Patent Publication Number: US-9840087-B2

Title: Liquid ejecting apparatus and liquid ejecting method

Description:
BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting apparatus and a liquid ejecting method. 
     2. Related Art 
     As an example of a liquid ejecting apparatus, a serial-type ink jet printer which performs printing on a medium by ejecting ink as an example of liquid onto the medium while moving an ejecting head in a scanning direction which intersects a transport direction of the medium is known. In such a printer, in a case in which a so-called non-ejecting nozzle (defective nozzle) in which ejection is not performed as intended by the nozzle due to mixing of dust or air bubbles into a nozzle is present, in order to resolve deterioration in image quality due to the non-ejecting nozzle, a non-ejecting complementing control operation, in which complementing is performed by ejecting ink to a region corresponding to a pixel to which the non-ejecting nozzle should eject ink using a substitute nozzle other than the non-ejecting nozzle, is executed. 
     An ink jet recording apparatus (liquid ejecting apparatus) in JP-A-2005-246840 performs multipass printing in which printing of one raster line is performed by repeating a movement of an ejecting head in a scanning direction, ejecting ink, and transporting a medium by a predetermined distance. In addition, in the liquid ejecting apparatus, when a non-ejecting nozzle is detected in the ejecting head, a plurality of substitute nozzles which perform non-ejecting complementing control are selected, and printing of a pixel which is to be recorded using the non-ejecting nozzle is performed by dispersing the ink in these substitute nozzles. 
     Meanwhile, in a liquid ejecting apparatus in the related art such as that in JP-A-2005-246840, as illustrated in  FIG. 12A , for example, in a case in which a nozzle No. 4 of an ejecting head  200  is detected as a defective nozzle, and a nozzle No. 9 is selected as a substitute nozzle, as illustrated in  FIG. 12B , during scanning of the first pass of the ejecting head  200 , nozzles No. 1 to 3 and 5, which can eject ink, form dots DT on a medium S (refer to  FIG. 12A ); however, the nozzle No. 4, which is the defective nozzle, does not form a dot DT on the medium S. 
     In such a case, in the liquid ejecting apparatus in JP-A-2005-246840, as illustrated in  FIG. 13A , in a case in which nozzles No. 6 to 10 form dots DT in a region adjacent to dots DT, which are formed using nozzles No. 1 to 5 on the medium S during scanning of the second pass of the ejecting head  200  after the medium S is transported by a predetermined distance, a dot DT is formed when the nozzle No. 9 ejects ink to a region corresponding to a pixel to which ink is to be ejected using the nozzles No. 4 on the medium S. 
     However, as illustrated in  FIG. 13B , when a position of a medium S with respect to the ejecting head  200  in a transport direction is shifted due to a transport error at a time of scanning of the second pass of the ejecting head  200 , the nozzle No. 9 ejects ink to a region on the medium S corresponding to a pixel of the nozzle No. 3, even though the nozzle No. 9 was originally to eject ink to a region on the medium S corresponding to a pixel of the nozzle No. 4. For this reason, an amount of ink of a dot DT formed in the region on the medium S corresponding to the pixel of the nozzle No. 3 increases excessively, and an amount of ink in the region on the medium S corresponding to the pixel of the nozzle No. 4 is zero. As a result, since the difference in the amount of ink between the region on the medium S corresponding to the pixel to which ink is to be ejected using the defective nozzle (nozzle No. 4) and the peripheral region thereof becomes large, there is a concern that image quality may deteriorate. 
     SUMMARY 
     An advantage of some aspects of the invention is to suppress deterioration in image quality in a case in which a region corresponding to a pixel to which a defective nozzle should eject liquid onto a medium is complemented with liquid which is ejected using a complementing nozzle. 
     Hereinafter, aspects of the invention, and operational effects thereof will be described. 
     A liquid ejecting apparatus includes an ejecting head which includes nozzle columns formed by aligning nozzles which can eject liquid onto a medium; a moving section which causes the ejecting head to move relative to the medium; an abnormal ejecting detection section which detects a defective nozzle, which is an abnormal nozzle; and a control section which controls operations of the ejecting head and the moving section, in which the ejecting head can eject the liquid onto the medium while performing scanning of a plurality of times with respect to a predetermined raster line which extends in a direction intersecting the nozzle columns, and in a case in which a defective nozzle is detected, the control section sets a nozzle use rate of a first complementing nozzle which is higher than a nozzle use rate in normal operation as a nozzle use rate of a complementing nozzle other than the defective nozzle, which forms a raster line to which the defective nozzle is allocated, and sets a nozzle use rate of a second complementing nozzle which is lower than the nozzle use rate of the first complementing nozzle as a nozzle use rate of a peripheral nozzle of the complementing nozzle. 
     According to the configuration, even if a region corresponding to a pixel to which a defective nozzle should eject liquid onto a medium is shifted with respect to the previous pass, and liquid is not ejected to the region by using a complementing nozzle, when a position of the medium with respect to an ejecting head is shifted due to an error in transporting the medium, or the like, for example, it is possible to eject liquid to the region by using the peripheral nozzle of the complementing nozzle. For this reason, since it is possible to prevent a difference in the amount of liquid between a dot formed in a region corresponding to a pixel to which a defective nozzle should eject ink onto a medium and a dot formed in the peripheral region thereof from becoming large, lightness and darkness of dots formed on the medium can be decreased, and it is possible to suppress deterioration in image quality. In addition, by definition, a defective nozzle includes a nozzle which ejects an amount of liquid smaller than that of a normal nozzle as well as a nozzle which is incapable of ejecting liquid at all. 
     In the liquid ejecting apparatus, it is preferable that the control section set a nozzle use rate of the first complementing nozzle so that a total of a nozzle use rate of the first complementing nozzle and a nozzle use rate of the defective nozzle when the ejecting head ejects liquid while performing scanning of a plurality of times becomes equal to a total of nozzle use rates in normal operation when the ejecting head ejects the liquid while performing scanning of a plurality of times. 
     According to the configuration, when a position of a medium with respect to the ejecting head is not shifted due to an error in transporting the medium, or the like, for example, an amount of liquid of a dot formed using a normal nozzle and an amount of liquid of a dot formed in a region corresponding to a pixel to which a defective nozzle should eject liquid on the medium become equal. For this reason, it is possible to reduce the variation in the amount of liquid between a region corresponding to the pixel to which the defective nozzle should eject ink on the medium and a region to which a normal nozzle ejects ink. 
     In the liquid ejecting apparatus, it is preferable that the control section set a nozzle use rate of a peripheral nozzle which is lower than that of the nozzle use rate in normal operation as a nozzle use rate of the peripheral nozzle of the defective nozzle. 
     According to the configuration, a dot formed of a small amount of liquid is formed when the peripheral nozzle with a low nozzle use rate ejects liquid to the peripheral region of the region corresponding to the pixel to which the defective nozzle should eject liquid on the medium. In addition, even when a position of the medium with respect to the ejecting head is shifted thereafter, and a complementing nozzle ejects liquid to the peripheral region on the medium, it is possible to prevent the amount of liquid of the dot formed in the peripheral region from being excessively increased. Accordingly, it is possible to reduce the variation in the amount of liquid between the dot formed in the region corresponding to the pixel to which the defective nozzle should eject liquid on the medium and the dot formed in the peripheral region thereof. 
     In the liquid ejecting apparatus, it is preferable that the control section set the nozzle use rate of the peripheral nozzle to be high when the peripheral nozzle is separated from the defective nozzle in a nozzle column direction, and set the nozzle use rate of the second complementing nozzle to be low when the second complementing nozzle is separated from the complementing nozzle in the nozzle column direction. 
     According to the configuration, even when a position of a medium with respect to the ejecting head is shifted due to an error in transporting the medium, or the like, for example, it is possible to further reduce the variation in the respective amounts of liquid of the dot formed in a region corresponding to the pixel to which the defective nozzle should eject liquid on a medium and of the dot formed in the peripheral region thereof. 
     In the liquid ejecting apparatus, it is preferable that the control section set the nozzle use rate of the second complementing nozzle and the nozzle use rate of the peripheral nozzle so that a total of the nozzle use rate of the second complementing nozzle and the nozzle use rate of the peripheral nozzle when the ejecting head ejects the liquid while performing scanning of a plurality of times becomes equal to a total of the nozzle use rates in normal operation when the ejecting head ejects the liquid while performing scanning of a plurality of times. 
     According to the configuration, when a position of a medium with respect to the ejecting head is not shifted due to an error in transporting the medium, or the like, for example, an amount of liquid of a dot formed using a normal nozzle and an amount of liquid of a dot formed in the peripheral region of the region corresponding to the pixel to which the defective nozzle should eject liquid on the medium become equal. For this reason, it is possible to suppress the variation in the amount of liquid in each dot. 
     In the liquid ejecting apparatus, it is preferable that the control section set a nozzle use rate in normal operation so that a nozzle use rate of nozzles in the nozzle column decreases from a nozzle at the center toward a nozzle at an end. 
     According to the configuration, in a case in which a position of a medium with respect to the ejecting head is shifted due to an error in transporting the medium, for example, it is possible to reduce the degree of influence of the shifting compared to a case in which the nozzle use rate of a nozzle column is constant. 
     In the liquid ejecting apparatus, it is preferable that the control section set a plurality of the complementing nozzles and set respective nozzle use rates of the plurality of complementing nozzles so that a total of the nozzle use rates of the plurality of complementing nozzles becomes equal to the nozzle use rate of the first complementing nozzle. 
     According to the configuration, since a plurality of complementing nozzles are set, it is possible to prevent a nozzle use rate of one complementing nozzle from becoming excessively high. For this reason, it is possible to suppress shortening of the service life of the complementing nozzle. 
     In the liquid ejecting apparatus, it is preferable that the control section increase the number of scanning times previously set for the ejecting head to form the raster line in a case in which the defective nozzle is present and in which it is not possible to set a complementing nozzle which complements the defective nozzle. 
     According to the configuration, even when a nozzle which can place liquid droplets on the same pixel as the pixel to which the defective nozzle should eject liquid is the defective nozzle, it is possible to set a nozzle other than the nozzle to be a complementing nozzle by increasing the number of scanning times of the ejecting head. For this reason, it is possible to eject liquid to a pixel to which a defective nozzle should eject liquid using a complementing nozzle. 
     A liquid ejecting method in a liquid ejecting apparatus which includes an ejecting head which includes nozzle columns formed by aligning nozzles which can eject liquid onto a medium, a moving section which causes the ejecting head to move relative to the medium, and an abnormal ejecting detection section which detects a defective nozzle which is an abnormal nozzle, in which the ejecting head can eject the liquid onto the medium while performing scanning of a plurality of times with respect to a predetermined raster line which extends in a direction intersecting the nozzle columns, the method including setting a nozzle use rate of a first complementing nozzle which is higher than a nozzle use rate in normal operation as a nozzle use rate of a complementing nozzle other than the defective nozzle, which forms a raster line to which the defective nozzle is allocated and setting a nozzle use rate of a second complementing nozzle which is lower than that of the first complementing nozzle as a nozzle use rate of a peripheral nozzle of the complementing nozzle, in a case in which the defective nozzle is detected. 
     According to the configuration, even when a region corresponding to a pixel to which a defective nozzle should eject liquid on a medium is shifted with respect to the previous pass, and when it is not possible to eject liquid to the region by using a complementing nozzle, when a position of the medium with respect to a ejecting head is shifted due to an error in transporting the medium, for example, it is possible to eject liquid to the region by using the peripheral nozzle of the complementing nozzle. For this reason, it is possible to suppress deterioration in image quality since the difference in the amount of liquid between a dot formed in the region corresponding to the pixel to which the defective nozzle should eject liquid on the medium and a dot formed in the peripheral region thereof is suppressed so as not to become large. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements. 
         FIG. 1  is a perspective view of one embodiment of a liquid ejecting apparatus. 
         FIGS. 2A and 2B  are planar schematic views which illustrate an ejecting head in the liquid ejecting apparatus, and the periphery thereof. 
         FIG. 3A  is a schematic view which illustrates a relationship between a nozzle column and a use amount of ink in a case in which a defective nozzle is not detected, in the liquid ejecting apparatus, and  FIG. 3B  is a schematic view which illustrates a relationship between a nozzle column in a region which is illustrated using a dashed line in  FIG. 3A  and a total use amount of ink in the first pass and the second pass. 
         FIG. 4  is a block diagram which illustrates a control configuration of the liquid ejecting apparatus. 
         FIG. 5A  is a schematic view which illustrates a part of a nozzle column in the first pass in a case in which a defective nozzle is present, and  FIG. 5B  is a schematic view which illustrates a part of a nozzle column in the second pass. 
         FIG. 6  is a table which illustrates a relationship of nozzle use rates among a defective nozzle, the peripheral nozzle, a complementing nozzle, and a supplementary complementing nozzle in the liquid ejecting apparatus. 
         FIG. 7A  is a schematic view which illustrates a relationship between a nozzle column and a use amount of ink when ink is ejected from each nozzle based on a normal mask pattern in a case in which a defective nozzle is detected, in the liquid ejecting apparatus, and  FIG. 7B  is a schematic view which illustrates a relationship between a nozzle column in a region which is illustrated using a dashed line in  FIG. 7A  and a total use amount of ink in the first pass and the second pass. 
         FIG. 8A  is a schematic view which illustrates a relationship between a nozzle column and a use amount of ink when ink is ejected from each nozzle based on a changed mask pattern in a case in which a defective nozzle is detected, in the liquid ejecting apparatus, and  FIG. 8B  is a schematic view which illustrates a relationship between a nozzle column in a region which is illustrated using a dashed line in  FIG. 8A  and a total use amount of ink in the first pass and the second pass. 
         FIG. 9  is a flowchart which describes a failure complementing control which is performed by the liquid ejecting apparatus. 
         FIGS. 10A to 10C  are diagrams for describing operations of the liquid ejecting apparatus, and in which  FIGS. 10A and 10B  are schematic views which illustrate a part of a nozzle column, and  FIG. 10C  is a schematic view which illustrates dots which are formed on a sheet using an ejecting head. 
         FIG. 11  is a base view of an ejecting head in a modification example. 
         FIG. 12A  is a schematic view which illustrates a positional relationship between an ejecting head and a medium in a liquid ejecting apparatus in the related art, and  FIG. 12B  is a schematic view when ink is ejected to the medium in a defective nozzle and other nozzles in the first pass in  FIG. 12A . 
         FIG. 13A  is a schematic view which illustrates a positional relationship between an ejecting head and a medium in the liquid ejecting apparatus in the related art, and  FIG. 13B  is a schematic view when ink is ejected to the medium in a defective nozzle and other nozzles in the second pass in  FIG. 13A . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, one embodiment of a liquid ejecting apparatus will be described with reference to the drawings. In addition, the liquid ejecting apparatus according to the embodiment is configured as, for example, an ink jet printer which performs printing by ejecting ink as an example of liquid onto a medium. In addition, the printer is a so-called serial-type printer with a printing system with which printing is performed by moving a carriage (ejecting head) in a direction intersecting a transport direction of a medium. 
     As illustrated in  FIG. 1 , a printer  11  as an example of the liquid ejecting apparatus includes a lower box-shaped frame  12  of which a part including the upper part is opened, and a supporting table  13  which supports a sheet P as an example of a medium is arranged on a base portion of the frame  12 . A guide member  14  which extends in a longitudinal direction of the supporting table  13  is extended at a position on the upper part of the supporting table  13  in a state in which both end portions are supported by the frame  12 . A carriage  15  as an example of a moving section is supported by the guide member  14  so as to reciprocate in a scanning direction X. In the carriage  15 , an ejecting head  30  is provided at a position at which the ejecting head can face the supporting table  13 . In addition, a plurality of liquid containers  16  (four in the embodiment) which accommodate ink are detachably mounted on the carriage  15 . 
     In addition, as an example, black (K), cyan (C), magenta (M), and yellow (Y) ink is accommodated in the four liquid containers  16 . Printing can be performed when ink supplied from each liquid container  16  is ejected onto a sheet P from the ejecting head  30  while moving in the scanning direction X along with the carriage  15 . 
     A driving pulley  17  and a driven pulley  18  are rotatably supported at both end portions of the frame  12 , which are separated by a predetermined distance in the scanning direction X. An output shaft of a carriage motor  19  as a driving source of the carriage  15  is connected to the driving pulley  17 . An endless timing belt  20  is placed on the pair of pulleys  17  and  18 . When a driving force of the carriage motor  19  is transmitted to the carriage  15  through the timing belt  20 , the carriage  15  reciprocates in the scanning direction X while being guided by the guide member  14 . 
     In addition, in the printer  11 , a transport motor  21  and various rollers, which are rotated using a driving force from the transport motor  21 , are provided. In addition, when each roller rotates using the driving force of the transport motor  21 , a sheet P is transported onto the supporting table  13  in a transport direction Y which is a direction intersecting (orthogonal, preferably) the scanning direction X. 
     In addition, in the inside of the frame  12 , a maintenance device  22  for performing maintenance of the ejecting head  30  is provided in a non-printing region as one end portion in a region in which the carriage  15  moves. That is, in the non-printing region, it is possible to perform brushing in which ink is ejected into a cap  23  from the ejecting head  30 , cleaning in which ink is discharged from an ink supply system through the ejecting head  30 , and the like. 
     As illustrated in  FIGS. 2A and 2B , a plurality of (four in the embodiment) nozzle columns  31 K,  31 C,  31 M, and  31 Y, which are formed of a plurality of nozzles  32  aligned in the transport direction Y at a constant nozzle pitch, are formed on a nozzle forming face as a base of the ejecting head  30 . These nozzle columns  31 K,  31 C,  31 M, and  31 Y are arranged at intervals in the scanning direction X. In addition, in  FIGS. 2A and 2B , only ten nozzles  32  are illustrated in order to simplify the figures; however, in practice, the respective nozzle columns  31 K,  31 C,  31 M, and  31 Y are formed of 360 nozzles  32 , for example. In addition, in  FIGS. 2A and 2B , each nozzle  32  is denoted by a solid line for ease of description. In addition, the nozzle columns  31 K,  31 C,  31 M, and  31 Y can eject ink of four colors of black (K), cyan (C), magenta (M), and yellow (Y), respectively. An abnormal ejecting detection section  33  (refer to  FIG. 4 ) which detects driving elements (not illustrated) of the same number as the nozzle  32  and which detects residual vibration of the driving elements are provided in the ejecting head  30 . In addition, the abnormal ejecting detection section  33  detects damped vibration of a vibrating plate (not illustrated) which vibrates due to driving of the driving element as residual vibration. In this manner, a nozzle among nozzles  32  in which intended ejection of ink is not performed (hereinafter, referred to as “defective nozzle”) is detected. In addition, the defective nozzle is considered an abnormal nozzle, for example, a nozzle which ejects only an amount of ink which is smaller than an amount of ink which is ejected from a normal nozzle, in addition to a nozzle from which ink is not ejected at all. 
     In the printer  11  with such a configuration, the ejecting head  30  ejects ink which is supplied from the liquid container  16  (refer to  FIG. 1 ) onto a sheet P, which is transported to the supporting table  13 , from each nozzle  32  while moving in the scanning direction X each time printing data of a raster line of one column, which is rasterized as a printing job, is received from a host computer  100  (refer to  FIG. 4 ). Printing of an image, or the like, is performed on a sheet P by repeating this job. 
     In addition, the printer  11  includes a one-pass printing mode in which printing is performed on a sheet P while causing the ejecting head  30  to perform one forward scanning movement or one backward scanning movement in the scanning direction X with respect to a raster line of one column extending in a direction intersecting (orthogonal in the embodiment) the nozzle columns  31 K,  31 C,  31 M, and  31 Y, and a multipass printing mode in which printing is performed on a sheet P while causing the ejecting head  30  to perform a plurality of scanning movements in the scanning direction X with respect to a raster line of one column. 
     In a case of a printing mode of two passes in particular, in the multipass printing mode, as illustrated in  FIG. 2A , the printer  11  performs printing of the second pass using the ejecting head  30  after transporting a sheet P in the transport direction Y by a distance of approximately one half the width of the ejecting head  30 , as illustrated in  FIG. 2B , after completing printing of the first pass using the ejecting head  30 . For this reason, a predetermined raster line on a sheet P is formed using a plurality of nozzle regions of nozzles  32  which execute printing of the first pass (nozzles in shaded region in  FIG. 2A ) and nozzles  32  which execute printing of the second pass (nozzles in shaded region in  FIG. 2B ). 
     As illustrated in  FIG. 3A , when image data for ejecting ink to all pixels is input, in the nozzle column  31 K (refer to  FIGS. 2A and 2B ) of the ejecting head  30 , a use amount of ink is largest at the center of the nozzle column  31 K in the transport direction Y, and the use amount of ink gradually decreases toward both ends of the nozzle column  31 K. In addition, as illustrated in  FIG. 3A , since a sheet P is transported by a half of the full length of the nozzle column  31 K in the transport direction Y, in the nozzle column  31 K in the second pass, a region in which a center nozzle  32  in the transport direction Y of the nozzle column  31 K in the first pass performs ejecting on a sheet P, and a region in which a nozzle  32  at an end on the upstream side in the transport direction Y of the nozzle column  31 K in the second pass performs ejecting on the sheet P become the same region. In addition, a region in which a nozzle  32  at an end on the downstream side in the transport direction Y of the nozzle column  31 K in the first pass performs ejecting on the sheet P, and a region in which the center nozzle  32  in the transport direction Y of the nozzle column  31 K in the second pass performs ejecting on the sheet P become the same region. In this manner, as illustrated in  FIG. 3B , in a rectangular region denoted by a dashed line in  FIG. 3A , for example, an amount of ink in a region in which the nozzle  32  in the first pass and the nozzle  32  in the second pass overlap in the transport direction Y becomes equal to a regulated use amount which is a necessary amount of ink in the region. That is, when the ratio of an amount of ink which is ejected using a nozzle  32  in the region of each pass to the regulated use amount is set as a nozzle use rate (%), a total of a nozzle use rate of the nozzle  32  in the first pass, and a nozzle use rate of the nozzles  32  in the second pass becomes “100%”. In addition, in the following descriptions, there is a case in which a nozzle use rate of each nozzle  32  which is illustrated in  FIG. 3A  is referred to as a “nozzle use rate at a normal time”. In addition, the above described nozzle use rate at a normal time is similarly set with respect to the nozzle columns  31 C,  31 M, and  31 Y. 
     In addition, as illustrated in  FIG. 4 , the printer  11  includes a control device  40  for controlling operations of the printer  11 . The control device  40  includes a CPU, a RAM, a ROM, and the like, and the CPU executes various control programs or processing programs which are stored in the ROM, or the like. The control device  40  is configured by including a printing control section  41 , a transport control section  44 , and the like, as an example of a control section. 
     In addition, a printing job which is generated by the host computer  100  is input to the control device  40 . The printing control section  41  and the transport control section  44  of the control device  40  control an ejecting state of ink from the ejecting head  30 , and a transport state of a sheet P using the transport motor  21  based on the printing job. 
     The printing control section  41  includes a complementing nozzle setting section  42  which performs setting so that ink is ejected using a complementing nozzle as a substitute nozzle of a defective nozzle, and a mask pattern changing section  43  which changes an ejecting state of ink of each nozzle  32  in order to set the complementing nozzle, in the same pixel as the pixel to which the defective nozzle should eject ink. 
     A detection signal of the abnormal ejecting detection section  33  is input to the printing control section  41 . The printing control section  41  detects a defective nozzle in each nozzle  32  of the ejecting head  30  based on the detection signal. As an example of the detecting method, it is possible to use an abnormal ejecting detecting method which is described in Japanese Patent No. 3794431. 
     As illustrated in  FIG. 5A , when a defective nozzle  32 E is detected in the nozzle column  31 K, as an example, the complementing nozzle setting section  42  sets a complementing nozzle (hereinafter, referred to as “complementing nozzle  32 A”) which can drop ink droplets to the same pixel as the pixel to which the defective nozzle  32 E should eject ink as illustrated in  FIG. 5B . In addition, hereinafter, descriptions will be made on the premise that the defective nozzle  32 E is detected in the nozzle column  31 K. 
     In addition, the complementing nozzle setting section  42  sets the peripheral nozzle (hereinafter, referred to as “peripheral nozzle  32 C”) of the defective nozzle  32 E in the nozzle column  31 K, and the peripheral nozzle of the complementing nozzle  32 A (hereinafter, referred to as “supplementary complementing nozzle  32 B”) in the nozzle column  31 K. As is denoted by Nos. 1 to 5 in  FIG. 5A , the peripheral nozzle  32 C is configured of a nozzle which is adjacent to the defective nozzle  32 E, and a plurality of nozzles which are continuously adjacent to each other from the adjacent nozzle, like the five nozzles  32  on the upstream side in the transport direction Y and the five nozzles  32  on the downstream side in the transport direction Y with the defective nozzle  32 E as the center. As is denoted by Nos. 1 to 5 in  FIG. 5B , the supplementary complementing nozzle  32 B is configured of a nozzle which is adjacent to the complementing nozzle  32 A, and a plurality of nozzles which are continuously adjacent to each other from the adjacent nozzle, like the five nozzles  32  on the upstream side in the transport direction Y and the five nozzles  32  on the downstream side in the transport direction Y with the complementing nozzle  32 A as the center. The supplementary complementing nozzle  32 B can drop ink droplets to the same pixel as the pixel to which the peripheral nozzle  32 C ejects ink. In addition, also in a case in which a defective nozzle is detected in the nozzle columns  31 C,  31 M, and  31 Y, the same setting as those of the complementing nozzle  32 A, the supplementary complementing nozzle  32 B, and the peripheral nozzle  32 C in the nozzle column  31 K is performed. 
     The printing control section  41  prepares a mask pattern in which a nozzle use rate of each nozzle  32  is regulated for each pass, and sets an ejecting state of ink per one pass based on the mask pattern, with reference to  FIGS. 4 to 5B . In addition, the printing control section  41  prepares a mask pattern which is stored in the RAM (hereinafter, referred to as “normal mask pattern”), for example, when a defective nozzle is not detected, and each nozzle  32  (refer to  FIGS. 2A and 2B ) ejects ink based on the mask pattern. Meanwhile, in the printing control section  41 , when the defective nozzle  32 E is detected, the complementing nozzle setting section  42  sets the complementing nozzle  32 A. Thereafter, the mask pattern changing section  43  changes the normal mask pattern to a mask pattern (hereinafter, referred to as “changed mask pattern”) which includes the complementing nozzle  32 A, or the like, which can drop ink droplets to the same pixel as the pixel to which the defective nozzle  32 E should eject ink. 
     The mask pattern changing section  43  generates a changed mask pattern using a table which denotes a relationship among a nozzle use rate of the complementing nozzle  32 A (hereinafter, referred to as “nozzle use rate of first complementing nozzle”), a nozzle use rate of the supplementary complementing nozzle  32 B (hereinafter, referred to as “nozzle use rate of second complementing nozzle”), and a nozzle use rate of the peripheral nozzle  32 C (hereinafter, referred to as “nozzle use rate of peripheral nozzle”) which is exemplified in  FIG. 6 . As illustrated in  FIG. 6 , the nozzle use rate of the second complementing nozzle is set to a value which is lower than the nozzle use rate of the first complementing nozzle, and is set to a low value when being a nozzle  32  which is separated from the complementing nozzle  32 A in the nozzle column direction (transport direction Y), among the supplementary complementing nozzles  32 B. In addition, the nozzle use rate of the peripheral nozzle is set to a value which is higher than that of the defective nozzle  32 E, and is lower than the nozzle use rate of the first complementing nozzle and the nozzle use rate at a normal time, and is set to a high value when being a nozzle  32  which is separated from the defective nozzle  32 E in the nozzle column direction (transport direction Y), among the peripheral nozzles  32 C. 
     As illustrated in  FIG. 7A , in the normal mask pattern, when a defective nozzle  32 E is generated, an amount of ink of the defective nozzle  32 E becomes “zero”. For this reason, as illustrated in  FIG. 7B , even when it is assumed that printing is performed in a two-pass printing mode using the normal mask pattern, an amount of ink of a dot which is formed in a region corresponding to a pixel to which the defective nozzle  32 E should perform ejecting on a sheet P becomes excessively low. 
     In such a case, as illustrated in  FIG. 8A , in the changed mask pattern, an amount of ink of the defective nozzle  32 E becomes “zero”, and a valley shape is formed as if an amount of ink of the peripheral nozzle  32 C increases by being separated from the defective nozzle  32 E in the transport direction Y. Meanwhile, in the changed mask pattern, an amount of ink of the complementing nozzle  32 A becomes the regulated use amount, and a mountain shape is formed as if an amount of ink of the supplementary complementing nozzle  32 B decreases by being separated from the complementing nozzle  32 A in the transport direction Y. In addition, a valley shape and a mountain shape are formed so that a total use rate of the nozzle use rate of the defective nozzle  32 E and the nozzle use rate of the first complementing nozzle, and a total use rate of the nozzle use rate of the peripheral nozzle and the nozzle use rate of the second complementing nozzle become “100”, respectively, that is, as illustrated in  FIG. 8B , a total of an amount of ink in the first pass and an amount of ink in the second pass of the ejecting head  30  becomes the regulated use amount. 
     In addition, the printing control section  41  (refer to  FIG. 4 ) forms a changed mask pattern from the normal mask pattern when the defective nozzle  32 E (refer to  FIGS. 5A and 5B ) is detected, and executes a defect complementing control which controls an ejecting state of ink using the ejecting head  30  (refer to  FIGS. 2A and 2B ) based on the changed mask pattern. The printing control section  41  receives a printing job from the host computer  100  (refer to  FIG. 4 ), and then executes a defect complementing control before executing printing of an image, or the like, on a sheet P based on the printing job. The defect complementing control is executed according to a processing procedure in the flowchart in  FIG. 9 . In addition, in the following descriptions, each constituent element of the printer  11  to which a reference numeral is attached denotes each constituent element of the printer  11  in  FIG. 1  to  FIG. 2B  and  FIG. 4 . 
     First, the printing control section  41  detects a defective nozzle from a nozzle  32  of the ejecting head  30  based on a detection signal of the abnormal ejecting detection section  33  (step S 11 ). In addition, the printing control section  41  sets a complementing nozzle, a supplementary complementing nozzle, and a peripheral nozzle in a set printing mode based on the detected defective nozzle (step S 12 ). For example, as illustrated in  FIG. 5A , in a case in which the printing mode is set to a two-pass printing mode, when one defective nozzle  32 E is detected, the complementing nozzle  32 A, the supplementary complementing nozzle  32 B, and the peripheral nozzle  32 C are set as illustrated in  FIGS. 5A and 5B . 
     Subsequently, the printing control section  41  determines whether or not there is a nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle should eject ink (step S 13 ). Here, for example, as illustrated in  FIGS. 5A and 5B , in a case in which the complementing nozzle  32 A itself as the nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink is a defective nozzle, it is determined that there is no nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink. Meanwhile, in a case in which the complementing nozzle  32 A itself is not a defective nozzle, it is determined that there is a nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink. 
     The printing control section  41  increases the number of passes in the multipass printing mode (step S 14 ), when it is determined that there is no nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle should eject ink (No in step S 13 ), and returns to step S 12 . In this manner, by increasing the number of passes in the multipass printing mode, a nozzle other than the complementing nozzle  32 A is set to the nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink. 
     Meanwhile, the printing control section  41  respectively calculates a nozzle use rate of the first complementing nozzle, a nozzle use rate of the second complementing nozzle, and a nozzle use rate of the peripheral nozzle (step S 15 ) in a state in which the number of passes in the multipass printing mode is maintained, when it is determined that there is the nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink (Yes in step S 13 ). In addition, the printing control section  41  generates a changed mask pattern from the normal mask pattern based on these nozzle use rates (step S 16 ), and generates a printing command for performing printing on a sheet P using the ejecting head  30  based on the changed mask pattern (step S 17 ). 
     Subsequently, operations of the printer  11  according to the embodiment will be described using  FIGS. 10A to 10C . 
     The printing control section  41  controls an ejecting state of ink of the ejecting head  30  so that an amount of ink of all of pixels to which ink is ejected becomes the regulated use amount by executing the defect complementing control. For example, in a case of the two-pass printing mode, as illustrated in  FIG. 10A , when a defective nozzle  32 E is detected in nozzles  32  in the first pass, the peripheral nozzle  32 C as the peripheral nozzle of the defective nozzle  32 E is set. In addition, as illustrated in  FIG. 10B , a complementing nozzle  32 A as a nozzle which can drop ink droplets on the same pixel as the pixel to which a defective nozzle  32 E should eject ink, and a supplementary complementing nozzle  32 B as the peripheral nozzle of the complementing nozzle  32 A are set, in nozzles  32  in the second pass. In addition, as denoted in the table in  FIG. 6 , each nozzle use rate is set so that a total nozzle use rate of the nozzle use rate of the defective nozzle  32 E and the nozzle use rate of the first complementing nozzle as the complementing nozzle  32 A, and a total nozzle use rate of the nozzle use rate of the peripheral nozzle as the peripheral nozzle  32 C and the nozzle use rate of the second complementing nozzle as the supplementary complementing nozzle  32 B become “100%”, respectively. 
     Meanwhile, when a printing region in a sheet P in the first pass is transported to regions of the nozzle columns  31 K,  31 C,  31 M, and  31 Y of the ejecting head  30  in the second pass due to a position shift of the sheet P with respect to the ejecting head  30  because of an error in transporting the sheet P, there is a case in which a positional relationship between the printing region and a nozzle  32  is slightly shifted in the transport direction Y. Due to this, as illustrated in  FIG. 10B , for example, when the sheet P is shifted by one nozzle in the transport direction Y with respect to the ejecting head  30  at a time of performing printing in the second pass using the ejecting head  30 , as illustrated in  FIG. 10C , each total nozzle use rate does not become “100%”. 
     However, a nozzle use rate of the peripheral nozzle which is adjacent to the defective nozzle  32 E in the peripheral nozzles  32 C is as small as “5%”. For this reason, even when the complementing nozzle  32 A ejects ink in a region to which the peripheral nozzle  32 C which is adjacent to the defective nozzle  32 E eject ink on the sheet P, a total nozzle use rate of the peripheral nozzle  32 C and the complementing nozzle  32 A becomes “105%”. Accordingly, it is possible to prevent an amount of ink of a dot DT which is formed in the region from becoming excessively large with respect to the regulated use amount. In addition, a nozzle use rate of the second complementing nozzle as the supplementary complementing nozzle  32 B which is adjacent to the complementing nozzle  32 A is as large as “95%”. For this reason, even when the supplementary complementing nozzle  32 B which is adjacent to the complementing nozzle  32 A ejects ink in a region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P, a total nozzle use rate of the supplementary complementing nozzle  32 B and the defective nozzle  32 E becomes “95%”. Accordingly, it is possible to prevent an amount of ink of a dot DT which is formed in the region from becoming excessively small with respect to the regulated use amount. Accordingly, as in the printer in the related art which is illustrated in  FIGS. 13A and 13B , it is possible to prevent a difference in amount of ink between a dot DT which is formed in the region corresponding to the pixel to which the defective nozzle should eject ink and a dot DT which is formed in a region which is adjacent to the region from becoming excessively large on a medium (sheet). 
     In addition, since a nozzle use rate of the peripheral nozzle as the peripheral nozzle  32 C is increased by being separated from the defective nozzle  32 E in the transport direction Y, and meanwhile the nozzle use rate of the second complementing nozzle as the supplementary complementing nozzle  32 B is decreased by being separated from the complementing nozzle  32 A in the transport direction Y, it is possible to prevent the nozzle use rate from being excessively increased or decreased even when the transport error occurs. For this reason, a variation in amount of ink of a dot DT which is formed in a region which is adjacent to a sheet P in the transport direction Y decreases, and lightness and darkness of an image becomes inconspicuous. In addition, as illustrated in  FIG. 10C , since a nozzle use rate is changed while repeating an increase and decrease gradually in the transport direction Y, an amount of ink of a dot DT which is formed in the transport direction Y is changed while repeating an increase and decrease gradually in the transport direction Y. For this reason, a variation in amount of ink of a dot DT decreases, and lightness and darkness of an image becomes inconspicuous. 
     According to the printer  11  in the embodiment, it is possible to obtain the following effects. 
     (1) The printing control section  41  sets the complementing nozzle  32 A, and the supplementary complementing nozzle  32 B as the peripheral nozzle of a nozzle column of the complementing nozzle  32 A using the complementing nozzle setting section  42 . For this reason, in a case of printing a raster line of one column on a sheet P using a plurality of times of scanning of the ejecting head  30 , even when the complementing nozzle  32 A is incapable of ejecting ink to a region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P due to an error in transporting the sheet P, the supplementary complementing nozzle  32 B can eject ink to the region. For this reason, it is possible to suppress deterioration in image quality since a difference in amount of ink between a dot DT which is formed in the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P and a dot DT which is formed in the peripheral region thereof decreases. 
     (2) In the printing control section  41 , it is set so that a total of the nozzle use rate of the first complementing nozzle and the nozzle use rate of the defective nozzle  32 E for forming a raster line of one column is the same as a total of the nozzle use rates at the normal time for forming a raster line of one column. For this reason, when there is no error in transporting of a sheet P, an amount of ink of a dot DT which is formed in the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P, and an amount of ink of a dot DT which is formed using a normal nozzle  32  become equal. For this reason, it is possible to suppress deterioration in image quality. 
     (3) The printing control section  41  sets the nozzle use rate of the peripheral nozzle  32 C as the peripheral nozzle  32 C of the defective nozzle  32 E to a nozzle use rate which is lower than a nozzle use rate at a normal time. For this reason, a dot DT with a small amount of ink is formed when the peripheral nozzle  32 C with a low nozzle use rate eject ink with respect to the peripheral region of the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P. In addition, even when a position of the sheet P with respect to the ejecting head  30  is shifted due to an error in transporting of the sheet P thereafter, and the complementing nozzle  32 A eject ink to the peripheral region on the sheet P, it is possible to prevent an amount of ink of a dot DT which is formed in the peripheral region thereof from excessively increasing. Accordingly, a variation in amount of ink between the dot DT which is formed in the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P and the dot DT which is formed in the peripheral region thereof is suppressed. For this reason, it is possible to suppress deterioration in image quality. 
     (4) The printing control section  41  sets a nozzle use rate of the peripheral nozzle as the peripheral nozzle  32 C to be high when being separated from the defective nozzle  32 E in the nozzle column direction, and sets a nozzle use rate of the second complementing nozzle as the supplementary complementing nozzle  32 B to be low when being separated from the complementing nozzle  32 A in the nozzle column direction. For this reason, even when a position of a sheet P with respect to the ejecting head  30  is shifted due to an error in transporting of the sheet P, or the like, since the complementing nozzle  32 A eject ink to the region corresponding to a pixel with a low nozzle use rate of the peripheral nozzle on the sheet P, it is possible to prevent an amount of ink of a dot DT which is formed in the region from becoming excessively large. In addition, since ink is ejected to a region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P, using the second complementing nozzle with the high nozzle use rate among the supplementary complementing nozzles  32 B, it is possible to prevent an amount of ink of a dot DT which is formed in the region from becoming excessively small. In this manner, respective variations in amount of ink of the dot DT which is formed in the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P, and an amount of ink of the dot DT which is formed in the peripheral region thereof are decreased. Accordingly, lightness and darkness of a dot DT which is formed on the sheet P is reduced, and it is possible to further suppress deterioration in image quality. 
     (5) In the printing control section  41 , it is set so that a total of the nozzle use rate of the second complementing nozzle and the nozzle use rate of the peripheral nozzle for forming a raster line of one column is equal to a total of the nozzle use rates at the normal time for forming a raster line of one column. For this reason, when there is no error in transporting of a sheet P, an amount of ink of a dot DT which is formed in the region corresponding to the pixel to which the defective nozzle  32 E should eject ink on the sheet P becomes equal to an amount of ink of a dot DT which is formed using a normal nozzle  32 . For this reason, it is possible to further suppress deterioration in image quality. 
     (6) The printing control section  41  sets an amount of ink of a nozzle  32  so that an amount of ink which is ejected from a nozzle  32  becomes small toward both ends from the center of the nozzle columns  31 K,  31 C,  31 M, and  31 Y in the transport direction Y. For this reason, in a case in which a position of a sheet P with respect to the ejecting head  30  is shifted in the transport direction Y due to an error in transporting of the sheet P, for example, it is possible to it is possible to reduce a degree of influences compared to a case in which a nozzle use rate of a nozzle column is constant. 
     (7) The printing control section  41  sets a nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink by increasing the number of passes of the ejecting head  30 , in a case in which there is no nozzle which can drop ink droplets on the same pixel as the pixel to which the defective nozzle  32 E should eject ink. Due to this, it is possible to reduce the frequency of not ejecting ink to the same pixel as the pixel to which the defective nozzle  32 E should eject ink. 
     Modification Example 
     The above described embodiment may be changed to another embodiment below. 
     The nozzle columns  31 K,  31 C,  31 M, and  31 Y of the ejecting head  30  according to the embodiment may be configured using two nozzle columns in each color as illustrated in  FIG. 11 . In this case, as a supplementary complementing nozzle which is the peripheral nozzle of a complementing nozzle, a nozzle in a nozzle column on a side on which a complementing nozzle in the two nozzle columns is not allocated may be allocated. That is, the supplementary complementing nozzle may not be formed in the same nozzle column as the complementing nozzle. 
     In the above described embodiment, a nozzle use rate of a nozzle at the periphery (peripheral nozzle) of a defective nozzle in a nozzle column may be set to a nozzle use rate at a normal time, instead of a nozzle use rate of the peripheral nozzle when the defective nozzle is detected. 
     In the above described embodiment, a nozzle use rate of each nozzle  32  of the nozzle columns  31 K,  31 C,  31 M, and  31 Y may be constant. 
     In a detecting method of a defective nozzle according to the above described embodiment, for example, a user may visually detect a defective nozzle from a check pattern by printing the check pattern before printing an image based on a printing job. In this case, the user operates an operation unit (not illustrated) of the printer  11 , and registers the defective nozzle. In addition, the printing control section  41  generates a changed mask pattern based on information of the registered defective nozzle. 
     In the above described embodiment, the number of supplementary complementing nozzles  32 B can be arbitrarily set. For example, the number of supplementary complementing nozzles  32 B may be two to four, or six or more. 
     In the above described embodiment, the number of peripheral nozzles  32 C can be arbitrarily set. For example, the number of peripheral nozzle  32 C may be two to four, or six or more. In addition, the number of peripheral nozzles  32 C may be different from that of the supplementary complementing nozzle  32 B. 
     In the above described embodiment, a nozzle use rate of the first complementing nozzle can be arbitrarily set. That is, the nozzle use rate of the first complementing nozzle may be a value which is less than “100%”. 
     In the above described embodiment, nozzle use rates of the second complementing nozzle and the peripheral nozzle can be arbitrarily set. 
     For example, a nozzle use rate of the second complementing nozzle according to the embodiment is lowered when the second complementing nozzle is separated from a complementing nozzle  32 A; however, it is not limited to this, and the nozzle use rate may be constantly set regardless of a position of the supplementary complementing nozzle  32 B. Similarly, a nozzle use rate of the peripheral nozzle may be set to be constant regardless of a position of the peripheral nozzle  32 C. 
     In addition, for example, a total nozzle use rate of the second complementing nozzle and the peripheral nozzle in the embodiment is set to “100%”; however, it is not limited to this, and may be set to a value other than “100%”. 
     In the above described embodiment, the printing control section  41  may set printing modes of three passes or more as a multipass printing mode. In this case, since there are two or more nozzles which can drop ink droplets to the same pixel as the pixel to which a defective nozzle  32 E eject ink, these nozzles may be set to the complementing nozzle  32 A. In this manner, dots DT are formed in a region corresponding to the pixel to which the defective nozzle  32 E should eject ink on a sheet P using the plurality of complementing nozzles  32 A. For this reason, it is possible to lower a nozzle use rate of the complementing nozzle  32 A, or a use frequency of the complementing nozzle  32 A compared to the two-pass printing mode. Accordingly, it is possible to prevent the service life of the complementing nozzle  32 A from being shortened. 
     In the above described embodiment, the printer  11  is not limited to a configuration of including only a printing function, and may be a multifunction printer. In addition, the printer  11  may be a printer of a lateral scanning type without being limited to a serial printer. 
     A medium is not limited to a sheet P, and may be a continuous sheet, a resin film, metallic foil, a metallic film, a composite film of a resin and metal (laminated film), a woven stuff, non-woven fabric, a ceramic sheet, and the like. 
     In the above described embodiment, a liquid ejecting apparatus has been embodied as an ink jet printer (printing apparatus); however, it is not limited to this, and may be a liquid ejecting apparatus which ejects fluid other than ink (including liquid, liquid body which is formed by dispersing or mixing particles of functional material into liquid, and liquid body such as gel). For example, the liquid ejecting apparatus may be a liquid ejecting apparatus which ejects a liquid body including a material such as an electrode material, or a coloring material (pixel material) which is used when manufacturing, for example, a liquid crystal display, an EL (electroluminescence) display, and a surface emission display, or the like, in a form of dispersion, or dissolution. In addition, the liquid ejecting apparatus may be a liquid ejecting apparatus which ejects a biological organic substance which is used when manufacturing a biochip, or a liquid ejecting apparatus which ejects liquid as a sample which is used as a precision pipette. In addition, the liquid ejecting apparatus may be a liquid ejecting apparatus which ejects a lubricant to a precision machine such as a clock, a camera, or the like, using a pinpoint, a liquid ejecting apparatus which ejects transparent resin liquid such as UV curable resin for forming a micro bulls-eye (optical lens) which is used in an optical communication element, or the like, onto a substrate, and a liquid ejecting apparatus which ejects an etching liquid such as an acid or alkali for etching a substrate, or the like. Further, the liquid ejecting apparatus may be a liquid ejecting apparatus which manufactures a three-dimensional structure by ejecting liquid. 
     This application claims priority to Japanese Patent Application No. 2015-068260 filed on Mar. 30, 2015. The entire disclosure of Japanese Patent Application No. 2015-068260 is hereby incorporated herein by reference.