JP2007038671A - Inkjet recording device and inkjet recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output a smooth image excellent in uniformity by minimizing the occurrence of secondary color satellite and distributing the landing positions of satellites as uniformly as possible. <P>SOLUTION: For this purpose, recording is made such that the satellites of two kinds of ink (for example, cyan ink and magenta) to be recorded in the same pixel are allowed to land separately on the opposite sides of a main dot recorded on the pixel. Accordingly, the arrangements of satellites are uniform and respective satellites are comparatively insignificant, thereby ensuring the uniformity of an image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus and a recording method for forming a uniform image.

  An ink jet recording apparatus (hereinafter referred to as an ink jet recording apparatus) performs recording by ejecting ink from a recording head onto a recording medium, and is relatively easy to achieve higher definition than other recording systems. . In addition, it has the advantages of high speed and quietness and low cost. In particular, in recent years, the demand for color output has increased, and it has been developed to output high-quality images comparable to silver halide photographs.

  Ink jet recording apparatuses are provided with a recording head in which a plurality of recording elements (electrothermal transducers and piezoelectric elements) are integrated and arranged to improve recording speed. In addition, many color heads equipped with a plurality of such recording heads are provided.

  FIG. 1 is a diagram showing a configuration of a main part of a general ink jet recording apparatus. In the figure, reference numeral 1101 denotes an ink jet cartridge. These are composed of an ink tank storing four color inks, that is, black, cyan, magenta and yellow inks, and a recording head 1102 corresponding to each ink.

  FIG. 2 is a schematic view of a group of ejection openings for one color provided corresponding to the recording elements of the recording head 1102 as viewed from the Z direction in FIG. In the figure, reference numeral 1201 denotes discharge ports arranged at a density D (Ddpi) per inch on the recording head 1102. Hereinafter, a portion including the printing element and the corresponding ejection port is referred to as a “nozzle”.

  Referring again to FIG. 1, reference numeral 1103 denotes a paper feed roller, which rotates in the direction of the arrow while holding the recording medium P together with the auxiliary roller 1104, and transports the recording medium P in the Y direction (sub-scanning direction) as needed. To do. Reference numeral 1105 denotes a pair of paper feed rollers that feeds the recording medium P. The paper feed roller pair 1105 rotates while holding the recording medium P, like the rollers 1103 and 1104, but its rotational speed is slightly lower than that of the paper feed roller 1103. Thereby, an appropriate amount of tension can be applied to the recording medium.

  Reference numeral 1106 denotes a carriage that supports the four ink jet cartridges 1101 and scans them in accordance with recording. The carriage 1106 waits at a home position h indicated by a broken line when recording is not being performed or when recovery processing of the recording head 1102 is performed.

  When a recording start command is input to the recording apparatus, ink is ejected at a predetermined frequency from the nozzle 1201 of the recording head 1102 while the carriage 1106 arranged at the home position h moves in the X direction (main scanning direction). Then, an image having a width of d / D inches is formed on the paper surface. Before the second recording scan starts after the end of the first recording scan, the paper feed roller 1103 rotates in the direction of the arrow, thereby conveying the recording medium by a predetermined amount in the Y direction. By repeatedly performing such recording main scanning and conveying operation, images can be formed sequentially.

  By the way, in such an ink jet recording apparatus, a multi-pass recording method is often adopted. The multipass recording method will be briefly described below.

  In the multi-pass printing method, printing main scanning is executed by thinning out image data that can be printed in one printing main scanning with a predetermined mask pattern. Further, in the next recording scan, the image data thinned out by the mask pattern having an interpolation relationship with the already used mask pattern is recorded. During each recording scan, a transport operation of an amount shorter than the recording width of the recording head is performed.

  For example, in the case of 2-pass multi-pass printing, the mask pattern applied in each printing main scan thins out image data to about 50%. Further, the conveyance amount in the conveyance operation is ½ of the recording width. By repeating such a recording operation, dots arranged in a pixel line extending in the main scanning direction are recorded by two different nozzles. Therefore, even if there is some variation in individual nozzles, recording is performed with a 1/2 distribution on the recording medium, so that a smoother image can be obtained than in the case of 1-pass printing without multi-pass printing. I can do it. Here, two-pass multi-pass printing has been described, but in multi-pass printing, a smoother image can be obtained as the number of multi-passes (number of divisions) is further increased. However, since the number of recording main scans and transport operations increases, extra output time is consumed. In order to reduce the output time as much as possible, in recent years, bi-directional multi-pass printing in which ink is ejected in both forward scanning and backward scanning has become mainstream.

JP 2003-053962 A JP-A-5-278232

  By the way, when ink is ejected from the ejection port of the ink jet recording head, a smaller sub-droplet may be ejected together with the main droplet responsible for image formation. Hereinafter, the dots formed by the main droplets are called main dots, and the dots formed by the sub droplets are called satellites. The relationship between the main droplet and the sub droplet is established in one discharge. One discharge described here is discharge performed by one electric signal. The sub-droplet is characterized in that the discharge speed is slower than that of the main droplet and the amount of the sub-droplet is small relative to the main droplet. However, the satellite is not necessarily smaller than the main dot.

  FIGS. 3A to 3D are diagrams for explaining the landing positions of the main dots and the satellite on the recording medium. In each figure, reference numeral 1301 indicates a main dot, and 1302 indicates a satellite. Moreover, the arrow described in the upper part of each figure shows the carriage traveling direction when the ejection is performed, and the arrow described in the lower part shows the ejection direction of the ejected droplets.

  FIG. 3A shows a case where the ejection direction is perpendicular to the recording medium. Normally, when the recording head is not inclined, the ejection port surface of the recording head is parallel to the recording medium and the ejection direction is thus perpendicular. In general, since the discharge speed of the sub-droplet is smaller than that of the main droplet, it lands on the recording medium after the main droplet. Since the carriage is moved in the direction of the arrow 1303 in the drawing, the carriage speed is added to the droplet discharge speed, and the landing time shift is the landing position shift in the main scanning direction. appear.

  FIG. 3B shows a case where a carriage traveling direction component is included in the ejection direction. When the ejection direction of the ink droplet has an inclination due to various factors such as swelling of the nozzle material or drawing of the ejected ink liquid into the liquid chamber, the ejection port surface is not parallel to the recording medium. Situation arises. In this case, the component indicated by the arrow 1304 is added to the velocity components of the main droplet and the subdrop. Therefore, the distance between the main dot 1301 and the satellite 1302 further increases in the main scanning direction.

  FIG. 3C shows a case where the ejection direction has an inclination opposite to that in FIG. 3B and a component (arrow 1305) opposite to the traveling direction of the carriage is included. In this case, the velocity component of the main droplet and the sub-droplet is in a state where the ejection direction component 1305 is subtracted from the velocity component 1303 of the carriage. Therefore, the distance between the main dot 1301 and the satellite 1302 is shorter than in the case of FIG. In the figure, a satellite is included in the main dot and landed.

  FIG. 3D shows a case where the amount of the sub-droplet is smaller while the speed component is the same as that in FIG. For the sub-droplet, the smaller the amount, the lower the discharge speed. Therefore, the smaller the sub-droplet, the larger the landing time difference from the main droplet, and the larger the positional deviation between them. In FIG. 3D, the landing time difference between the main droplet and the sub-droplet is larger than in FIG. 3C, and the satellite is landed separately from the main dot.

  As described above, the satellite recording position varies depending on various factors. In addition, when bidirectional multi-pass printing as described above is executed, the dots recorded in the forward direction and the dots recorded in the backward direction are the same image area (for example, the same pixel, the same pixel line, M A situation occurs in which the pixel regions are mixed in (× N pixel region).

  FIG. 4 is a diagram illustrating various landing states when bidirectional multi-pass printing is performed on a 2 × 2 pixel area. The satellite recording position relative to the main dot is reversed depending on whether each pixel is recorded in the forward or backward recording main scan. In FIG. 4, the right-pointing arrow (→) indicates the forward direction, the large shaded circle indicates the main dot recorded in the forward direction, and the small shaded circle indicates the satellite recorded in the forward direction. Yes. On the other hand, the left arrow (←) indicates the backward direction, the large white circle indicates the main dot recorded in the backward direction, and the small white circle indicates the satellite recorded in the backward direction.

  Even if the satellite described above is generated, if it is recorded at the same position as the main dot or if it is sufficiently smaller than the main dot, there will be no problem on the image. However, in the case of a recording head that discharges high-definition and small droplet ink as developed recently, the dot diameter of the main dot itself is small, and the presence of satellites cannot be ignored. In particular, when a secondary color is expressed by superimposing two types of ink, the problem becomes more serious.

  5A to 5C show a case where blue is expressed by superimposing cyan and magenta dots. In the figure, a state is shown in which two blue dots are recorded in the 2 × 2 pixel area while moving the carriage in the direction indicated by the arrow. Here, it is assumed that the conditions for generating satellites are the same in the two recording heads cyan and magenta. As a result, satellites are formed in a state where the two colors overlap each other beside the blue dots formed by the main droplets. In this way, satellites recorded by superimposing two color dots are more conspicuous than the primary color and are also likely to affect the image. In an image in which conspicuous satellites are unevenly generated, the uniformity is impaired and the quality of the image is lowered.

  Several countermeasures have already been proposed for the problems caused by the heterogeneity of satellites. For example, Patent Document 1 discloses that the amount of the recording medium transported is controlled so as to include an odd multiple or an even multiple of 1 / D inch (D = recording resolution in the sub-scanning direction) at least once. The contents for obtaining a uniform image by distributing positions as uniformly as possible are described. However, in the method described in Patent Document 1, pixels that generate satellites on both ends of the main dot and pixels that overlap the satellite on the main dot appear alternately, which is insufficient in terms of pixel uniformity. there were. In addition, the method of this document also causes a new problem that the control of the conveyance amount of the recording medium is restricted. Furthermore, according to the same document, the secondary color as described above is not considered, and the satellite problem of the secondary color that is conspicuous remains unresolved.

  The present invention has been made to solve the above problems. The purpose of the ink jet recording method is to suppress the generation of secondary color satellites as much as possible and to output a smooth and uniform image by dispersing the landing positions of the satellites as uniformly as possible. And providing a recording device.

  Therefore, the present invention is an inkjet recording apparatus that records an image on a recording medium using a recording head capable of ejecting a second ink in which at least one of the first ink and the first ink is different in color and amount. Means for relatively scanning the recording head relative to the recording medium in the forward and backward directions, and discharging the first and second inks to the same pixel on the recording medium in different directions. Means for performing scanning, and the satellite of the first ink ejected toward the same pixel is in the forward direction or the backward direction with respect to the main dots of the first and second inks that land on the same pixel. The satellite of the second ink is displaced from the main dot of the first and second inks, and the satellite of the first ink is displaced The direction and wherein the landing shifted in the opposite direction.

  In addition, a recording head having at least a second ejection port for ejecting a second ink that is different in at least one of a color and an amount of the first ejection port for ejecting the first ink and the first ink is used. An ink jet recording apparatus for recording an image on a recording medium, wherein the recording head performs main scanning relative to the recording medium in a forward direction and a backward direction, and the first for the same pixel on the recording medium. And a means for executing the ejection of the second ink during main scanning in different directions, and the plurality of pixels from which the first and second inks are ejected together have the first ink in the forward direction. A first pixel that is ejected and ejects the second ink in the return path direction, and a second pixel that ejects the first ink in the return path direction and ejects the second ink in the forward path direction The satellite of the first ink is landed with a shift in the forward direction with respect to the landing positions of the main dots of the first and second inks discharged to the first pixel, and the satellites of the second ink Is landed with a deviation in the backward direction, and the satellite of the first ink is landed with a deviation in the backward direction with respect to the landing positions of the main dots of the first and second inks ejected to the second pixel, The satellite of the second ink is landed with a deviation in the forward direction.

  An inkjet recording apparatus that records an image on a recording medium using a recording head capable of ejecting a second ink in which at least one of the first ink and the first ink is different in at least one of color and amount, the recording head Means for relatively scanning in the forward and backward directions with respect to the recording medium, and discharging the first and second inks to pixels adjacent to the recording medium in a direction orthogonal to the main scanning direction. For performing main scanning in different directions from each other, and the satellite of the first ink ejected toward one of the adjacent pixels is a main dot of the first ink that lands on the one pixel. In contrast, the second ink satellite that is landed with a shift in the forward or backward direction and ejected toward the other pixel is landed on the other pixel. The direction in which the first ink satellite is shifted with respect to the main dots characterized by land shifted in the opposite direction.

  In addition, a recording head having at least a second ejection port for ejecting a second ink that is different in at least one of a color and an amount of the first ejection port for ejecting the first ink and the first ink is used. An inkjet recording apparatus for recording an image on a recording medium, wherein the recording head is main-scanned relative to the recording medium in a forward direction and a backward direction, and orthogonal to a main scanning direction on the recording medium Means for performing discharge of the first and second inks on pixels adjacent in a direction during main scanning in different directions, and the adjacent pixels from which the first and second inks are discharged include: A first pixel from which the first ink is ejected in the forward direction and a second pixel from which the second ink is recorded in the backward direction, and the first ink that is ejected to the first pixel. The satellite of the first ink is landed with a deviation in the forward direction with respect to the landing position of the second ink, and the second ink is landed with respect to the landing position of the main dot of the second ink discharged to the second pixel. Satellites are characterized by landing in the return direction.

  Furthermore, there is provided an inkjet recording method for recording an image on a recording medium using a recording head capable of ejecting a second ink in which at least one of the first ink and the first ink is different in color and amount, and the recording head Performing a main scan relative to the recording medium in the forward direction and the backward direction, and executing the ejection of the first and second inks on the same pixel on the recording medium in different directions. The satellite of the first ink ejected toward the same pixel is landed with a shift in the forward or backward direction with respect to the main dots of the first and second inks that land on the same pixel. The satellite of the second ink is not in a direction opposite to the direction in which the satellite of the first ink is shifted from the main dot of the first and second inks. Characterized in that it landed Te.

  Furthermore, there is provided an ink jet recording method for recording an image on a recording medium using a recording head capable of discharging a second ink in which at least one of the first ink and the first ink is different in color and amount. A main scan of the head relative to the recording medium in the forward and backward directions, and the first and second inks for pixels adjacent to the recording medium in a direction perpendicular to the main scanning direction. A step of performing recording by main scanning in different directions, and the satellite of the first ink ejected toward one of the adjacent pixels is the main of the first ink that lands on the one pixel. A second ink satellite that lands on a dot with a shift in the forward or backward direction and is ejected toward the other pixel is landed on the other pixel. The direction in which to the main dots of the first ink satellite shifts, characterized in that the land shifted in the opposite direction.

  According to the present invention, since the landing positions of satellites are uniformly dispersed, an image with excellent uniformity can be obtained.

Embodiments of the present invention will be described below in detail with reference to the drawings.
(First embodiment)
In the present embodiment, the ink jet recording apparatus described in FIG. 1 is applied.

  FIG. 6 is a block diagram for explaining a control configuration of the ink jet recording apparatus according to the present embodiment. In the figure, a CPU 700 executes control of each unit and data processing described later. The CPU 700 executes head drive control, carriage drive control, data processing, and the like via the main bus line 705 in accordance with a program stored in the ROM 702. In addition to various programs, the ROM 702 also stores a plurality of mask patterns used in the characteristic recording operation of the present embodiment. The RAM 701 is used as a work area for data processing by the CPU 700. In addition to the ROM 702 and the RAM 701, the CPU 700 is also provided with a memory such as a hard disk.

  The image input unit 703 has an interface with a host device (not shown) connected to the outside, and temporarily holds image data input from the host device. The image signal processing unit 704 executes data processing such as color conversion processing and binarization processing.

  The operation unit 706 includes keys and the like, and enables control input by the operator.

  The recovery system control circuit 707 controls the recovery operation according to the recovery processing program stored in the RAM 701. That is, by driving the recovery system motor 708, the blade 709, the cap 710, the pump 711, and the like are operated with respect to the recording head 1102.

  The head drive control circuit 715 controls the drive of the recording elements (in this example, electrothermal transducers) provided in the individual nozzles of the recording head 1102 and executes preliminary ejection and ink ejection for recording on the recording head 1102. Let Further, the carriage drive control circuit 716 and the paper feed control circuit 717 also control carriage movement and paper feed according to the program.

  A heat retaining heater is provided on the substrate on which the electrothermal transducer of the recording head 1102 is provided, and the ink temperature in the recording head can be adjusted by heating to a desired set temperature. The thermistor 712 is also provided on the substrate, and measures the ink temperature inside the recording head. However, the thermistor 712 may be provided outside the substrate as long as it is near the periphery of the recording head.

  FIG. 7 is a view for explaining the arrangement of the ejection openings (nozzle arrangement) of the recording head 1102 applied to this embodiment. In the figure, 801 is a nozzle row for black ink, 802 is a nozzle row for cyan ink, 803 is a nozzle row for magenta ink, and 804 is a nozzle row for yellow ink. The four-color nozzle rows are each composed of an even nozzle row and an odd nozzle row, and 801a and 801b correspond to this in the black ink. Hereinafter, the arrangement of the ejection openings will be described in detail by taking the nozzle row 801 of black ink as an example.

  The odd nozzle row 801a and the even nozzle row 801b have 128 ejection openings arranged at a pitch of 600 dpi, and the odd nozzle row 801a and the even nozzle row 801b are displaced by 1200 dpi in the Y direction (sub-scanning direction). Has been. That is, by ejecting ink while the recording head scans in the X direction (main scanning direction), an image having a width of about 5.42 mm can be recorded in the sub scanning direction at a resolution of 1200 dpi.

  The other color nozzle rows also have the same configuration as the black nozzle row 801, and these four colors are arranged in parallel in the main scanning direction as shown in the figure.

  Next, a multipass printing method in the printing apparatus of this embodiment will be described.

  FIG. 26 is a schematic diagram for explaining an example of a random mask pattern applicable to this embodiment. In the figure, each area indicated by a square represents one pixel and is a minimum unit that determines dot recording / non-recording. The black portion indicates a pixel that allows ink recording in the recording scan (recording allowable pixel), and the white portion indicates a pixel that does not allow ink recording in the recording scan (non-recording allowable pixel). The random mask pattern is a pattern in which print permitting pixels are irregularly arranged, and the array of print permitting pixels is non-periodic. Such a non-periodic mask pattern has a characteristic that it does not synchronize with regular image data. Although a mask pattern having a size of 16 pixels × 16 pixels is shown here, it is preferable that the size of the mask pattern in the main scanning direction is larger. In this example, although not shown, the size in the main scanning direction is set to 1028 pixels in the mask pattern of this embodiment. The random mask pattern can be created by the method disclosed in Japanese Patent Registration No. 3176181.

  FIG. 26 shows a 4-pass multi-pass mask pattern that is complementary to each other. The CPU 700 performs AND between any one of the mask patterns A to D stored in the ROM 702 and print data to be recorded by each nozzle row in each print scan, and generates data to be ejected by the print scan. To do.

  8A and 8B are schematic diagrams for explaining how to use the mask patterns A to D. FIG. Here, the types of mask patterns for the cyan nozzle row 802 and the magenta nozzle row 803 are shown by taking 4-pass bidirectional multi-pass printing as an example. The Odd and Even nozzle arrays composed of 128 ejection openings are divided into 8 blocks of 16 in the sub-scanning direction, and one type of mask pattern A to D is applied to one block. It has become. In the figure, four recording scans of the first recording scan to the fourth recording scan are shown, and an amount of paper feeding corresponding to two blocks is performed between the recording scans. Here, the recording head moves relative to the recording medium.

  A to D in FIGS. 8A and 8B correspond to nozzle row regions to which the mask patterns of A to D shown in FIG. 26 are applied, and include four different patterns that are mutually exclusive and complementary. Show. That is, four types of mask patterns A to D are applied one by one in each of the four recording main scans, thereby completing an image to be recorded in the same image area of the recording medium.

  Here, FIG. 8B shows a conventional general mask pattern distribution state. Conventionally, the same type of mask pattern is applied to all nozzle rows regardless of whether they are even nozzle rows, odd nozzle rows, or nozzle rows of different colors. It was general. That is, according to the example in the figure, the mask pattern A is used for all nozzle rows in the first recording scan, the mask pattern B in the second recording scan, the mask pattern C in the third recording scan, and the mask in the fourth recording scan. Pattern D is used. After the fifth printing scan, the mask pattern A is used again in order, and the printing main scan is repeated with this order maintained.

  When an attempt is made to record the secondary color blue by applying such a mask, magenta dots are always recorded in pixels where cyan dots are recorded in a certain recording main scan. Therefore, the landing state is as shown in FIG. That is, cyan ink and magenta ink are recorded in a state where not only main dots but also satellites are overlapped, the satellite distribution is biased with respect to the main dots, and the satellites themselves are also conspicuous.

  In contrast, in the present embodiment, the mask patterns A to D are distributed as shown in FIG. In this embodiment, different types of mask patterns are applied in the same printing scan in the cyan nozzle row and the magenta nozzle row, and in each of the even nozzle row and the odd nozzle row. For example, in the first print scan in the figure, the cyan Even nozzle row is mask pattern A, the magenta Even nozzle row is mask pattern B, the cyan Odd nozzle row is mask pattern C, and the magenta Odd nozzle row is mask pattern D. It has become. In the subsequent second recording scan, each nozzle row uses a mask pattern different from that in the first recording scan. The image data given to each nozzle row is recorded by four recording main scans using the mask patterns A to D in order. However, in this embodiment, the same mask pattern is always used in the main recording scan in the opposite direction in two color nozzle arrays that record the same pixel, such as a cyan Even nozzle array and a magenta Even nozzle array. This is one of the features of the shape. For example, the mask pattern A applied in the first print scan (forward scan) in the cyan Even nozzle row is applied in the fourth print scan (return scan) in the magenta Even nozzle row.

  FIGS. 9A to 9C are diagrams illustrating dot landing states when recording a secondary color blue using the mask of the present embodiment. Here, FIG. 9A shows the sum of dots recorded in the forward recording scan, that is, the first recording scan and the third recording scan. Magenta dots are not recorded in pixels where cyan dots are recorded in the forward recording scan, and similarly cyan dots are not recorded in pixels where magenta dots are recorded.

  On the other hand, FIG. 9B shows the sum of dots recorded in the forward recording scan, that is, the second recording scan and the fourth recording scan. In the forward recording scan, magenta dots are not recorded on pixels where cyan dots are recorded, and similarly, cyan dots are not recorded on pixels where magenta dots are recorded.

  FIG. 9C shows a dot landing state completed by superimposing the sum of the forward scanning shown in FIG. 9A and the sum of the backward scanning shown in FIG. The cyan dots and magenta dots that land on the same pixel are recorded by scanning in opposite directions. Therefore, the satellites of two colors are landed separately on both sides of the main dot. In such a case, the distribution of satellites with respect to the main dots is uniform. In addition, since the satellites uniformly land on the blank portion, the gap between the dots is reduced, and the graininess caused by the color difference between the blank portion and the dot is reduced. Furthermore, since each satellite is a primary color, the satellite is not conspicuous and the graininess of the satellite is reduced as compared with the case of FIG. 5 in which the satellite is a secondary color. Therefore, by using the dot arrangement as shown in FIG. 9C, a uniform image can be obtained as compared with the dot arrangement as shown in FIG. Also, the dot arrangement with small satellites on both sides has the advantage that the center of gravity of the dots is more stable at the center of the recording pixel and the image design is easier than the arrangement with satellites that are conspicuous on one side.

  9A to 9C show the effect of the present invention in units of pixels, FIG. 17 shows the image effect of the present invention in a wider range. FIG. 17A shows a result in which cyan dots and magenta dots of the same pixel are printed in the same scanning direction with a conventional mask. FIG. 17B shows a result in which cyan dots and magenta dots are printed in different scanning directions in the embodiment of the present invention. Compared to FIG. 17 (a), FIG. 17 (b) has a uniform image with fewer blank portions because the satellites land uniformly on the main dots.

  The dot position control method in which these two colors of satellites are arranged in the opposite directions of the main droplet has been described above using cyan and magenta as examples. However, in the recording apparatus of the present embodiment, black and yellow other than the above two colors are mounted, and it is impossible to always arrange satellites of all four colors at different positions. However, if a combination of inks used for the secondary color that is particularly likely to be high in density and visually conspicuous is selected and the above method is adopted so that the satellites of the combination are preferentially arranged in the reverse direction, The effect of the embodiment can be sufficiently exerted. In the above, it has been determined that cyan and magenta correspond to the above combination, and a control method focusing on these two colors has been described.

  Furthermore, in the above description, four-pass bidirectional multi-pass recording has been described as an example, but the above-described effect can be obtained if bidirectional multi-pass recording with two or more passes is performed. Whatever the number of multi-passes, the satellite is the main dot if it has a mask pattern configuration in which the dots of the two colors of interest (cyan and magenta) are recorded in different directions for the same recording pixel. To land evenly. This is because the gaps between the dots are also reduced, and a uniform image is obtained that is dispersed in a state where it is inconspicuous. Also in the recording apparatus of the present embodiment, a plurality of recording modes may be prepared in advance so that the above effects can be obtained with different numbers of multipasses.

  By the way, in the above embodiment, FIG. 8B is used as a general conventional mask pattern, and FIG. 8A is used as a mask pattern of this embodiment. The same mask pattern is not always used for all colors of main scanning. For example, Patent Document 2 discloses the contents of using different mask patterns with different ink colors in the same recording main scan. Further, according to the same document, a two-pass bidirectional printing is taken as an example, and a mask pattern in which the focused two color dots are recorded by main scanning in different directions is illustrated for the same recording pixel. However, Patent Document 2 does not disclose that one satellite of the two colors of interest and the other satellite are arranged on both sides of the main dot. This is because the ejection amount at that time is considerably larger than that at the present time, so that the satellite overlaps the main tod in one of the forward scanning and the backward scanning, and the satellite does not appear on both sides of the main dot. Therefore, in the technique described in Patent Document 2, it is possible to land a satellite of one color by shifting it toward the forward path with respect to the main dot and landing a satellite of the other color by shifting toward the backward path with respect to the main dot. Can not.

  In addition, Patent Document 2 describes only a fixed mask pattern in a relatively narrow range of about 4 pixels × 4 pixels, for example. The fixed mask pattern refers to a pattern in which print permission pixels are regularly arranged.

  FIG. 10 is a diagram illustrating an example of a mask pattern of 4 pixels × 4 pixels as described in Patent Document 2. In FIG. Here, four types of mask patterns E to H that are complementary to each other are prepared so as to be applicable to 4-pass multi-pass printing. In the figure, pixels painted out in black indicate pixels that are permitted to be recorded in the recording scan (recording allowed pixels), and pixels shown in white indicate pixels that are not permitted to be recorded in the recording scan (non-recording permitted pixels). In actual recording scanning, recording is performed in a state where a mask pattern of a narrow region shown in the drawing is repeatedly arranged in the main scanning direction and the sub-scanning direction.

  In contrast, in the present embodiment, a mask pattern called a random mask as shown in FIG. 26 is applied instead of the fixed mask pattern as shown in FIG. The random mask is characterized in that since the recording permission pixels are randomly arranged, the region does not have periodicity even when considered in a relatively wide range. The dot landing state when a fixed mask is applied and when a random mask is applied will be described below.

  11A to 11C are diagrams for explaining a case where 4-pass bidirectional multi-pass printing is performed using the fixed mask pattern shown in FIG. Here, FIG. 11A shows blue image data to be recorded. A pixel indicated by a circle is a pixel that records a blue dot, that is, a cyan dot and a magenta dot.

  FIG. 11B is a diagram showing the dot landing state of each recording scan when the image data shown in FIG. 11A is recorded using the mask pattern shown in FIG. Here, the mask pattern for each printing scan is selected so that printing for the same pixel is performed in the main scanning in the reverse direction for cyan and magenta.

  FIG. 11C is a diagram showing the dot arrangement of an image completed by the four recording main scans shown in FIG. The cyan satellite and the magenta satellite are arranged separately on both sides of the main dot.

  FIG. 12 is a diagram showing a dot landing state in each printing scan when the image data shown in FIG. 11A is printed using a random mask pattern. Here, four 4 × 4 pixel areas in the printing area are arbitrarily extracted at three locations, and the dot landing state in four printing scans for the area is shown in the same manner as in FIG. Unlike the fixed mask pattern, the random mask pattern applied in the present embodiment does not have regularity having a predetermined period. Therefore, the arbitrarily extracted three patterns also have different dot arrangements.

  FIG. 13 is a diagram showing a dot arrangement of an image completed by four recording main scans in each of the three areas shown in FIG. As in FIG. 11C, the cyan satellite and the magenta satellite are arranged separately on both sides of the main dot, but their positions are different in the three regions.

  FIGS. 14A and 14B are diagrams showing an image completed using the fixed mask and the random mask in a wider range (16 pixels × 16 pixels). Here, the satellite landed on the main dot is also shown, but in the main dot, the cyan dot and the magenta dot overlap to form a blue dot, so that the satellite is landed further on it. However, there is no significant effect on the hue. On the other hand, a satellite landed on white paper alone has a considerable influence on the hue in the image area. Therefore, here, attention is focused on satellites that have been landed on white paper alone.

  In consideration of such a situation, referring to FIG. 14A, it can be seen that there are far more cyan satellites than magenta satellites. That is, in the case of FIG. 14A, the hue of the region (16 pixels × 16 pixels) is slightly inclined to cyan rather than regular blue.

  A mask pattern with fixed regularity as shown in FIG. 11B tends to be synchronized with regular image data as shown in FIG. As a result, the dot arrangement shown in FIG. 11C determined by the relationship between the image data and the mask pattern appears repeatedly in the main scanning direction and the sub-scanning direction. Therefore, the hue bias determined in a narrow area as shown in FIG. 11C is also stored in the entire area, and the entire image is affected. Here, the pattern of FIG. 11A is taken as an example of the image data. However, when a fixed mask pattern is used, such a phenomenon can occur even with other image data. In particular, when a binarization method having a relatively regularity such as a dither pattern is adopted, the hue may be inclined to cyan or magenta depending on the type of dither pattern and the gradation value. It becomes stable.

  On the other hand, in FIG. 14B showing a state using a random mask, the number of cyan satellites and the number of magenta satellites are almost equal. That is, in the case of FIG. 14B, it can be said that the hue of the region is substantially equivalent to that of regular blue. When a random mask is used, the mask pattern and the image data are not synchronized regardless of the input image data. Therefore, the number of cyan satellites and the number of magenta satellites are kept substantially the same, and even if they are considered in a wide range, the hue does not greatly deviate from regular blue.

  For the above reasons, it is preferable to use a mask pattern having no periodicity, such as a random mask, in order to exert the effect of the present embodiment. This is because when a fixed mask pattern as in Patent Document 2 is used, the hue is tilted by the synchronization of the image data and the mask pattern, and the uniform effect of the image is less than that of the random mask pattern. . However, the effect of the invention can be obtained even with a fixed mask pattern. Therefore, the present invention does not exclude the application of such a fixed mask pattern having periodicity.

  In the above-described embodiment, the description has been made with respect to the contents of applying the mask patterns A to D in order with different printing scans for cyan ink and magenta ink when performing four-pass bidirectional printing. However, the present invention is not limited to such a configuration. As in the present embodiment, when there are a plurality of forward scans and multiple backward scans, the sum of the forward paths of the cyan ink mask pattern and the return path of the magenta ink mask pattern may coincide. For example, the four types of mask patterns are not necessarily the same type.

  As described above, according to the present embodiment, the satellites of the first ink land on the main dots of the first and second inks while being shifted in the forward direction or the backward direction. In addition, the satellite of the second ink lands on the main dots of the first and second inks in a direction opposite to the direction in which the satellite of the first ink is shifted. Therefore, it is possible to output an image with excellent uniformity.

(Second Embodiment)
The second embodiment of the present invention will be described below. Also in this embodiment, the recording apparatus described with reference to FIGS. 1 and 6 is applied.

  FIG. 15 is a diagram for explaining the arrangement of the ejection openings of the recording head 1102 applied to this embodiment. In this embodiment, the basic four-color ink used in the first embodiment has a six-color ink structure in which light cyan ink and light magenta ink in which the density of a coloring material such as a dye or pigment is reduced are added. . 601 is a nozzle row for black ink, 602 is a nozzle row for cyan ink, 603 is a nozzle row for light cyan ink, 604 is a nozzle row for magenta ink, 605 is a nozzle row for light magenta ink, and 606 is yellow ink. This is a nozzle row. The six color nozzle rows are configured by an Even nozzle row and an Odd nozzle row, respectively, as in the first embodiment.

  FIG. 16 is a schematic diagram for explaining a mask pattern applied in the present embodiment. Here, the types of mask patterns for the cyan nozzle row 602 and the light cyan nozzle row 603 are shown by taking 4-pass bidirectional multi-pass printing as an example. The Odd and Even nozzle arrays composed of 128 ejection openings are divided into 8 blocks of 16 in the sub-scanning direction, and one type of mask pattern is applied to one block. In the figure, four recording scans of the first recording scan to the fourth recording scan are shown, and an amount of paper feeding corresponding to two blocks is performed between the recording scans. Here, the recording head moves relative to the recording medium.

  In FIG. 16, A to D indicate four different mask patterns that are mutually exclusive and complementary. That is, four types of mask patterns A to D are applied one by one to four main recording scans, thereby completing an image to be recorded on the same image area of the recording medium. In this embodiment as well, a random mask having no periodicity is applied to each of the mask patterns A to D.

  In the present embodiment, different types of mask patterns are applied in the same printing scan in the cyan nozzle row and the light cyan nozzle row, and also in the even nozzle row and the odd nozzle row. For example, in the first recording scan of FIG. 16, a cyan Even nozzle row is mask pattern A, a light cyan Even nozzle row is mask pattern B, a cyan Odd nozzle row is mask pattern C, and a light cyan Odd nozzle row is mask pattern D. It has become. In the subsequent second recording scan, each nozzle row uses a mask pattern different from that in the first recording scan. The image data given to each nozzle array is completed by four main print scans using the mask patterns A to D in order. However, the same mask pattern is always used in the main recording scan in the opposite direction in two types of light and dark nozzle arrays that record the same pixel, such as a cyan Even nozzle array and a light cyan Even nozzle array. ing.

  When the mask pattern as described above is employed, light cyan dots are not recorded in pixels in which the cyan dots are recorded in the forward recording scan, and cyan pixels are similarly recorded in pixels in which the light cyan dots are recorded. No dots are recorded. Therefore, the cyan satellite and the light cyan satellite are landed separately on both sides of the main dot.

  Even in the case of a combination of inks having substantially the same hue (inks of similar colors) such as cyan dots and light cyan dots, the influence on the image is further increased due to the overlapping of the two satellites. Therefore, as in this embodiment, keeping the two types of satellites as separated as possible is effective in maintaining the image quality. Further, as in the first embodiment, the dot arrangement with small satellites on both sides of the main dot is more stable in the center of the recording pixel than the arrangement with the satellite conspicuous on one side, and the image design There is also an advantage that it is easy to do.

  In the above, the dot position control method has been described in which these two color satellites are arranged in the opposite directions of the main dots, taking cyan and light cyan as an example. However, in the recording apparatus of the present embodiment, it is also possible to apply a mask pattern that can establish the above relationship for magenta and light magenta.

  In the above-described two embodiments, the combination of cyan and magenta, or the combination of cyan and light cyan has been described, but the present invention is naturally applicable to other combinations. For example, even for combinations such as cyan and light magenta or light cyan and light magenta, the present invention can function effectively if there is a problem caused by satellites formed by overlapping the two. Furthermore, even with ink of the same hue and the same density, it can be applied to a recording apparatus that expresses the density of one pixel by two types of ink droplets having different ejection amounts.

  As described above, according to the present embodiment, the satellite of the first ink and the satellite of the second ink of the same color as the first ink land on each other with the main dot interposed therebetween, so that the uniformity is excellent. Images can be obtained.

(Third embodiment)
The third embodiment of the present invention will be described below. Also in this embodiment, the recording apparatus described with reference to FIGS. 1 and 6 is applied.

  FIG. 18 is a diagram for explaining the arrangement of the ejection openings of the recording head 1102 applied to this embodiment. In the present embodiment, a part of the nozzle row used in the first embodiment is replaced with a nozzle row having a different discharge port diameter. In the figure, reference numeral 901 denotes a nozzle row for black ink, 902 denotes a nozzle row for cyan ink, 903 denotes a nozzle row for magenta, and 904 denotes a nozzle row for yellow ink. Unlike the first embodiment, the nozzle row is composed of nozzle rows of different sizes for the Even nozzle row and the Odd nozzle row, respectively. Here, for convenience, the dots ejected from the Odd nozzle row 901a are defined as large dots, and the dots ejected from the 901b are defined as small dots.

  FIG. 19 is a schematic diagram for explaining a mask pattern applied in the present embodiment. Here, the types of mask patterns corresponding to the large cyan nozzle row 901a and the small cyan nozzle row 901b of the cyan nozzle row 902 are shown by taking 4-pass bidirectional multi-pass printing as an example. The Odd and Even nozzle arrays comprising 128 ejection openings are divided into 8 blocks of 16 in the sub-scanning direction, and one type of mask pattern is used for one block. In the figure, four recording scans of the first recording scan to the fourth recording scan are shown, and an amount of paper feeding corresponding to two blocks is performed between the recording scans. Here, the recording head moves relative to the recording medium.

  In the figure, A to D show four different mask patterns that are mutually exclusive and complementary. That is, four types of mask patterns A to D are applied one by one to the four main recording scans, thereby completing an image to be recorded in the same image area of the recording medium. In this embodiment as well, a random mask having no periodicity is applied to each of the mask patterns A to D.

  In the present embodiment, different types of mask patterns are applied in the same printing scan in the large cyan nozzle row and the small cyan nozzle row. For example, in the first recording scan of FIG. 16, the large cyan nozzle row is the mask pattern A, and the small cyan nozzle row is the mask pattern B. In the subsequent second recording scan, each nozzle row uses a mask pattern different from that in the first recording scan. The image data given to each nozzle array is completed by four main print scans using the mask patterns A to D in order. However, the same mask pattern is always used in the main recording scan in the opposite direction in the two types of nozzle rows of the cyan row.

  If the same mask is used for each column, the first pixel in the region composed of 1 pixel in the main scanning direction × 2 pixels in the sub-scanning direction (1 pixel indicates a 1200 × 1200 dpi grid) is set to a large cyan and second pixel. If small cyan is recorded on the adjacent pixels, these adjacent pixels are recorded in the same scanning direction. Therefore, in the mask pattern, large dots and small dots recorded in adjacent pixels in 1 × 2 pixels are recorded in different recording directions.

  When the mask pattern as described above is adopted, as shown in FIG. 20A, in the 1 × 2 pixel region composed of large cyan and small cyan, large dots are arranged with respect to the main dot row arranged in the sub-scanning direction. Satellites and small dot satellites are distributed evenly from side to side. Therefore, a uniform image can be obtained.

  FIG. 20B shows the recording state of the present embodiment when viewed from a wide range. As seen from the nozzle row direction, the landing of the satellite non-uniformly on the left and right of the main dot has a considerable adverse effect on the image even in the same hue. FIG. 21A shows a landing state when the same mask is used for the large dot row and the small dot row in the same scan. When viewed from 1 × 2 pixels, since adjacent pixels are always recorded in the same scanning direction, satellites land on the respective main dots in the same direction. FIG. 21 (b) shows a wide range of recording states. Compared with FIG. 20 (b), it can be seen that the blank portion and the portion where satellites overlap are conspicuous and the satellite distribution is dense. Therefore, as in this embodiment, keeping two types of satellites separated as much as possible in adjacent pixels in the nozzle row direction (direction orthogonal to the main scanning direction, that is, the sub scanning direction) is to maintain image quality. It is valid. Further, as in the first embodiment, the dot arrangement with the small satellites on both sides of the main dot of the adjacent pixel is more stable at the center of the recording pixel than the arrangement with the satellite conspicuous on one side. There is also an advantage that image design is easy to perform.

  The feature of this embodiment is that, when the same color dots of different sizes are recorded from two nozzle rows on two pixels adjacent to each other in the nozzle row direction (direction orthogonal to the main scanning direction) instead of the same pixel, the satellites are mutually connected. The point is that they land on the main dots in opposite directions.

  In this embodiment, the case where adjacent pixels in the nozzle row direction are recorded with large dots and small dots of the same color has been described. However, a combination of different sizes (for example, medium dots) or a combination of inks of different colors. But you can. For example, the effect of the invention in the present embodiment can be obtained in the same way even with a combination of different colors of the same size, such as a combination of secondary colors of large dots cyan and magenta, or small dots cyan and magenta.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below. Also in this embodiment, the recording apparatus described in FIGS. 1 and 6 is applied.

  Also in the present embodiment, the recording head described with reference to FIG. 18 is used as in the third embodiment.

  FIG. 22 is a schematic diagram for explaining a mask pattern applied in the present embodiment. Here, taking four-pass bidirectional multi-pass printing as an example, a total of four rows of a large cyan nozzle row and a small cyan nozzle row in the cyan row 902, a large magenta nozzle row in the magenta row 903, and a small magenta nozzle row. The types of mask patterns for are shown. The Odd and Even nozzle arrays composed of 128 ejection openings are divided into 8 blocks of 16 in the sub-scanning direction, and one type of mask pattern is applied to one block. In the figure, four recording scans of the first recording scan to the fourth recording scan are shown, and an amount of paper feeding corresponding to two blocks is performed between the recording scans. Here, the recording head moves relative to the recording medium.

  In FIG. 22, A to D indicate four different mask patterns that are mutually exclusive and complementary. That is, four types of mask patterns A to D are applied one by one to the four main recording scans, thereby completing an image to be recorded in the same image area of the recording medium. In this embodiment as well, a random mask having no periodicity is applied to each of the mask patterns A to D.

  In this embodiment, different types of mask patterns are applied in the same printing scan in each of the large cyan nozzle row, the small cyan nozzle row, the large magenta nozzle row, and the small magenta nozzle row. For example, in the first printing scan shown in the figure, the large cyan nozzle row is mask pattern A, the small cyan nozzle row is mask pattern B, the large magenta nozzle row is mask pattern D, and the small magenta nozzle row is mask pattern C. It has become. In the subsequent second recording scan, each nozzle row uses a mask pattern different from that in the first recording scan. The image data given to each nozzle array is completed by four main print scans using the mask patterns A to D in order.

  However, the same mask pattern is always used for each combination of two types of nozzle rows, large and small, for cyan rows, two types of nozzle rows for magenta rows, two types of nozzle rows for large dots, and two types of rows for small dots. It is used in the main scanning in the opposite direction.

  FIG. 23 is a diagram schematically showing such a relationship. Although the recording scanning direction in the mask pattern A is described here, the same relationship holds for the mask patterns B, C, and D.

  When such a mask pattern is employed, a state as shown in FIG. That is, in a 1 × 2 pixel region constituted by superimposing large cyan and large magenta and superimposing small cyan and small magenta, large dot satellites and small dots are compared to the main dot array arranged in the sub-scanning direction. Satellites land on the left and right sides almost evenly. Therefore, a uniform image can be obtained. FIG. 24B shows the recording state of the present embodiment when viewed from a wide range.

  Non-uniform landing of satellites on the main dots adversely affects the image. FIG. 25A shows the landing when a secondary color is recorded using the same mask for the large and small cyan columns and the large and small magenta columns using the same scan. When viewed from 2 × 2 pixels, since the same pixel is always recorded in the same scanning direction, the satellite is recorded in the same direction with respect to the main dot of the same pixel. FIG. 25 (b) shows a wide range of figures. Compared with FIG. 24 (b), it can be seen that blank portions and portions where satellites overlap are conspicuous and the distribution of satellites is dense.

  The feature of this embodiment is that the position where satellites are recorded is set as the main dot by devising the order of the mask pattern even in the combination of nozzle rows that record dots of different sizes and nozzle rows that record dots of different colors. On the other hand, it can be uniformly distributed. In the present embodiment, large and small dots of cyan and magenta have been described. However, the present invention is not limited to this, and the same effect can be obtained by combining different colors or nozzle arrays having different sizes.

  Note that the random mask pattern applied in the above embodiment should be broadly understood as “a mask pattern having no strong periodicity such as a fixed mask pattern”. Therefore, the random mask pattern is not limited to a pattern in which the position of the recording allowable pixel is determined randomly (randomly).

  The mask pattern applicable in the present invention is not limited to a random mask pattern, and for example, a non-periodic mask pattern as disclosed in Japanese Patent Application Laid-Open No. 2002-144552 can be applied. That is, a mask pattern having a characteristic that the arrangement of the print permitting pixels is non-periodic and has low frequency components is also preferably used.

  The present invention employs a method of generating thermal energy for ink ejection (for example, an electrothermal converter, a laser beam, etc.) and causing a change in the state of ink by the thermal energy, among ink jet recording methods. Especially when it works. According to such a method, it is possible to reduce the discharge amount, and accordingly, it is possible to achieve higher recording density and higher definition, and satellites that are the subject of the present invention also tend to appear. .

1 is a diagram illustrating a configuration of a main part of an ink jet recording apparatus applicable to the present invention. FIG. 3 is a schematic diagram illustrating ejection openings for one color disposed in a recording head. (A)-(d) is a figure for demonstrating the landing position in the recording medium of a main dot and a satellite. FIG. 6 is a diagram illustrating various landing states when bidirectional multipass printing is performed on a 2 × 2 pixel area. (A)-(c) is a figure which shows the case where the dot of cyan and magenta are superimposed and blue is expressed. It is a block diagram for demonstrating the control structure of the inkjet recording device which concerns on embodiment of this invention. FIG. 4 is a diagram for explaining an arrangement configuration of ejection openings of a recording head applied to an embodiment of the present invention. (A) And (b) is a schematic diagram for demonstrating the characteristic of the mask pattern applied by embodiment of this invention. (A)-(c) is a figure which shows the landing state of a dot at the time of applying the mask of 1st Embodiment and recording blue which is a secondary color. It is a figure which shows the example of a fixed mask pattern of 4 pixels x 4 pixels. (A)-(c) is a figure for demonstrating the case where a 4-pass bidirectional | two-way multipass printing is performed using a fixed mask pattern. It is the figure which showed the dot landing state at the time of recording image data using a random mask pattern. FIG. 6 is a diagram illustrating a dot arrangement of an image completed by four recording main scans. (A) And (b) is the figure which showed the image completed using the fixed mask and the random mask in a wider range (16 pixels x 16 pixels). FIG. 4 is a diagram for explaining an arrangement configuration of ejection openings of a recording head applied to an embodiment of the present invention. It is a schematic diagram for demonstrating the mask pattern applied by embodiment of this invention. (A) and (b) are images in a wider range (8 × 8 pixels) when recording the secondary color blue by applying the mask of the conventional embodiment and the mask of the first embodiment. FIG. FIG. 10 is a diagram for explaining an arrangement configuration of ejection openings of a recording head applied to a third embodiment. It is a schematic diagram for demonstrating the mask pattern applied in 3rd Embodiment. (A) And (b) is a figure which shows the landing state of a dot when the mask of 3rd Embodiment is applied and a large dot and a small dot are recorded on the adjacent pixel of a nozzle direction. (A) And (b) is a figure which shows the landing state of the dot at the time of recording the large dot and the small dot to the adjacent pixel of a nozzle direction by applying the mask implemented conventionally. It is a schematic diagram for demonstrating the mask pattern applied in 4th Embodiment. It is a figure for demonstrating the recording direction of the dot recorded by the mask pattern A in 4th Embodiment. (A) And (b) is a figure which shows the landing state of the dot at the time of applying the mask of 4th Embodiment and trying to record blue with a large dot and a small dot. (A) And (b) is a figure which shows the landing state of the dot when it is going to record blue with a large dot and a small dot by applying the mask implemented conventionally. It is a schematic diagram for demonstrating an example of the random mask pattern applicable to this embodiment.

Explanation of symbols

601 Black ink nozzle row 602 Cyan ink nozzle row 603 Light cyan ink nozzle row 604 Magenta ink nozzle row 605 Light magenta ink nozzle row 606 Yellow ink nozzle row 700 CPU
701 ROM
702 RAM
703 Image input unit 704 Image signal processing unit 705 Main bus line 706 Operation unit 707 Recovery system control circuit 708 Recovery system motor 709 Cleaning blade 710 Cap 711 Suction pump 712 Thermistor 714 Head temperature control circuit 715 Head drive control circuit 716 Carriage drive control circuit 717 Paper feed control circuit 801 Black ink nozzle row 802 Cyan ink nozzle row 803 Magenta ink nozzle row 804 Yellow ink nozzle row 1101 Inkjet cartridge 1102 Recording head 1103 Paper feed roller 1104 Auxiliary roller 1105 Paper feed roller pair 1106 Carriage 1201 Discharge port (nozzle)
1301 Main droplet 1302 Satellite 1303 Carriage traveling direction 1304 Discharge direction

Claims (14)

An inkjet recording apparatus that records an image on a recording medium using a recording head capable of ejecting a second ink in which at least one of the first ink and the first ink is different in color and amount,
Means for main-scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Means for performing ejection of the first and second inks on the same pixel on the recording medium by main scanning in different directions,
The satellites of the first ink ejected toward the same pixel land on the main dots of the first and second inks that land on the same pixel, shifted in the forward direction or the backward direction, and land on the second ink. 2. An ink jet recording apparatus according to claim 1, wherein the satellite lands with respect to the main dots of the first and second inks in a direction opposite to a direction in which the satellite of the first ink is shifted. Further comprising dividing means for dividing the image data corresponding to the area on the recording medium that can be recorded by one main scanning into M in order to record the data by M main scanning;
2. The inkjet according to claim 1, wherein the dividing unit divides the image data so that printing of the first and second inks on the same pixel is performed in the main scanning in different directions. Recording device. For each of the first and second inks, the image forming apparatus further includes a storage unit that stores M types of mask patterns that are complementary to each other, in which print-permitted pixels and non-printable pixels are arranged,
The dividing unit divides the image data of the first and second inks into M based on mask patterns corresponding to the first and second inks stored in the storage unit, respectively. The ink jet recording apparatus according to claim 2.   4. The ink jet recording apparatus according to claim 3, wherein the mask pattern has no periodicity.   4. The ink jet recording apparatus according to claim 3, wherein the mask pattern is a pattern in which the recording allowable pixels are irregularly arranged.   6. The ink jet recording apparatus according to claim 1, wherein the first and second inks are inks having different hues.   7. The ink jet recording apparatus according to claim 6, wherein one of the first and second inks is cyan ink, and the other is magenta ink.   6. The ink jet recording apparatus according to claim 1, wherein the first and second inks have the same hue and are ejected in different amounts.   6. The ink jet recording apparatus according to claim 1, wherein the first and second inks have substantially the same hue and have different color material concentrations. A recording medium using a recording head provided with at least a second ejection port for ejecting a second ink, wherein the first ejection port for ejecting the first ink and the first ink differ in at least one of color and amount An inkjet recording apparatus for recording an image on
Means for main-scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Means for performing ejection of the first and second inks on the same pixel on the recording medium during main scanning in different directions;
The plurality of pixels from which both the first and second inks are ejected are the first pixel from which the first ink is ejected in the forward direction and the second ink is ejected in the backward direction, and the backward direction. A second pixel from which the first ink is ejected and the second ink is ejected in the forward direction;
With respect to the landing positions of the main dots of the first and second inks ejected to the first pixels, the satellites of the first ink are landed with a shift in the forward direction, and the satellites of the second ink are in the backward direction. The satellite of the first ink is landed with a shift in the backward direction with respect to the landing position of the main dots of the first and second inks discharged and ejected to the second pixel, and the second ink An ink jet recording apparatus characterized in that the satellites land with being shifted in the forward direction. An inkjet recording apparatus that records an image on a recording medium using a recording head capable of ejecting a second ink in which at least one of the first ink and the first ink is different in color and amount,
Means for main-scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Means for performing ejection of the first and second inks on pixels adjacent to each other in a direction orthogonal to the main scanning direction on the recording medium in main scanning in different directions;
The satellite of the first ink ejected toward one pixel of the adjacent pixels lands on the main dot of the first ink landing on the one pixel with a shift in the forward or backward direction, and the other pixel. The satellite of the second ink ejected toward the center of the second ink lands in a direction opposite to the direction in which the satellite of the first ink deviates from the main dot of the second ink that lands on the other pixel. Inkjet recording apparatus. A recording medium using a recording head provided with at least a second ejection port for ejecting a second ink, wherein the first ejection port for ejecting the first ink and the first ink differ in at least one of color and amount An inkjet recording apparatus for recording an image on
Means for main-scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Means for performing ejection of the first and second inks on pixels adjacent to each other in a direction orthogonal to the main scanning direction on the recording medium during main scanning in different directions;
The adjacent pixels from which the first and second inks are ejected include a first pixel from which the first ink is ejected in the forward direction and a second pixel from which the second ink is recorded in the backward direction. Configured,
The satellite of the first ink is landed with a shift in the forward direction with respect to the landing position of the main dot of the first ink discharged to the first pixel, and the second ink discharged to the second pixel 2. An ink jet recording apparatus according to claim 1, wherein the satellite of the second ink is landed while being displaced in the backward direction with respect to the landing position of the main dot. An inkjet recording method for recording an image on a recording medium using a recording head capable of discharging a second ink in which at least one of the first ink and the first ink is different in color and amount,
Main scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Performing the first and second ink ejections on the same pixel on the recording medium by main scanning in different directions, and
The satellites of the first ink ejected toward the same pixel land on the main dots of the first and second inks that land on the same pixel, shifted in the forward direction or the backward direction, and land on the second ink. 2. An ink jet recording method according to claim 1, wherein the satellite lands on the main dots of the first and second inks in a direction opposite to a direction in which the satellites of the first ink are shifted. An inkjet recording method for recording an image on a recording medium using a recording head capable of discharging a second ink in which at least one of the first ink and the first ink is different in color and amount,
Main scanning the recording head relative to the recording medium in the forward direction and the backward direction;
Performing the recording of the first and second inks on pixels adjacent to each other in a direction orthogonal to the main scanning direction on the recording medium by main scanning in different directions;
The satellite of the first ink ejected toward one pixel of the adjacent pixels lands on the main dot of the first ink landing on the one pixel with a shift in the forward or backward direction, and the other pixel. The satellite of the second ink ejected toward the center of the second ink lands in a direction opposite to the direction in which the satellite of the first ink deviates from the main dot of the second ink that lands on the other pixel. Inkjet recording method.

Images