JP2006240067A - 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 high quality level by complementing the black non-ejection data 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 detecting a black high duty region and a color adjacent region per matrix unit, a means for imparting color dot data to the black data in the detected region, and a means for complementing the Bk non-ejection data in the detected region with the color data. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording apparatus that performs recording using a plurality of recording heads capable of recording black ink and at least one color ink.

  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 a color ink with high penetrability on the black ink printing area (this method is hereinafter referred to as “underlay control method”). 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.

As another conventional example, Patent Document 2 can be cited.
JP 55-65269 A JP 2002-086694 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.

  In addition, in a recording head including a large number of high-definition recording elements, the probability that a defective recording element exists at the time of manufacture increases. Further, in order to prevent color misregistration and improve usability, there is a high possibility that a defective recording element will be further included in a head having a multi-color integrated structure. In a high-definition image, even if only one defective element among many recording elements is included, the image quality is adversely affected.

  Since the image is not recorded at the printing position corresponding to the defective recording element, there is a problem that the image quality is remarkably deteriorated particularly as a white line in the low duty region.

  The present invention has been made in view of the above points, and detects the duty of Bk data and masks data corresponding to a Bk defective recording element in a low duty region of Bk data that is greatly affected by the defective recording element. The present invention also relates to a method for suppressing smear and boundary bleeding in a high-duty area of Bk data and an area adjacent to color data and complementing with color data 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. That is, a black high-duty matrix detection unit that detects a matrix in which black dots are present at a relatively high duty, a color adjacent matrix detection unit that detects a matrix in which color dots are adjacent, and a logic of two matrices A means for generating an underscore matrix that is a sum, an underscore data generating means for generating underscore data by taking the logical product of the original black data, black mask data, and the underscore matrix and the underscore mask, and generation Generating means for generating color data for printing with underscoring added by taking the logical sum of the underscored data and original color data, and means for generating a black low duty matrix by inverting the black high duty matrix And black defective recording element information , A means for generating a Bk complementary mask that expresses a complementary recording element position, a means for generating Bk data to be complemented by taking a logical sum of the black low duty matrix and black data, and the complement target Means for generating Bk complementary data by ORing Bk data and the Bk complementary mask; means for generating color data for printing by combining the above-described underprinted color data and the Bk complementary data; and black original Bk data for printing in which data of defective recording elements is masked by the Bk complementary mask and recording means for recording data based on the color data for printing.

  According to this embodiment, smear is prevented by applying color dots to black data (solid image or the like) exceeding a duty that can be arbitrarily set, and color is applied to characters with a duty lower than the set value. By not adding dots and generating and adding color data (C, M, Y) for complementing Bk discharge failure data with color data based on Bk discharge failure information, image defects due to discharge failure By supplementing the Bk discharge failure in the black low-duty area, which is conspicuous with color data, it is possible to record black characters with sharp edges and high quality. Furthermore, by applying color dots to black data adjacent to the color, it is possible to record a high-quality color image with suppressed boundary bleeding between black and color.

  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. 11 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 that rotates in the direction of the arrow in the drawing while holding the print paper (107) together with the auxiliary roller 104, and feeds the print paper (107). ). 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, the carriage (106) located at the position (home position) in the figure, when a print start command is received, drives the recording element provided in the recording head (201) while moving in the x direction to move onto the paper surface. The area corresponding to the recording width of the recording head 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) is rotated 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 detachably held by the carriage (106). 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 means and supported so as to be able 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 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. 12 is a perspective view of a main part of the recording head (201) shown in FIG. As shown in FIG. 12, each of the recording heads (201) has a plurality of discharge ports (300) formed at a predetermined pitch, and connects the common liquid chamber (301) and each discharge port (300). A recording element (303) for generating ink discharge energy is disposed along the wall surface of the liquid path (302). 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. The silicon plate (308) on which these electrical wirings are made is bonded to the heat radiating aluminum base plate (307). Further, the circuit connection part (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 passage (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 from the ink tank to the common liquid chamber (301). It is a configuration to be supplied. 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 form the liquid path (302). Keep the condition that meets. 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). The ink droplet (313) is ejected from the ejection port (300) due to the expansion of the bubbles.

(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 the supply of print data to the printhead, and also controls data transfer between the interface (400), the MPU (401), and the 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 for driving the recording head (201). The EEPROM (411) includes information about defective nozzles in addition to the ejection information of the recording head (201), that is, rank information indicating optimum driving conditions. Specifically, the defective nozzle information is information indicating which number of recording elements of which color is defective. The defective nozzle information of the Bk head read from the EEPROM (411) on the head by the MPU (401) is also stored in the Bk discharge failure information (1026) by the MPU (401).

(4) Description of Gate Array Next, the print data generation will be described mainly with reference to the block diagram shown in FIG.

  Reference numeral 501 denotes a data receiving block for receiving data taken into the gate array. The received data is extracted from the data analysis / decompression block (502) and stored as raster data in the buffer 1 (503). To do. The raster data is stored for each color, and in subsequent block processing, the raster data is processed in time series for each color of Bk, C, M, and Y. The data stored in the buffer 1 (503) is subjected to column conversion in the raster-column conversion block (504) and stored as column data in the buffer 2 (505). At this time, the dots of the converted data are counted and the value is stored in the buffer 3 (506). The timing generation block (507) outputs timings for generating print data to 508, 510, and 512 in synchronization with the carriage motor (406).

  The column data extraction block (508) reads out the data stored in the buffer 3 (506) based on the print data generation timing generated by the timing generation block (507), and performs recording data extraction and mask processing. Next, index data is developed for color data in a data development block (509). In the print data transfer block (510), the developed print data is transferred to the recording head (201) based on the print data generation timing generated by the timing generation block (507).

(5) Explanation for complementing defective recording elements Next, a method for complementing defective recording elements of a specific Bk recording head in a series of these operations will be described.

  A recording element with a defect called a defective recording element, depending on the degree of the defect, in addition to an object that does not eject ink at all, ink is ejected but does not become regular ejection; Since the discharge is not performed, the recording quality is impaired as a result. Therefore, it is necessary to mask the data assigned to the defective recording element so that ink is not ejected by the corresponding recording element.

  In addition, the masked recording data is substituted, that is, the data to be recorded by the defective recording element of the Bk recording head is printed on the recording medium by the color recording head corresponding to the ink dot position recorded by the defective recording element. It is necessary to cause alternative discharge to be performed by a recording element that discharges the ink.

  As described above, the complementary operation is performed by two processes of substituting the mask of the recording data allocated to the defective recording element and the masked data with the recording element of the color recording head in the same area.

Overall Data Processing FIG. 1 is a schematic diagram of generating underlay data and adding it to color data, and generating color Bk complementary data for complementing Bk defective recording elements (hereinafter referred to as Bk discharge failure information). It is a block diagram explaining the flow which synthesize | combines a process and the underscore added data and color Bk complementary data produced | generated by the said method, and produces | generates color data for printing.

First, a description will be given of the underscore data generation and color data addition processing.
A black high duty matrix detection process (1002) is performed on the original Bk data (1001) to generate a black high duty matrix (1003).

  Color adjacency matrix detection processing (1009) using OR data (1007) of original C, M, and Y obtained by ORing original C data (1004), original M data (1005), and original Y data (1006) ) To generate a color adjacency matrix (1010).

  The logical sum of the black high duty matrix (1003) and the color adjacency matrix (1010) is taken to generate the undertone presence / absence matrix (1011).

Original Bk data (1001) is stored in a 506 buffer 3a described later. From this data, Bk data recorded on the same sheet area as the original C data (1004) is read and called C Bk data (1013). (Hereafter, the same applies to Bk data for M and Bk data for Y)
Underlay target Bk data (1016) for C by taking the logical product of the underscore presence / absence matrix (1011), C Bk data (1013), M Bk data (1014), and Y Bk data (1015), The underlay target Bk data for M (1017) and the underlay target Bk data for Y (1018) are generated. In addition, in order to thin out these data, the C underscore additional information (1019), M underscore additional information (1020), and Y underscore additional information are obtained by taking the logical product of each data and the underscore mask (1012). (1021) is generated.

  The generated data and original C data (1004), original M data (1005), and original Y data (1006) are combined 1 to perform underscore added C data (1022) and underscore added M data. (1023), underscored added Y data (1024) is generated.

  Next, a process of complementing with color data based on the Bk discharge failure information will be described.

  A black low duty matrix (1027) that is an inversion matrix of the black high duty matrix (1003) is generated. By taking the logical product of the black low duty matrix (1027), the C Bk data (1013), the M Bk data (1014), and the Y Bk data (1015), the C complement target Bk data (1028), M complement target Bk data (1029) and Y supplement target Bk data (1030) are generated.

  A Bk discharge failure mask is generated from the Bk discharge failure information (1026) storing the defective nozzle information of the Bk head, and C complementation target Bk data (1028), M complementation target Bk data (1029), and Y complementation By taking a logical product with the target Bk data (1030), C Bk complementary data (1031), M Bk target data (1032), and Y Bk complementary data (1033) are generated. These B B complementary data for C (1031), Bk target data for M (1032), B B complementary data for Y (1033), under-applied C data (1022) subjected to under-append processing, and under-applied M The data (1023) and the underprint added Y data (1024) are combined 2 to generate C data for printing (1034), M data for printing (1035), and Y data for printing (1036).

  The original Bk data (1001) is subjected to mask processing using the Bk discharge failure mask generated by the Bk discharge failure information (1026) to obtain Bk data (1025) for printing.

○ Outline of this embodiment The size of the detection matrix used in the underscore process is a response whether or not to add color dots if the matrix size is too small for images with a solid and blank area such as black characters. Even if it is a small character, a color dot will be given (underlay) and it will become impossible to maintain the sharpness of the character. On the other hand, if the matrix size is too large, the responsiveness deteriorates, and the desired color dot application (underlay) is not performed, leading to the occurrence of smear. Therefore, it is preferable to set the size appropriately according to the characteristics of the ink system and the recording apparatus.
In the present embodiment, the detection matrix size is 64 × 32.

  (1) Count the number of black dots existing in the 64 × 32 target matrix, which is the Bk data size of the raster-column conversion block. If there are 758 or more black dots, the target matrix is set to “1”. A black high duty matrix is generated. The size of this black high duty matrix is 120 bits in the horizontal direction in consideration of the A3 + size (12.7 inches) of the recording paper, and 120 × 32 in the vertical direction to match the data size (1024 bits) handled by the 508 data extraction block. . Next, the number of color dots existing in the four adjacent matrices and the 32 × 16 target matrix, which is the color data size of the raster-column conversion block, is counted, and the number of color dots in any of the matrices is 102 dots. In the above case, a color adjacency matrix with the target matrix of “1” is generated. The size of this color adjacency matrix is 240 bits in the horizontal direction in consideration of the A3 nobi size (12.7 inches) of the recording paper, and the vertical direction is 240 × 64 in accordance with the data handling size (1024 bits) of the 508 data extraction block. Then, by taking a logical sum of these two matrices in accordance with the size of the black high duty matrix 120 × 32, an undertone presence / absence matrix (120 × 32) is generated.

  (2) The underscore additional information is generated by taking the logical product of the above-described underscore presence / absence matrix, the underscore mask, and the original Bk data.

  (3) The underlay additional information and the original color data are combined and recorded as underprinted color data.

  (4) Generate an inversion matrix of the black high duty matrix and generate a color complement target Bk data by taking a logical product with the original Bk data, and use the color complement target Bk data and Bk discharge failure information. The color Bk complementary data corresponding to the discharge failure nozzle is generated.

  (5) Print color data is generated and recorded from the underprinted color data and the color Bk complementary data.

  (6) The non-discharge data is masked from the original Bk data by the Bk non-discharge information to generate print Bk data. By doing this, it is possible to prevent boundary bleeding and smearing by underlaying in the high-duty area and complementing Bk data with color data without undercoating in the low-duty area. Enable recording.

O Generation of black high duty matrix for smear prevention The following processing is performed for the purpose of detecting an area where the Bk data exceeds a set duty from the Bk dot count value.

  The original Bk has a dot count value obtained by counting dots within the conversion size when raster column conversion is performed by the raster-column conversion block 505 stored in the 506 buffer 3b. Using the dot count value of the original Bk data, a black high duty matrix detection process for smear prevention is performed.

  FIG. 2 is a flowchart of detection processing of a black high duty matrix for preventing smear.

  The number of black dots present in the 64 × 32 matrix of interest is counted (S101). Subsequently, it is determined whether or not the dot count value is 758 (printing duty = about 37%) or more (S102). If the number of black dots is 758 or more, the bit corresponding to the target matrix of the black high duty matrix information is set to 1 (S103). Otherwise, the bit corresponding to the target matrix of the black high duty matrix information is set to 0 (S104). Subsequently, the matrix of interest is shifted (S105). It is determined whether or not all the matrix processes have been completed (S106), and if completed, the process ends. (S107) If not, the above process is repeated.

  FIG. 3 shows an example of detection of a black high duty matrix.

  FIG. 3A shows a 64 × 32 attention matrix.

  FIG. 3B is a diagram showing the number of dots in each matrix of Bk data.

  FIG. 3C is a diagram showing black high duty matrix information (bitmap information) obtained as a result of performing the black high duty matrix detection process. While shifting the matrix of interest in the horizontal and vertical directions, 1 is set to the bit corresponding to the matrix having the number of dots of 758 or more, and 0 is set to the bit corresponding to the other matrix. Underlay data is added to Bk data existing in the matrix in which 1 is set.

○ Generation of color adjacency matrix for preventing bleeding Using the dot count value of color data, the following processing is performed for the purpose of detecting an area where Bk and color data are adjacent.

  Original C, M, and Y data are stored in the 506 buffer 3b as dot count values obtained by counting dots within the conversion size when raster column conversion is performed by the raster-column conversion block 505.

  Using the dot count values of the original C, M, and Y data, color adjacent matrix detection processing for preventing bleeding is performed.

  FIG. 4 is a flowchart of the color adjacent matrix detection process for preventing black and color bleeding.

  The number of color dots (total of C, M, and Y) existing in the four matrixes adjacent to the 32 × 16 target matrix is counted (S201). It is determined whether at least one of the four matrices adjacent to the target matrix is 102 dots or more (S202). If even one of the matrices has 102 or more color dots, the bit corresponding to the matrix of interest in the color adjacent matrix information is set to 1 (S203). Otherwise, the bit corresponding to the target matrix of the color adjacency matrix information is set to 0 (S204). Subsequently, the matrix of interest is shifted (S205). It is determined whether or not the processing of all the matrices has been completed (S206). If the processing has been completed, the processing ends (S207). If not, the above processing is repeated.

  FIG. 5 illustrates an example of detection of a color adjacency matrix for preventing bleeding. FIG. 5A shows a 32 × 16 matrix of interest and four adjacent matrices. In the present embodiment, the dot count values of the upper, lower, left and right matrices adjacent to the matrix of interest are detected. This is to prevent bleeding from occurring when the image data and the target matrix are synchronized, and the black data and the color data are adjacent to the boundary region between the target matrix and the adjacent matrix. The four matrixes present on the diagonal are not detected because the boundary region exists only at the points.

  FIG. 5B is a diagram showing the number of dots obtained by adding cyan, magenta, and yellow in each matrix.

  FIG. 5C is a diagram showing color adjacency matrix information (bitmap information) obtained as a result of performing the color adjacency matrix detection process. When at least 102 dots (printing duty = about 10%) of the target matrix and the adjacent matrix 1 to the adjacent matrix 4 while shifting the target matrix in the horizontal direction and the vertical direction, the color adjacent matrix information If the bit corresponding to the pixel of interest is set to 1, otherwise, the bit corresponding to the pixel of interest in the color adjacency matrix information is set to 0.

○ Generation of underscore presence / absence matrix In order to generate the underscore presence / absence matrix indicating the area to be underscored, the black high duty matrix for smear prevention and the color adjacent matrix for bleeding prevention are matched to the size of the black high duty matrix. And take the logical OR.

○ Generation of underscore additional information The following processing is performed for the purpose of generating the underscore additional information to be added to the original color data.

  FIG. 6 is a diagram showing generation of underscore additional information from the underscore presence / absence matrix.

For example, when generating C data for printing, (a) Bk data for C in the same paper area as the original C data read from the 506 buffer 3a, and an underprinting presence / absence matrix in the same paper area as the original C data. Underscore additional information is generated from the logical product of the selected (b) underscore presence / absence data and (c) underscore mask.
In the same manner, the underprint additional information is generated for the M and Y data.

  The underscoring presence / absence information data (32 bits) selected from the underscoring presence / absence matrix (120 × 32) to correspond to the same paper area as the C Bk data is expanded to correspond to the C Bk data (1024 bits) and logically expanded. The product is taken to generate C underlay target Bk data (1024 bits). The underscore presence / absence information data is 1 bit and corresponds to 32 bits in the vertical direction of the Bk data. 640 bits necessary for printing are selected from the C underlay target Bk data (1024 bits) and ANDed with the underlay mask data (32 bits). This is underlay additional information (640 bits).

  Here, FIG. 7 is used as the underlay mask, and the vertical 32 bits selected from the mask are repeatedly used as 640 bits. Move to the next column to move horizontally. In this embodiment, the duty of the mask is set to 1.6%, 1.6%, and 1.4% for cyan, magenta, and yellow, respectively. 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 color data with underscore added The following processing is performed to generate color data (C or M, Y) with underscore added with underscore data.

FIG. 8 is a diagram showing generation of underscored added data from underscored additional information.
When generating underscore added data C data (805), the original C data 1280 bits (802) and the underscore additional information 640 bits (801) are combined.

  The difference in data width here is due to the difference in resolution between Bk and color. As shown in FIG. 9, the same area is expressed by the 2-bit data information of the original color data with respect to the 1-bit data of the underlay additional information generated from the original Bk data. There are eight types of combinations of 1-bit data and 2-bit data as shown in FIGS. Among them, as shown in FIG. 9A, when the original C data is “00” and the underlay additional information is “1”, the print C data is set to “01”.

  With the above synthesis method, C data 2 bits and underscore additional information 1 bit are synthesized from the upper bits of the original C data (802) and the underscore additional information (801) to generate underscored added data C data (805).

  As a result, data can be added only to an area where there is no color data (here, C) in the same area as Bk. Here, the underlay addition process is performed to change the color 2-bit data “00” to “01”, but it may be changed to “10” or “11” instead of “01”.

Generation of color Bk complement data Based on the Bk discharge failure information, the following processing is performed to generate color Bk complement data for complementing Bk discharge failure data with color data. This is because the color data is used to complement the Bk discharge failure data in the black low-duty matrix region where image defects due to discharge failure are conspicuous.

  Using the black high duty matrix (1003) of the raster-column conversion unit detected for the underscore data addition processing described above, the bit information “1” and “0” of the matrix is inverted (NOT processing) and the black low A duty matrix (1027) is generated.

  In the following processing, the C data, M data, and Y data are generated sequentially in the same manner as the color data of the underlay data addition processing. Therefore, here, a method for generating the C Bk complementary data (1031) will be described. To do. The M Bk complementary data (1032) and the Y Bk complementary data (1033) are also generated by the same method.

  This will be described with reference to FIG. First, for the purpose of extracting Bk data in the low duty region, the same (a) Bk data for C (1024 bits) and (b) black low duty matrix used when generating underscored C data. (32 bits) is expanded so as to correspond to C Bk data (1024 bits), logical product is obtained, and 640 bits necessary for printing are selected from the resulting data 1024 bits (d) C complement target Bk data ( 640 bits). (E) A Bk discharge failure mask (640 bits) is generated from the defective nozzle position information of the Bk head stored in the Bk discharge failure information (1026), and a logical product with the C complement target Bk data (640 bits) is obtained. Thus, (f) C Bk complementary data (640 bits) is generated. “1” in the C Bk complementary data represents data to be recorded by the Bk discharge failure nozzle in the low duty region to be complemented.

○ Generation of print data The color data for printing is generated by combining the color data with underscore added with the underscore data and the color Bk complementary data for complementing the Bk discharge failure data with color data.

  FIG. 15 is a diagram showing the generation of printing color data from the underscored data and the color Bk complementary data.

  When generating the printing C data (1504), the underscored added C data 1280 bits (1502) and the C Bk complementary data 640 bits (1501) are combined.

  The difference in data width here is due to the difference in resolution between Bk and color. As shown in FIG. 16, the same area is expressed by 2-bit data information of C data added with underscore generated from original C data with respect to 1-bit data of C Bk complementary data generated from original Bk data. There are eight types of combinations of 1-bit data and 2-bit data as shown in FIGS. Among them, as shown in FIGS. 16A, 16B, and 16C, replacement data that can be arbitrarily set (here, “11”) to be replaced when the C Bk complementary data is “1”; The C data with the underscore added is compared, and a process of replacing small value data (in this case, “00”, “01”, “10”) with replacement data is performed.

  The C data 2 bits that have undergone underscore processing equivalent to or greater than the replacement data are used as they are as C data for printing.

  With the above combining method, C data 2 bits and underscore additional information 1 bit are synthesized from the upper bits of C data (1502) with underscore added and Bk complementary data for C (1501) to generate C data for printing (1504).

  The original Bk data (1001) is subjected to mask processing using the Bk discharge failure mask generated by the Bk discharge failure information (1026), and the data masked from the discharge failure data is set as print Bk data (1025).

FIG. 7 is a block diagram illustrating a flow of black high duty matrix detection, color adjacency matrix detection, color dot application data generation, Bk discharge failure complement color data generation, and print data generation according to the present exemplary embodiment. It is a flowchart figure of the detection process of the black high duty matrix for a smear prevention of a present Example. The detection example of the black high duty matrix of a present Example is a figure. It is a flowchart figure of the detection process of the color dot adjacency matrix for the black and color bleeding prevention of a present Example. FIG. 3 is a diagram illustrating a detection example of a color dot adjacent matrix for preventing bleeding according to the present embodiment. FIG. 6 is a diagram illustrating generation of underscore additional information from the underscore presence / absence matrix of the present embodiment. It is a figure of the underlay mask of a present Example. It is the figure which showed the production | generation of print data from the underlay additional information of a present Example. It is the figure which showed the synthetic | combination method of the underlay additional information and color data of a present Example. It is a figure showing the production | generation of the Bk complementary data for colors of a present Example. 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. It is a gate array block diagram of an ink jet recording apparatus to which the present invention can be applied. It is the figure which showed the production | generation of the color data for printing from the undercoating added data of a present Example, and the Bk supplement data for colors. It is the figure which showed the synthetic | combination method of the underscore added data of a present Example, and Bk complementary data for colors.

Claims (14)

In a recording apparatus that performs recording using a recording head capable of recording black ink and at least one color ink,
A black high duty matrix detection means for detecting a matrix in which black dots are present at a high duty; a color adjacent matrix detection means for detecting a matrix in which color dots are present adjacently;
Color dots that generate color dot data to be applied by taking the logical product of the black data in the undertone presence / absence matrix generated by the logical sum of the black high duty matrix and the color adjacency matrix and the mask for giving color dots Grant data generation means;
Means for generating black defective recording element complementary data in the black low duty region based on information of the black high duty matrix detecting means and Bk defective recording element information setting means;
Based on the information of the color dot application data generating means, the black defective recording element complementary data, the printing data generating means for generating color data for printing based on the original color data, and the Bk defective recording element information setting means, the black original Means for masking data;
An ink jet recording apparatus comprising: black data generated by a means for masking the black original data; and a recording means for performing recording based on the color data generated by the printing color data generating means.   2. The ink jet recording apparatus according to claim 1, wherein the black defective recording element complementary data in the black low duty region is generated in a color other than black.   The black high duty matrix detection means counts the number of black dots present in the LxM (L and M are natural numbers of 1 or more) focus matrix, and when the count value exceeds a predetermined value, 2. The ink jet recording apparatus according to claim 1, wherein a black high duty matrix is used.   The inkjet recording apparatus according to claim 1, wherein the black high duty matrix detection is performed simultaneously with raster-column conversion.   The color adjacency matrix detection unit counts LxM (L, M is a natural number of 1 or more) target matrix and color dots existing in at least one matrix adjacent to the target matrix, and any one of the count values is predetermined. The inkjet recording apparatus according to claim 1, wherein when the value is exceeded, the matrix of interest is a color adjacent matrix.   The inkjet recording apparatus according to claim 1, wherein the color adjacent matrix detection is performed simultaneously with raster-column conversion.   The inkjet recording apparatus according to claim 1, wherein a focused matrix size of the black high duty matrix and the color adjacency matrix is 2: 1.   The inkjet recording apparatus according to claim 1, wherein the color dot providing mask is 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 data detected by the color adjacency matrix detecting means is 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.   2. The ink jet recording apparatus according to claim 1, wherein recording is performed using a recording head in which black, cyan, magenta, and yellow chips are arranged side by side.

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