JP4948221B2 - Data generator - Google Patents

Description

  The present invention relates to a data generation device, and more particularly to recording of a boundary area with another area such as a color image in a black image when recording is performed using black ink and color ink.

  An ink jet recording apparatus that performs recording by ejecting ink onto a recording medium is capable of high-density and high-speed recording, and can perform recording on various recording media. This ink jet recording method has many advantages such as low running cost and low noise generated during recording. From such a point, it is widely used as various image output devices such as printers and portable printers, and is commercialized.

  As a recording method of an ink jet recording apparatus, a so-called serial method is known in which a carriage on which a recording head and an ink tank are mounted is scanned with respect to a recording medium, and ink is ejected during that time to record the area. In this method, the recording medium is conveyed by a predetermined amount in the direction substantially orthogonal to the scanning direction between the scans, and recording is performed on the entire recording medium by repeating these scanning and recording medium conveyance. As another recording method, a so-called full line method is also known. This method uses a recording head in which ejection openings are arranged in a range corresponding to the width of the recording medium, and performs recording while conveying the recording medium to the recording head.

  In recent years, many inkjet recording apparatuses having various advantages as described above have been provided as products for performing color recording using black and a plurality of color inks. In such a color ink jet recording apparatus, since black ink is generally used for recording characters and the like, an ink capable of realizing sharpness, sharpness, and high density of recorded characters is required. In this respect, in many cases, a black ink having low permeability to the recording medium is used, and one that suppresses penetration of a coloring material such as a dye or pigment in the black ink into the recording medium is often used. As a result, the amount of the colorant remaining on the recording medium and fixing is increased, and the sharpness and high density of the recorded image are realized. On the other hand, for color inks, when inks of different colors are applied to adjacent areas on the recording medium, these inks mix at the boundary and cause a phenomenon (bleeding) that degrades the quality of the color image. There is. In order to prevent this, it is known to use ink having improved permeability to a recording medium (see, for example, Patent Document 1). Accordingly, it is possible to prevent a large amount of ink applied to each region from penetrating into the recording medium and mixing with ink of other colors beyond the boundary.

  However, when the combination of black ink and color ink as described above is used, the following problems may occur. In an image in which black and color areas are adjacent to each other, the black ink has low penetrability, so that it may not mix quickly with the color ink beyond the boundary of the area without penetrating into the recording medium. That is, bleeding occurs at the boundary between the black area and the color area.

  In response, several countermeasures have been proposed.

  As a first countermeasure, there is a method of providing fixing means such as a heat fixing device. Thereby, the ink can be fixed on the recording medium at a high speed to prevent bleeding. In addition to this, it is possible to prevent smears in which an image is stained with ink that is not fixed.

  As a second countermeasure, a method is known in which highly penetrable color ink is applied over a black ink recording area. Since the black ink is applied in a state where the surface of the recording medium is coated with the color ink, the black ink easily penetrates into the paper surface, and smear can be suppressed. In addition, at the boundary between the black region and the color region, boundary bleeding is reduced by using an ink set (Patent Document 2) in which the black ink and the color ink react and aggregate.

  However, the first countermeasure is to increase the size of the apparatus and increase the cost because the fixing means is provided. Further, in the serial type recording apparatus, since the paper feeding (conveying) of the recording medium is intermittent, there is a possibility that unevenness is caused in fixing by the fixing device. Further, there is a problem that a certain amount of time is required for fixing, and therefore the time until paper discharge becomes long and throughput is lowered.

  Also, as a second measure, when a color ink with high penetrability is applied in order to promote fixing of the black ink, the black ink also permeates together when the color ink permeates the recording medium. Therefore, less black ink remains on the surface of the recording medium. Therefore, a problem arises in that the sharpness of the black image cannot be realized due to the penetration of the black ink particularly at the boundary of the black image. The second countermeasure solves this problem by agglomeration of the black ink and the color ink. However, since it causes agglomeration of each other, the problem arises that the composition of the black ink and the color ink is limited. . For example, there is a problem that one ink must be cationic and the other ink anionic, and the ink that can be used is limited.

  On the other hand, as the third countermeasure, as in the second countermeasure, it is possible to consider that the color ink having high penetrability is given while distinguishing the recording area of the black ink. That is, the black recording area is divided into a smear-preventing area and a boundary-bleeding-preventing area, and the required amount of color ink applied to each is controlled. Thereby, both reduction of smear and reduction of boundary bleeding can be achieved.

JP 55-65269 A Japanese Patent Laid-Open No. 9-25442

  However, in the third countermeasure, there is a problem in that the color image is overlapped and applied, so that the sharpness of the black image such as black characters is lost and the quality of the black image is deteriorated. One of the factors is that, among the boundary areas of the area to be recorded with black ink, the edge area adjacent to the color area and the edge area adjacent to the ground area of the recording medium to which no ink is applied are used. The main purpose of granting is different. In other words, the edge area adjacent to the color area is mainly intended to reduce bleeding with the color ink, while the edge area adjacent to the ground area of the recording medium ensures the sharpness of the black image. Is the purpose. Nevertheless, for example, if the same color ink is applied to both areas for the purpose of reducing bleeding, the quality of the black image may deteriorate.

  On the other hand, considering the change in color of the black image when the color ink is applied in an overlapping manner, it is desirable that the edge region adjacent to the color region is as narrow as possible and the range in which the color changes is as small as possible. On the other hand, in the case of the edge region adjacent to the region of the recording medium, there is also a fact that the change in color due to the application of the color ink is not so conspicuous.

  As described above, the edge region or its size (width) is an important factor when determining the amount of color ink applied in an overlapping manner or considering the influence of image quality deterioration due to a change in color.

  In view of the above, an object of the present invention is to provide a data generation apparatus that can record a high-quality black image with reduced bleeding at the boundary with a color image and sharpness.

  To this end, the present invention provides a data generation apparatus that generates data for recording on a recording medium by applying black ink and color ink having a higher permeability than the black ink, and records data at a first resolution. Mode setting means for setting one mode from a plurality of modes including a first mode for performing recording and a second mode for performing recording at a lower resolution than the first resolution and faster than the first mode; When recording an image including a black area to which black ink is applied and a white area to which neither the black ink nor the color ink is applied, an area including an edge adjacent to the white area in the black area is adjacent to white. Area setting means for setting as a black edge area, and the white edge adjacent black edge area. Superimposing data generating means for generating superimposing data for applying the color ink so as to overlap the black ink, and when the first mode is set, the region setting means The number of pixels indicating the width from the edge in the white adjacent black edge region is set to be larger than that in the case where it is set.

  According to the above configuration, bleeding at the boundary with the color image can be reduced, and a black image with high quality including color and sharpness can be recorded.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment described below, an ink jet printer will be described as an example of the ink jet recording apparatus.

Overview of Inkjet Printer FIG. 16 is a perspective view showing a schematic configuration of a color inkjet printer according to an embodiment of the present invention. In this figure, reference numeral 202 denotes an ink cartridge storing respective color inks and black inks of three colors of yellow, magenta, and cyan. These ink cartridges 202 are detachably mounted on the carriage 106. A recording head 201 corresponding to each of the inks is similarly detachably mounted on the carriage 106. The carriage 106 can move while being guided by the guide shaft 108 by a drive mechanism (not shown). As a result, the recording head 201 can scan the recording medium 107 such as recording paper for recording. Reference numeral 104 denotes a paper feed roller which rotates in the direction of the arrow in the drawing together with the auxiliary roller 103 (preferably a spur form). Similarly, a paper feed roller pair 105 is provided on the upstream side of the recording head 201 in the conveyance direction of the recording medium 107. The paper feed roller pair 105 rotates in synchronization with the transport roller 104. Thus, the recording medium is conveyed in the direction indicated by the arrow D in the drawing while maintaining the recording surface of the recording medium 107 flat.

  The carriage 106 moves in the x direction in the figure in accordance with a recording command and scans the recording head. During this scan, the ejection heater of the recording head 201 is driven according to the recording data to eject ink, and an area corresponding to the recording width of the recording head is recorded on the recording medium 107. After this recording scan is finished, before the next recording scan starts, the paper feed roller 104 feeds the paper in the direction indicated by the arrow D by the required width. By repeating scanning and paper feeding in this way, recording on a predetermined area of the recording medium is completed.

  In addition, recording is not performed only during main scanning in one direction, but in order to increase the recording speed, recording is performed also in the return path when the main scanning recording in the x direction ends and the carriage is returned to the home position side. It may be. In the example described above, the ink tank and the recording head are detachably mounted on the carriage 106. It may be in the form of an ink jet cartridge in which the ink cartridge 202 containing ink and the recording head 201 are integrated. Furthermore, a multi-color integrated recording head that can eject a plurality of colors of ink from one recording head may be used.

  The carriage movement range includes a capping mechanism (not shown) that caps the ejection port surface of the recording head, and a head recovery operation such as removing thickened ink and bubbles in the recording head in the capped state by the capping mechanism. A recovery unit (not shown) is provided. Further, the recovery unit is provided with a cleaning blade (not shown) and the like, and is supported so as to protrude toward the recording head 201, and can come into contact with the front surface of the recording head. Thus, after the recovery operation, the cleaning blade can be projected into the movement path of the recording head, and unnecessary ink droplets and dirt on the front surface of the recording head can be wiped off as the recording head moves.

Outline of Recording Head FIG. 17 is a perspective view showing a schematic configuration of a main part of the recording head 201 shown in FIG. As shown in FIG. 17, the recording head 201 has a plurality of ejection ports 300 formed at a predetermined pitch, and ejects ink along the wall surface of the liquid path 302 that connects the common liquid chamber 301 and the ejection ports 300. Discharge heaters 303 for generating energy for use are provided. The heater 303 and its circuit are created on the silicon using semiconductor manufacturing technology. The liquid path 302 and the common liquid chamber 301 are formed by a plastic cover 306 made by injection molding. Further, a temperature sensor (not shown) and a sub-heater (not shown) are collectively formed on the same silicon by the same process as the semiconductor manufacturing process. The silicon plate 308 on which these electrical wirings are made is fixed to an aluminum base plate 307 that forms a support substrate. Further, the circuit connection portion 311 on the silicon plate 308 and the printed circuit board 309 are electrically connected by an extremely thin wire 310 and a signal from the recording apparatus main body can be received via the signal circuit 312. The common liquid chamber 301 is connected to the ink cartridge shown in FIG. 1 via a joint pipe 304 provided with an ink filter 305, whereby ink is supplied from the ink cartridge to the common liquid chamber 301. The ink supplied to the common liquid chamber 301 and temporarily stored is supplied to the liquid path 302 by capillary action, forms a meniscus at the discharge port 300, and keeps the liquid path 302 filled. At this time, when the heater 303 is energized through an electrode (not shown) and heat is generated, the ink on the heater 303 is rapidly heated and bubbles are generated in the liquid path 302, and the discharge ports 300 are caused by the expansion of the bubbles. Ink droplets 313 are ejected.

Overview of Control Configuration FIG. 18 is a block diagram showing a control configuration in the ink jet printer of the embodiment shown in FIG. In the figure, reference numeral 400 denotes an interface for inputting recording data from a host device such as a personal computer (PC). The recording control unit 500 records a black image or a color image including an adjacent area with a color image in the black image, which will be described later with reference to FIGS. Execute data generation processing. In addition, the recording control unit 500 executes operation control of each unit operation mechanism accompanying the recording operation such as the paper feed motor 405 and the carriage motor 406.

  In the recording control unit 500, the MPU 401 executes the above-described data thinning process and recording operation control according to a control program stored in the program ROM 402. A RAM (DRAM) 403 is used as a work area when the MPU 401 executes such processing. That is, the RAM 403 temporarily stores data such as print data and ejection data supplied to the print head, and also stores the number of print dots, the number of print head replacements, and the like. The gate array 404 controls the supply of print data to the print head and also controls the transfer of data among the interface 400, the MPU 401, and the DRAM 403. Motor drivers 407 and 408 drive a transport motor 405 and a carrier motor 406, respectively. The head driver 409 drives the recording head 410 to discharge ink from each discharge port.

(Embodiment 1)
Outline of Embodiment 1 One embodiment of the present invention relates to an embodiment in which color ink is applied in a superimposed manner on a black area to be recorded with black ink. Then, in the black area, a certain edge area adjacent to the color area to be recorded with the color ink and a certain edge area adjacent to the ground area of the recording medium are defined, and the width is determined for each area. At the same time, the amount of color ink applied is varied. Further, the amount of color ink to be applied to the internal area other than the two edge areas is also appropriately determined. Hereinafter, the edge area adjacent to the color area is referred to as a color adjacent black edge area, the edge area adjacent to the ground area of the recording medium is referred to as a white adjacent black edge area, and the inner area is referred to as a black non-edge area. . More specifically, in this embodiment, an ink having a low permeability is used as the black ink, while an ink having a higher permeability than the black ink is used as the color ink. And the color adjacent black edge area mainly increases the amount of color ink applied to prevent bleeding, while the white adjacent black edge area mainly applies the amount of color ink applied to realize the sharpness of the black image. Reduce. In addition, the black non-edge region, which is a region other than the white adjacent black edge region, is applied with an appropriate amount of color ink to prevent smear.

  Further, in the present embodiment, the widths of the color adjacent black edge region and the white adjacent black edge region are determined according to the recording mode or recording resolution in the printer. As a result, even if the recording mode or the like is changed, the amount of color ink applied is determined appropriately, and the sharpness of the black image is appropriately realized.

Overall Data Processing FIG. 1 includes black (hereinafter also simply referred to as Bk), cyan (also C), magenta (also M), including the determination of the width of the edge region described above, according to one embodiment of the present invention. FIG. 6 is a block diagram illustrating a process for generating recording data for each color ink of yellow and yellow (also Y). As described above, “color” is also simply expressed as “Cl”, and “white” is also expressed as “White”.

  First, based on original Bk data (D1000), original C data (D1001), original M data (D1002), and original Y data (D1003) obtained from an original image to be recorded, black boundary processing (E1000) I do. The original C data, original M data, and original Y data constitute original color data. By the black boundary processing, the color adjacent black edge region, the white adjacent black edge region (the width thereof), and the black non-edge region in the original Bk image (region) are determined. That is, color adjacent black edge data (D1008), white adjacent black edge data (D1009), and black non-edge data (D1010), which are data of these areas, are generated.

  Next, Cl adjacent Bk edge thinning data (D1014) is generated by taking the logical product of Cl adjacent Bk edge data (D1008) and Cl adjacent Bk edge thinning mask (color adjacent black edge thinning mask; D1011). Similarly, the White adjacent Bk edge thinning data (D1015) is generated by calculating the logical product of the White adjacent Bk edge data (D1009) and the White adjacent Bk edge thinning mask (white adjacent black edge thinning mask; D1012). Further, Bk non-edge thinning data (D1016) is generated by taking the logical product of the Bk non-edge data (D1010) and the Bk non-edge thinning mask (D1013). The process using these thinning masks determines the amount of color ink applied to each of the Cl adjacent Bk edge region, the White adjacent Bk edge region, and the Bk non-edge region (hereinafter also referred to as “underscore”) by the mask. This is a process of adjusting the entire area. Note that “underlay” for setting the overlap amount means that the color ink is applied in an overlapping manner, and does not mean only the form in which the color ink is previously applied by ink ejection and the black ink is applied thereon. . Conversely, it also means a mode in which black ink is ejected in advance and each color ink is ejected on top of the black ink.

  Next, Cl adjacent Bk edge thinning data (D1014) obtained as described above, and C mask 1 (D1017), M mask 1 (D1018), and Y mask 1 (D1019) which are the first color underlay masks, respectively. ) Logical AND with each. Thereby, C underlay data 1 (D1020), M underlay data 1 (D1020), and Y underlay data 1 (D1022), which are data of color ink to be applied to the Cl adjacent Bk edge region, are generated. That is, the amount of color ink applied to the Cl adjacent Bk edge region is finally determined.

  Similarly, the logical product of the White adjacent Bk edge thinning data (D1015) and each of the C mask 2 (D1023), M mask 2 (D1024), and Y mask 2 (D1025), which are the second color underlay masks, respectively. Take. As a result, C underlay data 2 (D1026), M underlay data 2 (D1027), and Y underlay data 2 (D1028), which are data of color ink to be applied to the White adjacent Bk edge region, are generated. That is, the amount of color ink to be applied to the White adjacent Bk edge region is finally determined.

  Similarly, the logical product of the black non-edge thinning data (D1016) and each of the C mask 3 (D1029), the M mask 3 (D1030), and the Y mask 3 (D1031), which are the third color underlay masks, is obtained. As a result, C underlay data 3 (D1032), M underlay data 3 (D1033), and Y underlay data 3 (D1034), which are data of color ink to be applied to the black non-edge region, are generated. That is, the amount of color ink applied to the black non-edge region is finally determined.

  By the above-described underprint masking process for each ink color, the final underprint amount of each of the Cl adjacent Bk edge region, the White adjacent Bk edge region, and the Bk non-edge region is determined. In the present embodiment, the ratio of the printable pixels of the underlay mask is different for each color. As described above, the masks 1, 2, and 3 are used for C, M, and Y, respectively, and the sum of the ratios of the print allowable pixels of the masks 1 to 3 for each color can be seen from FIGS. , Cyan (C) is the largest. This is because the cyan has the best fixability with black, so that the most cyan is applied. In addition, when only cyan is applied, the color of the black image changes, so a small amount of magenta or yellow is applied to reduce the change in color. At this time, if magenta or yellow is applied in the same amount as cyan in order to reduce the change in color, the amount of ink applied increases, causing bleeding and smearing. Therefore, cyan ink is applied so as to improve the fixability of black ink, and magenta or yellow is applied so that the color of the black image does not change without causing bleeding or smear.

  As described above, in this embodiment, a plurality of types of color inks are prepared, and in accordance with this, the first color underprint mask, the second color undercoat mask, and the third color undercoat mask each have ink colors. Prepared separately for each.

  The C underscore data 1 (D1020), the C underscore data 2 (D1026), and the C underscore data 3 (D1032) obtained as described above are ORed to obtain the C underscore data (D1035). Generate. Further, the C underscore data (D1035) and the original cyan data (D1001) are logically ORed to generate final recording cyan data (D1005). Similarly, M underscore data 1 (D1020), M underscore data 2 (D1027), and M underscore data 3 (D1033) are ORed to generate M underscore data (D1036). The M underscore data (D1036) and the original magenta data (D1002) are logically ORed to generate final recording magenta data (D1006). Similarly, the logical sum of Y underscore data 1 (D1022) and Y underscore data 2 (D1028) Y underscore data 3 (D1034) is taken to generate Y underscore data (D1037). Then, the logical sum of the Y underscore data (D1037) and the original yellow data (D1003) is taken to generate the final recording yellow data (D1004).

  Also, the logical sum of the Cl adjacent Bk edge thinning data (D1014), the White adjacent Bk edge thinning data (D1015), and the Bk non-edge thinning data (D1016) is calculated to generate the final recording black data (D1004).

Black border processing (E1000)
FIG. 2 is a block diagram showing details of the black boundary processing (E1000) shown in FIG. This process is an area setting process or a black boundary generation process for determining the Cl adjacent Bk edge area and the White adjacent Bk edge area together with the width (hereinafter also referred to as edge width) as described above. The example shown in FIG. 2 shows a case where the maximum edge width is 4 dots (pixels).

  Black degeneration processing (E2000) is performed on the original Bk data (D1000). Thereby, black 1-dot degeneration data (D2000), black 2-dot degeneration data (D2001), black 3-dot degeneration data (D2002), and black 4-dot degeneration data (D2003) are generated. These black dot reduction processes are processes for determining the edge widths of the White adjacent Bk edge region and the Cl adjacent Bk edge region together with the later-described color bold processing performed as the processing in the black boundary processing.

(Black degeneration processing (E2000))
FIG. 3 is a flowchart showing black 1-dot reduction processing. FIGS. 4A to 4G are diagrams schematically illustrating this process by data for each pixel.

  In the black 1-dot reduction process, the following process is performed for each pixel of the black image. First, it is determined whether or not the total number of black dots present in the 3 × 3 matrix (FIG. 4A) centered on the pixel of interest in the black image is 9 dots (S101). When the total number of black dots is 9, the bit of the target pixel is turned on (S102). If not, the bit of the pixel of interest is turned off (S103). Subsequently, the pixel of interest is shifted (S104). If the process is completed for all the pixels of the black image, the process ends (S105). If not, the above process is repeated. In the above example, the threshold value for the total number of black dots is set to 9, but it is preferable to use an optimum value in accordance with the characteristics of the ink and the characteristics of the printing apparatus.

  By this black 1-dot reduction processing, an image (FIG. 4D) obtained by reducing the outline of the original black image (FIG. 4C) by 1 dot (pixel) is obtained.

  Similarly to the black 1-dot reduction process, the black 2-dot reduction process determines whether or not the total number of black dots existing in the 5 × 5 matrix is 25 dots. If the total number of black dots is 25, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. If the process is completed for all the pixels while shifting the pixel of interest, the process ends. If not, the above process is repeated. Here, the threshold value of the total number of black dots is set to 25, but it is the same that it is preferable to use an optimum value according to the characteristics of the ink and the characteristics of the printing apparatus. Similarly to the black 1-dot reduction process, the black 3-dot reduction process determines whether the total number of black dots existing in the 7 × 7 matrix is 49 dots. If the total number of black dots is 49, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. If the process is completed for all the pixels while shifting the pixel of interest, the process ends. If not, the above process is repeated. Similarly, the threshold value of the total number of black dots is not limited to 49, and an optimum value can be used according to the characteristics of the ink and the characteristics of the printing apparatus. Further, in the black 4-dot reduction process, similarly, it is determined whether or not the total number of black dots existing in the 9 × 9 matrix is 81 dots. When the total number of black dots is 81, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. Then, while shifting the target pixel, the above processing is repeated until the processing is completed for all the pixels. Similarly, the threshold value of the total number of black dots is not limited to 81, and an optimum value can be used according to the characteristics of the ink and the characteristics of the printing apparatus.

  By the above black 1-dot reduction process, black 2-dot reduction process, black 3-dot reduction process, and black 4-dot reduction process, the reduced black images shown in FIGS. 4D to 4G are obtained. That is, as shown in FIG. 4D, black 1-dot reduction processing results in data that is 1-dot reduction from the original Bk data. In addition, by the black 2-dot reduction process, data obtained by 2-dot reduction with respect to the original Bk data is obtained as shown in FIG. Further, the black 3-dot reduction process yields data that is 3-dot reduction of the original Bk data as shown in FIG. Further, by the black 4-dot reduction process, data obtained by reducing 4 dots with respect to the original Bk data is obtained as shown in FIG.

  Referring again to FIG. 2, the logical sum (FIG. 6 (e)) of the original C data (D1001), the original M data (D1002) and the original Y data (D1003) is taken, and color bold processing is performed on this logical sum image. (E2001) is performed. As a result, color 1-dot bold data (D2004), color 2-dot bold data (D2005), color 3-dot bold data (D2006), and color 4-dot bold data (D2007) are generated.

(Color bold processing)
FIG. 5 is a flowchart showing color 1-dot bold data generation processing by Cl bold processing (E2001). FIGS. 6A to 6I are diagrams schematically showing this process by data for each pixel.

  In color 1-dot bold data generation, the logical sum of the original C image (D1001), original M image (D1002), and original Y image (D1003) shown in FIGS. The color image shown in e) is processed. First, it is determined whether or not the total number of black dots present in the 3 × 3 matrix (FIG. 6A) of this color image is 1 dot or more (S501). If the total number of black dots is 1 dot or more, the bit of the pixel of interest is turned on (S502). Otherwise, the bit of the pixel of interest is turned off (S503). Subsequently, the pixel of interest is shifted (S504), and the above processing is repeated until the processing for all the pixels of the color image (FIG. 6E) is completed (S505). By this processing, a color 1-dot bold image (D2004) shown in FIG. 6F can be obtained. In the above example, the threshold value for the total number of black dots is 1 dot, but it is preferable to use an optimum value in accordance with the characteristics of the ink and the characteristics of the printing apparatus.

  Similarly to the color 1-dot bold process, the color 2-dot bold process determines whether or not the total number of black dots existing in the 5 × 5 matrix (FIG. 6A) is 1 or more. When the total number of black dots is 1 dot or more, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. Then, the pixel of interest is shifted, and the same processing is repeated for all the color pixels. By this processing, a color 2-dot bold image (D2005) shown in FIG. 6G can be obtained.

  Further, in the color 3-dot bold process, similarly to the color 1-dot bold process, it is determined whether or not the total number of black dots existing in the 7 × 7 matrix (FIG. 6A) is 1 or more. When the total number of black dots is 1 dot or more, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. Then, the pixel of interest is shifted, and the same processing is repeated for all the color pixels. By this processing, a color 3-dot bold image (D2006) shown in FIG. 6 (h) can be obtained.

  Finally, in the color 4-dot bold process, it is determined whether or not the total number of black dots present in the 9 × 9 matrix (FIG. 6A) is 1 dot or more in the same manner as the color 1-dot bold process. When the total number of black dots is 1 dot or more, the bit of the target pixel is turned on. Otherwise, the bit of the pixel of interest is turned off. Then, the pixel of interest is shifted, and the same processing is repeated for all the color pixels. By this processing, a color 4-dot bold image (D2007) shown in FIG. 6 (i) can be obtained.

  Each data generated by the black degeneration process and the color bold process described above is selected by the selector and used for the subsequent generation process of Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data.

  As shown in FIG. 2, selectors S2001, S2002, S2003, S2004, and S2005 are provided. These selectors are set according to the recording mode, and more specifically, the respective options are set corresponding to the widths of the Cl adjacent Bk edge region and the White adjacent Bk edge.

  FIG. 7 is a diagram illustrating a table in which options of the selectors S2001 to S2005 are determined according to combinations of the Cl adjacent Bk edge width and the White adjacent Bk edge width.

  In an embodiment of the present invention, when plain paper is used as a recording medium and the recording quality is “standard” and the recording resolution is 1200 dpi, the edge width of the Cl adjacent Bk edge region is 2 dots (pixels) and White adjacent The edge width of the Bk edge region is set to 4 dots (pixels). In the “fast” mode in which so-called column thinning recording is performed, when the recording resolution is 600 dpi, the edge width of the Cl adjacent Bk edge region is set to 2 dots, and the edge width of the White adjacent Bk edge region is set to 2 dots. Thus, in this embodiment, the edge width of each area can be set variably, or the edge width can be changed according to the recording mode. Note that the setting of the edge width according to this mode is performed by the MPU 401 (FIG. 18) referring to the table shown in FIG. 7 according to the recording mode information from the host device and setting the options for each selector. Do it.

  For example, in the case of the “standard mode”, each selector is set as follows according to the Cl adjacent Bk edge width of 2 dots and the White adjacent Bk edge width of 4 dots. Setting is performed such that the selector S2001 selects the data D2003, the selector S2002 selects the data D2001, the selector S2003 selects the data D2007, the selector S2004 selects the data D2005, and the selector S2005 selects the data D2014.

  An outline of processing for generating Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data using Bk dot degenerate data and Cl dot bold data based on the settings of the above selectors is as follows.

  In FIG. 2, the data selected by the selector S2001 is White adjacent Bk non-edge data (D2008), and the data selected by the selector S2002 is Cl adjacent Bk non-edge data (D2009). The data selected by the selector S2003 is Cl adjacent Bk edge width color bold data (D2011), and the data selected by the selector S2004 is White adjacent Bk edge width color bold data (D20010).

  Next, by negating the White adjacent Bk non-edge data (D2008) and taking the logical product of this, the original Bk data (D1000) and the Cl adjacent Bk non-edge data (D2009), the Bk non-edge uncertain data ( D2012). Further, the logical product of Bk non-edge uncertain data (D2012), original Bk data (D1000) and Cl adjacent Bk edge width Cl bold data (D20011) is obtained. Then, by taking the logical sum of this logical product and the Bk non-edge data (D2008) when White is adjacent, Bk non-edge data (D2014) when the White adjacent edge width is equal to or larger than the Cl adjacent edge width is generated. On the other hand, by calculating the logical product of the White adjacent Bk non-edge data (D2008) and the Cl adjacent Bk edge width Cl bold data (D2011), the White adjacent edge width <Cl adjacent edge width Bk non-edge data ( D2013).

  Next, the data selected by the selector S2005 is set as Bk non-edge data (D1008). Further, the Bk non-edge data (D1008) is negated, and the logical product of this Bk non-edge data (D1000) and the White adjacent Bk edge width Cl bold data (D20010) is obtained as Cl adjacent Bk edge data (D1009). To do. Further, the data is inverted by negating the logical sum of the Cl adjacent Bk edge data (D1009) and the Bk non-edge data (D1008). Then, the white adjacent Bk edge data (D1010) is generated by taking the logical product of the inverted data and the original Bk data (D1000).

  FIGS. 8A to 8I are diagrams schematically illustrating an example of generation processing of the above-described Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data by data for each pixel. Specifically, each selector generates Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data when the Cl adjacent Bk edge width is 2 dots and the White adjacent Bk edge width is 4 dots. Is shown.

  8A shows a Bk4 dot degenerate image, FIG. 8B shows a Bk2 dot degenerate image, FIG. 8C shows a Cl4 dot bold image, and FIG. 8D shows a Cl2 dot bold image.

  As described above, by negating the White adjacent Bk non-edge data (D2008) and taking the logical product of this and the original Bk data (D1000) and the Cl adjacent Bk non-edge data (D2009), FIG. The Bk non-edge uncertain image shown in FIG.

  First, a logical product of Bk non-edge uncertain data, original Bk data, and Cl adjacent Bk edge width color bold data is obtained. Then, by taking the logical sum of this logical product and the Bk non-edge data when White is adjacent, a Bk non-edge image when White adjacent edge width ≧ Cl adjacent edge width shown in FIG. 8F is generated. The selector S2005 selects the Bk non-edge image by the selection described with reference to FIG. 7, and thereby the Bk non-edge data shown in FIG. 8G is output.

  Also, the Bk non-edge data negated and inverted data, and the original Bk data and the white adjacent Bk edge width Cl bold data are ANDed, and the Cl adjacent Bk edge data shown in FIG. Is output as

  Further, what is obtained by negating the logical sum of Cl adjacent Bk edge data and Bk non-edge data and inverting the data and the original Bk data is the White adjacent shown in FIG. Output as Bk edge data.

Generation of recording data Based on the Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data obtained by the black boundary processing (E1000) described above, color data for recording as described above with reference to FIG. And Bk data is generated. Details thereof will be described with reference to FIGS.

(Thinning processing for each area)
FIGS. 9A to 9I are diagrams showing an example of generation of thinning data using a thinning mask for each region.

  Thinning processing (AND) is performed on the White adjacent Bk edge data (D1009) shown in FIG. 9A using the White adjacent black edge thinning mask (D1012) shown in FIG. 9B. As a result, a White adjacent Bk edge thinned image (D1015) shown in FIG. 9C is obtained.

  Further, a thinning process (AND) is performed on the Cl adjacent Bk edge data (D1008) shown in FIG. 9D using the Cl adjacent Bk edge thinning mask (D1011) shown in FIG. As a result, a Cl adjacent Bk edge thinned image (D1014) shown in FIG. 9F is obtained.

  Further, thinning processing (AND) is performed on the Bk non-edge image (D1010) shown in FIG. 9 (g) using the Bk non-edge thinning mask (D1013) shown in FIG. 9 (h). As a result, the Bk non-edge thinned image (D1016) shown in FIG. 9I is obtained.

  As described above, the masks shown in FIGS. 9B, 9E, and 9H each have a predetermined thinning rate. The ratio (100% −thinning rate) of the recording allowable pixels in each mask is 87.5% for the White adjacent Bk edge thinning mask, 75% for the Cl adjacent Bk edge thinning mask, and 50 for the Bk non-edge thinning mask. %.

  Note that the thinning amount and mask size of each color are preferably set to appropriate values according to the characteristics of the ink and the configuration of the printing apparatus. The dot arrangement method in the mask may be regular or may be pseudo-random.

(Thinning process using the first color underlay mask)
Next, as described above with reference to FIG. 1, the underprint amount for each color is determined based on the thinning data for each edge region obtained as described above. First, details of the thinning process using the underlay mask for the Cl adjacent Bk edge thinning data will be described.

  FIGS. 10A to 10G are diagrams for explaining the thinning process by the underlay mask 1 of each color for the Cl adjacent Bk edge thinning data.

  FIG. 10A shows Cl adjacent Bk edge thinning data. On the other hand, FIGS. 10B to 10D respectively show cyan, magenta, and yellow underlay masks 1 for performing mask thinning at a predetermined thinning rate. Here, the ratio of the underprint amount of each color mask (100% −thinning rate) is 25% for cyan, 6.25% for magenta, and 6.25% for yellow.

  By taking the logical product of these masks, Cl adjacent Bk edge thinning data and the underlay mask 1 for each color, the underprint data for each color shown in FIGS. 10 (e) to 10 (g) is generated. Here, the underprint amount and mask size of each color are preferably set to appropriate values according to the characteristics of the ink and the configuration of the printing apparatus. The dot arrangement method in the mask may be regular or may be pseudo-random.

(Thinning process using the second color underlay mask)
FIGS. 11A to 11G are diagrams for explaining the thinning process by the underprint mask 2 for each color for the White adjacent Bk edge thinning data.

  FIG. 11A shows White adjacent Bk edge thinning data. On the other hand, FIGS. 11B to 11D show the cyan, magenta, and yellow undercoat masks 2 that perform mask thinning at a predetermined thinning rate, respectively. Here, the ratio of the underprint amount of each color mask (100% −thinning rate) is 6.25% for cyan, 6.25% for magenta, and 6.25% for yellow.

  By taking the logical product of the White adjacent Bk edge thinning data and the underprint mask 2 for each color, the underprint data for each color shown in FIGS. 11E to 11G is generated.

(Thinning process using a third color underlay mask)
FIGS. 12A to 12G are diagrams for explaining the thinning process by the underlay mask 3 for each color for the Bk non-edge thinning data.

  FIG. 12A shows Bk non-edge thinning data. On the other hand, FIGS. 12B to 12D show the cyan, magenta, and yellow undercoat masks 3 for performing mask thinning at a predetermined thinning rate, respectively. Here, the ratio of the underprint amount of each color mask (100% −thinning rate) is 12.5% for cyan, 6.25% for magenta, and 6.25% for yellow.

  By taking the logical product of the Bk non-edge thinning data and the underprint mask 3 for each color, the underprint data for each color shown in FIGS. 12 (e) to 12 (g) is generated.

  FIG. 13 is a flowchart showing the generation processing of recording color data and black data including data generation for each area including each edge area described above with reference to FIG. FIGS. 14A to 14G are schematic diagrams showing each data obtained in the process and result of the generation process as data for each pixel.

  First, a black edge detection width is set (S901), and black boundary processing is performed based on this (S902). Next, a logical product of the Cl adjacent Bk edge data obtained by the black boundary processing and the Cl adjacent Bk edge thinning mask and the cyan, magenta, and yellow underlay masks 1 is obtained, and cyan, magenta, and yellow underprint data 1 is obtained. Is generated (S903). Similarly, the AND of the White adjacent Bk edge data obtained by the black boundary processing and the White adjacent Bk edge thinning mask and the cyan, magenta and yellow underlay masks 2 is obtained and the cyan, magenta and yellow underprint data 2 is obtained. Generate (S904). Further, the Bk non-edge data obtained by the black boundary processing, the Bk non-edge thinning mask, and the cyan, magenta, and yellow underlay masks 3 are ANDed to generate cyan, magenta, and yellow underlay data 3. (S905).

  Next, for each of cyan, magenta and yellow, the logical sum of the underscore data 1, the underscore data 2 and the underscore data 3 is obtained, and cyan and magenta shown in FIGS. 14 (a), (b) and (c) are obtained. , Yellow underlay data is generated. Then, by taking the logical sum of each of the underlay data and the original cyan, magenta, and yellow data, the recording data for cyan, magenta, and yellow shown in FIGS. 14D to 14F is generated. . Further, the recording black data shown in FIG. 14G is generated by taking the logical sum of the Cl adjacent Bk edge thinned data, the White adjacent Bk edge thinned data, and the Bk non-edge thinned data (S906).

(Other edge width examples)
FIGS. 15A to 15G are diagrams illustrating data in the black boundary processing according to another example of the Cl adjacent Bk edge width and the White adjacent Bk edge width. Specifically, in the black boundary processing in the case where the Cl adjacent Bk edge width is 2 dots and the White adjacent Bk edge width is 2 dots, corresponding to the “fast” mode in which column thinning recording is performed as described above with reference to FIG. Data are shown.

  FIG. 15A shows a Bk2 dot degenerate image, and FIG. 15B shows a Cl2 dot bold image.

  The negation of the White adjacent Bk non-edge data based on the Bk2 dot degenerated image and the logical product of the original Bk data and the Cl adjacent Bk black non-edge data based on the Bk dot degenerated image are taken. Thereby, the Bk non-edge uncertain image shown in FIG. 15C is generated. Further, a logical product of Bk non-edge uncertain data, original Bk data, Cl adjacent Bk edge width Cl bold data based on the Cl2 dot bold image, and White adjacent Bk non-edge data is obtained. As a result, a Bk non-edge image when White adjacent edge width ≧ Cl adjacent edge width shown in FIG. 15D is generated.

  Then, the data selected by the selector S2005, in the case of this example, a Bk non-edge image when White adjacent edge width ≧ Cl adjacent edge width is output, resulting in the Bk non-edge image shown in FIG. Further, the data obtained by negating Bk non-edge data and inverting the data, and the logical product of the original Bk data and the White adjacent Bk edge width Cl bold data are shown in FIG. Edge image. Further, the White adjacent Bk edge image shown in FIG. 15G is obtained by negating the logical sum of the Cl adjacent Bk edge data and the Bk non-edge data and inverting the data with the original Bk data. It becomes. In this way, an optimum image can be obtained by changing the edge width of the optimum black data depending on the recording mode.

  As described above, according to the present embodiment, the width of the edge region adjacent to the color region and the width of the edge region adjacent to white where recording is not performed in the black image are set according to the recording mode. Thereby, according to the recording mode and ink, the boundary bleeding between black and color can be suppressed, and a sharp and high-quality recording of a black image can be performed.

(Other embodiments)
In the above-described embodiment, an embodiment has been described in which image processing related to recording data generation illustrated in FIG. Of course, the application of the present invention is not limited to this form. For example, the above processing may be executed by a host device such as a personal computer. In this case, the host device performs the image processing method of the present invention.

FIG. 6 is a block diagram illustrating a process for generating recording data for each color ink including determination of the width of an edge region of a black image according to an embodiment of the present invention. It is a block diagram which shows the detail of the black boundary process shown in FIG. It is a flowchart which shows the black 1 dot degeneracy process in the said black boundary process. (A)-(g) is a figure which shows this process typically by the data for every pixel. It is a flowchart which shows the color 1 dot bold process in the said black boundary process. (A)-(i) is a figure which shows typically the process shown in FIG. 5 with the data for every pixel. It is a figure which shows the table which defined the choice of the selector according to the combination of Cl adjacent Bk edge width and White adjacent Bk edge width based on one Embodiment of this invention. (A)-(i) is a figure which shows typically an example of the production | generation process of Cl adjacent Bk edge data, White adjacent Bk edge data, and Bk non-edge data by the data for every pixel. (A)-(i) is a figure which shows the example of the production | generation of the thinning data by the thinning mask for every area | region. (A)-(g) is a figure explaining the thinning-out process by the underlay mask 1 of each color with respect to Cl adjacent Bk edge thinning data. (A)-(g) is a figure explaining the thinning-out process by the underlay mask 2 of each color with respect to White adjacent Bk edge thinning-out data. (A)-(g) is a figure explaining the thinning-out process by the underlay mask 3 of each color with respect to Bk non-edge thinning-out data. It is a flowchart which shows the production | generation process of the recording color data and black data containing the data production | generation for every area | region containing each edge area | region demonstrated in FIGS. (A)-(g) is a schematic diagram which shows each data obtained in the process and result of the production | generation process shown in FIG. 13 with the data for every pixel. (A)-(g) is a figure which shows the data in the black boundary process based on the other example of Cl adjacent Bk edge width and White adjacent Bk edge width. 1 is a perspective view illustrating a schematic configuration of a color inkjet printer according to an embodiment of the present invention. FIG. 17 is a perspective view illustrating a schematic configuration of a main part of the recording head 201 illustrated in FIG. 16. It is a block diagram which shows the control structure in the inkjet printer of embodiment shown in FIG.

Explanation of symbols

201 recording head 400 interface 401 MPU
402 ROM
403 DRAM (print buffer)
404 Gate array 500 Recording control unit S2001 to S2005 selector

Claims (5)

A data generation device that generates data for recording on a recording medium by applying a black ink and a color ink having higher permeability than the black ink,
One mode is set from a plurality of modes including a first mode for recording at a first resolution and a second mode for recording at a higher resolution than the first mode at a resolution lower than the first resolution. Mode setting means;
When recording an image including a black area to which the black ink is applied and a white area to which neither the black ink nor the color ink is applied, an area including an edge adjacent to the white area in the black area is white. Area setting means for setting as an adjacent black edge area;
Superimposing data generating means for generating superimposing data for applying the color ink so as to overlap the black ink applied to the white adjacent black edge region,
The region setting means sets a larger number of pixels indicating the width from the edge in the white adjacent black edge region when the first mode is set than when the second mode is set. A data generation device. When the image further includes a color region to which the color ink is applied,
The area setting means further sets an area including an edge adjacent to the color area in the black area as a color adjacent black edge area,
The overlapping data generating means further generates overlapping data for applying the color ink so as to overlap the black ink applied to the color adjacent black edge region,
When the first mode is set, the area setting means sets the number of pixels indicating the width from the edge in the white adjacent black edge area to be larger than the number of pixels indicating the width from the edge in the color adjacent black edge area. The data generation apparatus according to claim 1, wherein a large number is set.   The data generation apparatus according to claim 2, wherein the color ink includes three colors of cyan ink, magenta ink, and yellow ink.   The overlap data generation unit generates the overlap data so that cyan ink, magenta ink, and yellow ink are applied in the same ratio to the white adjacent black edge region. Data generator.   The overlapping data generating means sets the ratio of applying the cyan ink to the overlapping data for applying the color ink to the color adjacent black edge region higher than the ratio of applying the magenta ink and the yellow ink. The data generation apparatus according to claim 3, wherein the data generation apparatus generates the data as follows.

Images