JP2007001045A - Image recorder and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recorder in which visibility of line irregularity due to nonejection or the like can be reduced without requiring specification of abnormality of nozzle and the size and cost can be reduced, and to provide a recording method. <P>SOLUTION: The inkjet recorder comprises a means (13) for adhering processing liquid dots (92) on a recording medium in irregular distribution, and a means (50) for adhering ink dots (94) containing a color material onto the recording medium to which the processing liquid dots (92) are adhered depending on image data. Since irregularity is imparted to arrangement of the processing liquid dots (92), the ink dots (94) move randomly by surface tension. Consequently, irregular random noise can be imparted to arrangement of the ink dots (94) and visibility of line irregularity can be reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image recording apparatus and method, and more particularly to a technique for reducing the visibility of density unevenness (straight unevenness) in an inkjet recording apparatus or the like that forms an image on a recording medium using a treatment liquid and ink.

  An ink jet recording apparatus ejects ink from nozzles while moving a recording medium such as recording paper relative to a recording head (also referred to as a print head) having a plurality of ink ejection openings (nozzles). Thus, an image is formed on the recording medium. In such an ink jet recording apparatus, for some of the many nozzles, ink is no longer discharged for some reason, or the amount of ink discharged (the size of the dots deposited on the recording paper) and the flight direction (ie, landing) (Position) may become improper, resulting in ejection failure. Such non-ejection or landing position misalignment causes streaky density unevenness (non-uniform density) in the recorded image, resulting in print image quality. There is a problem of lowering.

For the purpose of correcting such unevenness, Patent Document 1 calls a printability improving ink (treatment liquid) in a priming manner with respect to a gap between ink dots expected to be generated due to non-ejection or the like. Therefore, a method has been proposed in which the surrounding ink (coloring material) dots are brought close to each other so as to make the streak unevenness less visible.
JP 2002-67297 A

  However, since the method proposed in Patent Document 1 requires a means for specifying a defective nozzle position where a nozzle abnormality such as non-ejection has occurred, the apparatus size increases and the cost increases.

  The present invention has been made in view of such circumstances, and it is not necessary to specify nozzle abnormality, can reduce the visibility of uneven stripes due to non-ejection, etc., and can reduce the size and cost of the apparatus. An object of the present invention is to provide an image recording apparatus and method.

  In order to achieve the above object, an image recording apparatus according to claim 1 includes a processing liquid adhering means for adhering the processing liquid dots to the ink dots in an irregular distribution on a recording medium, and the processing liquid dots. And an ink adhering means for adhering ink dots including a color material in accordance with image data on the adhering recording medium.

  According to the present invention, prior to the recording of ink dots, the treatment liquid dots are deposited on the recording medium, and the ink dots are hit in a state where the treatment liquid dots exist in the liquid state on the recording medium. A phenomenon occurs in which ink dots hit at a position overlapping with the treatment liquid dots are attracted to the treatment liquid dots by surface tension. Since the treatment liquid dots are arranged in an irregular distribution on the recording medium, the relative positional relationship between the ink dots and the treatment liquid dots is irregular (random), and the treatment liquid dots and the ink dots The movement of the ink dots due to the action of the liquids is also random. As a result, irregular random noise can be added to the arrangement of the ink dots that are shot according to the image data, and the visibility of the uneven stripes can be reduced.

  In addition, since the present invention can suppress unevenness without specifying an abnormality of an element that records ink dots, a means for determining an abnormality of the element is not required, and the apparatus size is reduced and the cost is reduced. Can be realized.

  In the present invention, for the treatment liquid adhering means and the ink adhering means, for example, means for ejecting the treatment liquid or ink into droplets using an ink jet type ejection head can be used. Alternatively, it is also possible to use a means that uses a transfer medium to transfer a pattern of treatment liquid dots or ink dots onto a recording medium.

The invention according to claim 2 provides an aspect of the invention according to claim 1. That is, in the image recording apparatus according to the second aspect, the processing liquid ejection unit in which a plurality of processing liquid ejection ports for ejecting the processing liquid is arranged, and the plurality of ink ejection ports in which the ink containing the color material is ejected are arranged. Ink ejection means;
A treatment liquid ejection control means for controlling the ejection operation of the treatment liquid ejection means to adhere the treatment liquid dots to the ink dots in an irregular distribution on the recording medium; and the ink ejection means based on the image data. Ink discharge control means for controlling the discharge operation and depositing ink dots on the recording medium after the treatment liquid dots are deposited.

  Configuration examples of the treatment liquid adhesion means and the ink adhesion means include nozzles (ejection ports) for ejecting droplets for forming treatment liquid dots or ink dots, and pressure generation means for generating ejection pressure (such as piezoelectric elements and heating elements) A liquid discharge head (treatment liquid discharge means, ink discharge means) having a liquid drop discharge element array in which a plurality of liquid drop discharge elements are arranged can be used.

  The treatment liquid ejection head and the ink ejection head may be provided separately, or the treatment liquid and the ink may be ejected from one head.

  As a configuration example of a liquid ejection head used as a processing liquid ejection unit and an ink ejection unit, a full line type having a droplet ejection element array in which a plurality of droplet ejection elements are arranged over a length corresponding to the entire width of a recording medium The head can be used. In this case, a combination of a plurality of relatively short head modules having a droplet discharge element array that is less than the length corresponding to the full width of the recording medium, and connecting them together, the length corresponding to the full width of the recording medium as a whole. There is a mode in which the droplet discharge element array is configured.

  A full-line type head is usually arranged along a direction perpendicular to the relative feeding direction (relative conveyance direction) of the recording medium, but has a certain angle with respect to the direction perpendicular to the conveyance direction. There may be a mode in which the head is arranged along the oblique direction.

  “Recording medium” is a medium that receives an image recording (adhesion of ink dots or processing liquid dots) by the action of a liquid discharge head, and is a resin sheet such as continuous paper, cut paper, seal paper, OHP sheet, film, cloth, etc. , An intermediate transfer medium, a printed circuit board on which a wiring pattern is printed by an ink jet recording apparatus, and other various media and shapes. The “recording medium” can be called by various terms such as an image forming medium, a recording medium, a printing medium, a printing medium, and an image receiving medium.

  The conveying means for relatively moving the recording medium and the liquid ejection head (the processing liquid ejection means and the ink ejection means) is a mode in which the recording medium is conveyed to the stopped (fixed) ejection means. In contrast, both the mode of moving the ejection unit and the mode of moving both the ejection unit (head) and the recording medium are included.

  In the case of forming a color image using an ink jet type ink discharge head, a head may be arranged for each color of a plurality of inks (recording liquids), or a structure capable of discharging a plurality of colors of ink from one head It is good.

  The present invention is not limited to the full-line head described above, but can also be applied to a shuttle scan type head (a head that ejects droplets while reciprocating in a direction substantially perpendicular to the recording medium conveyance direction). .

A third aspect of the present invention relates to an aspect of the image recording apparatus according to the second aspect, wherein the first binarization processing means for determining an ink dot arrangement pattern based on the image data, and the first And a second binarization processing unit that determines the arrangement pattern of the treatment liquid dots by an independent binarization process that has no correlation with the binarization processing unit, and the ink ejection control unit includes the first ink discharge control unit. The discharge operation of the ink discharge means is controlled based on the ink discharge data obtained through the processing of the binarization processing means, and the processing liquid discharge control means passes through the processing of the second binarization processing means. The discharge operation of the processing liquid discharge stage is controlled based on the obtained processing liquid discharge data.
The “first binarization processing unit” and the “second binarization processing unit” perform independent binarization processing that is not correlated with each other. As a result, the processing liquid dots are converted into ink dots. In contrast, the arrangement is irregular.

  According to a fourth aspect of the invention, there is provided the image recording apparatus according to the third aspect, further comprising a processing liquid discharge amount determining unit that determines a discharge amount of the processing liquid based on the image data. The binarization processing means determines the arrangement pattern of the treatment liquid dots based on the discharge amount determined by the treatment liquid discharge amount determination means.

  According to this aspect, the processing liquid discharge amount determining means can optimally set the processing liquid amount according to the density value of the image. In addition, since the discharge amount of the processing liquid is determined in consideration of the ink discharge area based on the image data, a necessary and sufficient processing liquid can be applied, and wasteful processing liquid consumption can be reduced. Can do.

  The invention according to claim 5 relates to an aspect of the image recording apparatus according to claim 3 or 4, wherein the first binarization processing unit and the second binarization processing unit are correlated with each other. No separate blue noise mask is used.

  By performing binarization processing that determines the arrangement of treatment liquid dots using another blue noise mask that has no correlation with the blue noise mask that is used for binarization processing that determines the arrangement of ink dots, the arrangement of ink dots and correlation It is possible to easily obtain the arrangement of the treatment liquid dots that do not exist.

The invention according to claim 6 relates to an aspect of the image recording apparatus according to claim 2, and includes a first binarization processing unit that determines an ink dot arrangement pattern determined based on the image data;
Random offset processing means for randomly offsetting dot positions constituting the ink dot arrangement pattern determined by the first binarization processing means, wherein the ink ejection control means is configured to output the first binary value. The discharge operation of the ink discharge means is controlled based on the ink discharge data corresponding to the arrangement pattern of the ink dots obtained through the processing of the conversion processing means, and the treatment liquid discharge control means is controlled by the random offset processing means. The discharge operation of the processing liquid discharge means is controlled based on the processing liquid discharge data corresponding to the dot arrangement pattern obtained through the processing.

  Based on the arrangement of the ink dots determined from the image data, the arrangement pattern of the treatment liquid dots is determined by randomly shifting the positions of the dots in the dot arrangement. By such a technique, it is possible to make the arrangement of the treatment liquid dots irregular.

  The invention according to claim 7 relates to an aspect of the image recording apparatus according to claim 6, wherein the random offset processing means constitutes an ink dot arrangement pattern determined by the first binarization processing means. It is characterized by including offset method selection means for randomly selecting at least one of the offset direction and the movement amount for all dot positions.

  For example, a plurality of offset methods (forms) defined by the combination of the offset direction and the movement amount are prepared in advance, and any one of the offset methods is randomly selected for each dot position, whereby the processing liquid dot arrangement pattern To decide. By such a technique, it is possible to make the arrangement of the treatment liquid dots irregular.

  The invention according to claim 8 provides a method invention for achieving the object. That is, the image recording method according to claim 8 includes a treatment liquid adhesion step of attaching treatment liquid dots to the ink dots in an irregular distribution on the recording medium, and the recording medium on which the treatment liquid dots are attached. And an ink adhering step for adhering ink dots including a color material based on image data.

  According to the present invention, by providing irregularity in the arrangement of the treatment liquid dots, the movement of the ink dots due to the surface tension becomes random, and as a result, irregular random noise is added to the arrangement of the ink dots. This can reduce the visibility of stripes.

  Further, in the present invention, since it is not necessary to specify the abnormality of the ink dot recording element, there is no need for a means for determining the abnormality of the ink dot recording element in the apparatus configuration, and the apparatus size is reduced and the cost is reduced. Can be realized.

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

[Principle to reduce unevenness]
First, the cause of the occurrence of uneven stripes in the ink jet recording apparatus and the principle for correcting this will be outlined. FIG. 1 is an explanatory diagram schematically showing an example of variation in nozzle discharge characteristics (here, landing position error) and unevenness (density unevenness) appearing as a printing result.

  In the figure, reference numeral 100 denotes a line head as a recording head for ejecting ink (coloring material), reference numeral 102-i (i = 1 to 8) denotes a nozzle, and reference numeral 104-i (i = 1 to 8). The circles represent ink dots (color material dots) ejected by the nozzles 102-i (i = 1 to 8). An arrow S indicates the relative conveyance direction (sub-scanning direction) of the recording medium (for example, recording paper) with respect to the line head 100.

  FIG. 1 shows an example in which a landing position error (landing with the landing position shifted from the original landing position upward in the figure) has occurred in the fourth nozzle 102-4 from the bottom. In this case, streaky density unevenness occurs at the position of the print image (position indicated by A in the figure) corresponding to the nozzle 102-4 where the landing position error occurs.

  FIG. 2 shows an example in which regular vibration is applied to the ink dots of the nozzle 102-4 with respect to the landing position deviation of FIG. In FIG. 2, the ink dots ejected by the nozzle 102-4 are vibrated alternately in the vertical direction (main scanning direction on the recording medium) in FIG. 2 for each dot. As a result, it is difficult to visually recognize the stripe unevenness as compared with FIG. 1, but the reduction effect of the stripe unevenness is not necessarily sufficient.

  FIG. 3 shows an example in which irregular randomness is given to the arrangement of the ink dots of the nozzle 102-4 with respect to the landing position deviation of FIG. In this case, it can be seen that the effect of reducing the stripe unevenness is higher than that in the example of FIG.

  As is clear from the discussion in FIGS. 1 to 3, as a general theory, it is possible to reduce the visibility of the uneven stripe due to the nozzle abnormality at a specific position by increasing the randomness of the colorant dot landing position (dot arrangement). .

  In the embodiment of the present invention, the dot arrangement of the treatment liquid is devised to increase the randomness of the ink dot positions, and as a result, aim to reduce streak.

  FIG. 4 is a schematic diagram for explaining the principle of movement of the ink landing position by the processing liquid. As shown in FIG. 4, the treatment liquid dots 110 are ejected before the ink dots and adhere to the recording medium 112 in a droplet state. Thereafter, the ink 114 is applied so as to overlap with the treatment liquid dot 110. At this time, when the ink 114 is applied to the left side of the processing liquid dot 110 that has landed earlier (the processing liquid dot 110 is applied to the right side of the ink dot 114 ′). If so, the ink dots 114 ′ are attracted and landed on the processing liquid dots 110 due to the surface tension of the liquid, and move with respect to the original landing position X 0. That is, the ink dot 114 ′ is recorded at the landing position X ′ that has moved by Δx closer to the treatment liquid dot 110 that has already been deposited than the original landing position X 0. By utilizing this phenomenon, the landing position of the ink dots can be moved to reduce streaking.

  That is, the moving direction and the moving amount of the ink dot landing position are determined by the relative positional relationship with the adjacent processing liquid dot. From such a viewpoint, by imparting randomness to the arrangement of the treatment liquid dots, it is possible to impart randomness to the landing positions of the ink dots, and as a result, unevenness can be reduced.

  FIG. 5 shows an example in which the treatment liquid is printed in an irregular pattern. In the figure, reference numeral 120 denotes a processing liquid discharge head (hereinafter referred to as a processing liquid head), 140 denotes an ink (color material) discharge head (hereinafter referred to as an ink head), and reference numeral 122 denotes a processing liquid dot. It is.

  As shown in FIG. 5, the arrangement of the treatment liquid dots 122 is not regular, and there is no spatial periodicity due to a certain repeating unit (pattern). By printing the treatment liquid dots 122 in an irregular pattern in this way, the ink dots 144-3 printed by the “target nozzle” (here, the nozzle having a landing position error) 142-3 shown in FIG. As shown in the drawing, the landing position is irregularly moved in the vertical direction in FIG. Therefore, as a result, irregular random noise as described with reference to FIG. 3 can be given, so that the visibility of the stripe unevenness is reduced.

  The method for creating an irregular pattern for printing the treatment liquid can be realized by using a known error diffusion method or dither method (blue noise mask). In this case, since it is not necessary to specify the nozzle abnormality (defective nozzle position), it is not necessary to provide a device (means) for determining the abnormality.

[Configuration of inkjet recording apparatus]
Next, an example of an ink jet recording apparatus having the above-described smoothing correction function will be described.

  FIG. 7 is an overall configuration diagram of an ink jet recording apparatus showing an embodiment of an image recording apparatus according to the present invention. As shown in the figure, the inkjet recording apparatus 10 includes a plurality of (here, different color) inks for ejecting black (K), magenta (M), cyan (C), and yellow (Y) inks. Ink heads (corresponding to ink adhering means and ink ejecting means) 12K, 12C, 12M, 12Y, and react with ink on the upstream side (front stage) of the ink heads 12K, 12C, 12M, 12Y for the respective colors. Processing liquid heads (corresponding to processing liquid adhering means and processing liquid discharging means) 13-1 to 13-4 arranged for discharging the processing liquid to be discharged.

  Further, the ink jet recording apparatus 10 includes an ink storage / loading unit 14 that stores color inks to be supplied to the ink heads 12K, 12C, 12M, and 12Y, and the processing liquid heads 13-1 to 13-4. A processing liquid storage / loading unit 15 for storing the processing liquid to be supplied, a medium supply unit 18 for supplying the recording medium 16, a decurling unit 20 for removing curl of the recording medium 16, and a conveyance of the recording medium A belt conveyance unit 22 as a means for the above and a discharge unit 26 for discharging the recorded recording medium 16 (printed material) to the outside.

  The ink storage / loading unit 14 has an ink tank that stores ink of a color corresponding to each of the ink heads 12K, 12C, 12M, and 12Y, and each tank is a printing unit via a required conduit (not shown). 21 ink heads 12K, 12C, 12M and 12Y. Further, the ink storage / loading unit 14 includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. ing.

  The processing liquid storage / loading unit 15 includes a processing liquid tank that stores the processing liquid, and the processing liquid tank is provided with processing liquid heads 13-1 to 13-13 of the printing unit 21 via a required pipe (not shown). -4. Similarly to the ink storage / loading unit 14, the processing liquid storage / loading unit 15 includes notifying means (display means, warning sound generating means) for notifying that the remaining amount of processing liquid is low, and the liquid type. It has a mechanism for preventing erroneous loading during the period.

  As the ink used in this example, for example, a color ink containing an anionic polymer that is a polymer containing negatively charged surface active ions is used. Further, for the treatment liquid used in this example, for example, a transparent reaction accelerator containing a cationic polymer which is a polymer containing positively charged surface active ions is used.

  When the ink and the treatment liquid are mixed, the color material in the ink is insolubilized (including dispersion prevention) and / or the fixing reaction proceeds by a chemical reaction. The term “insolubilization” includes, for example, a phenomenon in which a color material is precipitated and precipitated from a solvent, a phenomenon in which a liquid in which a color material is dissolved changes to a solid phase (solidification), and a phenomenon in which the liquid thickens and hardens. included. “Fixing” includes a mode in which the color material is held on the surface of the recording medium 16, a mode in which the color material penetrates and is held inside the recording medium 16, and a mode in which these are combined.

  The reaction rate and physical properties (surface tension, viscosity, etc.) of each liquid can be adjusted by adjusting the composition of each ink and treatment liquid and the concentration of substances that contribute to the reaction. And / or ink fixability (curing speed, fixing speed, etc.) can be realized.

  As for the supply system of the recording medium 16, in FIG. 7, a magazine for rolled paper (continuous paper) is shown as an example of the media supply unit 18. Further, instead of or in combination with the roll paper magazine, the paper (recording medium) may be supplied by a cassette in which cut papers are stacked and loaded.

  When a plurality of types of recording media can be used, an information recording body such as a bar code or a wireless tag that records the recording medium type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. Thus, it is preferable to automatically determine the type of recording medium to be used (media type) and perform ejection control so as to realize ejection of an appropriate processing liquid and ink according to the media type.

  The recording medium 16 delivered from the media supply unit 18 retains curl due to having been loaded in the magazine. In order to remove this curl, heat is applied to the recording medium 16 by the heating drum 30 in the direction opposite to the curl direction of the magazine in the decurling unit 20. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  In the case of an apparatus configuration using roll paper, a cutter (first cutter) 28 is provided as shown in FIG. 7, and the roll paper is cut into a desired size by the cutter 28. The cutter 28 includes a fixed blade 28A having a length equal to or greater than the conveyance path width of the recording medium 16, and a round blade 28B that moves along the fixed blade 28A. The fixed blade 28A is provided on the back side of the print. The round blade 28B is disposed on the printing surface side with the conveyance path interposed therebetween. Note that the cutter 28 is not necessary when cut paper is used.

  After the decurling process, the cut recording medium 16 is sent to the belt conveyance unit 22. The belt conveyance unit 22 is arranged to face the nozzle surface (liquid ejection surface) of the printing unit 21 and conveys the recording medium 16 while maintaining the flatness of the recording medium 16. The belt conveying unit 22 of this example has a structure in which an endless belt 33 is wound between rollers 31 and 32, and at least a portion facing the nozzle surface of the printing unit 21 forms a horizontal surface (flat surface). It is configured.

  The belt 33 has a width that is wider than the width of the recording medium 16, and a plurality of suction holes (not shown) are formed on the belt surface. As shown in FIG. 7, a suction chamber 34 is provided at a position facing the nozzle surface of the printing unit 21 inside the belt 33 spanned between the rollers 31 and 32, and the suction chamber 34 is connected to the fan 35. The recording medium 16 is sucked and held on the belt 33 by suctioning to negative pressure.

  The power of the motor (reference numeral 88 in FIG. 12) is transmitted to at least one of the rollers 31 and 32 around which the belt 33 is wound, so that the belt 33 is driven in the clockwise direction in FIG. The held recording medium 16 is conveyed from left to right in FIG.

  Since ink adheres to the belt 33 when a borderless print or the like is printed, the belt cleaning unit 36 is provided at a predetermined position outside the belt 33 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 36 are not shown, for example, there are a method of niping a brush roll, a water absorbing roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a roller / nip conveyance mechanism may be used instead of the belt conveyance unit 22, if the roller / nip conveyance is performed in the printing area, the roller is brought into contact with the printing surface of the sheet immediately after printing, so that the image is likely to bleed. There's a problem. Therefore, as in this example, suction belt conveyance that does not bring the image surface into contact with each other in the print region is preferable. Further, as the conveying means for the recording medium 16, an electrostatic adsorption system configuration can be used instead of the above suction adsorption system.

  The ink heads 12K, 12C, 12M, and 12Y and the processing liquid heads 13-1 to 13-4 of the printing unit 21 have a length corresponding to the maximum paper width of the recording medium 16 that is the target of the inkjet recording apparatus 10. The nozzle surface is a full line type head in which nozzles for ejecting ink or nozzles for ejecting treatment liquid are arranged over a length exceeding the length of at least one side of the maximum size recording medium (full width of the drawable range). ing.

  As shown in FIG. 7, the ink heads 12 </ b> K, 12 </ b> C, 12 </ b> M, 12 </ b> Y in the printing unit 21 are black (K), cyan (C), magenta (M), The processing liquid heads 13-1 to 13-4 are arranged upstream of the respective color heads in the order of yellow (Y) colors. These heads 12K, 12C, 12M, 12Y, 13-1 to 13-4 are fixedly installed so as to extend along a direction substantially orthogonal to the conveyance direction of the recording medium 16. With such a head arrangement, before the color ink is ejected by the ink heads 12K, 12C, 12M, and 12Y, the processing liquid heads 13-1 to 13-4 process the print surface (recorded surface) of the recording medium 16. Liquid can be deposited. In addition, the configuration in which the processing liquid heads 13-1 to 13-4 are provided for each color head enables an appropriate amount of processing liquid to be applied for each ink color.

  Further, a color image can be formed on the recording medium 16 by discharging different color inks from the ink heads 12K, 12C, 12M, and 12Y while the recording medium 16 is being conveyed by the belt conveyance unit 22.

  As described above, according to the configuration in which the full-line ink heads 12K, 12C, 12M, and 12Y having nozzle rows covering the entire width of the paper are provided for each color, the recording medium 16 and the recording medium 16 in the paper feeding direction (sub-scanning direction). An image can be recorded on the entire surface of the recording medium 16 by performing the operation of relatively moving the printing unit 21 once (that is, by one sub-scan). Thereby, it is possible to perform high-speed printing as compared with a shuttle type head in which the recording head reciprocates in a direction orthogonal to the paper transport direction, and productivity can be improved.

  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 jet head that discharges light ink such as light cyan and light magenta. Also, the arrangement order of the color heads is not particularly limited.

  A post-drying unit 42 is provided following the printing unit 21. The post-drying unit 42 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by pressurizing the paper holes with pressure. There is an effect to.

  A heating / pressurizing unit 44 is provided following the post-drying unit 42. The heating / pressurizing unit 44 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 45 having a predetermined surface uneven shape while heating the image surface to transfer the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the output unit 26. It is preferable that the original image to be printed and the test print (print result of the test pattern) are discharged separately. In the ink jet recording apparatus 10 of this example, there is provided sorting means (not shown) for switching the paper discharge path in order to select the printed matter of the main image and the printed matter of the test print and send them to the respective discharge portions 26A and 26B. It has been.

  Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by a cutter (second cutter) 48. The cutter 48 is provided immediately before the discharge unit 26, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 48 is the same as that of the first cutter 28 described above, and includes a fixed blade 48A and a round blade 48B.

  Although not shown in FIG. 7, the paper output unit 26A for the target prints is provided with a sorter for collecting prints according to print orders.

[Head structure]
Next, the structure of the head will be described. Since the structures of the ink heads 12K, 12C, 12M, and 12Y provided for the respective colors are common, the heads are represented by the reference numeral 50 in the following.

  FIG. 8A is a plan perspective view showing an example of the structure of the ink head 50, and FIG. 8B is an enlarged view of a part thereof. In order to increase the dot pitch printed on the recording medium 16, it is necessary to increase the nozzle pitch in the ink head 50. As shown in FIGS. 8A and 8B, the ink head 50 of this example is an ink chamber unit comprising a nozzle 51 that is an ink droplet ejection port, a pressure chamber 52 corresponding to each nozzle 51, and the like. It has a structure in which (droplet discharge elements) 53 are arranged in a zigzag matrix (two-dimensionally), and is thereby projected so as to be arranged along the head longitudinal direction (direction perpendicular to the paper feed direction). High density of substantial nozzle interval (projection nozzle pitch) is achieved.

  A configuration in which the nozzle row having a length corresponding to the full width Wm of the recording medium 16 is configured in a direction (arrow M direction; main scanning direction) substantially orthogonal to the feeding direction (arrow S direction; sub-scanning direction) of the recording medium 16 is as follows. It is not limited to this example. For example, instead of the configuration shown in FIG. 8 (a), as shown in FIG. 9, a short head module 50 'in which a plurality of nozzles 51 are two-dimensionally arranged is arranged in a staggered manner and connected to form a recording medium. You may comprise the line head which has a nozzle row of the length corresponding to the full width of 16.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape (see FIGS. 8A and 8B), and is connected to the nozzle 51 at both diagonal corners. An outlet and an inlet (supply port) 54 for supply ink are provided. The shape of the pressure chamber 52 is not limited to this example, and the planar shape may have various forms such as a rhombus, a rectangle, a pentagon, a hexagon and other polygons, a circle, and an ellipse.

  FIG. 10 is a cross-sectional view (a cross-sectional view taken along line 10A-10A in FIG. 8) showing a three-dimensional configuration of one droplet discharge element (an ink chamber unit corresponding to one nozzle 51). As shown in FIG. 10, each pressure chamber 52 communicates with a common flow channel 55 via a supply port 54. The common flow channel 55 communicates with an ink tank (not shown) as an ink supply source, and the ink supplied from the ink tank is distributed and supplied to each pressure chamber 52 via the common flow channel 55 of FIG.

  An actuator 58 having an individual electrode 57 is joined to a pressure plate (vibrating plate that also serves as a common electrode) 56 constituting a part of the pressure chamber 52 (the top surface in FIG. 10). By applying a driving voltage to the individual electrode 57, the actuator 58 is deformed to change the volume of the pressure chamber 52, and ink is ejected from the nozzle 51 due to the pressure change accompanying this. After the ink is ejected, when the displacement of the actuator 58 returns to its original state, new ink is refilled into the pressure chamber 52 from the common channel 55 through the supply port 54. The actuator 58 is preferably a piezoelectric element using a piezoelectric material such as lead zirconate titanate or barium titanate.

  As shown in FIG. 11, the ink chamber units 53 having such a 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. By arranging a large number of nozzles in a row, the effective nozzle spacing (projection nozzle pitch) projected so as to be aligned along the main scanning direction (direction perpendicular to the recording medium conveyance direction) is reduced, and the nozzle density is increased. Have achieved.

  That is, with a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along a certain angle θ with respect to the main scanning direction, the pitch P of the nozzles projected so as to be aligned in the main scanning direction is d × cos θ Thus, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, a high-density nozzle array can be realized.

  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 the nozzles are sequentially driven from one side to the other for each block, etc., and one line (1 in the width direction of the paper (direction perpendicular to the paper conveyance 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 51 arranged in a matrix as shown in FIG. 11, the main scanning as described in (3) above is preferable. That is, nozzles 51-11, 51-12, 51-13, 51-14, 51-15, 51-16 are made into one block (other nozzles 51-21,..., 51-26 are made into one block, The nozzles 51-31,..., 51-36 as one block,...), And the nozzles 51-11, 51-12,. One line is printed in 16 width directions.

  On the other hand, by moving the full line head and the recording medium (paper) relative to each other, printing of one line (a line formed by a single line or a line composed of a plurality of lines) formed by the main scanning described above is performed. Repeated execution 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. In other words, in the present embodiment, the conveyance direction of the recording medium 16 is the sub-scanning direction, and the direction orthogonal to it is the main scanning direction.

  In implementing the present invention, the nozzle arrangement structure is not limited to the illustrated example. In the present embodiment, a method of ejecting ink droplets by deformation of an actuator 58 typified by a piezo element (piezoelectric element) is adopted. However, in the practice of the present invention, the method of ejecting ink is not particularly limited. 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.

  Although the detailed structures of the treatment liquid heads 13-1 to 13-4 are not shown, they are generally the same as the ink head 50 described with reference to FIGS. However, since the treatment liquid has only to be deposited substantially uniformly (substantially uniformly) on the area where ink is ejected on the recording medium 16, formation of high-density dots is not required as compared with ink. Therefore, the processing liquid heads 13-1 to 13-4 can be configured to have a smaller number of nozzles (lower nozzle density) than the ink head 50. Further, the nozzle diameter of the treatment liquid heads 13-1 to 13-4 may be larger than the nozzle diameter of the ink head 50.

[Explanation of control system]
FIG. 12 is a block diagram illustrating a system configuration of the inkjet recording apparatus 110. The inkjet recording apparatus 10 includes a communication interface 70, a system controller 72, an image memory 74, a ROM 75, a motor driver 76, a heater driver 78, a print control unit 80, an image buffer memory 82, an ink head driver 84A, and a processing liquid head driver 84B. Etc.

  The communication interface 70 is an interface unit (means corresponding to an image input unit) that receives image data sent from the host computer 86. As the communication interface 70, a serial interface such as USB, IEEE 1394, Ethernet, and 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.

  Image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the image memory 74. The image memory 74 is a storage unit that temporarily stores an image input via the communication interface 70, and data is read and written through the system controller 72. The image memory 74 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 72 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 72 controls the communication interface 70, the image memory 74, the motor driver 76, the heater driver 78, and the like, and performs communication control with the host computer 86, read / write control of the image memory 74 and the ROM 75, and the like. At the same time, a control signal for controlling the motor 88 and the heater 89 of the transport system is generated.

  The ROM 75 stores programs executed by the CPU of the system controller 72 and various data necessary for control. The ROM 75 may be a non-rewritable storage means, or may be a rewritable storage means such as an EEPROM. The image memory 74 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 76 is a driver (driving circuit) that drives the conveyance motor 88 in accordance with an instruction from the system controller 72. The heater driver 78 is a driver that drives the heater 89 such as the post-drying unit 42 in accordance with an instruction from the system controller 72.

  The print control unit 80 includes an ink discharge data generation unit 80A and a treatment liquid discharge data generation unit 80B. Under the control of the system controller 72, the image data in the image memory 74 (multi-value input image data) ) To function as signal processing means for performing various processing and correction processing for generating a signal for controlling ink ejection and a signal for controlling processing liquid ejection. Further, the print control unit 80 supplies the generated ink ejection data and processing liquid ejection data to the ink head driver 84A and the processing liquid head driver 84B, respectively, and supplies the ink head 50 and the processing liquid head 13 (see FIG. 7). It functions as a discharge control means for controlling the discharge drive of the above described reference numerals 13-1 to 13-4 (denoted by reference numeral 13 in FIG. 12).

  The ink discharge data generation unit 80A performs signal processing (density conversion processing including UCR processing and color conversion and, if necessary, pixel number conversion processing) for generating density data for each ink color from input image data. Signal processing means including halftoning processing means for converting the obtained density data for each color into binary (or multi-valued) ink (color material) dot data.

  The ink discharge data generated by the ink discharge data generation unit 80A is given to the ink head driver 84A, and the ink discharge operation of the ink head 50 is controlled.

  The processing liquid ejection data generation unit 80B is a signal processing unit including a halftoning processing unit that converts input image data into binary (or multivalued) processing liquid dot data. The treatment liquid ejection data generated by the treatment liquid ejection data generation unit 80B is given to the treatment liquid head driver 84B, and the ink ejection operation of the treatment liquid head 13 is controlled.

  Each functional block (80A, 80B) in the print control unit 80 can be realized by ASIC, software, or an appropriate combination.

  The print control unit 80 includes an image buffer memory 82, and image data, parameters, and other data are temporarily stored in the image buffer memory 82 when image data is processed in the print control unit 80. In FIG. 12, the image buffer memory 82 is shown in a form associated with the print control unit 80, but it can also be used as the image memory 74. Also possible is an aspect in which the print controller 80 and the system controller 72 are integrated and configured with one 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 70 and stored in the image memory 74. At this stage, for example, RGB multivalued image data is stored in the image memory 74.

  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 image memory 74 is sent to the print control unit 80 via the system controller 72, and the ink ejection data generation unit 80A uses a dither method, an error diffusion method, or the like. By the toning process, it is converted into dot data for each ink color.

  That is, the print control unit 80 performs processing for 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 80 is stored in the image buffer memory 82. This dot data for each color is converted into KCMY droplet ejection data for ejecting ink from the nozzles of the ink head 50, and the ink ejection data to be printed is determined.

  The ink head driver 84 </ b> A outputs a drive signal for driving the actuator 58 corresponding to each nozzle 51 of the ink head 50 based on the ink discharge data given from the print control unit 80.

  Similarly, the processing liquid head driver 84 </ b> B is based on the processing liquid ejection data (that is, the processing liquid dot data stored in the image buffer memory 82) given from the print controller 80. A drive signal for driving an actuator corresponding to each nozzle is output.

  The ink head driver 84A and the treatment liquid head driver 84B may include a feedback control system for keeping the head driving conditions constant.

  When the drive signal output from the processing liquid head driver 84B is applied to the processing liquid head 13, the processing liquid is discharged from the corresponding nozzle. In addition, when the drive signal output from the ink head driver 84 </ b> A is applied to the ink head 50, ink is ejected from the corresponding nozzle 51. An image is formed on the recording medium 16 by controlling processing liquid ejection from the processing liquid head 13 and ink ejection from the ink head 50 in synchronization with the conveyance speed of the recording medium 16.

  As described above, the ejection amount and ejection timing of the droplets from the processing liquid head 13 and the ink head 50 based on the processing liquid ejection data and the ink ejection data generated through the required signal processing in the print controller 80. Is controlled. Thereby, a desired dot size and dot arrangement are realized.

  In the case of this example, the combination of the system controller 72 and the print control unit 80 (particularly, the ink discharge data generation unit 80A) corresponds to the “ink discharge control unit”, and the system controller 72 and the print control unit 80 (particularly the processing liquid discharge unit). The combination of the data generation unit 80B) corresponds to “processing liquid discharge control means”.

  FIG. 13 is a diagram showing a first example of a processing flow for determining the arrangement of ink dots and the arrangement of processing liquid dots. FIG. 14 shows the arrangement of ink dots and processing liquid dots realized by the processing flow shown in FIG. It is a schematic diagram which shows an example. In FIG. 14, reference numeral 92 represents a treatment liquid dot, and reference numeral 94 represents an ink dot.

  As shown in FIG. 13, first, image data of an image to be printed is input (step S10; image input step). Binarization processing is performed based on the input image data (step S12), and ink discharge data for each color is generated (step S14).

  On the other hand, based on the input image data, the required discharge amount of the processing liquid is determined (step S22; processing liquid discharge amount determination step). A binarization process is performed based on the determined processing liquid discharge amount (step S24), and processing liquid discharge data is generated (step S26).

  In the binarization process in step S12 and the binarization process in step S24, separate (independent two) blue noise masks having no correlation with each other are used. As a result, the position of the ink dots (ink dot arrangement) realized based on the ink discharge data and the position of the processing liquid dots (processing liquid dot arrangement) realized based on the processing liquid discharge data are There is no correlation (see FIG. 14). Thereby, it is possible to realize irregularity of the treatment liquid dot ejection position with respect to the ink dot ejection position. However, since the processing liquid discharge amount is determined based on the image data (step S22 in FIG. 13), there is a correlation between the ink amount within a certain area on the recording medium and the processing liquid amount. Note that the processing liquid discharge amount determination step (step S22) may be omitted.

  With the treatment liquid arrangement as described above (an arrangement having no correlation with the ink dot position), irregular movement of the ink dots can be caused and the randomness of the ink dot positions can be enhanced. As a result, uneven stripes can be reduced.

  The processing flow described in FIG. 13 is executed by the print control unit 80 described in FIG. Processing means (corresponding to the first binarization processing means) for performing the binarization process described in step S12 of FIG. 13, means for performing the process of determining the processing liquid discharge amount in step S22 (processing liquid discharge amount) Means corresponding to each processing step such as processing means (corresponding to the second binarization processing means) for performing the binarization processing step in step S24 is performed by software of the print control unit 80. Can be realized.

  Here, “irregular” includes the case where the droplet ejection positions of a small part of the ink dots and the treatment liquid dots coincide, but the droplet ejection positions of the treatment liquid dots for the majority of the ink dots are random. Therefore, the visibility of the stripe unevenness can be reduced.

  The “blue noise mask” will be outlined here. As a result of digital halftoning, a dot pattern is obtained. As a method for evaluating this dot pattern (dot arrangement), a method proposed by Robert and Ulichney is generally used ("Digital Halftoning"; published by The MIT Press).

  In other words, the two-dimensional power spectrum of the dot arrangement is converted into polar coordinates, and the indices corresponding to the average (RAPS) of all angles and the dispersion (Anisotropy) of the spatial frequency fr corresponding to the radius of the polar coordinates. Use.

  R.A.P.S is an index relating to the visibility of dot arrangement, and Anisotropy is an index relating to anisotropy of dot arrangement. When dot placement is evaluated using these indices, the characteristics are such that RAPS is small in the low frequency range, has a peak at the medium frequency, and is constant at the high frequency, and Anisotropy is -10 decibels [dB] or less. When the dot arrangement such as is “blue noise characteristics” and the dot arrangement determined by the threshold matrix has blue noise characteristics, the threshold matrix is referred to as a blue noise mask.

  Next, a second example of a processing flow for determining the arrangement of ink dots and the arrangement of treatment liquid dots will be described. FIG. 15 is a diagram illustrating a processing flow according to the second example. FIG. 16 is a schematic diagram showing an arrangement example of ink dots and processing liquid dots realized by the processing flow shown in FIG.

  In the processing flow of FIG. 15, first, image data of an image to be printed is input (step S30; image input step). A binarization process is performed based on the input image data (step S32), and ink discharge data for each color is generated (step S34).

  Subsequently, based on the ink ejection data obtained in step S34, a random offset process for randomly setting an offset amount for all ink dots indicated by the ink ejection data is performed (step S36). The dot arrangement data obtained by the random offset processing is generated as processing liquid ejection data (step S38).

  From another viewpoint, in the random offset processing step (step S36), initial data for arranging the processing liquid dots at the same positions as the ink dots is generated, and the dot positions of the processing liquid dots at the respective positions in the initial data are randomly set. To perform offset processing.

  For example, with respect to all the processing liquid dots in the initial data (same positions as the ink dots), one pixel (pixel) offset in the nozzle row direction (upward in FIG. 16, that is, the main scanning direction), and one pixel in the downward direction Pixel) Processing for randomly selecting three patterns with or without offset. The up and down arrows in FIG. 16 indicate that the processing liquid dot (initial data) at the same position as the ink dot 94 is offset by one pixel in the arrow direction.

  By such random offset processing, the treatment liquid dots 92 are irregularly arranged, and irregular movement of the ink dots 94 can be generated, and the randomness of the ink dot positions can be improved. As a result, uneven stripes can be reduced.

  In the second example described with reference to FIGS. 15 and 16, the offset direction and the amount of movement (number of pixels) can be set as appropriate, and an offset in a diagonal direction, an offset for a plurality of pixels, and the like are also possible. It is. As means for randomly selecting one of a plurality of offset patterns (corresponding to an offset method selecting means), for example, random number generating means for generating a random number corresponding to the pattern can be used.

  The randomness imparting process has an effect of reducing unevenness in a so-called solid part, but may cause deterioration in quality due to a jagged outline in an edge part or text part of an image. For this reason, a configuration may be adopted in which this processing is stopped at the edge portion or character portion of the image.

  The processing flow described in FIG. 15 is executed by the print control unit 80 described in FIG. Processing means (corresponding to the first binarization processing means) for performing the binarization processing step described in step S32 of FIG. 15 and means for performing the random offset processing step of step S36 (corresponding to the random offset processing means) The means corresponding to each processing step can be realized by software of the print control unit 80.

  According to the inkjet recording apparatus 10 having the above-described configuration, it is possible to obtain a good image in which unevenness due to nozzle abnormality such as landing position error is reduced.

[Specific examples of treatment liquid and ink]
In the present embodiment, for example, the following aqueous solution can be used as the treatment liquid.

(Processing liquid)
・ Daiichi Kogyo Seiyaku Co., Ltd. Charol DC-902P 1-20% by weight
・ As surface active material
Nissin Chemical Industry Co., Ltd. Olfin E1010 0.1 to 10% by weight
An aqueous solution containing at least the above, and in addition, as a high boiling point solvent, 0 to 30% by weight of glycerin
・ As a pH adjuster, triethanolamine 0 to 10% by weight
May be included.

  On the other hand, for example, the following aqueous solutions can be used as the ink containing the color material.

(ink)
An anionic dye compound,
For example, having a structure represented by the following general formula: 1 to 30% by weight

・表面活性剤として、
日信化学工業株式会社製 オルフィンＥ１０１０ ０．１〜１０重量％
・ポリスチレンスルホン酸ナトリウム ０〜２０重量％
・高沸点溶媒として、グリセリン ０〜３０重量％
・ｐＨ調整剤として、トリエタノールアミン ０〜１０重量％
を含んでもよい。

・ As a surfactant
Nissin Chemical Industry Co., Ltd. Olfin E1010 0.1 to 10% by weight
-Sodium polystyrene sulfonate 0-20% by weight
・ Glycerin 0-30% by weight as high boiling point solvent
・ As a pH adjuster, triethanolamine 0 to 10% by weight
May be included.

[Modification 1]
In FIG. 12, the configuration in which the processing liquid heads 13-1 to 13-are arranged on the upstream side of the ink heads 12 K, 12 M, 12 C, and 12 Y for each color has been described. The head arrangement method is not limited to this example. For example, instead of a configuration in which a processing liquid head is arranged between each color head in the printing unit, as shown in FIG. 17, only the uppermost stream of the printing unit 21 ′ (the left side of the black head 12K in FIG. 17) (one ) A configuration in which the treatment liquid head 13 is arranged is also possible. In FIG. 17, members that are the same as or similar to the configuration shown in FIG. 12 are given the same reference numerals, and descriptions thereof are omitted.

[Modification 2]
Further, the application range of the present invention is not limited to the reduction of streak due to landing position error, but density unevenness due to various factors such as streak due to droplet amount error, streak due to the presence of a non-ejection nozzle, and streak due to periodic printing error. In contrast, a reduction effect can be obtained.

  Further, the application of the present invention is not limited to a line head type printer, and an effective correction effect can be obtained even for stripe unevenness in a shuttle scan type printer.

Schematic diagram showing an example of the occurrence of streaks due to nozzle landing position error Schematic diagram showing an example of printing when regular vibration is applied to the ink dots at the corresponding positions with respect to the landing position deviation of FIG. Schematic diagram showing an example of printing when irregular randomness is given to the arrangement of ink dots at the corresponding position with respect to the landing position deviation of FIG. Schematic diagram used to explain the principle of movement of ink landing position by treatment liquid The figure which shows the example which printed the processing liquid with the irregular pattern The figure which illustrated a mode that random noise was given to an ink dot by arrangement of irregular processing liquid dots 1 is an overall configuration diagram of an ink jet recording apparatus showing an embodiment of an image recording apparatus according to the present invention. Plane perspective view showing a structural example of an ink head Plane perspective view showing another configuration example of a full-line head Sectional drawing which follows the 10A-10A line in FIG. Enlarged view showing an arrangement example of ink chamber units (droplet ejection elements) in the head Main part block diagram which shows the system configuration | structure of the inkjet recording device which concerns on this embodiment. The flowchart which shows the 1st example of the processing flow which determines arrangement | positioning of an ink dot, and arrangement | positioning of a process liquid dot. Schematic diagram showing an arrangement example of ink dots and processing liquid dots realized by the processing flow shown in FIG. The flowchart which shows the 2nd example of the processing flow which determines arrangement | positioning of an ink dot, and arrangement | positioning of a process liquid dot. Schematic diagram showing an arrangement example of ink dots and processing liquid dots realized by the processing flow shown in FIG. The whole block diagram of the inkjet recording device which concerns on other embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device (image recording device), 12K, 12C, 12M, 12Y ... Ink head, 13-1, 13-2, 13-3, 13-4, 13 ... Treatment liquid head, 21 ... Printing unit , 16 ... recording medium, 22 ... belt conveyor (conveyance means), 50 ... ink head, 51 ... nozzle, 52 ... pressure chamber, 53 ... ink chamber unit, 58 ... actuator, 72 ... system controller, 80 ... print control , 80A ... ink ejection data generation unit, 80B ... treatment liquid ejection data generation unit, 92 ... treatment liquid dot, 94 ... ink dot

Claims (8)

A treatment liquid attaching means for attaching the treatment liquid dots to the ink dots in an irregular distribution on the recording medium;
An ink adhering means for adhering ink dots including a color material on the recording medium to which the treatment liquid dots are adhered according to image data;
An image recording apparatus comprising: A treatment liquid discharge means in which a plurality of treatment liquid discharge ports for discharging the treatment liquid are arranged;
An ink discharge means in which a plurality of ink discharge ports for discharging ink containing a color material are arranged;
Treatment liquid discharge control means for controlling the discharge operation of the treatment liquid discharge means to attach the treatment liquid dots to the ink dots in an irregular distribution on the recording medium;
Ink discharge control means for controlling the discharge operation of the ink discharge means based on image data, and for attaching ink dots on the recording medium after the treatment liquid dots are attached;
An image recording apparatus comprising: First binarization processing means for determining an arrangement pattern of ink dots based on the image data;
Second binarization processing means for determining an arrangement pattern of treatment liquid dots by an independent binarization process having no correlation with the first binarization processing means;
With
The ink discharge control means controls the discharge operation of the ink discharge means based on the ink discharge data obtained through the processing of the first binarization processing means;
3. The processing liquid discharge control unit controls a discharge operation of the processing liquid discharge stage based on processing liquid discharge data obtained through the processing of the second binarization processing unit. The image recording apparatus described. Processing liquid discharge amount determining means for determining the discharge amount of the processing liquid based on the image data;
4. The image recording apparatus according to claim 3, wherein the second binarization processing unit determines an arrangement pattern of the processing liquid dots based on the discharge amount determined by the processing liquid discharge amount determination unit.   5. The image recording apparatus according to claim 3, wherein the first binarization processing unit and the second binarization processing unit use different blue noise masks having no correlation with each other. . First binarization processing means for determining an ink dot arrangement pattern determined based on the image data;
Random offset processing means for randomly offsetting dot positions constituting the ink dot arrangement pattern determined by the first binarization processing means;
With
The ink ejection control unit controls the ejection operation of the ink ejection unit based on ink ejection data corresponding to the arrangement pattern of the ink dots obtained through the processing of the first binarization processing unit;
The processing liquid ejection control unit controls the ejection operation of the processing liquid ejection unit based on processing liquid ejection data corresponding to a dot arrangement pattern obtained through processing by the random offset processing unit. Item 3. The image recording apparatus according to Item 2.   The random offset processing means randomly selects at least one of the offset direction and the moving amount for all the dot positions constituting the ink dot arrangement pattern determined by the first binarization processing means. 7. The image recording apparatus according to claim 6, further comprising an offset method selection means for selecting. A treatment liquid adhering step for adhering the treatment liquid dots to the ink dots in an irregular distribution on the recording medium;
An ink adhering step for adhering ink dots including a color material on the recording medium to which the treatment liquid dots are adhered, based on image data;
An image recording method comprising:

Images