CN106994827B

CN106994827B - Printing apparatus and printing method

Info

Publication number: CN106994827B
Application number: CN201710029879.6A
Authority: CN
Inventors: 藤田彻
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2016-01-25
Filing date: 2017-01-16
Publication date: 2021-04-30
Anticipated expiration: 2037-01-16
Also published as: EP3208090B1; EP3208090A3; JP6672830B2; JP2017132069A; CN106994827A; EP3208090A2

Abstract

The invention provides a printing apparatus and a printing method capable of preventing deterioration of the quality of an obtained image. Comprising: a printing mechanism unit that forms a first print region on a recording medium by ejecting a first ink on the recording medium being conveyed along a first path in a direction intersecting a conveying direction of the recording medium, and thereafter forms a second print region by ejecting a second ink on a second path different from the first path to form an image including the first print region and the second print region; a path decomposition unit that determines a first ejection position of the first ink in the first path and a second ejection position of the second ink in the second path when forming the image; and a correction determination unit that performs ejection position change correction that changes the first ejection position to eject the first ink on the second path and changes the second ejection position to eject a part of the second ink on the first path.

Description

Printing apparatus and printing method

Technical Field

The present invention relates to a printing apparatus and a printing method.

Background

A printing apparatus that performs printing by applying ink to a recording medium is currently used (for example, see patent document 1). The printing apparatus described in patent document 1 includes: a conveying unit that conveys a recording medium; and a printing unit that reciprocates in a direction intersecting a transport direction of the recording medium and includes a plurality of nozzle units that eject ink onto the transported recording medium.

In such a printing apparatus, the ink landing positions on the forward path and the return path of the printing section may vary significantly due to the distance between the recording medium and the printing section, the material of the recording medium, and the like, and the image quality of the obtained image may deteriorate. In view of the above, it is conceivable to perform the discharge position change correction so that ink to be discharged on one path is discharged on the other path so that ink is discharged only on one of the forward path and the return path of the printing portion.

However, in the printing apparatus described in patent document 1, when the discharge position change correction is performed, there is a possibility that the ink in the portion where the discharge position change correction is performed overlaps. In this case, in the portion where the discharge position change correction is performed, the hue is different between the region where the inks overlap and the region where the inks do not overlap. As a result, the obtained image may be deteriorated.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2010-5827

Disclosure of Invention

The invention aims to provide a printing device and a printing method capable of preventing the image quality of the obtained image from deteriorating.

Such an object is achieved by the present invention described below.

The printing device of the present invention comprises:

a printing unit that forms an image including a first print region on a recording medium by ejecting a first ink on the recording medium in a first path along a direction intersecting a transport direction of the recording medium, and then forms a second print region on the recording medium by ejecting a second ink on a second path different from the first path, the first and second print regions being formed on the recording medium; a determination unit that determines a first discharge position of the first ink in the first path and a second discharge position of the second ink in the second path when the image is formed; and a correction determination unit that performs discharge position change correction based on a determination result of the determination unit, the discharge position change correction changing the first discharge position to discharge the first ink on the second path, and changing the second discharge position to discharge a part of the second ink on the first path.

This can prevent, for example, overlapping of inks whose ejection position is corrected. Therefore, it is possible to prevent the occurrence of image quality deterioration due to the overlap between the inks whose ejection position change corrections have been performed.

In the printing apparatus of the present invention, it is preferable that: the printing unit forms an overlapping portion where the first printing region and the second printing region partially overlap in a plan view of the recording medium.

This prevents deterioration of the image quality when the discharge position is corrected.

In the printing apparatus of the present invention, it is preferable that: in the ejection position change correction, the second ink ejected in the first printing region and the first ink ejected in the second printing region are ejected with a shift in a plan view of the recording medium.

This can more effectively prevent the image quality from deteriorating when the discharge position is corrected.

In the printing apparatus of the present invention, it is preferable that: when the printing unit moves n times (n is a positive integer of 2 or more) to form the image, the correction determining unit divides the second printing area into n, and determines whether or not the discharge position change correction is performed in each of the divided areas.

This can more effectively prevent or suppress the image quality from deteriorating when the discharge position is corrected.

In the printing apparatus of the present invention, it is preferable that: in the ejection position change correction, the second ink ejected in the first printing region is ejected in the overlap portion.

This prevents the inks whose ejection position is corrected from overlapping with each other.

In the printing apparatus of the present invention, it is preferable that: in the ejection position change correction, the second ink ejected in the first printing region is ejected at a position different from the overlapping portion.

In the printing apparatus of the present invention, it is preferable that: the printing section ejects at least two inks having different hues from each other, and the correction determination section performs the ejection position change correction with respect to an ink having a small ejection amount per unit area in the image, among the two inks.

This can more effectively prevent the ink whose ejection position is changed and corrected from overlapping.

The printing method of the present invention is a printing method for performing printing using a printing apparatus, the printing apparatus including: a printing unit that forms an image composed of the first print area and the second print area by ejecting a first ink on a recording medium to be conveyed in a first path along a direction intersecting a conveying direction of the recording medium to form a first print area on the recording medium, and thereafter ejecting a second ink on a second path different from the first path to form a second print area at a position different from the first print area; and a determination unit that determines a first discharge position of the first ink in the first path and a second discharge position of the second ink in the second path when the image is formed, wherein the printing method performs discharge position change correction that changes the first discharge position to discharge the first ink in the second path, and changes the second discharge position to discharge a part of the second ink in the first path when the change is made.

This can prevent, for example, overlapping of inks whose ejection position is corrected. This prevents deterioration of image quality due to overlapping of the inks subjected to the discharge position change correction.

Drawings

Fig. 1 is a side view schematically showing a first embodiment of a printing apparatus of the present invention;

FIG. 2 is a block diagram of the printing apparatus shown in FIG. 1;

fig. 3 is a diagram illustrating a process of printing an image by the printing apparatus shown in fig. 1;

fig. 4 is a diagram illustrating a process of printing an image by correcting a discharge position change in a conventional printing apparatus;

fig. 5 is a diagram illustrating a process of correcting a discharge position change and printing an image in the printing apparatus shown in fig. 1;

fig. 6 is a diagram illustrating a process of correcting a discharge position change and printing an image in the printing apparatus shown in fig. 1;

fig. 7 is a flowchart for explaining a control operation of a control section included in the printing apparatus shown in fig. 1;

fig. 8 is a diagram illustrating a process of printing an image by correcting a discharge position change in a printing apparatus (second embodiment) according to the present invention;

fig. 9 is a diagram illustrating a process in which the printing apparatus (third embodiment) of the present invention performs the correction of the discharge position change and prints an image.

Detailed Description

Hereinafter, a printing apparatus and a printing method according to the present invention will be described in detail based on preferred embodiments shown in the drawings.

First embodiment

Fig. 1 is a side view schematically showing a first embodiment of a printing apparatus of the present invention. Fig. 2 is a block diagram of the printing apparatus shown in fig. 1. Fig. 3 is a diagram illustrating a process of printing an image by the printing apparatus shown in fig. 1. Fig. 4 is a diagram illustrating a process of printing an image by correcting a discharge position change in a conventional printing apparatus. Fig. 5 is a diagram illustrating a process of printing an image by correcting a discharge position change in the printing apparatus shown in fig. 1. Fig. 6 is a diagram illustrating a process of printing an image by correcting the discharge position change in the printing apparatus shown in fig. 1. Fig. 7 is a flowchart for explaining a control operation of the control unit included in the printing apparatus shown in fig. 1.

For convenience of explanation, the x-axis, the y-axis, and the z-axis are illustrated as three axes orthogonal to each other in fig. 1, 3, and 6. The x-axis is an axis along one of the horizontal directions (the width (depth in the drawing) direction of the printing apparatus), the y-axis is an axis along the horizontal direction, that is, a direction perpendicular to the x-axis (the longitudinal direction of the printing apparatus), and the z-axis is an axis along the vertical direction (up-down direction). The tip side of each arrow shown in the figure is referred to as "positive side (+ side)" and the base side is referred to as "negative side (-side)". The upper side of fig. 1 and 3 to 6 is referred to as "upper (upper)" and the lower side is referred to as "lower (lower)".

As shown in fig. 1 and 2, the printing apparatus 1 is an apparatus for executing the printing method of the present invention, and includes: a machine table 11; a conveying mechanism (conveying unit) 12 that conveys a processed product W as a recording medium; a printing mechanism (printing unit) 13 for applying ink 100 to the workpiece W to perform printing; a drying section 2 for drying the ink 100 on the processed product W; and a lifting mechanism 14.

In the present embodiment, a direction orthogonal to the conveying direction in which the processed product W is conveyed is an x-axis direction, a direction parallel to the conveying direction is a y-axis direction, and a direction orthogonal to the x-axis direction and the y-axis direction is a z-axis direction.

The conveyance mechanism section 12 includes: a delivery device 3 for delivering a long processed product W wound in a roll shape; a winding device 4 for winding the printed processed product W, and a support device 5, wherein the support device 5 is arranged on the machine base 11 and supports the processed product W during printing.

The delivery device 3 is disposed upstream of the machine base 11 in the feeding direction (y-axis direction) of the workpiece W. The delivery device 3 has: a delivery roller (delivery reel) 31 to which the processed product W is wound in a roll shape (delivery reel) 31 and from which the processed product W is delivered by the delivery roller (delivery reel) 31; and a tensioner 32, wherein the tensioner 32 applies tension to the workpiece W between the delivery roller 31 and the support device 5. The feed roller 31 is connected to a motor (not shown) and can be rotated by the operation of the motor.

Further, a material to be subjected to printing can be used as the processed product W. The material to be printed refers to cloth, clothes, other clothing products, and the like that are objects to be printed. The cloth includes: natural fibers such as cotton, silk and wool, chemical fibers such as nylon, and composite fibers obtained by mixing these fibers. Further, the clothing and other clothing products include not only daily goods such as T-shirts, handkerchiefs, scarves, towels, handbags, cloth bags, curtains, suits, bedspreads, etc. after sewing, but also cloth before and after cutting, etc. existing as a member in a state before sewing.

As the processed product W, in addition to the above-mentioned material to be subjected to textile printing, special paper for ink jet recording such as plain paper, high-quality paper, glossy paper, and the like can be used. As the processed product W, for example, a plastic film which is not subjected to surface treatment for inkjet printing (that is, an ink absorbing layer is not formed), a material in which a plastic is coated on a substrate such as paper, or a material in which a plastic film is adhered can be used. The plastic is not particularly limited, and examples thereof include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

The winding device 4 is disposed downstream of the feeder device 3 in the feeding direction (y-axis direction) of the workpiece W with respect to the machine base 11. The winding device 4 includes: a winding roll (winding reel) 41 that winds the work W in a roll shape, and

tensioners

42, 43, 44 that apply tension to the work W between the winding roll 41 and the support device 5. The winding roller 41 is connected to a motor (not shown) and rotated by the operation of the motor. The tensioners 42-44 are respectively arranged at intervals in sequence in the direction of separating from the winding roller 41.

The support means 5 are arranged between the delivery means 3 and the winding means 4. The support device 5 includes: a drive roller 51 and a driven roller 52 arranged at a distance from each other in the y-axis direction; an endless belt 53 which is straddled between the drive roller 51 and the driven roller 52 and supports the work W on an upper surface (support surface);

tensioners

54, 55 for applying tension to the processed product W between the driving roller 51 and the driven roller 52.

The drive roller 51 is connected to a motor (not shown) and can be rotated by the operation of the motor. The driven roller 52 is configured to transmit the rotational force of the drive roller 51 via the endless belt 53 and to be rotatable in conjunction with the drive roller 51.

The endless belt 53 is a belt having an adhesive layer having adhesiveness formed on the front surface thereof. A part of the work W is fixed to the adhesive layer and conveyed in the y-axis direction. Then, printing is performed on the processed product W during this conveyance. After the printing is performed, the processed product W is peeled off from the endless belt 53.

The

tensioners

54 and 55 are also arranged apart from each other in the y-axis direction, similarly to the drive roller 51 and the driven roller 52.

The tensioner 54 can nip the workpiece W together with the endless belt 53 between the drive roller 51, and the tensioner 55 can nip the workpiece W together with the endless belt 53 between the driven roller 52. Thus, the work W to which tension is applied by the

tensioners

54 and 55 is fixed to the endless belt 53 and conveyed in a state in which the tension is applied. In this state, since the occurrence of wrinkles and the like in the processed product W during conveyance is reduced, when printing is performed, the processed product W is printed accurately and with high quality.

The printing mechanism section 13 includes: a carriage unit 132, the carriage unit 132 having a plurality of inkjet heads 131, the plurality of inkjet heads 131 ejecting ink 100 onto the processed product W to perform recording by printing; and an x-axis table (not shown) that supports the carriage unit 132 so as to be movable in the x-axis direction. Each inkjet head 131 includes, for example: a head main body in which an in-head flow path filled with ink 100 is formed; and a plurality of nozzle groups 6 having openings.

Piezoelectric elements (piezoelectric bodies) corresponding to the respective ejection nozzles are formed in the head main body, and when a voltage is applied to the piezoelectric elements, the ink 100 is ejected from the nozzle group 6 as droplets.

The inkjet head 131 waits at a position (standby position) away from the workpiece W (endless belt 53) when viewed in the z-axis direction without ejecting the ink 100.

In the printing apparatus 1, the work W delivered by the delivery device 3 is intermittently fed in the y-axis direction in a fixed state of being fixed to the endless belt 53 (sub-scanning), and the ink 100 is ejected from the nozzle group 6 while the carriage unit 132 is reciprocated in the x-axis direction (main scanning) with respect to the fixed work W. This operation can be performed until printing is completed and an image pattern is formed on the work W. The image mode may be performed by multicolor printing (color printing) or by monochrome printing.

In the ink 100, there are four colors, for example, cyan (C), magenta (M), yellow (Y), and black (K), which contain a dye or a pigment as a colorant in water as a solvent. The inks 100 of the respective colors are independently discharged from the inkjet head 131.

The elevating mechanism 14 shown in fig. 1 and 2 can adjust the height of the nozzle group 6. The lifting mechanism 14 may be configured to include a motor, a ball screw, and a linear guide, for example. In addition, an encoder is incorporated in the motor. The height of the inkjet head 131 can be detected based on the rotation amount detected with the encoder. The lifting mechanism 14 is also electrically connected to the controller 15.

In this way, the distance between the nozzle group 6 and the workpiece W can be changed by the elevating mechanism 14. Therefore, good printing can be performed depending on the material of the processed product W.

As shown in fig. 1, the drying unit 2 is disposed downstream of the printing mechanism unit 13 in the conveying direction of the processed product W and between the support device 5 and the winding roller 41 of the winding device 4.

The drying section 2 includes: a chamber 21 and a coil 22 disposed in the chamber 21. The coil 22 is a heating element that generates heat by supplying electric power, and is made of, for example, nichrome wire. The ink 100 on the workpiece W passing through the chamber 21 can be dried by the heat generated by the coil 22.

As shown in fig. 2, the control unit 15 is electrically connected to the drying unit 2, the conveying mechanism unit 12, the printing mechanism unit 13, and the elevating mechanism 14, and has a function of controlling the operations thereof. The control Unit 15 includes a CPU (Central Processing Unit) 151 and a storage Unit 155.

The CPU151 executes programs for various processes such as the printing process described above. The CPU151 functions as a path decomposition unit (determination unit) 152, a correction determination unit 153, and an execution unit 154.

The path decomposition unit 152 performs path decomposition for determining at which position the ink 100 is ejected in the forward path and the return path, based on the input image data.

The correction determination unit 153 performs path shift (described in detail later) on the data subjected to the path decomposition by the path decomposition unit 152. The execution unit 154 executes printing based on the data on which the correction determination unit 153 has performed the path shift.

The storage unit 155 includes, for example, an EEPROM (Electrically Erasable Programmable Read-Only Memory) which is a kind of nonvolatile semiconductor Memory, and can store various programs and the like.

In the printing apparatus 1, as shown in fig. 3, the ink 100 is ejected to form an image while making N round trips (N is a positive integer of 2 or more). To explain this in detail, the first forward path is referred to as a first path (a path having N equal to 1), and the first return path is referred to as a second path (a path having N equal to 2). The second forward path is referred to as a third path (path N equal to 3), and the second return path is referred to as a fourth path (path N equal to 4) (the third forward path and the subsequent paths are also referred to as N in the same manner). The length L of the print area a1 printed in the first pass and the length L of the print area a2 printed in the second pass along the conveyance direction of the workpiece W are the same (the same applies to the print area A3 and later).

In the printing apparatus 1, first, in the first path, the ink 100 is ejected to the hatched area of the processed product W in fig. 3 to form the printing area a 1. Next, the printing area a2 is formed by shifting the printing area a1 to the upstream side in the conveying direction. At this time, the amount of the offset printing region a2 is 1/4 the length L of the printing region a 1. That is, the print area a1 and the print area a2 overlap each other by 3/4 of length L and are offset by 1/4 of length L. In the printing apparatus 1, the printing regions A3, a4, a5, a6 are similarly formed.

Hereinafter, a case of printing an image in which the dot density (droplet density) of the image is yellow (Y) 100% black (K) 12% will be described as an example. In this case, as an example, 100% of yellow and 12% of black are equally divided and printed in four paths, and the ratio of yellow (Y) to black (K) in each path is 25: 3. hereinafter, the ink in this ratio is referred to as "ink 100C".

Even if the same ink is used, the ink bleeding method is different between the case of printing on the processed product W that is not printed and the case of printing on the processed product W that has already been printed. Therefore, the color of the formed print area is produced by printing on the area where the printing has not been performed so far, or by printing on the already printed portion, and the color is changed.

Below, the ratio of yellow and black is 25: ink 100C of 3 has a color a of a region printed on work W that has not yet been printed, and a color b of a region printed after ink 100 has been printed.

When the printing of the first path is completed in the printing apparatus 1, the entire area is the color "a" in the printing area a 1. When the printing of the second path is finished, the color of the region on the downstream side 1/4 of the print region a1 is also color a. The color of the region where the print region a1 and the print region a2 overlap is color a + b. The region on the upstream side 1/4 of the print region a2 is color a. "+" shows color coincidence.

At the end of the printing of the third pass, in the printing region a1, the color of the region 1/4 on the downstream side is color a, and the color of the region where the printing region a1 and the printing region a2 overlap is color a + b. In addition, in the region where the print region a1, the print region a2, and the print region A3 overlap, there is a color a + b + b (color a +2 b). In addition, in an area where only the print area a2 and the print area A3 overlap, color a + b is present. In the area where only the printing area a3 is printed, the color "a" is indicated.

When the printing is similarly performed, the areas of the color a, the color a + b, the color a +2b, the color a +3b, the color a +2b, the color a + b, and the color a are arranged in order from the downstream side when the printing of the fourth pass is completed. When the printing of the fifth pass is finished, the regions of the color a, the color a + b, the color a +2b, the color a +3b, the color a +2b, the color a + b, and the color a are arranged in order from the downstream side. When the printing of the sixth pass is finished, the regions of the color a, the color a + b, the color a +2b, the color a +3b, the color a +2b, the color a + b, and the color a are arranged in order from the downstream side.

In the printing apparatus 1, the area of the ink 100 having the color a +3b is a part of the actual product, and the parts of the color a, the color a + b, and the color a +2b are discarded. In this way, in the printing apparatus 1, the product portion is obtained by the fourth pass printing, and the product portion is enlarged in the area in the fifth pass and subsequent passes.

In general, when ink is ejected to an arbitrary position in a printing apparatus, the position of the landing point of the ink is shifted between the forward path and the return path. This is because the inertial forces acting on the ink in the forward path and the return path are oriented differently. In particular, if the size of the droplet of ink is small or the distance between the nozzle and the recording medium is large, misalignment is liable to occur significantly at the landing position of the ink in the forward path and the return path. When such a misalignment occurs, a "path shift" described below is considered as a means for reducing the misalignment.

An example of the path shift of the printing apparatus 1 will be described below. Hereinafter, a path shift of the ink 100 of black (K) out of the inks 100 of yellow (Y) and black (K) will be described.

In the printing apparatus 1, among the first to fourth paths, the black (K) ink 100K ejected in the first, third, and fourth paths is ejected in the second path. That is, the discharge position is changed and corrected (path shift) to change the discharge position.

By performing the discharge position change correction, 25: 3 is such that the ratio of yellow (Y) to black (K) in each path is 25: 0. the ratio of yellow (Y) and black (K) in the second path is 25: 12. the ratio of yellow (Y) and black (K) in the third path is 25: 0. the ratio of yellow (Y) and black (K) in the fourth path is 25: 0. this makes it possible to omit the ejection of the black (K) ink 100K in the first path, the third path, and the fourth path. The black (K) ink 100K ejected in the fifth path, the seventh path, and the eighth path is ejected in the sixth path in the same manner as in the fifth to eighth paths (the same applies to the ninth and subsequent paths).

An image obtained when printing is performed by performing such a path shift will be described with reference to fig. 4. Hereinafter, the ratio of yellow (Y) and black (K) is 25: the color of the processed product W in which the ink 100 of 0 has not fallen is regarded as the color a (hereinafter, the ink in which the ratio of yellow (Y) to black (K) is 25: 0 is referred to as the ink 100A.). In addition, the color of the case where the ink 100A is overlapped with the other ink 100 is seen as the color b. And, the ratio of yellow (Y) and black (K) is 25: the color of the processed product W on which the ink 100 of 12 has fallen is regarded as the color c (hereinafter, the ink in which the ratio of yellow (Y) to black (K) is 25: 12 is referred to as the ink 100B.). The color of the case where the ink 100B overlaps with the other ink 100 is regarded as the color d.

When printing is performed in the same manner as in the printing method described above, the region of the color a is formed when the printing in the first pass is completed. When the printing in the second path is completed, the regions of the color a, the color a + d, and the color c are formed in parallel in this order from the downstream side. When the printing in the third pass is completed, the regions of the color a, the color a + d, the color a + b + d, the color b + c, and the color a are formed in parallel in this order from the downstream side. When the printing in the fourth pass is completed, the regions of the color a, the color a + d, the color a + b + d, the color a +2b + d, the color 2b + c, the color a + b, and the color a are formed in parallel in this order from the downstream side. When the printing in the fifth pass is completed, the regions of the color a, the color a + d, the color a + b + d, the color a +2b + d, the color 3b + c, the color a +2b, the color a + b, and the color a are formed in parallel in this order from the downstream side. When the printing in the sixth pass is completed, the regions of the color a, the color a + d, the color a + b + d, the color a +2b + d, the color 3b + c, the color a +2b + d, the color a + d, and the color c are formed in parallel in this order from the downstream side.

In the image subjected to such path shift, the areas of the color a +2b + d and the color 3b + c are portions that actually become products, and the remaining portions are discarded. Further, by performing the path shift, printing of three paths among the four paths can be omitted, and therefore, the positional shift of the landing positions of the ink 100 in the forward path and the return path as described above can be reduced. Further, since the ink 100 omitted by the path shift is distributed to other paths, when the entire image is viewed, the total ejection amount of the ink 100 is the same, and the image quality of the image is less likely to deteriorate.

However, even if the path shift is performed, if the difference in color between the region of the color a +2b + d and the region of the color 3b + c is large, streaks occur in the portion that actually becomes a product, and image quality deterioration occurs. This image quality deterioration may be significantly reflected when the difference between the color a and the color b and the difference between the color c and the color d are large.

In the printing apparatus 1, the image quality of the image can be prevented from deteriorating due to the path shift. This will be explained below.

As shown in fig. 5, in the printing apparatus 1, when the path is shifted, in the printing area a1, the ratio of yellow (Y) to black (K) is 25: ink 100A of 0 is ejected.

In addition, in the printing region a2, in the region a21 from the downstream side to 3/4, the ratio of yellow (Y) and black (K) is 25: ink 100B of 12 is ejected. Then, in a region a22 of 1/4 on the upstream side of the printing region a2, the ink 100A is ejected.

In the printing area A3, the ink 100A is ejected in the area a31 from the downstream side to 1/2 at four equal divisions along the transport direction. In addition, in the region a32 of 1/4 on the upstream side of the region a31, the ink 100B is ejected. In addition, in the region a33 of 1/4 on the upstream side of the region a32, the ink 100A is ejected.

In the print area a4, the ratio of yellow (Y) and black (K) is 25: ink 100A of 0 is ejected.

By such a path shift, a portion where the ink 100B directly lands on the processed product W can be omitted, and the ink 100B ejected in the printing area a2 and the printing area A3 lands so as to overlap the ink 100A. That is, the ink 100B is ejected at the overlapping portion where the printing regions a1 to a4 overlap each other. Therefore, as shown in fig. 6, the color c when the ink 100B is directly dropped on the processed product W can be prevented from appearing. Thus, despite the path shift, the color of the portion actually being the product becomes only the color a +2b + d. Therefore, it is possible to prevent deterioration of image quality due to a difference in color between the color a +2b + d and the color 3b + c, which is caused by the conventional path shift. As a result, in the printing apparatus 1, even if the path is shifted, an image with high printing accuracy can be formed. In fig. 6, hatching is given to the region where the ink 100B is ejected.

Next, the control operation of the control unit 15 will be described with reference to a flowchart shown in fig. 7.

In step S101, path decomposition is performed based on the image data input to the printing apparatus 1, and it is determined in which path the amount of ink 100 is ejected.

Next, in step S102, it is determined whether or not a path shift should be performed based on the machining product gap and the like. If it is determined in step S102 that there is a possibility that the image quality will deteriorate if no path shift is performed, the following path shift process is performed in step S103.

As shown in fig. 5, the printing area a1 to the printing area a4 are each quartered along the conveyance direction. Then, it is determined whether or not the path shift is performed for each divided area, that is, which of the

inks

100A and 100B is to be ejected.

In the printing area a2, it is determined that the ink 100B is ejected to the area a21 that is the area from the downstream side to 3/4 among the quarters. In the print area A3, it is determined that the ink 100A is ejected to the area a31 and the area a33, and the ink 100B is ejected to the area a 32. Then, it is determined to discharge the ink 100A to the entire printing area a1 and the printing area a 4.

By dividing each of the printing area a1 to the printing area a4 and distributing the ink 100A or the ink 100B to each of the divided areas in this way, it is possible to prevent the ink 100B, which is the portion subjected to the path shift processing, from landing in an overlapping manner in the formed image. Therefore, the image quality of the obtained image can be prevented from deteriorating.

The ink 100A and the ink 100B are also dispensed in the fifth path and thereafter in the same manner as in the first to fourth paths.

Next, in step S104, printing is performed with the setting determined in step S103. This enables formation of an image on which the path shift processing has been performed.

If it is determined in step S102 that the path shift is not performed, the printing is performed in a state where the path decomposition processing is performed in step S101 without performing the path shift.

As described above, when attention is paid to the printing area a2 and the printing area A3, in the conventional path shift, the ink 100 ejected in the printing area A3 is changed in the ejection position in the printing area a2, so that only the ink 100A as the first ink is ejected in the printing area A3 and only the ink 100B as the second ink is ejected in the printing area a 2. In contrast, in the present invention, when the path is shifted, not only the ejection position (first ejection position) of the ink 100 ejected in the printing area A3 is changed to the printing area a2, but also the ejection position (second ejection position) of a part of the ink 100B (second ink) ejected in the printing area a2 is changed to the printing area A3. This prevents deterioration in image quality of the image due to the path shift. As a result, even if the path is shifted, an image with high printing accuracy can be formed.

The path shift described above enables selection of whether or not each nozzle ejects the ink 100 among the plurality of nozzles included in the nozzle group.

In the present embodiment, the printing apparatus 1 is set to form images by using four paths as one set so as to form the first to fourth paths and the fifth to eighth paths, but the present invention is not limited to this, and may be set to form images by using two paths, three paths, or five or more paths as one set, for example. In addition, in the path shift at this time, when the number of one set of paths is n, each path is divided into n in the transport direction, and ink 100A and ink 100B are distributed to each divided region.

Second embodiment

Fig. 8 is a diagram illustrating a process in which the printing apparatus (second embodiment) of the present invention performs the discharge position change correction and prints an image.

Hereinafter, a second embodiment of the printing apparatus according to the present invention will be described with reference to the drawings, but differences from the above-described embodiments will be mainly described, and descriptions of the same matters will be omitted.

This embodiment is the same as the first embodiment except that the control for changing and correcting the ejection position is different.

As shown in fig. 8, in the present embodiment, when the path is shifted, the ink 100A and the ink 100B are dispensed as follows.

In the printing area a1, the ink 100A is ejected over the entire area. In the printing area a2, the ink 100B is ejected in the area a23 from the downstream side to 1/2 at four equal divisions along the transport direction. In a region a24 of 1/2 on the upstream side of the region a23 of the printing region a2, the ink 100A is ejected. In the print area a3, the ink 100A is ejected over the entire area. In the printing area a4, the ink 100B is ejected in the area a41 from the downstream side to 1/2 at four equal divisions along the transport direction. In a region a42 of 1/2 on the upstream side of the region a41 of the printing region a4, the ink 100A is ejected.

According to the present embodiment, as in the first embodiment, the portion of the processed product W onto which the ink 100B directly falls can be omitted. Therefore, it is possible to prevent the image quality from deteriorating due to the hue difference between the color a +2b + d and the color 3b + c caused by the conventional path shift. Further, the boundary of the region where the ink 100B lands when viewed as a whole image can be further reduced. As a result, the number of portions in which streaks are likely to occur in the obtained image is reduced. As described above, in the present embodiment, even if the path shift is performed, an image with high printing accuracy can be formed.

Third embodiment

Fig. 9 is a diagram illustrating a process in which the printing apparatus (third embodiment) of the present invention corrects the discharge position change and prints an image.

Hereinafter, a third embodiment of the printing apparatus according to the present invention will be described with reference to the drawings, but differences from the above-described embodiments will be mainly described, and descriptions of the same items will be omitted.

As shown in fig. 9, in the present embodiment, when the path is shifted, ink 100A and ink 100B are dispensed as follows.

In the printing area a1, the ink 100B is ejected over the entire area.

In the printing area a2, the ink 100A is ejected in the area a21 from the downstream side to 3/4 at four equal divisions along the transport direction. In a region a22 of 1/4 on the upstream side of the region a21 of the printing region a2, the ink 100B is ejected.

In the printing area A3, the ink 100A is ejected in the area a31 from the downstream side to 1/2 at four equal divisions along the transport direction. In a region a32 of 1/4 on the upstream side of the region a31 of the printing region A3, the ink 100A is ejected. In a region a33 of 1/4 on the upstream side of the region a31 of the printing region A3, the ink 100B is ejected.

In the printing area a4, the ink 100A is ejected in the area a41 from the downstream side to 3/4 at four equal divisions along the transport direction. In a region a42 of 1/4 on the upstream side of the region a41 of the printing region a4, the ink 100B is ejected.

According to the present embodiment, the ink 100B can be prevented from landing so as to overlap with the

inks

100A and 100B. That is, in the present embodiment, the ink 100B is ejected in a region different from the overlapping portion where the processed product W overlaps in a plan view, among the printing regions a1 to a 4. This can omit the color d caused by the landing of the ink 100B overlapping the

inks

100A and 100B. Therefore, the color of the portion of the processed product W actually used as a product is color 3b + c. Therefore, it is possible to prevent the image quality from deteriorating due to the hue difference between the color a +2b + d and the color 3b + c caused by the conventional path shift. Further, since the order of overlapping the ink 100A and the ink 100B is the same in each printing region, an image with higher printing accuracy can be formed.

Although the printing apparatus and the printing method of the present invention have been described in the illustrated embodiments, the present invention is not limited thereto, and each part constituting the printing apparatus may be replaced with an arbitrary structure that can exhibit the same function. In addition, any structure may be added.

The printing apparatus of the present invention may be an apparatus in which two or more arbitrary configurations (features) of the above-described embodiments are combined.

In the above embodiments, the case where the printing mechanism section ejects ink as droplets of the same size has been described, but the present invention is not limited to this, and may be a mechanism section that ejects ink as droplets of two or more sizes. In this case, the above-described correction of the discharge position change may be performed for each size of the ink droplets.

Description of the symbols

1 … printing device, 2 … drying unit, 21 … chamber, 22 … coil, 3 … delivery device, 31 … sending-out roller, 32 … tensioner, 4 … winding device, 41 … winding roller, 42 … tensioner, 43 … tensioner, 44 … tensioner, 5 … supporting device, 51 … driving roller, 52 … driven roller, 53 … endless belt, 54 … tensioner, 55 … tensioner, 6 … nozzle group, 11 … table, 12 … conveying mechanism unit, 13 … printing mechanism unit, 131 … inkjet head, 132 … bracket unit, … lifting mechanism, 15 … control unit, 151 … CPU, 152 … path decomposition unit, 153 … correction decision unit, 154 … execution unit, 155 … storage unit, 100 … ink, 100a … ink, 100B … ink, 100C … ink, S101 … step, S102 … step, S103S … step, step … printing area …, … a … area, A21 … region, a22 … region, a23 … region, a24 … region, A3 … printed region, a31 … region, a32 … region, a33 … region, a4 … printed region, a41 … region, a42 … region, a43 … region, a44 … region, a5 … printed region, A6 … printed region, L … length, and W … processed product.

Claims

1. A printing apparatus, comprising:

a printing unit that forms an image including a first print region and a second print region by ejecting a first ink on a first path along a direction intersecting a transport direction of a recording medium to be transported to form the first print region on the recording medium and then ejecting a second ink on a second path different from the first path to form the second print region on the recording medium;

a determination unit that determines a first discharge position of the first ink in the first path and a second discharge position of the second ink in the second path when the image is formed; and

and a correction determination unit that performs ejection position change correction that changes the first ejection position to eject the first ink on the second path and that changes the second ejection position to eject a part of the second ink on the first path, based on a determination result of the determination unit.

2. The printing apparatus according to claim 1, wherein the printing portion forms an overlapping portion where a part of the first printing region and the second printing region overlap in a plan view of the recording medium.

3. The printing apparatus according to claim 2, wherein in the ejection position change correction, the second ink ejected in the first printing region and the first ink ejected in the second printing region are ejected so as to be shifted in a plan view of the recording medium.

4. The printing apparatus according to claim 2 or 3, wherein when the printing unit moves n times to form the image, the correction determining unit divides the second printing area into n, where n is a positive integer equal to or greater than 2, and determines whether or not the discharge position change correction is performed in each of the divided areas.

5. The printing apparatus according to claim 2 or 3, wherein in the ejection position change correction, the second ink ejected in the first printing region is ejected in the overlap portion.

6. The printing apparatus according to claim 2 or 3, wherein in the ejection position change correction, the second ink ejected in the first printing region is ejected at a position different from the overlapping portion.

7. The printing apparatus according to any one of claims 1 to 3, wherein the printing section ejects at least two inks different in hue from each other,

the correction determination unit performs the discharge position change correction on the ink with a small discharge amount per unit area in the image, among the two inks.

8. A printing method for performing printing using a printing apparatus, the printing apparatus comprising:

a printing unit that forms an image including a first print region and a second print region by ejecting a first ink on a first path along a path intersecting a transport direction of a recording medium to be transported to form the first print region on the recording medium, and thereafter ejecting a second ink on a second path different from the first path to form the second print region at a position different from the first print region; and

a determination unit that determines a first discharge position of the first ink in the first path and a second discharge position of the second ink in the second path when the image is formed,

the printing method performs ejection position change correction for changing the first ejection position to eject the first ink in the second path, and when the first ink is changed, the second ink is changed to eject a part of the second ink in the first path.