JP2010005996A - Inkjet recorder and hit droplet detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recorder which realizes favorable drying processing of a recording medium and secures the delivering stability of an inkjet head, and to provide a hit droplet detecting method. <P>SOLUTION: A sensor unit (182) is set at nearly the center in an axial direction of gripper supporting parts (101 and 102) of a transfer cylinder (304) which conveys the recording medium (14). The sensor unit is equipped with an infrared sensor (520) and an optical sensor which includes a light receiving element (521) and a visible light source (522). The temperature of ink purged to a front end part of the recording medium is detected by the infrared sensor, and drying processing of the recording medium is controlled on the basis of the acquired temperature information. An optical density of the same position as a detection position of the infrared sensor is detected, and hit droplet correction of the inkjet head is carried out on the basis of information on the optical density. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus and a droplet ejection detection method, and more particularly to a droplet ejection detection technique in an inkjet head.

  The ink jet recording apparatus maintains a constant image quality by performing a preliminary ejection operation at regular intervals from the ink jet head. A general inkjet recording apparatus is configured to perform preliminary discharge (purge) by moving the head to a dedicated preliminary discharge operation position or cap position. However, this movement time is a bottleneck in shortening the preliminary discharge operation time.

  On the other hand, a method has been proposed in which preliminary ejection is performed on a position where the recording medium is not conspicuous or on a conveyance belt that conveys the recording medium. According to this method, it is not necessary to move the head every time the preliminary ejection operation is performed, but it is difficult to obtain high image quality such as photographic quality when performing preliminary ejection on a recording medium. When the preliminary discharge is performed, it is necessary to clean the conveyor belt every time the preliminary discharge operation is performed.

  Japanese Patent Application Laid-Open No. 2004-228561 describes a technique for performing a recovery discharge operation for recovering an ink discharge state to an appropriate state for at least one of the paper discarding areas.

  Patent Document 2 describes a structure in which a transfer unit is provided with a drying unit that dries a sheet varnish-coated in a sheet-fed printing machine that transports a recording medium using an impression cylinder and a transfer cylinder. Has been.

  In addition, in the ink jet recording apparatus, the ejection performance varies due to factors such as changes in environmental temperature and environmental humidity. In particular, when performing high-definition image recording, the variation in ejection performance causes a decrease in image quality. In order to minimize such image quality degradation, a technology is adopted that detects fluctuations in environmental factors and droplet ejection results, and controls ejection of the head based on the detection results to suppress fluctuations in ejection performance. .

  In Patent Document 3, the heating amount of the drying unit is varied based on the total concentration obtained from the ink discharge amount, the water content calculated according to at least one of the environmental temperature and the environmental humidity, and the measurement result of the weight of the recording medium. An ink jet recording apparatus provided with a heating control means is described.

In Patent Document 4, in a drying apparatus for an offset rotary press having a first zone and a second zone divided upstream and downstream with respect to a printing paper traveling method, printing that exits the first zone at the outlet of the first zone A first paper surface thermometer that measures the surface temperature of the paper, and a second paper surface thermometer that measures the surface temperature of the printed paper that exits the second zone at the exit of the second zone, the measurement result of the first paper surface thermometer Describes a technique for controlling the hot air temperature in the first zone based on the above, and controlling the hot air temperature in the second zone based on the measurement result of the second paper surface thermometer.
JP 2002-67346 A JP 2003-237018 A JP 2002-113853 A JP-A-1-237018

  However, in the discharge recovery operation (preliminary discharge) described in Patent Document 1, when weakly permeable paper such as coated paper is used, ink from the preliminary discharge tends to remain on the surface of the paper, and drying (fixing) is insufficient. It is easy to cause stains and contamination of the device other than the paper disposal area.

  The sheet printing machine described in Patent Document 2 can dry the sheet while the sheet is being conveyed by a transfer cylinder provided with a drying unit. It is difficult to carry out a stable drying process against differences in working paper, weighing, etc., environmental factors such as temperature and humidity, fluctuations in ink discharge amount, drying temperature and the like.

  In other words, even when the techniques described in Patent Documents 1 and 2 are applied, the dry state fluctuates due to differences in the types of paper, changes in temperature and humidity, and dirt other than the paper disposal area or contamination of the device. The occurrence of such is concerned.

  Although the ink jet recording apparatus described in Patent Document 3 can reduce variations in drying of the ink, it is difficult to cope with variations in the type of recording medium, thickness, coating thickness, liquid application amount, etc. Fine control is difficult when the content of the image is different for each sheet as in an on-demand printing machine such as an ink jet recording apparatus.

  Although the drying apparatus described in Patent Document 4 can stabilize the drying state under certain conditions, it is difficult to cope with individual variations for each sheet even if the temperature is controlled to be constant. As with the ink jet recording apparatus described in Patent Document 3, fine control is difficult when the content of an image is different for each sheet as in an on-demand printer.

  Further, in the printing apparatuses described in Patent Documents 2 to 3, when excessive drying processing is performed, the temperature in the apparatus increases, and in the ink jet recording apparatus, the ejection performance of the head varies. obtain.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an ink jet recording apparatus and a droplet ejection detection method that realize a preferable drying process of the recording medium and ensure the ejection stability of the ink jet head. To do.

  In order to achieve the object, an ink jet recording apparatus according to the present invention includes a transport unit that transports a recording medium in a predetermined transport direction, an ink jet head that ejects ink onto the recording medium, and a purge of the ink jet head. A droplet ejection control unit that controls droplet ejection of the ink jet head so that the ejected ink adheres to a margin area of the recording medium, a drying processing unit that performs a drying process on the recording medium, and an ink ejection on the margin area. A droplet ejection detecting means for detecting at least one of the temperature and water content of the ink caused by the dropped purge, and a drying process for controlling the drying amount by the drying processing means based on the detection result of the droplet ejection detecting means. And a control means.

  According to the present invention, the ink jet head is purged in the blank area of the recording medium, and at least one of the temperature and the water content of the ink ejected by the purging is detected, and the drying process for the recording medium is performed based on the detection result. Therefore, it is possible to perform a stable drying process against changes in the environment inside and outside the apparatus and differences in the types of recording media.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Overall configuration of inkjet recording apparatus>
FIG. 1 is a configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. As shown in FIG. 1, the ink jet recording apparatus 10 of the present embodiment is an impression cylinder direct drawing type ink jet recording in which an impression cylinder is configured as one form of a direct drawing method for directly forming an image on a recording medium 14. Device.

  The inkjet recording apparatus 10 includes a paper supply unit 22 that supplies a recording medium 14, a permeation suppression processing unit 24 that performs permeation suppression processing on the recording medium 14, and a treatment liquid such as an ink aggregating agent is applied to the recording medium 14. A processing liquid application unit 26 that performs the image formation by applying the color ink to the recording medium 14, a solvent drying unit 30 that dries the solvent of the color ink, and a hot-pressure fixing unit 32 that fastens the image. And a discharge unit 34 that conveys and discharges the recording medium 14 on which an image is formed.

  The paper supply unit 22 is provided with a paper supply tray 36 for supplying the recording medium 14 in the form of a sheet. The recording medium 14 sent out from the paper feed tray 36 by the adhesive roller 37 is fed to the peripheral surface of the pressure drum 40 of the permeation suppression processing unit 24 by a gripper (not shown) via the transfer drum 38.

  This apparatus uses an aggregating agent for the purpose of forming good images on various media using inkjet. In particular, an aggregation treatment agent to which gloss-stable polymer particles (Lx) have been added is applied. An ink with the addition of fixing polymer particles is deposited on a dried recording medium to form an image. After aggregation, the particles are heated to remove moisture and polymer particles. A method of melting and fixing to a recording medium is employed.

  In this method, it is desired that the aggregating agent and ink are dried uniformly and efficiently in consideration of the molten state of the added polymer particles and the drying temperature. In the conventional means proposed in Patent Documents 1 to 4 and the like, it is difficult to stabilize due to variations in drying wind unevenness, paper thickness, liquid application amount, etc., and drying is performed by measuring the outlet temperature of the drying section and the outlet moisture content. In the correction system, the response is likely to be delayed, and fine drying control of the sheet is difficult. The ink jet recording apparatus 10 of the present embodiment employs a drying means that solves these problems.

(Description of permeation suppression processing unit)
The permeation suppression processing unit 24 includes a liquid application device 42, a paper presser 44, and a sheet presser 44 at positions facing the circumferential surface of the impression cylinder 40 in order from the upstream side in the rotation direction of the impression cylinder 40 (counterclockwise direction in FIG. 1). And a permeation suppressor drying unit 46 are provided.

  FIG. 2 is a configuration diagram of the permeation suppression processing unit 24. As shown in FIG. 2, the liquid application device 42 presses a spiral roller 48 formed with a spiral groove on the outer periphery by rolling or the like against the rotating impression cylinder 40, and the spiral roller 48 is rotated by the rotation of the impression cylinder 40. By rotating at a predetermined constant speed in a direction opposite to the direction (counterclockwise in the figure), a desired region of the recording medium 14 that is held by a gripper (not shown) of the impression cylinder 40 and is rotated and moved. It is an apparatus that selectively applies a permeation inhibitor.

  Note that the peripheral surface of the impression cylinder 40 is covered with an elastic layer 41, whereby the positional deviation between the impression cylinder 40 and the spiral roller 48 is alleviated, and the winding of the recording medium 14 is stabilized. By making the elastic layer 41 on the circumferential surface of the impression cylinder 40 an elastic body having a hardness of 20 to 80 °, the contact of the spiral roller 48 is stabilized and the application is homogenized. Furthermore, the surface tension (surface energy) is 10 to 40 mN / m by making the material of the elastic layer 41 on the peripheral surface of the impression cylinder 40 one of fluorine rubber, urethane rubber, silicone rubber, fluorine elastomer, and silicon elastomer. Since the liquid repellency can be secured, the cleaning of the peripheral surface of the impression cylinder 40 is excellent. Further, it is preferable since the winding adhesion of the paper is improved.

  As a specific example, the impression cylinder 40 is efficiently formed of cast iron or the like, and the surface is 0.1 to 1 mm thick fluororubber, urethane rubber, silicone rubber, or fluoroelastomer (Shin-Etsu Chemical Co., Ltd .: SIFEL600 series, etc.) It is conceivable to provide the liquid-repellent elastic layer 41. The material of the elastic layer 41 may be a rubber surface coated with PFA or the like.

  FIG. 3 shows an enlarged view of the spiral roller 48. The spiral roller 48 is a coating roller in which a groove (dent) is formed substantially along the rotation direction by rolling a die or winding a wire on the outer peripheral surface thereof, and the width of the coated surface of the recording medium 14. It has a length (width dimension) equal to or greater than the dimension. The groove shape, pitch a, groove depth b, and the like of the spiral roller 48 are appropriately selected according to the amount of liquid to be applied (the thickness of the liquid film after application). For example, in the case of the liquid coating apparatus 42 of this embodiment, a spiral roller having a pitch a = 0.08 to 0.2 mm and a groove depth b = 5 to 20 μm is suitable.

  FIG. 4 is a schematic diagram showing the groove shape of the spiral roller 48. In FIG. 4, the groove shape, the groove pitch, and the like are simplified for easy understanding of the characteristics of the groove shape. As shown in FIG. 4, as the groove shape, in addition to a spiral shape (FIG. 4 (a)), an independent groove (FIG. 4 (b)), a left and right spiral (FIG. 4 (c)), and a multi-threaded spiral (not shown) And so on. In particular, in the case of the independent groove, the liquid flow in the width direction of the medium to be coated can be suppressed, and in the case of the left and right spiral, wrinkles of the medium to be coated (recording medium 14) can be suppressed. In addition, as a modified example in the case of the left and right spirals, an example in which one spiral roller 48 is divided into a spiral roller having a left spiral shape formed on the outer peripheral surface and a spiral roller having a right spiral shape formed on the outer peripheral surface is also conceivable. .

  FIG. 5 is a schematic diagram showing the cross-sectional shape of the outer peripheral surface of the spiral roller 48. As shown in FIG. 5, as the cross-sectional shape of the outer peripheral surface, in addition to the S-shaped curved surface (FIG. 5 (a)), a shape in which the peak is flat (FIG. 5 (b)) or a shape in which the valley is flat. (FIG. 5 (c)), a shape (FIG. 5 (d)) in which peaks and valleys are made flat is also conceivable. In particular, if the crest is flat, the wear resistance is improved, and if the trough is flat, a large amount of liquid can enter the groove and a large amount of liquid can adhere to the outer peripheral surface of the roller.

  As a means for applying a permeation inhibitor (first liquid) to the spiral roller 48 having such a configuration, the liquid application device 42 shown in FIG. 2 includes a liquid ejecting section 52 in the container 50 (see FIG. 2). As the ejecting member of the liquid ejecting unit 52, a one-fluid flat spray nozzle capable of controlling the ejecting angle or a pressurized two-fluid flat spray nozzle is applied. Specifically, for example, a one-fluid flat spray in which an orifice angle of about 0.2 to 0.4 mm and an injection angle of 60 to 100 ° are realized, and a pressurized two-fluid flat spray having the same size as this can be used.

  As shown in FIG. 2, the liquid ejecting unit 52 ejects the permeation suppression agent from below the spiral roller 48 toward the tip of the squeegee blade 60. At that time, the jetting pressure is controlled so that the jetting angle is a given width that matches the width of the image forming area. That is, the liquid ejecting unit 52 controls the width for supplying the permeation suppression agent on the outer peripheral surface of the spiral roller 48 as supply width control means for controlling the width for supplying the coating liquid.

  As shown in FIG. 6, in the flat spray nozzle, fluid is ejected at an ejection angle α, and therefore the actual spray range 58 depends on the distance L between the discharge surface of the nozzle body 54 and the spray surface 56 of the liquid ejecting unit 52. Specific injection width Wsp is defined. The flat spray nozzle is not limited to a single mode, and a plurality of flat spray nozzles may be arranged in the width direction of the spiral roller 48. In this case, removal control in the width direction can be performed in addition to the transport direction.

  FIG. 7 is an explanatory view schematically showing the relationship between the injection pressure and the injection width of the liquid injection unit 52. As shown in the drawing, the nozzles of the liquid ejecting section 52 can switch at least two kinds of ejection widths (ejection ranges in the width direction). Although FIG. 7 shows an example in which two types of injection widths are realized by the strength of the injection pressure, three or more types of injection widths are realized corresponding to the difference in the paper size type and image formation range of the recording medium 14. An embodiment is also possible. Information on the recording medium 14 may be automatically acquired by a sensor or the like, or may be acquired by being input by an operator.

  As shown in FIG. 8, the liquid spray pattern by the flat spray has a liquid amount distribution in the width direction. Also, the injection amount (flow rate) changes depending on the injection pressure. However, in the case of this example, the excess liquid is removed by the squeegee blade 60 so that a wider range than the effective image area can be applied. As a result, the liquid application amount to the spiral roller 48 can be kept stable. And uniform coating with controlled coating width is possible.

  In this embodiment, since the spiral roller 48 in which a spiral groove is formed is used, the overflow of the penetration inhibitor in the width direction can be reduced by the unevenness of the groove portion. Therefore, the width controllability is further improved, and the contact friction can be reduced even for the non-coated portion in the width direction by the lubrication effect of the coated paper.

  By injecting a permeation suppressant into a part of the spiral roller 48 (lower part in FIG. 2) from the liquid ejecting unit 52, the permeation suppressor enters the groove of the spiral roller 48 and suppresses permeation to the outer peripheral surface of the roller. The agent adheres (coating liquid supply step).

  As shown in FIG. 2, a squeegee blade 60 that is a squeegee member as a means for scraping off excess liquid from the outer peripheral surface of the spiral roller 48 is erected in the container 50. The “surplus liquid” here is a part of the liquid adhering to the outer peripheral surface of the spiral roller 48 and adhering to the outside of the groove formed in the spiral roller 48. The squeegee blade 60 is disposed such that the tip thereof is in contact with the spiral roller 48, and the tip is biased in a direction of pushing the peripheral surface of the spiral roller 48. The urging force may be due to elastic deformation of the squeegee blade 60 itself, or may be applied from the outside using a spring or other urging member (not shown).

  By rotating the spiral roller 48 to which the permeation inhibitor is applied in this manner, the excess liquid of the permeation inhibitor is scraped off by the squeegee blade 60, so that only the liquid held in the groove comes out of the squeegee blade 60 (squeegee process). ).

  Further, in the present embodiment, the rotation of the spiral roller 48 in the liquid application device 42 from the viewpoint of controlling the application range of the permeation suppression agent in the conveyance direction of the recording medium 14 (hereinafter sometimes referred to as “medium conveyance direction”). The main blade 62, which is a blade member, is disposed downstream of the squeegee blade 60 with respect to the direction, and is controlled so as to be in contact with and separated from the outer peripheral surface of the spiral roller 48.

  By bringing the main blade 62 into contact with a part of the outer peripheral surface of the spiral roller 48, the liquid applied to the outer peripheral surface including the permeation inhibitor in the groove of the spiral roller 48 can be removed (blade contact). Process).

  By controlling the removal range of the liquid from the spiral roller 48 by the main blade 62, it is possible to control the application range (area in the medium conveyance direction) of the permeation suppression agent to the recording medium 14 (blade contact / separation control process). .

  Specifically, the main blade 62 is brought into contact with the outer peripheral surface of the spiral roller 48 with respect to the area corresponding to the non-image forming portion on the recording medium 14, and the area corresponding to the image forming portion on the recording medium 14 is set. Thus, the main blade 62 is separated from the outer peripheral surface of the spiral roller 48. As described above, the processing liquid is not applied to the non-image forming portion on the recording medium 14, and the processing liquid can be selectively applied only to the image forming portion (see FIG. 9A).

  FIG. 9A shows the application range (application area) controlled in the conveyance direction of the recording medium 14. FIG. 9B shows the application range controlled in the width direction and the conveyance direction of the recording medium 14.

  The recording medium 14 has a larger width than the area of the effective image portion 68 on which an image is formed, and the permeation inhibitor is applied to an area wider than the effective image portion 68 (application portion indicated by reference numeral 70). .

  FIG. 9C shows the timing of the separation / contact control of the main blade 62. FIG. 9D shows the application control of the coating liquid (processing liquid) to the spiral roller 48.

  As shown in FIG. 9D, the application liquid is continuously applied to the spiral roller 48 itself, and the application range in the transport direction is controlled by the separation / contact control of the main blade 62 shown in FIG. (See FIGS. 9A and 9B).

  In response to the change in the paper size of the recording medium 14, the spray pressure of the liquid ejecting unit 52 is controlled to change the coating range in the width direction.

  According to this aspect, it is possible to suppress the application of the permeation suppressant to unnecessary areas, and it is possible to prevent the permeation suppressant from adhering to the impression cylinder 40 even when paper is supplied discontinuously such as a sheet. For this reason, operation | movement of an apparatus is stabilized and reliability, such as a stain | pollution | contamination and corrosion over time, also improves. As shown in FIG. 2, a liquid discharge port 64 is formed at the bottom of the container 50, and the liquid discharge port 64 is connected to a recovery tank via a discharge valve (not shown). The collected liquid can be reused as a coating liquid.

  FIG. 10 is a perspective view showing an outline of the moving mechanism (contact / separation mechanism) of the spiral roller 48 and the rotation driving means, the squeegee blade 60, the rotation mechanism of the main blade 62, and the like constituting the liquid application device 42.

  As shown in FIG. 10, as an example of the rotational driving means of the spiral roller 48, there is a form in which a motor 72 and a winding transmission means such as a timing belt 74 are combined. However, the present invention is not limited to this configuration, and direct drive (direct shaft connection) by an inverter motor, a combination of various motors and a reduction gear (gear, etc.), or the like may be used. A bearing 76 is provided on the rotation shaft of the spiral roller 48.

  The spiral roller 48 is supported by a moving mechanism (contact / separation mechanism) such as a push latch 78 so as to be movable in the vertical direction of FIG. Therefore, control is performed to switch between the state in which the spiral roller 48 is pressed against the impression cylinder 40 (the contact (nip) state shown in FIG. 2) and the state in which the spiral roller is separated (retracted) from the recording medium 14. It can be carried out.

  As shown in FIG. 10, the main blade 62 can be rotated about a rotation shaft 82 a by rotating an eccentric cam 82 by a cam motor 80. As a result, it is possible to perform control to switch between the state of being pressed against and contacted with the spiral roller 48 and the state of being separated from the spiral roller 48.

  Further, as shown by a broken line in FIG. 2, it is conceivable that the urging force of the main blade 62 is increased to separate the spiral roller 48 from the impression cylinder 40. Thus, friction between the spiral roller 48 and the medium to be coated can be avoided when the application is not performed such as in standby or when the liquid cleaning is stopped, and the stepped portion of the gripper (not shown) provided on the impression cylinder 40 and the spiral are prevented. Contact with the roller 48 can also be avoided. If the spiral roller 48 is separated from the impression cylinder 40 and fixedly supported by the push latch 78 (see FIG. 10), the reliability of the apparatus is further improved.

  According to the liquid application device 42 having the above-described configuration, the treatment liquid application width in the width direction is controlled by the liquid ejecting unit 52, and the liquid supply range in the paper conveyance direction (circumferential direction in the spiral roller 48) is controlled by the main blade 62. Be controlled.

  Further, instead of the configuration described with reference to FIG. 2, the urging force of the main blade 62 can be switched as shown in FIG. 11, and only the main blade 62 (only one blade) is applied without using the squeegee blade 60. A liquid application device 42 ′ that performs control is also possible.

  In addition, although not shown, the liquid ejection unit 52 may not be provided, and the permeation inhibitor may be attached to the outer peripheral surface of the spiral roller 48 by immersing the spiral roller 48 in the permeation inhibitor introduced into the container 50.

  Further, if the recording medium 14 having a coating layer on the surface or the recording medium 14 to which a liquid containing a lubricating component is applied is used, contact friction between the spiral roller 48 and the recording medium 14 can be reduced even in the non-coated portion. Reduction can be achieved, and more stable and highly reliable coating can be achieved.

  As the penetration inhibitor used in the present embodiment, a latex solution obtained by adding polymer particles such as LX-1 and LX-2 described in Table 1 to water or a solvent is suitably used. <Adjustment of each solution> (1) Adjustment of permeation inhibitor ”.

  In the above [Table 1], “Tg” is the glass transition point of the polymer added in the liquid, “MFT” is the minimum film forming temperature of the polymer, and “Tm” The melting point of the polymer.

  Of course, the penetration inhibitor is not limited to the latex solution, and for example, tabular grains (mica and the like), water repellent (fluorine coating agent) and the like can be applied.

  A sheet presser 44 (see FIGS. 2 and 11) disposed on the downstream side of the liquid application device 42 (42 ′) for applying the permeation suppressor is arranged at both ends of the recording medium 14 fed to the peripheral surface of the impression cylinder 40. It is a roller for sending out in the rotation direction of the impression cylinder 40 while pressing the rear end.

  The permeation suppression agent drying unit 46 is provided with a heater whose temperature can be controlled in the range of 50 to 130 ° C. and a fan that blows out downstream at a wind speed of 5 to 50 m / s. When the recording medium 14 held by the impression cylinder 40 serving as an application cylinder passes downstream from a position facing the permeation suppression agent drying unit 46, hot air heated to 50 to 130 ° C. by the heater is recorded by the fan. And the recording medium 14 is heated to pre-dry the penetration inhibitor.

  A treatment liquid application unit 26 is provided following the permeation suppression processing unit 24. A transfer drum 84 is provided between the pressure drum 40 of the permeation suppression processing unit 24 and the pressure drum 86 of the treatment liquid application unit 26 so as to be in contact therewith. As a result, the recording medium 14 held on the pressure drum 40 of the permeation suppression processing unit 24 is subjected to the permeation suppression processing and the pre-drying, and then the gripper (not shown in FIG. ) Is transferred to the pressure drum 86 of the treatment liquid application unit 26.

(Transfer cylinder structure)
Here, a structural example of the transfer drum 84 will be described.

  12 is a cross-sectional view showing details of a structural example (first example) of the transfer drum 84, and FIG. 13 is a cross-sectional view taken along the line AA of FIG. 12 (a cross-section taken along a cut surface including the central axis of the transfer drum 84). Figure). In FIG. 12, the previous recording medium (left side in FIG. 12) is transferred from the transfer cylinder 84 to the impression cylinder 86, and the leading end of the recording medium is sandwiched and conveyed by the gripper 87 of the impression cylinder 86. A state in which the next recording medium (right side in FIG. 12) is transferred from the impression cylinder 40 to the transfer cylinder 84, and the gripper 91 of the transfer cylinder 84 sandwiches and conveys the leading end portion of the next recording medium is illustrated.

  As shown in these drawings, there are two grippers 91 and 92 for holding and transporting the recording medium 14 (hereinafter sometimes referred to as “paper”) on the outer periphery of the transfer cylinder 84 while sandwiching (holding) the recording medium 14. It is placed symmetrically at the place. A hot air jet member 96 for jetting hot air for drying toward the recording medium 14 is fixedly installed inside the transfer cylinder 84 including the grippers 91 and 92. Further, openings 104 and 105 for allowing the hot air to pass therethrough are formed in the transfer drum peripheral surface area other than the two gripper support portions 101 and 102 in the transfer drum 84.

  The hot air injection member 96 has a cylindrical shape coaxial with the transfer drum 84, and a plurality of holes 108 serving as hot air outlets are formed in a partial region of the peripheral surface (region below the peripheral surface in FIG. 12). ing.

  Inside the hot air jet member 96, a heater 110 as a heating means is installed. The heater 110 is disposed in the central portion of the transfer drum 84 so as to extend along its axis. As the heater 110, for example, a halogen heater or an infrared (IR) heater can be used. A configuration in which hot air is introduced from the axial direction of the hot air injection member 96 by a hot air blower (not shown in FIG. 12, refer to FIG. 14), the temperature is adjusted by the heater 110, and the hot air injection member 96 is injected from the outlet (hole 108). (See FIG. 13).

  That is, as shown in FIG. 13, the axial end portion (right end portion in FIG. 13) of the hot air injection member 96 is supplied with hot air for connecting a blower (not shown in FIG. 13, see FIG. 14) as hot air generating means. A mouth 114 is formed. Hot air is introduced into the hot air injection member 96 through the hot air supply port 114, the heated air is further heated and adjusted by the heater 110, and discharged outward from the outlet (hole 108) of the hot air injection member 96. Is done.

  Further, on the inner side of the transfer drum 84 and on the outer side of the hot air jet member 96, an jet restricting member 116 for restricting the jet range of the hot air jetted onto the recording medium 14 in the paper transport direction is disposed (see FIG. 12). ). This injection restricting member 116 is a member provided independently of the transfer drum 84, has a cylindrical shape coaxial with the transfer drum 84, and is attached so as to be rotatable about an axis. A passage opening 118 through which hot air from the hot air injection member 96 passes and a shielding portion 120 that blocks the passage of hot air are formed on the peripheral surface of the injection regulating member 116.

  By controlling the rotation of the injection restricting member 116, the position of the passage opening 118 of the injection restricting member 116 with respect to the region where the blowout port (hole 108) is formed and the openings 104 and 105 of the transfer cylinder 84 is controlled. It can be moved relatively, and the hot air injection range in the paper conveyance direction can be expanded or reduced.

  Reference numeral 122 in FIG. 13 is a bearing that rotatably supports the injection restricting member 116. As a means for rotationally driving the injection restricting member 116, a gear 124 is formed at an appropriate position on the peripheral surface of the injection restricting member 116 (in this example, the end peripheral surface of the injection restricting member 116), and the injection restricting member driving motor 126 and A drive gear 128 that transmits the power of the motor to the gear 124 is provided.

  Similarly, the transfer cylinder 84 is rotatably supported by the bearing 132, and a gear 134 is formed on the peripheral surface of the transfer cylinder 84 as means for driving the transfer cylinder 84 to rotate, and the transfer cylinder drive gear 138 meshing with the gear 134 is formed. A motor (not shown) is provided. The power transmission means is not limited to the gear transmission mechanism, and may be a belt transmission mechanism or the like. Reference numeral 184 in FIG. 13 denotes a contact point (detection signal extraction unit and power supply unit) of the sensor 181.

  A large number of openings (exhaust holes 152) for electrostatically attracting the recording medium 14 and discharging the hot air described above are arranged along the width direction and the conveying direction at a position facing the transfer cylinder 84 having the above configuration. A conveyance guide 150 is provided (see FIG. 12). The conveyance guide 150 is fixedly installed at a predetermined position that constitutes the conveyance path of the recording medium 14, and the hot air flowing into the conveyance guide 150 through the exhaust hole 152 is discharged from the exhaust connection port 154 of the conveyance guide 150. The

  The conveyance guide 150 is provided with an electromagnetic induction heating means 156 (see FIG. 1), and the recording medium 14 conveyed in contact with the conveyance guide 150 is heated to 50 to 90 ° C.

  The surface of the recording medium 14 transferred to the transfer cylinder 84 by the grippers 91 and 92 is heated and dried by hot air sprayed from the transfer cylinder 84 while being electrostatically attracted to the conveyance guide 150. At this time, since the recording medium 14 (paper) is conveyed at intervals, the jetted hot air is exhausted through the opening 152 of the conveyance guide 150 from the gap between the trailing edge of the paper and the leading edge of the next paper to be conveyed. For this reason, even if it heat-drys, it is hard to produce defects, such as a wrinkle and a bevel, and it is hard to leave the trace of an exhaust hole, and it can prevent vapor | steam contamination of an apparatus.

  Furthermore, by returning the hot air exhausted from the conveyance guide 150 to the injection unit or using it as a heat exchanger of the hot air generating means, the thermal efficiency is improved and the vapor contamination of the apparatus can be prevented.

  FIG. 14 shows a configuration example of the hot air generating means. As shown in the figure, the blower 160 functioning as hot air generating means is provided with a heater 164 in the vicinity of the air outlet 162, and this air outlet 162 is connected to the hot air injection member 96 (see FIG. 13) via a pipe line 166. Connected to the hot air supply port 114.

  Further, the exhaust connection port 154 of the conveyance guide 150 described with reference to FIG. 13 is connected to the exhaust pipe line 170 of FIG. The exhaust pipe line 170 constitutes a heat exchanging unit 174 in the vicinity of the exhaust pipe line 172 of the blower 160, and performs heat exchange using the heat of the air exhausted from the conveyance guide 150 for heating the intake air to the blower 160.

  According to the configuration described with reference to FIGS. 12 to 14, the sheet held by the gripper 91 or 92 of the transfer cylinder 84 is electrostatically attracted to the conveyance guide 150, so that the recording surface (the surface to which the permeation suppressor is applied). ) Does not contact the member of the transfer cylinder 84, and even when heated and dried, defects such as wrinkles and burrs are less likely to remain, and traces of the exhaust holes are less likely to remain.

  In addition to the configuration in which the hot air is exhausted from the gap between the sheets in the conveyance guide 150, the configuration in which the exhaust width of the conveyance guide 150 is wider than the sheet width allows the hot air to move quickly in the width direction. Drying and drying air recovery are further stabilized (see FIG. 13).

  FIG. 15A illustrates an arrangement (pattern) of the openings 151 provided with the recording medium suction surface of the conveyance guide 150. It is preferable to arrange the openings in a staggered arrangement with a diameter of 0.5 to 3 mm and the number of openings in a pitch of 2 to 5 times the hole diameter. It is also possible to change the diameter of the opening 152 or increase the number of openings 151. FIG. 15B shows a conveyance guide 150 having a pattern of the opening 151 in which the diameter of the opening 151 is increased toward the upstream in the conveyance direction and the opening diameter of the central portion in the width direction is larger than that of the end portion. When the pattern shown in FIG. 15B is applied, the exhaust efficiency of the drying air after the trailing edge of the sheet has come out of the conveyance guide is further improved. Further, by increasing the suction amount at the center portion in the width direction, the sheet adsorbability is improved and the suction loss of narrow paper is reduced.

  FIG. 16 is a plan view schematically showing the relationship between the sheet on the conveyance guide 150 and the hot air jet area. In FIG. 16, reference numeral 14-1 indicates a downstream sheet, and reference numeral 14-2 indicates the next sheet. In addition, an area (reference numeral 180) indicated by a two-dot chain line in the drawing indicates an injection area of hot air injected from the transfer cylinder 84 to the preceding downstream sheet 14-1.

(About gaps between paper)
As shown in FIG. 16, the gap between the transported paper and the paper is at a position where at least a part of both the downstream paper 14-1 and the upstream paper 14-2 is opposed to the transport guide 150 (position that can be sucked). In some cases, the amount of air exhausted from the gap between the paper and the paper is set to be larger than the amount of air jetted from the hot air jet member 96 to the downstream paper 14-1, and the downstream and upstream paper 14- 1 and 14-2, even when the upper surface of the conveyance guide 150 is in a semi-sealed state, it is possible to reduce the retention of vapor when the paper which is conveyed to the transfer cylinder 84 by the gripper 91 or 92 and forms a humid air layer performs surface evaporation. In addition, it promotes drying and prevents steam contamination in the machine.

Specifically, the maximum is determined by the ejection regulating member 116 and the openings 104 and 105 of the transfer cylinder 84 when both the downstream side paper 14-1 and the upstream side paper 14-2 are at positions facing the conveyance guide 150. The exhaust air volume from the opening of the conveyance guide 150 located at a position corresponding to the gap between the paper sheets is made larger than the jet air volume. In particular, as shown in FIG. 17, the suction angle R corresponding to the gap between the sheet and the sheet from the injection angle _RA corresponding to the hot air injection range for the downstream sheet 14-1 when the rotation center of the transfer cylinder 84 is used as a reference. A configuration in which _B is increased is preferable because air flows smoothly and drying unevenness is reduced. The injection angle _RA is defined by the edge of the opening of the injection restricting member 116 and the edge of the opening 104 of the transfer cylinder 84. Suction angle R _B is defined by the tip of the rear end and the upstream sheet 14-2 of the downstream side sheet 14-1.

Based on setting information such as paper type (coating layer, basis weight, etc.), temperature / humidity, permeation suppression agent application amount and treatment liquid application amount described later, or detection information, the rotational position of the injection regulating member 116 is controlled. The amount of drying is adjusted by adjusting the injection angle _RA . Since the hot air injection range can be controlled in this way, strong hot air can be injected for an optimal time, so that the start-up of the drying is fast, the polymer particle melting state, film formation defects (porosity), solvent drying amount and penetration. The variation in the amount is reduced, and the image quality and the fixing quality can be stabilized. In addition, if an ultrasonic vibration type vibration means (not shown) provided on the conveyance guide 150 is also controlled, it is possible to perform control with even higher responsiveness, and the drying property is further stabilized.

  Further, the gripper support portions 101 and 102 of the transfer cylinder 84 are provided with a sensor 181 as a temperature or moisture measuring means such as an infrared thermometer or an infrared moisture meter, and the injection regulation is performed according to the measurement result of the sensor 181. The member 116 is controlled. For example, the sensor 181 measures the temperature change or moisture change with time (particularly the rising characteristics) near the leading edge of the sheet, and controls the injection restricting member 116 based on the measurement result. Since the hot air spraying range can be corrected even for paper, stable drying is possible even for variations in paper thickness, moisture absorption, permeation suppression agent application amount, and treatment liquid application amount described later.

(Description of the transfer drum drying process)
Next, details of the transfer drum drying will be described.

  FIG. 18 is a diagram illustrating an example of the monitor position 183 by the sensor 181. Here, imposition (eight pages) printing is exemplified, but the printing mode is not limited to multi-chamfer printing, and printing for one page may be performed on one sheet.

The upper direction in FIG. 18 is the printing direction (paper transport direction), and among the paper size L × W, the leading edge margin M ₁ (the portion to be adjusted by the grippers 91 and 92), the trailing edge margin M ₂ , The inside of the left margin M ₃ and the right margin M ₄ is the print effective area 186. Note that a permeation inhibitor is applied to the entire surface of the print effective area 186. Then, image recording is performed on the inner side of the print effective area while ensuring a product finishing dimension α × β and predetermined amounts of cuts γ and δ on the left and right sides.

  In FIG. 18, a monitor position 183 of the sensor 181 is a portion indicated by hatching with a reference numeral 183 in the vicinity of the center of the margin area of the sheet in the sheet width direction. As described with reference to FIG. 17, by arranging the sensor 181 at the same place for each of the grippers 91 and 92 of the transfer cylinder 84, the recording medium 14 is transferred to the transfer cylinder 84 to the next impression cylinder. It is possible to continuously detect the temperature until delivery. By recording the time change of the temperature, it is possible to acquire the time change (rise curve) of the surface temperature after the recording medium 14 is dried by the transfer cylinder 84 and the conveyance guide 150.

  FIG. 19 is a graph showing an example of the time variation of the acquired surface temperature. The horizontal axis represents the drying time, and the vertical axis represents the surface temperature. “MFT” on the vertical axis represents the minimum film-forming temperature of the polymer added to the coating solution.

  As shown in the figure, the temperature rises rapidly immediately after detection by heating by the conveyance guide 150 and heating by the dry wind sprayed from the transfer cylinder 84, and humid air is formed. After that, when evaporation continues, it reaches a certain equilibrium state, and rises to the right again when moisture decreases.

  Since the application amount of the permeation inhibitor and the treatment liquid described later is 1 to 10 μm, the temperature change occurs in a short time. By providing a radiation temperature sensor at the illustrated position, the temperature rises immediately after the gripper 91 or 92 picks up the paper, and the rotation of the injection restricting member 116 is controlled by looking at the gradient of this temperature change. .

A solid line (f ₁ ) is a graph when the drying amount is appropriately controlled according to the present embodiment. A broken line (f ₂ ) is a comparative example when drying is too strong. In this case, since the film formation of the added polymer starts before the evaporation of the solvent such as water, it tends to cause poor drying (the polymer film is formed at the point B). On the other hand, the broken line (f ₃ ) is a comparative example when drying is too weak. In this case, although a polymer film is formed at the point C, since it takes too much time to dry the solvent such as water, it cannot be dried within the passage time of the conveyance guide 150, and the solvent such as water remains on the recording medium 14. There is a problem that the drawability and fixability of ink are lowered.

In this embodiment, the amount of drying is appropriately controlled by measuring the time change of the surface temperature (f ₁ ) so as not to cause problems in these comparative examples (f ₂ ) and (f ₃ ).

  The drying amount can be controlled by a plurality of parameters such as the temperature of hot air, the amount of air, and the amount of suction by the conveyance guide 150. Here, instead of the direct quantitative specification of the hot air injection amount and the suction amount from the gap between the sheets, the hot air injection range correlated with these and the gap amount between the sheets The case of considering the relationship will be described.

Since the transfer cylinder 84 of this example is configured to transport two sheets of paper with two grippers, the gap between the sheets (during continuous feeding) is determined by the design of the maximum length of the paper to be handled and the diameter of the transfer cylinder 84. Maximum gap) is determined. On the other hand, the hot air injection range (the injection angle R _B described with reference to FIG. 17) can be variably controlled by the rotation position of the injection restricting member 116. The spray start position of the dry air with respect to the recording medium 14 (the front end position of the spray range) is constant because it is defined by the opening of the gripper support portion 112. The injection end position (the rear end position of the injection range) can be adjusted by the position of the opening of the injection restricting member 116. By rotating the injection restricting member 116 according to the measurement result of the surface temperature by the sensor 181, the end position of the dry air injection range can be appropriately controlled. The suction amount increases as the ejection range (ejection angle) in the sheet conveyance direction increases.

  In FIG. 17, the upstream side paper 14-2 is in an initial state of conveyance by the conveyance guide 150, and is a stage in which a humid air layer is formed in the vicinity of the sheet surface by heating by the conveyance guide 150 and hot air jet from the transfer cylinder 84. is there. At this stage, the amount of solvent evaporation such as water is still small.

  Eventually, as the transfer cylinder 84 rotates, the paper is transported downstream along the transport guide 150, during which the heating and drying process proceeds (see FIG. 19). In the vicinity of the position of the downstream paper 14-1 in FIG. 17, there is much evaporation from the surface, and steam is generated.

  The sensor 181 measures the time change (preferably the rising characteristics) of a solvent such as temperature and water, and controls the rotational position of the ejection restricting member 116, so that hot air is also applied to the paper being dried by the transfer cylinder 84. The injection range can be corrected. Thereby, stable drying is possible even with respect to variations such as the paper thickness and moisture absorption of each paper, the permeation treatment liquid, and the application amount of the treatment liquid described later.

  Next, another structural example (second example) of the transfer drum will be described.

  FIG. 20 shows a structural example (second example) of the transfer drum. 20, members that are the same as or similar to the components described in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. The second example of FIG. 20 is a mode in which the function of the hot air injection opening in the hot air injection member 96 of the first example described in FIGS. 12 to 17 is realized by an opening formed in the main body of the transfer drum.

  That is, as shown in FIG. 20, the transfer cylinder 84 ′ has a large number of injection openings 109 for radially injecting hot air to the outer peripheral surface of the transfer cylinder other than the gripper support portions 101 and 102 along the width direction and the conveyance direction. ing. An injection restricting member 116 that controls the injection range is disposed inside the transfer cylinder 84 '. The injection regulating member 116 is disposed coaxially with the transfer drum 84 ', can be controlled to rotate relative to the transfer drum 84', and rotates together with the transfer drum 84 '. As a result, the ejection opening 109 for ejection with respect to the recording medium 14 is maintained in a certain relationship.

  Further, a shielding member 188 for restricting the hot air injection start position onto the recording medium 14 is disposed outside the transfer drum 84 '. The shielding member 188 is disposed on the upstream side in the rotation direction of the transfer cylinder 84 ′ of the sheet transfer portion between the impression cylinder 40 and the transfer cylinder 84 ′. Hot air that has passed through the end portion 188 </ b> A of the shielding member 188 is jetted onto the recording medium 14 passed from the impression cylinder 40 to the gripper 91 or 92. In addition, the said shielding member 188 also fulfill | performs the function which suppresses the outflow of a hot air to the unnecessary part in a machine.

  The configuration of the conveyance guide 150 disposed to face the transfer drum 84 'is as described with reference to FIG. If the exhaust width of the conveyance guide 150 is wider than the paper width, the hot air can be moved quickly in the width direction, and the drying of the paper and the discharge and collection of the dry air are further stabilized. If the exhaust amount of the conveyance guide 150 is increased toward the upstream side in the conveyance direction, the efficiency of discharging the drying air after the trailing edge of the sheet has been removed from the conveyance guide 150 is further improved.

  Furthermore, the flow of drying air can be increased by increasing the spray amount of the spray opening 109 formed on the peripheral surface of the transfer cylinder 84 'toward the rear end of the sheet or the central portion in the width direction by increasing the diameter or number of the openings. Becomes smoother and the drying is more stable.

  An example is shown in FIGS. FIGS. 21A to 21C are developed plan views schematically illustrating an example of forming the injection opening 109 in the transfer cylinder 84 ′. In the drawing, the upper side is the downstream side (paper front end side) in the paper transport direction.

  FIG. 21A shows an opening pattern in which all the injection openings 109 have the same diameter. On the other hand, FIG. 21B shows an opening pattern in which the diameter of the ejection opening 109 is larger at the center in the width direction and the diameter of the ejection opening 109 is larger toward the upstream in the transport direction. The opening pattern shown in FIG. 21C is an opening pattern in which the diameter of the ejection opening 109 is larger at the center in the width direction and the diameter of the ejection opening 109 is larger toward the downstream in the transport direction. Specifically, it is preferable that the diameter of the ejection openings 109 is φ0.3 to 3 mm, and the number of the ejection openings 109 is staggered by 2 to 5 times the hole diameter at a pitch. When the opening pattern shown in FIG. 21B is applied, since the amount of hot air jetted on the upstream side in the transport direction is larger than that on the downstream side in the transport direction, drying of the front end portion of the recording medium 14 is promoted. On the other hand, when the opening pattern shown in FIG. 21C is applied, since the amount of hot air jetted on the downstream side in the transport direction is larger than that on the upstream side in the transport direction, drying of the rear end portion of the recording medium 14 is promoted.

According to the transfer cylinder 84 ′ configured as described above, as shown in FIG. 22, the injection angle R corresponding to the hot air injection range for the downstream side paper 14-1 when the rotation center of the transfer cylinder 84 ′ is used as a reference. the arrangement of increasing the paper and the amount of exhaust by increasing the suction angle R _B corresponding to the gap of the sheet than _a, the air flow becomes smooth, drying unevenness is also suitable to reduce.

  In addition, the jet restricting member 116 provided inside the transfer cylinder 84 ′ prevents jetting of hot air unnecessary for drying such as facing the conveyance guide 150, and the type of paper (coating layer, basis weight, etc.), sensor The drying amount can be adjusted based on setting information and detection information such as the temperature / humidity measured by 181, the permeation treatment liquid and the amount of treatment liquid described later.

  Since the spraying range can be controlled in this way, strong hot air can be sprayed for an optimal time, the rise of drying is fast, and the temperature can be adjusted to a temperature suitable for MFT of polymer particles. Therefore, variations in the melted state, film formation defects (porosity), solvent drying amount and penetration amount are reduced, and image quality and fixing quality can be stabilized. If the ultrasonic vibration type vibration means (not shown) provided in the conveyance guide 150 is also controlled, it is possible to perform control with even higher responsiveness and further stabilize the drying property.

  The configuration of the transfer cylinder 84 (or 84 ') described in FIGS. 20 to 22 is also applied to the other transfer cylinders 214 and 304 in FIG. The ejection amount of the ejection opening 109 formed in the drawing of the transfer cylinder 84 ′ is such that the leading edge of the sheet is increased in addition to the trailing edge of the sheet and the central portion in the width direction, and the trailing edge of the sheet is attracted to the conveyance guide 150. The float may be reduced by improving the property.

(Description of treatment liquid application unit 26)
Next, the treatment liquid application unit 26 (see FIG. 1) disposed at the subsequent stage of the transfer drum 84 will be described.

  In the treatment liquid application unit 26, the treatment liquid head 202 and the treatment liquid drying unit are arranged at positions facing the circumferential surface of the impression cylinder 86 in order from the upstream side in the rotation direction of the impression cylinder 86 (counterclockwise direction in FIG. 1). 204 is provided.

  The treatment liquid head 202 ejects treatment liquid onto the recording medium 14 held by the impression cylinder 86, and has the same configuration as the ink heads 210Y, 210M, 210C, and 210K disposed in the printing unit 28. However, according to the viscosity, surface tension, pH (hydrogen ion concentration) of the treatment liquid (aggregation treatment agent), the shape of the nozzle, the surface treatment, the driving waveform, and the like may be adjusted.

  Instead of the treatment liquid head 202, the same configuration as that of the permeation suppression processing unit 24 described with reference to FIGS.

  In addition, the pressure drum 86 that holds and conveys the recording medium 14 in the treatment liquid application unit 26 includes a gripper 87 (see FIG. 12) that holds the tip of the recording medium 14 with a step with respect to the outer peripheral surface. Therefore, the spiral roller 48 (see FIG. 2) of the treatment liquid application unit 26 is configured to be separated from the outer peripheral surface of the corresponding impression cylinder at the gripper 87 to avoid a step. The arrangement of the gripper 87 and the roller separation structure shown in FIG. 12 are also applied to the other impression cylinders 40, 306, and 326 (see FIG. 1) that convey the recording medium. On the other hand, since the heads 210K, 210C, 210M, and 210Y need to be close to the recording medium for the pressure drum 216 of the printing unit 28, a structure that prevents the gripper 87 from protruding from the outer peripheral surface is applied.

  About the process liquid drying unit 204, the structure similar to the penetration inhibitor drying unit 46 of the penetration suppression process part 24 mentioned above is applied. The treatment liquid drying unit 204 is provided with a heater (not shown) capable of controlling the temperature in the range of 50 to 130 ° C. and a fan (not shown) that blows out downstream at a wind speed of 5 to 50 m / s. When the recording medium 14 held on the pressure drum 86 of the treatment liquid application unit 26 passes downstream from a position facing the treatment liquid drying unit 204, hot air heated to 50 to 130 ° C. by the heater is recorded by the fan. 14, the recording medium 14 is heated to dry the treatment liquid.

  The processing liquid used in this example has an action of aggregating the color materials contained in the ink ejected from the respective ink heads 210K, 210C, 210M, and 210Y disposed in the printing unit 28 in the subsequent stage toward the recording medium 14. The acidic liquid which has is preferable. Specifically, a treatment solution described in Table 2 below, or a treatment solution to which an acid such as 2-pyrrolidone-5-carboxylic acid, phosphoric acid, succinic acid, or citric acid is added can be considered.

  In addition, by adding a small amount of a high boiling point solvent such as glycerin or polymer particles such as LX-1 or LX-2 described in Table 1, the above-described permeation suppression layer is made unnecessary by suppressing the permeation of the treatment liquid. Is also possible. Therefore, if the treatment liquid having such a permeation suppression effect is applied by the liquid application apparatus 42, the pressure drum 86 of the treatment liquid application unit 26, the treatment liquid application apparatus 202, the treatment liquid drying unit 204, and the like are unnecessary. It becomes.

  A printing unit 28 is provided following the treatment liquid application unit 26. A transfer drum 214 is provided between the pressure drum 86 of the treatment liquid application unit 26 and the pressure drum 216 of the printing unit 28 so as to be in contact therewith. Thus, the recording medium 14 held on the pressure drum 86 of the treatment liquid application unit 26 is applied with a gripper (not shown) via the transfer cylinder 214 after the treatment liquid is applied to form an aggregating treatment agent layer. The pressure is transferred to the impression cylinder 216 of the printing unit 28.

  A transport guide 150 is provided at a position facing the peripheral surface of the transfer drum 214 as in the case of the transfer drum 84. The drawing surface is in the range of 40 to 60 ° C. while the drawing surface is conveyed in a non-contact manner by hot air blown from the transfer cylinder 214 and hot suction of 50 to 130 ° C. and the electrostatic suction type conveyance guide 150 adjusted to 50 to 90 ° C. Then, a solid or semi-solid aggregation treatment agent layer (a thin film layer from which the treatment liquid has been dried) is formed on the recording medium 14. The “solid or semi-solid flocculating agent layer” as used herein refers to a layer having a moisture content in the range of 0 to 70% as defined in [Equation 1].

  The configuration of the transfer drum 214 is the same as that of the transfer drums 84 and 84 ′ of the permeation suppression processing unit 24 described above, and a description thereof will be omitted.

(Description of printing unit 28)
Black (K) is placed on the printing unit 28 at a position facing the peripheral surface of the impression cylinder 216 in order from the upstream side in the rotation direction (counterclockwise direction in FIG. 1) of the impression cylinder 216 adjusted to 30 to 50 ° C. ), Cyan (C), magenta (M), and yellow (Y), ink heads 210K, 210C, 210M, and 210Y corresponding to the four colors of ink, respectively, are provided.

  As each of the ink heads 210K, 210C, 210M, and 210Y, an ink jet type recording head (ink jet head) is applied. Each of the ink heads 210K, 210C, 210M, and 210Y discharges the corresponding color ink droplets toward the recording medium 14 held in a state of being vacuum-adsorbed or electrostatically adsorbed to the pressure drum 216.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink color and number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add an ink head that discharges light-colored ink such as light cyan and light magenta, and the arrangement order of the color heads is not particularly limited.

[Head structure]
Next, the structure of each head will be described. Since the structures of the color-specific heads 210K, 210C, 210M, and 210Y are the same, the head is represented by the reference numeral 210 as a representative of them. As described above, the structure similar to that of the ink head 210 may also be adopted for the treatment liquid coating apparatus 202 used in the treatment liquid application unit 26.

  FIG. 23A is a plan perspective view showing a structural example of the ink head 210, and FIG. 23B is an enlarged view of a part thereof. In order to increase the dot pitch printed on the recording medium 14, it is necessary to increase the nozzle pitch in the ink head 210. As shown in FIGS. 23A and 23B, the ink head 210 of this example includes a plurality of ink chamber units (nozzles 281 serving as ink discharge ports), pressure chambers 282 corresponding to the respective nozzles 281 and the like. It has a structure in which droplet ejection elements 283 as recording element units are arranged in a zigzag matrix (two-dimensionally), thereby arranging them in the longitudinal direction of the head (direction perpendicular to the paper transport direction). Thus, the density of the substantial nozzle interval (projection nozzle pitch) projected is increased.

  A configuration in which one or more nozzle rows are formed in a direction corresponding to the entire width of the image forming region in a direction (arrow M in FIG. 23) substantially orthogonal to the conveyance direction of the recording medium 14 (arrow S in FIG. 23) is illustrated. It is not limited to examples. For example, instead of the configuration of FIG. 23 (a), as shown in FIG. 24, long head modules 280 ′ in which a plurality of nozzles 281 are two-dimensionally arranged are arranged in a staggered manner and connected to each other. Therefore, a line head having a nozzle row having a length corresponding to the entire width of the image forming area of the recording medium 14 as a whole may be configured.

  The pressure chamber 282 provided corresponding to each nozzle 281 has a substantially square planar shape (see FIGS. 23A and 23B), and the nozzle 281 is provided at one of the diagonal corners. An outlet for supplying ink (supply port) 284 is provided on the other side. Note that the shape of the pressure chamber 282 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  25 is a cross-sectional view (a line BB in FIG. 23) showing a three-dimensional configuration of one-channel droplet discharge elements (ink chamber units corresponding to one nozzle 281) serving as a recording element unit in the ink head 210. FIG.

  As shown in FIG. 25, each pressure chamber 282 communicates with the common flow path 285 through the supply port 284. The common channel 285 communicates with an ink tank (not shown) that is an ink supply source, and the ink supplied from the ink tank is supplied to each pressure chamber 282 via the common channel 285.

  An actuator 288 provided with an individual electrode 287 is joined to a pressure plate (vibrating plate also used as a common electrode) 286 constituting a part of the surface of the pressure chamber 282 (the top surface in FIG. 25). By applying a driving voltage between the individual electrode 287 and the common electrode, the actuator 288 is deformed to change the volume of the pressure chamber 282, and ink is ejected from the nozzle 281 due to the pressure change accompanying this. For the actuator 288, a piezoelectric element using a piezoelectric body such as lead zirconate titanate or barium titanate is preferably used. After the ink is ejected, when the displacement of the actuator 288 is restored, new ink is refilled into the pressure chamber 282 from the common channel 285 through the supply port 284.

  By controlling the drive of the actuator 288 corresponding to each nozzle 281 according to dot data generated from the input image by digital halftoning processing, ink droplets can be ejected from the nozzle 281. A desired image can be recorded on the recording medium 14 by controlling the ink ejection timing of each nozzle 281 in accordance with the conveying speed while conveying the recording medium 14 in the sub-scanning direction at a constant speed.

  As shown in FIG. 26, the ink chamber units 283 having the above-described structure are latticed in a fixed arrangement pattern along a row direction along the main scanning direction and an oblique column direction having a constant angle θ not orthogonal to the main scanning direction. The high-density nozzle head of this example is realized by arranging a large number in the shape.

That is, with a structure in which a plurality of ink chamber units 283 are arranged at a constant pitch d along a direction of an angle θ with respect to the main scanning direction, the pitch P of the nozzles projected (orthographically projected) to be aligned in the main scanning direction. _N is d × cos θ, and in the main scanning direction, each nozzle 281 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a substantial increase in the density of nozzle rows projected so as to be aligned in the main scanning direction.

  When the nozzles are driven by a full line head having a nozzle row having a length corresponding to the entire printable width, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially moved from one side to the other. (3) The nozzles are divided into blocks, and each block is sequentially driven from one side to the other, and so on. One line (1 in the width direction of the recording medium 14 (direction perpendicular to the transport direction)) Driving a nozzle that prints a line of dots in a row or a line consisting of dots in a plurality of rows is defined as main scanning.

  In particular, when driving the nozzles 281 arranged in a matrix as shown in FIG. 26, the main scanning as described in the above (3) is preferable. That is, nozzles 281-11, 281-12, 281-13, 281-14, 281-15, 281-16 are made into one block (other nozzles 281-21,..., 281-26 are made into one block, .., 281-36 as one block,...), And the nozzles 281-11, 281-12,. One line is printed in the width direction of 14.

  On the other hand, by moving the full line head and the recording medium 14 relative to each other, printing of one line (a line formed by one line of dots or a line composed of a plurality of lines) formed by the main scanning described above is repeatedly performed. This is defined as sub-scanning.

  The direction indicated by one line (or the longitudinal direction of the belt-like region) recorded by the main scanning is referred to as a main scanning direction, and the direction in which the sub scanning is performed is referred to as a sub scanning direction. That is, in the present embodiment, the conveyance direction of the recording medium 14 is the sub-scanning direction, and the direction orthogonal to the recording medium 14 is the main scanning direction. In implementing the present invention, the nozzle arrangement structure is not limited to the illustrated example.

  In this embodiment, a method of ejecting ink droplets by deformation of an actuator 88 typified by a piezo element (piezoelectric element) is adopted. However, the method of ejecting ink is not particularly limited in implementing the present invention. Instead of the piezo jet method, various methods such as a thermal jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are ejected by the pressure can be applied.

(Description of solvent drying unit 30)
Following the printing unit 28, a solvent drying unit 30 is provided. FIG. 27 illustrates a schematic configuration of the solvent drying unit 30.

  As shown in FIG. 27, a transfer drum 304 is provided between the pressure drum 216 of the printing unit 28 and the pressure drum 306 of the solvent drying unit 30 so as to be in contact therewith. As a result, the recording medium 14 held on the pressure drum 216 of the printing unit 28 is delivered to the pressure drum 306 of the solvent drying unit 30 via the transfer drum 304 after each color ink is applied.

  Since the configuration of the transfer drum 304 is the same as that of the transfer drum 84 (or 84 'in FIG. 17) of the permeation suppression processing unit 24 described above, the description thereof is omitted.

  A transport guide 150 is provided at a position facing the peripheral surface of the transfer drum 304, as with the transfer drums 84 and 84 '. Then, while the drawing surface is conveyed in a non-contact manner by hot air of 50 to 130 ° C. blown from the transfer drum 304 and the electrostatic suction type conveyance guide 150 adjusted to 50 to 90 ° C., the drawing surface is heated to 40 to 60 ° C. It heats in the range, forms a moist air layer on the surface, and evaporates water mainly present on the surface out of the water contained in the ejected ink.

  A sensor unit 182 is provided on the gripper support portions 101 and 102 of the transfer drum 304. The sensor unit 182 reads the optical density (here, the amount of reflected light) of a check pattern (for example, the patch 550 in FIG. 37) drawn on the non-image portion of the recording medium 14, and the ink ejection volume and image data are read according to the read result. Is corrected, it is possible to stabilize the image density even when the ink discharge volume, the treatment liquid application amount, or the like changes due to the temperature rise in the apparatus. In addition to the optical density of the check pattern drawn on the non-image portion of the recording medium 14, it is also possible to correct the heating and drying conditions in real time by measuring the temperature and moisture content. The drying of the image area is also stable.

  In addition to the check pattern formed on the non-application portion by an in-line sensor (reference numeral 348 in FIG. 1) described later, ink is applied to the application portion and the non-application portion of the aggregation treatment agent in the recording medium 14, and the application portion. By measuring the optical density of the check pattern and the white background and detecting the degree of aggregation of the ink, the rotation number and the urging force of the coating roller are controlled to control the application amount of the aggregation treatment agent.

  When the check pattern is formed by dot separation such as staggered, it is possible to detect the degree of aggregation by measuring the dot diameter in addition to the optical density measurement by using an imaging device such as a CCD for the in-line sensor. Therefore, it is possible to detect aggregation with higher accuracy. Details of the check pattern detection method, temperature control based on the detection result, and droplet ejection correction will be described with reference to FIGS.

  A solvent drying unit 308 is disposed opposite to the peripheral surface of the impression cylinder 306 to which the recording medium 14 is transferred from the transfer cylinder 304. The solvent drying unit 308 can use infrared irradiation means or hot air injection means. Ink is used to prevent drying and adjust viscosity by heating the drawing surface of the recording medium 14 on the impression cylinder 306 to 40 to 80 ° C. by irradiation with infrared rays and hot air blowing by the solvent drying unit 308. The viscosity of the high boiling point solvent such as glycerin or diethylene glycol contained in is reduced. Further, if the polymer particles contained in the ink are melted to form a film, the fixability can be improved. The permeation suppression layer applied by the permeation suppression processing unit 24 is also gradually formed by the processing liquid applied by the processing liquid application unit 26 so that the high-boiling solvent can permeate into the recording medium 14.

  FIG. 27 illustrates a configuration example of the solvent drying unit 308 in which IR heaters 310 and blower fans 312 are alternately arranged along the outer peripheral surface of the impression cylinder 306. As shown in FIG. 27, a mode in which a heating control member (shutter) 314 is provided between the blower fan 312 and the outer peripheral surface of the pressure drum 306 to control the amount of wind radiated from the blower fan 312 is preferable.

  The heating control member 314 shown in FIG. 27 is configured to be slidable between the blower fan 312 and the outer peripheral surface of the impression cylinder 306, and by blocking a part of the radiation area of the blower fan 312, the amount of air radiated to the recording medium. Can be reduced. In FIG. 27, only the blower fan 312 on the most downstream side in the conveyance direction of the recording medium 14 is provided with the heating control member 314. Of course, the other blower fans 312 may be provided with the heating control member 314. Good.

  The IR heater 310 is configured such that the amount of radiant heat can be varied. When the surface temperature of the recording medium 14 is set, the amount of radiant heat of the IR heater 310 (or the IR heater 310 is turned on / off) corresponding to the set temperature. Is controlled.

  The solvent drying unit 308 shown in this example controls the amount of radiant heat corresponding to a preset surface temperature of the recording medium by appropriately controlling the amount of radiant heat of the IR heater 310 and the amount of air of the blower fan 312. Further, it is also preferable to control the radiant heat amount of the IR heater 310 and the radiant air amount of the blower fan 312 based on temperature information obtained from the sensor unit 182 provided in the transfer drum 304.

  A sensor unit 182 provided in the gripper support portions 101 and 102 of the transfer drum 304 is an infrared thermometer that detects the temperature of a liquid such as ink attached to a recording medium (not shown in FIG. 27, but indicated by reference numeral 520 in FIG. 33). And a reflection type optical sensor (not shown in FIG. 27, indicated by reference numerals 521 and 522 in FIG. 33) for detecting the reflection optical density of the liquid adhering to the recording medium, and the temperature detection result of the sensor unit 182 The ejection regulating member 116 is controlled according to (or the moisture amount detection result), and the droplet ejection correction of the printing unit 28 can be performed according to the detection result of the optical density of the ink.

  For example, the sensor unit 182 measures the time change (preferably the rising characteristic) of the temperature or moisture at the same location near the front end of the paper, and controls the injection restricting member 116 based on the measurement result to dry the transfer drum 304. Since the hot air spraying range can be corrected even for the inner paper, stable drying is possible even with respect to variations in paper thickness, moisture absorption, permeation suppression agent application amount, treatment liquid application amount, and the like.

  Although the transfer cylinder 304 located on the downstream side in the recording medium conveyance direction of the printing unit 28 has been described, the same configuration can be applied to other transfer cylinders.

(Description of the heat and pressure fixing unit 32)
Subsequent to the solvent drying unit 30, a hot-pressure fixing unit 32 is provided. A transfer drum 324 is provided between the pressure drum 306 of the solvent drying unit 30 and the pressure drum 326 of the heat and pressure fixing unit 32 so as to be in contact therewith. As a result, the recording medium 14 held on the pressure drum 306 of the solvent drying unit 30 removes the water of each color ink and the high boiling point solvent is reduced in viscosity, and then passes through the transfer drum 324 to the hot pressure fixing unit 32. Passed to the impression cylinder 326.

  The heat and pressure fixing unit 32 is provided with heat rollers (fixing rollers) 328 a, 328 b, and 328 c that are temperature-controlled at 60 to 120 ° C., facing the pressure drum 326 that is temperature-controlled at 40 to 80 ° C. The heat rollers 328a, 328b, and 328c are preferably those in which a surface such as rubber is coated with a liquid repellent material such as PFA or fluorine-based elastomer, or a hard material that is subjected to a treatment such as hard chrome plating. Further, a cleaning unit 329 having a release agent application function is in contact with the heat rollers 328a, 328b, and 328c. The release agent may be a general release silicone oil or a high-boiling solvent having paper permeability, and the coating thickness is preferably 30 nm to 1 μm from the viewpoint of release properties and glossiness.

  The transfer drum 324 is provided with a stamp-type member 325 using a winding-type non-woven fabric, and the stamp-type member 325 cannot penetrate into the recording medium 14 during conveyance of the impression drum 306 and the transfer drum 324. Absorbs high boiling solvents.

  Note that a conveyance guide 150 is provided at a position facing the peripheral surface of the transfer drum 324 in the same manner as the transfer drums 84, 214, and 304. Then, while the drawing surface is conveyed in a non-contact manner by hot air of 50 to 70 ° C. blown from the transfer drum 324 and the electrostatic suction type conveyance guide 150 adjusted to 50 to 70 ° C., the drawing surface is set to 40 to 60 ° C. The in-plane temperature distribution of the recording medium 14 heated to a high temperature by the solvent drying unit 308 and the film of polymer particles are stabilized.

  Thereafter, the recording medium 14 delivered to the impression cylinder 326 heated by a heating means (not shown) is hot-pressed by the heat rollers 328a, 328b, and 328c, thereby sufficiently forming the polymer particles added to the ink. As a result, the image is fastened and fixed on the recording medium 14.

  FIG. 28 is an enlarged view of the hot-pressure fixing unit 32, and shows an outline of the roller-switching type hot-pressure fixing unit 32. According to the roller-switching type hot-pressure fixing unit 32, it is possible to obtain an appropriate surface gloss according to the recording medium 14.

  Specifically, an uneven surface subjected to mat finishing blasting or the like at a position facing the peripheral surface of the impression cylinder 326 in order from the upstream side in the rotation direction of the impression cylinder 326 (counterclockwise direction in FIG. 28). A heat roller 328a having a smooth surface with a rubber surface coated with PFA or the like, and a heat roller 328c having a smooth surface with a metal surface coated with PFA or the like.

The nip pressure of the heat roller is set to 0.5 to 1.5 MPa for the heat rollers 328a and 328b and to 1 to 2 MPa for the heat roller 328c.
Table 2 shows a combination example of the nip (on) of the heat rollers 328a, 328b, and 328c to the impression cylinder 326 and the separation (release) from the impression cylinder 326 (off).

  As shown in Table 2, when the recording medium 14 is mat coated paper (combination No. 5), only the heat roller 328a is nipped, and the heat rollers 328b and 328c are separated from the impression cylinder 326 by a release mechanism (not shown). . By conveying the recording medium 14 in this state, the surface is finished in a mat shape, and the image can be reliably fixed to the recording medium 14 by heat pressure.

  When the recording medium 14 is gloss coated paper (combination No. 2 in Table 2), only the heat roller 328c is nipped, and the heat rollers 328a and 328b are separated from the impression cylinder 326 by a release mechanism (not shown). By conveying the recording medium 14 in this state, the surface is finished glossy, and the image can be reliably fixed to the recording medium 14 by heat pressure.

  When the recording medium 14 is located between the matte coated paper and the gloss coated paper (combination No. 3 in Table 2), only the heat roller 328b is nipped, and the heat rollers 328a and 328c are moved by a release mechanism (not shown). Separated from the impression cylinder 326. By transporting the recording medium 14 in this state, the surface is finished in an intermediate state, and the image can be reliably fixed to the recording medium 14 by heat pressure.

  When the recording medium 14 is thick gloss coated paper or solid printing (combination No. 4 in Table 2), the heat rollers 328b and 328c are nipped, and the heat roller 328a is moved by a release mechanism (not shown). Separated from the impression cylinder 326.

  Further, at the time of maintenance of the apparatus, or at the time of error processing such as coating failure, droplet ejection failure or drying failure of the recording medium 14 (combination No. 1 in Table 2), all the heat rollers 328a, 328b, 328c are moved to the impression cylinder. It is separated from 326.

  In addition, in the case of special finishing (combination Nos. 6, 7, and 8 in Table 2), as shown in Table 2, the nip of the heat rollers 328a, 328b, and 328c to the impression cylinder 326, and the impression cylinder 326, respectively. Separate from.

  Since the heat roller 328a arranged upstream has an uneven surface, the ink adheres lightly even when the solvent is penetrating into the recording medium 14, and the heat roller 328b arranged downstream has a smooth surface. Since the solvent penetration proceeds while passing through the heat roller 328a, the adhesion of ink can be reduced as in the heat roller 328a.

  Further, the heat roller 328c disposed downstream has a smooth surface and a high nip pressure, but since the solvent penetration proceeds while passing through the heat rollers 328a and 328b, the ink adheres similarly to the heat rollers 328a and 328b. It can be mitigated and reliable fixing is possible.

  The heat rollers 328a, 328b, and 328c may be used in combination. In this case, the heat rollers 328a, 328b, and 328c are set according to the thickness and penetration speed of the recording medium 14, the amount of ink droplets corresponding to the image, and the like. It becomes possible to secure more stable gloss and fixing properties.

(Description of discharge unit 34)
A discharge unit 34 is provided following the hot-pressure fixing unit 32. A transfer drum 344 is provided between the pressure drum 326 of the heat and pressure fixing unit 32 and the discharge tray 346 of the discharge unit 34 so as to be in contact therewith. As a result, the recording medium 14 held on the pressure drum 326 of the heat and pressure fixing unit 32 is transferred to the discharge tray 346 via the transfer drum 344 after the image is fastened by the heat and pressure fixing unit 32, It is discharged outside.

  The transfer drum 344 is heated by a heating means (not shown), and further promotes the penetration of the high boiling point solvent and corrects the curl of the recording medium 14.

  Further, the discharge unit 34 includes an image sensor such as a CCD for measuring a check pattern of the recording medium 14, a moisture content, a surface temperature, a glossiness, and an in-line sensor 348 such as an infrared thermometer, an infrared moisture meter, and a gloss meter. Is arranged. As described above, the optical density and dot diameter of the patch are measured by the inline sensor 348 to control the coating amount of the aggregating agent, the color registration is corrected by measuring the pattern of each color, the leading edge and the width direction. The pattern is measured to correct the magnification, and the fixing temperature is adjusted in real time from the surface temperature, so that the quality such as gloss, density, magnification, distortion and displacement is kept stable.

(Description of control system)
FIG. 29 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 470, a system controller 472, a memory 474, a ROM 475, a motor driver 476, a heater driver 478, a print controller 480, an image buffer memory 482, a head driver 484, a processing liquid application controller 501 and the like. ing.

  The communication interface 470 is an interface unit that receives image data sent from the host computer 486. As the communication interface 470, a serial interface such as USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), a wireless network, or a parallel interface such as Centronics can be applied. In this part, a buffer memory (not shown) for speeding up communication may be mounted. The image data sent from the host computer 486 is taken into the inkjet recording apparatus 10 via the communication interface 470 and temporarily stored in the memory 474.

  The memory 474 is a storage unit that temporarily stores an image input via the communication interface 470, and data is read and written through the system controller 472. The memory 474 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 472 includes a central processing unit (CPU) and its peripheral circuits, and functions as a control device that controls the entire inkjet recording apparatus 10 according to a predetermined program, and also functions as an arithmetic device that performs various calculations. . That is, the system controller 472 controls each part such as the communication interface 470, the memory 474, the motor driver 476, the heater driver 478, etc., performs communication control with the host computer 486, read / write control of the memory 474, etc. Control signals for controlling the motor 488 and the heater 489 are generated.

  The ROM 475 stores programs executed by the CPU of the system controller 472 and various data necessary for control. The ROM 475 may be a non-rewritable storage unit, or may be a rewritable storage unit such as an EEPROM. The memory 474 is used as a temporary storage area for image data, and is also used as a program development area and a calculation work area for the CPU.

  The motor driver 476 is a driver that drives the motor 488 in accordance with an instruction from the system controller 472. In FIG. 29, the reference numeral 488 represents a motor arranged in each part in the apparatus. The motor 488 includes motors for driving the pressure cylinders 40, 86, 216, 306, 326, transfer cylinders 84, 214, 304, 324, 344, paper press 44, heat rollers 328a, 328b, 328c described in FIG. And a motor of a moving mechanism for moving (separating from the impression cylinder) the spiral roller 48 of FIG.

  The heater driver 478 is a driver that drives the heater 489 in accordance with an instruction from the system controller 472. In FIG. 29, a plurality of heaters provided in the inkjet recording apparatus 10 are represented by reference numeral 489. The heater 489 includes a permeation suppressor drying unit 46, a treatment liquid drying unit 204, a heater for the solvent drying unit 308, and the like.

  The print control unit 480 has a signal processing function for performing various processes and corrections for generating a print control signal from the image data in the memory 474 under the control of the system controller 472. This is a control unit that supplies data (dot data) to the head driver 484. Necessary signal processing is performed in the print control unit 480, and the ejection amount and ejection timing of the ink droplets of the ink head 210 are controlled via the head driver 484 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 480 includes an image buffer memory 482, and image data, parameters, and other data are temporarily stored in the image buffer memory 482 when image data is processed in the print control unit 480. In FIG. 29, the image buffer memory 482 is shown in a mode accompanying the print control unit 480, but it can also be used as the memory 474. Also possible is an aspect in which the print control unit 480 and the system controller 472 are integrated to form a single processor.

  An overview of the flow of processing from image input to print output is as follows. Image data to be printed is input from the outside via the communication interface 470 and stored in the memory 474. At this stage, for example, RGB image data is stored in the memory 474.

  In the ink jet recording apparatus 10, a pseudo continuous tone image is formed by changing the droplet ejection density and dot size of fine dots with ink (coloring material) to the human eye. It is necessary to convert to a dot pattern that reproduces the gradation (shading of the image) as faithfully as possible. Therefore, the original image (RGB) data stored in the memory 474 is sent to the print control unit 480 via the system controller 472, and the print control unit 480 performs halftoning processing using a threshold matrix, an error diffusion method, or the like. Is converted into dot data for each ink color.

  That is, the print control unit 480 performs a process of converting the input RGB image data into dot data of four colors K, C, M, and Y. Thus, the dot data generated by the print control unit 480 is stored in the image buffer memory 482.

  The head driver 484 is a drive signal for driving the actuator 288 corresponding to each nozzle 281 of the ink head 210 based on print data (that is, dot data stored in the image buffer memory 482) given from the print control unit 480. Is output. The head driver 484 may include a feedback control system for keeping the head driving condition constant.

  When a drive signal output from the head driver 484 is applied to the head 210, ink is ejected from the corresponding nozzle 281. An image is formed on the recording medium 14 by controlling the ink ejection from the ink head 210 while conveying the recording medium 14 at a predetermined speed.

  The system controller 472 functions as a means for controlling hot air drying by the transfer drum 84 and the like and electrostatic adsorption by the transfer guide 150, and controls operations of the blower control unit 492, the transfer drum control unit 494, and the transfer guide control unit 498. To do. The blower control unit 492 controls the operations of the blower 160 and the heater 164 described with reference to FIG.

  The transfer drum controller 494 controls the drive mechanism of the injection restricting member 116 described with reference to FIGS. 12, 13, and the like, and controls the operation of the heater 110. The conveyance guide control unit 498 controls the operation of the heating unit 156.

  The system controller 472 functions as a time change measurement calculation unit that measures a time change of detection signals (measurement information) obtained from the sensor 181 and the sensor unit 182 and controls the transfer cylinder control unit 494 and the like according to the calculation result. To do. Further, the system controller 472 controls the operations of the permeation suppression agent application control unit 502, the solvent drying control unit 504, and the hot pressure fixing control unit 506.

  The reflective optical sensor included in the sensor unit 182 reads a patch (denoted by reference numeral 550 in FIG. 37) ejected onto a non-image portion of a recording medium, and read data of the patch read by the optical sensor. Is sent to the system controller 472. When the system controller 472 acquires the read data from the optical sensor, it sends a command signal to each part of the apparatus so as to control the application of the permeation inhibitor, the application of the treatment liquid, and the ink droplet ejection based on the read data.

  Further, the ink jet recording apparatus 10 of this example includes a processing liquid coating apparatus 202 as a means for applying a processing liquid, and a processing liquid coating control unit 501 for controlling the processing liquid coating apparatus 202. The treatment liquid application control unit 501 controls the treatment liquid application apparatus 202 based on the image data given from the print control unit 480. 2, the roller contact / separation mechanism driving means for the spiral roller 48, the rotational drive means of the spiral roller 48, the main blade contact / separation mechanism driving means, and the ejection of the liquid ejecting section 52. A precision variable regulator that adjusts the pressure is controlled by the processing liquid application controller 501. In the case of applying the ink jet method to the application of the treatment liquid, a drive signal to be applied to the actuator 288 (see FIG. 25) of the treatment liquid head is generated, and the drive signal is applied to the actuator 288 to generate the actuator 288. Including a driving circuit for driving the motor. As described above, a mode in which the treatment liquid is ejected according to the image data and the treatment liquid is selectively ejected to the position where the ink is ejected by the printing unit 28 is a preferable aspect. In addition, the aspect uniformly provided using a spray nozzle is also possible.

  In the case of the liquid application apparatus 42 described with reference to FIG. 2, the permeation suppression agent application control unit 502 is a roller contact / separation mechanism drive unit for the spiral roller 48, a rotation drive unit for the spiral roller 48, and a main blade contact / separation mechanism. The permeation inhibitor application control unit 502 controls the driving means, a precision variable regulator that adjusts the injection pressure of the liquid injection unit 52, and the like.

  The solvent drying control unit 504 controls the operation of the solvent drying unit 308 in the solvent drying unit 30 according to an instruction from the system controller 472.

  The heat and pressure fixing control unit 506 controls the operation of the stamp-type member 854 in the heat and pressure fixing unit 32 and the operations of the heat rollers 328 a to 328 c and the cleaning unit 329 according to an instruction from the system controller 472.

  The system controller 472 receives data of measurement results such as a check pattern, moisture content, surface temperature, and glossiness from an inline sensor 348 disposed in the discharge unit 34.

(About operation | movement of the inkjet recording device 10)
The operation of the inkjet recording apparatus 10 configured as described above will be described.

  The recording medium 14 supplied from the paper feed tray 36 is fed to the peripheral surface of the pressure drum 40 of the permeation suppression processing unit 24 by a gripper (not shown) via the transfer drum 38.

  The recording medium 14 is stocked in advance in a paper feed unit (not shown) preheated to 40 to 50 ° C. before being sent to the paper feed tray 36. Then, the recording medium 14 is supplied to the transfer drum 38 while being in contact with the adhesive roller 37 provided at a position facing the paper feed surface of the paper feed tray 36. In this way, the recording medium 14 is heated and dried by preheating the paper feed unit, and by bringing the recording medium 14 into contact with the adhesive roller 37, foreign matters such as paper dust and dust can be removed. It is possible to increase the speed and stability of drying.

  The recording medium 14 is held on the pressure drum 40 of the permeation suppression processing unit 24 via the transfer cylinder 38, and a permeation suppression agent is selectively applied to a desired region by the liquid application device 42. Thereafter, the recording medium 14 held by the impression cylinder 40 is heated by the permeation inhibitor drying unit 46 while being guided by the sheet presser 44 while being fed in the rotation direction of the impression cylinder 40, and the solvent component (liquid) of the penetration inhibitor. Ingredient) evaporates and dries.

  The recording medium 14 thus subjected to the permeation suppression process is transferred from the pressure drum 40 of the permeation suppression processing unit 24 to the pressure drum 86 of the treatment liquid application unit 26 via the transfer cylinder 84. In the transfer cylinder 84, the permeation inhibitor is heated and dried by the conveyance guide 150 by non-contact drying on the drawing surface. The processing liquid is applied to the recording medium 14 held on the impression cylinder 86 by the processing liquid application device 202. Thereafter, the recording medium 14 held on the impression cylinder 86 is heated by the treatment liquid drying unit 204, and the solvent component (liquid component) of the treatment liquid is evaporated and dried. As a result, a solid or semi-solid aggregation treatment agent layer is formed on the recording medium 14.

  The recording medium 14 to which the treatment liquid is applied to form a solid or semi-solid coagulation treatment agent layer is transferred from the impression cylinder 86 of the treatment liquid application section 26 to the impression cylinder 216 of the printing section 28 via the transfer cylinder 214. Is passed on. In the transfer drum 214, the acid remains on the permeation suppression layer by non-contact drying of the drawing surface by the conveyance guide 150. Corresponding color inks are ejected from the respective ink heads 210K, 210C, 210M, and 210Y to the recording medium 14 held by the impression cylinder 216 in accordance with the input image data.

  When the ink droplet lands on the aggregation treatment agent layer, the contact surface between the ink droplet and the aggregation treatment agent layer lands in a predetermined area due to the balance between the flight energy and the surface energy. The aggregation reaction starts immediately after the ink droplets land on the aggregation treatment agent, but the aggregation reaction starts from the contact surface between the ink droplets and the aggregation treatment agent layer. The agglomeration reaction occurs only in the vicinity of the contact surface, and the color material in the ink is agglomerated in a state where the adhesive force is obtained with a predetermined contact area at the time of ink landing, so that the color material movement is suppressed.

  Even if other ink droplets land adjacent to this ink droplet, the color material of the ink that has landed first is already agglomerated, so the color materials do not mix with the ink that landed later, Bleed is suppressed. After the color material is aggregated, the separated ink solvent spreads, and a liquid layer in which the aggregation treatment agent is dissolved is formed on the recording medium 14.

  The recording medium 14 to which ink has been applied is transferred from the pressure drum 216 of the printing unit 28 to the pressure drum 306 of the solvent drying unit 30 via the transfer drum 304. In the transfer drum 304, the drawing surface of the recording medium 14 is dried in a non-contact manner by the conveyance guide 150. In the impression cylinder 306, moisture is sufficiently removed by infrared irradiation or hot air blowing from the solvent drying unit 308.

  Thereafter, the recording medium 14 is transferred from the pressure drum 306 of the solvent drying unit 30 to the pressure drum 326 of the hot-pressure fixing unit 32 via the transfer drum 324. A stamp-type member 325 is disposed on the transfer drum 324, and the stamp-type member 325 absorbs the high boiling point solvent and permeates the paper through the voids of the permeation suppression layer increased by the treatment liquid and heat drying. In the transfer drum 324, the drawing surface of the recording medium 14 is dried in a non-contact manner by the conveyance guide 150. Then, the recording medium 14 delivered to the impression cylinder 326 heated by a heating unit (not shown) is pressed and heat-pressed by the heat rollers 328a, 328b, and 328c to fix the image on the recording medium 14.

  Thereafter, the recording medium 14 is transferred from the pressure drum 326 of the heat and pressure fixing unit 32 to the discharge tray 346 of the discharge unit 34 via the transfer drum 844 and discharged outside the apparatus. The transfer drum 344 is heated by a heating means (not shown), and further promotes the penetration of the high boiling point solvent and corrects the curl of the recording medium 14.

(Modification)
FIG. 30 is a configuration diagram of an inkjet recording apparatus 400 according to another embodiment of the present invention. 30, members that are the same as or similar to the components described in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. Instead of the pressure drum 306 and the front and rear transfer drums 304 and 324 arranged in the solvent drying unit 30 described with reference to FIG. 1, a form in which a conveying means using a chain 412 is employed as shown in FIG. 30 is also possible.

  The chain 412 has a gripper (not shown) for holding the recording medium 14. The chain 412 with the gripper is wound around sprockets 414 and 415 for driving the chain 412, and a hot air injector 416 is disposed in the conveyance path of the chain 412. An adsorption guide 450 that electrostatically adsorbs the back surface of the recording medium 14 is disposed at a position facing the conveyance surface of the chain 412.

  The suction guide 450 has a configuration similar to that of the conveyance guide 150 described with reference to FIG. The recording medium 14 is conveyed by the gripper of the chain 412, and the recording medium 14 is electrostatically adsorbed by the suction guide 450 arranged to face the recording medium 14, and hot air is ejected from the hot air ejector 416 to dry the recording medium 14. Note that instead of the hot air injector 416 or in combination with this, heat drying may be performed using a drying unit similar to the solvent drying unit 308 described in FIG. In this case as well, the same effects as those of the ink jet recording apparatus according to the embodiment described with reference to FIG. 1 can be obtained, and the heating unit can be simplified, which is preferable when the amount of drying is small, such as a small number of ink colors.

<Adjustment of each solution>
Next, an example of adjusting each liquid used in the ink jet recording apparatus according to the above-described embodiment will be described.

(1) Adjustment of permeation inhibitor While stirring a mixed solution of 10 g of dispersion stabilizing resin [Q-1] having the structure shown in [Chemical Formula 1], 100 g of vinyl acetate and 384 g of Isopar H (trade name of Exxon) under a nitrogen stream. The temperature was raised to 70 ° C.

  As a polymerization initiator, 0.8 g of 2,2′-azobis (isovaleronitrile) (abbreviation AIVN) was added and reacted for 3 hours. 20 minutes after the addition of the initiator, white turbidity occurred, and the reaction temperature rose to 88 ° C. Further, 0.5 g of the initiator was added and reacted for 2 hours, and then the temperature was raised to 100 ° C. and stirred for 2 hours to distill off unreacted vinyl acetate. After cooling, it was passed through a 200-mesh nylon cloth, and the resulting white dispersion was a latex with a good monodispersity having a polymerization rate of 90% and an average particle size of 0.23 μm. The particle size was measured with CAPA-500 (manufactured by Horiba, Ltd.).

  A part of the white dispersion was centrifuged (rotation speed 1 × 10 4 rpm, rotation time 60 minutes) to collect the precipitated resin particles, dried, and the weight average of the resin particles When molecular weight (Mw), glass transition point (Tg), and minimum film-forming temperature (MFT) were measured, Mw was 2 × 10 5 (polystyrene equivalent GPC value), Tg was 38 ° C., and MFT was 28 ° C.

(2) Adjustment of aggregation treatment agent (Adjustment of treatment liquid T-1)
The treatment liquid was adjusted with the composition shown in Table 3 below, and the physical properties of the obtained reaction liquid were measured. As a result, the viscosity was 4.9 mPa · s, the surface tension was 24.3 mN / m, and the pH was 1.5.

  By using these aggregating agents, it is possible to apply an aggregating agent excellent in the ejection properties of the head and the wetness of the recording medium.

(3) Preparation of ink (Preparation of polymer dispersant P-1)
In a 1000 ml three-necked flask equipped with a stirrer and a condenser, 88 g of methyl ethyl ketone was added and heated to 72 ° C. under a nitrogen atmosphere. Here, 50 g of methyl ethyl ketone was mixed with 0.85 g of dimethyl 2,2′-azobisisobutyrate, 60 g of benzyl methacrylate, A solution in which 10 g of methacrylic acid and 30 g of methyl methacrylate were dissolved was dropped over 3 hours. After completion of the dropwise addition, the reaction was further continued for 1 hour, and then a solution in which 0.42 g of dimethyl 2,2′-azobisisobutyrate was dissolved in 2 g of methyl ethyl ketone was added, heated to 78 ° C. and heated for 4 hours. The obtained reaction solution was reprecipitated twice in a large excess amount of hexane, and the precipitated resin was dried to obtain 96 g of polymer dispersant P-1.

  The composition of the obtained resin was confirmed by 1H-NMR, and the weight average molecular weight (Mw) determined by GPC (Gel Permeation Chromatography) was 44600. Furthermore, when the acid value of this polymer was calculated | required by the method of JIS specification (JISK0070: 1992), it was 65.2 mgKOH / g.

(Preparation of cyan dispersion)
Pigment Blue 15: 3 (Phthalocyanine-A220 manufactured by Dainichi Seika Co., Ltd.), 5 parts of the polymer dispersant P-1 obtained above, 42 parts of methyl ethyl ketone, and 1 mol / L NaOH aqueous solution. 5.5 parts and 87.2 parts of ion-exchanged water were mixed and dispersed in a bead mill using 0.1 mmΦ zirconia beads for 2 to 6 hours.

  Methyl ethyl ketone was removed from the obtained dispersion at 55 ° C. under reduced pressure, and a part of water was further removed to obtain a cyan dispersion having a pigment concentration of 10.2% by mass.

  As described above, a cyan dispersion liquid as a coloring material was prepared.

  Using the color material (cyan dispersion) obtained above, the ink was prepared so as to have the following ink composition (Table 4), and after the preparation, coarse particles were removed with a 5 μm filter, and ink C1-1 was used. It was adjusted. As a result of measuring the physical properties of the obtained ink C1-1, the pH was 9.0, the surface tension was 32.9 mN / m, and the viscosity was 3.9 mPa · s.

  Similarly, Magenta, Yellow, and Black inks were prepared.

(4) Addition polymer Particles such as a polymer resin are appropriately added to the aggregating agent and ink described above. The aggregation treatment agent is used for gloss adjustment, and the ink is used for image fixing. The particle diameter is 1 μm or less, the minimum film forming temperature is 28 to 50 ° C., and the glass transition point is 40 to 80 ° C. preferable.

(Purge description)
Next, the purge of the inkjet recording apparatus 10 shown in this example will be described. The term “purge” in the present embodiment includes not only preliminary droplet ejection (so-called preliminary ejection) that is not related to image recording, but also specific characters and symbols in the margin area using a droplet ejection operation by head maintenance. It is a concept including what forms a shape (pattern) or the like.

  Each of the ink heads 210Y, 210M, 210C, and 210K is a line head capable of ejecting the maximum recording width of the recording medium (see FIG. 23A), and is capable of high-speed and high-density image recording. On the other hand, line type heads generate nozzles that do not eject droplets or nozzles with low droplet ejection frequency depending on the image data. Especially when printing a large number of identical images continuously, ink thickening or nozzle clogging occurs for specific nozzles. It is easy to produce. Accordingly, a nozzle that does not eject droplets or a nozzle that has a low droplet ejection frequency is appropriately purged (dummy ejection or preliminary ejection) to discharge ink from the non-droplet ejection nozzle or the low-frequency ejection nozzle.

  The purging may be performed for each sheet (for each image recording) or for every several sheets (for each image recording for a plurality of times). One purge may be performed for all the heads (all heads of KCMY) or a single head (any head of KCMY), and is preferably performed within a certain time. If all the nozzles used for the image recording are purged in accordance with the image data before drawing, it becomes possible to form a more stable image.

In the purge shown in this example, ink droplets (hereinafter sometimes referred to as “purge ink”) by the purge are attached to the blank area (M _{1 to} M _{4 in} FIG. 18) of the recording medium. The medium is not wasted. Further, it is not necessary to collect ink droplets by purging, and purging can be executed as appropriate during continuous printing. Further, as in the case where purge ink is attached to the impression cylinder 216, cleaning of the impression cylinder does not occur each time purge is executed.
(Explanation of purge detection)
Next, the purge detection applied to this example will be described in detail. The purge detection (droplet detection) shown in this example uses purge ink when purging the purge area (for example, M ₁ in FIG. 18) provided in the blank area at the leading end of the recording medium 14. A patch having a predetermined pattern is formed, the patch is read by the sensor unit 182 provided on the transfer drum 304, and each part of the ink jet recording apparatus 10 is controlled based on the read result.

  The purge detection is applied when the inkjet heads are used for the heads 210Y, 210M, 210C, 210K and the treatment liquid coating apparatus 202. Hereinafter, purge detection of the heads 210Y, 210M, 210C, and 210K will be described.

  FIG. 31 is a perspective view showing an arrangement position of the sensor unit 182 of the transfer drum 304 provided between the printing unit 28 and the solvent drying unit 30. FIG. In FIG. 31, the detailed structure of the transfer drum 304 is not shown.

  As shown in the figure, a sensor unit 182 is provided at a substantially central portion of the gripper support portions 101 and 102 provided along a length corresponding to the entire width of the recording medium along the shaft method of the transfer drum 304. ing.

  The arrangement position of the sensor unit 182 shown in FIG. 31 corresponds to the monitor position 183 shown in FIG. 18, and the period during which the recording medium whose tip is held by the gripper 91 shown in FIG. In FIG. 18, the patches formed at the monitor position 183 in FIG. 18 can be continuously detected, and the detection information can be acquired within the period.

  FIG. 32 is a cross-sectional view schematically showing the vicinity of the sensor unit 182 in an enlarged manner. As shown in the figure, the sensor unit 182 includes an infrared thermometer (infrared sensor) 520 and a concentration sensor (optical sensor) including a light receiving element 521 and a visible light source 522, which are provided on one of the substrates 523. It is arranged on the surface.

  On the other surface of the substrate 523, a signal processing unit that performs predetermined signal processing (noise removal processing, waveform shaping processing, amplification processing, etc.) on detection signals obtained from the infrared sensor 520 and the optical sensor (light receiving element 521), In addition, a stabilizing circuit unit for supplying power is provided.

  The substrate 523 is provided with a wiring pattern for supplying power and a wiring pattern for transmitting a signal, as well as a wiring pattern in the impression cylinder 306 (provided inside the impression cylinder 306 and electrically connected to the contact 184 in FIG. 13). A connection member (connector or the like, indicated by reference numeral 534 in FIG. 35) is provided for electrical connection with the wiring pattern. In FIG. 31, wiring patterns and connecting members are collectively shown by reference numeral 524.

  Further, a lens 525 is provided in front of the incident surface (surface facing the recording medium 14) of the light receiving element 521, and the lens 526 is also positioned in front of the irradiation surface (surface facing the recording medium 14) of the visible light source 522. Is provided. Each component described above is housed in a housing 527.

  FIG. 33 schematically illustrates a state in which the patch 550 formed on the recording medium 14 is detected by the sensor unit 182.

  As shown in FIG. 33, the infrared sensor 520 detects the temperature of the patch 550 on the recording medium 14, and outputs a detection signal proportional to the detected temperature. By storing this detection signal continuously, information on temperature change (temperature history and temperature gradient) with the passage of time of the recording medium 14 can be obtained.

  An embodiment in which the infrared irradiation position is configured to be variable according to the thickness of the recording medium 14 and the ink droplet ejection amount is preferable.

  The optical sensor detects the optical density (reflection density) of the patch 550 on the recording medium 14. In front of the surface of visible light source 522 included in the optical sensor from which visible light is emitted (between the visible light source 522 and the recording medium 14), the visible light is placed at one point of the patch 550 (for example, the center position of the patch 550). Is provided with a condensing lens 525.

  Further, a condensing lens for collecting visible light reflected by the recording medium 14 in the light receiving area of the light receiving element is in front of the surface of the light receiving element 521 that receives visible light (between the light receiving element 521 and the recording medium 14). 526 and an aperture (restricting mechanism) 528 for restricting the light receiving area of the light receiving element 521 are provided.

  With this configuration, information on the optical density (reflection density) of the patch formed on the recording medium 14 can be obtained. In addition, since the light receiving element 521 and the visible light source 522 move integrally with the recording medium 14, the same detection position can be continuously detected even if the recording medium 14 moves, the light amount of the visible light source 522 is insufficient, Abnormal density detection due to insufficient sensitivity can be avoided. Further, even if the recording medium 14 is transported at the highest speed, a detection period of about 0.3 to 3 seconds can be secured, and the light receiving element 521 need not use a highly sensitive one but can use a general purpose one. it can. Similarly, the visible light source 522 does not need to use a high-powered one and can use a general-purpose one.

  In the purge detection shown in this example, the temperature detection using infrared rays and the optical density detection using visible light can be performed simultaneously for the same detection position. That is, even if visible light from the visible light source 522 is irradiated to the same detection point in the patch 550, the infrared ray to be measured and the visible light to be irradiated do not interfere with each other. Therefore, the temperature information and optical density at the same detection position. Information can be acquired simultaneously.

  Specifically, the wavelength range of visible light to be irradiated is preferably set to 360 nm to 960 nm, and the wavelength range of infrared to be detected is preferably set to 0.78 μm to 15 μm. In particular, visible light is absorbed at 400 nm to 700 nm. It is preferable that the infrared ray to be detected is set to a wavelength range of 8 μm to 14 μm that is less affected by the atmosphere.

  In addition, although the example which performs the temperature detection by infrared rays and the optical density detection by visible light simultaneously with respect to the same detection position was illustrated in this example, the application range of this invention is not limited to the combination of infrared rays and visible light. That is, the present invention is widely applicable to an embodiment using two types of light having frequency bands that do not cause mutual interference.

  FIG. 33 illustrates an example in which the light receiving element 521, the infrared sensor 520, and the visible light source 522 are arranged in this order from the downstream side along the conveyance direction of the recording medium 14, but the light receiving element 521, the infrared sensor 520, and the visible light source 522 are illustrated. May be arranged in the width direction of the recording medium 14 orthogonal to the conveyance direction of the recording medium 14 or in a direction oblique to the conveyance direction of the recording medium 14, and the arrangement order can be changed as appropriate.

  Furthermore, in place of or in combination with the mode in which the temperature of the recording medium 14 is detected by the infrared sensor 520, a mode in which the amount of water on the recording medium 14 is detected using an infrared moisture meter or the like is also preferable. By monitoring the amount of water on the recording medium 14, the rise of the amount of water (evaporation amount) can be measured, and drying control with good responsiveness is possible.

  FIGS. 31 to 33 show a mode in which the sensor unit 182 is arranged at a substantially central portion in the axial direction of the transfer drum 304. However, as shown in FIG. 34, a predetermined arrangement along the axial direction of the transfer drum 304 is shown. A mode in which a plurality of sensor units 182 (182-1 to 182-6) are provided at a pitch is also preferable.

  A plurality of patches are formed along the width direction of the recording medium 14 at positions corresponding to the positions of the plurality of sensor units 182, and each patch is read by the corresponding sensor unit 182. It is possible to obtain a temperature distribution and a concentration distribution in the width direction.

  FIG. 34 shows a configuration including a plurality of sensor units 182 (182-1 to 182-6) at a predetermined arrangement pitch along the axial direction of the transfer drum 304, but in the axial direction of the transfer drum 304. Even if one sensor unit 182 is scanned over the entire width of the recording medium 14 along the recording medium 14, it is possible to obtain the same effect as the configuration illustrated in FIG. 34.

  FIG. 35 shows a block diagram of the sensor unit 182. As shown in FIG. 35, the detection signal (temperature information) obtained by the infrared sensor 520 is subjected to predetermined signal processing such as noise removal, amplification, waveform shaping, and the like by the signal processing unit 530, and the connection member 534 and FIG. Are sent to the system controller 472 of FIG.

  When the system controller 472 acquires the temperature information output from the infrared sensor 520 in FIG. 35, the system controller 472 determines the temperature of the recording medium 14 based on the temperature information, and passes the transfer cylinder control unit 494 based on the temperature of the recording medium 14. The heater 110 and the injection regulating member 116 are controlled, and the drying control of the solvent drying unit 30 (solvent drying unit 308) at the rear stage of the transfer cylinder 304 is performed via the solvent drying control unit 504.

  That is, when the temperature of the recording medium 14 exceeds the predetermined temperature setting range, the heating amount by the heater 110 and the IR heater 310 of the solvent drying unit 30 is reduced, and the temperature of the recording medium 14 is less than the predetermined temperature setting range. In this case, the heating amount by the heater 110 and the IR heater 310 of the solvent drying unit 30 is increased.

  In this way, by monitoring the surface temperature of the recording medium 14 and controlling the heating of each part that performs the heat treatment, variations due to temperature changes and humidity changes inside and outside the apparatus, and differences in the type of the recording medium 14 can occur. A stable drying process (heating process) can be applied to the difference in recorded images (difference in the amount of ink ejected onto the recording medium).

  Further, the detection signal (density information) output from the light receiving element 521 in FIG. 35 is sent to the system controller 472 in FIG. 29 via the signal processing unit 536, the connection member 534, and the contact 184 (see FIG. 13).

  When acquiring the density information, the system controller 472 sends the density information to the print control unit 480. The print controller 480 generates ink droplet ejection amount (ink ejection volume) correction data or image data correction data based on the density information, and the heads 210Y, 210M, 210C via the head driver 484 based on the correction data. , 210K ink droplet ejection is controlled.

  For example, when the acquired density value (density information) exceeds a predetermined density value (density range), the ink ejection amount is reduced by the difference between the acquired density value and the predetermined density value, and the density value Is less than the predetermined density value, the ink ejection amount is increased by the difference between the predetermined density value and the acquired density value. It is preferable that the relationship between the density measurement value and the droplet ejection amount correction value is stored in a table in advance and the droplet ejection amount is corrected with reference to the table.

  The on / off of the visible light source 522 and the amount of light are controlled by the light source driver 538 based on a command signal sent from the system controller 472 of FIG.

  According to this configuration, the sensor unit 182 that detects the blank area of the recording medium 14 is provided in the vicinity of the gripper 87 that sandwiches the leading end portion of the recording medium 14 of the transfer cylinder 304, so that the sensor unit is conveyed along with the conveyance of the recording medium 14. Since the 182 also travels, a predetermined detection position on the recording medium 14 can be continuously monitored.

  Further, by providing the sensor unit 182 with the temperature sensor (infrared sensor) 520, the temperature of the recording medium 14 while being held by the gripper 87 can be acquired over time, and the temperature history of the recording medium 14 can be acquired. Based on the above, preferable drying control becomes possible.

  In addition, an infrared sensor is applied to the temperature sensor 520, and a density sensor using visible light is provided in the sensor unit 182 so that temperature detection and optical density detection are simultaneously performed at the same detection point on the recording medium 14. In addition, droplet ejection control (droplet ejection correction) can be performed simultaneously with drying control.

(Explanation of dry control drying of purge ink)
Next, the drying control of the ink (purge ink) attached to the recording medium 14 by the purge will be described.

  As described above, in the impression cylinders 40, 86, 306, and 326 that hold the recording medium excluding the impression cylinder 216 of the printing unit 28, the gripper 87 (see FIG. 12) that holds the leading end of the recording medium is used. Since there is a level difference, the spiral roller 48 (application roller) of the permeation suppression processing unit 24 and the processing liquid application unit 26 is configured to be separated from the surface of the impression cylinders 40 and 86 at the position where the gripper 87 is disposed. In such a structure, a permeation inhibitor and a treatment liquid are applied to the leading end portion of the recording medium (a portion sandwiched by the gripper 87 and the vicinity thereof) that passes immediately below the spiral roller 48 while the spiral roller 48 is separated. In other words, there is no permeation inhibitor or treatment liquid at the tip of the recording medium.

  Even if purge ink adheres to the blank area at the leading edge of the recording medium where no processing liquid is present, the purge ink is present on the recording medium in a non-aggregated state. There is a risk of moving on the recording medium. Since the ink applied to this example contains a polymer resin as shown in Table 4 above, the transfer cylinder 304 described with reference to FIGS. The purge ink can be fixed to the recording medium by performing the heat treatment by evaporating a solvent such as water and elevating the surface temperature.

  That is, the ink droplets purged from the heads 210K, 210C, 210M, and 210Y shown in FIG. 1 land on the non-application area of the treatment liquid at the leading end of the recording medium, and the ink droplets from the purge adhere and the printing is effective. The recording medium on which a desired image is formed in the region 186 (see FIG. 18) is conveyed along with the rotation of the impression cylinder 216, transferred to the transfer cylinder 304, and the recording medium transferred to the transfer cylinder 304 has hot air. The purge ink (and the image formed in the print effective area 186) is fixed to the recording medium.

  In the heat treatment described above, the temperature of at least the spot where the purge ink lands on the recording medium is equal to or higher than the minimum film-forming temperature of the polymer particles (latex) contained in the ink, and is equal to or higher than the glass transition point of the polymer particles. The heater 110 (see FIG. 12) is controlled so that

  High boiling solvents such as glycerin, diethylene glycol, and trioxypropylene glyceryl ether contained in the ink to prevent drying and adjust viscosity by heating to a temperature above the minimum film-forming temperature of the polymer particles contained in the ink. By forming polymer particles into a film while reducing the viscosity of the ink and allowing it to penetrate into the recording medium, the fixing property of the aggregated ink is ensured.

  In the state where water and high-boiling organic solvent remain, the polymer particles are difficult to form even if heated above the minimum film-forming temperature, so by evaporating water and allowing the high-boiling organic solvent to penetrate into the recording medium, It becomes possible to reliably form polymer particles into a film.

  Further, the purge ink adhering to the tip of the recording medium is heated to a temperature equal to or higher than the minimum film forming temperature of the polymer particles contained in the ink and to a temperature equal to or higher than the glass transition point of the polymer particles to form polymer particles. In addition, the non-aggregated ink can be reliably fixed to the recording medium by changing the polymer particles from the glass state to the rubber state. By setting the temperature of the recording medium to a temperature lower than the boiling point of water, it is possible to prevent blistering due to moisture in the recording medium and further stabilize the ink fixation.

  Of the heads 210K, 210C, 210M, and 210Y, when purging a plurality of heads on the same recording medium, ink droplet ejection in the purging of each head is controlled so that dots do not overlap between colors. That is, the ink ejection in the purge is controlled so that the dots are not deposited repeatedly from different heads on the same droplet ejection point, that is, the droplet ejection amount is 100% solid or less. Only a single dot is formed at a point. Details of ink droplet ejection control in purging a plurality of heads will be described with reference to FIG.

  If dots overlap, the amount of ink at the same droplet deposition point increases, so overlapping dots are more likely to move (liquid flow) and cause uneven patch in-plane, which may reduce the temperature and moisture measurement accuracy. However, such droplet ejection control prevents liquid flow and avoids a decrease in drying efficiency. Specifically, when the droplet ejection density is 1200 dip × 1200 dip and the ink droplet ejection amount is 2.5 to 5 pl, the average liquid thickness is controlled to 6 to 12 μm, preferably 6 μm or less.

  Further, even when purging the same head, it is also preferable to perform droplet ejection control that alleviates landing interference by thinning out arrangement (separation arrangement) such as a staggered arrangement so as not to overlap dots. In other words, when forming dots at adjacent droplet ejection points, if liquid dots come into contact with each other and landing interference occurs, the thickness of the overlapping dots (liquid (Thickness) non-uniform state occurs, and there is a concern that the flow of liquid and the measurement accuracy may be reduced by the hot air irradiation.

  By mitigating non-uniformity of the liquid thickness due to landing interference, liquid flow due to hot air during heat treatment is prevented, and measurement accuracy is further improved, which is preferable. The above-described droplet ejection control is particularly effective when a recording medium with low permeability such as a coated paper for printing is used.

  As a technique for preventing the landing interference due to the overlapping of dots described above, a technique of performing adjacent droplet ejection using a symmetrical droplet ejection type matrix head is effective. According to this symmetrical droplet ejection type matrix head, landing interference is reduced even when high density droplet ejection such as a solid image is performed without thinning droplet ejection. The details of the symmetrical droplet ejection type matrix head (symmetrical droplet ejection) will be described with reference to FIGS.

  Next, the ink droplet drying process (heating process) by purging in this example will be described with a specific example. In FIG. 36 (a), a 250% solid image, which is the maximum droplet ejection amount, is formed in the print effective area 186 (see FIG. 18) of the recording medium 14, and the margin area (M1) at the tip is purged and recorded. The temperature transition of the surface of the recording medium when the heat treatment is uniformly applied to the entire medium is shown.

  In this example, the droplet ejection amount of the purge ink is controlled to be 100% or less, but the temperature transition of 100% solid can be inferred from the temperature transition of the 250% solid image.

  As an example of forming a 250% solid image, a cyan ink is formed with 100% solid with a droplet ejection density of 1200 dip × 1200 dip and an ink ejection amount of 2.5 to 5 pl, and a 100% solid of magenta ink is formed on the same. After that, the yellow ink is ejected with the droplet ejection density or the droplet ejection amount being half that of the cyan (magenta) ink, thereby forming a 250% solid image in which black is present in spots on blue.

  In FIG. 36A, the vertical axis (surface temperature) represents the surface temperature of the recording medium, and the horizontal axis (time (position)) represents the elapsed time from the start of the heat treatment (position of the recording medium). In FIG. 36A, the timing at which the recording medium is transferred to the transfer drum 304 is the start timing of the heat treatment.

  In FIG. 36 (a), a curved line 507 indicated by a broken line is a temperature transition of a white background portion (portion to which only a permeation inhibitor or a treatment liquid has been applied), and a curved line 508 indicated by a solid line and a curved line 509 indicated by a one-dot broken line are respectively purged. This is a temperature transition of a portion (for example, a pattern indicated by reference numeral 550 in FIG. 37A) and a solid portion (a solid image of 250%). Moreover, about the temperature of each part, the temperature measured value was calculated | required about several places of each part with the infrared thermometer, and the average value of the said measured value was made into the temperature of each part.

  As shown in FIG. 36A, when the recording medium to which the ink droplets by the purge are attached is transferred to the transfer cylinder 304, the heating process for the recording medium is started. The temperature of the recording medium at the start of the heat treatment is substantially the same as the environmental temperature (for example, 25 ° C.) in the apparatus.

  When the recording medium is conveyed by the transfer drum 304, the heat treatment proceeds, and the temperature of the white background portion (the portion where the dried permeation inhibitor and the treatment liquid adhere), the purge portion, and the solid portion rise. The temperature change per unit time of each part becomes smaller as the amount of liquid held on the surface is larger.

  Immediately after the start of the heat treatment, a wet air layer evaporated from the liquid on the surface of the recording medium is formed in the vicinity of the surface of the recording medium, and when the heat treatment further proceeds, the wet air layer is removed by hot air or the like. In an evaporation state, in the vicinity of the intermediate position of the transfer cylinder 304 in the recording medium conveyance path, the temperature of the white background reaches the minimum film-forming temperature. Note that the minimum film forming temperature of the polymer particles contained in the ink showing the temperature transition in FIG.

  Further, the heat treatment proceeds, and the temperature of the purge portion reaches a temperature equal to or higher than the minimum film forming temperature near the intermediate position between the intermediate position of the recording medium conveyance path of the transfer drum 304 and the end position.

  That is, surface drying proceeds during a period in which the recording medium is being conveyed by the transfer cylinder 304, and at least the purge portion (portion to which ink droplets from the purge are attached) of the surface temperature of the recording medium has the lowest film formation. When the temperature is higher than the temperature, a film of polymer particles is formed on the surface of the ink droplets by purging, and the fixability of the ink droplets by purging to the recording medium is ensured.

  When the transfer cylinder 304 further rotates, the recording medium is transferred from the transfer cylinder 304 to the drying cylinder 306 at the transfer portion between the transfer cylinder 304 and the drying cylinder (impression cylinder 306).

  The recording medium held on the drying drum 306 is subjected to heat treatment by a solvent drying unit 308 (see FIG. 27). Due to the heat treatment of the drying cylinder 306, the surface temperature of the recording medium further rises, and the temperature of the white background reaches a temperature equal to or higher than the glass transition point of the polymer particles in the vicinity of the delivery position (immediately after delivery of the recording medium). Reaches the maximum temperature (temperature below the boiling point of water) in the vicinity of the intermediate position of the recording medium conveyance path. In addition, the glass transition point of the polymer particle contained in the ink which shows a temperature transition in Fig.36 (a) is 63 degreeC.

  The temperature of the solid portion reaches a temperature equal to or higher than the minimum film forming temperature in the vicinity of the intermediate position of the recording medium conveyance path of the drying cylinder 306, and the intermediate position of the recording medium conveyance path of the drying cylinder 306 and the recording medium conveyance path of the drying cylinder 306. The maximum temperature (temperature below the boiling point of water) is reached in the vicinity of the intermediate position from the end position.

  The temperature of the purge portion reaches a temperature equal to or higher than the glass transition point in the vicinity of the intermediate position of the recording medium conveyance path of the drying cylinder 306, and the intermediate position of the recording medium conveyance path of the drying cylinder 306 and the recording medium conveyance path of the drying cylinder 306. The maximum temperature (temperature below the boiling point of water) is reached in the vicinity of the intermediate position from the end position.

  That is, during the heat treatment period by the drying cylinder 306, the surface temperature of the recording medium is equal to or higher than the glass transition point, and internal evaporation of moisture from the recording medium and penetration of the high-boiling organic solvent contained in the permeation inhibitor and ink. The purge ink (non-aggregated ink) is completely fixed to the recording medium by changing the polymer particles of the purge ink from the glass state to the rubber state. In addition, the temperature of the solid portion is equal to or higher than the minimum film forming temperature, and a polymer film is formed on the surface of the solid portion.

  Further, in the heat treatment by the drying cylinder 306, the heating is stopped while the temperature of each part is lower than the boiling point of water, and the maximum temperature of each part on the surface of the recording medium is prevented from becoming a temperature higher than the boiling point of water. Yes. That is, when the recording medium reaches near the intermediate position of the recording medium conveyance path of the drying drum 306 (at the timing when the temperature of the purge portion exceeds the glass transition point), the IR heater 310 shown in FIG. 27 is stopped. Even if the IR heater 310 is stopped, the temperature of each part rises due to residual heat for a while, but the temperature of each part falls as time passes.

  When the recording medium reaches the delivery position between the drying cylinder 306 and the transfer cylinder 324, the recording medium is transferred from the drying cylinder 306 to the transfer cylinder 324. During the conveyance of the recording medium by the transfer cylinder 324, the surface temperature of the recording medium decreases in accordance with the temperature of the conveyance guide 150 of the transfer cylinder 324, and the recording medium reaches the transfer position between the transfer cylinder 324 and the fixing cylinder (impression cylinder 326). In the position where the temperature reaches, the temperature of each part of the recording medium becomes substantially uniform.

  In the fixing process by the fixing cylinder 326, the print effective area 186 (solid part) is heated, and the temperature of the solid part rises to a temperature equal to or higher than the glass transition point of the polymer particles.

  According to the ink jet recording apparatus 10 configured as described above, purging is performed on the blank area of the recording medium to which no treatment liquid is applied, and the purging is performed so that ink droplets generated by the purging do not overlap on the recording medium. In addition, the recording medium on which the ink droplets by purging are deposited is subjected to heat treatment so that the temperature becomes equal to or higher than the minimum film-forming temperature of the polymer particles contained in the ink. By performing a heat treatment so that the temperature is equal to or higher than the glass transition point, a film of polymer particles is formed on the surface of the ink droplets by purging, and the polymer particles are changed from glassy to rubbery, The purge ink can be fixed to the recording medium. Therefore, contamination in the apparatus due to liquid flow, show-through, and purging on the recording medium is prevented even in a blank portion to which no processing liquid is applied. In addition, by setting the temperature of the image (ink) formed in the print effective area to a temperature equal to or higher than the minimum film forming temperature, the image can be fixed to the recording medium. Further, it is not necessary to collect the purge ink during operation.

  Note that when switching the paper width corresponding to various paper sizes, purging may be performed only for the difference between the head discharge width and the paper width, and in particular, there is a margin at both ends of the paper in the printed matter, so the distance to the purge receiver is small. Even when a long and slight purge splatter is received, contamination of the image forming portion can be prevented and the amount of purge to the impression cylinder is small, so that the purge liquid can be easily processed. Also, the ink filling unit of the head may be adjusted to the paper width so that unused nozzles are not filled with ink, or a sheet holding portion may be provided on the nozzle surface so that the moisture retaining sheet is in close contact with the unused nozzles. .

  FIG. 36B shows a temperature transition on the surface of the recording medium when the arrangement pattern of the ejection openings 109 shown in FIG. 21C is applied to the transfer drum 304. In FIG. 36B, the same or similar parts as those in FIG. 36A are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 36 (b), the non-aggregated ink (purge ink) at the leading edge of the paper can be obtained even when the heating amount of the whole paper in the solvent drying unit 30 is reduced as compared with uniform heating (see FIG. 36 (a)). ) Can be set to a temperature equal to or higher than the minimum film-forming temperature of the polymer particles added to the ink and to a temperature equal to or higher than the glass transition point of the polymer particles. Problems can be prevented and the temperature difference in the surface of the paper can be suppressed, so that paper deformation such as cuckling can be reduced even in an image with a distribution of ink droplets. That, Delta] t ₂ in FIG. 36 (b) so has when compared to Delta] t ₁ in FIG. 36 (a) and Δt _1> Δt _2, it is possible to obtain the effects described above.

  The agglomerated ink of the printing unit 28 is formed by heating to a temperature equal to or higher than the minimum film forming temperature of the polymer particles added to the ink. Once fixed, it is possible to form an image with further improved image robustness and gloss while suppressing problems such as offset.

  Furthermore, by increasing the injection amount of the injection opening 109 toward the center in the width direction, the flow of the drying air can be further smoothed to further stabilize the drying.

(Explanation of purge pattern)
Next, a purge pattern formed by the purge ink applied to this example will be described. In the purge shown in this example, purge ink is ejected from all nozzles, and a plurality of inks are not ejected at the same ejection point, that is, the ejection amount is 100% solid (monochromatic solid) or less. The ejection of the purge is controlled so that Further, as described below, the droplet ejection of the purge is controlled to form a patch at a specific position using the ink droplet ejected by the purge.

<Purge pattern 1>
FIG. 37A illustrates a case where the patch 550 is formed at a position corresponding to the sensor unit 182 and the line pattern 552 is formed in another region. FIG. 37B shows the patch 550 in an enlarged manner.

  The surface temperature and moisture content of the patch 550 are measured by the sensor unit 182 (infrared thermometer or infrared moisture meter) shown in FIG. 12, and the moisture content and surface temperature of the patch 550 shown in FIGS. 37 (a) and (b) are measured. The amount of drying in the recording medium drying process is controlled by monitoring. With this configuration, it becomes possible to fix the purge ink more stably against changes in temperature and humidity inside and outside the apparatus, and variations in the paper, and the image fixability is also stabilized.

  FIG. 37B shows a patch 550 having an oblique pattern corresponding to the nozzle matrix arrangement. Even when the reading resolution of the optical sensor itself is sufficiently lower than the dot resolution by configuring a patch including a specific pattern in this way. High-precision reading is possible. Note that the pattern of the patch 550 applicable to this example is not limited to the pattern shown in FIG. 36B, and if the dots do not overlap (no landing interference occurs), a thinning pattern such as a staggered arrangement is used. Alternatively, a solid image by a symmetric droplet ejection type matrix head described later may be used.

<Purge pattern 2>
In FIG. 38A, KCMY color dots 570K, 570C, 570M, and 570Y are formed in the blank area, and KCMY color dots 572K, 572C, 572M, and 572Y dots are formed in the print effective area 186 using the same nozzle. FIG. 38 (b) shows an enlarged view of a region denoted by reference numeral 560. FIG.

Y dot 570Y, will be described. 572Y, inks and the diameter _{D 1} of the dots 570Y formed in the margin area (dot of ink droplets not aggregated), printing is formed in the effective region 186 dots 572Y (aggregation measuring the diameter D ₂ of the dots) by the droplet, obtained relation diameter D ₂ of diameter D ₁ and the dot 572Y dot 570Y, it is possible to control the coating thickness of the ink ejection amount and the treatment liquid.

  Further, the color registration can be corrected by forming the KCMY color patterns shown in FIGS. 38A and 38B and measuring the color patterns by the in-line sensor 348 shown in FIG. Further, a pattern is formed in both the margin area at the front end and the margin area at the rear end (not shown), and the magnification is corrected by measuring the pattern at the front and rear ends and the width direction. With such a configuration, quality such as gloss, density, magnification, distortion, and positional deviation is stably maintained.

<Purge pattern 3>
FIG. 39A shows a conceptual diagram of multicolor symmetrical droplet ejection. By performing multicolor symmetrical droplet ejection as shown in the figure, even when color ink is ejected onto an area where there is no processing liquid, unevenness can be effectively reduced. 39A and 39B, the vertical direction is the recording medium conveyance direction (upper side is the downstream side), and the horizontal direction is the width direction of the recording medium 14.

  In the multicolor symmetrical droplet ejection shown in FIG. 39A, K ink and C ink are alternately ejected in the first row (the top horizontal series in FIG. 39A). Further, in the second row, Y ink and M ink are alternately ejected.

  That is, in the first row, K ink is ejected by the first head (the K ink head 210K on the most upstream side in the recording medium conveyance direction) at the droplet ejection point surrounded by a solid line and marked with the numeral 1, and then The second ink (C ink head 210C) located adjacent to the downstream side of the first head in the recording medium conveyance direction causes C ink to be ejected to the droplet ejection points surrounded by a broken circle and marked with the numeral 2.

  In the second row, M ink is ejected by the third head (the M head 210M located next to the downstream side of the second head in the recording medium conveyance direction) at the droplet ejection point surrounded by the solid line and marked with the numeral 3. Next, Y ink is ejected to a droplet ejection point surrounded by a broken line Δ and marked with a numeral 4 by a fourth head (Y ink head 210Y) located adjacent to the downstream side of the third medium in the recording medium conveyance direction. The

  In other words, each of the heads 210K, 210C, 210M, and 210Y performs droplet ejection every other dot in the column direction (the width direction of the recording medium 14) and the row direction (the conveyance direction of the recording medium 14). By performing droplet ejection between ink droplets ejected from the head, when ink droplets land on the recording medium, there are no ink droplets on both the front, back, left, and right sides of the ink droplets, Alternatively, when ink droplets exist on both the front, back, left, and right sides of the ink droplet, and ink droplets exist only on one side, the landed ink droplets are already landed on the ink droplets. Contributes to the reduction of unevenness caused by being drawn.

  As shown in FIG. 39 (b), the ink ejected from each head 210K, 210C, 210M, 210Y is separated in the transport direction of the recording medium 14 (shifted in the transport direction of the recording medium 14). By doing so, the relative position between the colors can be measured, and the color registration can be detected.

<About other purge patterns>
Although not shown in the drawings, it is also preferable to change the head (color) for each recording medium as the purge ink pattern. That is, a purge pattern of only one color of KCMY is formed on one recording medium, and purge of all four colors of KCMY is executed using four recording media. In other words, purging is performed while switching the head for each recording medium, and purging is performed for all the heads using the same number of recording media as the number of heads.

  By using such a purge pattern, it is possible to detect a difference in drying properties depending on colors. In addition, it is possible to correct different colors.

  In addition, an aspect in which the droplet ejection amount or droplet ejection density of the purge ink is changed according to the image data is also preferable. Specifically, the average droplet ejection amount on the entire surface of the printed image is determined in the range of 0% (white background) to 250% (maximum value), and this is converted from 0% to 100% to determine the ink amount to be purged. The ink ejection volume and droplet ejection density are controlled.

  According to this aspect, correction based on the difference in image data is possible, and preferable drying control is possible even when the content of the image differs for each print such as on-demand printing.

  Furthermore, it is also preferable to form a character string with no missing dots. For example, an aspect in which additional information (for example, production management information, serial number, etc.) for each recording medium (for each image) is given by purge ink. Furthermore, a mode in which a monochromatic line pattern is formed for each color (each head) is also preferable. The width of the line pattern may be one dot width (approximately 35 μm in the case of 1200 dpi), or may be a plurality of dot widths (1 to 5 dot widths, 35 μm to 100 μm).

  Note that when purging is performed for each sheet of the recording medium 14 or when the same image is continuously recorded, purging may be performed only for unused nozzles or nozzles that are less frequently used.

  In the embodiment described above, the purge detection of the ink heads 210K, 210C, 210M, and 210Y has been described. However, the present invention can also be applied to the case where the aggregation treatment liquid is applied by an ink jet method.

  For example, the transfer cylinder 214 shown in FIG. 1 has the same configuration as that of the transfer cylinder 304, the front end of the recording medium 14 is purged, and the temperature and optical density of the treatment liquid deposited by the purge are detected, thereby transferring the transfer cylinder 214. In addition to optimizing the drying process by 214, it is possible to optimize the droplet ejection amount of the processing liquid.

  The effects of the ink jet recording apparatus and the droplet ejection detection method configured as described above are as follows.

  The heads 210K, 210C, 210M, and 210Y of the printing unit 28 are purged with respect to the non-image portion (the blank area at the leading end portion or the trailing end portion of the recording medium 14) to which the aggregation processing liquid is not applied, and the recording of the printing unit 28 is performed. The temperature (water content) of the purge ink is detected using the sensor unit 182 provided in the gripper support portions 101 and 102 of the transfer cylinder 304 on the downstream side in the medium conveyance direction, and the solvent drying unit 30 and the transfer cylinder are detected based on the detection result. Since the drying process in 304 is controlled, stable drying control can be realized against temperature changes and humidity changes inside and outside the apparatus, recording medium variations, image content differences, and the like.

  Further, by setting the ejection amount of purge ink to 100% or less, the ink flow and unevenness in the non-aggregated portion can be prevented.

  By controlling the droplet ejection by purging so as to form isolated dots such as staggered arrangement, landing interference is prevented, contributing to a reduction in unevenness of the drying process. In addition, using a line-type symmetrical droplet ejection head or performing two-dimensional symmetrical droplet ejection with multiple heads can reduce unevenness in the drying process by preventing landing interference, resulting in weak penetration of coated paper, etc. Even when a recording medium having the property is used, the landing interference of the non-aggregated portion is further reduced.

  Ink droplets (purge) on non-image areas are switched for each recording medium, and ink droplets on non-image areas are corrected according to the image data to correct for color differences and image data differences. And the drying process is further stabilized.

  By forming a patch having a predetermined pattern by purging, measuring the optical density of the patch at the same time as the temperature or the amount of water, and correcting the ink droplet amount or image data according to the measurement result, Monitor correction is possible, and image recording with a stable density is possible.

  By providing a thermometer or a moisture meter in the transfer cylinder having the heating and drying unit and monitoring the location where the purge ink is deposited, it is possible to measure the rise of temperature and moisture, and control with good responsiveness becomes possible. Further, by setting the amount of purge ink droplets to be a primary color or less, the rising gradient becomes steep and the detection accuracy is improved.

  A patch is also formed in the margin part such as the cutting margin where the aggregating treatment liquid is applied, and the density and dot diameter of the white background are measured by an inline sensor (imaging sensor) provided downstream in the recording medium conveyance direction. The level and the degree of aggregation can be detected, and the coating amount of the aggregation treatment liquid can be corrected in addition to the ink droplet ejection amount.

(Explanation of symmetrical droplet type matrix head)
Next, a head structure and ink droplet ejection control suitable for the purge method of the present invention will be described with reference to FIGS. The head described below is a “symmetrical droplet ejection type matrix head” published in Japanese Patent No. 3911690, which is effective in preventing landing interference of dots deposited at adjacent droplet ejection points. is there.

  FIG. 40 is a plan perspective view showing a structural example of the symmetrical droplet ejection type matrix head 650, and FIG. 41 is a partially enlarged view of FIG. 40 to 46, the description of the same or similar parts as in FIGS. 23 to 25 is omitted.

  The head 650 shown in FIG. 40 has a structure in which a plurality of ink chamber units 653 including nozzles 651 for ejecting ink droplets and pressure chambers 652 corresponding to the nozzles 651 are arranged in a staggered matrix. As a result, the apparent nozzle pitch is densified.

  Further, the head 650 includes one or more nozzles in which a plurality of nozzles 651 that eject ink are arranged over a length corresponding to the entire width of the print medium in the main scanning direction substantially orthogonal to the print medium feeding direction (sub-scanning direction). Full line head with rows.

  As shown in FIG. 40, the nozzles 651 (ink chamber units 653) provided in the head 650 are along a row direction along the main scanning direction and an oblique column direction having a certain angle not orthogonal to the main scanning direction. The nozzle array 712 includes nozzles 651-11, 651-12, and 651-13, and nozzles 651-14, 651-15, and 651-16. The nozzle row 714 and the nozzle row 714 are arranged with their phases shifted in the main scanning direction.

  That is, a nozzle row 710 arranged along an oblique direction composed of six nozzles is divided into two nozzle rows 712 and nozzle rows 714 each having three nozzles in the sub-scanning direction. 714 is arranged with a phase shift in the main scanning direction. The nozzle arrays 712 and 714 and the other nozzle arrays arranged in the main scanning direction have the same structure.

  In other words, the nozzles 651 in the head 650 are arranged in a nozzle group 722 and a nozzle row 714 that are arranged in a direction parallel to the main scanning direction. Are divided into two in the sub-scanning direction by the two nozzle groups of the nozzle group 724 composed of the nozzle row of one nozzle group (for example, the nozzle group 722) and the other nozzle group (for example, the nozzle group 724). The phase is shifted in the main scanning direction.

  Further, in the projection nozzle row in which the nozzles 651 included in the nozzle group 722 and the nozzle group 724 are projected in the main scanning direction, the phase in the main scanning direction of each nozzle group is determined so that the pitch between the nozzles becomes equal.

  In this example, a plurality of nozzles arranged in an oblique direction in each nozzle group is called a nozzle row. Further, for example, a nozzle row that belongs to two nozzle groups and functions as one nozzle row for droplet ejection control, such as a nozzle row 710 in FIG. 40, is also referred to as a nozzle row. When the nozzles in the nozzle row 710 are driven in a predetermined order, one cycle of droplet ejection (one cycle of discharge operation) can be performed.

  “One-cycle droplet ejection” refers to a droplet ejection operation in a minimum unit that forms one dot row in the main scanning direction, and all nozzles in a nozzle row arranged in an oblique direction with respect to the main scanning direction are in a predetermined order. There is a mode of driving at (timing). Of course, some of the nozzles in the nozzle row may be turned off at a predetermined timing.

  The head 650 also includes an ink supply system having a common flow path 655 including a main flow path 655A and a branch flow path 655B. The main flow paths 655A are provided in two upper and lower rows so as to sandwich the ink chamber units 653 arranged in a matrix in a staggered manner, and are arranged, for example, along the main scanning direction. Details of the nozzle arrangement of the head 650 shown in FIG. 40 will be described later.

  A main supply port (not shown) is formed at the left and right ends of the main channel 655A, and is connected to an ink supply system (not shown) via the main supply port. The two main channels 655A shown in FIG. 40 communicate with a common channel 655B common to the nozzle rows 712 and 714, and ink is supplied from the ink supply system to the pressure chambers 652 via the main channel 655A and the common channel 655B. Is supplied.

  Similarly to the head shown in FIG. 24, the short head modules 280 'may be arranged in a staggered manner and connected to form a length corresponding to the entire width of the recording medium.

  The pressure chamber 652 provided corresponding to each nozzle 651 has a substantially square planar shape, and the nozzle 651 and the supply port 654 are provided at both corners on the diagonal line. Each pressure chamber 652 communicates with a common channel (branch channel) 55B through a supply port 654.

  As shown in FIG. 41, a large number of ink chamber units 653 having such a structure are arranged along a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. The structure is arranged in a grid pattern. With a structure in which a plurality of ink chamber units 653 are arranged at a constant pitch d along a certain angle θ with respect to the main scanning direction, the pitch P0 of the nozzles projected so as to be aligned in the main scanning direction is (d × cos θ). / 2.

  That is, in the main scanning direction, each nozzle 651 can be handled equivalently as a linear arrangement with a constant pitch. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction. Hereinafter, for convenience of explanation, it is assumed that the nozzles 651 are linearly arranged at a constant interval (pitch P0) along the longitudinal direction (main scanning direction) of the head.

  Here, the standard specification of the head 650 according to the present invention is the same as the standard specification of the head 6500 according to the prior art. For example, the size of the pressure chamber 652 is 700 μm × 700 μm, and the actuator ( 25) is 500 μm × 500 μm, the nozzle pitch P1 between nozzles adjacent in the main scanning direction (the nozzle pitch of nozzles that eject droplets at the same timing) is 0.846 mm (= 30 npi), The droplet ejection interval is 1 mm, and the normally used ink viscosity is 2 cP to 3 cP.

  When the nozzles are driven by a full line head having a nozzle row corresponding to the full width of the paper, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially driven from one side to the other (3) ) The nozzle is divided into blocks, and each block is sequentially driven from one side to the other, etc., and a line of dots or a plurality of lines in the width direction of the paper (direction perpendicular to the paper conveyance direction) Nozzle driving that prints a line of dot rows is defined as main scanning.

  In particular, when driving the nozzles 651 arranged in a matrix as shown in FIGS. 40 and 41, the main scanning as described in the above (3) is preferable. That is, nozzles 651-11, 651-12, 651-13, 651-14, 651-15, 651-16 are made into one block (other nozzles 651-21,..., 651-26 are made into one block, No. 651-31,..., 651-36 as one block,...), And by sequentially driving the nozzles 651-11, 651-12,. Print one line in the width direction.

  On the other hand, it is defined as sub-scanning that the above-described full-line head and paper are moved relative to each other to repeatedly perform a line composed of one row of dots or a line composed of a plurality of dot rows formed by the above-described main scanning.

<Description of nozzle arrangement>
Next, the nozzle arrangement of the head 650 will be described in detail.

  As shown in FIGS. 40 and 41, the configuration of each nozzle row in which a plurality of nozzles are arranged in an oblique direction not orthogonal to the main scanning direction in the head 650 is the same. A description will be given using the nozzle rows 712 and 714 as representatives.

  FIG. 42 is a diagram for explaining nozzle arrangement and droplet ejection timing of the head 650 according to the present invention.

  As shown in FIG. 42, in the head 650 according to the present invention, a nozzle row 710 having six nozzles in an oblique row direction having a constant angle not orthogonal to the main scanning direction in the head 210 shown in FIG. The nozzle row is divided into two nozzle rows (nozzle row 712 and nozzle row 714) having three nozzles. The nozzle row 712 and the nozzle row 714 are divided in the main scanning direction by 1/2 of the inter-nozzle pitch P in the main scanning direction. They are staggered.

  That is, the head 650 includes two nozzle groups (corresponding to ejection hole groups) in which a plurality of nozzle rows having a predetermined inclination angle with respect to the main scanning direction in the head 210 shown in FIG. Each nozzle group 722 and nozzle group 724 divided in this manner and divided into two in the sub-scanning direction are nozzles (nozzles (nozzles) that are shifted in phase in the main scanning direction by 1/2 of the inter-nozzle pitch P in the main scanning direction). Column).

  In other words, the nozzles 651 arranged in a matrix along the row direction along the main scanning direction and the column direction forming a predetermined angle θ with the main scanning direction are divided into n nozzle groups in the sub-scanning direction. The nozzle groups are arranged with a phase shifted in the main scanning direction.

  Therefore, when the nozzle row 712 and the nozzle row 714 are projected so as to be aligned in the main scanning direction, the nozzles 651-11 to 651-16 constituting the nozzle rows 712, 714 are aligned at equal intervals along the main scanning direction. Furthermore, a nozzle 651-14 is arranged between the nozzle 651-11 and the nozzle 651-12, a nozzle 651-15 is arranged between the nozzle 651-12 and the nozzle 651-13, and the nozzle 651-16 is a nozzle. It is arranged on the opposite side of the nozzle 651-15 that is separated from the 651-13 by P / 2 in the main scanning direction.

  The head 650 projects the nozzle pitch P in the main scanning direction (projected so as to be aligned in the main scanning direction) so that the ink droplets ejected at the timings t1 to t3 shown in FIG. 42 do not interfere on the recording medium. The pitch between nozzles of the nozzle row) is determined.

  That is, of the dots formed continuously in the main scanning direction, the distance between two dots arranged every other dot is set such that these two dots do not overlap. It can be said that the inter-nozzle pitch P in the main scanning direction is larger than the inter-nozzle pitch shown in FIG.

  42, the numbers shown in the circles representing the nozzles 651 indicate the droplet ejection timing (droplet ejection order), and at the timing t1, the nozzles 651-11, 651-21, and 651-31 (not shown in FIG. 42). ), ..., droplet ejection is performed. Next, at timing t2, droplet ejection is performed from the nozzles 651-12,. Further, from timing t3 to timing t6, the nozzles 651-13,..., Nozzle 651-16, nozzle 651-26, nozzle 651-36,... Are ejected, and one cycle of droplet ejection from timing t1 to timing t6. Thus, one line of dot row can be formed in the main scanning direction.

  Here, in the droplet ejection performed at the timings t1 to t3, the ink droplets ejected at each timing do not come into contact with other ink droplets on the recording medium, and the ink droplets by the respective droplet ejections form dots independently. To do.

  On the other hand, at timing t4 to timing t6, when the ejected ink droplets have landed, ink droplets have already been deposited on the landing positions on both sides adjacent to the main scanning direction, and landed on the recording medium first. In order to be in contact with the ink droplets on both sides, it lands.

  That is, the ink droplets ejected at timing t4 land between the ink droplets ejected at timing t1 and timing t2, and the ink droplets ejected at timing t5 are similarly ejected at timing t2 and timing t3. The ink droplets that have landed between the ink droplets that have been ejected and that have been ejected at timing t6 land between the ink droplets that have been ejected at timing t1 and timing t3.

  Since the ink droplets ejected at the timing t4 to the timing t6 are attracted to the adjacent ink droplets that have landed first, the ink droplets ejected at the timing t4 to the timing t6 do not cause a phenomenon that moves in one direction. The dots formed by the ink droplets ejected at the timing t4 to the timing t6 have symmetry, and stripe unevenness caused by unidirectional aggregation can be reduced.

  In the present specification, in the head 650 whose nozzle arrangement is shown in FIG. 42, it is a boundary between nozzle rows adjacent to each other in the main scanning direction of the nozzle rows (712, 714, etc.) included in each nozzle group 722, 724, The inter-nozzle position where the inter-nozzle pitch in the scanning direction is larger than the others is defined as a folding position A.

  That is, in the nozzle arrangement shown in FIG. 42, between the nozzle 651-11 and the nozzle 651-23 (folding position A-1), between the nozzle 651-14 and the nozzle 651-26 (folding position A-3), etc. Is the folding position A.

  The landing time difference between the ink droplets at the turn-back position A (for example, the difference in landing time between the ink droplet ejected from the nozzle 651-11 and the ink droplet ejected from the nozzle 651-23) is the same nozzle row. Ink that has landed first is different from the difference in landing time between the droplets of the droplets ejected from adjacent nozzles (for example, nozzle 651-11 and nozzle 651-12, nozzle 651-12 and nozzle 651-13, etc.). The amount of ink droplet remaining on the recording medium is different. For this reason, since the aggregation condition changes between the folding position A and a position other than the folding position, streaks due to aggregation occur at the folding position A.

  In FIG. 42, the interval between the folding positions in the nozzle group 722 (pitch between the folding positions) P2B, such as the interval between the folding position A-1 and the folding position A-3, is P2B = 0.94 mm. The spatial frequency of streak unevenness due to the resulting agglomeration corresponds to 1.061 lp / mm and is in a spatial frequency region that is relatively easily visible.

  However, the interval P2C between the folding positions in the nozzle group 724, such as the interval between the folding position A-3 and the folding position A-4, is also P2C = 0.94 mm, and the spatial frequency is the same as the folding position of the nozzle row 712. Although it has 1.061 lp / mm, as shown in FIG. 42, since the folding position A-1 and the folding position A-4 are close to each other, the spatial frequency visually recognized in the recorded image is about 1.061 lp / mm. Can be thought of as

  On the other hand, in the nozzle arrangement shown in FIG. 43, in the main scanning direction, the intervals P2 between the folding position A-1 in the nozzle group 722 and the folding position A-3 in the nozzle group 724 are equal. The nozzle arrangement is shifted in phase by a half pitch of the pitch between the folding positions.

  Therefore, the substantial cycle of the folding position A is P2 = 0.47 mm, and the spatial frequency of the folding position having this cycle is 2.13 lp / mm. Compared with the nozzle arrangement shown in FIG. It is possible to arrange the nozzles shifted in a direction that is difficult to be visually recognized as density unevenness.

  In addition, it is preferable that the pitch P2 between the folding positions is such that the folding cycle is 2.0 lp / mm or more. If the folding cycle is 3.0 lp / mm or more, the visibility of the stripe unevenness can be greatly reduced. More preferable.

  In a print head having a nozzle arrangement in which the pitches P2 between the folding positions are equally spaced as shown in FIG. 43, the number n of nozzle groups in the sub-scanning direction is an even number.

<Explanation of landing time difference>
Depending on the type of ink and the type of recording medium (media type), instead of optimizing the pitch P2 between the folding positions shown in FIG. 42 and FIG. 43, the landing time difference (droplet ejection time difference) is optimized, thereby causing uneven density. Visibility can be effectively reduced. That is, the nozzle arrangement of the head 650 may be determined so that the landing time difference between ink droplets forming adjacent dots is smaller than the maximum landing time difference of the head 650.

  When forming a dot row arranged on one line continuously in the main scanning direction using the head 650 having the nozzle arrangement shown in FIG. 42, between two nozzles that eject ink droplets that form adjacent dots In the combination of nozzles having a maximum landing time difference δTmax1, a nozzle that performs droplet ejection (for example, nozzle 651-11) at timing t1 and a nozzle that performs droplet ejection at timing t6 (for example, nozzles 651-26) ) And a combination thereof.

  Of the combinations of nozzles that eject ink droplets that form adjacent dots, the combination of nozzles in which the landing time difference between the nozzles has the maximum value δTmax1 is the nozzle in which the landing time difference in the nozzle arrangement shown in FIG. It is a combination of. In other words, in the nozzle arrangement shown in FIG. 42, in order to perform droplet ejection that forms a dot adjacent in the main scanning direction using a nozzle that satisfies the relationship of δTmax1 = δTmax2 and has the maximum inter-nozzle distance in the sub-scanning direction. The landing time difference is larger than that of other nozzles that form droplets that form adjacent dots in the main scanning direction. Depending on the type of recording medium and the type of ink, unevenness due to this landing time difference may appear in the recorded image. There is a risk of it.

  In the nozzle arrangements shown in FIGS. 44 (a) and (b), the landing time difference is optimized with respect to the nozzle arrangement shown in FIG. 42, and the nozzles that deposit ink droplets forming adjacent dots have a landing time difference. The nozzle arrangement is determined so that a combination of nozzles different from the combination of nozzles having the maximum value δTmxa2 is used.

  That is, in the nozzle arrangement shown in FIGS. 44 (a) and 44 (b), when a dot row arranged on one line continuously in the main scanning direction is formed, the difference in the landing time of the nozzles of the head 650 is the maximum value δTmax2. As in the nozzle arrangement shown in FIG. 42, the combination of nozzles that become droplets is a nozzle that performs droplet ejection at timing t1 (for example, nozzle 651-11) and a nozzle that performs droplet ejection at timing t6 (for example, nozzle 651-). 16 etc.).

  On the other hand, for a combination of nozzles in which the landing time difference between two nozzles that eject ink droplets that form adjacent dots reaches the maximum value δTmax1, nozzles that eject droplets at timing t2 (for example, nozzles 651-12) And a nozzle that performs droplet ejection at timing t6 (for example, nozzle 651-16 or the like).

  Therefore, in the nozzle arrangement shown in FIGS. 44 (a) and 44 (b), when forming a dot row arranged on one line continuously in the main scanning direction, nozzles that perform droplet ejection for forming adjacent dots. The relationship between the maximum value δTmax1 of the adjacent maximum landing time difference and the maximum value δTmax2 of the maximum landing time difference of the nozzles of the head 650 satisfies δTmax1 <δTmax2.

  That is, since ink droplets that form adjacent dots are ejected using nozzles other than the two nozzles that have the maximum inter-nozzle distance in the sub-scanning direction in the head 650, the adjacent dots in the other main scanning directions The difference in landing time is not significantly different from that of nozzles that eject ink droplets forming the ink droplets, and streak unevenness caused by agglomeration due to an extreme landing time difference can be suppressed.

  When forming a dot row arranged on one line continuously in the main scanning direction using the head 650 having the nozzle arrangement shown in FIG. 44A, adjacent dots are formed in the main scanning direction. For the combination of nozzles in which the landing time difference between the nozzles that eject ink droplets is the minimum value δTmin1, nozzles that eject ink at timing t3 and nozzles that eject ink at timing t4 (for example, 51-23 and nozzle 651-14) For example).

  As shown in FIG. 44 (b), the inter-nozzle distance between these nozzles in the sub-scanning direction is set equal to the minimum value Ptmin of the inter-nozzle distance between the nozzles in the head 650.

  On the other hand, when forming a dot row that is arranged continuously on one line in the main scanning direction, a nozzle (for example, nozzle 651-23) in which the landing time difference between nozzles that form adjacent dots in the main scanning direction becomes the maximum value δTmax1. The nozzle pitch in the sub-scanning direction of the nozzles 651-16 and the like is set to 4 × Ptmin. At this time, the relationship between the minimum value δTmin1 of the landing time difference and the maximum value δTmax1 of the landing time difference is δTmin1 / δTmax1 = 0.25.

  When forming a dot row arranged on one line continuously in the main scanning direction using the head 650 having the nozzle arrangement shown in FIG. 44 (c), the nozzles for forming dots adjacent in the main scanning direction are arranged. Examples of the combination of nozzles in which the landing time difference is the minimum value δTmin1 include nozzles that eject droplets at timing t3 (for example, 51-12) and nozzles that deposit droplets at timing t4 (for example, nozzle 651-14). It is done.

  As shown in FIG. 44 (c), the inter-nozzle distance between these nozzles in the sub-scanning direction is the minimum inter-nozzle distance Ptmin (for example, the nozzles 651-11 and 651) of the nozzles in the head 650. Is set to 4 × Ptmin).

  Further, the nozzle pitch in the sub-scanning direction of the nozzle (for example, the nozzle 651-12 and the nozzle 651-16) in which the difference in landing time between the nozzles that form adjacent dots in the main scanning direction becomes the maximum value δTmax1 is 7 × Ptmin. Is set. At this time, the relationship between the minimum value δTmin1 of the landing time difference and the maximum value δTmax1 of the landing time difference is δTmin1 / δTmax1 = 0.57.

  Comparing streak unevenness due to aggregation between the nozzle arrangement shown in FIG. 44B and the nozzle arrangement shown in FIG. 44C, the ratio δTmin1 / δTmax1 of the landing time difference between the ink droplets forming adjacent dots is close to 1. (There is little variation in the ratio of landing time difference) The nozzle arrangement shown in FIG. 44 (c) shows a better tendency.

  In particular, it has been found from experiments that the ratio of landing time difference δTmin1 / δTmax1 changes with 0.5 as a boundary, and the tendency of the unevenness of streaks caused by agglomeration changes. .

  In other words, by optimizing the distance in the sub-scanning direction between the nozzle groups, it is possible to reduce the variation in the landing time difference between the ink droplets that land on the adjacent landing positions, and to suppress the visibility of uneven stripes caused by aggregation. be able to.

  In this modification, a print head including a nozzle group in which a plurality of nozzle rows each having three nozzles is arranged along the main scanning direction is illustrated, but the number of nozzles that the nozzle row has is not limited to three. Two nozzles may be provided in one nozzle row, or three or more nozzles may be provided. In this example, a plurality of nozzle groups having the same nozzle arrangement are shifted in the main scanning direction and arranged in the sub scanning direction. However, a plurality of nozzle groups having different nozzle arrangements may be arranged in the sub scanning direction. Good. The different nozzle arrangements described above include, for example, a mode in which the number of nozzles included in the nozzle row of each nozzle group is different, and a mode in which the pitch between nozzles in the sub-scanning direction of each nozzle group is different.

<Application example of symmetrical droplet-type matrix head>
Next, an application example in the case where the above-described symmetrical droplet ejection type matrix head is configured with 20 nozzles per nozzle row will be described.

  As shown in FIG. 45, the matrix-arranged nozzles of the head 650 ″ are divided into four in the sub-scanning direction, and each of the divided blocks (nozzle groups) 742, 744, 746, and 748 has a phase in the main scanning direction. They are staggered.

  The head 650 ″ shown in FIG. 45 includes nozzles 651-105 and 651-121, nozzles 651-110 and 651-126, nozzles 651-115 and 651-131, nozzle 651- The folding position A is formed at four positions between 120 and the nozzles 651-136, and the spatial frequency at the folding position A can be four times (high frequency) of the nozzle arrangement in the general matrix arrangement. The specificity in A can be improved, and the visibility of the stripe unevenness at the turn-back position A can be suppressed.

  In the nozzle arrangement shown in FIG. 45, as shown in FIG. 43, the nozzle groups 742, 744, 746, and 748 are shifted in the main scanning direction so that the pitch P2 between the folding positions is uniform. .

  That is, in the head 650 ″, n nozzle groups described above are arranged in the sub-scanning direction (where n is an integer of 2 or more, and n is an even number of 2 or more in a mode in which the pitch between turn-back positions is uniform), Each nozzle group is arranged with a phase shifted in the main scanning direction, and in order to obtain a higher-resolution image, an embodiment in which n ≧ 4 is preferable.

  The nozzle pitch P1 in the main scanning direction is equal to the distance obtained by dividing the nozzle pitch P adjacent in the main scanning direction by n. This is equivalent to assigning each nozzle group in the main scanning direction with a shift amount in units of P / n.

  The arrangement of the nozzle rows in the head 650 ″ is the same, and the nozzle row 730 including 20 nozzles 651-101 to 651-120 will be described as a representative of these nozzle rows. I will decide.

  The nozzle row 730 includes a nozzle row 732 composed of nozzles 651-101 to 651-105, a nozzle row 734 composed of nozzles 651-106 to 651-110, a nozzle row 736 composed of nozzles 651-111 to 651-115, The nozzle array 738 includes nozzles 651-116 to 651-120. The nozzle array 732 belongs to the nozzle group 742, the nozzle array 734 belongs to the nozzle group 744, the nozzle array 736 belongs to the nozzle group 746, and the nozzle array 738 belongs to the nozzle group 748.

  In the nozzle row in which the nozzles 651-101 to 651-120 are projected so as to be aligned in the main scanning direction, the nozzle row 732 is arranged such that the nozzles 651-109 are arranged between the nozzles 651-101 and 651-102. And the nozzle row 734 are arranged with their phases shifted in the main scanning direction, and the nozzle rows 734 and 736 are arranged such that the nozzles 651-115 are arranged between the nozzles 651-101 and 651-109. Are arranged with the phase shifted in the main scanning direction, and the nozzle row 736 and the nozzle row 738 are arranged in the main scanning direction so that the nozzles 651-118 are arranged between the nozzles 651-102 and 651-109. It has a structure in which the phases are shifted.

  That is, in the projected nozzle row in which the nozzles 651-101 to 651-120 included in each nozzle row 732, 734, 736, 738 are projected so as to be aligned in the main scanning direction, between adjacent nozzles in the same nozzle group, The nozzles of nozzle groups adjacent to each other in the sub-scanning direction are arranged. For example, in the projection nozzle row described above, the nozzles 651-109 belonging to the nozzle group 742 and the nozzle group 744 adjacent in the sub-scanning direction are positioned between the nozzles 651-101 and 651-102 belonging to the nozzle group 742. is doing.

  In the nozzle arrangement shown in FIG. 45, the pitch between nozzles in the main scanning direction (the pitch between adjacent nozzles in a nozzle row projected so as to be aligned in the main scanning direction within the same nozzle group) P = 0.169 mm, adjacent in the main scanning direction. The inter-nozzle pitch P1 of the matched nozzles is 0.846 mm, and the pitch P2 between the folding positions is 0.21 mm.

  FIG. 46 shows the relationship between the nozzle arrangement shown in FIG. 45 and the droplet ejection timing.

  As shown in FIG. 46, droplet ejection is performed from nozzles arranged in the main scanning direction with nozzle 651-101 at timing t1, and droplet ejection is performed from nozzles aligned in the main scanning direction with nozzle 651-102 at timing t2. Done. In this manner, from timing t3 to timing t20, droplet ejection is performed from the nozzles arranged in the main scanning direction to the nozzles 51-103 in sequence to the nozzles 651-120 and the nozzles arranged in the main scanning direction.

  In the head 650 and the head 650 ″, the nozzle row in which the nozzles 651 are arranged in an oblique direction not orthogonal to the main scanning direction is divided into n in the sub-scanning direction (where n is an even number), and the divided nozzle row is arranged in the main scanning direction. Since the phases are shifted, it is possible to improve the peculiarity of the landing interference of the ink droplet generated at the turn-back position A.

  Further, if the nozzle rows are arranged so that the pitches P2 between the folding positions are substantially equal, the visibility of the stripe unevenness occurring at the folding position A can be improved. Further, in a multi-color head provided with a print head corresponding to each color, if the present invention is applied to the turn-back position of the head (nozzle group) corresponding to each color, the unevenness can be further reduced.

  As described above, in the adjacent droplet ejection using the symmetrical droplet ejection type matrix head shown in this example, the adjacent dots are not continuously ejected, and the liquid dots are landed without contacting each other. Interference can be prevented, and purge ink can be ejected with high density (for example, a solid image).

  In this example, the apparatus configuration for forming an image by causing the ink to react with the processing liquid having the function of aggregating (or insolubilizing) the colorant contained in the ink has been described, but the present invention does not use the processing liquid. The present invention can also be applied to an apparatus configuration for fixing ink to a recording medium.

  The inkjet recording apparatus and droplet ejection detection method of the present invention have been described in detail above. However, the present invention is not limited to the above examples, and various improvements and modifications are made without departing from the gist of the present invention. Of course.

<Appendix>
As will be understood from the description of the embodiments of the invention described in detail above, the present specification includes disclosure of various technical ideas including at least the invention described below.

  (Invention 1): Conveying means for conveying a recording medium in a predetermined conveying direction, an ink jet head for ejecting ink onto the recording medium, and a blank area of the recording medium for ink ejected by purging the ink jet head Droplet ejection control means for controlling droplet ejection of the ink jet head so as to adhere to the ink, drying processing means for subjecting the recording medium to a drying process, and temperature and water content of the ink by purging droplets ejected on the blank area. A droplet ejection detecting means for detecting at least one of them, and a drying processing control means for controlling a drying amount by the drying processing means based on a detection result of the droplet ejection detecting means. Inkjet recording device.

  According to the present invention, the ink jet head is purged in the blank area of the recording medium, and at least one of the temperature and the water content of the ink ejected by the purging is detected, and the drying process for the recording medium is performed based on the detection result. Therefore, it is possible to perform a stable drying process against changes in the environment inside and outside the apparatus and differences in the types of recording media.

  The “purge” in the present invention includes not only the drop of deteriorated ink on the blank area of the recording medium but also the drop of ink for forming text, symbols, etc. on the blank area of the recording medium.

  The drying processing means in the present invention is a non-contact type, such as one that injects dry air onto a recording medium before ink ejection by an ink jet head, or one that injects dry air onto a recording medium after ink ejection. Those are preferred.

  The “recording medium” is sometimes called a print medium, an image forming medium, a recording medium, an image receiving medium, or the like. Further, the recording medium is not limited to the case of drawing directly on the medium, but once the primary image is formed on the intermediate transfer member, the intermediate image is transferred to the image (secondary image) on a sheet or the like. A transfer member may also be included in the concept of “recording medium”. The form and material of the recording medium are not particularly limited, and are a sheet of paper (cut paper), a sealing paper, a continuous paper, a resin sheet such as an OHP sheet, a printed board on which a film, a cloth, a wiring pattern, etc. are formed, rubber Sheets, metal sheets, and other various media, regardless of material or shape.

  The conveyance means for moving the recording medium and the inkjet head relatively includes an aspect for conveying the recording medium with respect to the stopped (fixed) head, an aspect for moving the head with respect to the stopped recording medium, or a head Any of the modes in which both recording media are moved is included. When forming a color image using an inkjet head, a head may be arranged for each color of a plurality of colors (recording liquids), or a configuration in which a plurality of colors of ink can be ejected from one head is also possible. Good.

  It is preferable that the recording medium includes a full-line type ink jet head in which a plurality of nozzles are arranged over a length corresponding to the length in the width direction orthogonal to the transport direction of the transport unit.

  (Invention 2): In the ink jet recording apparatus according to Invention 1, the droplet ejection control means is configured so that the droplet ejection amount of the ink in the purge is equal to or less than the droplet ejection amount when forming a solid image with the highest droplet ejection resolution. An ink jet recording apparatus for controlling droplet ejection of an ink jet head.

  According to this aspect, by suppressing the droplet ejection density of the purge ink to a primary color solid (100% solid) or less, the temperature rising gradient during the drying process is increased. It also contributes to reduction in unevenness.

  (Invention 3): The inkjet recording apparatus according to Invention 1 or 2, wherein the droplet ejection control unit performs droplet ejection control so that dots ejected by purge do not overlap each other. apparatus.

  According to such an aspect, landing interference is prevented and liquid thickness non-uniformity is mitigated.

  (Invention 4): The inkjet recording apparatus according to any one of Inventions 1 to 3, wherein the inkjet head includes a symmetrical droplet ejection type matrix head.

  According to this aspect, even when a recording medium having weak permeability such as coated paper is used, non-uniformity in the liquid due to landing interference is reduced and the drying process is stabilized.

  A symmetric matrix head is a nozzle in which a plurality of nozzles are arranged in an oblique direction that forms a predetermined angle θ (where 0 ° <θ <90 °) with respect to a direction perpendicular to the recording medium conveyance direction of the conveying means. There are provided n nozzle groups (n is an even number of 2 or more) in the sub-scanning direction in which rows are arranged at predetermined intervals in a direction orthogonal to the recording medium conveyance direction of the conveyance means, and adjacent to the recording medium conveyance direction of the conveyance means. In the matching nozzle group, in the projection nozzle row in which the nozzles of each nozzle group are projected so as to be aligned in the main scanning direction, the projection of the other nozzle group is performed between adjacent nozzles in the projection nozzle row of one nozzle group. The nozzle groups adjacent to each other in the recording medium transport direction of the transport unit are arranged with the phase changed in the main scanning direction so that the nozzles in the nozzle array are located and the nozzles in the projection nozzle array are evenly disposed. No Among the nozzle rows of the nozzle group, the nozzle rows adjacent to each other in the direction orthogonal to the recording medium conveyance direction of the conveyance means and the pitch between the nozzles in the recording medium conveyance direction of the conveyance means are between other nozzles. When the position between nozzles, which is larger than the inter-nozzle pitch in the sub-scanning direction, is the folding position, the folding position when the folding position is projected so as to be aligned in a direction perpendicular to the recording medium conveyance direction of the conveying unit The nozzle group has a structure in which the phase is changed in a direction perpendicular to the recording medium conveyance direction of the conveyance means so that the pitch between the two is uniform.

  (Invention 5): In the inkjet recording apparatus according to any one of Inventions 1 to 4, an inkjet head is provided for each color corresponding to a plurality of colors, and the droplet ejection control means is provided for one recording medium. An ink jet recording apparatus that controls the ejection of each ink jet head so as to purge all ink jet heads while switching the ink jet head each time the recording medium changes.

  According to this aspect, in an aspect including a plurality of heads corresponding to a plurality of colors, it is possible to detect a difference in drying property depending on ink colors.

  (Invention 6): In the inkjet recording apparatus according to Invention 5, the droplet ejection control unit performs droplet ejection control of the plurality of inkjet heads so as to perform symmetrical droplet ejection two-dimensionally using the plurality of heads. An ink jet recording apparatus characterized in that:

  According to this aspect, it is possible to prevent landing interference between ink colors and to measure the drying property by averaging the colors.

  Symmetrical droplet ejection using a plurality of inkjet heads includes a mode in which thinning droplet ejection is performed from the first head and droplet ejection is performed between dots ejected from the second head from the first head. Further, the present invention can also be applied to an aspect including three or more inkjet heads by using thinning droplets in combination in the width direction and the conveyance direction of the recording medium.

  (Invention 7): In the ink jet recording apparatus according to any one of Inventions 1 to 6, the droplet ejection controlling means performs ejection by purging in accordance with an ink droplet ejection amount based on image data to be recorded next. An ink jet recording apparatus, wherein droplet ejection by the ink jet head is controlled so as to change a volume of ink to be ejected.

  According to this aspect, it is possible to correct the difference in the image data, and the drying process is further stabilized.

  (Invention 8): In the ink jet recording apparatus according to any one of Inventions 1 to 6, the droplet ejection control means ejects droplets by purging according to an ink droplet ejection amount based on image data to be recorded next. An ink jet recording apparatus, wherein the ink droplet density is changed.

  According to such an aspect, stable drying control is possible even when the content of an image differs for each recording medium as in on-demand printing.

  (Invention 9): In the ink jet recording apparatus according to any one of Inventions 1 to 8, the optical of the ink ejected by the purge ejected on the blank area, being configured integrally with the droplet ejection detecting means. An ink jet recording apparatus comprising optical density detecting means for detecting density.

  According to this aspect, droplet ejection correction of the inkjet head can be performed using the optical density of the purge ink as a monitor, and image recording with a stable density is realized.

  (Invention 10): In the ink jet recording apparatus according to Invention 9, the optical density detection means has a different circumference from the means for detecting the temperature or the amount of water of ink ejected by the purge ejected on the blank area. An ink jet recording apparatus comprising: a light source that emits light having several bands; and a light receiving element that receives reflected light of light emitted from the light source.

  According to this aspect, it is possible to simultaneously detect both the temperature or the amount of moisture and the optical density using two types of light having different frequency bands.

  An embodiment in which the temperature or moisture content is detected using infrared rays and the optical density is detected using visible light is preferable.

  By controlling the drying process based on the detection result of the temperature or the amount of water and correcting the droplet ejection of the inkjet head based on the optical density, the variation in the drying process and the fluctuation in the ejection characteristics of the inkjet head due to the temperature are eliminated at the same time. It is possible.

  (Invention 11): In the ink jet recording apparatus according to Invention 9 or 10, the droplet ejection control means forms a predetermined pattern using ink ejected by purging, and the droplet ejection detection means is the predetermined ejection An ink jet recording apparatus, comprising: detecting at least one of ink temperature and water content in the pattern; and detecting the optical density in the predetermined pattern.

  The predetermined pattern may be formed by at least a part of the ink by purging, and droplets may be ejected in a line shape in a non-patterned portion. The predetermined pattern is formed corresponding to the detection position of the droplet ejection detection means and the detection position of the optical density detection means.

  (Invention 12): The ink jet recording apparatus according to any one of Inventions 9 to 11, wherein the optical density detection means detects an optical density at a position substantially the same as a detection position by the droplet ejection detection means. Inkjet recording apparatus.

  According to this aspect, it is possible to perform preferable drying processing control and droplet ejection control (droplet ejection correction) by simultaneously detecting the temperature or water content and optical density at substantially the same position.

  The “substantially the same position” is a concept including a region having substantially the same value on the temperature distribution and the concentration distribution.

  (Invention 13): In the ink jet recording apparatus according to any one of Inventions 9 to 12, the transport unit includes a holding unit that holds a leading end portion or a trailing end portion of a recording medium, and the droplet ejection detecting unit and the optical unit An ink jet recording apparatus, wherein the density detecting means is fixed to the holding means.

  According to this aspect, since the droplet ejection detection unit and the optical density detection unit move together with the recording medium, it is possible to obtain a change (history) with time in the detection position.

  The droplet ejection detecting means and the optical density detecting means may be provided at substantially the center in the width direction of the recording medium, or a plurality of droplet ejection detecting means and optical density detecting means are provided in the width direction of the recording medium. You may comprise so that temperature (water content) and an optical density may be detected about the whole width. Further, the droplet ejection detecting means and the optical density detecting means may be configured to be movable along the width direction of the recording medium, and the temperature (water content) and the optical density may be detected for the entire width of the recording medium.

  (Invention 14): In the ink jet recording apparatus according to any one of the inventions 9 to 13, the transport means includes a front end portion or a rear end portion of the recording medium in a droplet ejection area where ink is ejected from the ink jet head. A first impression cylinder that conveys the recording medium while being held by the holding member, a transfer cylinder that conveys the leading end or the rear end of the recording medium delivered from the impression cylinder by the holding member, and the transfer cylinder A second impression cylinder for holding the transferred recording medium and transporting the recording medium in a drying processing area by the drying means, wherein the purge ink detecting means and the optical density detecting means are An ink jet recording apparatus disposed on a holding member of a cylinder.

  According to such an aspect, by detecting the temperature or the amount of moisture during conveyance by the transfer cylinder, the subsequent drying process can be optimized, and by detecting the optical density during conveyance by the transfer cylinder, The next drop can be optimized.

  (Invention 15): A transport step for transporting the recording medium in a predetermined transport direction, and a purge for purging the ink jet head so that ink ejected by purging the ink jet head adheres to a blank area of the recording medium. A purge detection step for detecting at least one of the temperature of the ink and the amount of water by the purge that has been ejected onto the margin area, and the drying amount based on the detection result of the purge detection step, And a drying process step of performing a drying process on the recording medium.

  According to the present invention, it is possible to optimize the drying process of the recording medium based on the temperature of the purged ink or the amount of water in the blank area of the recording medium, and the drying due to the difference in the type of the recording medium, the environmental temperature, and the humidity Variations in processing are prevented.

  (Invention 16): Containing means for holding either the leading end or the trailing end of the recording medium, the conveying means for conveying the recording medium held by the holding means in a predetermined conveying direction, and the recording An ink jet head for ejecting ink onto a medium; and an ink ejection detecting means for detecting at least one of a temperature and a water content of the ink ejected from the ink jet head onto the recording medium. An ink jet recording apparatus, characterized in that the means is provided in the holding means.

  According to the present invention, since the droplet ejection detecting means moves together with the recording medium, it is possible to obtain a change (history) with the passage of time at the detection position.

  (Invention 17): In the ink jet recording apparatus according to invention 16, the optical density of the ink that is provided on the holding unit and is integrated with the droplet ejection detecting unit and is ejected from the inkjet head onto the recording medium is detected. An ink jet recording apparatus comprising: an optical density detecting means for performing

  According to this aspect, since the optical density detection unit moves together with the recording medium, it is possible to obtain a change (history) over time at the detection position. Further, the temperature or moisture content and optical density can be detected simultaneously.

  (Invention 18): In the ink jet recording apparatus described in Invention 16 or 17, the drying amount of the drying processing means is determined based on the detection result of the drying processing means for performing a drying process on the recording medium and the droplet ejection detection means. An ink jet recording apparatus comprising: a drying control means for controlling.

  According to this aspect, the drying process can be optimized based on the temperature or the amount of moisture.

  (Invention 19): The ink jet recording apparatus according to the invention 17 or 18, further comprising: a droplet ejection control unit that controls droplet ejection of the inkjet head based on a detection result of the optical density detection unit. Inkjet recording device.

  According to this aspect, it is possible to optimize the droplet ejection of the inkjet head based on the optical density.

  (Invention 20): Conveying means for conveying the recording medium in a predetermined conveying direction, an ink jet head for ejecting ink onto the recording medium, and a blank area of the recording medium for ink ejected by purging the ink jet head And droplet ejection control means for controlling droplet ejection of the ink jet head so as to form a predetermined pattern using ink ejected by purge, and drying processing means for subjecting the recording medium to drying processing , Droplet ejection detecting means for detecting at least one of the temperature and water content of the ink that has been ejected onto the margin area, and drying by the drying processing means based on the detection result of the droplet ejection detecting means An ink jet recording apparatus comprising: a drying processing control means for controlling the amount.

  (Invention 21): Holding means for holding either the front end portion or the rear end portion of the recording medium, and the temperature or moisture amount at a predetermined position of the recording medium provided in the holding means and held by the holding means And detecting the temperature or moisture content of the recording medium being conveyed by the detection means while conveying the recording medium held by the holding means in the circumferential direction. Torso.

  According to the present invention, the temperature history of the recording medium being conveyed by the transfer cylinder can be acquired by continuously detecting the temperature or moisture content of the recording medium being conveyed by the transfer cylinder. Further, the temperature history and temperature gradient from the timing when the recording medium is held on the transfer drum can be acquired, and preferable drying control based on the temperature history and temperature gradient can be realized.

  (Invention 22): a first sensor that detects either the temperature or the moisture content of the recording medium; a second sensor that is integrated with the first sensor and detects the optical density of the recording medium; Provided to the holding means of the transfer cylinder that conveys in the circumferential direction while holding the recording medium by the holding means that holds either the front end or the rear end of the recording medium, and is conveyed by the transfer cylinder A sensor unit for detecting a predetermined position of a recording medium inside.

  The temperature or moisture content and optical density of the recording medium can be detected simultaneously, and the temperature history or moisture history and optical density within the same period at the same position of the recording medium can be acquired.

1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. The block diagram which shows the 1st example of the liquid application apparatus applied to a osmosis | permeation inhibitor application part. Enlarged view of the outer peripheral surface of the spiral roller Schematic diagram showing the groove shape formed on the outer peripheral surface of the spiral roller Schematic diagram showing the cross-sectional shape of the outer peripheral surface of the spiral roller Illustration of flat spray nozzle Explanatory drawing schematically showing the relationship between the liquid ejecting section and the ejection width Graph showing liquid volume distribution of liquid spray pattern by flat spray Explanatory drawing showing an example of application range control A perspective view showing an outline of a spiral roller moving mechanism (contact / separation mechanism), a rotation driving means, a squeegee blade, a rotation mechanism of a main blade, and the like. The block diagram which shows the 2nd example of a liquid coating device Sectional drawing which shows the structure of the 1st example of a transfer drum Sectional drawing which follows the AA line of FIG. The figure which shows the structural example of a hot air generation means Plane development drawing schematically showing an example of paper support surface in transport guide Explanatory drawing schematically showing the relationship between the paper and hot air jet area on the transport guide Explanatory drawing of the injection range of hot air injected from the transfer drum It is a figure which shows the example of the monitor position by a sensor. Graph showing the time change of the surface temperature of the recording medium measured by the sensor Sectional drawing which shows the other structural example of a transfer drum Plane development view showing an example of an opening pattern of injection openings Explanatory drawing of the injection range of hot air injected from the transfer drum Plane perspective view showing a configuration example of an ink head Plan view showing another configuration example of the head Sectional drawing which follows the BB line in FIG. Plan view showing an example of nozzle arrangement of the head Enlarged view of solvent drying unit Enlarged view of the heat and pressure fixing section Block diagram showing system configuration of inkjet recording apparatus Configuration of an inkjet recording apparatus according to another embodiment of the present invention Schematic perspective view showing arrangement of sensor unit Partial enlarged view of FIG. Explanatory drawing of droplet ejection detection by the sensor unit shown in FIG. Schematic perspective view showing another arrangement example of the sensor unit Block diagram showing the configuration of the sensor unit Explanatory drawing of heat treatment in purging Explanatory drawing of purge pattern 1 Explanatory drawing of purge pattern 2 Explanatory drawing of multicolor symmetrical droplet ejection Plane perspective view showing a structural example of a symmetrical droplet-type matrix head 40 is an enlarged view showing the nozzle arrangement of the head shown in FIG. 40 is a diagram for explaining the relationship between the nozzle arrangement of the head shown in FIG. 40 and the droplet ejection timing. The figure explaining the relationship between the other aspect of nozzle arrangement of the head shown in FIG. 40, and droplet ejection timing FIG. 43 is a diagram for explaining the relationship between still another aspect of the nozzle arrangement shown in FIG. 43 and droplet ejection timing. Plane perspective view showing an application example of the nozzle arrangement of the head shown in FIG. The figure explaining the relationship between the nozzle arrangement shown in FIG. 45 and the droplet ejection timing

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,400 ... Inkjet recording device, 14 ... Recording medium, 28 ... Printing part, 30 ... Solvent drying part, 40, 86, 216, 306, 326 ... Impression cylinder, 84, 214, 304 ... Transfer cylinder, 87 ... Gripper, 182: Sensor unit, 210Y, 210M, 210C, 210K ... Ink head, 308 ... Solvent drying unit, 310 ... IR heater, 312 ... Blower fan, 480 ... Print controller, 484 ... Head driver, 492 ... Blower controller, 496 ... transfer cylinder controller, 520 ... infrared sensor, 521 ... light receiving element, 522 ... visible light source

Claims (22)

Conveying means for conveying the recording medium in a predetermined conveying direction;
An inkjet head for ejecting ink onto the recording medium;
Droplet ejection control means for controlling the droplet ejection of the ink jet head so that the ink ejected by the purge of the inkjet head adheres to the blank area of the recording medium;
A drying processing means for performing a drying process on the recording medium;
A droplet ejection detecting means for detecting at least one of the temperature and the amount of water of the ink by the purge deposited on the margin area;
Based on the detection result of the droplet ejection detection means, a drying processing control means for controlling the amount of drying by the drying processing means,
An ink jet recording apparatus comprising: The inkjet recording apparatus according to claim 1, wherein
The droplet ejection control means controls the droplet ejection of the inkjet head so that the droplet ejection amount in the purge is equal to or less than the droplet ejection amount when forming a solid image with the highest droplet ejection resolution. apparatus. The inkjet recording apparatus according to claim 1 or 2,
2. The ink jet recording apparatus according to claim 1, wherein the droplet ejection control unit performs droplet ejection control so that dots ejected by the purge do not overlap each other. The inkjet recording apparatus according to any one of claims 1 to 3,
2. The ink jet recording apparatus according to claim 1, wherein the ink jet head includes a symmetrical droplet type matrix head. The inkjet recording apparatus according to any one of claims 1 to 4,
While providing an inkjet head for each color corresponding to a plurality of colors,
The droplet ejection control means purges only one color for one recording medium, and switches each inkjet head every time the recording medium changes, and purges all inkjet heads so as to purge all inkjet heads. An ink jet recording apparatus that controls droplet ejection. The inkjet recording apparatus according to claim 5, wherein
The ink jet recording apparatus, wherein the droplet ejection control unit performs droplet ejection control of the plurality of inkjet heads so as to perform two-dimensional symmetrical droplet ejection using a plurality of heads. The inkjet recording apparatus according to any one of claims 1 to 6,
The droplet ejection control unit controls droplet ejection by the inkjet head so as to change the volume of ink ejected by purging according to the amount of ink ejection based on image data to be recorded next. An ink jet recording apparatus. The inkjet recording apparatus according to any one of claims 1 to 6,
The ink jet recording apparatus, wherein the droplet ejection control means changes a droplet ejection density of ink ejected by purging according to an ink ejection amount based on image data to be recorded next. The inkjet recording apparatus according to any one of claims 1 to 8,
An ink jet recording apparatus, comprising: an optical density detection unit configured to be integrated with the droplet ejection detection unit and detecting an optical density of ink ejected by a purge ejected on the blank area. The inkjet recording apparatus according to claim 9, wherein
The optical density detecting means is a light source for irradiating light having a frequency band different from a means for detecting the temperature or water content of ink ejected by purging ejected onto the blank area; and
A light receiving element that receives reflected light of light emitted from the light source;
An ink jet recording apparatus comprising: The inkjet recording apparatus according to claim 9 or 10,
The droplet ejection control means forms a predetermined pattern using ink ejected by purging,
The droplet ejection detecting means detects at least one of the temperature and moisture content of the ink in the predetermined pattern,
The ink jet recording apparatus, wherein the optical density detection means detects an optical density in the predetermined pattern. The inkjet recording apparatus according to any one of claims 9 to 11,
The ink jet recording apparatus, wherein the optical density detection means detects an optical density at a position substantially the same as a detection position by the droplet ejection detection means. The inkjet recording apparatus according to any one of claims 9 to 12,
The transport unit includes a holding unit that holds a front end portion or a rear end portion of the recording medium,
The ink jet recording apparatus, wherein the droplet ejection detecting unit and the optical density detecting unit are fixed to the holding unit. The inkjet recording apparatus according to any one of claims 9 to 13,
The transport means includes a first impression cylinder that transports while holding a front end portion or a rear end portion of the recording medium by a holding member in a droplet ejection region where ink is ejected from the inkjet head;
A transfer cylinder for transporting the recording medium while being held by a holding member at the front end or the rear end of the recording medium transferred from the impression cylinder;
A second impression cylinder that holds the recording medium delivered from the transfer cylinder and conveys the recording medium in a drying area by the drying means;
Including
The inkjet recording apparatus, wherein the purge ink detection unit and the optical density detection unit are disposed on a holding member of the transfer cylinder. A transport process for transporting the recording medium in a predetermined transport direction;
A purge step of purging the ink jet head so that ink ejected by purging the inkjet head adheres to a blank area of the recording medium;
A purge detecting step of detecting at least one of the temperature and the amount of water of the ink by purging droplets deposited on the blank area;
A drying process step of performing a drying process on the recording medium while controlling a drying amount based on a detection result of the purge detection process;
A droplet ejection detection method comprising: A holding means for holding either the front end or the rear end of the recording medium, and a conveying means for conveying the recording medium held by the holding means in a predetermined conveying direction;
An inkjet head for ejecting ink onto the recording medium;
Droplet ejection detecting means for detecting at least one of the temperature and water content of the ink droplets ejected from the inkjet head to the recording medium;
With
The ink jet recording apparatus, wherein the droplet ejection detecting means is provided in the holding means. The inkjet recording apparatus according to claim 16, wherein
Inkjet recording characterized by comprising optical density detecting means provided on the holding means and integrated with the droplet ejection detecting means and detecting the optical density of ink ejected from the inkjet head onto a recording medium. apparatus. The inkjet recording apparatus according to claim 16 or 17,
A drying processing means for performing a drying process on the recording medium;
A drying control means for controlling a drying amount of the drying processing means based on a detection result of the droplet ejection detecting means;
An ink jet recording apparatus comprising: The ink jet recording apparatus according to claim 17 or 18,
An ink jet recording apparatus comprising: a droplet ejection control unit that controls droplet ejection of the inkjet head based on a detection result of the optical density detection unit. Conveying means for conveying the recording medium in a predetermined conveying direction;
An inkjet head for ejecting ink onto the recording medium;
Ink ejected by the ink jet head purge is deposited on the blank area of the recording medium, and the ink jet head ejected is controlled to form a predetermined pattern using the ink ejected by the purge. Droplet ejection control means;
A drying processing means for performing a drying process on the recording medium;
A droplet ejection detecting means for detecting at least one of the temperature and the amount of water of the ink by the purge deposited on the margin area;
Based on the detection result of the droplet ejection detection means, a drying processing control means for controlling the amount of drying by the drying processing means,
An ink jet recording apparatus comprising: Holding means for holding either the front end or the rear end of the recording medium;
A detecting means provided in the holding means for detecting a temperature or a moisture amount at a predetermined position of the recording medium held by the holding means;
With
A transfer cylinder characterized in that the temperature or moisture content of the recording medium being conveyed is detected by the detection means while conveying the recording medium held by the holding means in the circumferential direction. A first sensor for detecting either the temperature of the recording medium or the moisture content;
A second sensor configured integrally with the first sensor for detecting the optical density of the recording medium;
With
A recording medium that is provided in the holding means of the transfer cylinder that conveys the recording medium in the circumferential direction while holding the recording medium by a holding means that holds either the front end or the rear end of the recording medium and is being conveyed by the transfer cylinder A sensor unit for detecting a predetermined position of a medium.

Images