is composed of an endless belt, and is wound around a driving roller 12 and a driven roller 13. A belt drive motor 14 is connected to the drive roller 12. The belt 11 travels by rotating the drive roller 12 by the belt drive motor 14. The paper P is adsorbed on the belt 11 by utilizing the negative pressure. The belt 11 has a large number of suction holes. Inside the belt 11, a suction unit 16 for sucking the belt 11 from the inside is provided. By performing suction from the inside of the belt 11 using the suction unit 16, the paper P is attracted to the surface of the belt 11.

The inkjet recording unit 20 records an image on the paper P conveyed by the belt 11 by an inkjet method. The inkjet recording unit 20 includes a plurality of inkjet headbars 21A and 21B that eject ink of the same color. Here, for the sake of simplicity, an example including two inkjet headbars 21A and 21B for ejecting ink droplets of the same color will be shown, but the number of inkjet headbars arranged in the inkjet recording unit 20 will be increased. The color combination of the ink used is not particularly limited. For example, the inkjet recording unit 20 includes two or more inkjet headbars that eject ink droplets of the same color for each ink color of cyan (C), magenta (M), yellow (Y), and black (K). May be.

Each of the inkjet headbars 21A and 21B ejects a droplet of ink toward the paper P, attaches a coloring material to the paper P, and records a desired image on the paper P. Each of the inkjet head bars 21A and 21B is a line head having an effective recording width corresponding to the paper width. Line heads are also called "page wide heads".

The two inkjet headbars 21A and 21B are arranged at regular intervals on the transport path of the paper P by the belt 11. Further, the two inkjet headbars 21A and 21B are arranged orthogonally to the conveying direction of the paper P by the belt 11. The paper transport direction by the belt 11 is referred to as "Y direction", and the paper width direction orthogonal to the Y direction is referred to as "X direction". Since each of the two inkjet headbars 21A and 21B is arranged orthogonally to the paper transport direction, the two inkjet headbars 21A and 21B are arranged parallel to each other along the paper width direction. Orthogonal.

The two inkjet headbars 21A and 21B are configured by connecting a plurality of head modules, respectively. This point will be described later with reference to FIGS. 3 and 4.

The paper P conveyed by the belt 11 has ink droplets ejected from at least one of the inkjet head bar 21A and the inkjet head bar 21B in the conveying process, and the ejected droplets adhere to the paper P. The image is recorded on the paper P.

The image reading unit 30 reads the image recorded on the paper P. The image reading unit 30 is provided with an image reading device 31. The image reading device 31 is a device that optically reads the image recorded on the paper P by the inkjet recording unit 20 and generates electronic image data indicating the read image. The image reading device 31 includes an imaging device that captures an image recorded on the paper P and converts it into an electric signal indicating image information. In addition to the image pickup device, the image reader 31 may include an illumination optical system that illuminates the reading target and a signal processing circuit that processes signals obtained from the image pickup device to generate digital image data.

The image reading device 31 is composed of, for example, a line scanner, and reads an image from the paper P conveyed by the belt 11. In this case, the image reading device 31 uses a CCD (Charge-Coupled Device) linear image sensor as the image pickup device. A CMOS (Complementary Metal Oxide Semiconductor) linear image sensor can be used instead of the CCD linear image sensor.

The paper feeding unit 40 includes a known paper feeding device, separates the paper P stacked on the tray one by one, and supplies the paper P to the paper conveying unit 10.

The paper ejection unit 50 receives the paper P on which the image is recorded from the paper transport unit 10 and collects the paper P on the tray.

<< Configuration example of inkjet head bar >>
Since the configurations of the two inkjet head bars 21A and 21B are the same, the configuration of the inkjet head bars 21A will be described here.

FIG. 3 is a bottom view showing a schematic configuration of the inkjet head bar. FIG. 3 is a view of the inkjet head bar 21A viewed from the nozzle surface side. The inkjet head bar 21A is a full-line type inkjet head configured in the shape of one bar by connecting a plurality of head modules 22A to lengthen them. In this example, each head module 22A has the same structure.

The number of head modules 22A constituting the inkjet head bar 21A is not particularly limited, and may be an appropriate number of 2 or more depending on the required recording area width. The number of head modules 22A constituting one inkjet head bar 21A is preferably 3 or more, and more preferably 5 or more. For example, the inkjet head bar 21A can be configured by connecting 17 head modules 22A. Each head module 22A is attached to the base frame 23A and integrated.

The base frame 23A has a bar shape and has a number of head module mounting portions (not shown) corresponding to the number of head modules 22A installed. Head module mounting portions are provided at regular intervals along the longitudinal direction of the base frame 23A. The longitudinal direction of the base frame 23A is the longitudinal direction of the inkjet head bar 21A, which is the X direction in FIG. The head module 22A is detachably and position-adjustably attached to the head module attachment portion. That is, the head module mounting portion has a holding mechanism for holding the head module 22A detachably, and also has a position adjusting mechanism for finely adjusting the position of the held head module 22A. As a result, the head module 22A can be replaced individually, and the position of the attached head module 22A can be adjusted individually.

The position adjusting mechanism includes an X direction adjusting mechanism for adjusting the position of the head module 22A in the X direction and a Y direction adjusting mechanism for adjusting the position of the head module 22A in the Y direction. By using the X direction adjustment mechanism, the distance between the head modules 22A adjacent to each other in the X direction can be adjusted. Further, by using the Y direction adjusting mechanism, the relative positions of the adjacent head modules 22A in the Y direction can be adjusted. As a configuration example of the position adjusting mechanism, for example, the configuration described in Patent Document 3 may be adopted.

FIG. 4 is a diagram schematically showing a configuration example of a nozzle surface of the head module. The head module 22A has a plurality of nozzles 25A on the nozzle surface 24A. By attaching each head module 22A to the base frame 23A, the nozzle surfaces 24A are located on the same surface.

The plurality of nozzles 25A are arranged so as to achieve a desired recording resolution. In the example of FIG. 4, a plurality of nozzles 25A are arranged in a matrix, and a desired recording resolution in the X direction, for example, 1200 dpi, is realized by this two-dimensional nozzle arrangement.

In the case of an inkjet head having a two-dimensional nozzle arrangement, a projection nozzle array in which each nozzle in the two-dimensional nozzle arrangement is projected (orthogonally projected) so as to line up along the X direction is a nozzle that achieves a desired recording resolution in the X direction. It can be considered to be equivalent to a row of nozzles in which each nozzle is arranged at approximately equal intervals in terms of density.

"Approximately evenly spaced" means that the drip points that can be recorded by the inkjet head are substantially evenly spaced. For example, the concept of "equal spacing" also includes those with slightly different spacing in consideration of manufacturing errors and / or movement of droplets on the paper due to landing interference. The projected nozzle array corresponds to a substantial nozzle array. Considering the projection nozzle array, it is possible to associate each nozzle with a nozzle number indicating the nozzle position in the order in which the projection nozzles are arranged along the X direction. In the present specification, when describing the positional relationship of nozzles, unless otherwise specified, it shall mean the positional relationship in the projected nozzle array (substantial nozzle array).

The arrangement form of the nozzles 25A in the head module 22A is not limited, and various nozzle arrangement forms can be adopted. For example, instead of the form of a matrix-like two-dimensional array, a line-shaped nozzle array, a V-shaped nozzle array, a polygonal line-shaped nozzle array such as a W-shaped array having a V-shaped array as a repeating unit, etc. are also possible. Is.

In a two-dimensional nozzle arrangement in which a plurality of nozzles 25A are arranged in each of the row direction and the column direction, the column direction may intersect the row direction diagonally, and the row direction and the X direction are not. It may be parallel.

<< Discharge method of head module 22A >>
The ejector of the head module 22A includes a nozzle 25A for discharging a liquid, a pressure chamber communicating with the nozzle 25A, and a discharge energy generating element for supplying discharge energy to the liquid in the pressure chamber. As the discharge energy generating element, for example, a piezoelectric element can be used. Regarding the ejection method for ejecting droplets from the ejector nozzle 25A, the means for generating the ejection energy is not limited to the piezoelectric element, and various ejection energy generating elements such as a heat generating element and an electrostatic actuator can be applied. For example, a method of ejecting droplets by utilizing the pressure of film boiling due to heating of a liquid by a heat generating element can be adopted. Depending on the ejection method of the inkjet head, a corresponding ejection energy generating element is provided in the flow path structure.

<< Control system of inkjet recording device >>
FIG. 5 is a block diagram showing a schematic configuration of a control system of an inkjet recording device. The entire operation of the inkjet recording device 1 is controlled by the control unit 100. The control unit 100 is configured by using a computer. The control unit 100 includes a CPU and a memory (not shown). The control unit 100 executes a predetermined control program to control the operation of each unit.

The control unit 100 controls the paper feed unit 40 so that the paper P is fed one by one, and controls the paper transport unit 10 so that the fed paper P is conveyed at a constant speed. .. Further, the control unit 100 controls the inkjet recording unit 20 so that a desired image is recorded on the conveyed paper P, and controls the image reading unit 30 so as to read the recorded image. Further, the control unit 100 controls the paper ejection unit 50 so that the recorded paper P is accumulated at a predetermined position. The control unit 100 functions as a calculation unit that performs various calculation processes including image data processing.

The control unit 100 includes an operation unit 101 for operating the inkjet recording device 1, a display unit 102 for displaying various information, a communication unit 103 for communicating with an external device, a program required for control, various data, and the like. A storage unit 104 or the like for storing the data is connected.

As the operation unit 101, a keyboard, a mouse, a touch panel, a trackball, a voice input device, or an appropriate combination of these input devices can be adopted.

The display unit 102 may be, for example, a liquid crystal display, an organic electro-luminescence (OEL) display, a projector, or an appropriate combination thereof.

A wired or wireless communication interface may be adopted for the communication unit 103.

The storage unit 104 may employ various storage devices such as, for example, a hard disk device, a semiconductor memory, an optical disk or other external storage device, or an appropriate combination thereof.

The image data recorded on the paper P using the inkjet recording unit 20 is acquired from a host computer or other external device (not shown) via the communication unit 103. The control unit 100 includes an image processing unit that generates dot data, which is data for recording, from the acquired image data. The image processing unit includes a color separation processing unit, a color conversion processing unit, a correction processing unit, and a halftone processing unit. In the image processing unit, for example, color separation processing for separating input image data into RGB colors, color conversion processing for converting RGB data into CMYK data, various correction processing such as gamma correction and unevenness correction, and each color Halftone processing is performed to convert the gradation value for each pixel to a gradation value less than the original gradation value. The correction process performed by the image processing unit includes a streak correction process for suppressing an image defect caused by a defective nozzle.

The input image data is continuous gradation image data. As an example of the input image data, raster data represented by a digital value from 0 to 255 can be mentioned. The dot data obtained as a result of the halftone processing may be a binary value, or may be a multi-value of three values or more and less than the gradation value before the halftone processing. A part or all of the processing functions of the image processing unit may be realized by a processor different from the control unit 100.

The control unit 100 controls the ink ejection operation of the inkjet head bars 21A and 21B based on the recording data generated by the image processing unit. That is, the control unit 100 determines the ejection timing and the ink ejection amount of each pixel position based on the dot data generated through the processing by the image processing unit, and corresponds to the ejection timing and the ink ejection amount of each pixel position. A control signal that determines the drive voltage and the ejection timing of each pixel is generated. The control signal generated by the control unit 100 is supplied to the inkjet head bars 21A and 21B, and dots are formed by the ink ejected from the inkjet head bars 21A and 21B.

The inkjet recording device 1 can use the two inkjet headbars 21A and 21B at the same time or alternately when recording an image. Further, when a ejection defect occurs in the nozzle of one inkjet head bar, it can be supplemented by ejection from the other inkjet head bar. That is, the defective nozzle in which the ejection defect has occurred can be made non-ejective and corrected by using the corresponding nozzle of the other inkjet head bar. "Ejection-free" is synonymous with "masking", that is, disabling a defective nozzle so that it is not used for dot recording. The inkjet recording device 1 records defective nozzles by, for example, making defective nozzles non-ejective and changing the drip rate or the amount of droplets of neighboring nozzles at overlapping positions in the paper transport direction of another inkjet head bar. It has a compensating correction function.

<< Need to adjust the relative position of dots between multiple inkjet headbars >>
Hereinafter, for the sake of simplification of the notation, one bar of the two inkjet head bars arranged in multiple arrangement will be referred to as a first bar, and the other bar will be referred to as a second bar. For example, the inkjet head bar 21A shown in FIG. 1 is the first bar, and the inkjet head bar 21B is the second bar.

<Relationship between the relative position of dots recorded by each multi-arranged bar and graininess>
FIG. 6 is an explanatory diagram showing an example of a grid pattern showing the arrangement of dots recorded by two multi-arranged bars. In FIG. 6, for simplification of the illustration, nozzle rows arranged in a row in the X direction are shown for the nozzles 25A and 25B of the first bar 61A and the second bar 61B, respectively. Each of the first bar 61A and the second bar 61B shall have a recording resolution of, for example, 1200 dpi. FIG. 6 shows an example of a 1200 dpi × 2 grid pattern in which the ideal arrangement patterns of dots recorded on the paper by each of the first bar 61A and the second bar 61B are combined.

In FIG. 6, each dot 62A represented by a white circle indicates a dot belonging to the 1200 dpi grid pattern recorded by the first bar 61A. In FIG. 6, each dot 62B painted in gray indicates a dot belonging to the 1200 dpi grid pattern recorded by the second bar 61B. As shown in FIG. 6, when the positional relationship is such that the dot 62B recorded by the second bar 61B is arranged in the center of the cell of the grid pattern of the dots 62A recorded by the first bar 61A. A dot pattern with the best graininess can be obtained.

As shown in FIG. 6, dots having a positional relationship such that the dots 62B recorded by the second bar 61B are arranged in the center of the cell of the grid pattern of the dots 62A recorded by the first bar 61A. The arrangement is called "staggered arrangement".

If the relative positions of the dots 62A recorded by the first bar 61A and the dots 62B recorded by the second bar 61B deviate from the staggered arrangement, the graininess deteriorates.

FIG. 7 is a graph showing the results of simulation when the graininess is analyzed by changing the relative positional relationship between the dot position of the first bar and the dot position of the second bar in various ways. That is, in FIG. 7, when the first bar and the second bar each have a recording resolution of 1200 dpi and the dots are arranged using these two bars, the degree of graininess depends on the relative positions of the dots. This is the result of simulating whether it changes. The horizontal axis of FIG. 7 indicates lightness, and the vertical axis indicates graininess.

FIG. 8 shows the relative positional relationship between the dot position of the first bar and the dot position of the second bar used as the conditions for the simulation of the graininess analysis shown in FIG. The four corners of the cell shown in FIG. 8 are the dot positions of the first bar 61A. The graph shown in FIG. 7 shows the results of analyzing the graininess of each dot pattern by changing the dot position of the second bar 61B from the center of the cell in multiple stages.

Graph G1 of FIG. 7 shows the graininess when the dot position of the second bar 61B is in the center of the cell (that is, in the case of staggered arrangement). Graph G2 of FIG. 7 shows the graininess when the dot position of the second bar 61B is within a range of a relatively short distance from the center of the cell. When the dot position of the second bar 61B is within "± 5.3 μm" in each of the X and Y directions from the center of the cell, the difference in granularity is not visible as compared with the graph G1.

Graph G3 of FIG. 7 shows the graininess when the dot position of the second bar 61B is within a range of a relatively long distance from the center of the cell. When the dot position of the second bar 61B is in the range exceeding "± 5.3 μm" in each of the X and Y directions from the center of the cell, the difference in granularity can be visually recognized as compared with the graphs G1 and G1.

As shown in the range surrounded by the broken line frame in FIG. 8, such an analysis result shows that it is possible to suppress the deterioration of graininess by suppressing the relative positional deviation of the dots within a certain range. Shown.

<Regarding the deviation of the local dot recording position of the head module>
FIG. 9 is a conceptual diagram showing an example of discharge characteristics of the head module. FIG. 9 shows an example of the local dot recording position deviation of the head module 22A. In FIG. 9, the arrow coming out of the nozzle surface 24A of the head module 22A indicates the ejection direction of the ink droplet ejected from the nozzle at that position. In the head module 22A illustrated in FIG. 9, the discharge direction is locally changed. FIG. 10 shows an example of a line pattern recorded on the paper surface of the paper P using the head module 22A shown in FIG.

For comparison, FIG. 10 also shows an example of a line pattern LP0 recorded on paper by a head module with ideal design ejection characteristics. The line pattern 70 shown in the lower part of FIG. 10 is the line pattern recorded by the head module 22A of FIG. As shown in FIGS. 9 and 10, a part of the head module is uniformly bent in the X direction and discharged. Alternatively, it may be understood that the nozzle-to-nozzle pitch of a part of the head module is shorter than the ideal nozzle-to-nozzle pitch in the design.

The head module illustrated in FIG. 9 has the same recordable width (total length of the nozzle row in the X direction) as compared with the ideal head module in design, but the dot recording position is locally provided for a part of the nozzle row. Is out of alignment. Although not shown in the figure, each head module may have various characteristics such as a short recordable width or a long recordable width as compared with an ideal head module in design.

<About pixel replacement due to misalignment of dot recording positions between bars>
Here, "pixel replacement", which is a problem in bar multiplexing, will be described. First, an ideal case in which pixel replacement does not occur will be described.

FIG. 11 shows an example in which the line spacing recorded by each nozzle of the first bar and the line spacing recorded by each nozzle of the second bar are uniform among the head modules. Has been done. FIG. 11 corresponds to an ideal state in design. In this case, the line positions of the line pattern 71 recorded by the first bar correspond to pixel numbers 1, 3, 5, 7, 9, ....

The line positions of the line pattern 72 recorded by the second bar correspond to pixel numbers 2, 4, 5, 7, 9, ....

When the line pattern 71 recorded by the first bar and the line pattern 72 recorded by the second bar are combined, the line positions of the combined line pattern 73 are pixel numbers 1, 2, 3, 4, ... The lines recorded by the first bar and the lines recorded by the second bar are alternately arranged in the X direction at a constant line interval.

FIG. 12 shows an example in which the line spacing recorded by each nozzle of the first bar and the line spacing recorded by each nozzle of the second bar differ between the head modules. There is.

Here, for the sake of simplicity, an example is shown in which the line spacing of the line pattern 82 recorded by the second bar is shorter than the line spacing of the line pattern 81 recorded by the first bar. That is, the example of FIG. 12 corresponds to an example in which the nozzle-to-nozzle pitch of the head module constituting the second bar is smaller than the nozzle-to-nozzle pitch of the head module constituting the first bar.

In this case, when the line pattern 81 recorded by the first bar and the line pattern 82 recorded by the second bar are combined, the pixels are exchanged at the line position indicated by the arrow C in the combined line pattern 83. (Pixel number replacement) occurs.

When such pixel replacement occurs, the dot arrangement pattern (lattice pattern) collapses, making it difficult to record a good image. Further, for example, when the ejection failure is corrected by the other bar when the pixels are replaced, the positional relationship between the nozzle position and the pixels becomes complicated, and very advanced processing is required.

<About ejection failure correction between multiple bars>
For example, if a defective nozzle occurs in one of the two bars, a general streak correction technique can make the defective nozzle non-ejective and increase the drip rate of nearby nozzles in the same bar. , Correction that suppresses the visibility of streaks is performed by using large drops. The correction method in which the defective nozzle is made non-ejective and the recording is supplemented by another proximity nozzle is called "ejection-free correction".

However, when the bars are multiplexed, the closest nozzle of the ejection-free nozzle becomes the nozzle of the other bar unless the pixel numbers are exchanged.

That is, from the viewpoint of performing better ejection failure correction, it is desired to control the relative positions of the dots within a range in which the pixel numbers are not exchanged.

<< Arrangement of issues >>
When a line head is formed by connecting a plurality of modules, it is necessary to adjust the distance between the modules of each module in the bar so as to realize a predetermined recording resolution for each bar. On the other hand, since the actual head module has different characteristics such as the pitch between nozzles and the discharge direction for each module, each bar is assumed so that the distance between modules in the bar is within the specified allowable range. If the distance between the modules is adjusted individually in, the deviation of the dot recording position due to the characteristics of each module is accumulated toward the end of the bar.

As a result, the pixel numbers are exchanged between the multiplely arranged bars, and the dot pattern is disturbed. If there is a deviation of 5 μm in the recording position for one module, and if this deviation of 5 μm is accumulated (integrated) in the entire bar, the maximum deviation is 80 μm in 17 modules.

When multiplexing bars, it is necessary not only to manage the distance between modules in the bar but also to manage the deviation of the dot recording position between the corresponding nozzles between the bars. The deviation of the dot recording position between the bars can be simply understood as the corresponding "displacement between the nozzles" between the bars.

"Definition of terms"
Before concretely explaining the inkjet head adjusting method according to the embodiment of the present invention, the main terms will be defined.

(1) Regarding "module Δx" For the distance between modules of head modules adjacent to each other in the bar, a reference distance and an allowable range are set for each of the X and Y directions, respectively. Regarding the distance between modules in the X direction, the ideal reference distance in design is called "reference distance between modules in the X direction". The difference between the distance between modules in the X direction and the reference distance between modules in the X direction in the actual bar is called "module Δx". The module Δx corresponds to the deviation of the distance between modules in the X direction from the reference distance between modules in the X direction, and may be understood as the “deviation in the distance between modules in the X direction”. FIG. 13 shows an explanatory diagram regarding the definition of the module Δx.

Assuming that the distance between modules in the X direction is dmx and the reference distance between modules in the X direction is Smx, the module Δx is given by the following equation.
Module Δx ＝ dmx−Smx
It becomes the relationship of.

The module Δx becomes a positive value when the distance between modules in the X direction is larger than the reference distance between modules in the X direction. The module Δx has a negative value when the distance between modules in the X direction is smaller than the reference distance between modules in the X direction. That is, the module Δx becomes a positive value when the distance between modules is far from the reference distance between modules in the X direction, and becomes a negative value when the distance between modules is closer than the reference distance between modules in the X direction.

Assuming that the number of head modules constituting one bar is N, modules Δx exist for each module connecting portion at (N-1).

A design allowable range is defined for the distance between modules in the X direction, and this allowable range is referred to as an "allowable range between modules in the X direction".

(2) About "Nozzle Δx" The deviation of the recording position on the paper surface of the dots recorded by the corresponding nozzles between the multiplely arranged bars in the X direction is called "Nozzle Δx". The nozzle Δx is a nozzle relative position representing a deviation of the relative position in the X direction between the dots recorded by the corresponding nozzles of the head modules that record the overlapping area of the paper conveyed in the Y direction. The nozzle Δx corresponds to the relative position of the nozzle in the X direction. Nozzle Δx is a positive value when the dot position is deviated in the positive direction of the X axis with reference to the dot recorded by the nozzle of either bar, and the dot position is deviated in the negative direction. A positive or negative sign is defined to take a negative value in some cases. In addition, in FIG. 13, the nozzle Δx is simply shown as a deviation in the X direction between the nozzles.

(3) “Module Δy” Similarly, “module Δy” and “nozzle Δy” are defined in the Y direction. Regarding the distance between modules in the Y direction, the ideal reference distance in design is called "reference distance between modules in the Y direction". The difference between the distance between modules in the Y direction and the reference distance between modules in the Y direction in the actual bar is called "module Δy". The module Δy corresponds to a deviation from the reference distance between modules in the Y direction of the distance between modules in the Y direction, and may be understood as “distance deviation between modules in the Y direction”. FIG. 14 shows an explanatory diagram regarding the definition of the module Δy.

Assuming that the distance between modules in the Y direction is dmy and the reference distance between modules in the Y direction is Smy, the module Δy is given by the following equation.
Module Δy ＝ dmy−Smy
It becomes the relationship of.

The module Δy becomes a positive value when the distance between modules in the Y direction is larger than the reference distance between modules in the Y direction. The module Δy has a negative value when the distance between modules in the Y direction is smaller than the reference distance between modules in the Y direction.

A design permissible range is defined for the distance between modules in the Y direction, and this permissible range is referred to as a "permissible range between modules in the Y direction".

(4) About "Nozzle Δy" The deviation of the dot position on the paper surface of the dots recorded by the corresponding nozzles between the multiplely arranged bars in the Y direction is called "Nozzle Δy". The nozzle Δy is a nozzle relative position representing a deviation of the relative position in the Y direction between the dots recorded by the corresponding nozzles of the head modules that record the overlapping area of the paper conveyed in the Y direction. The nozzle Δy corresponds to the relative position of the nozzle in the Y direction. Nozzle Δy is a positive value when the dot position is deviated in the positive direction of the Y axis with reference to the dot recorded by the nozzle of either bar, and the dot position is deviated in the negative direction. Positive and negative signs are defined so that the case takes a negative value.

<< Outline of Head Module Position Adjustment Method According to the Embodiment of the Present Invention >>
The head module position adjusting method according to the present embodiment adjusts each of the nozzles Δx and the nozzles Δy so as to keep them within a predetermined range over the entire print width between the bars.

Basically, each of the module Δx and the module Δy is not adjusted so as to keep the recording resolution uniform for each bar, but the relative positions between the bars are matched and the multiplex bars are combined (composite). This is an adjustment method based on the idea of adjusting the distance between modules as an adjustment unit for making the configured recording resolution uniform.

For example, as shown in FIG. 9, when a part of the module is uniformly bent in the X direction and discharged, or when the pitch between nozzles is shorter than the specified pitch, the modules are arranged so that the recording resolutions are the same in the same bar. By adjusting Δx, it is not possible to correct the nozzle Δx, which is a dot relative position shift between the bars.

In this regard, in the present embodiment, the nozzle Δx is measured at a plurality of points in the module, and the average value of the nozzles Δx obtained from the plurality of points is used as a representative value of the nozzles Δx in the module, and the average value of the nozzles Δx for each module is used. By adjusting the distance between modules in the bar using the value, the nozzle Δx average value is uniformly aligned in module units. As a result, the nozzle Δx can be suppressed to an allowable range in the entire multiplexed bar without accumulating the deviation of the recording position for each module.

After that, if necessary, the modules Δx between the modules in the same bar may be adjusted in the direction in which the recording resolutions in the same bar are aligned within the allowable range of the nozzle Δx.

The above description of the nozzle Δx and the module Δx is the same for the nozzle Δy and the module Δy in the Y direction.

That is, in the Y direction, the nozzles Δy are measured at a plurality of points in the module, and the average value of the nozzles Δy obtained from the plurality of points is used as a representative value of the nozzles Δy in the module, and the average value of the nozzles Δy for each module is used. By adjusting the distance between modules in the bar using, the average value of nozzles Δy is made uniform in units of modules. As a result, the nozzle Δy can be suppressed to an allowable range in the entire multiplexed bar.

Then, if necessary, the modules Δy between the modules in the same bar may be adjusted in the direction in which the recording resolutions in the same bar are aligned within the allowable range of the nozzle Δy.

When calculating the average value of each of the nozzle Δx and the nozzle Δy, general processing performed to improve the accuracy of the average value in the statistical calculation, such as excluding an abnormal value in the sample, may be added. Further, in this example, the average value is used as the representative value, but instead of the average value, the median value, the mode value of the histogram, or the like may be used.

In the present embodiment, the allowable ranges of the nozzles Δx and the nozzles Δy are within one pixel of the recording resolution of the dots recorded in each bar, preferably within 1 pixel, preferably in FIGS. 7 and 7, from the viewpoint of preventing the replacement of image numbers. As shown by the simulation result of No. 8, it means within 0.5 pixels in which the difference in graininess is within an invisible level.

<< Measurement method of nozzles Δx and Δy >>
In order to measure each of the nozzles Δx and the nozzles Δy, it is desirable to use a line recorded using a plurality of nozzles or a line calculated from a group of dots in order to eliminate the influence of a defective nozzle. ..

<Measurement example 1 of nozzle Δx>
The nozzle Δx is measured, for example, by recording a predetermined test chart. That is, a predetermined test chart is recorded, the recording result is read by the image reading unit 30, the image of the read test chart is analyzed, and the nozzle Δx between the bars is measured.

FIG. 15 is a diagram showing an example of a test chart used when measuring the nozzle Δx. FIG. 16 is an enlarged view of an area surrounded by a frame shown by a broken line in FIG.

In FIG. 15, for convenience of illustration, only two modules are shown for each of the first bar, the inkjet head bar 21A, and the second bar, the inkjet head bar 21B. The head module of the first bar is indicated by reference numeral 22A, and the head module of the second bar is indicated by reference numeral 22B. FIG. 15 shows an example of a test chart TC in which the nozzle Δx is measured by a plurality of line groups. The upper part of the test chart TC is the line L1 recorded by the first bar, and the lower part is the line L2 recorded by the second bar.

In the line pattern illustrated in FIG. 15, the x position of each line is measured, and the relative position of the difference between the bars is the nozzle Δxi. "I" is an index indicating the nozzle position in the module. In FIG. 16, nozzle Δxi, nozzle Δxi + 1, nozzle Δxi + 2, and nozzle Δxi + 3 at four positions of “i”, “i + 1”, “i + 2”, and “i + 3”. Is shown to be measured.

The value of the nozzle Δx is expressed as positive when the nozzles are aligned in the positive direction and negative when the nozzles are displaced in the opposite direction with respect to the reference nozzle. The reference nozzle is the nozzle of the first bar here.

By using the average value of a plurality of nozzles Δxi as one element and measuring at a plurality of points in the module, the local deviation in the module can be averaged. Desirably, the measurement points may be sampled evenly over the recording width of the target module, and the nozzles Δxi of all the nozzles in the module may be obtained to calculate the average value.

In the examples shown in FIGS. 15 and 16, the nozzles Δxi are measured at a plurality of points in the module for each head module. "I" is an index indicating the nozzle position in the module. In FIG. 16, nozzle Δxi, nozzle Δxi + 1, nozzle Δxi + 2, and nozzle Δxi + 3 at four positions of “i”, “i + 1”, “i + 2”, and “i + 3”. Is shown to be measured. In the example shown in FIG. 15, four measurement areas of the left end area, the center left side area, the center right side area, and the right end area in one module are measured at four points in each measurement area, for a total of four measurement points of the nozzle Δx. This is an example of measuring the nozzle Δxi at × 4 = 16 points.

From the viewpoint of alleviating the variation in the local dot recording position in the module and obtaining the representative value of the nozzle Δx representing the module, the plurality of measurement points are evenly distributed over the recording width in one module. It is preferable to have. In the example shown in FIG. 15, four measurement areas are distributed in the module at equal intervals in the X direction, and four measurement points in the measurement area are also distributed in the measurement area at equal intervals in the X direction.

In this way, a plurality of lines are recorded using a plurality of nozzles for each head module, and the nozzles Δxi are measured at a plurality of points in the head module.

<Measurement example 2 of nozzle Δx and nozzle Δy>
FIG. 17 shows an example of another method of measuring nozzle Δx and nozzle Δy from a group of dots recorded using a plurality of nozzles. FIG. 17 is an example of a measurement pattern used when measuring the nozzle Δx and the nozzle Δy. The four dots shown in the upper part of FIG. 17 indicate the positions of the dots recorded by using the nozzle of the inkjet head bar 21A, which is the first bar. Each dot is recorded by a different nozzle in the same module.

The four dots shown in the lower part of FIG. 17 indicate the positions of the dots recorded by using the nozzle of the inkjet head bar 21B, which is the second bar. Each dot is recorded by a different nozzle in the same module.

Instead of the line pattern described with reference to FIGS. 15 and 16, the nozzle Δx and the nozzle Δy may be measured by measuring the dot spacing using a measurement pattern including a dot group as shown in FIG. ..

By recording the dots on the paper with a predetermined offset in the Y direction as shown in FIG. 17, the nozzle Δy can be measured without the dots overlapping each other. By giving a predetermined time difference between the drip timing of the first bar and the drip timing of the second bar, a predetermined offset can be given with respect to the position of the dot in the Y direction.

From the group of dots of 4 dots × 2 rows shown in FIG. 17, the nozzles Δxi and the nozzles Δyi between the four corresponding nozzles between the bars can be measured, respectively. In FIG. 17, only a group of dots of 4 dots × 2 rows is shown, but as illustrated in FIG. 15, a large number of measurement points can be set over the recording width of each module.

Regarding the Y direction, if each head module has a Y direction adjustment mechanism for each nozzle, or if there are a plurality of Y direction adjustment mechanisms in the module, the nozzle Δy becomes the minimum for each Y direction adjustment mechanism unit. It may be adjusted as follows.

However, a configuration in which the head module has a Y-direction adjustment mechanism for each nozzle or a configuration in which a plurality of Y-direction adjustment mechanisms are provided in the module is rare, and in the case of a general device configuration, the Y-direction for each module is used. It has only an adjustment mechanism. In the case of a device configuration having only a single Y-direction adjustment mechanism for each module, it is preferable to handle the module as a unit as in the case of the X-direction adjustment.

<< Measurement method of module Δx and module Δy >>
Each of the module Δx and the module Δy can also be measured by recording a predetermined test chart. A test chart is synonymous with a test pattern. As a method for measuring the module Δx and the module Δy, for example, the method described in Japanese Patent Application Laid-Open No. 2014-83720 can be used. Alternatively, as a method for measuring the module Δx and the module Δy, in addition to the above, the module Δx and the module Δy can be measured by imaging the nozzle surface with a camera and analyzing the obtained image data.

Further, in the inkjet head bar, a sensor for detecting the position of each module and / or the distance between modules may be provided, and the module Δx and the module Δy may be grasped based on the signal of the sensor.

<< Specific example of adjustment procedure 1 >>
A specific example 1 of the adjustment procedure will be described with reference to FIGS. 18 and 19. Since the adjustment in the X direction and the adjustment in the Y direction are basically the same, only the adjustment in the X direction will be described in the following description. The description of the adjustment in the X direction using the "module Δx" and the "nozzle Δx" is applied to the adjustment in the Y direction by replacing the module Δx with the “module Δy” and the nozzle Δx with the “nozzle Δy”. ..

Further, for the sake of simplicity, a case where the two inkjet headbars 21A and 21B are each composed of three head modules will be illustrated (see FIG. 19).

In the examples shown in FIGS. 18 and 19, the nozzle Δx is first adjusted to the target range for the central module, and then the module positions of the peripheral modules are adjusted with reference to the central module. ..

FIG. 18 is a flowchart showing a specific example 1 of an adjustment procedure for adjusting the relative positional relationship between the multi-arranged inkjet headbars. FIG. 19 is an explanatory diagram schematically showing the adjustment process shown in the flowchart of FIG. In FIG. 19, the three modules constituting the first bar, the inkjet head bar 21A, are referred to as module MA1, module MA2, and module MA3 from the left. Further, the three modules constituting the inkjet head bar 21B, which is the second bar, are referred to as module MB1, module MB2, and module MB3 from the left.

FIG. 19 illustrates a case where each of the modules MA1, module MA2, and module MA3 constituting the first bar is smaller than each of the modules MB1, module MB2, and module MB3 constituting the second bar. ing. "Small module" means that the recording width is small and the pitch between nozzles is narrow. The white line attached to each module in FIG. 19 indicates the center position of each module.

In step S1 of FIG. 18, first, the nozzles Δx are measured at a plurality of points for the modules MA2 and MB2 located at the center of the bar. For example, by recording a predetermined test chart as illustrated in FIG. 15 or FIG. 17 and reading the recording result by the image reading device 31, the image of the test chart read by the control unit 100 is analyzed and the nozzle Δx is set. Measure. Modules MA2 and MB2 located in the center of the bar are examples of "head modules at reference positions". Step S1 is an example of a “measurement step”.

Next, in step S2, the module Δx of the central module is adjusted so that the average value of the nozzles Δx obtained from step S1 falls within the target range. In step S2, the module Δx between the adjacent modules in the bar is adjusted by moving at least one of the central modules MA2 and MB2. Step S2 is an example of the “first adjustment step”.

Of the two bars, only the central module of the other bar may be moved relative to one bar, or the central module of each of the two bars may be moved. When the module is moved in the X direction using the X-direction adjustment mechanism to adjust the position of the module, the module Δx between the adjacent modules changes.

Reference numeral 201 in FIG. 19 indicates the adjusted state of step S2. In step S2, the central module MA2, the module MB2, or both are moved to align the center positions of the module MA2 and the module MB2.

Next, in step S3 of FIG. 18, the module Δx is adjusted for the module adjacent to the central module. In step S3, each of the modules MA1 and MA3 adjacent to the central module MA2 in the first bar is moved in the X direction so that the pitch between the nozzles in the bar becomes a substantially ideal state in the entire first bar. Adjust the module Δx between each module.

Similarly, for the second bar, the modules MB1 and MB3 adjacent to the central module MA2 in the second bar are moved in each direction, and the pitch between nozzles in the bar is generally ideal for the entire second bar. Adjust the module Δx between each module so that it is in the state.

Reference numeral 202 in FIG. 19 indicates a state after adjustment in step S3. The state of reference numeral 202 is that the module MA1 has moved to the right in FIG. 19, the module MA3 has moved to the left, the module MB1 has moved to the left, and the module MB3 has moved to the left, respectively, as compared with the state of reference numeral 201. It has become.

In the state shown by reference numeral 202 in FIG. 19, the pitch between the nozzles is arranged when the bars are viewed alone, but when the two bars are viewed in combination, the desired dot arrangement can be obtained. Absent.

Next, in step S4 of FIG. 18, the nozzle Δx between the bars in the module adjacent to the central module is measured at a plurality of points. That is, the nozzles Δx are measured at a plurality of points in the module for the module MA1 and the module MB1. Further, the nozzles Δx are measured at a plurality of points in the module for the module MA3 and the module MB3.

Then, in step S5, based on the measurement result of step S4, the corresponding module is moved by the same amount in the opposite direction for each bar so that the average value of the nozzles Δx becomes “0” in module units, and the module Δx is moved. adjust. Modules MA1, MB1, MA3 and MB3 are examples of "head modules other than the reference position".

That is, the module MA1 and the module MB1 are moved equally in opposite directions so that the average value of the nozzles Δx measured from a plurality of points in the module is 0 for the module MA1 and the module MB1, and the module MA1 and the module MA2 are moved in equal amounts. Adjust the module Δx between and adjust the module Δx between module MB1 and module MB2. Similarly, for module MA3 and module MB3, module MA3 and module MB3 are moved equally in opposite directions so that the average value of nozzles Δx measured from multiple points in the module becomes 0, and module MA2 and module MB3 Adjust the module Δx between the MA3 and the module Δx between the module MB2 and the module MB3. The reason for moving the same amount in the opposite direction is to minimize the absolute value of the movement amount of each module. Step S5 is an example of the “second adjustment step”.

Reference numeral 203 in FIG. 19 indicates a state after adjustment in step S5. The state of reference numeral 203 is that the module MA1 has moved to the left in FIG. 19, the module MB1 has moved to the right, the module MA3 has moved to the left, and the module MB3 has moved to the right, respectively, as compared with the state of reference numeral 202. It has become. By adjusting in step S5, the center positions of the modules are matched.

Next, in step S6 of FIG. 18, it is determined whether or not the module Δx of each bar is within the specified range. The specified range is an adjustment allowable range that is predetermined as an adjustable range in the X direction. If the determination result in step S6 is "Yes determination", the adjustment flow of FIG. 18 ends.

If the determination result in step S6 is "No determination" and the module Δx of each bar exceeds the specified range, the process proceeds to step S7.

In step S7, the module mounted on each bar is shifted in the direction in which the module Δx falls within the specified range. The maximum adjustment width in step S7 is within the permissible range of the nozzle Δx adjusted in step S5. After step S7, the adjustment flow of FIG. 18 ends.

Reference numeral 204 in FIG. 19 indicates a state after adjustment in step S7. In the state of reference numeral 204, the module MA1 is slightly shifted to the right, the module MB1 is slightly shifted to the left, the module MA3 is shifted to the right, and the module MB3 is slightly shifted to the left, respectively, as compared with the state of reference numeral 203. It has become a thing.

FIG. 20 is a chart showing an example of the transition of the adjustment value in each step (S2, S3, S5, S7) when the adjustment is performed in the adjustment sequence described with reference to FIGS. 18 and 19. In FIG. 20, module Δx1 (1-2) indicates module Δx between modules MA1 and MA2 in the first bar. Module Δx1 (2-3) indicates module Δx between modules MA2 and MA3 in the first bar. Module Δx2 (1-2) indicates module Δx between module MB1 and module MB2 in the second bar, and module Δx2 (2-3) is a module between module MB2 and module MB3 in the second bar. It shows Δx. Regarding the value of the module Δx, the position where the recording resolutions are aligned in the bar is set as the reference position “0”. The unit of numerical value is micrometer [μm].

The "module number" represents the module position according to the order of the plurality of modules constituting each bar. From the left of FIG. 19, module number 1, module number 2, and module number 3 are shown.

The nozzle Δx1 in FIG. 20 indicates the average value of the nozzles Δx obtained from a plurality of locations of the modules MA1 and MB1 of the module number 1. The nozzle Δx2 indicates the average value of the nozzles Δx obtained from a plurality of locations of the modules MA2 and MB2 of the module number 2. The nozzle Δx3 indicates the average value of the nozzles Δx obtained from a plurality of locations of the modules MA3 and MB3 of the module number 3.

“Step.2” indicates the state adjusted in step S2 of FIG. 18, that is, the state of reference numeral 201 in FIG. “Step.3” indicates the state adjusted in step S3 of FIG. 18, that is, the state of reference numeral 202 in FIG. “Step.3” is a state in which the module Δx between each module is set to “0”.

“Step.5” indicates the state adjusted in step S5 of FIG. 18, that is, the state of reference numeral 203 in FIG. “Step.5” is a state in which the nozzle Δx of each module is set to “0”. “Step.7” indicates the state adjusted in step S7 of FIG. 18, that is, the state of reference numeral 204 in FIG. “Step.7” of the example shown in FIG. 20 shows a state after the portion where the size of the module Δx exceeds “2” is corrected to “2”. “2” here is an example of the specified range. That is, in the case of this example, for the module Δx, the range from “-2” to “+2” is the adjustable range, and “-2” in the minus direction and “+2” in the plus direction are the adjustment limit values. ing.

<< Specific example of adjustment procedure 2 >>
In the specific example 1 described with reference to FIGS. 18 to 20, the adjustment process is decomposed into steps S1 to S7, but as shown in FIG. 21, the calculated values of the nozzle Δx and the module Δx are used for calculation. The final adjustment target value may be calculated by the process, and the adjustment may be completed at once according to the calculated adjustment target value.

FIG. 21 is a flowchart showing a specific example 2 of an adjustment procedure for adjusting the relative positional relationship between the multi-arranged inkjet headbars. FIG. 22 is an explanatory diagram schematically showing the adjustment process shown in the flowchart of FIG. 21.

In step S10 of FIG. 21, the module Δx between each module in each bar is measured.

Next, in step S11, the nozzles Δx are measured at a plurality of points for each module in the bar. The order of steps S10 and S11 can be exchanged.

Next, in step S12, the module Δx of the central module is adjusted between the bars so that the average value of the nozzles Δx measured at a plurality of points for the central module in the bar falls within the target range. Reference numeral 211 in FIG. 22 indicates a state after adjustment in step S12. That is, in step S12, as shown by reference numeral 211 in FIG. 22, by moving at least one of the central modules MA2 and MB2, the module Δx between the adjacent modules in the bar is adjusted.

Next, in step S13 of FIG. 21, the modules are moved so that the total sum of the modules Δx of each bar is “0” and the total sum of the nozzles Δx is “0”. Reference numeral 212 in FIG. 22 indicates a state after adjustment in step S13. The state of reference numeral 212 is that the module MA1 has moved to the left in FIG. 22, the module MB1 has moved to the right, the module MA3 has moved to the left, and the module MB3 has moved to the right, respectively, as compared with the state of reference numeral 211. It has become. By adjusting in step S13, the center positions of the modules are matched.

Next, in step S14 of FIG. 21, it is determined whether or not the module Δx of each bar is within the specified range. The specified range is an adjustment allowable range that is predetermined as an adjustable range in the X direction. If the determination result in step S14 is "Yes determination", the adjustment flow of FIG. 21 is terminated.

If the determination result in step S14 is "No determination", that is, if the module Δx of each bar exceeds the specified range, the process proceeds to step S15.

In step S15, the module mounted on each bar is shifted in the direction in which the module Δx falls within the specified range. The processes of steps S14 and S15 are the same as those of steps S6 and S7 of FIG.

After step S15, the adjustment flow of FIG. 21 ends.

Reference numeral 213 in FIG. 22 indicates a state after adjustment in step S15. In the state of reference numeral 213, the module MA1 is slightly shifted to the right in FIG. 22, the module MB1 is slightly shifted to the left, the module MA3 is shifted to the left, and the module MB3 is slightly shifted to the right as compared with the state of reference numeral 212. It has become a thing.

<< Specific example of adjustment procedure 3 >>
Next, an adjustment example when the number of modules in each bar is 5 modules will be described. The flowchart of the adjustment procedure in the specific example 3 follows, for example, FIG. FIG. 23 is an explanatory diagram schematically showing the adjustment process in the case of 5 modules. Further, FIG. 24 is a chart showing an example of transition of the adjustment value in the case of 5 modules.

Reference numeral 221 in FIG. 23 indicates the adjusted state of step S2. In step S2, the central module MA3, the module MB3, or both are moved to align the center positions of the module MA3 and the module MB3.

Reference numeral 222 in FIG. 23 indicates a state after adjustment in step S3. Reference numeral 223 in FIG. 23 indicates a state after adjustment in step S5. Reference numeral 224 in FIG. 23 indicates a state after adjustment in step S7.

In FIG. 24, the relative positions of the three central modules are set to the same values as in the example of FIG. 20 for the sake of understanding. In FIG. 24, the notation rules for symbols are the same as those in FIG. Module Δx1 (3-4) in FIG. 24 indicates module Δx between modules MA3 and MA4 in FIG. Module Δx1 (4-5) shows module Δx between modules MA4 and MA5 in FIG.

Module Δx2 (3-4) in FIG. 24 indicates module Δx between modules MB3 and MB4 in FIG. Module Δx2 (4-5) shows module Δx between modules MB4 and MB5 in FIG.

In the state of “Step.5” in FIG. 25, the total sum of the modules Δx is “0” and the total sum of the nozzles Δx is “0”.

FIG. 25 shows the transition of the adjustment value when the “Step.5” part of the chart shown in FIG. 24 is decomposed into the two-step procedure of “Step.5-1” and “Step.5-2”. It is a chart which shows.

“Step.5-1” indicates a state in which the nozzles Δx of the modules (module numbers 2 and 4) at both ends of the center of the five modules are set to “0”.

“Step.5-2” indicates a state in which the nozzles Δx of the modules (module numbers 1 and 5) at both ends of the bar are set to “0”.

The state of "Step.5" in FIG. 24 can be reached through the stepwise adjustment procedure of "Step.5-1" → "Step.5-2".

<< Other application example 1 >>
In the adjustment sequence illustrated with reference to FIGS. 18 to 25, an example in which adjustment is performed with reference to the central module has been described, but the reference module is not limited to the central module and can be appropriately selected. it can.

<< Other application example 2 >>
According to the head module position adjustment method of the present disclosure, since the deviation of the relative position is reset for each module, the adjustment can be performed in the same manner even when the number of modules increases. Further, in the adjustment sequence illustrated with reference to FIGS. 18 to 25, the nozzles Δx are adjusted so as to be “0”, but as described in FIGS. 6 to 8, the staggered arrangement is ideal dots. When aiming as an arrangement, the ideal positions of the nozzles Δx and the nozzles Δy are in a staggered arrangement. In this case, the target ideal position is read as "0".

Further, in the specific examples 1 to 3 described with reference to FIGS. 18 to 25, the modules between the bars are arranged at positions overlapping in the paper transport direction, but the module connecting positions that cause unevenness and streaks are located between the bars. The principle of the adjustment method is the same even if the configuration is shifted.

<< Other application example 3 >>
In the above-mentioned specific examples 1 to 3, the adjustment process has been decomposed and described, but in the actual adjustment work, the final adjustment target value is calculated based on the information of the module Δx and the nozzle Δx in the initial state. The adjustment work can be performed according to the calculated adjustment target value. For example, if the numerical information shown in "Step. 2" of FIG. 20 or FIG. 24 is given as the initial value, the adjustment value shown in "Step. 5" and / or "Step. 7" can be calculated. ..

<< Measurement method of nozzle Δx using concentration >>
Instead of the example of measuring the line or dot spacing described with reference to FIGS. 15 to 17, "density" can be used to adjust the position of the module. As shown in FIG. 26, the recording position recorded using the first bar and the recording position recorded using the second bar overlap in the paper transport direction and deviate in the X direction. Then, the way the lines are filled in the space is different, and the density changes.

Reference numeral 91 in FIG. 26 indicates a line pattern recorded by the first bar. Reference numeral 92 in FIG. 26 indicates a line pattern recorded by the second bar. When these line patterns 91 and 92 are recorded in the same area on the paper using both the first bar and the second bar, and the nozzle Δx is 0, as shown by reference numeral 93, of each line. The positions overlap. On the other hand, when the nozzles Δx are misaligned, the lines are recorded without the positions of the lines overlapping, as shown by reference numeral 94. Comparing the average density of the pattern of reference numeral 93 with the average density of the pattern of reference numeral 94, the density of reference numeral 93 is lower.

When the nozzle Δx is 0, the density can be minimized, and when the nozzle Δx has the line of the other line pattern in the center of the line spacing of one line pattern, the density can be maximized. It is possible to associate the measured value of concentration with the nozzle Δx.

<< Processing when some head modules are replaced >>
Inkjet heads that are configured by connecting multiple head modules can be replaced in units of head modules when a problem occurs in some of them. When the head module is replaced, the head module may be mounted at the same position as before the replacement, or the module Δx may be adjusted and mounted on both sides so that the modules Δx are even. Further, the nozzle Δx may be measured after mounting and finely adjusted so that the nozzle Δx is within the allowable range.

<< Other examples of inkjet recording devices >>
The present invention can be widely applied to a general inkjet recording apparatus including a plurality of line-type inkjet heads configured by connecting a plurality of head modules. Therefore, the type of the medium, the transport form, and the like are not particularly limited. For example, the paper transport mechanism is not limited to the belt transport system, and may have a drum transport system.

<< Configuration example of adjustment support device >>
FIG. 27 is a block diagram showing a configuration of an adjustment support device according to an embodiment of the present invention. The adjustment support device is configured as a device that automatically calculates an adjustment target value of each head module of each inkjet head bar mounted on the inkjet recording device and outputs the result.

The adjustment support device 300 can be realized by using one or a plurality of computers and a program. The adjustment support device 300 can be configured as a device separate from the inkjet recording device 1. Further, the calculation function of the adjustment support device 300 may be incorporated into the function of the control unit 100 of the inkjet recording device 1.

The adjustment support device 300 includes a signal processing device 310, a display unit 320, and an operation unit 322. The display unit 320 and the operation unit 322 may be the display unit 102 and the operation unit 101 described with reference to FIG.

The signal processing device 310 includes a data acquisition unit 312, a nozzle Δx measurement unit 313, a module Δx measurement unit 314, an adjustment target value calculation unit 315, a data storage unit 316, and an output unit 317.

The data acquisition unit 312 is an interface for acquiring the read data of the test chart from the image reading device 31. The data acquisition unit 312 may be a signal input terminal or a communication interface.

The nozzle Δx measuring unit 313 analyzes the recording result of a predetermined test chart for measuring the nozzle Δx, and measures the nozzle Δx for each module of each inkjet head bar. The nozzle Δx measuring unit 313 can calculate the average value of the nozzles Δx measured from a plurality of locations. The recording result of the test chart is acquired from the image reading device 31 as image data. The nozzle Δx measuring unit 313 is an example of the “information acquisition unit” and the “nozzle relative position information acquisition unit”.

The module Δx measurement unit 314 analyzes the recording result of a predetermined test chart for the module Δx measurement, and measures the module Δx between each module of each inkjet headbar. The module Δx measuring unit 314 measures the module Δx by using, for example, the method described in Japanese Patent Application Laid-Open No. 2014-83720, and acquires the information of the module Δx. The module Δx measurement unit 314 is an example of the “inter-module distance information acquisition unit”.

The adjustment target value calculation unit 315 calculates an adjustment target value indicating the movement direction and the movement amount of the head module based on the information of the module Δx and the nozzle Δx. The adjustment target value calculation unit 315 adjusts to indicate the movement direction and movement amount of the head module required to keep the representative value of the nozzle Δx calculated based on the nozzles Δx measured from a plurality of locations for each module within the target range. Calculate the target value. For example, as described in the flowchart of FIG. 21, the adjustment target value indicating the moving direction and the moving amount is calculated so that the sum of the modules Δx is “0” and the sum of the nozzles Δx is “0”. Calculation of the adjustment target value is an example of determining the movement direction and movement amount of the module.

The output unit 317 outputs the information of the adjustment target value calculated by the adjustment target value calculation unit 315 in a signal format corresponding to a predetermined output destination. In this embodiment, the output is output to the display unit 320.

The data storage unit 316 is a storage device that stores various data required for calculation. The data storage unit 316 may be a semiconductor storage device such as a memory, a magnetic storage device such as a hard disk device, or an appropriate combination thereof.

The functions of the nozzle Δx measurement unit 313, the module Δx measurement unit 314, and the adjustment target value calculation unit 315 may be realized by using, for example, a CPU (Central Processing Unit) 318.

The display unit 320 and the operation unit 322 function as a user interface. The display unit 320 is configured by using, for example, a liquid crystal display, an organic electro-luminescence (OEL) display, a display device such as a projector, or an appropriate combination thereof. The display unit 320 can display various setting information necessary for the processing of the signal processing device 310 and various information such as information indicating the processing result.

The operation unit 322 is configured by using, for example, an input device such as a keyboard, a mouse, a touch panel, or an operation button, a voice input device, or an appropriate combination thereof. The user can input various instructions and / or information using the operation unit 322. The signal processing device 310 can execute various processes according to the instruction and / or information input from the operation unit 322.

The user can perform the work of adjusting the position of each head module based on the information displayed on the display unit 320.

By using the adjustment support device 300, information on the adjustment target value required for the adjustment work of the head module can be easily obtained.

<Modification example 1>
In the embodiment shown in FIG. 27, the information on the nozzle Δx and the module Δx is automatically acquired based on the read data of the test chart obtained from the image reading device 31, but the information on the nozzle Δx and the module Δx is obtained. , It may be configured to be generated by another device and to acquire only the information.

<Modification 2>
Further, the calculation result of the adjustment target value is not limited to the configuration to be output to the display unit 102. For example, the calculation result of the adjustment target value may be recorded on a sheet of paper and output.

<Modification example 3>
Further, in the case of an inkjet device having a function of automatically adjusting the position of each head module, control for automatically adjusting the module position may be performed based on the calculated adjustment target value. For example, for an inkjet head bar whose position can be adjusted by an actuator, the drive of the actuator may be controlled based on an adjustment target value to automatically adjust the position of each head module.

<< Example of arrangement configuration of inkjet head bar >>
Although the examples of the two inkjet headbars 21A and 21B have been described so far, it is possible to adopt a configuration in which the bars are multiplexed for each color according to the type of ink color used. FIG. 28 is a perspective view schematically showing an example of an arrangement form of an inkjet head bar in an inkjet recording apparatus using four color inks of cyan (C), magenta (M), yellow (Y), and black (K). It is a figure.

For example, in the case of an inkjet recording device using four colors of CMYK ink, as shown in FIG. 28, each color is provided with two inkjet headbars 21K1, 21K2, 21C1, 21C2, 21M1, 21M2, 21Y1 and 21Y2, respectively. ..

The number of ink colors (number of color types) and the arrangement order of the inkjet headbars are not particularly limited.

In a configuration in which a plurality of inkjet head bars are arranged in the paper transport direction for each color of a plurality of colors, the head module adjustment method described above is applied to apply the nozzle Δx over the entire recording width of the bars of each color to a single inkjet. It fits within one pixel of the recording resolution composed of the head bar. More preferably, the nozzle Δx is contained within 0.5 pixels of the recording resolution composed of a single inkjet head bar over the entire recording width of the bars of each color.

<< Example of head module form >>
In the above-described embodiment, the form of the inkjet head bar in which a plurality of parallelogram head modules are arranged side by side in the X direction in a plan view as shown in the figure has been described, but the configuration of the inkjet head bar is an example of this. Not limited to.

FIG. 29 is a plan view showing another embodiment of the head module. For example, as shown by reference numeral 401 in FIG. 29, an inkjet head bar in which the long sides of the parallelogram head module are arranged in an inclined posture with respect to the X direction may be used.

As shown by reference numeral 402 in FIG. 29, an inkjet head bar in which rectangular head modules in a plan view are arranged so as to partially overlap each other can be used.

Further, an inkjet head bar configured by connecting trapezoidal head modules as shown by reference numeral 403 in FIG. 20 can be used.

<< Advantages of Embodiments of the Present Invention >>
According to the above-described embodiment of the present invention, there are the following advantages.

(1) Since the nozzle Δx and / or the nozzle Δy are measured at a plurality of points in the module, the optimum adjustment target value can be obtained in consideration of the local change in the discharge characteristic inside the module.

(2) Since the position of each module is adjusted so that the nozzles Δx and / or the nozzles Δy are uniform over the recording area between bars of the same color, pixel replacement does not occur and a good image can be recorded. it can.

(3) Image recording can be speeded up by using bars of the same color, and productivity can be improved.

<< Hardware configuration of each processing unit and control unit >>
Various types such as the data acquisition unit 312 of the control unit 100 described with reference to FIG. 5 and the adjustment support device 300 described with reference to FIG. 27, the nozzle Δx measurement unit 313, the module Δx measurement unit 314, the adjustment target value calculation unit 315, and the output unit 317. The hardware structure of the processing unit that executes the processing of is the following various processors.

Various processors include CPUs (Central Processing Units) and FPGAs (Field Programmable Gate Arrays), which are general-purpose processors that execute programs and function as various processing units. A programmable logic device (PLD), a dedicated electric circuit which is a processor having a circuit configuration specially designed for executing a specific process such as an ASIC (Application Specific Integrated Circuit), and the like are included.

One processing unit may be composed of one of these various processors, or may be composed of two or more processors of the same type or different types. For example, one processing unit may be composed of a plurality of FPGAs or a combination of a CPU and an FPGA. Further, a plurality of processing units may be configured by one processor. As an example of configuring a plurality of processing units with one processor, first, one processor is configured by a combination of one or more CPUs and software, as represented by a computer such as a client or a server. There is a form in which a processor functions as a plurality of processing units. Secondly, as typified by System On Chip (SoC), there is a form in which a processor that realizes the functions of the entire system including a plurality of processing units with one IC (Integrated Circuit) chip is used. is there. As described above, the various processing units are configured by using one or more of the above-mentioned various processors as a hardware-like structure.

Further, the hardware structure of these various processors is, more specifically, an electric circuit (circuitry) in which circuit elements such as semiconductor elements are combined.

<< About the program to realize the adjustment support function in the computer >>
A program for realizing the function of the adjustment support device described in the above-described embodiment on a computer is recorded on an optical disk, a magnetic disk, or other computer-readable medium (a tangible non-temporary information storage medium), and the program is performed through the information storage medium. It is possible to provide. Instead of storing and providing the program in such an information storage medium, it is also possible to provide the program signal as a download service by using a communication network such as the Internet.

It is also possible to provide the function of the adjustment support device according to the embodiment as an application server and provide a service that provides a processing function through a communication network.

Further, by incorporating this program into the computer, each function of the image processing device can be realized in the computer, and the image processing function described in the above-described embodiment can be realized.

Further, a mode in which a part or all of the program for realizing the print control including the image processing function described in the present embodiment is incorporated into a higher-level control device such as a host computer, and a central processing unit (CPU) on the inkjet recording device side. ) Can also be applied as an operation program.

<< About the printed matter manufacturing method using an inkjet recording device >>
A printed matter can be produced by recording an image on paper using an inkjet recording apparatus in which the position of the head module is adjusted by using the head module position adjusting method of the present disclosure. According to this printed matter manufacturing method, it is possible to obtain a printed matter on which a high-quality image is recorded.

<< Combination of Embodiments and Modifications >>
The items described in the configuration and the modification described in the above-described embodiment can be used in combination as appropriate, and some items can be replaced.

<< About paper >>
"Paper" is a medium used for recording images. The term paper includes the concept of what is called by various terms such as a recording medium, a recording paper, a printing paper, a printing medium, a printing medium, a printed medium, an image forming medium, an image forming medium, an image receiving medium, and a ejection medium. The material and shape of the paper are not particularly limited, and various sheet bodies can be used regardless of the seal paper, resin sheet, film, cloth, non-woven fabric, and other materials and shapes. The paper is not limited to a sheet-fed medium, and may be a continuous medium such as continuous paper. Further, the sheet-fed paper is not limited to cut paper prepared in advance to a specified size, and may be obtained by cutting from a continuous medium to a specified size at any time.

The term "inkjet recording device" refers to the concept of terms such as a printing machine, a printer, a printing device, a printing device, an image forming device, an image recording device, an image output device, or a drawing device that records an image by an inkjet method. Including.

"Image" shall be interpreted in a broad sense, and includes color images, black-and-white images, single-color images, gradation images, uniform density (solid) images, and the like. The "image" is not limited to a photographic image, and includes a pattern, a character, a symbol, a line drawing, a mosaic pattern, a color-coded pattern, a line pattern, a dot pattern, various other patterns, a test chart, or an appropriate combination thereof. Used as a comprehensive term.

"Recording" of an image includes the concepts of terms such as image formation, printing, printing, drawing, and printing.

Further, the "image" is not limited to the one formed by the ink containing the coloring material, and the treatment liquid applied to the paper before the ink is applied and / or other functions such as varnish applied to the paper after the ink is applied. It may be an image formed by a sex material.

The term "orthogonal" or "vertical" as used herein refers to the case where the intersections are made at an angle of less than 90 ° or an angle of more than 90 ° and intersect at an angle of substantially 90 °. A mode in which the same action and effect as the above is generated is included. The term "parallel" as used herein includes aspects that are strictly non-parallel and can be regarded as substantially parallel to obtain substantially the same effects as in the case of parallel.

The term "uniform" as used herein includes aspects that are not strictly uniform and can be regarded as substantially "uniform" in which the same effects as those in the case of uniform are obtained.

《Others》
In the embodiment of the present invention described above, the constituent requirements can be appropriately changed, added, or deleted without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by a person having ordinary knowledge in an equivalent related field within the technical idea of the present invention. The technical scope of the present invention is not limited to the scope described in the above embodiments. The configurations and the like in each embodiment can be appropriately combined between the respective embodiments without departing from the spirit of the present invention.

1 Inkjet recording device 10 Paper transport unit 11 Belt 12 Drive roller 13 Driven roller 14 Belt drive motor 16 Suction unit 20 Inkjet recording unit 21A Inkjet head bar 21B Inkjet head bar 21C1 Inkjet head bar 21C2 Inkjet head bar 21K1 Inkjet head bar 21K2 Inkjet head Bar 21M1 Inkjet head bar 21M2 Inkjet head bar 21Y1 Inkjet head bar 21Y2 Inkjet head bar 22A, 22B Head module 23A Base frame 24A Nozzle surface 25A Nozzle 25B Nozzle 30 Image reading unit 31 Image reading device 40 Feeding unit 50 Paper ejection unit 61A No. 1 bar 61B 2nd bar 62A Dot 62B Dot 70, 71, 72, 73 Line pattern 81, 82, 83 Line pattern 91, 92 Line pattern 100 Control unit 101 Operation unit 102 Display unit 103 Communication unit 104 Storage unit 300 Adjustment support device 310 Signal processing device 312 Data acquisition unit 313 Nozzle Δx measurement unit 314 Module Δx measurement unit 315 Adjustment target value calculation unit 316 Data storage unit 317 Output unit 320 Display unit 322 Operation unit L1 line L2 line LP0 Line pattern MA1 module MA2 module MA3 module MA4 module MA5 module MB1 module MB2 module MB3 module MB4 module MB5 module P Paper TC test chart S1 to S7 Steps showing the adjustment procedure S11 to S15 Steps showing the adjustment procedure

Claims (28)

An inkjet headbar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet headbars as line heads for recording the same color are provided in the paper transport direction. A head module position adjusting method for adjusting the position of the head module in an arranged single-pass inkjet recording device.
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. Steps to measure at multiple points in
By adjusting the position of the head module for each inkjet head bar based on the representative value of the nozzle relative position calculated based on the nozzle relative position measured from the plurality of locations, the nozzle relative position can be determined. The step of keeping the representative value within the target range and
Head module position adjustment method including. The head module position adjusting method according to claim 1, wherein the representative value of the nozzle relative position for each of the plurality of head modules constituting the inkjet head bar is set within the target range. The head module position adjusting method according to claim 1 or 2, wherein the representative value is an average value. The head module position adjusting method according to any one of claims 1 to 3, wherein the target value in the target range is 0. The head module position adjusting method according to any one of claims 1 to 4, wherein the target range is within one pixel of a recording resolution composed of the single inkjet head bar. The head module position adjusting method according to any one of claims 1 to 5, wherein the target range is within 0.5 pixels of a recording resolution composed of the single inkjet head bar. The inkjet recording device adjusts the position of dots recorded by the nozzle for each head module in at least one of the paper transport direction and the paper width direction orthogonal to the paper transport direction. It has at least one mechanism and
Any one of claims 1 to 6 for determining the moving direction and the moving amount by the position adjusting mechanism in order to keep the representative value of the nozzle relative position within the target range based on the representative value of the nozzle relative position. The head module position adjustment method described in item 1. When the paper transport direction is the Y direction and the paper width direction orthogonal to the Y direction is the X direction,
The nozzle relative position includes an X-direction nozzle relative position representing a deviation of the relative position in the X direction.
Claims 1 to 7 keep the representative value of the X-direction nozzle relative position within the target range by adjusting the X-direction position of the head module based on the representative value of the X-direction nozzle relative position. The head module position adjustment method according to any one of the above. When the paper transport direction is the Y direction and the paper width direction orthogonal to the Y direction is the X direction,
The nozzle relative position includes a Y-direction nozzle relative position representing a deviation of the Y-direction relative position.
Claims 1 to 7 keep the representative value of the Y-direction nozzle relative position within the target range by adjusting the Y-direction position of the head module based on the representative value of the Y-direction nozzle relative position. The head module position adjustment method according to any one of the above. A first of the plurality of head modules constituting the inkjet head bar, the head module at a reference position is adjusted so that the representative value of the nozzle relative position is within the target range. Adjustment steps and
With respect to the head module other than the reference position, the second adjustment step of making the adjustment so that the representative value of the nozzle relative position is within the target range, and
Including
In the second adjustment step, the representative values of the nozzle relative positions are obtained by moving the head modules of the paper by equal amounts in opposite directions between the head modules that record the overlapping areas of the paper. The head module position adjusting method according to any one of claims 1 to 9, which is within the target range. An inkjet headbar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet headbars as line heads for recording the same color are provided in the paper transport direction. A head module position adjusting method for adjusting the position of the head module in an arranged single-pass inkjet recording device.
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. The step of acquiring the information on the relative position of the nozzle obtained by measuring at a plurality of points in the
The movement direction and the movement amount of the head module for each inkjet head bar are adjusted based on the representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from the plurality of locations. The sum of the representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from a plurality of locations is within the target range, and the distance between the adjacent head modules for each inkjet head bar is the distance between the modules. The step of adjusting the total deviation from the reference distance to 0, and
Head module position adjustment method including. The head module position adjusting method according to claim 11, wherein the representative value is an average value. The head module position adjusting method according to claim 11 or 12, wherein the target value in the target range is 0. For each inkjet head bar, the head modules are moved within a specified allowable range in a direction in which the recording resolution of the inkjet head bar alone is uniform, and the distance between the modules of the adjacent head modules is adjusted. The head module position adjusting method according to any one of claims 1 to 13, which comprises the step of performing. The head module according to any one of claims 1 to 14, wherein a line pattern is recorded using a plurality of the inkjet head bars, and the line spacing of the line pattern is measured to measure the relative position of the nozzles. Position adjustment method. The head module according to any one of claims 1 to 14, wherein a dot group is recorded using the plurality of inkjet headbars and the dot spacing of the dot group is measured to measure the relative position of the nozzle. Position adjustment method. Any of claims 1 to 14 for measuring the relative position of the nozzle by recording a line pattern in the same area of the paper using the plurality of inkjet headbars and measuring the density of the recorded pattern. The head module position adjustment method described in item 1. The head module position adjusting method according to claim 17, wherein the head module is adjusted to a position where the concentration is the maximum or the minimum. In the inkjet recording device, a plurality of the inkjet headbars are arranged in the paper transport direction for each of the plurality of colors.
The head module position adjustment according to any one of claims 1 to 18, wherein the nozzle relative position is kept within one pixel of the recording resolution composed of the single inkjet head bar over the entire recording width of each color. Method. In the inkjet recording device, a plurality of the inkjet headbars are arranged in the paper transport direction for each of the plurality of colors.
The head module according to any one of claims 1 to 18, wherein the nozzle relative position is kept within 0.5 pixels of the recording resolution composed of the single inkjet head bar over the entire recording width of each color. Position adjustment method. When a defective nozzle occurs in any one of the plurality of inkjet headbars, the inkjet recording device uses the nozzles of the other inkjet headbars to make corrections to supplement the recording of the defective nozzles. The head module position adjusting method according to any one of claims 1 to 20. It is a single-pass type inkjet recording device that uses an inkjet head bar configured by connecting a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged.
A plurality of the inkjet head bars as line heads for recording the same color are arranged in the paper transport direction.
The nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction, is within the target range over the recording area. Inkjet recording device that fits. A control unit for controlling ejection from each nozzle of the inkjet head bar is further provided.
When a defective nozzle occurs in any one of the plurality of inkjet headbars, the control unit uses the nozzles of the other inkjet headbars to make corrections to supplement the recording of the defective nozzles. Item 22. The inkjet recording apparatus according to Item 22. An inkjet head bar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet head bars as line heads for recording the same color are provided in the paper transport direction. It is an adjustment support device that supports the adjustment of the positional relationship of the head module in the arranged single-pass type inkjet recording device.
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. An information acquisition unit that acquires information on the relative position of the nozzle obtained by measuring at a plurality of locations in the
The moving direction of the head module for each inkjet head bar required to keep the representative value of the representative value of the nozzle relative position calculated based on the nozzle relative position measured from the plurality of locations within the target range, and the movement direction of the head module for each inkjet head bar. The adjustment target value calculation unit that calculates the adjustment target value indicating the amount of movement, and the adjustment target value calculation unit
An output unit that outputs the adjustment target value calculated by the adjustment target value calculation unit, and an output unit that outputs the adjustment target value.
Adjustment support device equipped with. An inkjet head bar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet head bars as line heads for recording the same color are provided in the paper transport direction. It is an adjustment support device that supports the adjustment of the positional relationship of the head module in the arranged single-pass type inkjet recording device.
An inter-module distance information acquisition unit that acquires information on deviations from a reference distance of inter-module distances between adjacent head modules for each inkjet head bar.
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. A nozzle relative position information acquisition unit that acquires information on the nozzle relative position obtained by measuring at a plurality of locations in the
The sum of the representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from the plurality of locations is within the target range, and the distance between the modules of the adjacent head modules for each inkjet head bar is within the target range. An adjustment target value calculation unit that calculates an adjustment target value indicating the movement direction and movement amount of the head module for each inkjet head bar required to make the total deviation from the reference distance of
An output unit that outputs the adjustment target value calculated by the adjustment target value calculation unit, and an output unit that outputs the adjustment target value.
Adjustment support device equipped with. An inkjet head bar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet head bars as line heads for recording the same color are provided in the paper transport direction. It is a program for realizing a function in a computer to support the adjustment of the positional relationship of the head module in the arranged single-pass type inkjet recording device.
On the computer
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. The function to acquire the information of the relative position of the nozzle obtained by measuring at a plurality of points in the
Indicates the moving direction and moving amount of the head module for each inkjet head bar required to keep the representative value of the nozzle relative position calculated based on the nozzle relative position measured from the plurality of locations within the target range. A function to calculate the adjustment target value and
A program that realizes the function of outputting the calculated adjustment target value. An inkjet head bar composed of a plurality of head modules having a nozzle surface in which a plurality of nozzles are arranged is used, and a plurality of the inkjet head bars as line heads for recording the same color are provided in the paper transport direction. A program that causes a computer to function as an adjustment support device that supports adjustment of the positional relationship of the head module in an arranged single-pass inkjet recording device.
On the computer
A function for acquiring information on the deviation of the distance between modules of adjacent head modules for each inkjet head bar from a reference distance, and
The range of the head module is the nozzle relative position, which represents the relative positional deviation between the dots recorded by the corresponding nozzles of the head modules, which records the overlapping area of the paper transported in the paper transport direction. The function to acquire the information of the relative position of the nozzle obtained by measuring at a plurality of points in the
The sum of the representative values of the nozzle relative positions calculated based on the nozzle relative positions measured from the plurality of locations is within the target range, and the distance between the modules of the adjacent head modules for each inkjet head bar is within the target range. A function to calculate an adjustment target value indicating the movement direction and movement amount of the head module for each inkjet head bar required to make the total deviation from the reference distance of
A function to output the calculated adjustment target value and
A program that realizes. A printed matter is produced by recording an image on the paper using the inkjet recording apparatus in which the position of the head module is adjusted by using the head module position adjusting method according to any one of claims 1 to 21. Printed matter manufacturing method.

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