JP4814369B2 - Inkjet printer - Google Patents

Description

  The present invention mainly relates to an ink jet printer apparatus, an ink jet printing method, and an ink jet printing program.

  An ink jet printer ejects (jets) ink from a plurality of nozzles of a print head, and forms an image by a plurality of head scans. If any nozzle of the print head is unable to eject properly even when the recovery means is used, the printed matter is constantly in a missing tooth state, that is, a missing dot state, and a defective nozzle causes a reduction in image quality.

In the conventional technology, in order to prevent this missing dot state, for example, as shown in Patent Document 1, as a method of replacing the defective nozzle, the number of scans of the print head is increased, and dots that cannot be printed due to a nozzle failure A method of printing data to be printed on the held dot at another position by another nozzle is disclosed.
JP 2001-146004 A

  However, when performing head scanning to replace nozzles that cannot be ejected normally by the method disclosed in Patent Document 1, an image having the width of the print head nozzle has been formed in N scans so far. However, since the image of the width of the print head nozzle is formed by (N + 1) times of scanning, there is a problem that the printing speed is lowered.

  Further, since the conveyance of the medium that is the printing medium is not performed at a constant feed, white stripes and black stripes are likely to be generated, and there is a problem that the image quality is deteriorated. In addition, during nozzle substitution scanning, many nozzles do not eject ink, and nozzles that do not eject ink during scanning increase the viscosity of ink in the nozzle, so that ejection failure is likely to occur even in normal nozzles. There's a problem.

  The present invention has been made in consideration of such circumstances, and has been made to solve the above-described problem. The object of the present invention is to replace the missing nozzles of defective nozzles by normal head scanning without performing nozzle replacement scanning. An ink jet printer apparatus, an ink jet printing method, and an ink jet printing program are provided.

In order to solve the above problems, the present invention is previously nozzle identification information is given, ink and Bei the print head comprising one or more ink colors are more provided with nozzles for dot injects said nozzle identification of the defective nozzle An input unit that inputs information as defective nozzle identification information, an image data storage unit that stores image data to be printed, and the nozzle identification information and the nozzle corresponding to the nozzle identification information print any dot position. Based on the print rule information indicating the correspondence relationship, the image data stored in the image data storage unit, and the defective nozzle identification information input from the input unit, Image data for substituting printing of the defective nozzle by a nozzle other than the defective nozzle for the dots around the print dot When generating the alternative data, the case be replaced by the defective nozzle of the same color ink, the dots adjacent to the print dots of the defective nozzle as an alternative candidate dots, non-printing of any one dot of the alternative candidate dots By rewriting dots as printing dots, image data that substitutes printing of the defective nozzle by nozzles other than the defective nozzle is generated as substitution data, and when all the substitution dot candidates are printing dots, substitution is not performed. A defective nozzle alternative data generating unit for writing the generated alternative data in the image data storage unit, and performing dot ejection of the ink while scanning the print head in a direction crossing the print medium feeding direction. In an inkjet printer that performs printing, the pitch between the nozzles is between the dots. Printing that completes an image by printing the image data in a predetermined area of the print medium by a plurality of scans, and the defective nozzle replacement data generation means includes the image data storage means The image data of the line including the image data corresponding to the defective nozzle and the image data of the lines before and after the line are captured, and the print dot at the position adjacent to the left and right and up and down with respect to the print dot of the defective nozzle is the alternative dot candidate The nozzle that forms the alternative data is the nozzle that forms the alternative data, and the nozzle that forms the alternative data is selected as the alternative data by selecting one of the alternative dot candidates from the left, right, top, and bottom in that order. Is used as the substitute nozzle, the substitute data is generated, and the image data corresponding to the defective nozzle is set as a non-printing dot. When the dots are formed on the print medium based on the image data written to the image data storage means and based on the image data written to the image data storage means, they are formed on the print medium instead of printing the defective nozzles. In the inkjet printer, a part of the dots overlapped with adjacent dots .

The ink jet printer according to the present invention may be configured such that the ink includes ink colors having different densities of the same color material, and the substitute nozzle that replaces the defective nozzle is a nozzle that ejects the same ink color as the ink color of the defective nozzle. It further comprises selection means for selecting whether to use a nozzle that ejects an ink color of the same color material as the ink color of the defective nozzle , and the defective nozzle replacement data generating means is configured to select the replacement nozzle by the selection means. When a nozzle that ejects an ink color of the same color material as the ink color of the defective nozzle is selected, a line including the image data corresponding to the defective nozzle from the image data storage unit and a line before and after the line Image data, and print the print dot and the position adjacent to the left and right of the print dot with respect to the print dot of the defective nozzle The alternative dot candidate, the nozzle for ejecting the ink color of the different density forming the alternative dot candidate as the alternative nozzle candidate, the dot selected from the alternative dot candidates as the alternative data, The nozzle for forming data is used as the substitute nozzle, the substitute data is generated, and the image data corresponding to the defective nozzle is set as a non-printed dot and is written in the image data storage means .

In the ink jet printer according to the present invention, when the defective nozzle replacement data generating unit replaces the defective nozzle with an ink having a different density of the same color material as the ink of the defective nozzle, the number of print dots formed by the replacement nozzle is the defective. The substitute data is generated so as to be a number corresponding to the ratio of the density of the color material of the ink of the alternative nozzle to the density of the color material of the ink of the nozzle .

  According to the present invention, a print head having one or a plurality of ink colors in which nozzle identification information is provided in advance and a plurality of nozzles that eject ink is provided is provided, and the print head is scanned in a direction crossing the print medium feeding direction. Ink jet printer that performs ink jet printing while performing printing, input means for inputting nozzle identification information of defective nozzles as defective nozzle identification information, image data storage means for storing image data to be printed, and nozzle identification information Rule information indicating which dot positions are printed by the nozzle corresponding to the nozzle identification information, image data stored in the image data storage means, and defective nozzles input from the input means Based on the identification information, a defective nozzle is printed on the print dot of the defective nozzle and the dots around the print dot. The image data to replace the printing of the defective nozzle by a nozzle other than Le generates Alternatively data, the generated substitute data was decided and a faulty nozzle substitute data generating means for writing the image data storage means.

  As a result, the inkjet printer can generate substitute data for substituting the print dots of the defective nozzles with other nozzles of the defective nozzles, and can print the generated substitute data, so that the print head does not perform alternative scanning. During normal print head scanning, it is possible to replace the print dots of defective nozzles. Therefore, compared to the case where the print head substitute scanning is performed, the printing speed is not reduced, the ink ejection failure during the nozzle substitute scan is prevented, and the conveyance of the media as the print medium is further fed. It is possible to perform printing with.

  Further, according to the present invention, the defective nozzle replacement data generating means of the ink jet printer substitutes the dot adjacent to the print dot of the defective nozzle as a replacement dot candidate when replacing with the same color ink as that of the defective nozzle. By rewriting any one dot that is not printed as a printed dot, image data that substitutes printing of a defective nozzle by a nozzle other than the defective nozzle is generated as replacement data.

  As a result, it is possible to replace the printing of the defective nozzle with a dot adjacent to the printing dot of the defective nozzle with the same color ink as the ink of the defective nozzle. There is a possible effect.

  According to the present invention, the defective nozzle replacement data generating means of the ink jet printer replaces the printing dot of the defective nozzle and the dot adjacent to the dot when replacing the dark ink of the defective nozzle with the same color light ink. By substituting a non-printing dot of the same light color ink with a predetermined number of dots as a print dot of the same light color ink among the alternative dot candidates, the printing of the defective nozzle is replaced by a nozzle other than the defective nozzle. Image data is generated as alternative data.

  As a result, even if different inks are used, it is possible to substitute printing that maintains the printing density around the printing dots of the defective nozzles with similar light-colored inks, so that natural printing results can be obtained. is there.

  Further, according to the present invention, the defective nozzle replacement data generating means of the ink jet printer counts the number of printed dots of the defective nozzle when replacing with the light ink of the same color as the light ink of the defective nozzle, and the counted number of dots is predetermined. Print dots of defective nozzles that have reached a predetermined number of dots, and dots that are adjacent to the defective nozzles that have reached a predetermined number of dots are used as alternative dot candidates. By rewriting non-printing dots of similar dark ink with the same number of dots as printing dots of similar dark ink, image data that substitutes printing of defective nozzles by nozzles other than defective nozzles is generated as replacement data. .

  As a result, even if different inks are used, it is possible to substitute printing that maintains the printing density around the printing dots of the defective nozzles with the same dark ink, so that natural printing results can be obtained. There is.

  Further, according to the present invention, the defective nozzle substitute data generating means of the ink jet printer counts the number of print dots of the defective nozzle in the scanning direction of the print head.

  This makes it possible to reduce the number of print missing dots lined up in the scanning direction of the print head, and to make print missing dots lined up in the scanning direction of the print head easy to detect to the human eye, i.e., make white stripes inconspicuous. There is an effect that becomes possible.

  Further, according to the present invention, the defective nozzle replacement data generating means of the ink jet printer does not perform replacement for dots on which all the alternative dot candidates are printed.

  As a result, when adjacent dots overlap each other, i.e., when the print dots of the defective nozzle are complemented by the adjacent dots, the defective nozzle is not replaced, and thus the ink is excessively removed. There is an effect that it is possible to reduce the phenomenon of ink see-through caused by printing, that is, the phenomenon that the ink passes through the back surface of the print medium.

  In addition, according to the present invention, it is possible to switch between a plurality of alternative means, and it is possible to increase the choices of dots that are print dot candidates for complementation. Further, by using an ink having a different density of the same color material as the substitute ink, the substitute color does not change extremely.

1 is a block diagram illustrating an overall configuration of an inkjet printing system according to an embodiment of the present invention. (A), (b), (c) is a figure which shows the structural example of the print head 106 by the embodiment. It is a figure which shows the data structural example of the band memory 107 by the embodiment. 3 is a block diagram showing an internal configuration of a band memory control unit 104 according to the same embodiment. FIG. (A), (b), (c), (d) is a figure which shows the printing procedure in case all the nozzles which the black ink head 401K in the embodiment has are normal nozzles. (A), (b), (c), (d) is a figure which shows the printing procedure in case only the nozzle K4 of the black ink head 401K in the embodiment becomes a defective nozzle, and a printing state. It is a flowchart which shows the operation | movement process in the same embodiment. It is a figure which shows the example of the alternative method by the same color ink in the embodiment. It is a figure which shows the example of the alternative method which substitutes the dark color ink in the same embodiment by a similar light color ink. It is a figure which shows the example of the alternative method of substituting the light color ink in the embodiment with similar dark ink. (A), (b) is a figure which shows the example of a printing state of 1 line in the embodiment. (A), (b), (c) is a figure which shows the example of the alternative method by the same color ink in the embodiment. (A), (b), (c) is a figure which shows the example of the actual ink printing state of the alternative method by the same color ink in the embodiment. (A), (b), (c), (d), (e) is a figure which shows the example of the alternative method which substitutes the dark color ink in the same embodiment by a similar light color ink. (A), (b), (c), (d), (e) is a figure which shows the example of the alternative method which substitutes the light color ink in the same embodiment by a similar dark color ink.

Explanation of symbols

101 Host computer 102 Printer (inkjet printer)
103 Host I / F Control Unit 104 Band Memory Control Unit 105 Print Control Unit 106 Print Head 107 Band Memory (Image Data Storage Unit)
108 CPU
109 Operation panel (input means)
110 Memory 401K Black Ink Head 401M Magenta Ink Head 401C Cyan Ink Head 401Y Yellow Ink Head 401Lk Light Black Ink Head 401Lm Light Magenta Ink Head 401Lc Light Cyan Ink Head 201 Defective Nozzle Replacement Data Generation Unit (Defective Nozzle Replacement Data Generation Unit)
202 Read address generation unit 203 Write address generation unit 204 Address selection unit 205 Band memory data control unit K1 Nozzle K2 Nozzle K3 Nozzle K4 Nozzle K5 Nozzle K6 Nozzle Lk1 Nozzle Lk2 Nozzle Lk3 Nozzle Lk4 Nozzle Lk5 Nozzle Lk6 Nozzle

  Hereinafter, a printer 102 according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing the ink jet printing system according to the present embodiment. The inkjet printing system includes a host computer 101 and a printer 102 to which the host computer 101 is connected.

  The host computer 101 transmits a print start command signal including image data to be printed to the printer 102. The host computer 101 is, for example, a computer terminal such as a personal computer, a PDA (Personal Digital Assistants: information portable terminal), or a cellular phone.

  The printer 102 includes a host I / F (interface) control unit 103, a band memory control unit 104, a print control unit 105, a print head 106, a band memory 107, a CPU 108, an operation panel 109, and a memory 110.

  The host I / F control unit 103 inputs a print start command signal received from the host computer 101 to the band memory control unit 104.

  The band memory control unit 104 performs control such as writing and reading of image data of the print start command signal input from the host I / F control unit 103 to the band memory 107, and outputs the image data to the print control unit 105. .

  Based on the image data input from the band memory control unit 104, the print control unit 105 performs printing by performing ink ejection control from each nozzle of the print head 106 in synchronization with print medium feed control by the CPU 108. Do.

  The print head 106 is based on a control signal input from the print control unit 105, black (K), magenta (M), cyan (C), yellow (Y), light black (Lk), light magenta (Lm), Each ink head has an ink head that ejects seven colors of light cyan (Lc). Here, four colors of black, magenta, cyan, and yellow are dark inks. Three colors of light black, light magenta, and light cyan are light inks.

  FIG. 2 is a configuration diagram of an ink head included in the print head 106. 2A, the print head 106 includes a black ink head 401K, a magenta ink head 401M, a cyan ink head 401C, a yellow ink head 401Y, a light black ink head 401Lk, and a light magenta. It has seven heads, an ink head 401Lm and a light cyan ink head 401Lc. Each ink head has six nozzles, that is, ink ejection openings, and the configuration thereof is the same. Therefore, as an example, the black ink head 401K shown in FIG. 2B and FIG. The ink head of the light black ink head 401Lk of light black ink, which is a light ink of the same color of black ink, shown in c) will be described as a representative example.

  As shown in FIG. 2B, the black ink head 401K has six nozzles: nozzle K1, nozzle K2, nozzle K3, nozzle K4, nozzle K5, and nozzle K6. The distance between the nozzles is a width corresponding to 360 dpi (dot per inch), that is, a width of 1/360 inch.

  FIG. 2B shows an example of the head when the nozzle K4 is a defective nozzle, that is, when ink cannot be ejected normally. The light black ink head 401Lk shown in FIG. 2C has the same configuration as the black ink head 401K, but the nozzle Lk1, nozzle Lk2, nozzle Lk3, nozzle Lk4, and nozzle Lk5 of the light black ink head 401Lk. This is an example illustrating a case where all the nozzles Lk6 are normal nozzles that normally eject ink.

  Returning to FIG. 1, the band memory 107 stores the image data input from the band memory control unit 104. FIG. 3 is a conceptual diagram illustrating a configuration example of image data stored in the band memory 107.

  In FIG. 3, a band memory 107 stores image data to be output to the print head 106 for each band for each ink. Here, the band is image data of 2 dot lines × print medium width in the paper feed direction in the image data output to the print head 106 as one band. Here, 2 × 2 4 dots surrounded by reference numeral 302 are defined as one unit. The 4 dots composed of 2 × 2 are dots that are printed in the first scan, the second scan, the third scan, and the fourth scan in printing in a four-scan cycle. In other words, when the entire area 302 is printed, the print head 106 scans a total of four scans.

  Further, as shown in the data configuration of the print data portion in FIG. 3, the data in the print data portion is configured by a print presence / absence flag indicating whether or not printing is performed for each dot. The print presence / absence flag data indicates whether or not the dot is to be printed depending on whether the value of the print presence / absence flag is 1 or 0, for example. Hereinafter, a dot scheduled to be printed with a printing presence / absence flag “1” will be referred to as a printing dot, and a dot that is not scheduled to be printed with a printing presence / absence flag “0” will be referred to as a non-printing dot.

  As shown in FIG. 3, a 1-bit flag is prepared for each band as a replacement band flag. Here, the replaced band flag is a flag indicating whether or not the defective nozzle replacement processing for the corresponding band has been completed. If the replaced flag is “1”, it means that the nozzle replacement process for the band has been completed, or that the nozzle replacement process for the band is not required, that is, the data to be printed by the defective nozzle in the band data. Indicates that one of the dots is not included. If the replacement flag is “0”, the band requires nozzle replacement processing, that is, the data of the band includes dots to be printed by defective nozzles, but the nozzle replacement processing is completed. Indicates not.

  Returning to FIG. 1, a central processing unit (CPU) 108 controls each unit included in the printer 102. The operation panel 109 is, for example, a keyboard, a mouse, a touch panel, buttons, keys, and the like, and inputs information input by the operation to the CPU 108 in response to a user operation. The memory 110 stores a program for the CPU 108 to control each unit of the printer 102 and temporarily stores data.

  Next, a detailed internal configuration of the band memory control unit 104 of the printer 102 will be described. FIG. 4 is a block diagram showing an internal configuration of the band memory control unit 104. The band memory control unit 104 includes a defective nozzle replacement data generation unit 201, a read address generation unit 202, a write address generation unit 203, an address selection unit 204, and a band memory data control unit 205.

  In FIG. 4, the defective nozzle replacement data generation unit 201 includes a line including a defective nozzle printing scheduled dot, that is, a line, and one line above and below the line, based on the defective nozzle identification information input from the CPU 108. The image data corresponding to a total of 3 lines is read from the band memory 107, the substitute image data of the dots to be printed for the defective nozzle is generated from the read image data of the three lines based on a predetermined substitute method to be described later, and the generated substitute The image data is written back to the original position in the band memory 107, that is, rewritten.

  Here, the defective nozzle alternative data generation unit 201 indicates the correspondence of which dot position each nozzle prints in advance, for example, print rule information as indicated by reference numeral 302 in FIG. It is stored in the storage area. When defective nozzle identification information is input, the defective nozzle replacement data generation unit 201 stores image data corresponding to the three lines including the print-scheduled dots described above based on the printing rule information and the defective nozzle identification information. Read address information on the current band memory 107 is generated. The defective nozzle substitute data generation unit 201 generates substitute image data for the image data read from the band memory 107 based on the read address information.

  The read address generation unit 202 outputs the memory address information of the image data output to the print control unit 105 on the band memory 107 to the band memory 107 via the address selection unit 204. The write address generation unit 203 outputs the memory address information on the band memory 107 to which the image data input from the host computer 101 is written to the band memory 107 via the address selection unit 204.

  The address selection unit 204 outputs the memory address information input from the defective nozzle alternative data generation unit 201, the read address generation unit 202, and the write address generation unit 203 to the band memory 107 at a predetermined timing. Here, the address selector 204 receives the memory address information input from the write address generator 203 simultaneously with the timing when the band memory data controller 205 outputs the image data input from the host computer 101 to the band memory 107. The data is output to the band memory 107. The address selection unit 204 outputs the memory address information input from the read address generation unit 202 to the band memory 107 based on the read timing of the image data output from the band memory data control unit 205 to the print control unit 105.

  The band memory data control unit 205 reads and writes image data to the band memory 107 via the data bus.

<Normal basic printing status>
Next, the basic printing state for one band of this embodiment will be described with reference to the drawings.

  FIG. 5 is a diagram illustrating a printing procedure when all the nozzles of the black ink head 401K are normal nozzles and printing is performed at a printing resolution of 720 dpi. FIG. 5A shows the printing state of the first scan. As the black ink head 401K moves to the right in the drawing direction in the scanning direction, the nozzle K1 ejects ink every other dot as shown by a black background in FIG. Here, the reason for ejecting every other dot is that the image quality is improved by printing one line in two scans.

  In addition, when ink is ejected every other dot and dots are printed in other scans than when ink is ejected for every dot, the print of the first scan is absorbed by the medium during other scans. For this reason, it is possible to reduce a phenomenon called beading that impairs image quality, which occurs when printing dot by dot, that is, a phenomenon in which adjacent dots are connected on the recording paper, resulting in irregular gaps, increased density, and the like. .

  FIG. 5B shows a printing state when the paper feed function unit of the printer 102 (not shown) sends paper after the first scan has been printed, and the second scan is performed. While the black ink head 401K moves in the scanning direction to the left in the drawing, the nozzle K3 ejects ink every other dot.

  Similarly, FIG. 5C shows a printing state when the paper feed function unit of the printer 102 (not shown) feeds paper and performs the third scan after printing of the second scan is completed. While the black ink head 401K moves in the scanning direction to the right in the drawing, the nozzle K4 ejects ink every other dot. FIG. 5D shows a printing state when the paper feed function unit of the printer 102 feeds paper after the third scan is finished and performs the fourth scan. While the black ink head 401K moves in the scanning direction to the left in the drawing, the nozzle K6 ejects ink every other dot.

  As described above, one band is printed by a total of 4 scans.

<Printing status due to nozzle failure>
Next, a printing state when the nozzle of the nozzle K4 becomes unable to eject ink due to ink clogging or the like will be described with reference to the drawings.

  FIG. 6 is a diagram showing a printing procedure and a printing state when only the nozzle K4 of the black ink head 401K becomes a defective nozzle and ink ejection becomes impossible. When four scans are performed, the first scan and the second scan in FIGS. 6A and 6B are the same as those in FIG. However, in the printing state of the third scan shown in FIG. 6C, since the nozzle K4 is unable to eject, the nozzle K4 is not printed on the dot to be originally printed, as shown in FIG. 6D. Even when the fourth scan is completed, unprinted dots become missing dots.

  Next, the operation of the printer 102 according to the embodiment of the present invention will be described with reference to the drawings. FIG. 7 is a flowchart showing the operation process of the printer 102.

  In the printer 102, the operation panel 109 is operated by the user and outputs the defective nozzle identification information and the nozzle replacement method input by the operation as input information to the CPU 108. When the defective nozzle identification information and the nozzle replacement method are input, the CPU 108 holds the input defective nozzle identification information and the nozzle replacement method in the memory 110 and simultaneously outputs the nozzle replacement method to the defective nozzle replacement data generation unit 201. (Step S1).

  The host I / F control unit 103 receives a print start command signal including image data to be printed from the host computer 101 (step S2).

  The host I / F control unit 103 inputs the received image data to the band memory control unit 104. In the band memory control unit 104, when image data is input from the host I / F control unit 103, the band memory data control unit 205 in FIG. 4 receives a write address generation command signal including data size information of the input image data. Is output to the write address generation unit 203 via the address selection unit 204. The write address generation unit 203 generates write address information in the band memory 107 based on the data size information of the image data of the input write address generation command signal, and outputs the generated write address information to the address selection unit 204.

  When the write address information is input from the write address generation unit 203, the address selection unit 204 outputs an image data write command signal to the band memory data control unit 205, and the band memory data control unit 205 In synchronization with the timing of writing image data to 107, the write address information input from the write address generation unit 203 is output to the band memory 107.

  In the band memory 107, the image data input from the band memory data control unit 205 is stored based on the write address information input from the address selection unit 204 (step S3).

  When the print data is written in the band of the band memory 107, the CPU 108 determines whether or not there is a line in charge of the ejection failure nozzle in the band. If it exists, the defective nozzle alternative data generation unit 201 sets whether the line including the defective ejection nozzle and the dot handled by the defective ejection nozzle is an even bit or an odd bit in the band memory 107. The defective nozzle replacement data generation unit 201 is a band memory that stores image data for a total of three lines, that is, a print line that includes a set print dot of a defective nozzle, and one upper and lower line adjacent to the print line. Read address information which is an address of 107 is generated.

  If the nozzle replacement method set in the defective nozzle replacement data generation unit 201 from the CPU 108 in step S1 is replacement by the same color ink, the defective nozzle replacement data generation unit 201 has a missing nozzle in the band memory 107. Read address information is generated for each line and upper and lower lines of the same color.

  If the nozzle replacement method set in the defective nozzle replacement data generation unit 201 by the CPU 108 in step S1 is a replacement with another color ink, the line with the nozzle missing dots in the band memory 107 and the band memory of the alternative ink color are stored. Read address information is generated for each line corresponding to nozzle missing dots and one line above and below.

  The defective nozzle replacement data generation unit 201 outputs the generated read address information to the address selection unit 204. The defective nozzle replacement data generation unit 201 outputs an image data read request signal to the band memory 107.

  The address selector 204 outputs the read address information input from the defective nozzle alternative data generation unit 201 to the band memory 107 in synchronization with the output timing of the image data read request signal of the defective nozzle replacement data generation unit 201.

  The band memory 107 outputs the image data to the defective nozzle replacement data generation unit 201 based on the image data read request signal and the read address information (step S4).

  The defective nozzle replacement data generation unit 201 prints out the dot to be printed for the defective nozzle from the image data of the replacement target that is the input image data and the image data of the line to which the defective nozzle belongs and the image data of the three lines responsible for the replacement process. 3 lines of substitute data are generated (step S5).

  Here, the alternative data generation method includes the following alternative method using the same color ink, the alternative method of substituting the dark color ink with a similar light ink having a similar color, and the same dark ink having a similar color to the light ink One of three methods is used, with an alternative method that is replaced by.

  The similar light color ink is an ink having a hue similar to that of the dark color ink and having a low density, such as a light color ink Lk (Light black K) ink for the dark color ink K (blacK) ink. Means. Similarly, the similar dark ink means an ink having a similar hue and high density to the light color ink, such as a K ink that is a dark color ink for the Lk ink that is a light color ink.

<Alternative method with same color ink>
FIG. 8 shows an example in which a dot indicated by reference numeral 500 on the band memory 107 is a dot to be printed by a defective nozzle, that is, a defective dot print dot is replaced by a dot at an adjacent print position of the same color ink. It is.

  Here, as the print data corresponding to the dot print position indicated by the reference numeral 500, the dot data A on the ink color band memory 107 for performing the substitution process is set as the print data corresponding to the dot print position indicated by the reference numeral 500. . Further, as print data adjacent to the dot 500 print position, that is, corresponding to the print positions of the left, right, top and bottom dots of the code 500, respectively, on the band memory 107 of the ink color for performing the substitution process, respectively. The dot data B, C, D, and E are set as print data corresponding to the print positions of the dots adjacent to the dot 500.

  In FIG. 8, dot data Ain corresponds to read data of dot data A, and dot data Aout corresponds to write-back data of dot data A. The same applies to the dot data Bin to Ein and the dot data Bout to Eout.

  The print condition column in the table of FIG. 8 is based on the dot data Ain that needs to be replaced and the read dot data Bin to Ein originally present on the left, right, top, and bottom of the dot data Bout or Cout or Dout or Eout. Is a logical expression of a VHDL (Very High Speed Integrated Circuit Hardware Description Language) description indicating a conditional expression in which the print presence / absence flags of the dot data Bout to Eout are “1”. The dot data of the alternative dot candidates that substitutes for the missing dot of the code 500 is printed or not printed in the order of priority from the left, right, up and down of the dot of the code 500, that is, in the order of the dot data B, C, D, E. The defective nozzle alternative data generation unit 201 selects dot data whose flag is “0” as alternative dot data.

  Therefore, for example, the condition of whether or not to print the dot data Bout is set when the dot printing presence / absence flag of the dot data Bin is “1” as shown in the logical expression of VHDL in the table of FIG. This is a condition in which the printing presence / absence flag of the dot data Bout is “1” when the printing presence / absence flag of the dots of the dot data Ain is “1”. Here, when the dot printing presence / absence flag of the dot data Ain is “1” and the dot printing presence / absence flag of the dot data Bin is “1”, that is, when the dot data Bout cannot be replaced with the dot, The alternative dot position candidate is the position of the dot data Cin, the priority of which is the next point of the dot position of the dot data Bin. In this manner, the defective nozzle alternative data generation unit 201 sets the position of the alternative dot with respect to the dot of the dot data Ain to any of the positions from the dot data Bin to Ein, that is, the upper, lower, left, and right dots of the missing dot of reference numeral 500. Select from one dot position.

  When the print presence / absence flag of all dots from the dot data Bin to Ein is “1”, the defective nozzle replacement data generation unit 201 does not replace the dot 501. This is because, when printing is actually performed, the ink of each dot is printed in an overlapping manner, and therefore, when all the dots from the dot data Bin to Ein are scheduled to be printed, the missing dots are not noticeable. This is because it is possible to obtain a better image quality than substituting a dot farther than the dots of the dot data B to E.

<Alternative method of replacing dark ink with similar light ink>
FIG. 9 shows light cyan, light magenta, or light black, respectively, which are similar light color inks when the dots indicated by reference numeral 500 on the band memory 107 are cyan, magenta, or black missing dots that are dark inks. It is an example of an alternative method.

  Here, it is assumed that the dot data A on the dark ink band memory 107 is dark ink print data corresponding to the dot printing position indicated by reference numeral 500. Similarly, the print data of the similar light color ink corresponding to the dark color ink to be replaced corresponds to the dot print position indicated by the reference numeral 500 in the dot data a on the band memory 107 of the same light ink color. The same light ink dot data b, c, d, and e on the band memory 107 are print data of the same light ink corresponding to the print positions of the left, right, upper and lower dots of the dot 500. That is, the dot data of the replacement target ink is indicated by a capital letter code, and the dot data of the replacement implementation ink is indicated by a lowercase alphabetic letter code.

  In FIG. 9, dot data Ain corresponds to read data of dot data A, and dot data Aout corresponds to write-back data of dot data A. The same applies to dot data ain to ein and dot data aout to eout.

  The print condition column in the table of FIG. 9 includes dot data a based on dark dot data A that needs to be replaced, dot data a of light color ink that replaces the dot, and dot data b to e that exist on the left, right, and top. Or a description of a logical expression of VHDL for generating alternative data in b or c or d or e. The dot data A indicates a dot missing from the dark ink nozzle. The dot data a is data corresponding to the same print position as the dot data A on the band memory 107 of the alternative ink. The dot data b to e are data of dots positioned on the left, right, top and bottom of the dot data A.

If the replacement ink is different from the replacement target, it is possible to print also on the dot data a of reference numeral 500, so the defective nozzle replacement data generation unit 201 uses the light ink corresponding to the same print position as the dots of the dot data A. Dot data a is also included in the dot data of alternative dot candidates.

  In the same way as the replacement method using the same color ink, the defective nozzle replacement data generation unit 201 sets the light color ink dot at the same position as the dot of the reference numeral 500 and the left, right, upper and lower positions of the dot of the reference numeral 500 in descending order of priority. As shown in the description of the logical formula of VHDL in the table of FIG. 9, the printing presence / absence flag is set in the order of dot data a, dot data b, dot data c, dot data d, and dot data e. Two dots that are “0” are selected as substitute dots that replace the missing dots of the reference numeral 500.

  Here, the defective nozzle replacement data generation unit 201 selects two replacement dots for replacing the dark color ink with the same light color ink. Here, by selecting two alternative dots, it is possible to maintain the print density around the missing dots in the original image data.

<Alternative method of replacing light color ink with similar dark color ink>
FIG. 10 shows similar dark inks in the case where the dots indicated by reference numeral 500 on the band memory 107 are light cyan, light magenta, or light black missing dots, which are light color inks, respectively, by cyan, magenta, or black. It is an example of an alternative method.

  Here, it is assumed that the dot data A on the band memory 107 of light color ink is the print data of light color ink corresponding to the dot printing position indicated by the reference numeral 500. Similarly, the print data of the similar dark ink for the light-color ink to be replaced is also the same dark ink corresponding to the dot print position indicated by the reference numeral 500 in the dot data a on the band memory 107 of the similar dark ink color. Print data of the same dark ink on the band memory 107 corresponding to the print positions of the left, right, upper, and lower dots of the reference numeral 500 on the band memory 107. And That is, the dot data of the replacement target ink is indicated by a capital letter code, and the dot data of the replacement implementation ink is indicated by a lowercase alphabetic letter code.

In FIG. 10, dot data Ain corresponds to read data of dot data A, and dot data Aout corresponds to write-back data of dot data A. The same applies to dot data ain to ein and dot data aout to eout.

  The printing condition column in the table of FIG. 10 includes dot data a, b, or c from dot A that needs to be replaced, dot data a of ink that replaces the dot, and dot data b to e that exist on the left, right, top, and bottom. Or a description of a logical formula of VHDL for generating alternative data in d or e.

  Note that the dot data A indicates dots of light-colored ink nozzles missing.

  Similarly to the alternative method of substituting dark color ink with similar light color ink, when the alternative ink is different from the alternative object, the dot position a of reference numeral 500 can also be printed. The dots of dot data a are also included in the alternative dot candidates.

  The defective nozzle substitution data generation unit 201 counts the number of missing dots of light color ink from the left to the right in the scanning direction of the ink head, and performs missing dot substitution processing for every two missing dots.

  In FIG. 10, the two dots denoted by reference numerals 500 and 501 are printing dots of defective nozzles of light-colored ink, and the dot denoted by reference numeral 501 will be described as the second missing dot.

  Similar to the alternative method of replacing dark ink with similar light ink, the dark ink dots at the same position as the dot 501 and the darkness at the left, right, top and bottom positions of the dot 501 in descending order of priority. The print presence / absence flag is “0” in the order of color ink dots, that is, in the order of dot data a, dot data b, dot data c, dot data d, and dot data e as shown in the VHDL description of the table of FIG. One of the dots is selected as an alternative dot that replaces the missing dots of the two dots of the code 500 and the code 501.

  Here, the defective nozzle alternative data generation unit 201 selects one alternative dot for two missing dots. It is possible to maintain the print density around the missing dots in the original image data by selecting one alternative dot of similar dark ink for two missing dots with light color ink.

  Next, specific alternative data generation methods of the above-described three alternative methods will be described with reference to FIGS.

<Specific examples of alternative methods using the same color ink>
As a specific example of the alternative data generation method, for example, when printing only one line in the third line in the paper feed direction, the nozzle K4 of the black ink head 401K for K ink ejects dots in the even-numbered columns in the third line. A method of substituting with other nozzles of the same color K ink will be described. FIG. 11A shows a state in which the third line shown in black is printed normally when all nozzles are normal during printing with K ink. FIG. 11B shows an intermittently printed print when the nozzle K4 responsible for scanning the dots in the even-numbered columns in the third row cannot normally eject ink, such as ink clogging, when printing K ink. Indicates the state.

  FIG. 12 is a diagram illustrating an alternative method using the same color ink. Here, as an example of nozzle replacement with the same color ink, a case where the K ink nozzle K4 responsible for scanning the dots in the even-numbered columns in the third row becomes defective and is replaced by another K ink nozzle will be described as an example. . FIG. 12A shows the K ink image data in the band memory 107 before the substitute data is written, and the dots shown in black are dots whose printing presence / absence flag is “1”.

  The defective nozzle replacement data generation unit 201 determines a dot that replaces the printing dot of the nozzle K4 because the nozzle K4 responsible for scanning the dots in the even-numbered columns of the third row is a defective nozzle. FIG. 12B shows the K ink image data in the band memory 107 after the substitute data is written. The defective nozzle substitution data generation unit 201 has the printing presence / absence flag “1” for both the left and right dots of the printing dot of the nozzle K4 in charge of scanning the even-numbered columns in the third row. In accordance with the priority order, the dot above the print dot of the defective nozzle, that is, the print dot of the scan of the even-numbered column in the second row is determined as the substitute dot. The defective nozzle replacement data generation unit 201 generates replacement data by writing “1” in the determined replacement dot printing presence / absence flag and writing “0” in the defective nozzle printing dot printing presence / absence flag.

  Here, rewriting the printing presence / absence flag of the dot in the even-numbered column of the third row, which is the printing dot of the nozzle K4 which is a defective nozzle, to “0” has the following effects. That is, for example, when a part of the ink ejection port of the nozzle is blocked by the thickened ink, the ink is ejected in a direction different from the direction to be ejected, and thus printed at a position where printing should not be performed. As a result, there is a problem that image quality is degraded. Also, there is a problem that ink ejected from defective nozzles accumulates on the nozzle plate surface of the head and reaches other nozzles by performing incomplete ink ejection in defective nozzles such as ink clogging, By setting the printing presence / absence flag of the printing dot of the defective nozzle to “0” in advance, it is possible to solve these problems.

  FIG. 12C is a schematic diagram illustrating a printing state of K ink after the substitution process. FIG. 13 is a diagram in which the actual printing state is plotted based on the dot diameter when each dot is printed. FIG. 13A corresponds to the one-line printing state shown in FIG. 11A when all the nozzles are normal. In FIG. 13A, there is a deviation in the paper feed direction between the print portion of the (4N + 1) th scan indicated by the circle character “1” and the print portion of the (4N + 3) th scan indicated by the circle character “3”. It is caused by a paper feed error.

  FIG. 13B shows the case where the dot indicated by the circle character “3” of the (4N + 3) th scan assigned to the nozzle K4 is not printed due to the failure of the nozzle K4 shown in FIG. 11B. This is a drawing corresponding to an example of the printing state of the line and in a printing state where the dots assigned by the nozzle K4 are not printed. In FIG. 13B, the printing by the (4N + 1) -th scan is printed almost on one line, but compared with the printing of FIG. 13A, printing is performed due to missing dots by the nozzle K4 to be printed. Since the amount is reduced, the printing dots by the nozzle K1 are independent, and the continuity of one line is reduced.

  FIG. 13C corresponds to the printing state when the defective nozzle K4 dot substitution is performed with the same color ink shown in FIG. In the printing state of FIG. 13C, the ink amount of printing for one line is the same as the printing amount of FIG. 13A, the printing dots of the (4N + 1) th scanning, and the (4N + 4) th scanning. Therefore, the continuity of one line can be maintained.

<Specific example of alternative method of replacing dark ink with similar light color ink>
FIG. 14 is a diagram showing an alternative method of replacing dark ink with similar light color ink when printing only one line in the third line of the paper feed direction with K ink. Here, when the nozzle K4 for K ink, which is dark ink, becomes defective and the even-numbered dot in the third row that the nozzle K4 is responsible for is missing, an example is used in which it is replaced by the Lk ink nozzle for similar light ink. explain. The printing density ratio between the dark ink and the similar light ink is (2: 1).

  FIG. 14A shows the K ink image data in the band memory 107 before the substitute data is written. The white dot indicated by reference numeral 601 is a dot whose printing presence flag is “0”, and reference numeral 602 is shown. The dots indicated by are the dots whose printing presence / absence flag is “1”.

  FIG. 14B shows the K ink image data in the band memory 107 after the substitute data is written.

  FIG. 14C is a diagram illustrating the image data of Lk ink in the band memory 107 before the replacement data is written. Before the replacement, all the print presence / absence flags are “0”.

  FIG. 14D shows the image data of Lk ink in the band memory 107 after the substitute data is written.

  Since the nozzle K4 is a defective nozzle, the defective nozzle replacement data generation unit 201 uses the K ink in the line where the nozzle is missing as a substitute for the printing dot in the scan of the even-numbered third-row dot that the nozzle K4 is responsible for. And image data of Lk ink. As described above, the defective nozzle replacement data generation unit 201 follows the priority order of the dots to be replaced on the Lk ink image data, and print dot positions for scanning the even-numbered columns of the third row that the nozzle K4 is responsible for. The two dots, the dot in the even-numbered column in the third row of Lk and the left dot corresponding to Lk, are determined as alternative dots.

  In the Lk ink image data, the defective nozzle replacement data generation unit 201 sets “1” to the printing presence / absence flag of the determined two dots, that is, the dot indicated by reference numeral 604, as shown in FIG. Write. Further, as shown in FIG. 14B, the defective nozzle replacement data generation unit 201 sets “0” to the printing presence / absence flag of the defective nozzle print dot, that is, the dot denoted by reference numeral 603 in the K ink image data. By writing, alternative data is generated.

  FIG. 14E is a schematic diagram illustrating a print state of a print target when printing is performed using alternative data. In FIG. 14E, the dot denoted by reference numeral 605 is a dot printed with only Lk ink, and the dot denoted by reference numeral 606 is a dot printed by overlapping two inks of K ink and Lk ink. It is.

<Specific example of an alternative method of replacing light color ink with similar dark color ink>
FIG. 15 is a diagram illustrating an alternative method in which light-color ink is replaced with similar dark ink when only one line in the third line of the paper feed direction is printed with Lk ink. Here, when the nozzle Lk4 of the light-colored Lk ink becomes defective and the dot of the scan of the even-numbered column in the third row that the nozzle Lk4 is responsible for is missing, the nozzle of the K ink of the similar dark ink The case of substituting by will be described as an example. FIG. 15A shows image data of Lk ink in the band memory 107 before the substitute data is written. A white dot indicated by reference numeral 701 is a dot whose printing presence flag is “0”, and reference numeral 702 is shown. The dots indicated by are the dots whose printing presence / absence flag is “1”.

  FIG. 15B is a diagram showing Lk ink image data in the band memory 107 after the substitute data is written.

  FIG. 15C is a diagram illustrating the K ink image data in the band memory 107 before the replacement data is written. Before the replacement, all the print presence / absence flags are “0”.

  FIG. 15D shows the K ink image data in the band memory 107 after the substitute data is written.

  Since the nozzle Lk4 is a defective nozzle, the defective nozzle replacement data generation unit 201 determines a dot that replaces the printing dot of the nozzle Lk4 from the Lk ink image data and the K ink image data of the line from which the nozzle is missing. As described above, the defective nozzle replacement data generation unit 201 counts the number of defective nozzles on the Lk ink image data, and determines a replacement dot for every two dots to be counted.

  The defective nozzle replacement data generation unit 201 follows the priority order of the dots to be replaced on the K ink image data with the Lk corresponding to the print dot position of the scan of the even-numbered columns in the third row, which the nozzle Lk4 is responsible for. Every other dot in the even-numbered columns in the third row is determined as a substitute dot.

  The defective nozzle replacement data generation unit 201 writes “1” in the printing presence / absence flag of the determined replacement dot, that is, the dot indicated by reference numeral 704 in the K ink image data, as shown in FIG. Further, as shown in FIG. 15B, the defective nozzle replacement data generation unit 201 sets “0” to the printing presence / absence flag of the defective nozzle print dot, that is, the dot denoted by reference numeral 703 in the Lk ink image data. By writing, alternative data is generated.

  FIG. 15E is a schematic diagram illustrating a print state of a print target when printing is performed using alternative data. In FIG. 15E, a dot indicated by reference numeral 705 is a dot substituted with K ink, a dot indicated by reference numeral 706 is a dot on which Lk ink is printed, and a dot indicated by reference numeral 707 is a similar dark color. By replacing with color ink, it is a dot that becomes a missing dot in order to maintain the overall peripheral ink density.

  Of the three alternative data generation methods described above, which alternative data generation method is used may be set by user input or may be set based on the type of image data. The set generation method is stored in the defective nozzle replacement generation unit 201, and the generation method is selected based on the stored information. One generation method may be set, or a plurality of generation methods may be set with priorities determined. If the priority cannot be replaced by a higher generation method, alternative data may be generated by a lower generation method. .

  Returning to the flow of the processing operation of the entire printer 102 in FIG. 7, the defective nozzle replacement data generation unit 201 generates the address of the storage area where the replacement target image data is stored as the write address information of the band memory 107.

  The defective nozzle replacement data generation unit 201 outputs the generated write address information to the address selection unit 204. The defective nozzle replacement data generation unit 201 outputs a replacement data write request signal including replacement data to the band memory 107.

  The address selection unit 204 outputs the write address information input from the defective nozzle replacement data generation unit 201 to the band memory 107 in synchronization with the output timing of the replacement data write request signal of the defective nozzle replacement data generation unit 201.

  The band memory 107 stores the substitute data of the inputted substitute data write request signal based on the substitute data write request signal and the read address information (step S6).

  The defective nozzle replacement data generation unit 201 repeats the processes of steps S4 to S6 until the replacement process of the dot data printed by the defective nozzles in the image data stored in the specific band of the band memory 107 is completed. When the replacement process for the entire band is completed, the replacement flag indicating that the replacement process for the band has been completed is rewritten to a value indicating that the replacement has been completed, here “1”.

  The print control unit 105 reads out image data to be printed required by the print head 106 from the band memory 107 shown in FIG. 3 via the band memory control unit 104, and outputs the read image data to the print head 106. The image data is output to the print medium (step S7). Here, the print control unit 105 reads the image data when the image data stored in the band memory 107 satisfies the following conditions.

  Here, the band of the image data read by the print control unit 105 is the band of the print data in all the bands in the range required by the print head 106, that is, the image data of a predetermined number of bands output to the print head 106. Read when the writing process is finished. At this time, if the image data replacement flag for all the bands required by the print head 106 is not “1”, the image data replacement process for the band to be read is terminated without outputting to the print head 106, and the read target It remains in a waiting state until the substitution flags of all the bands of “1” become “1”.

According to the embodiment described above, when a defective nozzle that does not eject ink normally occurs, before printing, the substitute data for replacing the defective dot print dot with the print dot of the other nozzle of the image data is generated, Writing to the band memory 107 eliminates the increase in the number of scans of the ink head, so that it is possible to increase the printing work efficiency when performing printing by substituting the printing dots of defective nozzles.

  In addition, since dots are printed at missing dots due to defective nozzles or at positions adjacent to missing dots, there is an effect that it is possible to make it difficult to see the white stripes that were visually recognized at the missing dot positions.

  In addition, when printing with a print head of ink with defective nozzles, it is possible to make it difficult to see the occurrence of white streaks due to missing dots, thus reducing the ink consumption by reducing the number of cleanings and the cost of replacing the head. There is an effect that reduction can be achieved.

  In this embodiment, the priority order of the dots to be replaced is the print dot (missing dot) of the defective nozzle, the left dot of the missing dot, the right dot of the missing dot, the dot above the missing dot, and the missing dot. Although the alternative dots are determined in the order of the lower dots, the present invention is not limited to this. Here, the missing dot direction in the human eye, that is, the missing dot in the scanning direction of the ink head is easy to detect. Therefore, as an alternative dot, the dot of the ink head is higher than the upper and lower dots adjacent in the paper feed direction. It is preferable to prioritize the left and right dots adjacent in the scanning direction.

  In this embodiment, the print density ratio between the dark color ink and the similar light color ink has been described as (2: 1). However, the present invention can be applied to inks having different density ratios. In this case, the number of alternative dots is determined as the predetermined number of dots at a ratio of the inverse ratio of the density ratio.

  Further, in this embodiment, when there is no ink of the same color, such as Y ink without the light ink of the same color, the replacement is performed by another nozzle of the same color ink.

  Further, in this embodiment, the defective nozzle identification information of the defective nozzle is input from the operation panel 109 by the user's operation. However, the present invention is not limited to this. For example, the printer 102 includes a defective nozzle detection unit. The defective nozzle may be detected by the defective nozzle detection unit, and the defective nozzle identification information of the detected defective nozzle may be input to the defective nozzle replacement data generation unit 201 of the band memory control unit 104.

  In the present embodiment, the printing dot of the defective nozzle is described as a method of substituting the printing dot or the adjacent dots on the upper, lower, left, and right sides. However, the present invention is not limited to this. Any dot that can complement the missing dot of the defective nozzle when printing, such as a dot that is in an intersecting positional relationship, that is, a dot that is diagonally before or diagonally behind the printed dot of the defective nozzle May be replaced by a dot.

  Note that the printing medium feeding direction described in the present invention corresponds to the paper feeding direction, and the non-printing dot described in the present invention corresponds to the dot having the printing presence / absence flag “0”, and the printing described in the present invention. The dot corresponds to a dot having a printing presence / absence flag of “1”, and the predetermined number of dots described in the present invention is the number of alternative dots determined based on the density ratio between the ink color of the defective nozzle and the alternative ink color. In correspondence with the number of alternative dots of the similar light color ink that substitutes for the dark ink, the print dot of the defective nozzle that has reached the predetermined number of print dots according to the present invention, the light ink is replaced with the same dark ink. The number of missing dots of light-colored ink when substituting with 1 corresponds to the second dot.

The host computer 101 and the printer 102 described above have a computer system inside. The operation processes of the host I / F control unit 103, the band memory control unit 104, the print control unit 105, the print head 106, and the CPU 108 of the printer 102 are stored in a computer-readable recording medium in the form of a program. When the computer system reads out and executes this program, the above processing is performed. The computer system here includes a CPU, various memories, an OS, and hardware such as peripheral devices.

  7 is recorded on a computer-readable recording medium, and the function of the defective nozzle replacement data generation unit 201 of the printer 102 shown in FIGS. 8 to 10 is realized. Is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed, so that when a defective nozzle occurs, the printed dot of the defective nozzle is replaced. Print processing may be performed to reduce image quality degradation due to generation of defective nozzles by generating substitute image data and printing the substitute image data. Here, the “computer system” may include an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

  The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

  Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

  INDUSTRIAL APPLICABILITY The present invention can be used for an ink jet printer apparatus, an ink jet printing method, and an ink jet printing program for forming an image by ejecting ink from a plurality of nozzles and performing a plurality of head scans.

Claims (3)

A print head having one or a plurality of ink colors in which nozzle identification information is given in advance and a plurality of nozzles for ejecting ink dots are provided ;
Input means for inputting the nozzle identification information of the defective nozzle as defective nozzle identification information;
Image data storage means for storing image data to be printed;
Print rule information indicating a correspondence relationship between the nozzle identification information and the dot position at which the nozzle corresponding to the nozzle identification information is printed; the image data stored in the image data storage unit; An image in which printing of the defective nozzle is substituted by a nozzle other than the defective nozzle with respect to the printing dot of the defective nozzle and dots around the printing dot based on the defective nozzle identification information input from the input unit. When generating data as substitute data, when replacing with ink of the same color as the defective nozzle, a dot adjacent to the print dot of the defective nozzle is set as a substitute dot candidate, and one of the dots of the substitute dot candidate is selected. By rewriting non-printing dots as printing dots, the nozzles other than the defective nozzles are used for the defective nozzles. Generates image data to replace the printing as alternative data, said when alternative candidate dots all of printing dots, and is not performed alternative, defective nozzle alternatives for writing the substitute data thus generated to the image data storage means Data generation means ;
An ink jet printer that performs printing by ejecting dots of the ink while scanning the print head in a direction crossing a print medium feeding direction,
The pitch between the nozzles is twice the pitch between the dots, and printing is performed to complete the image by printing the image data in a predetermined area of the print medium by scanning a plurality of times.
The defective nozzle substitution data generation means takes in the image data corresponding to the defective nozzle from the image data storage means and the image data of the lines before and after the line, and prints the defective nozzle with respect to the print dots. A print dot at a position adjacent to the left and right and up and down is set as the substitute dot candidate, a nozzle that forms the substitute dot candidate is set as a substitute nozzle candidate, and one of the non-print dots is selected from the alternative dot candidates in the order of the left and right and top and bottom The substitute data, the nozzle forming the substitute data as the substitute nozzle, the substitute data is generated, and the image data corresponding to the defective nozzle is set as a non-printed dot and is written in the image data storage means ,
When forming dots on the print medium based on the image data written in the image data storage means, a part of the dots formed on the print medium instead of the printing of the defective nozzle is adjacent. jet printer characterized by heavy for Rukoto the dot. The ink includes ink colors having different densities of the same color material,
Whether the alternative nozzle that substitutes for the defective nozzle is a nozzle that ejects the same ink color as the ink color of the defective nozzle or a nozzle that ejects an ink color having a density different from the ink color of the defective nozzle, A selection means for selecting
When the selection nozzle selects a nozzle from which the replacement nozzle ejects an ink color having a density different from the ink color of the defective nozzle by the selection unit , the defective nozzle replacement data generation unit selects the defect from the image data storage unit. The image data of the line including the image data corresponding to the nozzle and the image data of the line before and after the line are captured, and the print dot and the print dot at positions adjacent to the right and left of the print dot are set to the print dot of the defective nozzle A substitute dot candidate is formed, the nozzle that ejects the ink color of the different density that forms the substitute dot candidate is set as a substitute nozzle candidate, a dot selected from the substitute dot candidates is set as the substitute data, and the substitute data is formed. The nozzle is used as the substitute nozzle, and the substitute data is generated and corresponds to the defective nozzle. The ink jet printer according to claim 1, the serial image data and non-printing dots, and writes the image data storage means. In the case where the defective nozzle replacement data generation unit replaces the defective nozzle with the ink of the same color material as that of the defective nozzle, the number of print dots formed by the replacement nozzle corresponds to the density of the color material of the defective nozzle ink. 3. The ink jet printer according to claim 2 , wherein the substitute data is generated so as to be a number corresponding to a density ratio of the color material of the ink of the substitute nozzle .

Images