JP2011121209A - Recording apparatus, and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording apparatus in which a density fall of recording images is reduced even when two kinds of ink of the same color system are used, and to provide a recording method. <P>SOLUTION: Noting that an ink high in optical density differs by a recording duty when two kinds of ink of the same color system are used, ink application amounts of the two kinds of ink are determined on the basis of image data. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a recording apparatus and a recording method for forming an image on a recording medium by ejecting ink.

  As a recording method of an ink jet recording apparatus, a so-called serial method is known in which a carriage on which a recording head and an ink tank are mounted is scanned with respect to a recording medium, and ink is ejected during that time to record the area. In this method, the recording medium is conveyed by a predetermined amount in the direction substantially orthogonal to the scanning direction between the scans, and recording is performed on the entire recording medium by repeating these scans and the recording medium conveyance. . As another recording method, a so-called full line method is also known. This method uses a recording head in which ejection openings are arranged in a range corresponding to the width of the recording medium, and performs recording while conveying the recording medium to the recording head.

  In recent years, many inkjet recording apparatuses having various advantages as described above have been provided as products for performing color recording using a plurality of colors of ink. As such an ink jet recording apparatus, high speed recording and high image quality recording are required. In order to realize high-speed recording, the number of nozzles formed in the recording head is increased, or the speed of the carriage when performing recording scanning is increased. In order to realize high-quality recording, there is a technique for performing recording using two types of inks of the same color system (see Patent Document 1). In Patent Document 1, two types of Bk inks having different penetrability are prepared. The penetrable Bk ink is used for the black region when the black region and the color region are in contact with each other. A configuration for performing recording using Bk ink is disclosed.

Japanese Patent Laid-Open No. 08-295032

  In Patent Document 1, if poorly penetrating Bk ink is applied while in contact with a color area, the color ink in the color area and the Bk ink are mixed to cause bleeding called “beading”. When in contact, penetrating Bk ink is applied. However, if an image is recorded with highly penetrable ink, the optical density of the recorded image may decrease. This is presumably because when the highly penetrating ink lands on the recording medium, it penetrates in the thickness direction of the recording medium, so that the ink coloring material hardly remains on the surface of the recording medium and the optical density is lowered.

  An object of the present invention is to provide a recording apparatus and a recording method that can reduce a decrease in density of a recorded image even when two types of inks of the same color are used.

  The present invention provides a recording apparatus that performs recording based on image data on a recording medium using a recording head that discharges a plurality of inks of the same color system, and the plurality of units per unit area based on multivalued data of the image data. Determining means for determining the amount of ink to be applied, and recording means for recording on the recording medium based on the determined amount of ink applied, wherein the determining means applies the ink per unit area. The amount of ink to be applied to the recording medium before and after the multi-value data exceeds a predetermined value when an ink having a high recording density is used among the plurality of inks before and after the amount exceeds a predetermined application amount It is characterized by different inks.

  Further, the present invention provides a recording apparatus that performs recording based on image data on a recording medium using a recording head that discharges a plurality of inks of the same color system, based on multi-value data of the image data. A determination unit configured to determine an application amount of each of the plurality of inks; and a recording unit configured to perform recording on the recording medium based on the determined application amount, wherein the determination unit includes the ink per unit area. Before and after the application amount exceeds a predetermined application amount, the multi-value data is applied to the recording medium before and after the multi-value data exceeds a predetermined value when using inks having different recording densities among the plurality of inks. The ink having a large amount of ink is different.

  According to the present invention, by using two types of ink based on the image data, it is possible to record a dark image with a higher density so that a decrease in the density of the recorded image is reduced. Thereby, the color gamut of the dark part represented by the recorded image can be expanded. Alternatively, according to the present invention, by using two types of ink based on image data, it is possible to reduce the amount of ink applied to the recording medium, which is less likely to reduce the density of the recorded image. Furthermore, according to the present invention, it is possible to record a high-density image with a small amount of ink consumption.

It is the perspective view which showed the principal part of the inkjet recording device of 1st embodiment. It is a block diagram which shows the structure of the recording system of 1st embodiment. FIG. 6 is a diagram illustrating a relationship between recording duty and optical density of each of two types of ink. It is a flowchart at the time of recording of 1st embodiment. It is the figure which showed the relationship between input value and each ink application amount of two types of ink. It is a flowchart at the time of recording of 2nd embodiment.

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

(First embodiment)
FIG. 1 is a perspective view showing a main part of the ink jet recording apparatus of the present embodiment.

  The recording head 5 records an image by ejecting ink to the recording medium 1 from a plurality of arranged ejection openings. The recording head 5 includes five recording heads 5Bk1, 5Bk2, 5C, 5M, and 5Y that respectively discharge black (Bk1), black (Bk2), cyan (C), magenta (M), and yellow (Y) color inks. Have The recording heads 5Bk1, 5Bk2, 5C, 5M, and 5Y have 1280 ejection ports (also referred to as nozzles) arranged at a density of 1200 dpi, and the amount of ink ejected from each ejection port is about 4 ng. is there.

  The ink tank 6 stores ink for supplying ink corresponding to each of the recording heads 5Bk1, 5Bk2, 5C, 5M, and 5Y, and includes five ink tanks 6Bk1, 6Bk2, 6C, 6M, and 6Y. ing. The recording head and the ink tank constitute a head cartridge that can be integrated or separable, and the head cartridge is detachably mounted on a carriage (not shown). The recording head and the ink tank may be separately mounted on the carriage without constituting a head cartridge. The carriage on which the recording head is mounted is reciprocated in the main scanning direction (arrow X direction in the figure) by the carriage motor 23 via the belt 4. The recording medium 1 is transported by a transport roller in a sub-scanning direction (in the direction of arrow Y in the figure) that intersects (in the present example, orthogonal) with the main scanning direction. An image is formed on the recording medium 1 by repeating the recording scanning in which ink is ejected from the recording head 5 and the transport operation of the recording medium 1 while moving the carriage.

  The cap 7 caps the discharge port surface on which the discharge ports of the five recording heads are formed, and includes five caps 7Bk1, 7Bk2, 7C, 7M, and 7Y. The carriage on which the recording head 5 and the ink tank 6 are mounted returns to the home position with the cap 7 when recording is not performed. Further, when a predetermined time has elapsed after the carriage waits at the home position, a capping operation is performed in which the cap 7 is brought into contact with the ejection port surface of the recording head 5 so that the ejection port surface of the recording head 5 is not dried.

  In addition, when individually referring to these recording heads and ink tanks, the reference numbers assigned thereto are used, but when referring comprehensively, the recording heads are referred to as generic reference numbers. 5 ”,“ 6 ”for the ink tank, and“ 7 ”for the cap.

  FIG. 2 is a block diagram showing the configuration of the recording system of this embodiment.

  The recording system of FIG. 2 is a system that includes a host device 100 and an inkjet recording device 200. The host device 100 can be a personal computer or a digital camera having a function as an information processing device, and is a device connected to the ink jet recording apparatus (printer) 200. The host device 100 includes a CPU 10, a memory 11, an external storage unit 13, an input unit 12 such as a keyboard and a mouse, and an interface 14 for communicating with the printer 200. A user can create image data to be output from the inkjet recording apparatus 200 by executing a program (application) stored in the memory 11. The CPU 10 executes various processes according to programs stored in the memory 11 and executes image processing such as color processing and quantization processing on image data created or photographed by the user. The recording data subjected to the image processing is transmitted to the inkjet recording apparatus 200 connected via the interface.

  The inkjet recording apparatus 200 includes a control unit 20 that includes a CPU 20a such as a microprocessor, a RAM 20b that is used as a work area for the CPU 20a, and stores various data such as recording data and registration adjustment values. The control unit 20 also includes a ROM 20c that stores a control program for the CPU 20a and various data. Further, the ink jet recording apparatus 200 includes an interface 21, an operation panel 22, and drivers 27 and 28. The driver 27 controls driving of the motor 23 for driving the carriage, the motor 24 for driving the paper feed roller, the motor 25 for driving the first transport roller pair, and the motor 26 for driving the second transport roller pair, and the driver 28 controls the drive of the recording head 5. The recording data transmitted from the host apparatus 100 and received via the interface 21 of the inkjet recording apparatus 200 is stored in the RAM 20 b of the control unit 20. In accordance with the recording data stored in the RAM 20b, the control unit 20 outputs ON and OFF signals for driving the motors 23 to 26 to the driver 27, and discharge signals and the like to the driver 28, respectively. Form.

  Next, inks applicable in the present embodiment will be described. In the following description, “part” and “%” are based on mass unless otherwise specified. Further, “remaining” means that the total amount of ink or reaction liquid was adjusted with ion-exchanged water so as to be 100 parts.

[Preparation of each color ink]
First, black, cyan, magenta, and yellow inks each containing a pigment and an anionic compound were prepared as described below.

(Preparation of ink Bk)
<Preparation of pigment dispersion>
-Styrene-acrylic acid copolymer (acid value = 210,
(Weight average molecular weight = 9,000) 1.5 parts, monoethanolamine 1.0 part, diethylene glycol 5.0 parts, ion-exchanged water 81.5 parts The above ingredients are mixed and heated to 70 ° C in a water bath, Dissolve the resin completely. To this solution, 10 parts of newly produced carbon black (FW18, manufactured by Degussa) and 4 parts of ethylene glycol were added, premixed for 30 minutes, and then dispersed under the following conditions.
・ Disperser: Sand grinder (Igarashi Machine)
・ Crushing media: Zirconium beads, 1 mm diameter ・ Filling rate of grinding media: 50% (volume ratio)
-Grinding time: 3 hours Further, centrifugal separation (12,000 rpm, 20 minutes) was performed to remove coarse particles to obtain a pigment dispersion.

<Preparation of Ink Bk1>
Using the pigment dispersion obtained above, components having the following composition ratios were mixed to prepare an ink containing a pigment to obtain an ink. Surfinol 465 (trade name: manufactured by Nissin Chemical Co., Ltd.) used in the composition of the ink is a nonionic surfactant obtained by adding ethylene oxide to acetylene diol. The surface tension at this time was 37.1 mN / m. Further, the ink permeation coefficient Ka value in the Bristow method when using Canon plain paper (pbsk) was 2.1 ml / m ² · s ^1/2 .
-30.0 parts of the above pigment dispersion-10.0 parts of glycerin-5.0 parts of ethylene glycol-7.0 parts of trimethylolpropane-1.0 part of Surfynol 465-0.5 part of acetylene glycol-remaining part of ion-exchanged water

<Preparation of Ink Bk2>
In the same manner as the ink Bk1, the above-described pigment dispersion was used, and components having the following composition ratios were mixed to prepare an ink containing a pigment, which was used as an ink. Surfinol 465 (trade name: manufactured by Nissin Chemical Co., Ltd.) used in the composition of the ink is a nonionic surfactant obtained by adding ethylene oxide to acetylene diol. The surface tension at this time was 32.4 mN / m. The ink penetration coefficient Ka value in the Bristow method when using Canon plain paper (pbsk) was 4.0 ml / m ² · s ^1/2 .
-30.0 parts of the above pigment dispersion-10.0 parts of glycerin-5.0 parts of ethylene glycol-7.0 parts of trimethylolpropane-1.0 part of Surfynol 465-2.0 parts of acetylene glycol-remainder of ion-exchanged water

(Preparation of ink C)
Ink C containing a pigment was prepared in the same manner as ink Bk1, except that 10 parts of carbon black (FW18, manufactured by Degussa) used in preparing ink Bk1 was replaced with pigment blue 15.

(Preparation of ink M)
Ink M containing a pigment was prepared in the same manner as ink Bk1, except that 10 parts of carbon black (FW18, manufactured by Degussa) used in preparing ink Bk1 was replaced with pigment red 7.

(Preparation of ink Y)
Ink Y containing a pigment was prepared in the same manner as ink Bk1, except that 10 parts of carbon black (FW18, manufactured by Degussa) used in preparing ink Bk1 was replaced with pigment yellow 74.

  FIG. 3 shows the relationship between the recording duty of Bk1 and Bk2 ink and the optical density (recording density).

  FIG. 3 (a) uses the Bk1 and Bk2 inks among the inks described above, and records patches that gradually increase the amount of ink applied per unit area (also referred to as recording duty or simply duty). The optical density (simply referred to as density) of the patch is shown. In FIG. 3A, the optical density of a patch recorded with Bk1 ink is indicated by a solid line, and the optical density of a patch recorded with Bk2 is indicated by a broken line. At this time, since both are recorded based on the same image data, the amount of ink applied per unit area of each patch is the same. In both cases, recording is completed with the same number of recording scans. The optical density of each patch should be measured with a color transmission / reflection densitometer (trade names “X-Rite”, manufactured by X-Rite, Inc.) or a spectrophotometer (trade names “Spectorolino”, manufactured by Gretag Macbeth). Can do. In these measuring instruments, the optical density is measured by detecting the amount of light reflected from the measurement object when light is irradiated onto a region having a diameter of about 5 mm.

  As shown in FIG. 3A, when the ink application amount per unit area is relatively small, recording with Bk2 ink has a higher optical density, and when the ink application amount per unit area is relatively large, recording is performed with Bk1 ink. It can be seen that the optical density is higher. This is considered to be caused by the difference in permeability between the Bk1 ink and the Bk2 ink. When the optical density is measured by the above-described measuring instrument, the measurement target area of the measuring instrument is an area larger than the ink droplets that have landed on the recording medium. The whole is not covered with ink. Then, the reflected light received by the measuring instrument includes reflected light reflected by the ink surface on which the ink droplet has landed and reflected light reflected by the blank portion (paper white) of the recording medium on which the ink droplet has not landed. . Of the reflected light reflected from the ink surface and the reflected light reflected from the margin of the recording medium, the reflected light reflected from the margin is stronger (the amount of reflected light is larger), so the reflected light reflected from the ink surface. The optical density is lower than when only the measurement is performed. For this reason, in a patch having a relatively low recording duty, the optical density may change even when the measurement target surface is covered with ink. That is, in a patch with a low recording duty recorded with inks having the same color material density and the same darkness, the optical density is higher in a patch that covers a large amount of ink on the measurement symmetry plane. On the other hand, for a patch with a high recording duty, since the measurement target surface is almost covered with ink, the optical density is higher when the ink coloring material remains on the surface of the recording medium.

  In this embodiment, the penetrability of the two types of black inks Bk1 and Bk2 with respect to the recording medium is different. Specifically, Bk2 ink is more permeable than Bk1 ink. The dot diameter of one drop of Bk2 ink having a relatively high permeability landed on the recording medium is larger than the dot diameter of one drop of Bk1 ink having a relatively low permeability. This is because the relatively high permeability Bk2 ink that has landed on the recording medium penetrates and spreads in the surface direction of the recording medium, so that the dot diameter becomes larger than the Bk1 ink. Therefore, in FIG. 3A, it is considered that the density of the Bk2 ink having a relatively high permeability is higher in the patch having a relatively low recording duty than the Bk1 ink having a relatively low permeability.

  Further, in a patch having a relatively high recording duty in which the recording medium is almost covered with ink, the density of the Bk1 ink having a relatively low permeability is higher than that of the Bk2 ink having a relatively high permeability. The relatively highly penetrating Bk2 ink that has landed on the recording medium also penetrates in the thickness direction of the recording medium (the direction from the surface of the paper to the back), so that the ink remaining on the surface of the recording medium than the patch recorded with the Bk1 ink. This is thought to be because there are few coloring materials.

  In the present invention, when two types of inks of the same color are used, a patch with a relatively small amount of ink applied to a recording medium and a patch with a relatively large amount of ink applied are recorded. Attention was paid to the fact that the ink with the higher optical density was different from time to time. In particular, in the present embodiment, inks having different penetrability are used as two types of inks of the same color that have different optical density depending on the applied amount of ink.

  FIG. 4 shows a flowchart during recording. In the present embodiment, the characteristic configuration of the present invention is applied only to the Bk ink.

  When the user issues an image data recording instruction, the printer driver installed in the host apparatus 100 acquires RGB multi-value data of the image data (S401). Next, the printer driver converts the RGB multi-value data created in the RGB color space into CMYK multi-value data in the CMYK color space corresponding to the ink used for recording (S402). Further, conversion into CMYK1K2 binary data corresponding to C, M, Y, and K inks is performed (S403). At this time, the conversion process is performed with reference to a table (LUT) stored in the memory 11 of the host apparatus 100 for converting the CMYK multi-value data into the recording duty of each ink. As will be described later, in the present embodiment, print data is generated by converting K multilevel data into binary data of two types of Bk inks K1K2.

  The ink jet recording apparatus 200 performs recording based on the binary data received from the host apparatus 100 (S404). At this time, in the case of multi-pass recording in which an image is completed by performing a plurality of recording scans on the same area of the recording medium, the ROM 20c records the CMYK binary data in S403 so that the image is recorded by a plurality of recording scans. The data is sorted using the mask stored in. An image is formed in each recording scan based on the distributed data.

  Here, a method for generating print data for each of the two types of ink for the multi-value data of K in S403 described above will be described.

  FIG. 5 shows the relationship between the K multi-value data and the ink application amount (recording duty) of each of the two types of Bk inks. In this embodiment, when two types of Bk inks of the same color are used, recording is performed using Bk2 ink having a higher optical density when the recording duty is low, and Bk1 ink having a higher optical density is recorded when the recording duty is high. It is characterized by using and recording. In this way, by using different inks for recording depending on whether the recording duty is high or low, it is possible to always perform recording using ink having a high optical density. As a result, the amount of ink applied to the recording medium can be reduced without reducing the optical density. Based on the ink application amount of each Bk ink corresponding to the K multi-value data obtained from the graph of FIG. 5, binary print data is generated.

  In this embodiment, when two types of inks of the same color are used, attention is paid to the fact that the ink having a high optical density differs depending on the recording duty, and the feature is that two types of ink are used based on image data. To do. More specifically, it is characterized by using an ink that can obtain a high optical density (recording density) of two types of ink before and after the recording duty exceeds a predetermined duty. According to the present embodiment, by using two types of ink based on image data, it is possible to record a darker image with a higher density. Thereby, the color gamut of the dark part represented by the recorded image can be expanded.

  In this embodiment, the Bk ink is used as the two types of ink of the same color, but other colors of ink may be used as long as the ink having a high optical density differs depending on the recording duty.

  Since the density of the recorded image is increased by using two types of ink of the same color system for recording, it is possible to obtain an equivalent image density even with an ink amount smaller than the amount of ink required based on the image data. It is. For example, since a large amount of ink cannot be applied to a recording medium with low ink absorption characteristics such as plain paper, the color gamut represented by the recorded image may be narrowed. Even in such a case, according to the present embodiment, it is possible to obtain an image in which the density is not reduced without increasing the amount of ink applied to the recording medium.

  In addition, as two types of inks of the same color system applicable to the present invention, not only an ink in which the density of a recorded image is increased only once at a predetermined recording duty as shown in FIG. For example, as shown in FIG. 3B, the present invention can also be applied to an ink in which the density of a recorded image increases with a certain range of recording duty.

  Further, in the present embodiment, it has been described that the CPU and printer driver of the host apparatus perform the conversion from CMYK binary data to generation of recording data, but the recording apparatus acquires RGB multi-value data and performs subsequent processing. May be configured to be performed by the CPU of the recording apparatus.

  The conversion from the S401RGB multi-value data in FIG. 4 of this embodiment to the CMYBk1Bk2 binary data in S403 may be performed for each pixel of the image data or for each predetermined region including a plurality of pixels. either will do.

  In this embodiment, inks having different penetrability were used as two types of inks of the same color. A surfactant other than acetylene glycol or a permeable solvent may be used as a material that varies the permeability. The surfactant is not particularly limited as long as it imparts permeability, but a nonionic surfactant is preferably used. Examples of the nonionic surfactant include ethylene oxide adducts of higher alcohols, ethylene oxide adducts of alkylphenols, ethylene oxide-propylene oxide copolymers, ethylene oxide adducts of acetylene glycol, and the like.

  The content of the surfactant is not particularly limited depending on the type of the surfactant to be used, but is preferably in the range of 0.01 to 10% by weight with respect to the total weight of the ink. If it is less than 0.01% by weight, the desired permeability is generally low, and if it exceeds 10%, the initial viscosity of the ink increases, which is not preferable.

  Moreover, as a solvent which imparts permeability, ethers such as tetrahydrofuran and dioxane, ethylene glycol methyl ether, and diethylene glycol monomethyl ether are preferably used. Furthermore, polyhydric alcohol lower alkyl ethers such as triethylene glycol monomethyl ether, ethanol, isopropyl alcohol, 1,2-hexanediol and the like are also preferably used. The content of the solvent is not particularly limited by the type of solvent used, but is preferably in the range of 0.1 to 20% by weight with respect to the total weight of the ink. If it is less than 0.1% by weight, the desired penetrability is generally low, and if it exceeds 20% by weight, the solubility of the colorant is somewhat lowered, which is not preferable.

  In the present embodiment, two types of Bk ink are used as the same color ink, but three or more types of the same color ink may be used. In that case, the relationship between the input value of FIG. 5 and the respective ink application amounts may be derived based on the relationship between the recording duty and the optical density of each ink. The same effect as in the present embodiment can also be obtained by using three or more similar colors of ink.

(Second embodiment)
The first embodiment has been described in the form of a recording apparatus using five colors of inks CMYBk1Bk2. In the second embodiment, in addition to the five color inks CMYBk1Bk2, a form using a reactive ink (also referred to as a treatment liquid or a reaction liquid) that improves the color developability and fixability of the ink by contact with the ink. An example of The reactive ink may be either a colorless ink to which no coloring material is added or a colored ink to which a coloring material is added.

  Ink prepared by dispersing a pigment with an anionic resin is brought into contact with a reactive ink containing polyvalent metal ions, whereby the dispersed state of the pigment is destroyed and the pigment is aggregated or deposited. As the pigment in the ink aggregates or accumulates, color developability and fixability are improved. Specific examples of polyvalent metal ions that can be used in the reaction solution include divalent metal ions such as Ca2 +, Cu2 +, Ni2 +, Mg2 +, Zn2 +, and Ba2 +, and trivalent metals such as Al3 +, Fe3 +, Cr3 +, and Y3 +. And ions. The salt is a metal salt composed of the polyvalent metal ions mentioned above and anions that bind to these polyvalent metal ions, but is soluble in water. Cost. Examples of the anion for forming the salt include SO42-, Cl-, CO32-, NO3-, I-, Br-, ClO3- and CH3COO-, HCOO-. Of course, it is not limited to the above compounds.

  Next, reaction solutions applicable in this embodiment will be described. Note that the CMYBk1Bk2 ink can be the same as that of the first embodiment, and a description thereof will be omitted.

[Preparation of reaction solution]
After the components having the following composition were mixed and dissolved, they were further filtered under pressure with a membrane filter (trade name: fluoropore filter, manufactured by Sumitomo Electric) having a pore size of 0.22 μm, and the pH was adjusted to 4.0. Each reaction solution was obtained. Surfynol 465 (trade name: manufactured by Nissin Chemical Co., Ltd.) used in the composition of each reaction solution is a nonionic surfactant obtained by adding ethylene oxide to acetylenic diol.

<Composition of reaction solution>
-Diethylene glycol 8.0 parts-1,3-propanediol 12.0 parts-Magnesium nitrate 5.8 parts-Surfynol 465 0.2 parts-Remaining ion-exchanged water At a predetermined ratio with respect to the ink application amount of CMYBk1Bk2 By applying the reactive ink, the color developability of the CMYBk1Bk2 ink can be improved. In this embodiment, the application amount of the reactive ink is 40% of the application amount of the colored ink. Reactive ink application data is generated by performing logical AND (AND) processing with a mask that gives 40% ink to the recording data obtained by logical OR (OR) processing of each color ink recording data. Is possible.

  Using Bk1 and Bk2 inks and reactive inks, patches that gradually increase the applied amount of ink and the applied amount of reactive ink per unit area were recorded, and the optical density was measured. The same tendency as in FIG. showed that. As in the first embodiment, the optical density between when a patch with a relatively small amount of ink applied to a recording medium is recorded and when a patch with a relatively large amount of ink applied is recorded. The rising ink was different.

FIG. 6 shows a flowchart at the time of recording to which the present invention is applicable.
6 is different from FIG. 4 in that a process of reducing the value of CMYK multi-value data and converting it to C′M′Y′K ′ multi-value data is inserted between the processes of S 402 and S 403. The point is different. This is because when recording with only Bk2 ink, the density of the recorded image is higher than when recording with only Bk1 ink, so the ink application amount is reduced so that the density of the recorded image is the same as when recording with only Bk1 ink. The multi-value data value is decreased as much as possible (S4021). By doing so, it is possible to reduce the amount of ink applied to the recording medium.

The processing S4021 and S4022 will be described below with reference to the newly added FIG.
Based on the K multilevel data converted in S402 in FIG. 6, referring to the correspondence table in FIG. 5, when the respective ink application amounts of Bk1 ink and Bk2 ink are determined, the pixel is recorded with only Bk2 ink. It is determined whether it is a pixel to be processed (S4021). If it is determined in S4021 that recording is not performed using only Bk2 ink, the process of S403 is performed. If it is determined in S4021 that printing is performed with only Bk2 ink, the value of CMYK is decreased and converted to C′M′Y′K ′ multilevel data so that the ink application amount is reduced in subsequent S4022. In step S403, C′M′Y′K ′ multi-value data is converted into binary data of CMYBk1Bk2. The recording apparatus that has received the CMYBk1Bk2 binary data converted in S403 performs recording based on the binary data in S404.

  Thus, by performing recording as in the recording flow of FIG. 6, it is possible to reduce the amount of ink applied to the recording medium.

  In particular, in this embodiment, since colored ink and reactive ink are used, the amount of droplets applied to the recording medium increases. However, in a recording medium such as plain paper, the amount of ink applied cannot be increased so much. In such a case, the recording flow of FIG. 6 in which the ink application amount is reduced and the density of the recorded image is difficult to reduce becomes effective.

  In this embodiment using colored ink and reactive ink, it is of course possible to apply the recording flow of FIG. 4 of the first embodiment. When the recording flow of FIG. 4 is applied, the color gamut of the dark part can be expanded. Further, it goes without saying that the flow shown in FIG. 6 can also be applied to a recording apparatus system using only colored ink that does not use reactive ink.

(Other embodiments)
Since the relationship between the recording duty and the optical density varies depending on the characteristics of the ink and the recording medium, the present invention may be applied only to a predetermined recording medium. Further, a graph or table showing the relationship between the K multi-value data and the ink application amount as shown in FIG. 5 may be prepared for each recording medium, and the graph or table used may be switched depending on the type of the recording medium.

5 Recording head 6 Ink tank 10 CPU
11 Memory 20 Control Unit 100 Host Device 200 Inkjet Recording Device

Claims (7)

In a recording apparatus that performs recording based on image data on a recording medium using a recording head that discharges a plurality of inks of the same color system,
A determining means for determining an applied amount of each of the plurality of inks per unit area based on the multi-value data of the image data;
Recording means for recording on the recording medium based on the determined amount of grant;
Have
The determination means uses the ink having a high recording density among the plurality of inks before and after the ink application amount per unit area exceeds a predetermined application amount. A recording apparatus, wherein the amount of ink applied to the recording medium is different before and after the value is exceeded.   2. The recording apparatus according to claim 1, wherein the determination unit determines an application amount of each of the plurality of inks based on a table in which the multi-value data and the application amounts of the plurality of inks are associated with each other. .   The recording apparatus according to claim 2, wherein the table is a table based on an application amount of each of the plurality of inks per unit area to the recording medium and a density of a recorded image.   The recording apparatus performs recording using the plurality of inks including a color material and a reactive ink that causes the color material to aggregate or deposit by contacting the ink including the color material. Item 4. The recording device according to any one of Items 1 to 3.   The recording apparatus according to claim 1, wherein the plurality of inks of the same color are inks having different permeability.   When the value of the multi-value data is smaller than the predetermined value, the determination unit applies a relatively high permeability ink among the different permeability inks, and when the determination value is larger than the predetermined value The recording apparatus according to claim 5, wherein a large amount of ink having relatively low permeability among the inks having different permeability is provided. In a recording apparatus that performs recording based on image data on a recording medium using a recording head that discharges a plurality of inks of the same color system,
A determining means for determining an applied amount of each of the plurality of inks per unit area based on the multi-value data of the image data;
Recording means for recording on the recording medium based on the determined amount of grant;
Have
The determination means uses the ink having a high recording density among the plurality of inks before and after the ink application amount per unit area exceeds a predetermined application amount. A recording method, wherein the amount of ink applied to the recording medium is different before and after exceeding the value.

Images