JP2012011648A - Inkjet recorder and inkjet recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet recorder and an inkjet recording method which suppress deterioration in image quality caused by irregularity in satellite's landing.SOLUTION: Multi-value data (1306-1 and 1306-2) distributed in association with multi-path scanning are each quantized to a plurality of binary data (1308-1 and 1308-2) according to dot patterns different from each other. In such a case, the dot patterns respectively corresponding to two or more times of scanning are different from each other in arrangement of recording or non-recording of dots for each pixel. Thus, even when a recording position of the satellite is fluctuated by air flow, the satellite that independently lands on a blank area and the satellite that is superposed on a main dot and lands on it are made to coexist at a predetermined rate, thereby suppressing irregular density.

Description

  The present invention relates to an ink jet recording apparatus and a recording method for recording an image on a recording medium by ejecting ink droplets from an ink ejection port of a recording head based on recording data.

  Ink jet recording apparatuses are generally widely used because they can output color images with high quality while being relatively small and inexpensive. In particular, in recent years, the demand for higher-quality images has increased, and various recording methods for realizing high-quality image output have been proposed and adopted.

  Patent Document 1 discloses an image processing method in which multi-value image data is divided into a plurality of scans (multi-pass) in a multi-value state and then quantized for each scan when performing multi-pass printing. Has been. If the method of Patent Document 1 is adopted, even if a sudden transport error occurs in the recording apparatus or the distance between the recording head and the recording medium (inter-paper distance) fluctuates, image adverse effects such as density unevenness are caused. It is possible to output a stable image that is not confirmed.

JP 2009-246730 A

  By the way, in recent years, with the demand for higher quality image output, higher resolution of images and smaller droplets of ejected ink droplets have been promoted. However, in such a configuration in which small droplets of ink are ejected at high density, an air flow is generated in the vicinity of the ejection port of the recording head along with ejection, which may affect the ejection direction of the ejected ink droplets. .

  In particular, in an inkjet recording head, a sub-droplet smaller than the main droplet may be ejected together with a desired ink droplet called a main droplet in the ejection operation. The sub-drops follow the main droplets and land on the recording medium at a slower speed than the main droplets to form small dots called satellites.If the sub-drops are sufficiently smaller than the main droplets, If it is included in a dot, it does not affect the image. However, the recording position of this satellite varies greatly with the airflow.

  FIG. 7 is a diagram illustrating the influence of the airflow generated when ink is ejected from the 256 nozzles arranged at high density at a predetermined frequency on the landing positions of the main droplet and the sub-droplet. The horizontal axis indicates the arrangement position of the individual nozzles in the recording head, and the vertical axis indicates the amount of deviation of the main dots and satellites formed by the main droplets or sub-droplets discharged from the individual nozzles from the target position on the recording medium. Is shown. According to the figure, it can be seen that the landing position shift of the satellite is larger than that of the main dot, and the shift amount varies depending on the position of the nozzle.

  Such a distance between the main dot and the satellite also varies depending on the distance between the ejection port surface of the recording head and the recording medium, that is, the distance between the sheets. In particular, when performing marginless recording in which an image is recorded without providing a margin on the front end portion or the rear end portion of the recording medium or on the entire surface of the recording medium, the conveyance and support state of the recording medium changes. Changes, and the difference in the distance between the main dot and the satellite changes the image density.

  The present invention has been made merely to solve the above problems. Accordingly, an object of the present invention is to provide an ink jet recording apparatus and an ink jet recording method capable of suppressing a decrease in image quality due to disturbance of landing of satellites.

  To this end, the present invention provides a recording head configured by arranging a plurality of nozzles that eject ink in accordance with image data, a plurality of times in a direction intersecting the direction of the arrangement with respect to the same image area of the recording medium. An inkjet recording apparatus that records an image on the recording medium by scanning, and distributes multi-value image data into a plurality of multi-value data corresponding to each of the plurality of scans according to a predetermined distribution ratio Means and each of the plurality of multi-value data corresponding to each of the plurality of scans according to a dot pattern prepared corresponding to each of the plurality of scans and determined to record or not record dots for each pixel. Quantizing means for quantizing the plurality of binary data, and performing the plurality of scans on the same image area in accordance with each of the plurality of binary data. And means for rows, the dot patterns corresponding to the respective scan of said plurality of times, characterized in that the recording or non-recording of the sequence of dots for each pixel are different from each other.

  According to the present invention, it is possible to obtain an image with a low granularity that is recorded in a state in which main dots and satellites are relatively dispersed in a predetermined scan of multipass printing. On the other hand, in another scan of multi-pass printing, it is possible to obtain an image recorded with the main dots and satellites relatively overlapped and having little density fluctuation due to airflow. As a result, it is possible to suppress deterioration in image quality due to disturbance of the landing of the satellite while suppressing the graininess of the image and maintaining uniformity.

1 is a perspective view showing an internal configuration of an ink jet recording apparatus that can be used in the present invention. (A)-(C) are sectional drawings for demonstrating the support state of the recording medium of the step which records the front-end | tip part, center part, and rear-end part of a recording medium. It is a figure which shows each area | region of the front-end | tip part, a center part, and a rear-end part in a recording medium. It is a figure which shows the system configuration example applicable to this invention. It is a block diagram for demonstrating the process of the image processing applicable to this invention. It is a figure which shows the dot pattern applicable to this invention. It is a figure which shows the influence which an airflow has on the landing position of a main droplet and a subdrop. (A)-(D) is a figure which shows the positional relationship of the main droplet and satellite which are recorded on a recording medium by 1st scan and 2nd scan. It is a figure which shows the example of distribution of the multi-value data in an image data division part.

  FIG. 1 is a perspective view showing an internal configuration of an ink jet recording apparatus that can be used in an embodiment of the present invention. At the time of recording, the recording medium P is sandwiched between two roller pairs, that is, a roller pair of a conveyance roller 801 and a pinch roller 802 and a roller pair of a discharge roller 805 and a spur 806. It is conveyed in the A direction. The pinch roller 802 is elastically biased toward the conveying roller 801 by a pressing means such as a spring (not shown) so that the recording medium does not slide between the roller pair. Between these two roller pairs, a platen 803 that supports the recording medium from below is provided to maintain the smoothness of the recording medium in the recording area.

  The recording head 804 is detachably mounted on the carriage 808 with its ejection surface facing the platen 803 or the recording medium P. The carriage 808 is reciprocated along two guide rails 809 and 810 by driving means such as a motor (not shown), and the recording head 804 discharges ink toward the recording medium in the course of the movement. The moving direction of the carriage 808 is a direction that intersects the recording medium conveyance direction (arrow A direction), and is referred to as a main scanning direction. On the other hand, the recording medium conveyance direction is called a sub-scanning direction.

  Under such a configuration, an image is recorded in a stepwise manner on the recording medium P by alternately repeating the main scanning of the carriage or the recording head and the conveying operation (sub-scanning) of the recording medium.

  At this time, a general inkjet recording apparatus in recent years often employs a recording method called multipass recording. In multi-pass printing, a plurality of nozzles arranged in a printing head prints an area (same image area) that can be printed by one main scanning, divided into a plurality of main scannings. And between each main scanning, the conveyance operation | movement of the distance shorter than the recording width of the recording head in a subscanning direction is performed. By performing such multi-pass printing, even if there are variations in the discharge state of a plurality of arranged nozzles, or even if the conveyance amount of the recording medium is suddenly displaced, the adverse effects on the image are streaks or unevenness. It can be prevented from appearing. In such multi-pass printing, as the number of main scans required for printing the same image area, that is, the number of multi-passes increases, the uniformity of the obtained image increases.

  2A to 2C are cross-sectional views for explaining the support state of the recording medium at the stage of recording the leading end portion, the central portion, and the trailing end portion of the recording medium, respectively. The recording head 804 ejects ink toward the recording medium P while moving and scanning in a direction perpendicular to the drawing, and the recording head 804 is in a region of the recording medium P located between the transport roller 801 and the discharge roller 805. Form an image.

  FIG. 2A is a diagram showing a support state of the recording medium when recording is performed on the leading end portion of the recording medium. In a state where the leading end is located on the platen 803, the recording medium P is sandwiched between the pair of rollers of the transport roller 801 and the pinch roller 802, but is not sandwiched between the pair of rollers of the discharge roller 805 and the spur 806.

  FIG. 2B is a diagram illustrating a support state of the recording medium when recording is performed on the central portion of the recording medium. In a state where the central portion is located on the platen 803, the recording medium P is sandwiched by both the roller pair of the transport roller 801 and the pinch roller 802 and the roller pair of the discharge roller 805 and the spur 806.

  Further, FIG. 2C is a diagram showing a support state of the recording medium when recording is performed on the rear end portion of the recording medium. In a state where the rear end portion is positioned on the platen 803, the recording medium P is sandwiched between the pair of rollers of the discharge roller 805 and the spur 806, but is not sandwiched between the pair of rollers of the transport roller 801 and the pinch roller 802. .

  Comparing these three figures, the state in which the recording medium is sandwiched both upstream and downstream of the recording area as shown in FIG. 2B makes the recording surface of the recording medium P most smooth, The distance from the discharge port surface (distance between sheets) can be kept constant. Further, since the recording medium P is transported while being stretched between both the pair of transport rollers 902 and the pair of discharge rollers 805, the transport amount accompanying the rotation of these rollers is also stabilized.

  On the other hand, as shown in FIGS. 2A and 2C, in the state where the recording medium is sandwiched between only one of the upstream side and the downstream side of the recording area, the recording surface of the recording medium P is easily inclined, and the recording head It is difficult to maintain a constant distance (distance between papers) with the discharge port surface. That is, the landing position of the satellite with respect to the main droplet becomes more unstable. Further, since the recording medium P is conveyed by the rotation of only one of the pair of conveyance rollers 902 and the pair of discharge rollers 805, the conveyance amount becomes unstable. When multipass printing is performed under such circumstances, the area covering the recording medium by the main droplets and satellites is not stable, and the image density becomes unstable. For this reason, the image quality at the leading edge and the trailing edge of the recording medium is more likely to be impaired than at the center.

  FIG. 3 is a diagram showing respective regions of the front end, the center, and the rear end of the recording medium. In this specification, the front end portion of the recording medium indicates an area from the front end of the recording medium to a position where recording is performed by the recording head when the front end is sandwiched between the discharge roller pair. Further, the rear end portion of the recording medium indicates an area from the rear end of the recording medium to a position where recording is performed by the recording head when the rear end is released from the holding of the conveying roller pair. An area other than the front end and the rear end is defined as a central portion of the recording medium.

  Each of the front end portion, the central portion, and the rear end portion defined as described above has a certain area as shown in the drawing. Accordingly, when a difference in image quality as described with reference to FIGS. 2A to 2C appears in these regions, the difference can be visually confirmed. Based on the above, in the present embodiment, the recording method in which the area covering the recording medium by the main droplet and the satellite is relatively stable even at the leading end and the trailing end where the distance between the papers is unstable. Is adopted.

  FIG. 4 is a diagram showing a system configuration example applicable to this embodiment. The inkjet recording apparatus 100 according to the present embodiment is connected to a host apparatus 300 that is a provider of image data. The recording apparatus 100 is mainly composed of the following blocks. The CPU 311 executes processing based on programs stored in the ROM 313 and the RAM 312. The RAM 312 is a volatile storage and temporarily stores programs and data. The ROM 313 is a non-volatile storage and holds programs and data. The data transfer I / F 314 is a block for transmitting / receiving data to / from the host device 300. As a physical connection method of the data transfer I / F 314 between the host apparatus 300 and the recording apparatus 100, there are USB, IEEE 1324, LAN, and the like.

  The head controller 315 supplies recording data to the recording head that actually performs ejection, and performs recording control. As a specific implementation example, there is a method in which the head controller 315 is designed to read necessary parameters and data from a predetermined address in the RAM 312. When the CPU 311 writes necessary parameters and data to the predetermined address in the RAM 312, the head controller 315 is activated and an actual recording operation is performed. The image processing accelerator 316 is a block that performs image processing at a higher speed than the CPU 311. As a specific implementation example, there is a method in which the image processing accelerator 316 is designed to read necessary parameters and data from a predetermined address in the RAM 312. When the CPU 311 writes necessary parameters and data to the predetermined address in the RAM 312, the image processing accelerator 316 is activated and an actual recording operation is performed. The image processing accelerator 316 is not necessarily a block, and the image processing may be realized only by the processing by the CPU 311.

  FIG. 5 is a block diagram for explaining image processing steps performed by the host apparatus 300 and the recording apparatus 100 when the inkjet recording apparatus according to the present embodiment performs two-pass multipass recording to record an image. .

  An original image signal obtained by an image input device such as a digital camera or a scanner or computer processing is input to an image data input unit 1301. In the subsequent color conversion processing A, the 256-value RGB signal is also converted into the 256-value R′G′B so that the color reproduction area indicated by the input device is associated with the color reproduction area that can be expressed by the inkjet recording apparatus of the present embodiment. 'Convert to signal.

  The multi-value R′G′B ′ signal converted in this way is subsequently subjected to color conversion processing B, and 256 values corresponding to the ink colors (cyan, magenta, yellow, and black) used in this embodiment. To CMYK signals. In the color conversion process B, a three-dimensional lookup table (LUT) in which RGB values and CMYK values are associated one-to-one is prepared. Then, by using this LUT, RGB data is collectively converted into multi-value data (C, M, Y, K) for each ink. For input values that deviate from the table grid point value, the output value may be calculated by interpolation from the output values of neighboring grid points. The following processing is performed independently for cyan (C), magenta (M), yellow (Y), and black (K).

  In the gradation correction processing 1304, primary conversion processing is performed on multi-value data for each ink (for example, K) so that the density of the image recorded on the recording medium is linear with respect to the input value.

  In the image data division 1305, the multi-value data for each color received from the gradation correction processing 1304 is converted into multi-value data 1306-1 for the first scan and multi-value data 1306-2 for the second scan. Divide into After that, a specific quantization process is performed on each multi-value data. The multi-value data 1306-1 for the first scan is converted into binary data 1308-1 for the first scan by the quantization process 1307-1. At this time, in the quantization process 1307-1, recording (1) or non-recording (0) to each pixel is changed to a dot pattern for the first scanning that is predetermined according to the value of the multi-value data 1306-1. Based on this, the multi-value data 1306-1 is converted into binary data 1308-1.

  The multi-value data 1306-2 dedicated to the second scan is converted into binary data 1308-2 dedicated to the second scan by the quantization process 1307-2. At this time, in the quantization processing 1307-2, recording (1) or non-recording (0) to each pixel is changed to a dot pattern for the second scanning that is predetermined according to the value of the multi-value data 1306-2. Based on this, the multi-value data 1306-2 is converted into binary data 1308-2. The dot pattern for the first scan and the dot pattern for the second scan used in the above quantization processing are stored in the ROM 313 of the recording apparatus, respectively.

  When the series of image processing described above is completed, the recording head ejects ink in the first recording scan in accordance with the binary data 1308-1 for the first scanning, and the second recording scanning performs the first recording scan. Ink is ejected in accordance with binary data 1308-2 for two scans.

  FIG. 6 is a diagram showing a dot pattern used in the quantization process of the present embodiment. The left side of the figure shows multi-value data input to the quantization processing unit 1307-1 or 1707-2. Normally, the multi-value data input to the quantization processing unit can take a value of 0 to 255 (256 gradations). However, for the sake of simplicity, it is regarded as 16 gradations, and each input of 1/16 to 8/16 is assumed. The level.

  The pattern on the right side shows a dot pattern corresponding to the input level (multi-value data) in each of the first scan and the second scan. Each 4 × 4 area represents a minimum unit (pixel) that determines whether or not to record a dot. A circled area indicates a pixel that records a dot, and a blank area indicates a pixel that does not record a dot. . As the level increases, the number of pixels that record dots in 4 × 4 increases. However, these two patterns are different even at the same level, and the dot pattern for the second scanning has more pixels for recording dots in the scanning direction of the recording head than the dot pattern for the first scanning. The trend is getting stronger.

  In each pattern, pixels indicated by black circles indicate pixels on which dots are recorded in both the first scan and the second scan. As described above, preparing pixels in which dots are overlapped and recorded in both the first scan and the second scan in some places means that a recording position shift occurs between the first scan and the second scan. This is effective in suppressing fluctuations in the concentration. This is because, when a recording position shift occurs between the first scan and the second scan, there also occurs a place where two dots to be recorded at different positions overlap each other. The part where a dot separates also appears. Therefore, the dot coverage on the recording medium does not vary as much as the difference, and the image density can be stabilized. In this embodiment, in this way, dot patterns with different arrangements are prepared while providing overlapping pixels in some places for the first scanning and for the second scanning.

  FIGS. 8A to 8D are diagrams showing the positional relationship between the main droplets and satellites recorded on the recording medium by the first scanning and the second scanning, respectively. Here, in both scans, a state where printing is performed according to a dot pattern when the input multi-value data for the quantization processing is about 128, that is, when the input level in FIG. 6 is about 8/16 is shown. Yes.

  FIG. 8A shows a recording state in which recording is performed according to the dot pattern recorded in the first scan when there is no influence of the airflow. In general, in the case of a serial type ink jet recording apparatus that ejects ink while moving a recording head with respect to a recording medium, satellites appear at positions separated from main dots in the scanning direction of the carriage. Therefore, when there is no influence of the airflow, the satellite is recorded directly beside the traveling direction of the main droplet. Referring to FIG. 6, in the dot pattern of the first scan, no dot is arranged in the pixel directly beside the pixel for recording the dot. Therefore, in a recording medium recorded according to such a dot pattern, a single satellite is formed on a white paper.

  On the other hand, FIG. 8B is a diagram showing a dot pattern recorded in the first scan when a strong air current is generated. Under the influence of the strong airflow, the satellites are landed with a deviation of about 20 μm in the direction intersecting the carriage traveling direction. Referring to FIG. 6, in the dot pattern of the first scan, no dot is arranged in the pixel directly next to the pixel for recording the dot, but a dot is arranged in the pixel below that. Therefore, on a recording medium recorded according to such a dot pattern, the satellite is recorded so as to overlap with the main dot located below the satellite.

  Comparing the two figures, compared to FIG. 8A in which the satellite is recorded on the blank area alone, in FIG. 8B in which the satellite is recorded so as to overlap the main dot, the coverage area of the dots on the recording medium is larger. It decreases, and the exposed area of white paper increases. That is, when the dot pattern as in the first scan of FIG. 6 is used, the image density is likely to change due to the strength of the air flow, and when the satellite recording position varies depending on the nozzle position as shown in FIG. I will be invited.

  On the other hand, FIG. 8C is a diagram showing a dot pattern recorded in the second scan when there is no influence of the airflow. Referring to FIG. 6, in the second scanning dot pattern, dots are recorded in two pixels that are continuous in the scanning direction. Therefore, in a recording medium recorded according to such a dot pattern, there are places where satellites are formed alone on white paper, but there are also places where the main dots overlap and are recorded.

  On the other hand, FIG. 8D is a diagram showing a dot pattern recorded in the second scan when a strong airflow is generated. As in the case of the first scan, due to the influence of the strong airflow, the satellites are landed with a deviation of about 20 μm in the direction intersecting with the traveling direction of the carriage. However, in the case of the second scan, there are satellites that newly overlap adjacent main dots due to this shift, and there are satellites that separate from the overlapping main dots.

  Therefore, comparing FIG. 8C and FIG. 8D, in FIG. 8C in which the satellite is not displaced and FIG. 8D in which the satellite is displaced, the coverage area of the dots with respect to the recording medium is not so much. does not change. That is, when a dot pattern such as the second scan in FIG. 6 is used, the image density is unlikely to change due to the strength of the airflow, and density unevenness is not induced.

  As described above, the dot pattern in which a plurality of dots are arranged continuously to some extent as in the second scan, rather than the dot pattern in which individual dots are dispersed as in the first scan shown in FIG. It can be seen that the method is more resistant to uneven density due to airflow. However, when reducing graininess and emphasizing the smoothness of the entire image, the first scanning dot pattern in which dots are dispersed as much as possible may be preferable. Therefore, in the present embodiment, the dot pattern characteristics described above are utilized, and when air current is generated and density unevenness is a concern due to the influence, recording is actively performed by the second scanning. Specifically, the distribution ratio of the multi-value data to the first scan multi-value data 1306-1 and the second scan multi-value data 1306-2 in the image data dividing unit 1305 shown in FIG. 5 is controlled.

  FIG. 9 is a diagram illustrating an example of multi-value data distribution in the image data dividing unit 1305. The image data dividing unit 1305 receives multi-value data 1401 represented by values from 0 to 255 corresponding to individual pixels. Here, a case where the input multi-value data is distributed to the first scan and the second scan at a distribution ratio of 40% and 60% will be described. In this case, for example, for the upper left pixel, the input value 130 is distributed to 52 as the first scan multi-value data and 78 as the second scan multi-value data. For the lower pixel, the input value 30 is distributed to 12 as the first scan multi-value data and 18 as the second scan multi-value data.

  After that, the first scanning multi-value data 1306-1 and the second scanning multi-value data 1306-2 obtained by distributing in this way are quantized according to the respective dot patterns shown in FIG. Then, in the first scan recorded in accordance with the first scan binary data 1308-1, it is possible to obtain an image with a low graininess recorded in a state in which main dots and satellites are relatively dispersed. On the other hand, in the second scan recorded in accordance with the second scan binary data 1308-2, it is possible to obtain an image recorded with relatively large main dots and satellites and having little density fluctuation due to airflow.

  In FIG. 9, the case where the distribution ratio is set to 40% and 60% has been described as an example, but it is needless to say that such a distribution ratio can be variously adjusted according to the state of the output image. Further, such a distribution ratio may be a fixed value in the recording apparatus, but may be a form that can be changed according to the type of recording image, the type of recording medium, and the like. Further, the distribution ratio may be varied according to the value of the multi-value data. For example, in the low density part where the image density is low and the graininess is conspicuous, the distribution ratio to the first scan is set high, while in the medium density part and the high density part where the density unevenness due to the air current is noticeable, the second scan is performed. The distribution ratio may be set high.

  Further, in the above description, the sum of the distribution rates when the multi-value data input to the image data dividing unit 1305 is distributed to the first scan arrival data and the second scan multi-value data is 100% (= 40% + 60%). However, the present invention is not necessarily limited to such a distribution ratio. If necessary, even if the sum of the distribution ratios for the first scan reaching data and the second scan multi-value data is 100% or more or less than 100%, the distribution ratio bias is adjusted. Thus, the effects of the present invention described above can be obtained.

  Furthermore, in the above-described embodiment, the description has been given by taking an example of two-pass multi-pass printing, but of course the present invention is not limited to such a form. Even in multi-pass printing with 3 or more passes, the feature of the dot arrangement pattern corresponding to at least one scan is different from the feature of the dot arrangement pattern of other scans, and multi-value data is distributed at an appropriate distribution rate. As a result, the above-described effects of the present invention can be sufficiently exhibited.

  In the embodiment described above, the description has been made with the content of quantizing 256-valued multi-value data into binary data by using a predetermined dot pattern, but the present invention is not limited to such a form. For example, after 256-level multi-value data after image data division processing in the host device is quantized into multi-level data of about 17 levels, the recording device uses 17-level multi-level data according to a dot pattern stored in advance. A form in which each data is converted into binary data may be employed.

DESCRIPTION OF SYMBOLS 100 Recording apparatus 300 Host apparatus 804 Recording head 1305 Image data division | segmentation part 1306-1 First scanning multi-value data 1306-2 Second scanning multi-value data 1307-1 First scanning quantization processing part 1307-2 For second scanning Quantization processing unit 1308-1 First scan quantized data 1308-2 Second scan quantized data

Claims (6)

By scanning a recording head configured by arranging a plurality of nozzles for ejecting ink according to image data, a plurality of times in the direction intersecting the direction of the array with respect to the same image area of the recording medium, An inkjet recording apparatus that records an image on a recording medium,
Distributing means for distributing multi-value image data to a plurality of multi-value data corresponding to each of the plurality of scans according to a predetermined distribution ratio;
Each of the plurality of multi-value data is prepared corresponding to each of the plurality of scans, and a plurality of scan data corresponding to each of the plurality of scans is determined according to a dot pattern that determines dot recording or non-recording for each pixel. A quantization means for quantizing the binary data;
Means for performing the plurality of scans in accordance with each of the plurality of binary data with respect to the same image region,
An ink jet recording apparatus, wherein the dot pattern corresponding to each of the plurality of scans is different in dot recording or non-recording arrangement for each pixel.   Among the dot patterns corresponding to each of the plurality of scans, at least one dot pattern is more likely to have pixels that determine dot recording in the scanning direction than other dot patterns. The inkjet recording apparatus according to claim 1.   The distribution means is configured so that the distribution ratio to the scan corresponding to the dot pattern in which the pixels that determine dot recording in the scanning direction are likely to continue is higher than the distribution ratio to the other scans. 3. The ink jet recording apparatus according to claim 2, wherein the value image data is distributed to a plurality of multi-value data corresponding to each of the plurality of scans.   4. The ink jet recording apparatus according to claim 1, further comprising means for changing the predetermined distribution rate.   The quantization means converts each of the plurality of multi-value data into lower-level multi-value data, and then performs the plurality of scans according to a dot pattern prepared corresponding to each of the plurality of scans. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus performs quantization into a plurality of binary data corresponding to each of the data. By scanning a recording head configured by arranging a plurality of nozzles for ejecting ink according to image data, a plurality of times in the direction intersecting the direction of the array with respect to the same image area of the recording medium, An inkjet recording method for recording an image on a recording medium,
A distribution step of distributing multi-value image data to a plurality of multi-value data corresponding to each of the plurality of scans according to a predetermined distribution ratio;
Each of the plurality of multi-value data is prepared corresponding to each of the plurality of scans, and a plurality of scan data corresponding to each of the plurality of scans is determined according to a dot pattern that determines dot recording or non-recording for each pixel. A process of quantizing the binary data;
Performing the plurality of scans on the same image area in accordance with each of the plurality of binary data,
An ink jet recording method, wherein the dot pattern corresponding to each of the plurality of scans is different in dot recording or non-recording arrangement for each pixel.

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