JP4366436B2 - Recording apparatus, data processing apparatus and mask manufacturing method - Google Patents

Description

The present invention relates to a recording apparatus , a data processing apparatus, and a mask manufacturing method.

  In the ink jet printer, a so-called multi-pass recording method is widely adopted. The multi-pass printing method is a method in which when an arbitrary area of an image is viewed, ink dots constituting the image in that area are divided and formed by a plurality of scans of the print head. According to this method, it is possible to disperse unevenness due to variations in ejection performance, such as the ink ejection direction for each nozzle (or ejection port) that ejects ink, and due to transport errors in the recording paper, etc., to multiple scans. . As a result, it is possible to record a high-quality image in which density unevenness is not noticeable.

  By the way, the generation of dot recording data for forming a plurality of ink dots constituting a recording image by dividing it into a plurality of scans is generally performed by mask processing using a mask pattern (also simply referred to as “mask”). Do it. As shown in FIG. 5 to be described later, the mask pattern includes pixels that allow recording (hereinafter also referred to as “recording allowable pixels”) and pixels that do not allow recording (hereinafter also referred to as “non-recording allowable pixels”). It is an arrangement. The print permitting pixel corresponds to a portion indicated by black in FIG. 5, and the non-recording permitting pixel corresponds to a portion indicated by white. Then, by devising the arrangement of the print permitting pixels in this mask pattern, it is possible to adjust the number of dots to be recorded in each of a plurality of scans, or to eliminate the above-described density unevenness, etc. Can take.

  For example, the following two types of mask patterns are effective for image quality problems.

  As a typical mask pattern, there is a mask pattern based on a Bayer pattern. However, since such a pattern is regular, interference with image data is likely to occur, and image quality problems may occur.

  Therefore, in Patent Document 2, there is randomness in the arrangement of print permitting pixels in the mask pattern, and interference with image data occurs by using such a random mask pattern (hereinafter also referred to as a random mask). It is difficult. This improves the above problem.

  On the other hand, in Japanese Patent Application Laid-Open No. H10-260260, the arrangement of the print permitting pixels in the mask pattern is excellent in dispersibility, and the image quality due to the deviation of the dot formation position during bidirectional printing using such a mask pattern with high dispersibility is used. It is described that the decrease is suppressed. That is, the arrangement of the print permitting pixels in the mask described in the document is well dispersed using the concept of repulsive potential. In other words, this mask pattern is generated so as to avoid as close as possible the dots formed by using the mask pattern from each other. The frequency component is small. By using this mask, a dot formation position shift occurs in bidirectional recording, and even if the mask pattern itself (texture) appears in the recorded image due to the shift, it is well dispersed. This can make it difficult to visually recognize.

JP 2002-144552 A Japanese Patent Laid-Open No. 7-052390 JP 2002-96455 A

  By the way, in recent inkjet recording systems, with the increase in speed and density, and the diversification of ink types, the amount of ink applied per unit time and the amount of ink applied per unit area of the recording medium are increased. The amount tends to increase. For this reason, the beading problem is given as a more important issue than ever. In the beading, ink that cannot be absorbed by the recording medium comes in contact with each other on the medium, which causes unevenness in the recorded image.

  In order to reduce beading, it is important to dispose the ink applied within a short time at different positions as much as possible. For this reason, it is effective to use different mask patterns as much as possible for each color ink. By doing so, it is possible to reduce the probability that different color inks are driven into the same place.

  However, merely reducing the mask pattern for each color does not reduce the beading sufficiently.

  86 (a) to 86 (c) are diagrams for explaining this problem. This figure shows a process in which each ink is driven into a recording medium in the order of cyan, magenta, and yellow in a certain scan in multi-pass printing. As shown in FIG. 86 (a), cyan ink is first ejected onto a recording medium on which nothing has been printed yet. At this time, it goes without saying that the positions where the respective cyan inks are applied follow the arrangement of the print permitting pixels of the mask used. Before the ink is completely absorbed by the recording medium, the cyan ink droplet 10C exists on the recording medium in an arrangement according to the mask. Next, as shown in FIG. 86B, magenta ink is similarly ejected to a position according to the corresponding mask, and similarly forms an ink droplet 10M before absorption. Here, depending on the relationship of the printable pixel arrangement of the mask used for each of the cyan ink and magenta ink, the ink droplet 10B in which the cyan ink droplet 10C and the magenta ink droplet 10M are in contact with each other (those marked with an X in the figure). ) May form. Further, as shown in FIG. 86 (c), the yellow ink is similarly ejected to a position according to the corresponding mask to form an ink droplet 10Y before absorption. Also in this case, the connected ink droplets 10B (marked with x in the figure) are formed according to the relationship of the print permitting pixel arrangement of the mask used for each ink. When the scanning is further repeated and the ratio of the ink droplets to the pixels becomes high, the ink droplets may be ejected in the same pixel, and the same connected ink droplets are formed.

  In this way, when ink droplets that are sequentially ejected are applied to adjacent or adjacent pixels or the same pixel, they contact each other and attract each other by the surface tension of two or three (or more) A large droplet 10B (grain) in which the ink droplets are combined is formed. Once such a grain is formed, the ink droplet applied to the next or adjacent position is likely to be attracted to the grain. That is, the first generated grain gradually grows as a nucleus and eventually produces large grains. In particular, in a uniform image area, the grains fixed on the recording medium are scattered in an irregular manner and are visually recognized as beading.

  In general, a mask pattern is repeatedly used in a two-dimensional direction. For this reason, the above-described grain distribution is likely to be perceived by the human eye as a pattern of the mask pattern repetition period.

  These problems cannot be solved by the mask patterns described in Patent Documents 1 and 2. This is because these Patent Documents 1 and 2 do not design in consideration of dispersion between mask patterns of different colors.

  In the masks of Patent Documents 1 and 2 in which the mask design with such a relationship between different colors is not performed, the arrangement of the recordable pixels when the masks of different colors are overlapped is poorly distributed. It is impossible to avoid adjacent dots or overlapping dots in an image in the middle of recording (intermediate image).

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a recording apparatus and a data processing apparatus that can reduce image quality deterioration due to beading caused by grains in the middle of divided recording. And a mask manufacturing method.

  The grain is not generated only by the surface tension between the inks. For example, when liquids that react with each other, such as ink and a treatment liquid that agglomerates or insolubilizes them, are applied in the same scan, each contacted droplet is bound by a stronger chemical reaction, which forms a grain. There is also. Also, when ink of the same color is applied in the same scan, grain occurs between them. Therefore, another object of the present invention is to solve the problems caused by such grains.

In order to solve the above problems, the present invention provides a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot. A recording apparatus for recording an image in the predetermined area by scanning a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group for forming dots. Using the first pattern group having a plurality of mask patterns corresponding to a plurality of scans, the image data to be recorded in the predetermined area by the first nozzle group is used for each of the plurality of scans. first means for dividing the using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, to be recorded in the predetermined region by the second nozzle group Using a second means for dividing the image data into image data used in each of the plurality of scans, the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, said third nozzle group wherein said image data to be recorded in a predetermined area and a third means for dividing the image data used in each of the plurality of scans, corresponding to a predetermined scanning of the plurality of times of scanning by the first first mask patterns included in one pattern group, the third included in the third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to the predetermined scan mask pattern, respectively, different arrangement of print permitting pixels, use of the first, the three mask patterns a logical product of the second and third mask patterns The low frequency components of the arrangement pattern of print permitting pixels obtained by performing, based on the correspondence relationship, obtained by performing on the basis of the different relationship from that of the in use relationship a logical product of the three mask patterns It is characterized in that it is less than the low frequency component of the array pattern of the recording allowable pixels.

In another embodiment, a first nozzle group for forming the first type of dot, a second nozzle group for forming the second type of dot, and a third type of dot for forming the dot A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an ink jet recording head having at least a third nozzle group and records an image in the predetermined area, and supports the plurality of scans First means for dividing image data to be recorded in the predetermined area by the first nozzle group into image data used for each of the plurality of scans using the first pattern group having the plurality of mask patterns. When using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, said second of said plurality of image data to be recorded in the predetermined area by the nozzle group Using a second means for dividing the into image data used in scanning each of the third pattern group having a plurality of mask patterns corresponding to the plural scans, recorded in the predetermined area by the third nozzle group And third means for dividing the image data to be divided into image data used in each of the plurality of scans , and is included in the first pattern group corresponding to a predetermined scan among the plurality of scans the first mask pattern, the third mask pattern contained in said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to the predetermined scanning, respectively , different arrangement of print permitting pixels, based on the logical sum of said first, second and third mask patterns on a corresponding relationship when using these three mask patterns Low frequency components of the arrangement pattern of print permitting pixels obtained by performing, said three arrays of print permitting pixels obtained by performing based on different correspondence logical OR of the mask pattern and the corresponding relationship between the time of the use A recording apparatus characterized by being less than low frequency components of a pattern.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group and records an image in the predetermined area, A first pattern group having a plurality of corresponding mask patterns is used to divide image data to be recorded in the predetermined area by the first nozzle group into image data used in each of the plurality of scans. using the second pattern group having a means, a plurality of mask patterns corresponding to the plurality of scans, before the image data to be recorded in the predetermined area by said second nozzle group Using a second means for dividing the image data used in each of the plurality of scans, the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the predetermined region by the third nozzle group And a third means for dividing the image data to be recorded into image data used in each of the plurality of scans , the first pattern group corresponding to a predetermined scan among the plurality of scans. first mask patterns included, the third mask pattern contained in said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to the predetermined scan each different arrangement of print permitting pixels, said first, second and third mask pattern based on the corresponding relationship when using these three mask patterns Low frequency components of the arrangement pattern of print permitting pixels obtained by Riseki, the first, to logical product based on a different relationship than the relationship of the time using the second and third mask patterns less than the low frequency components of the arrangement pattern of print permitting pixels obtained by the first, the print permitting pixels obtained by ORing the basis of the second and third mask patterns on a corresponding relationship during the use low frequency components of the arrangement pattern, the first, low arrangement pattern of print permitting pixels obtained by ORing based on a different relationship to the second and third mask pattern during the use relationship Fewer than frequency components.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group and records an image in the predetermined area, A first pattern group having a plurality of corresponding mask patterns is used to divide image data to be recorded in the predetermined area by the first nozzle group into image data used in each of the plurality of scans . first means, said plurality of times of using the second pattern group having a plurality of mask patterns corresponding to the scanning, the image data to be recorded in the predetermined region by the second nozzle group The use of the third pattern group having a second means for dividing the image data used in each of the plurality of scans, a plurality of mask patterns corresponding to the plurality of scans, said third nozzle group and a third means for dividing the image data to be recorded in the predetermined area in the image data used in each of the plurality of scans by corresponding to a predetermined scanning of the plurality of scans included in the first mask pattern, the predetermined said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to scanning included in the first pattern group the third mask pattern, respectively, different arrangement of the print permitting pixels, the first, of a logical product of the second and third mask pattern three mask patterns Low frequency components in the arrangement pattern of print permitting pixels obtained by performing, based on the correspondence between the time of use is equal to or less than the high frequency components.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group and records an image in the predetermined area, A first pattern group having a plurality of corresponding mask patterns is used to divide image data to be recorded in the predetermined area by the first nozzle group into image data used in each of the plurality of scans . first means, said plurality of times of using the second pattern group having a plurality of mask patterns corresponding to the scanning, the image data to be recorded in the predetermined region by the second nozzle group The use of the third pattern group having a second means for dividing the image data used in each of the plurality of scans, a plurality of mask patterns corresponding to the plurality of scans, said third nozzle group and a third means for dividing the image data to be recorded in the predetermined area in the image data used in each of the plurality of scans by corresponding to a predetermined scanning of the plurality of scans included in the first mask pattern, the predetermined said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to scanning included in the first pattern group the third mask pattern, respectively, different arrangement of the print permitting pixels, and the first mask pattern and the second mask pattern of the third mask pattern The arrangement pattern of print permitting pixels obtained by Riseki is and the low frequency components in a non-cycle, characterized in that less than the high frequency components.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group and records an image in the predetermined area, A first pattern group having a plurality of corresponding mask patterns is used to divide image data to be recorded in the predetermined area by the first nozzle group into image data used in each of the plurality of scans . first means, said plurality of times of using the second pattern group having a plurality of mask patterns corresponding to the scanning, the image data to be recorded in the predetermined region by the second nozzle group The use of the third pattern group having a second means for dividing the image data used in each of the plurality of scans, a plurality of mask patterns corresponding to the plurality of scans, said third nozzle group and a third means for dividing the image data to be recorded in the predetermined area in the image data used in each of the plurality of scans by corresponding to a predetermined scanning of the plurality of scans included in the first mask pattern, the predetermined said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to scanning included in the first pattern group the third mask pattern, respectively, different arrangement of the print permitting pixels, the first, the logical sum of the second and third mask patterns of these three mask patterns Low frequency components in the arrangement pattern of print permitting pixels obtained by performing, based on the correspondence between the time of use is equal to or less than the high frequency components.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A recording apparatus that scans a predetermined area of a recording medium a plurality of times with an inkjet recording head having at least a third nozzle group and records an image in the predetermined area, A first pattern group having a plurality of corresponding mask patterns is used to divide image data to be recorded in the predetermined area by the first nozzle group into image data used in each of the plurality of scans . first means, said plurality of times of using the second pattern group having a plurality of mask patterns corresponding to the scanning, the image data to be recorded in the predetermined region by the second nozzle group The use of the third pattern group having a second means for dividing the image data used in each of the plurality of scans, a plurality of mask patterns corresponding to the plurality of scans, said third nozzle group and a third means for dividing the image data to be recorded in the predetermined area in the image data used in each of the plurality of scans by corresponding to a predetermined scanning of the plurality of scans included in the first mask pattern, the predetermined said third pattern group corresponding to the second mask pattern and the predetermined scanning included in the second pattern group corresponding to scanning included in the first pattern group the third mask pattern, respectively, different arrangement of the print permitting pixels, and the first mask pattern and the second mask pattern of the third mask pattern The arrangement pattern of print permitting pixels obtained by physical sum, and low frequency components in a non-cycle, characterized in that less than the high frequency components.

Further, the first to form a first type of dots nozzle group and the second type of the second to form a dot nozzle group and the third type of dot third to form the recording head having at least a nozzle group, there is provided a data processing apparatus for generating image data used in each of the plurality of times of scanning with respect to a predetermined area of the recording medium, having a plurality of mask patterns corresponding to the plural scans using the first pattern group, by dividing the image data to be recorded in the predetermined area by said first nozzle group, in order to generate the divided image data to be recorded by each scanning of said plurality of times first means, by using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans are recorded in the predetermined area by said second nozzle group Third pattern having by dividing the can image data, second means for generating a divided image data to be recorded by each of the plurality of scans, a plurality of mask patterns corresponding to the plural scans A third means for generating divided image data to be recorded in each of the plurality of scans by dividing the image data to be recorded in the predetermined area by the third nozzle group using a group ; has the door, said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second contained in the second pattern group corresponding to the predetermined scan the third mask pattern contained in the mask pattern and the predetermined said third pattern group corresponding to scanning, each different arrangement of print permitting pixels, the first The low frequency components of the arrangement pattern of print permitting pixels obtained by the mask pattern logical product of said second mask pattern third mask pattern by performing the corresponding relation during use of the three mask patterns, low-frequency arrangement pattern of print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical product of the third mask pattern and the first mask pattern and the second mask pattern Fewer than components.

In another embodiment, the first nozzle group for forming the first type of dot, the second nozzle group for forming the second type of dot, and the third type of dot for forming the dot A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a print medium of a print head having at least a third nozzle group, wherein the plurality of masks correspond to the plurality of scans Using the first pattern group having a pattern , the divided image data to be recorded in each of the plurality of scans is generated by dividing the image data to be recorded in the predetermined area by the first nozzle group. a first means for, by using the second pattern group having a plurality of mask patterns corresponding to the plural scans, serial to the predetermined region by the second nozzle group By dividing the image data to be, first with a second means for generating a divided image data to be recorded by each of the plurality of scans, a plurality of mask patterns corresponding to the plural scans with 3 pattern group, by dividing the image data to be recorded in the predetermined area by the third nozzle group, the first for generating the divided image data to be recorded by each of the plurality of scans 3 and means, included in said plurality of predetermined first mask patterns included in the first pattern group corresponding to the scanning, the second pattern group corresponding to said predetermined scanning of the scan third mask patterns included in the third pattern group corresponding to the second mask pattern and the predetermined scanning, respectively, different arrangement of print permitting pixels Low-frequency arrangement pattern of print permitting pixels obtained by performing a logical sum of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using these three mask patterns components, arrangement pattern of print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical sum of said third mask pattern and the first mask pattern and the second mask pattern Less than the low frequency component.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A data processing apparatus for generating image data used in each of a plurality of scans of a predetermined area of a print medium of a print head having at least a third nozzle group, wherein a plurality of scan data corresponding to the plurality of scans Using the first pattern group having a mask pattern , the divided image data to be recorded in each of the plurality of scans is obtained by dividing the image data to be recorded in the predetermined area by the first nozzle group. using a first means for generating to the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the predetermined territory by the second nozzle group By dividing the image data to be recorded on, second means for generating a divided image data to be recorded by each of the plurality of scans, a plurality of mask patterns corresponding to the plural scans In order to generate divided image data to be recorded in each of the plurality of scans by dividing the image data to be recorded in the predetermined region by the third nozzle group using the third pattern group having and a third means, said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to the second mask pattern and the predetermined scanning contained, respectively, the sequence of print permitting pixels Becomes, the arrangement pattern of print permitting pixels obtained a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern by performing the corresponding relation during use of the three mask patterns low frequency components of the print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern less than the low frequency components of the arrangement pattern of print permitting pixels obtained by performing a logical sum of said first mask pattern and the second mask pattern 3 of the mask pattern in the corresponding relation during the use low frequency components of the arrangement pattern is logical in the first said mask pattern and the second mask pattern of the third mask pattern It is characterized in that it is less than the low-frequency component of the array pattern of the print permitting pixels obtained by performing the logical sum with a correspondence different from the correspondence at the time of use .

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A data processing apparatus for generating image data used in each of a plurality of scans of a predetermined area of a print medium of a print head having at least a third nozzle group, wherein a plurality of scan data corresponding to the plurality of scans Using the first pattern group having a mask pattern , the divided image data to be recorded in each of the plurality of scans is obtained by dividing the image data to be recorded in the predetermined area by the first nozzle group. using a first means for generating to the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the predetermined territory by the second nozzle group By dividing the image data to be recorded on, second means for generating a divided image data to be recorded by each of the plurality of scans, a plurality of mask patterns corresponding to the plural scans In order to generate divided image data to be recorded in each of the plurality of scans by dividing the image data to be recorded in the predetermined region by the third nozzle group using the third pattern group having and a third means, said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to the second mask pattern and the predetermined scanning contained, respectively, the sequence of print permitting pixels Becomes, the arrangement pattern of print permitting pixels obtained a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern by performing the corresponding relation during use of the three mask pattern The low frequency component has less characteristics than the high frequency component.

In yet another embodiment, a first nozzle group for forming a first type of dot, a second nozzle group for forming a second type of dot, and a third type of dot are formed. A data processing apparatus for generating image data used in each of a plurality of scans of a predetermined area of a print medium of a print head having at least a third nozzle group, wherein a plurality of scan data corresponding to the plurality of scans Using the first pattern group having a mask pattern , the divided image data to be recorded in each of the plurality of scans is obtained by dividing the image data to be recorded in the predetermined area by the first nozzle group. using a first means for generating to the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the predetermined territory by the second nozzle group By dividing the image data to be recorded on, second means for generating a divided image data to be recorded by each of the plurality of scans, a plurality of mask patterns corresponding to the plural scans In order to generate divided image data to be recorded in each of the plurality of scans by dividing the image data to be recorded in the predetermined region by the third nozzle group using the third pattern group having and a third means, said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to the second mask pattern and the predetermined scanning contained, respectively, the sequence of print permitting pixels Becomes, the arrangement pattern of print permitting pixels obtained logical sum of said first mask pattern and the second mask pattern 3 of the mask pattern by performing the corresponding relation during use of the three mask pattern The low frequency component has less characteristics than the high frequency component.
Further, in the mask pattern manufacturing method, the first nozzle group for forming the first type of dots thins out the image data to be recorded in the predetermined area of the recording medium, thereby the first pattern for the predetermined area. A first determination step of determining an arrangement of print permitting pixels in a first mask pattern for generating image data to be recorded in one scan among a plurality of scans of one nozzle group; One of a plurality of scans of the second nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the types of dots. A second determination step for determining the arrangement of print-allowable pixels in the second mask pattern for generating image data to be recorded in one scan, and a third type of dot Recording is performed in one scan out of a plurality of scans of the third nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the third nozzle group for forming. A third determination step for determining an arrangement of print permitting pixels in a third mask pattern for generating image data to be performed; and the first determination step includes a print permitting pixel in the second and third mask patterns. By changing the arrangement of the print permission pixels in the first mask pattern based on the arrangement of the first mask pattern, the low frequency of the print permission pixel arrangement pattern obtained by the logical product of the first, second and third mask patterns. Including a step of reducing a component, wherein the second determination step includes the second determination step based on the arrangement of the print permission pixels in the first and third mask patterns. A step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical product of the first, second, and third mask patterns by changing the arrangement of print permitting pixels in the mask pattern, In the third determination step, the first, second and second arrangements are changed by changing the arrangement of the print permitting pixels in the third mask pattern based on the arrangement of the print allowance pixels in the first and second mask patterns. And a step of reducing a low-frequency component of the arrangement pattern of the print permitting pixels obtained by the logical product of the three mask patterns.
In another embodiment, the method of manufacturing a mask pattern, wherein the predetermined area is obtained by thinning out image data to be recorded in a predetermined area of a recording medium by a first nozzle group for forming a first type of dot. A first determining step of determining an arrangement of print permitting pixels in a first mask pattern for generating image data to be printed in one of a plurality of scans of the first nozzle group with respect to The second nozzle group for forming the second type of dots thins out the image data to be recorded in the predetermined area of the recording medium, thereby performing a plurality of scans of the second nozzle group with respect to the predetermined area. A second determination step for determining the arrangement of print-allowable pixels in the second mask pattern for generating image data to be recorded in one scan, and a third type of One scan out of a plurality of scans of the third nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the third nozzle group for forming the nozzle A third determination step for determining the arrangement of the print permitting pixels in the third mask pattern for generating the image data to be recorded in the first and second determination steps are the recording in the second and third mask patterns. By changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the allowance pixels, the arrangement pattern of the print permitting pixels obtained by the logical sum of the first, second and third mask patterns is changed. Including a step of reducing a low-frequency component, wherein the second determination step is performed based on an arrangement of print permission pixels in the first and third mask patterns. A step of reducing the low frequency component of the layout pattern of the print permitting pixels obtained by the logical sum of the first, second, and third mask patterns by changing the layout of the print permitting pixels in the second mask pattern. And the third determining step changes the arrangement of the print permitting pixels in the third mask pattern on the basis of the arrangement of the print permitting pixels in the first and second mask patterns. The method includes a step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical sum of the second and third mask patterns.
In yet another embodiment, a mask pattern manufacturing method is provided, wherein the predetermined data is obtained by thinning out image data to be recorded in a predetermined area of a recording medium by a first nozzle group for forming a first type of dot. A determination step for determining an arrangement of print permitting pixels in the first mask pattern for generating image data to be printed in one of a plurality of scans of the first nozzle group with respect to the region; In the determining step, the second nozzle group for the predetermined area is thinned out by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. An arrangement of print permitting pixels in the second mask pattern for generating image data to be printed in one of the plurality of scans, and a third One of a plurality of scans of the third nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by a third nozzle group for forming a kind of dot. By changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the third mask pattern for generating image data to be recorded in the scanning of the first, The low frequency component of the arrangement pattern of the print permission pixels obtained by the logical product of the mask pattern, the second mask pattern, and the third mask pattern is reduced.
In yet another embodiment, a mask pattern manufacturing method is provided, wherein the predetermined data is obtained by thinning out image data to be recorded in a predetermined area of a recording medium by a first nozzle group for forming a first type of dot. A determination step for determining an arrangement of print permitting pixels in the first mask pattern for generating image data to be printed in one of a plurality of scans of the first nozzle group with respect to the region; In the determining step, the second nozzle group for the predetermined area is thinned out by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. An arrangement of print permitting pixels in the second mask pattern for generating image data to be printed in one of the plurality of scans, and a third One of a plurality of scans of the third nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by a third nozzle group for forming a kind of dot. By changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the third mask pattern for generating image data to be recorded in the scanning of the first, The low frequency component of the arrangement pattern of the print permission pixels obtained by the logical sum of the mask pattern, the second mask pattern, and the third mask pattern is reduced.

  According to the present invention, it is possible to reduce image quality deterioration due to beading caused by grains in the middle of divided recording.

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

  Embodiments of the present invention relate to the manufacture of a mask for generating binary dot recording data used in each scan of multi-pass recording or the mask pattern thereof. Before describing some specific embodiments of the present invention, a configuration for manufacturing a mask pattern or generating dot recording data using the mask pattern will be described. Here, “dot recording data” in this specification means data indicating dot recording.

  FIG. 1 is a block diagram mainly showing hardware and software configurations of a personal computer (hereinafter also simply referred to as a PC) functioning as a host device according to an embodiment of the present invention. This host device generates image data to be recorded by the printer 104.

  In FIG. 1, a PC 100 as a host computer operates 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 such as creating image data to be displayed on the monitor 106.

  The printer driver 103 draws various drawing command groups (image drawing command, text drawing command, graphics drawing command, etc.) issued from the application software 101 to the OS 102, and finally outputs binary image data used by the printer 104. Generate. Specifically, binary image data for each of a plurality of ink colors used in the printer 104 is generated by executing image processing described later with reference to FIG.

  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 the process according to the software program stored in the hard disk 107 or the ROM 110, and the RAM 109 is used as a work area when the process is executed.

  The printer 104 according to the present embodiment is a so-called serial printer that performs recording by scanning a recording medium that ejects ink with respect to a recording medium and ejecting ink during that time. The recording head is prepared corresponding to each of the C, M, Y, and K inks, and can be scanned with respect to a recording medium such as a recording sheet by being mounted on the carriage. Each recording head has an ejection port array density of 1200 dpi, and ejects 3.0 picoliter of ink droplets from each ejection port. Further, the number of ejection ports of each recording head is 512.

  The printer 104 is a recording device that can execute multi-pass recording. For this purpose, a mask described in each embodiment described later is stored in a predetermined memory, and at the time of printing, binary divided image data is generated using a mask determined for each scanning and ink color. I do.

  Further, when the mask pattern is not stored in a predetermined memory in advance and the PC 100 functions as a data processing device for mask manufacture, a mask manufacturing process described in each embodiment described later is executed. The manufactured mask data is stored in a predetermined memory of the printer 104.

  FIG. 2 is a block diagram for explaining main data processing steps in the PC 100 and the printer 104 when recording is performed by the printer 104 in the configuration shown in FIG. As described above, the ink jet printer 104 according to the present embodiment performs recording with ink of four colors of cyan, magenta, yellow, and black, and includes a recording head J0010 that ejects ink of these four colors.

  A user can create image data to be recorded by the printer 104 via the application 101 of the host PC 100. When recording, the image data created by the application 101 is transferred to the printer driver 103.

  As the processing, the printer driver 103 executes a pre-stage process J0002, a post-stage process J0003, a γ correction J0004, a binarization process J0005, and a print data creation J0006. In the pre-stage process J0002, color gamut conversion is performed to convert the color gamut of the display device that displays the screen by the application into the color gamut of 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 a three-dimensional LUT. Next, in post-processing J0003, the color that reproduces the converted color gamut is separated into ink colors. Specifically, a process for obtaining 8-bit data C, M, Y, and K corresponding to the combination of inks for reproducing the colors represented by the 8-bit data R, G, and B obtained in the preceding process J0002 is performed. . In γ correction J0004, γ correction is performed on each of the CMYK data obtained by color separation. Specifically, conversion is performed so that each of the 8-bit data CMYK obtained by color separation is linearly associated with the gradation characteristics of the printer. Next, in the binarization process J0005, a quantization process is performed to convert the 8-bit data C, M, Y, and K subjected to the γ correction into 1-bit data C, M, Y, and K, respectively. Finally, in the print data creation process J0006, print data is created by attaching print control data or the like to binary image data containing binarized 1-bit data C, M, K, and Y. Here, the binary image data includes dot recording data indicating dot recording and dot non-recording data indicating non-recording of dots. The print control data includes “recording medium information”, “recording quality information”, and “other control information” such as a paper feed method. The print data generated as described above is supplied to the printer 4.

  On the other hand, the printer 104 performs a mask data conversion process J0008 on binary image data included in the input print data. In the mask data conversion process J0008, an AND process is applied to the input binary image data using a mask pattern which is stored in advance in a predetermined memory of the printer and described in each embodiment described later. As a result, binary divided image data used in each scan in multipass printing is generated, and the timing at which ink is actually ejected is determined. The binary divided image data includes dot recording data and dot non-recording data.

  FIG. 3 is a perspective view showing the inkjet printer 104. The carriage M4000 includes a recording head and an ink tank H1900 for supplying each ink of cyan (C), magenta (M), yellow (Y), and black (K) to the X direction (main scanning direction). ), And each nozzle of the recording head ejects ink at a predetermined timing based on the binary divided image data. When one main scan of the recording head is completed, the recording medium is conveyed by a predetermined amount in the Y direction (sub-scanning direction) in the figure. By alternately repeating the recording main scanning and the sub scanning described above, images by multipass recording are sequentially formed.

  In the following, a mask pattern manufacturing method used or manufactured in the above-described recording system and distinguished by the ratio of the number of scans (hereinafter also referred to as “pass”) to complete a multi-pass recording image and a print-allowable pixel, and thereby, Several embodiments of mask patterns are described.

[Embodiment 1: 100% uniform mask for 2-pass printing]
(1) Outline of the present embodiment This embodiment is a two-pass multi-pass that completes an image in two scans for each ink of cyan (C), magenta (M), yellow (Y), and black (K). Regarding recording. In addition, the mask used for each of a plurality of (two in the present embodiment) scans (hereinafter referred to as “one-plane mask”) for each of the ink colors used for the two-pass printing is only well dispersed. In addition, a combination of arbitrary plural planes of these masks is also well dispersed.

  FIG. 4 is a diagram schematically illustrating a recording head, a mask pattern, and a recording medium in order to explain two-pass recording. In this figure, for simplification of illustration and description, a case where two-pass printing is performed with three colors of cyan, magenta, and yellow will be described. The same applies to the mask described below.

  The cyan, magenta, and yellow color nozzle groups are divided into two groups, a first group and a second group, and each group includes 256 nozzles. Each group is associated with the mask pattern (C1, C2, M1, M2, Y1, Y2) of this embodiment, and the size of each mask pattern in the sub-scanning direction (conveyance direction) is the number of nozzles in each group. The same as 256 pixels. The size in the scanning direction is also 256 pixels. Also, the two mask patterns (C1 and C2, or M1 and M2, or Y1 and Y2) corresponding to the same color ink nozzle group are complementary to each other, and when these are superimposed, an area corresponding to 256 × 256 pixels. The record is completed.

  Each color nozzle group ejects ink onto a recording medium while scanning in a direction substantially perpendicular to the nozzle arrangement direction (“head scanning direction” indicated by an arrow in the figure). In this example, C, M, and Y ink ejection is performed on each region. Each time scanning is completed, the recording medium is conveyed by the width of one group (here, 256 pixels) in a direction orthogonal to the scanning direction ("recording medium conveyance direction" indicated by an arrow in the figure). The Thereby, an image having a size corresponding to the width of each group of the recording medium is completed by scanning twice.

  More specifically, in the first scan, for the area A on the recording medium, the first group of the C nozzle group, the first group of the M nozzle group, and the first group of the Y nozzle group are used in the order of CMY. Recording is done. In the first scan, the mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used for the region A.

  Next, in the second scan, the second group of the C nozzle group, the second group of the M nozzle group, and the second group of the Y nozzle group are arranged in the order of YMC with respect to the area A where the printing in the first scan is completed. And the remaining recording is performed, and for the unrecorded region B, the first group of the C nozzle group, the first group of the M nozzle group, and the first group of the Y nozzle group are used in the order of YMC. Recording is done. Accordingly, in the second scan, the mask pattern C2, the mask pattern M2, and the mask pattern Y2 are used for the region A, and the mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used for the region B. Further, by continuing such an operation, recording is performed for each area in the order of C1M1Y1Y2M2C2 or the order of Y1M1C1C2M2Y2.

  FIG. 5 is a schematic diagram conceptually illustrating the mask used in the two-pass printing described in FIG. 4 and its complementary relationship. In FIG. 5, P0001 indicates a recording head of one color among C, M, and Y shown in FIG. 4, and here, it is shown as having eight nozzles for simplification of illustration. The nozzles are divided into first and second groups as described above, and each nozzle group includes four nozzles. P0002A and P0002B indicate mask patterns corresponding to the nozzle rows of the first and second groups, respectively. That is, the mask pattern P0002A (lower pattern in the figure) used in the first scan and the mask pattern P0002B (upper pattern in the figure) used in the second scan. Each of these becomes a mask of one plane. In each mask pattern, the printable pixels are shown in black, and the non-printable pixels are shown in white. The mask pattern P0002A for the first scan and the mask pattern P0002B for the second scan are complementary to each other. Therefore, when these are overlaid, the print permitting pixels fill the entire 4 × 4 area. Note that the pattern shown in the figure is shown as a pattern different from the mask pattern of the present embodiment shown below for easy explanation. In this figure, the arrangement of the print permitting pixels is zigzag and reverse zigzag, but the mask pattern having such arrangement is not included in the scope of the present invention.

  Here, “recording allowable pixels” and “non-recording allowable pixels” are defined. As described above, the “recording allowable pixel” is a pixel that allows dot recording (ink ejection). If the binary image data corresponding to the recording pixel is data indicating ejection, dot recording is performed, and if it is data indicating non-ejection, dot recording is not performed. On the other hand, “non-recording-permitted pixels” are pixels that do not permit recording regardless of binary image data. Accordingly, even if the binary image data corresponding to the non-recording-permitted pixels is data indicating ink ejection, recording is not performed.

  P0003 and P0004 indicate images that are completed by two-pass printing, with the dot arrangement constituting them. Note that this image is a so-called solid image in which dots are formed on all pixels for the sake of easy explanation. Therefore, the arrangement of the print allowable pixels of the mask P0002 used for generating the dot print data is reflected as it is. The dot arrangement is shown. In the first scan, the first group of dot recording data is generated using the mask pattern P0002A. The recording medium is conveyed by the width of the nozzle group in the direction of the arrow in the figure. In the next second scan, the first group of dot recording data for the area shifted by the carry amount is generated using the mask pattern P0002A, and the second group of dots for the area recorded in the first group. The recording data is generated using the mask pattern P0002A. The image is completed by the two recording scans.

  FIG. 6 illustrates a case where the two-pass printing described with reference to FIGS. 4 and 5 is performed using C, M, and Y inks (black K is omitted for simplicity of description as described above). FIG. As shown in FIG. 6, using the masks C1, M1, Y1, C2, M2, and Y2, the inks of C, M, and Y are respectively applied in two scans (in the example shown in FIG. 6, forward scan and backward scan). Discharge and record a color image.

  FIG. 6A shows a state in which an image of an area recorded in the order of forward scanning (scanning in the right direction in FIG. 4) and backward scanning (scanning in the left direction in FIG. 4) is completed. Is. In the forward scan, which is the first scan, a cyan image is first recorded based on the dot recording data of the cyan divided image data generated using the first-pass cyan mask (mask C1). Based on the dot recording data of the divided image data generated using the magenta and yellow masks (masks M1 and Y1) in the same scan, the magenta image is superimposed on the cyan image recorded before that, and further the yellow image Are sequentially recorded on the cyan and magenta images recorded before that. In the reverse scan, which is the second scan after the recording medium is conveyed by a predetermined amount, similarly, based on the respective yellow, magenta and cyan dot recording data generated using the masks Y2, M2, and C2, It is recorded over the previously recorded image.

  On the other hand, FIG. 6B shows a state in which an image of an area recorded in the order of backward scanning (scanning in the left direction in FIG. 4) and forward scanning (scanning in the right direction in FIG. 4) is completed. It is shown. In the reverse scan, which is the first scan, first, a yellow image is recorded based on the dot recording data of the yellow divided image data generated using the first-pass yellow mask (mask Y1). Based on the dot recording data of the divided image data generated by using the magenta and cyan masks (masks M1 and C1) in the same scan, the magenta image is superimposed on the yellow image recorded earlier and further the cyan image. Are sequentially recorded on the yellow and magenta images recorded earlier. In the forward scan, which is the second scan after the recording medium is transported by a predetermined amount, similarly, based on the cyan, magenta, and yellow dot recording data respectively generated using the masks C2, M2, and Y2, It is recorded over the previously recorded image.

  In this way, when performing two-pass printing that uses three colors of C, M, and Y to complete an image in two scans, an image obtained by combining a cyan image in the first pass and a magenta image in the first pass, There is an intermediate image in which an image for each mask plane is superimposed, such as an image obtained by further superimposing the first pass yellow image on this image, and an image obtained by superimposing the second pass yellow image on the first pass image. . In such an intermediate image, the grain described in FIGS. 86A to 86C may occur. Especially when the amount of ink applied per unit time or the amount of ink applied per unit area of the recording medium increases as the recording speed increases, the density increases, and the type of ink used diversifies. The occurrence of this grain in the intermediate image becomes remarkable. Then, the grain generated in the intermediate image is visually recognized as beading such as an irregular mottled pattern in an image that is fixed and completed as it is.

  In the present embodiment, in order to avoid the occurrence of grains in such an intermediate image, the arrangement of the print permitting pixels when the masks of the respective planes are overlapped has a characteristic that there are few low frequency components. Since there are few low frequency components, the deviation of the ink dots in the intermediate image at each stage can be kept small. Further, as an important characteristic, in order to prevent interference with image data and other noises, an aperiodic pattern characteristic is provided. That is, the arrangement of the print permitting pixels when the plane masks are superposed is aperiodic and has a low frequency component and has excellent dispersibility. As a result, the proximity or adjacency of dots in the intermediate image at each stage leading to the completion of the image and the overlap of dots are eliminated as much as possible. Further, even if dot overlap and adjacency cannot be excluded, such an overlap portion is assumed to have high dispersibility.

  The “low frequency component” refers to a component on the lower frequency side than half of the spatial frequency region where the frequency component (power spectrum) exists.

(2) Mask Manufacturing Method The mask manufacturing method according to the embodiment of the present invention can be broadly divided into a method for simultaneously generating a mask for a plurality of passes (simultaneous generation) and a method for generating a mask sequentially for each pass (for each pass). Can be implemented in one of two ways. In the former simultaneous generation method, a mask for (pass number for completing an image (number of scans) -1) passes is generated at the same time, and the mask for the remaining one pass is a mask for which the print allowable pixels are simultaneously generated. It is generated so as to be exclusive to the arrangement of the print permitting pixels. The latter generation method for each pass is a method in which a mask is sequentially generated for each of a plurality of passes (scans) for completing an image, and the mask for the last pass is the same as the former method in which printable pixels are set. It is generated so as to be exclusive to the arrangement of the print permitting pixels of the mask generated so far. In the case of this embodiment, since it is a mask used for two-pass printing, simultaneous generation and generation for each pass are the same.

  Furthermore, for each of the above two generation methods, as a method of determining the arrangement of the print permitting pixels specifically, all the print permitting pixels of the mask are set in a predetermined arrangement in advance, and these are moved and distributed throughout the generated mask. A method of increasing the image quality (hereinafter referred to as “placement moving method”), a method of disposing the print permitting pixels one by one while increasing the dispersibility in the entire generated mask (hereinafter referred to as “sequential placement method”), Can be executed.

  FIG. 7 is a diagram conceptually showing a method for manufacturing a mask used in the two-pass printing of the present embodiment.

  As Step 1 of mask generation, masks C1, M1, and Y1 of the respective planes used in the first pass are generated. In step 2, the masks C2, M2, Y2 of the planes used for the second pass are generated so as to have a complementary relationship with the masks C1, M1, Y1 of the first pass. That is, the mask for the second pass is generated for each color so that the arrangement of the print permitting pixels has an exclusive relationship with the arrangement of the print permitting pixels of the first pass mask.

  In the above mask manufacturing method, the arrangement of the print permitting pixels for the first-pass masks C1, M1, and Y1 is performed as follows. First, the arrangement movement method will be described, and then the sequential arrangement method will be described. Of course, any of these arrangement methods may be used.

Arrangement Movement Method FIG. 8 is a flowchart showing the arrangement determination process by the arrangement movement method of the print permitting pixels of the mask used in the two-pass printing of this embodiment.

  First, in step S801, 50% density images of C, M, and Y corresponding to the sizes of the planes of the masks C1, M1, and Y1 in the first pass are acquired. In step S802, each image is binarized using a binarization method such as an error diffusion method. Accordingly, it is possible to obtain an initial arrangement in which the recording allowable pixels whose 1-bit data is “1” are arranged in 50% of the entire mask pixels for each of the masks C1, M1, and Y1. Note that the reason why the initial arrangement of the print permitting pixels is obtained by using this binarization method is that an arrangement with good dispersibility in the initial state can be obtained to some extent according to the binarization method used. This is because the calculation time or convergence time until the final placement determination can be shortened. In other words, the method of obtaining the initial arrangement is not essential in applying the present invention. For example, in the mask plane, the initial arrangement is such that the print permitting pixels whose 1-bit data is “1” are randomly arranged. May be.

Next, in step S803, the repulsive potential is calculated for all the print permitting pixels of the respective planes of the masks C1, M1, and Y1 obtained as described above. In particular,
(I) A repulsive force corresponding to the distance is applied between the recording allowable pixels in the same plane.
(Ii) Further, a repulsive force is given to the recording allowable pixels between different planes.
(Iii) Apply different repulsive forces between the same plane and different planes.
(Iv) Recognizing the overlap of print permitting pixels on different planes, the overlap of the print permitting pixels (two print permitting pixel overlaps, three record permitting pixel overlaps,...) Also gives a repulsive force according to the combination.

  FIG. 9 is a diagram schematically showing a function of the basic repulsive potential E (r) according to the present embodiment.

  As shown in the figure, the repulsive function defined in this embodiment has a repulsive range up to r = 16 (pixels: pixels of a mask in which print permitting pixels are arranged). By using a potential that decays with such a distance, basically, when the recording allowable pixels are arranged close to each other, the energy is high, that is, an unstable state. It can be prevented from being selected.

  It is more desirable to determine the shape of the repulsive force based on the ratio of the print allowable pixels to the entire mask pixels.

  In addition, when recording is performed using a plurality of colors of ink, ink dots are arranged over the position where ink dots can be arranged (in the case of resolution 1200, there are 1200 × 1200 possible positions in one inch square). Therefore, when calculating the repulsive potential for each print permitting pixel, it is considered that the record permitting pixel overlaps the record permitting pixel. For this reason, a function is defined so as to have a finite repulsive potential at r = 0. As a result, it is possible to perform dispersion in consideration of the overlap of the print allowable pixels.

  In the present embodiment, the repulsive potential of αE (r) is set for the print permitting pixels on the same plane, βE (r) is set for the print permitting pixels between different planes, and γs (n) E (r) is set for the overlapped print permitting pixels. Give the calculation. In other words, the potential due to the presence of a certain print-permitted pixel is the repulsive potential for a print-permitted pixel in the same plane, a print-permitted pixel in a different plane, and a print-permitted pixel in which different planes overlap. Is added.

  Although the size of the mask pattern is finite (in this embodiment, the size is 256 × 256 pixels), the potential calculation uses a periodic boundary condition as if the same pattern of 256 × 256 pixels is repeated. . Therefore, the left end of the mask pattern is adjacent to the right end, and the bottom is adjacent to the top.

  In the above repulsive potential, the coefficients α, β, and γ are weighting coefficients, and in this embodiment, values of α = 3, β = 1, and γ = 3 are used. The dispersibility of the print-allowed pixels is affected by the values of α, β, and γ. The values of α, β, and γ can be obtained, for example, by performing an experiment in practice and optimizing with reference to a recorded image recorded using a mask.

  Further, the coefficient s (n) is a coefficient that is further integrated in addition to γ in order to disperse the overlapping recordable pixels. The coefficient s (n) is set to a value corresponding to the number of overlaps in order to disperse these recordable pixels as the overlap increases. According to the experiment of the present inventor, good results regarding dispersion can be obtained by using s (n) obtained by either of the following two expressions.

  That is, when n is the number of overlaps, the sum of the number of combinations is s (n). Specifically, the print permitting pixels that overlap with the target record permitting pixel for calculating the repulsive force (at the same position in the same plane or different planes) are checked, and the record permitting pixel located at the distance r from the target record permitting pixel is checked. In this case, the number of common overlaps of the recording allowable pixel and the recording allowable pixel of another plane that overlaps at the same position as the target recording allowable pixel and the recording allowable pixel that overlaps similarly at the pixel of each plane at the distance r is n. And Then, consider the repulsive force caused by the overlapping print permitting pixels between these two pixels.

  In this case, for example, n = 3 when considering an example in which there are print-allowed pixels in common in the first plane, the second plane, and the third plane between certain two pixels. Then, a repulsive force caused by the overlap of the three recordable pixels is applied between these pixels. Here, when considering the repulsive force caused by the overlap of the three print permitting pixels, it is considered that the overlap of the two print permitting pixels and the repulsive force of one record permitting pixel act in a multiplexed manner. In other words, if the third plane is not considered, it can be considered as an overlap of the two print-permitted pixels of the first plane and the second plane, and if the second plane is not considered, the first plane and the third plane are not overlapped. It can also be considered as an overlap of two recordable pixels. If the first plane is not considered, it is considered that the second plane and the third plane overlap. In order to calculate the multiple effect of overlapping such print permitting pixels, the repulsive force due to the combination of overlaps is defined and s (n) as described above is used. According to this, it has been experimentally confirmed that it is possible to obtain a recording allowable pixel arrangement with good dispersibility.

  Referring to FIG. 8 again, in step S803, the total energy obtained by summing up the repulsive potentials of all the print permitting pixels is obtained. And the process which attenuates this total energy is performed.

  In this process, the print permitting pixel is moved to the pixel having the lowest repulsive potential among the pixels having the distance r within 4 in order for all the print permitting pixels. By repeating such processing (step S804), the total energy, which is the total value of the repulsive potentials of all the print permitting pixels, is decreased. That is, the process in which the total energy gradually decreases is a process in which the disposition of the print permitting pixels sequentially increases the dispersibility, that is, a process in which the low frequency components of the record permitting pixel disposition are sequentially decreased.

  In step S805, the reduction rate of the total energy in step S804 is calculated, and if it is determined that it is equal to or less than a predetermined value, the energy attenuation process is terminated. The predetermined value can be obtained as a reduction rate at which an image in which low frequency components are appropriately suppressed can be recorded based on the result of actual printing.

  Finally, in step S806, each plane in which the rate of decrease in total energy is equal to or less than a predetermined value as described above is set as the first-pass masks C1, M1, and Y1. Furthermore, masks C2, M2, and Y2 for the second pass are set with the print-permitted pixel positions at positions exclusive to the print-permitted pixel positions of these masks.

  In this embodiment, it is determined whether or not the reduction rate of the total energy is equal to or less than a predetermined value in step S805. If the reduction rate is equal to or less than the predetermined value, the process proceeds to step S806. However, the present embodiment is not limited to this example. For example, it may be determined in step S805 whether the total energy has become a predetermined value or less, and when the total energy has become a predetermined value or less, the process may proceed to step S806.

  FIGS. 10A to 10D are diagrams schematically illustrating the above-described repulsive potential calculation and total energy attenuation processing. Specifically, the three planes C1, M1, and Y1 according to the present embodiment are shown in a perspective view, and in particular, the movement of a print permitting pixel is shown in a plan view. Here, the smallest square represents a mask pixel, and overlapping pixels in the overlap of the three planes correspond to the same pixel position between the planes.

  FIG. 10A is a diagram for explaining that potential is applied (increased) by repulsive force between the print permitting pixels when the print permitting pixels exist in the same plane. The example shown in the figure is an example in which one recording allowable pixel exists in a pixel separated by a distance r in the same plane as the recording allowable pixel Do of the target pixel of the plane C1. In this case, α = 3 is applied, and recording allowable A potential of 1 × αE (r) is added as the potential of the pixel Do.

  FIG. 10B illustrates the repulsive potential applied in relation to the two print permitting pixels when the print permitting pixels exist in a plane (plane M1, Y1) different from the target recording permitting pixel Do. FIG. Because of the relationship with the print permitting pixels between different planes, β = 1 is applied, and the potential of 2 × βE (r) corresponding to 2 print permitting pixels is added as the potential of the print permitting pixel Do.

  FIG. 10 (c) shows the above two cases, where there are print permitting pixels in different planes compared to the case where print permitting pixels exist in the same plane, and there are print permitting pixels in the same pixel in different planes. FIG. 6 is a diagram for explaining a repulsive potential that is applied in relation to the print permitting pixels when there is an overlap of the print permitting pixels. In addition to the cases shown in FIGS. 10A and 10B, the presence of a print-allowed pixel in the same pixel of the plane Y1 that is different from the plane C1 of the print-allowable pixel Do of interest allows the repulsive potential 1 × αE (r) of the same plane. And the repulsive potential 1 × βE (0) due to one recording allowance pixel in different planes of the same pixel and the repulsive potential 2 × βE (r) due to two recording allowance pixels in different planes, the number n = 2 In this case, a repulsive potential γs (2) × E (r) due to overlap is applied, where γ = 3 is applied. As a result, the total repulsive potential due to the presence of the target recording allowable pixel Do in the recording allowable pixel arrangement shown in FIG. 10C is 1 × βE (0) + 1 × αE (r) + 2 × βE (r) + γs. (2) × E (r).

  FIG. 10D is a diagram for explaining that the total repulsive potential of the print permitting pixel changes by moving the print permitting pixel Do in the print permitting pixel arrangement shown in FIG. As shown in FIG. 10D, when the recording allowable pixel Do (recording allowable pixel of the plane C1) moves to a pixel adjacent to the same plane, the total repulsive potential due to the presence of the recording allowable pixel Do is the distance. Changes to .beta.E (1) + 1.times..alpha.E (r2) + 2.times..beta.E (r2). Then, the total repulsive potential 1 × βE (0) + 2 × αE (r) + 1 × βE (r) + γs (2) × E (r) in the case of the print allowable pixel arrangement shown in FIG. By comparing the total repulsive force resulting from the movement of the recording allowable pixel Do of 10 (d), the change in the total repulsive potential before and after the movement can be known.

  In the above description, the sum of the repulsive potentials is obtained by calculating the sum of the energy of the recording allowable pixels of three pixels when the two pixels or the recording allowable pixels are moved. In fact, it is a matter of course that it is obtained as an integral of the repulsive potential based on the relationship with the print permitting pixels including the print permitting pixels of other pixels that may exist other than these print permitting pixels. .

  As shown in FIGS. 10A to 10C, among the print permitting pixels for which the total repulsive potential is calculated, for example, when the print permitting pixel Do has the largest total repulsive potential, FIG. ), The change in repulsive potential before and after the movement is obtained, and the recording allowable pixel Do is moved to the pixel having the lowest total repulsive potential before and after the movement. By repeating such processing, the total energy of the entire three planes can be reduced. That is, the print permitting pixel distribution is an arrangement in which the low-frequency component is small and is well distributed in the overlap of the three plane masks.

  In addition, since the print permitting pixels are well dispersed in the overlap of the three-plane masks C1, M1, and Y1, the mask permitting pixels C2, M2, and Y2 that are complementary to these masks are also excellent in print permitting pixels. It will be distributed. Further, the distribution of the print permitting pixels in the overlap of an arbitrary number (2, 3, 4, or 5) of these 6 planes is also well distributed with few low frequency components. In the case of the present embodiment, for the area where the images are recorded in the order of reciprocation, the first pass mask C1, the first pass mask M1, the first pass mask Y1, the second pass mask Y2, and the second pass. The mask M2 and the mask C2 in the second pass are used so that the mask patterns overlap each other and printing is performed. Therefore, the intermediate image is “the first pass C + 1 pass M”, “the first pass C + 1 pass M + 1 pass Y”, “the first pass C + 1 pass M + 1 pass Y + 2 pass. "Y of the first pass", "C of the first pass, C + 1 pass, M + 1 pass, Y + 2 pass, Y + 2 pass M", "1st pass, C + 1 pass, M + 1 pass, Y + 2 pass, Y + 2 pass. The distribution of each ink dot of “M + 2nd pass C” has few low frequency components and excellent dispersibility. Similarly, for the area where the images are recorded in the order of return, the first pass mask Y1, the first pass mask M1, the first pass mask C1, the second pass mask C2, and the second pass mask. Recording is performed by using the mask patterns so as to overlap each other in the order of M2 and the second-pass mask Y2. Accordingly, the intermediate image is “M of the first Y + 1 pass”, “M of the first Y + 1 pass of the M + 1 pass of C”, and “the first pass of the Y + 1 pass of the M + 1 pass of the C + 1 pass. Eye C ”,“ Y + 1 pass M + 1 pass C + 1 pass C + 2 pass C + 2 pass M ”,“ 1 pass Y + 1 pass M + 1 pass C + 2 pass C + 2 pass The distribution of each ink dot of “M + 2nd pass Y” has few low frequency components and excellent dispersibility. The dots recorded by the dot recording data of each pass generated using such a mask are also well dispersed. That is, as described above, since the low-frequency component of the arrangement pattern of the print permitting pixels of the mask is small, the dot arrangement pattern recorded using the mask is the dot arrangement in the original image before mask processing. There will be no bias in the pattern. That is, each dot pattern recorded using the mask of each pass also has a low frequency component and good dispersibility like the mask pattern.

  As a result, from the relative relationship between the ink and the recording medium, even if the ink does not sufficiently penetrate at the intermediate image stage, the ink dots are dispersed, so that the inks that are insufficiently penetrated The probability of making grains by contact is low, and so-called beading due to grains can be suppressed. Even if grains are generated, the distribution of these grains is excellently distributed, so that the influence of the grains on the quality of the recorded image can be reduced.

  Thus, in consideration of the fact that ink penetration does not always have to be performed at the intermediate image stage as a result, in the printer 104, the recording time difference between the planes, that is, the ejection time difference can be shortened. It becomes. For example, the carriage speed or ejection frequency can be increased, or the number of passes in multi-pass printing is set to 4 passes in consideration of sufficient ink penetration, for example. It becomes possible.

  Although the above-described arrangement movement method is applied to the case of applying to the three-plane mask used in the first pass among the two-pass masks, this method is not limited to this mode, and is applied to all planes. Thus, the arrangement of the recording allowable pixels may be determined. In the case of a mask used for two-pass printing according to the present embodiment, the arrangement movement method may be applied to a six-plane mask for two passes of C, M, and Y, respectively. In this case, it is assumed that the range in which the print permitting pixels are moved is not limited to the neighboring pixels, but the movement of replacing the arranged pixels in relation to the print permitting pixels of other planes is allowed. Specifically, for example, a print permitting pixel arranged in a pixel of another plane corresponding to the moved pixel is moved to a pixel where the record allowance pixel of the same plane is not arranged. Is moved to a pixel corresponding to the pixel having the former recordable pixel in the same plane. As a result, the arrangement relationship of the print permitting pixels in all the planes related to the calculation of the repulsive potential is changed, and the replacement movement that minimizes the potential energy is possible.

Sequential Arrangement Method As described above, this method is a method in which the print permitting pixels are sequentially arranged in a portion of the mask plane where the record permitting pixels are not yet arranged.

  FIG. 11 is a flowchart showing the arrangement determination process of the print permission pixels by the sequential arrangement method of the present embodiment.

  The process shown in FIG. 11 is to arrange 50% print permitting pixels on each plate by sequentially arranging print permitting pixels one by one on three planes and repeating that. First, in step S1101, when a print permitting pixel is arranged, a repulsive potential generated between the print permitting pixel and the print permitting pixel already arranged in each plane of the masks C1, M1, and Y1 is calculated. .

  The calculation of the repulsive potential itself is the same as that described in the above-described arrangement movement method. The difference will be described with reference to the examples shown in FIGS. 10A to 10C, for example. Unlike the above-described arrangement movement method, the recording allowable pixels Do already have the pixels shown in FIG. Instead, when it is assumed that a new print permitting pixel Do is placed, the repulsive potential is calculated based on the relationship with the print permitting pixels already arranged and on the same plane C1 and different planes M1 and Y1. As is clear from the above, in the first stage where no print permitting pixels are arranged yet, the repulsive potential is the same regardless of the print permitting pixels.

  Next, in step S1102, the mask pixel having the minimum potential energy is determined among the repulsive potentials calculated when it is placed on each mask pixel. In step S1103, it is determined whether there are a plurality of mask pixels having the minimum energy. If there are a plurality of pixels, a mask pixel is determined from the plurality of pixels using a random number in step S1107. In the present embodiment, the pixel having the minimum energy is determined under the condition that it is not placed on the pixel where the print permitting pixel is already placed in the same plane. Depending on the parameters such as weighting coefficient and repulsive potential function, energy may be minimized when recoiling on the same plane in the calculation of repulsive potential due to the relationship with the recordable pixels of other planes, etc. In this case, the mask is for prohibiting overlap because only one print permitting pixel is allowed for one mask pixel.

  In step S1104, a print-allowed pixel is placed on the mask pixel having the determined minimum potential energy. That is, the mask data of the pixel is set to “1”.

  In step S1105, it is determined whether or not one recordable pixel image is arranged for each of the C, M, and Y planes. If not, the process from step S1101 is repeated.

  When the print permitting pixels are arranged one by one in this order in the order of planes C1, M1, and Y1, it is determined in step S1106 whether or not the print permitting pixels are arranged up to 50% with respect to all the mask pixels of each of the three planes. . If the printable pixels are not arranged up to 50% in each plane, the processing from step S1101 is repeated. Then, when 50% of print permitting pixels are arranged in all three planes, this processing is terminated. When the first-pass masks C1, M1, and Y1 are set as described above, the masks C2, M2, and Y2 that are complementary to these are subsequently set.

  Also by the sequential placement method described above, a mask having the same characteristics as the placement movement method described above can be obtained. That is, the three-plane masks C1, M1, and Y1 according to the sequential arrangement method have the print permitting pixels well dispersed in the overlap. As a result, the masks C2, M2, and Y2 that are complementary to each other also have well-distributed recording allowable pixels. In addition, the distribution of the print permitting pixels in the overlap of an arbitrary number (2, 3, 4, or 5) of these 6 planes is also well distributed with few low frequency components.

  As another feature of the mask manufacturing method described above, there is no generation of a periodic pattern that regularly repeats the arrangement of recordable pixels. For example, a pattern having periodicity that repeats a staggered pattern or a Bayer pattern is not generated. Even if it is generated, it can be converged to avoid the periodic pattern by resetting the repulsive potential parameter. Thus, the mask produced | generated by the mask manufacturing method of this embodiment becomes a non-periodic pattern.

  Further, in the above-described mask manufacturing method, setting that does not particularly use any print permitting pixel is not performed in each plane. However, even if a pixel that is not used as a print-allowed pixel is set in each plane, it is possible to obtain a well-distributed pixel with few low frequency components while avoiding the pixel.

(3) Mask characteristic evaluation
Effects of Weighting Factors α, β, γs (n) of Repulsive Potential in Mask First, repulsive potential calculation (with no discussion of distance ) is performed on the mask manufactured by the mask manufacturing method of the present embodiment described above. Only the influence of the coefficients) How each of the weighting coefficients α, β, γs (n) affects will be described in detail. As described above, the coefficient α affects the dispersion of the print permission pixels in the same plane, the coefficient β affects the dispersion of the print permission pixels between different planes, and γs (n) is the same for the print permission pixels of the different planes. This influences the dispersion of the overlap in the case of overlapping at the pixel at the position.

  In this embodiment, the same function (FIG. 9) is used for all terms as E (r), but different potential functions can be used for each term. In this case, the difference between αE (r), βE (r) ′, and γE (r) ″, which is the product of the respective weighting coefficients α, β, and γ (n) corresponding to each function E (r). Of course, the difference in dispersion, which will be explained below, has an influence.

  If the repulsive potential is defined only between the print allowable pixels in the same plane and the energy is attenuated to determine the print allowable pixel distribution, that is, α = 1 (α) and β = γ = 0 in αE (r). The recording allowable pixel distribution of one plane has good dispersibility of the arrangement of the recording allowable pixels in each plane. This is due to the effect of αE (r). However, a pattern obtained by extracting a pattern of overlapping print permitting pixels (logical product, logical sum) from a superposition of two (plural) planes has a bias in the arrangement of the print permitting pixels and has many low frequency components. Become. This is because a recording allowance that happens to overlap between two planes may occur, or a bias may occur because there is no relationship between the two planes.

  The “logical product” pattern is literally a pattern obtained by performing a logical product operation on the same pixel position between a plurality of planes, as shown in FIG. Specifically, when there are both print-permitted pixels (“1”) at corresponding pixel positions in a plurality of (two in the example shown in the figure) planes, a pattern obtained by extracting the positions is a logical product pattern. . This logical product pattern shows the distribution when there is an overlap of print permitting pixels between different planes.

  The “logical sum” pattern is literally a pattern obtained by performing a logical sum operation on the same pixel position between a plurality of planes, as shown in FIG. Specifically, when a print permitting pixel (“1”) is present at any pixel position of a plurality of (two in the example shown in the figure) plane, the pattern obtained by extracting the position is a logical sum pattern. . This logical sum pattern shows the arrangement of print permitting pixels on different planes as a single plane.

  Next, it is assumed that the same repulsive potential is applied to all the recording allowed pixels of the three planes, that is, α = β = 1 and γ = 0 in αE (r) and βE (r). In this case, the recording allowable pixel distribution of each plane has a low frequency component of a certain size and the distribution is biased. On the other hand, the recordable pixel distribution (logical sum) of the above-described three-color planes is well distributed. Since α and β are the same value, the effect of distributing the recording allowable pixels of the same plane is the same as the effect of distributing the recording allowable pixels of the other planes. This is because the recording allowable pixel distribution is insufficiently distributed.

  Therefore, in order to change the repulsive potential between the same plane and different planes, for example, α = 3 and β = 1. Thereby, the influence of other planes can be made relatively small, and the dispersibility within the same plane is improved. Furthermore, the print allowable pixel distribution (logical sum pattern) of the two planes overlapped is a distribution with good low dispersion with low frequency components. As described above, both the dispersibility of the print permitting pixels in the same plane and different planes are improved. That is, by causing the terms αE (r) and βE (r) to act and making the values of α and β different, the dispersibility both in the same plane and in different planes is improved.

  Next, let us consider a case where the term of γs (n) E (r) is not used when there is an overlap of print permitting pixels. An overlap recording allowable pixel is obtained from the recording allowable pixel distribution of the two planes having the recording allowable pixel distribution having no low frequency component, which are obtained without overlapping the term of γs (n) E (r). The extracted one (logical product) has a distribution with many low frequency components and poor dispersion.

  On the other hand, when the term of γs (n) E (r) is added, first, a recording allowable pixel distribution having no low frequency component is obtained for each plane. Then, the distribution (logical product) obtained by extracting the overlapping recording allowable pixels from the recording allowable pixel distribution obtained by superimposing these planes (logical product) is also an arrangement of the recording allowable pixels having no low frequency component.

  As described above, the term of γs (n) E (r) basically gives the effect of good dispersion of the overlapping recording allowable pixels, but will be described with reference to FIGS. 10 (a) to 10 (d). As described above, this term is set so that the potential increases as the overlap increases. By moving or arranging the recording allowable pixels one by one according to the potential and reducing the energy, the energy is reduced. This has the effect of reducing the number of overlaps in the process. This means that αE (r) has the same effect of reducing the number of adjacent print permitting pixels for adjacent print permitting pixels in the same plane. As described above, the term of γs (n) E (r) not only merely disperses the overlapping print permitting pixels as much as possible, but also has an effect of reducing the number of overlaps. By this effect, the number of print permitting pixels in the block of print permitting pixels due to adjacent or overlapping is reduced as much as possible, and as a result, a print permitting pixel distribution with few low frequency components can be obtained.

  From the above viewpoint, in this embodiment, the values of α = 3, β = 1, and γ = 3 are used as described above.

  Note that, for example, as α and β << γ, pay particular attention to the overlapping recording allowable pixels extracted in the overlapping of a plurality of planes, and due to the effect of the term of γs (n) E (r), the overlapping recording allowable pixels are In particular, it is possible to achieve good dispersion with less low frequency components.

  In this embodiment, the repulsive force between the planes is all βE (r), but it is effective to make the interactions different between the planes in consideration of the magnitude of the interaction. For example, when the number of planes is large, the repulsive potential between the mask planes used for ink that is applied as close as possible is made larger than other repulsive potentials, that is, the coefficient of βE (r) and the shape of E (r) are increased. It is also effective to change between planes. Also, for example, in the case of fixing using a reaction system, when a reaction liquid or ink having such a component is ejected by a recording head, the mask plane used for the reaction liquid or the like reacts with the reaction liquid or the like. It is also effective to increase the repulsive potential of the mask plane used for large inks. As a specific example of changing the repulsive potential function, an example of changing the distance r in the range where the repulsive force can be given can be given. For example, when the gradation value of the image data to be processed is 50% gradation, r = 16 as described above, and r can be increased as the gradation value is larger or smaller than 50%.

  In the present specification, the more uniformly the print-permitted pixels or their overlaps are distributed, the more “good dispersion” or “the better the dispersion” is. “Uniform dispersion” refers to a state where the total energy is as low as possible in the example of the repulsive potential, that is, when there are overlapping or adjacent lumps of recording allowable pixels, the overlapping or adjacent This is a state where the number is as small as possible. Further, in such a state, the print permitting pixels are arranged as evenly as possible. Furthermore, “low frequency component is reduced (decreased)” means that when the dispersion is good as described above, a region having a high sensitivity in human visual characteristics (low frequency region) in the power spectrum described later regarding the distribution. This means that the frequency component decreases (decreases) depending on the degree of good dispersion.

Mask Characteristic Evaluation FIGS. 14 to 16 are diagrams showing an arrangement pattern of print permitting pixels of the masks C1, M1, and Y1 (hereinafter referred to as “laminated masks”) of the present embodiment manufactured by the above-described manufacturing method. FIG. 17 shows a pattern of a mask (referred to as “distributed mask of only its own plane”) that can be used in the first pass of cyan ink , created according to the description of Patent Document 1 , and FIG. The pattern of the random mask created according to is shown. Each mask pattern shown in FIGS. 14 to 16 has an area of 256 × 256 pixels. In each pattern, the pixels shown in white are non-printable pixels (that is, pixels that are masked regardless of the image data of the pixels), and the pixels shown in black are dots that are printable pixels (that is, dots corresponding to the image data of the pixels). Each pixel is to be formed.

As shown in these figures, only the random mask shown in FIG. 18 has a higher visual roughness and less smoothness than other masks ( laminated mask and self-plane only dispersion mask ). . This is because when the random mask pattern is created, the arrangement of the print permitting pixels of the dots is determined at random without particularly considering the correlation of the dot arrangement in the plane (coefficient α). On the other hand, in the “dispersion mask of only the own plane” (FIG. 17) and the pattern of the lamination mask (FIGS. 14 to 16), in particular, the print permitting pixel considering the dispersibility in the same plane due to the effect of the coefficient α. Since they are arranged, there is no bias in the dispersion of the recordable pixels, and the overall impression is smooth.

19 and 20 are diagrams showing the logical sum pattern and logical product pattern of the two stacked masks (C1, M1) shown in FIGS. 14 and 15, respectively . FIGS. 21 and 22 are diagrams showing a logical sum pattern and a logical product pattern of the stacked masks C1, M1, and Y1 shown in FIGS. 14, 15, and 16, respectively. Furthermore, random 23 and 24, each of the dispersion mask only own planes different for each color is a diagram showing a logical sum pattern and logical product patterns, which 25 and 26 are different for each color It is a figure which shows each the logical sum pattern and logical product pattern of a mask. As described with reference to FIG. 13, the logical sum pattern is an array pattern of print permitting pixels obtained by logically summing two masks, and the logical product pattern is shown in FIG. As described above, this is an array pattern of print permitting pixels obtained by ANDing two masks.

  As shown in FIGS. 19 and 20, the arrangement (logical sum) of print permitting pixels when the two masks of the present embodiment are overlapped, and the arrangement (logical logic) of those obtained by overlapping the print permitting pixels are extracted. The product) is well distributed and has no rough feeling. This is because, as described above, the dispersion of the print allowable pixels is considered between the two planes (coefficient β) and the dispersion of the overlap itself is taken into account (coefficient γs (n)).

  Further, as shown in FIG. 21, the logical sum pattern of the print permitting pixels when the three masks of this embodiment are overlapped is such that the print permitting pixels are arranged without any gaps. In other words, since the present embodiment considers the dispersion of the recordable pixels among the three planes (coefficient β), the recordable pixels between the three planes are well dispersed, and as a result, are arranged without gaps throughout. Will be. Further, since each plane is a uniform mask for two-pass printing, print permitting pixels are arranged at 50% density. Accordingly, the density of the three planes overlapped is 150%, and the overlap cannot be excluded, but in the present embodiment, the overlap is limited to two overlaps by the coefficient γs (n). As a result, as shown in FIG. 22, in the logical product pattern in which three overlaps are extracted, the overlap does not exist.

In contrast, the logical sum pattern and logical product pattern when overlapping different color planes for was different for each color "dispersion mask only self plane", as shown in FIGS. 23 and 24, 19 Also, the dispersion is not as good as the pattern of logical sum and logical product shown in FIG . As described above, in Patent Document 1, although dispersion in the same plane is taken into consideration, the dispersion of the print allowable pixels between the planes (coefficient β) and the dispersion of the overlap of the print allowable pixels (coefficient γs (n)). ) Is not taken into account. Also in the case of random masks that differ for each color , as shown in FIGS. 25 and 26, both the logical sum pattern and the logical product pattern are not well dispersed.

  As another evaluation method of the mask pattern, a method using an “overlapping” pattern is defined. As shown in FIG. 27, this “overlapping” pattern corresponds to a case where a print allowable pixel (“1”) exists in any mask pixel of a plurality of (two in the example shown in the figure) planes. When the data “1” indicating the print permitting pixel exists in the pixel and the print permitting pixel overlaps with the same mask pixel, the data according to the number exists. For example, when the overlap is 2, “2” is set, and when it is 3, “3” is set. A “superimposition pattern” to be described later is represented by a density corresponding to the number indicated by the data. That is, it is shown that the black density becomes higher as the recording allowable pixels overlap. This superposition pattern can indicate the arrangement of print permitting pixels of different planes as a single plane, and can also indicate the arrangement of overlap of print permitting pixels together with the degree of overlap.

  FIG. 28 and FIG. 29 are diagrams illustrating “overlapping” patterns when two and three stacked masks of the present embodiment are stacked, respectively.

  The patterns shown in FIGS. 28 and 29 represent patterns close to the ink dot pattern of the intermediate image when printing is performed using the mask of this embodiment. Therefore, it can be seen from these patterns that ink dots and their overlap in the intermediate image are well dispersed.

Figure 30 is a Ru FIG der showing a "superposing" pattern obtained when the dispersion mask only own planes different for each color two superposed. FIG. 31 is a diagram showing an “overlapping” pattern when two random masks different for each color are overlapped . As shown in these figures 30 through 31, these "superposing" patterns, it can be seen that the dispersibility of the print permitting pixel and the overlapping is not good.

Evaluation by Power Spectrum Next, the mask of this embodiment is evaluated by a power spectrum indicating the frequency characteristics of the mask pattern. The power spectrum described below is obtained when the print permitting pixels are replaced with the dot arrangement, and is obtained for a plane having a size of 256 pixels × 256 pixels. Here, the power spectrum can be treated as a one-dimensional two-dimensional spatial frequency, “T. Mitsa and KJ Parker,“ Digital Halftoning using a Blue Noise Mask ”, Proc. SPIE 1452, pp. 47-56 (1991)”. It is described as a radially averaged power spectrum.

FIG. 32 is a diagram for explaining the frequency characteristics of a single mask pattern (C1) for each of the laminated mask, the dispersion mask of only the own plane made different for each color, and the random mask made different for each color . FIG. 33 is a diagram illustrating the frequency characteristics of the logical sum pattern of two masks (C1, M1) for each of these three types of masks. FIG. 34 is a diagram illustrating the frequency characteristics of the logical product pattern of two masks (C1, M1) for each of these three types of masks.

In FIG. 32, each curve indicates a power spectrum with respect to a spatial frequency of each mask pattern. Curve a represents the power spectrum of the mask pattern (FIG. 14) of the laminated mask, curve b represents the power spectrum of the dispersion mask pattern (FIG. 17) of only its own plane, and curve c represents the random mask pattern ( The power spectrum of FIG. 18) is shown respectively. Comparing these three curves, it can be seen that the random mask (curve c) has substantially uniform power over the entire spatial frequency. The random mask does not have a special feature in the interval at which the print permitting pixels are dispersed because the print permitting pixels are randomly arranged. Therefore, the distribution is substantially uniform from the low frequency region to the high frequency region. On the other hand, the laminated mask and the dispersion mask (curves a and b) having only the own plane have low power in the low frequency region, the power peak is present at high frequency , and the low frequency component is less than the high frequency component. It has become. This indicates that the print permitting pixels are distributed substantially evenly while maintaining a certain distance.

  As a performance evaluation of a mask pattern, it is a major feature of the present invention to pay attention to a “low frequency component” on the lower frequency side than about half of the frequency region where the power spectrum of the mask pattern exists. In the state where the low frequency component of the mask pattern is kept low, beading due to the grain distribution hardly appears as described above, and is hardly visible. As a result, the recorded image is not visually rough. In particular, the mask pattern is repeatedly used two-dimensionally for an image on which one pattern is recorded. When this certain mask pattern is repeated, the more low frequency components of the mask pattern are, the more easily the pattern of the repeated pattern is recognized by human eyes. Since the pattern greatly affects the occurrence and appearance of beading, a rough feeling related to the mask cycle occurs. Therefore, it is important to pay attention to the repetitive pattern and to suppress the low frequency component side of the mask pattern. In other words, the present invention focuses on the low frequency region where the roughness or the like is visually worrisome, and suppresses the low frequency region component to a low level. That is, the mask pattern of the present invention is characterized in that such low-frequency power is kept low.

  Further, the frequency characteristic related to the sensitivity of the human eye depends on the distance between the recorded material and the human eye, and is described, for example, by Dooley ("RP Dooley: Prediction Brightness Appearance at Edges Using Linear and Non"). -Liner Visual Describing Functions, SPES annual Meeting (1975) "). When viewing recorded matter from various experiments, it is said that components in a frequency region lower than about 10 cycles / mm are easily recognized by human eyes. In this regard, the present inventor has also confirmed experimentally. Therefore, it can be said that it is important to pay attention to a region (low frequency region) including a frequency lower than 10 cycles / mm. Note that the low-frequency region of interest in mask evaluation (for example, FIG. 50) of each embodiment described later substantially overlaps these ranges.

FIG. 33 and FIG. 34 show the logical sum and logical product pattern of two masks (C, M) for a stacked mask, a dispersion mask of only its own plane made different for each color, and a random mask made different for each color . It is a figure which shows a power spectrum . As is clear from FIGS. 33 and 34, the low frequency component of the logical sum pattern and logical product pattern of the laminated mask (curve a) is smaller than the high frequency component, and as described above, these logical sum and logical product. The arrangement of the pattern recordable pixels is excellent in dispersibility . In both cases of FIGS. 33 and 34, the low frequency component of the dispersion mask (curve b) of only its own plane that is different for each color is larger than that of the laminated mask (curve a). That is, as shown in FIGS. 23 and 24, the arrangement of the print permitting pixels in the dispersion mask of only the own plane made different for each color is compared with the laminated mask as shown in FIGS. Dispersion is inferior.

FIG. 35 and FIG. 36 show the power spectrum of the “superposition” pattern when two and three layer masks, a dispersion mask of only its own plane made different for each color, and a random mask made different for each color are overlaid, respectively. FIG. In each figure, a curve a represents the power spectrum of the overlay pattern (FIGS. 28 and 29) of the laminated mask of the present embodiment, and a curve b represents the overlay of the dispersion mask of only its own plane that is different for each color. The power spectrum of the matching pattern (FIG. 30) is shown, and the curve c shows the power spectrum of the overlay pattern (FIG. 31) of the random mask made different for each color .

Comparing the three curves, the random mask has substantially uniform power over the entire spatial frequency as in the power spectrum of the single mask, logical sum pattern, and logical product pattern. On the other hand, the overlapping pattern of the dispersion mask of only the own plane shown by the curve b has more low frequency components than the dispersion mask of only the single own plane shown in FIG. In addition, the superposed pattern of the dispersion mask mask having only its own plane indicated by the curve b has more low frequency components than the superposed pattern of the laminated mask indicated by the curve a . That is, as shown in FIG. 30, the dispersion becomes worse and the feeling of roughness of the pattern increases.

On the other hand, the low-frequency component of the overlay pattern of the laminated mask indicated by curve a in FIGS. 35 and 36 is hardly changed even when compared with the single laminated mask shown in FIG. This indicates that even in a state where the three planes are overlapped, the print permitting pixels are distributed substantially evenly while maintaining a certain distance.

Evaluation by Shifting One of the differences between the mask according to the embodiment of the present invention and the dispersion mask of only the self-plane described above is that the masks of different planes are overlapped at the normal positions and the masks at the non-normal positions. Change in dispersibility. In the mask according to the embodiment of the present invention, when the masks of different planes are intentionally shifted, the dispersibility of the print permitting pixels is greatly reduced. That is, in the present embodiment, since dispersion is taken into consideration even between different planes, dispersibility is greatly reduced if a superposition method different from the normal superposition method when considering the dispersion is used. On the other hand, in the case of a random mask or a dispersion mask that includes only its own plane, dispersibility between different planes is not taken into consideration, and therefore the dispersibility does not change even if the overlay method is different from the normal overlay method.

  This deviation is evaluated as follows. C1, M1, and Y1 created by the manufacturing method described above are shifted from each to the direction of each color raster. At this time, the masks themselves can be shifted because they are periodically arranged.

FIGS. 37 39, if the logical sum pattern of the case where the logical OR shifting the mask (C1, M1), the logical product pattern when the logical product is shifted masks (C1, M1), and the mask (C1, It is a figure which shows the superimposition pattern at the time of superimposing by shifting M1) . As is clear from these figures, the dispersibility of all of the logical sum, logical product, and “superposition” of the superposition patterns in which the superposition positions of the lamination masks C1 and M1 of the present embodiment are shifted is lowered, and the pattern is observed. The feeling of roughness is increasing.

Figure 40 is a logical sum pattern obtained when a logical sum staggered stacked masks (C1, M1), and, when the logical sum is not shifted stacked masks (C1, M1) (i.e., logic in the normal position It is a figure which shows the power spectrum of the logical sum pattern obtained in the sum case. FIG. 41 shows a logical sum pattern obtained when the dispersion masks (C1, M1) are shifted and ORed only for the own plane that is different for each color, and only the own plane that is different for each color. It is a figure which shows the power spectrum of the logical sum pattern obtained when the logical sum is performed without shifting M1) (that is, the logical sum at the normal position). FIG. 42 shows a logical sum pattern obtained by logically summing random masks (C1, M1) that are different for each color, and a random mask (C1, M1) that is different for each color. It is a figure which shows the power spectrum of the logical sum pattern obtained when the logical sum is obtained (that is, the logical sum at the normal position).

  In the laminated mask of the present embodiment shown in FIG. 40, the low frequency component when shifted is relatively large as compared with the case without shifting. This is because, as described above, since the laminated mask considers dispersion even between different planes, when the overlay method is different from the normal overlay method when considering the dispersion, the dispersibility is large. It is because it falls.

On the other hand, the dispersion mask of only the own plane and the random mask different for each color shown in FIG. 41 and FIG. 42 are the low frequency components of the power spectrum in the case of shifting and the case of no shifting. There is almost no change. This is because these masks do not originally take into account the dispersion of recording-allowed pixels between different planes, so even if the overlapping position is shifted, there is no significant difference in the dispersion in the pattern when superimposed. .

43 to 45 are comparison diagrams of power spectra in the case where the position where the logical product of the masks (C1, M1) is shifted is not shifted as in FIGS. FIG. 43 to FIG. 45 are diagrams showing the power spectrum of the logical product pattern of the laminated mask, the dispersion mask of only the own plane made different for each color, and the random mask made different for each color . Further, FIGS. 46 to 48, the mask (C1, M1) is a comparison diagram of the power spectrum when not shifted with the case of shifting the overlapping position, the only self-planes respectively stacked masks, different for each color dispersion It is a figure which shows the power spectrum of the "superposition" pattern of the random mask made different for every mask and color . As can be seen from these figures, in the laminated mask, the low frequency component when shifted is greatly increased as compared with the case where there is no shift. On the other hand, the dispersion mask of only the own plane made different for each color and the random mask made different for each color have almost no change in the low frequency component of the power spectrum between the case of shifting and the case of no shifting. Similarly, in the power spectrum of the “superposition” pattern when the three stacked masks C1, M1, and Y1 of the present embodiment shown in FIG. 49 are shifted and overlapped, the power increases as a whole in the frequency domain when shifted. .

FIG. 50 to FIG. 52 are diagrams showing the evaluation by the above shift in terms of the amount of the low frequency component. Each of the stacked masks of the present embodiment, the dispersion mask of only the own plane made different for each color, and each color are different. This is shown in the random mask. Here, the amount of the low frequency component is obtained by integrating 90 or less components corresponding to about half of the spatial frequency region where the power spectrum exists.

  As shown in FIG. 50, in the case of the laminated mask of the present embodiment, the shifted masks are the logical sum, logical product, “superposition” pattern of the masks C1, M1, and the “superposition” of the masks C1, M1, Y1. It can be seen that in any of the patterns, the amount of the low-frequency component is increased as compared with the case where the pattern is not shifted.

  On the other hand, there is no change in the amount of the low frequency component between the case where both the dispersion mask of only the own plane shown in FIG. 51 and the random mask shown in FIG. 52 are shifted.

As described above, when the logical sum, logical product or superposition of two masks is performed , depending on whether or not the evaluation value related to dispersibility changes greatly depending on whether the position is shifted or not. It can be determined whether or not the mask is applied with the invention. That is, the evaluation by the above-mentioned shift proves that the mask to which the present invention is applied takes into consideration the dispersibility in the logical sum, logical product or superposition.

[Embodiment 2: 100% uniform mask for 4-pass printing]
(1) Outline of the present embodiment The present embodiment is a four-pass multi-pass that completes an image with four scans for each ink of cyan (C), magenta (M), yellow (Y), and black (K). Regarding recording. In addition, the masks used for each of a plurality of (four in the present embodiment) scans for each of the ink colors used for the four-pass printing are not only well dispersed, but also a plurality of arbitrary planes of these masks are aligned. Are also well dispersed.

  In the following, for simplification of illustration and description, a case where 4-pass printing is performed with three colors of cyan, magenta, and yellow will be described.

  Each nozzle group of cyan, magenta, and yellow is divided into four groups of first to fourth groups, and each group includes 128 nozzles. Each group is associated with the mask pattern (C1, C2, C3, C4, M1, M2, M3, M4, Y1, Y2, Y3, Y4) of this embodiment, and the sub-scanning direction ( The size in the transport direction is 128 pixels, which is the same as the number of nozzles in each group. On the other hand, the size in the scanning direction is 256 pixels. Also, the four mask patterns (C1, C2, C3 and C4, M1, M2, M3 and M4, Y1, Y2, Y3 and Y4) corresponding to the nozzle group of the same color ink are complemented by four patterns, respectively. In other words, recording of an area corresponding to 128 × 256 pixels is completed by superimposing these pixels.

  In a recording operation using these masks, each color nozzle group ejects ink onto a recording medium while scanning in a direction substantially perpendicular to the nozzle arrangement direction. For example, C, M, and Y ink ejection is performed on each region. Each time scanning is completed, the recording medium is conveyed by the width of one loop (that is, 128 pixels) in the direction orthogonal to the scanning direction. As a result, an image having a size corresponding to the width of each group on the recording medium is completed by four scans.

  More specifically, when four continuous areas each having a size corresponding to the width of the nozzle group in the recording medium are sequentially set as areas A, B, C, and D in the conveyance direction of the recording medium, Recording is performed on the area A on the recording medium using the first group of the C nozzle group, the first group of the M nozzle group, and the first group of the Y nozzle group. In the first scan, the mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used for the region A.

  Next, in the second scan, recording is performed using the second group of the C nozzle group, the second group of the M nozzle group, and the second group of the Y nozzle group with respect to the area A in which the recording in the first scan is completed. In addition, recording is performed on the unrecorded region B using the first group of the C nozzle group, the first group of the M nozzle group, and the first group of the Y nozzle group. Accordingly, in the second scan, the mask pattern C2, the mask pattern M2, and the mask pattern Y2 are used for the region A, and the mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used for the region B.

  Further, in the third scan, recording is performed using the third group of the C nozzle group, the third group of the M nozzle group, and the third group of the Y nozzle group with respect to the area A where the recording in the second scan is completed. In addition, recording is performed on the area B using the second group of the C nozzle group, the second group of the M nozzle group, and the second group of the Y nozzle group, and further, the area C is recorded in the unrecorded area C. On the other hand, recording is performed using the first group of the C nozzle group, the first group of the M nozzle group, and the first group of the Y nozzle group. Accordingly, in the third scan, the mask pattern C3, the mask pattern M3, and the mask pattern Y3 are used for the region A, the mask pattern C2, the mask pattern M2, and the mask pattern Y2 are used for the region B, and The mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used.

  Further, in the fourth scan, recording is performed using the fourth group of the C nozzle group, the fourth group of the M nozzle group, and the fourth group of the Y nozzle group with respect to the area A where the recording of the third scan is completed. In addition, recording is performed on the region B using the third group of the C nozzle group, the third group of the M nozzle group, and the third group of the Y nozzle group. Recording is performed using the second group, the second group of the M nozzle group, and the second group of the Y nozzle group, and further, the first group of the C nozzle group and the M nozzle group for the unrecorded region D. The first group and the first group of the Y nozzle group are used for recording. Accordingly, in the fourth scan, the mask pattern C4, the mask pattern M4, and the mask pattern Y4 are used for the area A, the mask pattern C3, the mask pattern M3, and the mask pattern Y3 are used for the area B, and The mask pattern C2, the mask pattern M2, and the mask pattern Y2 are used, and the mask pattern C1, the mask pattern M1, and the mask pattern Y1 are used for the region D.

  As described above, the image recording for the area A on the recording medium is completed by four scans. Further, the recording is performed in the same manner for the area B and the subsequent area.

  In this embodiment, as in Embodiment 1 described above, in order to avoid the occurrence of grains in the intermediate image, the arrangement of the print permitting pixels when the masks of the respective planes are overlaid is aperiodic and has low frequency components and low dispersibility. It is good. As a result, the proximity or adjacency of dots in the intermediate image at each stage leading to the completion of the image and the overlap of dots are eliminated as much as possible. Further, even if dot overlap and adjacency cannot be completely eliminated, such overlap is highly dispersible.

(2) Mask Manufacturing Method Also in this embodiment, any of the simultaneous generation method described in the first embodiment and the generation method for each pass can be used as a mask manufacturing method. However, in the present embodiment, the simultaneous generation method and the generation method for each path are not the same. Hereinafter, these methods will be described in order.

Simultaneous Generation FIG. 53 is a diagram conceptually illustrating the simultaneous generation method of the present embodiment.

  As shown in the figure, the simultaneous generation method of the present embodiment uses masks (C1, M1, Y1), (C2, M2, Y2) and (C3, M3, Y3) is generated simultaneously in step 1. In step 2, the masks (C4, M4, Y4) of the respective planes used for the fourth pass are changed to the masks (C1, M1, Y1), (C2, M2, Y2) of the first to third passes. And (C3, M3, Y3) and each color are generated so as to have a complementary relationship. That is, for each color, the mask for the fourth pass is generated so that the arrangement of the print permitting pixels is in an exclusive relationship with the arrangement of the print permitting pixels of the masks for the first pass through the pass.

  As a specific arrangement method of the print permitting pixels in the generation of the first-pass to third-pass masks, either the “placement movement method” or the “sequential movement method” described in the first embodiment is shown below. Can be used.

(Placement transfer method)
Processing when this method is used is basically the same as the processing described in the first embodiment with reference to FIG. That is, as in step S801 in FIG. 8, the respective masks (C1, M1, Y1), (C2, M2, Y2), and (C3, M3, Y3) of the respective colors in the first to third passes. Acquire 25% density images of C, M, and Y corresponding to the size. As in step S802, each image is binarized using a binarization method such as an error diffusion method. As a result, for each of the masks (C1, M1, Y1), (C2, M2, Y2), (C3, M3, Y3), the initial arrangement in which the recordable pixels are arranged in 25% of the entire mask pixels. Can be obtained.

  Next, in the same manner as in step S803, all the print allowable pixels of each plane of the masks (C1, M1, Y1), (C2, M2, Y2), (C3, M3, Y3) obtained as described above are obtained. Calculate the repulsive potential.

  The calculation of the repulsive potential differs from the processing of the first embodiment as follows. For example, when calculating the repulsive potential of a certain allowable pixel on the plane C2, the influence of the recording allowable pixel on the distance r between other planes of different colors; the value of the weighting coefficient β of βE (r) is 1 as in the embodiment. To do. On the other hand, it is assumed that the influence of the recording allowable pixels at the distance r in the different planes C1 and C3 of the same color; the value of the weighting coefficient β of βE (r) is 2. Thereby, the dispersion (β = 2) of the print permission pixels when the masks of the same color are overlapped is ensured in preference to the dispersion (β = 1) with the print permission pixels of different colors.

  Next, as in step S804 of FIG. 8, energy attenuation is performed as described with reference to FIGS. Here, the differences from the first embodiment are as follows. That is, for all nine print permitting pixels calculated in the process so far, the record permitting pixels are sequentially transferred to the pixel having the lowest repulsive potential among the pixels whose distance r from the record permitting pixel is 4 or less. In this case, the overlapping of the print permitting pixels in the same color (plane) is prohibited. Thereby, the complementary relationship between the masks of the same color for 3 passes can be obtained.

(Sequential placement method)
The sequential arrangement method in the simultaneous generation is basically the same as the processing described in the first embodiment with reference to FIG. The difference is the same as that described in the arrangement movement method. That is, when calculating the repulsive potential, the influence of the print permitting pixels of other planes of different colors; the value of the weighting coefficient β of βE (r) is set to 1, and the print permitting pixels on the different planes of the same color are used. The value of the weighting coefficient β of βE (r) is 2. Further, when the target recording allowable pixel is arranged at the pixel having the lowest repulsive potential, overlapping of the recording allowable pixels in the same color (plane) is prohibited.

  Then, this arrangement ends the process of arranging the number of planes 25% (see step S1106 in FIG. 11).

Generation for Each Path FIG. 54 is a diagram for conceptually explaining the generation method for each path according to the present embodiment.

  As shown in the figure, in the simultaneous generation method of the present embodiment, a mask for the first pass (C1, M1, Y1) is generated in Step 1, and a mask for the second pass (Step 1) (C1, M1, Y1). C2, M2, Y2) are generated, and in step 3, a mask (C3, M3, Y3) for the third pass is generated. In step 4, the masks (C4, M4, Y4) of the planes used for the fourth pass are used as the masks (C1, M1, Y1), (C2, M2) of the generated first to third passes. , Y2) and (C3, M3, Y3) and the respective colors are generated in a complementary relationship. That is, for each color, the mask for the fourth pass is generated so that the arrangement of the print permitting pixels is in an exclusive relationship with the arrangement of the print permitting pixels of the masks for the first pass through the pass.

  As a specific arrangement method of the print permitting pixels in the generation of the first-pass to third-pass masks, either the “placement movement method” or the “sequential movement method” described in the first embodiment is shown below. Can be used.

(Placement transfer method)
Processing when this method is used is basically the same as the processing described in the first embodiment with reference to FIG. That is, similarly to step S801 in FIG. 8, images of 25% density of C, M, and Y corresponding to the sizes of the planes of the respective colors (C1, M1, and Y1) in the first pass are acquired. As in step S802, each image is binarized using a binarization method such as an error diffusion method. Thereby, it is possible to obtain an initial arrangement in which the print permitting pixels are arranged in 25% of the entire mask pixels for each plane of each mask (C1, M1, Y1).

  Next, as in step S803, the repulsive potential is calculated for all the print permitting pixels of each plane of the mask (C1, M1, Y1) obtained as described above.

  In this repulsive potential calculation, the difference from the application process of the first embodiment is the same as the arrangement movement method in the simultaneous generation described above. That is, when calculating the repulsive potential of a certain allowable pixel, the influence of other recording allowable pixels at the distance r between other planes of different colors; the value of the weighting coefficient β of βE (r) is 1 as in the embodiment. . On the other hand, the influence from the print permitting pixels at the distance r in different planes of the same color; the value of the weighting coefficient β of βE (r) is 3. Thereby, the dispersion (β is 3) of the print permitting pixels when the same color masks are overlapped is ensured in preference to the dispersion (β is 1) with the print permitting pixels of different colors. In addition, the influence of different color planes; the value of the coefficient β of βE (r) is 1 as in the first embodiment, so that, for example, a collection of recording allowable pixels of C, M, and Y has high dispersibility. A pattern to be arranged can be obtained.

  When the arrangement of the print permitting pixels of the first-pass mask (C1, M1, Y1) is obtained as described above, the second-pass (step 2) and third-pass (step 3) masks are performed in the same manner. Ask for a pattern. At this time, when the print permitting pixels are arranged (see step S804 in FIG. 8), the pass pattern generated so far; the arrangement of the print permitting pixels is fixed. Thereby, the mutual complementarity of the mask patterns from the first pass to the third pass can be guaranteed.

(Sequential placement method)
The sequential arrangement method in the generation for each path is basically the same as the processing described in the first embodiment with reference to FIG. The difference is the same as that described in the arrangement movement method. That is, when calculating the repulsive potential, the influence of the print permitting pixels of other planes of different colors; the value of the weighting coefficient β of βE (r) is set to 1, and from the print permitting pixels on different planes of the same color The value of the weighting coefficient β of βE (r) is set to 3. Further, when the target recording allowable pixel is arranged at the pixel having the lowest repulsive potential, the pass pattern generated so far; the arrangement of the recording allowable pixel is fixed. Thereby, the complementarity between the mask patterns in the first pass to the third pass can be guaranteed.

  Then, this arrangement ends the process of arranging the number of planes 25% (see step S1106 in FIG. 11).

(3) Mask Characteristic Evaluation FIGS. 55 to 57 are diagrams showing an arrangement pattern of print permission pixels for each of the laminated masks C1, M1, and Y1 for one plane of this embodiment manufactured by any of the above-described manufacturing methods. is there. Each mask pattern has an area of 128 × 256 pixels.

  As shown in these drawings, the mask pattern of the present embodiment has a printable pixel in consideration of dispersibility in the same plane due to the effect of the coefficient α in particular, so that the overall impression is smooth. Receive.

  58 to 60, there are three (C1, M1, Y1), six (C1, M1, Y1, C2, M2, Y2) and nine (C1, M1, Y1, It is a figure which shows a "superposition" pattern when superimposing C2, M2, Y2, C3, M3, Y3) in the regular position. The “overlapping” pattern when a plurality of these laminated masks are superimposed represents the logical sum pattern of those masks with a lighter density and the logical product pattern with a higher density.

  The “overlapping” patterns shown in these drawings represent patterns close to the ink dot pattern of the intermediate image when recording is performed using the mask of the present embodiment. Therefore, it can be seen from these patterns that ink dots and their overlap in the intermediate image are well dispersed.

Evaluation by Shift The evaluation by shift similar to that of the first embodiment is performed for the four-pass laminated mask according to this embodiment.

  FIG. 61 is a diagram showing a “superposition” pattern when the three lamination masks (C1, M1, Y1) shown in FIG. FIG. 62 is a diagram showing a “superposition” pattern when the six laminated masks (C1, M1, Y1, C2, M2, Y2) shown in FIG. Further, FIG. 63 shows the “overlapping” pattern when the nine stacked masks (C1, M1, Y1, C2, M2, Y2, C3, M3, Y3) shown in FIG. FIG.

  As is clear from these drawings, any of the overlapping patterns (FIGS. 61 to 63) in which the overlapping positions of the laminated masks of this embodiment are shifted are compared with the patterns (FIGS. 58 to 60) in which the overlapping positions are not shifted. As a result, the dispersibility is lowered, and the feeling of roughness when the pattern is observed is increased.

  FIG. 64 is a diagram showing the evaluation based on the above shift in terms of the amount of low frequency components. Here, the above-mentioned three (C1, M1, Y1), six (C1, M1, Y1, C2, M2, Y2) and nine (C1, M1, Y1, C2, M2, Y2, C3, M3, For each layered mask of Y3), the amount of the low frequency component when the “overlapping” pattern is shifted (FIGS. 61 to 63) and when not shifted (FIGS. 58 to 60) is shown in comparison.

  As shown in the figure, in the case of the laminated mask of the present embodiment, the shifted components are low frequency components compared to the case where they are not shifted in any pattern (that is, when they are stacked at regular positions). It can be seen that the amount of increases.

  As described above, when masks are overlaid, it is possible to determine whether or not the mask is the one to which the present invention is applied depending on whether or not the evaluation value related to dispersibility changes greatly when the overlapping position is shifted. As described above.

  The mask pattern in the present embodiment has a size of horizontal: 256 pixels × vertical: 128 pixels, and the vertical and horizontal sizes are different. When obtaining frequency components for such a pattern, the frequency components are obtained after aligning the vertical and horizontal sizes of the mask pattern. In the present embodiment, in order to align the vertical and horizontal sizes with the size in the longitudinal direction (in the present embodiment, 256 pixels in the horizontal direction), the pattern is repeated vertically and the frequency component is evaluated as a 256 pixel × 256 pixel pattern.

  The same applies to other sizes, and the frequency component is evaluated for a pattern in which the vertical and horizontal sizes are aligned in the longitudinal direction. Specifically, the pattern is repeated in the short direction until the size in the short direction of the pattern is equal to or greater than the size in the long direction, the pattern is cut out from the pattern, and the cut pattern is evaluated. At that time, the vertical and horizontal sizes are preferably 2 to the nth power (n is a positive integer) so that the fast Fourier transform can be used when performing the frequency conversion. If it is not 2 to the power of n, the 2 n power closest to the size in the longitudinal direction is specified, and the pattern is repeated vertically and horizontally so that it can be cut out with the specified 2 n size. Then, from the pattern generated by this repetition, the specified pattern of 2 n size is cut out, and the cut out pattern is evaluated. For example, consider a case where the mask pattern is horizontal: 500 pixels × vertical: 320 pixels. In this case, since the size in the longitudinal direction is “500”, the 2 n power closest to “500” is specified. The nearest 2 to the power of n is identified as “512”. Therefore, in order to cut out a pattern of 512 pixels × 512 pixels, the pattern is repeated once in the horizontal direction and the vertical direction to generate a pattern of 1000 pixels × 640 pixels. A 512 pixel × 512 pixel pattern is cut out from the 1000 pixel × 640 pixel pattern thus generated, and the cut pattern is evaluated.

[Embodiment 3: 100% gradation mask for 2-pass printing]
This embodiment relates to a so-called gradation mask. The gradation mask is known from, for example, Patent Document 3. The gradation is a mask having a different recording rate depending on the nozzle position, such that the recording rate at the end of the nozzle row is low and the recording rate at the center is set high. According to this mask, the effect of improving the image quality can be obtained by relatively reducing the frequency of the discharge of the end nozzle, which is likely to cause a harmful effect at the boundary of the recording area of each pass in multi-pass printing.

  Here, the “recording rate” of the mask pattern described above is the ratio of the number of pixels allowed for printing to the total number of pixels (the sum of pixels allowed for printing and pixels not allowed for printing) included in a certain area in the mask pattern. For example, the printing rate of the mask pattern corresponding to a single nozzle is the ratio of printing allowable pixels to the total number of pixels included in the region (single raster region) corresponding to the single nozzle.

  In the case of such a mask, when a mask pattern corresponding to the entire nozzle row is viewed at a spatial frequency, an increase in low frequency components due to a change in recording rate for each region is observed. However, if such a mask pattern in which unnecessary low-frequency components are suppressed while allowing the arrangement of the print permitting pixels such that the recording rate gradually changes is generated, the generation of grains can be suppressed. The effect of the present invention can be obtained. Therefore, the present invention and Patent Document 3 can be realized by providing a gradation mask in which a plurality of areas corresponding to each of the recording rates changing in the mask maintain a high dispersibility while changing the recording rate between the areas. It is possible to obtain both effects described in.

  FIGS. 65A and 65B are diagrams showing a recording rate corresponding to the nozzle position of the gradation mask according to the present embodiment and mutually exclusive mask patterns of two planes.

  In this embodiment, the two-plane masks are cyan two-plane masks C1 and C2, magenta two-plane masks M1 and M2, or yellow two-plane masks Y1 and Y2. Of these masks, in the figure, cyan masks C1 and C2 are representatively shown. As described in the first embodiment, the arrangement of the print permitting pixels of these six masks is dispersed with respect to each other.

  As shown in these drawings, in each scan, printing is performed with the nozzles numbered 0 to 255 corresponding to the mask C2, and the nozzles numbered 256 to 511 corresponding to the mask C1. As described above, the mask C1 and the mask C2 have a complementary relationship. Then, between the scans, the recording medium is conveyed by an amount corresponding to the length of the 256 nozzle arrays. By repeating scanning and conveyance in this way, two-pass printing is performed in which the areas corresponding to the 256 nozzle arrays are complemented by the mask C1 and the mask C2.

  As shown in FIG. 65 (a), the mask C1 and the mask C2 each have a recording rate varying from 0.3 to 0.7 for each raster (nozzle), and a total recording rate of 50% for each plane. Have As a result, the number of print permitting pixels of each raster of the mask is determined by the recording rate. For example, in a raster with a printing rate of 0.4 (40%), assuming that the size of the mask in the raster direction is 1000 pixels, about 400 printable pixels are arranged.

(2) Mask Manufacturing Method The mask manufacturing method according to the present embodiment can use basically the same method as described in the first embodiment. That is, any of the two methods of generating all the planes simultaneously and sequentially generating the mask for each pass can be performed. In the case of two-pass printing according to this embodiment, as described above in the first embodiment, the simultaneous generation method and the generation method for each pass are the same. Moreover, it is the same that both the placement movement method and the sequential placement method can be implemented for each of the two generation methods. Hereinafter, the placement movement method and the sequential placement method according to the present embodiment will be described in order.

Arrangement moving method Figure 66 is a flowchart showing the arrangement determining process by the arrangement moving method of the recording permitting pixels of the gradation mask used in 2-pass printing in the embodiment. The processing shown in the figure is basically the same as the processing shown in FIG. 8 regarding the first embodiment. Below, a different point is mainly demonstrated.

  The processing in steps S6601 and S6602 is the same as the processing in steps S801 and S802 shown in FIG. Also, the processing in step S6603 is the same as the processing in step S803, and the repulsive potential is calculated for all the print permitting pixels arranged for each raster in the planes of the masks C1, M1, and Y1, as described above.

  Next, in step S6604, as in step S804 of FIG. 8, the repulsive potentials that can be obtained as described above for the recording allowable pixels of each plane are totaled for the three planes C1, M1, and Y1 to obtain the total energy. . Then, as described above with reference to FIGS. 10A to 10D, the arrangement of the print permitting pixels is moved.

  At this time, if the limit of the number of arrangements of the raster exceeds the limit of the number of arrangements when the potential energy is moved to the lowest position, the pixel having the next lowest energy is a raster in which the number of arrangements is within the limit without moving to the raster. Move that raster to that low energy pixel. As a result, it is possible to obtain an arrangement of print permitting pixels with high dispersibility while maintaining the print rate for each raster.

  In the following, as in the process of FIG. 8, the reduction rate of the total energy is calculated, and when it is determined that it is equal to or less than a predetermined value, the energy attenuation process is terminated. Then, each plane in a state where the reduction rate of the total energy is equal to or less than a predetermined value is set as the first-pass masks C1, M1, and Y1. Furthermore, masks C2, M2, and Y2 for the second pass are set with the print-permitted pixel positions at positions exclusive to the print-permitted pixel positions of these masks. Here again, as in the first embodiment described above, whether or not to end the energy attenuation process is determined based on whether or not the total energy is equal to or less than a predetermined position, not based on the total energy reduction rate. You may make it do.

Sequential placement method This method is also basically the same as the method described above with reference to FIG. FIG. 67 is a flowchart showing the arrangement determination process of the print permission pixels by the sequential arrangement method of the present embodiment.

  The processes in steps S6701 to S6703, S6705, S6706, and S6707 in FIG. 67 are the same as the processes in S1101 to S1103, S1105, S1106, and S1107 in FIG.

  The difference is that in step S 6704, when placing the recording allowable pixel on the pixel of the minimum energy in the plane, if the number of arrangements per raster determined according to the recording rate is exceeded as described above, it is within the limitation of the number of arrangements. The point is that the pixel having the next lower energy in one raster is arranged in the pixel having the lower energy in the raster. Thereby, a gradation mask with high dispersibility can be obtained while changing the recording rate for each raster.

  In any example of the manufacturing method described above, the number of arrangements is managed for each raster, but the present invention is not limited to this. For example, when the recording rate of a mask pattern is determined for each of a plurality of predetermined rasters, the arrangement number is limited for each of the plurality of rasters.

(3) Mask Characteristic Evaluation FIGS. 68 to 70 are diagrams showing the arrangement patterns of the print permitting pixels for the masks C1, M1, and Y1 for one plane of this embodiment manufactured by any of the above-described manufacturing methods. . Each mask pattern has an area of 256 × 256 pixels.

  As shown in these figures, in the mask pattern of the present embodiment, since the print permitting pixels in consideration of the dispersibility in the same plane are arranged particularly by the effect of the coefficient α, the record permitting pixels possessed by the gradient are included. In other words, there is no bias in the dispersion of the print permitting pixels, and the overall impression is smooth.

  71 and 72 are diagrams showing a logical sum pattern and a logical product pattern of the stacked masks C1 and M1 of the present embodiment shown in FIGS. 68 and 69, respectively.

  As shown in FIGS. 71 and 72, the arrangement (logical sum) of the print permitting pixels when the two masks of the present embodiment are overlapped, and the arrangement (logic) of the extracted printable pixels that overlap with each other. The product is well distributed and has no rough feeling except for the uneven distribution due to gradation. This is because, as described above, the dispersion of the print allowable pixels is considered between the two planes (coefficient β) and the dispersion of the overlap itself is taken into account (coefficient γs (n)).

  73 and 74 are diagrams showing “overlapping” patterns when two and three stacked masks of this embodiment are stacked, respectively. The “overlapping” pattern when the stacked masks C1 and M1 are overlapped represents the logical sum pattern (FIG. 71) of these two masks with a lighter density and the logical product pattern (FIG. 72) with a higher density. The “overlapping” pattern when the stacked masks C1, M1, and Y1 are overlapped represents the logical sum pattern of these three masks with a low density and the logical product pattern with a darker density.

  The “overlapping” patterns shown in FIGS. 73 and 74 represent patterns that are close to the ink dot pattern of the intermediate image when printing is performed using the mask of this embodiment. Therefore, it can be seen from these patterns that ink dots and their overlap in the intermediate image are well dispersed.

Evaluation by shifting The gradation mask according to the present embodiment is also evaluated by shifting as in the above embodiments.

  75 to 77 are diagrams showing patterns of logical sum, logical product, and “superposition” when the masks C1 and M1 shown in FIGS. As is clear from these figures, the logical sum, logical product, and “superposition” patterns when the superposition positions of the lamination masks C1 and M1 of the present embodiment are shifted are various patterns (FIG. Compared with 71-FIG. 73), dispersibility falls and the feeling of roughness when a pattern is observed is increasing.

  FIG. 78 is a diagram showing an “overlapping” pattern when the stacked masks C1, M1, and Y1 are shifted and overlapped. As is clear from this figure, the “superposition” pattern when the superposition positions of the lamination masks C1, M1, and Y1 of the present embodiment are shifted is also more dispersed than the pattern superposed at the regular positions (FIG. 74). And the feeling of roughness when the pattern is observed is increased.

  79 to 81 are diagrams comparing the power spectra when the overlapping position is shifted and when the overlapping position is not shifted (that is, when overlapping is performed at the normal position). Specifically, it is a diagram showing a power spectrum when the logical sum, logical product, and [overlapping] pattern of the two laminated masks C1 and M1 of this embodiment are shifted and not shifted. FIG. 82 is a diagram showing a power spectrum when the [overlapping] pattern of the three laminated masks of this embodiment is shifted and when it is not shifted.

  As shown in these figures, in the laminated mask of this embodiment, the low frequency component when shifted is larger than that when no shift is performed in any of logical sum, logical product, and [superposition]. Become. This is because, as described above, since the laminated mask considers dispersion even between different planes, when the overlay method is different from the normal overlay method when considering the dispersion, the dispersibility is large. It is because it falls.

  Moreover, in the power spectrum without a shift of each figure, the power is large when the spatial frequency is around 1 to 20. This is because the recording rate is changed as a gradation mask. That is, such a relatively small spatial frequency, that is, a bias in the arrangement of the recordable pixels having a large period is recognized as gradation for the time being, and this is an unnecessary low to be controlled by the present invention. It is not recognized as a frequency component bias.

  FIG. 83 is a diagram showing the evaluation based on the shift described above in terms of the amount of low frequency components. Here, the logical sum, logical product, “overlapping” pattern of the two stacked masks C1, M1 and the “overlapping” pattern of the masks C1, M1, Y1 are shifted and not shifted. The amount of the low frequency component is compared and shown.

  As shown in the figure, in the case of the laminated mask of the present embodiment, the shifted ones are the logical sum, logical product, “superposition” pattern of the masks C1, M1, and the “superposition” of the masks C1, M1, Y1. It can be seen that in any of the patterns, the amount of the low-frequency component is increased as compared with the case where the pattern is not shifted.

  As described above, when masks are overlaid, it is possible to determine whether or not the mask is the one to which the present invention is applied depending on whether or not the evaluation value related to dispersibility changes greatly when the overlapping position is shifted. As described above.

[Embodiment 4: 150% uniform mask for 2-pass printing]
In each of the above-described embodiments, the masks of a plurality of planes of the same color are in a complementary relationship with each other, and the arrangement of print permitting pixels is exclusive between the planes. The application of the present invention is not limited to such a mask. The present invention can be applied to a mask having a plurality of planes exceeding 100% when the recording rates of a plurality of masks of the same color are combined. If a mask exceeding 100% is used, the maximum ink ejection amount can be increased even when the resolution of the image data is low.

  The fourth embodiment of the present invention relates to a mask in which two planes of the same color used for two-pass printing each have a recording rate of 75% and a combined recording rate of 150%.

  FIG. 84 is a schematic diagram conceptually illustrating a mask used for the two-pass printing. In FIG. 84, P0001 indicates a print head of one color among C, M, and Y, and here, it is shown as having eight nozzles for simplification of illustration. The nozzles are divided into first and second groups, and each nozzle group includes four nozzles. P0002A and P0002B indicate mask patterns corresponding to the nozzle rows of the first and second groups, respectively. That is, the mask pattern P0002A (lower pattern in the figure) used in the first scan and the mask pattern P0002B (upper pattern in the figure) used in the second scan. Each of these becomes a mask of one plane. In each mask pattern, the printable pixels are shown in black, and the non-printable pixels are shown in white. The first scanning mask pattern P0002A and the second scanning mask pattern P0002B each have a recording rate of 75%, that is, a pattern in which the ratio of the number of print-allowable pixels to all mask pixels in each pattern is 75%. Therefore, when these are overlaid, the pattern allows for a recordable pixel of 150% with respect to a 4 × 4 area, that is, a pattern including an overlap. Note that the pattern shown in the drawing is conceptually different from the mask pattern of the present embodiment shown below for easy explanation.

  P0003 and P0004 indicate images that are completed by two-pass printing, with the dot arrangement constituting them. When one dot is arranged in a pixel, it is represented as “1”, and when two dots are arranged, it is represented as “2”. Note that this image is a so-called solid image in which dots are formed on all pixels for the sake of easy explanation. Therefore, the arrangement of the print allowable pixels of the mask P0002 used for generating the dot print data is reflected as it is. The dot arrangement is shown. In the first scan, the first group of dot recording data is generated using the mask pattern P0002A. Thereby, in the case of a solid image, an image in which 75% of dots of all pixels are filled is formed. The recording medium is conveyed upward in the drawing by the width of the nozzle group.

  In the next second scan, the first group of dot recording data for the area shifted by the carry amount is generated using the mask pattern P0002A, and the second group of dots for the area recorded in the first group. The recording data is generated using the mask pattern P0002B. The image is completed by the two recording scans. At this time, if the completed image is a solid image, an image in which 150% of all pixels are filled is formed.

  The mask manufacturing method of this embodiment can be performed basically in the same manner as in the first embodiment.

  The difference is that in both the simultaneous generation method and the generation for each pass (see FIG. 7), after the 75% mask pattern of the first pass is generated in Step 1, the exclusive in Step 2 is as in Embodiment 1. Instead of arranging the printable pixel at the position, a second-pass mask pattern of 75% processing repetition similar to Step 1 is generated. In the following, the arrangement movement method and the sequential arrangement method, which are arrangement methods, will be described in more detail with respect to differences from the first embodiment.

Arrangement Movement Method The arrangement movement method of this embodiment also performs basically the same processing as the processing of FIG. 8 according to the first embodiment. The difference is that in the same processing as step S801, 75% binary data is obtained for each plane as the initial arrangement in any of the generations of steps 1 and 2 above. Further, in the generation of step 2, the same processing as in step S804 in FIG. 8 does not prohibit the overlap of the print permitting pixels of different planes of the same color when moving the print permitting pixels. That is, when an attempt is made to move to a position where the energy is the lowest, even if it overlaps with a print permitting pixel of another plane of the same color at that position, it is arranged there. As a result, it is possible to generate a mask having a recording rate of 150%, in which two masks are overlaid and the recording rate exceeds 100%.

For the sequential placement method and the sequential movement method, basically the same processing as that shown in FIG. 11 according to the first embodiment is performed. The difference is that, in the same process as in step S1106, it is determined whether or not the print permitting pixels have been arranged up to 75% in both generations of steps 1 and 2 above. Further, in the mask generation for the second pass in step 2 described above, the same process as in step S1104 in FIG. 11 does not prohibit overlapping the print permitting pixels of the same color and different planes when arranging the print permitting pixels. That is, when an attempt is made to arrange at the position where the energy is the lowest, even if it overlaps with the print permitting pixel of another plane of the same color at that position, it is arranged there. As a result, it is possible to generate a mask having a recording rate of 150%, in which two masks are overlaid and the recording rate exceeds 100%.

  If the mask manufactured by the above manufacturing method is used, the dispersibility of the place (pixel position) where two dots are arranged can be improved.

[Embodiment 5: Mask with Cluster Size of m × n]
The present invention can also be applied to a so-called cluster mask in which m × n recording allowable pixels are used as one unit.

  FIG. 85 is a diagram for explaining the concept of a 100% uniform mask having a cluster size of 1 × 2 for 2-pass printing. In FIG. 85, P0001 indicates a recording head of one color among C, M, and Y, and here, it is illustrated as having eight nozzles for simplification of illustration. The nozzles are divided into first and second groups, and each nozzle group includes four nozzles. P0002A and P0002B indicate mask patterns corresponding to the nozzle rows of the first and second groups, respectively. That is, the mask pattern P0002A (lower pattern in the figure) used in the first scan and the mask pattern P0002B (upper pattern in the figure) used in the second scan. Each of these becomes a mask of one plane. In each mask pattern, the 1 × 2 size cluster recording permissible pixel is shown in black, and the 1 × 2 size cluster non-recording permissible pixel is shown in white. The mask pattern P0002A for the first scan and the mask pattern P0002B for the second scan are patterns with a recording rate of 50%, respectively. Therefore, when these are overlaid, the cluster recording allowable pixel becomes a 100% pattern with respect to a 4 × 4 area.

  P0003 and P0004 show an image completed by two-pass printing in an arrangement with 1 × 2 dots constituting the image as a unit. Note that this image is a so-called solid image in which dots are formed on all pixels for the sake of easy explanation. Therefore, the arrangement of the print allowable pixels of the mask P0002 used for generating the dot print data is reflected as it is. Dot arrangement. In the first scan, the first group of dot recording data is generated using the mask pattern P0002A. As a result, in the case of a solid image, an image in which 50% of all pixels are filled is formed. The recording medium is conveyed upward in the drawing by the width of the nozzle group. In the next second scan, the first group of dot recording data for the area shifted by the carry amount is generated using the mask pattern P0002A, and the second group of dots for the area recorded in the first group. The recording data is generated using the mask pattern P0002B. The image is completed by the two recording scans. At this time, when the completed image is a solid image, an image in which 1 × 2 unit dots are filled in 100% of all pixels is formed.

  As is clear from the above description, when a recording allowable pixel having a size of m × n (1 × 2 in the present embodiment) is defined as one unit, a mask can be manufactured as described in the first embodiment. Is easy to understand. In addition, the mask of the present embodiment can obtain substantially the same effect as that described in the first embodiment.

[Other Embodiments]
In addition to the above-described embodiment, for example, the four-pass mode shown in the second embodiment can be combined with the third, fourth, and fifth embodiments, respectively, and the gradation shown in the third embodiment can also be combined. A combination of the embodiment and the fourth and fifth embodiments is also possible. Furthermore, the combination of Embodiment 4 and Embodiment 5 is also possible, and these combinations can be implemented from the description of each embodiment.

Further, the type of ink that can be applied in the present invention is not limited to the type of ink described in the above embodiment. For example, light ink (light cyan ink, light magenta ink) having a lower density than the basic colors of CMY and special color inks such as red, blue, and green can be further added and used. The present invention is also used in a recording apparatus. The laminated mask described in the above embodiment may be applied to all types of ink, or the laminated mask may be applied to a combination of some of the multiple types of ink used in the recording apparatus. Good.

  For example, when six color inks of cyan (C), magenta (M), yellow (Y), black (K), light cyan (Lc), and light magenta (Lm) are used, a laminated mask for all these six colors. May be applied. In this case, a laminated mask for six colors is generated by the manufacturing method described in the above embodiment.

  On the other hand, a laminated mask may be applied to combinations of some of the six colors (two colors, three colors, four colors, and five colors). In this case, two forms are possible. The first mode is a mode in which a laminated mask is generated for the above-mentioned part of the colors, and the mask manufacturing method for other colors is not limited. For example, for three colors (for example, CMY) among the six colors, a laminated mask is generated by the manufacturing method described in the above embodiment, and for the other three colors (KLcLm), a mask is generated by a known manufacturing method. The second form is a form in which a laminated mask is generated for the part of the colors, and for the other colors, one selected from the laminated masks generated for the part of colors is assigned. For example, for the three colors CMY among the six colors, a laminated mask is generated by the manufacturing method described in the above embodiment, and for the other three colors (KLcLm), it is selected from among the laminated masks generated for CMY. Apply things.

  In the above-described embodiment, the case where the laminated mask is applied to a combination of different ink colors has been described. However, the present invention is not limited to this embodiment. The present invention is also applicable to a mode in which printing is performed using dots of the same color and different diameters (same color inks having different ejection volumes). In this case, the above-described laminated mask may be applied to dots having the same color and different diameters (for example, large dots and small dots). For example, consider a case where six types of dots of large cyan, small cyan, large magenta, small magenta, yellow, and black are used. In this case, a laminated mask is generated for the large cyan and small cyan or large magenta and small magenta by the manufacturing method described in the above embodiment.

  Furthermore, in the form of using dots of the same color and different diameters (for example, large dots and small dots), the above-described laminated mask is applied to the combination of different color dots, and the same mask is applied to the combination of the same color dots having different diameters. It may be a form to do. For example, in the case of using the above-described six types of dots, a stacking mask is generated by the manufacturing method described in the above embodiment for large cyan and large magenta, and the same mask as that for large cyan is applied to small cyan. Applies the same mask as large magenta.

  The number of types of dots having the same color and different diameters is not limited to two types of large and small, and may be three types of large, medium, and small, or more. Further, the present invention is not effective only when applied to dots having at least one of different colors and sizes. For example, the present invention may be applied to the same color ink ejected from different nozzle groups at different timings. Demonstrate the effect. For example, in the form in which the nozzle groups are arranged in the order of CMYMC along the main scanning direction of the head, the stack manufactured by the above manufacturing method for the same color nozzle groups (C nozzle group, M nozzle group) that are separated from each other. Apply the mask.

Further, as described above, the present invention can also be applied to a form using a liquid other than the ink containing the color material . Examples of the liquid other than the ink containing the color material include a reaction liquid that aggregates or insolubilizes the color material in the ink. In this case, for at least one kind of ink and reaction liquid, a laminated mask is generated by the manufacturing method described in the above embodiment.

  In the present invention, any of a dye ink containing a dye as a color material, a pigment ink containing a pigment as a color material, and a mixed ink containing a dye and a pigment as a color material can be applied.

FIG. 2 is a block diagram mainly illustrating hardware and software configurations of a PC as an image processing apparatus according to an embodiment of the present invention. It is a block diagram for demonstrating the flow of the image data conversion process in the inkjet recording system of one Embodiment of this invention. 1 is a perspective view showing an ink jet recording apparatus applicable to an embodiment of the present invention. FIG. 3 is a diagram schematically illustrating a recording head, a mask pattern, and a recording medium in order to explain 2-pass recording. FIG. 6 is a diagram schematically illustrating a recording head and a recording pattern for explaining two-pass multi-pass recording. (A) And (b) is a figure which shows typically the binary data of the six planes which concern on each 2 division | segmentation recording of C, M, and Y. FIG. It is a figure explaining the mask manufacturing method concerning a first embodiment of the present invention. It is a flowchart which shows the procedure of the mask manufacturing method which concerns on 1st embodiment of this invention. It is a figure which shows typically the function of the basic repulsive potential E (r) which concerns on embodiment of this invention. (A)-(d) is a figure which illustrates typically the provision of the repulsive potential and attenuation | damping process of total energy concerning 1st embodiment of this invention. It is a flowchart which shows the procedure of the other mask manufacturing method which concerns on 1st embodiment of this invention. It is a figure explaining the logical product of a mask pattern. It is a figure explaining the logical sum of a mask pattern. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the recording permissible pixel of a dispersion | distribution mask pattern only for an own plane . It is a figure which shows arrangement | positioning of the recording permissible pixel of a random mask pattern. It is a figure which shows the arrangement | positioning pattern (logical sum pattern) of the print permission pixel obtained by the logical sum of two mask patterns which concern on 1st embodiment of this invention. It is a figure which shows the arrangement | positioning pattern (logical product pattern) of the printing permissible pixel obtained by the logical product of two mask patterns which concern on 1st embodiment of this invention. It is a figure which shows the arrangement | positioning pattern (logical sum pattern) of the printing permissible pixel obtained by the logical sum of the three mask patterns concerning 1st embodiment of this invention. It is a figure which shows the arrangement | positioning pattern (logical product pattern) of the printing permissible pixel obtained by the logical product of the three mask patterns which concern on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the print permission pixel of the logical sum of a dispersion | distribution mask pattern only for two self-planes . It is a figure which shows arrangement | positioning of the printing permissible pixel of the logical product of a dispersion | distribution mask pattern only for two self-planes . It is a figure which shows arrangement | positioning of the recording permission pixel of the logical sum of two random mask patterns. It is a figure which shows arrangement | positioning of the print permission pixel of the logical product of two random mask patterns. It is a figure explaining the "superposition" pattern of a mask pattern. It is a figure which shows the arrangement | positioning pattern (superimposition pattern) of the printing allowable pixel obtained by "superposition" of two mask patterns which concern on 1st embodiment of this invention. It is a figure which shows the arrangement | positioning pattern (superimposition pattern) of the printing permissible pixel obtained by "superimposition" of the three mask patterns which concern on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the printing | stacking permissible pixel of "superposition" of a dispersion | distribution mask pattern only in two self-planes . It is a figure which shows arrangement | positioning of the printing | stacking permissible pixel of "superposition" of two random mask patterns. It is a figure explaining the frequency characteristic of a mask. It is a figure explaining the frequency characteristic of the logical sum pattern of two masks. It is a figure explaining the frequency characteristic of the logical product pattern of two masks. It is a figure explaining the frequency characteristic of the "superposition" pattern of two masks. It is a figure explaining the frequency characteristic of the "superposition" pattern of three masks. It is a figure which shows the arrangement | positioning pattern of the recording permissible pixel obtained when the mask (C1, M1) of 1st embodiment of this invention is shifted and ORed. Slide the mask (C1, M1) of the first embodiment of the present invention is a drawing illustrating an arrangement pattern of print permitting pixels obtained when the logical product. It is a figure which shows the arrangement | positioning pattern of the recording permissible pixel obtained when the mask (C1, M1) of 1st embodiment of this invention is shifted and "superimposition" is performed . The power spectrum of the logical sum pattern when logically summed without shifting the masks (C1, M1) of the first embodiment of the present invention and the logical sum pattern when logically summed with the masks (C1, M1) shifted are shown. FIG. FIG. 4 is a diagram showing a power spectrum of a logical sum pattern when logical sum is performed without shifting the dispersion mask (C1, M1) only in its own plane and a logical sum pattern when logical sum is performed by shifting the mask (C1, M1). is there. It is a figure which shows the power spectrum of the logical sum pattern at the time of carrying out logical sum without shifting the random mask (C1, M1), and the logical sum pattern when shifting the mask (C1, M1). The power spectrum of the logical product pattern when the logical product is obtained without shifting the masks (C1, M1) of the first embodiment of the present invention and the logical product pattern when the logical product is obtained by shifting the masks (C1, M1). FIG. A diagram showing a power spectrum of logical sum pattern of the case where the logical product by shifting the logical sum pattern and the mask in the case of logical (C1, M1) is not shifted to N'nomi dispersion mask (C1, M1) - own Pre is there. It is a figure which shows the power spectrum of the logical sum pattern at the time of logical product without shifting the random mask (C1, M1) and the logical sum pattern when shifting the mask (C1, M1). The power spectrum of the superposition pattern when the masks (C1, M1) of the first embodiment of the present invention are superposed without being shifted and the superposition pattern when the masks (C1, M1) are superposed are shifted. FIG. FIG. 7 is a diagram showing a power spectrum of a superposition pattern when superposition is performed without shifting the dispersion mask (C1, M1) only for the own plane and a superposition pattern when superposition is performed while the mask (C1, M1) is superposed . is there. Is a diagram showing the power spectrum of the superposition pattern when superimposed by shifting superimposition pattern and the mask (C1, M1) in the case of superposed without offset the random mask (C1, M1). Overlay pattern when superimposed shifting the mask overlay pattern and the mask in the case of superposed without offset a (C1, M1, Y1) ( C1, M1, Y1) of the first embodiment of the present invention It is a figure which shows no power spectrum. The first logical sum is not shifted mask embodiment of the present invention, the arrangement pattern of print permitting pixels obtained when performing logical product and "superposing", a logical sum by shifting the mask, a logical product FIG. 5 is a diagram illustrating a difference in low frequency components from an array pattern of print permitting pixels obtained when [overlay] is performed . Own pre - N'nomi logical sum is not shifted dispersion mask, a sequence pattern of print permitting pixels obtained when performing logical product and "superposing", a logical sum by shifting the mask, logical product and Cascade It is a figure which shows the difference of a low frequency component with the arrangement | sequence pattern of a printing permissible pixel obtained when performing "combination". Logical sum is not shifted random mask was performed with sequence patterns of print permitting pixels obtained when performing logical product and "superposing", a logical sum by shifting the mask, a logical product and [overlay] It is a figure which shows the difference of the low frequency component with the arrangement | sequence pattern of the recording permissible pixel obtained in the case . It is a figure explaining the mask manufacturing method concerning a second embodiment of the present invention. It is a figure explaining the mask manufacturing method concerning a second embodiment of the present invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 2nd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 2nd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 2nd embodiment of this invention. It is a figure which shows arrangement | positioning of the print | recording permissible pixel of "superposition" of the three mask patterns concerning 2nd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing | stacking permissible pixel of "superposition" of six mask patterns which concerns on 1st embodiment of this invention. It is a figure which shows arrangement | positioning of the printing | non-printing permissible pixel of "superposition" of nine mask patterns which concerns on 2nd embodiment of this invention. It is a figure which shows arrangement | positioning of the print | recording permissible pixel of "superposition" of three mask patterns when the mask of 2nd embodiment of this invention is shifted. It is a figure which shows arrangement | positioning of the printing | stacking permissible pixel of "superposition" of six mask patterns when the mask of 2nd embodiment of this invention is shifted. It is a figure which shows arrangement | positioning of the printing allowable pixel of "superposition" of nine mask patterns when the mask of 2nd embodiment of this invention is shifted. The arrangement pattern of print permitting pixels obtained when performing "superposition" not shifted the mask of the second embodiment of the present invention, obtained when subjected to [overlay] by shifting the mask It is a figure which shows the difference of the low frequency component with the arrangement | sequence pattern of a recording permissible pixel . (A) And (b) is a figure explaining the mask which concerns on 3rd embodiment of this invention. It is a flowchart which shows the procedure of the mask manufacturing method which concerns on 3rd embodiment of this invention. It is a flowchart which shows the procedure of the other mask manufacturing method which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the printing permissible pixel of the mask pattern which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the recording permission pixel of the logical sum of two mask patterns which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the print permission pixel of the logical product of two mask patterns which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the print | permission permission pixel of "superposition" of two mask patterns which concerns on 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the print | recording permissible pixel of "superposition" of the three mask patterns concerning 3rd embodiment of this invention. It is a figure which shows arrangement | positioning of the recording permission pixel of the logical sum of two mask patterns when the mask of 3rd embodiment of this invention is shifted. It is a figure which shows arrangement | positioning of the printing allowable pixel of the logical product of two mask patterns when the mask of 3rd embodiment of this invention is shifted. It is a figure which shows arrangement | positioning of the print | recording permissible pixel of "superposition" of two mask patterns when the mask of 3rd embodiment of this invention is shifted. It is a figure which shows arrangement | positioning of the print | recording permissible pixel of "superposition" of three mask patterns when the mask of 3rd embodiment of this invention is shifted. The power spectrum of the logical sum pattern when the logical sum is performed without shifting the masks (C1, M1) of the third embodiment of the present invention and the logical sum pattern when the logical sum is performed while shifting the masks (C1, M1). FIG. The power spectrum of the logical product pattern when the logical product is obtained without shifting the masks (C1, M1) of the third embodiment of the present invention and the logical product pattern when the logical product is obtained by shifting the masks (C1, M1). FIG. The power spectrum of the superposition pattern when the masks (C1, M1) of the third embodiment of the present invention are superposed without shifting and the superposition pattern when the masks (C1, M1) are superposed while shifting is shown. FIG. Overlay pattern when superimposed shifting the mask overlay pattern and the mask in the case of superposed without offset a (C1, M1, Y1) ( C1, M1, Y1) of the third embodiment of the present invention It is a figure which shows no power spectrum. Third logical sum is not shifted mask embodiment of the present invention, the arrangement pattern of print permitting pixels obtained when performing logical product and "superposing", a logical sum by shifting the mask, a logical product FIG. 5 is a diagram illustrating a difference in low frequency components from an array pattern of print permitting pixels obtained when [overlay] is performed . It is a figure explaining the mask used for the multipass printing of 2 passes based on the 4th embodiment of this invention. It is a figure explaining the mask used for 2-pass multipass printing concerning a 5th embodiment of the present invention. It is a figure explaining the problem of a prior art.

Explanation of symbols

100 Host computer (PC)
101, J0001 Application 102 OS
103 Printer driver 104 Printer 107 HD
108 CPU
109 RAM
110 ROM
J0005 Binarization processing J0006 Print data creation J0008 Mask data conversion processing

Claims (25)

Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The first, low frequency components of the arrangement pattern of print permitting pixels obtained by the logical product of the second and third mask patterns performed on the basis of the correspondence between the use of these three mask pattern, the three A recording apparatus characterized in that the number of low frequency components of an array pattern of print-allowable pixels obtained by performing a logical product of mask patterns based on a correspondence relationship different from the correspondence relationship at the time of use is less. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The first, low frequency components of the arrangement pattern of print permitting pixels obtained by the logical sum of the second and third mask patterns performed on the basis of the correspondence between the use of these three mask pattern, the three A recording apparatus characterized in that the mask pattern has fewer logical components than the low-frequency component of an array pattern of print-allowable pixels obtained by performing a logical sum of mask patterns based on a correspondence relationship different from the correspondence relationship at the time of use . Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The first, low frequency components of the arrangement pattern of print permitting pixels obtained by logical product based on the second and third mask patterns on a corresponding relationship when using the three mask pattern, the first, less than the low frequency components of the arrangement pattern of print permitting pixels obtained by logical product based on a different relationship than the relationship of the time the use of the second and third mask pattern,
The first, low frequency components of the arrangement pattern of print permitting pixels obtained by ORing the basis of the second and third mask patterns on a corresponding relationship during the use, the first, second and third The recording apparatus is characterized in that the number of the mask patterns is less than the low-frequency component of the array pattern of the print permitting pixels obtained by performing a logical OR based on the correspondence different from the correspondence at the time of use . Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The first, lower-frequency components are high frequency components in the arrangement pattern of print permitting pixels obtained by performing, based on the correspondence between the use of these three mask patterns a logical product of the second and third mask patterns A recording device characterized by having a small amount. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The arrangement pattern of print permitting pixels obtained by the logical product of the first mask pattern and the second mask pattern 3 of the mask pattern, it and the low-frequency component by the aperiodic less than the high frequency component A recording apparatus. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The first, lower-frequency components are high frequency components in the arrangement pattern of print permitting pixels obtained by performing, based on the correspondence between the use of these three mask patterns a logical sum of the second and third mask patterns A recording apparatus characterized by a small amount. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A recording device that scans a predetermined area of a recording medium a plurality of times and records an image in the predetermined area,
An image used in each of the plurality of scans using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the first nozzle group. A first means for dividing the data;
The second pattern group having a plurality of mask patterns corresponding to the plurality of scans, and the image data to be recorded in the predetermined area by the second nozzle group is used for each of the plurality of scans. A second means for dividing the data;
An image used in each of the plurality of scans using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, and image data to be recorded in the predetermined area by the third nozzle group. A third means for dividing the data,
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The arrangement pattern of print permitting pixels obtained by the logical sum of the first mask pattern and the second mask pattern 3 of the mask pattern, it and the low-frequency component by the aperiodic less than the high frequency component A recording apparatus. Said first, second and third mask pattern, respectively, recorded according to any one of claims 1 to 7, characterized in that and the low frequency component by the aperiodic has fewer properties than the high-frequency component apparatus. The first type of dot is a cyan dot;
The second type of dot is a magenta dot,
The recording apparatus according to claim 1, wherein the third type of dot is a yellow dot. 9. The first, second, and third types of dots are three types of dots selected from a cyan, magenta, yellow, black, light cyan, and light magenta dot group. A recording apparatus according to any one of the above. The recording apparatus according to claim 1, wherein the predetermined scan is a first scan with respect to the predetermined area . The recording apparatus according to claim 1, wherein the low frequency component is a frequency component on a lower frequency side than a half of a highest spatial frequency determined based on the arrangement pattern. 12. The recording apparatus according to claim 1, wherein the low frequency component is a frequency component on a low frequency side with respect to 10 cycles / mm . Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a recording medium of a recording head having at least
Using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, the plurality of scans is performed by dividing image data to be recorded in the predetermined area by the first nozzle group. First means for generating divided image data to be recorded in each;
Using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the second nozzle group, thereby performing the plurality of scans. A second means for generating divided image data to be recorded respectively;
Using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the third nozzle group, thereby performing the plurality of scans. And a third means for generating divided image data to be recorded respectively.
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
Low-frequency arrangement pattern of print permitting pixels obtained by performing a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using these three mask patterns components, arrangement pattern of print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern A data processing apparatus characterized by being less than the low frequency component. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a recording medium of a recording head having at least
Using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, the plurality of scans is performed by dividing image data to be recorded in the predetermined area by the first nozzle group. First means for generating divided image data to be recorded in each;
Using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the second nozzle group, thereby performing the plurality of scans. A second means for generating divided image data to be recorded respectively;
Using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the third nozzle group, thereby performing the plurality of scans. And a third means for generating divided image data to be recorded respectively.
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
Low-frequency arrangement pattern of print permitting pixels obtained by performing a logical sum of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using these three mask patterns components, arrangement pattern of print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical sum of said third mask pattern and the first mask pattern and the second mask pattern A data processing apparatus characterized by being less than the low-frequency component. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a recording medium of a recording head having at least
Using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, the plurality of scans is performed by dividing image data to be recorded in the predetermined area by the first nozzle group. First means for generating divided image data to be recorded in each;
Using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the second nozzle group, thereby performing the plurality of scans. A second means for generating divided image data to be recorded respectively;
Using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the third nozzle group, thereby performing the plurality of scans. And a third means for generating divided image data to be recorded respectively.
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
Low-frequency arrangement pattern of print permitting pixels obtained by performing a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using these three mask patterns components, arrangement pattern of print permitting pixels obtained by performing a different relationship from that of the in use relationship a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern Less than the low frequency component of
Low frequency components of the arrangement pattern of print permitting pixels obtained by performing a logical OR of said third mask pattern and the first mask pattern and the second mask pattern at the corresponding relation during said use, said first than the low frequency components of the arrangement pattern of print permitting pixels obtained by performing a logical OR of 1 wherein the mask pattern and the second mask pattern of the third mask pattern in a different relationship than the relationship of time of the use A data processing apparatus characterized by having a small number. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a recording medium of a recording head having at least
Using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, the plurality of scans is performed by dividing image data to be recorded in the predetermined area by the first nozzle group. First means for generating divided image data to be recorded in each;
Using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the second nozzle group, thereby performing the plurality of scans. A second means for generating divided image data to be recorded respectively;
Using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the third nozzle group, thereby performing the plurality of scans. And a third means for generating divided image data to be recorded respectively.
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The arrangement pattern of print permitting pixels obtained by performing a logical product of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using the three mask pattern, low A data processing apparatus characterized in that a frequency component has a characteristic smaller than that of a high frequency component. Third nozzle group for forming a first nozzle group and a second nozzle group for forming a second type of dots third type of dots for forming a first type of dots A data processing device for generating image data used in each of a plurality of scans of a predetermined area of a recording medium of a recording head having at least
Using the first pattern group having a plurality of mask patterns corresponding to the plurality of scans, the plurality of scans is performed by dividing image data to be recorded in the predetermined area by the first nozzle group. First means for generating divided image data to be recorded in each;
Using the second pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the second nozzle group, thereby performing the plurality of scans. A second means for generating divided image data to be recorded respectively;
Using the third pattern group having a plurality of mask patterns corresponding to the plurality of scans, the image data to be recorded in the predetermined area is divided by the third nozzle group, thereby performing the plurality of scans. And a third means for generating divided image data to be recorded respectively.
Said plurality of first mask patterns included in the first pattern group corresponding to a predetermined scan of the scan, the second mask pattern and the included in the second pattern group corresponding to the predetermined scan third mask patterns included in the third pattern group corresponding to a predetermined scan, respectively, different arrangement of print permitting pixels,
The arrangement pattern of print permitting pixels obtained by performing a logical sum of said first mask pattern and the second mask pattern 3 of the mask pattern corresponding relationship when using the three mask pattern, low A data processing apparatus characterized in that a frequency component has less characteristics than a high frequency component. The data processing apparatus according to claim 14, wherein the predetermined scan is a first scan with respect to the predetermined area . 20. The data processing apparatus according to claim 14, wherein the low frequency component is a frequency component that is on a lower frequency side than half of the highest spatial frequency determined based on the arrangement pattern. . The data processing apparatus according to any one of claims 14 to 19, wherein the low frequency component is a frequency component on a lower frequency side than 10 cycles / mm . A mask pattern manufacturing method comprising:
  Of the plurality of scans of the first nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the first nozzle group for forming the first type of dots. A first determination step of determining an arrangement of print permitting pixels in a first mask pattern for generating image data to be recorded in one scan of
Of the plurality of scans of the second nozzle group for the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. A second determination step of determining an arrangement of print permitting pixels in the second mask pattern for generating image data to be recorded in one scan of
  Of the plurality of scans of the third nozzle group for the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the third nozzle group for forming the third type of dots. A third determination step of determining the arrangement of the print allowable pixels in the third mask pattern for generating the image data to be recorded in one scan of
  In the first determination step, the first, second, and second are determined by changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the second and third mask patterns. Including a step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical product of the third mask pattern,
In the second determining step, the first, second and second arrangements are changed by changing the arrangement of the print permission pixels in the second mask pattern based on the arrangement of the print permission pixels in the first and third mask patterns. Including a step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical product of the third mask pattern,
  In the third determination step, the first, second and second arrangements are changed by changing the arrangement of the print permitting pixels in the third mask pattern based on the arrangement of the print allowance pixels in the first and second mask patterns. A method of manufacturing a mask pattern, comprising a step of reducing a low frequency component of an arrangement pattern of print permission pixels obtained by a logical product of the third mask pattern. A mask pattern manufacturing method comprising:
  Among a plurality of scans of the first nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the first nozzle group for forming the first type of dots. A first determination step of determining an arrangement of print permitting pixels in a first mask pattern for generating image data to be recorded in one scan of
  Of the plurality of scans of the second nozzle group for the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. A second determination step of determining an arrangement of print permitting pixels in the second mask pattern for generating image data to be recorded in one scan of
  Of the plurality of scans of the third nozzle group for the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the third nozzle group for forming the third type of dots. A third determination step of determining the arrangement of the print allowable pixels in the third mask pattern for generating the image data to be recorded in one scan of
  In the first determination step, the first, second, and second are determined by changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the second and third mask patterns. Including a step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical sum of a third mask pattern,
  In the second determining step, the first, second and second arrangements are changed by changing the arrangement of the print permission pixels in the second mask pattern based on the arrangement of the print permission pixels in the first and third mask patterns. Including a step of reducing a low-frequency component of an arrangement pattern of print permitting pixels obtained by a logical sum of a third mask pattern,
  In the third determination step, the first, second and second arrangements are changed by changing the arrangement of the print permitting pixels in the third mask pattern based on the arrangement of the print allowance pixels in the first and second mask patterns. A method of manufacturing a mask pattern, comprising a step of reducing a low frequency component of an arrangement pattern of print permitting pixels obtained by a logical sum of third mask patterns.   A mask pattern manufacturing method comprising:
  Among a plurality of scans of the first nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the first nozzle group for forming the first type of dots. A determination step of determining an arrangement of print permitting pixels in the first mask pattern for generating image data to be recorded in one scan of
  In the determining step, a plurality of the second nozzle groups for the predetermined area are thinned out by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. Of the print-allowable pixels in the second mask pattern for generating image data to be recorded in one of the scans, and the third for forming the third type of dots. Image data to be recorded in one scan out of a plurality of scans of the third nozzle group for the predetermined area is generated by thinning out the image data to be recorded in the predetermined area of the recording medium by the nozzle group. Changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the third mask pattern for Method for producing a mask pattern, characterized in that to reduce the low-frequency component of the arrangement pattern of print permitting pixels obtained by the logical product of 1, wherein the mask pattern and the second mask pattern of the third mask pattern.   A mask pattern manufacturing method comprising:
  Of the plurality of scans of the first nozzle group with respect to the predetermined area by thinning out image data to be recorded in the predetermined area of the recording medium by the first nozzle group for forming the first type of dots. A determination step of determining an arrangement of print permitting pixels in the first mask pattern for generating image data to be recorded in one scan of
  In the determining step, a plurality of the second nozzle groups for the predetermined area are thinned out by thinning out image data to be recorded in the predetermined area of the recording medium by the second nozzle group for forming the second type of dots. Of the print-allowable pixels in the second mask pattern for generating image data to be recorded in one of the scans, and the third for forming the third type of dots. Image data to be recorded in one scan out of a plurality of scans of the third nozzle group for the predetermined area is generated by thinning out the image data to be recorded in the predetermined area of the recording medium by the nozzle group. Changing the arrangement of the print permitting pixels in the first mask pattern based on the arrangement of the print permitting pixels in the third mask pattern for Method for producing a mask pattern, characterized in that to reduce the low-frequency component of the arrangement pattern of print permitting pixels obtained by the logical sum of 1 wherein the mask pattern and the second mask pattern of the third mask pattern.

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