JP2007301989A - Data processor, recording device, and mask manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce beading caused by interference between a mask and a block pattern that is a drive pattern of each nozzle array when recording the same color while using two nozzle arrays. <P>SOLUTION: Repulsive potential is calculated in-between a plane of the block pattern when manufacturing the mask. Namely, when setting an arrangement of a recording allowance area in the mask, the repulsive potential is calculated between dots in the plane of the block pattern so that the recording allowance area is arranged at a position where energy is the lowest and is most dispersed. By this, it is possible to achieve that the recording allowance area is excellently dispersed in overlapping of the block pattern with the mask. As a result, dots, which are formed by driving nozzles while distributing mask-processed dot data to two nozzle arrays corresponding to the block pattern, are excellently dispersed without biasing the number of the dots in one nozzle array. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a data processing apparatus, a recording apparatus, and a mask manufacturing method. More specifically, the present invention uses a mask to divide the dot data to be used in a plurality of scans of the recording head, and uses a plurality of recording element arrays or heads for recording elements of the same color based on the divided data. The present invention relates to dot data generation processing when performing.

  With the spread of information processing equipment such as personal computers in recent years, recording devices as image forming terminals have been rapidly developed and have become widespread. Among various recording apparatuses, ink jet recording apparatuses that perform recording on recording media such as paper, cloth, plastic sheets, and OHP sheets by discharging ink from discharge ports are becoming mainstream for personal use. This is a non-impact recording system with low noise, high-density and high-speed recording operation, easy compatibility with color recording, and low cost. Because it is.

  Advances in inkjet recording technology have promoted higher image quality, higher speed, and lower cost of recording, thereby contributing to the spread of recording devices to personal users. The spread of personal computers and digital cameras also contributes to the spread of recording devices. This digital camera includes not only a single camera that fulfills its function, but also a device that is integrated with another device, such as a mobile phone. However, with such widespread use, personal users are required to further improve image quality. In particular, in recent years, there has been a demand for a printing system that allows easy printing of photos at home and image quality suitable for silver halide photography.

  When compared with a silver salt photograph, the graininess is conventionally regarded as a problem in the ink jet recording apparatus. Various measures for reducing the graininess have been proposed. For example, there is known an ink jet recording apparatus having an ink system in which light cyan or light magenta having a lower color material density is added in addition to normal cyan, magenta, yellow and black. In such an apparatus, the graininess is reduced by using light cyan or light magenta ink in a low image density region. Further, in a region where the image density is high, recording using ordinary cyan ink or magenta ink makes it possible to realize a wider color reproduction range and smooth gradation. There is also a method for reducing graininess by designing the size of dots formed on a recording medium to be smaller. This is generally realized by reducing the amount of ink droplets ejected from the nozzles of the recording head, and a technique for this purpose has also been proposed. In this case, it is possible not only to reduce the amount of ink droplets but also to form a higher resolution image without lowering the recording speed by configuring more ejection openings with a higher arrangement density.

  On the other hand, high-quality and high-speed recording is one of the requirements for recent recording apparatuses. Therefore, as a configuration, Patent Document 1 describes a method of performing recording by providing a plurality of nozzle rows for one color ink. FIG. 1A shows a recording head in the case of recording with one nozzle row for one color ink. On the other hand, FIG. 1B shows a print head used when printing is performed with two nozzle rows for one color ink. In these drawings, for simplification of illustration, one nozzle row is illustrated as comprising 16 nozzles. When recording an image to be recorded with one nozzle row in FIG. 1 (a) with two nozzle rows in FIG. 1 (b), even if the drive frequency of each nozzle row is the same as when recording with one nozzle row, The scanning speed of the nozzle row can be doubled, and the recording speed can be doubled. In addition, when using the two nozzle rows in FIG. 1B as compared with the case of one row in FIG. 1A, a certain amount of area, for example, one half of an area for printing, is recorded. Since the number of times of use is increased, the life of the recording head is extended.

  Such a process of distributing dot data to a plurality of nozzles in two rows or three or more rows is performed, for example, by the configuration shown in FIG. FIG. 2 shows a configuration from when image (dot) data is divided for so-called multi-pass printing and printing is performed by driving a print head based on the divided dot data. In FIG. 2, the image (dot) data input in step 201 is subjected to mask processing in step 202 to generate dot data for each of a plurality of scans. In step 203, the divided dot data for each scan is assigned to the nozzles of the respective nozzle rows. The assignment of dot data to the nozzle rows is performed according to a predetermined pattern. In this specification, this pattern is referred to as a “block pattern” or a “drive pattern”.

  FIG. 3 is a schematic diagram showing a block pattern (driving pattern), in particular, for assigning ejection data to two rows of nozzles.

  In the example shown in the figure, two nozzle arrays A and B that eject ink of the same color are arranged with 16 nozzles at an interval corresponding to 1200 dpi in the vertical direction of the figure. The image to be recorded is a so-called solid image (an image in which ink dots are recorded in all areas (unit areas for recording ink dots)) having a resolution of 1200 dpi. The drive frequency of each nozzle in the nozzle rows A and B is one discharge at an area interval corresponding to 600 dpi. In the case of multi-pass printing, the images assigned to the two nozzle rows are divided corresponding to a plurality of scans. In the above-described solid image, ink dots are recorded in an area with a division ratio corresponding to the number of scans in each scan. However, in the description with reference to FIG. 3 below, the solid image is recorded in one scan for easy understanding. This will be described as an example.

  In FIG. 3, dot data is assigned according to block pattern A for nozzle row A, and dot data is assigned according to block pattern B for nozzle row B. Specifically, when the column (vertical area row in the figure) 0 is recorded, in the nozzle row A, the nozzle numbers {1, 2}, {5, 6, 7}, {9, 10}, {14 }, And in nozzle row B, nozzle numbers {3, 4}, {8}, {11, 12, 13}, {15, 16} are used. When the column 1 is recorded, both the nozzle rows A and B are recorded using exclusive (complementary) nozzles used in the column 0. Of course, when three or more n nozzle rows are used, the pattern is complemented by n columns. Further, the example shown in FIG. 3 is an example in which a plurality of nozzle arrays of the same color ink are configured in one head. However, it is obvious that the above description applies also when each nozzle row is configured as one head and a plurality of recording heads are used for the same ink color.

  As described above, even if each nozzle is driven at a driving frequency of ejecting once at 600 dpi intervals, driving equivalent to the driving frequency of ejecting once at 1200 dpi intervals can be performed, so that the recording speed of a high-resolution image is reduced. It is possible to record without any error.

JP 2005-262788 A JP 2002-144552 A

  By the way, in general, when the recording speed is increased, such as a recording mode in which the number of nozzle rows is two or more, and the recording speed is increased by a plurality of times without changing the driving frequency as described above, May cause beading problems.

  That is, the increase in speed increases the amount of ink applied per unit time and per unit area of the recording medium. In this case, depending on the recording medium, even if all of the ink to which it is applied can finally be absorbed, it cannot be applied to the application speed and is still absorbed on the surface of the recording medium during recording. Ink droplets that are not in contact may come into contact with each other. Then, the ink that is combined by the contact and becomes relatively large may be conspicuous in the image finally obtained, and the image quality may be lowered.

  For example, consider a case where a blue image expressed by cyan ink and magenta ink is recorded on a recording medium by two-pass multi-pass printing. For example, the serial type recording apparatus performs recording by scanning a recording head in which nozzle rows of four colors of cyan, magenta, yellow, and black are arranged. In this scanning, ink is ejected from each nozzle row to the same area of the recording medium. When recording blue, cyan ink and magenta ink based on dot data obtained by decimating cyan and magenta image data by 1/2 are applied to the recording medium with a relatively short time difference in the same scan. At this time, when cyan ink and magenta ink are applied to the same area or adjacent areas on the recording medium, they are attracted by the surface tension of each other, and two (or more) large ink masses (or more) Hereinafter, it is also referred to as a grain). Once such a grain is formed, the ink applied to the next adjacent position is likely to be attracted to the grain. That is, the first generated grain gradually grows as a nucleus, and eventually a large grain is formed. Then, such a grain itself or an image detrimental effect called beading that exists in an irregularly scattered state is caused.

  Such grains are not generated only by the surface tension between the inks. For example, when recording liquids that react with each other are applied in the same scan, the liquids in contact may be bonded by a stronger chemical reaction, which may form grain nuclei.

  Conventionally, various recording methods and mask patterns for preventing beading have been proposed. Japanese Patent Application Laid-Open No. H10-228707 describes using a mask that increases the dispersibility of the dot arrangement recorded by the nozzle row in one scan for one ink color. According to this, it is possible to reduce the formation of grains by contacting the same color inks recorded in one scan.

  However, in Patent Document 2, although the dispersibility of the dot arrangement in one plane recorded by one ink color nozzle row in one scan is considered, the dispersibility is related to the dots of other planes. Not considered. For this reason, for example, the dispersibility between the dots of the planes of other colors recorded by the same scan and the dots of the plane recorded by other scans is poor, and grain may be generated.

  The inventors of the present application have found that the problem of dot dispersibility between different planes described above is the dot arrangement based on the respective block patterns and the dot arrangement based on the mask in the case of recording the same color using a plurality of nozzle rows. And found that this is also true.

  4A to 4E are diagrams for explaining this problem. FIG. 4A shows image (dot) data 401 of one color to be recorded. The dot data 401 is data for one scan among the plurality of scan data divided by the mask.

  4B and 4C are diagrams showing respective block patterns 402 and 403 in the case of printing with two nozzle rows A and B as shown in FIG. When the nozzle arrays A and B are driven according to these block patterns 402 and 403, the dot data 401 is recorded as dot arrangement patterns 404 and 405 shown in FIGS. 4D and 4E, respectively.

  As apparent from FIGS. 4D and 4E, the dot pattern by the mask and the block pattern interfere with each other, and the nozzles used for one of the two nozzle arrays are biased. If there is such a deviation in the nozzles used, the dispersibility of the dots recorded as a result will deteriorate, and beading due to the above-mentioned grains tends to occur. Thus, if there is interference of dot positions between the mask and the plurality of planes of the plurality of block patterns, the dispersibility of the dot arrangement of the finally recorded image is deteriorated, resulting in beading problems. is there.

  An object of the present invention is to provide a data processing apparatus capable of reducing beading caused by interference between a block pattern and a mask, which is a drive pattern for each nozzle array, when recording the same color using a plurality of nozzle arrays. It is to provide a recording apparatus and a mask manufacturing method.

  To this end, the present invention provides a data processing apparatus for generating data for printing by scanning a plurality of nozzle arrays for recording dots of a predetermined color in the same area of a recording medium a plurality of times, and in the same area. In order to divide the dot data of the predetermined color to be recorded into dot data to be used for each of the plurality of scans, a mask process is performed on the dot data of the predetermined color to be recorded in the same area using a mask pattern. And means for distributing the masked dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, The mask pattern includes an arrangement of print permitting areas in the mask pattern and driving in each driving pattern for each nozzle row. In the region where the frequency component in the low frequency region of the logical product pattern obtained by the logical product with the arrangement of the capacity areas is less than the frequency component in the high frequency region and is on the lower frequency side than half of the low frequency region, the peak of the frequency component It has the characteristic which does not exist.

  In another embodiment, there is provided a data processing device for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color in the same area of a printing medium a plurality of times, and printing the same area In order to divide the dot data of the predetermined color to be divided into dot data to be used for each of the plurality of scans, mask processing is performed on the dot data of the predetermined color to be recorded in the same area using a mask pattern. And means for distributing the mask-processed dot data to the plurality of nozzle rows according to a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and The mask pattern includes an arrangement of print allowance areas in the mask pattern and a drive allowance area in each drive pattern for each nozzle array. In the region where the frequency component in the low frequency region of the logical product pattern obtained by the logical product with the arrangement of is less than the frequency component in the high frequency region and is on the lower frequency side than 1/4 of the low frequency region, the peak of the frequency component is It has the characteristic which does not exist.

  In still another embodiment, there is provided a data processing device for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color in the same area of a printing medium a plurality of times, and in the same area In order to divide the dot data of the predetermined color to be recorded into dot data to be used for each of the plurality of scans, a mask process is performed on the dot data of the predetermined color to be recorded in the same area using a mask pattern. And means for distributing the masked dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, The mask pattern includes an arrangement of print permission areas in the mask pattern and a drive permission for each drive pattern for each nozzle row. The frequency component in the low frequency region of the logical product pattern obtained by the logical product with the arrangement of the areas is less than the frequency component in the high frequency region, and has a characteristic that no peak of the frequency component exists in the entire low frequency region. To do.

  A recording apparatus for recording a plurality of nozzle rows for recording dots of a predetermined color by scanning the same area of the recording medium a plurality of times, the dot data of the predetermined color to be recorded in the same area Means for performing a mask process using a mask pattern on the dot data of the predetermined color to be recorded in the same area to divide the dot data to be used in each of the plurality of scans, and the mask process Means for allocating dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, the mask pattern comprising: It is obtained by the logical product of the arrangement of the printable area and the arrangement of the drive allowable area in each drive pattern for each nozzle row. Characterized in that there is no peak frequency components in the region of from the low frequency half of the small and the low frequency range the frequency component than the frequency component of the high frequency range of the low frequency range of the logical product pattern that.

  Furthermore, the data processing device generates mask data by performing mask processing on dot data and scanning a plurality of nozzle arrays for recording dots of a predetermined color in the same area of the recording medium a plurality of times. Then, the masked dot data is distributed to the plurality of nozzle rows in accordance with the drive pattern that defines the nozzle drive allowable area and non-drive allowable area for each of the plurality of nozzle rows, and based on the distributed dot data A method of manufacturing a mask pattern used in the mask processing in a data processing apparatus that generates dot data for driving the nozzles of the plurality of nozzle rows, and a determination step for determining an arrangement of print permitting areas in the mask pattern; The determining step includes the arrangement of the print allowable area in the mask pattern and the nozzle row. Features that the including a step of determining an arrangement of print permitting areas as low frequency components of the logical product patterns obtained by the logical product is less than the high frequency components of the arrangement of the drive permissible area in the respective drive patterns.

  Further, there is a data processing method for generating data for printing by scanning a plurality of nozzle arrays for recording dots of a predetermined color a plurality of times in the same area of a recording medium, and the data should be recorded in the same area In order to divide the dot data of the predetermined color into dot data to be used for each of the plurality of scans, a step of performing mask processing on the dot data of the predetermined color to be recorded in the same area, and the mask processing And distributing the dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and a mask pattern used for the mask processing The arrangement of the print allowable area in the mask pattern and the arrangement of the drive allowable area in each drive pattern for each nozzle row The frequency component in the low frequency region of the logical product pattern obtained by the logical product is less than the frequency component in the high frequency region, and there is no frequency component peak in the region that is on the lower frequency side than half of the low frequency region. And

  In another embodiment, there is provided a data processing method for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color in the same area of a printing medium a plurality of times, and printing in the same area Performing a mask process on the dot data of the predetermined color to be recorded in the same area in order to divide the dot data of the predetermined color to be divided into dot data used in each of the plurality of scans; And distributing the processed dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and is used for the mask processing. The mask pattern includes the arrangement of the print allowance area in the mask pattern and the drive allowance area in each drive pattern for each nozzle row. The frequency component peaks in the region where the frequency component in the low frequency region of the logical product pattern obtained by the logical product with the device is lower than the frequency component in the high frequency region and is lower than 1/4 of the low frequency region. It is characterized by not.

  In still another embodiment, there is provided a data processing method for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color in the same area of a printing medium a plurality of times, and in the same area Performing a mask process on the dot data of the predetermined color to be recorded in the same area in order to divide the dot data of the predetermined color to be recorded into dot data used in each of the plurality of scans; Distributing the mask-processed dot data to the plurality of nozzle rows according to a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows. The mask pattern to be used is the arrangement of the print allowance area in the mask pattern and the drive allowance error in each drive pattern for each nozzle row. Wherein the frequency components in the low frequency range of the logical product patterns obtained by the logical product of the arrangement of A there is no peak frequency components in less and the low-frequency range entire than the frequency components of the high frequency range.

  According to the above configuration, a dot obtained using a mask in which the low frequency component of the pattern obtained by the logical product of the arrangement of the print allowable area in the mask and the drive allowable area of each nozzle group is smaller than the high frequency component is used. Mask processing is performed on the data. Thereby, the dispersibility of the recording allowable area arrangement of the mask itself to be manufactured is improved. At the same time, each dot arrangement in which dot data processed using this mask is distributed and recorded in a plurality of nozzle rows has good dispersibility. In addition, the uneven arrangement of dots by one nozzle row is reduced. That is, the interference between the mask recording allowable area and the plurality of drive patterns is appropriately reduced, and the image recorded using the plurality of nozzle rows has no dot deviation and has good dispersibility. As a result, beading that occurs in the middle of recording can be reduced and image quality can be improved.

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

  FIG. 5 is a block diagram mainly showing hardware and software configurations of a personal computer (hereinafter also simply referred to as a PC) as an image processing apparatus according to an embodiment of the present invention.

  In FIG. 5, a PC 3000 as a host computer operates each software of an application software 3001, a printer driver 3003, and a monitor driver 3005 by an operating system (OS) 3002. The application software 3001 performs processing related to a word processor, spreadsheet, Internet browser, and the like. The monitor driver 3005 executes processing such as creating image data to be displayed on the monitor 3006.

  The printer driver 3003 draws various drawing command groups (image drawing command, text drawing command, graphics drawing command, etc.) issued from the application software 3001 to the OS 3002, and finally generates image data used by the printer 3004. Specifically, by executing image processing described later in FIG. 6 and later, five values are obtained for each of the cyan (C), magenta (M), yellow (Y), and black (K) color components of the ink used in the printer 3004. Generate index data for. The printer 3004 outputs a dot arrangement pattern corresponding to each of the five values (levels) based on the index data.

  The host computer 3000 includes a CPU 3008, a hard disk (HD) 3007, a RAM 3009, a ROM 3010, and the like as various hardware for operating the above software. That is, the CPU 3008 executes the process in accordance with the software program stored in the hard disk 3007 or the ROM 3010, and the RAM 3009 is used as a work area when the process is executed.

  A printer 3004 as a recording apparatus is a so-called serial type printer that performs recording by scanning a recording medium for ejecting 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 2 picoliter (pl) of ink droplets from each ejection port. Further, the number of ejection ports of each recording head is 512. The multi-pass recording method of this embodiment performs recording of the number of passes according to each embodiment described later.

  FIG. 6 is a block diagram illustrating the flow of image data conversion processing in the recording system of the present embodiment. As described above with reference to FIG. 5, the printer (recording apparatus) of the present embodiment includes the respective recording heads J0010 for ejecting ink of four colors C, M, Y, and K. Each process shown in FIG. 6 is executed by a printer and a personal computer (PC) as a host device.

  The application J0001 executes processing for creating image data to be recorded by the printer. When recording, image data created by the application is passed to the printer driver. The printer driver includes pre-processing J0002, post-processing J0003, γ correction J0004, halftoning J0005, and print data creation J0006 as processing. Below, each process is demonstrated easily.

  The pre-stage process J0002 performs color gamut mapping. This process performs data conversion for mapping the color gamut reproduced by the image data R, G, B of the sRGB standard into the color gamut reproduced by the printer. Specifically, by using a three-dimensional LUT (look-up table), data of 256 gradations in which each of R, G, and B is represented by 8 bits is used, so that each of R, G, Convert to B data.

  The post-stage processing J0003 obtains 8-bit color separation data Y, M, and C, which are combinations of inks that reproduce the colors represented by the data, based on the R, G, and B data on which the color gamut is mapped. Here, as in the previous process, conversion is performed using a three-dimensional LUT together with an interpolation operation.

  The γ correction J0004 performs density value (gradation value) conversion for each color component of the color separation data obtained by the post-processing J0003. Specifically, conversion is performed using a one-dimensional LUT so that the color separation data is linearly associated with the gradation characteristics of the printer.

  Halftoning J0005 performs quantization on each of the 8-bit color separation data Y, M, and C, and quantizes the data into 4-bit data. In the present embodiment, 256-bit 8-bit data is converted into 4-bit data representing 5 gradations using a multi-level error diffusion method. The 4-bit data is gradation value information that serves as an index for conversion processing to a dot arrangement pattern, which is binarization processing in the printer.

  The print data creation process J0006 creates print data by adding print control information to the print image information containing the 4-bit index data.

  When the print data is sent to the printer by the above processing by the host device, the printer performs dot arrangement patterning processing J0007 and mask data conversion processing J0008 on the input print data.

  The dot arrangement patterning process J0007 performs a binarization process by outputting a dot arrangement pattern based on 9-value index data. As a result, binary information indicating whether or not to eject ink, which is used when the printer performs recording, can be obtained.

  FIG. 7 is a diagram showing a dot arrangement pattern according to this embodiment corresponding to 9-value index data. A dot arrangement pattern is defined for each of 9 values of level 0 to level 8 indicated by index data of C, M, and Y (K is not shown).

  The 2 × 4 area composed of 2 vertical areas and 4 horizontal areas shown in the figure corresponds to one pixel (pixel) output by halftone processing, and this 1 pixel is 600 dpi in both vertical and horizontal directions. The size corresponds to the area density of (dots / inch). Each area constituting one pixel is an area where dot recording / non-recording (ink ejection / non-ejection) is defined. In the same figure, an area filled with “black” defines dot recording. Area. The number of areas in which dot recording is defined is determined according to any value of level 0 to level 8 indicated by the index data.

  One area of these dot arrangement patterns corresponds to a recording density of 1200 dpi in the vertical direction and 2400 dpi in the horizontal direction in the printer of this embodiment. That is, the printer according to the present embodiment has a specification in which one dot is formed by ejecting 2 pl of ink droplets one by one from the recording head of each color in one area having a vertical length of about 20 μm and a horizontal size of about 10 μm. ing. The dot arrangement patterning process J0007 performs a process of binarizing the 9-value data using the dot arrangement pattern described above, and “1” or “0” 1 for the ejection port corresponding to each area and the printing column. Bit discharge data is generated.

  Next, the mask data conversion process J0008 performs a mask process on the dot arrangement of each color determined by the dot arrangement patterning process J0007 using a plurality of mask patterns that are complementary to each other. Thereby, ejection data for each scan constituting a multi-pass is generated for each color of C, M, Y, and K. That is, in order to record dots of a predetermined color, data for recording is generated by scanning the recording head a plurality of times in the same area. The mask pattern used in this process reduces interference with the block pattern related to the head drive of the two-row nozzle row used in the next head drive circuit J0008, as will be described in detail later with reference to FIG. Further, this mask pattern is obtained by increasing the dispersibility of the recording allowable area pattern of the mask itself. Furthermore, the mask of the second embodiment of the present invention to be described later has reduced interference between mask patterns in addition to the above points. Here, when the dot data corresponding to the mask area in which the print allowance area is arranged is “1” (ejection) or “0” (non-ejection), the mask print allowance area is “1” as it is. This is an area for outputting dot data of “or“ 0 ”. On the other hand, the recording non-permitted area is an area for outputting “0” dot data regardless of the content of the dot data.

  The ejection data obtained by the mask process is supplied to the head drive circuit J0009 at an appropriate timing in each of a plurality of scans in multipass printing. The 1-bit data of each color input to the drive circuit J0009 is distributed as dot data to the two nozzle rows according to the block pattern described later with reference to FIG. 11 for each ink color. Then, based on the distributed dot data, a driving pulse is supplied to the recording head J0010, and ink is ejected from the recording head J0010 for each color at a predetermined timing. Thus, ink is ejected according to the dot data, and an image is recorded on the recording medium. Note that data of a plurality of masks described in the following embodiments is stored in advance in a printer memory. Further, it is assumed that the above-described dot arrangement patterning process and mask data conversion process in the printer are executed under the control of the CPU constituting the control unit of the printing apparatus using dedicated hardware circuits for them. A printer that mainly performs mask data conversion processing in the above-described printer constitutes a data processing apparatus.

  In the following, some embodiments of a mask pattern manufacturing method and a mask pattern used by or used in the above-described recording system will be described. Before that, a basic method of mask pattern manufacturing and a method therefor will be described. The concept of repulsive force calculation to be used will be described.

(Mask manufacturing method)
In the following description of the basic mask manufacturing method, for simplification of description, one mask used for mask processing in which a mask printable area is arranged, and a block for driving a printhead having the same size as the mask. The pattern is commonly referred to as a “plane”. Further, the print allowable area and the drive allowable area (areas indicated by black in FIGS. 13A and 13B) arranged in these patterns are simply referred to as “dots”.

  In the mask manufacturing method according to the embodiment of the present invention, for such a block pattern or mask plane, first, as shown in FIGS. 8A to 8D, for example, three planes A1, A2, and A3 are used. Specifies two planes. In addition, a repulsive force is applied between dots in the same plane or between different planes, and overlapping of dots in different planes is recognized, and a repulsive force is also applied between such overlaps so that dots in each plane Determine the arrangement.

  The method for determining the arrangement of dots in a plane is roughly divided into one of two methods: a method for determining the arrangement of a plurality of planes simultaneously (simultaneous generation) and a method for sequentially determining each plane (generation for each plane). Furthermore, for each of the above two generation methods, as a way of specifically determining the dot arrangement, all the dots on the plane are pre-arranged in advance and moved while increasing the dispersibility over the entire generated plane. There is a way to go (hereinafter referred to as “placement movement method”). In addition, a method of arranging dots one by one while increasing dispersibility over the entire generated plane (hereinafter referred to as “sequential arrangement method”) can also be executed.

Summary of arrangement determination processing of a dot by the arrangement moving method arrangement moving method is as follows.

  For example, when a dot arrangement rate of 50% plane is determined, for each of the planes A1, A2, and A3, an initial arrangement in which dots with 1-bit data of “1” are arranged at 50% of the dot arrangement possible positions. For example, it is obtained by a binarization process such as an error diffusion method. The reason why the initial arrangement of dots is obtained by using this binarization technique is that an arrangement with good dispersibility in the initial state can be obtained to some extent according to the binarization technique used. This is because the calculation time or convergence time until the final placement determination can be shortened. In other words, the method for obtaining the initial arrangement is not essential in applying the present invention. For example, the initial arrangement may be such that dots whose 1-bit data is “1” are randomly arranged in the plane.

Next, the repulsive potential is calculated for all the dots of the planes A1, A2, and A3 obtained as described above. In particular,
(I) A repulsive force corresponding to the distance is applied between dots in the same plane.
(Ii) Further, repulsive force is given to dots between different planes.
(Iii) Different repulsive forces are applied between the same plane and different planes.
(Iv) The overlapping of dots in different planes is recognized, and the overlapping of dots (two dot overlaps, three dot overlaps,...) 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 force function defined in the present embodiment has a repulsive force range up to r = 16 (position where 16 dots are arranged). By using a potential that decays with such a distance, basically, when dots are placed close to each other, the energy becomes high, that is, an unstable state. As a result of convergence calculation, close placement is not selected as much as possible. Can be. It is more desirable to determine the shape of this repulsive force based on the ratio of dots to the entire mask area.

Further, when considering a dot arrangement in which a plurality of dots overlap, the dots are arranged so as to overlap more than positions where dots can be arranged (in the case of resolution 1200, there are 1200 × 1200 possible positions in one inch square). For this reason, when calculating the repulsive potential for each dot, it is considered that the dot overlaps on the dot. For this reason, a function is defined so as to have a finite repulsive potential at r = 0. This enables dispersion in consideration of dot overlap. In the present embodiment, αE (r) for dots on the same plane, βE (r) for dots between different planes, and γs (n for dots that overlap. ) The calculation is performed by giving the repulsive potential of E (r). In other words, the potential due to the presence of a certain dot is added to the repulsive potential of dots in the same plane, dots in different planes, and even overlapping dots in different planes within the distance r.

  In the above repulsive potential, coefficients α, β, and γ are weighting coefficients, and for example, values of α = 3, β = 1, and γ = 3 are used. The dispersion of dots 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 block pattern or a mask.

  The coefficient s (n) is a coefficient that is further integrated in addition to γ in order to disperse overlapping dots. This coefficient s (n) is set to a value corresponding to the number of overlaps so that the more overlaps, the more the dots are dispersed. According to experiments by the inventors of the present application, 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, a dot that overlaps with the target dot for calculating repulsive force (at the same position in the same plane or in a different plane) and a dot located at a distance r from the target dot are checked. In this case, let n be the number of overlaps in common between the dot of interest and the dots of other planes that overlap at the same position and the dots that overlap in the same way at each position of the distance r. Consider the repulsive force caused by the overlapping dots between these two positions.

  In this case, for example, n = 3 when considering an example in which dots commonly exist in the first plane, the second plane, and the third plane between two certain positions. A repulsive force resulting from the overlap of three dots is applied between these positions. Here, when the repulsive force due to the overlap of three dots is considered, it is considered that the overlap of two dots and the repulsive force of one dot act in a multiplexed manner together with the overlap of three dots. In other words, if the third plane is not considered, it can be considered that two dots of the first plane and the second plane overlap, and if the second plane is not considered, the two of the first plane and the third plane are considered. It can also be thought of as overlapping dots. 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 dots, 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 a dot arrangement with good dispersibility can be obtained.

  When the total energy obtained by summing up the repulsive potentials of all dots is obtained as described above, a process for attenuating the total energy is performed.

  In this process, for all the dots, the dots are sequentially transferred to an area where the repulsive potential is the lowest among the positions where the distance r is 4 or less. By repeating such processing, the total energy, which is the total value of the repulsive potential of all dots, is reduced. That is, the process in which the total energy decreases sequentially is a process in which the dot arrangement sequentially increases the dispersibility, that is, a process in which the low frequency components of the dot arrangement decrease in sequence.

  Then, the rate of reduction of the total energy 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, the dot arrangement of each plane in a state where the reduction rate of the total energy is equal to or less than a predetermined value as described above is set as the final dot arrangement.

  FIGS. 8A to 8D schematically show the repulsive potential calculation and the total energy attenuation process described above. Specifically, the three planes A1, A2, and A3 are shown in a perspective view, and in particular, the movement of dots is shown in a plan view. Here, the smallest square indicates the dot arrangement possible position, and the overlapping position in the overlap of the three planes corresponds to the same arrangement possible position between the planes.

  FIG. 8A is a diagram for explaining that potential is added (increased) by repulsive force between dots when dots exist in the same plane. The example shown in the figure is an example in which one dot exists at a position separated by a distance r on the same plane as the dot Do at the target position of the plane A1, and in this case, α = 3 is applied and the potential of the dot Do is 1 A potential of × αE (r) is added.

  FIG. 8B is a diagram for explaining the repulsive potential applied in relation to these two dots when dots exist in a plane (planes A2 and A3) different from the target dot Do. Because of the relationship with dots between different planes, β = 1 is applied and a potential of 2 × βE (r) corresponding to two dots is added as the potential of the dot Do.

  FIG. 8C is a diagram for explaining the repulsive potential applied in relation to the dots when dots exist at the same position on different planes and there are overlapping dots in addition to the above two cases. It is. In this case, in addition to the cases of FIGS. 8A and 8B, dots exist at the same position on the plane A3 different from the plane A1 of the target dot Do. Accordingly, the repulsive potential 1 × αE (r) of the same plane, the repulsive potential 1 × βE (0) due to one dot in a different plane at the same position, and the repulsive potential 2 × βE due to two dots in a different plane. (R) and a potential of repulsive force γs (2) × E (r) due to the overlap, where the overlapping number n = 2 and γ = 3 are applied. As a result, the total repulsive potential due to the presence of the dot of interest Do in the dot arrangement shown in FIG. 8C is 1 × βE (0) + 1 × αE (r) + 2 × βE (r) + γs (2) × E (r).

  FIG. 8D is a diagram for explaining that in the dot arrangement shown in FIG. 8C, when the dot Do is moved, the total repulsive potential of the dot changes. As shown in FIG. 8D, when the dot Do (the dot of the plane A1) moves to the area adjacent to the same plane, the total repulsive potential due to the presence of the dot Do is as follows. That is, the total repulsive potential changes to βE (1) + 1 × αE (r2) + 2 × βE (r2) because the distance is r2 and the number n of overlaps is 0. Then, the total repulsive potential of the dot arrangement shown in FIG. 8C is 1 × βE (0) + 2 × βE (r) + 1 × αE (r) + γs (2) × E (r), and FIG. It is possible to know the change in the total repulsive potential before and after the movement by comparing the total repulsive force due to the movement of the dots Do in d).

  In the above description, the sum of the repulsive potentials is the sum of the energy of the dots at three positions or when the dots are moved. However, this is for simplifying the explanation, and in fact, it is obtained as an integral of the repulsive potential based on the relationship with dots including dots at other positions that may exist in addition to these dots. It is.

  As shown in FIGS. 8A to 8C, among the dots for which the total repulsive potential is calculated, for example, when the dot Do has the largest total repulsive potential, the description has been given with reference to FIG. Thus, the change in repulsive potential before and after the movement is obtained. Then, the dot Do is moved to a position where the total repulsive potential becomes the lowest before and after the movement. By repeating such processing, the total energy of all three planes can be reduced. That is, in the overlap of the three planes, the dot distribution has a low frequency component and is well distributed.

  In this way, when dots are well dispersed in the overlap of the three planes A1 to A3, for example, when these three planes are each a two-pass mask, the masks that are complementary to these masks are also included. The dots are well dispersed. In addition, the dot distribution in the overlap of an arbitrary number (2, 3, 4, or 5) of these six planes is also well distributed with few low frequency components.

  Note that the above-described arrangement movement method relates to a case where three planes correspond to a two-pass mask and are applied to a three-color plane mask used for the first pass among the two-pass masks. However, this method is not limited to this mode, and may be applied to all planes to determine dot arrangement. For example, the arrangement movement method may be applied to a mask of six planes for two passes. In this case, it is assumed that the movement of exchanging the arrangement area in relation to the dots of other planes is allowed without limiting the range in which the dots are moved to the vicinity position. Specifically, for example, a dot on a certain plane is moved to an area where dots on the same plane are not arranged. At the same time, replacement is performed such that the dots arranged in the area of the other plane corresponding to the moved area are moved to the area of the same plane corresponding to the area having the former dot. Thereby, the arrangement relationship of dots in all the planes related to the calculation of the repulsive potential is changed, and the replacement movement that minimizes the potential energy becomes possible.

Sequential Arrangement Method As described above, this method is a method in which dots are sequentially arranged in a portion of the mask plane where dots are not yet arranged. For example, for each of the three planes shown in FIGS. 8A to 8C, dots are sequentially arranged one by one, and each dot is repeated according to the dot arrangement rate of the plane. Perform placement. In this case, first, when a dot is to be arranged, the repulsive potential generated between the dot at that position and the dots already arranged in the planes A1, A2, and A3 is calculated. The calculation of the repulsive potential itself is the same as that described in the above-described arrangement movement method. The difference is that in the example shown in FIGS. 8A to 8C, the dot Do is not already placed at the position shown in FIG. 8 but is already arranged when the dot Do is newly placed. This is a point where the repulsive potential is calculated between A1 and dots of different planes A2 and A3. As is clear from the above, the repulsive potential has the same value everywhere in the dot at the first stage where no dot is arranged yet.

  Next, the position where the lowest potential energy is determined among the repulsive potentials calculated when placed at each plane position is determined. Then, when there are a plurality of positions having the minimum energy, for example, one position is determined from the plurality of positions using a random number. In the present embodiment, the position of the minimum energy is determined under the condition that the dots are not overlapped at the positions where dots are already arranged in the same plane. Depending on parameters such as a weighting coefficient and a repulsive potential function, energy may be minimized when overlapping on the same plane when calculating repulsive potential due to the relationship with dots of other planes. In this case, the plane is forbidden to overlap because only one dot is allowed at one position. A dot is placed at the position of the determined minimum potential energy. That is, the dot data in that area is set to “1”. Then, it is determined whether one dot is arranged for each of the three planes A1, A2, A3. If not, the above process is repeated.

  When the dots are arranged one by one in this order in the planes A1, A2, and A3, the above process is repeated until 50% of the dots are arranged with respect to all possible arrangement positions of the three planes, and 50% is arranged. And this processing is terminated.

  A plane having characteristics similar to those of the above-described placement movement method can also be obtained by the sequential placement method described above. That is, in the three planes by the sequential arrangement method, dots are well dispersed even when they overlap.

  Another feature of the above-described plane manufacturing method is that a periodic pattern in which the arrangement of dots is regularly repeated is not generated. 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 plane generated by the mask manufacturing method of the present embodiment is an aperiodic pattern.

  In the above description, for simplification of description, the block pattern (drive pattern) plane and the mask pattern plane are not distinguished from each other. However, as will be described in the following embodiments, in the calculation of repulsive force, among the planes, a plane corresponding to a block pattern or dots in the plane are predetermined as a block pattern. That is, the dots of the plane corresponding to the block pattern composed of the drive allowable area and the non-drive allowable area are treated as fixed and are not determined by the movement of the dot arrangement or the dot arrangement according to the energy of the repulsive potential. That is, in the embodiment of the present invention, the target for determining the dot arrangement is a plane corresponding to the mask, and at this time, the plane corresponding to the block pattern or the dot is the target of repulsive force calculation. Specifically, in determining the dot arrangement of the plane corresponding to the mask, the term of the weighting coefficient α in the repulsive potential calculation is applied to the plane corresponding to the mask. The terms of the coefficients β and γ are applied between a plane corresponding to the mask and a plane corresponding to another mask or a plane corresponding to a block pattern.

  As a result, the arrangement of the printable area in the manufactured mask eliminates mutual interference in consideration of the arrangement of the drive allowable area in the block pattern, and the mask printable area arrangement pattern itself is also distributed. It becomes a high quality thing.

  Next, a mask manufacturing method according to some embodiments of the present invention using the basic mask manufacturing method described above will be described.

<Embodiment 1: 100% uniform mask for 2-pass printing>
Outline of the present embodiment In this embodiment, a single print head having a nozzle array that discharges cyan (C) ink is used as a printing element, and two-pass multi-pass printing is performed in which an image is completed in two scans. About. The mask used for the two-pass printing has reduced interference with the block pattern for driving the print head, and the mask pattern itself is well dispersed. As a result, the dots recorded in each of the two scans have no deviation in the number of dots. In addition, since dots are formed in a dispersed manner in each scan, for example, even if there is a shift in the recording position, the texture that can be caused by it is less likely to be visually obstructive, and the influence on the image quality is suppressed. .

  FIG. 10 is a diagram schematically showing mainly the positional relationship between the recording head, the mask pattern, and the recording medium in order to explain the two-pass recording. The print head includes two nozzle rows 1001A and 1001B for cyan, and each nozzle row has 512 nozzles arranged at an interval of 1200 dpi. In the case of two-pass printing, the print data is divided into a first group and a second group each including 256 nozzles. Each group is associated with a mask 1002 (two masks C1 and C2) whose manufacturing method will be described later, and the size of each mask C1 and C2 in the sub-scanning direction (conveyance direction) is the nozzle of each group. This is the same 256 areas as the number. The mask C1 and the mask C2 have a complementary relationship, and when they are overlapped, recording of an area corresponding to a 256 (horizontal) area × 256 (vertical) area can be completed. That is, in this embodiment, two nozzle rows that can be recorded in the same area in one scan are used for one color, but the mask process itself does not distinguish between these two nozzle rows. That is, the masks C1 and C2 are associated with one nozzle row. Then, after mask processing as described above, the dot data mask-processed by the head drive circuit J0009 is distributed to two nozzle rows according to a block pattern as will be described later with reference to FIG.

  As shown in FIG. 10, in the first scan, recording is performed on the area A of the recording medium 1003 using the mask C1, and after the recording medium is fed for 256 areas, the mask C2 is used for the area A. To record. The image recording is completed by these two passes.

Mask Manufacturing Method A mask manufacturing method according to this embodiment will be described using the sequential arrangement method described above.

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

  The process shown in FIG. 11 is to sequentially arrange the recordable areas on one plane and perform the recordable area arrangement with an arrangement rate of 50%. First, in step S901, the plane of the mask C and the plane of the block pattern in which the printable area is to be arranged are defined, and the repulsive potential is calculated for the arrangement of the printable area in these planes. At this time, as described above, dots (drive allowable areas) are already arranged on the plane corresponding to the block pattern, and these dots are fixed and are to be arranged on the plane of the dots and the mask C. Calculate the repulsive force with the recording allowable area.

  FIG. 12 is a diagram showing a concept for calculating the repulsive force related to the arrangement of the print permitting area of the mask C. In the calculation of repulsive force, the planes B1 and B2 of the block pattern to be considered are fixed patterns. The block patterns of these planes B1 and B2 determine which of the nozzle rows 1001A and 1001B the cyan dot data subjected to the mask process is distributed to.

  FIGS. 13A to 13C are diagrams for explaining this block pattern.

  FIG. 13A shows two nozzle arrays A and B and which one of them is assigned with dot data for driving, and is the same diagram as FIG. As described above with reference to FIG. 3, dot data is assigned according to block pattern A for nozzle row A, and dot data is assigned according to block pattern B for nozzle row B. Specifically, when recording column 0, nozzle row A uses nozzles with nozzle numbers {1, 2}, {5, 6}, {9, 10}, {13, 14}, and nozzle row B Then, nozzles with nozzle numbers {3, 4}, {7, 8}, {11, 12}, {15, 16} are used. When recording column 1, since two nozzle rows are used, nozzle rows A and B are exclusive (complementary) nozzles used in column 0.

  FIGS. 13B and 13C show the block patterns A and B, respectively. That is, each nozzle in nozzle row A is driven by being assigned dot data according to the block pattern of FIG. 13B, and is driven by being assigned dot data according to the block pattern shown in FIG. 13C of each nozzle in nozzle row B. Is done.

  In the present embodiment, the block pattern is a staggered pattern as shown in FIGS. 13B and 13C. However, the present invention is not limited to this. Any other pattern can be used as long as the effect of dispersion described in the present embodiment is exhibited in relation to the mask.

  In the process of determining the arrangement of the print allowance area of the mask C in consideration of the above block pattern, the repulsive potential between the print allowance areas in the mask pattern C, or the drive allowance in the print allowance area in the mask pattern C and the planes B1 and B2 Calculate the repulsive potential with the area. Then, as described above, the arrangement of the print allowable area of the mask C is determined based on the result of the repulsive potential calculation.

  That is, in the next step S902, an area having the minimum potential energy is determined from the repulsive potential calculated when the recording allowable area is set. In step S903, it is determined whether there are a plurality of areas having the minimum energy. If there are a plurality of areas, one area is determined from the plurality of areas using a random number in step S907.

  In step S904, the recording allowable area is arranged in the area of the minimum potential energy determined as described above.

  Finally, in step S905, it is determined whether or not a print allowance area is arranged on the C plane up to 50% of all mask areas. When the recordable area is not arranged up to 50%, the processing from step S901 is repeated. Then, when a 50% recording allowable area is arranged on the C plane, this process is terminated.

  As described above, the arrangement of the print allowable area is determined for the mask C1 in the first pass. For the mask C2 in the second pass, the arrangement of the print permitting area that is complementary to the mask C1 is determined.

  According to the mask manufacturing method of the present embodiment described above, the dispersibility of the recording allowable area arrangement of the mask C itself to be manufactured is improved. At the same time, each dot arrangement in which the dot data processed using these masks is distributed and recorded in two nozzle arrays has good dispersibility. In addition, the uneven arrangement of dots by one nozzle row is reduced. That is, the interference between the mask print allowable area and the two block patterns is appropriately reduced, and the image recorded using the two nozzle rows is free from the deviation of the dots and has good dispersibility. As a result, beading that occurs in the middle of recording can be reduced and image quality can be improved.

Mask Characteristic Evaluation / Comparison of Mask of This Embodiment and Mask of Comparative Example FIG. 14 is a diagram showing an arrangement pattern of print permitting areas of the mask C1 of this embodiment manufactured by the above-described manufacturing method. FIG. 15 is a view showing the pattern of the print allowable area of the mask described in Japanese Patent Application No. 2005-197873 relating to the related application. Note that the masks shown in these figures have an area of 256 × 256.

  As shown in FIGS. 14 and 15, both masks have a uniform impression of dispersibility in the arrangement of the print permitting areas, and receive an overall smooth impression.

  16 (a) and 16 (b) show a mask C1 created in consideration of the block pattern of the present embodiment shown in FIG. 14, and block patterns A and B shown in FIGS. 13 (b) and 13 (c). It is a figure which shows the pattern of each AND operation result. That is, the arrangement of dots recorded by distributing the dot data (solid image) masked with the mask C1 shown in FIG. 14 to the nozzle array A and the nozzle array B according to the block patterns A and B, respectively, is shown.

  On the other hand, FIG. 17A shows a logical product pattern of the mask and block pattern A of the related application shown in FIG. 13, and FIG. 17B shows a logical product pattern of the mask and block pattern B of the related application. FIG. That is, the arrangement of dots recorded by distributing the dot data (solid image) masked with the mask shown in FIG. 15 to the nozzle array A and the nozzle array B according to the block patterns A and B, respectively, is shown.

  Comparing FIGS. 16A and 16B with FIGS. 17A and 17B, in the former to which the present invention is applied, the arrangement pattern of recording dots is excellent in dispersibility in both the nozzle rows A and B. It can be seen that interference between the mask pattern and the block pattern is reduced.

Evaluation by Power Spectrum Next, the mask of the present embodiment is evaluated by the power spectrum indicating the frequency characteristics of the mask pattern. The power spectrum described below is obtained for a mask pattern having a size of 256 areas × 256 areas. Here, the power spectrum can treat a two-dimensional spatial frequency as one dimension, “T. Mitsa and K. J. Parker,“ Digital Halftoning a Blue Noise Mask ”, Proc. SPIE 1452, pp. 47-56 (1991). ) ”As described in“ radially averaged power spectrum ”.

  FIG. 18 is a diagram for explaining the frequency characteristics of the mask (C1) considering the block pattern of the present embodiment and the mask according to the related application. In FIG. 18, each curve represents a power spectrum with respect to the spatial frequency of each mask pattern. Curve a represents the power spectrum of the mask in consideration of the block pattern in the present embodiment, and curve b represents the power spectrum of the mask of the related application. Comparing the two curves shows that both have low power in the low frequency region where human vision is sensitive. That is, the mask of this embodiment considering the block pattern (driving pattern) also realizes pattern characteristics with few low frequency components and no peak in the low frequency region.

  FIG. 19 is a diagram for explaining the frequency characteristics of patterns (logical product patterns in FIGS. 16A and 17A) obtained by logical product of the mask patterns in FIG. 18 and the block pattern A in FIG. is there. In the figure, a curve a indicates a power spectrum of a logical product pattern (that is, a logical product pattern of FIG. 16A) of the mask considering the block pattern of the present embodiment and the block pattern A of FIG. . In short, this curve a is nothing but the frequency characteristic of a pattern in which one nozzle row indicates a dot position that can be printed in one scan in the present embodiment using the block pattern considering mask pattern and the block pattern. On the other hand, a curve b shows a power spectrum of a logical product pattern (that is, a logical product pattern of FIG. 17A) between the mask of the related application and the block pattern A of FIG.

Here, in the specification and claims of the present application, the “low frequency component” means a frequency component on the lower frequency side from the center of the spatial frequency region where the frequency component (power spectrum) exists. Say. On the other hand, the “high frequency component” refers to a frequency component located on the higher frequency side than the center of the region. Accordingly, taking FIG. 19 as an example, the vicinity of the spatial frequency “90” is considered as the heel, the low frequency side (approximately 0 to 90) is the “low frequency region”, and the high frequency side (approximately 91 to 180) is the “high frequency region”. "
Further, in the specification of the present application, “the frequency component in the low frequency region (low frequency wave number component) is less than the frequency component in the high frequency region (high frequency component)” means that the frequency component (low frequency component present in the low frequency region) ) Is smaller than the integral value of the frequency component (high frequency component) existing in the high frequency region.

  In the curve b in FIG. 19, there are peaks in the low frequency region, and there are relatively many low frequency components. The presence of frequency component peaks in the low-frequency region means that the dot arrangement formed by each nozzle array is biased due to interference between the mask pattern and drive pattern (block pattern), which can be perceived as noise. It means that there is sex.

  On the other hand, the curve a in FIG. 19 shows the characteristic that the low frequency component is less than the high frequency component, and in particular, there is no substantial peak in the low frequency region and the low frequency component is relatively small. . The absence of frequency component peaks in the low frequency region means that there is almost no dot deviation caused by interference between the mask pattern and the drive pattern, and the dots formed by each nozzle row are arranged in a well-distributed state. Means that. If such a dot arrangement is realized, noise can be reduced.

  The characteristics of the curve a in FIG. 19 will be described in further detail. In general, the human eye has a so-called low-pass filter characteristic in which the sensitivity to low frequency components is high and the sensitivity decreases as the frequency increases. Therefore, it is effective for reducing the noise feeling to suppress the low frequency component as low as possible so that there is no peak of the frequency component in the entire low frequency region as shown by the curve a.

  In the low frequency range, noise detection has a significant effect on noise detection, especially the frequency components on the low frequency side from the center (half) of the low frequency range, and more strictly speaking, the frequency component is lower than 1/4 of the low frequency range. This is the frequency component on the side. That is, 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 Usage Linear and Non”). -Liner Visual Describing Functions, SPES annual Meeting (1975) "). From various experiments, it is said that components in a frequency region lower than about 9 to 10 cycles / mm are easily recognized by human eyes. In the example of FIG. 19, the spatial frequency “50” corresponds to approximately 10 cycles / mm, and the vicinity of the center of the low frequency region (spatial frequency “45”) corresponds to approximately 9 cycles / mm. Therefore, it is effective in reducing the noise feeling to keep the frequency component low so that there is no frequency component peak in the frequency region of 9 cycles / mm or less (that is, the region on the lower frequency side than the center (half) of the low frequency region). The curve a satisfies this condition.

  The visual sensitivity gradually increases as the frequency decreases from 9 cycles / mm, and the visual sensitivity increases rapidly from around 4.5 cycles / mm (spatial frequency “22.5” in the figure). The visual sensitivity is maximized in the vicinity of 1 to 2 cycles / mm (spatial frequency “5 to 10” in the figure). Accordingly, the frequency component of the frequency component (region lower than 1/4 of the low frequency region) in the frequency region below 4.5 cycles / mm (spatial frequency “22.5” in the figure), which is a point at which the visual sensitivity increases drastically. It is important to keep the frequency component low so that there are no peaks. This condition is also satisfied in the curve a.

  As described above, according to the present embodiment, as shown by the curve a in FIG. 19, the low frequency in the region on the lower frequency side than the quarter of the low frequency region (region of about 4.5 cycles / mm or less). The low frequency component is kept low to such an extent that no component peak exists. Therefore, it is possible to obtain an image with less noise. In the curve a in FIG. 19, no low frequency component peaks are observed in the entire region on the low frequency side from the vicinity of half of the low frequency region (region of 9 cycles / mm or less), so there is almost no noise.

  As is apparent from the above, the mask of this embodiment has the following characteristics (a) and (b1) obtained by the logical product of the arrangement of the print allowable area in the mask and the drive allowable area arrangement in the drive pattern. Any one of (b3) is satisfied. In this embodiment, in addition to (a), at least (b1) needs to be satisfied, more preferably (b2) is satisfied, and still more preferably (b3) is satisfied.

(A) The frequency component in the low frequency region is less than the frequency component in the high frequency region.
(B1) There is no frequency component peak in a region on the lower frequency side than 1/4 of the low frequency region.
(B2) The peak of the frequency component does not exist in a region on the low frequency side from half of the low frequency region.
(B3) There is no frequency component peak in the entire low frequency region.

  Thus, by using a mask in consideration of the block pattern, the arrangement pattern of the recording dots is excellent in dispersibility in both the nozzle rows A and B, and interference between the mask pattern and the block pattern is reduced. As a result, beading can be reduced. The shorter the distance between the two nozzle rows, the greater the effect that can be obtained.

  As described above, when the dot data is distributed by the block pattern, it can be seen that the present invention is applied when the low frequency component in the frequency characteristics of the pattern recorded by each nozzle row is small.

<Embodiment 2: 100% uniform mask for 4-pass printing>
Outline of the Present Embodiment In the second embodiment of the present invention, the two nozzle arrays A and B shown in FIG. 13A for each of cyan (C), magenta (M), and yellow (Y) inks are arranged. The present invention relates to 4-pass multi-pass printing in which an image is completed by four scans (two reciprocating scans). Then, the mask used for the 4-pass printing is a mask considering the block pattern. In the mask of this embodiment, each mask has reduced interference with the block pattern as in the first embodiment, and also has reduced interference with other masks. According to this, it becomes possible to reduce the occurrence of beading that is caused by the collection of ink droplets ejected during a plurality of scans.

  In this embodiment, the order of printing is as follows: cyan nozzle row A1 pass → cyan nozzle row B1 pass → magenta nozzle row A1 pass → magenta nozzle row B1 pass → 1 yellow nozzle row A1 pass → yellow nozzle row B1 The order of the pass →... → Cyan nozzle row B4 pass → Cyan nozzle row A4 pass. Accordingly, the order of masks to be used is C1, M1, Y1, Y2, M2, C2, C3, M3, Y3, Y4, M4, and C4. In this embodiment, since the pattern is dispersed between the masks as described above, an image with high dispersibility of dots formed in the middle scanning is obtained, thereby reducing the occurrence of beading.

Mask Production Method The mask production method according to the present embodiment arranges print permitting areas on each mask by the above-described generation method and sequential arrangement method for each plane.

  FIG. 20 is a flowchart showing the mask creation processing of this embodiment. The basic process is the same as the process of the first embodiment described in FIG. The difference is that there are multiple (C, M, Y) planes for determining the arrangement (S1805), and when the target recording allowable area is arranged in the area where the repulsive potential is the lowest, it has been created so far. The pass mask pattern is fixed (S1802). In addition, since it is a mask for four-pass printing, the above-described creation process is repeated for the masks for three passes (C1, C2, C3; Y1, Y2, Y3; M1, M2, M3) for each color. Of course.

  When there are a plurality of masks that determine the arrangement by calculating the repulsive force, as shown in FIG. 21, the repulsive potential is calculated in consideration of the block pattern of each color nozzle row when generating the mask pattern of each color. For example, when a Y plane mask is generated, a repulsive potential is calculated between the Y nozzle row block pattern (for A and B 2 rows), the M mask plane, and the C mask plane, and the Y plane recording allowable area. To decide. In addition, in order to generate a mask of each color, for example, a Y mask, in addition to the M plane, C plane, and Y nozzle row block patterns, all of the M nozzle row block patterns and the C nozzle row block patterns The repulsive potential may be calculated between However, the effect is somewhat reduced compared to the method described above.

  Of course, the block patterns considered in the mask pattern generation may be the same or different between the ink colors. 22A and 22B are diagrams showing block patterns A and B, respectively, used in the present embodiment. C and Y are the same, and M has a different block pattern. These block patterns are basic patterns and are repeated according to the number of nozzles in the direction of the nozzle rows in the recording head. Of course, a repetitive pattern is formed in the scanning direction of the recording head.

Mask Characteristic Evaluation FIGS. 23 to 25 are diagrams showing the layout patterns of the print permitting areas of the masks C1, M1, and Y1 for one plane of this embodiment manufactured by the above-described manufacturing method. Each mask pattern has a size of 128 areas × 256 areas. As shown in these drawings, it is understood that the recording allowable area is arranged with good dispersibility in the mask of any plane.

  26 to 28 are diagrams showing the logical products of the masks C1, M1, and Y1 and the corresponding block patterns of the two nozzle arrays A and B, respectively. That is, (a) and (b) in each figure are dot arrangements in which a solid image masked with the masks C1, M1, and Y1 is printed by driving the nozzle arrays A and B according to the block patterns of the respective colors. Is shown.

  As is apparent from these drawings, the arrangement of dots recorded by driving the nozzle arrays A and B in accordance with the block patterns of the respective colors shows good dispersibility. Similarly, the positions of the dots in the second pass and the third pass also have better dispersibility.

  Also, the frequency characteristics (not shown) of the logical product patterns shown in FIGS. 26 to 28 are the same as in the first embodiment, but the frequency components in the low frequency region are smaller than the frequency components in the high frequency region, and in the entire low frequency region. The frequency component peak does not exist.

  The mask of the second embodiment is not limited to the mask whose logical product pattern with the block pattern is as shown in FIGS. 26 to 28, and the following characteristics (a) and (b1) are the same as in the first embodiment. ) To (b3) may be satisfied. The same applies to Embodiments 3 to 6 described later.

(A) The frequency component in the low frequency region is less than the frequency component in the high frequency region.
(B1) There is no frequency component peak in a region on the lower frequency side than 1/4 of the low frequency region.
(B2) The peak of the frequency component does not exist in a region on the low frequency side from half of the low frequency region.
(B3) There is no frequency component peak in the entire low frequency region.

  As described above, according to the present embodiment, even in color four-pass printing, the block pattern and the mask pattern do not interfere with each other, and printing with excellent dispersibility can be performed in which the printing dots of each nozzle row are not biased. .

<Embodiment 3: 100% gradation mask for 2-pass printing>
The third embodiment of the present invention relates to a technique for reducing the interference between the mask and the block pattern or improving the dispersibility when a gradation mask in which the ratio of the printable area changes in the nozzle arrangement direction is used. Specifically, as in each of the above embodiments, the repulsive potential is calculated for the gradation mask and the block pattern of the present embodiment, and the arrangement of the printable area is determined.

  In the gradation mask, a recording rate (ratio of recording allowable area arranged in a predetermined area) corresponding to the nozzle position is determined. In the present embodiment, the number of print permitting areas corresponding to the corresponding print rate is arranged according to the nozzle number. When generating a one-color mask as in the first embodiment, the block pattern planes considered in the calculation of the repulsive potential are the two planes B1 and B2 shown in FIG.

  The mask manufacturing method is basically the same as that of the first embodiment. The difference is that when placing the printable area in the minimum energy area, if the number of rasters that are determined according to the printing ratio corresponding to the nozzle exceeds the number of rasters, the raster that is within the limit of the number of placements, then the energy It is a point to place in that area of the raster where there is a low area. Thereby, it is possible to obtain a gradation mask with high dispersibility in consideration of the block pattern while varying the recording ratio for each raster.

<Embodiment 4: 150% uniform mask for 2-pass printing>
The present invention can also be applied to a plurality of masks exceeding 100% when the recording ratios of a plurality of masks in a complementary relationship are combined. 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 printing ratio of 75% and a total printing ratio of 150%.

  The mask manufacturing method of this embodiment can be performed basically in the same manner as in the first embodiment. The difference is that after a mask pattern with a 75% printing rate for the first pass is created, a mask for the second pass is created by arranging a print permitting area at the exclusive position as in the first embodiment. It is. That is, for the second pass mask, the same process as the first pass mask creation is repeated to generate a 75% pattern.

  Details of mask fabrication will be described below using a sequential arrangement method. Basically, the same processing as that shown in FIG. 11 according to the first embodiment is performed. The difference is in the same determination step as in step S905, in which it is determined whether or not the recording allowable area is arranged up to 75%. Further, in the mask creation for the second pass, in the same process as step S904 in FIG. 11, when the print permitting area is arranged, the overlap with the print permitting area of the same color different plane is not prohibited. That is, when an attempt is made to arrange at the position where the energy is lowest, the arrangement is made even if it overlaps with the recording allowable area of another plane of the same color at that position. 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%.

<Embodiment 5: Mask with Cluster Size of m × n>
The fifth embodiment of the present invention relates to the creation of a so-called cluster mask in which m × n recording permissible areas are one unit. Here, m indicates the number of areas that are continuous in the main scanning direction, and n indicates the number of areas that are continuous in the sub-scanning direction. The mask manufacturing method of this embodiment can be performed basically in the same manner as in the first embodiment.

  As a cluster mask having m × n area as one unit, for example, a mask having 2 × 2 area as one unit is preferably used. However, the present invention is not limited to this. For example, a mask having 1 × 2 pixels as one unit, a mask having 2 × 4 pixels as one unit, or the like may be used. It should be noted that the values of m and n may be such that both m and n are positive integers and at least one of m and n is an integer of 2 or more.

  As described above, in the case of a cluster mask, the number of dots formed by scanning is not biased and the dispersibility of the pattern is improved by considering the block pattern. Due to the high dispersibility, even if a texture is generated, it is hardly visually disturbed and the influence on the image quality is suppressed.

<Sixth Embodiment: Mask Considering Both Index Pattern and Block Pattern>
In addition to the block pattern, the index pattern shown in FIG. 7 can be considered, and a mask can be manufactured so as not to interfere with these patterns. A specific method considers an index pattern in the same manner as the block pattern in the first embodiment.

<Other embodiments>
In each of the above-described embodiments, the mask used for 2-pass or 4-pass multi-pass printing has been described, but the number of passes is not limited thereto. It is apparent from the description of each of the above embodiments that a mask used for three or more multi-pass printings can be created regardless of the number of passes in consideration of a block pattern related to driving of a plurality of nozzles of the same color.

  In each of the above-described embodiments, the recording apparatus (printer) functions as the data processing apparatus of the present invention to perform mask processing and related processing. However, the application of the present invention is not limited to this configuration. Of course. For example, a data supply device (for example, the host device in FIGS. 5 and 6) that supplies binary data for each scan generated by mask processing to a printer functions as the data processing device of the present invention. The configuration may be such that mask processing using the described mask is performed.

  Furthermore, the present invention can also be realized by a program code that realizes the functions of the above-described embodiments and that realizes the procedures of the flowcharts shown in FIGS. 11 and 20, or a storage medium storing the program code. It can also be achieved by reading and executing the program code stored in the storage medium by the computer (or CPU or MPU) of the system or apparatus. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  As a storage medium for supplying the program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like is used. be able to.

  In addition, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the OS running on the computer performs an actual process based on the instruction of the program code. Part or all may be performed.

(A) And (b) is a figure explaining one nozzle row and two nozzle rows used about the ink of 1 color. FIG. 6 is a diagram for explaining processing until image data is recorded by a recording head by multipass recording. It is a figure explaining the block pattern which concerns on the nozzle drive in the case of recording using two nozzle rows about one color ink. FIG. 6 is a diagram for explaining that recording dots are biased by a block pattern when a dot pattern that is image data is recorded by two nozzle rows. FIG. 2 is a block diagram mainly illustrating hardware and software configurations of a personal computer 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 recording system which concerns on one Embodiment of this invention. It is a figure which shows the dot arrangement pattern according to the index data which concerns on one Embodiment. (A)-(d) is a figure which shows typically calculation of the repulsive potential and attenuation | damping process of total energy which concern on one Embodiment of this invention. It is a figure which shows typically the function of the basic repulsive potential E (r) which concerns on one Embodiment. It is a figure which shows typically two nozzle rows, a mask, and a printing medium position for demonstrating 2 pass printing which concerns on 1st embodiment of this invention. It is a flowchart which shows the arrangement | positioning determination process of the recording permissible area by the sequential arrangement method by 1st Embodiment. It is a figure explaining the concept of the mask C production method by 1st Embodiment. (A)-(c) is a figure explaining the relationship between the two nozzle row which concerns on 1st Embodiment, and a block pattern. It is a figure which shows the pattern of the mask C1 produced by 1st Embodiment. It is a figure which shows the pattern of the mask by the related application which concerns on a comparative example. (A) And (b) is a figure which shows the logical product pattern of the mask C1 which considered the block pattern shown in FIG. 12, and each block pattern of FIG.13 (b), (c). (A) And (b) is a figure which shows the logical product pattern of the mask C which concerns on the comparative example shown in FIG. 15, and each block pattern of FIG.13 (b), (c). It is a figure explaining the frequency characteristic of each of the mask of 1st Embodiment shown in FIG. 14, and the mask which concerns on the comparative example shown in FIG. It is a figure explaining the frequency characteristic of each of the logical product pattern of 1st Embodiment shown in FIG. 16, and the logical product pattern of the comparative example shown in FIG. It is a flowchart which shows the arrangement | positioning determination process of the recording permissible area by the sequential arrangement method by 2nd embodiment of this invention. It is a figure explaining the concept of the manufacturing method of the masks C, M, and Y by 2nd Embodiment. (A) And (b) is a figure which shows the block pattern of each nozzle row based on 2nd Embodiment. It is a figure which shows the mask C1 which considered the block pattern by 2nd Embodiment. It is a figure which shows the mask M1 which considered the block pattern by 2nd Embodiment. It is a figure which shows the mask Y1 which considered the block pattern by 2nd Embodiment. (A) And (b) is a figure which shows the logical product of the mask C1 and the cyan block pattern by 2nd Embodiment 2. FIG. (A) And (b) is a figure which shows the logical product of the mask M1 and the block pattern of magenta by 2nd Embodiment 2. FIG. (A) And (b) is a figure which shows the logical product of the mask Y1 and the yellow block pattern by 2nd Embodiment.

Explanation of symbols

1001A Nozzle row A
1001B Nozzle row B
5004 Printer J0007 Dot arrangement patterning process J0008 Mask data conversion process J0009 Head drive circuit J0010 Print head

Claims (18)

A data processing device for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color a plurality of times in the same area of a printing medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used in each of the plurality of scans, a mask pattern is used for the dot data of the predetermined color to be recorded in the same area. Means for performing mask processing,
Means for distributing the mask-processed dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows,
In the mask pattern, the frequency component of the low frequency region of the logical product pattern obtained by the logical product of the layout of the print allowable area in the mask pattern and the drive allowable area in each of the drive patterns for each nozzle row is a high frequency region. A data processing device characterized by having no frequency component peak in a region that is less than half of the low frequency region and on a lower frequency side than half of the low frequency region. A data processing device for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color a plurality of times in the same area of a printing medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used in each of the plurality of scans, a mask pattern is used for the dot data of the predetermined color to be recorded in the same area. Means for performing mask processing,
Means for distributing the mask-processed dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows,
In the mask pattern, the frequency component of the low frequency region of the logical product pattern obtained by the logical product of the layout of the print allowable area in the mask pattern and the drive allowable area in each of the drive patterns for each nozzle row is a high frequency region. A data processing apparatus characterized by having no frequency component peak in a region that is less than ¼ of the frequency component and on a lower frequency side than ¼ of the low frequency region. A data processing device for generating data for printing by scanning a plurality of nozzle rows for printing dots of a predetermined color a plurality of times in the same area of a printing medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used in each of the plurality of scans, a mask pattern is used for the dot data of the predetermined color to be recorded in the same area. Means for performing mask processing,
Means for distributing the mask-processed dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows,
In the mask pattern, the frequency component of the low frequency region of the logical product pattern obtained by the logical product of the layout of the print allowable area in the mask pattern and the drive allowable area in each of the drive patterns for each nozzle row is a high frequency region. A data processing apparatus characterized by having a characteristic in which no frequency component peak exists in the entire low frequency region. The mask pattern is each mask pattern used in three or more scans of the same color,
The frequency component in the low frequency region in the logical product pattern obtained by the logical product of the arrangement of the print allowable areas of the mask patterns used in the three or more scans is smaller than the frequency component in the high frequency region. The data processing device according to any one of 1 to 3. The mask patterns are mask patterns of different colors,
4. The frequency component in the low frequency region in the logical product pattern obtained by the logical product of the arrangement of the print permitting areas of the mask patterns of different colors is smaller than the frequency component in the high frequency region. A data processing apparatus according to any one of the above.   4. The data processing apparatus according to claim 1, wherein the mask pattern is biased in a ratio of a print allowable area in a nozzle arrangement direction of the plurality of nozzle rows in the print head. 5.   4. The plurality of mask patterns used in a plurality of scans for recording the same area has a total printable area ratio exceeding 100%. Data processing device.   4. The data processing apparatus according to claim 1, wherein the mask pattern is one in which the recording allowable area is arranged with an m × n area as one unit. The data processing device further includes a memory for storing the mask pattern,
The mask processing means generates dot data used for each of the plurality of scans by performing a logical product operation of the mask pattern read from the memory and the dot data of the predetermined color. The data processing device according to any one of 1 to 3.   4. The data processing apparatus according to claim 1, wherein the data processing apparatus is a recording apparatus that performs recording based on dot data distributed according to the drive pattern.   The data processing device is a data supply device for supplying dot data distributed according to the drive pattern to a recording device that performs recording based on the dot data distributed according to the drive pattern. Item 4. The data processing device according to any one of Items 1 to 3. A recording apparatus for recording a plurality of nozzle rows for recording dots of a predetermined color by scanning the same area of the recording medium a plurality of times,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used in each of the plurality of scans, a mask pattern is used for the dot data of the predetermined color to be recorded in the same area. Means for performing mask processing,
Means for distributing the mask-processed dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows,
In the mask pattern, the frequency component of the low frequency region of the logical product pattern obtained by the logical product of the layout of the print allowable area in the mask pattern and the drive allowable area in each of the drive patterns for each nozzle row is a high frequency region. The recording apparatus is characterized in that there is no frequency component peak in a region that is less than a half of the low frequency region and on a lower frequency side than half of the low frequency region. A data processing device that performs mask processing on dot data, and generates data for recording by scanning a plurality of nozzle rows for recording dots of a predetermined color in the same area of the recording medium a plurality of times, The mask-processed dot data is distributed to the plurality of nozzle rows in accordance with a drive pattern that defines nozzle drive permissible areas and non-drive permissible areas for each of the plurality of nozzle rows, and the plurality of the plurality of nozzle data based on the distributed dot data A mask pattern manufacturing method used in the mask processing in a data processing device that generates dot data for driving the nozzles of the nozzle row,
A determining step for determining an arrangement of the print permitting area in the mask pattern;
In the determining step, the low frequency component of the logical product pattern obtained by the logical product of the arrangement of the print allowable area in the mask pattern and the drive allowable area in each of the drive patterns for each nozzle row is less than the high frequency component. The step of determining the arrangement of the recordable area as described above,
The mask pattern manufacturing method characterized by including.   The determining step determines the arrangement of the print allowance area based on a repulsive potential obtained between the arrangement of the print allowance area and the arrangement of each drive allowance area in the drive pattern for each nozzle row. The method of manufacturing a mask pattern according to claim 13, The determination step includes
A first step of calculating a repulsive potential between a recording allowable area at the position and another recording allowable area and a driving allowable area disposed in the driving pattern when the recording allowable area of the mask pattern is disposed;
A second step of disposing the recording permissible area at a position where the repulsive potential is minimized for each recording permissible area for which the repulsive potential is calculated;
A third step of repeating the first step and the second step, and arranging a number of print permitting areas corresponding to the recording rate of the mask for the mask pattern;
The mask pattern manufacturing method according to claim 14, comprising: A data processing method for generating data for printing by scanning a plurality of nozzle arrays for printing dots of a predetermined color a plurality of times in the same area of a printing medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used for each of the plurality of scans, a mask process is performed on the dot data of the predetermined color to be recorded in the same area. Process,
Distributing the masked dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and
The mask pattern used for the mask processing is a frequency component in a low frequency region of a logical product pattern obtained by a logical product of the arrangement of the print allowable area in the mask pattern and the drive allowable area in each drive pattern for each nozzle row. A data processing method characterized in that there is no frequency component peak in a region where the frequency component is less than the frequency component in the high frequency region and on the lower frequency side than half of the low frequency region. A data processing method for generating data for recording by scanning a plurality of nozzle rows for recording dots of a predetermined color a plurality of times in the same area of a recording medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used for each of the plurality of scans, a mask process is performed on the dot data of the predetermined color to be recorded in the same area. Process,
Distributing the masked dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and
The mask pattern used for the mask processing is a frequency component in a low frequency region of a logical product pattern obtained by a logical product of the arrangement of the print allowable area in the mask pattern and the drive allowable area in each drive pattern for each nozzle row. The data processing method is characterized in that there is no frequency component peak in a region where the frequency component is less than the frequency component in the high frequency region and on the lower frequency side than 1/4 of the low frequency region. A data processing method for generating data for recording by scanning a plurality of nozzle rows for recording dots of a predetermined color a plurality of times in the same area of a recording medium,
In order to divide the dot data of the predetermined color to be recorded in the same area into dot data to be used for each of the plurality of scans, a mask process is performed on the dot data of the predetermined color to be recorded in the same area. Process,
Distributing the masked dot data to the plurality of nozzle rows in accordance with a drive pattern that defines a nozzle drive permissible area and a non-drive permissible area for each of the plurality of nozzle rows, and
The mask pattern used for the mask processing is a frequency component in a low frequency region of a logical product pattern obtained by a logical product of the arrangement of the print allowable area in the mask pattern and the drive allowable area in each drive pattern for each nozzle row. The data processing method is characterized in that the frequency component is less than the frequency component in the high frequency region and no peak of the frequency component exists in the entire low frequency region.

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