JP5737955B2 - Ink jet recording apparatus, ink jet recording system, and method of controlling ink jet recording apparatus - Google Patents

Description

  The present invention relates to an ink jet recording apparatus, an ink jet recording system, and a method for controlling an ink jet recording apparatus that record an image by applying a plurality of types of inks on a recording medium.

  Many models equipped with only three-color inks (cyan, magenta, and yellow) are commercially available in order to reduce the cost and size of the ink jet recording apparatus. However, when black (hereinafter also referred to as “composite black”) is recorded using three-color ink, the color tone may be different from the original black color tone. The reason why the color tone is different is considered to be the difference in the penetration depth of the color material in the ink with respect to the recording medium.

  In Patent Document 1, before applying a dye ink containing a dye as a coloring material to a recording medium, a clear ink containing a compound that insolubilizes the dye is applied (preliminary) to determine the penetration depth of the dye. The method of keeping it on the surface is proposed. Patent Document 2 proposes a method of aligning the penetration depth of the coloring material by using the penetration promoting ink. Patent Document 3 proposes a method for realizing a color tone close to the original black in various recording media by changing the application order of a plurality of colors of ink for each recording medium.

JP-A-64-63185 JP 2008-87417 A Japanese Patent Laid-Open No. 10-16672

  However, the methods described in Patent Documents 1 and 2 may increase the image recording cost and increase the size of the recording apparatus. In addition, the method described in Patent Document 3 forms fine holes such as glossy paper as a dedicated paper for ink-jet recording, particularly when the change in the application order of a plurality of colors has a small effect on the color tone. If the recording medium is used, a sufficient effect cannot be obtained. This is because it is difficult to set a sufficient time difference between the application timings of the inks of a plurality of colors.

  An object of the present invention is to record a high-quality image by minimizing the adverse effect of a difference in the depth of penetration of these inks on a recording medium when the image is recorded using a plurality of types of ink. Is to realize.

An inkjet recording apparatus according to the present invention has a recording head for discharging a first type of ink and a second type of ink different from the first type with respect to a predetermined recording area on a recording medium. An inkjet recording apparatus that records an image by ejecting the first and second types of ink while scanning N (N ≧ 2) times in a scanning direction, wherein the predetermined number of times of each of the N scans With respect to the ratio to the total amount of the first type ink ejected to the recording area, the first type is defined as N scans for ejecting the first type ink to the predetermined recording area. N-K to the ink discharge in the first and scanning of K (K <N) times of the high printing ratio for discharging at a higher percentage ratio of said first type of ink low ratio than the first ratio of configure, and scanning times of low printing ratio A first setting means that, the relates percentage of the total of the amount of the second type of ink ejected to the predetermined recording area in each of the N scans, the second to the predetermined recording area As the N scans for ejecting this kind of ink, L (L <N) times of the high recording ratio scan for ejecting the second type of ink at a ratio higher than the second ratio, and the second scan Set by the first and second setting means, and a second setting means for setting NL times of low recording ratio scans for discharging different types of ink at a ratio lower than the second ratio . Control means for controlling to eject ink while performing scanning, and the first type of ink penetrating into the recording medium when a predetermined amount of the first type of ink is applied to the recording medium The penetration depth of the ink is the predetermined amount of the second type. Deeper than the penetration depth of the second type of ink permeates into the recording medium in the case of applying the ink to the recording medium, at each scan of the K times of high printing ratio of the first type of ink The sum of the ratios is higher than the sum of the ratios in each of the NK times of the low recording ratio scans of the first type ink, and the L times of high recordings of the second type ink. The sum of the ratios in each ratio scan is higher than the sum of the ratios in each of the NL low recording ratio scans of the second type ink, and the first and second setting means The K high-scanning ratio scan of the first type of ink is set to a scan before the L high-recording ratio scan of the second type of ink. .

The inkjet recording system of the present invention is an inkjet recording system including an inkjet recording apparatus that records an image based on recording data, and an image processing apparatus that supplies the recording data to the inkjet recording apparatus. The apparatus has a recording head for ejecting a first type of ink and a second type of ink different from the first type in a scanning direction N ( N ≧ 2) The first and second types of ink are ejected while scanning, and the inkjet recording system ejects the predetermined recording area in each of the N scans. relates percentage of the total amount of the first type of ink, N for discharging said first type of ink with respect to the predetermined recording area As the scan, the first type of ink and the scanning of K (K <N) times of the high printing ratio for discharging at a higher rate than the first ratio, the first type of ink the first ratio A first setting means for setting NK times of low recording ratio scanning for discharging at a lower ratio; and the second type of discharging for discharging to the predetermined recording area in each of the N times of scanning. Regarding the ratio to the total amount of ink, the second type of ink is ejected at a ratio higher than the second ratio as N scans for ejecting the second type of ink to the predetermined recording area. L (L <N) times of scanning with a high printing ratio and NL times of scanning with a low printing ratio for discharging the second type ink at a rate lower than the second ratio are set. and second setting means, the first, the scan set by the second setting means There and a control means for controlling to eject ink while, in the first type of ink permeates into the recording medium when the first type of ink of a predetermined amount has been applied to the recording medium The penetration depth is deeper than the penetration depth of the second type of ink that penetrates the recording medium when the predetermined amount of the second type of ink is applied to the recording medium, and the first type The sum of the ratios of each of the K high recording ratio scans of the ink is higher than the sum of the ratios of the NK low recording ratio scans of the first type of ink, and The sum of the ratios of the second type of ink in each of the L high recording ratio scans is the ratio of the ratios of the second type of ink in the NL low recording ratio scans. Higher than the total, the first and second setting hands The stage sets the K high-recording ratio scan of the first type of ink to a scan before the L high-recording ratio scan of the second type of ink. And

The control method of the ink jet recording apparatus of the present invention is a control method for controlling the ink jet recording apparatus, and the ink jet recording apparatus includes a first type of ink and a second type different from the first type. The first and second types of ink are ejected while scanning a predetermined recording area on the recording medium N (N ≧ 2) times in the scanning direction with a recording head for ejecting a predetermined amount of ink. And the control method relates to a ratio with respect to a total amount of the first type of ink ejected to the predetermined recording area in each of the N scans, with respect to the predetermined recording area. As N scans for ejecting the first type of ink, K (K <N) scans with a high recording ratio for ejecting the first type of ink at a higher ratio than the first ratio; The first type A first setting step of setting a scan of N-K times lower printing ratio for discharging a click at a low ratio than the first ratio, the discharge in the predetermined recording area in each of the N scans With respect to the ratio of the amount of the second type ink to the total, the second type ink is set to the second number as N scans for ejecting the second type ink to the predetermined recording area. and scanning of L (L <N) times of the high printing ratio for discharging at a higher percentage ratio of, N-L times the low printing ratio for discharging the second type of ink at a lower ratio than said second ratio A second setting step for setting the scanning, and a control step for controlling to discharge ink while performing the scanning set by the first and second setting steps. The above description when the first type of ink is applied to the recording medium. The penetration depth of the first type of ink penetrating into the medium is the second type of ink penetrating into the recording medium when the predetermined amount of the second type of ink is applied to the recording medium. The sum of the ratios of the first type of ink in each of the K high recording ratio scans is deeper than the penetration depth of the first type of ink and the NK times of the low recording ratio of the first type of ink. The sum of the ratios of each of the second types of ink is higher than the sum of the ratios of the respective scans, and the sum of the ratios of each of the L high scan ratio scans of the second type of ink is the NL of the second type of ink. Higher than the sum of the ratios in each of the low recording ratio scans, and the first and second setting steps perform the K high recording ratio scans of the first type of ink in the second. In the scan before the L times of the high recording ratio scan of the type of ink It is characterized by setting.

  In the present invention, when an image is recorded using a plurality of inks having different penetration depths with respect to a recording medium, the ink having a deep penetration depth is preferentially applied earlier, and as a result, The difference in penetration depth can be kept small. Therefore, it is possible to record a high-quality image while minimizing the adverse effect of the difference in the penetration depth of a plurality of inks on the recording medium on the recorded image. For example, when recording black, which is called composite black, by superimposing three colors of cyan, magenta, and yellow, the black becomes a color close to the original black (the reflectance is flat in the visible light wavelength region). can do.

1 is a block configuration diagram of an inkjet recording system in an embodiment of the present invention. It is a block block diagram of the host apparatus in FIG. FIG. 2 is a perspective view of the inside of the ink jet recording apparatus in FIG. 1. It is explanatory drawing of a 2 pass recording system. It is explanatory drawing of the mask pattern in a 2-pass printing system. (A) is explanatory drawing of the behavior of the incident light with respect to a recording medium, (b) is explanatory drawing of the penetration depth of the ink provided before and after the recording medium. It is explanatory drawing of the nozzle group of the recording head corresponding to the 1st case in embodiment of this invention. (A), (b), (c) is a figure for demonstrating the recording ratio corresponding to the 1st case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. (A), (b), (c) is a figure for demonstrating the mask pattern corresponding to the 1st case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. It is explanatory drawing of the recording method corresponding to the 1st case in embodiment of this invention. It is explanatory drawing of the nozzle group of the recording head corresponding to the 2nd case in embodiment of this invention. (A), (b), (c) is a figure for demonstrating the recording ratio corresponding to the 2nd case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. (A), (b), (c) is a figure for demonstrating the mask pattern corresponding to the 2nd case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. It is explanatory drawing of the recording method corresponding to the 2nd case in embodiment of this invention. (A), (b), (c) is a figure for demonstrating the recording ratio corresponding to the 3rd case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. (A), (b), (c) is a figure for demonstrating the mask pattern corresponding to the 3rd case in embodiment of this invention regarding magenta, yellow, and cyan ink, respectively. It is explanatory drawing of the recording method corresponding to the 3rd case in embodiment of this invention. (A), (b), and (c) are explanatory diagrams of gradation masks for magenta, yellow, and cyan ink, respectively. (A), (b), (c) is a figure for demonstrating the recording ratio at the time of using an overlap mask about magenta, yellow, and cyan ink, respectively. (A), (b), (c) is a figure for demonstrating the overlap mask for magenta, yellow, and cyan ink, respectively. It is a flowchart for demonstrating the setting process of the mask pattern in embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Basic configuration)
FIG. 1 is a block diagram mainly showing hardware and software of a host device 100 constituting the inkjet recording system of the present invention. The host device 100 of this example is also referred to as a personal computer (hereinafter simply referred to as “PC”). ) Form. The PC 100 generates image data recorded by a printer (recording apparatus) 104.

  In FIG. 1, a PC 100 that is a host computer operates software of application software 101, a printer driver 103, and a monitor driver 105 by an operating system (OS) 102. The application software 101 performs processing related to a word processor, spreadsheet, internet browser, and the like. The monitor driver 105 executes processing for displaying image data on the monitor 106. The printer driver 103 performs drawing processing on various drawing command groups (image drawing commands, text drawing commands, graphics drawing commands, etc.) output from the application software 101 to the OS 102. The printer driver 103 generates multi-value or binary image data that is finally used by the printer 104. Specifically, by executing image processing to be described later, multi-value or binary image data corresponding to each of a plurality of ink colors used in the printer 104 is generated.

  The host computer 100 includes a CPU 108, a hard disk (HD) 107, a RAM 109, a ROM 110, and the like as various hardware for operating the above software. That is, the CPU 108 executes various processes in accordance with the software programs stored in the hard disk 107 and the ROM 110, and the RAM 109 is used as a work area when executing these processes.

  The printer 104 of this example is a so-called serial type inkjet printer that records an image on a recording medium by ejecting ink from the recording head while the recording head capable of ejecting ink is scanned with respect to the recording medium. Inkjet recording apparatus). In this example, three recording heads are prepared to correspond to cyan (C), magenta (M), and yellow (Y) inks. These recording heads are mounted on a carriage movable in the main scanning direction, and can scan a recording medium such as a recording sheet. The recording medium is intermittently conveyed in the sub-scanning direction that intersects (or orthogonally intersects in this example) with the main scanning direction. In each print head, a plurality of nozzles that can eject ink are arranged in a direction that intersects the main scanning direction (orthogonal in this example), and ink can be ejected from the ejection port at the tip of these nozzles. It is. In the case of this example, the arrangement density of these nozzles is 1200 dpi, and 4.5 picoliter of ink droplets are ejected from each ejection port. The number of nozzles in each recording head is 1280.

  The printer 104 of this example can execute so-called multi-pass recording, in which an image is recorded by scanning the recording head a plurality of times on a predetermined area on the recording medium. Therefore, as will be described later, a mask for thinning out print data is stored in a predetermined memory, and a mask set for each ink color according to the scan direction and the number of scans of the print head is used for printing. With reference, binary divided recording data is generated. If the image data input to the printer 104 is multi-value image data, as will be described later, the multi-value data is divided according to the distribution ratio information, and then the divided multi-value data is divided into divided recording data. Convert.

  FIG. 2 is a block diagram for explaining main data processing steps in the PC 100 and the printer 104.

  As described above, the printer 104 of this example performs recording with inks of three colors of cyan, magenta, and yellow. For this purpose, the printer 104 includes the recording head 10 for ejecting these three colors of ink. A user can create image data to be recorded by the printer 104 using the application 101 of the host PC 100. When recording, image data created by the application 101 is passed to the printer driver 103. The printer driver 103 executes pre-stage processing J2, post-stage processing J3, γ correction J4, binarization processing J5, and recording data creation processing J6. In the pre-stage process J2, color gamut conversion is performed to convert the color gamut reproduced by the display device that displays the screen into the color gamut reproduced by the printer 104. Specifically, image data R, G, and B in which R, G, and B are each expressed by 8 bits are converted into 8-bit data R, G, and B in the printer color gamut by using a three-dimensional LUT. To do.

  In the post-process J3, the color that reproduces the color gamut converted by the pre-process J2 is separated into ink colors. Specifically, processing for obtaining 8-bit data C, M, and Y corresponding to the combination of inks for reproducing the colors represented by the 8-bit data R, G, and B obtained in the pre-stage processing J2 is performed. In the γ correction J4, γ correction is performed on each of the CMY data obtained by the color separation in the post-processing J3. Specifically, conversion is performed so that each of the 8-bit data CMY obtained by color separation is linearly associated with the gradation characteristics of the printer. The processing data at this stage may be transferred to the printer 104 as input multivalued image data.

  In the binarization process J5, a quantization process is performed for converting the 8-bit data C, M, and Y subjected to the γ correction into 1-bit data C, M, and Y, respectively. Finally, in the recording data creation process J6, recording data is added to the image data including the multi-value data before quantization or binarized 1-bit data C, M, and Y with recording control data or the like. create. Here, the binary image data includes dot recording data indicating dot recording and dot non-recording data indicating non-recording of dots. The recording control data includes “recording medium information”, “recording quality information”, and “other control information” such as a paper feeding method. The recording data generated as described above is supplied to the printer 104.

  On the other hand, the printer 104 performs a mask data conversion process J8 on the binary image data included in the input recording data. In the mask data conversion process J8, an AND process is performed on the input binary image data using a mask pattern, which will be described later, stored in advance in a predetermined memory of the printer, and this is divided and recorded in binary. Data. Also, multi-value input image data is converted into divided multi-value data based on distribution ratio information described later, and then binarized to obtain binary divided record data. As a result, binary divided image data used in each scan in multi-pass printing is generated, and the timing for actually ejecting ink is determined. The binary divided recording data includes dot recording data and dot non-recording data.

  FIG. 3 is a perspective view showing a mechanical configuration of the printer 104. M4 is a carriage that can move in the main scanning direction indicated by an arrow X, and has a recording head 10 (not shown in FIG. 3) and an ink tank H19 that contains ink to be supplied to the recording head detachably mounted. Yes. In the case of this example, three recording heads corresponding to cyan (C), magenta (M), and yellow (Y) inks, and cyan (C), magenta (M), and yellow (Y) supplied to them. Ink tanks H19Y, H19M, and H19C for storing the ink are mounted. The recording head ejects ink from each nozzle at a predetermined timing based on the binary divided recording data while moving in the main scanning direction together with the carriage M4 and the ink tank. When one recording scan of the recording head is completed, the recording medium is conveyed by a predetermined amount in the sub-scanning direction of an arrow Y that intersects (in the present example, orthogonal) with the main scanning direction. Images are sequentially recorded on the recording medium by alternately repeating the recording scan of the recording head and the conveyance of the recording medium.

  In this example, a bidirectional recording method is employed, and when the recording head moves in the forward direction indicated by the arrow X1 and in the backward direction indicated by the arrow X2, an image is recorded by ejecting ink. Accordingly, an image is recorded on the recording medium by sequentially repeating the forward recording scan by the recording head, the conveyance of the recording medium, the backward recording scan by the recording head, and the conveyance of the recording medium.

  In FIG. 4, binary recording data is divided into binary divided recording data using a division mask (mask pattern), and then an image is recorded by a multi-pass recording method based on the divided recording data. It is explanatory drawing about the procedure until. In this example, a recording head, a mask pattern, and a recording medium are schematically shown in order to explain a recording employing a two-pass recording method in which an image is completed by two recording scans for a predetermined recording area. It was. Reference numerals 10Y, 10M, and 10C denote recording heads that discharge yellow (Y), magenta (M), and cyan (C) ink, respectively. In each recording head, a plurality of nozzles N are formed so as to form nozzle rows extending along a direction intersecting (in the present example, orthogonal) with the conveyance direction of the arrow Y. In this example, a nozzle row is formed by 1280 nozzles N, and a first group (first nozzle group) G1 on the upstream side in the transport direction indicated by the arrow Y and a second group (first nozzle group) on the downstream side in the transport direction ( The second nozzle group G2 is divided. Each of the first and second groups includes 640 nozzles N.

  Mask groups P1, P2 are associated with groups G1, G2, respectively. The mask pattern group P1 includes mask patterns Y1, M1, and C1 corresponding to the first group G1 of the recording heads 10Y, 10M, and 10C. The mask pattern P2 includes mask patterns Y2, M2, and C2 corresponding to the second group G2 of the recording heads 10Y, 10M, and 10C. The size of these mask patterns in the main scanning direction is the size of 640 pixels corresponding to the number of nozzles of each group G1, G2, and similarly the size in the sub-scanning direction is the size of 640 pixels. is there. The two mask patterns Y1 and Y2 corresponding to the yellow ink are in a complementary relationship, and the pixels recorded based on the divided recording data divided by the mask patterns are overlapped to correspond to 640 × 640 pixels. Area recording is completed. Similarly, the two mask patterns M1 and M2 corresponding to magenta ink and the two mask patterns C1 and C2 corresponding to cyan ink are also in a complementary relationship.

  The recording head ejects C, M, and Y inks while scanning in the forward direction and the backward direction. Each time such scanning is completed, the recording head is equivalent to 256 pixels corresponding to the widths of the nozzle groups G1 and G2. The recording medium W is conveyed in the arrow Y direction. By repeating such a recording scan and a transport operation of the recording medium W, an image is obtained by performing the scanning twice on a recording area of 256 pixels corresponding to the widths of the groups G1 and G2 on the recording medium W. Complete.

  More specifically, in the first scanning in which the recording head moves in the forward direction (arrow X1 direction), the ink is sequentially applied from the first group of recording heads to the area A on the recording medium W in the order of C, M, and Y. Discharged. In the first scan, ink is ejected based on the divided image data divided using the mask patterns C1, M1, and Y1. Thereafter, the recording medium W is conveyed by 256 pixels in the backward scanning direction. In the subsequent second scan, ink is ejected in the order of Y, M, and C while the recording head moves in the backward direction (arrow X2 direction). That is, ink is ejected in the order of Y, M, and C from the first group of recording heads to the area A on the recording medium W, and the second recording head is applied to the area B on the recording medium W. Ink is ejected from the group in the order of Y, M, and C. At that time, ink is ejected to the region A based on the divided image data divided using the mask patterns C2, M2, and Y2, and the mask patterns C1, M1, and Y1 are used to the region B. Ink is ejected based on the divided image data. By such second scanning, an image for the region A is completed.

  FIG. 5 is an explanatory diagram of the relationship between the image completed by the two-pass printing as described above and the dots constituting the image. The dots are formed by ink ejected from the recording head. For ease of explanation, the image in FIG. 5 is a so-called solid image in which dots are formed in all pixels. In mask patterns P1 and P2 used to generate divided image data corresponding to one recording head 10, black square portions correspond to pixels that allow dot formation, and white square portions correspond to pixels that do not allow dot formation. To do. In the case of recording a solid image, the arrangement of black square portions of the mask pattern corresponds to the arrangement of dots formed on the recording medium W as they are as shown in FIG.

  First, in the first scan, dots are formed in the region A on the recording medium W by ejecting ink from the nozzles N of the first group G1 of the recording head 10. At that time, ink is ejected based on the divided image data generated using the mask pattern P1. Thereafter, the recording medium W is conveyed in the sub-scanning direction indicated by the arrow Y by the width of the first and second groups G1 and G2 (in this example, 4 pixels). In the next second scan, ink is ejected from the second group of nozzles N to the area A, and ink is ejected from the first group of nozzles N to the area B. At that time, the second group of nozzles N ejects ink based on the divided image data generated using the mask pattern P2, and the first group of nozzles N generates the divided image generated using the mask pattern P1. Ink is ejected based on the data. The image of region A is completed by the first and second scans. By repeating such a recording scan and a recording medium conveyance operation, images are sequentially recorded on the recording medium.

(About the penetration depth of ink into the recording medium)
The penetration depth of the ink with respect to the recording medium affects the color tone. For example, when black (composite black) is recorded using inks of three colors Y, M, and C, the color tone of black may differ depending on the difference in penetration depth of these inks. The mechanism is influenced by light scattering of particles constituting the ink receiving layer of the recording medium. FIG. 6A is a diagram for explaining the mechanism.

  In FIG. 6, reference numeral 601 denotes a receiving layer of the recording medium, and 602 denotes a receiving layer portion colored with ink. Reference numeral 603 denotes incident light, and reference numeral 604 denotes light that is reflected to the outside after passing through the receiving layer portion 602. The receiving layer 601 of the recording medium is composed of particles of several tens to 100 nm, and incident light 603 is scattered by the particles of the receiving layer 601, and a part thereof is reflected outside the receiving layer 601. Since the scattering increases as the depth increases in the interior of the receiving layer 601, the incident light 603 is less likely to enter as the depth increases. Therefore, the color material in the upper layer portion of the receiving layer 601 has the most influence on the color tone, and the influence of the color material in the lower layer portion is reduced. This is the reason why the color tone such as black differs depending on the penetration depth difference.

  Next, the mechanism by which the penetration depth difference is caused by the ink will be described. Since the ink receiving layer in a recording medium such as glossy paper has a capillary diameter of several tens to 100 nm, the speed of ink penetrating into the receiving layer is slow. Since the speed at which the color material adsorbs to the particles in the receiving layer of the recording medium is faster than the ink penetration speed, the color material is separated from the solvent such as water in the ink, and only the color material is received by the recording medium. Adsorbed on the particles of the layer. Since the adsorption speed is different for each color material, it is considered that the penetration depth difference is generated for each ink due to the speed difference. Another factor that increases the penetration depth difference is the influence of the time difference in the timing of ink landing on the recording medium. That is, the penetration depth of the ink applied to the area on the recording medium on which the ink has already been recorded becomes deeper than the ink applied to the recording medium first.

  FIG. 7 is a diagram for explaining a phenomenon in which such a difference in penetration depth occurs. This phenomenon is an influence of a solvent containing water contained in the ink. That is, when a solvent containing water remains in the area on the recording medium, the solvent penetrates into the area together with the ink applied later, and the amount of the ink applied later is increased accordingly. Deep penetration. The penetration depth is related to the remaining amount of moisture in the previously applied ink. If the moisture disappears due to evaporation or the like, the penetration depth of the ink applied thereafter is first applied to the recording medium. The ink penetration depth is almost the same. Further, the difference in the penetration depth of the ink applied later to the region where the ink is applied first tends to become deeper as the penetration depth of the ink applied first to the recording medium is deeper.

  With such a mechanism, when composite black is recorded using inks of three colors, Y, M, and C, the ink with the deeper penetration depth has less influence on the color development of the composite black. For this reason, the color of the ink whose penetration depth is deepened becomes light, and when the ink is different, the black tone of the composite black changes.

  In particular, in a recording medium in which fine holes such as glossy paper are formed as dedicated paper for an ink jet recording apparatus, not only the type of ink color material but also the effect of the time difference of ink application timing causes the ink There is a difference in the penetration depth. That is, as described above, the penetration depth of the ink applied to the area where the ink has already been applied becomes deeper than the penetration depth of the ink applied to the recording medium first, and the latter ink is disadvantageous in terms of color development. become. In particular, the deeper the penetration depth of the ink recorded on the recording medium, the slower the speed at which the color material of the ink applied later is adsorbed to the particles constituting the receiving layer of the recording medium. Therefore, the difference of the penetration depth becomes remarkable.

In the present invention, in consideration of the relationship between the ink penetration depth and the color tone, ink having a deep penetration depth is preferentially applied.
(Configuration example of recording head)
FIG. 7 shows a specific configuration example of the recording head used in this embodiment. Each of the recording heads 10Y, 10M, and 10C for yellow, magenta, and cyan ink has a plurality of nozzles along two nozzle rows. In each recording head, 640 nozzles N are formed in each of the two nozzle rows at an arrangement density corresponding to a resolution of 600 dpi, and the nozzles N in one nozzle row and the nozzles N in the other nozzle row are 1200 dpi. Is shifted by a distance corresponding to the resolution. Accordingly, each recording head is substantially formed with an array density corresponding to a resolution of 1200 dpi with 1280 nozzles N. Each nozzle N discharges an ink droplet of 4.5 picoliter from the discharge port at the tip. The nozzle N of this example is configured to eject ink using an electrothermal conversion element (heater) as an ejection energy generating element. That is, the ink is foamed by the heat generated by the electrothermal conversion element, and the ink is ejected from the ejection port using the foaming energy.

  Further, in this example, BCI-321C, BCI-321M, and BCI-321Y manufactured by Canon are used as cyan, magenta, and yellow ink, and glossy paper for inkjet (PT101) manufactured by Canon is used as a recording medium. ) Was used. When the recording ratio is 100%, one ink droplet is applied to an area corresponding to a resolution of 1200 dpi.

(Measurement of ink penetration depth)
A method of measuring the ink penetration depth in the recording medium will be described.

  First, cyan, magenta, and yellow ink are ejected from each recording head at a recording ratio of 100% by a one-pass recording method. A portion of the recording medium to which the ink is applied is cut by a cutting device, and the cross section is photographed with an optical microscope. The distance from the top of the receiving layer of the recording medium to the tip of the ink that has permeated the receiving layer is measured, and this is taken as the ink penetration depth. The penetration depth is measured for each of cyan, magenta and yellow inks. In this example, a Leica microtome was used as the cutting device. Thus, in this example, the penetration depth of the ink was measured using a cutting method. However, the penetration depth of the ink may be measured by using a confocal laser microscope without cutting the recording medium.

(Recording ratio setting)
Next, setting of the recording ratio will be described.

In order to explain this embodiment in an easy-to-understand manner, a case where an image is recorded by a 6-pass printing method using three colors of ink of cyan, magenta, and yellow will be described. In that case, combinations of the penetration depths of these inks are classified into the following three cases: first, second, and third.
First case: all three inks have unequal penetration depths.
Second case: the penetration depth of the two inks is shallow and equal, and the penetration depth of the other ink is deep.
Third case: the penetration depth of the two inks is deep and equal, and the penetration depth of the other ink color is shallow.

  Here, “the penetration depth is equal” means that the difference in penetration depth measured by the above-described penetration depth measurement method is within ± 1 μm.

In the present embodiment, the recording ratio is set according to each case. A specific recording ratio setting method will be described below.
(Recording ratio setting method in the first case)
When an image is recorded by the 6-pass recording method, the recording heads 10Y, 10M, and 10C are divided into three equal groups of the first, second, and third nozzle groups G1, G2, and G3 as shown in FIG. Use. For each Y, M, and C ink, an image is recorded using any two nozzle groups. For the same recording area on the recording medium, twice for each Y, M, and C ink. The image is completed by scanning. That is, a 2-pass printing method is used for each ink color, and a 6-pass printing method is used for all ink colors. In this example, it is assumed that the penetration depth is deeper in the order of magenta, yellow, and cyan inks.

  The recording head 10M ejects magenta ink from the nozzles of the first nozzle group G11, the recording head 10Y ejects yellow ink from the nozzles of the second nozzle group G12, and the recording head 10C is the third nozzle group. Cyan ink is ejected from the nozzle of G13. The vertical width (length in the nozzle row direction) of the nozzle groups G1, G2, and G3 is set to a width corresponding to the number of nozzles obtained by dividing all the nozzles of the recording head by the number of passes of all ink colors. Multiply by the number of passes. The number of passes of all ink colors for all nozzles of the print head is equivalent to the product of the number of nozzle groups and the number of passes for each ink color. The nozzle of the quotient obtained by dividing all the nozzles of the print head by the number of passes of all ink colors The width of several minutes corresponds to the conveyance amount by which the recording medium is conveyed in the backward scanning direction for each pass. In the case of this example, since the total number of nozzles of the recording head is 1278, the number of nozzle groups is 3, the number of passes for each ink color is 2, and the number of passes for all ink colors is 6, the recording medium is conveyed for each pass. The conveyed amount corresponds to the width of 213 nozzles. Accordingly, the vertical width of each of the nozzle groups G1, G2, and G3 is a width corresponding to 426 nozzles, which is twice that of 213 nozzles.

  When the recording ratios of Y, M, and C ink colors in the total number of passes (6 passes) are 100%, the recording ratios of the Y, M, and C ink colors in each pass are shown in FIGS. ) And (c). The magenta ink is ejected from the recording head 10M at a recording ratio of 50% in the first pass and the second pass, and is not ejected from the third pass to the sixth pass because the recording ratio is 0%. Yellow ink is ejected from the recording head 10Y at the recording pass 10Y at the third pass and the fourth pass, and the recording rate is 0% at the first pass, the second pass, the fifth pass, and the sixth pass. Not. The cyan ink is ejected from the recording head 10C at a recording ratio of 50% in the fifth pass and the sixth pass, and is not ejected from the first pass to the fourth pass because the recording ratio is 0%. Such a recording ratio is determined by a mask pattern that divides recording data into divided recording data as described above.

  FIGS. 9A, 9B, and 9C are explanatory diagrams of mask patterns for setting the recording ratio of magenta, yellow, and cyan ink colors. The mask pattern for magenta ink includes patterns P1 (M) and P2 (M) that thin out the recording data by 50% in the first pass and the second pass, and these patterns are in a complementary relationship. The mask pattern for yellow ink includes patterns P1 (Y) and P2 (Y) for thinning recording data by 50% in the third pass and the fourth pass. The mask pattern for cyan ink includes patterns P1 (C) and P2 (C) for thinning print data by 50% in the fifth pass and the sixth pass.

  In the present embodiment, as shown in FIG. 10, magenta ink is ejected from only the first nozzle group G11 of the recording head 10M. Similarly, yellow ink is ejected from only the second nozzle group G12 of the recording head 10Y, and cyan ink is ejected from only the third nozzle group 13 of the recording head 10C. That is, the same color ink is ejected from nozzles belonging to the same nozzle group, and is not ejected from nozzles belonging to different nozzle groups. Therefore, after starting recording by ejecting magenta ink from the nozzles belonging to the first nozzle group G11, after completing recording with the magenta ink, ejecting yellow ink from the nozzles belonging to the second nozzle group G12. Start recording with. Furthermore, after completing the recording with the yellow ink, the recording by the discharge of the cyan ink from the nozzles belonging to the third nozzle group G13 is started. Finally, recording with cyan ink is completed, whereby recording with magenta, yellow, and cyan inks is completed.

  In this example, the ink is applied onto the recording medium W in the order of magenta, yellow, and cyan inks, that is, in the order of deep penetration depth. Therefore, the magenta ink that is first applied to the recording medium W is adsorbed by the particles constituting the receiving layer of the recording medium. Next, the yellow ink to be applied penetrates deeper into the recording medium when it is applied to the area to which the magenta ink is applied than to the area to which the ink is not applied. However, since the penetration depth of yellow ink is shallower than that of magenta ink, the difference in penetration depth of yellow ink between the former case and the latter case becomes small. Finally, cyan ink is applied to the area on the recording medium where the magenta and yellow ink solvents (including moisture) remain. The cyan ink penetrates deeper into the recording medium when it is applied to a region to which magenta ink and / or yellow ink is applied than to a region to which ink is not applied. However, since the penetration depth of cyan ink is shallower than that of yellow ink and magenta ink, the difference in penetration depth of yellow ink between the former case and the latter case becomes small. By the way, the highly penetrable ink applied earlier is slightly swept away by the less penetrable ink applied later, but the change in permeability is less than when applied after applying the less penetrable ink. small.

(Recording ratio setting method in the second case)
In the second case, that is, the case where the penetration depth of the two inks is shallow and equal and the penetration depth of the other one ink is deep, when recording by the 6-pass recording method, the recording head as shown in FIG. Is divided into two equal parts for use in the first and second nozzle groups G21 and G22.

  As described above, since the penetration depth of the ink is related to the evaporation of moisture in the ink, the penetration depth becomes shallower as the recording ratio per pass is smaller. Further, when the application order of inks having the same penetration depth is changed, the ink applied later penetrates deeply. Therefore, it is desirable to apply the inks having the same penetration depth at the same time by reducing the recording ratio per pass. Therefore, in the present embodiment, a three-pass printing method is used for each ink color, and a six-pass printing method is used for all ink colors. Here, as an example, a case where the penetration depth of magenta ink is the deepest and the penetration depth of yellow ink and cyan ink is equal will be described.

  Magenta ink is applied using the first nozzle group G21 of the recording head 10M, and yellow ink and cyan ink are applied using the second nozzle group G22 of the recording heads 10Y and 10C. As described above, the vertical width (the length in the nozzle row direction) of the nozzle groups G21 and G22 is equal to the width corresponding to the number of nozzles obtained by dividing all the nozzles of the recording head by the number of passes of all ink colors. Multiply by the number of passes for each color. The number of passes of all ink colors for all nozzles of the print head is equivalent to the product of the number of nozzle groups and the number of passes for each ink color. The nozzle of the quotient obtained by dividing all the nozzles of the print head by the number of passes of all ink colors The width of several minutes corresponds to the conveyance amount by which the recording medium is conveyed in the backward scanning direction for each pass. In this example, the number of nozzles of the recording head is 1278, the number of nozzle groups is 2, the number of passes for each ink color is 3, and the number of passes for all ink colors is 6, so the recording medium is conveyed for each pass. The conveyed amount corresponds to the width of 213 nozzles. Accordingly, the vertical width of each of the nozzle groups G21 and G22 is 639 nozzles, which is three times the 213 nozzles.

  When the recording ratios of the Y, M, and C ink colors in the total number of passes (6 passes) are 100%, the recording ratios of the Y, M, and C ink colors in each pass are shown in FIGS. ) And (c). The magenta ink is ejected from the recording head 10M by the recording ratio (100/3)% from the first pass to the third pass, and is not ejected from the fourth pass to the sixth pass because the recording ratio is 0%. The yellow ink is ejected from the recording head 10Y by the recording ratio (100/3)% from the fourth pass to the sixth pass, and is not ejected from the first pass to the third pass because the recording ratio is 0%. The cyan ink is ejected from the recording head 10Y by the recording ratio (100/3)% from the fourth pass to the sixth pass, and is not ejected from the first pass to the third pass because the recording ratio is 0%. Such a recording ratio is determined by a mask pattern that divides recording data into divided recording data as described above. In this example, the recording ratio in a total of three passes for each ink color is (100/3)%. However, the recording ratio in a total of three passes does not necessarily need to be (100/3)% each, and it is sufficient that the total is 100%.

  FIGS. 13A, 13B, and 13C are explanatory diagrams of mask patterns for setting the recording ratio of magenta, yellow, and cyan ink colors. The magenta ink mask patterns include patterns P1 (M), P2 (M), and P3 (M) for thinning out the recording data by (100/3)% in the first to third passes, and these patterns are complemented. There is a relationship. The mask pattern for yellow ink includes patterns P1 (Y), P2 (Y), and P3 (Y) that thin out print data by (100/3)% in the fourth to sixth passes. The mask pattern for cyan ink includes patterns P1 (C), P2 (C), and P3 (C) that thin out the recording data by (100/3)% in the fourth to sixth passes.

  In the present embodiment, as shown in FIG. 14, magenta ink is ejected only from the first nozzle group G21 of the recording head 10M. Similarly, yellow ink is ejected from only the second nozzle group G22 of the recording head 10Y, and cyan ink is ejected from only the second nozzle group 22 of the recording head 10C. That is, the same color ink is ejected from nozzles belonging to the same nozzle group, and is not ejected from nozzles belonging to different nozzle groups. Therefore, after starting recording by ejecting magenta ink from the nozzles belonging to the first nozzle group G21, recording with the magenta ink is completed, and then yellow ink and cyan from the nozzles belonging to the second nozzle group G22 are completed. Recording by ink ejection is started. Finally, recording with yellow ink and cyan ink is completed, thereby completing recording with magenta, yellow, and cyan inks.

(Recording ratio setting method in the third case)
In the second case, that is, the case where the penetration depth of two inks is deep and equal and the penetration depth of the other one ink is deep, when recording by the 6-pass recording method, the recording head as shown in FIG. Is divided into two equal parts for use in the first and second nozzle groups G21 and G22.

  As described above, since the penetration depth of the ink is related to the evaporation of moisture in the ink, the penetration depth becomes shallower as the recording ratio per pass is smaller. Further, when the application order of inks having the same penetration depth is changed, the ink applied later penetrates deeply. Therefore, it is desirable to apply the inks having the same penetration depth at the same time by reducing the recording ratio per pass. Therefore, in this embodiment, a three-pass printing method is used for each ink color, and a six-pass printing method is used for all ink colors. Here, as an example, a case where the penetration depth of magenta ink and yellow ink is equal and deeper than the penetration depth of cyan ink will be described.

  Magenta ink and yellow ink are applied using the first nozzle group G21 of the recording heads 10M and 10Y, and cyan ink is applied using the second nozzle group G22 of the recording head 10C. As described above, the vertical width (the length in the nozzle row direction) of the nozzle groups G21 and G22 is equal to the width corresponding to the number of nozzles obtained by dividing all the nozzles of the recording head by the number of passes of all ink colors. Multiply by the number of passes for each color. The number of passes of all ink colors for all nozzles of the print head is equivalent to the product of the number of nozzle groups and the number of passes for each ink color. The nozzle of the quotient obtained by dividing all the nozzles of the print head by the number of passes of all ink colors The width of several minutes corresponds to the conveyance amount by which the recording medium is conveyed in the backward scanning direction for each pass. In this example, the number of nozzles of the recording head is 1278, the number of nozzle groups is 2, the number of passes for each ink color is 3, and the number of passes for all ink colors is 6, so the recording medium is conveyed for each pass. The conveyed amount corresponds to the width of 213 nozzles. Accordingly, the vertical width of each of the nozzle groups G21 and G22 is 639 nozzles, which is three times the 213 nozzles.

  When the recording ratios of the Y, M, and C ink colors in the total number of passes (6 passes) are 100%, the recording ratios of the Y, M, and C ink colors in each pass are shown in FIGS. ) And (c). The magenta ink is ejected from the recording head 10M by the recording ratio (100/3)% from the first pass to the third pass, and is not ejected from the fourth pass to the sixth pass because the recording ratio is 0%. The yellow ink is ejected from the recording head 10M by the recording ratio (100/3)% from the first pass to the third pass, and is not ejected from the fourth pass to the sixth pass because the recording ratio is 0%. The cyan ink is ejected from the recording head 10Y by the recording ratio (100/3)% from the fourth pass to the sixth pass, and is not ejected from the first pass to the third pass because the recording ratio is 0%. Such a recording ratio is determined by a mask pattern that divides recording data into divided recording data as described above. In this example, the recording ratio in a total of three passes for each ink color is (100/3)%. However, the recording ratio in a total of three passes does not necessarily need to be (100/3)% each, and it is sufficient that the total is 100%.

  FIGS. 16A, 16B, and 16C are explanatory diagrams of mask patterns for setting the recording ratio of magenta, yellow, and cyan ink colors. The magenta ink mask patterns include patterns P1 (M), P2 (M), and P3 (M) for thinning out the recording data by (100/3)% in the first to third passes, and these patterns are complemented. There is a relationship. The mask pattern for yellow ink includes patterns P1 (Y), P2 (Y), and P3 (Y) that thin out recording data by (100/3)% in the first to third passes. The mask pattern for cyan ink includes patterns P1 (C), P2 (C), and P3 (C) that thin out the recording data by (100/3)% in the fourth to sixth passes.

  In the present embodiment, as shown in FIG. 17, magenta ink is ejected only from the first nozzle group G21 of the recording head 10M. Yellow ink is ejected only from the first nozzle group G21 of the recording head 10Y, and cyan ink is ejected only from the second nozzle group 22 of the recording head 10C. That is, the same color ink is ejected from nozzles belonging to the same nozzle group, and is not ejected from nozzles belonging to different nozzle groups. Therefore, after starting recording by discharging magenta ink and yellow ink from the nozzles belonging to the first nozzle group G21, and after completing the recording by these inks, cyan from the nozzles belonging to the second nozzle group G22 is completed. Recording by ink ejection is started. Finally, recording with cyan ink is completed, whereby recording with magenta, yellow, and cyan inks is completed.

(Gradient mask)
In the above, for easy understanding, the recording ratio in one scan is constant, and the change curve is flat without change. However, the same effect can be obtained by changing the recording ratio in one scan and making the change curve a gradation shape such as a mountain shape. For example, instead of the mask patterns shown in FIGS. 9A, 9B, and 9C in the case 1 described above, the mask patterns (gradation mask) shown in FIGS. 15A, 15B, and 15C are used. It may be used to change the recording ratio within one scan. When such a mask pattern is used, it is possible to suppress the occurrence of recording density unevenness (connection streaks) between the recording area of the previous scan and the recording area of the next scan.

(Overlap mask)
In the cases 1, 2, and 3 described above, their recording ratios are set so that each of the three colors of ink is ejected from one specific nozzle group. However, the recording ratio may be set so that ink is ejected from a plurality of nozzle groups or all nozzle groups. Hereinafter, an example of the case 1, that is, the case where the penetration depths of all ink colors are not equal, will be described as a method for setting such a recording ratio.

  In this example, a 6-pass printing method is used for each ink color, and a 6-pass printing method is used for all ink colors. Here, a case where the penetration depth is deeper in the order of magenta, yellow, and cyan inks will be described. Since there are six passes for all ink colors, the vertical width of the nozzles that eject the respective inks corresponds to the width of all the nozzles (1278 nozzles) of the recording head. The recording heads 10M, 10Y, and 10C are used by being divided into six nozzle groups each having 213 nozzles. These six nozzle groups are first, second,..., Sixth nozzle groups from the upstream side to the downstream side in the conveyance direction of the recording medium.

  When the recording ratios of Y, M, and C ink colors in the total number of passes (6 passes) are 100%, the recording ratios of Y, M, and C ink colors in each pass are shown in FIGS. ) And (c). For magenta ink having the deepest penetration depth, the center value described later is 469.1. A method for obtaining the center value will be described later. The center value of yellow ink is 639.5, and the center value of cyan ink is 809.9. Such a recording ratio is determined by a mask pattern that divides recording data into divided recording data as described above.

  20A, 20B, and 20C are explanatory diagrams of a mask pattern (overlap mask) for setting the recording ratio of magenta, yellow, and cyan ink colors. The mask pattern for magenta ink includes patterns P1 (M) and P2 (M) for thinning print data by 30% in the first and second passes, and a pattern P3 for thinning print data by 10% in the third to sixth passes. (M) to P6 (M). Those patterns are complementary. The mask patterns for yellow ink include patterns P1 (Y), P2 (Y), P5 (Y), P6 (Y), and 3 and 4 for thinning out recording data by 10% in the first, second, fifth and sixth passes. In the pass, the patterns P3 (Y) and P4 (Y) for thinning the recording data by 30% are included. The mask patterns for cyan ink are patterns P1 (C) to P4 (C) where print data is thinned out by 10% from the first pass to the fourth pass, and a pattern P5 from which print data is thinned out by 30% at the fifth and sixth passes. (Y) and P6 (Y).

  In this example, for easy understanding, the recording ratio in one scan is constant and the change curve is a flat shape with no change. However, the same effect can be obtained by changing the recording ratio in one scan and making the change curve a gradation shape such as a mountain shape.

(Calculation method of center value)
The above-described center value is obtained based on the nozzle numbers continuously assigned to the nozzles and the recording ratio for each nozzle. The nozzle numbers are continuously assigned to 1,278 nozzles as 1, 2, 3,..., 1278 from the upstream side to the downstream side in the recording medium conveyance direction. For each nozzle, the nozzle number of the nozzle and the recording ratio are integrated (nozzle number × recording ratio), and the sum of the (nozzle number × recording ratio) for 1278 nozzles is divided by the sum of the recording ratios. Find the center value. When this central value is small, there is a relatively large proportion of ink applied from the nozzles (first half nozzles) on the first half side (upstream side in the conveyance direction of the recording medium). Since the first-half nozzle is used in the first-half pass in the multi-pass (one pass in the case of six passes), a large amount of ink having a small center value is applied in the first-half pass (first-pass). Means that. On the other hand, when the center value is large, there is a relatively large proportion of ink applied from the nozzles (second half nozzles) on the second half side (downstream side in the conveyance direction of the recording medium). Since the latter half nozzle is used in the latter half of the multi-pass (6 passes in the case of six passes), a large amount of ink having a small center value is applied in the latter half (second half). Means that.

  Specifically, in the case of magenta ink in FIG. 8A, the sum of (nozzle number × recording ratio) for 1278 nozzles is (1 × 0.5) + (2 × 0.5) +. (426 × 0.5) + (427 × 0.0) + (1278 × 0.0) = 45475.5. The total recording ratio is 0.5 × 426 = 213. Therefore, the center value of magenta ink is 213.5 (= 454755.5 / 213). In the case of the yellow ink in FIG. 8B, the sum of (nozzle number × recording ratio) for 1278 nozzles is 136213.5. That is, (1 × 0.0) + (426 × 0.0) + (427 × 0.5) + (852 × 0.5) + (853 × 0.0) + (1278 × 0.0) = 136213.5 The total recording ratio is 0.5 × 426 = 213. Therefore, the center value of yellow ink is 639.5 (= 136213.5 / 213). In the case of the cyan ink in FIG. 8C, the sum of (nozzle number × recording ratio) for 1278 nozzles is (1 × 0.0) +... (852 × 0.0) + (853 × 0). .5) +... (1278 × 0.5) = 226951.5. The total recording ratio is 0.5 × 426 = 213. Therefore, the center value of cyan ink is 1065.5 (= 226951.5 / 213).

(Image recording operation)
FIG. 21 is a flowchart for explaining a process of selecting a mask pattern used in the mask data conversion process J8 of FIG.

  First, the type of recording medium used for recording and the recording mode are set (step S1). The penetration depth of ink varies depending on the type of recording medium. Therefore, the penetration depth of each ink is measured in advance for each recording medium by the measurement method described above, and the penetration depth is stored in the ROM 110 of FIG. In the recording operation, one recording medium is set from a plurality of types of recording media. Also, a recording mode (for example, a high-definition recording mode, a high-speed recording mode, etc.) is set. The selection of the recording medium may be performed based on user input, or may be automatically performed by the host device based on information regarding the recording medium. The selected recording medium and recording mode are set in the host device. Thereafter, the host device selects a mask pattern according to the selected recording medium and recording mode (step S2). The mask pattern corresponding to the recording medium is held for the number of recording modes or at least one type.

(Other embodiments)
The present invention can be applied to the case where black, which is called composite black, is recorded by superimposing inks of three colors, cyan, magenta, and yellow. However, the present invention is not limited to this, and can be widely applied to various recording apparatuses and recording systems that record images by a multi-pass recording method using a plurality of types of ink. That is, the present invention can be applied to various recording apparatuses that record an image using at least the first ink and the second ink. In the recording apparatus, as a plurality of scans for applying the first ink, a high recording ratio scan with a high ink application rate and a low recording ratio scan with a low ink application rate are set ( (First setting process) In addition, as a plurality of scans for applying the second ink, a scan with a high recording ratio with a high ink application rate and a scan with a low recording ratio with a low ink application rate are set (second setting step). ) I can do it. Further, the ink jet recording apparatus is not limited to the bidirectional recording method in which the recording scanning is performed while the recording head is moving in the forward direction and the backward direction, and the unidirectional recording is performed in which the recording head is scanned while the recording head is moving in the forward direction or the backward direction. It may be a method. Further, the recording head may be configured to eject ink using various ejection energy generating elements such as piezo elements.

  In the present invention, it is sufficient that the recording ratio setting function described above can be achieved in a recording system including a recording apparatus and a host apparatus. Therefore, the recording apparatus may be configured to have part or all of such setting functions, or the host apparatus may be configured to have part or all of the functions. Moreover, as a form of this invention, the program for implementing the function mentioned above with a computer and the storage medium which stored the program can be included.

100 Host device (image processing device)
104 Printer (inkjet recording device)
10 (10C, 10M, 10Y) Print head N Nozzle G1, G2, G11, G12, G13 Nozzle group P1 (M), P2 (M), P3 (M) Mask patterns for magenta ink P1 (Y), P2 ( Y), P3 (Y) Mask pattern for yellow ink P1 (C), P2 (C), P3 (C) Mask pattern for cyan ink

Claims (14)

A recording head for discharging the first type of ink and the second type of ink different from the first type is N (N ≧ 2) in the scanning direction with respect to a predetermined recording area on the recording medium. ) An ink jet recording apparatus for recording an image by discharging the first and second types of ink while scanning the image;
Relates percentage of the total amount of the first type of ink ejected to the predetermined recording area in each of the N scans, N for discharging said first type of ink with respect to the predetermined recording area As the scanning of the first time, the first type of ink is ejected at a rate higher than the first ratio K (K <N) times of the high recording ratio, and the first type of ink is ejected from the first type of ink. A first setting means for setting NK times of a low recording ratio for discharging at a ratio lower than the ratio;
Relates percentage of the total of the amount of the second type of ink ejected to the predetermined recording area in each of the N scans, N for discharging the second type of ink with respect to the predetermined recording area As the second scan, the second type ink is ejected at a higher ratio than the second ratio L (L <N) times, and the second type ink is ejected at the second rate. Second setting means for setting NL times of low recording ratio scanning for discharging at a ratio lower than the ratio;
Control means for controlling to eject ink while performing the scanning set by the first and second setting means ,
The penetration depth of the first type ink penetrating into the recording medium when a predetermined amount of the first type ink is applied to the recording medium is the same as that of the predetermined amount of the second type ink. Deeper than the penetration depth of the second type of ink penetrating into the recording medium when applied to the recording medium,
The sum of the ratios of the first type ink in each of the K high recording ratio scans is the sum of the ratios in each of the NK low recording ratio scans of the first type of ink. And the sum of the ratios of the L-type inks in the L high-recording ratio scans is the NL times of the second-type inks in the low-recording-ratio scanning. Higher than the sum of each ratio,
The first and second setting means perform the K high recording ratio scanning of the first type ink before the L high recording ratio scanning of the second type ink. An ink jet recording apparatus characterized in that the scanning is set to the scanning. Scanning of the N-K times lower recording ratio of the first type of ink includes a scanning without discharging the first type of ink,
2. The inkjet recording apparatus according to claim 1, wherein the NL times of low recording ratio scans of the second type of ink include scans that do not eject the second type of ink. 3. The inkjet recording apparatus according to claim 1 , wherein K ≧ 2 and L ≧ 2 . The recording head includes a plurality of first nozzles for discharging the first type of ink arranged in an arrangement direction intersecting the scanning direction, and the second type of ink arranged in the intersecting direction. A plurality of second nozzles for ejecting ink,
The first setting unit divides the plurality of first nozzles into K nozzle groups, and for the first nozzles belonging to the same nozzle group, the first type ink is ejected from the nozzles. Set the ratio to be the same,
The second setting means divides the plurality of second nozzles into L nozzle groups, and for the second nozzles belonging to the same nozzle group, the second type ink is ejected from the nozzles. The inkjet recording apparatus according to claim 1, wherein the ratios are set to be the same. 5. The apparatus according to claim 1, wherein the first and second setting means set a ratio of ejecting the first and second types of ink using a mask pattern. 6. The ink jet recording apparatus described. The recording head further discharges a third type of ink different from the first and second types,
Relates percentage of the total amount of the third type of ink ejected to the predetermined recording area in each of the N scans, N for discharging the third type of ink with respect to the predetermined recording area As the scanning of the first time, M (M <N) times of scanning with a high recording ratio for ejecting the third type of ink at a ratio higher than the third ratio, and the third type of ink for the third type of ink. And a third setting means for setting NM times of low recording ratio discharges ejected at a ratio lower than the ratio,
The penetration depth of the second type ink penetrating into the recording medium when the predetermined amount of the second type ink is applied to the recording medium is the predetermined amount of the third type ink. Deeper than the penetration depth of the third type of ink penetrating into the recording medium when applied to the recording medium,
The sum of the ratios in each of the M high recording ratio scans of the third type ink is the sum of the ratios in each of the NM low recording ratio scans of the third type ink. Higher than
The second and third setting means scan the L high recording ratio scans of the second type ink before the M high recording ratio scans of the third type ink. The inkjet recording apparatus according to any one of claims 1 to 5, wherein the scanning is set to the scanning.   The ink jet recording apparatus according to claim 1, wherein the first and second types of ink contain different color materials.   8. The ink jet recording apparatus according to claim 7, wherein the color materials contained in the first and second types of ink each exhibit a color other than black.   9. The ink jet recording apparatus according to claim 8, wherein the color material contained in the first and second types of ink exhibits a color of cyan, magenta, or yellow, respectively. The ratios of the first type ink in the K high recording ratio scans are substantially equal to each other, and the ratio of the second type ink in the L high recording ratio scans is The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatuses are substantially equal to each other . The ratios of the first type of ink in the NK times of the low recording ratio scans are substantially equal to each other, and the NL times of the second type of ink of the low recording ratio scans are respectively equal. 11. The inkjet recording apparatus according to claim 1, wherein the ratios are substantially equal to each other . The inkjet recording apparatus according to claim 1, wherein K = L. An inkjet recording system comprising: an inkjet recording apparatus that records an image based on recording data; and an image processing apparatus that supplies the recording data to the inkjet recording apparatus,
In the ink jet recording apparatus, a recording head for ejecting a first type of ink and a second type of ink different from the first type is scanned in a scanning direction with respect to a predetermined recording area on the recording medium. The image is recorded by ejecting the first and second types of ink while scanning N (N ≧ 2) times,
The inkjet recording system includes:
Relates percentage of the total amount of the first type of ink ejected to the predetermined recording area in each of the N scans, N for discharging said first type of ink with respect to the predetermined recording area As the scanning of the first time, the first type of ink is ejected at a rate higher than the first ratio K (K <N) times of the high recording ratio, and the first type of ink is ejected from the first type of ink. A first setting means for setting NK times of a low recording ratio for discharging at a ratio lower than the ratio;
Relates percentage of the total of the amount of the second type of ink ejected to the predetermined recording area in each of the N scans, N for discharging the second type of ink with respect to the predetermined recording area As the second scan, the second type ink is ejected at a higher ratio than the second ratio L (L <N) times, and the second type ink is ejected at the second rate. Second setting means for setting NL times of low recording ratio scanning for discharging at a ratio lower than the ratio;
Control means for controlling to eject ink while performing the scanning set by the first and second setting means ,
The penetration depth of the first type ink penetrating into the recording medium when a predetermined amount of the first type ink is applied to the recording medium is the same as that of the predetermined amount of the second type ink. Deeper than the penetration depth of the second type of ink penetrating into the recording medium when applied to the recording medium,
The sum of the ratios of the first type ink in each of the K high recording ratio scans is the sum of the ratios in each of the NK low recording ratio scans of the first type of ink. And the sum of the ratios of the L-type inks in the L high-recording ratio scans is the NL times of the second-type inks in the low-recording-ratio scanning. Higher than the sum of each ratio,
The first and second setting means perform the K high recording ratio scanning of the first type ink before the L high recording ratio scanning of the second type ink. An ink jet recording system characterized in that the scanning is set to the scanning. A control method for controlling an ink jet recording apparatus,
In the ink jet recording apparatus, a recording head for ejecting a first type of ink and a second type of ink different from the first type is scanned in a scanning direction with respect to a predetermined recording area on the recording medium. The image is recorded by ejecting the first and second types of ink while scanning N (N ≧ 2) times,
The control method is:
Relates percentage of the total amount of the first type of ink ejected to the predetermined recording area in each of the N scans, N for discharging said first type of ink with respect to the predetermined recording area As the scanning of the first time, the first type of ink is ejected at a rate higher than the first ratio K (K <N) times of the high recording ratio, and the first type of ink is ejected from the first type of ink. A first setting step for setting NK times of a low recording ratio for discharging at a ratio lower than the ratio;
Relates percentage of the total of the amount of the second type of ink ejected to the predetermined recording area in each of the N scans, N for discharging the second type of ink with respect to the predetermined recording area As the second scan, the second type ink is ejected at a higher ratio than the second ratio L (L <N) times, and the second type ink is ejected at the second rate. A second setting step for setting NL times of low recording ratio scanning for discharging at a ratio lower than the ratio;
A control step for controlling to discharge ink while performing the scanning set by the first and second setting steps ,
The penetration depth of the first type ink penetrating into the recording medium when a predetermined amount of the first type ink is applied to the recording medium is the same as that of the predetermined amount of the second type ink. Deeper than the penetration depth of the second type of ink penetrating into the recording medium when applied to the recording medium,
The sum of the ratios of the first type ink in each of the K high recording ratio scans is the sum of the ratios in each of the NK low recording ratio scans of the first type of ink. And the sum of the ratios of the L-type inks in the L high-recording ratio scans is the NL times of the second-type inks in the low-recording-ratio scanning. Higher than the sum of each ratio,
In the first and second setting steps, the K high-recording ratio scan of the first type ink is performed before the L high-recording ratio scan of the second type ink. A method of controlling an ink jet recording apparatus, characterized in that the scanning is set to the above.

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