Image formation apparatus, method for examining discharge of transparent droplets, and program for examining discharge of transparent droplets

An image formation apparatus includes a first discharge unit to form an image on a recording medium; and a second discharge unit including a nozzle line that discharges transparent droplets on the image formed on the recording medium. The second discharge unit moves in a first direction relative to the recording medium and the nozzle line has nozzles in a second direction orthogonal to the first direction. After the image formation, the second discharge unit discharges the transparent droplets from the nozzles spaced at m−1 nozzle intervals to form a row of dots in the second direction, and repeats the forming while moving to form m rows in the first direction, such that the dots in the rows are formed at m−1 nozzle intervals and positions of the dots between n-th and n−1-th rows are displaced together by one nozzle in the second direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on and claims the benefit of priorities of Japanese Priority Application No. 2014-185659 filed on Sep. 11, 2014 and Japanese Priority Application No. 2015-139226 filed on Jul. 10, 2015, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image formation apparatus, a method for examining a discharge of transparent droplets, and a program for examining the discharge of transparent droplets.

2. Description of the Related Art

It is difficult to visually observe patterns formed with transparent droplets unlike patterns formed with color ink droplets.

Some documents describe a technique of performing registration adjustment through detection of recording positions of transparent droplets by a detection unit based on the fact that if transparent droplets are placed on color ink when printing is performed, color is different from a case where printing is performed with only the color ink (see Patent Documents 1 and 2, for example).

However, it is difficult to visually detect nozzle clogging or a curved discharge from multiple patterns formed with transparent droplets discharged from multiple nozzles.[Patent Document 1] Japanese Laid-Open Patent Application No. 2012-035446[Patent Document 2] Japanese Laid-Open Patent Application No. 2000-141624

SUMMARY OF THE INVENTION

It is a general object of at least one embodiment of the present invention to provide an image formation apparatus capable of improving visibility of patterns formed with transparent droplets discharged from multiple nozzles.

In an embodiment, an image formation apparatus is provided. The image formation apparatus includes a first discharge unit including a first nozzle line having a plurality of nozzles, the first nozzle line discharging color droplets to form a predetermined image on a recording medium, the first discharge unit moving relative to the recording medium; and a second discharge unit including a second nozzle line that discharges transparent droplets on the recording medium on which the predetermined image is formed, the second discharge unit moving in a first direction relative to the recording medium, and the second nozzle line having a plurality of nozzles arranged in a second direction orthogonal to the first direction. When a discharge operation of the second discharge unit is examined, after the predetermined image is formed with the color droplets discharged by the first discharge unit, the second discharge unit discharges the transparent droplets from two or more of the nozzles thereof spaced at m−1 nozzle intervals in the second direction to form a row of dots extending in the second direction, and repeats forming the rows while successively moving in the first direction relative to the recording medium so as to form m rows arranged side by side in the first direction, positions of the discharging nozzles being successively shifted together by one nozzle in the second direction upon a successive movement of the second discharge unit relative to the recording medium in the first direction, such that the dots in each of the rows are formed at m−1 nozzle intervals, and positions of the dots in an n-th one of the rows are displaced together by one nozzle in the second direction relative to positions of the dots in an n−1-th one of the rows.

According to an embodiment, it is possible to improve visibility of patterns formed with transparent droplets discharged from multiple nozzles.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(Configuration of Image Formation Apparatus)

An image formation apparatus100according to an embodiment of the present invention will be described with reference toFIGS. 1-5B. In the present embodiment, the image formation apparatus100has a discharge head (recording head, ink head) of four colors: black (K), cyan (C), magenta (M), and yellow (Y). However, image formation apparatuses to which the present invention can be applied are not limited to those image formation apparatuses having such a discharge head. In other words, image formation apparatuses to which the present invention can be applied include those image formation apparatuses further having a discharge head for green (G), red (R), light cyan (LC), and/or another color or having only a discharge head for black (K). In the following description, a reference numeral provided with K, C, M, or Y as a suffix is assumed to correspond to black, cyan, magenta, or yellow, respectively.

Further, although rolled continuous paper is used as a recording medium (hereafter “roll paper Md”) in the present embodiment, recording mediums on which the image formation apparatus100according to the present invention can form an image are not limited to the roll paper Md. In other words, recording media on which the image formation apparatus100according to the present invention can form an image may include cut paper. Further, recording media on which the image formation apparatus100according to the present invention can form an image may include regular paper, high-quality paper, thin paper, cardboard, recording paper, roll paper, OHP sheet, synthetic resin film, metallic thin film, and other materials on which an image can be formed using ink or the like. The roll paper Md here includes continuous paper (continuous sheets, continuous form paper) in which perforations that allow cutting are formed at predetermined intervals. Further, a page in the roll paper Md is assumed to be a region between the perforations formed at predetermined intervals, for example.

As shown inFIG. 1, the image formation apparatus100according to the embodiment of the present invention includes a carrying-in unit10that carries in the roll paper Md (recording medium), a pretreatment unit20that pretreats the roll paper Md that has been carried in, and a drying unit30that dries the roll paper Md that has been pretreated. Further, the image formation apparatus100includes an image formation unit40that forms an image on a surface of the roll paper Md, a post-treatment unit50that performs post-treatment on the roll paper Md on which the image is formed, and a carrying-out unit60that carries out the roll paper Md that has been subjected to the post-treatment. The image formation unit40, the post-treatment unit50, and maintenance and recovery units90A and90B are disposed on a case74of a printer engine72E. The case74serving as an inkjet printer body includes a carrying unit80having a carrying belt81or the like. The image formation unit40, the post-treatment unit50, the maintenance and recovery units90A and90B, cases73and74, and a post-treatment drying unit32correspond to the printer engine72E to be described later. Further, the image formation apparatus100includes a control unit70(seeFIG. 11) that controls operations of the image formation apparatus100.

In the image formation apparatus100according to the present embodiment, the carrying-in unit10carries in roll paper Md, the pretreatment unit20pretreats a surface of the roll paper Md, and the drying unit30dries the surface of the roll paper Md. Further, in the image formation apparatus100, the image formation unit40forms an image on the surface of the roll paper Md that has been pretreated and dried. Further, in the image formation apparatus100, the post-treatment unit50performs post-treatment on the roll paper Md on which the image is formed. Then, in the image formation apparatus100, the carrying-out unit60rolls up (ejects, carries out) the roll paper Md.

In the following, each configuration of the image formation apparatus100according to the embodiment of present invention will be specifically described. The image formation apparatus100to which the present invention is applied may be configured without including one or more of the pretreatment unit20and the like described below depending on a type of the recording medium on which the image is formed.

The carrying-in unit10carries the recording medium to the pretreatment unit20, for example. In the present embodiment, the carrying-in unit10is configured with a paper feeding unit11and a plurality of carrying rollers12. The carrying-in unit10uses the carrying rollers12to carry in (move) the roll paper Md rolled up and held on a paper feeding roller of the paper feeding unit11and carries the roll paper Md to the pretreatment unit20using a platen, for example.

The pretreatment unit20pretreats the recording medium before an image is formed. In the present embodiment, the pretreatment unit20pretreats a surface of the roll paper Md with a pretreatment liquid, the roll paper Md been carried in by the carrying-in unit10.

The pretreatment here refers to treatment to evenly coat the surface of the roll paper Md (recording medium) with the pretreatment liquid that has a function of coagulating ink. In accordance with this, when the image formation apparatus100forms an image on paper exclusively used for inkjet printing or on a recording medium other than such an exclusive paper, the image formation apparatus100can coat the surface of the recording medium with the pretreatment liquid that has the function of coagulating ink by using the pretreatment unit20before the image is formed on the recording medium.

Accordingly, the image formation apparatus100is capable of reducing generation of a quality problem in an image to be formed involving blur, density, color tone, and set-off and reducing generation of a problem related to water resistance, weatherability, and image fastness. Accordingly, it is possible to improve quality of an image to be formed thereafter.

An example of the pretreatment unit20that uses a roll coating method is described with reference toFIG. 2. As shown inFIG. 2, the pretreatment unit20in the present embodiment coats the surface of the roll paper Md with a stored pretreatment liquid20L, the roll paper Md being carried in (carried to) the pretreatment unit20by the carrying-in unit10(FIG. 1).

Specifically, the pretreatment unit20first transfers (moves) the pretreatment liquid20L to a surface of a coating roller23in a film state by using a stirring (providing) roller21and a thinning (transport) roller22. Next, the pretreatment unit20presses the coating roller23on a rotating platen roller24in order to rotate the coating roller23. In this case, the pretreatment unit20can coat the surface of the roll paper Md with the pretreatment liquid20L by carrying the roll paper Md between the coating roller23and the platen roller24.

Further, the pretreatment unit20uses a pressure regulating device25to control a nip pressure (applied to a position where the coating roller23and the platen roller24are brought into contact) when the pretreatment liquid20L is being applied. In addition or alternatively, the pretreatment unit20controls a rotational speed of the coating roller23and the platen roller24. In accordance with this, the pretreatment unit20changes the rotational speed of the coating roller23and the like. In accordance with these features, the pretreatment unit20can control (change) a coating amount (such as film thickness, liquid amount, adhesion amount, or dry adhesion amount) of the pretreatment liquid20L by changing the nip pressure using the pressure regulating device25. Accordingly, the pretreatment unit20can coat the surface of the roll paper Md (recording medium) with the pretreatment liquid20L while adjusting the coating amount to be suitable for image formation and post-treatment thereafter.

The drying unit30dries the recording medium by heating, for example. The drying unit30of the present embodiment includes a pretreatment drying unit31that dries the roll paper Md pretreated by the pretreatment unit20and a post-treatment drying unit32that dries the roll paper Md subjected to post-treatment by the post-treatment unit50.

The pretreatment drying unit31using heating rollers is described below. Heating rollers311-316are preferably disposed in multiple stages as shown inFIG. 3in order to improve drying effects. In accordance with this, the pretreatment drying unit31uses the heating rollers311-316to heat the surface of the roll paper Md coated with the pretreatment liquid and vaporize moisture of the pretreatment liquid, thereby drying (the pretreatment liquid of) the roll paper Md. In this configuration, if drying intensity is to be lowered, a temperature of the heating rollers is lowered to be 40-80° C., for example. Further, only the heating rollers311and312are heated while the other heating rollers313-316are not heated. By contrast, it is possible to raise the drying intensity by increasing a number of heating rollers to be used or raising the temperature of the heating rollers.

While the drying intensity is controlled here in accordance with the temperature of the heating rollers and the number of the heating rollers to be used, the drying intensity can also be controlled by either of them. As mentioned above, it is possible to control the drying intensity using the temperature of the heating rollers and/or the number of the heating rollers to be used.

In addition, in the pretreatment drying unit31, elements used for drying are not limited to heating rollers. In other words, the pretreatment drying unit31may employ infrared drying, microwave drying, hot-air drying, or other drying methods. Further, the pretreatment drying unit31may use a drying method in which a plurality of drying methods are combined. Further, the pretreatment drying unit31may heat the roll paper Md (recording medium) before the pretreatment unit20coats the roll paper Md with the pretreatment liquid (preheating step).

A configuration of the post-treatment drying unit32is the same as the configuration of the pretreatment drying unit31, so that a description thereof is omitted.

(Configuration of Image Formation Unit)

The image formation unit40forms an image on a recording medium. The image formation unit40in the present embodiment forms an image on a surface of the roll paper Md by discharging droplets (hereafter “ink”) onto the roll paper Md dried by the drying unit30.

An example of an outer shape of the image formation unit40is described with reference toFIGS. 4A and 4B.FIG. 4Ais a schematic plan view showing an entire configuration of the image formation unit40of the image formation apparatus100according to the embodiment of the present invention.FIG. 4Bis a schematic plan view showing a main body (discharge head40K for black (K)) of the image formation unit40.

As shown inFIG. 4A, in the present embodiment, the image formation unit40may use a full-line type head. In other words, in the image formation unit40, four discharge heads40K,40C,40M, and40Y for black (K), cyan (C), magenta (M), and yellow (Y) are disposed upstream in a carrying direction Xm of the recording medium.

In the present embodiment, the discharge head40K for black (K) includes four head units40K-1,40K-2,40K-3, and40K-4disposed in a staggered manner in a direction orthogonal to the carrying direction Xm of the roll paper Md. In accordance with this, the image formation unit40can form an image on an entire area in a width direction (orthogonal to the carrying direction Xm) of an image formation region (printing region) on the roll paper Md (recording medium). Since the recording medium is carried in the carrying direction Xm by the carrying belt81, the discharge head40K is moved relative to the recording medium (in a direction opposite to the carrying direction Xm of the recording medium). In addition, a configuration of the other discharge heads40C,40M, and40Y is the same as the configuration of the discharge head40K for black (K), so that a description thereof is omitted.

FIG. 4Bis an enlarged view of the head unit40K-1of the discharge head40K for black (K) of the image formation unit40. As shown inFIG. 4B, the head unit40K-1in the present embodiment includes a plurality of discharge ports (nozzles, printing nozzles)40N on a nozzle surface (outer surface of a nozzle plate43shown inFIG. 5Adescribed below). The plurality of discharge ports40N are arranged in line in a longitudinal direction of the head unit40K-1and constitute a nozzle line. The head unit40K-1may include a plurality of nozzle lines. While the discharge heads shown inFIG. 4Ahave two nozzle lines and two adjacent head units discharge droplets for one line, the head may have another shape. For example, a plurality of head units may be connected and arranged in line to constitute the head. Further, one head unit that has one nozzle line extending in the width direction of the recording medium for one line may constitute one head.

These discharge heads40K,40C,40M, and40Y installed on a carriage46(seeFIG. 7) serve as a first discharge unit that discharges ink (color droplets).

A cross-sectional shape of the discharge head of the image formation unit40is described with reference toFIGS. 5A and 5B.FIG. 5Ais a schematic cross-sectional view illustrating a flow channel (cross section in a longitudinal direction of a liquid chamber40F) of the image formation unit40.FIG. 5Bis a cross-sectional view illustrating arrangement of the discharge ports40N of the image formation unit40(cross section (taken along line SC1-SC1inFIG. 5A) in a lateral direction of the liquid chambers40F (direction where the discharge ports are arranged)).

As shown inFIG. 5A, the discharge head (40K, for example) of the image formation unit40according to the embodiment of the present invention includes a flow channel plate41that forms a passage of ink to be discharged, a vibration plate42joined to an undersurface (inner direction of the discharge head) of the flow channel plate41, the nozzle plate43joined to an upper surface (outer direction of the discharge head) of the flow channel plate41, and a frame member44that holds a peripheral part of the vibration plate42. Further, the discharge head also includes a pressure generation unit (actuator unit)45that deforms the vibration plate42.

Since the flow channel plate41, the vibration plate42, and the nozzle plate43are piled up, the discharge head (40K, for example) according to the present embodiment can form the liquid chamber40F and a nozzle communication channel40R that is in communication with the discharge port (nozzle)40N. Further, since the frame member44is further piled up, the discharge head can form an ink inflow port40S to supply the liquid chamber40F with ink and a common liquid chamber40D to supply the liquid chamber40F with ink.

Further, the discharge head can deform (deflective deformation) the vibration plate42by using the pressure generation unit45. In accordance with this, the discharge head can change capacity (volume) of the liquid chamber40F and change pressure applied to ink within the liquid chamber40F. As a result of this, the discharge head can discharge the ink from the discharge ports40N.

In the present embodiment, in the frame member44, a housing portion where the pressure generation unit45is housed, a concave part that serves as the common liquid chamber40D, and an ink supply port401N to supply the common liquid chamber40D with ink from the outside of the discharge head are formed.

The pressure generation unit45may employ an electromechanical conversion element. The pressure generation unit45in the present embodiment includes a piezoelectric element45P that serves as the electromechanical conversion element, a base substrate45B that joins and fixes the piezoelectric element45P, and a support disposed in a space between adjacent piezoelectric elements45P. Further, the pressure generation unit45includes an FPC cable45C, for example, to connect the piezoelectric element45P to a driving circuit (driving IC) (not shown).

The piezoelectric element45P may employ a laminated piezoelectric element (PZT) as shown inFIG. 5Bin which a piezoelectric material45Pp and an internal electrode45Pe are alternately laminated. The internal electrode45Pe includes a plurality of individual electrodes45Pei and a plurality of common electrodes45Pec. In the present embodiment, the individual electrode45Pei and the common electrode45Pec are alternatively connected to an end surface of the piezoelectric material45Pp. Further, the piezoelectric element45P uses d33 direction as a piezoelectric direction of the piezoelectric element45P. In accordance with this, the pressure generation unit45can pressurize or depressurize ink within the liquid chamber40F by using piezoelectric effects (displacement in the d33 direction) of the piezoelectric element45P. The pressure generation unit45may pressurize or depressurize the ink within the liquid chamber40F by using displacement in d31 direction of the piezoelectric element45P. Further, in the pressure generation unit45, a line of piezoelectric elements may be disposed for one discharge port40N. In addition, the support may be formed together with the piezoelectric element45P when a piezoelectric element member (piezoelectric element45P) is divided. In other words, the discharge head can use the piezoelectric element member as the support by not applying voltage to the piezoelectric element45P.

The pressure generation unit45used in the present embodiment is not limited to the above-mentioned example (piezoelectric element45P). In other words, the pressure generation unit45may employ a method (what is called a thermal type) for generating bubbles by heating the ink within the liquid chamber40F using a heating element (see Japanese Laid-Open Patent Application No. 61-59911, for example). Further, the pressure generation unit45may employ a method (what is called an electrostatic type) by which a vibration plate and an electrode are disposed on wall surfaces of the liquid chamber40F to face each other, and the vibration plate is deformed by electrostatic force generated between the vibration plate and the electrode (see Japanese Laid-Open Patent Application No. 6-71882, for example).

The post-treatment unit50performs post-treatment on the recording medium on which an image has been formed. The post-treatment unit50uses a post-treatment liquid to perform the post-treatment on a surface of the roll paper Md on which the image has been formed by the image formation unit40.

The post-treatment refers to treatment to discharge (deposit) a post-treatment liquid50L (described later) onto the roll paper Md (recording medium). The post-treatment liquid50L is applied in spots or in stripes, for example. In accordance with this, it is possible to improve abrasion resistance, glossiness, and preservation stability (such as water resistance, light resistance, and gas resistance) of the recording medium on which the image is formed. As shown inFIGS. 6A and 6B, for example, when the post-treatment by the post-treatment unit50starts, the surface of the roll paper Md has already been coated with the pretreatment liquid20L and ink40Ink that forms the image has been further discharged thereon. The post-treatment unit50of the image formation apparatus100according to the embodiment of the present invention performs the post-treatment to discharge (deposit) the post-treatment liquid50L onto the roll paper Md on which the image has been formed.

FIG. 6Bis a schematic diagram illustrating a predetermined cross section of the recording medium. The post-treatment liquid50L is discharged (deposited) in an area smaller than at least an area of the pretreatment liquid20L. Further, in this cross section, the ink40Ink is discharged onto an entire area and the post-treatment liquid50L is discharged (deposited) in the area smaller than an area of the ink40Ink.

While the post-treatment liquid50L seems to be formed in spots inFIG. 6B, the post-treatment liquid50L may be formed in stripes in a direction orthogonal to the cross section.

The post-treatment liquid50L may be discharged (deposited) in a portion where the image is formed on the recording medium, in an area smaller than a surface area where the image is formed. The post-treatment liquid50L may or may not be discharged in a portion where the image is not formed.

As a post-treatment method, the post-treatment liquid50L is preferably deposited (discharged) onto only a specified portion in a field of the roll paper Md where the image is formed. Further preferably, the post-treatment unit50changes a discharging amount (coating amount) and a discharging (coating) method of the post-treatment liquid50L based on a type, permeability, glossiness, and/or resolution of the recording medium, and/or a coating amount (liquid amount) of the pretreatment liquid20L coated by the pretreatment unit20.

Further, the post-treatment unit50according to the present embodiment can discharge the post-treatment liquid50L in any region (any location) with a desired discharging amount (in desired spots or desired stripes) using the same discharge head as in the image formation unit40shown inFIGS. 4A and 4B.

Specifically, the post-treatment unit50can select (1) discharging in an entire field of an area of the roll paper Md where an image can be formed; (2) discharging in a field where the image is formed; (3) discharging only in a field of an image formation portion (where dots are discharged); or (4) discharging in a field larger than the image formation portion of the roll paper Md (recording medium), the field being larger than an outer edge of the image formation portion by 1 or more dots, for example. Further, the post-treatment unit50can discharge the post-treatment liquid50L in an no field (in spots or in stripes) relative to a selected field where the post-treatment liquid50L is to be discharged. In this case, no may be set to 5-50%. Further, n % may be predetermined through experiments, numerical calculation, or the like.

Further, the post-treatment unit50according to the present embodiment can select, as a method for discharging the post-treatment liquid50L, (1) discharging based on a printing duty or (2) discharging based on a droplet amount of the post-treatment liquid50L to be discharged, for example. In this case, the post-treatment unit50may calculate the printing duty and the droplet amount of the post-treatment liquid50L from input information (print image data, for example) and determine the method for discharging based on a calculated printing duty or the like.

Thus, according to the image formation apparatus100in the embodiment of the present invention, it is possible to use the post-treatment unit50to deposit (discharge) the post-treatment liquid50L only in a specified portion in a field where an image is formed in comparison with a case where the post-treatment liquid50L is coated (discharged) onto an entire area of the recording medium. Thus, according to the image formation apparatus100in the present embodiment, it is possible to reduce time required for post-treatment or time required for drying the post-treatment liquid50L in particular. Further, it is possible to reduce a liquid amount of the post-treatment liquid50L required for post-treatment. Thus, it is possible to reduce cost required for the post-treatment.

In addition, the post-treatment method performed by the post-treatment unit50is not especially limited, so that another post-treatment method may be selected where necessary depending on a type of the post-treatment liquid50L. The post-treatment method performed by the post-treatment unit50preferably employs the same method as used for discharging ink of the image formation unit40in terms of size reduction of an apparatus and preservation stability of the post-treatment liquid50L. Accordingly, a configuration of the post-treatment unit50is determined in the same manner with reference toFIG. 4A. A post-treatment liquid discharge unit includes a plurality of discharge ports (nozzles, printing nozzles)50N on a nozzle surface (outer surface of a nozzle plate53shown inFIG. 5A). A head50that serves as the post-treatment liquid discharge unit including the nozzle plate53is installed on a carriage56(seeFIG. 7) and the head50serves as a second discharge unit that discharges the post-treatment liquid50L (transparent droplets).

When the post-treatment liquid50L is to be discharged, a suitable amount of a water-soluble organic solvent (wetting agent) used in a method for discharging ink of the image formation unit40is preferably contained. Further, in the post-treatment unit50according to the present embodiment, a dry adhesion amount of the post-treatment liquid50L is preferably 0.5 g/m2to 10 g/m2.

The post-treatment unit50according to the present embodiment may use, as the post-treatment liquid50L, a treatment liquid that contains a component that can form a transparent protective layer on the roll paper Md (recording medium). Examples of such a treatment liquid that contains a component that can form a transparent protective layer include a treatment liquid that contains water-dispersible resin (resin), water-soluble organic solvent (wetting agent), penetrant, surface-active agent, water, and/or other components where necessary. Further, the post-treatment liquid50L may be a resin composition that contains a component that polymerizes under ultraviolet irradiation and/or thermoplastic resin. Further, the post-treatment liquid50L preferably includes a thermoplastic resin emulsion in order to improve glossiness and a fixing property. In accordance with this, the post-treatment unit50can increase the glossiness of a surface of the roll paper Md on which an image is formed or protect the surface of the roll paper Md with a resin layer depending on a discharging (coating) method.

By using such a post-treatment apparatus, it is possible to prevent detachment (removal) of an image (ink) on the recording medium when the surface of the roll paper Md on which the image is formed rubs against another object (another recording medium, for example). In other words, it is possible to improve abrasion resistance (friction resistance). Further, it is possible to reduce generation of a quality problem in an image to be formed involving blur, density, color tone, glossiness, and set-off and to reduce generation of a problem related to water resistance, weatherability, and image fastness.

(Maintenance and Recovery Unit)

The maintenance and recovery units90A and90B maintain and recover (restore performance of) the image formation unit40and the post-treatment unit50. When the image formation unit40and the post-treatment unit50that employ the above-mentioned head (seeFIG. 4A) are used for a long period of time, the head may be clogged with the ink or the post-treatment liquid. Accordingly, it is desirable to perform a maintenance and recovery operation (cleaning and maintenance) when not performing printing such as before printing.FIGS. 7-9show the maintenance and recovery units90A and90B in which a line type head is used for the image formation unit40and the post-treatment unit50.

FIG. 7is a schematic diagram illustrating a discharge head, a post-treatment liquid output unit, and a maintenance and recovery unit in the embodiment of the present invention. InFIG. 7, the image formation unit (ink head)40and the post-treatment unit (post-treatment liquid output unit, head)50are disposed so as to face the carrying belt81serving as a carrying unit. The carrying belt81carries the recording medium in the carrying direction Xm shown by an arrow. The maintenance and recovery unit90A (maintenance unit) is disposed upstream (right side inFIG. 7) relative to the image formation unit40and the maintenance and recovery unit90B (maintenance unit) is disposed downstream (left side inFIG. 7) relative to the post-treatment unit50in the carrying direction Xm of the recording medium. The maintenance and recovery units90A and90B maintain and recover the image formation unit40and the post-treatment unit50each including a line type head.

The heads of the image formation unit40and the post-treatment unit50are configured to be vertically movable. The discharge heads40K,40C,40M and40Y (first discharge unit) for four colors serving as the image formation unit are disposed on the carriage46and the head50(second discharge unit) that discharges the post-treatment liquid50L is disposed on the carriage56.

The carriages46and56can move between a position close to the carrying unit80shown inFIG. 7, namely, a recording position which is a printing position to discharge a liquid (ink, post-treatment liquid) and a spaced position which is a position spaced apart from the carrying unit80as shown inFIG. 8. This spaced position functions as a maintenance position to maintain the image formation unit40and the post-treatment unit50by the maintenance and recovery units90A and90B. The spaced position also functions as a standby position to wait for a next operation and as a recovery position to perform maintenance.

In order to perform this vertical movement, the carriages46and56are respectively supported by carriage position movement units47and57. When the carriage position movement units47and57are operated, positions of the carriages46and56are vertically moved relative to the case74of the printer engine72E having the carrying belt81. In addition, while the carriage position movement units47and57are indicated by arrows inFIG. 7, a movement mechanism including a rail and a roller used in combination may be employed for the carriage position movement units47and57or an arm or the like may be used to lift the carriage position movement units47and57.

In the carrying unit80, the carrying belt81is stretched and installed for rotational movement between a driving roller83rotated by a motor and a driven roller82. The recording medium is carried in accordance with the rotational movement of the carrying belt81supported by a supporting member84. The supporting member84may include a suction unit or an electrostatic attraction unit in order to attract paper while carrying the paper.

Further, the maintenance and recovery unit90A includes an engagement unit91A and a cleaning unit95A. The maintenance and recovery unit90B includes an engagement unit91B and a cleaning unit95B.

When maintenance is performed, the engagement unit91A is reciprocated to an opposite field that faces the discharge heads40K,40C,40M and40Y serving as the image formation unit40in the spaced position (dotted line inFIG. 7) and the engagement unit91A is selectively engaged with the discharge heads40K,40C,40M and40Y. When maintenance is performed, the engagement unit91B is reciprocated to an opposite field that faces the head50serving as the post-treatment unit50in the spaced position (dotted line inFIG. 7) and the engagement unit91B is engaged with the head50.

Since the maintenance and recovery units90A and90B have the same configuration except a number of cap units and liquid to be received (ink, post-treatment liquid), the same configuration is described with reference to the maintenance and recovery unit90B of the post-treatment unit50to be controlled in the present embodiment and a description of the same configuration of the maintenance and recovery unit90A is omitted. Further, for elements used in common in the maintenance and recovery units90A and90B, reference numerals added to ends thereof are omitted.

The engagement unit91includes a cap unit92, a wiper93, and a fixing member94that fixes the cap unit92and the wiper93. The cap unit92engages the head50in the spaced position in order to seal and cap the nozzles50N of the head50. When the maintenance is performed, the head50performs what is called an idle discharge to discharge the post-treatment liquid50L while the cap unit92is engaged. The cap unit92functions as an idle discharge receiver that receives the post-treatment liquid50L discharged from the head50by the idle discharge. The wiper93performs cleaning (wiping) on the head50by wiping off the post-treatment liquid50L flowing from the head50in the spaced position.

A cleaning unit95performs cleaning on the cap unit92, the wiper93, and the like while the engagement unit91is in a home position thereof after the engagement unit91is reciprocated when the maintenance is performed. In addition, the cleaning of the engagement unit91by the cleaning unit95may be regularly performed after a predetermined number of images are formed, for example.

The maintenance and recovery unit90also includes a pump96serving as a suction unit that suctions the post-treatment liquid50L inside the head50and drains the post-treatment liquid50L to the outside of the head50while the cap unit92is engaged with the head50in the spaced position. The maintenance and recovery unit90further includes a drain passage that connects the cap unit92to the pump96and drains the post-treatment liquid50L to the outside of the head50and a fluid collection unit connected to the drain passage, the fluid collection unit collecting liquids (ink, post-treatment liquid) draining to the outside of the head50.

FIG. 9is a plan view ofFIG. 7. As shown inFIG. 9, the maintenance and recovery unit90A includes cap units92K,92C,92M, and92Y for each head segment serving as the image formation unit40in a direction orthogonal to the carrying direction Xm of the recording medium, and the maintenance and recovery unit90B includes a cap unit92B.

Further, the maintenance and recovery unit90includes a movement unit that moves the engagement unit91. As the movement unit of the engagement unit91, the maintenance and recovery unit90includes a reciprocation unit (97,98,99) that reciprocates the engagement unit91to the heads40,50and a vertical movement unit (75) that supports the reciprocation unit and moves the cap unit92vertically, the vertical movement unit (75) being integrated with the engagement unit91.

The reciprocation unit includes the fixing member94integrated with the engagement unit91, an endless belt97whose portion fixes the fixing member94, and two pulleys98on which the endless belt97is wound. The reciprocation unit further includes a position sensor99(99K,99C,99M,99Y, and99B) that detects being positioned directly below the head40or50and being positioned in the home position (where reciprocation starts). The reciprocation unit further includes a support table that supports the engagement unit91from below reciprocatively as mentioned above and a motor or the like that rotates the pulley98as a driving unit.

Further, the vertical movement unit75includes base members75A and75B on which the support table including the endless belt97is placed, the base members75A and75B being arranged and fixed below from above the case74across a paper movement space. A bottom face of these base members75A and75B is screwed with a shaft serving as a driving shaft and connected to a plurality of gears fixed on the other end of the shaft, the plurality of gears being rotated together with the shaft. The plurality of gears are connected to a stepping motor that rotates the gears.

Accordingly, it is possible to reciprocate the engagement unit91by driving the motor to rotate the pulley98for rotation movement of the endless belt97as the reciprocation unit. In this case, by driving the motor such that any one of the position sensors99detects the fixing member94, it is possible to position the cap units92K,92C,92M, and92Y or the cap unit92B to face the discharge heads40K,40C,40M, and40Y or the head50in the spaced position or to position the cap units92K,92C,92M, and92Y or the cap unit92B in the home position with precision.

Further, while the cap units92K,92C,92M,92Y, and92B are positioned to face the discharge heads40K,40C,40M,40Y, and the head50by the position sensor99, by driving the stepping motor a predetermined amount, namely, a predetermined number of pulses, the base members75A and75B are moved upward. In accordance with this, it is possible to move the engagement units91A and91B upward by a predetermined amount and engage them with the discharge heads40K,40C,40M and40Y or the head50in the spaced position the cap units92K,92C,92M,92Y, and92B face. In addition, instead of using the stepping motor, a sensor that detects a position of the cap unit92in the vertical direction may be used in combination with a motor.

When such a configuration is used to perform a maintenance and recovery operation, as shown inFIG. 8, the image formation unit40and the post-treatment unit50are moved upward to be in the spaced position while the engagement units91A and91B of the maintenance and recovery units90A and90B are stopped directly below each head in the spaced position and are engaged.

In the embodiment of the present invention, before the maintenance and recovery operation is performed, test patterns to be described below are formed and a user, an administrator, or a service person confirms the test patterns printed on the recording medium by visual observation. Further, a maintenance and recovery operation described below is performed only if maintenance (cleaning, for example) is determined to be necessary by visual observation. Further, maintenance is performed only on a head segment that requires such maintenance depending on a result of the visual observation of the test patterns.

Specifically, depending on the result of the visual observation of the test patterns, the maintenance and recovery operation is performed only on the cap unit92K,92C,92M,92Y, or92B that requires maintenance. Further, in each cap unit such as the cap unit92B for post-treatment, the maintenance and recovery operation can be performed only on a portion for a specific nozzle (50N) within a corresponding head segment.

In the maintenance and recovery operation, the nozzles40N and50N of the heads in the image formation unit40and the post-treatment unit50are capped with the cap unit92for idle charge reception. Ink and post-treatment liquid within the heads are suctioned by the pump96from the discharge ports40N and the nozzles50N via the cap unit92.

When nozzle suction is complete as the maintenance and recovery operation, after the engagement units91A and91B are returned to the home position, the image formation unit40and the post-treatment unit50move downward to a printing position on the carrying unit80and assume a printable state.

In the embodiment described with reference toFIGS. 7-9, the discharge heads40K,40C,40M and40Y serving as the image formation unit and the head50serving as the post-treatment unit are installed on the carriages46and56that are independent of each other. In accordance with this, it is possible to maintain the image formation unit and the post-treatment unit at different times.

However, the image formation unit40and the post-treatment unit50may be integrally configured and installed on the same carriage. In such a configuration, the maintenance and recovery units90A and90B are also integrally configured, so that the movement mechanism is simplified and the cap units92K,92C,92M,92Y, and92B are also simplified. In this case, the integrally configured engagement unit91collectively caps the discharge heads40K,40C,40M and40Y and the head50and performs a maintenance and recovery operation. Accordingly, it is possible to collectively dispose the maintenance and recovery units upstream or downstream relative to the image formation unit40or the post-treatment unit50in the carrying direction Xm of the roll paper Md.

The carrying-out unit60carries out (ejects) a recording medium on which an image or the like is formed. As shown inFIG. 1, the carrying-out unit60in the present embodiment is configured with a storage unit61and a plurality of carrying rollers62. The carrying-out unit60uses the carrying rollers62to roll up and store the roll paper Md having the image thereon on a storage roller of the storage unit61.

If pressure applied to the roll paper Md is great when the roll paper Md is rolled on the storage roller of the storage unit61, a drying device that further dries the roll paper Md immediately before the roll paper Md is rolled up may be disposed in order to prevent transfer of another image to a rear surface of the roll paper Md.

(Configuration of Control Unit)

The control unit70controls operations of the image formation apparatus100. The control unit70in the present embodiment sends an instruction to each element of the image formation apparatus100to perform an operation and controls the operation. The control unit70according to the present embodiment is described with reference toFIGS. 10A-13.

In addition, the image formation apparatus100according to the embodiment of the present invention may employ production printing as a printing system. The production printing here refers to a production system capable of printing (image formation, character printing) on a huge amount of printed matter (image forming medium, character printed matter) in a short time by efficiently performing job management and print data management, for example. Specifically, the image formation apparatus100according to the present embodiment performs, with different devices (units), a Raster Image Processor (RIP) process to control an operation to print bitmap data or the like and a print process based on the bitmap data controlled by the RIP process.

Further, the image formation apparatus100(control unit70) according to the present embodiment has a workflow system that manages from creation of print data to distribution of printed matter. In other words, the image formation apparatus100(control unit70) according to the present embodiment is capable of accelerating printing by separating a device that performs the RIP process that requires processing time from a device that performs the print process.

As shown inFIG. 10A, the control unit70of the image formation apparatus100according to the embodiment of the present invention includes a higher-level device (DFE: Digital Front End)71that performs the RIP process and a printer device72that performs the print process. The higher-level device71and the printer device72here are connected to each other via a plurality of data lines70LD and a control line70LC.

In the following, the higher-level device71and the printer device72according to the present embodiment are described in detail.

The higher-level device71of the control unit70in the image formation apparatus100according to the embodiment of the present invention performs the RIP process based on print job data (job data, print data) output from a host device. In other words, the higher-level device71according to the present embodiment creates sets of bitmap data (hereafter “print image data”) one set being created for each color based on the print job data. The print image data in the present embodiment further includes data about discharge of a post-treatment liquid to be discharged by the post-treatment unit50(hereafter “image data about post-treatment”).

Further, the higher-level device71according to the present embodiment creates data to control a print operation (hereafter “control information data”) based on the print job data and information about the host device. The control information data here includes data about print conditions (print form, print type, paper feed or ejection information, order of printing surfaces, size of printing paper, data size of print image data, resolution, paper type information, tones, color information, and a number of pages to be printed). Further, the control information data in the present embodiment further includes data about discharge of a post-treatment liquid to be discharged by the post-treatment unit50(hereafter “control data about post-treatment”).

Further, when maintenance and recovery is performed, a user, an administrator, or a serviceman inputs information detected by visual observation to the higher-level device71.

As shown in10B, the higher-level device71in the present embodiment includes a Central Processing Unit (CPU)71a, a Read Only Memory (ROM)71b, Random Access Memory (RAM)71c, and a Hard Disk Drive (HDD)71d. Further, the higher-level device71includes an external I/F71e, a control information I/F71f, and an image data I/F71g. Further, the higher-level device71includes a bus71hthat connects the CPU71aand the like. In other words, in the higher-level device71, the CPU71aand the like are connected to one another to be able to perform transmission and reception mutually via the bus71h.

The CPU71acontrols an entire operation of the higher-level device71. The CPU71auses a control program stored in the ROM71band/or the HDD71dto control the operation of the higher-level device71.

The ROM71b, the RAM71c, and the HDD71dstore data and the like, the ROM71band/or the HDD71dstore the control program to control the CPU71ain advance, and the RAM71cis used as a work memory for the CPU71a.

The external I/F71econtrols communication (transmission and reception) with an external device (such as the host device) placed outside the image formation apparatus100. The control information I/F71fcontrols communication of control information data. The image data I/F71gcontrols communication of print image data. The image data I/F71gin the present embodiment has a plurality of channels (described below) for each color of the print image data.

The higher-level device71of the control unit70according to the present embodiment receives print job data at the external I/F71e, the print job data being transmitted from the host device, and uses the CPU71ato store the print job data in the HDD71d. The higher-level device71further uses the CPU71ato read out the print job data from the HDD71d. Further, the higher-level device71uses the CPU71ato create bitmap data about each color (yellow (Y), cyan (C), magenta (M), and black (K)) based on the print job data that is read out, and stores created bitmap data about each color in the RAM71c. In this case, the higher-level device71(CPU71a) can create bitmap data about each color by rendering with Page Description Language (PDL), for example, as an RIP process and write the bitmap data onto the RAM71c.

Next, the higher-level device71compresses and encodes the bitmap data about each color written onto the RAM71cand temporarily stores encoded bitmap data in the HDD71d.

Then, when a print operation starts at the printer device72, the higher-level device71(CPU71a) reads out the encoded bitmap data about each color from the HDD71d, decodes the encoded bitmap data, and writes each set of bitmap data about the corresponding color in the RAM71c. Then, the higher-level device71reads out the bitmap data about each color from the RAM71cand outputs the bitmap data as print image data about each color to the printer device72(printer engine72E described below) via each channel of the image data I/F71g. In this case, the higher-level device71can output the print image data to the printer device72via the data lines70LD (70LD-Y,70LD-C,70LD-M, and70LD-K) as the channels of the image data I/F71gshown inFIG. 11.

Further, in accordance with progress of the print operation, the higher-level device71according to the present embodiment uses the CPU71ato transmit or receive control information data to or from a printer controller72C of the printer device72via the control information I/F71f(control line70LC).

Further, when a post-treatment starts at the post-treatment unit50, the higher-level device71according to the present embodiment uses the CPU71ato read out encoded image data about the post-treatment from the HDD71dand outputs the image data to the printer engine72E via a data line70LD-P (FIG. 11) in the same manner as the above-mentioned bitmap data.

The printer device72of the control unit70in the image formation apparatus100according to the embodiment of the present invention controls an operation to form an image on a recording medium based on the print image data and the control information data input from the higher-level device71. The printer device72in the present embodiment includes the printer controller72C and the printer engine72E. As shown inFIGS. 1 and 11, the printer engine72E includes the case (for carrying)73, the case (inkjet printer body)74, the image formation unit (head)40, the post-treatment unit (head)50, the maintenance and recovery units90A and90B, and the post-treatment drying unit32.

The printer controller72C controls an operation of the printer engine72E described below. The printer controller72C transmits or receives the control information data to or from the higher-level device71via the control line70LC. Further, the printer controller72C transmits or receives the control information data to or from the printer engine72E via a control line72LC. In accordance with this, the printer controller72C can store print conditions by writing print information such as various types of print conditions included in the control information data and data about a test pattern for discharge in a register of a print control unit72Cc. Further, the printer controller72C can control the printer engine72E based on the control information data and perform printing in accordance with the print job data (control information data).

As shown inFIG. 11, the printer controller72C in the present embodiment includes a CPU72Cp and the print control unit72Cc. Further, in the printer controller72C, the CPU72Cp and the print control unit72Cc are connected to each other to be able to perform transmission and reception mutually via a bus72Cb. The bus72Cb here is connected to the control line70LC via a communication I/F.

The CPU72Cp uses the control program stored in a ROM to control an entire operation of the printer device72. The print control unit72Cc transmits or receives a command and status information to or from the printer engine72E based on the control information data transmitted from the higher-level device71. In accordance with this, the print control unit72Cc can control an operation of the printer engine72E.

The printer engine72E controls an operation to form an image on a recording medium based on the print image data input from the higher-level device71and the control information data input from the printer controller72C. Further, the printer engine72E controls an operation for post-treatment based on the print image data (image data about post-treatment) input from the higher-level device71and the control information data (control data about post-treatment) input from the printer controller72C.

As shown inFIG. 11, a plurality of data lines70LD (70LD-Y,70LD-C,70LD-M,70LD-K, and70LD-P) are connected to the printer engine72E. The printer engine72E receives the print image data from the higher-level device71via the plurality of data lines70LD. In accordance with this, the printer engine72E can perform a print operation of each color and a post-treatment using a post-treatment liquid based on the received print image data.

The printer engine72E in the present embodiment includes a plurality of data management units72EC,72EM,72EY,72EK, and72EP. Further, the printer engine72E includes an image output unit72Ei to which a print image, for example, is input from the data management unit72EC and a carrying control unit72Ecc that controls carrying of a recording medium. Further, the printer engine72E in the present embodiment includes a post-treatment liquid output unit72Epp to which image data about post-treatment is input from the data management unit72EP and a drying control unit after post-treatment72Epb that controls an operation of the drying unit30(FIG. 1). Further, the printer engine72E in the present embodiment further includes a maintenance and recovery control unit72Er that controls an operation of a maintenance and recovery mechanism (maintenance and recovery units90A and90B and carriage position movement units47and57shown inFIG. 7).

Further, in the present embodiment, test patterns used for a maintenance and recovery operation to be described below other than normal printing are included as image data. In addition, the printer engine72E may further include a pretreatment liquid coating control unit, a drying control unit after pretreatment, and a drying control unit before rolling up.

A configuration of the data management unit72EC is described with reference toFIG. 12. In addition, a configuration of other data management units72EM,72EY,72EK, and72EP is the same as the configuration of the data management unit72EC, so that a description thereof is omitted. The data management units72EC,72EM,72EY, and72EK used for image formation function as a first driving waveform creation unit. The data management unit72EP related to discharge of a post-treatment liquid functions as a second driving waveform creation unit.

As shown inFIG. 12, the data management unit72EC includes a logic circuit72EC1and a memory unit72ECm. The data management unit72EC (logic circuit72EC1) is connected to the higher-level device71via the data line70LD-C. The data management unit72EC (logic circuit72EC1) is also connected to the printer controller72C (print control unit72Cc) via the control line72LC.

In the present embodiment, the memory unit72ECm stores print image data output from the higher-level device71based on a control signal output from the printer controller72C (print control unit72Cc).

Further, the logic circuit72EC1reads out print image data (driving waveform) Ic (FIG. 12) corresponding to cyan (C) from the memory unit72ECm based on the control signal output from the printer controller72C (print control unit72Cc) and outputs the print image data Ic to the image output unit72Ei.

Specifically, the logic circuit72EC1of the data management unit72EC creates the driving waveform by creating driving waveform data based on image data received from the higher-level device71and the print control unit72Cc, performing digital-to-analog conversion on the created driving waveform data, and performing voltage amplification and current amplification.

As for post-treatment, in a case of a logic circuit72ECp (data management unit72EP), post-treatment liquid discharge data Ip (FIG. 11) about post-treatment and data to control a discharge position of a test pattern for a discharge examination are output to the post-treatment liquid output unit72Epp.

The logic circuit72ECp of the data management unit72EP creates a driving waveform by creating driving waveform data based on a post-treatment liquid test pattern received from the higher-level device71and control information about the test pattern received from the print control unit72Cc, performing digital-to-analog conversion on the created driving waveform data, and performing voltage amplification and current amplification.

The memory unit72ECm here may have a capacity that can store print image data for at least three pages. The print image data for three pages includes print image data about a page being forwarded (received) from the higher-level device71, print image data about a page being output to the image output unit72Ei, and print image data about a next page, for example.

In addition, the data management unit72EC may employ a hardware logic circuit configured with a combination of logic circuits, for example. In accordance with this, the data management unit72EC can realize faster processing. Further, the data management unit72EC may use the logic circuit72EC1to perform a logical decision on a control signal based on a bit string, for example, and determine a process to be performed.

A configuration of the image output unit72Ei is described with reference toFIG. 13. A configuration of the post-treatment liquid output unit72Epp is basically the same as the configuration of the image output unit72Ei, so that a description thereof is omitted.

As shown inFIG. 13, the image output unit72Ei includes an output control unit72Eic. The output control unit72Eic outputs print image data about each color to the corresponding discharge heads40C,40M,40Y, and40K (FIG. 4). Specifically, driving waveforms created by the logic circuits of the data management units72EC,72EM,72EY, and72EK are applied to the piezoelectric element45P that serves as a pressure generation unit in the discharge heads (first discharge units)40C,40M,40Y, and40K while timing of the driving waveforms is controlled by the output control unit72Eic. When the driving waveform is applied, the piezoelectric element45P is expanded or contracted. Force of expansion or contraction acts on ink within a pressure chamber40R from the piezoelectric element45P via the vibration plate42. When a pressure change occurs within the pressure chamber40R, ink droplets are discharged from the nozzles40N. In this manner, the output control unit72Eic can control an operation of the discharge head40C and the like based on the print image data (driving waveform).

Specifically, the output control unit72Eic individually controls a plurality of discharge heads40C and the like. Further, the output control unit72Eic may simultaneously control the plurality of discharge heads40C and the like using print image data (such as Ic inFIG. 13) that is input. Further, the output control unit72Eic may control the discharge heads40C and the like based on a control signal that is input from a control device (not shown). The output control unit72Eic may control the discharge head40C and the like based on an operation input by a user, for example.

In the same manner as inFIG. 13, the post-treatment liquid output unit72Epp includes an output control unit. The output control unit outputs post-treatment data to the head50(FIG. 4, second discharge unit). Specifically, driving waveforms created by a logic circuit of the data management unit72EP are applied to the piezoelectric element45P of the head50while timing of the driving waveforms is controlled by an output control unit. Ink droplets are discharged from the nozzles50N in accordance with a pressure change having occurred within the pressure chamber40R via the vibration plate42. The output control unit can control an operation of the head50based on the post-treatment liquid discharge data Ip (driving waveforms).

Further, as mentioned above, as a part of a position movement recovery operation, positional information is input and controlled such that the image formation unit (image output unit)40and the post-treatment unit (post-treatment liquid output unit)50are moved vertically for maintenance and recovery by the position movement units when printing is not being performed.

In accordance with this, the printer device72according to the present embodiment uses the data management unit72EC and the output control unit72Eic to input print image data output from the higher-level device71to the plurality of discharge heads40C and the like. In this case, the printer device72can control a set of the print image data about each color independently of other sets of the print image data. Further, the printer device72can easily change a configuration of the printer engine72E in accordance with a number of colors of the print image data (such as C, M, Y, and K or only K) or a number of discharge heads. In other words, the printer device72provides advantageous effects on size reduction and low cost of an apparatus by installing therein only the data management unit72EC and the like and the discharge head40C and the like that are required.

In the printer device72according to the present embodiment, if full-color printing is to be performed with four colors such as K, C, M, and Y, the data management unit72EC and the like can be disposed on the printer engine72E. In accordance with this, the printer device72can use the output control unit72Eic to connect each output from the data management unit72EC and the like to the corresponding discharge head40C and the like.

Further, in the printer device72, if printing is to be performed with a single color such as K, only a single data management unit72EK and the discharge head40K can be disposed to give priority to cost reduction of an apparatus. In accordance with this, the printer device72can use the output control unit72Eic to connect an output of the data management unit72EK to the discharge head40K.

Or, if printing is to be performed with a single color such as K, one data management unit72EK and four discharge heads may be disposed to give priority to printing speed. In accordance with this, the image formation apparatus100can use the output control unit72Eic to connect the output of the data management unit72EK to each of the four discharge heads. In this case, the image formation apparatus100can print by overlapping (superposing) the same color (K) plural times. Accordingly, it is possible to realize high-speed printing (image formation) four times faster as compared with a case where image formation is performed by a single discharge head.

In the following, a specific example of the present invention in the above-mentioned image formation apparatus is described. In the specific example, the ink40Ink and the post-treatment liquid50L are discharged through droplets sent flying by a droplet discharge head. Before printing to form an image on a recording medium using this droplet flying method starts, test patterns for a discharge examination as shown inFIG. 14are printed on the recording medium in order to check for an abnormal discharge such as a non-discharge or a curved discharge of ink droplets discharged by the ink jet head for each color. In these test patterns, an image is formed by discharging the ink40Ink which is color droplets onto the recording medium from each of the nozzles40N, so that it is possible to visually examine the test patterns. However, in a case of the post-treatment liquid50L which is transparent droplets (transparent ink), when test patterns for a discharge examination are printed on the recording medium in the same method as mentioned above, it is difficult to examine the test patterns by visual observation due to transparency.

Accordingly, in order to examine a discharge (discharge operation) of the post-treatment liquid50L, as shown inFIG. 15, for example, it is necessary to print an area (solid area) on the recording medium in advance, the area being filled with a single color using color ink (40Ink) in a peripheral part of the test patterns of the post-treatment liquid50L to be printed. When the test patterns of the post-treatment liquid50L are printed on the solid area, it becomes easy for the human eyes to recognize the test patterns.

This examination uses an illusion phenomenon that occurs in human color recognition. Specifically, when the post-treatment liquid50L is printed on the area (solid area) filled with a single color using the color ink, a color contrast phenomenon such as brightness contrast, chroma contrast, and hue contrast occurs by which how an object is seen is changed in accordance with a peripheral color. Accordingly, the test patterns of the post-treatment liquid50L becomes more recognizable by visual observation with the use of the illusion phenomenon that occurs in human color recognition.

Further, when an ink image is printed on the recording medium and test patterns of the post-treatment liquid50L for a discharge examination are printed thereon, the ink image is preferably an image filled with a single color (solid image), so that the test patterns of the post-treatment liquid for the discharge examination become recognizable by visual observation. This is because if the image is filled with a plurality of colors or has a pattern or tones, the color image becomes noticeable by the human eyes so that the illusion phenomenon is less likely to occur, and the test patterns of the post-treatment liquid which are transparent droplets become less recognizable.

The single color is not limited to use of only a single color from color ink but ink of a plurality of colors may be used to print an image filled with a single color (solid image). This single color may be selected where necessary by searching for colors and density thereof in advance in order to be able to visually examine easily depending on recording mediums.

In the following, an operation (pull-push injection operation) to discharge ink from the nozzles40N by the discharge head is specifically described.

First, the discharge head in the present embodiment lowers a voltage from a reference potential, the voltage being applied to the piezoelectric element45P (pressure generation unit45), to contract the piezoelectric element45P in a lamination direction thereof. Further, the discharge head causes the vibration plate42to have deflective deformation due to the contraction of the piezoelectric element45P. In this case, the discharge head increases (expands) capacity (volume) of the liquid chamber40F by the deflective deformation of the vibration plate42. In accordance with this, the discharge head can make ink flow into the liquid chamber40F from the common liquid chamber40D.

Next, the discharge head raises the voltage applied to the piezoelectric element45P to expand the piezoelectric element45P in the lamination direction. Further, the discharge head deforms the vibration plate42in a direction of the nozzles40N by the expansion of the piezoelectric element45P. In this case, the discharge head reduces (contracts) the capacity (volume) of the liquid chamber (pressure chamber)40F by the deformation of the vibration plate42. In accordance with this, the discharge head can apply pressure to the ink within the liquid chamber40F. Further, the discharge head can discharge (inject) the ink from the nozzles40N by pressurizing the ink.

Then the discharge head returns the voltage applied to the piezoelectric element45P to the reference potential and returns (restores) the vibration plate42to an initial position. In this case, the discharge head depressurizes the liquid chamber40F by expanding the liquid chamber40F and fills (supplies) the liquid chamber40F with ink from the common liquid chamber40D. Next, the discharge head proceeds to an operation to discharge another ink after a vibration of a meniscus surface of the nozzles40N is attenuated (stabilized) and repeats the above-mentioned operation.

In addition, a method for driving the discharge head that can use the present invention is not limited to the above-mentioned example (pull-push injection operation). In other words, the method for driving the discharge head can perform pull-injection or push-injection by controlling a voltage (driving waveform) applied to the piezoelectric element45P.

In accordance with this, the image formation apparatus100according to the present embodiment can form a black and white or full-color image in the entire area of the image formation region by using the image formation unit40(four discharge heads40K,40C,40M, and40Y) in a single carrying operation of the recording medium (roll paper Md).

Further, when printing is not performed such as before printing, test patterns are created in order to determine necessity of maintenance. For such test patterns, test patterns to detect clogging of the heads of each color in the image formation unit40and test patterns to detect clogging of the head in the post-treatment unit50are created. In addition, the image formation unit40preferably forms a solid image with a single color selected from any one of the four colors in order to detect the clogging of the head in the post-treatment unit50.

In order to examine the clogging of the head in the post-treatment unit50, a predetermined image is formed with color droplets discharged from the image formation unit40when any one of the data management units (first driving waveform creation unit)72EC,72EM,72EY, and72EK applies a driving waveform for continuously discharging droplet dots to a plurality of piezoelectric elements within a plurality of nozzles in a nozzle line of the image formation unit40.

FIG. 15is a diagram illustrating test patterns for a discharge examination of the post-treatment unit50according to Example 1-1 of the present invention. In the test patterns for an examination of the post-treatment unit50shown inFIG. 15, the test patterns discharged from the image formation unit40form a solid image. Accordingly, a driving waveform created by any one of the data management units72EC,72EM,72EY, and72EK for image formation (seeFIG. 11) has a form as shown inFIG. 16, for example.

FIG. 16shows a driving waveform of the image formation unit40when forming the test patterns for a discharge examination shown inFIG. 15. As shown inFIG. 16, a waveform for a large droplet is continuously applied in order to create a solid area which is a field to be filled by arranging ink dots. In addition, a phase of the driving waveform to be applied to an adjacent nozzle may be shifted so as not to have a space in the solid area.

In the test patterns for an examination of the post-treatment unit50shown inFIG. 15, linear patterns are discharged from the post-treatment unit50. A driving waveform created by the data management unit72EP for post-treatment liquid output has a form as shown inFIG. 17, for example.

FIG. 17is a diagram illustrating a driving waveform of the post-treatment unit50when forming test patterns for a discharge examination shown inFIG. 15. InFIG. 17, the driving waveform expands and contracts the liquid chamber40F to discharge four droplets by rising and falling from the reference potential four times. A rising and falling from the reference potential set last in the driving waveform also functions as a vibration control waveform to stabilize meniscuses of ink in the nozzles.

Specifically, when a discharge operation of the post-treatment unit50is examined, the following waveform control is performed after a predetermined image is formed with color droplets by the image formation unit40as mentioned above.

The data management unit72EP (second driving waveform creation unit) forms a first pattern line where a plurality of dots are arranged by applying a second driving waveform for discharging a predetermined number of transparent droplets to a plurality of second piezoelectric elements45P disposed at (m−1) intervals and facing a plurality of nozzles50N disposed at (m−1) intervals in a nozzle line of the post-treatment unit50.

Further, after (immediately after) the first pattern line is formed, the data management unit72EP forms a second pattern line by applying the second driving waveform for discharging the predetermined number of transparent droplets to a plurality of second piezoelectric elements45P facing nozzles adjacent to the plurality of nozzles50N disposed at (m−1) intervals.

In this manner, after the second driving waveform is applied to the adjacent nozzles (piezoelectric elements facing the nozzles), the data management unit72EP forms m pattern lines in a first direction which is a relative movement direction as shown inFIG. 15by successively applying the second driving waveform m times in total.

A flow of steps to examine a discharge of a post-treatment liquid using the above-mentioned method is described with reference toFIG. 18.FIG. 18is a flowchart of steps to examine a discharge of the post-treatment liquid. First, before printing, an instruction to create test patterns is input (S1). Then, a solid image (predetermined image) filled with color ink is printed (image formation) on a recording medium (S2). Subsequently, discharge patterns (patterns) are formed with the post-treatment liquid on the formed solid image and printed (S3).

The head serving as the post-treatment unit50includes a nozzle line that discharges transparent droplets onto the recording medium where the solid image is formed while moving relative to the recording medium. In the nozzle line, a plurality of nozzles50N are arranged in a second direction orthogonal to the first direction which is the relative movement direction.

When the discharge patterns are formed in S3, the post-treatment unit50serving as a discharge unit discharges the post-treatment liquid (transparent droplets) from each of the nozzles50N in the nozzle line arranged in the second direction, so that m (m: a natural number more than 1) pattern lines where a plurality of patterns are arranged in the second direction are formed in the first direction on the recording medium and the plurality of patterns are arranged at (m−1) intervals in each of the m pattern lines. For example, inFIG. 15, a number of the pattern lines m is eight and the plurality of patterns are arranged at seven line intervals in the pattern lines.

The printed test patterns are visually examined (S4) to check whether there is an abnormal discharge such as a non-discharge or a curved discharge of the post-treatment liquid (S5).

If the abnormal discharge is confirmed (Yes in S5), cleaning of the head50is performed by the maintenance and recovery unit90B (S6) shown inFIGS. 7-9and this flow is repeated until there is no such abnormal discharge. If no abnormal discharge is confirmed (No in S5), this discharge examination ends.

When control is performed in this manner, even if the post-treatment liquid is transparent and colorless, it is possible to visually examine a discharge with ease by printing an image with color ink on a recording medium and printing test patterns for a discharge examination on the image, the test patterns being printed with the transparent post-treatment liquid. In addition, the control of this discharge examination may be performed by the print control unit (computer)72Cc.

With this method, an abnormal discharge of the post-treatment liquid is eliminated, so that it is possible to prevent detachment the image (ink) or deterioration of abrasion resistance, glossiness, and preservation stability (such as water resistance, light resistance, and gas resistance) of the image on the recording medium that may result from a non-discharge of the post-treatment liquid. Accordingly, it is possible to provide an image formation apparatus with improved reliability by applying this method for examining a discharge of the post-treatment liquid by the image formation apparatus.

When the solid image is printed with color ink on the recording medium, as ink concentration becomes higher, an illusion phenomenon is more likely to occur in the test patterns printed with the post-treatment liquid on the solid image, so that recognition of the test patterns by visual observation becomes easy. However, in order to increase the ink concentration, an amount of ink to be discharged onto the recording medium is also increased. This will have a substantial influence on subsequent drying conditions. In view of this, the inventors have discovered that if a relative printing density between the solid image and the recording medium is not more than 2.0, it is possible to sufficiently dry the recording medium and to prevent transfer when the recording medium is carried.

By contrast, an amount of color ink to be consumed is preferably small in order to dry the ink so that the recording medium on which the test patterns are printed may be carried. If a discharging amount of the color ink is reduced, it is possible to further reduce cost. The inventors have discovered that in order to visually recognize the test patterns formed with the post-treatment liquid, the relative printing density between the filled image (solid image) and the recording medium may have a difference not less than 0.2.

Accordingly, by adjusting the image density of the color ink image printed on the recording medium when the image is formed such that the image density ranges from not less than 0.2 to not more than 2.0, it is possible to reduce the amount of color ink to be used while generating an illusion phenomenon, so that it is possible to perform a discharge examination at low cost.

FIG. 19is a diagram illustrating test patterns for a discharge examination of a post-treatment unit according to Example 1-2 of the present invention. In the present example, a dot diameter is set to be large by increasing an amount of droplets to be discharged.

FIG. 20is a diagram illustrating a driving waveform of the post-treatment unit when forming the test patterns for a discharge examination shown inFIG. 19. InFIG. 20, a change of pressure in the liquid chamber40F is increased by increasing a fluctuation range of voltage for a driving waveform in comparison with the driving waveform in Example 1-1 shown inFIG. 17, namely, by widening a reduction range and an increase range of an applied voltage (peak value). Accordingly, it is possible to increase the amount of droplets to be discharged.

FIG. 21is a flowchart of steps of a discharge examination of transparent droplets of a post-treatment unit according to Example 1-2 of the present invention.

First, before printing, an instruction to create test patterns is input and the test patterns of Example 1-1 are selected first (S1). Then, a solid image (predetermined image) filled with color ink is printed (image formation) on a recording medium (S2).

Subsequently, discharge patterns (patterns) are formed with the post-treatment liquid on the formed solid image and printed (S3).

Then, the printed test patterns are visually examined (S4) to see whether the test patterns are recognizable (S5).

If the test patterns are recognizable (Yes in S5), whether there is an abnormal discharge such as a non-discharge or a curved discharge of the post-treatment liquid is checked (S6) in the same manner as inFIG. 18mentioned above.

If the abnormal discharge is confirmed (Yes in S6), cleaning of the head50is performed by the maintenance and recovery unit90B shown inFIGS. 7-9(S7) mentioned above.

By contrast, when the test patterns are visually examined in S4, if the test patterns are unrecognizable (No in S5) due to poor visibility depending on a type of paper, the process proceeds to S8.

In S8, an instruction to create enlarged test patterns is input and test patterns of Example 1-2 (or Example 1-3 described below) are selected. Then, in the same manner as in S2, a solid image (predetermined image) filled with color ink is printed (image formation) on the recording medium (S9).

Enlarged test patterns are subsequently formed with the post-treatment liquid on the formed solid image and printed (S10).

Then, the printed test patterns whose visibility is improved by being enlarged are visually examined (S11) to check whether there is an abnormal discharge such as a non-discharge or a curved discharge of the post-treatment liquid (S12).

If the abnormal discharge is confirmed (Yes in S12), the process proceeds to S7and cleaning of the head50is performed by the maintenance and recovery unit90B (S7).

This flow is repeated until there is no such abnormal discharge.

If no abnormal discharge is confirmed (No in S6, S12), this discharge examination ends.

When control is performed in this manner, even if the post-treatment liquid is transparent and colorless, it is possible to visually examine a discharge with increased ease by printing an image with color ink on a recording medium and printing test patterns for a discharge examination on the image, the test patterns being printed with the transparent post-treatment liquid. In addition, the control of this discharge examination may be performed by the print control unit (computer)72Cc.

FIG. 22is a diagram illustrating test patterns for a discharge examination of a post-treatment unit according to Example 1-3 of the present invention. In the present example, dot density is set to be high by increasing a number of droplets to be discharged per cycle.

FIG. 23is a diagram illustrating a driving waveform of the post-treatment unit when forming the test patterns for a discharge examination shown inFIG. 22. InFIG. 23, it is possible to increase the number of droplets to be discharged per unit time by increasing a frequency of a driving waveform (discharge frequency). By increasing a number of discharge pulses per unit time relative to a previous waveform, it is possible to increase the number of droplets to be discharged.

If the number of droplets is increased in this manner and the droplets land on paper, it is possible to increase dot density and improve visibility in comparison with Example 1-1.

Example 2 of the present invention is described with reference toFIGS. 24A-24C.FIGS. 24A-24Cshow other examples of test patterns of the post-treatment liquid50L, in which a solid area is formed first on the recording medium with a single color using the color ink40Ink in a peripheral part of the test patterns of the post-treatment liquid50L to be printed and the test patterns of the post-treatment liquid50L are printed on the solid area.

In this case, when the post-treatment liquid50L is discharged onto the solid area of the recording medium, a group (block) is formed and printed by discharging the post-treatment liquid50L from every n-th (n is a natural number including 0) nozzle of a plurality of nozzles in a nozzle line of the head. In addition, in this nozzle line, the plurality of nozzles are arranged in the second direction orthogonal to the first direction (the carrying direction Xm of the recording medium in the present example) which is a relative movement direction with respect to the recording medium. In each block, the post-treatment liquid50L is regularly arranged in a linear manner. If there is a curve or a missing portion in the regularly arranged linear block, this will be noticeably recognizable to the human eyes.

If the interval n=0, a solid image of the post-treatment liquid50L is printed. In this case, the missing portion resulting from a non-discharge nozzle appears as a streak and becomes recognizable as an abnormal discharge by visual observation.

FIGS. 24A-24Cshow examples where the interval n=0 to n=2. However, the interval is not limited to this but a value of the interval may be selected where necessary for optimum recognition depending on a color or density of an area (solid area) filled with a single color using color ink (40Ink).

As in this example, if the test patterns for a discharge examination of the post-treatment liquid50L are discharged from every n-th (n is a natural number including 0) nozzle of the plurality of nozzles in the nozzle line of the head and the group (block) is formed, it is possible to confirm occurrence of a discharge failure in a short time.

In addition, in consideration of ease of specification of a nozzle location having a discharge failure by visual observation, the interval is preferably provided (interval n=1 or more). For example, inFIG. 24B, two pattern lines (m=2) where a plurality of patterns are arranged in the second direction (lateral direction inFIG. 24) are formed in the first direction (longitudinal direction inFIG. 24B) on the recording medium. In each of the two pattern lines, a plurality of patterns are arranged at one pattern (number of pattern lines m−1=n) intervals (lateral direction). Further, inFIG. 24C, three pattern lines (m=3) where a plurality of patterns are arranged in the second direction are formed in the first direction (longitudinal direction inFIG. 24C) on the recording medium. In each of the three pattern lines, a plurality of patterns are arranged at two pattern intervals (lateral direction inFIG. 24C).

While pattern lines of this example have a shape in Example 1-1, pattern lines having a shape in Example 1-2 or Example 1-3 may be applied.

Example 3 of the present invention is described. A head of the post-treatment liquid50L in the present example shown inFIG. 25Aincludes a plurality of discharge ports (nozzles, printing nozzles)50N on an outer surface of the nozzle plate53in order to increase density of the nozzles and reduce a size thereof. In this case, the plurality of discharge ports50N are arranged in four lines in a longitudinal direction of the head and constitute four nozzle lines. When the plurality of nozzle lines are formed, piezoelectric elements55P and frame members50R are disposed for the four lines of nozzles50N. These nozzle lines are disposed in the carrying direction of the recording medium as shown inFIG. 25B, such that the nozzles of the nozzle lines are arranged at regular intervals such as 600 dpi.

FIG. 26shows that on an area (solid area, predetermined image) filled with a single color using color ink (shown by40Ink), the post-treatment liquid50L is discharged from the head of the present example and test patterns are printed (where nozzle lines L=pattern lines m=4, interval n=3). If n=3, in a group (block) discharged and formed by the nozzles, the post-treatment liquid50L is discharged from the discharge ports (nozzles, printing nozzles)50N of the same nozzle line and regularly arranged at 4/600 inch intervals in a linear manner.

In other words, in the head of the post-treatment liquid50L, the m nozzle lines are arranged in the first direction and a plurality of nozzles included in the nozzle lines are arranged at different positions in the second direction.

The m nozzle lines correspond to the same number of the pattern lines (4inFIG. 26). Each nozzle in the nozzle line discharges the post-treatment liquid50L (transparent droplets) to form its respective pattern within the pattern line that corresponds to the nozzle line. Patterns formed in this manner are arranged at (m−1) intervals in the pattern line (3 intervals inFIG. 26). All patterns formed in all the pattern lines are formed at different positions in the first direction (Xm) and the second direction.

In accordance with this, if there is a curve or a missing portion in the block due to a non-discharge nozzle, this will be noticeably recognizable to the human eyes. Further, since this block corresponds to the nozzle line of the head, it is possible to readily recognize a non-discharge nozzle line.

In other words, if the interval n=a number of nozzle lines L−1, namely, if the number of the nozzle lines L is set to the interval n+1(L=n+1), a test pattern group (block) of the post-treatment liquid50L is discharged from the discharge ports50N of the corresponding nozzle line, so that it is possible to clearly specify the non-discharge nozzle and its nozzle line more easily.

Further, if the non-discharge nozzle is specified, a discharge recovery operation (maintenance) may be performed only on the specified non-discharge nozzle in the corresponding nozzle line. Accordingly, it is possible to reduce an amount of ink or a post-treatment liquid to be used for this operation.

While pattern lines of this example have the shape in Example 1-1, pattern lines having the shape in Example 1-2 or Example 1-3 may be applied.

Serial Type Head

While the line type head is used as shown inFIG. 4Ain the method for depositing the post-treatment liquid (transparent droplets) in the descriptions above, a serial type head may be used for a method for discharging the post-treatment liquid.

FIG. 27Ais a diagram illustrating a carriage460including nozzles of the serial type head and the carrying direction of the recording medium. In this example, the carriage460is moved in a direction orthogonal to the direction in which the recording medium is carried and the carriage460coats ink or a post-treatment liquid.

In this case, nozzle lines of an image formation unit (recording head)400serving as a recording head and a post-treatment unit500in the carriage460are extended in the carrying direction of the recording medium. The carriage460can move in a main scanning direction. In other words, the carriage460in which the discharge heads40K-40Y (first discharge unit) serving as an image formation unit are integrated with a head of the post-treatment unit500(second discharge unit) moves relative to the recording medium (in a direction orthogonal to the carrying direction of the recording medium). In addition, while the image formation unit is integrated with the post-treatment unit in the serial type head in this example, the image formation unit and the post-treatment unit may be disposed on another carriage in the serial type head.

FIG. 27Bis a diagram showing a configuration around the carriage of the serial type head shown inFIG. 27A. A guide rod470serving as a main guide member laterally bridged between main side plates740A and740B which constitute a frame member of an apparatus body and a guide member (guide rod, guide stay, or the like) slidably hold the carriage460in the main scanning direction (longitudinal direction of the guide rod470). The carriage460includes a main scanning motor, a driving pulley, a driven pulley, and a timing belt. The carriage460is disposed in the vicinity of a carriage driving unit461and is moved to perform scanning in the main scanning direction by a main scanning mechanism that drives the carriage driving unit461.

On the carriage460, the head500that discharges the post-treatment liquid50L and the four recording heads400including a liquid discharge head whose subtanks are integrated and serving as an image formation unit that discharges black (K), cyan (C), magenta (M), and yellow (Y) ink droplets are installed. In the recording heads400and the head500, nozzle lines including a plurality of nozzles are arranged in a sub-scanning direction orthogonal to the main scanning direction (relative movement direction) and installed such that droplets are discharged downward.

Below the carriage460, a carrying belt810serving as a carrying unit that carries a recording medium such as paper in the sub-scanning direction is disposed. The carrying belt810is an endless belt and is stretched and installed between a carrying roller820and a tension roller830rotatably held between sub-side plates. The carrying belt810is rotated and moved in a direction Xm (belt carrying direction) shown by an arrow when the carrying roller820is rotatably driven by a sub-scanning motor. In accordance with this configuration, the carriage460can be moved in a direction (main scanning direction, first direction) orthogonal to the belt carrying direction, namely, the carrying direction of the recording medium.

Further, a maintenance and recovery unit900is disposed at one end outside a printing area in the main scanning direction. While the maintenance and recovery unit900is disposed at one end in FIG.27B, maintenance and recovery units may be disposed at both ends outside the printing area depending on a purpose of use.

FIG. 28is a diagram illustrating test patterns for a discharge examination when control in Example 3 is applied to a serial type head. InFIG. 28, the configuration shown inFIG. 26is employed as the serial type head in Example 3 in which a nozzle arrangement direction (second direction) is the same as the carrying direction of the recording medium. A difference fromFIG. 26is that the carriage460in which the heads are installed is movable in the main scanning direction.

The serial type head can include a plurality of discharge ports (nozzles, printing nozzles)50N on an outer surface of the nozzle plate53in order to increase density of the nozzles and reduce a size thereof. In the nozzle lines, a plurality of nozzles are arranged in the second direction orthogonal to the first direction (carriage movement direction in this example) which is a relative movement direction with respect to the recording medium.

The plurality of discharge ports50N are arranged in four lines in a longitudinal direction of a head unit50-1serving as the post-treatment unit50and constitute four nozzle lines. In these nozzle lines, the nozzles are disposed as shown inFIG. 25Bsuch that the nozzle are arranged at regular intervals, such as 600 dpi, in the carrying direction of the recording medium.

FIG. 28(n=3) is a diagram illustrating this configuration. On an area (solid area) filled with a single color using color ink (40Ink), test patterns are printed by discharging the post-treatment liquid from the head of this example. If n=3, in a group (block) discharged and formed by the nozzles, the post-treatment liquid50L is discharged from the discharge ports (nozzles, printing nozzles)50N of the same nozzle line and regularly arranged at 4/600 inch intervals in a linear manner. In accordance with this, if there is a curve or a missing portion in the block due to a non-discharge nozzle, this will be noticeably recognizable to the human eyes. Further, since this block corresponds to the nozzle line of the head, it is possible to readily recognize a non-discharge nozzle line.

In other words, if the interval n=a number of nozzle lines L−1, namely, if the number of the nozzle lines L is set to the interval n+1(L=n+1), a test pattern group (block) of the post-treatment liquid50L is discharged from the discharge ports50N of the corresponding nozzle line, so that it is possible to clearly specify the non-discharge nozzle and its nozzle line more easily. Further, if the non-discharge nozzle is specified, a discharge recovery operation (maintenance) may be performed only on the specified non-discharge nozzle in the corresponding nozzle line. Accordingly, it is possible to reduce an amount of ink or a post-treatment liquid to be used for this operation.

In this description, control in Example 3 where a plurality of nozzle lines are formed is applied to the serial type head. However, control in Example 1 or control in Example 2 where a single nozzle line is formed may be applied to the serial type head.

While pattern lines of this example have the shape in Example 1-1, pattern lines having the shape in Example 1-2 or Example 1-3 may be applied.

When the serial type head is used, since the head can be moved in the direction orthogonal to the carrying direction of the recording medium, ink droplets may not be discharged onto an entire area in the width direction of the recording medium which is a head movement direction but an image may be formed only on an area to be used to detect an abnormal discharge.

In the above-mentioned embodiments and examples, the image formation apparatus includes the carrying-in unit10, the pretreatment unit20, the pretreatment drying unit31, the image formation unit40, the post-treatment unit50, the maintenance and recovery units90A and90B, the post-treatment drying unit32, and the carrying-out unit60. However, each element may be configured as a separate device and such devices may be combined to form a system. For example, an image formation system includes, in an operably connected manner, a pretreatment device, a pretreatment drying device, an image formation device, a post-treatment device, a maintenance and recovery device, a post-treatment drying device, and a carrying-out device, the devices being independent of one another.

Although preferred embodiments and examples of the present invention are described above, the present invention is not limited to the above-mentioned embodiments and examples. Further, the present invention can be varied or modified in various manners in light of the attached claims.

For example, in addition to an image formation apparatus, the present invention can be applied to any one of a printer, a scanner, a copier, a plotter, a facsimile machine, and the like as long as a discharger (discharge head, ink head, recording head, ink jet, or the like) discharges droplets (such as ink) and forms (printing, picture printing, character printing, recording, or the like) an image on a surface of a recording medium.

Further, the present invention is not limited to these embodiments, and various variations and modifications may be made without departing from the scope of the present invention.