JP2006240058A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device which can record a black character image of a high quality level while inhibiting smears and also a color image of high picture quality with a realized reduction of a border bleeding between black and color. <P>SOLUTION: The inkjet recording device comprises a means for properly detecting a region high in black duty and a border region between black and color to apply color dots to each region. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus that performs recording using a plurality of recording heads capable of recording black ink and at least one color ink and having different resolutions of black dots and color dots.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses that perform recording on various recording media are capable of high-density and high-speed recording operations, and thus are applied as printers or portable printers as output media of various apparatuses, and It has been commercialized.

  In general, an ink jet recording apparatus includes a carriage on which recording means (recording head) and an ink tank are mounted, a transport means for transporting a recording medium, and a control means for controlling them. A recording head that ejects ink droplets from a plurality of ejection openings is serially scanned in the direction (main scanning direction) perpendicular to the recording paper transport direction (sub-scanning direction), while recording the recording medium during non-recording. Intermittent conveyance with an amount equal to the width.

  This recording method performs recording by ejecting ink onto a recording sheet in accordance with a recording signal, and is widely used as a quiet recording method at a low running cost. In recent years, many products using a plurality of colors of ink and applied to a color recording apparatus have been put into practical use.

  In such a color ink jet recording apparatus, since black ink is frequently used for printing characters and the like, printing sharpness, sharpness, and high printing density are required. Therefore, a technique is known in which the penetrability of the black ink with respect to the recording material is reduced and the coloring material in the black ink is prevented from penetrating into the recording material.

  On the other hand, the color ink has a phenomenon (bleeding) that, when two kinds of inks of different colors are applied to the recording material adjacent to each other, the inks are mixed at the boundary portion to deteriorate the quality of the color image. appear. In order to prevent this, a technique for increasing the permeability to the recording material and preventing the color inks from being mixed on the surface of the recording material is known (for example, JP-A-55-65269).

  However, when the ink set is used, the following two problems occur.

  First, although the color ink has high penetrability, the fixing time is fast. However, the black ink has low penetrability, so that the dry fixing time is long. As a result, when the next page is continuously discharged after the previous page is discharged, the black ink of the previous page is not completely dried, so the print surface of the previous page and the next page The back side of the print may be soiled. (Stains on the printed surface and the back surface are hereinafter referred to as “smear”.) This problem becomes a major problem as the printing speed increases.

  Second, since black ink has low permeability, blur (boundary bleeding) occurs in the boundary region between black and color in an image where black and color are in contact. This is a problem that the quality of the color recording image is remarkably deteriorated.

  Conventionally, the following countermeasures have been taken as these two solutions.

  The first countermeasure is a method of providing fixing means such as a heat fixing device. As a result, it is possible to prevent smear and boundary bleeding by fixing the ink on the paper surface at high speed.

  As a second countermeasure, there is a method of performing paper discharge waiting control. In this case, the printing start of the second sheet is temporarily stopped until the first sheet is printed and sufficiently dried, or the paper discharge operation is temporarily stopped after the second sheet is printed. As a result, smear can be suppressed.

A third countermeasure is a method of printing by superimposing highly penetrating color ink on the black ink printing area. Since the black ink is printed on the paper surface coated with the color ink, the black ink is easily fixed on the paper surface, and smear can be suppressed. Furthermore, boundary bleeding can be suppressed by using an ink set in which black and color inks react and aggregate.
JP 55-65269 A

  However, the above method has the following problems.

  The first problem is that the fixing device is provided to avoid the increase in size and cost of the apparatus. Further, in the serial printer, since the paper feeding is intermittent, there is a possibility that uneven feeding occurs when the paper is passed through the fixing device.

  The problem with the second countermeasure is that throughput is reduced by waiting for paper discharge.

  The defect of the third countermeasure is that the sharpness of the black image is deteriorated and the quality of the black character is deteriorated by printing the color inks on top of each other. In addition, when the amount of color ink applied for preventing smearing and the amount of color ink applied for preventing boundary bleeding are different, it is difficult to achieve both suppression of smear and boundary bleeding.

  The present invention has been made in view of the above points, and it is an object of the present invention to provide an ink jet recording apparatus capable of suppressing smear and boundary bleeding and recording high quality black character quality.

  In order to achieve the above object, a recording apparatus according to the present invention comprises the following arrangement. In other words, black dot proximity pixel detection means for detecting black pixels close to black dots, color dot reduction means for matching color dot resolution to black resolution, and color dot proximity pixels for detecting black pixels close to color dots Detection means, black dot proximity pixel detection means, black dot proximity pixels detected by the color dot proximity pixel detection means, color dot expansion means for matching the color dot proximity pixels to the resolution of the color dots, and the black dot proximity pixels First color dot application data generation means for generating color dot data to be applied by taking the logical product of the pixel and the first color dot application mask, and the color dot proximity pixel and the second color dot application Appended by taking the logical product with the mask The color dot provision data generated by the second color dot provision data generation means for generating the color dot data to be generated, the first color dot provision data generation means, and the second color dot provision data generation means is the original. Color dot addition data combining means for combining the color data by logical OR, and recording means for performing recording based on the rack original data and the color data combined by the color dot addition data combining means.

  Preferably, the proximity black dot proximity pixel detection means performs an AND operation on all dots in an L × M (L, M = 1, 3, 5... N, n + 2) matrix centered on the pixel of interest. The presence / absence of a black dot is detected, and if a black dot exists in the pixel of interest and the logical product is false, the black dot adjacent pixel of the pixel of interest is turned off.

  Preferably, the proximity black dot proximity pixel detecting means sets data obtained by hollowing out the original black data in the vicinity 8 directions by a predetermined number of pixels as a black dot proximity pixel.

  Preferably, the color dot reduction means corresponds to one black dot when the black dot resolution and the color dot resolution are in a ratio of 1: N (N = 1, 3, 5,... N, n + 2). The color data is put into an N × N matrix and the logical sum of all the color dots is taken. If it is true, the color dot reduction data for the color data in the N × N matrix is turned on.

  Preferably, the proximity color dot proximity pixel detection means reduces all the color dots in an L × M (L, M = 1, 3, 5... N, n + 2) matrix centered on the pixel of interest. The logical OR of the data is taken, and when the black dot exists in the target pixel and the logical sum is true, the color dot adjacent pixel of the target pixel is turned on.

  Preferably, the proximity color dot proximity pixel detection means obtains data obtained by ANDing the data obtained by bolding the original color data by a predetermined number of pixels in the vicinity of eight directions and the pixel of interest with a black dot proximity pixel. Color pixel proximity pixel.

  Preferably, the color dot developing means replaces the data with an N × N development matrix when the black dot neighboring pixels are on in order to make the black dot neighboring pixels have the resolution of the color dots. If the pixel near the color dot is turned on in order to make the pixel near the dot developed, and the pixel near the color dot has the resolution of the original color dot, the pixel replaced by the N × N development matrix is replaced with the data near the color dot. This is a developed pixel.

  Preferably, the first color dot provision mask and the second color dot provision mask are provided independently for each ink color.

  Preferably, the color ink has three colors of yellow, magenta, and cyan.

  Preferably, the color dots detected by the color dot proximity pixel detection means are data obtained by logically summing data obtained by logically summing yellow, magenta, and cyan data and data obtained by inverting the original black data. .

  Preferably, the black ink is an ink with relatively low permeability, and the color ink is an ink with relatively high permeability.

  Preferably, at least one of the color inks is a reactive ink that reacts with the black ink and aggregates.

  Preferably, the type of ink that reacts and aggregates with the black ink is a cyan ink.

  Preferably, logical sum data of data obtained by excluding color dot proximity pixels from the black original data and data obtained by ANDing the color dot proximity pixels and the black data thinning mask is recorded as black data.

  Preferably, logical sum data of data obtained by excluding black adjacent pixels from the black original data and data obtained by ANDing the black adjacent pixels and the black data thinning mask is recorded as black data.

  Preferably, the recording head should be scanned relative to the recording medium, the recording medium should be transported by a predetermined amount in a direction crossing the scanning direction, and recording should be performed in one scan. Means for counting black data and color data of all or a part of the area with a predetermined matrix size, and the first applied color dot generation and the second applied color based on the dot count result Color dot application determination means for determining whether or not to perform dot generation means, and black data and color data processed based on the determination of the color dot application determination means are recorded.

  Preferably, recording is performed using a recording head in which black, cyan, magenta, and yellow chips are arranged side by side.

  Preferably, the dot count is performed in the difference area between the scan width scanned with one black color and the scan width scanned with four colors.

  Preferably, the printing direction is defined so that the color ink is recorded before the black ink.

  As described above, according to the present embodiment, in a recording apparatus that performs recording using recording heads having different resolutions of black dots and color dots, relatively high-duty black data excluding character edge regions is used. By applying color dots, it is possible to prevent smearing in a high duty area and to record high quality black characters with sharp edges. Furthermore, by applying color dots that differ from the amount of smear color dots applied to the boundary area between black and color, it is possible to record high-quality color images that suppress boundary bleeding between black and color. Become.

  Hereinafter, embodiments of the recording apparatus of the present invention will be described with reference to the drawings. In the embodiments described below, a printer is taken as an example of a recording apparatus using an inkjet recording method.

(1) Description of Color Recording Apparatus FIG. 12 is a schematic perspective view showing the configuration of an embodiment of a color inkjet recording apparatus to which the present invention can be applied. In this figure, 202 is an ink cartridge. These are composed of an ink tank in which four color inks (black, cyan, magenta, and yellow) are respectively placed, and a recording head 201. Reference numeral 103 denotes a paper feed roller which rotates in the direction of the arrow in the figure while holding the printing paper 107 together with the auxiliary roller 104, and feeds the printing paper 107, and also serves to hold the printing paper 107 in the same manner as 103 and 104. Yes. A carriage 106 supports four ink cartridges and moves the mounted ink cartridge 202 and recording head 201 together with printing. The carriage 106 is controlled to stand by at the home position indicated by the dotted line in the drawing when the recording apparatus is not printing or when the recovery operation of the recording head is performed.

  Prior to the start of printing, when a print start command is received, the carriage 106 located at the position shown in the figure (home position) drives the recording element provided in the recording head 201 while moving in the x direction to move the recording head on the paper surface. The area corresponding to the recording width is printed. When printing is completed up to the end of the paper along the scanning direction of the carriage, the carriage returns to the original home position and performs recording in the x direction again. The paper feed roller 103 rotates in the direction of the arrow shown in the figure after the previous print scan is finished and before the next print scan is started to feed the paper in the y direction by the required width. In this way, printing on one sheet is completed by repeating main scanning and paper feeding for printing. A recording operation for ejecting ink from the recording head is performed based on control from a recording control means (not shown).

  In addition, in order to increase the recording speed, recording is not performed only during main scanning in one direction, but recording is also performed in the return path when the main scanning recording in the x direction ends and the carriage returns to the home position side. There may be.

  In the example described above, the ink tank and the recording head are held on the carriage 106 so as to be separable. An ink jet cartridge in which an ink tank 202 that stores recording ink and a recording head 201 that discharges ink toward the recording paper 107 are integrated may be used. Furthermore, a multi-color integrated recording head that can eject a plurality of colors of ink from one recording head may be used.

  Further, at the position where the above-described recovery operation is performed, a capping unit (not shown) for capping the front surface (ejection port surface) of the head, thickened ink and bubbles in the recording head are removed in a capped state by the capping unit, etc. A recovery unit (not shown) for performing the head recovery operation is provided. Further, a cleaning blade (not shown) or the like is provided on the side of the capping unit and is supported so as to protrude toward the recording head 201 so that it can come into contact with the front surface of the recording head. Thus, after the recovery operation, the cleaning blade is projected into the moving path of the recording head, and unnecessary ink droplets and dirt on the front surface of the recording head are wiped off as the recording head moves.

(2) Description of Recording Head Next, the above-described recording head 201 will be described with reference to FIG. FIG. 13 is a perspective view of a main part of the recording head 201 shown in FIG. As shown in FIG. 13, the recording head 201 has a plurality of discharge ports 300 each formed at a predetermined pitch, and along the wall surface of each liquid path 302 that connects the common liquid chamber 301 and each discharge port 300. A recording element 303 for generating ink discharge energy is provided. The recording element 303 and its circuit are made on silicon using semiconductor manufacturing technology. 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. A silicon plate 308 on which these electrical wirings are made is bonded to a heat radiating aluminum base plate 307. In addition, the circuit connection portion 311 on the silicon plate and the printed board 309 are connected by an extra fine wire 310, and a signal from the recording apparatus main body is received through the signal circuit 312. The liquid path 302 and the common liquid chamber 301 are formed of a plastic cover 306 made by injection molding. The common liquid chamber 301 is connected via the ink tank (see FIG. 12), the joint pipe 304, and the ink filter 305, and ink is supplied to the common liquid chamber 301 from the ink tank. . The ink supplied from the ink tank to the common liquid chamber 301 and temporarily stored enters the liquid path 302 by capillary action and forms a meniscus at the discharge port 300 to keep the liquid path 302 filled. At this time, when the recording element 303 is energized through the electrodes (not shown) and generates heat, the ink on the recording element 303 is rapidly heated to generate bubbles in the liquid path 302, and the bubbles expand to discharge ports. Ink droplets 313 are ejected from 300.

(3) Description of Control Configuration Next, a control configuration for executing recording control of each part of the apparatus configuration will be described with reference to a block diagram shown in FIG. In the figure showing a control circuit, 400 is an interface for inputting a recording signal, 401 is an MPU, 402 is a program ROM for storing a control program executed by the MPU 401, 403 is various data (supplied to the recording signal and the head). In this case, the number of print dots, the number of ink recording head replacements, and the like can be stored. Reference numeral 404 denotes a gate array that controls supply of print data to the print head, and also controls data transfer among the interface 400, MPU 401, and DRAM 403. Reference numeral 405 denotes a carrier motor (CR motor) for conveying the recording head, and reference numeral 406 denotes a conveyance motor (LF motor) for conveying the recording paper. Reference numerals 407 and 408 denote motor drivers for driving the transport motor 405 and the carrier motor 406, respectively. Reference numeral 409 denotes a head driver that drives the recording head 410.

[Embodiment 1]
○ Outline of Embodiment 1 In this embodiment, the logical product of dots in a 3 × 3 matrix centered on the pixel of interest of black is calculated, and when black dots exist in the 3 × 3 matrix, The pixel of interest is a black dot adjacent pixel, and the first color dot provision data is obtained by taking the logical product of the black dot adjacent development pixel obtained by replacing the black dot adjacent pixel with the development pattern and the first color dot provision mask. Generate. Then, the color dot reduction data obtained by reducing the color data is ORed with dots in the 6 × 6 matrix centered on the target pixel of color black, the black pixel exists in the target pixel, and the color dot reduction data is When one or more dots are present, the pixel of interest is a color dot adjacent pixel, and a logical product of a color dot adjacent development pixel obtained by replacing the color dot adjacent pixel with a development pattern and a second color dot provision mask is obtained. Second color dot provision data is generated. The first color dot provision data and the second color dot provision data are combined with the original color data and recorded, thereby preventing boundary bleeding and smearing and recording high-quality black characters.
Overall Data Processing FIG. 1 is a block diagram illustrating the flow of black dot proximity pixel detection, color dot proximity pixel detection, color dot application data generation, and print data generation.

  By using the original Bk data (D1000), black dot proximity pixel data (D1001) is generated by performing detection processing (E1000) of black dot proximity pixels to which color dots should be added for smear prevention. The black dot proximity pixel data (D1001) is subjected to black dot proximity pixel data development processing (E1010) to generate black dot proximity development pixel data (D1018). The C addition data 1 (D1002) and M assignment are obtained by taking the logical product of the C mask 1 (E1001), M mask 1 (E1002), and Y mask 1 (E1003) with respect to the black dot adjacent development pixel data (D1018). Data 1 (D1003) and Y addition data 1 (D1004) are generated.

Next, OR processing (D1008) of original C, M, Y obtained by ORing original C data (D1005), original M data (D1006), and original Y data (D1007) is compressed into color OR data (E1009). ) Using the color dot reduction data and the original Bk data (D1000), color dot proximity pixel data (D1009) is generated by performing color dot proximity pixel detection processing (E1004) to which color dots should be added to prevent boundary bleeding. Then, color dot proximity development pixel data (D1018) is generated by performing color dot vicinity pixel data development processing (E1010). The C addition data 2 (D1010), M is obtained by taking the logical product of the C mask 2 (E1005), M mask 2 (E1006), and Y mask 2 (E1007) with respect to the color dot adjacent development pixel data (D1018). Grant data 2 (D1011) and Y grant data 2 (D1012) are generated. The logical sum of the original C data (D1005), C addition data 1 (D1002), and C addition data 2 (D1010) is taken to generate C data for printing (D1013). By performing the same processing, M data for printing (D1014) and Y data for printing (D1015) are generated. The original Bk data (D1000) is used as printing Bk data (D1016) without being processed.
Detection processing of color dot application target pixel / detection of black dot proximity pixel for smear prevention FIG. 2 is a flowchart of detection processing of black dot proximity pixel for smear prevention.

  It is determined whether there is a black dot in the pixel of interest and a black dot in the 3 × 3 matrix (S101). If the logical product of black dots in the 3 × 3 matrix is true, the bit of the pixel of interest is turned off (S102). Otherwise, the bit of the pixel of interest is not changed (S103). Subsequently, the pixel of interest is shifted (S104). If all the data is completed, the process ends (S105). Otherwise, the above process is repeated.

  FIG. 3 is a diagram illustrating an example of detection of pixels adjacent to black dots.

  FIG. 3A shows a 3 × 3 matrix centered on the pixel of interest. FIG. 3B is a black original image. The black original data is processed while sequentially shifting the 3 × 3 matrix one pixel at a time. If the bit of the pixel of interest is turned off when the logical product in the matrix is true, a black dot proximity pixel for smear prevention can be detected as shown in FIG.

As can be seen from FIG. 3- (c), only the black area having a relatively high duty is detected by this processing. Since an edge region having a relatively low duty is not detected, color dots are not added, and the sharpness of the black image can be maintained.
FIG. 4 shows a processing example of color OR data compression processing.

  FIG. 4A shows a color data 2 × 2 matrix corresponding to one black dot. FIG. 4B shows a color original image. If all the logical sums of the original color data corresponding to black in this matrix are true, the color dot reduction data is turned on, otherwise it is turned off, as shown in FIG. Can process dot reduction data.

  FIG. 5 is a flowchart of color dot proximity pixel detection processing for preventing black and color bleeding.

  It is determined whether or not black dots exist in the pixel of interest and color dot reduction data exists in the 3 × 3 matrix (S201). If the logical sum of the color dot reduction data in the 3 × 3 matrix is true, the bit of the pixel of interest is turned on (S202). Otherwise, the bit of the pixel of interest is not changed (S203). Subsequently, the pixel of interest is shifted (S204). If all the data is completed, the process ends (S205). Otherwise, the above process is repeated.

  FIG. 6 is a diagram illustrating an example of detection of color dot proximity pixels for preventing bleeding.

FIG. 6A shows a 3 × 3 matrix centered on the pixel of interest. 6B is a black original image, and FIG. 6C is a color original image. The black original data and the color original data are processed while sequentially shifting the 3 × 3 matrix one pixel at a time. When the bit of the pixel of interest is turned on when the total number of color dots in the matrix is 1 or more, a color dot application target pixel for preventing bleeding can be detected as shown in FIG.
As can be seen from FIG. 6D, only the boundary area between black and color is detected by this processing. By providing color dots in the boundary region, boundary bleeding can be prevented.
Generation of Color Dot Development Data FIG. 7 shows an example of color dot proximity pixel development processing and black dot proximity pixel development processing.

  FIG. 7A shows a development matrix corresponding to color dot neighboring pixels and one black dot neighboring pixel. FIG. 7B is a color dot proximity pixel. By taking the logical product of the development matrix and the color dot proximity pixels, color dot proximity development data can be processed as shown in FIG.

Further, FIG. 7- (d) is a black dot proximity pixel. By taking the logical product of the development matrix of FIG. 7- (a) and the black dot proximity pixel, the black dot proximity development data can be processed as shown in FIG. 7- (e). Here, the development pattern is preferably set to an appropriate value according to the characteristics of the ink and the configuration of the recording apparatus. Further, the arrangement of dots in the development pattern may be updated every column and every raster, or may be pseudo-random.
O Generation of color dot application data / Generation of color dot application data for smear prevention FIG. 8 is a diagram showing an example of generation of color dot application data for smear prevention. FIG. 6A shows black dot proximity development pixel data. FIGS. 8B to 8D show a cyan, magenta, and yellow mask 1 for generating a predetermined amount of application data. Here, the ratio of the amount of applied data for each color is 18% for cyan, 6% for magenta, and 5% for yellow. By giving the logical product of the black dot proximity pixel data and the mask 1 of each color, the provision data of each color shown in FIGS. 8E to 8G is generated. Here, it is preferable that the amount of data to be applied for each color and the mask size are 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.
Generation of color dot application data for preventing bleeding FIG. 9 illustrates an example of generation of color dot application data for preventing bleeding. FIG. 9A shows color dot proximity development pixel data. FIGS. 9B to 9D show a cyan, magenta, and yellow mask 1 for generating a predetermined amount of application data. Here, the ratio of the amount of applied data for each color is 30% for cyan, 5% for magenta, and 5% for yellow. By giving the logical product of the color dot proximity pixel data and the mask 2 of each color, the application data of each color shown in FIGS. 9- (e) to (g) is generated. Here, the reason why the amount of cyan applied is relatively large is that a recording apparatus of an ink system in which only cyan ink has reactivity with black ink and is aggregated is assumed. The amount of data to be applied for each color and the mask size 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.
Generation of printing color data FIG. 10 is a flowchart of printing color data generation processing. Black dot proximity pixel data is detected (S301). Subsequently, by giving the logical product of the black dot proximity pixel data and the cyan, magenta, and yellow mask 1, cyan, magenta, and yellow imparted data 1 is generated (S 302). Next, color dot proximity pixel data is detected (S303), and the addition data 2 of cyan, magenta, and yellow is generated by taking the logical product with the mask 2 of cyan, magenta, and yellow (S304). Finally, the logical sum of the original cyan, magenta, and yellow data, each color imparting data 1 and each color imparting data 2 is obtained to obtain printing cyan, magenta, and yellow data (S305).
○ Original Black Data Thinning Process FIG. 11 is a diagram showing a thinning example of original black data. FIG. 11- (a) represents original black data. FIG. 11B shows color dot proximity pixel data. Here, the color original data is assumed to be the same as in the first embodiment. The black thinning data shown in FIG. 11- (f) is generated by taking the logical product of the color dot proximity pixel data and the black thinning mask shown in FIG. 11- (d). On the other hand, data outside the proximity of color dots is shown in FIG. The black data for printing shown in FIG. 11- (e) is generated by taking the logical sum of the black thinning data and the color dot non-proximity data.

  In this way, it is possible to improve the bleeding suppression effect by thinning out the black data in the boundary region.

  Further, the smear prevention effect may be improved by performing a process of thinning out black data in the same manner for black dot neighboring pixel data.

FIG. 3 is a block diagram illustrating a flow of detection of color dot application target pixels, generation of color dot application data, and generation of print data according to the first exemplary embodiment. FIG. 3 is a flowchart of detection processing for a color dot application target pixel for smear prevention according to the first embodiment. FIG. 2 is a diagram illustrating a detection example of a color dot application target pixel for preventing smear according to the first embodiment. FIG. 5 is a diagram illustrating a processing example of color OR data compression processing according to the first embodiment. FIG. 3 is a flowchart of detection processing of a pixel to be applied with color dots for preventing black and color bleeding in the first embodiment. FIG. 4 is a diagram illustrating a detection example of a color dot application target pixel for preventing bleeding according to the first exemplary embodiment. FIG. 6 is a diagram illustrating a processing example of color dot neighboring pixel development processing and black dot neighboring pixel development processing according to the first exemplary embodiment. FIG. 5 is a diagram illustrating an example of generation of smear prevention color dot application data according to the first exemplary embodiment. FIG. 4 is a diagram illustrating an example of generation of color dot application data for preventing bleeding according to the first exemplary embodiment. FIG. 5 is a flowchart of print color data generation processing according to the first embodiment. FIG. 3 is a diagram illustrating an example of thinning out original black data according to the first embodiment. 1 is a schematic perspective view showing a configuration of an embodiment of a color inkjet recording apparatus to which the present invention can be applied. 1 is a perspective view of a main part of a recording head to which the present invention can be applied. It is a control block diagram of an ink jet recording apparatus to which the present invention can be applied.

Claims (17)

In an ink jet recording apparatus capable of recording black ink and at least one color ink, and recording using a recording head having different resolutions of black dots and color dots,
Black dot proximity pixel detection means for detecting black pixels close to black dots, color dot reduction means for matching color dot resolution to black resolution, and color dot proximity pixel detection means for detecting black pixels close to color dots And a color dot developing means for adjusting the reduced color dot neighboring pixels detected by the color dot neighboring pixel detecting means and the black dot neighboring pixel detecting means to the resolution of the black dots,
First color dot application data generating means for generating color dot data to be applied by taking a logical product of the black dot proximity pixel and the first color dot application mask;
Second color dot application data generation means for generating color dot data to be applied by taking a logical product of the color dot proximity pixel and the second color dot application mask;
Color dot giving data combining means for combining the color dot giving data generated by the first color dot giving data generating means and the second color dot giving data generating means by ORing with the original color data; An ink jet recording apparatus comprising: black original data and recording means for performing recording based on the color data synthesized by the color dot application data synthesizing means.   The black dot proximity pixel detection means calculates a logical product of black dots in an L × M (L, M = 1, 3, 5... N, n + 2) matrix centered on the pixel of interest, and determines the pixel of interest. 2. The ink jet recording apparatus according to claim 1, wherein when the black dot exists and the logical product is true, the black dot adjacent pixel of the target pixel is turned off.   2. The ink jet recording apparatus according to claim 1, wherein the black dot proximity pixel detection unit cuts out original black data by a predetermined number of pixels in eight directions in the vicinity, and sets the cut out data as black dot proximity pixels. .   When the black dot resolution and the color dot resolution are in a ratio of 1: N (N = 1, 3, 5,... N, n + 2), the color dot reduction means converts the color data corresponding to one black dot to N × The data is put into an N matrix, the logical sum of all color dots is taken, and if it is true, the color dot reduction data for the color data in the N × N matrix is turned on. Item 10. The ink jet recording apparatus according to Item 1.   The color dot proximity pixel detecting means calculates the logical sum of all the color dot reduced data in the L × M (L, M = 1, 3, 5... N, n + 2) matrix centered on the target pixel. 2. The ink jet recording apparatus according to claim 1, wherein when a black dot exists in the target pixel and the logical sum is true, the color dot adjacent pixel of the target pixel is turned on.   The color dot proximity pixel detecting means uses data obtained by ANDing the data obtained by bolding the color dot reduction data in the vicinity of eight directions by a predetermined number of pixels and the black dot proximity pixel as the color dot proximity pixel. The inkjet recording apparatus according to claim 1.   When the black dot neighboring pixel is ON in order to make the black dot neighboring pixel the resolution of the color dot, the color dot developing means replaces the data with an N × N developing matrix as the black dot neighboring developing pixel. If the pixel near the color dot is on in order to make the pixel near the color dot have the resolution of the original color dot, the pixel replaced with the N × N development matrix is used as the color dot neighborhood developed pixel. The inkjet recording apparatus according to claim 1, wherein:   The inkjet recording apparatus according to claim 1, wherein the first color dot provision mask and the second color dot provision mask are provided independently for each ink color.   2. The ink jet recording apparatus according to claim 1, wherein the color inks are three colors of yellow, magenta, and cyan.   2. The ink jet recording apparatus according to claim 1, wherein the color dots detected by the color dot proximity pixel detecting means are data obtained by logically summing yellow, magenta, and cyan data.   The inkjet recording apparatus according to claim 1, wherein the black ink is an ink with relatively low permeability, and the color ink is an ink with relatively high permeability.   2. The ink jet recording apparatus according to claim 1, wherein at least one of the color inks is a reaction type ink that reacts and aggregates with the black ink.   7. The ink jet recording apparatus according to claim 6, wherein the ink that aggregates by reacting with the black ink is a cyan ink.   The logical sum data of data obtained by excluding color dot proximity pixels from the black original data and data obtained by ANDing the color dot proximity pixels and the black data thinning mask is recorded as black data. 2. An ink jet recording apparatus according to 1.   2. The logical sum data of data obtained by excluding black adjacent pixels from the black original data and data obtained by ANDing the black adjacent pixels and the black data thinning mask is recorded as black data. The ink jet recording apparatus described.   14. The ink jet recording apparatus according to claim 13, wherein recording is performed using a recording head in which black, cyan, magenta, and yellow chips are arranged side by side.   14. The ink jet recording apparatus according to claim 13, wherein the printing direction is defined so that the color ink is recorded before the black ink.

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