Inkjet recording device and inkjet recording method

Abstract

To provide an inkjet recording device that can improve the scratch resistance of recorded images while suppressing ink consumption by applying transparent ink in proportion to the relationship between the amount of ink applied and the amount of processing solution applied, in gradations where a large amount of processing solution is applied for image performance. [Solution] The amount of transparent ink applied in a second recording gradation where the amount of colored ink applied to each predetermined area is a second amount and the ratio of the applied amounts is the second ratio is greater than the amount of transparent ink applied in a first recording gradation where the amount of colored ink applied to each predetermined area is a first amount which is less than the second amount and the ratio of the applied amounts is a first ratio which is smaller than the second ratio, and the amount of transparent ink applied in a second recording gradation where the amount of colored ink applied to each predetermined area is a second amount is greater than the amount of transparent ink applied in a third recording gradation where the amount of colored ink applied to each predetermined area is a third amount which is more than the second amount and the ratio of the applied amounts is a third ratio which is smaller than the second ratio.

Description

Technical Field

[0001] The present invention relates to a recording apparatus and a recording method for forming an image by ejecting ink.

Background Art

[0002] In recent years, inkjet recording apparatuses using pigment ink have become capable of achieving both high color development comparable to dye ink and image fastness such as image strength and long-term storage properties due to advancements in manufacturing technology. Therefore, in addition to photographic applications with high requirements for long-term storage of recorded images, it has been widely used in mass posting applications such as outdoor / POP posters, facility signs, and displays. In such large-format printing images, there is also a high demand for high productivity. Furthermore, in order to reduce the printing costs for a variety of small quantities, there is an increasing demand for inkjet recording on printing paper, which is coated paper for commercial / publishing printing, polyvinyl chloride sheets (hereinafter referred to as vinyl sheets) used for wallpapers and tarpaulins, etc.

[0003] For these recording media, there is an inkjet recording method that improves the recording quality by ejecting a treatment liquid that aggregates by reacting with a colored ink containing a coloring material and reacting it with the colored ink on the recording media. By using the treatment liquid, the components of the composition of the colored ink such as pigments aggregate and are fixed on the recording media, thereby making it possible to improve the recording quality.

[0004] On the other hand, it is known that the smoothness of the coating film and the abrasion resistance decrease by aggregating the ink composition using the treatment liquid.

[0005] Regarding such problems, for example, according to Patent Document 1, a technique has been proposed to improve the abrasion resistance over all recording gradations by applying a transparent ink in an amount corresponding to the recording gradation, that is, the amount of colored ink applied.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2008-149514, Canon Inc. [Overview of the project] [Problems that the invention aims to solve]

[0007] The decrease in scratch resistance of recorded images varies depending on the ratio of the amount of colored ink to the processing solution applied. Therefore, the required amount of transparent ink also varies depending on the ratio of the colored ink to the processing solution applied. Consequently, determining the amount of transparent ink to be applied according to the recording gradation can result in applying more transparent ink than necessary depending on the recording gradation, leading to issues such as increased drying load and running costs.

[0008] This invention has been made in view of the above-mentioned problems. When applying a processing solution to maintain recording quality, the aim is to suppress the reduction in scratch resistance that tends to occur in certain gradations by applying an appropriate amount of transparent ink containing resin according to the ratio of the amount of colored ink to the amount of processing solution applied, using a smaller amount of transparent ink. [Means for solving the problem]

[0009] A recording head comprising: a plurality of discharge ports for dispensing colored ink containing resin particles and colorants; a plurality of discharge ports for dispensing transparent ink containing resin particles but without colorants; and a plurality of discharge ports for dispensing a processing liquid containing reactive components that react with the resin particles and colorants in the colored ink and the resin particles in the transparent ink to cause aggregation or gelation; The recording head is provided with an application amount determination means for determining the amount of colored ink, transparent ink, and processing liquid applied to each predetermined area of ​​the recording medium, The amount-to-apply means determines the amount of transparent ink and the amount of processing solution to be applied for at least three different recording gradations with varying ratios of the amount of processing solution applied to the colored ink, characterized in that the amount of transparent ink applied in a second recording gradation where the amount of colored ink applied in each predetermined region is a second amount and the ratio of the application amounts is the second ratio is greater than the amount of transparent ink applied in a first recording gradation where the amount of colored ink applied in each predetermined region is a first amount less than the second amount and the ratio of the application amounts is a first ratio smaller than the second ratio, and the amount of transparent ink applied in a second recording gradation where the amount of colored ink applied in each predetermined region is a second amount is greater than the amount of transparent ink applied in a third recording gradation where the amount of colored ink applied in each predetermined region is a third amount greater than the second amount and the ratio of the application amounts is a third ratio smaller than the second ratio. [Effects of the Invention]

[0010] According to the present invention, in recording gradations where the ratio of the processing solution applied to the total amount of ink applied per unit area tends to be high, and a decrease in scratch resistance is likely to occur, the required amount of transparent ink is applied to the required area. As a result, while suppressing the amount of transparent ink applied, the decrease in scratch resistance is suppressed, and a highly robust recorded image can be obtained across the entire gradation range. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view and a cross-sectional view showing the configuration of the inkjet recording device in the first embodiment. [Figure 2] This is a schematic diagram of the recording head in the first embodiment as seen from the discharge port side. [Figure 3] This is a schematic diagram showing the recording control system in the first embodiment. [Figure 4] This is a flowchart illustrating the image data processing process in the first embodiment. [Figure 5]This figure shows a table that stores the relationship between the amount of colored ink applied and the amount of processing solution applied in the first embodiment, and a figure that shows the relationship between the amount of colored ink applied and the ratio of the amount of processing solution applied to the amount of colored ink applied. [Figure 6] The first embodiment includes a diagram showing a table that stores the relationship between the amount of colored ink dispensed and the amount of transparent ink dispensed, and a diagram showing the relationship between the amount of colored ink dispensed and the ratio of the total amount of processing solution dispensed (the total amount of processing solution for colored ink and transparent ink) to the total amount of ink dispensed (the total amount of colored ink and transparent ink dispensed). [Figure 7] This is a diagram showing the image data used in the second embodiment. [Figure 8] This is a flowchart showing the image data processing process in the second embodiment. [Figure 9] The diagram shows a table storing the relationship between the amount of colored ink dispensed and the amount of transparent ink dispensed in the third embodiment, and a diagram showing the relationship between the amount of colored ink dispensed and the ratio of the total amount of processing solution dispensed (the total amount of processing solution for colored ink and transparent ink) to the total amount of ink dispensed (the total amount of colored ink and transparent ink dispensed). [Modes for carrying out the invention]

[0012] An embodiment of the present invention will be described with reference to the drawings.

[0013] (Form of the first embodiment) The first embodiment will be described below.

[0014] This explanation will use an inkjet recording device as an example. The recording device may be, for example, a single-function printer that only has a recording function, or it may be a multi-function printer that has multiple functions such as a recording function, a fax function, and a scanner function. It may also be a manufacturing device for producing, for example, color filters, electronic devices, optical devices, microstructures, etc., using a predetermined recording method.

[0015] In the following description, "recording" not only means forming significant information such as characters and figures, but also includes cases regardless of whether the information is significant or not. Further, it represents cases where images, patterns, structures, etc. are formed on a recording medium widely, or the medium is processed, regardless of whether or not it is manifested so that it can be perceived visually by humans.

[0016] Also, the "recording medium" not only represents paper used in general recording devices, but also includes cloth, plastic film, metal plate, glass, ceramics, resin, wood, leather, etc., which can receive ink. Further, examples of non-absorbent recording media include those not manufactured as recording media for aqueous inkjet ink, such as glass, plastic, film, and Yupo. Also, for example, those that have not been surface-treated for inkjet printing (i.e., have not formed an ink absorption layer), such as those with plastic coated on a base material such as plastic film or paper, are included. Examples of plastics include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc. Also, specific examples of low-absorbent recording media include recording media such as printing paper used in offset printing, such as art paper and coated paper.

[0017] When the transfer amount of aqueous ink was measured for general printing coated paper by the known Bristol method, the transfer amount at a transfer time of 1 second was 20 ml / m2 or less. However, although many transfer amounts measured by the Bristol method for inkjet dedicated paper show 30 ml / m2 or more, there are also some with a transfer amount of 20 ml / m2 or less. Such a recording medium can be said to be a low-absorbent recording medium although it is an inkjet dedicated paper. That is, for low-absorbent recording media not limited to printing coated paper, the effects can be obtained by using the present invention for general recording media as well.

[0018] (Overall Configuration) Figure 1(a) is a perspective view showing a partially disassembled portion of the inkjet recording apparatus 100 of this embodiment to illustrate its internal mechanism, and Figure 1(b) is a cross-sectional view. As shown in Figure 1, the recording medium 12 is transported in the -Y direction in the figure by the drive of a sub-scanning motor (not shown). The guide shaft 13 is also arranged to extend in the X direction, which intersects with the transport direction of the recording medium 12. The carriage 11, which is equipped with a recording head 15 positioned opposite the platen 10, is supported by the guide shaft 13 and moves back and forth along the X axis in the figure (reciprocating scan) by the drive of a main scanning motor (not shown). The recording head 15 mounted on the carriage 11 ejects ink onto the recording medium 12 according to the recording data during the movement and scanning of the carriage 11, and recording is performed on the recording medium 12.

[0019] In the inkjet recording device 100 of this embodiment, a so-called bidirectional recording method is employed, in which ink is ejected and recorded on the recording medium whether the recording head 15 is moving along the forward path or along the return path. When a scan accompanied by one recording by the recording head 15 is performed, the recording medium 12 is transported by a sub-scanning motor (not shown) by a predetermined amount. The main scanning speed is variable and can scan at 10 to 70 inches per second. The recording resolution is also variable and can be performed at 300 to 2400 Dpi. After the above-mentioned scan, the recording medium 12 is transported and then recording is performed for the next bandwidth.

[0020] When a recording command is input from an externally connected host computer (external device), the recording medium 12 is fed to a recordable position by the recording head 15 mounted on the carriage 11. Subsequently, an image is formed by alternately repeating the main scanning operation of the recording head 15 while ejecting ink in accordance with the recording signal, and the transport operation of a predetermined amount of the recording medium 12. Furthermore, the image formed on the recording medium 12 on the platen 10 is transported along the transport direction, and hot air is applied by a heating mechanism 14 consisting of a hot air fan, heating the recording medium to 100°C and fixing it by heating. This heating unit also has a function to heat and form a film of water-soluble resin particles, which will be described later, within the recording device. These water-soluble resin particles are resins that form a film when heated after being applied to the recording medium, improving the scratch resistance of the image.

[0021] The recording head 15 will now be described in detail. As shown in Figure 2, the recording head 15 has a row of ejection ports for one color, arranged in the Y direction with a density of 1200 ports per inch and 1280 ports in total. Figure 2 is a view of the recording head 15 as seen from the ejection port surface. In the first embodiment, six ejection port row forming substrates are mounted, each comprising an ejection port row 21R for processing liquid, an ejection port row 21K for black, an ejection port row 21C for cyan, an ejection port row 21M for magenta, an ejection port row 21Y for yellow, and an ejection port row 21CL for transparent ink. In this embodiment, in addition to the colored inks, there is a transparent ink containing resin fine particles but no colorant, and a processing liquid containing a reactant that reacts with solid components such as colorants and resin fine particles contained in each ink to promote their aggregation. Details of each ink will be described later. The ejection amount of each ink ejected from each ejection port 20 is approximately 4.5 pl. However, this is not the only option; different settings may be used for the colored ink, processing solution, and transparent ink, or the amount of ink dispensed may be changed within the colored ink. The recording head 15 dispenses ink from the discharge port 20 using a means of generating discharge energy, such as an electrothermal converter (heater) or a piezoelectric element. When an electrothermal converter is used, the heat generated causes the water in the ink to foam, and the foaming energy can be used to dispense the ink. Furthermore, these rows of discharge ports do not necessarily have to be formed on the same recording head and may be separated. Each of these rows of discharge ports is connected to an ink tank (not shown) that stores the corresponding ink, and ink is supplied. The recording head 15 and ink tank used in this embodiment may be configured as an integral unit, or they may be configured to be separable.

[0022] During image recording, the system repeatedly performs a recording operation in which ink is ejected from the recording head 15 while the carriage 11 moves in the X direction, and a transport operation in which a predetermined amount of the recording medium 12 is transported in the transport direction. Furthermore, a multi-pass recording method can also be employed, which involves scanning the same area on the recording medium multiple times to perform the recording. By employing such multi-pass recording, variations in the ejection characteristics of each ejection port and the amount of recording medium transported can be distributed across the entire recorded image, making these variations less noticeable.

[0023] In this embodiment, the recording head 15 is moved in the X direction while processing liquid, black, cyan, magenta, yellow, and transparent ink are applied to the recording medium in that order by forward scanning to record one scan's worth of image. If a unidirectional recording method is adopted, the recording medium 12 is then transported by a predetermined amount, and the recording head 15 is moved in the -X direction to return to its original home position, and the next scan's worth of image is recorded again by forward scanning. On the other hand, if bidirectional recording is adopted, the recording medium 12 is transported by a predetermined amount after the forward scanning, and then the recording head 15 is moved in the -X direction of arrow X while ejecting ink. That is, the transparent ink, yellow, magenta, cyan, black ink, and processing liquid are applied to the recording medium in that order (return scanning) to record the next scan's worth of image. The processing liquid can fully demonstrate its performance by being applied to the recording medium before the colored and transparent inks. During the return scan of the recording head 15, the processing liquid is applied to the recording medium after the colored and transparent inks, so there is a risk that the function of the processing liquid will not be fully demonstrated. This is particularly undesirable in a one-pass recording method, where the recording head 15 is scanned once over the same area on the recording medium. In the case of multi-pass recording, where the same area on the recording medium is recorded by scanning it two or more times, the processing solution only needs to be applied during the first scan, and the performance of the processing solution can be fully utilized even when a bidirectional recording method is adopted. In particular, in the case of multi-pass recording, where the same area on the recording medium is recorded by scanning it two or more times, the more transparent ink is applied during subsequent scans, the more fully the performance of the transparent ink can be utilized.

[0024] In the block diagram of the control system in the recording device shown in Figure 3, 311 is an image input unit (interface) that receives various image data. This image data includes, for example, multi-level image data from image input devices such as scanners and digital cameras, and multi-level image data stored on various recording media such as hard disks. 300 is an image processing unit that converts the multi-level image data input to the image input unit 311 into binary image data through image processing described later. This binary image data includes image data for black, cyan, magenta, yellow, transparent ink, and processing liquid. 301 is a CPU that controls the various parts of the recording device. 302 is a ROM for storing control programs and error handling programs executed by the CPU 301. 303 is a RAM for temporarily storing various data (such as image data and recording signals supplied to the recording head). 304 is a gate array 304 that controls the supply of image data to the recording head 15, and also controls data transfer between the image input unit 311, the CPU 301, and the RAM 303.

[0025] 30 is an image output unit, which receives the binary image data converted by the image processing unit 300 and records the image. 310 is a main scanning motor (CR motor) for moving the recording head 15, and 309 is an LF motor for transporting the recording medium 12. 305 and 306 are motor drivers for driving the LF motor 309 and the CR motor 310, respectively. 307 is a head driver for driving the recording head 15. The recording signal input through the image input unit 311 is converted into binary image data by the gate array 304 and the CPU 301. Then, the LF motor 309 and the CR motor 310 are driven via the motor drivers 305 and 306, and the recording head 15 is driven based on the binary recording data sent to the head driver 307, thereby recording the image.

[0026] Figure 4 is a flowchart illustrating the image processing in the image processing unit 300. In Figure 4, rectangular blocks represent image processing steps, and parallelogram blocks represent data.

[0027] First, in step S401, multi-level input image data in RGB format is input from the image input unit 31. In step S402, the input image data is converted into multi-level colored ink data corresponding to each of the multiple types of colored inks (C, M, Y, K) used for recording the image by ink color separation processing by the ink color separation processing means. Specifically, while referring to a color conversion lookup table (3D-LUT), the input image data in step S401 is converted into multi-gradation data (colored ink data) of multiple ink colors usable by the recording device for each predetermined area. Furthermore, the amount of colored ink processing solution to be applied is determined from the sum of the colored inks in each pixel, and it is converted into 8-bit image data corresponding to that amount. Details regarding the data generation of the colored ink processing solution will be described later. The number of dimensions of the lookup table means the number of components of the input image data. In this embodiment, since the input image data has three components, R, G, and B, a 3D (Dimension)-LUT is used. The CMYK data generated in step 403 is, for example, 8-bit data with approximately 256 gradation levels, and at this stage has a resolution of 600 dpi. The recording device performs gradation representation for each 4x2 recording area, consisting of 4 pixels in the X direction and 2 pixels in the Y direction, in order to support the 2400 dpi x 1200 dpi recording mode. In other words, gradation representation is performed for each unit area (unit area) corresponding to a resolution of 600 ppi x 600 ppi. Now, let's explain the recording duty cycle. For example, if we define one pixel as a unit area corresponding to a resolution of 1200 dpi x 1200 dpi, the recording duty cycle is an indicator that shows how many dots of a size large enough to fill that one pixel are formed for that one pixel. A recording duty cycle of 100% is defined as a state where one dot is formed per pixel.

[0028] In step S404, the transparent ink and transparent ink processing solution data generation process sets the amount of transparent ink and transparent ink processing solution to be applied, based on a table that stores the relationship between the amount of colored ink applied and the amount of transparent ink processing solution to be applied for each type of recording medium, and generates 8-bit image data corresponding to that amount.

[0029] In step S406, the multi-level CMYK data corresponding to various inks, the processing solution data for CMYK, the transparent ink, and the processing solution data for transparent ink are converted into binary bitmap data of various inks and processing solutions by a binarization processing means, according to the binarization pattern stored in the binarization pattern storage means. This generates binary image data for assigning multiple types of inks (C, M, Y, K), transparent ink, and processing solutions.

[0030] In step S408, based on the image data generated in steps 403 and 405, binary recording data for driving the recording head is generated by the ejection data generation process for colored ink, processing liquid, and transparent ink.

[0031] (Ink composition) Next, the composition of the ink and water-soluble resin particle ink used in this embodiment will be described. Hereinafter, "parts" and "%" refer to mass unless otherwise specified.

[0032] 1. Ink composition The composition of each ink is described in detail below.

[0033] The colored inks (K, C, M, Y), transparent ink, and processing solution (RCT) used in this embodiment all contain a water-soluble organic solvent. For reasons of wetting and moisturizing the recording head face, the water-soluble organic solvent is preferably one with a boiling point between 150°C and 300°C. Furthermore, from the viewpoint of its function as a film-forming aid for resin particles and its swelling solubility in the recording medium on which the resin layer is formed, ketone compounds such as acetone and cyclohexanone, ethylene glycol derivatives such as tetraethylene glycol dimethyl ether, and heterocyclic compounds having a lactam structure, such as N-methyl-pyrrolidone and 2-pyrrolidone, are particularly preferred. From the viewpoint of discharge performance, the content of the water-soluble organic solvent is preferably between 3 wt% and 30 wt%. Specifically, water-soluble organic solvents include, for example, alkyl alcohols having 1 to 4 carbon atoms, such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; and amides such as dimethylformamide and dimethylacetamide. Ketones or keto alcohols such as acetone and diacetone alcohol. Ethers such as tetrahydrofuran and dioxane. Polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Alkylene glycols containing 2 to 6 carbon atoms in an alkylene group, such as ethylene glycol, propylene glycol, butylene glycol, triethylene glycol, 1,2,6-hexanetriol, thiodiglycol, hexylene glycol, and diethylene glycol. Lower alkyl ether acetates such as polyethylene glycol monomethyl ether acetate. Glycerin. Lower alkyl ethers of polyhydric alcohols such as ethylene glycol monomethyl (or ethyl) ether, diethylene glycol methyl (or ethyl) ether, and triethylene glycol monomethyl (or ethyl) ether. Polyhydric alcohols such as trimethylolpropane and trimethylolethane. Examples include N-methyl-2-pyrrolidone, 2-pyrrolidone, and 1,3-dimethyl-2-imidazolidinone. The above-mentioned water-soluble organic solvents can be used individually or in mixtures. It is also desirable to use deionized water as the water.The content of the water-soluble organic solvent in the treatment solution (RCT) is not particularly limited, but in addition to the above components, defoaming agents, preservatives, fungicides, etc. may be added to the colorant inks (K, C, M, Y) as needed to give them desired physical properties.

[0034] Furthermore, the colored inks (K, C, M, Y), transparent ink, and processing solution (RCT) used in this embodiment all contain surfactants. Surfactants are used to improve the wetting spread of the ink onto the recording medium. The more surfactant added, the stronger the property of lowering the surface tension of the ink, and the better the wetting spread of the ink onto the recording medium. In this embodiment, a small amount of acetylene glycol EO adduct or the like was added as a surfactant to adjust the static surface tension of each ink to 30 dyn / cm or less, and further, to keep the difference in static surface tension between the colored inks within 2 dyn / cm. More specifically, the static surface tension of all the colored inks was adjusted to approximately 22-24 dyn / cm. A fully automatic surface tensimeter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the static surface tension of the inks. Note that the measuring instrument is not limited to the example given above, as long as it can measure the static surface tension of the inks.

[0035] Furthermore, the pH of each colorant ink in this embodiment is stable on the alkaline side, with a value of 8.5 to 9.5. From the viewpoint of preventing the elution and deterioration of components that come into contact with each colorant ink in the recording device and recording head, and the decrease in the solubility of the dispersed resin in the colorant ink, it is preferable that the pH of each colorant ink be between 7.0 and 10.0. pH was measured using a pH METER model F-52 manufactured by Horiba, Ltd. Note that the measuring instrument is not limited to the example given above, as long as it is capable of measuring the pH of the ink.

[0036] 2. Water-soluble resin emulsion The colored and transparent inks used in this embodiment contain a water-soluble resin emulsion.

[0037] In this embodiment, "water-soluble resin emulsion" refers to polymer microparticles that exist in a dispersed state in water. Specifically, examples include acrylic resin particles synthesized by emulsion polymerization of monomers such as alkyl (meth)acrylate or alkyl (meth)acrylate amide; styrene-acrylic resin particles synthesized by emulsion polymerization of monomers such as alkyl (meth)acrylate or alkyl (meth)acrylate amide with styrene; polyethylene resin particles, polypropylene resin particles, polyurethane resin particles, and styrene-butadiene resin particles. Furthermore, core-shell type resin particles in which the polymer composition differs between the core and shell parts constituting the resin particle, or resin particles obtained by using pre-synthesized acrylic microparticles as seed particles to control particle size and emulsion polymerization around them, are also acceptable. Moreover, hybrid type resin particles in which different resin particles, such as acrylic resin particles and urethane resin particles, are chemically bonded are also acceptable.

[0038] 3. Lubricant The colored and transparent inks used in this configuration contain a lubricant.

[0039] In this embodiment, "lubricant" refers to wax particles or silicone oil. Specifically, examples of wax particles include synthetic wax particles such as Fischer-Tropsch wax (EMUSTAR-6315) manufactured by Nippon Seiro Co., Ltd. and polyolefin wax (Hi-Tec E-9500) manufactured by Toho Chemical Industry Co., Ltd., as well as natural wax particles such as carnauba wax (Cerosol 524) manufactured by Chukyo Oils Co., Ltd. and paraffin wax (AQUACER 497) manufactured by BIC Chemie Japan Co., Ltd. Silicone oil may also be used as a lubricant, for example, polyether-modified silicone (BYK333) manufactured by BIC Chemie Japan Co., Ltd.

[0040] 4. Reactant In this embodiment, a system is employed, if necessary, that uses a processing solution to insolubilize some or all of the solid components of the colored and transparent inks in order to solve image problems such as bleeding and beading.

[0041] To insolubilize dissolved dyes, dispersed pigments, and resins, the reactants in the treatment solution may include, for example, polyvalent metal ions (e.g., magnesium sulfate, magnesium nitrate, magnesium chloride, calcium emulsion, aluminum sulfate, iron chloride, etc.). As one type of flocculation using such cations, a system using a low molecular weight cationic polymer flocculant can also be used for the purpose of neutralizing the charge of water-soluble resin emulsions and insolubilizing anionic soluble substances.

[0042] Another reaction system involves an insolubilization system using a treatment solution that utilizes a difference in pH. As mentioned earlier, most colored inks used in inkjet recording are stable on the alkaline side due to the properties of their colorants, and the pH is generally between 7.0 and 10.0. From an industrial standpoint and considering the influence of the external environment, it is often set to around 8.5 to 9.5. To agglomerate and solidify such colored inks, an acidic solution can be mixed in, and by changing the pH, the stable state can be disrupted and the dispersed components can be agglomerated. Acidic solutions can also be used as treatment solutions for this purpose.

[0043] The following describes how to prepare each ink and processing solution.

[0044] Preparation of resin particle dispersion In the first embodiment, the resin particle dispersion was first heated to 70°C under a nitrogen atmosphere and stirred while gradually adding the following three additive solutions dropwise, and polymerization was carried out for 5 hours. Each additive solution was a mixture containing a hydrophobic monomer consisting of 28.5 parts methyl methacrylate, a hydrophilic monomer consisting of 4.3 parts sodium p-styrene sulfonate and 30 parts water, and a polymerization initiator consisting of 0.05 parts potassium persulfate and 30 parts water. In this way, a 20% by mass resin particle dispersion was obtained.

[0045] Black ink (1) Preparation of dispersion First, an anionic polymer P-1 [styrene / butyl acrylate / acrylic acid copolymer (polymerization ratio (by weight) = 30 / 40 / 30), acid value 202, weight-average molecular weight 6500] was prepared. This was neutralized with potassium hydroxide aqueous solution and diluted with deionized water to prepare a homogeneous 10% by mass polymer aqueous solution.

[0046] 600 g of the above polymer solution, 100 g of carbon black, and 300 g of deionized water were mixed and mechanically stirred for a predetermined time. Then, non-dispersed material containing coarse particles was removed by centrifugation to obtain a black dispersion. The resulting black dispersion had a pigment concentration of 10% by mass.

[0047] (2) Preparation of ink The ink was prepared by using the black dispersion described above and adding the following components to it to the desired concentration. After thoroughly mixing and stirring these components, the mixture was pressure filtered through a 2.5 μm pore size microfilter (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 2% by mass.

[0048] 20 parts of the above black dispersion. 40 parts of the above resin particle dispersion. Wax particles (3 parts) Zonyl FSO-100 (DuPont fluorine-based surfactant) 0.05 parts 2-methyl-1,3-propanediol 15 parts 2-Pyrrolidone Part 5 Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 parts Deionized water remaining

[0049] Cyan ink (1) Preparation of dispersion First, using benzyl acrylate and methacrylic acid as raw materials, an AB-type block polymer with an acid value of 250 and a number-average molecular weight of 3000 was prepared by a conventional method. This polymer was then neutralized with an aqueous potassium hydroxide solution and diluted with deionized water to prepare a homogeneous 50% by mass polymer aqueous solution.

[0050] 200 g of the above polymer solution, 100 g of 15:3 CI pigment blue, and 700 g of deionized water were mixed and mechanically stirred for a predetermined time. Then, non-dispersed material containing coarse particles was removed by centrifugation to obtain a cyanide dispersion. The resulting cyanide dispersion had a pigment concentration of 10% by mass.

[0051] (2) Preparation of ink The ink was prepared by using the above-mentioned cyanide dispersion and adding the following components to it to the desired concentration. After thoroughly mixing and stirring these components, the mixture was pressure-filtered through a 2.5 μm pore size microfilter (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 2% by mass.

[0052] 20 parts of the above cyanide dispersion. 40 parts of the above resin particle dispersion. Wax particles (3 parts) Zonyl FSO-100 (DuPont fluorine-based surfactant) 0.05 parts 2-methyl-1,3-propanediol 15 parts 2-Pyrrolidone Part 5 Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 parts Deionized water remaining

[0053] Magenta ink (1) Preparation of dispersion First, using benzyl acrylate and methacrylic acid as raw materials, an AB-type block polymer with an acid value of 300 and a number-average molecular weight of 2500 was prepared by a conventional method. This polymer was then neutralized with potassium hydroxide aqueous solution and diluted with deionized water to prepare a homogeneous 50% by mass polymer aqueous solution.

[0054] 100 g of the above polymer solution, 100 g of CI Pigment Red 122, and 800 g of deionized water were mixed and mechanically stirred for a predetermined time. Then, non-dispersed material containing coarse particles was removed by centrifugation to obtain a magenta dispersion. The resulting magenta dispersion had a pigment concentration of 10% by mass.

[0055] (2) Preparation of ink The ink was prepared by using the magenta dispersion described above and adding the following components to it to the desired concentration. After thoroughly mixing and stirring these components, the mixture was pressure filtered through a 2.5 μm pore size microfilter (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 3% by mass.

[0056] 30 parts of the above magenta dispersion 40 parts of the above resin particle dispersion. Wax particles (3 parts) Zonyl FSO-100 (DuPont fluorine-based surfactant) 0.05 parts 2-methyl-1,3-propanediol 15 parts 2-Pyrrolidone Part 5 Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 parts Deionized water remaining

[0057] • Yellow ink (1) Preparation of dispersion First, the anionic polymer P-1 was neutralized with an aqueous potassium hydroxide solution and diluted with deionized water to prepare a homogeneous 10% by mass polymer aqueous solution.

[0058] 300 g of the above polymer solution, 100 g of CI Pigment Yellow 74, and 600 g of deionized water were mixed and mechanically stirred for a predetermined time. Then, non-dispersed material containing coarse particles was removed by centrifugation to obtain a yellow dispersion. The resulting yellow dispersion had a pigment concentration of 10% by mass.

[0059] (2) Preparation of ink The following components were mixed, thoroughly stirred to dissolve and disperse, and then pressure filtered through a 1.0 μm pore size microfilter (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 3% by mass.

[0060] 30 parts of the above yellow dispersion. 40 parts of the above resin particle dispersion. Wax particles (3 parts) Zonyl FSO-100 (DuPont fluorine-based surfactant) 0.025 parts 2-methyl-1,3-propanediol 15 parts 2-Pyrrolidone Part 5 Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 1 part Deionized water remaining

[0061] • Transparent ink The transparent ink of this embodiment is prepared by adding the following components to reach a predetermined concentration. After thoroughly mixing and stirring these components, the mixture is pressure filtered through a 2.5 μm pore size microfilter (manufactured by Fujifilm Corporation) to prepare a transparent ink with a resin particle concentration of 12% by mass.

[0062] 60 parts of the above resin particle dispersion. Wax particles (3 parts) Zonyl FSO-100 (DuPont fluorine-based surfactant) 0.05 parts 2-methyl-1,3-propanediol 15 parts 2-Pyrrolidone Part 5 Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 parts Deionized water remaining

[0063] • Processing liquid The processing solution used in this embodiment contains a reactant that reacts with the pigment contained in the ink to cause the pigment to agglomerate or gel. In this embodiment, a polyvalent metal salt was used as the reactant, specifically magnesium sulfate heptahydrate.

[0064] It is not necessary to use magnesium sulfate heptahydrate; in this embodiment, various water-soluble organic acids and polyvalent metal salts can be used as reactants in the treatment solution. The content of organic acids and polyvalent metal salts is preferably 0.1% by mass or more and 90.0% by mass or less, and more preferably 1.0% by mass or more and 70.0% by mass or less, based on the total mass of the composition contained in the treatment solution.

[0065] It is not necessary to use magnesium sulfate; in this embodiment, various organic acids and polyvalent metal salts can be used as reactive components in the treatment solution, as long as they are water-soluble. The content of organic acids and polyvalent metal salts is preferably 0.1% by mass or more and 90.0% by mass or less, and more preferably 1.0% by mass or more and 70.0% by mass or less, based on the total mass of the composition contained in the treatment solution.

[0066] (1) Preparation of the treatment solution In this embodiment, as described above, magnesium sulfate heptahydrate was used and the following components were mixed to prepare the treatment solution.

[0067] Magnesium sulfate heptahydrate 4 parts 1,2-Butanediol 10 parts Acetylene glycol EO adduct 0.5 parts (Manufactured by Kawaken Fine Chemical Co., Ltd.) Ion-exchanged water, remaining portion

[0068] (Evaluation method) ·Abrasion resistance The evaluation and evaluation criteria for abrasion resistance after image recording in this embodiment are shown below.

[0069] The evaluation machine used was a device conforming to the Type II friction tester (JSPS type) specified in the JIS L-0849 method for testing colorfastness against friction, which is also commonly used for "friction resistance and abrasion tests" of inks. Test pieces, which had solid images recorded on PVC sheets with varying amounts of black ink and then heat-fixed, were attached to a curved surface. The transfer to the cloth and the degree of abrasion of the image recording area were evaluated by visual observation when the cloth was rubbed back and forth 150 times with a white cotton cloth fixed to a friction element.

[0070] (Setting the amount of processing solution to be applied for colored inks) The following describes in detail a suitable processing solution and method for determining the amount of transparent ink to be applied when performing the image recording method of this embodiment.

[0071] First, we will describe the colored ink processing solution data generation process, which determines information regarding the processing solution to be applied to each predetermined area of ​​the recording medium based on information about the amount of colored ink applied. Figure 5(a)A is a diagram illustrating the contents of the processing solution data lookup table used in step 404 for a recording made on a vinyl chloride sheet IJ1220-10 (3M Japan Ltd.) using the inkjet recording device of the first embodiment of the present invention, which was used in the processing solution image data generation process in this embodiment. Figure 5(b) shows the relationship between the amount of colored ink applied and the ratio of the amount of processing solution applied to each pixel when using the lookup table shown in Figure 5(a). Here, the amount of colored ink applied refers to the total amount of colored ink applied to each predetermined area of ​​the recording medium. The control system in Figure 3 controls the amount of processing solution applied according to the amount of colored ink applied based on this relationship. Note that the optimal relationship between the amount of colored ink and the amount of processing solution applied varies depending on the recording medium and recording mode. Therefore, typically, multiple tables corresponding to each recording mode are pre-prepared in the ROM 302. The control unit processes the data by referring to the appropriate lookup table according to the set recording mode. This table, which consists of the relationship between the amount of colored ink applied and the amount of processing solution applied, is determined for each recording condition, taking into consideration the granularity of the recorded image and the suppression of bleeding. The details are described below.

[0072] Generally, in the midtone region, where the granularity of the recorded image is particularly susceptible to change due to the proximity of ink dots, the increase in granularity can be suppressed by applying the same amount of processing solution as the colored ink. In this case, it is more desirable that the processing solution dots overlap with the colored ink dots. In the low-gradation region, where the total duty cycle of the colored ink is lower than in the gradation region, the probability of adjacent dots being present is lower even without applying as much processing solution as in the midtone region, so an increase in granularity is less likely to occur. When recording on a vinyl chloride sheet IJ1220-10 with the inkjet recording device of the first embodiment of the present invention, the table showing the relationship between the amount of colored ink applied and the amount of processing solution for colored ink required when considering granularity is shown in Figure 5(a)B.

[0073] The table of processing solution amounts necessary to suppress the increase in granularity described above is obtained by reading recorded images using a pattern for detecting the granularity state and an image scanner. The optimal amount of processing solution for a given amount of colored ink is determined using a judgment image in which a pattern is placed with predetermined amounts of colored ink and processing solution applied to a predetermined area. For the evaluation method of granularity, for example, Graininess (compliant with ISO 13660) as an evaluation scale for the granularity of solid images was used. In addition, Scotchcal Graphical Film IJ1220N (glossy specification, 3M Japan Ltd.), an inkjet recording medium for outdoor signage applications, was used as the recording medium. In the judgment image, among the patterns in which the amount of processing solution varies for each amount of colored ink, images are read sequentially from the pattern with the largest amount of processing solution to the pattern with the smallest amount of processing solution. The amount of processing solution just before the granularity changes by a predetermined amount is considered to be the condition with the smallest amount of processing solution without image defects, and the necessary amount of processing solution is determined. While an Epson ES-2200 image scanner was used to measure graininess, the measuring instrument is not limited to this one, as long as it is capable of measuring graininess.

[0074] On the other hand, in the gradation region, where the total duty cycle of the colored ink is greater than in the halftone region, a processing solution is required to suppress bleeding in adjacent color regions. In this gradation region, the color dots overlap and form an ink film, so the need to apply a processing solution to reduce granularity is reduced. Also, from the viewpoint of increasing ink costs and drying load, it is desirable to reduce the amount of processing solution applied as much as possible. When recording on a vinyl chloride sheet IJ1220-10 with the inkjet recording device of the first embodiment of the present invention, the table showing the relationship between the amount of colored ink applied and the amount of processing solution applied for the colored ink, considering bleed performance, is shown in Figure 5(a)C.

[0075] The table of processing solution amounts necessary to suppress the bleeding described above is obtained by reading the pattern for detecting the bleeding state and the changes in the output value of the optical sensor, and evaluating the clarity of the boundary. A first colored ink is applied as the background color to a predetermined area, and a second colored ink is applied as the fine line color to the adjacent area, and the processing solution is applied to the entire pattern. Using a judgment image in which this pattern is arranged for predetermined amounts of colored ink and processing solution, the optimal amount of processing solution for a predetermined combination of the first and second colored inks is determined. In such a pattern, the change in the output of the optical sensor becomes large when the bleeding phenomenon occurs. In the judgment image, among the patterns in which the amount of processing solution varies for each amount of colored ink, the output values ​​are read sequentially from the pattern with the largest amount of processing solution to the pattern with the smallest amount of processing solution. The amount of processing solution just before the output value changes by more than a predetermined amount is considered to be the condition with the smallest amount of processing solution without image distortion, and the necessary amount of processing solution is determined.

[0076] The recorded judgment images need to be read, and the results need to be fed back to the control means. The reading means could be configured to include measuring devices for evaluating granularity and measuring bleed within the main unit, and to process automatically. However, if such a configuration is included in the main unit, the device would become excessively large in practice. Therefore, it is generally considered advantageous in terms of cost and configuration to perform these judgments using external measuring devices or by visual inspection by the user, and to feed the results back to the control means of the main unit from a panel host or similar device.

[0077] The table showing the relationship between the amount of colored ink applied and the amount of processing solution applied for the colored ink used in this embodiment is shown in Figure 5(a)A, based on the above findings. At the boundaries between the midtone region and the regions with higher and lower tonal levels, the amount of processing solution applied is set to be continuous, taking into consideration the continuity of the image. The second tone region in Figure 5(b) shows an example of the midtone region described above, and this region contains the maximum value that can be taken as the ratio of the amount of processing solution applied for the colored ink to the amount of colored ink applied. Furthermore, a first tone region is provided on the lower tone side where the total amount of colored ink applied is less than that of the second tone region, and a third tone region is provided on the higher tone side where the total amount of colored ink applied is greater than that of the second tone region. Furthermore, the above-mentioned intermediate reference value (amount of colored ink dispensed), which serves as an indicator for selecting the appropriate dispensing control for such processing solutions, varies depending on the type of ink, processing solution, and recording medium used. However, it is preferably selected appropriately within the range of 4 to 20 ng / 600 dpi, depending on the type of ink, processing solution, and recording medium.

[0078] (Setting the amount of transparent ink and processing solution for transparent ink to be applied) The following describes in detail a method for determining the amount of transparent ink and processing liquid for transparent ink that is suitable for performing the image recording method of this embodiment.

[0079] As mentioned above, by determining the amount of colored ink processing solution applied relative to the amount of colored ink applied, taking into account the granularity and bleed performance of the recorded image, there are tonal regions, such as the second tonal region, where the ratio of the amount of colored ink processing solution applied to the amount of colored ink applied is high depending on the tone. Since it is known that the scratch resistance of the recorded image decreases in such regions compared to other tonal regions, in this embodiment, the amount of transparent ink applied in the second tonal region is controlled to be greater than the amount of transparent ink applied in the first and third tonal regions.

[0080] The following describes the transparent ink and transparent ink processing solution data generation process in step 404, which determines information regarding the transparent ink to be applied to each predetermined area of ​​the recording medium based on the amount of colored ink and processing solution applied.

[0081] Figure 6(a) is a diagram illustrating an example of the contents of the lookup table for transparent ink data and the lookup table for transparent ink processing solution data used in the transparent ink and transparent ink processing solution data generation process in step 404 of this embodiment. In this data generation process, the amount of transparent ink and transparent ink processing solution to be applied is set based on the relationship between the amount of colored ink applied and the amount of colored ink processing solution applied to each predetermined area of ​​the recording medium. According to experiments by the inventors, sufficient abrasion resistance can be obtained when the ratio of the total processing solution amount (sum of colored ink and transparent ink applied to each predetermined area of ​​the recording medium) to the total ink application amount (sum of colored ink and transparent ink applied) is 40% or less. Figure 6(a)B shows an example of a table when controlled to be 40% or less across all recording gradations, and Figure 6(a)A shows an example of a table in which transparent ink of 18ng / 600dpi is applied uniformly regardless of gradation, unlike the control of the present invention. In Figure 6(a)B, the amount of transparent ink applied is determined so that the second region includes the maximum amount of transparent ink that can be applied for each recording gradation of the colored ink based on the table above. The control system in Figure 3 controls the amount of transparent ink applied according to the amount of colored ink applied, based on this relationship. While it is not necessary to use such a table, it is desirable that the amounts of processing solution and transparent ink applied are continuous with respect to the amount of colored ink applied, as shown in this table. Furthermore, the ratio of the amount of processing solution for transparent ink applied to the amount of transparent ink applied is set to 15%, which is equivalent to the ratio of the amount of processing solution for colored ink applied to the amount of colored ink applied in the third gradation region. However, it is not necessary to use such a ratio.

[0082] Figure 6(b) shows the relationship between the amount of colored ink applied to each predetermined area of ​​the recording medium and the ratio of the total amount of processing solution applied (the total amount of processing solution for colored ink and transparent ink) to the total amount of ink applied (the total amount of colored ink and transparent ink). Figure 6(a)A shows the ratio of the total amount of processing solution applied to the total amount of ink applied when using a table that applies a uniform amount of transparent ink of 18 ng / 600 dpi regardless of the gradation, Figure 6(a)B shows the ratio of the total amount of processing solution applied to the total amount of ink applied when using a table that is controlled to be 40% or less across all recording gradations, and Figure 6(a)C shows the ratio of the amount of processing solution applied for colored ink to the amount of colored ink applied, as shown in Figure 5(b).

[0083] Using table A in Figure 6(a), when transparent ink and a processing solution for transparent ink were applied using a table that uniformly applied 18 ng / 600 dpi of transparent ink regardless of the gradation, the scratch resistance in the second gradation region of the recorded image was good compared to when only colored ink and a processing solution for colored ink were applied. However, no significant improvement was observed in the first and third gradation regions. This is thought to be because in the second gradation region, the ratio of the amount of processing solution for colored ink applied to the amount of colored ink applied was large, resulting in reduced scratch resistance. Applying transparent ink reduced this ratio, thus improving scratch resistance. On the other hand, in the first and third gradation regions, the ratio of the amount of processing solution for colored ink applied to the amount of colored ink applied was smaller compared to the second gradation region, and this is thought to be because the effect of applying transparent ink on improving scratch resistance was not significant. Therefore, in the first and third grayscale regions, more transparent ink and processing solution for the transparent ink than necessary are being applied, which is undesirable in terms of drying load and ink cost.

[0084] When transparent ink was applied using the table shown in Figure 6(a)B, the abrasion resistance evaluation in the second grayscale region showed good results, similar to when using the table in Figure 6(a)A. Furthermore, in the first and third grayscale regions, although the amount of transparent ink and transparent ink treatment solution applied was less compared to when using the table in Figure 6(a)A, no difference was observed in the abrasion resistance evaluation.

[0085] As in this embodiment, by controlling the amount of transparent ink and processing solution applied, it is possible to reduce the amount of transparent ink and processing solution used while simultaneously improving the image quality performance of the recorded image, such as suppressing granularity and bleeding, and improving scratch resistance.

[0086] (Second Embodiment) In a second embodiment of the present invention, control of the application of transparent ink for the purpose of changing image performance is described. Changing image performance refers to, for example, changes in the weather resistance, water resistance, alkali resistance, gloss, haze, and bronzing properties of the image, or changes in the uneven shape of the image surface. Figure 7 is image data in which the inside of a star shape is a region to which transparent ink is applied in order to change image performance, and the outside of the star shape is a region to which transparent ink is not applied in order to change image performance.

[0087] Figure 8(a) shows the data processing flow in the second embodiment. Here, the lookup tables for transparent ink data and transparent ink processing solution data used in the first embodiment, as shown in Figure 6(a), are referred to as the "table for scratch-resistant transparent ink data" and the "table for scratch-resistant transparent ink processing solution data," respectively. In this embodiment, the lookup tables for transparent ink data and transparent ink processing solution data used to determine the amount of transparent ink to be added for the purpose of changing the image performance are referred to as the "table for image performance transparent ink data" and the "table for image performance transparent ink processing solution data."

[0088] An example of the "transparent ink data table for image performance" used in the transparent ink ejection data generation process in step 805 of this embodiment will be described. In this embodiment, a table was used in which transparent ink is uniformly applied at 80 ng / 600 dpi in the region where it is determined that transparent ink should be applied, regardless of the amount of colored ink applied. In this case, a table was used as the "transparent ink processing solution data table for image performance" in which the amount of transparent ink processing solution applied is 15% of the amount of transparent ink applied.

[0089] In step 804, based on the input image data, the amount of transparent ink and the amount of transparent ink processing solution to be applied are set for each predetermined area of ​​the recording medium, based on a table that stores the relationship between the amount of transparent ink applied and the amount of colored ink applied for each type of recording medium, and 8-bit image data corresponding to the applied amount is generated. At this time, the larger value is selected from the amount of transparent ink applied, which is set based on the "table for data on scratch-resistant transparent ink" and the "table for data on transparent ink for image performance". Furthermore, regarding the amount of transparent ink processing solution to be applied, when the amount of transparent ink applied from the "table for data on data on scratch-resistant transparent ink" is selected, the amount of application based on the "table for data on data on transparent ink processing solution for scratch resistance" is selected, and when the amount of transparent ink applied from the "table for data on data on transparent ink for image performance" is selected, the amount of application based on the "table for data on data on transparent ink processing solution for image performance" is selected.

[0090] By implementing this control, even in the second grayscale region where scratch resistance tends to decrease without the application of transparent ink, more transparent ink than the amount applied based on the relationship of the "transparent ink data table for scratch resistance" will be applied, making it less likely for scratch resistance to decrease. On the other hand, even when transparent ink is applied for purposes other than improving scratch resistance, the control prevents the application of additional transparent ink to further improve scratch resistance, thus suppressing the use of transparent ink more than necessary.

[0091] Furthermore, the information for determining whether or not to apply this transparent ink may be provided by the user's input image or by data processing based on the user's input image, in which case control is performed by the data processing flow shown in Figure 8(b). At this time, in the region where the determination process in step 814 determines that there is data for transparent ink to change image performance, the amount of transparent ink and transparent ink processing liquid to be applied is set based on the "transparent ink data table for image performance" and the "transparent ink processing liquid data table for image performance". In the region where it is determined that there is no data for transparent ink to change image performance, the "transparent ink data table for scratch resistance" and the "transparent ink processing liquid data table for scratch resistance" are used preferentially to set the amount of transparent ink and transparent ink processing liquid to be applied.

[0092] As in this embodiment, in addition to the method of referring to both tables and applying the larger value, it is also possible to control the process so that it determines whether or not transparent ink for image performance is applied to each predetermined area, and performs the same processing as in the first embodiment only in areas where it is determined that no transparent ink for changing image performance is applied.

[0093] (Third embodiment) In this embodiment, the ratio of the total amount of processing solution applied to the total amount of ink applied in the second grayscale region is controlled to be smaller than the ratio of the total amount of processing solution applied to the total amount of ink applied in the third grayscale region. Figure 9 is a diagram illustrating a third embodiment of the present invention. The processing other than the transparent ink ejection data generation process that determines the amount of transparent ink applied to each predetermined area of ​​the recording medium and the transparent ink processing solution ejection data generation process that determines the amount of processing solution applied to the transparent ink is the same as in the first embodiment. The control features of the third embodiment will be described below.

[0094] Figure 9(a) is a diagram illustrating the contents of the lookup table for transparent ink ejection data in a recorded image recorded with the inkjet recording apparatus of the third embodiment used in the transparent ink ejection data generation process in this embodiment. In this case, the amount of transparent ink processing solution applied was set to 15% of the amount of transparent ink applied, similar to the first embodiment. Figure 9(b) shows the relationship between the amount of colored ink applied and the ratio of the total processing solution amount (sum of colored ink processing solution and transparent ink processing solution) to the total ink application amount (sum of colored ink and transparent ink applied per pixel of the recording medium) when transparent ink and transparent ink and transparent ink processing solution are applied using the lookup table shown in Figure 9(a).

[0095] The lookup table shown in Figure 9(a) is set so that for each pixel of the recording medium, the ratio of the total amount of processing solution applied to the total amount of ink applied in the second grayscale region is the same as or smaller than the ratio of the total amount of processing solution applied to the total amount of ink applied in the third grayscale region.

[0096] By controlling the amount of transparent ink and processing solution applied in this way, it becomes possible to improve the abrasion resistance in the second gradation region to the same level as that in the third gradation region. This is thought to be because the ratio of the amount of processing solution applied to the total amount of ink applied in the second gradation region was kept below that of the third gradation region, thereby suppressing the decrease in abrasion resistance.

[0097] As in this embodiment, by applying transparent ink and a processing solution for transparent ink according to the relationship between the amount of colored ink and processing solution applied to each predetermined area of ​​the recording medium, it is possible to improve the scratch resistance of the recorded image across the entire grayscale range, although the consumption of transparent ink increases compared to the first embodiment.

[0098] (Other embodiments) The inks applicable to this invention are not limited to the compositions described above. Furthermore, as colored inks, dye inks, pigment inks, or both can be used. Also, for example, when using multiple processing solutions with different reagent concentrations, control similar to that in this embodiment is possible by changing the calculated ratio of the reagent concentration to the amount of ink dispensed. As transparent inks, liquids with various functions can be used, and they may even be semi-transparent.

[0099] Furthermore, the present invention is applicable to various inkjet recording methods, and can be applied, for example, to so-called full-line type recording methods that use a long recording head extending in the width direction of the recording medium. [Explanation of Symbols]

[0100] 10 Platen 11 Carriage 12 Recording media 15 Recording head 21 Discharge port row 301 CPU 302 ROM 303 RAM

Claims

1. A recording head comprising: a plurality of discharge ports for dispensing colored ink containing resin particles and colorants; a plurality of discharge ports for dispensing transparent ink containing resin particles but without colorants; and a plurality of discharge ports for dispensing a processing liquid containing reactive components that react with the resin particles and colorants in the colored ink and the resin particles in the transparent ink to cause aggregation or gelation; The recording head is provided with an application amount determination means for determining the amount of colored ink, transparent ink, and processing liquid applied to each predetermined area of ​​the recording medium, The amount-to-amount determination means determines the amount of transparent ink and the amount of processing liquid to be applied for at least three different recording gradations with varying ratios of the amount of processing liquid applied to the colored ink. The amount of transparent ink applied in a second recording gradation where the amount of colored ink applied to each predetermined area is a second amount, and the ratio of the applied amounts is a second ratio, is greater than the amount of transparent ink applied in a first recording gradation where the amount of colored ink applied to each predetermined area is a first amount less than the second amount, and the ratio of the applied amounts is a first ratio less than the second ratio, In a second recording gradation where the amount of colored ink applied to each predetermined area is the second amount, the amount of transparent ink applied in a third recording gradation where the amount of colored ink applied to each predetermined area is greater than the second amount, and the ratio of the applied amounts is smaller than the ratio of the second ratio. An inkjet recording device characterized by the following:

2. The system includes a judgment image that determines the granularity of a recorded image by changing the ratio of the amount of colored ink and processing liquid applied. The inkjet recording apparatus according to claim 1, characterized in that, in the region of the second recording grayscale, the amount of the processing liquid applied to the colored ink is determined by a determination image for determining granularity.

3. The system includes a judgment image that determines the clarity of the boundary area when the ratio of the amount of colored ink and processing solution applied to the recorded image is changed. The inkjet recording apparatus according to claim 1, characterized in that, in the region which is the third recording grayscale, the amount of the processing liquid applied to the colored ink is determined by a determination image used to determine the clarity of the boundary.

4. The inkjet recording apparatus according to claim 1, further comprising a second means for determining the amount to be dispensed, separate from the aforementioned means for determining the amount to be dispensed, wherein the amount of transparent ink dispensed is selected from the larger of the amounts determined by the two means for determining the amount to be dispensed.

5. The inkjet recording apparatus according to claim 4, characterized in that, when the amount of transparent ink to be dispensed is set by the second amount to be dispensed, the amount of transparent ink to be dispensed determined by the second amount to be dispensed is given priority.

6. The inkjet recording apparatus according to claim 1, characterized in that the amount of colored ink, the transparent ink, and the processing liquid are determined in the amount of application means such that the ratio of the amount of application of the processing liquid to the total amount of application of the amount of application of the colored ink and the amount of application of the transparent ink per predetermined area in the area that is the first recording grayscale is less than or equal to the ratio of the amount of application of the processing liquid to the total amount of application of the colored ink and the amount of application of the transparent ink per predetermined area in the area that is the third recording grayscale.

7. The inkjet recording apparatus according to claim 1, characterized in that the recording medium has an ink transfer amount of 20 ml / m2 or less per transfer time of 1 second, as measured by the Bristow method.

8. A recording head comprising: a plurality of discharge ports for dispensing colored ink containing resin particles and colorants; a plurality of discharge ports for dispensing transparent ink containing resin particles but without colorants; and a plurality of discharge ports for dispensing a processing liquid containing reactive components that react with the resin particles and colorants in the colored ink and the resin particles in the transparent ink to cause aggregation or gelation; The recording head is provided with an application amount determination means for determining the amount of colored ink, transparent ink, and processing liquid applied to each predetermined area of ​​the recording medium, The amount-to-amount determination means determines the amount of transparent ink and the amount of processing liquid to be applied for at least three different recording gradations with varying ratios of the amount of processing liquid applied to the colored ink. The amount of transparent ink applied in a second recording gradation where the amount of colored ink applied to each predetermined area is a second amount, and the ratio of the applied amounts is a second ratio, is greater than the amount of transparent ink applied in a first recording gradation where the amount of colored ink applied to each predetermined area is a first amount less than the second amount, and the ratio of the applied amounts is a first ratio less than the second ratio, The amount of transparent ink applied in the second recording gradation, where the amount of colored ink applied to each predetermined area is the second amount, is greater than the amount of transparent ink applied in the third recording gradation, where the amount of colored ink applied to each predetermined area is the third amount, and the ratio of the application amounts is the third ratio, which is smaller than the ratio of the second amount. An inkjet recording method characterized by the following:

Images