Printing apparatus, printing method, and program

Abstract

To reduce color misalignment in a printing apparatus that performs the printing process in multiple stages. [Solution] In a printing apparatus that performs drying between a first recording unit and a second recording unit, a first amount of registration misalignment between the first and second recording units is calculated based on a pattern printed in a first area for detecting registration misalignment between the first and second recording units, and the amount of registration misalignment in the recording head of the first recording unit and the amount of registration misalignment in the recording head of the second recording unit. A second amount of registration misalignment between the recording units is calculated based on the calculated first amount of registration misalignment between the recording units and a pattern printed in a second area for detecting registration misalignment between the first and second recording units, caused by the expansion and contraction of the sheet in the transport direction due to heating and cooling. Depending on the calculated second amount of registration misalignment between the recording units, the image data for the first recording unit is subjected to scaling, or the ejection frequency of the recording head of the first recording unit is adjusted.

Description

Technical Field

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

Background Art

[0002] In recent years, in a printing apparatus that prints on a recording medium by an inkjet method, high-quality printing of white and color has been demanded. Therefore, there is also a printing apparatus in which the recording portions for white and color are separated and a drying portion is provided between them. By providing a drying portion between the recording portion for white and the recording portion for color as in such a printing apparatus, it is possible to print an image without color mixing of white ink and color ink. Patent Document 1 discloses a printing apparatus that performs color printing with an inkjet printer, white printing with a gravure roll coating of white ink, and a drying process downstream of each printing process in a method of printing white and color on a film. In the printing apparatus described in Patent Document 1, after heating the film, cooling is performed to suppress deformation such as elongation, shrinkage, and undulation of the film.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique described in Patent Document 1, although large deformation of the recording medium due to temperature management can be suppressed, minute expansion and contraction that vary for each recording medium due to residual stress in the manufacturing process of the recording medium cannot be suppressed. Therefore, there is a problem that color misregistration occurs due to the expansion and contraction of the recording medium.

[0005] Therefore, an object of the present invention is to reduce color misregistration in a printing apparatus that performs a printing process in multiple steps. [Means for solving the problem]

[0006] The present invention relates to a printing apparatus comprising: a first recording means for printing a first image on a recording medium; a drying means for drying the recording medium on which the first image has been printed by the first recording means; a second recording means for printing a second image on the recording medium dried by the drying means; and a control means for controlling the printing position of the first recording means or the printing position of the second recording means in accordance with the expansion and 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 misalignment in a printing apparatus that performs the printing process in multiple stages. [Brief explanation of the drawing]

[0008] [Figure 1] Schematic diagram showing the internal configuration of a printing device. [Figure 2] Perspective view of the sheet transport housing of the recording unit according to one embodiment. [Figure 3] Perspective view of a recording head lifting mechanism according to one embodiment. [Figure 4] Block diagram of the control unit of a printing apparatus according to one embodiment. [Figure 5] A flowchart illustrating the process from printing the maintenance pattern according to Embodiment 1 to reading the printed maintenance pattern. [Figure 6] This figure shows maintenance patterns A and B printed in each of the two recording units according to Embodiment 1. [Figure 7] This figure illustrates the maintenance pattern formed by superimposing maintenance patterns A and B according to Embodiment 1, and the patterns of each region. [Figure 8] A flowchart illustrating the process of calculating the registration deviation amount from the maintenance pattern read according to Embodiment 1. [Figure 9]This figure shows an example of the configuration of a recording head according to one embodiment. [Figure 10] Flowchart showing the process of automatic register adjustment according to Embodiment 2 [Figure 11] A diagram illustrating a method for adjusting the position of the sheet edge using a meandering correction unit according to one embodiment. [Figure 12] A diagram showing an example of a widthwise register adjustment pattern according to Embodiment 2. [Figure 13] This figure shows an example of applying widthwise registration adjustment values ​​to the recording positions of detection marks and maintenance patterns. [Figure 14] This figure shows an example of the configuration of a recording head according to one embodiment. [Figure 15] Diagram showing a maintenance pattern for calculating the inter-column register adjustment value according to Embodiment 3. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be specifically described below with reference to the drawings. It should be noted that the components described in the following embodiments are merely illustrative, and the configuration and various conditions of the apparatus 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 arrangements of the components described in the following embodiments can be changed as appropriate depending on the configuration and various conditions of the apparatus to which the present invention is applied, and unless otherwise specified, the present invention is not limited to the following embodiments.

[0010] [Embodiment 1] First, in Figure 1, the top of the device is defined as "up," the right to left direction is defined as the longitudinal direction, and the front to back of the paper surface, perpendicular to the recording medium transport direction, is defined as the sheet width direction. Printing device 1 is a high-speed line printer that uses a continuous sheet wound in a roll as the recording medium.

[0011] <Printing device> FIG. 1 shows a schematic cross-sectional view of a printing apparatus 1 according to the present embodiment. The printing apparatus 1 of the present embodiment includes a conveyance mechanism including an unwinding unit 2, a first dancer unit 3, a first main conveyance unit 4, a serpentine 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 recording image position detection unit 10, a scanner unit 11, a maintenance unit 15, a drying unit 40, and a cooling unit 50. The continuous sheet S as the recording medium is conveyed along the sheet conveyance path shown by the solid line in the figure and processed by each unit. In the present embodiment, the drying unit 40 and the cooling unit 50 are distinguished, but the drying unit 40 and the cooling unit 50 may be combined as a drying unit.

[0012] The printing apparatus 1 has a configuration for performing a first recording step and a second recording step along the sheet conveyance path. In the first recording step, an image is fixed and recorded on the sheet S through the first recording unit 7a, the first drying unit 40a, and the first cooling unit 50a. In the second recording step, an image is fixed and recorded on the sheet S that has undergone the first recording step through the second recording unit 7b, the second drying unit 40b, and the second cooling unit 50b. Thus, the printing apparatus 1 can continuously print images on the sheet S without color mixing by performing the first recording step and the second recording step on the sheet S. The printing apparatus 1 can also selectively select a recording step according to the printing conditions and print an image on the sheet S by performing only the selected recording step. The conveyance of the sheet S is defined as forward (+x) conveyance in the direction from the unwinding unit 2 to the winding unit 14, and reverse (-x) conveyance in the opposite direction. Also, the right side with respect to the conveyance direction in the width direction (recording head nozzle row direction) intersecting the conveyance direction is defined as the +y direction, the direction perpendicular to the conveyance surface of the conveyance path, and the direction on the side where the recording medium contacts is defined as the +z direction.

[0013] The unwinding unit 2 is a unit for holding and supplying roll paper, which is a continuous sheet wound in a roll shape. The unwinding unit 2 is configured to store the roll paper and pull out the roll paper to supply the sheet S. Note that the roll paper that can be stored is not limited to one, and a configuration may be adopted in which a plurality of roll papers are stored and the sheet S is supplied by pulling out one of the plurality of roll papers. Note that the unwinding unit 2 is rotationally controlled by a motor (not shown) so as to be capable of normal rotation and reverse rotation.

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

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

[0016] The skew correction unit 5 is a unit for correcting the skew in the sheet width direction when the sheet S is conveyed under tension. In the present embodiment, the skew correction unit 5 includes a first skew correction unit 5a and a second skew correction unit 5b provided upstream of each recording process in the sheet conveying path. The skew correction unit 5 includes a skew correction roller and a skew detection sensor (not shown) for detecting the skew of the sheet S. The skew correction roller can change the inclination with respect to the sheet S by a motor (not shown), and corrects the skew of the sheet S based on the measurement result by the skew detection sensor. The skew correction unit 5 enhances the skew correction function by winding the sheet S around the skew correction roller.

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

[0018] The recording unit 7 applies a liquid composition (ink) onto the conveyed sheet S from above using a recording head 22 to form an image. The sheet conveyance path in the recording unit 7 is composed of guide rollers 23 arranged in an upwardly convex arc shape, and a certain tension is applied to the sheet S, ensuring a certain clearance between the sheet S and the recording head 22. Multiple recording heads 22 are installed in the recording unit 7 along the conveyance direction. In this embodiment, the first recording unit 7a has a total of two line-type recording heads corresponding to W (white) ink and 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 the reaction liquid and three special colors. The reaction liquid is a liquid containing components that increase the viscosity of the ink. Here, increasing the viscosity of the ink refers to a state in which the colorants and resins constituting the ink come into contact with the components that increase the viscosity of the ink, resulting in a chemical reaction or physical adsorption, and an increase in ink viscosity. Increasing the viscosity of ink is not limited to an overall increase in viscosity, but also includes cases where localized viscosity increases occur due to partial aggregation of components that make up the ink, such as colorants and resins. There are no particular restrictions on the components used to increase the viscosity of the ink; however, substances that cause a change in the ink's pH and aggregate the colorants in the ink can be used, and organic acids can also be used. Applying the reaction solution before applying the ink to the sheet S allows the ink to be fixed immediately upon reaching the sheet S. This suppresses bleeding, where adjacent inks mix together.

[0019] The types and number of colors and the number of recording heads 22 are not limited to those of this embodiment. The inkjet method can employ methods using heating elements, piezoelectric elements, electrostatic elements, MEMS elements, etc. Ink is supplied to the recording heads 22 from ink tanks (not shown) via ink tubes.

[0020] As shown in Figure 2, the sheet transport housing 71 of the recording unit 7 is equipped with multiple recording head positioning members 711 for positioning the recording head 22. In this embodiment, one recording head positioning member 711 is installed on the front side and two on the back side for each recording head 22, sandwiching the sheet S in the sheet width direction. Also, as shown in Figure 3, the recording head 22 is pivotally supported by a recording head holding unit 26 that holds the recording head 22 and moves it up and down, with the recording head support shaft 27 being supported from below. The recording head holding unit 26 moves up and down along a lifting rail 29 provided in the recording head lifting frame 28 by a drive mechanism (not shown) provided inside. In this example, ink is applied to the sheet S using an inkjet head, but the method of applying ink to the sheet in the recording unit 7 is not limited to this. For example, in this example, the reaction liquid is applied by the recording head 22, but it may also be applied using rollers, a die coating device (die coater), a blade coating device (blade coater), etc.

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

[0022] The recorded 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 winds the side of the sheet S opposite to the ink-applied surface downstream of the conveying second recording unit 7b 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 located 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 in the liquid composition applied to the sheet S by the recording section 7, thereby improving the adhesion of the ink to the sheet S. The drying section 40 dries the applied ink by applying air at a predetermined temperature to the printed sheet S. Inside the drying section 40, warm air is applied to the sheet S passing through, at least from the ink-applied surface side, to dry the ink-applied surface of the sheet S. In addition to the method of applying warm air, the drying method may also be configured by combining a method of irradiating the surface of the sheet S with electromagnetic waves (such as ultraviolet rays or infrared rays) or 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 in the downstream processes of the printing apparatus to an appropriate temperature. Inside the cooling section 50, air at a temperature lower than that of the sheet S is blown onto the passing sheet S from at least the ink-applied side to cool the ink-applied surface of the sheet S. The cooling method is not limited to blowing air; it may also be a conductive heat transfer method using contact with heat dissipation members, or a combination of both.

[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 in the control unit 31, which will be described later, to detect positional misalignment and ink density of the images recorded by the recording unit 7.

[0027] As a means of correcting the misalignment of this image, registration adjustment, which will be described later, is commonly performed and is an important control for achieving high-resolution image recording. Hereafter, the recording position will be referred to as registration, and the misalignment of the recording position will be referred to as registration misalignment.

[0028] The second main conveying unit 12, together with the first main conveying unit 4, conveys the sheet S while applying tension to it, and is a unit that adjusts the tension of the sheet S. The second main conveying unit 12 is driven by a motor (not shown) and controls the conveying speed according to a tension control unit (not shown) according to the tension value detected by the conveying tension detection unit 9. In addition, as an additional configuration for adjusting the tension of the sheet S, a configuration in which the tension of the sheet S is adjusted by a clutch (not shown) that can control the torque connected to the drive may be added. In this case, there are two methods for tension control: 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 unit 12. The tension control method can be switched or both can be used simultaneously depending on the purpose.

[0029] The second dancer unit 13 is a unit for applying a constant sheet tension between the second main conveying unit 12 and the winding unit 14. The sheet tension is applied to the second dancer unit 13 by a tension-applying means (not shown).

[0030] The winding unit 14 is a unit for winding the recorded sheet S onto a winding core. The number of recoverable rolls is not limited to one; it may have two or three or more winding cores, and the sheet S may be recovered as multiple rolls by selectively switching between them. The winding unit 14 is independently controlled to rotate in both forward and reverse directions by a drive motor (not shown). By controlling the forward or reverse rotation of the respective drive motors (not shown) of the unwinding unit 2 and the winding unit 14, the sheet S is conveyed in the forward and reverse directions. In the case of reverse conveyance, tension conveyance is performed between the first main conveying unit 4 and the second main conveying unit 12, similar to forward conveyance. Depending on the processing of the sheet S after recording, instead of winding it onto a winding core, the sheet S may be cut using a cutter and the cut sheet S may be loaded.

[0031] [Recording head] Figure 9 is a schematic diagram of the recording head 22 used in the printing apparatus 1 according to this embodiment. In the recording head 22, a plurality of recording element substrates 902 are arranged continuously in the y direction while creating an overlap region D by shifting their positions in the x direction. Each recording element substrate 902 is equipped with a plurality of nozzles 901 arranged at a constant pitch. As the recording medium is transported in the x direction at a constant speed, each nozzle 901 ejects ink at a constant frequency according to the recording data, thereby forming an image on the recording medium with a resolution corresponding to the arrangement pitch of the nozzles 901. In this embodiment, the arrangement pitch is 1200 dpi. The pixel size at 1200 dpi is approximately 20 μm, and accuracy in units of 20 μm is required for registration adjustment. Here, "recording data" refers to data that defines the content of various processes performed by the printing apparatus 1, including image data used in image formation.

[0032] The control unit 31 is a unit that controls all parts of the entire printing apparatus. The control unit 31 includes a controller equipped with various control units, an external interface, and an operation unit 32 for user input and output.

[0033] The operation of the printing device 1 is controlled based on commands from a 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 CPU 404, RAM 405, ROM 406, a print control unit 402, and an image reading calculation unit 403. The CPU 404 executes processing according to the respective embodiments described later, based on the programs and various data held in the RAM 405 or ROM 406. The RAM 405 is volatile storage that temporarily holds programs and data. The ROM 406 is non-volatile storage that stores various data such as table data and programs used in the processing described later.

[0034] In this embodiment, the host device 33 is assumed to be a separate PC from the printing device 1, but these implementations are not particularly limited as long as similar processing can be performed. For example, the host device 33 may be a device built into the printing device 1, or it may be a server. Alternatively, the host device 33 may be a mobile terminal such as a smartphone, tablet, or imaging device.

[0035] Figure 4 shows a block diagram of the control unit 31, specifically the image processing unit 401, the print control unit 402, and the image reading calculation unit 403.

[0036] The image processing unit 401 performs gamma correction, color processing, binarization (halftone processing), and scaling on the recorded data (multi-level image data) transferred from a host computer or the like via the interface.

[0037] The print control unit 402 controls the recording head 22 shown in Figure 9 based on the recorded data. Specifically, the print control unit 402 can be configured to read control parameters and recorded data from a predetermined address in the RAM 405.

[0038] When the CPU 404 writes the control parameters and recording data to a predetermined address in the RAM 405, the print control unit 402 starts the image formation process, and the recording head 22 performs the ink ejection operation.

[0039] The print control unit 402 controls the recording head 22 shown in Figure 9 based on the recorded data. Specifically, the print control unit 402 can be configured to read control parameters and recorded data from a predetermined address in the RAM 405.

[0040] When the CPU 404 writes the control parameters and recording data to a predetermined address in the RAM 405, the print control unit 402 starts the image formation process, the recording head 22 performs an ink ejection operation, and outputs a sheet S with the image printed on it.

[0041] The image reading calculation unit 403 acquires the scanned image read by the scanner unit 11, reads the test image and maintenance pattern, calculates the registration misalignment information and color 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 print position of the recording unit 7. In this specification, the method of adjusting the print position based on the position information of the maintenance pattern read by the scanner unit 11 is called automatic registration adjustment.

[0042] In adjusting the print position, in addition to adjusting the print start positions of the first recording unit 7a and the second recording unit 7b, the print position is adjusted so that the size of the image printed by the first recording unit 7a changes in accordance with the expansion and contraction of the recording medium due to drying. Note that the print position adjustment may be performed in the second recording unit 7b instead of the first recording unit 7a, or a portion of the adjustment may be shared between the two. One way to adjust the print position in accordance with the expansion and contraction of the recording medium is, for example, by having the image reading calculation unit 403 calculate the amount of expansion and contraction of the maintenance pattern printed by the first recording unit 7a, and the image processing unit 401 perform scaling processing on the recording data for the first recording unit 7a. Another method is to have the image reading calculation unit 403 calculate the amount of expansion and contraction of the maintenance pattern printed by the first recording unit 7a, and the print control unit 402 adjust the ejection timing of the first recording unit 7a. The amount of expansion and 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 of automatic registration adjustment will be described later.

[0043] 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 to protect the ink ejection surface of the recording head 22, a wiper mechanism to wipe the ink ejection surface, and a suction mechanism to draw ink from the ink ejection surface of the recording head 22 using negative pressure. The maintenance unit 15 is also provided with a drive mechanism (not shown) and rails, and the maintenance unit 15 is capable of reciprocating horizontally along the rails. The maintenance unit 15 moves directly below the recording head 22 only when maintenance is being performed, and moves to a position retracted from directly below the recording head 22 at all other times. In this embodiment, the first recording unit 7a and the second recording unit 7b are each provided with a corresponding first maintenance unit 15a and second maintenance unit 15b.

[0044] Figure 5 shows a flowchart illustrating the operation of the printing apparatus according to this embodiment, from recording a maintenance pattern on a recording medium (sheet S) to reading the recorded maintenance pattern.

[0045] The maintenance pattern is used to calculate the register adjustment value (hereinafter sometimes referred to as the adjustment value) based on the measurement results, and this adjustment value is stored, for example, in RAM411. Furthermore, based on the adjustment value stored in RAM411, for example, the timing of ink ejection from each nozzle is adjusted to correct the landing position (print position) of the dots formed on the recording medium.

[0046] In S501, the control unit 31 starts transporting the sheet S using the transport mechanism.

[0047] In S502, when the sheet S reaches a constant speed, the control unit 31 starts recording a maintenance pattern A, which will be described later, consisting of a reaction solution and white ink, on the sheet S using the first recording unit 7a. The maintenance pattern A includes a detection mark P, which is detected by the second transport detection unit 6b and the scanner unit 11.

[0048] In S503, the control unit 31 performs a drying process on the portion of the sheet S on which the maintenance pattern A is printed using the first drying unit 40a.

[0049] In S504, the control unit 31 performs a cooling process on the portion of the sheet S on which the maintenance pattern A has been printed and dried by the first cooling unit 50a.

[0050] Maintenance pattern A is heated by drying in the first drying section 40a in S503, cooled by the first cooling section 50a in S504, and reaches the upstream of the second recording section 7b.

[0051] Through this heating and cooling process, the sheet S undergoes slight deformation in both the same direction as the conveying motion and in both the conveying direction and the vertical direction, and the maintenance pattern A also deforms in accordance with the deformation of the sheet S.

[0052] In S505, when the maintenance pattern A reaches the upstream of the second recording unit 7b and the second transport detection unit 6b detects the detection mark P, the control unit 31 determines the printing timing of the image by the second recording unit 7b.

[0053] In S506, the control unit 31 starts printing maintenance pattern B, consisting of reaction solution and color (C, M, Y, K, spot color) ink, onto maintenance pattern A on sheet S using the second recording unit 7b, according to the printing timing determined in S505. As a result, maintenance pattern A and maintenance pattern B are formed on sheet S overlapping. 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 along with the expansion and contraction of sheet S, resulting in a color misalignment between maintenance pattern A and maintenance pattern B.

[0054] In S507, the control unit 31 performs a drying process on the portion of the sheet S on which maintenance patterns A and B are printed using the second drying unit 40b.

[0055] In S508, the control unit 31 performs a cooling process on the portion of the sheet S on which maintenance patterns A and B have been printed and dried by the second cooling unit 50b.

[0056] In S509, the control unit 31 detects maintenance patterns A and B using the scanner unit 11, triggered by the detection of the detection mark P by the scanner unit 11.

[0057] In S510, when maintenance patterns A and B are transported to the winding unit 14, the control unit 31 stops transporting the sheet S.

[0058] Figures 6 and 7 show the maintenance pattern used in this embodiment. As shown in Figure 6, the maintenance pattern is printed by superimposing maintenance pattern A (Figure 6(a)), which consists of a reaction solution and white ink, and maintenance pattern B (Figure 6(b)), which consists of a reaction solution and color ink (Figure 7(a)). As shown in Figures 6 and 7, the maintenance pattern is divided into regions 601 to 606 in order from the upstream side in the transport direction.

[0059] Area 601 has a detection mark P printed on it using white ink. Areas 602 to 606 are printed by the first recording unit 7a and the second recording unit 7b, respectively, triggered by the detection of the detection mark P by the second transport detection unit 6b.

[0060] Area 602 has a recording unit registration misalignment pattern printed on it, which is used to detect the relative misalignment of the recording position between the first recording unit 7a and the second recording unit 7b, and is composed of multiple combinations of white (W) and color (Bk) patterns. From area 602, the recording unit registration misalignment, which is the misalignment between the printing positions of the first recording unit 7a and the second recording unit 7b, can be read, triggered by the detection of a detection mark P by the second transport detection unit 6b. When reading this 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 a separate area, are reflected. The registration misalignment within the recording head is a registration misalignment caused by variations in the positional relationship between the recording chips and nozzle rows of each recording head 22. Furthermore, the widthwise recording unit registration misalignment caused by the expansion and contraction of the sheet S in the widthwise direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a can also be read from area 602.

[0061] Area 603 has a color recording head registration misalignment pattern printed on it, which is a combination of multiple patterns of Bk, Y, M, Cy, and spot colors. From area 603, it is possible to read the misalignment of the print position caused by variations in the positional relationships between recording chips and nozzle rows within the recording head 22 for each color ink in the second recording unit 7b.

[0062] Area 604 has a white recording head misalignment pattern printed on it, which is a combination of multiple W patterns. From area 604, it is possible to read the misalignment of the print position caused by variations in the positional relationships between recording chips and nozzle rows within the recording head 22 of the first recording unit 7a's W ink.

[0063] Area 605 records registration misalignment patterns between color recording heads, which are combinations of multiple patterns of Bk, Y, M, Cy, and spot colors. The misalignment of the print positions between the color recording heads 22 (Bk, Y, M, Cy, and spot colors) of the second recording unit 7b can be read.

[0064] Area 606 records a registration misalignment pattern between recording units, which is a combination of multiple white (W) and color (Bk) patterns. The registration misalignment pattern between recording units in area 606 is the same as the registration misalignment pattern between recording units in area 602, but inverted in the sheet transport direction (left and right in Figures 6 and 7). Therefore, the same registration misalignment as in S602 can be read from S606. In addition, area 606 is used to read the registration misalignment between recording units caused by the expansion and contraction of the sheet S in the transport direction and width direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a. The reason for reading the registration misalignment between recording units due to the expansion and contraction of the sheet S in the transport direction in area 606 is that the amount of expansion and contraction of the sheet S in the transport direction increases the further it is from the detection mark P. Therefore, it is easier to read the registration misalignment between recording units due to the expansion and contraction of the sheet S in the transport direction in area 606 than in area 602, and high-precision reading is possible.

[0065] Furthermore, when recording maintenance pattern A on sheet S, an unillustrated pattern is printed outside the printing area of ​​maintenance patterns A and B, using the average amount of white ink used in actual printing, and ensuring uniform ink density. This pattern is intended to reproduce the expansion and contraction of the white ink due to its latent heat when sheet S and ink are heated and cooled by the first drying section 40a and the first cooling section 50a during actual printing, not test printing.

[0066] This reduces the difference in conditions between test printing and actual printing, thereby reducing the error between the registration deviation calculated from maintenance patterns A and B and the registration deviation in actual printing. While the above example described uses only white ink, both white and color inks can be used. In that case, the results can be more closely matched to actual printing.

[0067] In this embodiment, the maintenance pattern is shown in Figures 6 and 7 and has been described above. However, the order of regions 601 to 606 is not limited to this, and the order may be changed or some may be omitted. In addition, other maintenance patterns may be combined, or the maintenance pattern may be divided and the divided patterns may be placed with intervals between them. For example, if a maintenance pattern is specifically designed to correct registration misalignment (color misalignment) between recording sections caused by the expansion and contraction of the sheet S due to heating and cooling, only the correction patterns for regions 601, 602, and 606 should be used. In this case, the interval between region 602 and region 606 should be set appropriately according to the correction accuracy.

[0068] Figure 8 shows a flowchart illustrating the method for calculating various registration misalignment amounts from the maintenance pattern in this embodiment. Note that the registration misalignment amount can be calculated as the difference between the center or predetermined edges of corresponding patterns at predetermined positions, but the method for calculating the registration misalignment amount is not limited to this, and other existing calculation methods may be used.

[0069] In S801, the amount of registration misalignment 1 in each recording head included in the second recording unit 7b is calculated based on the registration misalignment pattern detected in region 603 within the color recording head.

[0070] In other words, the registration deviation amount 1 includes the registration deviation amounts for each of Bk, Y, M, Cy, and the special color.

[0071] In S802, the amount of registration misalignment 2 in the white (W) recording head 22 of the first recording unit 7a is calculated based on the registration misalignment pattern detected in region 604.

[0072] In S803, the amount of registration misalignment 3 between the different colored recording heads 22 included in the second recording unit 7b is calculated based on the registration misalignment pattern between the colored recording heads 605. The amount of registration misalignment 503 may, for example, be calculated based on Bk, specifically between the Bk recording head 22 and the recording heads 22 of the other colors.

[0073] In S804, the inter-recording unit registration misalignment amount 4 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 region 602 and the registration misalignment amounts 1 and 2 calculated in S801 and S802. More specifically, this registration misalignment amount 4 is the registration misalignment amount between the white (W) recording head 22 of the first recording unit 7a and the black (Bk) recording head 22 of the second recording unit 7b.

[0074] In S805, the amount of registration misalignment 5 between recording sections caused by the expansion and contraction of the sheet S in the width direction due to heating and cooling is calculated based on the registration misalignment pattern between recording sections detected in region 602 and the registration misalignment amounts 1 and 2 calculated in S801 and S802. Here, heating and cooling are performed by the first drying section 40a and the first cooling section 50a.

[0075] In S806, the amount of registration misalignment 6 between recording units caused by the expansion and contraction of the sheet S in the transport direction due to heating and cooling is calculated based on the inter-recording unit misalignment pattern detected in region 606 and the registration misalignment amount 4 calculated in S804. In the maintenance pattern of this embodiment, regions 602 to 605 are placed between region 601 and region 606, ensuring a long distance for calculating the expansion and contraction amount of the sheet S. As a result, the amount of expansion and contraction of the sheet S in the transport direction that is read becomes large, and the expansion and contraction ratio can be calculated with high accuracy.

[0076] Thus, in the maintenance pattern of this embodiment, multiple types of register misalignment amounts can be calculated with a single maintenance pattern.

[0077] Next, we will describe an automatic register adjustment method in which the registration deviation amounts 1 to 6 calculated by the image reading calculation unit 403 are reflected in the actual printing via the image processing unit 401 and the print control unit 402.

[0078] The image reading calculation unit 403 outputs the calculated value of the registration misalignment amount 1 in the recording head of the second recording unit to the print control unit 402. Based on the input registration misalignment amount 1, the print control unit 402 corrects the ejection timing of each nozzle for each recording head 22 of the second recording unit 7b.

[0079] The image reading calculation unit 403 outputs the calculated value of the registration misalignment amount 2 in the recording head of the first recording unit 7a to the print control unit 402. Based on the input registration misalignment amount 2, the print control unit 402 corrects the ejection timing of each nozzle for the white (W) recording head 22 of the first recording unit 7a.

[0080] The image reading calculation unit 403 outputs the calculated value of the registration misalignment amount 3 between the color recording heads of the second recording unit 7b to the print control unit 402. Based on the input registration misalignment amount 3, the print control unit 402 corrects the ejection timing between the recording heads of different colors in the second recording unit 7b.

[0081] The image reading calculation unit 403 outputs the registration misalignment amount 4 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 4, the print control unit 402 corrects the ejection timing of each recording head 22 in the second recording unit 7b, triggered by the detection of the detection mark P by the transport detection unit 6.

[0082] The image reading calculation unit 403 outputs to the image processing unit 401 a calculated value of the registration misalignment amount 5 between recording units caused by the 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. The image processing unit 401 calculates the expansion / contraction ratio in the width direction based on the input registration misalignment amount 5 and the distance between the Bk patterns arranged in the width direction in the region 602, and performs expansion / contraction processing in the width direction on the image data for the first recording unit 7a based on the calculated expansion / contraction ratio. Alternatively, the image reading calculation unit 403 may calculate this expansion / contraction ratio and output it to the image processing unit 401. In that case, the image processing unit 401 performs expansion / contraction processing on the image data based on the input expansion / contraction ratio without calculating the expansion / contraction ratio.

[0083] The image reading calculation unit 403 outputs to the image processing unit 401 the calculated value of the registration misalignment amount 506 between recording units caused by the expansion and contraction of the sheet S in the transport direction due to heating and cooling by the first drying unit 40a and the first cooling unit 50a. The image processing unit 401 calculates the expansion / contraction ratio in the transport direction based on the input registration misalignment amount 6 and the distance from the detection mark P to the region 606, and performs expansion / contraction processing in the transport direction on the image data for the first recording unit 7a based on the calculated expansion / contraction ratio.

[0084] Alternatively, instead of performing expansion or contraction processing on the image data in the transport direction, the ejection frequency of the recording head 22 of the first recording unit 7a may be adjusted based on the calculated expansion / contraction ratio.

[0085] Alternatively, instead of performing the above-mentioned 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, the processing 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 scaled or the ejection frequency of the recording head 22 of the second recording unit 7b may be adjusted based on the calculated expansion / contraction ratio to match the image printed by the first recording unit 7a and distorted by the expansion / contraction of the sheet S.

[0086] Furthermore, the image processing unit 401 may maintain stretch information including the stretch ratio for each type of sheet S, and perform registration adjustments such as scaling the image data and adjusting the output frequency based on the stretch ratio corresponding to the type of sheet S received from the user. In this case, the step of calculating the stretch ratio of the recording medium from the maintenance pattern can be omitted.

[0087] Furthermore, the automatic register adjustment that reflects the above-mentioned register misalignment amounts 1-6 in the print may be performed after stopping the sheet transport once after printing the maintenance pattern, accepting a normal print job, and then performing normal printing. Alternatively, it may be performed after printing the maintenance pattern without stopping the sheet transport and when performing normal printing continuously.

[0088] The configuration described above enables the printing of high-quality images with minimal color misalignment in a printing apparatus where the recording section is divided into white and color sections, and a drying section is provided between the white and color recording sections.

[0089] 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 Embodiment 1, white ink was used in the first recording unit 7a and color ink in the second recording unit 7b, but the ink configuration is not limited to this, and other ink configurations may also be used. In other words, this embodiment makes it possible to print high-quality images with minimal color misalignment as long as a printing device is provided with multiple recording units and a drying unit between them.

[0090] Furthermore, although this embodiment has been described as Printing Apparatus 1, it is not necessary to include all of Printing Apparatus 1; it is sufficient to have a configuration that allows the Printing Apparatus to perform at least the processing in the Image Processing Unit 401, Printing Control Unit 402, and Image Reading and Calculation Unit 403.

[0091] [Embodiment 2] The aforementioned Embodiment 1 is characterized by its ability to adjust the register so that the positions of the dots in the first and second recording processes overlap by using detection marks that focus on the misalignment of the printing position in the transport direction. However, misalignment of the printing position can occur not only in the transport direction but also perpendicular to the transport direction, i.e., in the width direction of the recording medium. As will be described later, depending on the settings at the time of paper feeding, it may not be possible to perform register adjustment depending on the amount of misalignment in the width direction of the recording medium. This embodiment is characterized by reducing the inability to perform register adjustment of the first and second recording units by taking into account the positional misalignment in the width direction. More specifically, Embodiment 2 is a technology relating to the recording position of the detection marks and maintenance patterns described in Embodiment 1.

[0092] Figure 10 shows a flowchart illustrating the paper feeding process in Embodiment 2. When the printing device 1 transports the sheet, which is the recording medium, as described above using Figure 1, the meandering correction units 5a and 5b perform meandering correction to suppress meandering in the width direction of the sheet.

[0093] In S1001, a sheet, which is a recording medium to be used for printing, is set, and at that time, the width of the set sheet is input to the printing device 1. The printing device 1 determines the printing range in the width direction of the image data according to the input sheet width value. For example, consider the case where image data with a width larger than the sheet width is input when printing on a narrow sheet. In this case, the control unit 31 adjusts the size of the image to be printed according to the sheet width, so that printing is not performed outside the sheet and the transport path of the printing device 1 is not soiled with ink. The width of the fed sheet can also be detected by a sensor capable of detecting the sheet width in the printing device 1, but in this embodiment, the user inputs it from the operation panel or application of the printing device 1.

[0094] In S1002, the positions of the meandering correction units 5a and 5b are adjusted according to the width of the fed sheet. The meandering correction units 5a and 5b have a configuration that allows specifying the edge position in order to define the position of the sheet in the width direction. The user adjusts the dials attached to the meandering correction units 5a and 5b according to the width of the fed sheet. The meandering correction units 5a and 5b suppress variations in the width direction of the sheet by controlling the sheet so that the edges of the sheet are transported stably at the set edge positions. In other words, the positional relationship between the sheet edges and the recording head in the first recording unit and the second recording unit is determined by the user's dial adjustment. The user needs to change the position of the meandering correction units 5a and 5b each time the width of the sheet being used changes.

[0095] S1003 is used for transporting the sheets. In S1004, the widthwise position adjustment of the transport detection units 6a and 6b is performed. The transport detection units 6a and 6b need to be adjusted to a position where they can detect the detection marks printed on the sheet. It is desirable that the detection marks be positioned at the edge of the sheet so that they do not overlap with images other than the detection marks during printing, and in this embodiment as well, they are printed at the sheet edge in the -y direction. Since the transport detection units 6a and 6b adjust their position while the sheet is being transported, adjustment can be made at an edge position where the widthwise fluctuation of the sheet caused by the meandering correction units 5a and 5b is suppressed. The user adjusts the position of the transport detection units 6a and 6b to align with the sheet edge in the -y direction so that the detection marks to be detected pass directly below the transport detection units 6a and 6b.

[0096] Furthermore, the position adjustment of the transport detection units 6a and 6b may be performed using a mechanism that reads the sheet edge position with a sensor or the like and automatically moves the transport detection units 6a and 6b to an appropriate position based on the read sheet edge position. Naturally, user adjustment can reduce equipment costs, and in this embodiment as well, the configuration is set up to perform position adjustment manually. The value is determined by the user by measuring the length, and an accuracy of about 0.5 mm can be expected, but the accuracy of several tens of micrometers required for register adjustment cannot be achieved.

[0097] Furthermore, since the user also adjusts the position of the transport detection units 6a and 6b, positional misalignment issues can occur, similar to those with the meandering correction units 5a and 5b. Since the transport detection units 6a and 6b only need to detect the detection mark, the tolerance for positional misalignment can be increased by making the detection mark larger. In this embodiment, by setting the size of the detection mark to 3 mm in the width direction, detection is possible as long as the positional misalignment from the sheet edge position is within ±1 mm, allowing for sufficient user adjustment. However, if the sheet edge position and the position of the detection mark are misaligned, the detection mark cannot be detected. Therefore, the distance between the sheet edge position and the printing position of the detection mark is adjusted by applying a width direction registration adjustment value based on the edge registration value described later to the printing position of the image data.

[0098] Figures 11(a) and (b) show diagrams illustrating the details of S1001 to S1004. In Figures 11(a) and (b), only the parts of the meandering correction sections 5a and 5b that define the sheet edge position are shown, and the user adjusts the position of the meandering correction sections 5a and 5b in the direction of arrow 1103 according to the sheet width. The dashed line 1101 indicates the ideal transport position corresponding to the width of the fed sheet, and the sheet width is the value entered by the user as described above. In the first recording section 7a, the position of the meandering correction section 5a is appropriately adjusted to the position of dashed line 1101. The W image 1102 represents the image of W printed by the recording head 22, and is printed with a certain amount of margin from both ends of the sheet.

[0099] In the second recording unit 7b, the position of the meandering correction unit 5b is adjusted to a position shifted from the dashed line 1101. The sheet is also shifted from the ideal position by the distance indicated by arrow 1106, and the BK image 1105 printed by the BK recording head 22 is printed over the edge of the sheet. In order to prevent the BK image 1105 from overflowing the sheet, it is necessary to check the distance from the dashed line 1101 in the second recording unit 7b to the edge of the sheet (hereinafter referred to as the edge registration value) and shift the printing position of the image. On the other hand, in Figure 11(b), the initial printing position of the BK image 1105 is shifted by the edge registration value in the direction indicated by arrow 1107 by applying a width-direction registration adjustment value calculated using the method described later to the printing position of the BK image 1105. As a result, in Figure 11(b), the BK image 1105 is printed in the appropriate position in the width direction, similar to the W image 1102 in which the position setting of the meandering correction section 5a is not shifted.

[0100] In S1005, a width-direction registration adjustment pattern is printed to obtain the width-direction registration adjustment value indicated by arrow 1107. Figure 12 shows an example of a width-direction registration adjustment pattern 1201 printed in S1005 to obtain the width-direction registration adjustment value. A straight line pattern 1202 for W and a straight line pattern 1203 for BK are printed to measure the width-direction printing position deviation from the edge of the sheet. Even if the maximum expected positional adjustment deviation of the meandering correction section 5b occurs, a predetermined margin is defined so that the edges of the straight line patterns 1202 and 1203 do not extend beyond the sheet, and in this embodiment, this margin is set to 5 mm. In the sequence for printing the width-direction registration adjustment pattern, the ejection timing of the second recording unit 7b is determined from the internal time of the printing device 1, without using a detection mark to determine the printing start timing of the second recording unit 7b. In printing the width-direction registration adjustment pattern, the distance from the edge of the sheet is measured for the straight line pattern 1202 for W and the straight line pattern 1203 for BK, so it is preferable that they do not overlap. Therefore, when printing the width direction registration adjustment pattern, detection marks are not used, and it is not a problem if the straight pattern 1202 for W and the straight pattern 1203 for BK are misaligned in the transport direction. Furthermore, since the end registration value is determined at the position of the meandering correction section 5b, it is not necessary to measure the end registration values ​​of colors other than BK in the second recording section 7b, and they can be considered to have the same end registration value as BK.

[0101] In S1006, the user measures the distance between the sheet edge and the linear patterns 1202 and 1203 of the printed widthwise registration adjustment pattern, and inputs this information into the printing device 1.

[0102] In S1007, the widthwise registration adjustment value is calculated based on the distance of the input widthwise registration adjustment pattern from the sheet edge. The edge registration value is obtained as the difference between the distance from the sheet edge to the printed widthwise registration adjustment pattern and the distance from the sheet edge to the ideal position of the widthwise registration adjustment pattern. Note that in Figure 11, for the sake of simplicity, it is assumed that the sheet edge of the first recording unit 7a is aligned to the ideal position 1101, but in reality, even in the first recording unit 7a, the sheet edge is offset from the ideal position 1101. Therefore, in S1007, the widthwise registration adjustment value is also calculated for the straight pattern 1202 of W. The method for calculating the widthwise registration adjustment value is explained below using specific numbers. Assume that the distance from the sheet edge measured in S1006 to the straight pattern 1202 printed in W was 7 mm. If the meandering correction unit 5a is adjusted to the ideal position, that distance should be 5 mm, so the meandering correction unit 5a is offset by 2 mm in the -y direction. Therefore, the edge registration value in the first recording unit 5a is 2 mm, and the widthwise registration adjustment value is -2 mm. On the other hand, if the distance from the sheet edge measured in S1006 to the straight pattern 1203 printed in BK is 4 mm, then the meandering correction section 5b will be shifted by 1 mm in the +y direction. Therefore, the edge registration value in the second recording section 5b is 1 mm, and the width direction registration adjustment value is 1 mm.

[0103] Furthermore, in this embodiment, since the recording head 22 is longer than the sheet width, it is possible to print all of the input image data even if the print position of the image is moved in the width direction.

[0104] The method for calculating the print position deviation in the sheet width direction between the first recording unit 7a and the second recording unit 7b, which originates from the position adjustment results of the meandering correction units 5a and 5b, has been explained using Figures 10 and 11. By applying the width direction registration adjustment value calculated in S1007 to the print position of the image data, it is possible to suppress the print position deviation in the width direction even if the positions of the meandering correction units 5a and 5b are deviated from the ideal transport position 1101.

[0105] This embodiment aims to correct the register misalignment in the sheet width direction caused by the user's adjustment of the positions of the meandering correction sections 5a and 5b. However, as described in the previous embodiment, even if thermal shrinkage occurs due to the heat drying mechanism, register misalignment in the width direction can still occur. In this embodiment, the register adjustment value in the width direction is calculated using the pattern after thermal shrinkage has occurred, making it possible to correct the edge position.

[0106] In S1008, the maintenance pattern described in Figure 5 in Embodiment 1 is printed, and the register misalignment amount described in Figure 8 is calculated. By determining the printing position of the detection marks in the maintenance pattern by applying the width-direction register adjustment value calculated in S1007, the detection marks can be printed within the detection range of the transport detection unit 6b even if the sheet position is misaligned in the width direction.

[0107] As described above, by performing the adjustments to the printing positions of the first recording unit 7a and the second recording unit 7b as shown in Figures 10 to 12, the printing device 1 becomes capable of detecting the detection marks printed on the edge of the sheet. As a result, by printing a maintenance pattern for acquiring register values ​​between the recording units of the first recording unit 7a and the second recording unit 7b and between chips, and reading it with the scanner unit 11, it becomes possible to adjust the printing position with high precision on the order of several tens of micrometers.

[0108] However, applying the widthwise register adjustment value to the maintenance pattern may prevent automatic register adjustment, particularly register adjustment between chips. Figure 13 illustrates the potential problems and countermeasures that may arise when the widthwise register adjustment value is applied to the entire maintenance pattern, including the detection marks.

[0109] Figure 13(a) shows the case where the widthwise registration adjustment value is calculated and then applied to the detection mark P and the maintenance pattern. The sequence for calculating the widthwise registration adjustment value described above is performed, and the widthwise registration adjustment value of the first recording unit 5a was 2 mm in the -y direction. A widthwise registration adjustment value of +2 mm means that the sheet is shifted by 2 mm in the -y direction from the ideal position 1101, so the printing positions of the detection mark P and the maintenance pattern 1301 are shifted by 2 mm in the -y direction as indicated by arrow 1302. Next, the sheet is transported to the second recording unit 5b, but since the edge registration value is applied to the detection mark P, it is detected by the transport detection unit, and the maintenance patterns 1303 of BK, C, M, and Y are printed. Since the edge registration value of the second recording unit 5b is -1 mm, the maintenance pattern 1303 is shifted by 1 mm in the +y direction as indicated by arrow 1304.

[0110] Maintenance patterns 1301 and 1303 are designed to print one pattern per chip on the recording head 22 and detect it to calculate the inter-chip registration value. However, looking at the area enclosed by the dashed frames 1305 and 1306, it appears that applying the widthwise registration adjustment value to the printing positions of maintenance patterns 1301 and 1303 has resulted in patterns that should have been printed on the same chip being printed on multiple chips.

[0111] Applying the widthwise registration adjustment value to the maintenance pattern in this way may not be appropriate when acquiring registration values ​​between head chips. On the other hand, applying the widthwise registration adjustment value is necessary to detect the detection mark P in the transport detection unit. Therefore, in this embodiment, the widthwise registration adjustment value is applied to the detection mark P when printing, but the widthwise registration adjustment value is not applied to the maintenance pattern, and it is printed in a way that maintains the original printing position. As a result, even if the adjustment positions of the meandering correction units 5a and 5b are misaligned, it is possible to detect the detection mark P and adjust the inter-chip registration appropriately.

[0112] Furthermore, the method for calculating the edge registration value in this embodiment is not limited to the case where the user measures the edge registration value and inputs it to the printing device 1, as shown in S1006. The same effect as in this embodiment can be achieved in a recording device that automatically detects the edge registration value with a sensor and adjusts the image printing position accordingly. [Embodiment 3]

[0113] The previously described embodiments addressed issues related to inter-color registers and inter-chip registers. This embodiment addresses issues related to inter-column registers within a chip.

[0114] The recording head shown in Figure 9 had one row per chip, but it is preferable to have multiple rows within each chip. By using multiple rows, even if printing is done in a single scan, the image is less likely to be distorted even if there are bullet impact errors, similar to when printing in multiple passes, thus improving so-called robustness.

[0115] Figure 14 shows an example configuration of a recording head 1401 having multiple nozzle rows within a chip. The recording head 1401 is composed of multiple head chips (head substrates) 1402, each with a parallelogram shape, connected together in the y direction. Each head chip 1402 has 16 nozzle rows, and the nozzles constituting each nozzle row are offset in the x and y directions at a pitch that results in a resolution of 600 dpi. Although the nozzles in each nozzle row are arranged at a pitch that results in a resolution of 600 dpi, the nozzles between rows are offset by 1 / 4 pitch in the nozzle arrangement direction (y direction). Therefore, by combining four consecutive nozzle rows, for example, nozzle rows 0-3 and nozzle rows 4-7, it is possible to print with a resolution of 2400 dpi in the y direction. By setting the ejection timing for each nozzle to cancel out the amount and direction of the ink droplet landing position shift due to these x and y direction shifts, the ink can be made to land straight in the y direction.

[0116] Figure 15 illustrates a maintenance pattern 1502 for inter-column register adjustment, which is used to adjust the register values ​​(hereinafter referred to as inter-column registers) for each nozzle row within the same head chip 1402 in the recording head 1401. A pattern is placed for each nozzle row to adjust the inter-column register misalignment within the head chip 1402. The inter-column register adjustment pattern 1502 for one head chip 1402 is printed using the nozzles within the range indicated by the dashed line 1501 of each nozzle row of the head chip 1402.

[0117] Pattern sequences 1503 to 1506 within maintenance pattern 1502 include patterns corresponding to predetermined nozzle rows, represented by blocks with numbers. The patterns corresponding to nozzle rows are printed using only the nozzle row indicated by the number. Based on the nozzle arrangement used to print pattern sequences 1503 to 1506, the positional deviation is calculated from the relative position of the patterns in each of the remaining nozzle rows, with the pattern in nozzle row 0 as the reference point.

[0118] In this embodiment, the widthwise registration adjustment value obtained in the same manner as in the previously described embodiment is applied to the printing position of the detection mark, thereby enabling the detection mark to be detected by the transport detection unit. On the other hand, if the widthwise registration adjustment value is applied to the inter-column registration adjustment pattern, when printing a pattern associated with a predetermined nozzle row, a part of the pattern may be printed on another nozzle row adjacent to the associated nozzle row.

[0119] Thus, even in inter-column register adjustment, depending on the configuration of the recording head 1401, applying the width direction register adjustment value to the maintenance pattern for inter-column register adjustment may result in an inability to obtain an appropriate register adjustment value. Similar to Embodiment 2, by not applying the width direction register adjustment value to the maintenance pattern 1502, it becomes possible to obtain an appropriate inter-column register adjustment value even with a recording head 1401 having a diagonally arranged nozzle row as shown in Figure 14.

[0120] (Other examples) The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0121] This disclosure includes the following configurations and methods:

[0122] [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, Control means for controlling the recording position of the first recording means or the recording position of the second recording means in accordance with the expansion and contraction of the recording medium due to drying by the drying means, A printing apparatus characterized by being equipped with

[0123] [Configuration 2] The control means controls the recording position of the first recording means by controlling the position and size at which the recording of the first image begins. The printing apparatus according to configuration 1, characterized in that it is a printing apparatus.

[0124] [Configuration 3] The control means controls the recording position by changing the ejection frequency of the recording head of the first recording means. The printing apparatus according to configuration 1, characterized in that it is a printing apparatus.

[0125] [Structure 4] The system further comprises an acquisition means for acquiring a read image obtained by reading an image recorded in the recording means, 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 the expansion / contraction ratio of the recording medium calculated from the reading image obtained by reading the recording medium on which the maintenance pattern acquired by the acquisition means is recorded. A printing apparatus according to any one of configurations 1 to 3, characterized by the above.

[0126] [Composition 5] The maintenance pattern includes two first patterns for adjusting the relative recording position difference 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. The printing apparatus according to configuration 4, characterized by the features described above.

[0127] [Composition 6] The two first patterns are arranged at a predetermined interval in the transport direction of the recording medium. The printing apparatus according to configuration 5, characterized in that

[0128] [Composition 7] The control means calculates the expansion / contraction ratio of the recording medium in the transport direction from the two first patterns and the distance between the two first patterns in the transport direction of the recording medium. The printing apparatus according to configuration 5 or 6, characterized by the above.

[0129] [Structure 8] The first recording means and the second recording means each have an inkjet recording head. A printing apparatus according to any one of configurations 5 to 7, characterized by the above.

[0130] [Composition 9] The maintenance pattern includes the first pattern and a second pattern for adjusting the recording position within the recording head. The printing apparatus according to configuration 8, characterized by the above.

[0131] [Configuration 10] The second pattern is placed between the two first patterns. The printing apparatus according to configuration 9, characterized in that

[0132] [Composition 11] The control means adjusts the recording position in the width direction perpendicular to the transport direction of the recording medium based on at least one of the two first patterns. A printing apparatus according to any one of configurations 5 to 10, characterized by the above.

[0133] [Composition 12] The system further comprises a detection means for detecting detection marks included in the maintenance pattern recorded by the first recording means, The control means starts recording in the second recording means in response to the detection of the detection mark by the detection means. A printing apparatus according to any one of configurations 4 to 11, characterized by the features described herein.

[0134] [Composition 13] The control means maintains the 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. The printing apparatus according to configuration 1, characterized in that it is a printing apparatus.

[0135] [Composition 14] The control means controls the recording position by scaling the image recorded by the first recording means. A printing apparatus according to any one of configurations 1 to 13, characterized by the features described herein.

[0136] [Composition 15] The steps include recording the first image onto a recording medium, The steps include drying the recording medium on which the first image is recorded, A step of recording a second image on the recording medium that has been dried by the drying step, A step of controlling the recording position in the step of recording the first image or the recording position in the step of recording the second image, in accordance with the expansion and contraction of the recording medium due to drying by the drying means, A printing method characterized by having the following features.

[0137] [Composition 16] A first recording means for recording a first image on a recording medium, A second recording means for recording a second image on the recording medium on which the first image has been recorded by the first recording means, Control means for controlling the recording position of the first recording means and the recording position of the second recording means, A detection means for detecting a detection mark recorded by the first recording means in order to determine the timing of recording by the second recording means, An acquisition means for acquiring a first amount of displacement in the width direction of the recording position on the recording medium by the first recording means and a second amount of displacement in the width direction of the recording position on the recording medium by the second recording means, Equipped with, When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control means controls the recording position of the detection mark recorded by the first recording means to fall within the detection range of the detection means, based on the first and second deviation amounts acquired by the acquisition means. A printing apparatus characterized by the following features. [Composition 17] When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control means controls the first recording means and the second recording means to maintain the positional relationship between the maintenance pattern and the first recording means and the second recording means, without adjusting the recording position of the maintenance pattern recorded by the first recording means and the second recording means, based on the first and second deviation amounts acquired by the acquisition means. The printing apparatus according to configuration 16, characterized in that... [Composition 18] A drying means disposed between the first recording means and the second recording means for drying the recording medium on which the first image is recorded, The printing apparatus according to configuration 16 or 17, further comprising the above. [Composition 19] The control means calculates the first displacement and the second displacement based on the distance between the widthwise edge of the recording medium and the image recorded by the first recording means and the second recording means. A printing apparatus according to any one of the configurations 16 to 18, characterized by the above. [Configuration 20] The maintenance pattern includes a maintenance pattern for register adjustment between head chips included in the recording heads of the first recording means and the second recording means. A printing apparatus according to any one of the configurations 16 to 19, characterized by the features described herein. [Composition 21] The nozzle rows of the recording heads of the first recording means and the second recording means are not parallel to the width direction of the recording medium. A printing apparatus according to any one of the configurations 16 to 20, characterized by the features described herein. [Composition 22] The maintenance pattern includes a maintenance pattern for register adjustment between nozzle rows in the recording heads of the first and second recording means, A printing apparatus according to any one of the configurations 16 to 21, characterized by the features described herein. [Composition 23] The steps include recording the first image onto a recording medium, The steps include recording a second image on the recording medium on which the first image has been recorded by the step of recording the first image, A step of controlling the recording position of the first image and the recording position of the second image, A step to detect the detection mark recorded by the first image recording step in order to determine the timing of recording the second image, A step of obtaining a first amount of displacement in the width direction of the recording position on the recording medium by recording the first image and a second amount of displacement in the width direction of the recording position on the recording medium by recording the second image, It has, When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control step controls the recording position of the detection mark recorded by the step for recording the first image to fall within the detection range of the detection step, based on the first and second deviation amounts acquired by the acquisition means. A printing method characterized by the following features. [Composition 24] A program that causes a computer to perform each step of the printing method described in configuration 15 or 23.

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, Control means for controlling the recording position of the first recording means or the recording position of the second recording means in accordance with the expansion and contraction of the recording medium due to drying by the drying means, A printing apparatus characterized by being equipped with

2. The control means controls the recording position of the first recording means by controlling the position and size at which the recording of the first image begins. The printing apparatus according to feature 1.

3. The control means controls the recording position by changing the ejection frequency of the recording head of the first recording means. The printing apparatus according to feature 1.

4. The system further comprises an acquisition means for acquiring a read image obtained by reading an image recorded in the recording means, 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 the expansion / contraction ratio of the recording medium calculated from the reading image obtained by reading the recording medium on which the maintenance pattern acquired by the acquisition means is recorded. The printing apparatus according to feature 1.

5. The maintenance pattern includes two first patterns for adjusting the relative recording position difference 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. The printing apparatus according to feature 4.

6. The two first patterns are arranged at a predetermined interval in the transport direction of the recording medium. The printing apparatus according to feature 5.

7. The control means calculates the expansion / contraction ratio of the recording medium in the transport direction from the two first patterns and the distance between the two first patterns in the transport direction of the recording medium. The printing apparatus according to feature 5.

8. The first recording means and the second recording means each have an inkjet recording head. The printing apparatus according to feature 5.

9. The maintenance pattern includes the first pattern and a second pattern for adjusting the recording position within the recording head. The printing apparatus according to feature 8.

10. The second pattern is placed between the two first patterns. The printing apparatus according to feature 9.

11. The control means adjusts the recording position in the width direction perpendicular to the transport direction of the recording medium based on at least one of the two first patterns. The printing apparatus according to feature 5.

12. The system further includes a detection means for detecting detection marks included in the maintenance pattern recorded by the first recording means, The control means starts recording in the second recording means in response to the detection of the detection mark by the detection means. The printing apparatus according to feature 4.

13. The control means maintains the 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. The printing apparatus according to feature 1.

14. The control means controls the recording position by scaling the image recorded by the first recording means. The printing apparatus according to any one of claims 1 to 13.

15. The steps include recording the first image onto a recording medium, The steps include drying the recording medium on which the first image is recorded, A step of recording a second image on the recording medium that has been dried by the drying step, A step of controlling the recording position in the step of recording the first image or the recording position in the step of recording the second image, in accordance with the expansion and contraction of the recording medium due to drying by the drying means, A printing method characterized by having the following features.

16. A first recording means for recording a first image on a recording medium, A second recording means for recording a second image on the recording medium on which the first image has been recorded by the first recording means, Control means for controlling the recording position of the first recording means and the recording position of the second recording means, A detection means for detecting a detection mark recorded by the first recording means in order to determine the timing of recording by the second recording means, An acquisition means for acquiring a first amount of displacement in the width direction of the recording position on the recording medium by the first recording means and a second amount of displacement in the width direction of the recording position on the recording medium by the second recording means, Equipped with, When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control means controls the recording position of the detection mark recorded by the first recording means to fall within the detection range of the detection means, based on the first and second deviation amounts acquired by the acquisition means. A printing apparatus characterized by the following features.

17. When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control means controls the first recording means and the second recording means to maintain the positional relationship between the maintenance pattern and the first recording means and the second recording means, without adjusting the recording position of the maintenance pattern recorded by the first recording means and the second recording means, based on the first and second deviation amounts acquired by the acquisition means. The printing apparatus according to feature 16.

18. A drying means disposed between the first recording means and the second recording means for drying the recording medium on which the first image is recorded, The printing apparatus according to claim 16, further comprising the features described above.

19. The control means calculates the first displacement and the second displacement based on the distance between the widthwise edge of the recording medium and the image recorded by the first recording means and the second recording means. The printing apparatus according to feature 16.

20. The maintenance pattern includes a maintenance pattern for register adjustment between head chips included in the recording heads of the first recording means and the second recording means. The printing apparatus according to feature 16.

21. The nozzle rows of the recording heads of the first recording means and the second recording means are not parallel to the width direction of the recording medium. The printing apparatus according to feature 16.

22. The maintenance pattern includes a maintenance pattern for adjusting the registration between nozzle rows in the recording heads of the first and second recording means. The printing apparatus according to feature 16.

23. The steps include recording the first image onto a recording medium, The steps include recording a second image on the recording medium on which the first image has been recorded by the step of recording the first image, A step of controlling the recording position of the first image and the recording position of the second image, A step to detect the detection mark recorded in the first image recording step in order to determine the timing of recording the second image, A step of obtaining a first amount of displacement in the width direction of the recording position on the recording medium by recording the first image and a second amount of displacement in the width direction of the recording position on the recording medium by recording the second image, It has, When a maintenance pattern for register adjustment is recorded on the recording medium as the first image and the second image, the control step controls the recording position of the detection mark recorded by the step for recording the first image to fall within the detection range of the detection step, based on the first and second deviation amounts acquired by the acquisition means. A printing method characterized by the following features.

24. A program for causing a computer to perform each step of the printing method described in claim 15 or 23.

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