Liquid discharge device and liquid discharge method

Abstract

To provide a technique that can reduce erroneous detection of a mark image formed on a recording medium.SOLUTION: A liquid discharge device according to one embodiment described in the disclosure, which can form an image on a recording medium conveyed in a conveying direction, comprises the recording medium including mark images formed by the liquid discharge device, a reading-out part that reads out the images formed on the recording medium, and a correcting part that corrects the images formed on the recording medium, on the basis of information about the reading-out by the reading-out part. The mark images include a first mark image constituted of two or more vertical lines extending in the conveying direction and two or more lateral lines extending in a width direction crossing the conveying direction and respectively crossing the two or more vertical lines respectively.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a liquid ejection apparatus and a liquid ejection method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a technique for correcting an image formed on a recording medium by a liquid ejection device, based on the result of reading the image formed on the recording medium by the liquid ejection device.

[0003] Also, a technology has been disclosed that uses a mark image formed on a recording medium by a liquid ejection device to detect the amount of misalignment in the relative position between the recording medium and an image formed on the recording medium by the liquid ejection device (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the technique described in Patent Document 1, if a noise image other than the mark image is present on the recording medium, the noise image may be erroneously detected as the mark image.

[0005] An object of the present disclosure is to provide a technique capable of reducing erroneous detection of a mark image formed on a recording medium. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present disclosure is a liquid ejection device capable of forming an image on a recording medium transported in a transport direction, and includes: a recording medium including a mark image formed by the liquid ejection device; a reading unit that reads the image formed on the recording medium; and a correction unit that corrects the image formed on the recording medium based on read information by the reading unit, wherein the mark image includes a first mark image composed of two or more vertical lines extending in the transport direction and two or more horizontal lines extending in a width direction intersecting the transport direction and each intersecting with each of the two or more vertical lines. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a technique capable of reducing erroneous detection of a mark image formed on a recording medium. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram illustrating an overall configuration of a liquid ejection device according to a first embodiment. [Diagram 2] 2 is a schematic diagram of the head unit according to the first embodiment, as viewed from the normal direction of the nozzle plate. FIG. [Diagram 3] FIG. 2 is a diagram showing a hardware configuration of the liquid ejection device according to the first embodiment. [Figure 4] 1 is a diagram showing a recording medium on which a mark image and a rectangular image are formed according to the first embodiment; [Diagram 5] 5 is an enlarged view of a first example of a first mark image in FIG. 4. [Figure 6] 5 is an enlarged view of a second example of the first mark image in FIG. 4. [Figure 7] 5 is an enlarged view of a second mark image in FIG. 4. FIG. [Figure 8] 3 is a block diagram showing the functional configuration of a processing unit according to the first embodiment. FIG. [Figure 9] 4 is a flow chart showing the operation of the liquid ejection device according to the first embodiment. FIG. [Figure 10] 13 is a diagram showing a display screen of the detection result of the second mark image by the display unit. FIG. [Figure 11] FIG. 13 is a diagram showing a display screen of a notification displayed by a display unit. [Figure 12] FIG. 13 is a diagram showing a display screen of a position deviation threshold value displayed by a display unit. [Figure 13] 13 is a diagram showing the positional relationship between a recording medium on which a mark image is formed and a reading unit according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A liquid ejection device and a liquid ejection method according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, the following embodiments are examples of a liquid ejection device and a liquid ejection method for embodying the technical concept of the present embodiment, and are not limited to the following. The size, positional relationship, etc. of the members shown in each drawing may be exaggerated to clarify the explanation. In the following explanation, the same names and symbols indicate the same or similar members, and detailed explanations will be omitted as appropriate.

[0010] In the following figures, the direction in which the arrow indicating the transport direction A of the recording medium in the embodiment points may be referred to as the +A side, and the opposite side to the +A side may be referred to as the -A side, and the direction in which the arrow indicating the width direction B that intersects with the transport direction A points may be referred to as the +B side, and the opposite side to the +B side may be referred to as the -B side.

[0011] The term "image" in this specification may refer to both an "image" formed on a recording medium according to the embodiment and an "image" in the read information by the reading unit according to the embodiment. Whether it refers to an image formed on a recording medium or an image in the read information can be appropriately distinguished depending on the context.

[0012] [First embodiment] <Configuration example of liquid ejection device according to the first embodiment> Fig. 1 is a schematic diagram showing the overall configuration of a liquid ejection device 100 in this embodiment. Fig. 1 shows a schematic view of the inside of the liquid ejection device 100 seen through from the -B side. The liquid ejection device 100 is capable of forming an image on a recording medium P transported in a transport direction A. As an example, the liquid ejection device 100 is an image forming device for commercial printing that forms a desired image on a large number of recording media P such as paper using a liquid ejection method.

[0013] 1, the liquid ejection device 100 has a recording medium P on which a mark image is formed by the liquid ejection device 100, a reading unit 5 that reads the image formed on the recording medium P, and a processing unit 6. The processing unit 6 includes a correction unit that corrects the image formed on the recording medium P based on the read information by the reading unit 5. The correction by the correction unit includes correction of the position of the image formed on the recording medium P by the liquid ejection device 100, correction of the density of the image formed on the recording medium, and the like. The liquid ejection device 100 uses the mark image formed on the recording medium P by the liquid ejection device 100 for the correction by the correction unit.

[0014] The recording medium P on which the mark image is formed is a so-called test chart used to detect the position and density of an image formed on the recording medium P by the liquid ejection device 100. The liquid ejection device 100 detects the position of the mark image based on read information of the mark image on the test chart. The liquid ejection device 100 can correct the position and density of the image formed on the recording medium P based on the detected position of the mark image.

[0015] For example, a liquid ejection device that forms an image on a recording medium transported in a transport direction A may form noise images on the recording medium, such as vertical streak images that include vertical lines (hereinafter simply referred to as vertical lines) extending in the transport direction A, or horizontal streak images that include horizontal lines (hereinafter simply referred to as horizontal lines) extending in the width direction B. If the mark image is composed of a simple image, such as an image of only vertical lines or an image of only horizontal lines, the correction unit may erroneously detect the noise image formed on the recording medium P as a mark image, resulting in a decrease in the accuracy of image correction. If the accuracy of image correction decreases, the quality of the image formed on the recording medium by the liquid ejection device will decrease.

[0016] As will be described in detail later with reference to Figs. 4 to 7, the mark image according to this embodiment includes a first mark image that is configured of two or more vertical lines extending in the transport direction A and two or more horizontal lines extending in a width direction B intersecting the transport direction A and intersecting each of the two or more vertical lines. For example, the first mark image can be configured of three or more vertical lines extending in the transport direction A and three or more horizontal lines extending in the width direction B and intersecting each of the three or more vertical lines. Such a first mark image has a larger difference in shape from a vertical streak image or a horizontal streak image compared to a mark image consisting of only vertical lines or only horizontal lines. Due to this difference in shape, the liquid ejection device 100 can reduce erroneous detection of a noise image as a mark image, thereby increasing the correction accuracy by the correction unit and improving the quality of the image formed on the recording medium P by the liquid ejection device 100.

[0017] 1, the liquid ejection device 100 may mainly include a paper feed section 1, an image forming section 2, a drying section 3, and a paper ejection section 4. The liquid ejection device 100 forms an image on a recording medium P fed from the paper feed section 1 in the image forming section 2 using ink, which is a liquid for image formation. Then, after the ink attached to the recording medium P is dried in the drying section 3, the recording medium P is ejected from the paper ejection section 4. The recording medium P is a recording material in the form of a sheet material, for example, paper in the form of a cut sheet cut to a predetermined size.

[0018] (Paper feed section 1) The paper feed section 1 mainly includes a paper feed tray 11 on which a plurality of recording media P are stacked, a feed device 12 that separates and sends out the recording media P one by one from the paper feed tray 11, and a pair of registration rollers 13 that sends the recording media P to the image forming section 2. The feed device 12 can be any type of feed device, such as a device using rollers or a device using air suction. After the leading edge of the recording medium P sent out from the paper feed tray 11 by the feed device 12 reaches the pair of registration rollers 13, the pair of registration rollers 13 is driven at a predetermined timing to feed the recording medium P to the image forming section 2. In this embodiment, the paper feed section 1 is not limited in its configuration as long as it sends out the recording media P to the image forming section 2.

[0019] (Image forming unit 2) The image forming unit 2 is mainly composed of a receiving drum 21 that receives the fed recording medium P, a carrying drum 22 that carries the recording medium P carried by the receiving drum 21 on its outer circumferential surface and carries it in the carrying direction A, a liquid ejecting unit 24 that ejects ink toward the recording medium P carried by the carrying drum 22, and a transfer drum 25 that transfers the recording medium P carried by the carrying drum 22 to the drying unit 3. The recording medium P that has been carried from the paper feeding unit 1 to the image forming unit 2 is gripped at its leading end by a gripper provided on the surface of the receiving drum 21, and is transported as the surface of the receiving drum 21 moves. The recording medium P transported by the receiving drum 21 is delivered to the carrying drum 22 at a position facing the carrying drum 22. The width direction B is a direction that is approximately perpendicular to the carrying direction A.

[0020] A gripper is also provided on the surface of the carrying drum 22, and the leading end of the recording medium P is gripped by the gripper. A plurality of suction holes are formed in a dispersed manner on the surface of the carrying drum 22, and a suction device 23 generates a suction airflow inwardly of the carrying drum 22 at each suction hole. The recording medium P transferred from the receiving cylinder 21 to the carrying drum 22 has its leading end gripped by the gripper, and is adsorbed to the surface of the carrying drum 22 by the suction airflow, and is transported as the surface of the carrying drum 22 moves.

[0021] The liquid ejection unit 24 of this embodiment ejects four colors of liquid, namely, C (cyan), M (magenta), Y (yellow), and K (black), to form an image. The liquid ejection unit 24 includes individual head units 24C, 24M, 24Y, and 24K for each color of liquid. The head units 24C, 24M, 24Y, and 24K are not limited in configuration as long as they eject liquid, and any configuration can be adopted. If necessary, a head unit that ejects liquid of a special color such as white, gold, or silver, or a head unit that ejects liquid that does not form an image, such as a surface coating liquid, may be provided.

[0022] The discharge operation of each of the head units 24C, 24M, 24Y, and 24K is controlled by a drive signal corresponding to image information. When the recording medium P supported on the support drum 22 passes through an area facing the liquid discharge unit 24, liquid of each color is discharged from the head units 24C, 24M, 24Y, and 24K, and an image corresponding to the image information is formed. In this embodiment, the image forming unit 2 is not limited in its configuration as long as it forms an image by depositing liquid on the recording medium P.

[0023] (Drying section 3) The drying section 3 is mainly composed of a drying mechanism 31 for drying the ink attached on the recording medium P in the image forming section 2, and a transport mechanism 32 for transporting the recording medium P transported from the image forming section 2. The recording medium P transported from the image forming section 2 is received by the transport mechanism 32, then transported to pass through the drying mechanism 31, and delivered to the paper discharge section 4. When passing through the drying mechanism 31, the ink on the recording medium P is subjected to a drying process, whereby liquid components such as water in the ink evaporate, the ink is fixed on the recording medium P, and curling of the recording medium P is suppressed.

[0024] (Paper ejection section 4) The paper discharge unit 4 is mainly composed of a paper discharge tray 41 on which a plurality of recording media P are stacked. The recording media P conveyed from the drying unit 3 are sequentially stacked and held on the paper discharge tray 41. In this embodiment, the paper discharge unit 4 is not limited in its configuration as long as it discharges the recording media P.

[0025] (Reading unit 5) The reading unit 5 reads an image formed on the recording medium P. The reading unit 5 reads, for example, a mark image formed on the recording medium P by the liquid ejection device 100. The reading unit 5 can also read a rectangular image formed by the liquid ejection device 100 and extending in the width direction B at a predetermined density.

[0026] The reading unit 5 is disposed in the drying section 3 near the outlet of the drying mechanism 31. The reading unit 5 can read an image formed on the recording medium P after the recording medium P is dried by the drying mechanism 31. However, the position at which the reading unit 5 is disposed is not limited to the position shown in FIG. 1 as long as the image formed on the recording medium P can be read. For example, the reading unit 5 may be disposed between the support drum 22 and the transport mechanism 32, or may be disposed in the paper discharge section 4.

[0027] The reading unit 5 can be configured with an in-line sensor that reads a mark image formed on the conveyed recording medium P. The in-line sensor includes a one-dimensional imaging element made of a charge coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) in which pixels are arranged linearly along the width direction B. The reading unit 5 can obtain read information of the recording medium B as two-dimensional image data by imaging the recording medium B conveyed in the conveying direction A with the one-dimensional imaging element in which pixels are arranged in the width direction B. The reading unit 5 can output the obtained read information to the processing unit 6.

[0028] (Other functional parts) The liquid ejection device 100 may appropriately include other functional units in addition to the paper feed unit 1, the image forming unit 2, the drying unit 3, the paper discharge unit 4, and the reading unit 5. The other functional units include a pre-processing unit that is disposed between the paper feed unit 1 and the image forming unit 2 and performs pre-processing before the image formation, and a post-processing unit that is disposed between the drying unit 3 and the paper discharge unit 4 and performs post-processing after the image formation.

[0029] An example of the pre-treatment section is a section that performs a treatment liquid application process to apply a treatment liquid to the recording medium P to suppress bleeding by reacting with the ink. However, there is no particular restriction on the content of the pre-treatment process by the pre-treatment section. An example of the post-treatment section is a reversal transport process to reverse the recording medium P on which an image has been formed in the image forming section 2 and send it back to the image forming section 2 to form images on both sides of the recording medium P, a process to bind multiple recording media P on which images have been formed, a correction mechanism to correct deformation of the recording medium P, a cooling mechanism to cool the recording medium P, and the like. However, there is no particular restriction on the content of the post-treatment process by the post-treatment section.

[0030] (Head units 24C, 24M, 24Y, 24K) The configuration of head unit 24C included in liquid ejection section 24 shown in Fig. 1 will be described with reference to Fig. 2. Fig. 2 is a schematic diagram of head unit 24C viewed from the normal direction of nozzle plate 241 arranged in ejection head 240 included in head unit 24C. Head units 24M, 24Y, and 24K included in liquid ejection section 24 differ only in the color of the liquid they eject, and all have the same configuration as head unit 24C. Here, head unit 24C will be described as a representative example.

[0031] In the example shown in FIG. 2, the head unit 24C is a full-line type head unit in which ten ejection heads 240 are arranged on a base member 243. The ten ejection heads 240 are arranged in a line in the width direction B so that an image can be formed within a predetermined range in the width direction B of the recording medium P transported in the transport direction A. The ten ejection heads 240 are arranged in two rows in the transport direction A, each row including five ejection heads 240 arranged in the width direction B, and the rows of ejection heads 240 are arranged offset from each other in the width direction B. This arrangement can prevent an area on the recording medium P where an image is not formed from occurring at the boundary between the ejection heads 240 arranged in the width direction B.

[0032] The number of ejection heads 240 possessed by the head unit 24C is not limited to 10 and can be changed appropriately depending on the width in the width direction B of the recording medium P. The number of rows of ejection heads 240 aligned in the transport direction A is not limited to two rows and may be one or more rows. Furthermore, the rows of ejection heads 240 aligned in the transport direction A do not necessarily have to be arranged so as to be shifted from each other in the width direction B.

[0033] Each of the ten ejection heads 240 has a nozzle plate 241 and a plurality of nozzles 242. The nozzle plate 241 is disposed on the side of the storage unit that stores the liquid, facing the carrier drum 22 (see FIG. 1), and constitutes a part of the storage unit. Each of the plurality of nozzles 242 may be a through-hole formed in the nozzle plate 241. The plurality of nozzles 242 are aligned in the width direction B to constitute a nozzle row. In FIG. 2, the plurality of nozzles 242 that constitute the nozzle row are simply represented by lines extending in the width direction B.

[0034] The ejection head 240 ejects the liquid contained in the storage portion through the nozzles 242 toward the recording medium P carried on the carrying drum 22. The liquid ejection device 100 can eject the liquid within a predetermined range of the recording medium P in the width direction B by the multiple nozzles 242 that each of the ten ejection heads 240 has.

[0035] The discharge operation of each of the head units 24C, 24M, 24Y, and 24K is controlled by a drive signal corresponding to information related to image formation. When the recording medium P supported on the support drum 22 passes through an area facing the liquid discharge unit 24, the liquid discharge device 100 discharges liquid of each color from the head units 24C, 24M, 24Y, and 24K, thereby forming an image on the recording medium P according to the image data.

[0036] (Hardware configuration) Fig. 3 is a block diagram for explaining an example of an electrical hardware configuration of the liquid ejection device 100. In the example shown in Fig. 3, the liquid ejection device 100 has an image forming unit 2, a reading unit 5, a processing unit 6, a display unit 101, and an operation unit 102. The processing unit 6 has a CPU 601, a ROM 602, a RAM 603, a HDD / SSD 604, an I / F 605, and a control circuit 606. The components shown in Fig. 3 are connected to each other so as to be able to communicate with each other via a system bus SB.

[0037] The processing unit 6 controls the overall operation of the liquid ejection device 100. As described above, the image forming unit 2 is an image forming engine for forming an image on the recording medium P. The display unit 101 is a display that displays messages such as notifications and warnings on a display screen. The display unit 101 can be configured with a liquid crystal panel, an organic EL (Electro Luminescence) display panel, or the like.

[0038] The CPU 601 uses the RAM 603 as a working area, and executes processes defined in a program stored in the ROM 602 .

[0039] The HDD / SSD 604 is used as a storage unit and stores preset setting values. The information stored in the HDD / SSD 604 may be read by the CPU 601 and used when executing a program.

[0040] The I / F 605 is an interface that enables communication between the liquid ejection apparatus 100 and an external device. The I / F 605 can also enable communication between the liquid ejection apparatus 100 and an external server or the like via the Internet or the like.

[0041] The control circuit 606 is an electric circuit or electronic circuit that performs control or arithmetic processing that requires high speed processing.

[0042] (Examples of mark images and rectangular images) The mark image and rectangular image according to the first embodiment will be described with reference to Figs. 4 to 7. Fig. 4 is a diagram showing an example of a recording medium P on which a mark image and rectangular image according to the first embodiment are formed. Fig. 5 is an enlarged view showing a first example of the first mark image in Fig. 4. Fig. 6 is an enlarged view showing a second example of the first mark image in Fig. 4. Fig. 7 is an enlarged view showing an example of the second mark image in Fig. 4.

[0043] Fig. 4 shows a part of the recording medium P viewed from a direction substantially perpendicular to each of the transport direction A and the width direction B. Figs. 5 to 7 show the mark images viewed from a direction perpendicular to each of the transport direction A and the width direction B.

[0044] 4, the mark image 50 has a first mark image 51. The mark image 50 can also have a plurality of second mark images 52 and a plurality of rectangular images 53. The first mark image 51 can include a first image 511 and a second image 512. The width W is the width of the recording medium P in the width direction B. The width W corresponds to a predetermined range of the recording medium P in the width direction B.

[0045] 4 and 5, the first image 511 is composed of three vertical lines V11, V12, and V13 extending in the transport direction A, and three horizontal lines H11, H12, and H13 extending in the width direction B and intersecting with the three vertical lines V11, V12, and V13, respectively. The first image 511 is disposed at the corners of the +A side and the -B side of the recording medium P.

[0046] The first image 511 is not limited to those shown in Figs. 4 and 5, and may be composed of two or more vertical lines extending in the transport direction A and two or more horizontal lines extending in the width direction B and intersecting with each of the two or more vertical lines. For example, as shown in Fig. 6, the first image 511 may be composed of two vertical lines V11a, V12a extending in the transport direction A and two or more horizontal lines H11a, H12a extending in the width direction B and intersecting with each of the two or more vertical lines V11a, V12a.

[0047] As shown in FIG. 4, the second image 512 is formed within a predetermined distance from the first image 511. As shown in FIG. 4 and FIG. 7, the second image 512 has one vertical line V21 extending in the conveying direction A and one horizontal line H21 extending in the width direction B. The second image 512 can include a position where the one vertical line V21 and the one horizontal line H21 intersect as a reference position HP. By including the second image 512, the mark image 50 can set a reference position HP that is a reference for the position of the second mark image 52. There is no particular limit to the predetermined distance as long as the second image 512 can be detected after the first image 511 is detected. However, from the viewpoint of reducing erroneous detection of a noise image, it is preferable that the predetermined distance is short, that is, that the first image 511 and the second image 512 are formed as close as possible.

[0048] In the example shown in FIG. 4, the second mark image 52 is a vertical line extending in the transport direction A. Ten second mark images 52 are lined up in the width direction B. The positions of the ten second mark images 52 represent the positions of the boundaries between the ten ejection heads 240 shown in FIG. 2. The positions of the boundaries between the ten ejection heads 240 correspond to the positions in the width direction B where, for example, a reference nozzle located furthest on the -B side among the multiple nozzles 242 provided in each of the ten ejection heads 240 in FIG. 2 is disposed. However, this reference nozzle is not limited to the nozzle located furthest on the -B side among the multiple nozzles 242, and may be the nozzle located furthest on the +B side.

[0049] The reference position HP of the first mark image 51 and the positions of the ten second mark images 52 are associated in advance. The liquid ejection device 100 detects the relative positions of the ten second mark images 52 with respect to the reference position HP based on the position of the reference position HP in the read information Im by the reading unit 5, thereby identifying the boundary positions of the ten ejection heads 240. The liquid ejection device 100 can then identify the positions in the width direction B of all of the nozzles 242 that are arranged at predetermined positions with respect to the boundary positions of the ten ejection heads 240.

[0050] The rectangular image 53 is an image formed on the recording medium P by the liquid ejection device 100 and extends in the width direction B. If there is no density difference in the images formed by each of the multiple nozzles 242 provided in the ten ejection heads 240, the rectangular image 53 will have almost no density distribution and will be an image with a substantially uniform density. However, if the amount of liquid ejected in response to the drive signal differs for each of the multiple nozzles 242, for example, a density difference will occur in the image formed on the recording medium P by each of the multiple nozzles 242. Depending on this density difference, vertical streaks extending in the transport direction A may be visible in the rectangular image 53.

[0051] The liquid ejection device 100 can identify the nozzles 242 that cause density differences by identifying positions in the rectangular image 53 that correspond to each of the multiple nozzles 242 based on the read information Im of the mark image 50. The liquid ejection device 100 corrects the amount of liquid ejected from the nozzles 242 that cause density differences so that no density difference occurs in images formed by the other nozzles 242, thereby reducing the density difference in the image formed on the recording medium P and making it possible to form a high-quality image.

[0052] On the other hand, for example, in the read information Im, if an attempt is made to directly detect the second image 512 without passing through the first image 511, the second image 512 has a shape similar to a noise image such as an image with vertical or horizontal stripes, and therefore the noise image may be erroneously detected as the second image 512. If such an erroneous detection occurs, the reference position HP cannot be detected accurately, and the image cannot be corrected accurately.

[0053] The liquid ejection device 100 first detects the first image 511 from the read information Im by the reading unit 5, and then detects the second image 512 arranged at a predetermined position relative to the first image 511, and identifies the reference position HP. Then, after identifying the positions of the second mark images 52 based on the reference position HP, it identifies the positions of all of the multiple nozzles 242. The liquid ejection device 100 can reduce erroneous detection of the second image 512 by detecting the second image 512 via the first image 511, which has a shape significantly different from that of the noise image. This makes it possible to accurately detect the reference position HP and accurately correct the image.

[0054] As shown in Fig. 4, the rectangular image 53 can include nine rectangular images 531-539 that are aligned in the conveying direction A and have different densities. For example, the density difference between images may be noticeable differently depending on the density of the image to be formed. By detecting the density difference using the nine rectangular images 531-539 that are different from each other in densities, the density difference between images can be detected at various densities, and therefore the detection accuracy of the density difference can be improved and the accuracy of correcting the density of the image can be improved. Note that the number of rectangular images 53 is not limited to nine and may be one or more, and can be appropriately determined depending on the required correction accuracy, etc.

[0055] The second image 512 and the second mark image 52 in the first mark image 51 may be formed on the recording medium P at a predetermined distance or more apart in at least one of the transport direction A and the width direction B. In the example shown in Fig. 4, the second image 512 and the second mark image 52 are separated by a distance dA in the transport direction A and a distance dB in the width direction B. By forming the second image 512 and the second mark image 52 at a distance on the recording medium P, it is possible to reduce the occurrence of the second image 512 and the second mark image 52 being formed overlapping with each other or being erroneously detected, thereby improving the detection accuracy of each position.

[0056] The arrangement of the first image 511, the second image 512, the multiple second mark images 52, and the multiple rectangular images 53 on the recording medium P can be changed as appropriate. For example, the first image 511 and the second image 512 may be arranged in the center of the recording medium P in the width direction B, or in the corners on the +A side and the +B side.

[0057] (Functional configuration of processing unit 6) Next, a functional configuration of the processing unit 6 will be described. Fig. 5 is a block diagram showing an example of the functional configuration of the processing unit 6. In the example shown in Fig. 5, the processing unit 6 has a correction unit 67. The processing unit 6 can also have an input / output unit 61, a theoretical position calculation unit 62, a detection unit 63, a determination unit 64, a reception unit 65, and a notification unit 66.

[0058] The functions of the theoretical position calculation unit 62, the detection unit 63, the determination unit 64, the notification unit 66 and the correction unit 67 can be realized by the CPU 601 shown in Fig. 3 executing processes defined in a program stored in the ROM 602 or the like, or by the control circuit 606 or the like. The functions of the input / output unit 61 and the reception unit 65 can be realized by the I / F 605 or the like shown in Fig. 3. Note that some of the functions of the processing unit 6 may be realized by a configuration other than the processing unit 6, or may be realized by distributed processing between the processing unit 6 and a configuration other than the processing unit 6. An example of the configuration other than the processing unit 6 is an external server or the like.

[0059] The input / output unit 61 controls communications with each of the image forming unit 2, the display unit 101, the operation unit 102, and the reading unit 5 shown in FIG. 3, thereby enabling transmission and reception of information and signals between each component.

[0060] The theoretical position calculation unit 62 calculates the theoretical position of the mark image 50 to be formed on the recording medium P based on size information of the recording medium P indicating A4 size, A3 size, etc., received from the image forming unit 2 or the operation unit 102, etc., via the input / output unit 61. For example, the theoretical position calculation unit 62 can calculate the theoretical position of each of the ten second mark images 52 in the mark image 50. The theoretical position calculation unit 62 passes information related to the calculated theoretical positions of the mark images to the determination unit 64.

[0061] The detection unit 63 detects the position of the mark image 50 formed on the recording medium P based on the read information Im by the reading unit 5. The detection unit 63 receives the read information Im by the reading unit 5 from the reading unit 5 via the input / output unit 61, and can detect the position of each of the ten second mark images 52 relative to the reference position HP based on this read information Im.

[0062] The determination unit 64 determines whether or not the amount of positional deviation of the mark image 50 from the theoretical position obtained based on the size information of the recording medium P is equal to or smaller than a predetermined positional deviation threshold value.

[0063] For example, the determination unit 64 calculates the amount of positional deviation of each of the second mark images 52 from the theoretical positions of the ten second mark images 52 calculated by the theoretical position calculation unit 62 and the positions of the ten second mark images 52 detected by the detection unit 63. The determination unit 64 compares the calculated amount of positional deviation with a positional deviation threshold, and determines that the amount of positional deviation of the mark image 50 from the theoretical position is equal to or less than the positional deviation threshold when all of the amounts of positional deviation of the ten second mark images 52 from the theoretical positions are equal to or less than the positional deviation threshold.

[0064] In the liquid ejection device, if the position of the mark image formed on the recording medium P is deviated from the theoretical position, the correction accuracy by the correction unit may be reduced. In the liquid ejection device 100, if the determination unit 64 determines that the amount of positional deviation is equal to or less than the positional deviation threshold, the correction unit 67 performs correction, thereby reducing the reduction in correction accuracy.

[0065] When the determination unit 64 determines that the amount of positional deviation of the mark image 50 from the theoretical position is equal to or smaller than the positional deviation threshold, it passes to the correction unit 67 information on the positions of the nozzles 242 in the read information Im.

[0066] On the other hand, when the determination unit 64 determines that the amount of positional deviation of the mark image 50 from the theoretical position is not equal to or less than the positional deviation threshold, it counts the number of consecutive times that it has determined that the amount is not equal to or less than the positional deviation threshold. The "number of consecutive times that it has determined" refers to the number of times that the determination unit 64 has repeatedly performed a determination when the liquid ejection device 100 repeatedly performs a series of operations of detection by the detection unit 63 and judgment by the determination unit 64.

[0067] Since the position detection of the mark image 50 by the detection unit 63 includes a certain degree of error, if it is determined that an error has occurred based on only one determination that is not equal to or less than the position deviation threshold, the accuracy of the error determination may be low. Examples of such errors include an error in which the mark image 50, etc. is formed on the recording medium P with a large error, an error in which the reading unit 5 reads the mark image 50 with a large error, and the like.

[0068] The liquid ejection device 100 repeats a series of operations of detection by the detection unit 63 and judgment by the judgment unit 64, and judges that an error has occurred when the number of consecutive judgments that the position deviation is not equal to or less than the position deviation threshold reaches a predetermined number of times threshold. This makes it possible to increase the accuracy of error judgment.

[0069] The reception unit 65 receives a positional deviation threshold setting input In from an operator. For example, the reception unit 65 receives the positional deviation threshold setting input In input by the operator using the operation unit 102 shown in Fig. 3 via the input / output unit 61. The reception unit 65 passes the received setting input In to the determination unit 64. The determination unit 64 can change the positional deviation threshold in accordance with the received setting input In.

[0070] In the liquid ejection device 100, the receiving unit 65 can receive a positional deviation threshold setting input In from an operator, thereby making the positional deviation threshold variable and increasing the reliability of the determination by the determining unit 64 using the positional deviation threshold. Note that the receiving unit 65 can also receive operation inputs other than the positional deviation threshold setting input In from the operator.

[0071] The notification unit 66 notifies an error when the number of times that the determination unit 64 has consecutively determined that the amount of positional deviation of the mark image 50 from the theoretical position is equal to or greater than the positional deviation threshold reaches a predetermined number of times threshold. For example, the notification unit 66 can notify an error by controlling the operation of the display unit 101 shown in FIG. 3 via the input / output unit 61 and causing the display unit 101 to display information about the error. By notifying an error using the notification unit 66, the liquid ejection device 100 can prompt the operator of the liquid ejection device 100 to re-form the mark image 50 on the recording medium P or to re-read the mark image 50 using the reading unit 5, or to adjust the image forming unit 2.

[0072] In the liquid ejection device 100, the display unit 101 can also display the amount of misalignment calculated by the determination unit 64. For example, the display unit 101 can display the amount of misalignment under the control of the notification unit 66 via the input / output unit 61. By displaying the amount of misalignment, the display unit 101 can make the operator of the liquid ejection device 100 aware of the need to re-form the mark image 50 on the recording medium P, re-read by the reading unit 5, adjust the image forming unit 2, or the like.

[0073] The correction unit 67 corrects the image formed on the recording medium P by the liquid ejection device 100 based on the read information Im by the reading unit 5. The correction unit 67 corrects the image formed on the recording medium P when the determination unit 64 determines that the amount of positional deviation of the mark image 50 from the theoretical position is equal to or less than the positional deviation threshold. The correction unit 67 can correct the density of the image formed by each of the multiple nozzles 242 based on the position of the mark image 50 in the read information Im of the recording medium P and the density of the rectangular image 53.

[0074] When there is a density difference in the rectangular image 53, the correction unit 67 may vary the density of the image formed on the recording medium P by the liquid ejection device 100 so as to approach the minimum density among the densities of the rectangular image 53 having density differences. By varying the density of the image so as to approach the minimum density, the correction unit 67 can correct the image so as to reduce the density difference.

[0075] <Operation Example of Liquid Ejection Apparatus 100> Fig. 9 is a flowchart showing an example of the operation of the liquid ejection device 100. Fig. 9 shows the operation of the liquid ejection device 100 correcting the density of an image formed on a recording medium P by the liquid ejection device 100. For example, the liquid ejection device 100 starts the operation shown in Fig. 9 on the condition that the liquid ejection device 100 accepts a correction start operation by an operator using the operation unit 102.

[0076] First, in step S11, the liquid ejection device 100 causes the image forming unit 2 to form a mark image 50 and a rectangular image 53 on the recording medium P. In the drying unit 3, the liquid ejection device 100 causes the recording medium P on which the mark image 50 and the rectangular image 53 have been formed to be conveyed by the conveying mechanism 32 while heating and drying it by the drying mechanism 31.

[0077] Next, in step S12, the liquid ejection device 100 reads the mark image 50 and the rectangular image 53 on the recording medium P dried by the drying unit 3 with the reading unit 5. The read information Im by the reading unit 5 is passed to the processing unit 6.

[0078] Next, in step S13, the liquid ejection device 100 causes the detection unit 63 of the processing unit 6 to detect the first image 511 of the first mark image 51 in the read information Im.

[0079] Next, in step S14, the liquid ejection device 100 causes the detection unit 63 to detect the reference position HP of the first mark image 51 in the read information Im.

[0080] Next, in step S15, the liquid ejection device 100 detects the relative positions of each of the ten second mark images 52 with respect to the reference position HP by the detection unit 63. The detection unit 63 passes information on the positions of each of the ten detected second mark images 52 to the determination unit 64.

[0081] Next, in step S16, the liquid ejection device 100 determines, by the determination unit 64 of the processing unit 6, whether or not the amount of positional deviation of each of the ten second mark images 52 from the theoretical position is equal to or less than the positional deviation threshold value.

[0082] In step S16, if it is determined that one or more of the ten second mark images 52 have a positional deviation amount that is not less than the positional deviation threshold (step S16, NO), in step S17, the liquid ejection device 100 determines whether the number of consecutive judgments made by the judgment unit 64 has reached a predetermined number threshold.

[0083] When it is determined in step S17 that the number of times threshold value has been reached (step S17, YES), in step S18, the liquid ejection device 100 notifies an error by the notification unit 66. For example, the notification unit 66 can notify the operator of the liquid ejection device 100 of the error by causing the display unit 101 to display a notice regarding the error.

[0084] On the other hand, if it is determined in step S17 that the number of times threshold value has not been reached (step S17, NO), the liquid ejection device 100 performs the operations from step S13 onwards again.

[0085] Furthermore, in step S16, if it is determined that the amount of positional deviation of each of the ten second mark images 52 is equal to or less than the positional deviation threshold (step S16, YES), in step S19, the liquid ejection device 100 passes information on the positions of each of the multiple nozzles 242 in the read information Im to the correction unit 67 via the determination unit 64. Based on the information received from the determination unit 64, the correction unit 67 can identify the positions corresponding to each of the multiple nozzles 242 in the rectangular image 53 of the read information Im.

[0086] Next, in step S20, the liquid ejection device 100 uses the correction unit 67 to identify, based on the rectangular image 53, the nozzles that cause a density difference among the multiple nozzles 242.

[0087] Next, in step S20, the liquid ejection device 100 causes the correction unit 67 to correct the amount of liquid ejected from the nozzles that cause a density difference among the multiple nozzles 242, so that the density difference is prevented.

[0088] In this manner, the liquid ejection device 100 can correct the density of the image formed on the recording medium P by the liquid ejection device 100 based on the mark image 50 and rectangular image 53 formed on the recording medium P.

[0089] <Example of display screen by display unit 101> Various display screens by the display unit 101 will be described with reference to Figs. 10 to 12. Fig. 10 is a diagram showing an example of a display screen of the detection results of the ten second mark images 52 by the display unit 101. Fig. 11 is a diagram showing an example of a display screen of a notification by the display unit 101. Fig. 12 is a diagram showing an example of a display screen of a position deviation threshold by the display unit 101.

[0090] In the example shown in FIG. 10, the display screen 101a displays the comparison results between the detected values ​​and the theoretical values ​​for the positions of the ten second mark images 52.

[0091] In the example shown in FIG. 11, the display screen 101b displays a notification that the position deviation of the second mark image 52 from the theoretical value is large, and a notification urging the user to re-form the mark image 50 on the recording medium P.

[0092] 12, the display screen 101c displays the positional deviation threshold of the second mark image 52. The display screen 101c includes a text box 111 and an increase / decrease button 112. The operator of the liquid ejection device 100 can change the positional deviation threshold by operating the increase / decrease button 112.

[0093] [Second embodiment] Next, a second embodiment will be described. Note that the same names and reference numerals as those in the first embodiment indicate the same or similar members, and detailed descriptions thereof will be omitted as appropriate.

[0094] The liquid ejection device of this embodiment differs from the first embodiment in that it includes two or more reading units arranged at different positions in the width direction B, and the first mark image and the multiple second mark images are each formed within the reading range of each of the two or more reading units on the recording medium.

[0095] FIG. 13 is a diagram for explaining an example of the positional relationship between a recording medium P on which a mark image 50 according to this embodiment is formed and two reading units 5a and 5b.

[0096] 13, the reading unit 5a and the reading unit 5b are disposed at different positions in the width direction B. Moreover, the reading unit 5a and the reading unit 5b are disposed at positions slightly offset from each other in the transport direction A, and are disposed so as to partially overlap each other in the width direction B. This arrangement allows the reading unit 5 to read the entire recording medium P in the width direction B without omissions.

[0097] The reading units 5a and 5b may be arranged without overlapping in the width direction B, so long as they are arranged at different positions in the width direction B. Furthermore, the reading units 5a and 5b may be arranged at different positions or at approximately the same position in the transport direction A.

[0098] The reading unit 5a is capable of reading a range of width Wa of the recording medium P in the width direction B. The reading unit 5b is capable of reading a range of width Wb of the recording medium P in the width direction B. The width Wa and the width Wn may be the same or different.

[0099] The recording medium P according to the present embodiment can have mark images 50a and 50b. The mark image 50a can include a first mark image 51a and a plurality of second mark images 52a. The first mark image 51a can include a first image 511a and a second image 512a. The mark image 50b can include a first mark image 51b and a plurality of second mark images 52b. The first mark image 51b can include a first image 511b and a second image 512b.

[0100] In the example shown in FIG. 13, the mark images 50a and 50b are formed within the reading ranges of the reading unit 5a and the reading unit 5b on the recording medium P. Specifically, a first mark image 51a and five second mark images 52a are formed within the reading range Wa in the width direction B of the reading unit 5a. A first mark image 51b and five second mark images 52b are formed within the reading range Wb in the width direction B of the reading unit 5b. The number of each of the second mark images 52a and 52b is not limited to five, and can be appropriately changed depending on the size in the width direction B of the ejection head 240 shown in FIG. 2, etc.

[0101] For example, in a configuration in which a recording medium P is read by one reading unit, the reading range in the width direction B is limited, and it may not be possible to read a recording medium P that is wide in the width direction B. Furthermore, if a reading unit with a large reading range is installed in the liquid ejection device in order to be able to read a recording medium P that is wide in the width direction B, the manufacturing cost of the liquid ejection device may increase, and the liquid ejection device may become larger.

[0102] The liquid ejection device according to this embodiment has two reading units 5a, 5b arranged at different positions in the width direction B, and by reading different reading ranges in the width direction B with the two reading units 5a, 5b, it is possible to alleviate the restriction on the reading range. Also, by forming each of the first mark image and the multiple second mark images within the reading ranges of the two reading units 5a, 5b on the recording medium P, it is possible to perform the density correction of the image described in the first embodiment using the read information by each of the two reading units 5a, 5b. The other operational effects of this embodiment are the same as those of the first embodiment.

[0103] The number of reading units according to the present embodiment is not limited to two, and may be three or more in accordance with the width in the width direction B of the recording medium P. A first mark image 51 and a plurality of second mark images 52 may be formed on the recording medium P for each reading range of the plurality of reading units.

[0104] Although the preferred embodiments have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0105] The liquid ejection device of the embodiment can not only correct the density of the image formed on the recording medium P, but can also correct the position of the image formed on the recording medium P based on the mark image formed on the recording medium P.

[0106] In the embodiment, the liquid discharged from the liquid discharger 24 may be a solution, suspension, emulsion, etc. containing a solvent such as water or an organic solvent, a colorant such as a dye or a pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, an amino acid, a protein, or calcium, an edible material such as a natural dye, etc. These can be used for applications such as inkjet ink, paint for coating, surface treatment liquid, liquid for forming components of electronic elements or light-emitting elements or electronic circuit resist patterns, material liquid for three-dimensional modeling, etc.

[0107] The recording medium P means something to which a liquid adheres and sticks, or something to which a liquid adheres and penetrates, etc. Specific examples include media such as car bodies, building materials, paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, all things to which a liquid adheres are included.

[0108] The ordinal numbers, quantities, and other numbers used in the description of the embodiments are all provided as examples to specifically explain the technology of the present invention, and the present invention is not limited to the exemplified numbers. Furthermore, the connection relationships between the components are provided as examples to specifically explain the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0109] The division of blocks in the functional block diagram is an example, and multiple blocks may be realized as one block, one block may be divided into multiple blocks, or some functions may be moved to other blocks. Furthermore, the functions of multiple blocks having similar functions may be processed in parallel or in time-sharing by a single piece of hardware or software. Furthermore, some or all of the functions may be distributed to multiple computers.

[0110] Each function of the embodiment can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a processor implemented by an electronic circuit, and a device such as an ASIC (Application Specific Integrated Circuit), a DSP (digital signal processor), an FPGA (field programmable gate array), or a conventional circuit module designed to execute each function described above.

[0111] For example, aspects of the present invention are as follows. <1> A liquid ejection device capable of forming an image on a recording medium transported in a transport direction, the liquid ejection device comprising: a recording medium including a mark image formed by the liquid ejection device; a reading unit that reads the image formed on the recording medium; and a correction unit that corrects the image formed on the recording medium based on read information by the reading unit, wherein the mark image has a first mark image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in a width direction intersecting the transport direction and each intersecting with each of the two or more vertical lines. <2> the first mark image includes three vertical lines extending in the transport direction and three horizontal lines extending in the width direction and intersecting the three vertical lines, respectively; <1> The liquid ejection apparatus according to claim 1, <3> a detection unit that detects a position of the mark image formed on the recording medium based on read information by the reading unit, and a determination unit that determines whether or not a positional deviation amount of the mark image with respect to a theoretical position obtained based on size information of the recording medium is equal to or less than a predetermined positional deviation threshold. <1> or the above <2> The liquid ejection apparatus according to claim 1, <4> a notification unit that notifies an error when the number of times that the determination unit has consecutively determined that the amount of positional deviation is greater than the positional deviation threshold reaches a predetermined number of times threshold, <3> The liquid ejection apparatus according to claim 1, <5> a display unit for displaying the amount of positional deviation; <3> or the above <4> The liquid ejection apparatus according to claim 1, <6> a receiving unit that receives a setting input of the position deviation threshold value by an operator; <3> From the above <5> 1 is a liquid ejection apparatus according to any one of the above items. <7> a liquid ejection head having a plurality of nozzles that eject liquid within a predetermined range of the recording medium in the width direction, the recording medium further including a rectangular image formed by the liquid ejection device and extending in the width direction, and the correction unit corrects the density of the image formed by each of the plurality of nozzles based on a position of the mark image in the read information of the recording medium and a density of the rectangular image; <1> From the above <6> 1 is a liquid ejection apparatus according to any one of the above items. <8> the mark image further includes a plurality of second mark images, and a detection unit detects, in the read information, a position of each of the plurality of second mark images relative to a reference position specified based on the first mark image; <7> The liquid ejection apparatus according to claim 1, <9> the second mark image is a vertical line extending in the transport direction, and the second mark images are arranged in the width direction; <8> The liquid ejection apparatus according to claim 1, <10> the first mark image includes a first image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in the width direction and each intersecting with one of the two or more vertical lines, and a second image formed within a predetermined distance from the first image, the second image having one vertical line extending in the transport direction and one horizontal line extending in the width direction, and including a position where the one vertical line intersects the one horizontal line as the reference position; <8> or the above <9> The liquid ejection apparatus according to claim 1, <11> the second mark image and the second mark image in the first mark image are formed on the recording medium at a distance equal to or greater than a predetermined distance in at least one of the transport direction and the width direction; <10> The liquid ejection apparatus according to claim 1, <12> the recording medium includes a plurality of rectangular images formed side by side in the transport direction and having different densities from one another; <7> From the above <11> 1 is a liquid ejection apparatus according to any one of the above items. <13> When the rectangular image has a density difference, the correction unit varies the density so as to approach a minimum density among the densities of the rectangular image having the density difference. <7> From the above <12> 1 is a liquid ejection apparatus according to any one of the above items. <14> the recording medium includes two or more reading units arranged at different positions in the width direction, and each of the first mark image and the plurality of second mark images is formed within a reading range of each of the two or more reading units on the recording medium; <8> From the above <13> 1 is a liquid ejection apparatus according to any one of the above items. <15> A liquid ejection method using a liquid ejection device capable of forming an image on a recording medium transported in a transport direction, wherein the liquid ejection device reads a mark image formed on the recording medium by the liquid ejection device using a reading unit, and corrects the image formed on the recording medium based on information read by the reading unit using a correction unit, and the mark image has a first mark image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in the width direction and each intersecting with each of the two or more vertical lines. [Explanation of symbols]

[0112] 1 Paper feed section 11 Paper feed tray 12 Feeding device 13 Registration roller pair 2 Image forming section 21 Receiving torso 22 Carrying drum 23 Suction device 24 Liquid discharge part 24C, 24M, 24Y, 24K head units 240 Discharge Head 241 Nozzle plate 242 Nozzle 243 Base material 25 Delivery Body 3 Drying section 31 Drying mechanism 32 Transport mechanism 4 Paper ejection section 41 Output tray 5 Reading unit 50, 50a, 50b mark images 51, 51a, 51b First mark image 511, 511a, 511b 1st image 512, 512a, 512b 2nd image 52, 52a, 52b 2nd mark image 53, 531-539 Rectangular images 6 Processing section 61 Input / output section 62 Theoretical position calculation section 63 Detection unit 64 Judgment section 65 Reception 66 Notification Department 67 Correction section 601 CPU 602 ROM 603 RAM 604 HDD / SSD 605 Interface 606 Control Circuit 100 Liquid dispensing device 101 Display section 101a~101c Display screen 102 Operation section 111 Text Box 112 Increase / decrease button A Conveying direction B Width direction dA, dB distance H11, H12, H13, H11a, H12a, H21 Horizontal line V11, V12, V13, V11a, V12a, V21 vertical lines HP reference position In Operation input Im reading information P Recording medium SB System Bus W, Wa, Wb Width [Prior art documents] [Patent documents]

[0113] [Patent Document 1] Patent No. 2009-226703

Claims

1. A liquid ejection apparatus capable of forming an image on a recording medium transported in a transport direction, the recording medium including a mark image formed by the liquid ejection device; A reading unit that reads an image formed on the recording medium; a correction unit that corrects the image formed on the recording medium based on the read information by the reading unit, A liquid ejection device, wherein the mark image has a first mark image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in a width direction intersecting the transport direction and each intersecting with each of the two or more vertical lines.

2. The liquid ejection device according to claim 1 , wherein the first mark image includes three vertical lines extending in the transport direction and three horizontal lines extending in the width direction and intersecting with each of the three vertical lines.

3. a detection unit that detects a position of the mark image formed on the recording medium based on read information by the reading unit; 3. The liquid ejection device according to claim 1, further comprising a determination unit that determines whether an amount of positional deviation of the mark image from a theoretical position obtained based on size information of the recording medium is equal to or less than a predetermined positional deviation threshold.

4. The liquid ejection device according to claim 3 , further comprising a notification unit that notifies an error when the number of times that the determination unit has consecutively determined that the amount of positional deviation is greater than the positional deviation threshold value reaches a predetermined number of times threshold value.

5. The liquid ejection device according to claim 3 , further comprising a display unit that displays the amount of positional deviation.

6. The liquid ejection device according to claim 3 , further comprising a receiving unit that receives a setting input of the position deviation threshold value from an operator.

7. an ejection head having a plurality of nozzles that eject liquid within a predetermined range of the recording medium in the width direction; the recording medium further includes a rectangular image formed by the liquid ejection device and extending in the width direction, 3. The liquid ejection device according to claim 1, wherein the correction unit corrects the density of the image formed by each of the plurality of nozzles based on the position of the mark image in the read information of the recording medium and the density of the rectangular image.

8. The mark image further includes a plurality of second mark images; The liquid ejection device according to claim 7 , further comprising a detection unit that detects, in the read information, a position of each of the plurality of second mark images relative to a reference position specified based on the first mark image.

9. the second mark image is a vertical line extending in the transport direction, The liquid ejection device according to claim 8 , wherein the plurality of second mark images are aligned in the width direction.

10. the first mark image includes a first image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in the width direction and intersecting with each of the two or more vertical lines, and a second image formed within a predetermined distance from the first image; The liquid ejection device according to claim 8 , wherein the second image has one vertical line extending in the transport direction and one horizontal line extending in the width direction, and includes a position where the one vertical line and the one horizontal line intersect as the reference position.

11. The liquid ejection apparatus according to claim 10 , wherein the second image in the first mark image and the second mark image are formed on the recording medium at least a predetermined distance apart in at least one of the transport direction and the width direction.

12. The liquid ejection device according to claim 7 , wherein the recording medium includes a plurality of the rectangular images formed side by side in the transport direction and having different densities from one another.

13. The liquid ejection device according to claim 7 , wherein, when there is a density difference in the rectangular image, the correction section varies the density so as to approach a minimum density among the densities of the rectangular image having the density difference.

14. Two or more of the reading units are arranged at different positions in the width direction, The liquid ejection device according to claim 8 , wherein the first mark image and the plurality of second mark images are each formed within a reading range of each of the two or more reading units on the recording medium.

15. A liquid ejection method using a liquid ejection device capable of forming an image on a recording medium transported in a transport direction, the liquid ejection device comprising: a reading unit reading a mark image formed on the recording medium by the liquid ejection device; a correction unit correcting the image formed on the recording medium based on the read information by the reading unit; A liquid ejection method, wherein the mark image has a first mark image including two or more vertical lines extending in the transport direction and two or more horizontal lines extending in a width direction intersecting the transport direction and each intersecting with each of the two or more vertical lines.

Images