JP2007106117A - Image formation method and image formation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation apparatus which can realize dot diameters corresponding to desired image densities and provide high-quality images both in low-density areas and high-density areas. <P>SOLUTION: The image formation apparatus according to the present invention has an ink jet head for imparting inks containing color materials to a recording medium, a treatment liquid discharge head for imparting a processing liquid, which insolubilizes the color materials, to the recording medium, and a system control unit which controls the treatment liquid discharge head. A system control unit 100 controls a treatment liquid imparting means so that the imparting amount of the treatment liquid in the high-density areas on the recording medium is smaller than the imparting amount of the treatment liquid in the low-density areas. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus, and more particularly to a technique for insolubilizing a color material contained in a target liquid such as ink with a predetermined processing liquid.

  In recent years, inkjet recording apparatuses (inkjet printers) have become widespread as image forming apparatuses that print images. An ink jet recording apparatus prints a desired image by ejecting ink droplets from an ink jet recording head toward a recording medium while relatively moving a recording medium such as recording paper and an ink jet recording head.

  In an ink jet recording apparatus, it is preferable to quickly fix a color material contained in ink to a recording medium in order to prevent blurring and obtain a clear image. Against this background, several techniques have been proposed for quickly fixing a color material to a recording medium by insolubilizing the ink color material adhering to the recording medium with a predetermined processing liquid.

For example, in Patent Document 1, the amount of reaction liquid applied per unit area of the recording medium is changed according to the landing time difference between the reaction liquid and the colored ink on the recording medium, and the reaction amount of the reaction liquid and the reaction amount of the colored ink are the same. Ink jet recording apparatuses have been proposed. Patent Document 2 proposes an ink jet recording apparatus that controls a low resolution mode using only ink and a high resolution mode using ink and processing liquid.
JP 2005-119115 A JP-A-8-72229

  In an image forming apparatus such as an ink jet recording apparatus, it is desirable that the dot diameter formed on a recording medium by ink droplets is adjusted according to a desired density. For example, in the high density region, it is preferable to increase the dot diameter to prevent the occurrence of a white background in order to form a dark image. On the other hand, in the low density region, it is preferable to reduce the dot diameter sufficiently to improve the granularity of the image.

  However, in the ink jet recording apparatus described in Patent Document 1 described above, since the reaction amount of the reaction liquid and the reaction amount of the colored ink are approximately the same, the dot diameter of the ink is substantially constant. Therefore, the dot diameter of the ink cannot be positively changed. For example, when the dot diameter is relatively small, adjacent ink dots cannot be in contact with each other in the high density region, and a white background is likely to occur. . On the other hand, when the ink dot diameter is relatively large, it is difficult to ensure good graininess of the image. As described above, in the inkjet recording apparatus disclosed in Patent Document 1, it is difficult to efficiently achieve both “improvement of image graininess in a low density region” and “prevention of white background in a high density region”.

  Further, the ink jet recording apparatus described in Patent Document 2 is disadvantageous in terms of “improving the graininess of an image in a low density region” because the processing liquid is not used in the low resolution mode, so that the dot diameter cannot be sufficiently reduced. It is. On the other hand, since a certain amount of processing liquid is used in the high resolution mode, the dot diameter may be too small, which is disadvantageous in terms of “preventing the occurrence of white background in a high density region”.

Therefore, there is a demand for a proposal of a technique that efficiently achieves both “improvement of image graininess in a low density region” and “prevention of white background in a high density region”.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to realize a dot diameter corresponding to a desired image density and to provide a high-quality image in both a low density area and a high density area. It is an object to propose an image forming method and an image forming apparatus that can be used.

  In order to achieve the object, one aspect of the present invention includes a step of applying a target liquid containing a coloring material to a recording medium, a step of applying a treatment liquid that insolubilizes the coloring material to the recording medium, The amount of application of the treatment liquid in the high-concentration region on the recording medium in which the amount of application of the target liquid per predetermined area is large is the amount of application of the target liquid per predetermined area. The amount is less than the amount of the treatment liquid applied in a low concentration region on the recording medium.

  In this case, the application amount of the treatment liquid in the high concentration region on the recording medium is smaller than the application amount of the treatment liquid in the low concentration region. Accordingly, in the low concentration region, a large amount of processing liquid is applied relative to the amount of the target liquid applied, so that insolubilization of the color material of the target liquid is promoted and the dot diameter of the target liquid (color material) on the recording medium is increased. Can be reduced. In a high concentration region, a small amount of processing liquid is applied relative to the amount of target liquid applied, so that the color material of the target liquid diffuses and the dot diameter of the target liquid (color material) on the recording medium is increased. can do.

  The “target liquid” referred to here refers to all liquids containing a coloring material, and for example, ink is used as the target liquid. In addition, “insolubilization” means, for example, when ink is used as the target liquid, the state where the color material in the ink is dissolved or dispersed in the liquid solvent by the action of the treatment liquid on the ink, and the color material component Precipitation / aggregation / precipitation phenomenon, a phenomenon in which a liquid in which a coloring material is dissolved changes to a solid phase (solidification), a phenomenon in which the liquid thickens and hardens, and the like. In addition, the application order of the target liquid and the processing liquid to the recording medium is not particularly limited, and the target liquid may be applied after the processing liquid is applied.

  The recording medium may be divided into a plurality of areas according to the application amount of the target liquid per predetermined area, and the application amount of the treatment liquid to the recording medium may be adjusted stepwise according to the area.

  In this case, since the application amount of the processing liquid to the recording medium is adjusted stepwise according to the area, the processing liquid can be applied to the recording medium by relatively simple control.

  The treatment liquid may also be applied to an intermediate concentration region between the high concentration region and the low concentration region on the recording medium. In this case, the treatment liquid is applied even in the intermediate concentration region and the insolubilization of the coloring material of the target liquid is promoted, so that the image quality in the intermediate concentration region can be improved.

  A plurality of regions including the low concentration region, the high concentration region, and a medium concentration region between the low concentration region and the high concentration region in the recording medium according to the application amount of the target liquid per the predetermined area The amount of the treatment liquid applied in the medium concentration region is less than the amount of the treatment liquid applied in the low concentration region, and the amount of the treatment liquid applied in the high concentration region is reduced to the medium concentration region. The amount of treatment liquid applied may be larger than the amount of treatment liquid applied, and may be less than the amount of treatment liquid applied in the low concentration region.

  In this case, the amount of treatment liquid applied to the recording medium decreases in the order of the low concentration region, the high concentration region, and the medium concentration region, so that the treatment liquid can be applied according to each concentration region.

  In the area on the recording medium, the application amount of the treatment liquid may be half or less of the maximum application amount of the target liquid. In this case, in the region on the recording medium where the application amount of the target liquid is maximized, the application amount of the treatment liquid is adjusted to be equal to or less than half of the maximum application amount of the target liquid, thereby improving the image quality.

  In the region on the recording medium where the application amount of the target liquid is maximized, the application amount of the treatment liquid may be approximately half of the maximum application amount of the target liquid. In this case, in the region on the recording medium where the application amount of the target liquid is maximum, the application amount of the treatment liquid is adjusted to be approximately half of the maximum application amount of the target liquid, thereby improving the image quality.

  In another aspect of the present invention, a target liquid applying unit that applies a target liquid containing a coloring material to a recording medium, and a processing liquid applying unit that applies a processing liquid that insolubilizes the coloring material to the recording medium. And the amount of the treatment liquid applied in the high concentration region on the recording medium where the amount of the target liquid applied per predetermined area is large is low on the recording medium where the amount of the target liquid applied per predetermined area is small. The present invention relates to an image forming apparatus comprising: a control unit that controls the processing liquid application unit so as to be less than an application amount of the processing liquid in a concentration region.

  The control means divides the recording medium into a plurality of areas according to the application amount of the target liquid per predetermined area, and the application amount of the treatment liquid to the recording medium is adjusted stepwise according to the areas. As described above, the treatment liquid application unit may be controlled.

  The control unit may control the processing liquid application unit so that the processing liquid is applied to an intermediate concentration region between the high concentration region and the low concentration region on the recording medium. Good.

  The control means includes the recording medium in the low concentration region, the high concentration region, and a medium concentration region between the low concentration region and the high concentration region according to the application amount of the target liquid per the predetermined area. The amount of the treatment liquid applied in the medium concentration region is less than the amount of the treatment liquid applied in the low concentration region, and the amount of the treatment liquid applied in the high concentration region is The treatment liquid application unit may be controlled so as to be larger than the application amount of the treatment liquid in the medium concentration region and smaller than the application amount of the treatment liquid in the low concentration region.

  The control means controls the treatment liquid application means so that the application amount of the treatment liquid is not more than half of the maximum application amount of the target liquid in an area on the recording medium where the application amount of the target liquid is maximum. You may control.

  The control means applies the treatment liquid application means so that the application amount of the treatment liquid is approximately half of the maximum application amount of the object liquid in an area on the recording medium where the application amount of the object liquid is maximum. May be controlled.

  According to the present invention, since the application amount of the treatment liquid in the high concentration area on the recording medium is controlled to be smaller than the application amount of the treatment liquid in the low concentration area, insolubilization and diffusion of the coloring material of the target liquid are prevented. It is adjusted according to the application amount of the treatment liquid. Therefore, the dot diameter corresponding to the image density is realized on the recording medium, and a high-quality image can be formed in both the low density area and the high density area.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, examples in which the present invention is applied to an inkjet recording apparatus will be described.

(First embodiment)
FIG. 1 is an overall configuration diagram of an inkjet recording apparatus 10 according to an embodiment of the present invention. The ink jet recording apparatus 10 is provided so as to correspond to a processing liquid discharge head 11 that discharges a processing liquid and inks of each color of black (K), cyan (C), magenta (M), and yellow (Y). A plurality of inkjet heads (hereinafter also referred to as “heads”) 12K, 12C, 12M, and 12Y, and an ink storage / loading unit that stores color inks to be supplied to the inkjet heads 12K, 12C, 12M, and 12Y. Unit 14, a processing liquid storage / loading unit 15 for storing the processing liquid to be supplied to the processing liquid discharge head 11, a medium supply unit 18 for supplying the recording medium 16, and a decurling unit 20 for removing the curl of the recording medium 16. And the recording medium 16 while maintaining the flatness of the recording medium 16. Comprising a suction belt conveyance unit 22 for conveying a print determination unit 24 for reading the printed result by the printing unit 12, a discharge unit 26 for discharging the recorded recording medium 16 (printed matter) to the outside.

  The ink storage / loading unit 14 has a plurality of ink tanks, and each ink tank stores ink of a color corresponding to each inkjet head 12K, 12C, 12M, 12Y. Each ink tank communicates with the inkjet heads 12K, 12C, 12M, and 12Y through a predetermined pipe line. The ink storage / loading unit 14 has notifying means (display means, warning sound generating means) for notifying that when the ink remaining amount is low, and also has a mechanism for preventing erroneous loading between colors.

  Similar 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 when the remaining amount of processing liquid is low, and between the liquid types. It has a mechanism to prevent erroneous loading.

  As the ink used in this example, for example, a color ink containing an anionic polymer which 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. Specific components of the ink and the treatment liquid will be described later.

  When the ink and the processing liquid are mixed, the color material in the ink is insolubilized and / or the fixing reaction proceeds by a chemical reaction. The term “insolubilization” includes, for example, a phenomenon in which the coloring material component is precipitated / aggregated / precipitated by removing the state in which the coloring material in the ink is dissolved or dispersed in the liquid solvent by the action of the treatment liquid on the ink. A phenomenon in which the liquid in which the material is dissolved changes to a solid phase (solidifies), a phenomenon in which the liquid thickens and hardens, and the like are 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 into the recording medium 16, and a mode in which these are combined.

  By adjusting the composition of the ink and the treatment liquid and the concentration of the substance that contributes to the reaction, the reaction rate and the physical properties (surface tension, viscosity, etc.) of each liquid are adjusted, and the desired ink insolubility and / or Desirable ink fixing properties (curing speed, fixing speed, etc.) can be realized. The physical properties of the treatment liquid and ink used in this embodiment will be described later.

  As for the supply system of the recording medium 16, FIG. 1 shows a magazine for rolled paper (continuous paper) as an example of the media supply unit 18, but a plurality of magazines having different paper widths, paper quality, etc. may be provided side by side. . Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  When a configuration in which a plurality of types of recording media can be used, an information recording body such as a barcode or a wireless tag that records the type information of the recording media may be attached to the magazine. In this case, the type of the recording medium to be used (medium type) is automatically determined by reading the information of the information recording body with a predetermined reading device, and an appropriate treatment liquid and ink are ejected according to the medium type. It is preferable that the discharge control is performed so that the above is realized.

  The recording medium 16 delivered from the medium 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, as shown in FIG. 1, a first cutter 28 for cutting is provided, and the roll paper is cut to a desired size by the first cutter 28. The first 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. A fixed blade 28A is provided on the printing back surface side of the recording medium, and a round blade 28B is disposed on the printing surface side with the conveyance path interposed therebetween. Note that the first cutter 28 is not necessary when cut paper is used.

  After the decurling process, the cut recording medium 16 is sent to the suction belt conveyance unit 22. The suction belt conveyance unit 22 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 12 and a sensor surface of the printing detection unit 24. It is comprised so that a part may make a horizontal surface (flat surface).

  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. 1, the position facing the nozzle surface of the printing unit 12 and the position facing the sensor surface of the printing detection unit 24 inside the belt 33 spanned between the rollers 31 and 32 are An adsorption chamber 34 is provided. The suction chamber 34 is sucked by the fan 35 to be a negative pressure, whereby the recording medium 16 is sucked and held on the belt 33.

  The power of a motor (see reference numeral “88” in FIG. 9) is transmitted to at least one of the rollers 31 and 32 around which the belt 33 is wound, whereby the belt 33 is driven in the clockwise direction in FIG. The recording medium 16 held on 33 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 mode using a roller / nip conveyance mechanism instead of the suction belt conveyance unit 22 is also conceivable, if the roller / nip conveyance is performed in the print area, the image easily spreads because the roller contacts the printing surface of the sheet immediately after printing. There is 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.

  A heating fan 40 is provided on the upstream side of the printing unit 12 on the media conveyance path formed by the suction belt conveyance unit 22. The heating fan 40 heats the recording medium 16 by blowing heated air onto the recording medium 16 before printing. By heating the recording medium 16 immediately before printing, the ink becomes easy to dry after landing.

  Each of the inkjet heads 12K, 12C, 12M, and 12Y of the treatment liquid discharge head 11 and the printing unit 12 has a length corresponding to the maximum paper width of the recording medium 16 targeted by the inkjet recording apparatus 10 (see FIG. 2). 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). .

  The inkjet heads 12K, 12C, 12M, and 12Y of the printing unit 12 are arranged in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side along the feeding direction of the recording medium 16. The processing liquid discharge head 11 is disposed further upstream of the printing unit 12. The processing liquid discharge head 11 and the ink jet heads 12K, 12C, 12M, and 12Y 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, the treatment liquid can be attached to the print surface (recorded surface) of the recording medium 16 by the treatment liquid discharge head 11 before the color ink is ejected by the printing unit 12.

  A color image can be formed on the recording medium 16 by ejecting ink of different colors from the respective ink jet heads 12K, 12C, 12M, and 12Y while conveying the recording medium 16 by the suction belt conveyance unit 22.

  As described above, according to the configuration in which the full-line type ink jet heads 12K, 12C, 12M, and 12Y having nozzle rows that cover the entire width of the paper are provided for each color, the recording medium 16 and the printing in the paper feed 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 portion 12 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 ink jet heads for each color is not particularly limited.

  The print detection unit 24 shown in FIG. 1 includes an image sensor for imaging the droplet ejection result of the printing unit 12, and means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor. Function as.

  The print detection unit 24 of this example is composed of a line sensor having a light receiving element array wider than at least the ink discharge width (image recording width) by each of the inkjet heads 12K, 12C, 12M, and 12Y. The line sensor includes an R sensor row in which photoelectric conversion elements (pixels) provided with red (R) color filters are arranged in a line, a G sensor row provided with green (G) color filters, The color separation line CCD sensor is composed of a B sensor array provided with a blue (B) color filter. Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  Test patterns or practical images printed by the ink jet heads 12K, 12C, 12M, and 12Y of the respective colors are read by the print detecting unit 24, and ejection determination of the ink jet heads 12K, 12C, 12M, and 12Y is performed. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 42 is provided following the print detection unit 24. 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 (printed target image) and the test print are discharged separately. The ink jet recording apparatus 10 is provided with a sorting means (not shown) for switching the paper discharge path in order to select the print product of the main image and the print product of the test print and send them to the discharge units 26A and 26B. .

  When the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by the second cutter 48. The second 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 second 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.

  The paper output unit 26A for the target prints is provided with a sorter (not shown) for collecting prints according to print orders.

  Next, the structure of the inkjet heads 12K, 12C, 12M, and 12Y will be described. Since the structures of the ink-jet heads 12K, 12C, 12M, and 12Y for each color are the same, the ink-jet heads 12K, 12C, 12M, and 12Y are represented by the reference numeral 50 in the following.

  FIG. 3 is a perspective plan view showing an example of the structure of the inkjet head 50. FIG. 4 is an enlarged view of a part of the inkjet head 50. In order to increase the dot pitch printed on the recording medium 16, it is necessary to increase the nozzle pitch in the inkjet head 50. As shown in FIGS. 3 and 4, the ink jet head 50 of this example includes an ink chamber unit (droplet discharge element) including a nozzle 51 that is an ink droplet discharge port, a pressure chamber 52 corresponding to each nozzle 51, and the like. 53 has a structure in which 53 are arranged in a staggered matrix (two-dimensionally), so that the substantial nozzle interval projected so as to be aligned along the head longitudinal direction (direction orthogonal to the paper feed direction) High density (projection nozzle pitch) is achieved.

  The form in which the nozzle row having a length corresponding to the full width of the recording medium 16 is configured in a direction substantially orthogonal to the feeding direction of the recording medium 16 is not limited to this example. FIG. 5 is a perspective plan view showing another structural example of the inkjet head 50. For example, instead of the configuration of FIG. 3, as shown in FIG. 5, a short head unit 50 ′ in which a plurality of nozzles 51 are two-dimensionally arranged is arranged in a staggered manner and joined together to connect the entire width of the recording medium 16. You may comprise the line head which has a nozzle row of the length corresponding to.

  The pressure chamber 52 provided corresponding to each nozzle 51 of the inkjet head 50 has a substantially square planar shape (see FIG. 3 and FIG. 4), and is connected to the nozzle 51 at both diagonal corners. An outlet and an inlet (supply port) 54 for supply ink are provided.

As shown in FIG. 6, 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. 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 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 nozzle is divided into blocks, each block is sequentially driven from one side to the other, etc., and one line is formed in the width direction of the recording medium (direction perpendicular to the conveyance direction of the recording medium). The driving of the nozzle that prints (a line composed of a single line of dots or a line composed of a plurality of lines of dots) is defined as main scanning.

  In particular, when the nozzles 51 arranged in a matrix as shown in FIG. 6 are driven, the main scanning as described in the above (3) 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 the width direction.

  On the other hand, by moving the full line head and the recording medium 16 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.

  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.

  The structure of the treatment liquid discharge head 11 is substantially the same as the inkjet head 50 of the printing unit 12 described above.

  In addition, 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 generally not required as compared with ink. Therefore, the treatment liquid discharge head 11 can also reduce the nozzle density by reducing the number of nozzles as compared with the ink jet head 50 for discharging ink. Further, a configuration in which the nozzle diameter of the treatment liquid discharge head 11 is larger than the nozzle diameter of the ink jet head 50 for discharging ink is also possible.

  FIG. 7 is a cross-sectional view (cross-sectional view taken along line 7-7 in FIG. 4) showing a three-dimensional configuration of one droplet discharge element (an ink chamber unit corresponding to one nozzle 51). As shown in FIG. 7, each pressure chamber 52 communicates with a common channel 55 through a supply port 54. The common flow channel 55 communicates with an ink tank 60 (see FIG. 8) as an ink supply source, and the ink supplied from the ink tank 60 is distributed and supplied to each pressure chamber 52 via the common flow channel 55 in FIG. The

  An actuator 58 having an individual electrode 57 is joined to a pressure plate (vibrating plate that also serves as a common electrode) 56 that forms the top surface of the pressure chamber 52. 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 ink discharge, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54. For the actuator 58, a piezoelectric body such as a piezoelectric element is preferably used.

  FIG. 8 is a schematic diagram showing the configuration of the ink supply system in the inkjet recording apparatus 10. The ink tank 60 is a base tank that supplies ink to the inkjet head 50 and is installed in the ink storage / loading unit 14 described with reference to FIG. That is, the ink tank 60 in FIG. 8 is equivalent to the ink storage / loading unit 14 in FIG. In the form of the ink tank 60, there are a system that replenishes ink from a replenishing port (not shown) and a cartridge system that replaces the entire tank when the remaining amount of ink is low. A cartridge system is suitable for changing the ink type according to the intended use. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type.

  As shown in FIG. 8, a filter 62 is provided between the ink tank 60 and the inkjet head 50 in order to remove foreign substances and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter. Although not shown in FIG. 8, a configuration in which a sub tank is provided in the vicinity of the inkjet head 50 or integrally with the inkjet head 50 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the inkjet head.

  Further, the inkjet recording apparatus 10 is provided with a cap 64 as a means for preventing the nozzle 51 from drying or preventing an increase in ink viscosity near the nozzle, and a cleaning blade 66 as a means for cleaning the nozzle surface 50A. . The maintenance unit (recovery means) including the cap 64 and the cleaning blade 66 can be moved relative to the ink jet head 50 by a moving mechanism (not shown), and if necessary, maintenance is performed below the ink jet head 50 from a predetermined retraction position. Moved to position.

  The cap 64 is displaced up and down relatively with respect to the inkjet head 50 by an elevator mechanism (not shown). The cap 64 is raised to a predetermined raised position when the power is turned off or during printing standby, and is brought into close contact with the inkjet head 50, thereby covering the nozzle surface 50 </ b> A with the cap 64.

  The cleaning blade 66 is made of an elastic member such as rubber, and can slide on the nozzle surface 50A (nozzle plate surface) of the inkjet head 50 by a blade moving mechanism (not shown). When ink droplets or foreign matter adheres to the nozzle plate surface, the nozzle plate surface is wiped by sliding the cleaning blade 66 on the nozzle plate.

  During printing or standby, when a specific nozzle is used less frequently and the ink viscosity in the vicinity of the nozzle increases, preliminary ejection is performed toward the cap 64 (also used as an ink receiver) to discharge the deteriorated ink. .

  If the ink jet head 50 is not ejected for a certain period of time, the ink solvent in the vicinity of the nozzles evaporates and the viscosity of the ink in the vicinity of the nozzles increases. Ink cannot be ejected. Therefore, before this state is reached (within the range of viscosity at which ink can be discharged by the operation of the actuator 58), the actuator 58 is operated toward the ink receiver to discharge ink near the nozzle whose viscosity has increased. "Preliminary discharge" is performed. In addition, after the dirt on the surface of the nozzle plate is cleaned by a wiper such as a cleaning blade 66 provided as a cleaning means for the nozzle surface 50A, the foreign matter is prevented from entering the nozzle 51 by the wiper rubbing operation. Also, preliminary discharge is performed. Note that the preliminary discharge may be referred to as “empty discharge”, “purge”, “spitting”, or the like.

  On the other hand, if bubbles are mixed into the nozzle 51 or the pressure chamber 52 or if the viscosity of the ink in the nozzle 51 rises above a certain level, ink cannot be ejected by the preliminary ejection. In such a case, the cap 64 as a suction means is brought into contact with the nozzle surface 50A of the inkjet head 50, and the ink in the pressure chamber 52 (ink mixed with bubbles or thickened ink) is sucked by the suction pump 67. Ink removed by the suction operation is sent to the collection tank 68. The ink collected in the collection tank 68 may be reused, or may be discarded if it cannot be reused.

  Since the above suction operation is performed on the entire ink in the pressure chamber 52, the amount of ink consumption is large. Therefore, when the increase in viscosity is small, it is preferable to perform preliminary discharge as much as possible. Note that the above-described suction operation is also performed when the ink is initially loaded into the inkjet head 50 or when use is started after a long stop.

  Although not shown, the processing liquid supply system is substantially the same as the ink supply system described with reference to FIG.

  FIG. 9 is a block diagram showing an example of the hardware configuration of the system control unit 100 of the inkjet recording apparatus 10 and its periphery. The system control unit 100 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, a head driver 84, and the like.

  The communication interface 70 is an interface 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 each part such as the communication interface 70, the image memory 74, the motor driver 76, the heater driver 78, etc., performs communication control with the host computer 86, read / write control of the image memory 74, and the like. 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 unit, or may be a rewritable storage unit 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 (drive circuit) that drives the 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 has a signal processing function for performing various processing and correction processes for generating a print control signal from image data in the image memory 74 in accordance with the control of the system controller 72, and the generated print It is a control unit that supplies data (dot data) to the head driver 84. Necessary signal processing is performed in the print control unit 80, and the droplet ejection range of the treatment liquid, the ink ejection amount and ejection timing are controlled via the head driver 84 based on the print data. Thereby, a desired dot size and dot arrangement are realized.

  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. 9, the image buffer memory 82 is shown as being attached to the print control unit 80, but 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.

  The head driver 84 drives the actuator 58 of each color inkjet head 50 based on the print data given from the print controller 80 and also drives the actuator of the treatment liquid discharge head 11. The head driver 84 may include a feedback control system for keeping the head driving conditions constant.

  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, RGB image data is stored in the image memory 74.

  The image data stored in the image memory 74 is sent to the print controller 80 via the system controller 72, and converted to dot data for each ink color by a halftoning technique such as a dither method or an error diffusion method in the print controller 80. Converted. 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.

  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. Further, the print controller 80 discriminates the treatment liquid droplet ejection area (the area on the recording surface where the treatment liquid droplet ejection is necessary) based on the dot data of each color, and generates the treatment liquid droplet ejection dot data. . In this way, the dot data (for the treatment liquid and for each color) generated by the print control unit 80 is stored in the image buffer memory 82.

  The head driver 84 generates drive control signals for the processing liquid ejection head 11 and the inkjet head 50 for each color ink based on the dot data stored in the image buffer memory 82. When the drive control signal generated by the head driver 84 is applied to the processing liquid discharge head 11 and the ink jet head 50 for each color ink, the processing liquid is discharged from the processing liquid discharge head 11 and the ink is discharged from the ink jet head 50. The An image is formed on the recording medium 16 by controlling the discharge of the processing liquid from the processing liquid discharge head 11 and the discharge of the ink from the inkjet head 50 in synchronization with the conveyance speed of the recording medium 16.

  As described in FIG. 1, the print detection unit 24 is a block including a line sensor, reads an image printed on the recording medium 16, performs necessary signal processing, etc. Variation, optical density, etc.) and the detection result is provided to the print controller 80.

  The print controller 80 performs various corrections on the inkjet head 50 based on information obtained from the print detector 24 as necessary. Further, the system controller 72 performs control to perform a predetermined recovery operation such as preliminary ejection, suction, or the like based on information obtained from the print detection unit 24.

  The ink jet recording apparatus 10 of this example further includes an ink information reading unit 90, a treatment liquid information reading unit 92, and a media type detection unit 94. The ink information reading unit 90 is a means for acquiring ink type information. Specifically, for example, ink identification information and physical properties from the shape of the cartridge of the ink tank 60 (see FIG. 8) (a specific shape capable of identifying the ink type), or a barcode or IC chip incorporated in the cartridge. Means for reading information can be used. In addition, the operator may input necessary information using a user interface.

  Similarly, the processing liquid information reading unit 92 is means for acquiring information related to the type of processing liquid. Specifically, for example, the shape of the cartridge of the treatment liquid tank (not shown) of the treatment liquid storage / loading unit 15 (a specific shape that can identify the liquid type), or a barcode or IC chip incorporated in the cartridge A means for reading processing liquid identification information and physical property information can be used. In addition, the operator may input necessary information using a user interface.

  The media type detection unit 94 is means for detecting the type (paper type) and size of the recording medium. For example, means for reading information such as a barcode attached to a magazine of the media supply unit 18 (identification information, media type information, etc.), and a sensor (media width detection sensor, media placed at an appropriate location in the media transport path) A sensor for detecting the thickness of the recording medium, a sensor for detecting the reflectance of the medium, and the like are used, and appropriate combinations thereof are also possible. Further, in place of or in combination with these automatic detection means, it is possible to specify information such as paper type and size by input from a predetermined user interface.

  Information obtained from each means of the ink information reading unit 90, the processing liquid information reading unit 92, and the media type detection unit 94 is sent to the system controller 72, and processing liquid selection and ink ejection control (e.g., ejection amount and ejection timing) are performed. Control), etc., and appropriate droplet ejection corresponding to the conditions is executed. That is, the system controller 72 determines the permeation speed characteristic of the recording medium 16 based on the information obtained from each means of the ink information reading unit 90, the processing liquid information reading unit 92, and the media type detection unit 94, and the processing liquid In the case of using a processing liquid, the liquid type is selected and the discharge amount is controlled.

As described with reference to FIG. 1, the inkjet recording apparatus 10 of the present example includes the processing liquid discharge head 11 at the uppermost stream of the printing unit 12, and before the ink is ejected by the printing unit 12, by the preceding processing liquid discharge head 11. The processing liquid is previously attached to the printing surface of the recording medium 16 only once. In the case of such a configuration, the amount of processing liquid on the recording medium 16 gradually decreases as the amount of ink ejected by the printing unit 12 increases, so that the processing on the recording medium 16 proceeds toward the downstream side of the printing unit 12. The amount of liquid decreases. The treatment liquid needs to remain in the vicinity of the surface of the recording medium 16 until the droplet ejection by the final stage (the most downstream) inkjet head (the yellow inkjet head 12Y in FIG. 1) in the printing unit 12 is completed. Therefore, the amount of treatment liquid ejected by the treatment liquid ejection head 11 is such that the required treatment liquid amount can be secured from the type of the recording medium 16, the physical properties of the treatment liquid, the ink ejection amount, the conveyance speed of the recording medium 16, and the like. It is determined.

  The inkjet recording apparatus 10 includes information storage means (for example, the ROM 75 shown in FIG. 9 or an internal memory or an external memory (not shown)) that stores data of a media type table in which media types and permeation speed characteristics are associated with each other. The system controller 72 refers to the media type table and determines the permeation speed characteristic of the recording medium 16 to be used.

  For example, when a penetrating paper having a high penetrating speed is used, a treatment liquid having a higher surface tension is selected as compared with a penetrating paper having a slow penetrating speed (or a non-penetrating medium). In the present embodiment, if the surface tension of the processing liquid A is larger than the surface tension of the processing liquid B, the processing liquid A is discharged from the processing liquid discharge head 11 when using a penetrating paper having a high penetration speed. The actuator corresponding to the nozzle row 11 </ b> A is driven, and the processing liquid A is discharged from the processing liquid discharge head 11. On the other hand, when a permeation paper or a non-penetrable medium having a slow permeation speed is used, an actuator corresponding to the nozzle row 11B for ejecting the processing liquid B in the processing liquid ejection head 11 is driven, and the processing liquid ejection head 11 is driven. The processing liquid B is discharged from

  As described above, even if the permeation paper has a high permeation rate, the permeation rate of the treatment liquid A can be reduced by using the treatment liquid A having a large surface tension.

  Alternatively, when penetrating paper having a high penetrating speed is used, there is also a control mode in which the processing liquid is not used (an image is formed only with ink without performing droplet ejection of the processing liquid).

  The “penetrating paper having a high permeation speed” as used herein refers to a permeating paper in which the first liquid (processing liquid) finishes penetrating due to the difference in droplet ejection time between the first liquid (processing liquid) and the second liquid (ink). means. When using a medium with a high permeability so that a predetermined amount of processing liquid cannot be held on the recording surface when ink is ejected, it is not meaningful to use the processing liquid, and on the contrary, it promotes ink bleeding. Therefore, in such a case, an embodiment in which no treatment liquid is used is preferable.

  That is, when ink is ejected onto penetrating paper alone and when ink is ejected from the top of the treatment liquid, ink ejection alone causes less bleeding. This is because when the surface tension is larger, there is less bleeding, and when ink is ejected from the top of the processing liquid, the ink bleeding oozes according to the bleeding of the processing liquid. Therefore, the surface tension of the treatment liquid is selected depending on whether the penetrating paper is used or the non-penetrating paper is used, or whether or not the treatment liquid is used is selected and droplets are ejected according to the characteristics of the recording medium. Thus, bleeding can be suppressed.

  As a means for grasping the permeation speed characteristic of the recording medium 16, the medium ID (identification information) is acquired from the media type detection unit 94, and the permeation speed characteristic of the medium is grasped by referring to the media type table. Alternatively, information indicating the media penetration rate characteristic may be recorded on an information recording medium such as a barcode attached to the magazine, and the media penetration rate characteristic information may be read directly from the media type detection unit 94. Good.

  Alternatively, it is possible to use means for actually measuring the permeation speed of the recording medium 16. For example, ink or treatment liquid or both of them are ejected onto the recording medium 16, and the state of the dots formed by the test ejection is read by a detection means such as an image sensor (which can be substituted by the print detection unit 24). Based on the information obtained, the penetration rate can be calculated.

  FIG. 10 is a block diagram illustrating a functional configuration of the system control unit 100, and particularly relates to control of the inkjet head 50 and the treatment liquid discharge head 11. The system control unit 100 includes an image data reading unit 102, an ink discharge data determination unit 103, a processing liquid discharge data determination unit 107, a table storage unit 112, an ink head control unit 113, and a processing liquid head control unit 114.

  The image data reading unit 102 supplies data such as image data (print data) and operation mode sent from the external host computer 86 to the system control unit 100 to the ink discharge data determination unit 103 and the treatment liquid discharge data determination unit 107. To do.

  The ink ejection data determination unit 103 includes an ink application data generation unit 104 and an ink application amount calculation unit 106, and determines data necessary for ejecting ink from the inkjet head 50.

  The ink application data generation unit 104 relates to ink ejection from the inkjet head 50 to the recording medium 16 necessary for image formation based on the image data and the operation mode data sent from the image data reading unit 102. Ink application data is generated. The ink application data includes, for example, information on “from which nozzle and at which timing ink droplets are ejected”, information on the voltage (voltage waveform) applied to the piezoelectric element 59 of the inkjet head 50, and the like. Note that the ink application data generation unit 104 of the present embodiment generates ink application data for each of the divided areas set by dividing the print range of the recording medium 16 into a plurality of areas.

  The ink application amount calculation unit 106 calculates the total ink amount to be applied on the recording medium 16 based on the ink application data created by the ink application data generation unit 104. At this time, the ink application amount calculation unit 106 calculates the total ink amount for each divided region.

  The ink head control unit 113 applies a predetermined voltage to the piezoelectric element 59 of the inkjet head 50 based on information such as the ink application data determined by the ink ejection data determination unit 103 and the total ink amount for each divided region. . Thereby, ink droplets are ejected from the inkjet head 50 toward the recording medium 16, and a desired image is formed on the recording medium 16. In the present embodiment, a single waveform voltage is applied to the piezoelectric element 59. Therefore, the number of ink droplets ejected to the recording medium 16 is adjusted by the number of times of voltage application to the piezoelectric element 59, and the ink droplet ejection amount is adjusted by the number of ink droplets ejected to the recording medium 16. .

  The table storage unit 112 stores a predetermined ink-treatment liquid application amount table. This ink-processing liquid application amount table is read by the processing liquid ejection data determination unit 107 and is used when the processing liquid ejection data determination unit 107 obtains the processing liquid application amount to the media supply unit 18. It is done. The ink-treatment liquid application amount table will be described later (see FIG. 11).

  The processing liquid discharge data determination unit 107 includes a processing liquid application data generation unit 108 and a processing liquid application amount calculation unit 110 and determines data necessary for discharging the processing liquid from the processing liquid discharge head 11.

  The processing liquid application data generation unit 108 supplies ink color material to the recording medium 16 based on various data sent from the image data reading unit 102, the ink ejection data determination unit 103, and the processing liquid application amount calculation unit 110. Processing liquid application data relating to droplet ejection of the processing liquid from the processing liquid discharge head 11 to the recording medium 16 necessary for fixing is generated. The processing liquid application data includes, for example, information on “from which nozzle and ink droplets are discharged at which timing”, information on voltage (voltage waveform) applied to the piezoelectric element of the processing liquid discharge head 11, and the like. Note that the processing liquid application data generation unit 108 of the present embodiment generates processing liquid application data for each of the divided areas of the print range of the recording medium 16.

  The processing liquid application amount calculation unit 110 includes the “total ink amount to be applied to the recording medium 16” calculated by the ink application amount calculation unit 106, and the ink-processing liquid application amount table stored in the table storage unit 112. Based on the above, the total amount of processing liquid to be applied on the recording medium 16 is calculated. At this time, the processing liquid application amount calculation unit 110 calculates the total processing liquid amount for each divided region based on the total ink amount for each divided region.

  The processing liquid head control unit 114 applies the processing liquid application data determined by the processing liquid discharge data determination unit 107 to the piezoelectric elements of the processing liquid discharge head 11 based on information such as the total processing liquid amount for each divided region. Apply voltage. As a result, the processing liquid is discharged from the processing liquid discharge head 11 toward the recording medium 16, and a desired amount of the processing liquid is applied to a desired position on the recording medium 16. In the present embodiment, a single waveform voltage is applied to the piezoelectric element of the processing liquid ejection head 11. Accordingly, the discharge amount of the processing liquid is adjusted by the number of processing droplets discharged to the recording medium 16 by adjusting the number of times the voltage is applied to the piezoelectric element 59.

  In the present embodiment, each of the functional blocks shown in FIG. 10 is realized by the hardware configuration of the system control unit 100 shown in FIG. 9 alone or in cooperation.

  FIG. 11 is a diagram illustrating an example of the ink-treatment liquid application amount table showing the relationship between the ink application amount and the treatment liquid application amount. In the present embodiment, the table indicated by “Embodiment 1” in FIG. 11 is used. Note that the ink application amount and the treatment liquid application amount shown in FIG. 11 are based on the divided areas of the recording medium 16. Further, the density range based on the ink application amount is divided into three, a range where the density is 0 or more and 0.5 or less is low, a range where the density is higher than 0.5 and 1.0 or less is medium density, A range where the density is higher than 1.0 is referred to as high density. FIG. 11 shows a table indicating “conventional example 1” in which the ratio between the ink application amount and the treatment liquid application amount is substantially constant at any concentration, and the treatment liquid application amount is substantially 0 regardless of the ink application amount. A table indicating “conventional example 2” is described as a comparative example. In the following description, “low density area” refers to an area on the recording medium 16 where the density is low, and “medium density area” refers to an area on the recording medium 16 where the density is medium density. “Area” refers to an area on the recording medium 16 having a high density.

  In this embodiment, as shown in FIG. 11, the treatment liquid application amount decreases continuously and proportionally according to the ink application amount. For example, the processing liquid application amount calculation unit 110 and the processing liquid head control unit 114 may use the processing liquid application amount equal to the maximum ink application amount Q in a high concentration region where the ink application amount per predetermined area on the recording medium 16 is large. In the region on the recording medium 16 where the ink application amount is the maximum (see “A” in FIG. 11), the processing liquid application amount becomes approximately 0 so that the maximum ink application amount becomes approximately zero. The liquid discharge head 11 is controlled. Even when the concentration is lower than a predetermined value (see “B” in FIG. 1) at a low concentration, the amount of treatment liquid applied to the recording medium 16 is substantially zero.

  In the present embodiment having the above-described configuration, the target liquid applying unit that applies the ink (target liquid) containing the coloring material to the recording medium 16 is realized by at least the inkjet head 50. Further, the processing liquid applying means for applying the processing liquid for insolubilizing the coloring material to the recording medium is realized by at least the processing liquid discharge head 11. The control means for controlling the treatment liquid application means is realized by at least the system control unit 100.

  Next, the operation of this embodiment will be described.

  When an image is printed on the recording medium 16 by the ink jet recording apparatus 10 shown in FIG. 1, first, the processing liquid is discharged from the processing liquid discharge head 11 toward the conveyed recording medium 16. The recording medium 16 to which the treatment liquid is applied is conveyed downstream and passes under each printing unit 12. At this time, ink droplets are ejected from each of the printing units 12, ink is applied onto the recording medium 16, and the processing liquid and ink already applied onto the recording medium 16 are mixed on the recording medium 16. As a result, the color material component of the ink reacts with the processing liquid and becomes insoluble, so that the color material component and the solvent component of the ink are separated, and the color material component is effectively fixed on the recording medium 16. Thereafter, the recording medium 16 is conveyed to the post-drying unit 42, and the solvent component separated from the color material component is dried and removed. As a result, the color material component is firmly fixed on the recording medium 16 and a desired image is formed.

  As described above, in this embodiment, by mixing the ink and the treatment liquid on the recording medium 16, fixing of the color material component of the ink to the recording medium 16 is effectively promoted, and a clear image is formed. The application of ink and treatment liquid to the recording medium 16 will be described in more detail with reference to FIGS.

  FIG. 12 is a flowchart showing a series of steps in which ink and treatment liquid are applied to the recording medium 16. First, image data (print data) sent from the host computer 86 is read by the image data reading unit 102 (S11 in FIG. 12) and sent to the ink ejection data determining unit 103. Based on this image data, ink application data relating to ink ejection is generated in the ink application data generation unit 104 (S12). Based on the ink application data, the total ink application amount for a predetermined area of the divided area on the recording medium 16 is calculated by the ink application amount calculation unit 106 (S13). On the other hand, the treatment liquid ejection data determination unit 107 refers to the ink-treatment liquid application amount table stored in the table storage unit 112 (S14). Then, based on the ink-processing liquid application amount table and the total ink application amount for the predetermined area calculated by the ink ejection data determination unit 103, the total application amount of the processing liquid in the predetermined area is calculated as the processing liquid application amount. Calculated in the unit 110 (S15). Further, the processing liquid application data generation unit 108 calculates the processing liquid application data based on the information such as the total amount of the processing liquid applied to the predetermined area thus obtained (S16).

  Then, based on the processing liquid total application amount and the processing liquid application data calculated in this way, an applied voltage is applied to the piezoelectric element of the processing liquid ejection head 11 by the processing liquid head control unit 114, and the processing liquid ejection head 11. The processing liquid is discharged from the recording medium 16 toward the recording medium 16 (S17). At this time, the piezoelectric element of the treatment liquid discharge head 11 is disposed in the treatment liquid head control unit 114 so that the treatment liquid application amount in the high concentration region on the recording medium 16 is smaller than the treatment liquid application amount in the low concentration region. Controlled by. In addition, the piezoelectric element of the treatment liquid discharge head 11 is processed so that the treatment liquid application amount in the medium concentration region is between the treatment liquid application amount in the low concentration region and the treatment liquid application amount in the high concentration region. It is controlled by the liquid head controller 114.

  After the treatment liquid is applied to the recording medium 16, the ink head control unit 113 applies a voltage to the piezoelectric element 59 of the inkjet head 50 based on the calculated total ink application amount and ink droplet ejection data. Thereby, ink droplets are ejected from each of the inkjet heads 50 toward the recording medium 16 to which the treatment liquid is applied (S18), and a desired image is formed.

  FIG. 13 is a diagram illustrating an example of the state of ink and processing liquid on the recording medium 16. FIG. 13A shows a state immediately after the processing liquid and the ink have adhered to the recording medium 16, and FIG. 13B shows a state after a predetermined time has elapsed after the processing liquid and the ink have adhered to the recording medium 16. Shows the state. A region surrounded by a dotted line and a solid line in the figure means a unit region having a predetermined size, and is used when determining the image density. In this embodiment, the ink amount per drop is substantially the same, and the processing liquid amount per drop is also the same. Therefore, in this embodiment, the amount of treatment liquid applied is controlled by changing the number of droplets of the treatment liquid in accordance with the concentration region on the recording medium 16.

  As shown in FIG. 13A, in the present embodiment, the amount of applied ink (number of droplet ejection) increases in the order of the low density area, the medium density area, and the high density area on the recording medium 16, but the processing is performed. The amount of liquid applied (number of droplets deposited) decreases. For this reason, in the low concentration region where the amount of ink applied per unit region is small, the ink reacts with a sufficient amount of the processing liquid, so that the color material component of the ink becomes insoluble, and the ink on the recording medium 16 is finally obtained. The dot diameter becomes smaller (FIG. 13B). In the middle density region and the high density region, the ratio of the reaction amount of the processing liquid to the ink decreases as the density increases, so that the degree of insolubilization of the color material component of the ink by the processing liquid decreases and the color material component diffuses. To do. Therefore, as shown in FIG. 13B, finally, the dot diameter of the ink increases and the white background decreases in the order of the low density area, the medium density area, and the high density area.

  FIG. 14 is a diagram illustrating evaluation of an image formed on the recording medium 16 by the inkjet recording apparatus 10. The evaluation in the first embodiment described above is described in the column of “Embodiment 1” in FIG. 14, and “Conventional Example 1” and ink application in which the ratio between the ink application amount and the treatment liquid application amount is substantially constant. FIG. 14 also shows data relating to “Conventional Example 2” (see FIG. 11) in which the treatment liquid application amount is substantially 0 regardless of the amount. In FIG. 14, “low density area dot diameter” indicates the dot diameter of ink (particularly color material) in the low density area on the recording medium 16, and “high density area dot diameter” indicates the high density area on the recording medium 16. The dot diameter of ink (particularly color material) in the density region is shown. The “low density area granularity” indicates the granularity of the image in the low density area on the recording medium 16, and the “medium density area granularity” indicates the granularity of the image in the intermediate density area on the recording medium 16. Showing gender. Further, “high density area density” indicates whether an image in a high density area on the recording medium 16 has a uniform enough density. “High density area landing coherence” indicates the degree of interference between adjacent ink dots in the high density area on the recording medium 16. In FIG. 14, double circles indicate “very good state”, single circles indicate “good state”, triangles indicate “general state”, and x indicates “general state”. Compared to the state of being amber.

  As shown in FIG. 14, in the first embodiment described above, the dot density of the low density region can be made smaller than those of Conventional Example 1 and Conventional Example 2. This is because a sufficient amount of processing liquid is applied to the ink application amount in the low density region on the recording medium 16 (see FIG. 11). Thereby, the low density region granularity can be made very good, and a clear image can be printed in the low density region on the recording medium 16. In the first embodiment, the high density region dot diameter can be kept large. This is because the use of only a small amount of the processing liquid in the high concentration region on the recording medium 16 restricts the insolubilization of the ink color material component and the ink color material diffuses (FIG. 13A). ) And FIG. 13B). As a result, a very good high density area density can be ensured, and a clear image with a sufficiently dark color can be printed in the high density area.

  In the present embodiment, a general state can be secured for the medium density region granularity. On the other hand, since the amount of the treatment liquid used in the high concentration region on the recording medium 16 is limited, it is difficult to sufficiently prevent excessive diffusion of the ink coloring material on the recording medium 16. Therefore, the high density region landing coherence is in a state of being inferior to the general state.

  As described above, according to the present embodiment, a sufficient amount of processing liquid is applied in the low concentration region to effectively insolubilize the ink color material component, and in the high concentration region, the ink color material component is applied. Is applied to such a degree that effectively diffuses. Therefore, in the low density region, the dot diameter of the ink (coloring material component) can be made sufficiently small to improve the granularity of the image, while in the high density region, the dot diameter of the ink (coloring material component) can be reduced. It can be made sufficiently large to effectively prevent white background. As described above, the ink jet recording apparatus 10 according to the present embodiment can realize a dot diameter corresponding to a desired image density, and can provide a high-quality image in both the low density area and the high density area.

(Second Embodiment)
This embodiment is substantially the same as the first embodiment described above, and the same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

  In the table storage unit 112 of this embodiment, a table indicated by “Embodiment 2” in FIG. 11 is stored as an ink-treatment liquid application amount table. According to the ink-treatment liquid application amount table, the treatment liquid application amount is proportionally decreased in accordance with the ink application amount, and the treatment liquid application amount is the ink in the region of the recording medium 16 where the ink application amount is maximum. Is about half of the maximum amount Q of. Therefore, the treatment liquid ejection data determination unit 107 and the treatment liquid head control unit 114 indicate that the treatment liquid application amount is the ink supply amount in the region of the recording medium 16 where the ink application amount is maximum (see “A” in FIG. 11). The processing liquid discharge head 11 is controlled so as to be approximately half of the maximum application amount Q.

  Other configurations are substantially the same as those of the first embodiment described above.

  Evaluation of an image formed on the recording medium 16 by the inkjet recording apparatus 10 of the present embodiment is described in the column “Embodiment 2” of FIG. As shown in FIG. 14, according to the present embodiment, the medium density area granularity and the high density area landing interference are also good. This is because the application amount of the treatment liquid in the medium concentration region and the high concentration region on the recording medium 16 is adjusted. That is, in the present embodiment, even in the high density region of the recording medium 16, the processing liquid that is approximately half the maximum application amount Q of ink is applied, and the color material component of the ink mixed with the processing liquid is insolubilized to some extent. Therefore, the diffusion of the color material component of the ink in the high density region is suppressed to some extent, and interference between adjacent ink dots is prevented, so that the high density region landing interference property is good. However, since the diffusion of the color material component of the ink in the high density region is limited to some extent, the high density region density is maintained in a good state, but compared with the case of the first embodiment (see “Embodiment 1”). Somewhat inferior. On the other hand, in the medium concentration region of the recording medium 16, a larger amount of processing liquid is applied than in the case of the first embodiment, so that the color material component of the ink in the medium concentration region can be appropriately insolubilized by the processing liquid. It is possible to improve the medium density region granularity.

  As described above, according to the present embodiment, the total amount of treatment liquid applied is adjusted for each density area, and the dot diameter corresponding to the desired image density is realized. Can provide high-quality images. In addition, graininess with good image quality is ensured in the medium density region, and landing interference between ink dots is effectively prevented even in the high density region. Thus, according to the present embodiment, good image quality is realized in any of the low density area, the medium density area, and the high density area.

(Third embodiment)
This embodiment is substantially the same as the first embodiment described above, and the same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

  In the table storage unit 112 of this embodiment, a table indicated by “Embodiment 3” in FIG. 11 is stored as an ink-treatment liquid application amount table. According to this ink-treatment liquid application amount table, at low and medium concentrations, the treatment liquid application amount is proportionally reduced according to the ink application amount, as in the first embodiment. However, at a high concentration, the treatment liquid application amount increases proportionally with the ink application amount, and the treatment liquid application amount is an abbreviation of the maximum ink application amount Q in the region of the recording medium 16 where the ink application amount is maximum. It becomes about half. Therefore, the treatment liquid ejection data determination unit 107 and the treatment liquid head control unit 114 indicate that the treatment liquid application amount is the maximum of the ink in the region of the recording medium 16 where the ink application amount is maximum (see “A” in FIG. 11). The processing liquid discharge head 11 is controlled so that it is about half of the applied amount Q.

  Specifically, the processing liquid ejection data determination unit 107 classifies the recording medium 16 into a low density area, a medium density area, and a high density area according to the amount of ink applied per predetermined area. Then, the treatment liquid ejection head 11 is controlled by the treatment liquid ejection data determination unit 107 and the treatment liquid head controller 114 so that the treatment liquid application amount in the medium concentration region is smaller than the treatment liquid application amount in the low concentration region. Is done. Further, the processing liquid discharge data is set such that the maximum application amount of the processing liquid in the high concentration region is larger than the minimum application amount of the processing liquid in the medium concentration region and is smaller than the minimum application amount of the processing liquid in the low concentration region. The processing liquid discharge head 11 is controlled by the determination unit 107 and the processing liquid head control unit 114.

  Other configurations are substantially the same as those of the first embodiment described above.

  Evaluation of an image formed on the recording medium 16 by the inkjet recording apparatus 10 of the present embodiment is described in the column “Embodiment 3” of FIG. As shown in FIG. 14, according to the present embodiment, the high-density region landing coherence is in a good state. This is because, even in the high density region of the recording medium 16, a treatment liquid that is approximately half the maximum application amount Q of ink is applied, and insolubilization of the color material component of the ink mixed with the treatment liquid proceeds to some extent. Thereby, the diffusion of the color material component of the ink in the high density region is suppressed to some extent and the interference between the adjacent ink dots is prevented, so that the high density region landing interference property is in a good state. However, since the application amount of the treatment liquid in the intermediate concentration region is the same as that in the first embodiment, it is difficult to effectively insolubilize the color material component of the ink in the intermediate concentration region. Therefore, in the third embodiment, the general medium density region granularity is shown as in the first embodiment.

  As described above, also in the present embodiment, the total amount of treatment liquid applied is adjusted for each density region, and the dot diameter corresponding to the desired image density is realized. Therefore, in either the low density region or the high density region Provides high-quality images. Further, since the ink and the treatment liquid react even in the high concentration region and insolubilization of the color material component is promoted, the landing interference between the ink dots in the high concentration region can be improved.

(Fourth embodiment)
This embodiment is substantially the same as the first embodiment described above, and the same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

  FIG. 15 is a diagram illustrating an ink-treatment liquid application amount table used in the fourth embodiment. The table storage unit 112 of the present embodiment stores the ink-treatment liquid application amount table shown in FIG. According to this ink-treatment liquid application amount table, the application amount of the treatment liquid to the recording medium 16 is adjusted stepwise according to each of the low density, medium density, and high density classified by density. It gradually decreases in the order of medium concentration and high concentration. The amount of treatment liquid applied at a low concentration is substantially the same as the maximum amount Q of ink that can be applied to the recording medium 16. Further, the application amount of the treatment liquid at a high concentration is substantially half of the maximum amount Q of ink that can be applied to the recording medium 16. Further, the amount of treatment liquid applied at medium concentration is approximately three-fourths of the maximum amount Q of ink that can be applied to the recording medium 16.

  Other configurations are substantially the same as those of the first embodiment described above.

  The processing liquid ejection data determination unit 107 of the system control unit 100 according to the present embodiment includes a plurality of print portions of the recording medium 16 as a low density area, a medium density area, and a high density area according to the amount of ink applied per predetermined area. Into areas. Then, the processing liquid ejection data determination unit 107 refers to the ink-processing liquid application amount table so that the processing liquid application amount to the recording medium 16 is adjusted stepwise according to the area. The application amount and the treatment liquid application data are calculated. Then, based on the calculated treatment liquid total application amount and the treatment liquid application data, the treatment liquid ejection head 11 is arranged so that the treatment liquid application amount to the recording medium 16 is adjusted stepwise according to the area. It is controlled by the control unit 114.

  Also in the present embodiment, since a large amount of processing liquid is applied to the low concentration area and a small amount of processing liquid is applied to the high concentration area, a dot diameter corresponding to the image density is realized, High-quality images are provided in both the low density area and the high density area. In particular, according to the present embodiment, since the application amount of the processing liquid to the recording medium 16 is adjusted stepwise, it is not necessary to finely change the discharge control of the processing liquid, and the application of the processing liquid to the recording medium 16 can be performed. Control can be simplified.

  Next, a first modification of the fourth embodiment will be described. FIG. 16 is a diagram illustrating an ink-treatment liquid application amount table used in the first modification of the fourth embodiment. In the present modification, the ink-treatment liquid application amount table shown in FIG. 16 is stored in the table storage unit 112. According to this ink-treatment liquid application amount table, a relatively large amount of treatment liquid is applied to the low concentration region and the medium concentration region on the recording medium 16, and a relatively small amount of processing is applied to the high concentration region. Liquid is applied. Specifically, for the low density region and the medium density region, a treatment liquid of approximately the same amount as the maximum amount Q of ink that can be applied to the recording medium 16 is applied. Is applied with approximately half of the maximum amount Q of ink.

  As a result, in the low density area and the medium density area on the recording medium 16, the color material component of the ink is insolubilized by a sufficient amount of the processing liquid, and an image having excellent graininess is formed. Further, in the high density region, a balance between the insolubilization of the ink color material component by the treatment liquid and the diffusion of the ink color material component is achieved, and an image having a high density is formed in which landing interference of the ink dots is prevented. .

  Next, a second modification of the fourth embodiment will be described. FIG. 17 is a diagram illustrating an ink-treatment liquid application amount table used in the second modification of the fourth embodiment. In the present modification, the ink-treatment liquid application amount table shown in FIG. 17 is stored in the table storage unit 112. According to this ink-treatment liquid application amount table, a relatively large amount of treatment liquid is applied to the low concentration area on the recording medium 16, and a relatively small amount of treatment liquid is applied to the medium concentration area. An intermediate amount of treatment liquid is applied to the concentration region. More specifically, the processing liquid of approximately the same amount as the maximum amount Q of ink that can be applied to the recording medium 16 is applied to the low density area, and the ink is applied to the high density area. Approximately half of the maximum amount Q of processing liquid is applied, and about one-fourth of the maximum amount Q of ink is applied to the medium density region.

  Therefore, the processing liquid discharge data determination unit 107 divides the print range of the recording medium 16 into a low density area, a medium density area, and a high density area according to the amount of ink applied per predetermined area, and performs processing in the medium density area. The treatment liquid discharge head 11 is controlled so that the application amount of the liquid is smaller than the application amount of the treatment liquid in the low concentration region. Further, the treatment liquid discharge head 11 controls the treatment liquid application amount so that the treatment liquid application amount in the high concentration region is larger than the treatment liquid application amount in the medium concentration region and is smaller than the treatment liquid application amount in the low concentration region. Is done.

  As a result, in the low density region on the recording medium 16, the color material component of the ink is insolubilized by a sufficient amount of the processing liquid, and an image having excellent graininess is formed. In the medium density region, sufficient ink diffusion is ensured, so that an image having a sufficient density is formed. Further, in the high density region, the insolubilization of the ink color material component by the treatment liquid and the diffusion of the ink color material component are balanced to form a dark image in which landing interference of the ink dots is prevented. Is done.

(Fifth embodiment)
In the above-described first to fourth embodiments, an example in which a single ink-processing liquid application amount table is used has been described. However, a plurality of ink-processing liquid application amount tables may be used depending on applications. Is possible. In the present embodiment, an example will be described in which the ink-treatment liquid application amount table used in the first embodiment, the second embodiment, and the third embodiment is selectively used based on the operation mode.

  This embodiment is substantially the same as the first embodiment described above, and the same parts as those in the first embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

  FIG. 18 is a block diagram illustrating a functional configuration of the system control unit 100 according to the fifth embodiment, and particularly relates to control of the inkjet head 50 and the treatment liquid discharge head 11. The system control unit 100 according to this embodiment includes only an image data reading unit 102, an ink ejection data determination unit 103, a processing liquid ejection data determination unit 107, a table storage unit 112, an ink head control unit 113, and a processing liquid head control unit 114. Instead, the operation mode detector 116 is also included.

  The operation mode detection unit 116 detects the operation mode of the inkjet recording apparatus 10 from data regarding the operation mode sent from the host computer 86 via the image data reading unit 102. In the present embodiment, three types of operation modes are prepared: a low speed mode, a high speed mode, and a high speed high image quality mode.

  The table storage unit 112 stores the ink-treatment liquid application amount table used in the first embodiment (see “Embodiment 1” in FIG. 11) and the ink-treatment liquid used in the second embodiment. A plurality of ink-treatment liquids: an application amount table (see “Embodiment 2” in FIG. 11) and an ink-treatment liquid application amount table (see “Embodiment 3” in FIG. 11) used in the third embodiment. A grant amount table is stored.

  The processing liquid application amount calculation unit 110 includes the “total ink amount to be applied to the recording medium 16” calculated by the ink application amount calculation unit 106, and the ink-processing liquid application amount table stored in the table storage unit 112. Based on the above, the total amount of processing liquid to be applied on the recording medium 16 is calculated. At this time, the processing liquid discharge data determination unit 107 determines an ink-processing liquid application amount table used for calculation of the total processing liquid amount according to the operation mode determined by the operation mode detection unit 116. In this embodiment, for example, when the operation mode is the low speed mode, the ink-treatment liquid application amount table of “Embodiment 1” in FIG. 11 is selected, and when the operation mode is the high speed high image quality mode, “Embodiment 2” is selected. The ink-processing liquid application amount table of “Embodiment 3” is selected when the operation mode is the high-speed mode.

  Other configurations are substantially the same as those of the first embodiment described above.

  FIG. 19 is a flowchart showing a series of steps in which ink and processing liquid are applied to the recording medium 16 in the fifth embodiment. First, image data (print data) sent from the host computer 86 is read by the image data reading unit 102 (S31 in FIG. 19). Based on the read image data, the operation mode of the inkjet recording apparatus 10 is detected by the operation mode detection unit 116 (S32).

  On the other hand, in the ink ejection data determination unit 103, the ink application data generation unit 104 calculates the ink application data based on the image data read by the image data reading unit 102 and the operation mode (S33). Based on the ink application data, the total ink application amount for a predetermined area of the divided area on the recording medium 16 is calculated by the ink application amount calculation unit 106 (S34).

  Further, the processing liquid discharge data determination unit 107 selects any of the ink-processing liquid application amount tables stored in the table storage unit 112 based on the detection result of the operation mode by the operation mode detection unit 116. It is determined whether it should be (S35). For example, when the detected operation mode is the “low speed mode”, the ink-treatment liquid application amount table for the low speed mode is selected (see “Embodiment 1” in FIG. 11) (S36). When the detected operation mode is the “high-speed high-quality mode”, the ink-processing liquid application amount table for the high-speed high-quality mode is selected (see “Embodiment 2” in FIG. 11) (S37). When the detected operation mode is the “high speed mode”, the ink-treatment liquid application amount table for the high speed mode is selected (see “Embodiment 3” in FIG. 11) (S38).

  Then, the selected ink-processing liquid application amount table is referred to, and the predetermined area is determined based on the ink-processing liquid application amount table and the total ink application amount for the predetermined area calculated by the ink application amount calculation unit 106. The total applied amount of the processing liquid is calculated by the processing liquid applied amount calculating unit 110 (S39). Further, the processing liquid application data generation unit 108 calculates the processing liquid application data based on the total amount of the processing liquid applied to the predetermined area thus obtained (S40).

  Then, based on the processing liquid total application amount and the processing liquid application data calculated in this way, an applied voltage is applied to the piezoelectric element of the processing liquid ejection head 11 by the processing liquid head control unit 114, and the processing liquid ejection head 11. The processing liquid is discharged from the recording medium 16 toward the recording medium 16 (S41). After that, the ink head controller 113 applies an applied voltage to the piezoelectric element 59 of the ink jet head 50 based on the calculated total applied amount of ink and ink droplet ejection data, and the processing liquid is already applied. Ink is ejected from each of the inkjet heads 50 toward the medium 16 (S42). In this manner, the processing liquid and ink are appropriately applied to the desired position on the recording medium 16, and a desired image is formed.

  As described above, according to the present embodiment, a plurality of ink-treatment liquid application amount tables are selectively used according to the operation mode selected by the user. Therefore, it is possible to print flexibly adapted to user needs.

  The present invention is not limited to the above-described embodiments and modifications thereof, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The described embodiments can also be included in the scope of the present invention.

  For example, in each of the embodiments described above, one processing liquid ejection head 11 is disposed upstream of the printing unit 12 (see FIG. 1), but the arrangement of the processing liquid ejection head is not limited to this example. For example, it is possible to install the treatment liquid discharge head 11 at at least one location between the heads of the printing unit 12 or to install the treatment liquid discharge head 11 for each head of the printing unit 12.

  Further, the means for applying the treatment liquid to the recording medium is not limited to the above-described ink jet type ejection head, but instead of or in combination with this, other members such as rollers, brushes, blades, etc. May be used.

  In each of the above embodiments, an example in which a full-line type head is used has been described. However, other types of heads may be used. For example, it is possible to perform image recording while reciprocating a short recording head such as a shuttle head.

  In the first embodiment described above, the example in which the amount of treatment liquid applied to the recording medium 16 is controlled by the “number of droplets ejected” from the treatment liquid ejection head 11 has been described (see FIG. 13), but this is not limitative. Is not to be done. For example, the amount of treatment liquid applied to the recording medium 16 can be controlled based on the droplet ejection amount per droplet, the thickness of the treatment liquid applied to the recording medium 16, and the like.

FIG. 20 is a diagram illustrating an example of controlling the amount of treatment liquid applied to the recording medium 16 based on the thickness of the treatment liquid applied to the recording medium 16. In the example shown in FIG. 20, the thickness of the processing liquid in the order of the thickness t ₁ of the processing liquid in the low concentration region, the thickness t ₂ of the processing liquid in the middle concentration region, and the thickness t ₃ of the processing liquid in the high concentration region. Is gradually reduced (t ₁ > t ₂ > t ₃ ), the thickness of the processing liquid is controlled by the system control unit 100. Thereby, the application amount of the treatment liquid in the high concentration region becomes smaller than the application amount of the treatment liquid in the low concentration region, and the same operations and effects as those in the first embodiment described above are shown. Note that control of the thickness of the treatment liquid with respect to the recording medium 16 can be realized by an arbitrary method. For example, when the processing liquid is applied to the recording medium 16 with a dividing roller or a brush, the recording medium 16 is adjusted by adjusting the amount of the processing liquid contained in the dividing roller or the pressing force against the recording medium 16. The thickness of the treatment liquid can be controlled.

  Further, when the amount of treatment liquid applied to the recording medium 16 is controlled by changing the amount of treatment liquid ejected per droplet discharged from the treatment liquid ejection head 11, for example, the piezoelectric element of the treatment liquid ejection head 11. It is necessary to change the voltage (voltage waveform) applied to.

  In each of the above-described embodiments, an example in which the printing range of the recording medium 16 is divided into three areas, that is, a low density area, a medium density area, and a high density area according to the density has been described. It is not limited. The present invention can be applied if the printing range of the recording medium 16 is divided into two or more regions according to the density. Further, when the printing range of the recording medium 16 is divided according to the density, the density used as the reference for the classification is not limited to the above-described embodiment, and the printing range is set according to the appropriate density according to the use conditions. It can be divided into areas.

(Specific examples of treatment liquid and ink)
In each of the above-described embodiments, 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 solvent, 0 to 30% by weight of glycerin
・ As a pH adjuster, triethanolamine 0 to 10% by weight
May be included.

  Moreover, the following aqueous solutions can be used as ink containing a coloring material, for example.

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

・ 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.

1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. It is a principal part top view of the printing part periphery of an inkjet recording device. It is a plane perspective view which shows the structural example of an inkjet head. It is a partial enlarged view of an inkjet head. It is a plane perspective view which shows the other structural example of an inkjet head. It is a figure which shows the nozzle arrangement | sequence of a head. It is sectional drawing which follows the 7-7 line | wire of FIG. It is the schematic which showed the structure of the ink supply system in an inkjet recording device. 2 is a block diagram illustrating an example of a system control unit of the inkjet recording apparatus and a hardware configuration around the system control unit. FIG. It is a block diagram which shows the function structure of the system control unit in 1st Embodiment. It is a figure which shows the example of the ink-processing liquid application amount table | surface which shows the relationship between an ink application amount and a process liquid application amount. It is a flowchart which shows a series of processes in which an ink and a process liquid are provided to a recording medium. It is a figure which shows an example of the state of the ink on a recording medium, and a process liquid. It is a figure which shows evaluation of the image formed on the recording medium with the inkjet recording device. It is a figure which shows the ink process liquid application amount table used in 4th Embodiment. It is a figure which shows the ink-treatment liquid application amount table used in the 1st modification of 4th Embodiment. It is a figure which shows the ink-treatment liquid application amount table used in the 2nd modification of 4th Embodiment. It is a block diagram which shows the function structure of the system control unit in 5th Embodiment. 10 is a flowchart illustrating a series of steps in which ink and a treatment liquid are applied to a recording medium in a fifth embodiment. It is a figure which shows the example which controls the application amount of the process liquid with respect to a recording medium based on the thickness of the process liquid provided to a recording medium.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Inkjet recording apparatus, 11 ... Processing liquid discharge head, 12 ... Printing part, 16 ... Recording medium, 50 ... Inkjet head, 59 ... Piezoelectric element, 100 ... System control unit, 102 ... Image data reading part, 103 ... Ink discharge Data determining unit 104 ... Ink application data generating unit 106 ... Ink application amount calculating unit 107 ... Processing liquid ejection data determining unit 108 ... Processing liquid application data generating unit 110 ... Processing liquid application amount calculating unit 112 ... Table Storage unit 113 ... Ink head control unit 114 ... Treatment liquid head control unit 116 ... Operation mode detection unit

Claims (7)

A target liquid applying means for applying a target liquid containing a coloring material to a recording medium;
Treatment liquid application means for applying a treatment liquid for insolubilizing the coloring material to the recording medium;
The application amount of the treatment liquid in the high concentration region on the recording medium in which the application amount of the target liquid per predetermined area is large is the low concentration region on the recording medium in which the application amount of the target liquid per predetermined area is small. Control means for controlling the treatment liquid application means so as to be less than the application amount of the treatment liquid in
An image forming apparatus comprising:   The control means divides the recording medium into a plurality of areas according to the application amount of the target liquid per predetermined area, and the application amount of the treatment liquid to the recording medium is adjusted stepwise according to the areas. The image forming apparatus according to claim 1, wherein the processing liquid application unit is controlled.   The control means controls the treatment liquid application means so that the treatment liquid is also applied to an intermediate concentration region between the high concentration region and the low concentration region on the recording medium. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The control means includes the recording medium in the low concentration region, the high concentration region, and a medium concentration region between the low concentration region and the high concentration region according to the application amount of the target liquid per the predetermined area. The amount of the treatment liquid applied in the medium concentration region is less than the amount of the treatment liquid applied in the low concentration region, and the amount of the treatment liquid applied in the high concentration region is 3. The processing liquid application unit is controlled so as to be larger than an application amount of the processing liquid in an intermediate concentration region and to be less than an application amount of the processing liquid in the low concentration region. The image forming apparatus described in 1.   The control means controls the treatment liquid application means so that the application amount of the treatment liquid is not more than half of the maximum application amount of the target liquid in an area on the recording medium where the application amount of the target liquid is maximum. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled.   The control means applies the treatment liquid application means so that the application amount of the treatment liquid is approximately half of the maximum application amount of the object liquid in an area on the recording medium where the application amount of the object liquid is maximum. The image forming apparatus according to claim 1, wherein the image forming apparatus is controlled. A step of applying a target liquid containing a coloring material to a recording medium;
Applying a treatment liquid for insolubilizing the coloring material to the recording medium, and an image forming method comprising:
The application amount of the treatment liquid in the high concentration region on the recording medium where the application amount of the target liquid per predetermined area is large is set as the low concentration region on the recording medium where the application amount of the target liquid per predetermined area is small. An image forming method, wherein the amount is less than the amount of the treatment liquid applied.