Printer, printing method, and program

Abstract

To provide a printer including a drying step during a printing step which reduces color shift.SOLUTION: A printer performs drying between a first recording part and a second recording part calculates a first misregistration amount between the first recording part and the second recording part, on the basis of a pattern for detecting misregistration between the first recording part and the second recording part printed in a first region, misregistration in a recording head of the first recording part and a misregistration amount in the recording head of the second recording part. The printer calculates a second misregistration amount between the recording parts generated by expanding / contracting a sheet in a conveyance direction by heating and cooling, on the basis of the calculated first misregistration amount between the recording parts, and the pattern for detecting the misregistration between the first recording part and the second recording part printed in the second region. The printer expands / contracts image data for the first recording part according to the calculated second misregistration amount between the recording parts, or adjusts a discharge frequency of the recording head of the first recording part.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a control technique for a printing apparatus that dries a recording medium after printing. [Background technology]

[0002] In recent years, there has been a demand for high-quality printing of white and color inks in inkjet printing devices that record on recording media. To this end, some printing devices have separate white and color recording sections with a drying section between them. By providing a drying section between the white and color recording sections, such printing devices enable recording of images without mixing of the white and color inks. Patent Document 1 discloses a printing device that performs color printing using an inkjet printer and white printing using gravure roll coating of white ink, with a drying process downstream of each printing process. The printing device described in Patent Document 1 also reduces deformation of the film, such as stretching, shrinking, and waviness, by heating and then cooling the film. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-005716 Summary of the Invention [Problem to be solved by the invention]

[0004] However, while the technology described in Patent Document 1 can prevent large deformations of recording media due to temperature control, it cannot prevent minute expansion and contraction that differs for each recording medium due to residual stress in the manufacturing process of the recording medium, resulting in the problem of color shifts occurring due to the expansion and contraction of the recording medium.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to reduce color misregistration in a printing apparatus that performs a drying process between printing processes. [Means for solving the problem]

[0006] The present invention is a printing device comprising a first recording means for recording a first image on a recording medium, a drying means for drying the recording medium on which the first image has been recorded by the first recording means, a second recording means for recording a second image on the recording medium dried by the drying means, and a control means for controlling the recording position of the first recording means or the recording position of the second recording means in accordance with expansion or contraction of the recording medium due to drying by the drying means. [Effects of the Invention]

[0007] According to the present invention, it is possible to reduce color misregistration in a printing device that performs a drying process between printing processes. [Brief explanation of the drawings]

[0008] [Figure 1] Schematic diagram showing the internal configuration of a printing device [Figure 2] FIG. 1 is a perspective view of a housing of a sheet conveying unit of a recording unit according to an embodiment; [Figure 3] 1 is a perspective view of a recording head lifting mechanism according to an embodiment; [Figure 4] 1 is a block diagram of a control unit of a printing apparatus according to an embodiment; [Figure 5] 1 is a flowchart showing the process of printing a maintenance pattern and reading the printed maintenance pattern in an embodiment. [Figure 6] FIG. 10 shows maintenance patterns A and B printed on two recording units in an embodiment. [Figure 7] FIG. 10 is a diagram illustrating a maintenance pattern in which maintenance patterns A and B are superimposed, and an explanation of the patterns in each region in the embodiment. [Figure 8] 10 is a flowchart showing a process for calculating a registration misalignment amount from a read maintenance pattern in an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the components described in the following embodiments are merely examples, and the configuration and various conditions of the device to which the present invention is applied can be modified or changed as appropriate without departing from the spirit of the present invention, and the present invention is not limited to the following embodiments. For example, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments can be modified as appropriate depending on the configuration and various conditions of the device to which the present invention is applied, and unless otherwise specified, the present invention is not limited to the following embodiments.

[0010] 1 is defined as the top, right to left as the longitudinal direction, and the sheet width direction from the front to the back of the paper, which is perpendicular to the recording medium transport direction. The printing device 1 is a high-speed line printer that uses a rolled continuous sheet as the recording medium.

[0011] <Printing device> FIG. 1 shows a schematic cross-sectional view of a printing apparatus 1 according to this embodiment. The printing apparatus 1 of this embodiment includes a conveyance mechanism including an unwinding unit 2, a first dancer unit 3, a first main conveyance unit 4, a meandering correction unit 5, a conveyance detection unit 6, a conveyance tension detection unit 9, a second main conveyance unit 12, a second dancer unit 13, and a winding unit 14. The printing apparatus 1 also includes a recording mechanism including a recording unit 7, a recorded image position detection unit 10, a scanner unit 11, a maintenance unit 15, a drying unit 40, and a cooling unit 50. A continuous sheet S, which is a recording medium, is conveyed along the sheet conveyance path indicated by the solid line in the figure and processed by each unit. While the drying unit 40 and the cooling unit 50 are distinguished in this embodiment, the drying unit 40 and the cooling unit 50 may be combined together to form a drying unit.

[0012] The printing apparatus 1 is configured to perform a first recording process and a second recording process along a sheet transport path. In the first recording process, an image is fixed and recorded on the sheet S as it passes through the first recording unit 7a, the first drying unit 40a, and the first cooling unit 50a. In the second recording process, an image is fixed and recorded on the sheet S as it passes through the second recording unit 7b, the second drying unit 40b, and the second cooling unit 50b after the first recording process. In this way, the printing apparatus 1 performs the first and second recording processes on the sheet S, thereby enabling continuous recording of overlapping images on the sheet S without color mixing. The printing apparatus 1 can also select a recording process depending on the printing conditions, and records an image on the sheet S by performing only the selected recording process. Note that the direction of transport of the sheet S from the unwinding unit 2 to the winding unit 14 is defined as forward transport, and the opposite direction is defined as reverse transport.

[0013] The unwinding unit 2 is a unit for holding and supplying roll paper, which is a continuous sheet wound into a roll. The unwinding unit 2 is configured to store roll paper and pull out the roll paper to supply sheet S. Note that the number of roll paper that can be stored is not limited to one, and the unwinding unit 2 may be configured to store multiple rolls of paper and pull out one of the rolls to supply sheet S. Note that the unwinding unit 2 is controlled by a motor (not shown) so that it can rotate forward and backward.

[0014] The first dancer section 3 is a unit for applying a constant sheet tension between the unwinding section 2 and the first main conveying section 4 by a tension applying means (not shown).

[0015] The first main conveying section 4 is a unit for applying sheet tension together with the second main conveying section 12 while feeding the sheet S to each unit arranged along the sheet conveying path, and is driven by a motor not shown to convey the sheet S under tension.

[0016] The meandering correction unit 5 is a unit for correcting meandering in the sheet width direction when the sheet S is conveyed under tension. In this embodiment, the meandering correction unit 5 is provided with a first meandering correction unit 5a and a second meandering correction unit 5b upstream of each recording process on the sheet conveyance path. The meandering correction unit 5 is configured to include a meandering correction roller and a meandering detection sensor (not shown) that detects meandering of the sheet S. The meandering correction roller can change its inclination relative to the sheet S by a motor (not shown), and corrects meandering of the sheet S based on the measurement results from the meandering detection sensor. The meandering correction unit 5 enhances the meandering correction function by winding the sheet S around the meandering correction roller.

[0017] The transport detection unit 6 is a unit for detecting a predetermined detection mark printed in advance on the sheet S in order to control the timing of image recording in the recording unit 7. In this embodiment, the transport detection unit 6 includes a first transport detection unit 6a and a second transport detection unit 6b, which are provided upstream of each recording process in the sheet transport path. The first transport detection unit 6a and the second transport detection unit 6b are used to control the timing of image recording in the first recording unit 7a and the second recording unit 7b, respectively.

[0018] The recording unit 7 forms an image by applying a liquid composition (ink) onto the transported sheet S from above using a recording head 22. The sheet transport path in the recording unit 7 is formed by guide rollers 23 arranged in an arc-shaped convex upward configuration. A constant tension is applied to the sheet S, ensuring a constant clearance between the sheet S and the recording head 22. Multiple recording heads 22 are installed in the recording unit 7 along the transport direction. In this embodiment, the first recording unit 7a has a total of two line-type recording heads corresponding to W (white) ink and a reaction liquid. The second recording unit 7b has a total of eight line-type recording heads corresponding to four colors: Bk (black), Y (yellow), M (magenta), and C (cyan), as well as a reaction liquid and three spot colors. The reaction liquid is a liquid containing a component that increases the viscosity of the ink. Here, increasing the viscosity of the ink refers to a state in which the coloring material, resin, etc. that make up the ink come into contact with the component that increases the viscosity of the ink, resulting in a chemical reaction or physical adsorption, resulting in an increase in the ink viscosity. Increasing the viscosity of ink does not only mean an increase in the viscosity of the ink as a whole, but also includes localized increases in viscosity due to partial aggregation of components that make up the ink, such as colorants and resins. There are no particular restrictions on the components that increase the viscosity of the ink, such as metal ions and polymer flocculants. However, substances that cause a change in the pH of the ink and aggregate the colorants in the ink can be used, and organic acids can also be used. Applying a reaction liquid before applying the ink to the sheet S allows the ink to immediately settle once it reaches the sheet S. This can prevent adjacent inks from mixing together, which causes bleeding.

[0019] The types and number of colors and the number of recording heads 22 are not limited to those in this embodiment. The inkjet method may employ a method using a heat generating element, a method using a piezoelectric element, a method using an electrostatic element, a method using a MEMS element, or the like. Ink is supplied to the recording heads 22 from ink tanks (not shown) via ink tubes.

[0020] As shown in FIG. 2, the sheet conveying unit housing 71 of the recording unit 7 is provided with multiple recording head positioning members 711 for positioning the recording heads 22. In this embodiment, the recording head positioning members 711 are provided at the front and rear of each recording head 22, sandwiching the sheet S between them in the sheet width direction. As shown in FIG. 3, the recording head 22 is supported by a recording head holding unit 26 that holds the recording head 22 and raises and lowers it vertically, with the recording head support shaft 27 supported from below. The recording head holding unit 26 is raised and lowered vertically along lift rails 29 provided within a recording head lift frame 28 by an internal drive mechanism (not shown). In this example, ink is applied to the sheet S using an inkjet head, but the method of applying ink to a sheet in the recording unit 7 is not limited to this. For example, although the reaction liquid is applied by the recording head 22 in this example, it may be applied by a roller, a die coating device (die coater), a blade coating device (blade coater), or the like.

[0021] The conveying tension detection unit 9 is a unit for detecting tension when the sheet S is conveyed between the first main conveying unit 4 and the second main conveying unit 12 under tension.

[0022] The recording image position detection unit 10 is a unit that detects the misalignment of the image formed on the sheet S by the recording unit 7 during printing and corrects the printing.

[0023] The winding guide roller R1 is a roller that wraps the surface of the sheet S downstream of the second recording unit 7b opposite to the ink application surface at a constant winding angle. In this embodiment, two winding guide rollers R1 are arranged between the second recording unit 7b and the second drying unit 40b, the sheet S is folded back approximately parallel to the top and bottom of the device, and the second drying unit 40b is arranged below the second recording unit 7b.

[0024] The drying section 40 (first drying section 40a, second drying section 40b) is a unit that reduces the liquid content contained in the liquid composition applied to the sheet S in the recording section 7 and improves the fixability of the ink on the sheet S. The drying section 40 dries the applied ink by blowing air at a predetermined temperature onto the recorded sheet S. Inside the drying section 40, hot air is blown onto the passing sheet S from at least the ink-applied side to dry the ink-applied surface of the sheet S. Note that the drying method may be a combination of a method of applying hot air, a method of irradiating the surface of the sheet S with electromagnetic waves (ultraviolet rays, infrared rays, etc.), and a conductive heat transfer method by contact with a heating element.

[0025] The cooling section 50 (first cooling section 50a, second cooling section 50b) cools the sheet S heated in the drying section 40, solidifies the softened ink, and controls the temperature of the sheet S to an appropriate temperature for downstream processes in the printing device. Inside the cooling section 50, air at a lower temperature than the sheet S is blown onto at least the ink-applied surface side of the passing sheet S to cool the ink-applied surface of the sheet S. Note that the cooling method is not limited to the air blowing method, and may also be a conductive heat transfer method using contact with a heat dissipation member, or a combination of these.

[0026] The scanner unit 11 is a unit that reads test images and maintenance patterns formed on the sheet S by the recording unit 7 before actual printing. The images read by the scanner unit 11 are used by the control unit 31, which will be described later, to detect misalignment and ink density of the image printed by the recording unit 7.

[0027] The second main conveying section 12 is a unit that conveys the sheet S while applying tension to it together with the first main conveying section 4, and adjusts the tension of the sheet S. The second main conveying section 12 is driven by a motor (not shown), and controls the conveying speed according to a tension value detected by a conveying tension detection section 9 in accordance with a tension control section (not shown). As an additional configuration for adjusting the tension of the sheet S, a configuration for adjusting the tension of the sheet S by a clutch (not shown) that can control the torque connected to the drive shaft may be added. In this case, there are two tension control methods: a torque control method that controls the torque value transmitted from the clutch, and a speed control method that controls the roller speed of the second main conveying section 12. The tension control methods can be switched depending on the purpose, or both can be used simultaneously.

[0028] The second dancer section 13 is a unit for applying a constant sheet tension between the second main conveying section 12 and the winding section 14. The second dancer section 13 applies sheet tension by a tension applying means (not shown).

[0029] The winding unit 14 is a unit for winding the recorded sheet S onto a core. The number of recoverable rolls is not limited to one; two or three or more cores may be provided, and the sheet S may be collected as multiple rolls by selectively switching between them. The winding unit 14 is independently controlled to rotate forward and reverse by a drive motor (not shown). The sheet S is conveyed forward and backward by controlling the drive motors (not shown) of the unwinding unit 2 and the winding unit 14 to rotate forward or backward. In the case of reverse conveyance, tension conveyance is also performed between the first main conveyance unit 4 and the second main conveyance unit 12, as in the case of forward conveyance. Note that, depending on the processing content of the printed sheet S, instead of winding it onto a core, the sheet S may be cut using a cutter and the cut sheets S may be stacked.

[0030] The control unit 31 is a unit that controls each part of the entire printing device. The control unit 31 has a CPU, a storage device, a controller equipped with various control units, an external interface, and an operation unit 32 through which the user performs input and output. The operation of the printing device 1 is controlled based on commands from the controller or a host device 33 such as a host computer connected to the controller via an external interface. The control unit 31 includes an image processing unit 401, a print control unit 402, and an image reading and calculation unit 403. Figure 4 shows a block diagram of the image processing unit 401, print control unit 402, and image reading and calculation unit 403 of the control unit 31.

[0031] An image processing unit 401 performs gamma correction, color processing, binarization (halftone processing), enlargement / reduction processing, etc. on print data (multi-value image data) transferred from a host computer or the like via an interface.

[0032] The print control unit 402 controls the recording unit 7, motors, and sensors in accordance with various programs and parameters stored in the storage device for the image data developed by the image processing unit 401, thereby printing an image on the sheet S and outputting the sheet S with the image printed on it.

[0033] The image reading and calculation unit 403 acquires the scanned image read by the scanner unit 11, reads the test image and maintenance pattern, calculates misregistration information and color gamut information, and transmits the calculation results to the image processing unit 401 and the print control unit 402. The image processing unit 401 and the print control unit 402 adjust the recording position of the recording unit 7. Adjusting the recording position involves adjusting the start positions of recording for the first recording unit 7a and the second recording unit 7b, as well as adjusting the recording position so that the size of the image printed by the first recording unit 7a changes in response to expansion and contraction of the recording medium due to drying. The adjustment of the recording position may be performed by the second recording unit 7b rather than the first recording unit 7a, or both may share some of the adjustment. The adjustment of the recording position in response to expansion and contraction of the recording medium can be achieved, for example, by having the image reading and calculation unit 403 calculate the amount of expansion and contraction of the maintenance pattern printed by the first recording unit 7a, and then having the image processing unit 401 perform enlargement / reduction processing on the recording data for the first recording unit 7a. Another method is to have the image reading and calculation unit 403 calculate the amount of expansion or contraction of the maintenance pattern printed by the first recording unit 7a, and then have the print control unit 402 adjust the ejection timing of the first recording unit 7a. The amount of expansion or contraction of the maintenance pattern printed by the first recording unit 7a can be calculated from the registration misalignment between the maintenance pattern printed by the first recording unit 7a and the maintenance pattern printed by the second recording unit 7b. Details will be described later.

[0034] The maintenance unit 15 is a unit equipped with a mechanism for restoring the ejection performance of the recording head 22. Examples of mechanisms for restoring ejection performance include a cap mechanism for protecting the ink ejection surface of the recording head 22, a wiper mechanism for wiping the ink ejection surface, and a suction mechanism for negatively pressurizing ink inside the recording head 22 and away from the ink ejection surface. The maintenance unit 15 is also provided with a drive mechanism and rails (not shown), and is capable of horizontally reciprocating along the rails. The maintenance unit 15 moves directly below the recording head 22 only when maintenance is performed, and moves to a position retracted from directly below the recording head 22 at other times. In this embodiment, a first maintenance unit 15a and a second maintenance unit 15b are provided for the first recording unit 7a and the second recording unit 7b, respectively.

[0035] FIG. 5 shows a flowchart illustrating the operation of the printing device according to this embodiment, from recording a maintenance pattern on a recording medium (sheet S) to reading the recorded maintenance pattern.

[0036] In S501, the control unit 31 starts conveying the sheet S using the conveying mechanism.

[0037] In S502, when the sheet S reaches a constant speed, the control unit 31 starts recording a maintenance pattern A (described later) made of reaction liquid and white ink on the sheet S by the first recording unit 7a. The maintenance pattern A includes a detection mark P that is detected by the second conveyance detection unit 6b and the scanner unit 11.

[0038] In S503, the control unit 31 causes the first drying unit 40a to perform a drying process on the portion of the sheet S on which the maintenance pattern A is recorded.

[0039] In S503, the control unit 31 performs a cooling process on the portion of the sheet S on which the maintenance pattern A has been recorded and dried by the first cooling unit 50a.

[0040] The maintenance pattern A is heated by drying in the first drying unit 40a in S503, and cooled by the first cooling unit 50a in S504 before reaching the upstream of the second recording unit 7b. By undergoing this heating and cooling process, the sheet S is slightly deformed in both the same direction as the conveyance, the conveyance direction, and the vertical direction, and the maintenance pattern A also deforms along with the deformation of the sheet S.

[0041] In S505, when the maintenance pattern A reaches the upstream side of the second recording unit 7b and the second conveyance detection unit 6b detects the detection mark P, the control unit 31 determines the timing of recording an image by the second recording unit 7b.

[0042] In S506, the control unit 31 starts recording a maintenance pattern B made of reaction liquid and color (C, M, Y, K, spot color) inks on maintenance pattern A of sheet S using the second recording unit 7b, according to the recording timing determined in S505. As a result, maintenance pattern A and maintenance pattern B are formed overlapping each other on sheet S. At this time, the portion of sheet S on which maintenance pattern A is printed expands and contracts slightly due to the heating and cooling process, and maintenance pattern A also expands and contracts in accordance with the expansion and contraction of sheet S, resulting in color misalignment between maintenance pattern A and maintenance pattern B.

[0043] In S507, the control unit 31 causes the second drying unit 40b to perform a drying process on the portion of the sheet S on which the maintenance patterns A and B are printed.

[0044] In S508, the control unit 31 performs a cooling process on the portion of the sheet S on which the maintenance patterns A and B have been recorded and dried by the second cooling unit 50b.

[0045] In S509, the control unit 31 causes the scanner unit 11 to detect the maintenance patterns A and B, triggered by the detection of the detection mark P by the scanner unit 11.

[0046] In S510, when the maintenance patterns A and B are conveyed to the winding unit 14, the control unit 31 stops conveying the sheet S.

[0047] 6 and 7 show the maintenance pattern used in this embodiment. As shown in Fig. 6, the maintenance pattern is formed by printing a maintenance pattern A (Fig. 6(a)) made of reaction liquid and white ink on top of a maintenance pattern B (Fig. 6(b)) made of reaction liquid and color ink (Fig. 7(a)). As shown in Figs. 6 and 7, the maintenance pattern is divided into areas 601 to 606, starting from the upstream side in the transport direction.

[0048] A detection mark P is recorded in white ink in area 601. Areas 602 to 606 are recorded by the first recording unit 7a and the second recording unit 7b, respectively, triggered by detection of the detection mark P by the second conveyance detection unit 6b.

[0049] Area 602 contains an inter-recording-unit registration misalignment pattern, which is a combination of multiple white (W) and color (Bk) patterns and is used to detect relative misalignment between the first and second recording units 7a and 7b. Area 602 can read inter-recording-unit registration misalignment, which is the misalignment between the recording positions of the first and second recording units 7a and 7b triggered by the detection of the detection mark P by the second conveyance detection unit 6b. When reading this inter-recording-unit registration misalignment, the registration misalignment within the white (W) recording head 22 of the first recording unit 7a and the registration misalignment within the color (Bk) recording head 22 of the second recording unit 7b, which were read in separate areas, are reflected. Intra-recording-head registration misalignment is registration misalignment caused by variations in the positional relationships between the recording chips and nozzle rows of each recording head 22. Area 602 can also read widthwise inter-recording-unit registration misalignment caused by expansion and contraction of the sheet S in the width direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a.

[0050] A color print head misregistration pattern, which is a combination of multiple patterns for Bk, Y, M, Cy, and special colors, is recorded in area 603. From area 603, it is possible to read the misregistration of the print position caused by variations in the positional relationships between print chips and nozzle rows in the print head 22 for each color ink of the second recording unit 7b.

[0051] A white print head internal laser misalignment pattern, which is a combination of multiple W patterns, is printed in area 604. From area 604, it is possible to read the print position misalignment caused by variations in the positional relationships between print chips and nozzle rows in the print head 22 for W ink of the first recording unit 7a.

[0052] A color recording head misregistration pattern, which is a combination of multiple patterns of Bk, Y, M, Cy, and special colors, is recorded in area 605. This allows the misregistration of the recording positions between the color recording heads 22 (Bk, Y, M, Cy, and special colors) of the second recording unit 7b to be read.

[0053] An inter-recording unit registration mismatch pattern, which is a combination of multiple white (W) and color (Bk) patterns, is recorded in region 606. The inter-recording unit registration mismatch pattern in region 606 is the inter-recording unit registration mismatch pattern in region 602, inverted in the sheet conveyance direction (left-right inverted in Figures 6 and 7). Therefore, the same registration mismatch as in S602 can be read from S606. In addition, region 606 reads inter-recording unit registration mismatch caused by expansion and contraction of the sheet S in the conveyance direction and width direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a. The reason why region 606 reads inter-recording unit registration mismatch caused by expansion and contraction of the sheet S in the conveyance direction is because the amount of expansion and contraction of the sheet S in the conveyance direction increases the farther it is from the detection mark P. Therefore, it is easier to read inter-recording unit registration mismatch caused by expansion and contraction of the sheet S in the conveyance direction in region 606 than in region 602, and reading can be performed with high accuracy.

[0054] Furthermore, when recording maintenance pattern A on sheet S, a pattern (not shown) that achieves an average and uniform amount of white ink ejection in actual printing is printed outside the printing areas of maintenance patterns A and B. This pattern is intended to reproduce the expansion and contraction caused by the latent heat of the white ink when the sheet S and ink are heated and cooled by the first drying unit 40a and first cooling unit 50a in actual printing that is not test printing. This makes it possible to reduce the difference in conditions between test printing and actual printing, and to reduce the error between the amount of registration misalignment calculated from maintenance patterns A and B and the amount of registration misalignment in actual printing. Note that although an example using only white ink has been described above, it is also possible to use both white ink and color inks. In this case, it is possible to more closely resemble actual printing. 6 and 7 and described above, the order of the maintenance patterns in this embodiment is not limited to this; the order of the regions 601 to 606 may be changed or some may be omitted. Also, other maintenance patterns may be combined, or the maintenance pattern may be divided and the divided patterns may be arranged at intervals. For example, if the maintenance pattern is specialized for correcting misregistration (color misregistration) between printing units caused by expansion and contraction of the sheet S due to heating and cooling, only the correction patterns of the regions 601, 602, and 606 may be used. In this case, the interval between the regions 602 and 606 may be set appropriately depending on the correction accuracy.

[0055] 8 shows a flowchart illustrating a method for calculating various registration misalignment amounts from maintenance patterns in this embodiment. Note that the registration misalignment amount may be calculated as a difference between a predetermined position such as the center or a predetermined edge between corresponding patterns, but the method for calculating the registration misalignment amount is not limited to this, and other existing calculation methods may also be used.

[0056] In S801, the amount of misregistration 501 in each recording head included in the second recording unit 7b is calculated based on the misregistration pattern in the color recording head detected in the area 603. That is, the amount of misregistration 501 includes the amount of misregistration for each of Bk, Y, M, Cy, and the spot color.

[0057] In S802, based on the pattern of misregistration in the white recording head detected in the area 604, the amount of misregistration 502 in the white (W) recording head 22 of the first recording unit 7a is calculated.

[0058] In S803, the registration misalignment amount 503 between the recording heads 22 of different colors included in the second recording unit 7b is calculated based on the registration misalignment pattern between the color recording heads detected in the area 605. Note that the registration misalignment amount 503 may be calculated, for example, using Bk as the reference, to calculate the registration misalignment amount between the Bk recording head 22 and the recording heads 22 of other colors.

[0059] In S804, a registration misalignment amount 504 between the first recording unit 7a and the second recording unit 7b is calculated based on the inter-recording unit registration misalignment pattern detected in area 602 and the registration misalignment amounts 501 and 502 calculated in S801 and S802. More specifically, this registration misalignment amount 504 is the registration misalignment amount between the white (W) recording head 22 of the first recording unit 7a and the Bk recording head 22 of the second recording unit 7b.

[0060] In S805, based on the misregistration pattern between recording units detected in region 602 and the misregistration amounts 501 and 502 calculated in S801 and S802, a misregistration amount 505 between recording units caused by expansion and contraction of the sheet S in the width direction due to heating and cooling is calculated. The heating and cooling here is performed by the first drying unit 40a and the first cooling unit 50a.

[0061] In S806, based on the inter-recording unit registration misalignment pattern detected in area 606 and the registration misalignment amount 504 calculated in S804, the registration misalignment amount 506 between the recording units caused by expansion and contraction of the sheet S in the conveying direction due to heating and cooling is calculated. In the maintenance pattern in this embodiment, areas 602 to 605 are arranged between area 601 and area 606, ensuring a long distance for calculating the expansion and contraction amount of the sheet S. Therefore, the expansion and contraction amount in the conveying direction of the sheet S to be read is large, and the expansion and contraction rate can be calculated with high accuracy.

[0062] In this way, with the maintenance pattern in this embodiment, it is possible to calculate a plurality of types of registration misalignment amounts with one maintenance pattern.

[0063] Next, a registration adjustment method in the present invention, in which the registration misregistration amounts 501 to 506 calculated by the image reading and calculation unit 403 are reflected in actual printing via the image processing unit 401 and the print control unit 402, will be described.

[0064] The image reading and calculation unit 403 outputs the calculated value of the registration deviation amount 501 in the recording head of the second recording unit to the print control unit 402. Based on the input registration deviation amount 501, the print control unit 402 corrects the ejection timing of each nozzle for each recording head 22 of the second recording unit 7b.

[0065] The image reading calculation unit 403 outputs the calculated value of the registration deviation amount 502 in the recording head of the first recording unit 7a to the print control unit 402. Based on the input registration deviation amount 502, the print control unit 402 corrects the ejection timing of each nozzle of the white (W) recording head 22 of the first recording unit 7a.

[0066] The image reading and calculation unit 403 outputs the calculated value of the registration misalignment amount 503 between the color recording heads of the second recording unit 7b to the print control unit 402. The print control unit 402 corrects the ejection timing between the recording heads of different colors of the second recording unit 7b based on the input registration misalignment amount 503.

[0067] The image reading and calculation unit 403 outputs the registration misalignment amount 504 between the first recording unit 7a and the second recording unit 7b to the print control unit 402. Based on the input registration misalignment amount 504, the print control unit 402 corrects the ejection timing of each recording head 22 in the second recording unit 7b, which is triggered by the detection of the detection mark P by the conveyance detection unit 6.

[0068] The image reading and calculation unit 403 calculates a registration misalignment amount 505 between the recording units caused by expansion and contraction of the sheet S in the width direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a, and outputs the calculated value to the image processing unit 401. The image processing unit 401 calculates a widthwise expansion / contraction rate based on the input registration misalignment amount 505 and the distance between the black patterns arranged in the width direction in the region 602, and performs widthwise expansion / contraction processing on the image data for the first recording unit 7a based on the calculated expansion / contraction rate. Note that this expansion / contraction rate may be calculated by the image reading and calculation unit 403 and output to the image processing unit 401. In this case, the image processing unit 401 performs expansion / contraction processing on the image data based on the input expansion / contraction rate without calculating the expansion / contraction rate.

[0069] The image reading and calculation unit 403 calculates a registration misalignment amount 506 between the recording units caused by expansion and contraction of the sheet S in the conveying direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a, and outputs the calculated value to the image processing unit 401. The image processing unit 401 calculates the expansion / contraction rate in the conveying direction based on the input registration misalignment amount 506 and the distance from the detection mark P to the area 606, and performs a conveying direction expansion / contraction process on the image data for the first recording unit 7a based on the calculated expansion / contraction rate. Note that instead of performing a conveying direction expansion / contraction process on the image data, the ejection frequency of the recording head 22 of the first recording unit 7a may be adjusted based on the calculated expansion / contraction rate.

[0070] Incidentally, instead of performing the processing based on the expansion / contraction ratio on the image data for the first recording unit 7a or the recording head 22 of the first recording unit 7a, it may be performed on the image data for the second recording unit 7b or the recording head 22 of the second recording unit 7b. In this case, the image data for the second recording unit 7b may be expanded or contracted based on the calculated expansion / contraction ratio, or the ejection frequency of the recording head 22 of the second recording unit 7b may be adjusted to match the image printed by the first recording unit 7a and distorted due to expansion / contraction of the sheet S.

[0071] The image processing unit 401 may also store expansion / contraction information including the expansion / contraction rate for each type of sheet S, and perform registration adjustments such as the expansion / contraction process of the image data and adjustment of the ejection frequency based on the expansion / contraction rate corresponding to the type of sheet S received from the user, for example. In this case, the process of calculating the expansion / contraction rate of the recording medium from the maintenance pattern can be omitted.

[0072] The registration adjustment that reflects the above-described registration misalignment amounts 501 to 506 in printing may be performed by stopping sheet transport once after printing the maintenance pattern, and then performing normal printing after accepting a normal print job. Alternatively, the registration adjustment may be performed when normal printing is continued without stopping sheet transport after printing the maintenance pattern.

[0073] The above-described configuration makes it possible to print high-quality images with little color shift in a printing device in which the printing section is divided into white and color and a drying section is provided between the white printing section and the color printing section.

[0074] In this embodiment, a configuration using inkjet recording heads as the first recording unit 7a and the second recording unit 7b has been described, but a printing device using other recording methods may also be used. Furthermore, in the first embodiment, white ink is used in the first recording unit 7a and color ink is used in the second recording unit 7b, but the present invention is not limited to this ink configuration and other ink configurations may also be used. In other words, this embodiment makes it possible to print high-quality images with little color shift, as long as the printing device is provided with multiple recording units and a drying unit between the recording units.

[0075] Furthermore, although this embodiment has been described so far as a printing device 1, it is not necessary to include all of the printing device 1; it is sufficient if the configuration allows the printing device to perform processing at least in the image processing unit 401, the printing control unit 402, and the image reading and calculation unit 403.

[0076] (Other Examples) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0077] The present disclosure includes the following configurations and methods.

[0078] [Configuration 1] a first recording means for recording a first image on a recording medium; a drying means for drying the recording medium on which the first image has been recorded by the first recording means; a second recording means for recording a second image on the recording medium dried by the drying means; a control means for controlling a recording position of the first recording means or a recording position of the second recording means in accordance with expansion or contraction of the recording medium due to drying by the drying means; A printing device comprising:

[0079] [Configuration 2] the control means controls the recording position of the first recording means by controlling the position and size at which recording of the first image starts. 2. The printing device according to configuration 1.

[0080] [Configuration 3] the control means controls the recording position by changing the ejection frequency of the recording head of the first recording means. 2. The printing device according to configuration 1.

[0081] [Configuration 4] The image recording device further includes an acquisition unit for acquiring a read image obtained by reading the image recorded in the recording unit, the control means causes the first recording means and the second recording means to record a maintenance pattern, and controls the recording position of the first recording means based on an expansion / contraction ratio of the recording medium calculated from a read image obtained by reading the recording medium on which the maintenance pattern is recorded and acquired by the acquisition means. 4. The printing device according to any one of configurations 1 to 3.

[0082] [Configuration 5] the maintenance pattern includes two first patterns for adjusting a relative deviation in recording position between the first recording means and the second recording means; the control means calculates the expansion / contraction ratio of the recording medium from the two first patterns; 5. The printing device according to configuration 4.

[0083] [Configuration 6] the two first patterns are arranged at a predetermined interval in the conveyance direction of the recording medium; 6. The printing device according to configuration 5.

[0084] [Configuration 7] the control means calculates an expansion / contraction ratio of the recording medium in the transport direction from the two first patterns and a distance between the two first patterns in the transport direction of the recording medium; 7. The printing device according to configuration 5 or 6.

[0085] [Configuration 8] the first recording means and the second recording means have inkjet recording heads; 8. The printing device according to any one of configurations 5 to 7.

[0086] [Configuration 9] the maintenance pattern includes the first pattern and a second pattern for adjusting a printing position within the print head; 9. The printing device according to configuration 8.

[0087] [Configuration 10] The second pattern is disposed between two of the first patterns. 10. The printing device according to configuration 9.

[0088] [Configuration 11] the control means adjusts the recording position in a width direction perpendicular to a conveyance direction of the recording medium based on at least one of the two first patterns; 11. The printing device according to any one of configurations 5 to 10.

[0089] [Configuration 12] further comprising a detection means for detecting a detection mark included in the maintenance pattern recorded by the first recording means, the control means starts recording by the second recording means in response to detection of the detection mark by the detection means. 12. The printing device according to any one of configurations 4 to 11.

[0090] [Configuration 13] the control means holds an expansion / contraction ratio for each type of recording medium, and controls the recording position of the first recording means based on the expansion / contraction ratio corresponding to the type of recording medium. 2. The printing device according to configuration 1.

[0091] [Configuration 14] the control means controls the recording position by enlarging or reducing the image recorded by the first recording means. 14. The printing device according to any one of configurations 1 to 13.

[0092] [Configuration 15] recording a first image on a recording medium; drying the recording medium on which the first image is recorded; a step of recording a second image on the recording medium dried by the drying step; a step of controlling a recording position in the step of recording the first image or a recording position in the step of recording the second image according to expansion or contraction of the recording medium caused by drying by the drying means; A printing method comprising:

[0093] [Configuration 16] 16. A program for causing a computer to execute each step of the printing method according to claim 15.

Claims

1. a first recording means for recording a first image on a recording medium; a drying means for drying the recording medium on which the first image has been recorded by the first recording means; a second recording means for recording a second image on the recording medium dried by the drying means; a control means for controlling a recording position of the first recording means or a recording position of the second recording means in accordance with expansion or contraction of the recording medium due to drying by the drying means; A printing device comprising:

2. the control means controls the recording position of the first recording means by controlling the position and size at which recording of the first image starts; 2. The printing device according to claim 1.

3. the control means controls the recording position by changing the ejection frequency of the recording head of the first recording means.

2. The printing device according to claim 1.

4. The image recording device further includes an acquisition unit for acquiring a read image obtained by reading the image recorded in the recording unit, the control means causes the first recording means and the second recording means to record a maintenance pattern, and controls the recording position of the first recording means based on an expansion / contraction ratio of the recording medium calculated from a read image obtained by reading the recording medium on which the maintenance pattern is recorded and acquired by the acquisition means.

2. The printing device according to claim 1.

5. the maintenance pattern includes two first patterns for adjusting a relative deviation in recording position between the first recording means and the second recording means, the control means calculates the expansion / contraction ratio of the recording medium from the two first patterns; 5. The printing device according to claim 4.

6. the two first patterns are arranged at a predetermined interval in the conveyance direction of the recording medium; 6. The printing device according to claim 5.

7. the control means calculates an expansion / contraction ratio of the recording medium in the transport direction from the two first patterns and a distance between the two first patterns in the transport direction of the recording medium; 6. The printing device according to claim 5.

8. the first recording means and the second recording means have inkjet recording heads; 6. The printing device according to claim 5.

9. the maintenance pattern includes the first pattern and a second pattern for adjusting a printing position within the print head; 9. The printing device according to claim 8.

10. The second pattern is disposed between two of the first patterns.

10. The printing device according to claim 9.

11. the control unit adjusts the recording position in a width direction perpendicular to a conveyance direction of the recording medium based on at least one of the two first patterns; 6. The printing device according to claim 5.

12. a detection unit that detects a detection mark included in the maintenance pattern recorded by the first recording unit, the control means starts recording by the second recording means in response to detection of the detection mark by the detection means.

5. The printing device according to claim 4.

13. the control means holds an expansion / contraction ratio for each type of recording medium, and controls the recording position of the first recording means based on the expansion / contraction ratio corresponding to the type of recording medium.

2. The printing device according to claim 1.

14. the control means controls the recording position by enlarging or reducing the image recorded by the first recording means.

14. The printing device according to claim 1, wherein the printing device is a printer.

15. recording a first image on a recording medium; drying the recording medium on which the first image is recorded; a step of recording a second image on the recording medium dried by the drying step; a step of controlling a recording position in the step of recording the first image or a recording position in the step of recording the second image according to expansion or contraction of the recording medium caused by drying by the drying means; A printing method comprising:

16. A program for causing a computer to execute each step of the printing method according to claim 15.

Images