The present application is based on, and claims priority from JP Application Serial Number 2022-117168, filed Jul. 22, 2022, the disclosure of which is hereby incorporated by reference herein in its entirety.
The present disclosure relates to a recording device and a recording method.
There is disclosed a technique for adjusting a transport amount of a medium in a sub scanning direction so as to eliminate an error between a dot landing position on the medium by a previous scan by a recording head and a dot landing position on the medium by a subsequent scan following the transport of the medium.
As the related art, a recording device is disclosed that includes a first recording device for recording a plurality of reference patterns on a recording medium in a main scanning direction, a second recording device that records a plurality of adjustment patterns in the main scanning direction after transport of the recording medium by a sub scanning unit and that uses a nozzle corresponding to a region in which the reference pattern is recorded or a nozzle near the above nozzle, makes a nozzle or a combination of nozzles used for recording each of the plurality of adjustment patterns different, and records the plurality of adjustment patterns that are gradually and positionally shifted in a sub scanning direction with respect to the reference pattern, and a calculation device that calculates a transport amount of the recording medium transported by the sub scanning unit based on a density difference of a plurality of patterns formed by a first pattern and a second pattern (see JP 2006-272957 A).
When an error occurs in anything other than the transport amount of an adjustment target between a process of recording a pattern by a previous scan and a process of recording a pattern by a subsequent scan, the transport amount cannot be accurately grasped from a recording result of the pattern and appropriate adjustment cannot be performed. In particular, skew in which the medium is inclined with respect to a transport direction may occur between a previous scan and a subsequent scan. When the skew of the medium occurs, the plurality of patterns by the first and second patterns in JP 2006-272957 A are different in degree of influence of the skew depending on a position of each pattern, thus it is difficult to appropriately calculate the transport amount of the recording medium by evaluating a recording result of the plurality of patterns. Note that the error that occurs in anything other than the adjustment target between the recording by the previous scan and the recording by the subsequent scan is not limited to the skew of the medium.
In view of such a situation, improvement is required for, even when an error occurs in anything other than an adjustment target between recording by a previous scan and recording by a subsequent scan, removing influence of the error as much as possible and correctly acquiring necessary information from a result of recording by a plurality of scans.
A recording device including a recording head including a plurality of nozzles for discharging liquid onto a medium and a control unit for controlling the recording head, and the recording device being configured to perform recording on the medium by a scan for causing the recording head to discharge the liquid while moving the recording head along a predetermined main scanning direction, wherein the control unit controls the recording head to record n test patterns from which a shift amount between the scan and the scan different from each other is acquirable on the medium in the main scanning direction, where n is an integer of 3 or more, at least three of the test patterns is formed by a plurality of patches recorded by a plurality of the scans, and the n test patterns are formed so as to be different from each other in positional relationship of the plurality of patches and recorded side by side in the main scanning direction in an order different from an order in which the positional relationship of the plurality of patches gradually changes.
A recording method of performing recording on a medium by a scan for causing a recording head to discharge liquid while moving, along a predetermined main scanning direction, the recording head, the recording head including a plurality of nozzles for discharging the liquid onto the medium, the recording method including a recording control step for controlling the recording head to record n test patterns from which a shift amount between the scan and the scan different from each other is acquirable on the medium in the main scanning direction, where n is an integer of 3 or more, and in the recording control step, at least three of the test patterns is formed by a plurality of patches recorded by a plurality of the scans, and the n test patterns are formed so as to be different from each other in positional relationship of the plurality of patches and recorded side by side in the main scanning direction in an order different from an order in which the positional relationship of the plurality of patches gradually changes.
Embodiments of the present disclosure will be described below with reference to the accompanying drawings. Note that each of the drawings is merely illustrative for describing the embodiment. Since the drawings are illustrative, proportions, shapes and shading are not precise, do not match each other, or are partially omitted in some cases.
The recording device 10 includes a control unit 11, a display unit 13, an operation receiving unit 14, a storage unit 15, a communication IF 16, a transport unit 17, a carriage 18, a recording head 19 and the like. IF is an abbreviation for interface. The control unit 11 is configured to include, as a processor, one or more ICs including a CPU 11a, a ROM 11b, a RAM 11c, and the like, another non-volatile memory, and the like.
In the control unit 11, the processor, that is, the CPU 11a executes arithmetic processing in accordance with a program 12 stored in the ROM 11b, the other memory, or the like, using the RAM 11c or the like as a work area, to realize various functions such as a TP recording control unit 12a and an adjustment value calculating unit 12b. TP is an abbreviation for test pattern. The program 12 corresponds to a recording control program. The TP recording control unit 12a and the adjustment value calculating unit 12b are only some of the functions realized by the recording device 10 according to the program 12. The processor is not limited to the single CPU, and a configuration may be adopted in which the processing is performed by a hardware circuit such as a plurality of CPUs, an ASIC, or the like, or a configuration may be adopted in which the CPU and the hardware circuit work in concert to perform the processing.
The display unit 13 is a device for displaying visual information, and is configured, for example, by a liquid crystal display, an organic EL display, or the like. The display unit 13 may be configured to include a display, and a drive circuit for driving the display.
The operation receiving unit 14 is a device for receiving an operation or input by a user, and is realized, for example, by a physical button, a touch panel, a mouse, a keyboard, or the like. The display unit 13 and the operation receiving unit 14 may be collectively referred to as an operating panel of the recording device 10. The operation receiving unit 14 as the touch panel is realized as a function of the display unit 13. Therefore, it may be understood that the display unit 13 is configured to include the operation receiving unit 14.
The storage unit 15 is, for example, also a hard disk drive, a solid-state drive or another storage device using a memory. A part of the memory included in the control unit 11 may be regarded as the storage unit 15. The storage unit 15 may be regarded as a part of the control unit 11.
The communication IF 16 is a generic term for one or a plurality of IFs for the recording device 10 to perform communication with an external device in a wired or wireless manner, in accordance with a prescribed communication protocol including a known communication standard. The communication IF 16 corresponds to a communication unit. The external device is, for example, a communication device such as a personal computer (PC), a server, a smart phone or a tablet-type terminal. In the example of
The transport unit 17 is a device for transporting the medium 30 along a predetermined transport path under the control of the control unit 11. The transport unit 17 includes, for example, a roller that rotates to transport the medium 30, a motor as a power source of rotation, and the like. In addition, the transport unit 17 may be a mechanism in which the medium 30 is mounted on a drum, a belt or a pallet that is driven by a motor, for transporting the medium 30. The medium 30 is, for example, paper, but may be any medium that can be a target of recording with liquid, and may be a material other than paper, such as film or fabric.
The carriage 18 is a moving device that reciprocates along a predetermined main scanning direction by power of a carriage motor (not illustrated) under the control of the control unit 11. The carriage 18 is mounted with the recording head 19.
The recording head 19 is a device that performs recording by discharging liquid onto the medium 30 by an ink jet method under the control of the control unit 11. A liquid droplet discharged by the recording head 19 is referred to as a dot. The liquid is mainly ink.
The recording head 19 is capable of discharging colors of ink, such as cyan (C), magenta (M), yellow (Y) and black (K), for example. Of course, the recording head 19 may be capable of discharging ink of a color other than CMYK or liquid other than ink. The movement of the carriage 18 is synonymous with movement of the recording head 19. The carriage 18 and the recording head 19 may be collectively regarded as a recording head or may be referred to as a recording unit.
The recording device 10 is a single printer in which configurations thereof are integrated.
Alternatively, the recording device 10 may be a recording system realized by communicably coupling a plurality of devices or apparatuses. The recording system includes, for example, an information processing device that mainly serves as the control unit 11, and a printer that includes the transport unit 17, the carriage 18 and the recording head 19 and performs recording under the control of the information processing device. In this case, the information processing device can be grasped as a recording control device, an image processing device or the like. The display unit 13, the operation receiving unit 14 or the storage unit 15 may be a part of the information processing device or the printer or may be a peripheral device coupled to the information processing device or the printer.
The recording head 19 includes a nozzle group for each liquid type. In
The nozzle group 21C is a nozzle group in which a plurality of the nozzles 20 that discharge a C ink are aligned. Similarly, the nozzle group 21M is a nozzle group in which a plurality of the nozzles 20 that discharge an M ink are aligned, the nozzle group 21Y is a nozzle group in which a plurality of the nozzles 20 that discharge a Y ink are aligned, and the nozzle group 21K is a nozzle group in which a plurality of the nozzles 20 that discharge a K ink are aligned. The plurality of nozzle groups 21C, 21M, 21Y and 21K are aligned along the main scanning direction D1, and positions thereof are the same in the sub scanning direction D2. In
The control unit 11 causes the recording head 19 to discharge ink based on recorded data representing an image to be recorded. As is known, in the recording head 19, a driving element is provided for each nozzle 20, and when application of a driving signal to the driving element of each nozzle 20 is controlled in accordance with the recorded data, each nozzle 20 does or does not discharge a dot of corresponding ink, and the image represented by the recorded data is recorded on the medium 30. The recorded data is data that defines dot discharge or dot non-discharge for each pixel and for each of ink colors such as CMYK. A discharge of a dot is also referred to as dot-on, and non-discharge of a dot is also referred to as dot-off.
An ink discharge by the recording head 9 along with movement of the recording head 19 along the main scanning direction D1 by the carriage 18 is referred to as a “scan” or a “pass”. Further, downstream transport by a predetermined distance performed by the transport unit 17 between a pass and a pass is referred to as “paper feeding”. The control unit 11 records a two dimensional image on the medium 30 by alternately repeating a pass and paper feeding.
Movement from one side to another side along the main scanning direction D1 is referred to as forward movement, and movement from the other side to the one side is referred to as backward movement. Further, a pass by forward movement is referred to as a forward pass, and a pass by backward movement is referred to as a backward pass. Recording by a forward pass and a backward pass is bidirectional recording, and recording by only one of a forward pass and a backward pass is unidirectional recording. Although the bidirectional recording is basically employed in the present embodiment, the unidirectional recording may also be employed.
The carriage 18 may be a moving device capable of performing, together with the recording head 19, not only reciprocating along the main scanning direction D1 but also reciprocating along the sub scanning direction D2. That is, the recording head 19 may record a two dimensional image on the medium 30 by moving upstream by a predetermined distance instead of paper feeding between a pass and a pass. In this case, the transport unit 17 transports the medium 30 not along the sub scanning direction D2 but along the main scanning direction D1. That is, the transport unit 17 may intermittently transport the medium 30 along the main scanning direction D1, and the recording head 19 may move, to record an image, along the main scanning direction D1 or the sub scanning direction D2 with respect to the medium 30 that is temporarily stopped.
The recording method described with reference to
With reference to
A plurality of the patches 41 and 42 forming one TP are recorded by different passes, respectively. That is, each of the TPs 40a, 40b, 40c, 40d and 40e is recorded by two passes. Further, the TPs 40a, 40b, 40c, 40d and 40e are formed so as to be different from each other in positional relationship of the first patch 41 and the second patch 42. −2α, −α, 0, +α and +2α illustrated in
The position adjustment value for the TP 40c located at a center, among the TPs 40a, 40b, 40c, 40d and 40e, is 0, which means that positions of the first patch 41 and the second patch 42 are not adjusted. That is, in the TP 40c in which the positions of the first patch 41 and the second patch 42 are not adjusted, after a pass for recording the first patch 41, through paper feeding according to an instruction of a “reference feeding amount” which is a predetermined one time paper feeding amount, the second patch 42 is recorded by a subsequent pass.
In order to simplify the description, it is assumed that a length of the first patch 41 or the second patch 42 in the sub scanning direction D2 corresponds to a nozzle group length. In other words, each of the first patch 41 and the second patch 42 is a band image recorded by one pass of the recording head 19. The reference feeding amount is a distance smaller than the nozzle group length by a length corresponding to a predetermined number of nozzles. Therefore, after the recording head 19 records the first patch 41 by one pass, the transport unit 17 performs paper feeding by the reference feeding amount once and the recording head 19 records the second patch 42 by a subsequent pass, then an upstream end portion of the first patch 41 and a downstream end portion of the second patch 42 slightly overlap as long as there is no error in the paper feeding. The reference feeding amount is set to the distance smaller than the nozzle group length by the length corresponding to the predetermined number of nozzles so that no gaps occur in the sub scanning direction D2 between the images recorded by the respective successive passes.
When an amount of an overlapping portion in which the upstream end portion of the first patch 41 and the downstream end portion of the second patch 42 overlap each other is increased more than necessary, density of the overlapping portion is increased and the overlapping portion is likely to be visually recognized as dark stripe-like irregularity. On the other hand, between the first patch 41 and the second patch 42, when the amount of the overlapping portion is too small, or there is no overlapping portion and a gap is generated, density between the first patch 41 and the second patch 42 is decreased, and bright stripe-like irregularity is likely to be visually recognized. In the following, stripe-like irregularity darker than a color of a patch is referred to as a “black stripe”, and stripe-like irregularity brighter than a color of a patch is referred to as a “white stripe”.
In
In
In the TPs 40a, 40b, 40c, 40d and 40e, the positional relationship of the first patch 41 and the second patch 42 gradually changes according to an alignment order thereof in the main scanning direction D1. As described above, in the TP group 40 of the related art, the n TPs 40a, 40b, 40c, 40d and 40e are recorded on the medium 30, side by side in the main scanning direction Dl in the order in which the positional relationship of the patches 41 and 42 gradually changes.
A lower stage in
After acquiring the stripe density for each of the TPs 40a, 40b, 40c, 40d and 40e, the processor calculates an approximate straight line of the stripe density. In the lower stage in
However, the description related to
Similar to
In a lower stage in
When such skew occurs, in the TP 40a and the TP 40b recorded on a left side of the medium 30 among the TPs 40a, 40b, 40c, 40d and 40e, a distance between positions of the first patch 41 and the second patch 42 in the sub scanning direction D2 decreases so as to be less than a distance corresponding to the feeding amount adjusted with −2α or −α as described above. On the other hand, in the TP 40d and the TP 40e recorded on a right side of the medium 30, a distance between positions of the first patch 41 and the second patch 42 in the sub scanning direction D2 increases so as to be further greater than a distance corresponding to the feeding amount adjusted with +α or +2α as described above. Further, the TP 40a on a left end and the TP 40e on a right end are more strongly affected by the skew.
As a result, the stripe density for each of the TPs 40a, 40b, 40c, 40d and 40e is affected by the skew per position of the TP and has a value different from that when there is no skew, and as shown in the lower stage in
Similar to
In step S100, the TP recording control unit 12a of the control unit 11 starts controlling the transport unit 17, the carriage 18 and the recording head 19 and causes the recording head 19 to discharge ink based on recorded data representing the TP group 43 to record the TP group 43 on the medium 30. According to
The recording method of the TP group 43 in step S100 will be supplemented.
The control unit 11 controls the recording head 19 to record the first patch 41 corresponding to each of the n TPs 40a, 40e, 40d, 40c and 40b by a first pass, and to record the second patch 42 corresponding to each of the n TPs 40a, 40e, 40d, 40c and 40d by a second pass such that a position of the second patch 42 with respect to the first patch 41 is different for each second patch 42. That is, the control unit 11 causes the recording head 19 to record all of the first patches 41 of the respective TPs 40a, 40e, 40d, 40c and 40b by one pass. Then, the second patch 42 of each of the TPs 40a, 40e, 40d, 40c and 40b is recorded by the second pass after the pass by which the first patch 41 of each of the TPs 40a, 40e, 40d, 40c, and 40b is recorded.
The method of recording the second patch 42 of each of the TPs 40a, 40e, 40d, 40c and 40b can be classified into a first method of recording the second patches 42 by one common pass and a second method of recording the second patches 42 by different passes, respectively. Either the first method or the second method may be employed.
According to the first method, the control unit 11 makes the positional relationship of the patches 41 and 42 different for each TP, by making a range of the nozzles 20 used for recording the patch in the transport direction D2 different for each TP.
In
Symbols P1 and P2 each added in parentheses to the nozzle group 21C mean a first pass P1 and a second pass P2, respectively. That is, between the time when the first pass P1 is performed and the time when the second pass P2 is performed, a relative positional relationship between the nozzle group 21C and the medium 30 in the sub scanning direction D2 changes due to paper feeding between the passes P1 and P2.
The control unit 11 records the first patches 41 of the respective TPs 40a, 40e, 40d, 40c and 40b in the same manner at intervals along the main scanning direction D1 by the first pass P1 of the recording head 19. For the paper feeding after the first pass P1, a “reference feeding amount −2α” is instructed to the transport unit 17 in accordance with the TP 40a of the position adjustment value=−2α that brings the second patch 42 closest to the first patch 41, and the paper feeding by the instructed feeding amount is performed. Then, in the second pass P2 for recording the second patches 42 of the respective TPs 40a, 40e, 40d, 40c and 40b, it is sufficient that the control unit 11, for the second patch 42 of the TP 40a, records the second patch 42 by discharging ink using the entire nozzle group 21C including the most downstream nozzle 20.
On the other hand, for the recording of the second patches 42 of the respective TPs 40e, 40d, 40c and 40b, the control unit 11 sets ranges of unused nozzles that are different for the respective TPs 40e, 40d, 40c and 40b in a downstream range of the nozzle group 21C including the most downstream nozzle 20 in accordance with the position adjustment value for the respective TPs 40e, 40d, 40c and 40b, such as +2α, +α, 0 or −α. Then, in the same second pass P2, it is sufficient to record the second patches 42 for the respective TPs 40e, 40d, 40c and 40b by discharging ink using ranges of the used nozzles 20 that are different for the respective TPs 40e, 40d, 40c and 40b.
For example, a downstream end of the second patch 42 of the TP 40e of the position adjustment value=+2α needs to be shifted upstream from a downstream end of the second patch 42 of the TP 40a by a distance corresponding to 4×α. Therefore, during the second pass P2, the control unit 11 sets, in a period in which the second patch 42 of the TP 40e is recorded, a range of unused nozzles corresponding to 4×α in the sub scanning direction D2 within a downstream range of the nozzle group 21C including the most downstream nozzle 20. In
According to the second method, the control unit 11 makes positional relationship of the patches 41 and 42 different for each TP by making a distance of transport that the transport unit 17 performs between a pass and a pass each for recording a patch different for each TP. That is, after the first pass for collectively recording the first patches 41 of the respective TPs 40a, 40e, 40d, 40c and 40b, the control unit 11 controls the transport unit 17, the carriage 18 and the recording head 19 to repeatedly perform paper feeding, a second pass and back-feeding in order to record the second patches 42 of the respective TPs 40a, 40e, 40d, 40c and 40b. The back-feeding is transport of the medium 30 from downstream to upstream and is necessary, after a second pass for recording the second patch 42 of one TP, to record the second patch 42 of a subsequent TP. After the first pass, the control unit 11 performs each of the paper feeding and the second pass n times and performs the back-feeding between the second pass and the paper feeding n−1 times. A paper feeding amount for recording the second patch 42 of each of the TPs 40a, 40e, 40d, 40c and 40b is as described with reference to
A plurality of patches forming a TP may be recorded with liquid of the same color. That is, the control unit 11 records the first patch 41 and the second patch 42 forming one TP with ink of the same color. Referring to
As can be seen from
Furthermore, the control unit 11 may control the recording head 19 to record the n TPs in a bilaterally symmetrical arrangement with a center of the medium 30 in the main scanning direction Dl as an axis. In the example of
Furthermore, the control unit 11 may control the recording head 19 to record, in a vicinity of each of the n TPs, information indicating positional relationship of a plurality of patches forming the TP. In the example of
In step S110, the adjustment value calculating unit 12b of the control unit 11 acquires read data of the TP group 43. That is, the reading device 1 reads the medium 30 on which the TP group 43 is recorded and outputs the read data as a reading result to the recording device 10. Accordingly, the control unit 11 can acquire the read data of the TP group 43.
In step S120, the adjustment value calculating unit 12b acquires stripe density for each of the TPs 40a, 40b, 40c, 40d and 40e from the read date of the TP group 43 and calculates an approximate straight line F3 of the stripe density. Then, in step S130, the adjustment value calculating unit 12b acquires and stores a position adjustment value at which the approximate straight line F3 gives the stripe density D0 and ends the flowchart of
In a lower stage in
In the lower stage in
First, attention is paid to the TP 40a of the position adjustment value=−2α. The TP 40a is recorded on a leftmost side in the TP group 43. Therefore, when skew as indicated by a two dot chain line in
Next, when attention is paid to the TP 40b of the position adjustment value=−α, the TP 40b is recorded on a rightmost side in the TP group 43. Therefore, when the skew as indicated by the two dot chain line in
Similarly, when attention is paid to the TP 40c of the position adjustment value=0, the TP 40c is recorded at a second position from right in the TP group 43. Therefore, when the skew as indicated by the two dot chain line in
Similarly, when attention is paid to the TP 40d of the position adjustment value=+α, the TP 40d is recorded at a center of the TP group 43. Therefore, even when the skew as indicated by the two dot chain line in
Similarly, when attention is paid to the TP 40e of the position adjustment value=+2α, the TP 40e is recorded at a second position from left in the TP group 43. Therefore, when the skew as indicated by the two dot chain line in
According to such a result, among the vectors a, b, c and e indicated in the lower stage in
The effect of the random order alignment of the TPs in the TP group 43 of
The covariance of X and Y is an averaged (Ave) of (a deviation of X x a deviation of Y), thus is represented by the following Expression (1).
The covariance of X and Y={(Xi−XAve) (Yi−YAve)+(X2−XAve) (Y2−YAve)+(X3−XAve) (Y3−YAve)+(X4−XAve) (Y4−YAve)+(X5−XAve) (Y5−YAve)}/5 (1)
X1 to X5 are position adjustment values for the respective TPs 40a, 40b, 40c, 40d and 40e and are at equal intervals, thus X2 to X5 are defined as follows with X1 as a reference.
X
2
=X
1+8
X
3
=X
1+16
X
4
=X
1+24
X
5
=X
1+32
Thus, Expression (1) can be represented by the following Expression (2). Y1 to Y5 are stripe density of the respective TPs 40a, 40b, 40c, 40d and 40e.
The covariance of X and Y={X1(Y1+Y2+Y3+Y4+Y5)−XAve(Y1+Y2+Y3+Y4+Y5)−5X1YAve+5XAveYAve−80YAve+8(Y2+2Y3+3Y4+4Y5)}/5 (2)
When Y1 to Y5 to which stripe density errors ε1 to ε5 due to the skew are added are defined as to Y1′ to Y5′, respectively, Y1′ to Y5′ are as follows according to the random order alignment.
Y
1
′=Y
1+ε1
Y
2
′=Y
2+ε5
Y
3
′=Y
3+ε4
Y
4
′=Y
4
+ε
3
Y
5
′=Y
5+ε2
Numbers 1 to 5 relating to the errors ε1 to ε5 are not numbers in the order of the TPs 40a, 40b, 40c, 40d and 40e such as numbers 1 to 5 relating to X1 to X5 and Y1 to Y5, but are numbers corresponding to a positional order of the TPs in the main scanning direction D1. For example, since the TP 40b is recorded at a rightmost position, that is, a fifth position from left, the error ε5 is added to the stripe density Y2 of the TP 40b.
In addition, assuming that positive and negative of the errors ε1 to ε5 are reversed from left to right with reference to ε3=0 at a center and are proportional to a distance from the center, the errors are represented as follows.
ε1=−2ε
ε2=−ε
ε3=0
ε4=ε
ε5=2ε
Under these definitions, Y1′, Y2′, Y3′, Y4′ and Y5′ are substituted for Y1, Y2, Y3, Y4 and Y5 in Expression (2). The average XAve of X and the average YAve of Y do not change regardless of the presence or absence of skew. As a result of the substitution, all error components ε are eliminated in the term 8(Y2+2Y3+3Y4+4Y5), and all the error components ε are also eliminated in each term including the term (Y1+Y2+Y3+Y4+Y5). In other words, it can be said that the regression coefficient p does not change regardless of the presence or absence the stripe density errors due to the skew. Since the intercept q is YAve−pXAve, when the regression coefficient p does not change, the intercept q also does not change. Therefore, according to the recording of the TP group 43 adopting the random order alignment of the present embodiment, the same approximate straight line can be calculated from read data regardless of whether or not skew occurs in the medium 30 during paper feeding, and an appropriate position adjustment value from which influence of skew is removed is obtained.
Needless to say, the random order alignment of the TPs in the TP group 43 may be reverse to the order illustrated in
As described above, the control unit 11 controls the recording head 19 to record, on the medium 30, TPs from which a shift amount between different passes is acquirable. The shift amount may be a shift amount in the main scanning direction D1, in addition to the shift amount in the transport direction D2 as described above. A shift in the main scanning direction D1 between different passes is a shift between recording by a forward pass and recording by a backward pass, that is, a shift in bi-directional recording. Therefore, in the present modification, the bidirectional recording is assumed.
The plurality of patches 51 and 52 forming one TP are recorded by different passes, respectively. That is, the first patch 51 is recorded by a forward pass of the recording head 19, and the second patch 52 is recorded by a backward pass of the recording head 19. Further, the TPs 50a, 50b, 50c, 50d and 50e are formed so as to be different from each other in positional relationship of the first patch 51 and the second patch 52. −2α, −α, 0, +α, and +2α illustrated in
For example, when a position adjustment value is positive, timing at which the second patch 52 next to the first patch 51 recorded by a forward pass is recorded by a backward pass is advanced according to a numerical value such as α or 2 α, as compared with a case where the position adjustment value is 0. +2α indicates earlier timing than +α. Therefore, a TP having a positive position adjustment value is likely to be recorded at a position where the second patch 52 is away from the first patch 51. On the other hand, when the position adjustment value is negative, timing at which the second patch 52 next to the first patch 51 recorded by the forward pass is recorded by the backward pass is delayed according to a numerical value such as α or 2α, as compared with a case where the position adjustment value is 0. −2α indicates later timing than −α. Therefore, in a TP having a negative position adjustment value, the second patch 52 is likely to be recorded so as to overlap the first patch 51 to a greater extent.
That is, in the TP group 50, the n TPs 50a, 50b, 50c, 50d and 50e are recorded along the main scanning direction D1 in a random order alignment which is different from an “order of the TPs 50a, 50b, 50c, 50d and 50e for which the positional relationship of the patches 51 and 52 gradually changes”. With respect to the TP group 50, a black line in an overlapping portion between the patches 51 and 52 illustrated in
In the recording device 10, when a distance between the recording head 19 and the medium 30 in a certain scan is different between one side and another side in the main scanning direction D1, that is, between a left side and a right side, due to various factors such as mechanical errors and vibrations of the device, a time required for a dot discharged from the recording head 19 to land on the medium 30 is different between the left side and the right side. For example, when external force such as vibration is applied to the recording device 10 and the distance between the recording head 19 and the medium 30 during recording is different between the left side and the right side, a black stripe is likely to occur in a position where the distance between the recording head 19 and the medium 30 is large, and a white stripe is likely to occur in a position where the distance is small. That is, when the time to land is long in a forward pass, a dot is shifted in a forward direction and lands, and conversely, when the time to land is short, the dot is shifted in a backward direction from an intended position and lands. When such a shift in the distance between the recording head 19 and the medium 30 is grasped in the same manner as the skew described above, a device is necessary for obtaining a position adjustment value from which influence of the shift is eliminated as much as possible. Therefore, from such a viewpoint, it can be said that it is beneficial to record the TP group 50 as illustrated in
In the present modification, the example of the TP group to be recorded on the medium 30 is not limited to the TP group 50 illustrated in
The first patch 54 is formed by aligning several ruled lines each having a length component in the sub scanning direction D2 in the main scanning direction D1. The second patch 55 is formed by aligning several ruled lines each having a length component in the sub scanning direction D2 in the main scanning direction D1. In
As an interpretation of
As described above, according to the present embodiment, the recording device 10 includes the recording head 19 having the plurality of nozzles 20 for discharging liquid onto the medium 30 and the control unit 11 for controlling the recording head 19, and performs recording on the medium 30 by a scan for causing the recording head 19 to discharge the liquid while moving the recording head 19 along the predetermined main scanning direction D1. The control unit 11 controls the recording head 19 to record n TPs from which a shift amount is acquirable between a scan and a scan different from each other on the medium 30 in the main scanning direction D1, where n is the integer of 3 or more, one TP is formed by a plurality of patches recorded by a plurality of scans, the n TPs are formed so as to be different from each other in positional relationship of the plurality of patches and recorded side by side in an order different from an order in which the positional relationship of the plurality of patches gradually changes in the main scanning direction D1.
According to this configuration, the recording device 10 records the plurality of TPs in a random order alignment in the main scanning direction D1. Accordingly, even when an error such as skew in anything other than a shift of an adjustment target occurs between recording of a patch by a previous scan and recording of a patch by a subsequent scan, appropriate information in which influence of such an error is reduced can be acquired from recording results of the plurality of TPs.
In addition, according to the present embodiment, the shift amount is a shift amount in the transport direction D2 of the medium 30 intersecting the main scanning direction D1.
According to the above-described configuration, even when the skew occurs, the control unit 11 can acquire an appropriate adjustment value for eliminating a shift in transport obtained by reducing influence of such an error.
Additionally, according to the present embodiment, the control unit 11 may make positional relationship of a plurality of patches different for each TP, by making a range of the nozzles 20 used for recording the patch in the transport direction D2 different for each TP.
According to the above-described configuration, the control unit 11 can record the plurality of TPs aligned in the main scanning direction D1 with a minimum number of scans.
The recording device 10 includes the transport unit 17 that transports the medium 30 in the transport direction D2.
Then, the control unit 11 may make the positional relationship of the plurality of patches different for each TP, by making a distance of transport that the transport unit 17 performs between a scan and a scan each for recording a patch different for each TP.
According to the above-described configuration, the control unit 11 reliably records the plurality of TPs different from each other in positional relationship of the plurality of patches by actually making transport distance between a scan and a scan different for each TP.
Further, according to the present embodiment, the shift amount may be a shift amount in the main scanning direction D1. According to the above-described configuration, even when an error such as a shift in a distance between the recording head 19 and the medium 30 or the like occurs between recording of a patch by a previous scan and recording of a patch by a subsequent scan, the control unit 11 can acquire an appropriate adjustment value for eliminating a shift in bidirectional recording obtained by reducing influence of such an error. Note that “between recording of a patch by a previous scan and recording of a patch by a subsequent scan” means not only a temporal interval but also a distance interval between a recording result of a patch and a recording result of a patch on the medium 30.
In addition, according to the present embodiment, the control unit 11 controls the recording head 19 to record first patches respectively corresponding to n TPs by a first scan and to record second patches respectively corresponding to the n TPs by a second scan such that a position of the second patch with respect to the first patch is different for each second patch.
According to the above-described configuration, the control unit 11 can record at least the first patches of the respective TPs by one scan and can increase recording efficiency of the plurality of TPs.
In addition, according to the present embodiment, the plurality of patches forming the TP may be recorded with liquid of the same color.
According to the above-described configuration, it is possible to prevent various errors between nozzle groups or nozzle chips corresponding to different inks from affecting a recording result of the TP.
However, the present embodiment does not exclude a case where the plurality of patches forming the TP are recorded with different colors of ink.
In addition, according to the present embodiment, n TPs may be recorded at equal intervals in the main scanning direction D1.
In addition, according to the present embodiment, n TPs may be recorded in a bilaterally symmetrical arrangement with a center of the medium 30 in the main scanning direction D1 as an axis.
According to these configurations, influence of skew on recording of each TP can be changed proportionally according to a position of a TP in the main scanning direction D1. Therefore, when a reading result of each TP is evaluated or when an approximate straight line is calculated, the influence is easily canceled and removed.
Furthermore, according to the present embodiment, the control unit 11 may control the recording head 19 to record, in a vicinity of each of n TPs, information indicating positional relationship of a plurality of patches forming the TP.
According to the above-described configuration, in the medium 30 on which the TP is recorded, it is possible to inform a user of the positional relationship of the plurality of patches forming the TP in an easy-to-understand manner.
The present embodiment discloses not only a category such as the recording device 10 or a system but also various categories such as a method performed by a device or a system and the program 12 for causing a processor to execute the method.
For example, a recording method that performs recording on the medium 30 by a scan for causing the recording head 19 to discharge liquid while moving the recording head 19 having a plurality of the nozzles 20 that discharge the liquid onto the medium 30 along the predetermined main scanning direction Dl includes a recording control step for controlling the recording head 19 so as to record n TPs from which a shift amount between different scans is acquirable on the medium 30 in the main scanning direction Dl, where n is an integer of 3 or more. Step S100 corresponds to the recording control step. According to the recording control step, one TP is formed by a plurality of patches recorded by a plurality of scans, and the n patterns are formed so as to be different from each other in positional relationship of the plurality of patches and are recorded side by side in an order different from an order in which the positional relationship of the plurality of patches gradually changes in the main scanning direction D1.
Needless to say, n is not limited to 5. N may be 3, 4 or 6 or more. Also, there may be more than two patches that form one TP.
Number | Date | Country | Kind |
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2022-117168 | Jul 2022 | JP | national |