JP2017043088A - Post-processing liquid application device, image formation system having post-processing liquid application device, post-processing liquid application method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a post-processing liquid application device which prevents quality abnormality and reduces the cost of post-processing liquid.SOLUTION: A post-processing liquid application device 50 includes: a discharge head 50H which discharges post-processing liquid 50L in a specific discharge pattern to a recording medium Md after formation of at least one of a character and image generated on the basis of image information by adhering ink; and control means 72EPI which selects the discharge pattern of the post-processing liquid discharged by the discharge head on the basis of the printing rate calculated from the image information. The control means selects the discharge pattern for discharging the post-processing liquid to the printing part adhered with ink forming at least one of the character and image or the printing part and the periphery of the printing part in a printing region of the recording medium when the printing rate is low, and selects the discharge pattern of discharging the post-processing liquid to the entire surface of the printing region of the recording medium when the printing rate is high.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a post-processing liquid application apparatus, an image forming system having the post-processing liquid application apparatus, a post-processing liquid application method, and a program.

  In order to improve the fixability (abrasion resistance) of a printed material, there is a technique in which a post-treatment liquid (Protector Coat liquid) is ejected after printing with KCMY ink. There has been proposed an apparatus that uniformly deposits the post-treatment liquid on the entire surface regardless of whether or not the post-treatment liquid ink is printed (Patent Document 1, etc.).

  However, in order to reduce the cost per page (CPP) and improve the drying property, it is necessary to reduce the droplet deposition amount of the post-treatment liquid. Therefore, as a method of reducing the post-treatment liquid, regardless of the printing rate (Coverage Rate: the integrated area of the printing part in the page (printing area)), the paper printing part (ink is ejected to form characters and images) There is already known a technique in which the post-treatment liquid is partially ejected only on the ink adhering portion). There is also an example in which the amount of post-processing liquid is determined based on the image forming speed by such a droplet ejection method (Patent Document 2).

  As in Patent Document 1, when the post-treatment liquid is applied to the entire surface regardless of the printing rate, the post-treatment liquid is also applied to unnecessary portions if the integrated area of the print portion in the print area is small. This wastes a large amount of post-treatment liquid.

  Further, as in the above-mentioned Patent Document 2, in the method in which the post-treatment liquid is partially ejected only on the printing portion, when the post-treatment liquid is not ejected on the other paper when the printed materials are scraped, Since the coefficient of friction is greater than the post-treatment liquid droplet ejection surfaces and the scratch resistance is poor, the post-treatment liquid droplet ejection amount per unit area is increased to maintain the same scratch resistance as the full droplet ejection method. There is a need.

  However, when the post-treatment liquid droplet ejection amount per unit area is increased, quality abnormalities (picking / blocking phenomenon, etc.) due to poor drying are likely to occur, and the cost per page may be higher than the full droplet ejection method. there were.

  In view of the above circumstances, an object of the present invention is to provide a post-treatment liquid application apparatus that prevents quality abnormalities and reduces the cost of the post-treatment liquid.

In order to solve the above problems, according to one embodiment of the present invention, a recording medium after at least one of a character or an image generated based on image information is formed by attaching ink to a recording medium with a specific ejection pattern. A discharge head for discharging the treatment liquid;
Control means for selecting a discharge pattern of post-processing liquid discharged from the discharge head based on a printing rate calculated from image information;
When the printing rate is low, the control means has a printing unit on which the ink that forms at least one of the characters or the image is adhered within the printing area of the recording medium, or the periphery of the printing unit and the printing unit. In addition, the discharge pattern for discharging the post-treatment liquid is selected, and when the printing rate is high, the discharge pattern for discharging the post-treatment liquid to the entire surface of the print area of the recording medium is selected.
A post-treatment liquid application apparatus is provided.

  According to one aspect, in the post-treatment liquid application apparatus, quality abnormalities are prevented and the cost of the post-treatment liquid is reduced.

1 is an overall view (schematic side view) illustrating an example of an image forming apparatus according to an embodiment of the present invention. (A) is the schematic of the example of an arrangement structure of the droplet discharge head of the image formation means and post-processing liquid provision means which concerns on embodiment of this invention, (b) is a one part enlarged view of (a). . FIG. 2 is a bottom view and an enlarged view illustrating a case where a line-type head is used as an example of an image forming unit and a post-processing liquid discharge unit of the image forming apparatus in FIG. 1. 1A is a conceptual diagram of an example of an image forming system in an embodiment of the present invention, and FIG. 1 is a functional block diagram of an image forming apparatus in an embodiment of the present invention. It is a functional block diagram explaining an example of the data management part of the control means in embodiment of this invention. It is a functional block diagram explaining an example of the image output of the control means in embodiment of this invention. 5 is a flowchart illustrating an example of an operation of the image forming apparatus according to the embodiment of the present invention. It is a schematic diagram of post-treatment liquid droplet ejection, (a), (b) shows a partial droplet ejection method, (c) shows a whole droplet ejection method. It is explanatory drawing of the definition of the printing rate in the case of roll paper. It is a graph which shows the relationship between the amount of post-processing liquids, and an abrasion resistance rank.

  An image forming apparatus (image forming system) 100 according to an embodiment of the present invention will be described with reference to FIGS. In this embodiment, an image forming apparatus having four color ejection heads (recording head, ink head) of black (K), cyan (C), magenta (M), and yellow (Y) will be described. The image forming apparatus to which the invention can be applied is not limited to those having these discharge heads. That is, the image forming apparatus to which the present invention can be applied has an ejection head corresponding to green (G), red (R), light cyan (LC) and / or other colors, or only black (K). And the like having a discharge head. Here, symbols to which subscripts K, C, M, and Y are assigned correspond to black, cyan, magenta, and yellow, respectively.

  1 illustrates an example in which continuous paper wound in a roll shape (hereinafter referred to as “roll paper Md”) is used as a recording medium. However, the image forming apparatus according to the present invention may form an image. The recording medium that can be used is not limited to roll paper. That is, the recording medium on which the image forming apparatus according to the present invention can form an image may be a cut sheet. The recording medium on which an image can be formed using the image forming apparatus according to the present invention includes plain paper, fine paper, thin paper, cardboard, recording paper and roll paper, and an OHP sheet, a synthetic resin film, a metal Including thin film and other surface capable of forming an image with ink or the like.

  Here, the roll paper is a continuous paper longer than a standard size. The roll paper includes continuous paper in which severable perforations are formed at predetermined intervals, and continuous paper in which perforations are not formed. In a continuous form in which perforations are formed, a page (page) is an area sandwiched between perforations at a predetermined interval, for example. Detailed types of pages will be described later with reference to FIG.

(1. Configuration of image forming apparatus)
As shown in FIG. 1, an image forming apparatus 100 according to an embodiment of the present invention includes a carry-in means 10, a pretreatment liquid application means 20, a pretreatment liquid drying means 31, an image formation means 40, and a posttreatment liquid application means. 50, an infiltration means 55, a post-treatment liquid drying means 32, and an unloading means 60.

  The carrying-in means 10 carries in the roll paper Md (recording medium). The pretreatment means (pretreatment liquid application means) 20 applies the pretreatment liquid to the carried roll paper Md (performs pretreatment). The pretreatment liquid drying means 31 in the drying means 30 dries the pretreated roll paper Md.

  The image forming unit 40 forms an image on the surface of the roll paper Md. The post-processing means (post-processing liquid applying means) 50 applies the post-processing liquid (post-processing) on the roll paper Md on which the image is formed.

  The printer devices 400F and 400R include the image forming unit 40 and the post-processing unit 50, and a turn bar 80 is provided between the two printer devices 400F and 400R. In the turn bar 80, for example, a plurality of bars and rollers are combined and the roll paper Md to be conveyed is turned upside down. In addition, the apparatus provided upstream of the processing liquid drying means 31 functions upstream as the front side printer apparatus 400F, and the downstream side apparatus functions as the back side printer apparatus 400R, and the turn bar 80 is provided. Thus, double-sided printing becomes possible.

  The infiltration means 55 infiltrates the droplets on the roll paper Md. The post-processing liquid drying means 32 dries the droplets (ink and post-processing liquid) on the roll paper. The carry-out means 60 carries out (rolls or discharges) the post-processed roll paper Md. Further, the image forming apparatus 100 includes a control unit 70 (FIG. 5) that controls the operation of the image forming apparatus 100.

  Hereinafter, each configuration of the image forming apparatus 100 according to the embodiment of the present disclosure will be specifically described. Further, the image forming apparatus may be configured not to include any one or a plurality of pretreatment liquid application means 20, drying means 30 (31, 32), permeation means 55, and the like, which will be described later.

(2. Configuration of import means)
The carry-in means 10 is a means for transporting the recording medium to the pretreatment liquid application means 20 or the like. In the present embodiment, the carry-in means 10 includes a paper feed unit 11 and a plurality of transport rollers 12. The carry-in means 10 carries in (moves) the roll paper Md that is wound around the paper feed roll of the paper feed unit 11 using the transport roller 12 and transports it to the pretreatment liquid coating means 20 and the like described later.

(3. Configuration of pretreatment liquid application means)
The pretreatment liquid application unit 20 is a unit that processes the recording medium before the image is formed. In this embodiment, the pretreatment liquid application unit 20 pretreats the surface of the roll paper Md carried in by the carry-in means 10 with the pretreatment liquid.

  Here, the pretreatment is a treatment for uniformly applying a pretreatment liquid (described later) having a function of aggregating ink onto the surface of the roll paper Md (recording medium). As a result, even when the image forming apparatus 100 forms an image on a recording medium other than the inkjet-type dedicated paper, the image forming apparatus 100 applies the pretreatment liquid coating unit 20 to the surface of the recording medium, thereby applying the recording medium. When the image is formed, the ink can be aggregated.

(4. Configuration of pretreatment liquid drying means)
The drying means 30 is means for drying the recording medium by heating or the like. As shown in FIG. 1, the drying unit 30 includes, as the drying unit 30, a pretreatment liquid drying unit 31 that dries the roll paper Md pretreated by the pretreatment liquid application unit 20, and a posttreatment liquid. And post-processing liquid drying means 32 for drying the roll paper Md post-processed by the applying means 50.

  In the pretreatment liquid drying means 31, the plurality of heat rollers are heated to, for example, 80 ° C. to 100 ° C., and the back surface of the roll paper Md is brought into contact with the heat roller. A warm air mechanism similar to the warm air mechanism (warm air heater) shown in the upper trapezoidal shape included in the infiltration means 55 of FIG. 1 may be added to the drying means 30. Thereby, the pretreatment liquid drying means 31 can evaporate the moisture (solvent) of the pretreatment liquid and dry the roll paper Md.

(5. Configuration of image forming means)
The image forming unit 40 is a unit that forms an image on a recording medium. In this embodiment, the image forming unit 40 forms an image on the surface of the roll paper Md by discharging droplets (ink) onto the roll paper Md dried by the pretreatment liquid drying unit 31.

  An example of the outer shape of the image forming unit 40 will be described with reference to FIG. Here, FIG. 2A is a schematic plan view showing an example of the entire configuration of the image forming unit 40 of the image forming apparatus 100 according to the embodiment of the present invention. FIG. 2B is a schematic plan view showing an example of a main part of the image forming unit 40 (black (K) ejection head 40K).

  As shown in FIG. 2A, in this embodiment, the image forming unit 40 is a full-line head, and black (K), cyan (C), magenta from the upstream side in the conveyance direction Xm of the recording medium. Four ejection heads 40K, 40C, 40M and 40Y corresponding to (M) and yellow (Y) are arranged.

  In this embodiment, the black (K) ejection head 40K includes four head units 40K-1, 40K-2, 40K-3, and 40K-4 in a direction perpendicular to the transport direction Xm of the roll paper Md. Arranged in a staggered pattern. As a result, the image forming unit 40 can form an image in the entire width direction (direction perpendicular to the transport direction) of the image forming area (printing area) of the roll paper Md (recording medium). The configuration of the head and the like will be described below using the ejection head 40K, but the configuration of the other ejection heads 40C, 40M, and 40Y is the same as the configuration of the black (K) ejection head 40K, and thus the description is omitted. To do.

  An enlarged plan view of the head unit 40K-1 of the black (K) discharge head 40K of the image forming means 40 is shown in FIG. As shown in FIG. 2B, in this embodiment, the head unit 40K-1 has a plurality of nozzles (discharge ports, prints) on the nozzle surface (the outer surface of the nozzle plate 43 in FIG. 3A described later). Nozzle) 40N. Here, the plurality of nozzles 40N is a single-pass ink jet system having nozzle rows in the main scanning direction, which are arranged in one row in the longitudinal direction of the head unit 40K-1. The head unit 40K-1 may include a plurality of nozzle rows.

  In FIG. 3A, the ejection head (40K, etc.) of the image forming means 40 is joined to the flow path plate 41 that forms the path of the ink to be ejected and the lower surface of the flow path plate 41 (inner direction of the ejection head). The vibration plate 42, the nozzle plate 43 joined to the upper surface of the flow path plate 41 (outward direction of the ejection head), and a frame member 44 that holds the peripheral portion of the vibration plate 42. Further, the ejection head has a pressure generating means (actuator means) 45 for deforming the diaphragm 42.

  The discharge head according to the present embodiment includes a nozzle communication path 40R and a liquid chamber which are flow paths communicating with a nozzle (discharge port) 40N by stacking a flow path plate 41, a vibration plate 42, and a nozzle plate 43. 40F is formed. Further, the discharge head further forms a common liquid chamber 40L for supplying ink to the liquid chamber 40F, an ink inlet 40S for supplying ink to the liquid chamber 40F, and the like by further laminating the frame member 44.

  In the present embodiment, the frame member 44 has an accommodating portion for storing the pressure generating means 45, a recess serving as the common liquid chamber 40L, and an ink supply port for supplying ink from the outside of the ejection head to the common liquid chamber 40L. 40IN is formed.

  In the present embodiment, the pressure generating unit 45 includes a piezoelectric element 45P that is an electromechanical conversion element, a base substrate 45B that bonds and fixes the piezoelectric element 45P, and a column portion that is disposed in a gap between adjacent piezoelectric elements 45P. ing. The pressure generating unit 45 includes an FPC cable 45C for connecting the piezoelectric element 45P to a drive circuit (drive IC).

  Here, as shown in FIG. 3B, the piezoelectric element 45P is a stacked piezoelectric element (PZT) in which piezoelectric materials 45Pp and internal electrodes 45Pe are alternately stacked. The internal electrode 45Pe has a plurality of individual electrodes 45Pei and a plurality of common electrodes 45Pec. In the present embodiment, the internal electrodes 45Pe connect the individual electrodes 45Pei or the common electrodes 45Pec alternately to the end faces of the piezoelectric elements 45Pp.

  Hereinafter, the operation of the ejection head ejecting ink from the nozzles 40N (drawing-pushing operation) will be specifically described.

  In the ejection head, first, the voltage applied to the piezoelectric element 45P (pressure generating means 45) is lowered from the reference potential, and the piezoelectric element 45P is reduced in the stacking direction. Further, the ejection head bends and deforms the diaphragm 42 by reducing the piezoelectric element 45P. At this time, the ejection head expands (expands) the volume (volume) of the liquid chamber 40 </ b> F by the bending deformation of the vibration plate 42. By this operation, ink is caused to flow into the liquid chamber 40F from the common liquid chamber 40L in the ejection head.

  Next, the ejection head increases the voltage applied to the piezoelectric element 45P, and extends the piezoelectric element 45P in the stacking direction. Further, the ejection head deforms the diaphragm 42 in the direction of the nozzle 40N by the extension of the piezoelectric element 45P. At this time, the ejection head reduces (contracts) the volume (volume) of the liquid chamber 40 </ b> F by the deformation of the vibration plate 42. By this operation, the ejection head applies pressure to the ink in the liquid chamber 40F. Further, the ejection head ejects ink from the nozzles 40N by pressurizing the ink.

  Thereafter, the ejection head returns the voltage applied to the piezoelectric element 45P to the reference potential, and returns (restores) the diaphragm 42 to the initial position. At this time, the discharge head depressurizes the liquid chamber 40F by the expansion of the liquid chamber 40F, and fills (replenishes) ink from the common liquid chamber 40L to the liquid chamber 40F. Next, after the vibration of the meniscus surface of the nozzle 40N is attenuated (stable), the ejection head shifts to an operation for ejecting the next ink and repeats the above operation.

  As described above, the ejection head deforms (bends and deforms) the diaphragm 42 using the pressure generating means 45. Thus, the ejection head changes the pressure acting on the ink in the liquid chamber 40F by changing the volume (volume) of the liquid chamber 40F, and as a result, the ejection head ejects ink from the nozzles 40N. .

  The ejection head driving method to which the present invention is applicable is not limited to the above example (pull-push). For example, the ejection head may be driven by striking or pushing by controlling the voltage (driving waveform) applied to the piezoelectric element 45P. Further, the pressure generating means 45 is a thermal type that generates heat bubbles by heating ink in the liquid chamber 40F using a heating resistor, or a vibration plate and an electrode that are opposed to each other on the wall surface of the liquid chamber 40F. An electrostatic type that deforms the diaphragm by an electrostatic force generated between the electrode and the electrode may be used.

  As described above, the image forming apparatus 100 according to the present embodiment uses the image forming unit 40 (four ejection heads 40K, 40C, 40M, and 40Y) to perform the image transfer operation for one recording medium (roll paper Md). A black and white or full color image is formed over the entire formation area.

(6. Configuration of post-treatment liquid applying means)
The post-processing liquid application unit (post-processing liquid application device) 50 is a unit that processes the recording medium after the image is formed. In the present embodiment, the post-processing liquid application unit 50 post-processes the surface of the roll paper Md on which the image is formed by the image forming unit 40 with the post-processing liquid. As shown in FIG. 2A, the post-processing liquid application unit 50 is disposed downstream of the image forming unit 40 in the recording medium conveyance direction Xm. Further, similarly to the image forming unit 40, the post-processing liquid applying unit 50 has the discharge heads 50 </ b> H (discharge units) arranged in a staggered manner in a direction perpendicular to the transport direction Xm of the roll paper Md.

  Further, the post-treatment liquid application unit 50 controls the discharge amount of the post-treatment liquid by controlling the drive waveform input to the ejection head 50H. Accordingly, the post-processing liquid application unit 50 uses the ejection head 50H to apply the post-processing liquid to the entire width direction (direction perpendicular to the transport direction) of the image forming area (printing area) of the roll paper Md (recording medium). Can be discharged. However, as will be described later, the area where the post-processing liquid application unit 50 discharges the post-processing liquid is not limited to the entire printing area, and the post-processing liquid is discharged only to the printing unit or the printing unit and the periphery of the printing unit. Partial droplet ejection may be performed. Details will be described later with reference to FIG. The configuration of the ejection head 50H is the same as the configuration of the image forming unit 40 (FIGS. 2 and 3), and thus the description thereof is omitted.

  Here, the post-processing is processing for discharging (depositing) the post-processing liquid onto the roll paper Md. By this process, the image (ink) on the recording medium is peeled off (removed) by rubbing the surface of the recording medium Md on which the image is formed with another object (for example, another recording medium). ), That is, scratch resistance (scratch resistance) is improved. Furthermore, glossiness, storage stability (water resistance, light resistance, gas resistance, etc.) and the like can be improved.

(7. Structure of penetration means)
The penetrating means 55 is means for penetrating the solvent in the ink into the recording medium. In the permeation unit 55, the time for the solvent to permeate is gained by increasing the transport distance of the recording medium Md. Further, the recording medium and the ink are heated by the heating means 56 shown in FIG. 1 and set to an ambient temperature of 30 ° C. to 100 ° C. (moisture does not evaporate), so that the state of the aqueous solution containing the high-boiling solvent in the ink is reached. The viscosity is lowered and the penetration rate is accelerated.

(8. Configuration of post-treatment liquid drying means)
In the post-processing liquid drying means 32 shown in FIG. 1, several heat rollers are heated to, for example, 80 ° C. to 100 ° C., and the back surface of the roll paper Md is brought into contact with the heat roller. You may add the warm air mechanism (warm air heater) shown to the trapezoid shape of the upper part of FIG. Thereby, the post-processing liquid drying means 32 can evaporate the water in the ink and the post-processing liquid and dry the roll paper Md.

(9. Configuration of unloading means)
The carry-out means 60 is means for carrying out (ejecting) the recording medium on which an image is formed. As shown in FIG. 1, the carrying-out means 60 is comprised by the storage part 61, several conveyance roller 62 grade | etc., In this embodiment. The carry-out means 60 winds and stores the roll paper Md on which the image is formed on the storage roll of the storage unit 61 using the transport roller 62 or the like.

  Note that, when the roll paper Md is wound around the storage roll of the storage unit 61 and the pressure acting on the roll paper Md becomes large, in order to prevent another image from being transferred to the back surface of the roll paper Md, the winding is performed. You may provide the drying means which dries roll paper Md further just before taking.

(10. Configuration of control means)
The control unit 70 is a unit that controls the operation of the image forming apparatus 100. In this embodiment, the control unit 70 instructs each component of the image forming apparatus 100 to operate, and controls the operation. The control means 70 according to this embodiment will be described with reference to FIGS.

  Note that the image forming apparatus 100 according to the embodiment of the present invention may use production printing as a printing system. Here, production printing efficiently prints a large amount of printed matter (recorded medium on which an image is formed, printed matter) in a short time by efficiently managing jobs and print data. It is a manufacturing system that can. Specifically, the image forming apparatus 100 according to the present embodiment includes a plurality of devices, for example, a RIP (Raster Image Processor) device and a printer device. The RIP device is a device that controls the print order of print data and converts the print data into raster image data. The printer device is a control device for a printing operation based on the converted raster image data.

  In addition, the image forming apparatus 100 (control unit 70) according to the present embodiment constructs a workflow system that performs management from creation of print data to distribution of printed matter. In other words, the image forming apparatus 100 (control unit 70) according to the present embodiment prints by separating the apparatuses such as the RIP apparatus and the printer apparatus and distributing the processes in a system with a long processing time such as the workflow. Speed up. The entire image forming system has a control device (RIPS device).

  FIG. 4A is a conceptual diagram of an example of an image forming system in the embodiment of the present invention, and FIG. 4B is a schematic configuration diagram of an example of a host device.

  As shown in FIG. 4A, the control unit 70 of the image forming apparatus 100 according to the embodiment of the present invention includes a host device (RIP device, DFE, Digital Front End) 71 that performs RIP processing, print processing, and the like. And a printer device 72 for performing the above. Here, the host device 71 and the printer device 72 are connected by a plurality of data lines 70LD and control lines 70LC.

<High-level device>
The host device 71 of the image forming apparatus 100 (control unit 70) according to the embodiment of the present invention is a device that performs RIP processing based on print job data (job data, print data) output from a host device. That is, the host device 71 according to the present embodiment functions as a calculation unit that creates print image data corresponding to each color based on print job data. Here, in the present embodiment, the print image data further includes “image data related to post-processing” related to the discharge of the post-processing liquid discharged by the post-processing liquid applying unit 50.

  Further, the upper level apparatus 71 according to the present embodiment creates control information data for controlling the printing operation based on the print job data, the host apparatus information, and the like. Here, the control information data includes, as printing conditions, printing form, printing type, paper supply / discharge information, printing surface order, printing paper size, data size of printing image data, resolution, paper type information, gradation, color information. And data on the number of pages to be printed. Further, in the present embodiment, the control information data further includes post-processing liquid control data related to the discharge of the post-processing liquid discharged by the post-processing liquid application unit 50.

  As shown in FIG. 4B, in the present embodiment, the host device 71 includes a CPU (Central Processing Unit) 71a, a ROM (Read Only Memory) 71b, a RAM (Random Access Memory) 71c, and an HDD (Hard Disk Drive). 71d. The host device 71 includes an external I / F 71e, a control information I / F 71f, and an image data I / F 71g. Furthermore, the host device 71 includes a bus 71h that connects the CPU 71a and the like, so that the host device 71 can transmit and receive the CPU 71a and the like to each other via the bus 71h.

  The CPU 71a controls the overall operation of the host device 71. The CPU 71a controls the operation of the host device 71 using a control program or the like stored (stored) in the ROM 71b and / or the HDD 71d.

  The ROM 71b, RAM 71c, and HDD 71d are storage means for storing data and the like. A control program for controlling the CPU 71a is stored in advance in the ROM 71b and / or the HDD 71d. The RAM 71c is used as a work memory for the CPU 71a.

  The external I / F 71e controls communication (transmission / reception) with the outside of the image forming apparatus 100 (host device or the like). The control information I / F 71f controls communication (transmission / reception) of control information data. The image data I / F 71g controls communication (transmission / reception) of print image data.

<Printer device>
FIG. 5 is a functional block diagram of the image forming apparatus in the embodiment of the present invention. The printer device 72 of the control means 70 of the image forming apparatus 100 according to the embodiment of the present invention controls the operation of forming an image on a recording medium based on the print image data and control information data input from the host device 71. Device. The printer device 72 includes a printer controller 72C and a printer engine 72E.

  The printer device 72 shown in FIGS. 4 to 6 shows an example of a functional configuration related to control in the two printer devices 400F and 400R on the front side and the back side shown in FIG. 4 to 6 show one example of the printer device 72, the control means 70 assumes that there is another printer device having the same configuration as the printer device 72, and two prints on the front side and the back side are provided. Suppose that it has a function.

  The printer controller 72C controls the operation of the printer engine 72E. The printer controller 72C transmits and receives control information data and the like to and from the host device 71 via the control line 70LC. Further, the printer controller 72C transmits / receives control information data and the like to / from the printer engine 72E via the control line 72LC. Further, the printer controller 72C controls the printer engine 72E based on the control information data, and executes printing according to the control information data including the type of recording medium, the printing speed, the volume of droplets to be ejected, and the like. Can do.

  As shown in FIG. 5, the printer controller 72C includes a CPU 72Cp and a print control unit 72Cc in the present embodiment. In addition, the printer controller 72C connects the CPU 72Cp and the print control unit 72Cc via a bus 72Cb so that they can transmit and receive each other. Here, the bus 72Cb is connected to the control line 70LC via the communication I / F.

  The CPU 72Cp controls the operation of the entire printer device 72 using a control program stored in the ROM 71b (FIG. 4B). The print control unit 72Cc transmits and receives commands and status information to and from the printer engine 72E based on the control information data transmitted from the host device 71. The print control unit 72Cc controls the operation of the printer engine 72E. .

  The printer engine 72E is a device that controls the operation of forming an image on a recording medium based on print image data input from the host device 71 and control information data input from the printer controller 72C. The printer engine 72E controls the post-processing operation based on the print image data and post-processing ejection pattern data input from the host apparatus 71 and the control information data and post-processing control data input from the printer controller 72C. Device.

  As shown in FIG. 5, the printer engine 72E is connected to a plurality of data lines 70LD (70LD-Y, 70LD-C, 70LD-M, 70LD-K, and 70LD-P). The printer engine 72E receives print image data from the host device 71 via a plurality of data lines 70LD-C and the like. Thus, the printer engine 72E can perform the printing operation and post-processing operation for each color based on the received print image data.

  In this embodiment, the printer engine 72E includes a plurality of data management units 72EC, 72EM, 72EY, 72EK, and 72EP. The printer engine 72E includes an image output unit (for example, a head module) 72Ei to which print image data and the like are input from the data management unit 72EC and the like, and a conveyance control unit 72Ec that controls conveyance of the recording medium. Further, in this embodiment, the printer engine 72E includes a post-processing liquid output unit 72Ep to which image data related to post-processing is input from a data management unit (post-processing control unit) 72EP.

  The printer engine 72E further includes a post-processing liquid drying control unit, a pre-processing liquid application control unit, a pre-processing liquid drying control unit, an infiltration control unit 73, a pre-winding drying control unit (not shown), or the like. It may be connected.

  Here, the configuration of the data management unit 72EP related to post-processing will be described with reference to FIG. As shown in FIG. 6, the data management unit 72EP includes a logic circuit 72EPl and a memory unit 72EPm. The data management unit 72EP (logic circuit 72EPl) is connected to the host device 71 through the data line 70LD-P. The data management unit 72EP (logic circuit 72EPl) is connected to the printer controller 72C (print control unit 72Cc) via the control line 72LP.

  In the present embodiment, the logic circuit 72EPl (control means) stores image data related to post-processing output from the host device 71 in the memory 72EPm based on a control signal output from the printer controller 72C (print control unit 72Cc). (Remember.

  In the present embodiment, the memory 72EPm stores print image data output from the upper apparatus 71 based on a control signal output from the printer controller 72C (print control unit 72Cc).

  The logic circuit 72ECl reads print image data (drive waveform) Ic corresponding to cyan (C) from the memory 72ECm based on a control signal output from the printer controller 72C (print control unit 72Cc), and outputs an image output unit. To 72Ei.

  Furthermore, the logic circuit 72EPl receives information such as the resolution of the image to be created, such as the type of the recording medium and the printing speed, from the print control unit (control unit) 72Cc which is a control unit of the entire image forming system. The logic circuit 72EP1 further receives the printing rate from the host device 71. 5 and 6 show an example in which the print rate is received from the host device 71, the print control unit 72Cc may calculate the print rate and send it to the logic circuit EP1.

  The logic circuit EP1 selects a combination of the post-processing liquid droplet ejection method and the droplet ejection amount (droplet ejection density) per unit area based on the printing rate received from the host device 71 (or the printing control unit Cc). Specifically, when the printing rate is high, “entire droplet ejection method × low droplet ejection density” is selected, and when the printing rate is low, “partial droplet ejection method × high droplet ejection density” is selected.

  Further, the logic circuit EP1 adjusts the droplet ejection amount (droplet ejection density) per unit area based on the type of recording medium received from the print control unit Cc, the printing speed, and the resolution of the image to be formed.

  The logic circuit EP1 outputs a driving waveform corresponding to the post-treatment ejection pattern selected as described above and the post-treatment ejection pattern (specific ejection pattern) Ip adjusted to the post-treatment liquid output unit 72Ep. Alternatively, the post-processing ejection pattern Ip is temporarily stored in the memory 72EPm, and is output to the post-processing liquid output unit 72Ep according to the control signal.

  Here, the data management unit 72EP may use a hardware logic circuit configured by a combination of logic circuits and the like.

  The configuration of the image output unit 72Ei will be described with reference to FIG. As illustrated in FIG. 7, the image output unit (head module) 72Ei includes an output control unit 72Eic and each ejection head 40. The output control unit 72Eic outputs a print image pattern (drive waveform) based on the print image data (image information) corresponding to each color to the ejection heads 40C, 40M, 40Y, and 40K (FIG. 4) corresponding to each color. Thereby, the output control unit 72Eic can control the operation of the ejection head 40C and the like based on the print image data.

  Specifically, the drive waveforms corresponding to the image forming patterns (Ic, Im, Iy, Ik) created by the logic circuits of the data management units 72EC, 72EM, 72EY, 72EK are controlled by the output control unit 72Ec. Then, it is applied to the piezoelectric element 45P which is the pressure generating means of the ejection heads 40C, 40M, 40Y and 40K. When the drive waveform is applied, the piezoelectric element 45P expands and contracts. The expansion and contraction force acts on the ink in the pressure chamber 40R from the piezoelectric element 45P through the vibration plate 42, and a pressure change is generated in the pressure chamber 40R, whereby ink droplets are ejected from the nozzle 40N. As described above, the output control unit 72Eic can control the operation of the ejection head 40C and the like based on the print image patterns (drive waveforms) Ic to Ik.

  The output control unit 72Eic individually controls the plurality of ejection heads 40C and the like. Further, the output control unit 72Eic may simultaneously control the plurality of ejection heads 40C and the like using the input print image data (for example, Ic in FIG. 5). Further, the output control unit 72Eic may control the ejection head 40C and the like based on a control signal input from a control device (not shown). The output control unit 72Eic may control the ejection head 40C and the like based on, for example, a user operation input.

  Similarly to FIG. 7, the post-processing liquid output unit (head module) 72 </ b> Ep includes an output control unit and the ejection head 50. The output control unit outputs the post-processing liquid discharge pattern Ip to the discharge head 50 (FIG. 2). Specifically, the drive waveform corresponding to the post-processing liquid discharge pattern Ip created by the logic circuit 72ECl of the data management unit 72EP is applied to the piezoelectric element 45P of the discharge head 50 while the timing is controlled by the output control unit. An ink droplet is ejected from the nozzle 50N due to a pressure change generated in the pressure chamber 40R via the vibration plate. The output control unit can control the operation of the ejection head 50 based on the post-processing liquid ejection pattern (drive waveform) Ip.

  As described above, the printer device 72 can control the image formation of each color independently of each other. Further, the printer device 72 may change the configuration of the printer engine 72E according to the number of colors of print image data (C, M, Y and K, or only K colors, etc.) or the number of ejection heads.

  Returning to FIG. 5, the image forming apparatus 100 uses the permeation control unit and the post-processing liquid drying control unit connected to the print control unit 72 </ b> Cc to apply the type of recording medium, the amount of ink and post-processing liquid (droplet ejection). The drying means 30 and the permeation means 55 are controlled using the amount.

  Further, the image forming apparatus 100 appropriately controls the preprocessing operation of the preprocessing control unit and the preprocessing liquid drying control unit connected to the print control unit 72Cc according to the type of the recording medium and the image data.

(11. Control of post-processing liquid discharge pattern)
FIG. 8 is a diagram illustrating an image forming operation (flow) and a post-treatment liquid application method. Each unit in the image forming apparatus 100 performs an image forming operation according to the following steps.

  In step S1101, formation of at least one of a character and an image is started by ejecting ink and attaching it to a recording medium based on print job data or the like input from the outside of the image forming apparatus 100. Further, the image forming apparatus 100 stores the input print job data or the like in storage means (ROM 71b, RAM 71c, HDD 71d, etc.) that is above the control means 70.

  In step S1102, the image forming apparatus 100 determines the type of the recording medium using the control unit 70, and sets (stores) the determined type of recording medium (paper) in the storage units 71b, 71c, and 71d.

  In step S1103, the image forming apparatus 100 generates print image data, control information data, and the like based on the contents stored in the storage units 71b, 71c, and 71d and the control unit 70. Specifically, print image data, control information data, and the like are generated based on print job data stored in an HDD or the like and at least the type of recording medium. Further, the printing rate is calculated from the created print image data and control information data.

  In step S1104, the image forming apparatus 100 uses the control unit 70 to determine the amount of pretreatment liquid (the amount applied in the present embodiment) and the drying strength of the pretreatment liquid in step S1108.

  In step S <b> 1105, the image forming apparatus 100 uses the control unit 70 to perform post-processing liquid amount (droplet ejection amount in the present embodiment) and droplet ejection method (in this embodiment, “partial droplet ejection method × high droplet ejection”). Density "or" full-surface droplet ejection method x low droplet ejection density "). Also, the drying strength in step S1112 is determined.

  Here, a desired discharge amount (desired amount) is applied to an arbitrary region (arbitrary location) using the discharge (droplet ejection onto the recording medium) discharge head of the post-processing liquid applying unit 50 according to the present embodiment of the present invention. The post-treatment liquid can be discharged in a spot shape or a desired stripe shape.

For example, the post-treatment liquid application unit 50 according to this embodiment is a method for discharging the post-treatment liquid 50L.
(1) Based on the printing rate, select the droplet ejection method and set the pattern.
(2) The amount of droplets of the post-treatment liquid 50L to be discharged is controlled.

  Specifically, the post-processing liquid application unit 50 calculates the printing rate and the amount of the post-processing liquid 50L from the input information (print image data and the like), and determines the pattern to be ejected based on the calculated print duty and the like. May be.

  Further, the post-processing liquid application means 50, for example, creates a database of the above data in advance, calculates the print duty (printing rate) and the ink amount from the input information, that is, image data, compares it with the database, and performs the post-processing liquid The application range may be determined.

  Here, the post-treatment liquid is partially applied only to the printing portion (the portion where the ink that forms at least one of characters or images adheres within the printing area of the recording medium) or only around the printing portion and the printing portion. In the method of dripping, when the printed material is abraded, the friction coefficient is larger than that between the post-treatment liquid droplet ejection surfaces at the portion where the post-treatment liquid is not ejected on the other paper, resulting in poor scratch resistance. .

  Therefore, in the partial droplet ejection method, it is necessary to increase the droplet amount of the post-treatment liquid per unit area in order to maintain the scratch resistance equivalent to the entire surface droplet ejection method. Specific definitions of the partial droplet ejection method and the full droplet ejection method will be described in detail with reference to FIG.

  When the printing rate is low, the amount of the post-processing liquid is unnecessarily consumed by applying the post-processing liquid to the entire surface of the printing area even though the area occupied by the printing portion is small in the printing area. Can be resolved.

  However, in the method in which the post-treatment liquid is partially ejected only on the periphery of the print unit or the print unit and the print unit, when the post-treatment liquid droplet deposition amount per unit area is increased, if the print rate is high, it is dried. Quality anomalies (picking / blocking phenomenon, etc.) due to defects are likely to occur, and the cost per page may be higher than that of the whole surface droplet ejection method.

  In view of the above circumstances, the present invention sets a threshold value and performs control so as to select either the full droplet ejection method or the partial droplet ejection method, whichever has a smaller liquid amount. That is, in the image forming apparatus 100 according to the present embodiment, the “full droplet ejection method × low droplet ejection density” is selected when the printing rate is high, and “partial droplet ejection method × high ejection” when the printing rate is low. "Drop density" will be selected.

  This selection can reduce the amount of post-treatment liquid applied in any case, so that it is possible to reduce poor drying and cost required for post-processing (cost CPP per page) that occurs when the printing rate is high. .

  In step S <b> 1106, the image forming apparatus 100 uses the carry-in unit 10 to carry (convey) the recording medium to the preprocessing unit 20 or the like. Note that the image forming apparatus 100 may start step S1106 immediately after the start of image formation in step S1101.

  In step S <b> 1107, the image forming apparatus 100 performs preprocessing using the preprocessing unit 20 and applies a preprocessing liquid.

  In step S <b> 1108, the image forming apparatus 100 uses the pretreatment liquid drying unit 31 to dry the recording medium. Here, the pretreatment liquid drying means 31 dries the recording medium based on the pretreatment liquid dry strength determined in step S1104.

  In step S1109, the image forming apparatus 100 uses the image forming unit 40 to form an image on the surface of the recording medium based on the print image data (step S1103) generated in step S1103.

  Here, the image forming unit 40 can form an image by further using the type of the recording medium and the resolution of the image to be formed. The image forming unit 40 can control the operation of forming an image by controlling the voltage (drive voltage) applied to the piezoelectric element.

  In step S <b> 1110, the image forming apparatus 100 uses the post-processing unit 50 to post-process the recording medium. Specifically, the post-processing unit 50 has ink that forms at least one of characters or images in the print area of the recording medium based on the amount of the post-processing liquid determined in step S1105 and the droplet ejection method. The post-treatment liquid is ejected onto the printing unit, the periphery of the printing unit and the printing unit, or the entire printing area.

  In step S <b> 1111, the image forming apparatus 100 causes the ink and the post-processing liquid to permeate the recording medium using the permeation unit 55.

  In step S <b> 1111, the image forming apparatus 100 uses the drying unit 32 to dry the recording medium. Here, the drying means 32 dries the recording medium based on the drying strength determined in step S1105.

In step S1112, the recording medium is unloaded (discharged) using the unloading means 60.
Thereafter, the image forming apparatus 100 proceeds to END in the drawing, and ends the operation for forming an image.

(12. Example of post-processing liquid discharge pattern)
FIG. 9 is a diagram illustrating a post-treatment liquid droplet ejection method. In the embodiment of the present invention, for example, before the post-processing liquid application unit 50 starts discharging the droplets of the post-processing liquid 50L, the pre-processing liquid 20L is applied to the surface of the roll paper Md (not shown). ), An ink 40Ink for forming an image is further applied. The post-processing liquid application unit 50 according to the embodiment of the present invention performs a process of discharging (depositing) the post-processing liquid 50L onto the roll paper Md on which the image is formed as post-processing. Yes.

  Here, for the post-treatment liquid droplet ejection method, one of the following droplet ejection methods is selected based on the print rate of the job data in step S1105. At this time, when the printing rate is lower than a preset threshold value, “partial droplet ejection method × high droplet ejection density” (FIGS. 9A and 9B) is selected. “Drop Method × Low Droplet Density” (FIG. 9C) is selected.

  Specifically, either (a) or (b) “partial droplet ejection method × high droplet ejection density” in FIG. 9 or (c) “entire droplet ejection method × low droplet ejection density” is selected. The partial droplet ejection method is a discharge that discharges post-treatment liquid to the print area where ink that forms at least one of characters or images is attached, or around the print area and the print area, in the print area of the recording medium. A method of forming a pattern is shown. The whole surface droplet ejection method (overall droplet ejection method) indicates a method in which a discharge pattern for discharging a post-treatment liquid is formed on the entire printing area of a recording medium.

  Here, as the setting of each element in printing on the recording medium, the outer margin is defined as the margin, the printing area defining the border (outer frame), the character inside the border (in the printing area), A portion where an image is to be formed is a content portion (Contents, element forming portion), and a portion which is a margin inside the border and is not a content portion is padding (padding).

  The print area is a printable area inside the border excluding the margin (outer margin) on the recording medium.

  The content part is a part excluding padding (inner margin) in the print area. For example, when forming an image or a character, the content part is not recognized separately one by one, but set padding (inner margin) Each part is defined as a lump of a predetermined amount, for example, a lump (content-box) for each specific content.

  Here, in the case of printing a solid image (an image that does not include white) or the like as shown in FIG. 9A, the content portion becomes the content portion = printing portion, but as shown in FIG. 9B, In the case of forming characters, the content portion includes a print portion (character portion) and a white background portion.

  The printing part means an ink adhering part where ink is ejected for forming characters and images. In the case of an image including characters or white (such as a black and white line drawing), since a white background portion that is a portion to which ink is not attached is included, content portion> print portion.

  Here, the print rate (Coverage Rate, print duty (Duty), print ratio) is the integrated area of the print portion in the page (print area) of the recording medium, and is expressed as “the integrated area of the print portion / the print area”. It is calculated by “the area of”. For example, as shown in FIG. 9A, when a plurality of content parts are included in the print area, the print area of all the plurality of content parts in the print area is determined when calculating the integrated area for calculating the print part. Add the areas. Similarly, even when a plurality of content parts such as characters, images, line drawings, and the like are included in one print area, the areas of the respective print parts are added together.

  When the calculated printing rate is low, the image (color portion other than white) that is the printing portion shown in FIG. 9A is covered, or the character portion that is the printing portion shown in FIG. 9B is traced. The post-treatment liquid is partially ejected at a high density (partial ejection is performed) so as to cover (cover). For example, when printing a sentence, etc., there is a tendency for characters to be continuous and the printing rate to be low. Therefore, when the partial droplet ejection method is selected, a post-processing liquid is used to trace each small character in the sentence. Is ejected.

  In addition, the above calculation method of the details of the printing rate can be calculated by an image area ratio (Print Coverage) using the actually measured area of the printed part (for example, used for copying), or printing converted by the number of dots of the print data Any of the calculation by the image dot ratio (Dot Ratio) using the area of the part (for example, used for data output) may be used.

  Further, in the partial droplet ejection method, as shown in FIGS. 9A and 9B, post-processing is performed not only on the printing unit but also on a portion protruding a predetermined width from the printing unit = a periphery (periphery) of the printing unit. The liquid may be ejected.

  Here, the “periphery of the printing unit” means a region having a predetermined width that surrounds the printing unit (extends from the printing unit). The predetermined width may be several μm to several cm. As an example, the predetermined width is several hundred μm.

  In the partial droplet ejection method, it is possible to set the predetermined width of the protruding portion, which is the peripheral portion of the printing unit, to 0 (none) and eject the post-treatment liquid only on the printing unit.

  Here, it is preferable that the predetermined width of the peripheral portion of the printing unit can be appropriately changed according to the ink ejection position accuracy (printing position accuracy) of the image forming unit and the resolution. For example, when the accuracy of the image forming unit is poor or when the resolution is high, the predetermined width of the peripheral portion of the printing unit is set wide, and when the accuracy of the image forming unit is high or the resolution is low, the predetermined width is set. Set narrower. This is because the lower the resolution, the larger the dots and the more difficult the ink adhering part is to peel off.

  In addition, when the printing unit is a line segment inclined with respect to the width direction or the conveyance direction of the recording medium as shown in FIG. 9B or includes a curve, the ejection positions of the arranged nozzles are regular. Therefore, it is difficult to discharge the post-treatment liquid with the predetermined width of the peripheral portion of the printing portion being strictly constant. In such a case, in one printing area, the width (predetermined width) of the protruding portion that is the peripheral portion of the printing unit may be slightly different for each place.

(13. Method for selecting post-processing liquid discharge pattern)
The threshold value for selecting either “partial droplet ejection method × high droplet ejection density” or “entire droplet ejection method × low droplet ejection density” is set by evaluating in advance based on the printing rate as follows: To do.

Here, the reference unit for calculating the printing rate is a page unit. Depending on the type of recording medium to be printed, “one page” is recognized as follows.
(1) For cut sheets: One print area excluding margin (outer margin) is set on one sheet.
(2) Roll paper: A plurality of print areas are set within one width as shown by the hatched portion in FIG.

  Here, one page in the case of roll paper will be described. Since the roll paper is a continuous paper, when printing, it is configured as “print page width (print region) + margin” as shown in FIG. In FIG. 10, the shaded area is the print area.

  As shown in the upper part of FIG. 10, when the printing method is one printing area (printing area A) in one page (one page), the area (= reference area) of the printing area (one page) A ratio of a printing area (a printing portion to which ink forming at least one of a character or an image is attached) is defined as a printing rate.

  On the other hand, as shown in the lower part of FIG. 10, in the case of a printing method in which a plurality of printings are performed within one page (multiple pages), a reference area is set for each of a plurality of printing regions (B, C, D, E). Set and calculate the print rate for each page (each print area). Note that in multi-sided printing, pages corresponding to a plurality of print areas are printed in the roll width of one roll paper, and are cut in a subsequent process so that the same pages are stacked.

  In margins outside the print area, register marks (cutting positions), output information (dates, etc.) and color confirmation patch information are output, and ink (droplet) thickening is eliminated. It may be thrown away (flushing).

  Also, even if the printing rate is the same in one page, there are cases where the printing portion is scattered and solid in the printing area of the recording medium. The state of solid solid coating is not divided into cases, and it is determined whether it is a whole droplet ejection or a partial droplet ejection only according to the printing rate.

  The scratch resistance in that region is uniquely determined by the relationship between the amount of heat applied per unit area and the amount of post-treatment liquid applied per unit area.

  Further, evaluation and calculation for determining a threshold value for selecting either (A) “partial droplet ejection method × high droplet ejection density” or (B) “full surface droplet ejection method × low droplet ejection density” in FIG. The procedure is as follows.

<Threshold setting>
The following evaluation is performed on the recording medium (media / paper) to be printed.
(1) A print sample is prepared by ejecting droplets by shaking the level of the amount of post-treatment liquid in a predetermined print pattern.
(2) Two types of rubbing paper (scratch) of “without post-processing” and “with post-processing” are prepared, and predetermined rubbing evaluation is performed to obtain the relative relationship shown in the graph of FIG. The rubbing evaluation is evaluated based on, for example, fixability evaluation (stretching, scratch test), time characteristics of strength in the shear direction of the ink film, and the like.

  Here, the required amount of post-treatment liquid is, as a rule, based on the amount of post-treatment liquid obtained from the area where droplets are deposited and the droplet ejection density per area, with reference to the scrub evaluation in FIG. Set.

FIG. 11 is a graph showing the relationship between the amount of post-treatment liquid and the scratch resistance rank.
(3) The post-treatment liquid amount X [mg / cm ² ] required for the entire droplet ejection and the post-treatment liquid amount Y [mg / cm ² ] necessary for the partial droplet ejection are obtained from FIG. 11 (generally X <Y). (4) A reference area (for example, each page (printing region) A to E in FIG. 10) is S [cm ² ] and a printing rate is p (%), and the amount of post-treatment liquid applied within the reference area is equal. A printing rate p _TH (%) is obtained.
S [cm ² ] x X [mg / cm ² ] = S [cm ² ] x p _TH (%) x Y [mg / cm ² ]
Ｐ p _TH (%) = X / Y (≈Low droplet ejection density at the time of whole droplet ejection / High droplet ejection density at the portion at the time of partial droplet ejection)
This printing rate p _TH (%) is a threshold value (limit threshold value) obtained by prior evaluation.

The threshold value p _TH (%) for the printing rate varies depending on the combination of paper type, ink, and post-treatment liquid. For example, in the case of paper having a high friction coefficient, the difference in scratch resistance increases depending on the presence or absence of the post-treatment liquid, and therefore X / Y (= p _TH (%)) decreases.

  When the printing rate is low, (A) “partial droplet ejection method × high droplet ejection density” is selected, and when the printing rate is high, (B) “entire droplet ejection method × low droplet ejection density” is selected.

Here, whether the printing rate is high or low is determined by comparing it with the threshold value _pTH as a reference. The limit threshold value p _TH corresponds to a printing rate in which the amount of post-treatment liquid applied with partial droplet ejection × high droplet ejection density exceeds the amount of post-treatment liquid with full-surface droplet ejection method × low droplet ejection density.

The printing rate limit threshold p _TH calculated by such evaluation is stored in advance in a storage unit (for example, the memory unit 72EPm, FIG. 6). The printing rate is calculated from the image data information, and the logic circuit 72EPl selects a combination of the post-treatment liquid droplet ejection method and the droplet ejection amount (droplet density) per unit area according to the calculation result.

  As a further adjustment of the post-treatment liquid adhesion amount, the friction coefficient and resolution of the recording medium to be used may be considered. After selecting "Partial droplet ejection method x High droplet ejection density" or "Full droplet ejection method x Low droplet ejection density", the type of recording medium (particularly the friction coefficient) and the image to be formed are common to both methods. The amount of the post-treatment liquid per unit area may be adjusted according to the resolution.

  As described above, in the embodiment of the present invention, the printing rate is calculated from the image data information, and the combination of the post-treatment liquid droplet ejection method and the droplet ejection amount (droplet ejection density) per unit area is selected according to the calculation result. doing. Specifically, when the printing rate is high, “entire droplet ejection method × low droplet ejection density” is selected, and when the printing rate is low, “partial droplet ejection method × high droplet ejection density” is selected. Therefore, since the amount of the post-treatment liquid applied can be reduced in any case, poor drying of the post-treatment liquid and an increase in cost per page can be prevented.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the following Example. For example, the correlation shown in FIG. 11 described above is obtained by an experiment (evaluation result) in which rank evaluation is performed. As an example, Table 1 shows an experimental result in which the scratch resistance is described in rank notation (A: good to D: bad), and shows an evaluation result for determining a threshold value for determining a droplet ejection method.

表１において、後処理液付着量（％）について、「１００％＝打滴可能な最大付着量（即ち、単位面積あたりの打滴密度が最大）」と定義する。

In Table 1, the post-treatment liquid deposition amount (%) is defined as “100% = maximum deposition amount that can be ejected (that is, the droplet ejection density per unit area is maximum)”.

  In the example of Table 1, the fretting ranks A and B are higher (possible) than the rubbing resistance target value, and the rubbing ranks C and D are lower than the rubbing resistance target value (impossible).

  It is assumed that the post-treatment liquid adhesion amounts are the same 8%, 10%, and 15%. At this time, the total amount of post-treatment liquid at the time of full droplet ejection is obtained from “1 (whole printing area) x low droplet ejection density in the whole”, and the total amount of post-treatment liquid at the time of partial droplet ejection is “ It is calculated | required from the "high droplet density in the printing rate px part." The whole droplet ejection method has a higher scuffing rank than the partial droplet ejection method, and the result obtained by plotting these results is shown in FIG.

  Here, as shown in Table 1, if the partial droplet deposition method is used and the post-treatment liquid adhesion amount is small and the droplet ejection density per unit area is low, the scratching rank becomes impossible. Therefore, in the case of partial droplet ejection, the droplet ejection density is increased. (In the example of Table 1, at least 15%)

  Further, even in the whole droplet ejection method, if the post-treatment liquid adhesion amount is high and the droplet ejection density per unit area is high, the scuffing rank is improved, but a large amount of post-treatment liquid is unnecessarily consumed. Therefore, it is preferable to set the overall droplet ejection method so that the rank satisfies the target fretting rank and is lower than the partial droplet ejection method.

In this example, based on the rubbing rank of the evaluation results in Table 1 (B is set as the rubbing resistance target value), the printing rate limit threshold P _TH is set.
p _TH = partial post-treatment adhesion rate / total post-treatment adhesion rate = 10 (%) / 15 (%) = 2/3
Is required.
Therefore, in this example, “partial droplet ejection method × high droplet ejection density (15%)” is set when the printing rate is 2/3 or less per page, and when the printing rate is greater than 2/3, “ It is preferable to select the “all-surface droplet ejection method × low droplet ejection density (10%)” method.

  Here, the recording medium is common to both methods when setting a threshold value for selecting “partial droplet ejection method × high droplet ejection density” and “entire droplet ejection method × low droplet ejection density” and after selecting the droplet ejection method. Depending on the type and resolution of the image to be formed, the amount of post-treatment liquid per unit area may be adjusted as shown in the table below.

記録媒体の摩擦係数が低い紙の場合、必要な後処理液量が少なくすることができる。

In the case of paper with a low friction coefficient of the recording medium, the amount of necessary post-treatment liquid can be reduced.

  Moreover, when the resolution is low, the amount of necessary post-treatment liquid can be reduced. This is because the lower the resolution, the larger the dots and the more difficult it is to peel off.

  The present invention is not limited to the above-described ink jet image forming apparatus, but can be used for droplets (discharge head, ink head, recording head, ink jet, etc.) from a discharger (discharge head, ink head, recording head, ink jet, etc.) Any ink can be used as long as it forms an image on the surface of a recording medium (or printing, printing, printing, recording, etc.).

  In the above-described embodiment, the image forming apparatus includes the carry-in means 10, the pretreatment liquid application means 20, the pretreatment liquid drying means 31, the image forming means 40, the posttreatment liquid application means 50, the permeation means 55, and the posttreatment liquid drying means. 32 and unloading means 60 were provided. However, each means is used as a separate device (carry-in device, pre-treatment coating device, image forming device, post-treatment liquid coating device, permeation device, post-treatment liquid drying device, and carry-out device). May be used. The image forming system may include a host device as a control device.

  Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples. The present invention can be variously modified or changed in light of the appended claims.

100 Image forming apparatus (image forming system)
400F, 400R, 72 Printing device 40 Image forming means (image forming device)
40 Ink ink (image)
50 Post-treatment liquid application means (post-treatment liquid application device)
50H Discharge means (Discharge head)
50L post-treatment liquid 71 host device (calculation means)
72EPl Logic circuit (control means)
72EIC Output control unit 72EPm Memory unit (storage unit)
Md roll paper (recording medium)
Ip Post-treatment liquid discharge pattern (discharge pattern)
p Print rate
p _TH printing rate limit threshold

JP 2007-055257 A JP 2014-176997 A

Claims (11)

An ejection head that ejects a post-treatment liquid in a specific ejection pattern onto a recording medium on which at least one of a character or an image generated based on image information by attaching ink is formed;
Control means for selecting a discharge pattern of post-processing liquid discharged from the discharge head based on a printing rate calculated from image information;
When the printing rate is low, the control means has a printing unit on which the ink that forms at least one of the characters or the image is adhered within the printing area of the recording medium, or the periphery of the printing unit and the printing unit. In addition, the discharge pattern for discharging the post-treatment liquid is selected, and when the printing rate is high, the discharge pattern for discharging the post-treatment liquid to the entire surface of the print area of the recording medium is selected.
Post-treatment liquid application device. When the printing rate is low and the post-treatment liquid is discharged around the printing unit or the printing unit and the printing unit, the control unit increases the droplet ejection density per unit area,
When the printing rate is high and the post-treatment liquid is discharged over the entire printing area of the recording medium, the control means lowers the droplet ejection density per unit area.
The post-treatment liquid application apparatus according to claim 1. A storage unit for storing a correlation between a discharge pattern of the post-processing liquid to be applied, a droplet ejection density per unit area of the post-processing liquid, and a scratch resistance in the recording medium to which the post-processing liquid is applied;
The control means calculates a print rate limit threshold based on the stored correlation, and compares the calculated limit threshold with the print rate calculated from the image information to increase or decrease the print rate. judge,
The post-treatment liquid application apparatus according to claim 2. One or more print areas are set for the recording medium,
The printing rate is calculated for each printing area in the recording medium.
The post-treatment liquid application apparatus according to any one of claims 1 to 3. When the friction coefficient of the recording medium is high, the control means increases the droplet ejection density per unit area.
The post-treatment liquid application apparatus according to any one of claims 1 to 4. When the friction coefficient of the recording medium is low, the control means lowers the droplet ejection density per unit area.
The post-treatment liquid application apparatus according to any one of claims 1 to 4. When the resolution of the image to be formed is low, the control means lowers the droplet ejection density per unit area.
The post-treatment liquid applying apparatus according to any one of claims 1 to 6. When the resolution of the image to be formed is high, the control means increases the droplet ejection density per unit area.
The post-treatment liquid applying apparatus according to any one of claims 1 to 6. An image forming apparatus that forms at least one of a character and an image on a recording medium by attaching ink based on image information;
Calculating means for calculating a printing rate from the image information;
A post-treatment liquid application device that applies a post-treatment liquid to the recording medium on which the image is formed, and an image forming system comprising:
The post-treatment liquid application device is
When the printing rate is low, a post-processing liquid is applied around the printing unit on which the ink for forming at least one of the characters or the image is adhered, or around the printing unit and the printing unit, in the printing area of the recording medium. When the ejection pattern to be ejected is selected and the printing rate is high, the image is formed by the control means for selecting the ejection pattern for ejecting the post-processing liquid over the entire surface of the printing area, and the selected ejection pattern. A discharge means for discharging the post-treatment liquid with a specific discharge pattern on the recording medium,
Image forming system. A post-treatment liquid application method according to any one of claims 1 to 8, comprising:
Calculating a printing rate from image information;
When the printing rate is low, the post-treatment liquid is ejected to the printing part on which the ink for forming at least one of characters or images adheres, or to the periphery of the printing part and the printing part, in the printing area of the recording medium Selecting a discharge pattern, and when the printing rate is high, selecting a discharge pattern for discharging a post-treatment liquid over the entire printing area of the recording medium; and
Discharging a post-treatment liquid with a specific discharge pattern onto a recording medium on which an image generated based on image information with the selected discharge pattern is formed.
Post-treatment liquid application method. A program for executing a post-treatment liquid application method according to any one of claims 1 to 8,
A process for calculating the printing rate from the image information;
When the printing rate is low, the post-treatment liquid is ejected to the printing part on which the ink for forming at least one of characters or images adheres, or to the periphery of the printing part and the printing part, in the printing area of the recording medium A process of selecting a discharge pattern and, when the printing rate is high, selecting a discharge pattern for discharging the post-treatment liquid over the entire print area of the recording medium;
A process of ejecting a post-treatment liquid with a specific ejection pattern onto a recording medium on which an image generated based on image information is formed with the selected ejection pattern.
program.

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