JP2017105179A - Liquid injection device and liquid injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reactivity between pretreatment liquid and ink irrespective of a type of a medium, and to improve printing image quality.SOLUTION: A liquid injection device 10 comprises: a transportation mechanism 32 transporting a medium 22 in a first direction; a pretreatment liquid coating mechanism coating the medium 22 with pretreatment liquid 40; a liquid injection section including a plurality of ink nozzles N[C], N[M], N[Y] and N[K] injecting ink 41; and a control section 30 controlling the pretreatment liquid coating mechanism and the liquid injection section. The pretreatment liquid coating mechanism includes: a first mechanism disposed in a first region A; and a second mechanism disposed in a second region B positioned closer to an upstream side in the first direction than the first region A. The plurality of ink nozzles has portions overlapping with the first mechanism in a second direction intersecting with the first direction and portions not overlapping with the second mechanism in the second direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a technique for ejecting a liquid such as ink onto a medium.

  In an ink jet type liquid ejecting apparatus, in order to improve the fixability of ink to a medium, a pretreatment liquid containing a reaction component such as an aggregating agent and ink are ejected by a liquid ejecting head to land the pretreatment liquid on the medium. Then, a technique has been developed in which the ink is landed and then both are reacted on the surface of the medium. For example, in the inkjet head disclosed in Patent Document 1, since the nozzle row for ejecting the pretreatment liquid (reaction liquid) is provided upstream of the nozzle row for ejecting ink in the medium conveyance direction, After the pretreatment liquid is landed on the ink, the ink can be landed.

JP 2013-256136 A

  However, as in Patent Document 1, when the ink is landed after the pretreatment liquid is landed first, depending on the type of the medium, the larger the landing time difference between the pretreatment liquid and the ink, the lower the print image quality. May end up. For example, since the pretreatment liquid is likely to permeate in a medium with high liquid absorbency, the larger the landing time difference between the pretreatment liquid and the ink, the more pretreatment liquid that has landed penetrates the medium and the reaction component on the surface of the medium. Since the remaining amount of the ink decreases, the amount of reaction with the ink that has landed later decreases, and there is a problem that the print image quality is likely to deteriorate. In particular, in the configuration in which the nozzle row of the pretreatment liquid is provided only upstream of the ink nozzle row in the medium transport direction as in the ink jet head of Patent Document 1, there is a difference in landing time difference between the pretreatment liquid and the ink. It tends to be large, and the amount of reaction with ink that has landed later tends to decrease. In consideration of the above circumstances, the present invention is configured to change the landing time difference between the pretreatment liquid and the ink, thereby improving the reactivity between the pretreatment liquid and the ink regardless of the type of the medium. The purpose is to improve the printing image quality.

  In order to solve the above problems, a liquid ejecting apparatus of the present invention includes a transport mechanism that transports a medium in a first direction, a pretreatment liquid coating mechanism that coats the pretreatment liquid onto the medium, and a plurality of ink ejecting inks. A liquid ejecting unit including an ink nozzle; a pretreatment liquid coating mechanism; and a control unit that controls the liquid ejection unit. The pretreatment liquid coating mechanism includes: a first mechanism disposed in a first region; A second mechanism disposed in a second region located upstream of the region in the first direction, and the plurality of ink nozzles overlap with each other in a second direction intersecting the first direction with respect to the first mechanism. The second mechanism has a portion that does not overlap in the second direction. According to the arrangement of the first mechanism and the plurality of ink nozzles in the above configuration, the medium is not transported in the transport direction, and the pretreatment liquid is coated on the medium by the first mechanism, and then the plurality of ink nozzles are used. Since the ink can be ejected, the difference in landing time between the pretreatment liquid and the ink can be reduced. On the other hand, according to the arrangement of the second mechanism and the plurality of ink nozzles of this aspect, the medium is transported in the transport direction after the medium is covered with the pretreatment liquid by the first mechanism, and the plurality of ink nozzles By ejecting ink from the ink, the landing time difference between the pretreatment liquid and the ink can be increased. In this way, by configuring the liquid ejecting apparatus so that the landing time difference between the pretreatment liquid and the ink can be changed, the landing time difference between the pretreatment liquid and the ink can be changed according to the type of the medium. Therefore, regardless of the type of medium, the reactivity between the pretreatment liquid and the ink can be increased, and the printing image quality can be improved.

  In a preferred aspect of the present invention, the determination unit for determining the type of the medium, and the control unit select either the first mechanism or the second mechanism according to the type of the medium determined by the determination unit, The medium is coated with the pretreatment liquid by the selected mechanism. According to the above aspect, the control unit selects either the first mechanism or the second mechanism according to the type of medium determined by the determination unit, and covers the medium with the pretreatment liquid from the selected mechanism. Then, since the ink is ejected, the landing time difference between the pretreatment liquid and the ink can be changed according to the determined medium type. Therefore, regardless of the type of medium, the reactivity between the pretreatment liquid and the ink can be increased, and the printing image quality can be improved.

  In a preferred aspect of the present invention, the first area is further divided into an upstream area and a downstream area in the first direction, and the plurality of ink nozzles are arranged on the upstream area and the downstream area of the first area. The first mechanism is arranged in each of the upstream region and the downstream region of the first region, and the control unit determines the first mechanism according to the type of medium determined by the determination unit. One of the ink nozzles in the upstream region of the one region and the ink nozzles in the downstream region of the first region is selected, and ink is ejected from the selected nozzle. According to the above aspect, not only the first mechanism and the second mechanism can be selected, but also the nozzles in the upstream area and the downstream area of the second area can be selected for the ink nozzles. Therefore, since the combination of the selection of the pretreatment liquid coating mechanism and the ink nozzle increases, the room for selecting the landing time difference between the pretreatment liquid and the ink also increases, so that the landing time difference can be finely adjusted.

  In a preferred aspect of the present invention, the second region is further divided into an upstream region and a downstream region in the first direction, and the second mechanism includes an upstream region and a downstream region of the second region. When the second mechanism is selected, the control unit further selects either the second mechanism in the upstream region of the second region or the second mechanism in the downstream region. Alternatively, both are selected, and the pretreatment liquid is ejected from the selected mechanism. According to the above aspect, the mechanism in the upstream region and the mechanism in the downstream region of the first region can be selected for the first mechanism, and the mechanism and the downstream region in the upstream region of the second region can also be selected for the second mechanism. You can select the side area mechanism. Therefore, since the combination of selection of the pretreatment liquid mechanism and the ink nozzle is further increased, there is a room for selecting the landing time difference between the pretreatment liquid and the ink, so that the landing time difference can be adjusted more finely.

  In a preferred aspect of the present invention, the pretreatment liquid is a first pretreatment liquid and a second pretreatment liquid of a different type from the first pretreatment liquid, and the first mechanism uses the first pretreatment liquid. The second mechanism includes a nozzle that ejects the second pretreatment liquid. According to the above aspect, the first pretreatment liquid and the second pretreatment liquid are used, and depending on the type of medium, not only the landing time difference between the pretreatment liquid and ink but also the pretreatment liquid according to the type of medium. The type can be changed to either the first pretreatment liquid or the second pretreatment liquid.

  In a preferred aspect of the present invention, the liquid ejecting head includes a pretreatment liquid coating mechanism and a liquid ejecting unit, and a moving mechanism that reciprocates the liquid ejecting head in the second direction. A plurality of nozzle rows arranged in the second direction at intervals, each of the plurality of nozzle rows having a plurality of nozzles arranged from the first region to the second region; In one of the nozzle rows, the plurality of nozzles arranged in the first region are used as the first mechanism, the plurality of nozzles arranged in the second region are used as the second mechanism, and among the plurality of nozzle rows In other nozzle rows, a plurality of nozzles arranged in the first region are used as a plurality of ink nozzles. According to the above configuration, some of the plurality of nozzle arrays arranged in the second direction at intervals from each other are used as the first mechanism, the second mechanism, and the ink nozzle in the liquid ejecting head. Therefore, the arrangement of the pretreatment liquid and the ink can be changed depending on the position of the nozzle to be used.

  In a preferred aspect of the present invention, a liquid ejecting head including a pretreatment liquid coating mechanism and a liquid ejecting unit, and a moving mechanism that reciprocates the liquid ejecting head in the second direction are provided. A pretreatment liquid and a second pretreatment liquid that is more permeable than the first pretreatment liquid, and the first mechanism includes two nozzle rows arranged in a second direction at intervals from each other, One nozzle row is composed of nozzles that eject the first pretreatment liquid, and the other nozzle row is composed of nozzles that eject the second pretreatment liquid, and nozzles that eject these first pretreatment liquids And the nozzle for injecting the second pretreatment liquid overlap in a plan view in the second direction, and the second mechanism includes two nozzle rows arranged in the second direction so as to be spaced apart from each other, and one of them When the nozzle row is composed of nozzles that eject the first pretreatment liquid The other nozzle row is composed of nozzles that eject the second pretreatment liquid, and the nozzles that eject the first pretreatment liquid and the nozzles that eject the second pretreatment liquid are planar views in the second direction. Overlap. According to the above configuration, not only the landing time difference between the pretreatment liquid and the ink, but also the order of stacking the first pretreatment liquid and the second pretreatment liquid is changed according to the type of medium. It is possible to stabilize the penetrability and wettability of the pretreatment liquid irrespective of the characteristics of the medium. This makes it possible to improve the wettability of the pretreatment liquid while increasing the reactivity between the pretreatment liquid and the ink regardless of the type of the medium, so that only the landing time difference between the pretreatment liquid and the ink can be improved. Compared with the case of changing the print quality, it is possible to provide a higher print quality.

  In a preferred aspect of the present invention, the two nozzle rows of the first mechanism include a nozzle row of nozzles that eject the second pretreatment liquid and a nozzle that ejects the first pretreatment liquid along the moving direction of the liquid ejection head. The two nozzle rows of the second mechanism eject the first pretreatment liquid and the nozzle array of the nozzles that eject the first pretreatment liquid along the moving direction of the liquid ejection head. The nozzles are arranged in the order of the nozzle rows. According to the above configuration, when the first mechanism is selected while moving the liquid ejecting head in the same direction, the liquid can be landed on the medium in the order of the second pretreatment liquid and the first pretreatment liquid. When the mechanism is selected, the medium can be landed in the order of the first pretreatment liquid and the second pretreatment liquid. According to this, when stacking the first pretreatment liquid and the second pretreatment liquid, the order of stacking the first pretreatment liquid and the second pretreatment liquid can be changed without returning the liquid jet head. Therefore, even if the order of stacking the first pretreatment liquid and the second pretreatment liquid is changed, it is possible to prevent a difference in landing time between the first pretreatment liquid and the second pretreatment liquid.

  In a preferred aspect of the present invention, the apparatus includes a transport mechanism that transports the medium in the first direction, and a liquid ejecting head that includes a pretreatment liquid coating mechanism and a liquid ejecting unit, and the liquid ejecting head is disposed in the first direction. This is a line head that is long in the intersecting second direction. According to the above aspect, even when the liquid ejecting head is a line head, the landing time difference between the pretreatment liquid and the ink can be changed according to the type of the medium. Therefore, regardless of the type of medium, the reactivity between the pretreatment liquid and the ink can be increased, and the printing image quality can be improved.

  A liquid ejecting method according to a preferred aspect of the present invention is a liquid ejecting method of a liquid ejecting apparatus in which a medium is coated with a pretreatment liquid and then ink is landed on the medium. A transport mechanism that transports in a first direction; a pretreatment liquid coating mechanism that coats a pretreatment liquid onto a medium; and a liquid ejecting unit that includes a plurality of ink nozzles that eject ink. The first mechanism disposed in the first region and the second mechanism disposed in the second region located upstream of the first region in the first direction, and the plurality of ink nozzles include the first mechanism In the second direction intersecting the first direction, and a portion that does not overlap the second mechanism in the second direction, the type of the medium is determined, and the determined type of the medium is determined. Depending on which of the first and second mechanisms Select, to coat the pretreatment liquid to the medium by the selected mechanism. According to the above configuration, the landing time difference between the pretreatment liquid and the ink can be changed according to the type of the medium. Therefore, regardless of the type of medium, the reactivity between the pretreatment liquid and the ink can be increased, and the printing image quality can be improved.

1 is a configuration diagram of a liquid ejecting apparatus according to a first embodiment. FIG. 6 is a plan view of an ejection surface of the liquid ejection head. FIG. 3 is a cross-sectional view of a liquid ejecting head. It is a figure for demonstrating the state of the pre-processing liquid when the landing time difference of a pre-processing liquid and an ink is changed with respect to a different type medium. FIG. 5 is a diagram for explaining an ink state after ink landing in FIG. 4. 3 is a flowchart illustrating control of the liquid jet head according to the first embodiment. FIG. 6 is a plan view of an ejection surface of a liquid ejection head according to a first modification example of the first embodiment. FIG. 10 is a plan view of an ejection surface of a liquid ejection head according to a second modification example of the first embodiment. FIG. 9 is a plan view of an ejection surface of a liquid ejection head according to a third modification example of the first embodiment. FIG. 10 is a plan view of an ejection surface of a liquid ejection head according to a fourth modification example of the first embodiment. It is a figure for demonstrating the state of the pre-processing liquid at the time of making the pre-processing liquid with which permeability differs on the medium of a different kind. FIG. 9 is a plan view of an ejection surface of a liquid ejection head according to a second embodiment. 10 is a flowchart illustrating control of a liquid jet head according to a second embodiment. It is a figure for demonstrating the state of a pre-processing liquid in the case where the order which accumulates a pre-processing liquid is changed according to the kind of medium. In FIG. 14, it is a figure for demonstrating the state of the ink immediately after ink landing and after a fixed time progress. FIG. 9 is a plan view of an ejection surface of a liquid ejection head according to a third embodiment. 10 is a flowchart illustrating control of a liquid jet head according to a third embodiment. FIG. 10 is a configuration diagram of a liquid ejecting apparatus according to a fourth embodiment.

<First Embodiment>
FIG. 1 is a configuration diagram of a liquid ejecting apparatus 10 according to the first embodiment of the present invention. The liquid ejecting apparatus 10 is a printing apparatus (inkjet apparatus) that prints an image on the surface of the medium 22 by ejecting ink 41 that is an example of a liquid onto the medium 22. The medium 22 is a recording medium such as a printing paper or a film to be ejected with the ink 41. Details of the type of medium used in the first embodiment will be described later.

  The liquid ejecting apparatus 10 is equipped with a liquid container 24 that stores liquid, and the liquid container 24 stores pretreatment liquid 40 and ink 41. The ink 41 is a liquid (color ink) containing a color material such as a pigment or a dye. For example, a total of four inks 41 of cyan (C), magenta (M), yellow (Y), and black (K) are stored in the liquid container 24. Note that a resin material may be included in the ink 41.

  The pretreatment liquid 40 is a liquid (optimizer ink) for improving the fixability of the ink 41 that lands on the surface of the medium 22. For example, a reaction component such as an aggregating agent that reacts with the ink 41 and moisture or a solvent. And other solution components. Color materials and resin materials contained in the ink 41 are not contained in the pretreatment liquid 40. The pretreatment liquid 40 may contain a surfactant. In FIG. 1, the liquid container 24 is illustrated as one element for the sake of convenience, but a configuration in which the pretreatment liquid 40 and a plurality of types of ink 41 are stored in separate liquid containers 24 or a plurality of types of ink 41 are used. For each of these, a configuration stored in a separate liquid container 24 may be employed.

  The liquid ejecting apparatus 10 includes a control unit 30, a transport mechanism 32, a moving mechanism 34, and a liquid ejecting head 36. The control unit 30 is, for example, a control unit such as a CPU (Central Processing Unit) or FPGA (Field Programmable Gate Array), a ROM (Read Only Memory) 301, a RAM (Random Access Memory) 302, and a determination unit that determines the type of the medium 22. 303. The ROM 301 is a rewritable flash ROM, for example. The ROM 301 stores a program executed by the control unit 30 and various data (such as a medium data table described later) necessary for executing the program. The RAM 302 stores data temporarily used when the control unit 30 executes the program. A management device (not shown) such as a personal computer is connected to the control unit 30. The control unit 30 comprehensively controls each element of the liquid ejecting apparatus 10 according to an instruction from the management apparatus. The determination unit 303 determines the type of the medium 22 based on the medium data table. Details of the type determination of the medium 22 will be described later.

  The transport mechanism 32 transports the medium 22 in the Y direction (example of the first direction) under the control of the control unit 30. The transport mechanism 32 of the first embodiment includes a supply roller 322 and a discharge roller 324. The supply roller 322 is installed on the upstream side (negative side in the Y direction) of the discharge roller 324 and conveys the medium 22 to the discharge roller 324 side. The discharge roller 324 downstream of the medium 22 supplied from the supply roller 322 Transport to (positive side in Y direction). In addition, the structure of the conveyance mechanism 32 is not limited to the above illustration.

  The moving mechanism 34 is a mechanism that reciprocates the liquid ejecting head 36 in the X direction under the control of the control unit 30. The X direction in which the liquid ejecting head 36 reciprocates is a direction that intersects (typically orthogonal) the Y direction in which the medium 22 is conveyed. The moving mechanism 34 includes a carriage 342 and a conveyance belt 344. The carriage 342 is a substantially box-shaped structure that supports the liquid ejecting head 36, and is fixed to the transport belt 344. The conveyor belt 344 is an endless belt constructed in the X direction. The liquid ejecting head 36 reciprocates in the X direction together with the carriage 342 by rotating the transport belt 344 under the control of the control unit 30. In addition, the structure of the moving mechanism 34 is not limited to the above illustration. For example, the liquid container 24 can be mounted on the carriage 342 together with the liquid ejecting head 36.

  The liquid ejecting head 36 ejects the pretreatment liquid 40 and the ink 41 supplied from the liquid container 24 onto the medium 22 under the control of the control unit 30. In parallel with the conveyance of the medium 22 by the conveyance mechanism 32 and the reciprocation by the movement mechanism 34, the liquid ejecting head 36 ejects the pretreatment liquid 40 and the ink 41 onto the medium 22, whereby a desired image is formed on the surface of the medium 22. Is formed.

(Configuration example of liquid jet head)
The liquid ejecting head 36 according to the first embodiment is configured to change the landing time difference between the pretreatment liquid 40 and the ink 41 with respect to the medium 22. A specific configuration example of such a liquid jet head 36 is shown in FIG. FIG. 2 is a plan view of a surface (hereinafter referred to as “ejection surface”) 360 facing the medium 22 in the liquid ejection head 36. One pretreatment liquid nozzle row LP and four ink nozzle rows LI1 to LI4 are arranged on the ejection surface 360 of the liquid ejection head 36 shown in FIG. The pretreatment liquid nozzle row LP and the ink nozzle rows LI1 to LI4 are a group of a plurality of nozzles N arranged linearly along the Y direction. Each of the pretreatment liquid nozzle row LP1 and each of the ink nozzle rows LI1 to LI4 may be a plurality of rows (for example, a staggered arrangement or a staggered arrangement).

  2, for example, assuming a straight line G parallel to the X direction on the ejection surface 360, the liquid ejecting head 36 has a first region A on the positive side in the Y direction (downstream in the conveyance direction of the medium 22) with respect to the straight line G. The second region B is divided into the second region B on the negative side in the Y direction from the straight line G (upstream side in the transport direction of the medium 22). The pretreatment liquid nozzle row LP is arranged from the first region A to the second region B, and the ink nozzle rows LI1 to LI4 are arranged in the first region A.

  The pretreatment liquid nozzle row LP includes a plurality of first region nozzles N [A] arranged in the first region A and a plurality of second region nozzles N [B] arranged in the second region B. The first region nozzle N [A] and the second region nozzle N [B] can eject the pretreatment liquid 40 supplied from the liquid container 24 separately. On the other hand, from the nozzles N [C], N [M], N [Y], and N [K] of the ink nozzle rows LI1 to LI4, inks 41 of different colors, that is, cyan (C) and magenta (M), respectively. , Yellow (Y) and black (K) inks 41 of four colors are ejected. The ink nozzle rows LI1 to LI4 are arranged in the X direction with a space therebetween.

  In the liquid jet head 36 of FIG. 2, the range in which the plurality of first region nozzles N [A] are distributed in the X direction is the nozzles N [C], N [M], N of the ink nozzle rows LI1 to LI4 in the X direction. [Y], N [K] overlaps with the range in which the plurality of second region nozzles N [B] are distributed in the X direction. The range in which the nozzles N [C] of the ink nozzle rows LI1 to LI4 in the X direction are distributed. N [M], N [Y], and N [K] do not overlap with the range in which they are distributed, and are upstream of the conveyance direction (Y direction) of the medium 22. Accordingly, the plurality of first region nozzles N [A] are substantially in the same positions as the ink nozzle rows LI1 to LI4 in the transport direction (Y direction) of the medium 22, and the plurality of second region nozzles N [B] are transported. In the direction (Y direction), it is at a position away from the upstream side when viewed from the ink nozzle rows LI1 to LI4.

  According to the liquid jet head 36 having such a configuration, either the first region nozzle N [A] or the second region nozzle N [B] is selected and the pretreatment liquid 40 is ejected, and thereafter The landing time difference with the ink 41 ejected from the nozzles N [C], N [M], N [Y], and N [K] of the ink nozzle rows LI1 to LI4 and landing on the medium 22 can be changed.

  FIG. 3 is a cross-sectional view focusing on any one nozzle N in the liquid jet head 36. As illustrated in FIG. 3, in the liquid jet head 36, the pressure chamber substrate 72, the vibration plate 73, the piezoelectric element 74, and the support body 75 are disposed on one side of the flow path substrate 71 and the nozzle plate 76 is disposed on the other side. Is a structure in which is arranged. The flow path substrate 71, the pressure chamber substrate 72, and the nozzle plate 76 are formed of, for example, a silicon flat plate material, and the support body 75 is formed of, for example, an injection molding of a resin material. The plurality of nozzles N are formed on the nozzle plate 76.

  In the flow path substrate 71, an opening 712, a branch flow path (restricted flow path) 714, and a communication flow path 716 are formed. The branch flow path 714 and the communication flow path 716 are through holes formed for each nozzle N, and the opening 712 is an opening continuous over a plurality of nozzles N. A space in which the accommodating portion (concave portion) 752 formed in the support body 752 and the opening 712 of the flow path substrate 71 communicate with each other is supplied from the liquid container 24 through the introduction flow path 754 of the support body 75. It functions as a common liquid chamber (reservoir) SR for storing the pretreatment liquid 40 or the ink 41.

  An opening 722 is formed for each nozzle N in the pressure chamber substrate 72. The vibration plate 73 is an elastically deformable flat plate that is installed on the surface of the pressure chamber substrate 72 opposite to the flow path substrate 71. The space sandwiched between the diaphragm 73 and the flow path substrate 71 inside each opening 722 of the pressure chamber substrate 72 is the pretreatment liquid 40 or ink 41 supplied from the common liquid chamber SR via the branch flow path 714. Functions as a pressure chamber (cavity) SC in which is filled. Each pressure chamber SC communicates with the nozzle N via the communication channel 716 of the channel substrate 71.

  A piezoelectric element 74 is formed for each nozzle N on the surface of the diaphragm 73 opposite to the pressure chamber substrate 72. Each piezoelectric element 74 is a drive element in which a piezoelectric body is interposed between electrodes facing each other. When the diaphragm 73 is vibrated by the deformation of the piezoelectric element 74 due to the supply of the drive signal, the pressure in the pressure chamber SC varies and the ink 41 in the pressure chamber SC is ejected from the nozzle N.

  Note that each of the ink nozzle arrays LI1 to LI4 in FIG. 2 may be disposed in the independent liquid ejecting head 36, and each of the liquid ejecting heads 36 may be mounted on a separate carriage 342. In this case, one or a plurality of liquid ejecting heads 36 that eject one color of ink or two or more colors of ink may be mounted for each carriage 342. In this case, the liquid ejecting head 36 including the nozzle for ejecting the pretreatment liquid 40 can also be configured independently and mounted on another carriage 342. In this manner, by separating the carriage 342, it is easy to adjust the timing at which the pretreatment liquid 40 is landed on the medium 22 and the timing at which the ink 41 is landed on the medium 22.

(Determination of media type)
The determination unit 303 of the control unit 30 according to the first embodiment determines the type of the medium 22. Specifically, the determination unit 303 determines the medium 22a having a high liquid absorbency and the medium 22b having a low liquid absorbency. Examples of the medium 22a having a high liquid absorbency include plain paper, inkjet paper, and coating media. Examples of the medium 22b having low liquid absorbency include plastic films such as polyvinyl chloride (polyvinyl chloride), polyethylene terephthalate (PET), and polycarbonate (PC), films in which a base material is coated with a plastic or a receiving layer, metal, and printed wiring. Examples include substrates and fabrics. In addition, the absorptivity of a fabric may differ with the fibers which comprise a fabric. The cloth here is assumed to be composed of fibers having low absorbency, and is included in the medium 22b having low liquid absorbency, but is not limited to this, and is composed of fibers having high absorbency. The cloth to be used may be included in the medium 22a having a high liquid absorbency.

  For example, the ROM 301 stores in advance a medium data table including a group listing the medium 22a having high liquid absorbency and a group listing the medium 22b having low liquid absorbency. The type of the medium 22 can be selected by the user from an operation unit (not shown) connected to the control unit 30. The discriminating unit 303 discriminates the medium 22a having a high liquid absorbency and the medium 22b having a low liquid absorbency according to which group in the medium data table the medium 22 selected by the user is included.

  Note that the method of determining the type of the medium 22 is not limited to the case described above. The determination unit 303 may determine the type of the medium 22 based on, for example, a detection signal from the medium sensor 37 illustrated in FIG. The medium sensor 37 is connected to the control unit 30. The medium sensor 37 is composed of, for example, an optical sensor, and irradiates the medium 22 with light and detects the reflected light. The discriminating unit 303 discriminates between the medium 22a having high liquid absorbency and the medium 22b having low liquid absorbency depending on whether or not the detection signal from the medium sensor 37 exceeds a predetermined threshold.

  For example, since the light reflection intensity varies depending on the type of the medium 22, the medium 22 that can determine whether the liquid absorbency is high or low can be set as the threshold value of the light reflection intensity. Specifically, in the case of a plurality of media 22 in which the higher the light reflection intensity, the lower the liquid absorbency, if the detection signal from the media sensor 37 does not exceed a predetermined threshold value, It is determined that the medium 22a has high absorbency, and if it exceeds the threshold, it is determined that the medium 22b has low liquid absorbency. The medium sensor 37 may not be provided when the type of the medium 22 is determined by the user selecting the medium 22 as described above.

  In the first embodiment, the type of the medium 22 is determined as described above, and a plurality of first region nozzles N [A] and a plurality of second region nozzles N [B] are determined according to the determined type of medium. Is selected, the pretreatment liquid 40 is ejected to land on the medium 22, and the landing time difference with the ink 41 to be landed later is changed. Accordingly, the reactivity between the pretreatment liquid 40 and the ink 41 can be increased and the print image quality can be improved regardless of the type of medium.

(Relationship between media type and landing time difference between pretreatment liquid and ink)
Here, the relationship between the type of medium and the landing time difference between the pretreatment liquid 40 and the ink 41 will be described. FIG. 4 is a diagram for explaining the state of the pretreatment liquid 40 in the four cases 1 to 4 in which the landing time difference between the pretreatment liquid 40 and the ink 41 is changed for different types of media. The medium 22 having a different type is either a medium 22a having a high liquid absorbency (for example, coated paper having an ink absorption layer) or a medium 22b having a low liquid absorbency (for example, a plastic film such as vinyl chloride). It is. 4 and FIG. 5 is the landing time difference between the pretreatment liquid 40 and the ink 41 when the ink 41 is landed after the pretreatment liquid 40 is landed.

  In FIG. 4, Case 1 is a case where the landing time difference with the ink 41 is large when the pretreatment liquid 40 is landed on the highly absorbent medium 22 a, and Case 2 has a small landing time difference with the ink 41. Is the case. Case 3 is a case where the landing time difference from the ink 41 is large when the pretreatment liquid 40 is landed on the medium 22b having low absorbency, and Case 4 is a case where the landing time difference from the ink 41 is small. FIG. 5 is a diagram for explaining the state of the ink 41 after ink landing in the cases 1 to 4 of FIG. In FIG. 5, the black portion is the ink 41.

  The surface residual amount in FIG. 4 is the residual amount of the pretreatment liquid 40 remaining on the surface of the medium 22a or 22b immediately before ink landing. As the degree of penetration of the pretreatment liquid 40 from the surface of the medium 22a or 22b (permeability) increases, the surface residual amount of the pretreatment liquid 40 decreases. 4 is an area where the pretreatment liquid 40 remaining on the surface of the medium 22a or 22b immediately before ink landing covers the medium 22a or 22b. As the pretreatment liquid 40 wets and spreads on the surface of the medium 22a or 22b (wetting spreadability) increases, the coverage area of the pretreatment liquid 40 also increases. In FIG. 4, when the surface residual amount is large, it is expressed as “large”, when it is small, it is expressed as “low”, when the covering area is large, it is expressed as “large”, when it is small, it is expressed as “small”. When the covering area is medium, it is described as “medium”.

  First, the highly absorbent medium 22a in case 1 and case 2 of FIG. 4 will be described. When the pretreatment liquid 40 is landed on the highly absorbent medium 22a, if the landing time difference is large as shown in case 1 in FIG. 4, the surface remaining amount of the pretreatment liquid 40 is “small” immediately before ink landing. In contrast, when the difference in landing time is small as shown in case 2 of FIG. 4 while the covering area is “small”, the remaining amount of the surface of the pretreatment liquid 40 and the covering area are “medium” immediately before ink landing. It is.

  That is, since the pretreatment liquid 40 easily permeates in the medium 22a having high absorbability, if the landing time difference between the pretreatment liquid 40 and the ink 41 is large as shown in Case 1 in FIG. Since the pretreatment liquid 40 permeates too much, the remaining amount of the surface of the pretreatment liquid 40 becomes too small immediately before ink landing, and the covering area also becomes small. In this case, as shown in Case 1 of FIG. 5, when the ink 41 is landed, the reactivity between the pretreatment liquid 40 and the ink 41 becomes low, so that the landed dots spread and overlap each other on the surface of the medium 22a. Aggregation tends to occur and print image quality may be reduced.

  On the other hand, when the landing time difference is small as shown in case 2 in FIG. 4, the ink 41 can be reacted before the pretreatment liquid 40 penetrates too much. In this case, as in the case 2 shown in FIG. 4, since the remaining amount of the surface of the pretreatment liquid 40 and the covering area are “medium” just before the ink landing, the ink 41 is landed as shown in the case 2 of FIG. In addition, the reactivity with the ink 41 can be improved, the ink 41 is difficult to condense, and the print image quality can be improved.

  Next, the medium 22b having low absorbency in the case 3 and the case 4 of FIG. 4 will be described. When the pretreatment liquid 40 is landed on the medium 22b having low absorbability, if the landing time difference is small as shown in case 4 of FIG. 4, the surface residual amount of the pretreatment liquid 40 is “large”, and the covering area is small. In contrast to “medium”, when the landing time difference is large as shown in case 3 in FIG. 4, the remaining amount of the surface of the pretreatment liquid 40 is “medium” and the covering area is “large”.

  That is, since the pretreatment liquid 40 is difficult to permeate in the medium 22b having low absorbability, if the landing time difference is small as shown in the case 4 in FIG. 4, the surface residual amount of the pretreatment liquid 40 increases and the ink 41 is condensed. It becomes difficult to do. However, if the difference in landing time is small, the drying cannot be made in time, the surface remaining amount of the pretreatment liquid 40 until the ink landing is too large, and the time for drying the solution components such as moisture and solvent is short, so that the drying is insufficient. Easy to be. In this case, when the ink 41 is landed as shown in the case 4 in FIG. 5, if the drying of the pretreatment liquid 40 is insufficient, the reactivity between the pretreatment liquid 40 and the ink 41 becomes low, and printing is performed. There is a risk that the image quality will deteriorate.

  On the other hand, when the landing time difference is large as shown in case 3 of FIG. 4, the time for drying the pretreatment liquid 40 remaining on the surface of the medium 22b can be increased. In this case, when the ink 41 is landed as shown in the case 3 of FIG. 5, the reactivity with the ink 41 can be improved, and the print image quality can be improved.

  As described above, in order to improve the print image quality, it is preferable to reduce the landing time difference between the pretreatment liquid 40 and the ink 41 in the medium 22a having high absorbency, whereas in the medium 22b having low absorbency, It can be seen that it is preferable to increase the landing time difference between the pretreatment liquid 40 and the ink 41.

(Liquid jetting method of the first embodiment)
Based on the above, the liquid ejecting method according to the first embodiment will be described by taking the control of the liquid ejecting head 36 according to the first embodiment as an example. FIG. 6 is a flowchart illustrating control of the liquid ejecting head 36 in print control. The control unit 30 reads a predetermined program from the ROM 301 in accordance with an instruction from the management apparatus, and executes print control on the medium 22. In the printing control, the control unit 30 controls the liquid ejecting head 36 shown in FIG.

  First, in step S101, the determination unit 303 determines the type of the medium 22 to be printed. For example, the determination unit 303 determines the type of the medium 22 based on the above-described medium data table. Specifically, the determination unit 303 compares the medium 22 selected by the user with the medium 22 in the medium data table, and determines whether the medium 22 is a highly absorbent medium 22a or a less absorbable medium 22b. In step S101, the medium 22 may be determined based on the detection signal from the medium sensor 37 as described above.

  If the determination unit 303 determines that the medium 22a is highly absorbent in step S101, the control unit 30 moves the carriage 342 forward in step S102, and the first region nozzle of the pretreatment liquid nozzle row LP. N [A] is selected and the pretreatment liquid 40 is injected. In step S104, the control unit 30 moves the carriage 342 in the Y direction without transporting the medium 22a in the Y direction, and the nozzles N [ C], N [M], N [Y], and N [K] eject ink 41 of a necessary color to land on the medium 22a.

  On the other hand, if the determination unit 303 determines that the medium 22b has low absorbency in step S101, the control unit 30 moves the carriage 342 forward while moving the carriage 342 in step S103. The second region nozzle N [B] is selected and the pretreatment liquid 40 is ejected. In step S104, the control unit 30 conveys the medium 22b in the Y direction, and then the nozzles N [C] and N [M] of the ink nozzle rows LI1 to LI4 are applied to the portions where the pretreatment liquid 40 has landed. Necessary colors of ink 41 are ejected from N [Y] and N [K] to land on the medium 22b.

  According to such printing control of the first embodiment, in order to land the ink 41 on the portion of the medium 22 on which the pretreatment liquid 40 has landed, the first area nozzle N [A] is selected and the pretreatment liquid is selected. When 40 is ejected, the preprocessing is performed more than when the second region nozzle N [B] that needs to transport the medium 22 in the Y direction is selected in that the medium 22 does not have to be transported in the Y direction. The landing time difference between the liquid 40 and the ink 41 can be reduced.

  Accordingly, by selecting the first region nozzle N [A] for the highly absorbent medium 22a, the difference in landing time between the pretreatment liquid 40 and the ink 41 can be reduced as in the case 2 of FIG. As in Case 2 of FIG. 5, the reactivity with the ink 41 can be improved, and the print image quality can be improved. On the other hand, for the medium 22b having low absorbency, by selecting the second region nozzle N [B], the difference in landing time between the pretreatment liquid 40 and the ink 41 can be increased as in the case 3 of FIG. The reactivity with the ink 41 can be improved as in the case 3 of FIG. 5, and the print image quality can be improved.

  As described above, in the case of the medium 22a having high absorbency, the pretreatment liquid 40 is ejected from the first region nozzle N [A] when the carriage 342 moves forward (step S102), and the ink nozzles are moved when the carriage 342 moves backward. Although the case where the ink 41 is ejected from the rows LI1 to LI4 (step S104) has been described, the present invention is not limited to this. For example, in the case of the highly absorbent medium 22a, both the pretreatment liquid 40 and the ink 41 may be ejected when the carriage 342 moves forward. That is, in the liquid ejecting head 36 of FIG. 2, the first region nozzle N [A] is arranged in the same first region A so as to overlap the ink nozzle rows LI1 to LI4 in the X direction in plan view. During the forward movement of 342, both the pretreatment liquid 40 and the ink 41 can be ejected. As a result, the pretreatment liquid 40 and the ink 41 can be landed on the medium 22 almost simultaneously so that there is almost no time difference.

(First modification of the first embodiment)
A liquid jet head 36 according to a first modification of the first embodiment will be described. FIG. 7 is a plan view of the ejection surface 360 of the liquid ejection head 36 according to the first modification of the first embodiment. 7 differs from FIG. 2 in that the first region A of the liquid ejecting head 36 is further divided into an upstream region A1 and a downstream region A2 in the Y direction (the conveyance direction of the medium 22). It is a divided point. For example, assuming a straight line GA parallel to the X direction in the first region A of the ejection surface 360, the upstream side in the Y direction from the straight line GA is the region A1, and the downstream side in the Y direction from the straight line GA is the region A2.

  In the configuration of FIG. 7, the nozzles N [C], N [M], N [Y], and N [K] of the ink nozzle rows LI1 to LI4 are the upstream area A1 and the downstream area of the first area A. A2 and A2, respectively. The first region nozzle N [A] is disposed in the region A1 upstream of the first region A, and the second region nozzle N [B] is disposed in the second region B. As shown in FIG. 7, the nozzles N [C], N [M], N [Y], and N [of the ink nozzle rows LI1 to LI4 in the upstream area A1 and the downstream area A2 of the first area A K] may be shifted in the X direction. Further, the first region nozzle N [A] and the second region nozzle N [B] may also be arranged shifted in the X direction.

  Also in the configuration of FIG. 7, the range in which the plurality of first region nozzles N [A] is distributed in the X direction is the range in which the ink nozzle rows LI1 to LI4 in the region A1 upstream of the first region A are distributed in the X direction. The range in which the plurality of second region nozzles N [B] are distributed in the X direction is both the range in which the ink nozzle arrays LI1 to LI4 in the region A1 and the region A2 in the first region A are distributed in the X direction. It is upstream without overlapping.

  In the printing control of the liquid jet head 36 in FIG. 7, the control unit 30 selects either the first region nozzle N [A] or the second region nozzle N [B] according to the type of the medium 22. Then, the pretreatment liquid 40 is sprayed, and the nozzles N [C], N [M], N [Y], and N [K] are also in the upstream area A1 and the downstream area A2 of the first area A. One of the nozzles is selected, and the ink 41 is ejected from the selected nozzle. For example, when the first region nozzle N [A] is selected, the region A2 is selected between the case where the ink nozzle rows LI1 to LI4 in the region A1 are selected and the case where the ink nozzle rows LI1 to LI4 in the region A2 are selected. If the ink nozzle rows LI1 to LI4 are selected, the landing time difference between the pretreatment liquid 40 and the ink 41 can be slightly increased. Even when the second region nozzle N [B] is selected, the region A2 is selected when the ink nozzle rows LI1 to LI4 in the region A1 are selected and when the ink nozzle rows LI1 to LI4 in the region A2 are selected. The difference in landing time between the pretreatment liquid 40 and the ink 41 can be increased by selecting the ink nozzle rows LI1 to LI4.

  As described above, according to the configuration of FIG. 7, for the pretreatment liquid nozzle row LP, not only the first area nozzle N [A] and the second area nozzle N [B] can be selected, but also the ink nozzle For the rows LI1 to LI4, the nozzles in the region A1 and the nozzles in the region A2 can be selected. Accordingly, since the number of combinations of nozzle selections for the pretreatment liquid 40 and the ink 41 increases, there is also room for selection of the landing time difference between the pretreatment liquid 40 and the ink 41, so that the landing time difference can be finely adjusted. In the liquid ejecting head 36 shown in FIG. 7, the case where the first region nozzle N [A] in the pretreatment liquid nozzle row LP is arranged in the region A1 upstream of the first region A is exemplified. The one area nozzle N [A] may be arranged in the area A2 on the downstream side of the first area A, and the first area nozzle N [A] is arranged on the upstream area A1 and the downstream area of the first area A. You may arrange | position to both A2.

(Second modification of the first embodiment)
A liquid jet head 36 according to a second modification of the first embodiment will be described. FIG. 8 is a plan view of the ejection surface 360 of the liquid ejection head 36 according to the second modification of the first embodiment. In the configuration of FIG. 7, in the region A1 upstream of the first region A, the range in which the first region nozzles N [A] are distributed in the X direction is the nozzles N [C], N [M], and N [Y]. , N [K] is illustrated as being overlapped over the entire range distributed in the X direction, but is not limited thereto. As shown in FIG. 8, in the area A1 upstream of the first area A, the range in which the first area nozzles N [A] are distributed in the X direction is the nozzles N [C], N [M], N [Y ], N [K] may overlap a part of the range distributed in the X direction.

  In the configuration of FIG. 8, the range in which the first region nozzles N [A] are distributed in the X direction is the nozzles N [C], N [M], N [Y], and the regions A1 upstream of the first region A. The case where N [K] is half of the range distributed in the X direction is illustrated. In this case, as shown in FIG. 8, the nozzles N [C], N [M], and the nozzles N [C] in the area A1 upstream of the first area A are also distributed in the range where the second area nozzles N [B] are distributed in the X direction. N [Y] and N [K] may be half of the range in which they are distributed in the X direction.

  With such a configuration of FIG. 8, not only the first area nozzle N [A] and the second area nozzle N [B] can be selected for the pretreatment liquid nozzle array LP, but also the ink nozzle array LI1. Also for -LI4, the nozzles in the area A1 and the nozzles in the area A2 can be selected.

(Third Modification of First Embodiment)
A liquid jet head 36 according to a third modification of the first embodiment will be described. FIG. 9 is a plan view of the ejection surface 360 of the liquid ejection head 36 according to the third modification example of the first embodiment. The liquid ejecting head 36 in FIG. 9 is different from FIG. 7 in that not only the first region A of the liquid ejecting head 36 but also the second region B is an upstream region in the Y direction (transport direction of the medium 22). This is a point divided into B1 and a downstream area B2. For example, assuming a straight line GB parallel to the X direction in the first region B of the ejection surface 360, the upstream side in the Y direction from the straight line GB is the region B1, and the downstream side in the Y direction from the straight line GB is the region B2. In the liquid ejecting head 36 of FIG. 9, the first region nozzle N [A] is arranged in the upstream region A1 and the downstream region A2 of the first region A, and the upstream region B1 of the second region B. The second region nozzle N [B] is disposed in each of the downstream region B2 and the downstream region B2.

  According to the configuration of FIG. 9, also for the pretreatment liquid nozzle row LP, the first region nozzle N [A] and the second region nozzle N [B] are nozzles in the region A1 upstream of the first region A, respectively. The nozzle corresponding to one of the downstream area A2 or the nozzle corresponding to one of the upstream area B1 and the downstream area B2 of the second area B can be selected and the pretreatment liquid 40 can be ejected. Also for the ink nozzle rows LI1 to LI4, the nozzles in the area A1 and the nozzles in the area A2 can be selected. Accordingly, since the combination of nozzle selection of the pretreatment liquid 40 and the ink 41 is further increased as compared with the liquid ejecting head 36 shown in FIG. 7, the room for selecting the landing time difference between the pretreatment liquid 40 and the ink 41 is also increased. The landing time difference can be adjusted more finely.

  Further, according to the configuration of FIG. 9, in the case of the medium 22a having high absorbency, the pretreatment liquid 40 is ejected from both the nozzles of the area A1 and the area A2 for the first area nozzle N [A] and absorbed. In the case of the medium 22b having low properties, the pretreatment liquid 40 can be ejected from both the nozzles in the areas B1 and B2 for the second area nozzle N [B]. For the nozzles N [C], N [M], N [Y], and N [K], the ink 41 is ejected from the nozzles in the upstream area A1 and the downstream area A2 of the first area A. Can be made. According to this, the pretreatment liquid 40 or the ink 41 is ejected at a time as compared with the case where either the nozzle of the area A1 or the area A2 is selected or the case where any of the nozzles of the area B1 or the area B2 is selected. Since the range of nozzles to be widened in the Y direction, the printing speed can be increased.

(Fourth modification of the first embodiment)
A liquid jet head 36 according to a fourth modification of the first embodiment will be described. FIG. 10 is a plan view of the ejection surface 360 of the liquid ejection head 36 according to the fourth modification example of the first embodiment. In the configuration of FIG. 10, a plurality of nozzle rows L 0 are formed on the ejection surface 360 of the liquid ejection head 36. The plurality of nozzle rows L0 is a set of a plurality of nozzles N arranged in the Y direction from the first region A to the second region B. The range in the Y direction where the plurality of nozzles N are distributed is common over the plurality of nozzle rows L0. One arbitrary nozzle row L0 is used as the pretreatment liquid nozzle row LP, and the other four nozzle rows L0 are used as the ink nozzle rows LI1 to LI4.

  In the nozzle row L0 used as the pretreatment liquid nozzle row LP, a predetermined number of nozzles N located in the first region A are used as the first region nozzle N [A] and are predetermined in the second region B. The nozzles N are used as the second region nozzle N [B]. Of the four nozzle rows L0 used as the ink nozzle rows LI1 to LI4, a predetermined number of nozzles N located in the first region A are nozzles N [C], N [M], N [Y], N [K ] Is used. That is, the positional relationship of each nozzle is the same as in FIG. For each nozzle N that is not used among the plurality of nozzle rows L0, for example, the flow path to the nozzle N is closed and maintained in a non-ejection state (a state in which liquid cannot be ejected). Since the positional relationship between the nozzles used in FIG. 10 is the same as that in FIG. 2, the same operational effects as those of the liquid jet head 36 in FIG. 2 can be achieved. In addition, although the positional relationship of each nozzle utilized in FIG. 10 was given as an example in the same manner as in FIG. 2, it is not limited to this, and by adjusting the number of nozzle rows L0 and the interval in the X direction, By appropriately selecting the nozzles to be used, the same nozzle arrangement as in FIGS. As described above, according to the configuration in FIG. 10, some of the plurality of nozzle rows arranged in the X direction at intervals from each other are arranged on the liquid jet head 36 with the pretreatment liquid 40 and the ink 41. Therefore, the arrangement of the pretreatment liquid 40 and the ink 41 can be changed depending on the position of the nozzle to be used.

Second Embodiment
A second embodiment of the present invention will be described. In the first embodiment, the case where one kind of pretreatment liquid 40 is used and the landing time difference between the pretreatment liquid 40 and the ink 41 is changed according to the type of the medium 22 has been described. A case where the pretreatment liquid 40 is used and the type of the pretreatment liquid 40 is changed according to the type of the medium 22 as well as the landing time difference between the pretreatment liquid 40 and the ink 41 according to the type of the medium 22 will be described. In addition, about the element which an effect | action and function are the same as that of 1st Embodiment in each form illustrated below, the code | symbol used by description of 1st Embodiment is diverted, and each detailed description is abbreviate | omitted suitably.

  In the first embodiment, the larger the landing time difference between the pretreatment liquid 40 and the ink 41, the more the pretreatment liquid 40 penetrates immediately before the landing of the ink 41 and the pretreatment liquid 40 remaining on the surface of the medium 22. It has been described that the amount of the reaction component is changed and the reactivity between the pretreatment liquid 40 and the ink 41 may be lowered. Such a phenomenon may appear more conspicuously depending on not only the landing time difference between the pretreatment liquid 40 and the ink 41 but also the combination of the pretreatment liquid 40 having different media types and permeability. For example, the pretreatment liquid 40b ′ having a high permeability is more likely to penetrate the medium 22 than the pretreatment liquid 40a ′ having a low permeability, so that the permeability is high even if the landing time difference between the pretreatment liquid 40 and the ink 41 is the same. The pretreatment liquid 40 b ′ permeates the pretreatment liquid 40 too much, and the amount of reaction components of the pretreatment liquid 40 remaining on the surface of the medium 22 is also reduced.

(Relationship between media type and pretreatment liquid permeability)
Hereinafter, the relationship between the type of the medium and the permeability of the pretreatment liquid 40 will be described in more detail. FIG. 11 is a diagram for explaining the state of the pretreatment liquid 40 in the four cases 5 to 8 where the pretreatment liquid 40 having different permeability is landed on different types of media.

  Here, one kind of pretreatment liquid 40 having different permeability is either a pretreatment liquid 40a 'having low permeability or a pretreatment liquid 40b' having high permeability. Using a slow penetration pretreatment liquid as the low-penetration pretreatment liquid (first pretreatment liquid) 40a ′, and using a super-penetration pretreatment liquid as the high permeability pretreatment liquid (second pretreatment liquid) 40b ′, The landing time difference between the pretreatment liquid 40a ′ or 40b ′ and the ink 41 is the same. The medium 22 having a different type is either a medium 22a having a high liquid absorbency (for example, coated paper having an ink absorption layer) or a medium 22b having a low liquid absorbency (for example, a plastic film such as vinyl chloride). It is.

  In FIG. 11, Case 5 is a case where a highly permeable pretreatment liquid 40 b ′ is landed on a highly absorbent medium 22 a, and Case 6 is a case where a highly permeable medium 22 a has a low permeability. This is a case where the treatment liquid 40a ′ is landed. Case 7 is a case where the pretreatment liquid 40b ′ having high permeability is landed on the medium 22b having low absorbency, and the case 8 is that the pretreatment liquid 40a ′ having low permeability is applied to the medium 22b having low absorbency. This is the case where

  11 is the remaining amount of the pretreatment liquid 40a 'or 40b' remaining on the surface of the medium 22a or 22b immediately before ink landing, as in the case of FIG. Similarly to FIG. 4, the covering area in FIG. 11 is also an area where the pretreatment liquid 40a 'or 40b' remaining on the surface of the medium 22a or 22b immediately before ink landing covers the medium 22a or 22b.

  In addition, the ultra-slow osmotic solution, which is the pretreatment solution 40b 'having high permeability, penetrates quickly into the medium 22a or 22b, and easily spreads on the surface of the medium 22a or 22b. On the other hand, the slow osmotic solution that is the low-permeability pretreatment liquid 40a ′ is less permeable to the inside of the medium 22a or 22b than the ultra-low osmosis liquid that is the high-penetration pretreatment liquid 40b ′. Difficult to spread on the surface of the medium 22a or 22b. For this reason, the remaining amount of the surface of the pretreatment liquid 40a 'or 40b' and the coating area differ depending on the combination of the pretreatment liquid 40a 'or 40b' and the medium 22a or 22b as in the cases 1 to 4 in FIG. Hereinafter, each case 5-8 will be specifically described.

  First, the highly absorbent medium 22a in case 5 and case 6 of FIG. 11 will be described. As shown in Case 5 of FIG. 11, when the highly permeable pretreatment liquid 40b ′ is landed on the highly absorbent medium 22a, the surface residual amount of the pretreatment liquid 40b ′ is “low”. The covering area is also “small”. That is, in this case, since the medium 22a has high absorbability, in the pretreatment liquid 40b ′ having high permeability, the pretreatment liquid 40b ′ is immediately after the landing of the pretreatment liquid 40b ′ to immediately before the ink 41 is landed. Since it permeates too much, the amount of the remaining surface of the pretreatment liquid 40b ′ remaining on the surface of the medium 22a becomes too small immediately before ink landing, and the covering area also becomes small. In addition, since the pretreatment liquid 40b 'having higher permeability is more easily spread and wet, the wet spread is increased. In this case, when the ink 41 is landed in the same manner as in the case 1 of FIG. 5, the surface remaining amount of the pretreatment liquid 40b ′ is too small and the covering area is small. Reactivity is lowered. For this reason, since the dots that have landed on the surface of the medium 22a spread and easily aggregate, there is a risk that the print image quality will deteriorate.

  On the other hand, as shown in the case 6 of FIG. 11, when the pretreatment liquid 40a ′ having low permeability is landed on the highly absorbent medium 22a, the surface residual amount and the coating area of the pretreatment liquid 40a ′ are as follows. Both are “medium”. In this case, since the permeability of the pretreatment liquid 40a ′ is low even with the medium 22a having high absorbency, the pretreatment is performed immediately after the pretreatment liquid 40a ′ has landed on the medium 22a and immediately before the ink 41 has landed. The liquid 40a ′ does not penetrate too much. For this reason, the remaining amount of the surface of the pretreatment liquid 40a 'does not become too small immediately before ink landing and the covering area is medium, so that the dots that have landed on the surface of the medium 22a are less likely to aggregate. In the pretreatment liquid 40a ′ having low permeability, the penetration is slow and the wetting spread is weak. However, when the medium 22a has high absorbability, if the landing time difference with the ink 41 is large, the pretreatment liquid immediately before the landing of the ink 41 40a 'permeates the medium 22a too much and the remaining amount of the surface decreases, and the dots of the ink 41 that have landed on the surface of the medium 22a spread and are likely to agglomerate so as to overlap each other.

  Thus, although the state of the pretreatment liquid 40a ′ in the case 6 of FIG. 11 is not bad, the state of the pretreatment liquid 40a ′ changes due to the time difference from the landing of the pretreatment liquid 40a ′ to the landing of the ink 41. Since the variation tends to occur, it is not always possible to provide a stable and favorable environment for the pretreatment liquid 40a ′ in all the printing regions of the medium 22a.

  Next, the low-absorbency medium 22b in case 7 and case 8 of FIG. 11 will be described. As shown in case 7 of FIG. 11, when the pretreatment liquid 40b ′ having high permeability is landed on the medium 22b having low absorbency, the surface residual amount of the pretreatment liquid 40b ′ becomes “medium”. The covering area is “large”. That is, in this case, since the medium 22b has low absorbability, in the pretreatment liquid 40b ′ having high permeability, the pretreatment liquid 40b ′ is formed immediately after the pretreatment liquid 40b ′ has landed and immediately before the ink 41 has landed. Does not penetrate too much, has good fixing properties and is good. For this reason, the remaining amount of the surface of the pretreatment liquid 40 b ′ does not decrease too much, the dots of the ink 41 that land on the surface of the medium 22 b hardly aggregate, and the color developability of the ink 41 is good. However, even if the pretreatment liquid 40b ′ having high permeability has a low absorbability of the medium 22b, if the difference in landing time with the ink 41 is small, the pretreatment liquid 40b ′ cannot be dried in time, and until the ink 41 just before landing. The surface treatment amount of the pretreatment liquid 40b ′ is too large and the drying of the solution components such as moisture and solvent is insufficient, so that the reactivity between the pretreatment liquid 40b ′ and the ink 41 is lowered, and the print image quality may be deteriorated. There is.

  Thus, although the state of the pretreatment liquid 40b ′ in the case 7 of FIG. 11 is not bad, the state of the pretreatment liquid 40b ′ changes due to the time difference from the landing of the pretreatment liquid 40b ′ to the landing of the ink 41. Since the variation tends to occur, it is not always possible to provide a stable and favorable environment for the pretreatment liquid 40b ′ in all the printing regions of the medium 22b.

  On the other hand, as shown in case 8 of FIG. 11, when the pretreatment liquid 40a ′ having low permeability is landed on the medium 22b having low absorbency, the surface residual amount of the pretreatment liquid 40a ′ is “large”. Thus, the covering area becomes “medium”. That is, in this case, since the medium 22b has low absorbability, in the pretreatment liquid 40a ′ having low permeability, the pretreatment liquid 40a ′ immediately after the pretreatment liquid 40a ′ has landed and immediately before the ink 41 has landed. The remaining amount of the surface does not become too small. In this case, when the ink 41 is landed as shown in the case 4 of FIG. 5, the dots landed on the surface of the medium 22b are less likely to aggregate. However, on the other hand, the pretreatment liquid 40a 'is more difficult to permeate and the fixability is poor, so the color developability of the ink 41 is lowered. In addition, since the permeability of the pretreatment liquid 40a 'is low, it is difficult for the pretreatment liquid 40a' to spread, the contact area between the pretreatment liquid 40a 'and the ink 41 is reduced, and the reactivity is also lowered.

  According to the above, in order to improve the printing image quality, from the viewpoint of the surface residual amount (penetration) of the pretreatment liquid, the medium 22a having high absorbency like the case 6 in FIG. The pretreatment liquid 40a ′ having a lower permeability than the pretreatment liquid 40b ′ is better, and the medium 22b having a low absorbability as in the case 7 of FIG. 11 has a permeability that is lower than the pretreatment liquid 40a ′ having a low permeability. It can be seen that a higher pretreatment liquid 40b 'is better. However, even in a combination such as Case 6 and Case 7, there is much room for improvement in order to obtain an appropriate surface residual amount of the pretreatment liquid 40 immediately before the ink 41 is landed.

  Therefore, in the second embodiment, the pretreatment liquid 40a 'having low permeability is used for the medium 22a having high absorbency, and the pretreatment liquid 40b' having high permeability is used for the medium 22b having low absorbency. Accordingly, the reactivity between the pretreatment liquid 40 and the ink 41 can be increased regardless of the type of the medium 22. Further, as in the first embodiment, by changing the landing time difference between each pretreatment liquid 40 and the ink 41, the permeability and drying property can be adjusted, so that the wet spreading property of the pretreatment liquid 40 can also be adjusted.

(Liquid ejecting head of the second embodiment)
Next, a configuration example of the liquid ejecting head 36 according to the second embodiment in which the kind of the pretreatment liquid 40 is changed along with the landing time difference between the pretreatment liquid 40 and the ink 41 according to the medium 22 will be described. FIG. 12 is a plan view of the ejection surface of the liquid ejection head according to the second embodiment. As the pretreatment liquid 40 of the liquid jet head 36 in FIG. 12, the first pretreatment liquid 40a ′ having low permeability to the medium 22 and the second pretreatment liquid 40b having higher permeability than the first pretreatment liquid 40a ′. As an example, a case where two types of pretreatment liquids 40 are used.

  The first pretreatment liquid 40a 'and the second pretreatment liquid 40b' are reaction components similar to the pretreatment liquid 40 of the first embodiment, and have different permeability to the medium 22. As a specific example of the first pretreatment liquid 40a ', there is a slow penetration pretreatment liquid that has low permeability to the medium 22 and slowly permeates. As a specific example of the second pretreatment liquid 40 b ′, there is a super-penetration pretreatment liquid that has a higher permeability to the medium 22 than the slow penetration pretreatment liquid and permeates rapidly. The terms “superosmosis” and “slow penetration” herein refer to their relative properties.

  FIG. 12 shows a configuration in which two types of pretreatment liquids 40, ie, a first pretreatment liquid 40a ′ and a second pretreatment liquid 40b ′, are supplied to the liquid jet head 36 having the same configuration as in FIG. . In the liquid container 24 shown in FIG. 12, the first pretreatment liquid 40a 'and the second pretreatment liquid 40b' are stored separately. In FIG. 12, the liquid container 24 is illustrated as one element for convenience, but a configuration in which a plurality of pretreatment liquids 40 and a plurality of types of ink 41 are stored in separate liquid containers 24, or a plurality of types of liquid containers 24 are illustrated. A configuration in which each of the inks 41 is stored in a separate liquid container 24 can also be employed.

  According to the liquid ejecting head 36 of FIG. 12, the plurality of first region nozzles N [A] eject the first pretreatment liquid 40a ′, and the plurality of second region nozzles N [B] are the second pretreatment liquid 40b. By being configured to eject ', the landing time difference between each of the pretreatment liquids 40a' and 40b 'and the ink 41 can be changed according to the type of the medium 22, and the kind of the pretreatment liquid is also the first. It can be changed to either the pretreatment liquid 40a ′ or the second pretreatment liquid 40b ′.

(Liquid jetting method of the second embodiment)
Based on the above, the liquid ejecting method of the second embodiment will be described by taking the control of the liquid ejecting head 36 in FIG. 12 as an example. FIG. 13 is a flowchart illustrating control of the liquid ejecting head 36 in print control. The control unit 30 reads a predetermined program from the ROM 301 in accordance with an instruction from the management apparatus, and executes print control on the medium 22. In the printing control, the control unit 30 controls the liquid ejecting head 36 shown in FIG. 13 while controlling the conveyance of the medium 22.

  First, in step S201, the determination unit 303 determines the type of the medium 22 to be printed. Specifically, the same processing as step S101 in FIG. 6 is performed. If the determination unit 303 determines in step S201 that the medium 22a has high absorbency, the control unit 30 moves the carriage 342 forward in step S202, and the first region nozzle of the pretreatment liquid nozzle row LP. N [A] is selected and the first pretreatment liquid 40a 'having low permeability is injected. Then, in step S204, the control unit 30 moves the carriage 342 backward without transporting the medium 22a in the Y direction, and sets the ink nozzle rows LI1 to LI4 on the portions where the first pretreatment liquid 40a ′ has landed. Necessary colors of ink 41 are ejected from the nozzles N [C], N [M], N [Y], and N [K] to land on the medium 22a.

  On the other hand, when the determination unit 303 determines that the medium 22b has low absorbency in step S201, the control unit 30 moves the carriage 342 forward in step S203 and moves the pretreatment liquid nozzle row LP. The second region nozzle N [B] is selected and the second pretreatment liquid 40b ′ having high permeability is ejected. In step S204, the controller 30 conveys the medium 22b in the Y direction, and then the nozzles N [C] and N [of the ink nozzle rows LI1 to LI4 are applied to the portions where the second pretreatment liquid 40b ′ has landed. The ink 41 of a necessary color is ejected from M], N [Y], and N [K] to land on the medium 22b.

  According to the printing control of the second embodiment as described above, the first region nozzle N [A] is selected for the medium 22a having high absorbency, and the penetrable as in the case 6 of FIG. Since the low first pretreatment liquid 40a ′ can be ejected and the landing time difference between the first pretreatment liquid 40a ′ and the ink 41 can be reduced, the effect of suppressing the penetration into the medium 22a can be enhanced. On the other hand, by selecting the second region nozzle N [B] for the medium 22b having low absorbability, the second pretreatment liquid 40b ′ having high permeability is ejected as in the case 7 of FIG. Furthermore, since the difference in landing time between the second pretreatment liquid 40b ′ and the ink 41 can be increased, the wettability and drying properties of the medium 22b can be improved. Therefore, compared with the case where only the landing time difference between the pretreatment liquid and the ink is changed, the effect of improving the reactivity with the ink 41 can be further enhanced regardless of the type of the medium 22, and the print image quality can be further improved. Can be improved.

  In the control shown in FIG. 13, in the case of the medium 22a having high absorbency, when the carriage 342 moves forward, the first pretreatment liquid 40a ′ is ejected from the first region nozzle N [A] (step S202), and the carriage 342 is obtained. The case where the ink 41 is ejected from the ink nozzle rows LI1 to LI4 at the time of the backward movement has been described (step S204). However, the present invention is not limited to this. That is, the liquid ejecting head 36 of FIG. 12 is the same as the configuration of FIG. 2, and therefore, the first region nozzle N [A] has the same first so as to overlap the ink nozzle rows LI1 to LI4 in the X direction in plan view. Since it is arranged in one area A, both the first pretreatment liquid 40a ′ and the ink 41 can be ejected when the carriage 342 moves forward. Thereby, the first pretreatment liquid 40a 'and the ink 41 can be landed on the medium 22a almost simultaneously so that there is almost no time difference.

<Third Embodiment>
A third embodiment of the present invention will be described. In the second embodiment, a liquid jet capable of landing one of two kinds of pretreatment liquids 40 having different permeability according to the type of the medium 22 using two kinds of pretreatment liquids 40 having different permeability. Although the head 36 has been described, in the third embodiment, a plurality of pretreatment liquids 40 having different permeability are used to change the order in which the plurality of pretreatment liquids 40 are stacked according to the type of the medium 22. The head 36 will be described. According to this, compared with the case where only one kind of pretreatment liquid 40 is selected and used, the permeability and wettability can be further improved.

(Media type and multiple pretreatment liquids)
Here, the state of the pretreatment liquid 40 and the state of the ink 41 when a plurality of pretreatment liquids 40 having different permeability are stacked will be described. FIG. 14 is a diagram for explaining the state of the pretreatment liquid 40 in the two cases 9 and 10 in which the order of stacking the pretreatment liquid 40 is changed according to the type of medium. In FIG. 14, two types of pretreatment liquids 40 having different permeability are used: a first pretreatment liquid 40 a having low permeability and a second pretreatment liquid 40 b having high permeability. The slow penetration pretreatment liquid is used as the first pretreatment liquid 40a with low permeability, the super-penetration pretreatment liquid is used as the second pretreatment liquid 40b with high permeability, and the landing time difference between the pretreatment liquid 40 and the ink 41 is The same. The medium 22 having a different type is either a medium 22a having a high liquid absorbency (for example, coated paper having an ink absorption layer) or a medium 22b having a low liquid absorbency (for example, a plastic film such as vinyl chloride). It is.

  The case 9 of FIG. 14 is a case where the second pretreatment liquid 40b having high permeability is landed on the medium 22a having high absorbability, and then the first pretreatment liquid 40a having low permeability is landed and stacked. . The case 10 in FIG. 14 is a case where the first pretreatment liquid 40a having low permeability is landed on the medium 22b having low absorbability, and then the second pretreatment liquid 40b having high permeability is landed and stacked. . FIG. 15 is a diagram for explaining the state of the ink 41 immediately after the landing of the ink 41 and after a lapse of a predetermined time in each of the cases 9 and 10 in FIG. The pretreatment liquid 40 in FIGS. 14 and 15 is the second pretreatment liquid 40b and the first pretreatment liquid 40a after being overlaid.

  As shown in the case 9 of FIG. 14, after the second pretreatment liquid 40b having high permeability is landed on the medium 22a having high absorbency, the first pretreatment liquid 40a having low permeability is landed and stacked. . In Case 9, the remaining amount of the surface of the pretreatment liquid 40 is “medium” and the covering area is also “medium”. According to the case 9, by allowing the second pretreatment liquid 40b having high permeability to land first, it is possible to suppress the penetration of the first pretreatment liquid 40a having low permeability that will land later. Accordingly, it becomes easy to spread and spread as a whole, the surface remaining amount of the pretreatment liquid 40 remaining on the surface of the medium 22 can be increased, and the covering area can be increased. Therefore, as shown in the case 9 in FIG. Not only the aggregation of the ink 41 hardly occurs, but also the reactivity with the ink 41 can be improved, and the wetting and spreading property can be improved. In addition, the first pretreatment liquid 40a is landed where the second pretreatment liquid 40b is wet and spread first, so that the second pretreatment liquid 40b having a high permeability has a low permeability. 1 As a sealant for the pretreatment liquid 40a, the fixability of the pretreatment liquid 40 can be improved, so that the color development of the ink 41 can also be improved. Thereby, compared with the case where only the 1st pretreatment liquid 40a with low permeability is used for medium 22a with high absorbency, print quality can be improved further.

  On the other hand, as shown in the case 10 of FIG. 14, the first pretreatment liquid 40 a having low permeability is landed on the medium 22 b having low absorbability, and then the second pretreatment liquid 40 b having high permeability is landed. And repeat. Also in case 10 of FIG. 14, the surface remaining amount of the pretreatment liquid 40 is “medium” and the covering area is also “medium”. According to the case 10, the first pretreatment liquid 40a having low permeability is landed first, thereby suppressing the wet spreading of the second pretreatment liquid 40b having high permeability to land later and reacting with the ink 41. Can increase the sex. Here, when the absorbency of the medium 22b is very low, it is difficult for the second pretreatment liquid 40b having high permeability to penetrate and the drying property is poor, so that the droplets of the first treatment liquid 40a and the second pretreatment liquid 40b are used. The drying property can be improved by reducing the amount of the ink and reducing the dots. In addition, even if the amount of droplets of the second pretreatment liquid 40b is reduced, the reaction component can be supplemented by the first pretreatment liquid 40a having a low permeability that landed first remaining on the medium 22b. Therefore, the reactivity with the ink 41 can be increased. Therefore, since the wetness and spreadability as a whole and the drying property can be controlled and the surface residual amount of the pretreatment liquid 40 can be made more appropriate, the reaction with the landed ink 41 as shown in the case 10 of FIG. It is possible to improve wettability and drying properties while improving the properties. Thereby, compared with the case where only the 2nd pretreatment liquid 40b with high permeability is used for medium 22b with low absorbency, print quality can be improved.

  Further, in the third embodiment, not only the order of stacking the two types of pretreatment liquids 40 is changed according to the medium 22 as described above, but also the landing time difference between the pretreatment liquid 40a or 40b and the ink 41 is changed. Therefore, it is possible to provide a higher print quality.

(Liquid Ejection Head of Third Embodiment)
Next, a configuration example of the liquid ejecting head 36 according to the third embodiment in which not only the landing time difference between the pretreatment liquid 40 and the ink 41 but also the order of stacking the two types of pretreatment liquid 40 can be changed according to the medium 22 as described above. Will be described. FIG. 16 is a plan view of the ejection surface of the liquid ejection head according to the third embodiment. The liquid ejecting head 36 of FIG. 16 differs from that of FIG. 12 in that in the first region A, the two pretreatment liquid nozzle rows LP1 and LP2 are arranged in the X direction with a space therebetween, and the first region In B, two pretreatment liquid nozzle rows LP1 ′ and LP2 ′ are arranged in the X direction with a space between each other. The configuration of the ink nozzle rows LI1 to LI4 is the same as that shown in FIG.

  Both the pretreatment liquid nozzle rows LP1 and LP2 are a set of a plurality of first region nozzles N [A] arranged linearly along the Y direction, and the pretreatment liquid nozzle rows LP1 ′ and LP2 ′ are both It is a set of a plurality of second region nozzles N [B] arranged linearly along the Y direction. In the configuration of FIG. 16, the pretreatment liquid nozzle rows LP1 and LP2 are arranged in the order of the pretreatment liquid nozzle row LP2 and the pretreatment liquid nozzle row LP1 along the moving direction of the carriage 342 (positive side in the X direction). The pretreatment liquid nozzle rows LP1 ′ and LP2 ′ are arranged in the order of the pretreatment liquid nozzle row LP2 ′ and the pretreatment liquid nozzle row LP1 ′ along the moving direction of the carriage 342 (positive side in the X direction). Has been. The first region nozzles N [A] of the pretreatment liquid nozzle rows LP1 and LP2 overlap in plan view in the X direction, and the second region nozzles N [B] of the pretreatment liquid nozzle rows LP1 ′ and LP2 ′ In the X direction, they overlap in plan view.

  According to such a configuration, one of the first region nozzles N [A] of each of the pretreatment liquid nozzle rows LP1 and LP2 is a nozzle that ejects the first pretreatment liquid 40a, and the other is the second pretreatment. It can be set as the nozzle which injects the liquid 40b. Also, one of the second region nozzles N [B] of each of the pretreatment liquid nozzle rows LP1 ′ and LP2 ′ is a nozzle that ejects the first pretreatment liquid 40a, and the other is the second pretreatment liquid 40b. It can be a nozzle.

  Here, the first region nozzle N [A] of the pretreatment liquid nozzle row LP1 is used as a nozzle for ejecting the first pretreatment liquid 40a, and the first region nozzle N [A] of the pretreatment liquid nozzle row LP2 is used as the second front. A nozzle that ejects the treatment liquid 40b is used. Further, the second region nozzle N [B] of the pretreatment liquid nozzle row LP1 ′ is used as a nozzle for ejecting the second pretreatment liquid 40b, and the second region nozzle N [B] of the pretreatment liquid nozzle row LP2 ′ is the first. A nozzle that ejects the pretreatment liquid 40a is used. That is, in the first region A and the first region B, the nozzle row for ejecting the first pretreatment liquid 40a and the nozzle row for ejecting the second pretreatment liquid 40b are arranged in a staggered order as viewed from the Y direction. To place.

  In the liquid ejecting head 36 of FIG. 16, the first region nozzles N [A] of the pretreatment liquid nozzle rows LP 1 and LP 2 are arranged in the first region A so as to overlap with a range where a plurality of ink nozzles are distributed in the X direction. The second region nozzles N [B] of the pretreatment liquid nozzle rows LP1 ′ and LP2 ′ are arranged in the second region so as not to overlap with a range where a plurality of ink nozzles are distributed in the X direction. Therefore, by selecting the first region nozzle N [A] of the pretreatment liquid nozzle rows LP1, LP2 or by selecting the second region nozzle N [B] of the pretreatment liquid nozzle rows LP1 ′, LP2 ′, It is possible to change the landing time difference from the ink 41 that lands.

  Further, when the first region nozzle N [A] is selected and when the second region nozzle N [B] is selected, the order of the first pretreatment liquid 40a and the second pretreatment liquid 40b is changed. Can land. In this case, in the first region A and the first region B, the nozzle row that ejects the first pretreatment liquid 40a and the nozzle row that ejects the second pretreatment liquid 40b are arranged in a staggered order as viewed from the Y direction. By arranging in this way, when the carriage 342 moves in the same direction, the first pretreatment liquid 40a and the second pretreatment liquid 40b can be landed in different orders, so the first pretreatment liquid 40a is ejected. When the first pretreatment liquid 40a and the second pretreatment liquid 40b are overlapped as compared with the case where the nozzle line that performs the nozzle row that injects the second pretreatment liquid 40b is arranged in the same order as viewed from the Y direction. Even if the carriage 342 is not returned, the order of stacking the first pretreatment liquid 40a and the second pretreatment liquid 40b can be changed. Therefore, even if the order of stacking the first pretreatment liquid 40a and the second pretreatment liquid 40b is changed, it is possible to prevent the landing time difference between the first pretreatment liquid 40a and the second pretreatment liquid 40b from occurring. . As described above, according to the configuration of FIG. 16, not only the landing time difference between the pretreatment liquid 40 and the ink 41 depending on the type of the medium 22, but also the first pretreatment liquid 40 a and the second pretreatment liquid 40 a according to the type of the medium 22. The order of stacking the pretreatment liquid 40b can also be changed.

(Liquid ejection method of the third embodiment)
Based on the above, the liquid ejecting method of the third embodiment will be described by taking the control of the liquid ejecting head 36 in FIG. 16 as an example. FIG. 17 is a flowchart illustrating control of the liquid ejecting head 36 in print control. The control unit 30 reads a predetermined program from the ROM 301 in accordance with an instruction from the management apparatus, and executes print control on the medium 22. In the printing control, the control unit 30 controls the liquid ejecting head 36 shown in FIG.

  First, in step S301, the determination unit 303 determines the type of the medium 22 to be printed. Specifically, the same processing as step S101 in FIG. 6 is performed. If the determination unit 303 determines in step S301 that the medium 22a has high absorbency, the control unit 30 moves the carriage 342 forward in step S302, and the first region nozzle of the pretreatment liquid nozzle row LP2. N [A] is selected, the second pretreatment liquid 40b having high permeability is ejected to land on the medium 22a, and the first region nozzle N [A] of the pretreatment liquid nozzle row LP1 is selected in step S303. The first pretreatment liquid 40a having low permeability is ejected to land on the medium 22a, and the first pretreatment liquid 40a is superimposed on the second pretreatment liquid 40b.

  Then, in step S306, the control unit 30 moves the carriage 342 backward without conveying the medium 22a in the Y direction, and on the portion where the second pretreatment liquid 40b and the first pretreatment liquid 40a are overlapped. The ink 41 of a necessary color is ejected from the nozzles N [C], N [M], N [Y], and N [K] of the ink nozzle rows LI1 to LI4 to land on the medium 22a.

  On the other hand, when the determination unit 303 determines that the medium 22b has low absorbency in step S301, the control unit 30 moves the carriage 342 forward while moving the carriage 342 in step S304. The second region nozzle N [B] is selected and the first pretreatment liquid 40a having low permeability is ejected to land on the medium 22b, and then in step S305, the second pretreatment liquid nozzle row LP1 ' The area nozzle N [B] is selected, the second pretreatment liquid 40b having high permeability is ejected and landed on the medium 22b, and the second pretreatment liquid 40b is superimposed on the first pretreatment liquid 40a.

  Then, in step S306, the control unit 30 conveys the medium 22b in the Y direction and moves the carriage 342 in the backward direction, while the ink is applied to the portion where the first pretreatment liquid 40a and the second pretreatment liquid 40b are overlapped. The ink 41 of a required color is ejected from the nozzles N [C], N [M], N [Y], and N [K] of the nozzle rows LI1 to LI4 to land on the medium 22b.

  According to the print control of the third embodiment, when the determination unit 303 determines that the medium 22a is highly absorbent, the control unit 30 penetrates the second pretreatment liquid 40b having high permeability on the medium 22. The first pretreatment liquid 40a having low properties is piled and landed, and then the ink 41 is landed. On the other hand, if the determination unit 303 determines that the medium 22b has low absorbability, the control unit 30 causes the second pretreatment liquid 40b that has high permeability to the first pretreatment liquid 40a that has low permeability on the medium 22. Are landed, and then ink 41 is landed. As a result, in both the medium 22a having high absorbency and the medium 22b having low absorbency, the wettability can be increased while increasing the reactivity of the pretreatment liquid 40, so that printing can be performed regardless of the type of the medium 22. Image quality can be improved.

  Moreover, since the landing time difference between the pretreatment liquid 40 and the ink 41 can be changed according to the medium 22 as in the first embodiment, the pretreatment remaining on the surface of the medium 22 is high in the highly absorbent medium 22a. The amount of the reaction component of the liquid 40 can be increased, and in the medium 22b having low absorbability, the drying time of the solution components such as moisture and solvent of each pretreatment liquid 40 can be secured.

  As described above, according to the third embodiment, compared to the first embodiment in which only the landing time difference between the pretreatment liquid 40 and the ink 41 is changed according to the type of the medium 22, it is more independent of the type of the medium 22. A high-quality print image quality can be provided. In FIG. 17, as in the case of FIG. 6, in the case of the highly absorbent medium 22a, not only each pretreatment liquid 40 but also the ink 41 may be ejected when the carriage 342 moves forward. . That is, in the liquid ejecting head 36 of FIG. 16, the same first first nozzle N [A] of the pretreatment liquid nozzle rows LP1 and LP2 overlaps the ink nozzle rows LI1 to LI4 in the X direction in plan view. Since it is arranged in the region A, when the carriage 342 moves forward, not only the pretreatment liquid 40 but also the ink 41 can be ejected. Thereby, each pretreatment liquid 40 and the ink 41 can be landed on the medium 22a almost simultaneously so that there is almost no time difference.

  Further, the liquid jet head according to the third embodiment is not limited to the configuration described above. For example, in the configuration of FIG. 16, both the first region nozzle N [A] and the second region nozzle N [B] of the pretreatment liquid nozzle rows LP1, LP1 ′ are nozzles that eject the first pretreatment liquid 40a. Both the first area nozzle N [A] and the second area nozzle N [B] of the treatment liquid nozzle rows LP2 and LP2 ′ may be nozzles that eject the second pretreatment liquid 40b.

<Fourth embodiment>
A fourth embodiment of the present invention will be described. In the first to third embodiments, the liquid ejecting apparatus 10 including the serial head in which the carriage 342 on which the liquid ejecting head 36 is mounted moves in the X direction is illustrated. However, in the fourth embodiment, the conveyance direction of the medium 22 The liquid ejecting apparatus 10 including the liquid ejecting head 36 configured as a long line head in a direction intersecting with (here, the X direction) is illustrated.

  FIG. 18 is a partial configuration diagram of the liquid ejecting apparatus 10 according to the fourth embodiment of the invention. In the liquid ejecting head 36 in the liquid ejecting apparatus 10 shown in FIG. 18, the four nozzle rows LP1 to LP4 arranged in the second region B and the four nozzle rows LI1 to LI4 arranged in the first region A are mutually connected. The line heads are arranged in the Y direction at intervals. The nozzle rows LP1 to LP4 in the second region B and the nozzle rows LI1 to LI4 in the first region A are a set of a plurality of nozzles N arranged linearly along the X direction. Each of the nozzle rows LP1 to LP4 in the second region B and the nozzle rows LI1 to LI4 in the first region A may be a plurality of rows (for example, a staggered arrangement or a staggered arrangement).

  As shown in the enlarged view on the upper side of FIG. 18, the nozzle rows LP1 to LP4 in the second region B are configured by a plurality of nozzles N [B] that eject the pretreatment liquid 40. On the other hand, as shown in the enlarged view on the lower side of FIG. 18, the nozzle rows LI1 to LI4 in the first region A include a plurality of nozzles N [A] that eject the pretreatment liquid 40 and nozzles N that eject the ink 41. [C], N [M], N [Y], and N [K]. Specifically, in the nozzle row LI1 in the first region A, the nozzles N [A] and the nozzles N [C] are alternately arranged in the X direction, and in the nozzle row LI2 in the first region A, the nozzles N [A ] And nozzles N [M] are alternately arranged in the X direction. In the nozzle row LI3 in the first region A, the nozzles N [A] and nozzles N [Y] are alternately arranged in the X direction, and the first In the nozzle row LI4 in the region A, the nozzles N [A] and the nozzles N [K] are alternately arranged in the X direction.

  According to such a configuration of FIG. 18, the range in which the plurality of first region nozzles N [A] are distributed in the X direction is the nozzles N [C], N [M], and N [Y] of the ink 41 in the X direction. ], N [K] overlaps the distribution range, and the distribution range of the plurality of second region nozzles N [B] in the X direction is the nozzles N [C], N [M], N of the ink 41 in the X direction. [Y] and N [K] are on the upstream side that does not overlap with the distribution range.

  Therefore, even if the liquid ejecting head 36 is a line head as shown in FIG. 18, similarly to the liquid ejecting head 36 shown in FIG. 2, the first region nozzle N [A] and the second region nozzle N [B] Ink 41 that is ejected from nozzles N [C], N [M], N [Y], and N [K] and then landed on the medium 22 by ejecting the pretreatment liquid 40 by selecting one of them You can change the landing time difference.

  In addition, the liquid ejecting head 36 of each embodiment described above functions as a liquid ejecting unit that ejects the ink 41 and also functions as a pretreatment liquid coating mechanism that coats the medium 22 with the pretreatment liquid 40. Specifically, the component for ejecting ink 41 (including the nozzles of ink nozzle rows LI1 to LI4) of the liquid ejecting head 36 functions as a liquid ejecting unit and is disposed in the first region A. The component (including the first region nozzle N [A]) that ejects 40 functions as the first mechanism, and the component (second region nozzle N [[2] that ejects the pretreatment liquid 40 disposed in the second region B). B]) function as the second mechanism.

<Modification>
Each embodiment illustrated above can be variously modified, for example, can be appropriately combined within a range not contradicting each other. Further, the following examples may be combined with each embodiment.

(1) The structure of the liquid jet head 36 is appropriately changed. For example, in each of the above-described embodiments, the piezoelectric liquid ejecting head 36 using a piezoelectric element that imparts mechanical vibration to the pressure chamber is exemplified, but a heating element that generates bubbles in the pressure chamber by heating is used. It is also possible to employ a thermal type liquid jet head. Further, the configuration of the plurality of nozzles N in the liquid ejecting head 36 is not limited to the illustrations of the above-described embodiments. For example, the pretreatment liquid 40 nozzle row and the ink nozzle row may be configured separately. In each of the above-described embodiments, the case where two pretreatment liquids 40 are landed and stacked on the medium has been described. However, the present invention is not limited to this, and three or more pretreatment liquids 40 are landed. You may make it overlap.

(2) In each of the above-described embodiments, the case where the liquid ejecting head 36 functions as a pretreatment liquid coating mechanism that coats the medium 22 with the pretreatment liquid 40 is exemplified, but the present invention is not limited thereto, and the pretreatment is performed. The liquid coating mechanism may be provided separately from the liquid ejecting head 36. In this case, the pretreatment liquid coating mechanism may be configured by a spray mechanism that coats the medium 22 by spraying the pretreatment liquid 40. For example, in the liquid ejecting head 36 in FIG. 18, the portions of the nozzle rows LP1 to LP4 in the second region B may be configured by a spray mechanism separate from the liquid ejecting head 36.

(3) In the above-described embodiment, the injection amounts of the first pretreatment liquids 40a and 40a ′ and the second pretreatment liquids 40b and 40b ′ can be further adjusted. For example, in the case of the medium 22 that does not substantially absorb liquid, the small pre-penetration liquid having low penetrability is landed on the second pre-treatment liquid having small penetrability, or large dots penetrate. A highly pretreatment liquid can be landed. Further, for example, in the case of the medium 22 that slightly absorbs liquid, it is possible to land the second pretreatment liquid with small penetrability with low permeability so that the pretreatment liquid with high penetrability with large dots overlaps. . Further, for example, in the case of the medium 22 that slightly absorbs the liquid, it is possible to land the second pretreatment liquid having a high permeability of small dots so as to overlap the pretreatment liquid of a low permeability of large dots. Further, for example, in the case of the medium 22 that absorbs a large amount of liquid, it is possible to land the second pretreatment liquid having a large dot penetration rate so as to overlap the pretreatment liquid having a large dot penetration rate.
In other words, the medium with higher absorbability shortens the time difference from the landing of the pretreatment liquid to the landing of the ink, increases the amount of the pretreatment liquid to be ejected, and selects the order in which the pretreatment liquid is ejected. Therefore, it is possible to improve the printing image quality. In addition, the lower the medium is, the longer the time difference from the landing of the pretreatment liquid to the landing of the ink, the smaller the amount of pretreatment liquid sprayed, and the selection of the order of pretreatment liquid ejection. Therefore, it is possible to improve the printing image quality.

(4) The liquid ejecting apparatus exemplified in each of the above-described embodiments can be employed in various apparatuses such as a facsimile apparatus and a copying machine in addition to apparatuses dedicated to printing. However, the use of the liquid ejecting apparatus of the present invention is not limited to printing. For example, a liquid ejecting apparatus that ejects a solution of a coloring material is used as a manufacturing apparatus that forms a color filter of a liquid crystal display device. Further, a liquid ejecting apparatus that ejects a solution of a conductive material is used as a manufacturing apparatus that forms wiring and electrodes of a wiring board.

DESCRIPTION OF SYMBOLS 10 ... Liquid ejecting apparatus, 22 ... Medium, 22a ... Highly absorbable medium, 22b ... Low absorbable medium, 24 ... Liquid container, 30 ... Control part, 301 ... ROM, 302 ... RAM, 303 ... Discrimination part, 32 ... transport mechanism, 322 ... supply roller, 324 ... discharge roller, 34 ... moving mechanism, 342 ... carriage, 344 ... transport belt, 36 ... liquid ejection head, 360 ... ejection surface, 37 ... medium sensor, 40 ... pretreatment liquid, 40a ... first pretreatment liquid, 40a '... pretreatment liquid with low permeability, 40b ... second pretreatment liquid, 40b' ... pretreatment liquid with high permeability, 41 ... ink, 71 ... channel substrate, 712 ... Opening, 714 ... Branching channel, 716 ... Communication channel, 72 ... Pressure chamber substrate, 722 ... Opening, 722 ... Each opening, 73 ... Diaphragm, 74 ... Piezoelectric element, 75 ... Support, 754 ... Introduction Channel, 76 ... Nozzle plate A ... first region, A1 ... region upstream of the first region, A2 ... region downstream of the first region, B ... second region, B1 ... region upstream of the second region, B2 ... second region L0: Nozzle row, LP, LP1, LP2, LP3, LP4, LP1 ', LP2' ... Pretreatment liquid nozzle row, LI1, LI2, LI3, LI4 ... Ink nozzle row, N [A] ... First region nozzle, N [B] ... second region nozzle, SC ... pressure chamber, SR ... common liquid chamber.

Claims (10)

A transport mechanism for transporting the medium in the first direction;
A pretreatment liquid coating mechanism for coating the medium with a pretreatment liquid;
A liquid ejecting section including a plurality of ink nozzles for ejecting ink;
A controller for controlling the pretreatment liquid coating mechanism and the liquid ejecting unit;
The pretreatment liquid coating mechanism includes a first mechanism disposed in a first region, and a second mechanism disposed in a second region located upstream of the first region in the first direction,
The plurality of ink nozzles include a portion that overlaps the first mechanism in a second direction that intersects the first direction, and a portion that does not overlap the second mechanism in the second direction. A discriminator for discriminating the type of the medium;
The control unit selects either the first mechanism or the second mechanism according to the type of the medium determined by the determination unit, and coats the medium with the pretreatment liquid by the selected mechanism. The liquid ejecting apparatus according to claim 1. The first region is further divided into an upstream region and a downstream region in the first direction,
The plurality of ink nozzles are respectively disposed in an upstream region and a downstream region of the first region,
The first mechanism is disposed in each of an upstream region and a downstream region of the first region,
The control unit selects either the ink nozzle in the upstream region of the first region or the ink nozzle in the downstream region of the first region according to the type of the medium determined by the determination unit. The liquid ejecting apparatus according to claim 2, wherein the liquid ejecting apparatus selects and ejects the ink from the selected nozzle. The second region is further divided into an upstream region and a downstream region in the first direction,
The second mechanism is disposed in each of an upstream region and a downstream region of the second region,
In the case of selecting the second mechanism, the control unit further selects and selects one or both of the second mechanism in the upstream area of the second area and the second mechanism in the downstream area. The liquid ejecting apparatus according to claim 2, wherein the pretreatment liquid is ejected from the mechanism. The pretreatment liquid is a first pretreatment liquid and a second pretreatment liquid of a different type from the first pretreatment liquid,
The first mechanism includes a nozzle that ejects the first pretreatment liquid,
The liquid ejecting apparatus according to claim 1, wherein the second mechanism includes a nozzle that ejects the second pretreatment liquid. A liquid ejecting head comprising the pretreatment liquid coating mechanism and the liquid ejecting section;
A moving mechanism for reciprocating the liquid jet head in the second direction,
The liquid ejecting head includes a plurality of nozzle rows arranged in the second direction at intervals from each other,
Each of the plurality of nozzle rows has a plurality of nozzles arranged from the first region to the second region,
In one nozzle row of the plurality of nozzle rows, a plurality of nozzles arranged in the first region are used as the first mechanism, and a plurality of nozzles arranged in the second region are used as the second mechanism. Used as
5. The liquid ejecting apparatus according to claim 1, wherein a plurality of nozzles arranged in the first region are used as the plurality of ink nozzles in another nozzle row of the plurality of nozzle rows. A liquid ejecting head comprising the pretreatment liquid coating mechanism and the liquid ejecting section;
A moving mechanism for reciprocating the liquid jet head in the second direction,
The pretreatment liquid is a first pretreatment liquid and a second pretreatment liquid that is more permeable than the first pretreatment liquid,
The first mechanism includes two nozzle rows arranged in the second direction with a space between each other, and one of the nozzle rows is composed of nozzles that eject the first pretreatment liquid, The other nozzle row is composed of nozzles that eject the second pretreatment liquid, and the nozzles that eject the first pretreatment liquid and the nozzles that eject the second pretreatment liquid are in the second direction. Overlap in plan view,
The second mechanism includes two nozzle rows arranged in the second direction with a space between each other, and one of the nozzle rows is composed of nozzles that eject the first pretreatment liquid, The other nozzle row is composed of nozzles that eject the second pretreatment liquid, and the nozzles that eject the first pretreatment liquid and the nozzles that eject the second pretreatment liquid are in the second direction. The liquid ejecting apparatus according to claim 1, which overlaps in plan view. The two nozzle rows of the first mechanism include a nozzle row of nozzles that eject the second pretreatment liquid and a nozzle row of nozzles that eject the first pretreatment liquid along the moving direction of the liquid jet head. Arranged in order,
The two nozzle rows of the second mechanism include a nozzle row of nozzles that eject the first pretreatment liquid and a nozzle row of nozzles that eject the second pretreatment liquid along the moving direction of the liquid jet head. The liquid ejecting apparatus according to claim 7, which is arranged in order. A transport mechanism for transporting the medium in a first direction;
A liquid ejecting head including the pretreatment liquid coating mechanism and the liquid ejecting unit;
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting head is a line head that is long in a second direction intersecting the first direction. A liquid ejecting method for a liquid ejecting apparatus in which a medium is coated with a pretreatment liquid and then ink is landed on the medium,
The liquid ejecting apparatus includes: a transport mechanism that transports the medium in a first direction; and a pretreatment liquid coating mechanism that coats the medium with the pretreatment liquid. A first mechanism disposed in the region, and a second mechanism disposed in a second region located upstream of the first region in the first direction, wherein the plurality of ink nozzles are the first It is configured to have a portion that overlaps in the second direction intersecting the first direction with respect to the mechanism and a portion that does not overlap in the second direction with respect to the second mechanism,
The type of the medium is determined, and either the first mechanism or the second mechanism is selected according to the determined type of the medium, and the medium is covered with the pretreatment liquid by the selected mechanism. Liquid injection method.

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