Inkjet recording device and inkjet recording method

Abstract

To provide an inkjet recording device which can inhibit failure caused by application of a pretreatment liquid in an inline method, and to provide an inkjet recording method.SOLUTION: An inkjet recording device 1 includes: a transport part 2 which transports a recording medium M; an image formation part 3 which forms an image on the recording medium M; and a detection part 5 which detects a state of the recording medium M. The image formation part 3 includes: a first discharge head 32a which discharges a first liquid to the recording medium M; and a second discharge head 32b which discharges a second liquid to the recording medium M. The detection part 5 detects the state of the recording medium M in a time period after the first discharge head 32a discharges the first liquid and the second discharge head 32b discharges the second liquid.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an inkjet recording apparatus and an inkjet recording method. [Background technology]

[0002] 2. Description of the Related Art Inkjet recording apparatuses that eject ink onto a recording surface of a recording medium to record an image are known. In particular, in-line type inkjet recording apparatuses that eject a pretreatment liquid while the recording medium is being transported are known.

[0003] However, when an excessive amount of pretreatment liquid is discharged onto a recording medium, the recording medium may absorb and expand, causing wrinkles, and when the head of an inkjet recording device comes into contact with the wrinkles, image formation defects may occur.

[0004] Therefore, for example, Patent Document 1 describes an inkjet recording device that is provided with a light-shielding sensor upstream of a conveying device, and that temporarily halts image formation and issues a warning when it detects floating of the recording medium. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2015-110275 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the inkjet recording device of Patent Document 1 can detect the lifting that originally occurred on the recording medium, but cannot detect the lifting wrinkles that occurred due to the ejection of the pretreatment liquid. Moreover, it cannot suppress defects caused by the application of the pretreatment liquid, including the lifting wrinkles.

[0007] Similarly, when a post-treatment liquid is also discharged in an in-line manner after the ink is discharged onto the recording medium, the post-treatment head may come into contact with the wrinkles caused by the ink discharge. However, the inkjet recording device of the cited document 1 could not suppress such a problem.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an inkjet recording apparatus and an inkjet recording method that are capable of suppressing defects caused by application of a first liquid such as a pretreatment liquid in an in-line system. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides an inkjet recording apparatus, comprising: A conveying unit that conveys the recording medium; an image forming unit that forms an image on a recording medium; a detection unit for detecting a state of the recording medium, The image forming unit includes a first ejection head that ejects a first liquid onto a recording medium; a second ejection head that ejects a second liquid onto a recording medium; Equipped with The detection section detects a state of the recording medium after the first ejection head ejects the first liquid and before the second ejection head ejects the second liquid.

[0010] The invention described in claim 2 is the inkjet recording apparatus described in claim 1, The first liquid is a pretreatment liquid, and the second liquid is an ink.

[0011] The present invention as set forth in claim 3 is the inkjet recording apparatus as set forth in claim 1, The first liquid is ink, and the second liquid is a post-treatment liquid.

[0012] The invention described in claim 4 is the inkjet recording apparatus according to any one of claims 1 to 3, The detection unit detects floating of the recording medium from a reference surface.

[0013] The invention described in claim 5 is the inkjet recording apparatus described in claim 4, The ink jet head includes a carriage that transports the first ejection head and the second ejection head in a width direction perpendicular to a transport direction of the recording medium.

[0014] The invention described in claim 6 is the inkjet recording apparatus described in claim 4, the detection unit is a light-shielding sensor, the light-shielding sensor includes a light-emitting portion and a light-receiving portion on the outer side of the conveying portion in a width direction perpendicular to a conveying direction of the recording medium, The light emitting section and the light receiving section have optical axes arranged in the width direction and detect the floating of the recording medium from the reference surface.

[0015] The invention described in claim 7 is the inkjet recording apparatus described in claim 6, The light emitting section emits a line-shaped laser having a width in a height direction perpendicular to the transport direction and the width direction.

[0016] The invention described in claim 8 is the inkjet recording apparatus described in claim 5, the detection unit is a range finder, The distance meters are provided on both side surfaces of the carriage in the width direction, The distance meter detects floating of the recording medium from a reference surface by measuring the distance between the recording medium and the second ejection head.

[0017] The invention described in claim 9 is the inkjet recording apparatus described in claim 4, a notification unit that issues a warning; and a notification control unit that, when the detection unit detects floating of the recording medium from the reference surface, stops image formation at the image forming unit and causes the notification unit to issue a warning.

[0018] The invention described in claim 10 is the inkjet recording apparatus described in claim 9, the notification unit includes a display unit that displays a floating displacement of the recording medium from a reference surface, The detection unit detects in real time the floating displacement of the recording medium from the reference surface.

[0019] The invention described in claim 11 is the inkjet recording apparatus described in claim 4, the first ejection head is mounted on the upstream side of the second ejection head in a conveying direction of a recording medium, The detection unit is provided downstream of the first ejection head in the transport direction.

[0020] The invention described in claim 12 is the inkjet recording apparatus described in claim 5, the first ejection head and the second ejection head are mounted substantially parallel to the width direction of the carriage, The detection unit is provided on a straight line parallel to the nozzle row of the second ejection head.

[0021] The invention described in claim 13 is the inkjet recording apparatus described in claim 4, The recording medium is a fabric.

[0022] The invention described in claim 14 is the inkjet recording apparatus described in claim 4, The detection unit includes an image forming control unit that detects floating of the recording medium after the recording medium is transported in the transport unit, and causes the image forming unit to form an image if the floating does not exceed a predetermined threshold.

[0023] The invention described in claim 15 is the inkjet recording apparatus described in claim 14, The predetermined threshold value is the distance between the second ejection head and the reference surface.

[0024] The invention described in claim 16 is a first ejection head that ejects a first liquid onto a recording medium; a second ejection head that ejects a second liquid onto a recording medium, a conveying step of conveying the recording medium; an image forming step of forming an image on a recording medium; a detection step of detecting a state of the recording medium, The detection step detects a state of the recording medium after the first ejection head ejects the first liquid and before the second ejection head ejects the second liquid. Effect of the Invention

[0025] According to the present invention, problems caused by application of the first liquid in an in-line manner can be suppressed. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a perspective view of an inkjet recording apparatus. [Diagram 2] FIG. 1 is a block diagram of an inkjet recording apparatus. [Diagram 3] FIG. 2 is a side view of the inkjet recording apparatus as viewed in the width direction. [Figure 4] FIG. 2 is a plan view of an image forming unit of the inkjet recording apparatus as viewed from the height direction. [Diagram 5] 1 is a plan view of an inkjet recording apparatus according to a first embodiment, as viewed from the transport direction. [Figure 6] 4 is a flowchart of an image forming process of the inkjet recording apparatus. [Figure 7] FIG. 11 is a plan view of an inkjet recording apparatus according to a second embodiment, as viewed from the transport direction. [Figure 8] 13 is a side view of an inkjet recording apparatus according to a modified example, as viewed from the width direction. FIG. [Figure 9A] 13 is a plan view of an inkjet recording apparatus according to a modified example, as viewed from the height direction. FIG. [Figure 9B] FIG. 11 is a plan view of an inkjet recording apparatus according to a modified example, as viewed from the height direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, an inkjet recording apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples. In the following description, components having the same functions and configurations are given the same reference numerals, and the description thereof will be omitted.

[0028] [Overall configuration of the inkjet recording device according to the first embodiment] Fig. 1 is a perspective view of an inkjet recording apparatus according to a first embodiment of the present invention. Fig. 2 is a block diagram of the inkjet recording apparatus according to the first embodiment of the present invention. Fig. 3 is a side view of the inkjet recording apparatus 1. The inkjet recording apparatus 1 includes a transport unit 2, an image forming unit 3, a maintenance unit 4, a detection unit 5, a notification unit 6, an operation input unit 7, and a control unit 8.

[0029] In the following, the X direction, Y direction, and Z direction refer to the directions shown in Fig. 1. In the following, the X direction, Y direction, and Z direction are respectively referred to as the width direction, the conveying direction, and the height direction. For convenience, the maintenance unit 4 is omitted from Fig. 1.

[0030] (Transportation section) The transport unit 2 transports the recording medium M in the transport direction so as to pass below the image forming unit 3. The transport unit 2 includes, for example, two transport rollers 2a and 2b that rotate in the transport direction around a rotation axis extending in the width direction. The transport unit 2 also includes a loop-shaped transport belt 2c.

[0031] The inner side of the conveyor belt 2c is supported by the conveyor rollers 2a and 2b. An adhesive is applied to the conveyor surface of the conveyor belt 2c, which is the outer surface on which the recording medium M is placed and is different from the inner surface that contacts the conveyor rollers 2a and 2b. The recording medium M is placed on the conveyor surface of the conveyor belt 2c. The conveyor rollers 2a and 2b rotate and move in the conveyor direction in response to the operation of the roller conveyor motor. As a result, the conveyor belt 2c conveys the recording medium M in the conveyor direction.

[0032] The recording medium M is, for example, a fabric. The recording medium M is supplied onto the conveyor belt 2c by a medium supply unit (not shown). Ink is ejected from the image forming unit 3 onto the recording medium M, an image is recorded thereon, and the recording medium M is ejected to an ejection unit (not shown). Note that the recording medium M is not limited to a fabric. The recording medium M may be any medium, such as paper, as long as it is capable of fixing the ink that has landed on it.

[0033] When the recording medium M is a fabric, the thickness is 0.4 mm or less, or the basis weight is 90 g / m 2 In the case of a thin fabric such as that described below, or a fabric made of cotton or polyester, floating wrinkles are likely to occur due to an excessive application of a pretreatment liquid, which will be described later. Normally, if an image is formed on the recording medium M with floating wrinkles, image formation defects occur, but with the inkjet recording apparatus 1 according to this embodiment, the floating wrinkles can be detected before the image is formed.

[0034] (Image forming section) The image forming unit 3 forms an image by ejecting ink at appropriate timing based on image data acquired from an external device or the like onto the recording medium M transported by the transport unit 2. Fig. 4 is a diagram of the image forming unit 3 as viewed from the height direction. As shown in Fig. 4, the image forming unit 3 includes a carriage 31 and a head unit 32.

[0035] {carriage} The carriage 31 is a member that moves the mounted head unit 32. The carriage 31 has, for example, a belt that is stretched between two pulleys that are rotated by a motor (not shown). The carriage 31 scans the head unit 32 in the width direction by the rotation of the motor based on a drive signal output by the control unit 8. In addition, the pulleys and the belt are provided so as to extend further outward than the transport path along which the recording medium M is transported. Therefore, the carriage 31 can move further outward than the transport path of the recording medium M.

[0036] The inkjet recording device 1 according to this embodiment forms an image by ejecting ink from a head unit 32 while scanning in the width direction a carriage 31 whose width length is shorter than the recording medium M. Note that the inkjet recording device 1 may be of a single pass type in which an image is formed by scanning the carriage 31 once, or of a multi-pass (scan) type in which an image of one line is formed by scanning the carriage 31 multiple times.

[0037] {Head unit} The head unit 32 is composed of multiple inkjet heads. Each inkjet head includes an ink tank, a flow path, a piezoelectric element, multiple nozzles, etc. Under the control of the control unit 8, the head unit 32 ejects ink by applying pressure fluctuations to ink supplied from the tank to the nozzles via the flow path using the piezoelectric element. The inkjet heads constituting the head unit 32 are a first ejection head 32a and a second ejection head 32b.

[0038] <First ejection head> The first ejection head 32a is an inkjet head that ejects a first liquid onto the recording medium M before the second ejection head 32b. In this embodiment, the first liquid is a pretreatment liquid containing a flocculant. As shown in Fig. 4, the first ejection head 32a is mounted on the carriage 31 on the upstream side in the transport direction than the second ejection head 32b.

[0039] The pretreatment liquid discharged by the first discharge head 32a is mixed in liquid form with the second liquid discharged by the second discharge head 32b on the recording medium M. The pretreatment liquid contains at least an aggregating agent, and may also contain other components such as a solvent, a surfactant, or water. The aggregating agent contained in the pretreatment liquid is not particularly limited as long as it generates an aggregating substance when it comes into contact with the second liquid, and is, for example, a polyvalent metal salt, an organic acid, or an inorganic acid.

[0040] <Second ejection head> The second ejection head 32b ejects a second liquid after the first ejection head 32a ejects the pretreatment liquid, which is the first liquid. In this embodiment, the second liquid is a colored ink. As shown in FIG. 4, the image forming unit 3 may include a plurality of second ejection heads 32b. The plurality of second ejection heads 32b eject, for example, C (cyan), M (magenta), Y (yellow), and K (black) colored inks, respectively.

[0041] The colored ink ejected by the second ejection head 32b is, for example, a pigment ink. The pigment ink is an ink that contains a pigment, resin particles (binder resin), and water. When the pigment ink is applied to the recording medium M to which the pretreatment liquid has been applied, the components contained in the pigment ink do not penetrate into the recording medium M, improving color development and making it difficult for the texture to be damaged. Also, unlike dye ink, pigment ink does not require a heating process for dyeing or a process for washing away dye that has not been dyed.

[0042] (Maintenance Department) 5 is a view seen from the downstream side in the transport direction of the inkjet recording apparatus 1. The maintenance unit 4 includes a liquid receiving unit 41, a cleaning unit 42, and a moisturizing unit 43 on the outer side in the width direction of the recording medium M than the transport path.

[0043] {Liquid receiving part} The liquid receiving unit 41 contains an absorbent such as a hydrophilic sponge inside, and receives the liquid (pretreatment liquid and colored ink) ejected from the head unit 32. The liquid receiving unit 41 also discharges the liquid ejected from the head unit 32 and received from an outlet provided on the bottom surface or the like. The liquid receiving unit 41 includes a discharge bucket 41a and a maintenance bucket 41b.

[0044] <Spit Bucket> The disposal bucket 41a is provided closer to the transport path of the recording medium M than the maintenance bucket 41b. The length of the disposal bucket 41a in the width direction is slightly larger than one row of nozzles in one inkjet head.

[0045] The control unit 8 causes the discharge bucket 41a to discharge ink every time the carriage 31 scans. This control makes it possible to prevent the liquid (pre-treatment liquid and colored ink) from drying and thickening in the nozzles of each inkjet head.

[0046] 5 shows an example of a configuration in which the discharge bucket 41a is provided only on one side in the width direction of the inkjet recording device 1, but this is not limiting. For example, in a configuration in which an image is formed not only when the carriage 31 is scanned from one side to the opposite side in the width direction, but also when the carriage 31 is scanned from the other side to one side, the discharge bucket 41a may be provided on both sides of the inkjet recording device 1.

[0047] <Maintenance bucket> The maintenance pail 41b is provided farther away from the conveyance path of the recording medium M than the disposal pail 41a. The maintenance pail 41b is provided such that the length in the width direction is slightly larger than the width of the carriage 31 in the width direction.

[0048] When normal pressure is not applied to the ink in the nozzles of each inkjet head, causing the ink to be ejected and resulting in image defects (so-called missing nozzle phenomenon), the control unit 8 transports the carriage 31 above the maintenance pail 41b to execute purging. Specifically, in order to expel foreign matter, air bubbles, aggregates, etc., from within each inkjet head to the outside, the control unit 8 increases the ink supply pressure to each inkjet head to forcibly expel the ink.

[0049] The amount of ink discharged by purging is greater than the amount of ink discharged by discarding, so as shown in FIG. 5, the maintenance bucket 41b is provided to have a larger volume than the discarding bucket 41a.

[0050] {Cleaning Department} The cleaning unit 42 is provided near the maintenance tub 41b, and wipes the ink ejection surface of the head unit 32 after purging with a wiping cloth or the like. The cleaning unit 42 includes a wiping cloth and a moving mechanism that moves the wiping cloth along the ink ejection surface of the head unit 32. The wiping operation of the cleaning unit 42 can remove ink, foreign matter, and the like that has adhered to the ink ejection surface of the head unit 32 during purging.

[0051] {Moisturizing part} The moisturizing unit 43 is a container that contains a predetermined liquid, such as water, and is open on the nozzle surface side of the image forming unit 3. The liquid contained in the moisturizing unit 43 evaporates to humidify the nozzles of the head unit 32 when not in use, thereby preventing nozzle clogging and the like.

[0052] (Detection unit) The detection unit 5 detects the state of the recording medium M, in particular, the floating of the recording medium M from the reference surface B. The detection unit 5 is, for example, a light-shielding sensor, and includes a light-emitting unit 51a that emits a line-shaped laser having a predetermined width in the height direction, and a light-receiving unit 51b that acquires the laser.

[0053] As shown in FIG. 5, the light-emitting unit 51a and the light-receiving unit 51b are provided outside the conveying unit 2 in the width direction and outside the print scanning width, which is the range in which the carriage 31 moves during image formation. The light-receiving unit 51b is disposed on the optical axis of the light-emitting unit 51a and parallel to the width direction. More specifically, as shown in FIG. 4, the light-emitting unit 51a and the light-receiving unit 51b are disposed downstream in the conveying direction of the first ejection head 32a and on a straight line parallel to the nozzle row of the second ejection head 32b. Therefore, the detection unit 5 can detect floating of the recording medium M after the first ejection head 32a ejects the pretreatment liquid, which is the first liquid, and before the second ejection head 32b ejects the second liquid.

[0054] The detection unit 5 detects wrinkles on the recording medium M during image formation by the image forming unit 3. Specifically, the light receiving unit 51b detects light blocking, i.e., the occurrence of wrinkles, when the floating of the recording medium M exceeds a predetermined threshold, for example, the distance between the second ejection head 32b and the reference surface B, and the amount of light acquired from the light emitting unit 51a decreases by a predetermined value or more. The light receiving unit 51b that detects the occurrence of wrinkles transmits a signal to the control unit 8. The control unit 8 that receives the signal stops the image forming operation by the image forming unit 3 and causes the notification unit 6 to issue a warning.

[0055] The height of the detection unit 5 can be adjusted. Therefore, the reference plane B can be set appropriately depending on the thickness of the recording medium M. In addition, although the reference plane B is the surface of the recording medium M in FIG. 5, it is not limited to this.

[0056] In this embodiment, the light-emitting unit 51a and the light-receiving unit 51b are arranged so that the disposal bucket 41a and the maintenance bucket 41b are located under their optical axes, as shown in Fig. 5. With this configuration, the light-receiving unit 51b transmits a signal to the control unit 8 not only when there are wrinkles on the recording medium M, but also when the light is blocked by the disposal bucket 41a or the maintenance bucket 41b.

[0057] If a blockage occurs in the outlet of the disposal bucket 41a or the maintenance bucket 41b, the color ink and the pretreatment liquid may become mixed. Then, the color ink and the pretreatment liquid may aggregate in the disposal bucket 41a or the maintenance bucket 41b to form an aggregate. Then, when the aggregate reaches a certain height, it may come into contact with the head unit 32, causing damage to the head unit 32.

[0058] However, by arranging as described above, even if the height of the agglomerates in the disposal bucket 41a or maintenance bucket 41b exceeds a predetermined threshold, for example the distance between the second ejection head 32b and the disposal bucket 41a or maintenance bucket 41b, the light receiving unit 51b sends a signal to the control unit 8, thereby preventing damage to the head unit 32.

[0059] (Notification Department) The notification unit 6 notifies various pieces of information under the control of the control unit 8. The notification unit 6 is, for example, a display unit having a screen, a sound output unit that outputs a predetermined sound, a communication unit that can communicate with other devices via a network, etc.

[0060] (Operation input section) The operation input unit 7 is composed of, for example, various operation keys and the like, and converts the user's input operation into an operation signal and outputs it to the control unit 8. When the notification unit 6 is a display unit, the operation input unit 7 may be a touch panel.

[0061] (Control unit) The control unit 8 includes a central processing unit (CPU), a random access memory (RAM), and a read only memory (ROM). The control unit 8 controls the overall operation of the inkjet recording apparatus 1.

[0062] The CPU controls each part of the inkjet recording device 1. The RAM is a volatile memory that temporarily stores various information in a writable and readable manner. The ROM is a non-volatile memory in which various information and programs are stored in a readable manner. More specifically, the control unit 8 reads out a specified program from the various programs stored in the ROM using the CPU and expands it in the RAM. The control unit 8 then executes various processes in cooperation with the expanded program.

[0063] In particular, the control unit 8 functions as an image formation control unit that controls whether to cause the image forming unit 3 to form an image, depending on the detection result of the detection unit 5. In addition, the control unit 8 functions as an alarm control unit that causes the alarm unit 6 to issue a warning, depending on the detection result of the detection unit 5.

[0064] [Image formation processing] The image forming process in the inkjet recording apparatus 1 will be described with reference to the flowchart of FIG.

[0065] First, the control unit 8 judges whether the detection unit 5 detects floating (light blocking) (step S101). If the detection unit 5 detects floating (step S101; Yes), the control unit 8, which is a notification control unit, causes the notification unit 6 to issue a warning (step S102). In addition, the control unit 8, which is an image formation control unit, causes the transport unit 2 and the image forming unit 3 to stop the image formation operation (step S103).

[0066] Upon receiving the notification from the notification unit 6, the user smooths out and corrects the wrinkles that have occurred on the recording medium M. Alternatively, the user manually transports the recording medium M to move the wrinkles out of the printing area. Then, the user adjusts the amount of pretreatment liquid ejected by the first ejection head 32a to be reduced. Alternatively, the user cleans the disposal bucket 41a or the maintenance bucket 41b. After processing the wrinkles on the recording medium M or the aggregates in the liquid receiving unit 41, the user operates the operation input unit 7 to send an instruction to the control unit 8 to resume the image forming operation.

[0067] The control unit 8 determines whether or not an instruction to resume the image forming operation has been acquired (step S104). If an instruction to resume the image forming operation has been acquired (step S104; Yes), the control unit 8 resumes the image forming operation (step S105) and transitions to step S101 to detect floating again.

[0068] If the detection unit 5 does not detect a lift (step S101; No), the control unit 8 ejects ink from the second ejection head 32b while scanning the carriage 31, thereby forming an image on the recording medium M (step S106). After the carriage 31 has scanned, the control unit 8 conveys the recording medium M by a predetermined amount using the conveyance unit 2 (step S107).

[0069] The control unit 8 determines whether the image forming operation is completed (step S108). If the image forming operation is completed (step S108; Yes), the control unit 8 ends the image forming process. If the image forming operation is not completed (step S108; No), the control unit 8 transitions to step S101.

[0070] [Effects of the embodiment] As described above, the inkjet recording apparatus 1 according to this embodiment includes a transport unit 2 that transports a recording medium M. The inkjet recording apparatus 1 also includes an image forming unit 3 that forms an image on the recording medium M. The inkjet recording apparatus 1 also includes a detection unit 5 that detects the state of the recording medium M. The image forming unit 3 also includes a first ejection head 32a that ejects a pretreatment liquid, which is a first liquid, onto the recording medium M. The image forming unit 3 also includes a second ejection head 32b that ejects an ink, which is a second liquid, onto the recording medium M. The detection unit 5 detects the state of the recording medium M after the first ejection head 32a ejects the first liquid and before the second ejection head 32b ejects the second liquid.

[0071] According to this configuration, even if a state in which a defect occurs due to application of the pretreatment liquid by the first ejection head 32a occurs, this can be suppressed by detection by the detection unit 5. In particular, since the detection unit 5 detects floating of the recording medium M from the reference surface, it is possible to suppress image formation defects from occurring on the recording medium M.

[0072] In the above, the light-shielding sensor serving as the detection unit 5 includes only one pair of the light-emitting unit 51a and the light-receiving unit 51b, but the present invention is not limited to this. That is, a light-shielding sensor including a plurality of pairs of the light-emitting unit 51a and the light-receiving unit 51b corresponding to all the nozzle rows of the head unit 32 may be provided as the detection unit 5. With this configuration, problems caused by the application of the pretreatment liquid can be further suppressed.

[0073] [Overall configuration of the inkjet recording device according to the second embodiment] Next, an inkjet recording apparatus 1 according to a second embodiment will be described. Note that the same components as those in the inkjet recording apparatus 1 according to the first embodiment will be designated by the same reference numerals and detailed description thereof will be omitted. Fig. 7 shows a front view of the inkjet recording apparatus 1 according to the second embodiment. The inkjet recording apparatus 1 according to the second embodiment differs from the first embodiment in that the carriage 31 is provided with a range finder 52, which is a detection unit 5.

[0074] 7, the inkjet recording device 1 according to the second embodiment includes a range finder 52 on each side in the width direction of the carriage 31. The range finder 52 measures the distance (height) from the second ejection head 32b to the recording medium M during image formation by the image forming unit 3, and detects floating of the recording medium M from the reference surface B based on the measured value. The range finder 52 may have a known configuration, and may be, for example, any of a laser beam type, an ultrasonic type, or an optical type.

[0075] In this way, even if the detection unit 5 includes the distance meter 52, it is possible to detect and suppress a state in which a problem occurs due to application of the pretreatment liquid by the first ejection head 32a.

[0076] [Overall configuration of the inkjet recording device according to the third embodiment] Next, an inkjet recording apparatus 1 according to a third embodiment will be described. Note that the same components as those in the inkjet recording apparatus 1 according to the first and second embodiments will be denoted by the same reference numerals and detailed description thereof will be omitted. The inkjet recording apparatus 1 according to the third embodiment differs from the first and second embodiments in that the first liquid ejected from the first ejection head 32a is a colored ink, and the second liquid ejected from the second ejection head 32b is a post-treatment liquid.

[0077] In the inkjet recording device 1 according to the third embodiment, the post-treatment liquid, which is the second liquid ejected by the second ejection head 32b, is, for example, a colorless coating ink. Even when the first ejection head 32a ejects colored ink, the recording medium M may shrink and expand, causing wrinkles. Then, the second ejection head 32b may come into contact with the wrinkles, causing problems such as damage.

[0078] However, in the present invention, as described above, the detection unit 5 is provided to detect the state of the recording medium M after the first ejection head 32a ejects the first liquid and before the second ejection head 32b ejects the second liquid. Therefore, in the inkjet recording device 1 according to the third embodiment, even if a state that causes a malfunction due to the application of ink by the first ejection head 32a occurs, the detection unit 5 can detect it and suppress it.

[0079] [Other configurations] Although the present invention has been specifically described above based on the embodiment, the present invention is not limited to the above embodiment. Of course, the present invention can be modified in various ways within the scope of the invention described in the claims and its equivalents.

[0080] For example, in the above, the detection unit 5 detects the presence or absence of floating as the state of the recording medium M, but is not limited to this. The detection unit 5 may detect, for example, the presence or absence of clumps of the first liquid on the recording medium M or the presence or absence of folds as the state of the recording medium M. Furthermore, although a light shielding sensor and a distance sensor are exemplified as the detection unit 5, a contact type sensor or the like may also be used.

[0081] In the above, as shown in Fig. 3, the inkjet recording apparatus 1 is provided with a conveying unit 2, and a configuration in which the recording medium M is conveyed by a belt conveying method is exemplified, but the present invention is not limited to this. That is, as shown in Fig. 8, the inkjet recording apparatus 1 may convey the recording medium M by a so-called roll-to-roll method in which the recording medium M is unwound while tension is applied to the recording medium M and conveyed. Note that Fig. 8 illustrates a case in which a platen 2d is provided, but the present invention is not limited to this.

[0082] In the above, as shown in FIG. 4, the first ejection head 32a is provided upstream of the second ejection head 32b in the transport direction of the carriage 31, but the present invention is not limited to this.

[0083] That is, as shown in Fig. 9A, the first ejection head 32a may be provided at a first end in the width direction of the carriage 31, and the second ejection head 32b may be provided so as to be parallel to the first ejection head 32a in the width direction. With this configuration, the carriage 31 can be made smaller than the configuration shown in Fig. 4A. However, with this configuration, when the carriage 31 is scanned in one direction (from left to right in Fig. 9A), the first liquid cannot be ejected before the second liquid, which reduces the productivity of the image forming process. Therefore, as shown in Fig. 9B, it is preferable to provide the first ejection head 32a at both ends in the width direction of the carriage 31.

[0084] In the above, the second liquid ejected by the second ejection head 32b is a colored ink, but the present invention is not limited to this. That is, in the first and second embodiments, the second liquid may be not only a colored ink, but also a pretreatment liquid, particularly a white ink. Specifically, after ejecting a pretreatment liquid containing an aggregating agent from the first ejection head 32a, white ink may be ejected from the second ejection head 32b on the upstream side in the transport direction or width direction, and colored ink may be ejected from the second ejection head 32b on the downstream side.

[0085] In addition, in the above, a serial type inkjet recording device 1 that forms an image by scanning the carriage 31, whose width length is shorter than the recording medium M, in the width direction has been exemplified, but the present invention is not limited to this. That is, in the first and third embodiments, the inkjet recording device 1 may be a line type inkjet recording device that forms an image without scanning the head unit 32, whose width length is longer than the recording medium M, in the width direction.

[0086] Furthermore, in the case where the notification unit 6 includes a display unit, the floating displacement of the recording medium M from the reference surface B acquired by the detection unit 5 may be displayed on the display unit in real time.

[0087] In addition, in the flowchart of the image forming process, after the image forming operation is stopped in step S103, the user performs processing related to the lifted wrinkles of the recording medium M or the agglomerates in the liquid receiving portion 41, and issues an instruction to resume the image forming operation through the operation input portion 7, but this is not limited to the above. That is, a mechanism capable of executing processing related to the lifted wrinkles of the recording medium M or the agglomerates in the liquid receiving portion 41 may be provided, and the image forming operation may be automatically resumed when the detection portion 5 no longer detects the lifted wrinkles through processing under the control of the control portion 8. [Explanation of symbols]

[0088] 1 Inkjet recording device 2. Conveyor section 3. Image forming section 31 Carriage 32a First ejection head 32b Second discharge head 41a Spit bucket 41b Maintenance bucket 5. Detection section 51a Light emitting part 51b Light receiving part 52 Distance meter 6. Notification Department 8 Control unit (image formation control unit, notification control unit) M Recording medium B Reference plane

Claims

1. A conveying unit that conveys the recording medium; an image forming unit that forms an image on a recording medium; a detection unit for detecting a state of the recording medium, The image forming unit includes a first ejection head that ejects a first liquid onto a recording medium; a second ejection head that ejects a second liquid onto a recording medium; Equipped with The inkjet recording apparatus, wherein the detection unit detects a state of the recording medium after the first ejection head ejects the first liquid and before the second ejection head ejects the second liquid.

2. 2. The inkjet recording apparatus according to claim 1, wherein the first liquid is a pretreatment liquid, and the second liquid is an ink.

3. 2. The inkjet recording apparatus according to claim 1, wherein the first liquid is ink, and the second liquid is a post-treatment liquid.

4. The inkjet recording apparatus according to claim 1 , wherein the detection section detects floating of the recording medium from a reference surface.

5. 5. The inkjet recording apparatus according to claim 4, further comprising a carriage that transports the first and second ejection heads in a width direction perpendicular to a transport direction of the recording medium.

6. the detection unit is a light-shielding sensor, the light-shielding sensor includes a light-emitting portion and a light-receiving portion on the outer side of the conveying portion in a width direction perpendicular to a conveying direction of the recording medium, The inkjet recording apparatus according to claim 4 , wherein the light emitting section and the light receiving section have optical axes arranged in the width direction, and detect floating of the recording medium from the reference surface.

7. The inkjet recording apparatus according to claim 6 , wherein the light emitting section emits a line-shaped laser having a width in a height direction perpendicular to the transport direction and the width direction.

8. the detection unit is a range finder, The distance meters are provided on both side surfaces of the carriage in the width direction, The inkjet recording apparatus according to claim 5 , wherein the distance meter detects floating of the recording medium from a reference surface by measuring a distance between the recording medium and the second ejection head.

9. a notification unit that issues a warning; 5. The inkjet recording apparatus according to claim 4, further comprising: a notification control unit that, when the detection unit detects floating of the recording medium from the reference surface, stops image formation at the image forming unit and causes the notification unit to issue a warning.

10. the notification unit includes a display unit that displays a floating displacement of the recording medium from a reference surface, The inkjet recording apparatus according to claim 9 , wherein the detection section detects in real time a floating displacement of the recording medium from the reference surface.

11. the first ejection head is mounted on the upstream side of the second ejection head in a conveying direction of a recording medium, The inkjet recording apparatus according to claim 4 , wherein the detection unit is provided downstream of the first ejection head in the transport direction.

12. the first ejection head and the second ejection head are mounted substantially parallel to the width direction of the carriage, The inkjet recording apparatus according to claim 5 , wherein the detection unit is provided on a straight line parallel to the nozzle row of the second ejection head.

13. 5. The ink jet recording apparatus according to claim 4, wherein the recording medium is a fabric.

14. The inkjet recording apparatus according to claim 4 , wherein the detection unit detects floating of the recording medium after the recording medium is transported in the transport unit, and includes an image forming control unit that causes the image forming unit to form an image if the floating does not exceed a predetermined threshold value.

15. The inkjet recording apparatus according to claim 14, wherein the predetermined threshold value is a distance between the second ejection head and the reference surface.

16. a first ejection head that ejects a first liquid onto a recording medium; a second ejection head that ejects a second liquid onto a recording medium, a conveying step of conveying the recording medium; an image forming step of forming an image on a recording medium; A detection step of detecting a state of the recording medium, The inkjet recording method, wherein the detecting step detects a state of the recording medium after the first ejection head ejects the first liquid and before the second ejection head ejects the second liquid.

Images