The present application is based on, and claims priority from JP Application Serial Number 2019-218555, filed Dec. 3, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.
Embodiments of the present disclosure relate to a method for manufacturing a printing apparatus, and a printing apparatus.
A printing apparatus capable of improving the quality of an image by adjusting a variable adjustment amount is known in the art. For example, a technique of generating a test pattern is disclosed in JP-A-2006-014332.
To obtain an ideal adjustment result in a printing apparatus, in general, an adjustment pattern is printed with different values of the amount of adjustment, and an ideal adjustment result is determined based on the adjustment pattern. However, if the adjustment pattern is printed while varying the amount of adjustment within the maximum variable range of the amount of adjustment in order to determine an ideal adjustment result, the amount of printing the adjustment pattern will be inevitably large.
An advantage of some aspects of the present disclosure is to provide a technique for efficiently printing an adjustment pattern in order to obtain an ideal adjustment result. This makes it possible to make an ideal adjustment with a smaller amount of printing than in the art, thereby making it possible to manufacture a printing apparatus adjusted ideally.
Provided by one aspect of the present disclosure is a method for manufacturing a printing apparatus configured to perform printing while varying an amount of adjustment of a target of adjustment, comprising: printing a first adjustment pattern on a printing medium; reading the printed first adjustment pattern to acquire a first adjustment amount; printing a part of a second adjustment pattern on the printing medium, the printed part of the second adjustment pattern corresponding to only a part of the amount of adjustment according to the first adjustment pattern; reading the printed part of the second adjustment pattern to acquire a second adjustment amount; setting a first parameter that is a result of adjusting the target of adjustment by using the first adjustment amount; and setting a second parameter that is a result of adjusting the target of adjustment by using the second adjustment amount.
If the first adjustment pattern is printed while varying the amount of adjustment, the printing will be performed with differences in print quality, differing from amount to amount of adjustment. Therefore, it is possible to determine the first adjustment amount that is suitable based on the print quality of the first adjustment pattern. Once the first adjustment amount that is suitable has been determined, it is possible to estimate the amount of adjustment with which the quality of printing will be good and the amount of adjustment with which the quality of printing will not be good in the second adjustment pattern that is to be printed on the premise that an adjustment based on the first adjustment amount has been done. Therefore, by excluding the amount of adjustment with which the quality of printing will not be good and by printing a part of a second adjustment pattern corresponding to only a part of the amount of adjustment, it is possible to make the amount of printing the second adjustment pattern smaller, as compared with a case where printing is performed while adjusting the amount of adjustment for the entirety of the second adjustment pattern. Therefore, it is possible to perform adjustment pattern printing efficiently. The printed adjustment pattern may be read by a sensor to acquire the amount of adjustment. The printed adjustment pattern may be read by a human who makes an input via a keyboard, thereby acquiring the amount of adjustment.
In setting the first parameter, the first parameter may be stored in a first area of a nonvolatile memory, and, in setting the second parameter, the second parameter may be stored in a second area different from the first area of the nonvolatile memory. This configuration enables the printing apparatus to operate according to different parameters set using the amount of adjustment determined based on different adjustment patterns.
The first parameter may be a parameter that is used when printing with first print quality is performed and is not used when printing with second print quality is performed, and the second parameter may be a parameter that is used when printing with the second print quality is performed and is not used when printing with the first print quality is performed. This configuration makes it possible to provide a printing apparatus that performs printing with parameters for predetermined levels of print quality.
A range of the part of the amount of adjustment according to the first adjustment pattern may be relatively narrow when a minimum value of misalignment occurring in the first adjustment pattern is relatively small, as compared with when the minimum value is relatively large. This configuration makes it possible to vary the amount of printing the second adjustment pattern depending on the amount of adjustment acquired using the first adjustment pattern.
The following configuration may be adopted: A printing apparatus configured to perform printing while varying an amount of adjustment of a target of adjustment, executing: printing a first adjustment pattern on a printing medium; reading the printed first adjustment pattern to acquire a first adjustment amount; printing a part of a second adjustment pattern on the printing medium, the printed part of the second adjustment pattern corresponding to only a part of the amount of adjustment according to the first adjustment pattern; reading the printed part of the second adjustment pattern to acquire a second adjustment amount; setting a first parameter that is a result of adjusting the target of adjustment by using the first adjustment amount; setting a second parameter that is a result of adjusting the target of adjustment by using the second adjustment amount; and performing printing using the set parameters. That is, a printing apparatus capable of printing an adjustment pattern efficiently may be provided.
Exemplary embodiments of the present disclosure will now be explained in the following order.
(1) First embodiment
(2) Printing an adjustment pattern
(3) Adjustment processing
(4) Other embodiments
When the print control program is run, the controller 20 is able to control a printing unit 41 and a transportation mechanism 60, etc. to print an image on a printing medium. The adjustment program is a program for adjusting variable factors in the printing apparatus 10 in order to prevent a decrease in print quality due to an error occurring in the printing apparatus 10. When the adjustment program is run, the controller 20 is able to control the printing unit 41 and the transportation mechanism 60, etc. to print an adjustment pattern on a printing medium. The controller 20 is able to control a sensor unit 42 and the transportation mechanism 60, etc. to read the printing medium.
The printing apparatus 10 according to the present embodiment is an ink-jet printer. The printing apparatus 10 includes a carriage 40, a storage medium interface 50, and the transportation mechanism 60. A portable storage medium 50a can be attached to the storage medium interface 50. The controller 20 is able to acquire various kinds of data including image data from the attached storage medium 50a. Needless to mention, the source from which the image data, etc. is acquired is not limited to the portable storage medium 50a. The image data, etc. may be acquired from a computer connected via wired or wireless communication, etc. Various kinds of configuration can be adopted.
The transportation mechanism 60 is a device that transports a printing medium in a predetermined direction. The controller 20 is able to control the transportation mechanism 60 to transport a printing medium in a predetermined procedure. The printing unit 41 and the sensor unit 42 are mounted on the carriage 40. The controller 20 is able to cause the carriage 40 to reciprocate in a predetermined direction. In the printing apparatus 10, the carriage 40 is designed to move in the predetermined direction while being kept at a predetermined distance from a platen.
The printing unit 41 includes a print head and ink tanks. The print head ejects ink of four types of color, which are CMYK (C: cyan, M: magenta, Y: yellow, K: black). The ink tanks are attached to the print head and contain the ink of CMYK respectively. Needless to mention, these ink colors, and the number of the colors, are nothing more than an example. Ink of other types of color and other number of colors may be used instead. The print head has a plurality of ejection nozzles arranged in a direction orthogonal to the direction of movement of the carriage 40. The controller 20 is able to control the amount of ink ejected from each ejection nozzle, the timing of ejection, etc.
Therefore, it is possible to print an image on a printing medium by ejecting ink of the colors from the ejection nozzles in the process of moving the carriage 40 in the predetermined direction. It is possible to print an image at a targeted position in a printable area on a printing medium by repeating the transportation of the printing medium by the transportation mechanism 60, the movement of the carriage 40, and the ejection of ink from the print head. In the present embodiment, the direction in which a printing medium is transported is referred to as sub-scan direction, and the direction in which the carriage 40 moves is referred to as main-scan direction.
The sensor unit 42 has a function of reading a printing medium on the platen. In the present embodiment, on the carriage 40, the sensor unit 42 is provided next to the print head of the printing unit 41 in the main-scan direction. Therefore, the controller 20 is able to move the sensor unit 42 in the main-scan direction by moving the carriage 40. In the present embodiment, because of the movement of the sensor unit 42, the entirety of the printable area on the printing medium in the main-scan direction can be captured within the field of vision. Accordingly, the printed image can be read no matter where in the main-scan direction it is printed.
In the present embodiment, the result of reading by the sensor unit 42 can be used for keeping or enhancing print quality. The printing apparatus 10 according to the present embodiment will be able to perform printing with predetermined expected quality if components such as the carriage 40 and the transportation mechanism 60, etc. have sizes as designed, are assembled as designed, and operate as designed. However, a decrease in print quality could happen due to a possible error in at least a part of these factors. By making adjustments for various kinds of target of adjustment corresponding to the error factors, the printing apparatus 10 according to the present embodiment is able to be brought into a finished-product state, in which it is possible to perform printing with predetermined expected quality, from an unfinished state, in which the quality of printing is low due to the error.
Specifically, for example, in the printing apparatus 10, the carriage 40 is designed to move in the main-scan direction while keeping a distance between the carriage 40 and a printing medium (i.e., platen gap) at a predetermined value. However, the actual platen gap could be different from the predetermined value, for example, due to a possible deviation in position and/or shape of the platen from the design or due to a possible deviation in position and/or moving direction of the carriage 40 from the design.
In
Each of the traveling trajectory indicated by the dot-and-dash line and the traveling trajectory indicated by the double-dotted dashed line is an example of a case where the platen gap and the moving speed in the printing apparatus 10 are as designed and thus where printing is performed with predetermined expected quality with the recording of the ink at the print position pp. If they are as designed, the ink droplet ejected toward the print position pp lands at the print position pp regardless of whether the carriage 40 moves in the x direction or in the direction that is the opposite of the x direction. However, if any component of the printing apparatus 10 contains an error with a deviation from the design, an error could occur in the position where the ink is recorded.
In
The target of adjustment in the present embodiment is a factor that could change the result of printing by selecting the amount of adjustment. Examples of such factors are: the timing of ejecting ink, the speed of moving the print head, the amount of ink ejected, the waveform and magnitude of a voltage for ejecting ink, the amount of feeding a sheet. In the present embodiment, one of these factors is taken as the target of adjustment, and an ideal adjustment amount is determined by printing an adjustment pattern that is constituted of a plurality of patterns whose amount of adjustment of the target of adjustment is varied. In the following description, when it is intended to distinguish a part of an adjustment pattern from a whole of the adjustment pattern, each individual part printed with the same amount of adjustment in patterned arrangement is simply referred to as “pattern”, and the entire series of patterned arrangement formed by the plurality of patterns is referred to as “adjustment pattern”.
The adjustment pattern according to the present embodiment includes bars printed while keeping the amount of adjustment fixed and bars printed while varying the amount of adjustment, and is configured such that an ideal adjustment amount can be determined by examining the degree of overlapping of the former with the latter. The shape of the pattern is not limited to this example. It suffices to design the pattern suitably for the target of adjustment.
Specifically, the adjustment pattern illustrated in
In the adjustment pattern illustrated in
In the adjustment pattern illustrated in
For example, in the example shown at the middle row in
The adjustment pattern illustrated at the bottom row in
For example, in the example illustrated in
The amount of adjustment is varied at a change pitch determined in advance within a range determined in advance when the carriage 40 moves in the direction that is the opposite of the x direction. Each of the nine patterns printed by moving the carriage 40 in the direction that is the opposite of the x direction is associated with the amount of adjustment applied when the pattern is printed. By finding the pattern that has the highest lightness among those in the adjustment pattern, therefore, it is possible to determine the amount of adjustment corresponding to the found pattern as an ideal adjustment amount.
The adjustment pattern explained above is used for making an adjustment for the mismatch in the timing of ejecting ink when the carriage 40 reciprocates. Needless to mention, however, various kinds of other adjustment pattern may be used. Anyway, in the present embodiment, it is possible to determine an ideal adjustment amount by utilizing the overlapping of patterns printed with the amount of adjustment that is not different from setting and patterns printed while making the amount of adjustment different from the setting.
For the purpose of determining the above-described adjustment amount and making settings automatically, the printing apparatus 10 according to the present embodiment is equipped with the sensor unit 42.
As illustrated in
The LED 42b is a light source for lighting the area of detection by the lightness sensor 42a. In
The controller 20 detects the lightness of each of the patterns that constitute the adjustment pattern (in the example illustrated in
The above-described adjustment using the adjustment pattern is made for a plurality of factors. That is, in the printing apparatus 10, a parameter indicating the amount of adjustment for each of a plurality of targets of adjustment is determined and set based on the adjustment pattern. Moreover, even when the target of adjustment is the same, printing could be performed using a different amount of adjustment for a different level of print quality. For example, mode selection is available also in a scheme of performing printing while reciprocating the carriage 40, such as selecting one of a mode for performing printing with first print quality that is relatively high (“quality-first mode”) and a mode for performing printing with second print quality that is relatively low but faster in print speed (“speed-first mode”). In the printing apparatus 10, for each of these modes, a parameter indicating the amount of adjustment for each of a plurality of targets of adjustment is determined and set based on the adjustment pattern.
As explained above, in the present embodiment, based on adjustment patterns for modes corresponding to different levels of print quality, adjustments for these levels of print quality are made. In such adjustments, a later adjustment pattern is printed in a state in which the amount of adjustment for an earlier adjustment has already been determined by using an earlier adjustment pattern. On the premise that the adjustment procedure using the earlier adjustment pattern has already been done, it is possible to narrow down the range of printing (the number of patterns to be printed) of the later adjustment pattern.
For example, suppose that the amount of adjustment for the first print quality and the amount of adjustment for the second print quality are acquired using adjustment patterns that are similar to the adjustment pattern illustrated at the bottom row in
In addition, in this example, as shown at the bottom row in
In this instance, next, the amount of adjustment for the second print quality is determined using the second adjustment pattern. The amount of adjustment for the second print quality has the same tendency as that of the amount of adjustment for the first print quality. That is, since the carriage 40 reciprocates both when printing with the first print quality is performed and when printing with the second print quality is performed, the cause of an error is common to these two. For example, if there is an error of a decreasing platen gap as shown in
Since the amount of adjustment for the first print quality has already been determined using the first adjustment pattern, therefore, it suffices to perform pattern printing with the amount of adjustment having the same tendency for the second print quality. It is unnecessary to perform pattern printing with the amount of adjustment having a different tendency. For example, in the example illustrated in
Considering that the amount of adjustment for the first print quality has already been determined in the example illustrated in
Specifically, suppose that the first adjustment pattern illustrated in
The adjustment pattern described above has been determined in advance for each target of adjustment such that the difference in the amount of adjustment will appear as the difference in the result of printing, varying from pattern to pattern. Then, adjustment pattern data 30a representing an adjustment pattern for each target of adjustment has been defined in advance and stored in the nonvolatile memory 30. In the adjustment pattern data 30a, an amount of adjustment is associated with each of the plurality of patterns Pt constituting the adjustment pattern. For example, in the example illustrated in
In the present embodiment, based on the amount of adjustment acquired using the earlier adjustment pattern, the controller 20 determines the amount of printing the later adjustment pattern. Therefore, the controller 20 determines the target of adjustment in an order determined in advance or in an order instructed by the user, and commands that the adjustment pattern corresponding to the determined target of adjustment should be printed. That is, the controller 20 looks up the nonvolatile memory 30 to acquire the adjustment pattern data 30a corresponding to the target of adjustment.
When adjustments are made respectively for different levels of print quality of the same kind of target of adjustment, adjustment patterns that are to be used for the adjustments respectively have been determined in advance. When a plurality of adjustment patterns is printed for the same kind of target of adjustment, the adjustment pattern printer earlier is the first adjustment pattern, and the adjustment pattern printer later is the second adjustment pattern. The number of adjustment patterns printed for the same kind of target of adjustment may be three or more. However, the number of adjustment patterns is assumed to be two in this example.
In this example, the controller 20 acquires the adjustment pattern data 30a representing the first adjustment pattern. Then, the controller 20 controls the carriage 40 and the transportation mechanism 60 to print the first adjustment pattern based on the acquired data. That is, the controller 20 commands that the first adjustment pattern should be printed by printing the patterns in a state in which different values of the amount of adjustment represented by the adjustment pattern data 30a are reflected.
After printing the first adjustment pattern, the controller 20 controls the transportation mechanism 60 to move the printing medium to a position where the sensor unit 42 is able to read the portion at which the first adjustment pattern has been printed. Then, the controller 20 causes the sensor unit 42 to read each of the patterns that constitute the first adjustment pattern while controlling the carriage 40 so as to cause the carriage 40 to move in the main-scan direction.
After reading each of the patterns Pt that constitute the first adjustment pattern, the controller 20 acquires the lightness of each pattern. Then, based on the adjustment pattern data 30a, the controller 20 acquires the amount of adjustment associated with the pattern that has the highest lightness. The amount of adjustment acquired based on the first adjustment pattern is referred to as first adjustment amount herein. In the example illustrated in
Next, the controller 20 looks up the nonvolatile memory 30 to acquire the adjustment pattern data 30a representing the second adjustment pattern. Then, the controller 20 determines the target of printing, that is, patterns that are to be printed from among those in the adjustment pattern data 30a. In this determination, the controller 20 chooses, as the target of printing, patterns that are to be printed with the amount of adjustment having the same tendency as that of the first adjustment amount. For example, the controller 20 chooses, as the target of printing, patterns associated with the amount of adjustment included within a predetermined range the center of which is the same as the first adjustment amount. The controller 20 regards patterns associated with the amount of adjustment outside the predetermined range as those that should be excluded from the target of printing.
Then, the controller 20 controls the carriage 40 and the transportation mechanism 60 to print a part of the second adjustment pattern based on the adjustment pattern data 30a specifying the patterns that are to be printed as the target of printing. As a result, for example, as illustrated in
After reading each of the patterns Pt (Pt2) that constitute (the printed part of) the second adjustment pattern, the controller 20 acquires the lightness of each pattern Pt (Pt2) Then, based on the adjustment pattern data 30a, the controller 20 acquires the amount of adjustment associated with the pattern that has the highest lightness. The amount of adjustment acquired based on the second adjustment pattern is referred to as second adjustment amount herein. In the example illustrated in
After acquiring the first adjustment amount and the second adjustment amount, based on each adjustment amount, the controller 20 sets parameters that are to be used for controlling the printing apparatus 10. That is, the controller 20 sets a first parameter that is the result of adjusting the target of adjustment by using the first adjustment amount, and sets a second parameter that is the result of adjusting the target of adjustment by using the second adjustment amount.
The first parameter indicates the amount of adjustment as the result of adjustment determined based on the first adjustment amount. Therefore, the first parameter may be the same as the first adjustment amount or may be an adjustment amount determined from the first adjustment amount. The example in the present embodiment is the former, and the controller 20 makes settings such that the first adjustment amount will be applied when printing with the first print quality is performed. Specifically, the controller 20 causes the nonvolatile memory 30 to store, in a first area, the first parameter for performing printing, with the first adjustment amount applied.
The second parameter indicates the amount of adjustment as the result of adjustment determined based on the second adjustment amount. Therefore, the second parameter may be the same as the second adjustment amount or may be an adjustment amount determined from the second adjustment amount. The example in the present embodiment is the former, and the controller 20 makes settings such that the second adjustment amount will be applied when printing with the second print quality is performed. Specifically, the controller 20 causes the nonvolatile memory 30 to store, in a second area, the second parameter for performing printing, with the second adjustment amount applied. The configuration described above enables the printing apparatus to operate according to different parameters set using the amount of adjustment determined based on different adjustment patterns.
In the present embodiment, the first parameter is a parameter that is used when printing with the first print quality is performed. The first parameter is not used when printing with the second print quality is performed. The second parameter is a parameter that is used when printing with the second print quality is performed. The second parameter is not used when printing with the first print quality is performed. That is, in the present embodiment, regarding each target of adjustment, different adjustment patterns are printed for the purpose of making adjustments for the respective levels of print quality, and parameters suited for the respective levels of print quality are set. Consequently, in the printing apparatus 10 capable of performing printing with different levels of print quality, it is possible to perform printing with the amount of adjustment suited for the respective levels of print quality applied.
In the present embodiment, printing an adjustment pattern, acquiring an adjustment amount, and setting a parameter are performed for each target of adjustment and for each level of print quality. Therefore, it can be said that a printing apparatus that eliminates print misalignment will be manufactured. In the configuration described above, it is possible to limit the target of printing of the second adjustment pattern in accordance with acquiring the first adjustment amount. Therefore, when printing is performed with different levels of print quality for the same target of adjustment, it is possible to make the amount of printing the second adjustment pattern smaller, as compared with a case where printing is performed while adjusting the amount of adjustment for the entirety of the second adjustment pattern. Consequently, it is possible to perform adjustment pattern printing efficiently.
Next, the controller 20 sets the target of printing in an N-th adjustment pattern (step S105). The following is a more detailed explanation. The controller 20 limits the range of printing of the next adjustment pattern based on printing the preceding adjustment pattern. Therefore, the controller 20 looks up the nonvolatile memory 30 to acquire the adjustment pattern data 30a of the N-th adjustment pattern. In the present embodiment, the order of adjustment patterns that are to be printed for the purpose of setting the amount of adjustment of the target of adjustment (i.e., the order of print quality for which adjustments are made) has been determined in advance. Therefore, the adjustment pattern data 30a of the N-th adjustment pattern is data representing the adjustment pattern that is to be printed N-th.
Then, the controller 20 extracts a part of the patterns represented by the acquired adjustment pattern data 30a. That is, the controller 20 extracts patterns associated with the amount of adjustment included within a predetermined range the center of which is the same as an (N−1) adjustment amount acquired in a step S120 (described later) that was executed for an (N−1)-th adjustment pattern, and sets the extracted patterns as the target of printing. If N=1, the controller 20 sets the whole of the patterns represented by the adjustment pattern data 30a as the target of printing.
Next, the controller 20 commands that the N-th adjustment pattern should be printed (step S110). Specifically, based on the adjustment pattern data 30a of the patterns set as the target of printing in the step S105, the controller 20 controls the carriage 40 and the transportation mechanism 60 to print the adjustment pattern.
Next, the controller 20 commands that the N-th adjustment pattern should be read (step S115). Specifically, the controller 20 controls the transportation mechanism 60, the carriage 40, and the sensor unit 42 to read the adjustment pattern printed in the step S110. Next, the controller 20 acquires an N-th adjustment amount (step S120). Specifically, the controller 20 chooses the pattern that has the highest lightness from among the patterns read in the step S115, and acquires the amount of adjustment associated with the chosen pattern as the N-th adjustment amount.
Next, the controller 20 sets an N-th parameter (step S125). Specifically, the controller 20 determines each parameter that needs to be set in each component of the printing apparatus 10 in order to perform printing with the N-th adjustment amount in the printing apparatus 10. Then, the controller 20 causes the nonvolatile memory 30 store the value as the parameter for an N-th mode (i.e., mode for performing printing with N-th print quality).
Next, the controller 20 determines whether the adjustment pattern printing has finished or not (step S130). Specifically, the controller 20 determines in the step S130 that the adjustment pattern printing has finished if the adjustment pattern having been printed last is the last one in the order of printing adjustment patterns. If so, the adjustment processing is ended.
If the adjustment pattern printing has not finished yet, the controller 20 increments the variable N (step S135) and repeats the processing in the step S105 and the subsequent steps. As a result of the above processing, an adjustment for the target of adjustment for each of different levels of print quality ends.
The foregoing embodiment is just for giving an example. Various other embodiments can be adopted. For example, the printing apparatus 10 may be integrated into an apparatus that has a print function and other functions. The printing apparatus 10 may use other printing method instead of ink-jet printing, for example, electrophotographic printing. Moreover, the technique described in the foregoing embodiment for making the amount of printing the later adjustment pattern smaller based on the amount of adjustment acquired based on the earlier adjustment pattern, as compared with a case where the amount of adjustment is unknown, can be implemented as an invention of a printing apparatus, an invention of an adjustment pattern printing program that is to be executed by a computer, for example.
The functions recited in the appended claims may be implemented by hardware resources the functions of which are defined by hardware architecture itself, by hardware resources the functions of which are defined by a program, or by a combination of them. These functions of components do not necessarily have to be implemented by physically independent hardware resources. Moreover, since the foregoing embodiment is just for giving an example, partial omission of the disclosed configuration, addition of other configuration to the disclosed configuration, and/or replacement may be applied.
Furthermore, the target of adjustment is not limited to the timing of ejecting ink described in the foregoing embodiment. Nor is the adjustment pattern limited to the foregoing example.
In order to eliminate the misalignment, for example, the timing of ejecting ink of predetermined colors is adjusted. Specifically, the timing of ejecting ink of a particular color is set as designed, and the timing of ejecting ink of the rest of colors is adjusted. By this means, it is possible to eliminate the misalignment in print position between the colors.
In
Also in the adjustment pattern illustrated in FIG. 7, each pattern array is constituted of nine patterns arranged in the main-scan direction. In the example illustrated in
On the other hand, in the adjustment pattern illustrated in
Therefore, by controlling the carriage 40, the transportation mechanism 60, and the sensor unit 42 by the controller 20 to read the adjustment pattern and find the pattern that has the highest lightness, it is possible to determine the amount of adjustment associated with the found pattern as an ideal adjustment amount. In the patterns illustrated in
It is possible to reduce the amount of printing when another adjustment pattern is printed for the same target of adjustment after determining the amount of adjustment using the adjustment pattern described above. For example, suppose that the adjustment pattern illustrated in
In order to eliminate the misalignment, for example, the timing of ejecting ink from a certain print head is set as designed, and the timing of ejecting ink from another print head is adjusted. By this means, it is possible to eliminate the misalignment in print position between the print heads.
In
Also in the adjustment pattern illustrated in
On the other hand, in the adjustment pattern illustrated in
Therefore, by controlling the carriage 40, the transportation mechanism 60, and the sensor unit 42 by the controller 20 to read the adjustment pattern and find the pattern that has the highest lightness, it is possible to determine the amount of adjustment associated with the found pattern as an ideal adjustment amount. It is possible to reduce the amount of printing when another adjustment pattern is printed for the same target of adjustment after determining the amount of adjustment using the adjustment pattern described above. For example, suppose that the adjustment pattern illustrated in
In order to eliminate the misalignment, for example, it is necessary to determine a parameter for operating the transportation mechanism 60 such that the deviation from the designed amount of feed will be eliminated. It is difficult to configure the transportation characteristics of the transportation mechanism 60 exactly as designed. However, once the characteristics of an amount of transportation for each amount of adjustment (transportation amount versus voltage) in a certain individual are known, it is possible to realize a transportation amount as designed. Therefore, if the transportation characteristics of the transportation mechanism 60 are determined by printing an adjustment pattern, it becomes possible to determine an ideal parameter.
The patterns P1 to P5, which are printed earlier, are printed using nozzles selected from the area R1 of a print head H. The patterns P6 to P10, which are printed later, are printed using nozzles selected from the area R2 of the print head H. Among the patterns P1 to P10, the same pattern is printed using particular nozzles determined in advance, and different patterns are printed using different nozzles.
The patterns P6 to P10, which are printed later, are printed at an area overlapping with the patterns P1 to P5, which are printed earlier. For example, the pattern P6 is printed at an area overlapping with the pattern P1. Therefore, if there is a complete pattern overlap after printing the later pattern (the highest lightness), it tells that the distance of transportation by the transportation mechanism 60 is the same as the distance between the nozzles used for the pattern printed earlier and the pattern printed later. By predetermining nozzles that are to be used for printing the patterns P1 to P10, therefore, it is possible to know the amount of transportation by the transportation mechanism 60, based on the pitch between the nozzles that were used for printing the patterns that overlap best.
In a configuration of transporting a printing medium by the transportation mechanism 60 as described above wherein the amount of feed is defined as a transportation amount PF, in the present embodiment, printing with different values of the transportation amount PF is performed more than once. Specifically, the controller 20 repeats processing of printing the earlier pattern and the later pattern more than once, with the amount of adjustment for varying the transportation amount PF predetermined, and with the nozzles to be used predetermined, thereby printing an adjustment pattern.
Next, the controller 20 controls the sensor unit 42 to read each of the patterns that constitute the adjustment pattern. Then, the controller 20 deems the nozzle pitch associated with the pattern whose lightness is equal to or greater than a predetermined value as the amount of transportation by the transportation mechanism 60. Then, based on the deemed amount of transportation and the amount of adjustment (voltage) at the transportation mechanism 60, the controller 20 finds a relation between arbitrary amount of adjustment and amount of transportation (characteristics of the transportation mechanism 60). The controller 20 deems, as the first adjustment amount, the amount of adjustment (voltage) that is necessary for obtaining the amount of transportation as designed.
It is possible to reduce the amount of printing when another adjustment pattern is printed for the same target of adjustment after determining the amount of adjustment using the adjustment pattern described above. For example, suppose that the adjustment pattern illustrated in
It suffices that the printing apparatus is able to perform printing while varying the amount of adjustment of the target of adjustment. The target of adjustment may be any factor among variable factors of the printing apparatus as long as it could change the result of printing. For example, if it is possible to adjust the amount of an error that could occur by adjusting a variable amount in the printing apparatus, this adjustable amount can be taken as the amount of adjustment of the target of adjustment. Examples of the error are: an error in the amount of movement and/or the direction of movement when a print head reciprocates, a print head level error, a platen gap error, a carriage speed error, an error between a plurality of print heads of a multi-head printing apparatus, an error in the amount of paper feed, and a nozzle pitch error.
The target of adjustment for which the amount of such an error is adjusted could be a plurality of targets of adjustment. Examples of the target of adjustment are: the timing of ejecting ink, the speed of moving the print head, the amount of ink ejected, the waveform and magnitude of a voltage for ejecting ink, the amount of feeding a sheet, as described earlier. Needless to mention, examples are not limited to those enumerated here, and an adjustment with the amount of adjustment may be made for any other kind of target of adjustment. The printing apparatus for which an adjustment is made is not limited to an ink-jet printer. Needless to mention, the target of adjustment may contain a plurality of items. The amount of adjustment may be a variable amount for each target of adjustment. When an adjustment pattern is printed, a plurality of adjustment amounts covering the entirety of an adjustable range may be selected, or a plurality of adjustment amounts covering a part of an adjustable range may be selected.
The first adjustment pattern may be any predetermined patterned arrangement as long as it is printed using different values of the amount of adjustment. That is, the first adjustment pattern is patterned arrangement for knowing the differences in print quality (the degree of an error), differing from amount to amount of adjustment. Therefore, it will be advantageous if the first adjustment pattern is patterned arrangement of the same print contents printed repeatedly with differences in the amount of adjustment. Such patterned arrangement makes it possible to know which one of different values of the amount of adjustment is suited for being taken as the first adjustment amount based on the print result of the first adjustment pattern.
Regarding the first adjustment amount, as long as the first adjustment amount is acquired by reading the printed first adjustment pattern, it suffices. Since the first adjustment pattern is patterned arrangement producing the differences in print quality, differing from amount to amount of adjustment, a configuration of a plurality of patterned elements that vary in item for evaluating print quality, for example, lightness, line misalignment, chroma, etc. can be adopted. It suffices to take, as the first adjustment amount, the amount of adjustment that was set when printing the one offering the best print quality (minimizing the error) as the result of reading them. Although the first adjustment pattern is read by a sensor in the foregoing embodiment, the one offering the best print quality among those in the patterned arrangement may be found by a human, and the first adjustment amount may be determined based on an input by the human via a non-illustrated user interface specifying the one offering the best print quality.
Similarly to the first adjustment pattern, the second adjustment pattern may be any patterned arrangement as long as it is obtained by printing a predetermined image using different values of the amount of adjustment. However, when the second adjustment pattern is printed, the amount of adjustment is not varied throughout the entire variable range of the amount of adjustment supposed as the second adjustment pattern. That is, the second adjustment pattern is printed while omitting a part of the variable range and varying the amount of adjustment for the rest only.
The amount of adjustment varied when the first adjustment pattern is printed and the amount of adjustment varied when the second adjustment pattern is printed may be for adjustment for the same cause of an error or may be for different causes. Anyway, it is sufficient as long as the determination of the first adjustment amount makes it possible to narrow down the range of the amount of adjustment varied when the second adjustment pattern is printed. The print position of the second adjustment pattern may be any position. For example, if partial printing is performed in a case where patterns would exist throughout the entire area in the main-scan direction if the entirety of the second adjustment pattern were printed, the patterns will not be distributed throughout the entire area in the main-scan direction. In such a case, the second adjustment pattern may be printed at and near the center in the main-scan direction. If patterns that are to be printed exist at a non-center position in an unbalanced manner due to omission of a part of the second adjustment pattern, the second adjustment pattern may be printed without correcting the unbalance.
Similarly to the acquisition of the first adjustment amount, it suffices that the second adjustment amount is acquired by reading the second adjustment pattern. Since the second adjustment pattern is patterned arrangement producing the differences in print quality, differing from amount to amount of adjustment, a configuration of a plurality of patterned elements that vary in item for evaluating print quality, for example, lightness, line misalignment, chroma, etc. can be adopted. It suffices to take, as the second adjustment amount, the amount of adjustment that was set when printing the one offering the best print quality (minimizing the error) as the result of reading them. Although the second adjustment pattern is read by a sensor in the foregoing embodiment, the one offering the best print quality among those in the patterned arrangement may be found by a human, and the second adjustment amount may be determined based on an input by the human via a non-illustrated user interface specifying the one offering the best print quality.
The first parameter indicates the amount of adjustment as the result of adjustment determined based on the first adjustment amount. Therefore, the first parameter may be equal to the first adjustment amount or may be an adjustment amount determined from the first adjustment amount. One of examples of the latter is: if an adjustment amount A and an adjustment amount B are determined to offer equal highest print quality based on the first adjustment pattern, an adjustment amount between the adjustment amount A and the adjustment amount B (e.g., the average) is taken as the first parameter. Another example is to take an adjustment amount determined based on the first adjustment amount and another adjustment amount (e.g., the average, the value before the adjustment) as the first parameter. The second parameter is similar to the first parameter in that the second parameter indicates the amount of adjustment as the result of adjustment determined based on the second adjustment amount. Therefore, similarly to the first parameter, various kinds of configuration are adoptable for the second parameter.
In the foregoing embodiment, in order to set parameters to be used for different levels of print quality for the same target of adjustment, adjustment patterns are printed with the respective levels of print quality. However, this printing may be performed for the same/similar kind of target of adjustment. The “same/similar kind of target of adjustment” means the target of adjustment for which the print result that changes due to the change in the amount of adjustment is the same or similar. For example, if the timing of ejecting ink is adjusted for each of different levels of print quality, the target of adjustment in each level of print quality is the timing of ejecting ink, meaning the same target of adjustment. On the other hand, adjusting the timing of ejecting ink makes it possible to change an ink recording position in the main-scan direction, and adjusting the speed of moving the carriage 40 also makes it possible to change an ink recording position in the main-scan direction. Therefore, the timing of ejecting ink and the speed of moving the carriage 40 can be said as similar kind of target of adjustment in relation to each other.
When the second adjustment pattern is printed, it suffices to select a partial range of the amount of adjustment determined according to the first adjustment amount from the entire range of the amount of adjustment used for printing the second adjustment pattern, wherein this range may be variable. For example, the partial range may be made relatively narrow if the minimum value of the misalignment that has occurred in the first adjustment pattern is relatively small, as compared with a case where it is relatively large. More specifically, suppose two cases: one where the minimum value of the misalignment that has occurred in the first adjustment pattern is zero and the other where the minimum value of the misalignment that has occurred in the first adjustment pattern is greater than zero. In this example, the reliability of the first adjustment amount of the former is higher. Therefore, the probability is high that the change width of the amount of adjustment required for making an adjustment will be narrower for the former when the amount of adjustment is varied based on the first adjustment amount, for example, with the first adjustment amount taken as the center.
Therefore, it is possible to reduce the amount of printing the second adjustment pattern if the minimum value of the misalignment that has occurred in the first adjustment pattern is relatively smaller, as compared with a case where it is relatively large. For example, the following configuration may be adopted. In the example illustrated in
The target of adjustment may be selectable by a user. In such a user-selectable configuration, an adjustment pattern printed for making an adjustment for a case where a certain target of adjustment is selected first time may be different from an adjustment pattern printed for making an adjustment for a case where, before the certain target of adjustment, other target of adjustment relevant thereto was selected to make an adjustment. That is, the entirety of the first adjustment pattern is printed for making an adjustment if a certain target of adjustment is selected first time. If a selection and an adjustment are made after selecting other target of adjustment relevant thereto and making an adjustment, only a part of the first adjustment pattern is printed. This part may be determined according to the result of adjusting the other target of adjustment relevant thereto.
Number | Date | Country | Kind |
---|---|---|---|
JP2019-218555 | Dec 2019 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
7773774 | Rasmussen et al. | Aug 2010 | B2 |
9501842 | Totsuka | Nov 2016 | B2 |
20110242174 | Kakutani | Oct 2011 | A1 |
20180086049 | Ueshima | Mar 2018 | A1 |
Number | Date | Country |
---|---|---|
2006-014332 | Jan 2006 | JP |
Number | Date | Country | |
---|---|---|---|
20210162736 A1 | Jun 2021 | US |