Ink-jet recording device, recording control method and program

Abstract

To suppresses irregularity occurring on an area recorded before and after stopping while suppressing the deterioration of through-put in multi-pass recording.SOLUTION: An ink-jet recording device includes : recording means which records an image by scanning a head provided with a plurality of ink ejection ports for ejecting ink a plurality of times, with respect to the same recording area of a recording medium; and recording control means which controls recording movement by means of the recording means so as to contain a usual scanning which performs recording by discharging the ink on the basis of recording data generated by using a prescribed mask pattern, a first scanning which scans with non-rerecording the recording area not subjected to recording yet in at least one-time scanning before stoppage and a second scanning which performs recording satisfying a recording rate in the usual scanning, in at least one-time scanning which resumes after a predetermined time elapsed from the stoppage, with respect to the recording area which is made non-recorded in the first scanning.SELECTED DRAWING: Figure 13

Description

Technical Field

[0001] The present disclosure relates to an inkjet recording apparatus, a recording control method, and a program for recording an image on a recording medium by a multi-pass recording method.

Background Art

[0002] An inkjet recording apparatus using a multi-pass recording method is provided, which records an image by scanning a recording head a plurality of times over a predetermined recording area on a recording medium. During multi-pass recording, the recording operation may be stopped between one scan and the next. For example, the stop is performed for various reasons such as wiping, sucking the ink adhering to the ejection port surface of the recording head, temperature control of the recording head, cutting of the recording medium, and the like. And when such a stop occurs, the color and gloss of the area where recording was performed before and after the stop may be different from those of other areas, and may be visually recognized as unevenness.

[0003] Regarding the unevenness caused by the stop, Patent Document 1 discloses a method of completing the multi-pass recording before the stop occurs, and then restarting the normal multi-pass recording after a predetermined stop time has elapsed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the method of Patent Document 1 requires additional scanning to temporarily complete the multi-pass recording. Specifically, in the case of multi-pass recording with n passes, it was necessary to perform (n - 1) additional scans. That is, the throughput decreases significantly as the number of passes increases, which has been a problem.

[0006] The present disclosure aims to suppress the occurrence of unevenness in the recorded area before and after stopping while suppressing a decrease in throughput in multi-pass recording.

Means for Solving the Problems

[0007] The inkjet recording apparatus of the present disclosure includes a recording unit that records an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times with respect to the same recording area of a recording medium, a normal scan that performs recording by ejecting ink based on recording data generated using a predetermined mask pattern, a first scan that scans a non-recorded recording area without recording in at least one scan before stopping, and a second scan that performs recording satisfying the recording rate in the normal scan in at least one scan restarted after a predetermined time has elapsed from stopping with respect to the recording area that was non-recorded in the first scan, and recording control means for controlling the recording operation by the recording unit so as to include the above. It is characterized by comprising.

Effects of the Invention

[0008] According to the present disclosure, in multi-pass recording, it is possible to suppress the occurrence of unevenness in the recorded area before and after stopping while suppressing a decrease in throughput.

Brief Description of the Drawings

[0009]

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Embodiments for Carrying Out the Invention

[0010] <First Embodiment> Hereinafter, with reference to the drawings, the first embodiment of the present disclosure will be described.

[0011] (1) Configuration of Inkjet Recording Apparatus FIG. 1 is a perspective view schematically showing the configuration of an inkjet recording apparatus (hereinafter referred to as recording apparatus 100) according to the present embodiment. FIG. 2 is a Y-Z cross-sectional view schematically showing the carriage unit 102 and the conveyance unit of the recording apparatus 100. In FIG. 1, in order to explain the internal mechanism of the recording apparatus 100, a state in which the upper cover is opened is shown.

[0012] As shown in FIGS. 1 and 2, the recording apparatus 100 includes a carriage unit 102, a guide shaft 108, a recording head 109, a platen 104, an encoder 107, a conveyance roller 103, an auxiliary roller 105, a spool 106, a take-up spool 112, a heater 110, and the like.

[0013] The carriage unit 102 is movably supported in the X direction, which is the main scanning direction, by a guide shaft 108 extending in the X direction in the figure. The carriage unit 102 is reciprocated in the main scanning direction by a moving mechanism constituted by a carriage motor, a carriage belt, and the like. A recording head 109 is mounted on the carriage unit 102. A flexible wiring board 119 is attached to the recording head 109, and drive pulses for performing an ink ejection operation, signals for head temperature adjustment, and the like are supplied thereto. The other end of the flexible wiring board 119 is connected to the main control unit 400 (FIG. 4) of the recording apparatus 100.

[0014] The recording head 109 moves in the main scanning direction together with the carriage unit 102, and during that time, ejects ink according to a recording signal to perform recording on the recording medium P.

[0015] The recording medium P is conveyed in a conveyance direction (Y direction in the figure) intersecting (orthogonal in this example) with the main scanning direction (X direction). The conveyance of the recording medium P is performed by a pair of conveyance rollers 103 and an auxiliary roller 105 operated by a conveyance motor (not shown). In the conveyance operation (sub-scanning), the recording apparatus 100 conveys the recording medium P held by the spool 106 by a predetermined conveyance amount in the +Y direction by rotating the conveyance roller 103 while pressing the recording medium P with the auxiliary roller 105. As a result, the recording medium P is guided to the recording position on the platen 104, that is, within the scanning area of the recording head 109. The platen 104 serves to stably support the recording medium P.

[0016] The recording apparatus 100 of this embodiment is a so-called serial scanning type recording apparatus. The serial scanning type recording apparatus 100 alternately repeats a conveyance operation for conveying the recording medium P in the conveyance direction and a recording operation for scanning the recording head 109 in the main scanning direction.

[0017] When a command to start recording is input from a host device connected to the recording apparatus 100, the recording medium P is fed to the recording position under the control of the main control unit 400. Thereafter, when the recording data for one scan, that is, the recording data for one band, is accumulated in the buffer, the carriage unit 102 is scanned and the recording operation is performed. In this specification, the recording operation accompanied by the scanning of the carriage unit 102 is referred to as a recording scan.

[0018] In the process of the recording scan, ink ejection according to the recording data is performed from the ejection port of the recording head 109 at a timing based on the position signal obtained from the encoder 107. Thereby, an image is recorded in a recording area having a band width corresponding to the range in which the ejection ports are arranged. Thereafter, the recording medium P is conveyed by a predetermined amount, and the next recording scan is performed. In this embodiment, as an example, the recording scan speed is set to 30 inches per second, and the ink ejection operation is performed at a recording resolution of 1200 dpi (interval of 1 / 1200 inch). Note that this example is merely an example, and this embodiment is not limited to these values.

[0019] Further, the recording apparatus 100 of this embodiment performs so-called multi-pass recording in which the recording head 109 is scanned a plurality of times with respect to the same recording area on the recording medium P to record an image. The multi-pass recording will be described in detail later.

[0020] A curing area is provided at a downstream (+Y) position in the conveyance direction with respect to the recording head 109. A heater 110 is disposed in the curing area. The heater 110 dries the liquid ink applied to the recording medium P by heating. As the heater 110, for example, a sheathed heater or a halogen heater is used. The heater cover 111 covers the heater 110 and has a function of efficiently irradiating the recording medium P with the heat of the heater 110 and a function of protecting the heater 110.

[0021] The heating temperature in the above-described curing area is set in consideration of the film-forming property and productivity of the water-soluble resin fine particles and the heat resistance of the recording medium P. As the heating means in the curing area, hot air blowing heating from above or contact-type heat conduction heater heating from below the recording medium P is used. In the present embodiment, there is one heating means for the heating part in the curing area, but two or more heating means may be provided as long as the measured temperature by a radiation thermometer (not shown) on the recording medium P does not exceed the set value of the heating temperature.

[0022] The recording medium P on which recording is performed by the recording head 109 and heating is performed by the heater 110 is wound up by a winding spool 112 to form a roll-shaped wound medium 113.

[0023] In the above description, an example in which the movement mechanism of the carriage unit 102 is constituted by a carriage motor, a carriage belt, etc. is shown, but the present invention is not limited to this example. Instead of the carriage belt, for example, a lead screw that is rotationally driven by a carriage motor and extends in the X direction may be provided, and the groove of the lead screw and an engaging portion provided on the carriage unit 102 side may be engaged to drive the carriage unit 102, and other driving methods may be used.

[0024] Also, usually, capping is applied to the discharge port surface of the recording head 109 in the standby state. Therefore, it is necessary to open the cap before recording to make the carriage unit 102 scannable.

[0025] (2) Configuration of Recording Head Figure 3 shows an example of the ejection surface of the recording head 109. The recording head 109 includes an ejection port array 31K that ejects black ink (K) as an ink containing a coloring material, an ejection port array 31C that ejects cyan ink (C), an ejection port array 31M that ejects magenta ink (M), and an ejection port array 31Y that ejects yellow ink (Y). Since these inks contain a coloring material, in the following description, they are also referred to as coloring material inks or color inks.

[0026] In addition, the recording head 109 includes an ejection port array 31RCT that ejects a reaction liquid ink (RCT) that does not contain a coloring material. The reaction liquid ink does not contain a coloring material, contains a reactive component that reacts with the coloring material contained in the coloring material ink, reacts by coming into contact with the coloring material ink on the recording medium P, and can suppress bleeding and bleeding of the coloring material ink.

[0027] In the recording head 109, the ejection port arrays 31K, 31C, 31M, 31Y, and 31RCT are arranged in this order from the left side to the right side in the X direction in the figure. The ejection port arrays 31K, 31C, 31M, 31Y, and 31RCT each have 1280 ejection ports 30 that eject ink arranged in the Y direction (array direction) at a density of 1200 dpi. The amount of ink droplets ejected from one ejection port 30 (ejection amount) is approximately 4.5 pl.

[0028] The ejection port arrays 31K, 31C, 31M, 31Y, and 31RCT are each connected to an ink tank that stores the corresponding ink, and ink is supplied from each ink tank. Note that the recording head 109 and the ink tank may be integrally configured, or each may be a separable configuration. In addition, water-soluble resin fine particles that form a film by heating and improve the scratch resistance of the image recorded on the recording medium P may be included in each of the above-described coloring material inks.

[0029] Note that the recording head 100 used in the recording apparatus 100 of the present disclosure is not limited to the example shown in FIG. 3. The density, arrangement, diameter, ink ejection amount, ink type, etc. of the ejection ports can be appropriately changed.

[0030] (3) Control Configuration of the Recording Device Figure 4 is a block diagram showing the control configuration of the recording device 100 in this embodiment. The main control unit 400 of the recording device 100 includes a CPU 401, a ROM 402, a RAM 403, an input / output port 404, a memory 405, etc. Via the input / output port 404, a drive circuit 406, 407, 408, 409, an interface circuit 413, and an operation panel 150, etc. are connected to the main control unit 400.

[0031] The CPU 401 calls and executes the program stored in the memory 405 or the ROM 402 in the work area of the RAM 403. The ROM 402 permanently holds programs such as a boot program and BIOS, data, etc. The RAM 403 temporarily holds the program loaded from the memory 405 or the ROM 402 and provides a work area used for the CPU 401 to execute processing.

[0032] The memory 405 is a storage device such as an HDD, an SSD, or a flash memory. The memory 405 stores programs, various data necessary for program execution, mask patterns described later, and printing job data, printing log data, etc. of the recording device 100.

[0033] The drive circuit 406 is connected to the conveyance motor (LF motor) 410. The drive circuit 407 is connected to the carriage motor (CR motor) 411. The drive circuit 408 is connected to the recording head 109. The drive circuit 409 is connected to the heater 110. In addition, drive circuits are connected to the main control unit 400 for the actuator in the cutting unit that cuts the recording medium P and other drive units. Each drive circuit 406, 407, 408, 409,... drives the conveyance motor, carriage motor, recording head 109, heater 110, actuator, etc. according to the control signal from the CPU 401.

[0034] The operation panel 150 includes a touch panel display and buttons, etc., and displays the display information input from the CPU 401. The display information includes, for example, the state of the recording device 100 and the information of the recording medium P, etc. Further, the operation panel 150 receives operations for starting and stopping the recording operation from the user and inputs an operation signal to the CPU 401.

[0035] Furthermore, the main control unit 400 is connected to the host device 414 via the interface circuit 413. The host device 414 is a computer such as a PC, a smartphone, or a server device, etc., and transmits a print job to the recording device 100. The main control unit 400 stores the received print job in the memory 405 or the RAM 403 and executes a recording operation according to the print job. The main control unit 400 transmits information regarding the state of the recording device 100 and the recording medium P, etc. to the host device 414 and causes it to be displayed on the display unit of the host device 414.

[0036] (4) Multi-pass recording method As described above, the recording device 100 of the present embodiment records an image by a so-called multi-pass recording method in which each of the inks of K, C, M, Y, and RCT is used to complete the recording of an image by performing a plurality of recording scans on the same recording area on the recording medium P. This multi-pass recording method will be described below.

[0037] FIG. 5 is a diagram for explaining the multi-pass recording method. FIG. 5 shows an example of 6 passes. In the case of 6-pass recording, the ejection port row 31 of the recording head 109 is divided into 6 ejection port groups in the Y direction (ejection port groups A1 to A6), and for the recording area 500 of the recording medium P, ink is ejected once for each division, and the image is completed by a total of 6 recording scans. The length in the Y direction of each of the ejection port groups A1 to A6 corresponds to the width in the Y direction of the recording area 500.

[0038] In actuality, the recording medium P is conveyed downstream in the Y direction (Y(+) direction) between one recording scan of the recording head 109 and the next recording scan, but in this figure, for the sake of explanation, a figure in which the recording head 109 is moved upstream in the Y direction (Y(-) direction) is used.

[0039] In the first recording scan (first pass), the recording area 500 on the recording medium P and the ejection port groups A1 are in a facing positional relationship. In this positional relationship, the recording head 109 scans in the X direction. During the scan, ink ejection according to the recording data corresponding to the first recording scan is performed from each of the ejection port groups A1 to A6 of the recording head 109. As a result, focusing on the recording area 500, the ink droplets ejected from the ejection port group A1 land, and an image is formed. Note that the recording data is generated for each type of ink.

[0040] After the first recording scan, the recording medium P is conveyed in the Y direction by a distance corresponding to one ejection port group, that is, by the width of the recording area 500. By this conveyance operation, the ejection port group A2 comes to face the recording area 500 in a positional relationship.

[0041] In the second recording scan (second pass), the ink droplets ejected from the ejection port group A2 land on the recording area 500. After the second recording scan, the recording medium P is conveyed in the Y direction by a distance corresponding to one ejection port group. By this conveyance operation, the ejection port group A3 comes to face the recording area 500 in a positional relationship.

[0042] Thereafter, in the third to sixth recording scans as well, the ejection operation from the recording head 109 and the conveyance operation of the recording medium P are alternately performed. As a result, the ink droplets ejected from the ejection port groups A3 to A6 land on the recording area 500. In this way, the recording for six passes with respect to the recording area 500 is completed.

[0043] (5) Mask pattern FIG. 6 is a diagram showing a general mask pattern used when generating recording data. Among the mask patterns shown in FIG. 6, the pixels filled in black indicate the pixels that permit ink ejection (hereinafter referred to as recording-permitted pixels), and the pixels shown as blank indicate the pixels that do not permit ink ejection (hereinafter referred to as non-recording-permitted pixels). Even for the pixels whose ink ejection is determined by quantization data, by applying the mask pattern, ink is ejected for the recording-permitted pixels and no ink is ejected for the non-recording-permitted pixels.

[0044] Note that FIG. 6 shows six types of mask patterns 601 to 606 with a size of 4 pixels (in the Y direction) × 8 pixels (in the X direction) as one unit area. The mask pattern 601 is applied to the ejection port group A1, the mask pattern 602 is applied to the ejection port group A2, and the mask pattern 603 is applied to the ejection port group A3. Similarly, the mask patterns 604 to 606 are applied to the ejection port groups A4 to A6, respectively. By repeatedly applying these mask patterns 601 to 606 in the X direction and the Y direction, distribution processing is performed for all of the quantization data corresponding to the recording area, and recording data is generated.

[0045] The number of pixels existing in the unit area shown in FIG. 6 is 4 pixels × 8 pixels = 32 pixels, and the total number of recording-permitted pixels (black) in the six types of mask patterns 601 to 606 is 48 pixels. When the ratio of the number of recording-permitted pixels to the number of pixels in the mask pattern is called the recording rate, the total recording rate of the mask patterns shown in FIG. 6 is 150 (= 48 / 32 × 100)%.

[0046] Here, looking at the mask patterns used for each recording scan with respect to the recording area 500 of interest, the mask pattern 601 corresponding to the first recording scan (ejection port group A1) and the mask pattern 606 corresponding to the sixth recording scan (ejection port group A6) each have 5 to 6 recording-permitted pixels arranged. Therefore, the recording rates of the mask patterns corresponding to the first and sixth recording scans are each approximately 20% (= 6 / 32 × 100).

[0047] Also, in the mask pattern 602 corresponding to the second (second pass) recording scan (nozzle group A2) and the mask pattern 605 corresponding to the fifth (fifth pass) recording scan (nozzle group A5), eight recording allowable pixels are arranged respectively. Therefore, the recording rates of the mask patterns corresponding to the second and fifth recording scans are approximately 25% (= 8 / 32 × 100) respectively.

[0048] And, in the mask pattern corresponding to the third (third pass) recording scan (nozzle group A3) and the mask pattern corresponding to the fourth (fourth pass) recording scan (nozzle group A4), eleven recording allowable pixels are arranged respectively. Therefore, the recording rates of the mask patterns corresponding to the third and fourth recording scans are approximately 30% (= 11 / 32 × 100) respectively.

[0049] That is, when using the mask pattern 600 shown in FIG. 6, among the 1st to 6th passes, the ink amounts ejected in the third and fourth passes are the largest, and the ink amounts ejected in the first pass and the sixth pass are the smallest. That is, in the nozzle groups on the end side in the conveyance direction, the recording rate is the minimum, and in the central portion, it is the maximum.

[0050] (6) Ink composition (Outline of ink composition) Details of each ink constituting the ink set used in this embodiment will be described. Hereinafter, “part” and “%” are based on mass unless otherwise specified.

[0051] (6-1) Composition of each ink Hereinafter, the composition of each ink will be described in detail.

[0052] The colorant inks (C, M, Y, K), clear ink (Em), and reaction liquid ink (RCT) used in this embodiment all contain a water-soluble organic solvent. The water-soluble organic solvent preferably has a boiling point of 150°C or higher and 300°C or lower for reasons of wettability and moisture retention of the nozzle surface of the recording head 109.

[0053] Also, from the viewpoints of the function of the film-forming aid for the resin fine particles and the swelling solubility in the recording medium P on which the resin layer is formed, ketone compounds such as acetone and cyclohexanone, propylene glycol derivatives such as tetraethylene glycol dimethyl ether, and heterocyclic compounds having a lactam structure typified by N-methyl-pyrrolidone and 2-pyrrolidone are particularly preferred. From the viewpoint of ejection performance, the content of the water-soluble organic solvent is preferably 3 wt% or more and 30 wt% or less.

[0054] Specific examples of the water-soluble organic solvent include 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. Amides such as dimethylformamide and dimethylacetamide. Ketones or ketoalcohols such as acetone and diacetone alcohol. Ethers such as tetrahydrofuran and dioxane. Polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Ethylene glycol. Or alkylene glycols having 2 to 6 carbon atoms in the alkylene group such as 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. N-methyl-2-pyrrolidone, 2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and the like.

[0055] The water-soluble organic solvent as described above can be used alone or as a mixture. Also, it is desirable to use deionized water as the water. Note that the content of the water-soluble organic solvent in the reaction liquid ink (RCT) is not particularly limited, but for the colorant inks (C, M, Y, K), in order to give desired physical property values as necessary, in addition to the above components, surfactants, defoamers, preservatives, fungicides, etc. can be appropriately added.

[0056] Also, the colorant inks (C, M, Y, K) and the reaction liquid ink (RCT) used in this embodiment all contain surfactants. The surfactant is used as a penetrant for the purpose of improving the permeability of the ink to the inkjet-exclusive recording medium P. The greater the amount of the surfactant added, the stronger the property of reducing the surface tension of the ink, and the wettability and permeability of the ink to the recording medium P are improved.

[0057] In this embodiment, a small amount of an acetylene glycol EO adduct or the like is added as a surfactant, and the surface tension of each ink is adjusted to be 30 dyn / cm or less, and further the difference in the surface tension between the inks is within 2 dyn / cm. More specifically, the surface tension of each ink is adjusted to be about 22 - 24 dyn / cm. The surface tension was measured using a fully automatic surface tension meter CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.). Note that as long as the surface tension of the ink can be measured, the measuring instrument is not limited to the one exemplified above.

[0058] Also, the pH of each ink in this embodiment is stable on the alkaline side, and its value is 8.5 - 9.5. From the viewpoint of preventing the elution and deterioration of the members in contact with each ink in the recording apparatus 100 and the recording head 109, and the decrease in the solubility of the dispersion resin in the ink, it is preferable that the pH of each ink is 7.0 or more and 10.0 or less. The pH was measured using a pH METER model F-52 manufactured by Horiba, Ltd. Note that as long as the pH of the ink can be measured, the measuring instrument is not limited to the one exemplified above.

[0059] (6-2) Reaction Liquid In this embodiment, in order to solve problems such as bleeding and beading, a reaction solution for insolubilizing part or all of the solid components of the coloring material ink is used.

[0060] For the purpose of insolubilizing the dissolved dyes, dispersed pigments and resins, examples of the reaction solution include a solution containing polyvalent metal ions (such as magnesium nitrate, magnesium chloride, aluminum sulfate, iron chloride, etc.). As one type of flocculation action using such cations, a system using a low-molecular-weight cationic polymer flocculant for the purpose of charge neutralization of water-soluble resin fine particles and insolubilization of anionic soluble substances can also be used.

[0061] Another reaction system is an insolubilization system using a reaction solution that utilizes a pH difference. As described above, in general, the coloring material inks used for inkjet recording are mostly stable on the alkaline side due to the properties of the coloring materials and the like. The pH is generally around 7 to 10, and is often set mainly around 8.5 to 9.5 in consideration of the influence of the external environment and other factors from an industrial perspective. In order to aggregate and solidify the coloring material ink of such a system, an acidic solution can be mixed in to change the pH, thereby destroying the stable state and aggregating the dispersed components. For such an action, a solution exhibiting acidity can also be used as the reaction solution.

[0062] (6-3) Water-soluble resin fine particles The colorant ink and the clear ink (Em) used in this embodiment contain water-soluble resin fine particles. The "water-soluble resin fine particles" mean polymer fine particles present in a state of being dispersed in water. Specifically, acrylic resin fine particles synthesized by emulsion polymerization of monomers such as (meth)acrylic acid alkyl esters and (meth)acrylic acid alkylamides; styrene-acrylic resin fine particles synthesized by emulsion polymerization of monomers such as (meth)acrylic acid alkyl esters and (meth)acrylic acid alkylamides and styrene; polyethylene resin fine particles, polypropylene resin fine particles, polyurethane resin fine particles, styrene-butadiene resin fine particles, and the like. Further, core-shell type resin fine particles in which the polymer composition is different between the core part and the shell part constituting the resin fine particles, or resin fine particles obtained by using acrylic fine particles synthesized in advance as seed particles and carrying out emulsion polymerization around them to control the particle size may be used. Furthermore, hybrid type resin fine particles in which different resin fine particles such as acrylic resin fine particles and urethane resin fine particles are chemically bonded may be used.

[0063] (6-4) Composition of Each Ink Details of each ink constituting the ink set used in this embodiment will be described. Hereinafter, "parts" and "%" are based on mass unless otherwise specified.

[0064] (6-4-1) Black Ink (i) Preparation of Dispersion First, an anionic polymer P-1 [styrene / butyl acrylate / acrylic acid copolymer (polymerization ratio (weight ratio)=30 / 40 / 30), acid value 202, weight average molecular weight 6500] was prepared. This was neutralized with an aqueous potassium hydroxide solution and diluted with ion-exchanged water to prepare a homogeneous 10 mass% water-soluble resin fine particle dispersion.

[0065] 600 g of the above polymer solution, 100 g of carbon black, and 300 g of ion-exchanged water were mixed and mechanically stirred for a predetermined time, and then non-dispersed matter containing coarse particles was removed by centrifugation to obtain a black dispersion. The obtained black dispersion had a pigment concentration of 10 mass%.

[0066] (ii) Preparation of Ink For the preparation of the ink, the above black dispersion is used, and the following components are added thereto to a predetermined concentration. Then, after sufficiently mixing and stirring these components, pressure filtration is performed using a microfilter with a pore size of 2.5 μm (manufactured by Fujifilm Corporation) to prepare a pigment ink having a pigment concentration of 2% by mass.

[0067] 20 parts of the above black dispersion 40 parts of the above water-soluble resin fine particle dispersion 0.05 part of Zonyl FSO-100 (fluorine-based surfactant manufactured by DuPont) 15 parts of 2-methyl-1,3-propanediol 5 parts of 2-pyrrolidone 0.5 part of acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) The balance of ion-exchanged water

[0068] (6-4-2) Cyan Ink (i) 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 is prepared by a conventional method, neutralized with an aqueous potassium hydroxide solution, and diluted with ion-exchanged water to prepare a homogeneous 50% by mass water-soluble resin fine particle dispersion.

[0069] 200 g of the above polymer solution, 100 g of C.I. Pigment Blue 15:3, and 700 g of ion-exchanged water are mixed, mechanically stirred for a predetermined time, and then non-dispersed substances containing coarse particles are removed by centrifugation to obtain a cyan dispersion. The obtained cyan dispersion had a pigment concentration of 10% by mass.

[0070] (ii) Preparation of Ink The ink is prepared by using the above cyan dispersion liquid, adding the following components thereto to a predetermined concentration, and after sufficiently mixing and stirring these components, subjecting them to pressure filtration through a microfilter with a pore size of 2.5 μm (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 2% by mass.

[0071] 20 parts of the above cyan dispersion liquid 40 parts of the above water-soluble resin fine particle dispersion liquid 0.05 part of Zonyl FSO-100 (a fluorine-based surfactant manufactured by DuPont) 15 parts of 2-methyl-1,3-propanediol 5 parts of 2-pyrrolidone 0.5 part of acetylene glycol EO adduct (manufactured by Kawaken Fine Chemicals Co., Ltd.) The balance of ion-exchanged water

[0072] (6-4-3) Magenta ink (i) Preparation of the dispersion liquid 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, neutralized with an aqueous potassium hydroxide solution, and diluted with ion-exchanged water to prepare a homogeneous 50% by mass water-soluble resin fine particle dispersion liquid.

[0073] 100 g of the above polymer solution, 100 g of C.I. Pigment Red 122, and 800 g of ion-exchanged water were mixed, mechanically stirred for a predetermined time, and then non-dispersed substances containing coarse particles were removed by centrifugation to obtain a magenta dispersion liquid. The obtained magenta dispersion liquid had a pigment concentration of 10% by mass.

[0074] (ii) Preparation of the ink The ink is prepared by using the above magenta dispersion liquid, adding the following components thereto to a predetermined concentration, and after sufficiently mixing and stirring these components, subjecting them to pressure filtration through a microfilter with a pore size of 2.5 μm (manufactured by Fujifilm Corporation) to prepare a pigment ink with a pigment concentration of 3% by mass.

[0075] 30 parts of the above magenta dispersion liquid 40 parts of the above water-soluble resin fine particle dispersion Zonyl FSO-100 (fluorine-based surfactant manufactured by DuPont) 0.05 part 2-methyl-1,3-propanediol 15 parts 2-pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 0.5 part Ion-exchanged water the balance

[0076] (6-4-4) Yellow Ink (i) Preparation of dispersion First, the anionic polymer P-1 was neutralized with an aqueous potassium hydroxide solution and diluted with ion-exchanged water to prepare a homogeneous 10 mass% water-soluble resin fine particle dispersion.

[0077] 300 g of the above polymer solution, 100 g of C.I. Pigment Yellow 74, and 600 g of ion-exchanged water were mixed and mechanically stirred for a predetermined time, and then non-dispersed matter containing coarse particles was removed by centrifugation to obtain a yellow dispersion. The obtained yellow dispersion had a pigment concentration of 10 mass%.

[0078] (ii) Preparation of ink The following components were mixed, sufficiently stirred for dissolution and dispersion, and then pressure-filtered through a microfilter (manufactured by Fujifilm Corporation) with a pore size of 1.0 μm to prepare a pigment ink with a pigment concentration of 4 mass%.

[0079] 40 parts of the above yellow dispersion 40 parts of the above water-soluble resin fine particle dispersion Zonyl FSO-100 (fluorine-based surfactant manufactured by DuPont) 0.025 part 2-methyl-1,3-propanediol 15 parts 2-pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemical Co., Ltd.) 1 part Ion-exchanged water the balance

[0080] (6-4-5) Clear Ink Preparation of Ink The following components were mixed, stirred well for dissolution and dispersion, and then pressure-filtered through a microfilter with a pore size of 1.0 μm (manufactured by Fujifilm Corporation).

[0081] 80 parts of the above water-soluble resin fine particle dispersion Zonyl FSO-100 (fluorine-based surfactant manufactured by DuPont) 0.025 part 2-Methyl-1,3-propanediol 15 parts 2-Pyrrolidone 5 parts Acetylene glycol EO adduct (manufactured by Kawaken Fine Chemicals Co., Ltd.) 1 part Ion-exchanged water the balance

[0082] (6-4-6) reaction solution The reaction solution used in this embodiment contains a reactive component that reacts with the pigment contained in the ink to aggregate or gel the pigment. Specifically, this reactive component is a component that can destroy the dispersion stability of the ink when mixed with an ink having a pigment stably dispersed in an aqueous medium by the action of an ionic group, etc., on a recording medium or the like. In detail, glutaric acid is used in this embodiment.

[0083] Note that it is not necessarily required to use glutaric acid. In this embodiment, various organic acids or polyvalent metal salts can be used as the reactive component of the reaction solution as long as they are water-soluble. The content of the organic acid or polyvalent metal salt 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 reaction solution.

[0084] Preparation of Ink In this embodiment, as described above, glutaric acid (manufactured by Fujifilm Wako Pure Chemical Corporation) was used, and the following components were mixed to prepare reaction solution 1.

[0085] Glutaric acid 2 parts 2-Pyrrolidone 5 parts 2-Methyl-1,3-propanediol 15 parts 0.5 part of acetylene glycol EO adduct (manufactured by Kawaken Fine Chemicals Co., Ltd.) Ion-exchanged water, the balance

[0086] (7) Recording medium In this embodiment, a low-permeability recording medium in which moisture hardly penetrates inside is used. The low-permeability recording medium is a medium that has no water absorbency or has an extremely small water absorption amount. Therefore, when using an aqueous ink that does not contain an organic solvent, the ink is repelled, making it difficult to form an image. On the other hand, it is excellent in water resistance and weather resistance and is suitable as a medium used for records used outdoors. Usually, a recording medium having a water contact angle of 45° or more, preferably 60° or more at 25°C is used.

[0087] Examples of the low-permeability recording medium include a recording medium in which a plastic layer is formed on the outermost surface of the base material, a recording medium in which an ink receiving layer is not formed on the base material, or a sheet, film, banner, etc. made of glass, Yupo, plastic, etc. Examples of the plastic used for coating include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, polypropylene, etc. These low-permeability recording media are excellent in water resistance, light resistance, and abrasion resistance, and are generally used when recording records for outdoor display.

[0088] As an example of a method for evaluating the permeability of a recording medium, the Bristol method described in "Liquid Absorbency Test Method for Paper and Paperboard" of JAPAN TAPPI Paper Pulp Test Method No. 51 can be used. In the Bristol method, a predetermined amount of ink is injected into a holding container having an opening slit of a predetermined size, and through the slit, it is brought into contact with a recording medium that has been processed into a strip shape and wound around a disk. While fixing the position of the holding container, the disk is rotated to measure the area (length) of the ink band that is transferred to the recording medium. From the area of this ink band, the transfer amount (ml·m-2) per unit area per second can be calculated. In the present embodiment, a recording medium in which the ink transfer amount (water absorption amount) at 30 msec1 / 2 by the above Bristol method is less than 10 ml·m-2 is regarded as a low-permeability recording medium. Therefore, it may be a non-permeable recording medium.

[0089] In the present embodiment, as the low-permeability recording medium, Scotchcal Graphic Film (IJ1220-10), which is a self-adhesive vinyl film manufactured by 3M, was used.

[0090] (8) Recording control (8-1) Stopping the recording operation There may be a stop for a predetermined time between a certain recording scan and a subsequent recording scan. There are several reasons for the stop, and representative ones are shown.

[0091] One is a stop of about several seconds for wiping off the ink attached to the discharge port surface of the head by a mechanism that moves a cloth or a wiper. The second is a stop of ten to several tens of seconds for sucking the ink from the discharge port of the head by a suction mechanism to recover poor ink discharge. In addition, there are stops for temperature drop when the head overheats, stops for cutting the recording medium, and the like.

[0092] (8-2) Problems due to stopping the recording operation When the recording operation stops during the recording operation, color and gloss changes may occur in the area recorded in the recording scan after resuming the recording operation, and unevenness may occur.

[0093] FIG. 7 is a diagram for explaining the occurrence of unevenness during stoppage. This figure shows a multi-pass recording with six passes. FIG. 7(a) shows the respective positions of the ejection port row 31 in each of the four recording scans before stoppage, and the image 710 recorded in the recording scans up to before stoppage. Let the recording scan immediately before stoppage be the i-th recording scan, the recording scan one before that be the (i - 1)-th, the recording scan two before that be the (i - 2)-th, the recording scan three before that be the (i - 3)-th, and so on. Regions 711 to 719 show the recording states in the recording regions in the recording scans up to the i-th scan in shading.

[0094] In the recording scans up to the (i - 3)-th scan, ink droplets land on regions 711 to 716, In the (i - 2)-th recording scan, ink droplets land on regions 712 to 717, In the (i - 1)-th recording scan, ink droplets land on regions 713 to 718, In the i-th recording scan, ink droplets land on regions 714 to 719. Regions 711 to 714 show six recordings, region 715 shows five recordings, region 716 shows four recordings, region 717 shows three recordings, region 718 shows two recordings, and region 719 shows one recording. That is, the images in regions 711 to 714 are complete. Regions 715 to 719 are in a state where the images are incomplete.

[0095] After the i-th recording scan, the recording operation is stopped, and after a predetermined stop time has elapsed, the recording operation is restarted. FIG. 7(b) shows the state where the recording scans from the (i + 1)-th to the (i + 6)-th have progressed after restart. In the (i + 1)-th recording scan, ink droplets land on regions 715 to 720, In the (i + 2)-th recording scan, ink droplets land on regions 716 to 721, In the (i + 3)-th recording scan, ink droplets land on regions 717 to 722, In the (i + 4)-th recording scan, ink droplets land on regions 718 to 723, In the (i + 5)-th recording scan, ink droplets land on regions 719 to 724, In the (i + 6)-th recording scan, ink droplets land on regions 720 to 725.

[0096] As described above, the region 730 including the regions 715 to 719 is a region where six multi-pass recordings were not completed before the stop and the image was incomplete. Mura occurs in this region 730.

[0097] In the inventors' study, it was found that there is a difference in the degree of mura depending on the position within the region 730 that was being recorded before the stop. Specifically, among the regions 730 that were being recorded before the stop, regions with a small number of recording times (number of passes) tend to have a relatively large degree of mura, and in particular, it was found that mura occurs significantly in the region 719 where only one recording (only the first pass) was made before the stop.

[0098] The reason considered for this is the bleeding of ink droplets. FIG. 8 is a diagram for explaining the bleeding phenomenon of ink droplets when recording is performed in a normal operation without stopping. FIG. 8(a) shows the state of the ink droplet 800 that landed on the recording medium P after one recording, and FIG. 8(b) shows the state immediately after the ink droplet 801 of the subsequent pass was recorded adjacent to the ink droplet 800. FIG. 8(c) is a diagram showing the state after a predetermined time has elapsed since the ink droplet 801 of the subsequent pass was recorded. As shown in FIG. 8, most of the ink droplets 800 in the first pass are recorded in isolation, but during the subsequent pass recording, the ink droplet 800 in the first pass and the ink droplet 801 in the subsequent pass are in contact. As a result, a certain amount of bleeding occurs while a predetermined time elapses.

[0099] On the other hand, FIG. 9 is a diagram for explaining the bleeding state of ink droplets when recording is stopped after one-time recording (after the first pass recording) and then recording is resumed. FIG. 9(a) shows the state of the ink droplet 900 that has landed on the recording medium P after one-time recording. After that, recording is stopped, and when the recording operation is resumed after a predetermined time has elapsed, as shown in FIG. 9(b), the ink droplet 901 of the subsequent pass (the second pass) is recorded adjacent to the ink droplet 900. During the stop, the moisture of the ink droplet 900 in the first pass dries and its viscosity increases. FIG. 9(c) shows the states of the respective ink droplets 900 and 901 after a predetermined time has elapsed since the ink droplet 901 of the subsequent pass (the second pass) was recorded. When recording is stopped, even after a predetermined time has elapsed, the degree of bleeding is small. This is presumably because the viscosity of the ink droplet 900 in the first pass has increased due to the stop.

[0100] When comparing the case where recording is not stopped (FIG. 8(c)) with the case where recording is stopped (FIG. 9(c)), there is a difference in the degree of bleeding of the ink droplets, which is visually recognized as a difference in color and gloss and causes unevenness. This phenomenon is particularly likely to occur when recording is stopped in a state where the ink droplets are recorded in isolation. During the stop, among the recording areas that were being recorded, the area with more isolated ink droplets, that is, the area with a smaller number of recorded passes, has a greater degree of unevenness, and particularly significant unevenness occurs in the recording area of the first pass with a large number of isolated ink droplets.

[0101] Also, when the stop time is short, the drying of the ink droplets is also slight, so the unevenness is relatively slight. When the stop time is long, excessive drying occurs, so the degree of unevenness also increases.

[0102] (8-3) Recording control during stop As described above, since unevenness is more likely to occur as the stop time becomes longer, among the multiple types of stops, it is preferable to perform the recording control at the time of stop in the present embodiment when the stop time is longer than a predetermined time. For example, when the stop time is ten seconds or more, the recording control at the time of stop in the present embodiment shall be performed. Note that the stop time to which the recording control of the present embodiment is applied is not limited to the case of ten seconds or more, and it may also be a stop time less than or more than that. Further, the stop time to which the recording control at the time of stop in the present embodiment is applied may be determined in consideration of conditions. The conditions are, for example, factors affecting the drying of the ink such as the ambient temperature and humidity, the type of the recording medium (hygroscopicity, etc.), the discharge state of the head (increase or decrease in the amount of ink droplets and discharge speed), the recording data ratio of the recorded image, and the like.

[0103] (8-4) Mask pattern Next, in the present embodiment, the mask pattern used for the recording control at the time of stop will be described. In the normal recording scan other than before and after the stop, it is assumed that the recording scan is performed with the mask pattern 600 shown in FIG. 6 (hereinafter referred to as the normal mask 600). Note that in the present embodiment, the mask pattern used in the normal recording scan is not limited to the normal mask 600 shown in FIG. 6, and any mask pattern may be used. Also, in FIG. 6, the total recording rate is set to 150%, but other recording rates may also be used.

[0104] (8-4-1) Mask pattern before stop FIG. 10(a) is a diagram showing an example of the mask pattern 1000 before stop used in the recording scan immediately before the stop (the i-th recording scan). The mask pattern 1000 before stop includes a mask pattern 1001 in which no recording-permitted pixels are provided in the discharge port group A1 corresponding to the first pass recording for the recording area of interest. That is, non-recording (recording rate 0%) is set for the unrecorded (the number of recorded times is less than 1) recording area.

[0105] For the mask patterns 1002 to 1006 of the ejection port groups A2 to A6 corresponding to the recording in the 2nd to 6th passes for the target recording area, they are the same as the mask patterns 602 to 606 of the ejection port groups A2 to A6 of the normal mask 600. That is, when the number of recorded times for the target recording area is 1 or more, recording is performed such that the recording rate is the same as that of the mask pattern 600 applied in normal recording scanning.

[0106] Note that the recording rate of the mask pattern 1001 used for the ejection port group A1 of the mask pattern 1000 is 0%, the recording rate of the mask pattern 1002 used for the ejection port group A2 is about 25%, the recording rate of the mask pattern 1003 used for the ejection port group A3 is about 30%, the recording rate of the mask pattern 1004 used for the ejection port group A4 is about 30%, the recording rate of the mask pattern 1005 used for the ejection port group A5 is about 25%, and the recording rate of the mask pattern 1006 used for the ejection port group A6 is about 20%.

[0107] (8-4-2) Mask pattern after restart After the elapse of the stop time, the recording operation is restarted. This recording scan after restart (the (i + 1)-th scan) is performed on the same recording area as the recording scan before stop (the i-th scan). FIG. 10(b) is a diagram showing an example of the mask pattern 1010 after restart used in the recording scan after restart (the (i + 1)-th recording scan). In the mask pattern 1010 after restart, the ejection port groups A2 to A6 where there were recording-permitted pixels in the mask pattern 1000 before stop are set to non-recording (recording rate 0%), and recording-permitted pixels are provided only in the ejection port group A1 that was non-recording before stop. The mask pattern 1011 of the ejection port group A1 is the same as the mask pattern 601 of the 1st pass (ejection port group A1) in the normal mask 600. That is, for the recording area that was non-recording in the recording scan before stop, recording is performed to supplement the immediately preceding non-recording after restart.

[0108] Note that in the mask pattern 1010 after restart, the recording rate of the mask pattern 1001 for the ejection port group A1 is about 20%, and the recording rates of the mask patterns 1002 to 1006 for the ejection port groups A2 to A6 are 0%.

[0109] That is, by two recording scans (the i-th and the (i + 1)-th) before and after the stop, the recording rates satisfying the same recording rate as the normal recording scan are respectively achieved in the ejection port groups A1 to A6. The total recording rate of the mask patterns 1001 and 1011 used for the ejection port group A1 is about 20%, the total recording rate of the mask patterns 1002 and 1012 used for the ejection port group A2 is about 25%, the total recording rate of the mask patterns 1003 and 1013 used for the ejection port group A3 is about 30%, the total recording rate of the mask patterns 1004 and 1014 used for the ejection port group A4 is about 30%, the total recording rate of the mask patterns 1005 and 1015 used for the ejection port group A5 is about 25%, and the total recording rate of the mask patterns 1006 and 1016 used for the ejection port group A6 is about 20%. Therefore, the recording rates in the two recording scans before and after the stop are consistent with the recording rate of the normal mask 600 shown in FIG. 6.

[0110] (8-5) Recording control using mask patterns With reference to FIG. 11, the recording control using the pre-stop mask pattern 1000 and the post-resume mask pattern 1010 will be described. FIG. 11 shows the relationship between the mask pattern to be applied, the presence or absence of conveyance of the recording medium after the recording scan, and the scanning direction with respect to the number of recording scans since the start of the recording operation. In the present embodiment, the recording scan immediately before the stop is defined as the i-th recording scan.

[0111] In the recording scans from the 1st to the (i - 1)-th recording scans, the normal mask 600 shown in FIG. 6 is used, and the recording medium is conveyed after each recording scan. Also, taking the 1st recording scan as the forward direction, bidirectional recording in which the next recording scan is performed in the reverse return direction is repeatedly performed.

[0112] A stop occurs between the i-th recording scan and the (i + 1)-th recording scan. The i-th recording scan is the recording scan immediately before the stop, and the (i + 1)-th recording scan is the first recording scan after the stop time has elapsed and after resumption.

[0113] In the i-th recording scan, the pre-stop mask pattern 1000 shown in FIG. 10(a) is used. As a result, the ejection port group A1 becomes non-recording, and an image is not recorded in the area on the recording medium P facing the ejection port group A1 at this time. For the ejection port groups A2 to A6, an image according to the pre-stop mask pattern 1000 is recorded. Also, the conveyance of the recording medium after the i-th recording scan is controlled not to be performed.

[0114] (In the (i + 1)-th recording scan, the post-resume mask pattern 1010 shown in FIG. 10(b) is used. As a result, the ejection port groups A2 to A6 become non-recording, and an image is not recorded in the area on the recording medium P facing the ejection port groups A2 to A6 at this time. On the other hand, for the ejection port group A1 that was non-recording in the i-th recording scan, an image according to the post-resume mask pattern 1010 is recorded. Also, after the (i + 1)-th recording scan, the recording medium is conveyed.

[0115] Also, in this embodiment, the i-th recording scan and the (i + 1)-th recording scan are in the same recording scan direction. As shown in the table of FIG. 11, both the i-th recording scan immediately before the stop and the (i + 1)-th recording scan immediately after the resume are, for example, forward scans. This is to prevent the correspondence of the reciprocation of the recording data from being interchanged and the control from becoming complicated due to additional recording scans. Therefore, when the i-th recording scan is completed, the main control unit 400 of the recording apparatus 100 returns the carriage unit 102 to a position on the opposite side in the X direction (main scan direction) before, during, or after the stop. After that, the added (i + 1)-th recording scan is performed in the same scan direction as the i-th recording scan.

[0116] For subsequent recording scans (the (i + 2)-th, (i + 3)-th,...), the normal mask 600 is used, the recording medium is conveyed after each recording scan, and the scan directions are alternately repeated in the reverse direction and the forward direction.

[0117] FIG. 12 is a flowchart showing the flow of recording control executed in the present embodiment. The processes shown in this flowchart are executed by the CPU 401 after a program stored in the ROM 402 or the memory 405 of the main control unit 400 of the recording apparatus 100 is called by the CPU 401, expanded in the RAM 403. The CPU 401 starts this process when receiving a print job from the host device 414. In the following description, the symbol "S" means step.

[0118] In S1201, the CPU 401 determines whether there is a stop request. If there is no stop request (S1201; NO), the process proceeds to S1202. If there is a stop request (S1201; YES), the process proceeds to S1205.

[0119] In S1202, the CPU 401 performs normal recording scanning. In normal recording scanning, the CPU 401 generates recording data for one scan using the normal mask 600 and outputs it to the drive circuit 408. The drive circuit 408 drives the recording head 109 so that recording is performed on the recording area on the recording medium P facing the recording head 109 while the carriage unit 102 performs one scan under the control of the CPU 401. The recording head 109 is controlled by the drive circuit 408 to eject ink from a plurality of ink ejection ports and perform recording for one scan while synchronized with the carriage movement.

[0120] In S1203, the CPU 401 conveys the recording medium P. In the conveyance operation, the CPU 401 controls the drive circuit 406 to drive the conveyance motor (LF motor) 410 and conveys the recording medium P in the Y direction by a predetermined movement amount. This movement amount is 1 / n of the column direction length of the ejection port array of the recording head 109 when the number of passes in the multi-pass is n times.

[0121] In S1204, the CPU 401 determines whether the recording of one page has been completed. If there is subsequent recording data, it is determined that the recording has not been completed (S1204; NO), and the process returns to S1201. If there is no subsequent recording data, it is determined that the recording has been completed (S1204; YES), and this flowchart ends.

[0122] In S1205, the CPU 401 switches to the pre-stop mask pattern 1000 and generates recording data for the i-th recording scan.

[0123] In S1206, the CPU 401 performs the i-th recording scan. In the i-th recording scan, the ejection port group A1 facing the unrecorded recording area among the recording areas facing the ejection port array is made non-recordable by the mask pattern 1001. That is, no recording-allowed pixels are provided. As a result, no image is recorded in the unrecorded recording area. For the ejection port groups A2 to A6, the mask patterns 1002 to 1006 are applied. The mask patterns 1002 to 1006 have recording rates corresponding to the mask patterns 602 to 606 used for the ejection port groups A2 to A6 of the normal mask 600, respectively. Therefore, recording similar to normal recording scan is performed. The CPU 401 controls not to convey the recording medium P after the i-th recording scan.

[0124] In S1207, the CPU 401 stops the recording operation until a predetermined stop time elapses. During the stop time, if other operations other than the recording operation are to be performed, the CPU 401 executes that operation.

[0125] In S1208, the CPU 401 switches to the post-resume mask pattern 1010 and generates recording data for the (i + 1)-th recording scan. The switching to the post-resume mask pattern 1010 and the generation of recording data in S1208 may be performed before the predetermined stop time elapses, and the recording data may be stored in the buffer (memory 405).

[0126] In S1209, the CPU 401 performs the (i + 1)-th recording scan according to the recording data generated in S1208. In the (i + 1)-th recording scan, the ejection port group A1 facing the recording area that was not recorded in the i-th (before stopping) recording scan is recorded using the mask pattern 1011. The mask pattern 1011 has the same recording rate as the mask pattern 601 used for the ejection port group A1 of the normal mask 600. Therefore, recording similar to normal recording scans is performed. Also, in the (i + 1)-th recording scan, for the ejection port groups A2 to A6 facing the recording areas that are the 2nd to 6th passes among the recording areas facing the ejection port array, non-recording is performed using the mask patterns 1012 to 1016.

[0127] In S1210, the CPU 401 conveys the recording medium P in the Y direction by a predetermined movement amount. Then, it proceeds to S1204 and determines whether the recording for one page has been completed. If there is no subsequent recording data, it is determined that the recording has ended, and this flowchart ends.

[0128] FIG. 13 shows the changes in the positions of each ejection port in the ejection port array 31 in each recording scan before and after stopping and the formed image. Note that the position of the ejection port array 31 indicates the relative position with respect to the recording area. In FIG. 13, the image 1300 shows the stacked image formed by the recording scan until immediately before the stop (the i-th time). Up to the (i - 1)-th time, the recording scan using the normal mask 600 is performed, and in the i-th recording scan, the pre-stop mask pattern 1000 is used. Therefore, in the i-th recording scan, the area 1301 facing the ejection port group A1 becomes non-recorded (recorded 0 times). Also, by the recording scans up to the i-th time, the area 1302 is recorded 2 times, the area 1303 is recorded 3 times, the area 1304 is recorded 4 times, the area 1305 is recorded 5 times, and the area 1306 is recorded 6 times.

[0129] In the (i+1)th print scan, which is the first print scan after the restart, the post-restart mask pattern 1010 is used. Therefore, in the (i+1)th print scan, the areas 1302 to 1306 facing the ejection opening groups A2 to A6 are not printed, and the first pass is printed on the ejection opening group A1. That is, the first print is performed on the area 1301 that was not printed in the print scan (i) before the stop, and the other areas 1302 to 1306 are not printed.

[0130] In the second and subsequent print scans (i+2 and subsequent) after the restart, the normal mask 600 is used for print scans. An image 1320 in FIG. 13 shows a layered image formed by the i+2th to i+7th print scans. For each of the printing areas 1301 to 1306, the total number of printing times for the images 1300, 1310, and 1320 is six, and it can be seen that multi-pass printing has been completed.

[0131] As described above, the printing device 100 of this embodiment scans the unprinted printing area in a non-printing manner in the printing scan immediately before the stop, and prints the printing area that was unprinted before the stop in a printing scan after the restart so as to satisfy the printing rate in the normal printing scan. Therefore, the first pass printing, in which unevenness was noticeable due to the stop, is performed after the restart, and then the normal printing scan is resumed. Therefore, the drying state of the ink droplets can be made closer to the state in the normal printing scan, and the occurrence of density unevenness due to the stop is suppressed.

[0132] Also, in areas other than the printing area that was not printed in the printing scan before the stop, printing is performed using the same mask pattern as the mask pattern applied in the normal printing scan, and after restarting, printing is not performed. Therefore, printing is performed in the printing area at the same printing rate as in the normal printing scan, just like other printing areas, so printing can be performed without changing the image quality.

[0133] The throughput of the printing control of this embodiment will be explained in comparison with the prior art. FIG. 14 shows the known recording control disclosed in Japanese Patent Application Laid-Open No. 2000-15868 in the same format as FIG. 13. In this known recording control method, multi-pass recording is completed before stopping. Therefore, additional recording scans are required at the i-th, i-1-th, i-2-th, i-3-th, and i-4-th times before stopping. For example, in the case of 6-pass recording as in the present embodiment, 5 additional recording scans are required, and generally, n-1 additional recording scans are required for n-pass recording.

[0134] On the other hand, in the recording control of the present embodiment, as shown in FIG. 13, the additional recording scan is only once (the (i + 1)-th time) after resumption. Therefore, an image can be completed with fewer scan times compared to the prior art, and a decrease in throughput can be suppressed. In particular, this effect becomes greater as the number of passes increases. In multi-pass recording of several tens to several hundreds of passes that may be implemented in a multi-layer recording system represented by white ink, a very large effect can be obtained.

[0135] Although the present embodiment shows an example of recording on a non-absorbent medium as the recording medium, the recording control of the present embodiment may be applied to a general absorbent recording medium such as plain paper. Even in an absorbent recording medium such as plain paper, unevenness similar to that of a non-absorbent recording medium may occur. In that case, by implementing the recording control of the present embodiment, a similar effect can be obtained.

[0136] <Second Embodiment> Next, a second embodiment of the present disclosure will be described. The recording control of the second embodiment provides a non-recording area before and after stopping in the same manner as the first embodiment, but the range of that area is different from that of the first embodiment. Since the configuration of the recording apparatus 100 of the second embodiment is the same as that of the first embodiment, redundant description will be omitted.

[0137] In the first embodiment, an example of suppressing unevenness that significantly occurred in the area where recording was performed once before stopping was shown using six-pass recording as an example. However, when completing an image with a larger number of passes, or due to differences in the physical properties of the ink and other conditions, similar unevenness may occur not only in the area where recording was performed once, but also in the areas where recording was performed twice or three times. Examples of the conditions include the recording data ratio of the recorded image, factors affecting the drying of the ink such as the ambient temperature and humidity, the type of recording medium, the ejection state of the head (increase or decrease in the amount of ink droplets and ejection speed), and the like. In such a case, in multiple recording scans before stopping, it may be better to set the corresponding area as non-recording and perform recording after restarting.

[0138] In the second embodiment, the area to be set as non-recording before stopping is made wider compared to the first embodiment. As a specific example, a mask pattern is applied in which an area with a width corresponding to three of the six divided ejection port groups A1 to A6 is set as non-recording. Then, after restarting, a mask pattern for performing recording is applied only to the area that was set as non-recording before stopping.

[0139] Figs. 15(a), (b), and (c) show mask patterns 1501, 1502, and 1503 used for three recording scans before stopping. The pre-stop mask 1501 shown in Fig. 15(a) is a mask pattern used for the recording scan three times before stopping (the (i - 2)-th time), and is a mask pattern that makes ejection port group A1 non-recording. The pre-stop mask 1502 shown in Fig. 15(b) is a mask pattern used for the recording scan two times before stopping (the (i - 1)-th time), and is a mask pattern that makes ejection port groups A1 and A2 non-recording. The pre-stop mask 1503 shown in Fig. 15(c) is a mask pattern used for the recording scan immediately before stopping (the i-th time), and is a mask pattern that makes ejection port groups A1, A2, and A3 non-recording. In these mask patterns 1501, 1502, and 1503, the mask patterns other than the ejection port groups to be made non-recording are the same as the normal mask 600 shown in Fig. 6.

[0140] Figures 15(d), (e), and (f) show mask patterns 1504, 1505, and 1506 used for three recording scans after resumption. The post-stop mask 1504 shown in Fig. 15(d) is the mask pattern used for the first recording scan (the (i + 1)-th scan) after resumption. The recording allowable pixels identical to the ejection port group A1 of the normal mask 600 in Fig. 6 are assigned to the ejection port group A3. The other ejection port groups A1, A2, A4, A5, and A6 are non-recording. The post-stop mask 1505 shown in Fig. 15(e) is the mask pattern used for the second recording scan (the (i + 2)-th scan) after resumption. The recording allowable pixels identical to the ejection port groups A1 and A2 of the normal mask 600 are assigned to the ejection port groups A2 and A3, respectively. The other ejection port groups A1, A4, A5, and A6 are non-recording. The post-stop mask 1506 shown in Fig. 15(f) is the mask pattern used for the third recording scan (the (i + 3)-th scan) after resumption. The recording allowable pixels identical to the ejection port groups A1 to A3 corresponding to the first to third passes of the normal mask 600 are assigned to the ejection port groups A1 to A3, respectively. The other ejection port groups A4 to A6 are non-recording.

[0141] Note that the mask patterns shown in Fig. 15 are merely examples, and the present embodiment is not limited to this example. In the recording scan after resumption, for the areas that were non-recording in the recording scan before stopping, the recording rate in the normal recording scan may be complemented, and it is not necessarily required to use the same mask pattern as the normal mask. However, it is desirable to ensure that there is no change in image quality between the recording areas before and after stopping and the recording area where recording was performed in the normal recording scan.

[0142] In this regard, after the restart of the present disclosure, masks 1504 to 1506 satisfy the required recording rate through three recording scans after the restart, that is, the same recording rate as when using mask patterns 601 to 603 in the first to third passes of the normal mask 600. Further, the mask pattern is such that the recording rate for the areas that were non-recorded in the recording scan before the stop changes in the same order as in the normal recording scan. That is, for the recording areas that were non-recorded before the stop, a mask with a low recording rate is used in the first pass, similar to the normal mask, and gradually changed to a mask with a higher recording rate. Therefore, ink droplets are overlaid on the recording areas before and after the stop in the same order as in other recording areas. Thus, the same color and gloss as in other recording areas can be maintained.

[0143] The recording control using mask patterns 1501 to 1506 will be described with reference to FIG. 16. FIG. 16 shows the relationship between the mask pattern to be applied, the presence or absence of conveyance of the recording medium after the recording scan, and the recording scan direction with respect to the number of recording scans since the start of the recording operation. In the second embodiment, the recording scan immediately before the stop is defined as the i-th recording scan.

[0144] In the recording scans from the first to the (i - 3)-th recording scans, the normal mask 600 is used, and the recording medium is conveyed after each recording scan. Also, with the first recording scan as the forward direction, bidirectional recording is repeatedly performed in which the next recording scan is recorded in the reverse return direction.

[0145] In the (i - 2)-th recording scan, which is the recording scan three times before the stop, the pre-stop mask 1501 is assigned, and a forward scan in the direction opposite to the (i - 3)-th scan is performed. The recording medium is conveyed after the recording scan.

[0146] In the (i - 1)-th recording scan, which is the recording scan two times before the stop, the pre-stop mask 1502 is assigned, and a reverse scan in the direction opposite to the (i - 2)-th scan is performed. The recording medium is conveyed after the recording scan.

[0147] In the i-th recording scan, which is the recording scan immediately before stopping, the pre-stop mask 1503 is assigned, and a forward scan in the direction opposite to that of the (i-1)-th scan is performed. In the i-th recording scan, the setting is such that the recording medium is not conveyed after the recording scan.

[0148] A stop occurs between the i-th recording scan and the (i+1)-th recording scan. During this stop, or before the first recording scan (the (i+1)-th scan) after resumption, the carriage unit 102 is returned to the reverse position in the X direction. This is the same as in the first embodiment, to prevent the correspondence of the reciprocation of the recording data from being interchanged by additional recording scans and the control from becoming complicated.

[0149] In the (i+1)-th recording scan, which is the first recording scan after resumption, the post-resumption mask 1504 is assigned. The recording scan direction is a forward scan in the same direction as the i-th scan. After the (i+1)-th recording scan, the setting is such that the recording medium is not conveyed.

[0150] In the (i+2)-th recording scan, which is the second recording scan after resumption, the post-resumption mask 1505 is assigned. The scan direction is a reverse scan in the direction opposite to that of the (i+1)-th scan. After the (i+2)-th recording scan, the setting is such that the recording medium is not conveyed.

[0151] In the (i+3)-th recording scan, which is the third recording scan after resumption, the post-resumption mask 1506 is assigned. The scan direction is a forward scan in the direction opposite to that of the (i+2)-th scan. After the (i+3)-th recording scan, the recording medium is conveyed.

[0152] For subsequent recording scans (the (i+4)-th scan, the (i+5)-th scan,...), the normal mask 600 is used, and the recording medium is conveyed after each recording scan. The scan directions alternate between the reverse direction and the forward direction.

[0153] FIG. 17 is a flowchart showing the flow of recording control executed in the second embodiment. In S1701, the CPU 401 determines whether there is a stop request. If there is no stop request (S1701; NO), it proceeds to S1702. If there is a stop request (S1701; YES), it proceeds to S1705.

[0154] S1702 to S1703 are normal recording operations and are the same processing as S1202 to S1203 in the first embodiment (FIG. 12), so the description is omitted.

[0155] In S1704, the CPU 401 determines whether the recording of one page has been completed. If there is subsequent recording data, it determines that the recording has not been completed (S1704; NO) and returns to S1701. If there is no subsequent recording data, it determines that the recording has been completed (S1704; YES) and ends this flowchart.

[0156] In S1705, the CPU 401 switches to the pre-stop mask 1501 and generates recording data for the (i - 2)-th recording scan.

[0157] In S1706, the CPU 401 performs the (i - 2)-th recording scan. In the (i - 2)-th recording scan, the ejection port group A1 facing the unrecorded recording area among the recording areas facing the ejection port row is made non-recordable by a mask. That is, no recording allowable pixels are provided. As a result, no image is recorded in the unrecorded recording area. For the ejection port groups A2 to A6, a mask pattern having the same recording rate as the mask patterns 602 to 606 for the ejection port groups A2 to A6 of the normal mask 600 shown in FIG. 6 is used. Therefore, the same recording as the normal recording scan is performed in the areas facing the ejection port groups A2 to A6.

[0158] In S1707, the CPU 401 performs recording medium conveyance.

[0159] In S1708, the CPU 401 switches to the pre-stop mask 1502. The CPU 401 generates recording data for the (i - 1)-th recording scan using the pre-stop mask 1502.

[0160] In S1709, the CPU 401 performs the (i - 1)-th recording scan. In the (i - 1)-th recording scan, the ejection port groups A1 and A2 that face the unrecorded recording areas among the recording areas facing the ejection port array are made non-recording by the mask pattern 1502. As a result, no image is recorded in the unrecorded recording areas. For the ejection port groups A3 to A6, mask patterns having the same recording rate as the mask patterns 603 to 606 for the ejection port groups A3 to A6 of the normal mask 600 shown in FIG. 6 are used. Therefore, the same recording as in the normal recording scan is performed on the areas facing the ejection port groups A3 to A6.

[0161] In S1710, the CPU 401 conveys the recording medium.

[0162] In S1711, the CPU 401 switches to the pre-stop mask 1503. The CPU 401 generates recording data for the i-th recording scan using the pre-stop mask 1503.

[0163] In S1712, the CPU 401 performs the i-th recording scan. In the i-th recording scan, the ejection port groups A1, A2, and A3 that face the unrecorded recording areas among the recording areas facing the ejection port array are made non-recording by the mask pattern 1503. As a result, no image is recorded in the unrecorded recording areas. For the ejection port groups A4 to A6, mask patterns having the same recording rate as the mask patterns 604 to 606 for the ejection port groups A4 to A6 of the normal mask 600 shown in FIG. 6 are used. Therefore, the same recording as in the normal recording scan is performed on the areas facing the ejection port groups A4 to A6. Note that the CPU 401 controls so as not to convey the recording medium P after the i-th recording scan.

[0164] In S1713, the CPU 401 stops the recording operation until a predetermined stop time elapses. When performing other operations other than the recording operation during the stop time, the CPU 401 executes that operation.

[0165] In S1714, the CPU 401 switches to the post-resumption mask 1504 and generates recording data for the (i + 1)-th recording scan. The switching to the post-resumption mask pattern 1504 and the generation of the recording data in S1714 are performed before a predetermined stop time elapses, and the recording data may be stored in a buffer (memory 405).

[0166] In S1715, the CPU 401 performs the (i + 1)-th recording scan according to the recording data generated in S1714. In the (i + 1)-th recording scan, among the ejection port groups A1 to A3 facing the recording areas that were non-recorded in the i-th (before stop) recording scan, recording-allowed pixels are provided in the ejection port group A3. The mask pattern for the ejection port group A3 has a recording rate corresponding to the mask pattern 601 for the ejection port group A1 of the normal mask 600. Therefore, the same recording as in the first pass in the normal recording scan is performed on the recording area facing the ejection port group A3. Also, the ejection port groups A1, A2, A4, A5, and A6 other than the ejection port group A3 are made non-recorded. Note that the conveyance of the recording medium P is not performed after the (i + 1)-th recording scan.

[0167] In S1716, the CPU 401 switches to the post-resumption mask 1505 and generates recording data for the (i + 2)-th recording scan.

[0168] In S1717, the CPU 401 performs the (i + 2)-th recording scan according to the recording data generated in S1716. In the (i + 2)-th recording scan, among the ejection port groups A1 to A3 facing the recording areas that were non-recorded in the i-th (before stop) recording scan, recording-allowed pixels are provided in the ejection port groups A2 and A3. The mask pattern for the ejection port group A3 has a recording rate corresponding to the mask pattern 602 for the ejection port group A2 of the normal mask 600. The mask pattern for the ejection port group A2 has a recording rate corresponding to the mask pattern 601 for the ejection port group A1 of the normal mask 600.

[0169] Therefore, in the recording area facing the ejection port group A3, recording similar to the second pass in normal recording scanning is performed, and in the recording area facing the ejection port group A2, recording similar to the first pass in normal recording scanning is performed. Also, the ejection port groups A1, A4, A5, and A6 other than the ejection port groups A2 and A3 are set to non-recording. Note that the recording medium P is not conveyed after the (i + 2)-th recording scan.

[0170] In S1718, the CPU 401 switches to the post-resumption mask 1506 and generates recording data for the (i + 3)-th recording scan.

[0171] In S1719, the CPU 401 performs the (i + 3)-th recording scan according to the recording data generated in S1718. In the (i + 3)-th recording scan, recording allowable pixels are provided in the ejection port groups A1 to A3 facing the recording areas that were set to non-recording in the i-th (before stopping) recording scan. The mask pattern for the ejection port group A3 has a recording rate corresponding to the mask pattern 603 for the ejection port group A3 of the normal mask 600. The mask pattern for the ejection port group A2 has a recording rate corresponding to the mask pattern 602 for the ejection port group A2 of the normal mask 600. The mask pattern for the ejection port group A1 has a recording rate corresponding to the mask pattern 601 for the ejection port group A1 of the normal mask 600.

[0172] Therefore, in the recording area facing the ejection port group A3, recording similar to the third pass in normal recording scanning is performed. Also, in the recording area facing the ejection port group A2, recording similar to the second pass in normal recording scanning is performed. Also, in the recording area facing the ejection port group A1, recording similar to the first pass in normal recording scanning is performed. Also, the ejection port groups A4, A5, and A6 other than the ejection port groups A1, A2, and A3 are set to non-recording.

[0173] In S1720, the CPU 401 conveys the recording medium. Then, it proceeds to S1704.

[0174] In S1704, as described above, it is determined whether the recording has ended. If there is subsequent recording data, it is determined that the recording has not ended (S1704; NO), and the process returns to S1701. If there is no subsequent recording data, it is determined that the recording has ended (S1704; YES), and this flowchart ends.

[0175] FIG. 18 shows the positions of each of the ejection port rows 31 in each recording scan before and after stopping and the change in the formed image in the recording control of the second embodiment. Note that the positions of the ejection port rows 31 indicate the relative positions with respect to the recording area.

[0176] In FIG. 18, the image 1800 shows the laminated image formed by the recording scan until immediately before the stop (the i-th time). Up to the (i - 3)-th time, the recording scan is performed using the normal mask 600, and in the three recording scans of the (i - 2)-th, (i - 1)-th, and i-th times, the pre-stop masks 1501, 1502, and 1503 are used, respectively. Also, the recording medium is conveyed before each recording scan. Therefore, in the recording scan up to the i-th time, the regions 1801, 1802, and 1803 facing the ejection port groups A1 to A3 become non-recorded.

[0177] Specifically, in the (i - 3)-th recording scan (recording scan using the normal mask 600), the ejection port row 31 faces the regions 1804 to 1809. The first recording is performed on the region 1804, the second recording is performed on the region 1805, the third recording is performed on the region 1806, the fourth recording is performed on the region 1807, the fifth recording is performed on the region 1808, and the sixth recording is performed on the region 1809.

[0178] (i - 2)-th recording scan (recording scan using the pre-stop mask 1501), the ejection port row 31 faces the regions 1803 to 1808. Also, the region 1803 is non-recorded, the second recording is performed on the region 1804, the third recording is performed on the region 1805, the fourth recording is performed on the region 1806, the fifth recording is performed on the region 1807, and the sixth recording is performed on the region 1808.

[0179] In the (i - 1)-th recording scan (recording scan using the pre-stop mask 1502), the ejection port row 31 faces regions 1802 to 1807. Also, recording is not performed on regions 1802 and 1803, the third recording is performed on region 1804, the fourth recording is performed on region 1805, the fifth recording is performed on region 1806, and the sixth recording is performed on region 1807.

[0180] In the i-th recording scan (recording scan using the pre-stop mask 1503), the ejection port row 31 faces regions 1801 to 1806. Also, recording is not performed on regions 1801, 1802, and 1803, the fourth recording is performed on region 1804, the fifth recording is performed on region 1805, and the sixth recording is performed on region 1806.

[0181] After resumption, since recording is performed on the regions that were non-recorded before stopping, three additional recording scans are added.

[0182] The image 1810 in FIG. 18 shows the image formed in the first recording scan (the (i + 1)-th scan) after resumption. In the (i + 1)-th recording scan, the ejection port row 31 faces regions 1801 to 1806, similar to the last recording scan (the i-th scan) before stopping. Also, in the (i + 1)-th recording scan, the post-resumption mask pattern 1504 is used, and regions 1801, 1802, 1804, 1805, and 1806 facing the ejection port groups A1, A2, A4, A5, and A6 become non-recorded. The first recording is performed on region 1803.

[0183] Also, the image 1820 in FIG. 18 shows the image formed in the second recording scan (the (i + 2)-th scan) after resumption. In the (i + 2)-th recording scan, the ejection port row 31 faces regions 1801 to 1806, similar to the last recording scan (the i-th scan) before stopping. Also, in the (i + 2)-th recording scan, the post-resumption mask pattern 1505 is used, and regions 1801, 1804, 1805, and 1806 facing the ejection port groups A1, A4, A5, and A6 become non-recorded. The first recording is performed on region 1802, and the second recording is performed on region 1803.

[0184] The image 1830 in Fig. 18 shows the image formed in the third (i + 3) recording scan after resumption. In the (i + 3) - th recording scan, the ejection port array 31 faces the regions 1801 to 1806 in the same way as in the last recording scan (i - th scan) before stopping. Also, in the (i + 3) - th recording scan, the mask pattern 1506 after resumption is used, and the regions 1804, 1805, and 1806 facing the ejection port groups A4, 5, and A6 become non - recording. For region 1801, the first recording is performed, for region 1802, the second recording is performed, and for 1803, the third recording is performed.

[0185] In other words, in the three recording scans added after resumption ((i + 1) - th to (i + 3) - th scans), recording is sequentially performed on the regions 1801 to 1803 that were non - recording in the three recording scans before stopping (the (i - 2) - th to i - th scans), and the other regions 1804 to 1806 become non - recording. Also, in the three recording scans after resumption, the conveyance of the recording medium is not performed immediately before. Therefore, correct recording is performed on each of the recording regions 1801 to 1803 that were non - recording before stopping. Furthermore, in the recording scan after resumption, recording is performed at the same recording rate in the same order as 1 to 3 passes in a normal recording scan on the recording regions that were non - recording in the recording scan before stopping. Therefore, ink droplets are overlapped in the same order as other recording regions for the recording regions before and after stopping. Thus, changes in color and gloss are suppressed.

[0186] After the fourth time (i + 2) and later after resumption, recording scans using the normal mask 600 are performed. The image 1840 in Fig. 18 shows the laminated image formed by the recording scans from the (i + 4) - th to (i + 9) - th scans. When the number of recording times of the images 1800, 1810, 1820, 1830, and 1840 is totaled for each recording region 1801 to 1806, it becomes 6 times each, indicating that the multi - pass recording is completed.

[0187] As described above, in the second embodiment, in the recording scans for the three times before stopping, the non-recording areas are scanned without recording, and for the recording areas that were non-recorded before stopping, recording is performed so as to satisfy the recording rate in the normal recording scan in the three recording scans after resumption. Therefore, it is possible to prevent unevenness from occurring in a wider area than in the first embodiment.

[0188] On the other hand, when compared with the first embodiment, since the number of additional recording scans increases from one to three, the throughput reduction effect is not significant. However, in the prior art (Japanese Patent Laid-Open No. 2000-15868), five additional recording scans are required in the case of 6-pass recording, so a higher throughput can be maintained compared with the prior art.

[0189] Next, the effect in the case of multiple passes in this embodiment will be described. As the number of passes in multi-pass recording increases, the number of ink droplets recorded in one recording scan tends to decrease. Therefore, it is considered that the number of areas during recording where ink droplets are recorded in isolation increases. For example, in the case of 6-pass recording, many ink droplets are recorded in isolation in the first pass. Considering 18-pass recording here, since the number of passes is three times that of 6-pass recording, in terms of ratio, ink droplets equivalent to those in the first pass of 6-pass recording are recorded up to the third pass. That is, it is considered that ink droplets similar to those in the first pass of 6-pass recording are isolated up to the third pass in the case of 18-pass recording.

[0190] As described above, the areas where ink droplets are recorded in isolation are likely to have unevenness when stopping occurs. Therefore, in the case of 18-pass recording, it is considered that unevenness is likely to occur up to the area where the third pass is recorded before stopping. When performing recording with a larger number of passes in this way, recording control such as providing a group of ejection ports that are non-recorded in a plurality of recording scans before stopping and adding a recording scan to complement the non-recording after resumption, as in the second embodiment, is considered to be more effective.

[0191] That is, in multiple recording scans before stopping, a pre-stop mask having ejection ports to be non-recorded may be used. The number of recording scans may be determined by the ratio to the number of passes in multi-pass. After resuming, recording is performed for the same number of recording scans as the number of times the pre-stop mask was used, so as to satisfy the same recording rate as that of the normal mask for the areas that were non-recorded before stopping. Furthermore, it is preferable to perform recording for the areas that were non-recorded before stopping in the same recording order as the normal mask so as to satisfy the recording rate after resuming. Note that since the drying efficiency of ink droplets during normal recording varies depending on the number of passes, there may be some differences in the appearance of unevenness. In that case, the number of recording scans using the pre-stop mask may be adjusted according to the actual appearance of unevenness from the ratio to the number of passes.

[0192] <Modification Example> In the above-described embodiment, a part of the mask pattern is non-recorded, but within the range where the effects of the present disclosure can be obtained, a certain number of recordable pixels may be included. That is, in at least one recording scan before stopping, recording is performed at a first recording rate B for unrecorded or recording areas where the number of recording times is less than a predetermined number of times. In this case, for the recording areas where recording is performed at the first recording rate B, in at least one recording scan after resuming, recording is performed at a second recording rate C that complements the first recording rate B and satisfies the recording rate A in normal recording scans. Note that the second recording rate C is greater than the first recording rate B.

[0193] That is, in the recording scans before and after stopping, for unrecorded or recording areas where the number of recording times is less than a predetermined number of times, a pre-stop mask pattern and a post-resumption mask pattern are used such that the recording rate satisfies the relationship of the following formula (1).

[0194] A = B + C, and B < C …(1)

[0195] Note that the recording rate B is less than a predetermined recording rate, and preferably, it is preferably less than 1%.

[0196] As described above, the preferred embodiments according to the present disclosure have been described with reference to the accompanying drawings, but the present disclosure is not limited to such examples. In each of the above-described embodiments, an inkjet recording apparatus that executes the recording control shown in FIG. 11 or FIG. 16 has been described. However, the present disclosure is not limited thereto, and it can also be applied to an image processing apparatus or the like that generates data for performing the recording control in each of the above-described embodiments and supplies the generated data to the recording apparatus. Further, it can also be applied to a program for a computer to execute the recording control in each embodiment and a storage medium storing the program.

[0197] In addition to the thermal jet type inkjet recording apparatus, the present disclosure can be applied to various recording apparatuses such as a so-called piezo type inkjet recording apparatus that discharges ink using a piezoelectric element.

[0198] In addition, it is obvious that those skilled in the art can conceive of various modification examples or correction examples within the scope of the technical idea disclosed in the present application, and it is naturally understood that they also belong to the technical scope of the present invention.

[0199] <Other Embodiments> The present disclosure can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and causing one or more processors in a computer of the system or apparatus to read and execute the program. Further, it can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

[0200] Note that the disclosure of the above-described embodiments includes the following configurations. (Configuration 1) Recording means for recording an image by scanning a head having a plurality of ink ejection ports for ejecting ink a plurality of times with respect to the same recording area of a recording medium, Normal scanning for performing recording by ejecting ink based on recording data generated using a predetermined mask pattern, In at least one scan before stopping, a first scan that scans the unrecorded recording area without recording, and a second scan that performs recording satisfying the recording rate in the normal scan in at least one scan restarted after a predetermined time has elapsed from the stop, on the recording area that was not recorded in the first scan, recording control means for controlling the recording operation by the recording means to include the above, An inkjet recording apparatus comprising:

[0201] (Configuration 2) The recording control means performs recording at the same recording rate as the mask pattern applied in the normal scan in the first scan on areas other than the unrecorded recording area, and controls to be non-recording in the second scan. The inkjet recording apparatus according to Configuration 1, characterized in that.

[0202] (Configuration 3) Further comprising conveyance control means for controlling conveyance of the recording medium in a direction intersecting the scanning direction of the head, The conveyance control means controls not to convey the recording medium before each scan in the second scan. The inkjet recording apparatus according to Configuration 1 or Configuration 2, characterized in that.

[0203] (Configuration 4) The recording control means controls to execute the first and second scans when the stop time is longer than a predetermined time. The inkjet recording apparatus according to any one of Configurations 1 to 3, characterized in that.

[0204] (Configuration 5) The first scanning direction of the second scan is the same as the last scanning direction of the first scan. The inkjet recording apparatus according to any one of Configurations 1 to 4, characterized in that.

[0205] (Configuration 6) The inkjet recording apparatus according to any one of Configurations 1 to 5, wherein the first scanning is one scanning immediately before the stop.

[0206] (Configuration 7) When the first scanning is performed in a plurality of scans before the stop, the number of times of the first scanning and the second scanning is determined by a ratio to the number of passes of the multi-pass. The inkjet recording apparatus according to any one of Configurations 1 to 5.

[0207] (Configuration 8) The recording rate in the ejection port group on the end side in the conveyance direction of the recording medium of the mask pattern is smaller than the recording rate in the ejection port group in the central portion of the mask pattern. The inkjet recording apparatus according to any one of Configurations 1 to 7.

[0208] (Configuration 9) When the first scanning is performed in a plurality of scans before the stop, in the second scanning, recording is performed in order from the first scan in the normal scanning on the recording area that was not recorded in the first scanning. The inkjet recording apparatus according to any one of Configurations 1 to 5, Configuration 7, and Configuration 8.

[0209] (Configuration 10) Recording means for recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times with respect to the same recording area of the recording medium; Normal scanning for performing recording by ejecting ink based on recording data generated using a predetermined mask pattern; In at least one scan before the stop, a first scan for performing recording at a first recording rate on a recording area where the number of recordings is less than a predetermined number of times; For the recording area recorded at the first recording rate in the first scan, in at least one scan restarted after a predetermined time has elapsed since the stop, the first recording rate is complemented so as to satisfy the recording rate in the normal scan, and a second scan for recording at a second recording rate higher than the first recording rate is performed. Recording control means for controlling the recording operation by the recording means so as to include An inkjet recording apparatus characterized by comprising

[0210] (Configuration 11) The inkjet recording apparatus according to Configuration 10, wherein the first recording rate is less than a predetermined recording rate.

[0211] (Configuration 12) A recording control method for recording an image by causing a head having a plurality of ejection ports for ejecting ink to scan a same recording area of a recording medium a plurality of times, comprising: Executing a normal scan for recording by ejecting ink based on recording data generated using a predetermined mask pattern; Executing a first scan for non-recording scan on an unrecorded recording area in at least one scan before stopping; Executing a second scan for recording that satisfies the recording rate in the normal scan in at least one scan restarted after a predetermined time has elapsed since the stop on the recording area that was non-recorded in the first scan; A control method including

[0212] (Configuration 13) A recording control method for recording an image by causing a head having a plurality of ejection ports for ejecting ink to scan a same recording area of a recording medium a plurality of times, comprising: Executing a normal scan for recording by ejecting ink based on recording data generated using a predetermined mask pattern; In at least one scan before stopping, performing a first scan of recording at a first recording rate on a recording area where the number of recordings is less than a predetermined number; In at least one scan restarted after a predetermined time has elapsed since stopping, with respect to the recording area recorded at the first recording rate in the first scan, performing a second scan of recording at a second recording rate that complements the first recording rate so as to satisfy the recording rate in the normal scan; A control method including the above.

[0213] (Configuration 14) A program for causing a computer to execute a recording control method of recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times with respect to the same recording area of a recording medium, Performing a normal scan of recording by ejecting ink based on recording data generated using a predetermined mask pattern; In at least one scan before stopping, performing a first scan of non-recording scanning on an unrecorded recording area; In at least one scan restarted after a predetermined time has elapsed since stopping, with respect to the recording area that was non-recorded in the first scan, performing a second scan of recording that satisfies the recording rate in the normal scan; A program including the above.

[0214] (Configuration 15) A program for causing a computer to execute a recording control method of recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times with respect to the same recording area of a recording medium, Performing a normal scan of recording by ejecting ink based on recording data generated using a predetermined mask pattern; In at least one scan before stopping, performing a first scan of recording at a first recording rate on a recording area where the number of recordings is less than a predetermined number; In at least one scan that resumes after a predetermined time has elapsed from a stop with respect to a recording area recorded at the first recording rate in the first scan, the first recording rate is complemented so as to satisfy the recording rate in the normal scan, and a second scan is performed in which recording is performed at a second recording rate greater than the first recording rate. A program including the above.

Claims

1. a recording means for recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same recording area of ​​a recording medium; A normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; a first scan for scanning an unrecorded recording area without recording in at least one scan before stopping; a second scanning that performs printing on a printing area that has not been printed in the first scanning, in at least one scanning that is resumed after a predetermined time has elapsed since the first scanning was stopped, with the printing rate satisfying that of the normal scanning; a recording control means for controlling a recording operation by the recording means so as to include An inkjet recording apparatus comprising:

2. The print control means performs control so that, in the first scan, printing is performed at the same printing rate as the mask pattern applied in the normal scan in the areas other than the unprinted print areas, and is not printed in the second scan.

2. The inkjet recording apparatus according to claim 1,

3. a transport control unit for controlling transport of the recording medium in a direction intersecting the scanning direction of the head, The transport control means controls so as not to transport the recording medium before each scan in the second scan.

2. The inkjet recording apparatus according to claim 1,

4. The recording control means 2. The inkjet recording apparatus according to claim 1, wherein when the stop time is longer than a predetermined time, the first and second scans are executed.

5. 2. The inkjet recording apparatus according to claim 1, wherein the initial scanning direction of the second scan is the same as the final scanning direction of the first scan.

6. 2. The ink jet recording apparatus according to claim 1, wherein the first scan is a single scan performed immediately before the stop.

7. 2. The inkjet recording apparatus according to claim 1, wherein, when the first scan is performed in a plurality of scans before the stop, the number of times of the first scan and the second scan is determined by a ratio to the number of passes of a multi-pass.

8. 2. The inkjet printing apparatus according to claim 1, wherein a printing rate of a group of ejection ports on an end side of the mask pattern in a conveying direction of the printing medium is smaller than a printing rate of a group of ejection ports in a central portion of the mask pattern.

9. 2. The inkjet printing apparatus according to claim 1, wherein, when the first scan is performed multiple times before stopping, in the second scan, printing is performed in the printing area that was left unprinted in the first scan in sequence starting from the first scan in the normal scan.

10. a recording means for recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same recording area of ​​a recording medium; A normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; a first scan for performing printing at a first printing rate on a printing area where the number of printing operations has been less than a predetermined number of times in at least one scan before the stop; a second scan for performing printing at a second printing rate greater than the first printing rate by supplementing the first printing rate so as to satisfy the printing rate in the normal scanning in at least one scan that is resumed after a predetermined time has elapsed since the first scan was stopped, in a printing area printed at the first printing rate; a recording control means for controlling a recording operation by the recording means so as to include An inkjet recording apparatus comprising:

11. 11. The inkjet recording apparatus according to claim 10, wherein the first recording rate is less than a predetermined recording rate.

12. A printing control method for printing an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same printing area of ​​a printing medium, comprising: A step of performing a normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; performing a first scan in which a non-recorded area is scanned in a non-recorded manner in at least one scan before the stop; a step of performing a second scan for performing printing on a printing area not printed in the first scan, the second scan being restarted after a predetermined time has elapsed since the first scan was stopped, at least once, to perform printing at a printing rate that satisfies the printing rate of the normal scan; A recording control method comprising:

13. A printing control method for printing an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same printing area of ​​a printing medium, comprising: A step of performing a normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; executing a first scan for performing printing at a first printing rate on a printing area where the number of printing operations has been less than a predetermined number of times in at least one scan before the stop; a step of executing a second scan for printing at a second printing rate greater than the first printing rate by supplementing the first printing rate so as to satisfy the printing rate in the normal scan in at least one scan that is resumed after a predetermined time has elapsed since the first scan was stopped, in a printing area printed at the first printing rate in the first scan; A recording control method comprising:

14. A program for causing a computer to execute a recording control method for recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same recording area of ​​a recording medium, the program comprising: A step of performing a normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; performing a first scan in which an unrecorded recording area is scanned without recording in at least one scan before the stop; a step of performing a second scan for performing printing on a printing area not printed in the first scan, the second scan being restarted after a predetermined time has elapsed since the first scan was stopped, at least once, to perform printing at a printing rate that satisfies the printing rate of the normal scan; Programs including.

15. A program for causing a computer to execute a recording control method for recording an image by scanning a head having a plurality of ejection ports for ejecting ink a plurality of times over the same recording area of ​​a recording medium, the program comprising: A step of performing a normal scan in which printing is performed by ejecting ink based on print data generated using a predetermined mask pattern; executing a first scan for performing printing at a first printing rate on a printing area where the number of printing operations has been less than a predetermined number of times in at least one scan before the stop; a step of executing a second scan for printing at a second printing rate greater than the first printing rate by supplementing the first printing rate so as to satisfy the printing rate in the normal scan in at least one scan that is resumed after a predetermined time has elapsed since the first scan was stopped, in a printing area printed at the first printing rate in the first scan; Programs including.

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