JP2008207385A - Data processing method, data processing unit, and data recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To output very uniform images by appropriately arranging places of coagulation inevitably occurring while abating coagulation caused by contact between inks. <P>SOLUTION: Ink colors which pose the danger of causing an evil such as coagulation for example are made specific colors, and a masking pattern which is exclusive but capable of restraining a low frequency component of a dot arrangement in the lamination process is prepared for the specific color and ink colors other than the specific color. This permits contact and superposition of dots at every stage until an image is completed to be eliminated as much as possible and color irregularities and time difference irregularities to be restrained. Furthermore, even if the contact and superposition of dots cannot be eliminated, since such places of contact can be appropriately arranged in a distributed manner, visually inoffensive images can be obtained. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a data processing method, a data processing apparatus, and a data recording method when an image is formed using a characteristic mask pattern when recording ink of a plurality of colors as droplets on a recording medium.

  With the recent spread of information processing equipment such as personal computers, recording devices as image forming terminals have been rapidly developed and spread. In particular, among various recording apparatuses, an ink jet recording apparatus that performs recording on various recording media by ejecting ink as droplets is capable of high-density and high-speed recording operations with low noise and is easy for color recording. It is compatible and inexpensive. As described above, because of its many excellent features, the ink jet recording apparatus is now becoming the mainstream of personal use recording apparatuses.

  However, slight variations in the direction and amount of ink discharge inevitably occur between the plurality of nozzles of the ink jet recording head due to the manufacturing process. Further, in the serial type recording apparatus, the sub-scanning amount (paper feed) performed during each recording scan includes a structural error to some extent. Such errors and variations cause image defects such as streaks and density unevenness in a recording medium on which ink is recorded.

  In order to avoid such image damage, a serial type ink jet recording apparatus often employs a recording method called multipass recording.

  FIG. 1 is a diagram schematically showing a recording head and a recording pattern for explaining multi-pass recording. P1001 indicates a recording head, and here it is assumed that it has eight nozzles for simplicity. The nozzles are divided into first and second groups as shown in the figure, and each nozzle group includes four nozzles. P0002A and P0002B indicate mask patterns, in which pixels (recording allowable pixels) that each nozzle is allowed to perform recording are painted black, and pixels that are not permitted (recording non-permitted pixels) are painted white. The patterns recorded by each nozzle group are complementary to each other. When these patterns are overlapped, recording of a region corresponding to 4 × 4 pixels is completed.

  Each pattern indicated by P003 and P0004 indicates a state in which an image is completed by overlapping recording scans. When each recording scan is completed, the recording medium is conveyed by the group width in the direction of the arrow in the figure. Therefore, in the same area of the recording medium (area corresponding to the width of each nozzle group), an image is completed by two recording scans.

  By adopting such multi-pass printing, it is possible to reduce image adverse effects such as streaks and density unevenness described above. This is because even if there are variations in the ejection characteristics and the transport amount of each nozzle, these characteristics are dispersed over a wide range and become inconspicuous.

  Although FIG. 1 illustrates an example of two-pass multi-pass printing in which the same image area is scanned twice, multi-pass printing is not limited to this. The image may be completed with a larger number of recording scans. As the number of multi-passes increases, the variation in ejection characteristics and transport amount of each nozzle is distributed over a wider range, so that a smoother image can be obtained.

  In order to sufficiently obtain the effect of multi-pass printing, it is necessary to print approximately the same number of dots in each of a plurality of printing scans performed on the same image area. This is because if there is an extreme deviation in the number of dots to be recorded, variations in the ejection characteristics and transport amount of each nozzle will not be dispersed, and image defects such as streaks and uneven density will not be reduced.

  In FIG. 1, the case where the recording data is 100% duty has been described as an example, but the dot data to be recorded varies depending on the gradation value and the area gradation method (quantization method) employed. Considering such a situation, even if image data of any gradation by any area gradation method is input, as a mask pattern that satisfies the above conditions as much as possible, print permitting pixels and non-permissible pixels are randomly arranged. A technique for generating a mask pattern is disclosed. (For example, refer to Patent Document 1) Many recording apparatuses that implement such a technique are also provided.

  In multi-pass printing, it is possible to suppress various mechanical problems unique to the printing apparatus from appearing in the image by further devising the arrangement of the mask pattern while taking the above conditions into consideration.

  For example, Patent Document 2 discloses a method of applying a dot arrangement mask pattern that has excellent dispersibility and has low frequency components suppressed as compared with high frequency components. In multi-pass printing, when the printing position of one printing scan is deviated from the other printing scans, the mask pattern used (texture) is visually recognized. In particular, such a phenomenon appears remarkably when the recording head is reciprocally scanned with respect to the recording medium. Even in this case, if the method of Patent Document 2 is adopted, even if the pattern of the mask pattern becomes obvious, the pattern is excellent in dispersibility and is visually favorable, so that it does not become annoying and has an effect on image quality. Is difficult to appear.

  According to Patent Document 2, a mask pattern generation method is disclosed in which the arrangement of print permitting pixels is determined using the concept of repulsive potential. According to this mask pattern, it is configured to avoid as much as possible that dots formed using the mask pattern are arranged as close as possible. It will be less.

  By the way, in recent inkjet recording systems, the density of recording elements (nozzles), the speed of discharge frequency, and the variety of ink types are remarkable, and the amount of ink applied per unit time to the unit area of the recording medium. The amount is increasing. Under such circumstances, depending on the recording medium, a situation has arisen in which the ink absorption speed cannot sufficiently correspond to the ink application speed. Specifically, a plurality of applied ink droplets contacted and fused with each other on the surface of the recording medium before absorption, causing image problems. When ink droplets recorded at adjacent positions on the recording medium are not rapidly absorbed into the recording medium, they attract each other due to their surface tension to form a large mass. Such a mass is referred to herein as a grain. Once such a grain is generated, the ink droplet applied to the next adjacent position is more likely to be attracted to this grain. In other words, the first generated grain gradually grows as a nucleus and eventually produces large grains. In particular, when two or more types of ink such as blue, red, and green are recorded on the same pixel, if all of these inks are applied almost simultaneously, the grain generated here becomes even larger, which is the cause of this. In this case, an image problem called beading is invited.

  In order to reduce beading, it is effective to use a mask pattern in which ink of each color is recorded at positions as dispersed as possible. This is because the grains themselves generated from different color inks can be suppressed as much as possible. However, this alone is not always sufficient to reduce beading.

  2A to 2C are schematic views for explaining the problem of the beading. Here, the process in which ink is applied to the recording medium in the order of cyan, magenta, and yellow in one scan in multi-pass printing is shown step by step. FIG. 2A shows a state immediately after the cyan dot 10C is recorded. Each cyan dot 10C is recorded based on the cyan mask pattern to be used and arranged in a raised state on the surface of the recording medium as shown in the drawing until it is completely absorbed by the recording medium.

  FIG. 2B shows a state immediately after the magenta dots 10M are recorded after the cyan dots 10C are recorded and before being absorbed by the recording medium. The magenta dots 10M are also arranged on the surface of the recording medium as shown in the drawing until they are recorded based on the magenta mask pattern to be used and completely absorbed by the recording medium. Although the mask patterns used for cyan ink and magenta ink are different from each other, the cyan dot 10C and the magenta dot 10M may be in contact with each other depending on the relationship between the printable pixels of the mask or the print duty of each color. In such a case, these two dots are connected by their surface tension to form a grain. In the figure, such a portion is indicated by a cross.

  FIG. 2C shows a state immediately after the yellow dots 10Y are recorded after the cyan dots 10C and the magenta dots 10M are recorded and before being absorbed by the recording medium. The yellow dots 10Y are also recorded on the surface of the recording medium as shown in the drawing until they are recorded based on the yellow mask pattern and completely absorbed by the recording medium. The yellow ink also uses a mask pattern different from that of cyan ink and magenta ink. However, a portion in contact with cyan dots 10C and magenta dots 10M also occurs, and a grain is formed. In the figure, such a portion is indicated by a cross.

  As shown in the figure, even when a highly dispersive mask as described in Patent Document 2 is prepared for cyan, magenta, and yellow, respectively, and these are arranged differently from each other. Grain is generated and scattered irregularly. This state is visually recognized as beading. In other words, the conventional mask pattern including Patent Document 2 was not created in consideration of the process in which different ink colors are laminated over time, so that the ink absorption speed can fully correspond to the recording speed. If not, beading was inevitable.

  In order to cope with such a problem, in Patent Document 3, the concept of the mask pattern described in Patent Document 2 is further developed, and a mask in which grains generated on a recording medium are arranged in a highly dispersive state is considered. A pattern is disclosed. In other words, in order to place the grains in a highly dispersive state, assuming that the grains are generated, they are related to each other so as to suppress the logical product of the masks of each color and the low frequency component of the logical sum. Design with it. Hereinafter, in this specification, a mask pattern having such a feature is referred to as a laminated mask. In recent years, the density of recording elements (nozzles), the size of droplets, the speed of ejection frequency, and the diversification of ink types are remarkable. By using the laminated mask described in Patent Document 3, silver is used. It is possible to output high-definition and high-quality images comparable to salt photographs.

  By the way, the above-described multi-pass recording is an effective means for improving the image quality, but has a drawback of reducing the recording speed. Under such circumstances, bidirectional recording by the recording head is effective as a method for improving the recording speed without reducing the number of multipasses. However, bi-directional multi-pass printing is liable to cause image problems called bi-directional unevenness, and solving this problem is a major issue. One cause of bidirectional unevenness is color unevenness associated with the recording order of different color inks. Hereinafter, the color unevenness will be briefly described.

  In a serial type inkjet recording apparatus, there are many configurations in which nozzle rows for ejecting a plurality of colors of ink are arranged in parallel in the main scanning direction. When bi-directional printing is performed with such a configuration, the order of colors for applying ink to the printing medium is reversed between forward scanning and backward scanning.

  FIGS. 3A and 3B are schematic diagrams for explaining the ink application sequence during bidirectional recording. Here, a state in which a color image is recorded by two-pass multi-pass is shown. In the case of 2-pass multi-pass printing, in the area where the first print scan (1 pass) is performed in the forward pass scan, the next print scan (2 passes) is performed in the return pass scan. In the region adjacent to this region, the backward scanning is the first recording scanning (1 pass), and the subsequent forward scanning is the next recording scanning (2 passes). FIGS. 3A and 3B show the difference in the ink application order with respect to these adjacent regions. That is, a region (a) where ink is applied in the order of cyan → magenta → yellow → yellow → magenta → cyan, and a region (b) where ink is applied in the order of yellow → magenta → cyan → cyan → magenta → yellow. Are arranged alternately. In a recording medium, it is generally known that even if the combination of inks is the same, the color development is different if the order of application to the recording medium is different. In other words, when two types of regions having different ink application orders in the direction of recording scanning are alternately arranged in the sub-scanning direction, two types of regions having different colors are alternately arranged. This is recognized as color unevenness.

  By the way, such color unevenness is also affected by the time difference for applying each ink color.

  FIG. 4 is a schematic diagram for explaining an absorption state in the recording medium when cyan and magenta are applied as droplets to the same portion. Here, as an example, a recording state in which magenta dots are recorded on cyan glossy paper on inkjet recording glossy paper is shown from the top surface and cross section of the recording medium. FIG. 4A shows a state where cyan dots have been recorded but magenta dots have not yet been recorded. In general, on glossy paper developed for inkjet, the applied ink droplets form dots as shown in a shape that is almost a perfect circle. FIG. 5B shows a state where cyan dots are recorded and magenta dots are recorded after a relatively short time has elapsed. The cyan dots recorded in advance are more blurred in both the depth direction and the plane direction of the recording medium than in the state of FIG. On the other hand, FIG. 5C shows a state in which cyan dots are recorded and magenta dots are recorded after a relatively long time. The cyan dots recorded in advance penetrate into the recording medium in a state substantially equivalent to the state shown in FIG.

  Although both FIGS. 4B and 4C are in a state where printing is performed in the order of cyan → magenta, such a difference in ink permeation state appears depending on the timing of printing both. Such a difference in the permeation state appears as a difference in coloring when observed from the surface. Here, a combination of cyan and magenta has been described as an example, but such a phenomenon is not limited to this combination. This is a phenomenon that occurs not a little when two dots are applied to the same position of the recording medium at different timings. Although the figure shows a situation in which magenta dots are provided at the same position with respect to cyan dots, there may be a situation where the two dots are displaced from each other depending on the state of the recording head. In such a case, since only the overlapping region shows the tendency shown in the figure, the shape of the formed dot changes more complicatedly.

  FIG. 5 is a schematic diagram for explaining the time difference unevenness that occurs in accordance with the difference in ink application timing as described above when performing bidirectional recording. Here, a state where two-pass multi-pass printing is performed bidirectionally using the print head 102 is shown. First, in the first recording scan, the recording head 102 records about 50% of the image in the forward scan. Thereafter, the recording medium is conveyed by an amount corresponding to half the width of the recording head in the sub-scanning direction in the figure, and the recording head 102 is disposed at the position of the second recording scan in the figure with respect to the recording medium.

  In the subsequent second recording scan, the recording head 102 also records 50% of the image in the backward direction. At this time, the area where 50% has already been recorded in the first recording scan is recorded so that the remaining 50% of the image is complemented. In the area A in the figure, the second recording scan is performed after a relatively long time after the first recording scan. That is, the recording head scans up to the right edge of the image after the recording by the first recording scan and before the recording by the second recording scan, reverses, and further scans in the backward direction and returns. Time to come has passed. On the other hand, in the region B, the second recording scan is performed relatively immediately after the first recording scan. That is, only the time for which the recording head is reversed is included from when recording is performed by the first recording scan to when recording is performed by the second recording scan.

  In a region where the first recording scan and the second recording scan are performed with a relatively long time as in the region A, the penetration state of the dots recorded by overlapping the two recording scans is as shown in FIG. It becomes like this. FIG. 5 shows such a region with a relatively high concentration. Further, in the region where the first recording scan and the second recording scan are performed with a relatively short time as in the region B, the penetration state of the dots that are overlapped by the two recording scans is shown in FIG. )become that way. FIG. 5 shows such a region with a relatively low concentration. As a result, when bi-directional recording is performed, an area that exhibits color development such as area A and an area that exhibits color development such as area B appear alternately in the sub-scanning direction, resulting in uneven time difference. It is recognized. The time difference unevenness appears more prominently as the width of the image to be recorded (length in the main scanning direction) is larger.

  FIG. 6 is a diagram for explaining time difference unevenness when 4-pass bidirectional multi-pass printing is performed. In the case of 4-pass bidirectional printing, an image is formed in all areas by four printing scans, and the time difference between the printing scans varies. That is, for example, in the area A in the figure, the recording timing interval of the first recording scan and the recording timing interval of the second recording scan and the interval of the third recording timing and the fourth recording timing are long, but the recording in the second recording scan is performed. The interval between the timing and the third recording timing is short. The reverse is true for region B. Since the printing scan is performed a plurality of times at various timings in both the area A and the area B, the influence of the time difference unevenness does not appear as in the case of 2-pass multi-pass printing. However, not all the recording timings of the area A and the area B are the same. Again, a certain degree of time difference unevenness appears.

  As described above, bidirectional unevenness represented by color unevenness and time difference unevenness has been a major problem in bidirectional multipass printing.

  Patent Document 4 discloses an ink jet recording method in which a mask pattern different from that of other inks is prepared for an ink color that is easily noticeable in order to avoid color unevenness and time difference unevenness during bidirectional recording as much as possible. . Specifically, a mask pattern is used in which ink that is likely to cause harmful effects is recorded at a position different from other ink colors in the same recording scan. If a cyan ink, which is likely to cause harmful effects due to overlapping with other colors, is used with a mask that is different (exclusive) from other inks, a uniform image with reduced color unevenness and time difference unevenness can be expected. .

JP 7-52390 A JP 2002-144552 A JP 2006-044258 A JP-A-5-278232

  By the way, as a result of investigations by the present inventors, it was confirmed that cyan ink, in particular, among the four basic colors, makes the adverse effects more conspicuous with regard to the previously described grains, or time difference unevenness and color unevenness. It was done. By analogy, the cause is considered to be the chemical nature of the color material having a basic skeleton of phthalocyanine, which is often used for cyan ink. It is considered that cyan ink is likely to cause a difference in the degree of aggregation of the color material that causes a difference in the fixing state in the recording medium depending on the mixing condition with other colors, and is likely to deteriorate time difference unevenness and color unevenness.

  However, even in a situation where a specific ink causes the cause of image degradation in this way, the methods described in Patent Documents 1 to 3 treat each ink color at the same level. Therefore, agglomeration due to the contact between the specific ink and the other color ink cannot be completely eliminated, and the image quality is deteriorated.

  On the other hand, Patent Document 4 discloses an ink jet recording method in which a mask pattern different from that of other inks is prepared for an ink color that is easily noticeable in order to avoid color unevenness and time difference unevenness during bidirectional recording as much as possible. Has been. Specifically, a mask pattern is used that causes cyan ink, which is likely to cause harmful effects when in contact with other colors, to be recorded at positions exclusive of other ink colors (positions that do not completely overlap) in the same recording scan. To do. In this way, overlapping of ink with cyan ink is completely avoided, and uniform image output with reduced color unevenness and time difference unevenness can be expected while suppressing beading.

  However, the mask pattern described in Patent Document 4 is not created in consideration of the dispersibility of dots as in Patent Documents 2 and 3. Furthermore, in recent years when recording elements (nozzles) have higher density, smaller droplets, and higher ejection frequency, ink that tends to agglomerate can be used even if a different (exclusive) mask pattern is used. It is difficult to completely avoid contact between drops. Therefore, in Patent Document 4, although the number is small, some degree of aggregation occurs, and no consideration is given to the aggregation after the occurrence. That is, even if any of the patent documents already described is adopted, beading, color unevenness and time difference unevenness caused by aggregation still remain unsolved.

  The present invention has been made to solve the above-described problems. That is, the object is to reduce the difference between the generation of grains and the aggregation caused by the contact between the inks, and to appropriately arrange the locations where the difference between the generation of grains and the generation of aggregation is generated. It is to output an image with excellent appearance.

  For this purpose, the present invention provides a plurality of nozzle groups for recording a plurality of types of dots on a recording medium, in order to scan the same area of the recording medium a plurality of times. A data processing method for generating an image in which image data corresponding to the plurality of types of dots is recorded in each of the plurality of scans using a plurality of types of mask patterns corresponding to the plurality of types of dots, respectively. An array of print-permitted pixels in the plurality of first mask patterns corresponding to the plurality of scans for recording at least a first type of dot among the plurality of types of mask patterns. And the arrangement of print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for recording the second type of dots is exclusive. In the arrangement pattern of the print permission pixels obtained by the logical product of the predetermined first mask pattern of the plurality of first mask patterns and the predetermined second mask pattern of the plurality of second mask patterns. The print permission pixels of the predetermined first mask pattern and the predetermined second mask pattern are arranged in association with each other so that the low frequency component has a characteristic smaller than that of the high frequency component.

  Further, in order to scan a plurality of nozzle groups for recording a plurality of types of dots on a recording medium a plurality of times for the same region of the recording medium, image data to be recorded by each of the plurality of scans is generated. A data processing method, wherein image data corresponding to the plurality of types of dots is divided into image data to be recorded in each of the plurality of scans using a plurality of types of mask patterns corresponding to the plurality of types of dots. A plurality of first mask patterns corresponding to the plurality of scans for recording at least a first type of dots among the plurality of types of mask patterns, and a second The arrangement of the print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for recording the types of dots is in an exclusive relationship. The low frequency component in the array pattern of the print permitting pixels obtained by the logical sum of the predetermined first mask pattern of the plurality of first mask patterns and the predetermined second mask pattern of the plurality of second mask patterns is high. The print permission pixels of the predetermined first mask pattern and the predetermined second mask pattern are arranged in association with each other so as to have characteristics smaller than the frequency component.

  Further, in order to scan a plurality of nozzle groups that record a plurality of types of dots on a recording medium a plurality of times with respect to the same area of the recording medium, image data to be recorded in each of the plurality of scans is generated. A data processing method, wherein image data corresponding to the plurality of types of dots is divided into image data to be recorded in each of the plurality of scans using a plurality of types of mask patterns corresponding to the plurality of types of dots. A plurality of first mask patterns corresponding to the plurality of scans for recording at least a first type of dots among the plurality of types of mask patterns, and a second The arrangement of the print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for recording the types of dots is in an exclusive relationship. The low frequency component in the array pattern of print permitting pixels obtained by the logical product of the predetermined first mask pattern of the plurality of first mask patterns and the predetermined second mask pattern of the plurality of second mask patterns is high. A characteristic having a characteristic smaller than a frequency component, and a low frequency component in an array pattern of print permitting pixels obtained by a logical sum of the predetermined first mask pattern and the predetermined second mask pattern is smaller than a high frequency component. The recording allowable pixels of the predetermined first mask pattern and the predetermined second mask pattern are arranged so as to be associated with each other.

  According to the present invention, it is possible to eliminate contact and overlap of dots at each stage leading to completion of an image as much as possible, and to suppress color unevenness and time difference unevenness. Furthermore, even when contact and overlap of dots cannot be eliminated, such contact portions are preferably dispersed and arranged, so that an image that is not visually disturbing can be obtained.

Hereinafter, embodiments of the present invention will be described in detail.
(First embodiment)
7A and 7B are block diagrams for explaining the control configuration of a personal computer (hereinafter also simply referred to as a PC) as a data processing apparatus according to the present embodiment and a recording apparatus connected thereto. .

  In FIG. 7A, a PC 100 that is a host computer operates application software 101, a printer driver 103, and a monitor driver 105 by an operating system (OS) 102. The application software 101 performs processing related to a word processor, spreadsheet, Internet browser, etc., and also generates an image. The monitor driver 105 executes processing for displaying an image created by the application software 101 on the monitor 106.

  The printer driver 103 processes image data transmitted from the application software 101 to the OS 102, and generates binary ejection data that can be recorded by the recording device 104. The ejection data generated at this time is for the four types of ink used in the printing apparatus 104, cyan (C), magenta (M), yellow (Y), and black (K). Details of image processing executed by the printer driver 103 will be described later.

  The host computer 100 includes a CPU 108, a hard disk (HD) 107, a RAM 109, a ROM 110, and the like as hardware for operating the above software. The CPU 108 executes processing of each software according to a program stored in the ROM 110, and the RAM 109 is used as a work area at that time.

  FIG. 7B is a block diagram for explaining a control configuration of the recording apparatus 104 that performs recording on a recording medium in accordance with the image data received from the PC 100 described above. Image data and various commands input from the PC 100 are input to the recording apparatus 104 via an interface (I / F) 703. A CPU 700 provided in the recording apparatus controls each mechanism provided in the recording apparatus 104 and controls the operation of the entire apparatus. The ROM 701 stores various parameters related to the operation of the printing apparatus, such as a program executed by the CPU 700 and a mask pattern characteristic of the present invention described later. The RAM 702 is used as a work area when the CPU 700 performs various processes. The CPU 700, the I / F 703, and each mechanism are connected by a main bus line 705.

  In the figure, an operation unit 706 is provided on the front surface of the recording apparatus to directly exchange commands with the user, and is provided with a power ON / OFF key, a resume key, various LEDs, and the like. The recovery system control circuit 707 drives a recovery system motor in response to a command from the CPU 700, and operates a plurality of mechanisms for performing print head maintenance processing.

  The head temperature control circuit 714 acquires the temperature of the recording head J0010 with the thermistor 712 provided in the recording head J0010, and adjusts the temperature of the recording head according to this temperature. The head driving circuit J0009 drives the recording head J0010 according to the recording data received from the I / F 703 and subjected to image processing by the CPU 700, and causes ink ejection.

  The carriage drive circuit 716 reciprocates and scans the carriage M4000 (see FIG. 8) on which the recording head J0010 is mounted at a predetermined speed. The paper transport control circuit 717 feeds and discharges the recording medium and transports the recording medium being recorded by a predetermined amount.

  FIG. 8 is a perspective view for explaining the internal mechanism of the recording apparatus 104. The recording apparatus 104 of the present embodiment is a serial type inkjet recording apparatus, and forms an image on a recording medium using a recording head J0010 having a plurality of nozzles that eject ink. The recording head J0010 is supplied with ink from an ink tank H1900 that contains cyan (C), magenta (M), yellow (Y), and black (K) inks. The carriage M4000 is moved in the X direction (main scanning direction) by the carriage drive control circuit 716 in a state where the recording head J0010 and the ink tank H1900 are mounted. During this movement, each nozzle of the recording head J0010 ejects ink based on the binary ejection data by the head drive circuit J0009. When one recording main scan by the recording head J0010 is completed, the recording medium is conveyed by the paper conveyance control circuit 717 by a predetermined amount in the Y direction (sub-scanning direction) in the drawing. Images are sequentially formed on the recording medium by alternately repeating the above-described recording main scanning and sub-scanning.

  FIGS. 9A and 9B are views for explaining the ejection port surface of the recording head J0010 of the present embodiment. In the recording head J0010, as shown in FIG. 6B, six color chips including black (K), cyan (C), magenta (M), and yellow (Y) chips are arranged in parallel in the main scanning direction. Configured. FIG. 9A is an enlarged view for explaining a chip configuration for one color. Reference numeral 2805 denotes a common liquid chamber, and ink is supplied from the ink tank. The ink in the common liquid chamber 2805 is supplied to a plurality of liquid paths 2804 arranged on the left and right. An electrothermal converter is provided inside each liquid passage, and ink droplets are ejected from the ejection port 2803 by applying a predetermined voltage pulse thereto. In the left and right discharge port arrays, 256 individual discharge ports are arranged at a pitch of 600 dpi (dot / inch; reference value). Further, since the left and right ejection port arrays are arranged with a half-pitch shift in the sub-scanning direction, 512 ejection ports with a density of 1200 dpi (dot / inch; reference value) in the sub-scanning direction in one chip. Will be arranged. In the present embodiment, approximately 3 picoliters of ink droplets are ejected from each ejection port.

  FIG. 10 is a block diagram for explaining the flow of image processing performed by the host PC 100 and the recording apparatus 104. At the time of recording, the image data created by the application 101 is transferred to the printer driver 103 via the OS 102. The printer driver 103 executes pre-stage processing J0002, post-stage processing J0003, γ correction J0004, binarization processing J0005, and print data creation J0006 on the received image data. Below, each process is demonstrated easily.

  The pre-stage process J0002 performs color gamut mapping. This processing is 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 recording apparatus. Specifically, 256-gradation data in which each of R, G, and B is expressed by 8 bits is converted into 8-bit data of R, G, and B having different contents by using a three-dimensional LUT.

  The post-process J0003 obtains color separation data Y, M, C, and K corresponding to the combination of inks that reproduce the color represented by the data based on the R, G, and B data on which the color gamut is mapped. Here, similarly to the pre-stage processing, the processing is performed using the interpolation calculation together with the three-dimensional LUT.

  The γ correction J0004 performs density value (tone value) conversion for each color data of the color separation data obtained by the post-processing J0003. Specifically, a one-dimensional LUT corresponding to the gradation characteristics of each color ink of the printing apparatus is used to perform conversion such that the color separation data is linearly associated with the gradation characteristics of the printing apparatus.

  The binarization process J0005 performs a quantization process on each of the 8-bit color separation data Y, M, C, and K to convert it into 1-bit data. In the present embodiment, 256-bit 8-bit data is converted into 2-gradation 1-bit data using an error diffusion method.

  In the print data creation process J0006 at the end of the process of the printer driver 103, print data is added to the binary image data containing the binarized 1-bit data C, M, K, and Y as print data. Create The binary image data includes dot recording data indicating dot recording and dot non-recording data indicating dot non-recording. The print control data includes information related to recording control such as “recording medium information”, “recording quality information”, and “paper feeding method”. The print data generated as described above is supplied to the recording device 104.

  In the recording apparatus 104, a mask data conversion process J0008 is executed on the binary data received from the printer driver 100. In the mask data conversion process J0008, a logical product is obtained between the obtained dot recording data and the mask pattern defined by the print control data. The features of the mask pattern used in this embodiment will be described in detail later. The binary data obtained as a result of the logical product becomes ejection data ejected by each recording element in one recording scan of a plurality of scans, and is transferred to the head drive circuit J0009. The 1-bit data of each color input to the driving circuit J0009 is converted into a driving pulse for the recording head J0010, and ink is ejected from the recording head J0010 for each color at a predetermined timing. Thereby, one recording main scan is executed.

  The recording apparatus 104 of the present embodiment can execute various forms of multi-pass recording based on various recording modes. A plurality of types of mask patterns used for multi-pass printing are prepared for each printing mode and for each ink color, and these are stored in advance in a memory provided in the printing apparatus.

  The features of the mask pattern used in this embodiment will be described below. Here, it is assumed that 4-pass multi-pass printing is performed, and the mask pattern of each color has a print allowance of about 25%. The dispersibility of the print permitting pixels has the characteristics of the laminated mask described in Patent Document 3. That is, for each color mask pattern, even when mask patterns of other colors are further superimposed (logical sum), the dispersibility is excellent so that the low frequency component can be kept lower than the high frequency component. Arrangement is defined in association with each color. In this specification, “low frequency component” refers to a component on the lower frequency side than half of the spatial frequency region where the frequency component (power spectrum) exists, and “high frequency component” refers to more than half. A component on the high frequency side.

  In addition, as a feature of the present embodiment, the specific color cyan is designed so that an exclusive relationship is established with respect to the other three colors while satisfying the above condition.

  FIGS. 11 to 14 are schematic diagrams for explaining the features of the mask pattern of this embodiment used when recording the same area of the recording medium. FIG. 11 is a diagram showing a part (8 pixels × 8 pixels region) of a random mask common to each color described in Patent Document 1 and the like. Here, the mask pattern for the same region is common in cyan, magenta, yellow, and black. The figure shown below shows a state in which four colors are superimposed, and a situation occurs in which dots of four colors overlap each other in one scan. In such a recording state, the beading caused by the grain is intensely generated, and the color unevenness and the time difference unevenness in the bidirectional recording as described in the problem section are easily noticeable.

  FIG. 12 is a diagram showing a part (8 pixels × 8 pixels region) of the laminated mask disclosed in Patent Document 3 and the like. Here, the mask patterns are individual for cyan, magenta, yellow, and black, and each has high dispersibility, that is, the low frequency component is kept higher than the high frequency component. The figure shown below shows a state in which four colors are overlaid. Even in this state, the dispersibility of dot recording pixels is kept high. If the respective colors can be kept completely exclusive in this way, problems such as beading, color unevenness, and time difference unevenness due to grain can be suppressed.

  However, in general, the dots recorded in one pixel are designed to be larger than the area of the pixel. In other words, the dots recorded in the adjacent pixels have a number of areas where they overlap each other, and it is inevitable that the areas such as the above-described grain, color unevenness, and time difference unevenness will be adversely affected. Further, in order to make all colors completely exclusive, for example, when four colors of ink are used as in the present embodiment, it cannot be realized unless the multi-pass printing has four or more passes. When more types of ink are used as in recent years, a larger number of multi-passes is required to make all ink colors completely exclusive.

  In such a situation, the present inventors have an ink color (hereinafter referred to as a “specific color”) that is particularly prominent in the above-mentioned adverse effects, and when the adverse effects between other colors are not so problematic, only the specific colors are used. Has come to the knowledge that it is effective to devise such that it is completely exclusive to other colors. In this case, the specific color indicates an ink that easily changes the degree of causing aggregation by chemically reacting with other colors, for example.

  FIG. 13 is a diagram showing a part (8 pixels × 8 pixels region) of the mask pattern of the present embodiment. Here, as in FIG. 12, the mask patterns are individual for cyan, magenta, yellow, and black, and each maintains a highly dispersive state. However, for the combination of magenta, yellow and black, these are not completely exclusive of each other, and only cyan is completely exclusive for the other three colors. The figure shown below shows a state in which four colors are superimposed, but only the cyan dots do not overlap other dots in any pixel.

  FIG. 14 shows a result of measuring the color difference at both ends in the main scanning direction over time when a uniform gray image is recorded in both directions by using the mask patterns described in FIGS. 11 to 13. FIG. Here, both ends in the main scanning direction are portions corresponding to the regions A and B in FIG. In the figure, the horizontal axis indicates the elapsed time after recording. In general, in inkjet recording, a certain amount of time is required from immediately after ink is applied to the recording medium until the ink is absorbed and completely fixed by the recording medium. The color development also changes depending on the degree of fixing. The color difference between the areas AB is not completely zero, but gradually decreases with time as shown in the figure.

  A curve a shows the result when the random mask pattern common to all colors shown in FIG. 11 is used. A curve “b” shows a result in the case of using a completely exclusive layered mask shown in FIG. Further, a curve c shows a case where the mask pattern of this embodiment shown in FIG. 13 is used. As can be seen from the figure, the mask pattern of this embodiment has the smallest hue difference between the areas AB. In other words, the difference in hue between regions that are continuous in the sub-scanning direction is not noticeable, which means that the adverse effects of bidirectional unevenness due to color unevenness and time difference unevenness are the smallest among the three mask patterns.

  For the mask pattern generation method of this embodiment, the method of Patent Document 3 can be used. However, in the process of setting the recording allowable pixels of the mask patterns for each color, if a laminated mask according to Patent Document 3 is generated on the condition that cyan is completely exclusive to the other three colors. Good.

  In the above description, cyan has been described as a specific color, but the present invention and this embodiment are not limited to this. The reason why cyan is used as a specific color is that, as described above, cyan color materials often have phthalocyanine as a basic skeleton, and easily change cohesion when mixed with other colors. That is, by setting the cyan mask pattern exclusively, mixing of cyan ink and other colors in the same printing scan is positively avoided, and color unevenness as described with reference to FIG. 3 and color unevenness described with reference to FIGS. This is because such a time difference unevenness is suppressed. However, it is needless to say that if the ink that specifically changes the cohesiveness of such a cyan color material can be specified, the same effect as described above can be obtained even if the ink is defined as a specific color. .

  However, if only a specific color is simply excluded from other colors, only the same effect as in Patent Document 4 can be obtained. On the other hand, according to the present invention, the dispersibility of each color dot that is stacked in the same printing scan (obtained by logical sum) is preferable, and the specific color has an exclusive dot arrangement. It is characterized by. By satisfying these two conditions at the same time, it is possible to realize image output with excellent uniformity even in bidirectional multi-pass printing. In the configuration of only Patent Document 4, the dispersibility of dots is not considered in the stacking process of each color. Therefore, even if the dots of a specific color can be arranged exclusively, the grains that are inevitably generated are not dispersed in a preferable state, so that an image adverse effect that impairs uniformity of beading is confirmed.

  In the present invention and this embodiment, in order to suppress agglomeration caused by contact of a specific color with other inks, the other ink colors are different from each other as long as only the specific color is exclusive to the other ink. The same mask pattern may be used. Even if a plurality of ink-colored dots are recorded in the same pixel, the adverse effect is suppressed as long as the relationship of excellent dispersibility and the exclusive relationship are maintained between these and the dots of the specific color. This is because an effect can be obtained. In this case, it is sufficient that at least two mask patterns are prepared, and the memory can be reduced as compared with a case where different mask patterns are prepared for all colors. Furthermore, if the number of pixels in which dots other than the specific color are recorded in this way is reduced, there is an advantage that contact between the specific color and the other color can be more actively avoided.

  Hereinafter, in order to verify this embodiment, some experiments conducted by the present inventors and their results will be described. In the experiment, a uniform gray image is recorded with a plurality of inks by four-pass bidirectional multi-pass recording on a recording medium, and bidirectional unevenness and time difference unevenness of the recorded image are visually confirmed.

  In the following verification examples, the recording apparatus described in FIG. 7 and the recording head described in FIG. 9 were used. The drive frequency of the recording head was 30 KHz, and the scanning speed of the carriage was 25 KHz. PR101 made by Canon was used as the recording medium, and BCI7 made by Canon was used as the ink.

(Verification example 1)
In Verification Example 1, cyan was treated as a specific color. Specifically, a mask pattern in which only cyan is completely exclusive to the other two colors is used while suppressing low frequency components in the stacking relationship of cyan, magenta, and yellow. And the recorded matter recorded in this way was compared with the recorded matter recorded by using several mask patterns created based on the prior art. In the mask pattern of the prior art, for example, a mask pattern which is different in three colors but does not consider dispersibility, and cyan which is a specific color, although dispersibility is considered in the stacking relationship of three colors, is exclusive. Contains a mask pattern that is not configured. It was confirmed that the recorded matter recorded using the mask pattern of the present embodiment had less adverse effects of color unevenness, time difference unevenness and beading than the recorded matter recorded using any mask pattern.

(Verification example 2)
FIG. 15 is a schematic diagram for explaining the mask pattern used in this verification example. Here, two types (0ch and 1ch) of mask patterns having a region of 32 pixels × 32 pixels are shown. In Verification Example 2, recording was performed using cyan as a specific color and a mask pattern indicated by 0ch. The other two colors used the mask pattern shown by 1ch. That is, while only cyan is exclusive to the other two colors, the two colors other than cyan are the same mask pattern, and the mask pattern having excellent dot dispersibility in the stacked relationship between cyan and other colors It has become. And the recorded matter recorded in this way was compared with the recorded matter recorded using several mask patterns created based on the conventional technique as in the first verification example. As a result, it was confirmed that the recorded matter recorded using the mask pattern of this verification example had less adverse effects of color unevenness and time difference unevenness.

(Verification Example 3)
In Verification Example 3, light cyan and light magenta were further added to basic three colors cyan, magenta, and yellow for verification. Also in this example, the mask pattern shown in FIG. 15 was used. However, in this verification example, a 0ch mask pattern was used for cyan, magenta, and yellow, and a 1ch mask pattern was used for light cyan and cyan. That is, while light cyan and cyan are exclusive to the other three colors, two colors of light cyan and cyan containing the same color material are the same mask pattern, and the other three colors are also the same mask pattern. did. Furthermore, in the stacking relationship between these two types of mask patterns, the dot dispersibility is excellent. And when the recorded matter recorded in this way was compared with the recorded matter recorded using the mask pattern of the prior art in the same manner as the above-mentioned verification example, the recorded matter recorded using the mask pattern of this verification example was It was confirmed that the adverse effects of color unevenness and time difference unevenness were the least.

  As described above, in the present embodiment, for ink colors that are likely to agglomerate with each other, a mask pattern is prepared so that the arrangement of dots is excellent in dispersibility in the stacking process while being mutually exclusive. . In other words, the mask pattern is associated with each color so that the low-frequency component is suppressed to be less than the high-frequency component in the frequency components of the print-allowed pixels obtained by logical sum (at least logical product) of the mask patterns of each color. . As a result, it is possible to eliminate contact and overlap of dots at each stage leading to the completion of the image as much as possible, and to suppress color unevenness and time difference unevenness. Furthermore, even when contact and overlap of dots cannot be eliminated as in the case of recording a relatively high density image, such contact points are preferably dispersed and arranged, which is visually disturbing. An image that is difficult to be formed can be obtained.

(Second Embodiment)
Also in the present embodiment, the recording apparatus shown in FIG. 8 and the recording head shown in FIG. 9 are used as in the first embodiment. However, in this embodiment, two-pass multi-pass printing is performed, and the mask pattern of each color has a print allowance of about 50%.

  FIG. 16 is a diagram schematically illustrating a recording head, a mask pattern, and a recording medium in order to explain two-pass recording. Also in this embodiment, cyan, magenta and yellow inks are used, and the nozzle groups of the respective colors are arranged in parallel as shown in the drawing with respect to the scanning direction of the recording head. When recording is performed by forward scanning, ink is applied to the recording medium in the order of cyan, magenta, and yellow. On the other hand, when printing is performed by backward scanning, ink is applied to the recording medium in the reverse order of forward scanning, that is, in the order of yellow, magenta, and cyan. In the case of 2-pass multi-pass printing, the nozzle groups arranged in the paper feed direction are divided into a first group and a second group, and the mask patterns addressed to the respective groups have a complementary relationship. In the figure, the masks for the first group of cyan, magenta, and yellow are represented as C1, M1, and Y1, and the second group is represented as C2, M2, and Y2. C1 and C2, M1 and M2, and Y1 and Y2 are complementary to each other. At the end of each recording scan, the recording medium is conveyed by the group width in the sub-scanning direction in the figure. Therefore, in the same area of the recording medium (area corresponding to the width of each nozzle group), an image is completed by two recording scans.

  The area A on the recording medium is an area where the first recording scan is performed by the forward scanning, and the ink application order to the area is C1 → M1 → Y1 → Y2 → M2 → considering the type of mask. C2. On the other hand, the ink application order for the region B in which the first recording scan is performed by the backward scan is Y1 → M1 → C1 → C2 → M2 → Y2.

  In the present embodiment, cyan is a specific color, and only cyan is a mask pattern exclusive to other colors.

  FIG. 17 is a schematic diagram for explaining a mask pattern used in this embodiment. Here, for simplicity, is shown by a mask pattern having an area of 32 pixels × 32 pixels, but in actuality, in the sub-scanning direction, the number of pixel areas included in each nozzle group is further increased in the main scanning direction. It has a large pixel area. In this embodiment, two types of mask patterns (0ch and 1ch) are prepared, and recording is performed using only a specific color cyan, which is a 0ch mask pattern, and magenta and yellow, which are 1ch mask patterns.

  When performing two-pass multi-pass printing as in the present embodiment, since the recording allowance of each mask pattern is 50%, 0ch and 1ch in the first group satisfy the mutually exclusive and complementary relationship. In the same channel, the mask pattern for the first group and the mask pattern for the second group are in a complementary relationship, so that the first group 0ch and the second group 1ch, and the first group 1ch and the second group The 0ch of the group has the same mask pattern. That is, according to the present embodiment, two types of mask patterns can be alternately used in the three color nozzle arrays, and less memory is prepared for the mask pattern than in the first embodiment.

  In the case of the present embodiment, the specific color and the non-specific color are mutually exclusive in the same recording scan, so aggregation is suppressed to some extent, but the specific color and the non-specific color are recorded in adjacent pixels in the same recording scan. Therefore, aggregation cannot be avoided completely. However, it is expected that the agglomerated portions generated in this way are not visually recognized as image adverse effects because they are dispersed in a visually suitable state.

  As described above, according to the present embodiment, the mask pattern of the specific color and the other colors are mutually exclusive and excellent in dispersibility even in the two-pass bidirectional multi-pass (low frequency components can be suppressed). It was in the state. As a result, it is possible to suppress both the image adverse effect due to color unevenness and time difference unevenness and the image adverse effect due to beading.

(Third embodiment)
Also in this embodiment, the recording apparatus shown in FIG. 8 is used as in the above embodiment. However, a recording head that can record large dots and small dots with the same ink color is used.

  18A and 18B are views showing the recording head used in this embodiment in the same manner as FIG. In the recording head according to the present embodiment, the arrangement pitch and the number of the ejection ports are the same as those in the recording head in FIG. 9, but for cyan and magenta, two nozzle groups having different ejection port sizes on the left and right sides are prepared. Has been. Referring to FIG. 18A, approximately 3 picoliters of ink droplets are ejected from the large dot ejection ports included in the left column and approximately 1 picoliter of ink droplets are ejected from the small dot ejection ports included in the right column. Is done.

  When two-step dot diameters, that is, two-step gradations can be expressed with the same ink color as described above, the ratio of using large dots and small dots varies depending on the density of the image to be expressed.

  FIG. 19 shows signal values for decomposing 256 gradation density data (input values) corresponding to a predetermined ink color (cyan or magenta) into density data for large dots and density data for small dots. It is a figure for demonstrating conversion. When the input value is low gradation, only small dots are used. As the input value increases, the output value of small dots also increases. Large dot recording is started from the stage when the input value reaches the substantially intermediate value (128), and the output value of the large dot increases as the output value increases. On the other hand, the output value of small dots after the intermediate value decreases as the output value of large dots increases.

  In this way, by performing recording using a plurality of stages of dot diameters, a wider range of gradations can be expressed more smoothly. Then, for example, when the output value of both the large dot and the small dot is not 0 as in the input value indicated by the arrow in FIG. 19, it is more finely recorded to the position where the large dot and the small dot do not overlap each other. It is known that it is preferable for smooth gradation expression.

  Therefore, in the present embodiment, a mask pattern exclusive for large dots and small dots is used so that dots of the same color and different diameters are not overlapped and recorded as much as possible. For example, the 0ch mask pattern shown in FIG. 15 is used for cyan and magenta large dots, and the 1ch mask pattern is used for small dots of the same color. By doing so, as shown in FIG. 20, the recording positions of the large dots and the small dots can be suitably dispersed, so that the gradation of each color is suppressed while suppressing aggregation due to the large dots and small dots. Can be expressed smoothly.

  On the other hand, when the cohesion of the ink of a specific color is regarded as a problem rather than the improvement in gradation, a mask pattern of 0ch is used for large dots and small dots of a specific color, and other ink colors are used. All 1ch mask patterns may be used.

  Thus, the present invention not only avoids aggregation caused by highly reactive ink, but also for other purposes such as improvement of gradation when using large dots and small dots. Can also be suitably employed.

  Note that the signal value conversion as shown in FIG. 19 can be processed in the final stage of the post-processing J0003 described in FIG. 10 or the pre-stage of the γ correction J0004.

  In the above description, the case of using two-stage dot diameters of large dots and small dots has been described. However, the present invention is not limited to this, and there are three types of large, medium, and small, or more types. The case where a dot diameter is used may be used.

  In the embodiment described above, the mask pattern which is a feature of the present invention has been described as being stored in the memory in the printing apparatus, but the present invention is not limited to such a configuration. The PC 100 shown in FIG. 7 may function as a data processing apparatus that executes processes up to the mask data conversion process J0008. In this case, binary data manufactured in the PC 100 is recorded before the recording operation. 104 may be transferred. It is included in the scope of the present invention whether the image processing unit that executes the mask data conversion process is in the recording apparatus, the host apparatus, or an apparatus in which these are integrally configured.

  Further, the type of ink that can be applied in the present invention is not limited to the type of ink described in the above-described embodiment. For example, in addition to light-based (light cyan, light magenta, etc.) inks in addition to CMY and black basic colors, special color inks such as red, blue, and green can be further added. In addition, the present invention is suitably employed even when there is a concern about aggregation between the dye ink and the pigment ink while using a dye ink containing a dye as the color material or a pigment ink containing a pigment as the color material. I can do it.

  Furthermore, the present invention can also be applied to the case of discharging a liquid other than ink for improving image quality and handling. Examples of the liquid other than the ink include a reaction liquid that aggregates or insolubilizes the color material in the ink. In this case, the same mask pattern as that of the reaction liquid is used for ink that is desired to react positively with the reaction liquid, and the mask pattern exclusive to these is used for ink that is not desired to react with the reaction liquid as much as possible. You can do that.

  The specific color in the present invention is not limited to an ink containing a material that reacts chemically by contacting with another color. Even if it is to suppress image damage caused by aggregation as in the first and second embodiments, or to improve gradation as in the third embodiment, it is separated from the others. In the present invention, a specific color can be used for an ink that produces a preferable result when recorded.

  Further, in the above embodiment, the method of recording by classifying into the specific color and the other color group by applying the laminated mask described in the above embodiment to all the plural types of ink used in the recording apparatus has been described. However, in the present invention, ink that is a part of the other color group but hardly causes image defects can be recorded using the same mask pattern as the specific color. For example, an ink whose recording duty (number of recording dots) is expected to be lower than other colors, such as black, an ink with a low degree of interaction with a specific color, or a component similar to a specific color. Ink or the like corresponds to this.

FIG. 3 is a diagram schematically illustrating a recording head and a recording pattern for explaining multi-pass recording. (A)-(c) is a schematic diagram for demonstrating the problem of beading. (A) And (b) is a schematic diagram for demonstrating the application order of the ink at the time of bidirectional | two-way recording. (A)-(c) is a schematic diagram for demonstrating the absorption state to the recording medium at the time of providing cyan and magenta as a droplet to the same location. It is a schematic diagram for explaining the time difference unevenness that occurs according to the difference in ink application timing as described above when performing bidirectional recording. It is a figure for demonstrating the time difference nonuniformity at the time of performing 4-pass bidirectional | two-way multipass recording. (A) And (b) is a block diagram for demonstrating the control structure of the personal computer as a data processor which concerns on this embodiment, and the recording device connected with this. It is a perspective view for demonstrating the internal mechanism of a recording device. (A) And (b) is a figure for demonstrating the discharge port surface of the recording head J0010 of this embodiment. 4 is a block diagram for explaining a flow of image processing performed by a host PC 100 and a recording apparatus 104. FIG. It is a schematic diagram for demonstrating an example of the mask pattern used when recording the same area | region of a recording medium. It is a schematic diagram for demonstrating an example of the mask pattern used when recording the same area | region of a recording medium. It is a schematic diagram for demonstrating the mask pattern of this embodiment used when recording the same area | region of a recording medium. FIG. 11 is a diagram showing the results of measuring the color difference at both ends in the main scanning direction over time when a uniform gray image is recorded in both directions by using the mask patterns described in FIGS. It is. It is a schematic diagram for demonstrating the mask pattern used in the verification example 2. FIG. FIG. 3 is a diagram schematically illustrating a recording head, a mask pattern, and a recording medium in order to explain 2-pass recording. It is a schematic diagram for demonstrating the mask pattern used in 2nd Embodiment. (A) And (b) is the figure which showed the recording head used by this embodiment similarly to FIG. It is a figure for demonstrating signal value conversion for decomposing the density data (input value) of 256 gradations into the density data for large dots, and the density data for small dots. It is a figure for demonstrating the dispersion state of a large dot and a small dot.

Explanation of symbols

100 Host device 104 Recording device 700 CPU
701 ROM
702 RAM
J0008 Mask data conversion processing J0009 Head drive circuit J0010 Recording head

Claims (10)

Data processing for generating image data to be recorded in each of the plurality of scans in order to scan a plurality of nozzle groups that record a plurality of types of dots on the recording medium a plurality of times with respect to the same area of the recording medium A method,
Using a plurality of types of mask patterns corresponding to each of the plurality of types of dots, and dividing the image data corresponding to the plurality of types of dots into image data recorded in each of the plurality of scans,
Among the plurality of types of mask patterns, an array of print permitting pixels and a second type of dots in the plurality of first mask patterns corresponding to the plurality of scans for recording at least the first type of dots are recorded. The arrangement of the print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for performing the above is in an exclusive relationship,
A low frequency component in an array pattern of print permitting pixels obtained by a logical product of a predetermined first mask pattern of the plurality of first mask patterns and a predetermined second mask pattern of the plurality of second mask patterns is obtained. A data processing method, wherein the print permission pixels of the predetermined first mask pattern and the predetermined second mask pattern are arranged in association with each other so as to have characteristics smaller than a high frequency component. Data processing for generating image data to be recorded in each of the plurality of scans in order to scan a plurality of nozzle groups that record a plurality of types of dots on the recording medium a plurality of times with respect to the same area of the recording medium A method,
Using a plurality of types of mask patterns corresponding to each of the plurality of types of dots, and dividing the image data corresponding to the plurality of types of dots into image data recorded in each of the plurality of scans,
Among the plurality of types of mask patterns, an array of print permitting pixels and a second type of dots in the plurality of first mask patterns corresponding to the plurality of scans for recording at least the first type of dots are recorded. The arrangement of the print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for performing the above is in an exclusive relationship,
A low frequency component in an array pattern of print permitting pixels obtained by a logical sum of a predetermined first mask pattern of the plurality of first mask patterns and a predetermined second mask pattern of the plurality of second mask patterns is obtained. A data processing method, wherein the print permission pixels of the predetermined first mask pattern and the predetermined second mask pattern are arranged in association with each other so as to have characteristics smaller than a high frequency component. Data processing for generating image data to be recorded in each of the plurality of scans in order to scan a plurality of nozzle groups that record a plurality of types of dots on the recording medium a plurality of times with respect to the same area of the recording medium A method,
Using a plurality of types of mask patterns corresponding to each of the plurality of types of dots, and dividing the image data corresponding to the plurality of types of dots into image data recorded in each of the plurality of scans,
Among the plurality of types of mask patterns, an array of print permitting pixels and a second type of dots in the plurality of first mask patterns corresponding to the plurality of scans for recording at least the first type of dots are recorded. The arrangement of the print permitting pixels in the plurality of second mask patterns corresponding to the plurality of scans for performing the above is in an exclusive relationship,
A low frequency component in an array pattern of print permitting pixels obtained by a logical product of a predetermined first mask pattern of the plurality of first mask patterns and a predetermined second mask pattern of the plurality of second mask patterns is obtained. The low-frequency component in the array pattern of print permitting pixels that has characteristics smaller than the high-frequency component and is obtained by the logical sum of the predetermined first mask pattern and the predetermined second mask pattern is smaller than the high-frequency component. A data processing method characterized in that the print permission pixels of each of the predetermined first mask pattern and the predetermined second mask pattern are arranged in association with each other so as to have characteristics.   4. The data processing method according to claim 1, wherein the predetermined first mask pattern and the predetermined second mask pattern are used in the same recording scan.   5. The data processing method according to claim 1, wherein the plurality of first mask patterns are complementary to each other, and the plurality of second mask patterns are also complementary to each other.   The first type dot is an ink dot containing a specific material, and the second type dot is a liquid dot containing a component that chemically reacts with the specific material. A data processing method according to any one of claims 1 to 3.   A data processing apparatus comprising: an image processing unit that executes the data processing method according to claim 1.   8. The recording apparatus according to claim 7, wherein the data processing apparatus is a recording apparatus that performs recording by scanning the plurality of nozzle groups that record the plurality of types of dots a plurality of times on the same area of a recording medium. Data processing equipment.   The data processing apparatus is a host apparatus connected to a recording apparatus that performs recording by scanning a plurality of nozzle groups that record the plurality of types of dots a plurality of times on the same area of a recording medium. The data processing apparatus according to claim 7.   7. Data according to claim 1, wherein the plurality of nozzle groups are scanned a plurality of times over the same area of the recording medium in accordance with the image data generated according to the data processing method according to claim 1. Recording method.

Images