Patent Publication Number: US-9844943-B2

Title: Wiping mechanism, liquid droplet jetting apparatus, and wiping method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of PCT International Application No. PCT/JP2015/074098 filed on Aug. 26, 2015, which claims priority under 35 U.S.C §119(a) to Patent Application No. 2014-195593 filed in Japan on Sep. 25, 2014, all of which are hereby expressly incorporated by reference into the present application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a wiping mechanism, a liquid droplet jetting apparatus, and a wiping method. 
     2. Description of the Related Art 
     A technique for wiping a nozzle surface of an ink jet head with a wiping member such as a fabric having absorbability for maintenance of the ink jet head is known (refer to JP2010-234667A). 
     In the configuration of JP2010-234667A, the nozzle surface is wiped two times by changing the direction of the wiping member. Specifically, in the configuration of JP2010-234667A, first, unwiped portions are prevented by wiping the nozzle surface along a first direction with high liquid absorption power, and second, wiping traces due to ink withdrawn from a nozzle are prevented by wiping the nozzle surface along a second direction with low liquid absorption power. 
     SUMMARY OF THE INVENTION 
     Here, in the configuration in which the nozzle surface is wiped by the wiping member, when the nozzle surface is wiped by the wiping member, if bubbles infiltrate into the nozzle formed at the nozzle surface, there may be cases where ink jetting failure (non-jetting, bending in the jetting direction, and the like) occurs due to the nozzle into which bubbles infiltrate. When such jetting failure occurs, there may be cases where image failure such as streaks occurs in an image formed on a recording medium such as a sheet. 
     An object of the present invention is to prevent infiltration of bubbles into a nozzle when a nozzle surface is wiped by a wiping member. 
     According to a first aspect of the present invention, a wiping mechanism comprises: a wiping member which comes into contact with a nozzle surface with a nozzle through which liquid droplets are jetted, and is formed by weaving weft yarns and warp yarns, the weft yarns being further exposed to the nozzle surface side than the warp yarns; and a moving mechanism which moves the wiping member relative to the nozzle surface along the warp yarns. 
     In the wiping mechanism according to the first aspect, the weft yarns of the wiping member are further exposed to the nozzle surface than the warp yarns, and among the warp yarns and the weft yarns constituting the wiping member, the weft yarns come into contact with the nozzle surface. Furthermore, as the wiping member is moved relative to the nozzle surface along the warp yarns of the wiping member, the wiping member wipes the nozzle surface. 
     Therefore, the weft yarns that come into contact with the nozzle surface move relative to the nozzle in a direction substantially perpendicular to its own axis. Therefore, compared to a case where the weft yarns move relative to the nozzle along its own axial direction, a contact time for which each individual weft yarn comes into contact with the nozzle is shortened. Accordingly, the ink in the nozzle is not drawn more than necessary, and infiltration of bubbles into the nozzle can be prevented. 
     According to a second aspect of the present invention, in the wiping mechanism, the weft yarns have a diameter smaller than that of the warp yarns and/or are weaved more loosely than the warp yarns. 
     In the wiping mechanism according to the second aspect, since the diameter of the weft yarn that comes into contact with the nozzle surface is smaller than the diameter of the warp yarn, compared to a case where the diameter of the weft yarn is equal to or greater than the diameter of the warp yarn, small foreign matter such as ink semi-solidified by drying can be scraped off. In addition, since the weft yarns are more loosely weaved than the warp yarns, the weft yarns behave during movement and increases the effect of scraping off the foreign matter. 
     On the other hand, since the diameter of the warp yarn is greater than the diameter of the weft yarn, compared to a case where the diameter of the warp yarn is equal to or smaller than the diameter of the weft yarn, the strength of the wiping member can be secured by the warp yarns. 
     As described above, in the wiping mechanism according to the second aspect, among the weft yarns and the warp yarns constituting the wiping member, the weft yarns that come into contact with the nozzle surface have a function of removing foreign matter including ink, and the warp yarns have a function of securing the strength of the wiping member. That is, the weft yarns and the warp yarns are functionally separated (roles are divided). 
     According to a third aspect of the present invention, in the wiping mechanism, the diameter of the weft yarn is smaller than an opening diameter of the nozzle. 
     In the wiping mechanism according to the third aspect, since the diameter of the weft yarn is smaller than the opening diameter of the nozzle, when the nozzle surface is wiped, the weft yarn can enter the nozzle and can scrape off the liquid semi-solidified by drying in the vicinity of the opening of the nozzle. 
     According to a fourth aspect of the present invention, in the wiping mechanism, a plurality of weft yarn bundles are formed by binding a plurality of the weft yarns, a gap is formed between the weft yarn bundles, and a width of the gap is greater than the opening diameter of the nozzle in at least a portion of the gap. 
     In the wiping mechanism according to the fourth aspect, when the wiping member moves relative to the nozzle surface, in a case where a portion of the wiping member in which the width of the gap is greater than the opening diameter of the nozzle passes through the nozzle, weft yarns that belong to different weft yarn bundles do not simultaneously come into contact with a single nozzle. That is, in a case where the portion of the wiping member in which the width of the gap is greater than the opening diameter of the nozzle passes through the nozzle, weft yarns that belong to a certain weft yarn bundle come into contact with the nozzle and absorb the liquid, and absorption of the liquid is stopped once. Weft yarns that belong to a weft yarn bundle which subsequently passes through the nozzle come into contact with the nozzle and absorb the liquid again. As described above, absorption of the liquid is stopped once. Therefore, not a large amount of the liquid is absorbed from the nozzle. Accordingly, infiltration of bubbles into the nozzle can be prevented. 
     According to a fifth aspect of the present invention, the wiping mechanism further comprises: a measuring part which measures the amount of liquid adhered to the wiping member that has wiped the nozzle surface; and a notification part which notifies predetermined notification to a user of an apparatus in a case where the amount of the liquid measured by the measuring part is equal to or more than a specified amount. 
     Here, when the liquid is absorbed from the nozzle, bubbles infiltrate into the space where the liquid is not present in the nozzle. Accordingly, as the amount of the liquid absorbed from the nozzle increases, there is a higher possibility of infiltration of bubbles into the nozzle. In addition, the amount of the liquid absorbed from the nozzle is proportional to the amount of the liquid adhered to the wiping member which wipes the nozzle surface. Therefore, in a case where the amount of the liquid adhered to the wiping member which wipes the nozzle surface is equal to or more than a specified amount, it is understood that there is a high possibility of infiltration of bubbles into the nozzle. 
     In addition, as in the wiping mechanism according to the fifth aspect, in a case where the amount of the liquid adhered to the wiping member which wipes the nozzle surface is equal to or more than the specified amount, the possibility of infiltration of bubbles into the nozzle can be notified to the user of the apparatus by notifying predetermined notification to the user of the apparatus. 
     According to a sixth aspect of the present invention, a liquid droplet jetting apparatus comprises: a liquid droplet jetting head having a nozzle surface with a nozzle through which liquid droplets are jetted; and the wiping mechanism according to any one of the first to fifth aspects, which wipes the nozzle surface of the liquid droplet jetting head with the wiping member. 
     In the liquid droplet jetting apparatus according to the sixth aspect, since infiltration of bubbles into the nozzle can be prevented by the wiping mechanism according to any one of the first to fifth aspects, liquid droplet jetting failure caused by the infiltration of bubbles into the nozzle of the liquid droplet jetting head can be prevented. 
     According to a seventh aspect of the present invention, a wiping method comprises: moving a wiping member, which comes into contact with a nozzle surface with a nozzle through which liquid droplets are jetted, and is formed by weaving weft yarns and warp yarns, the weft yarns being further exposed to the nozzle surface side than the warp yarns, relative to the nozzle surface along the warp yarns. 
     In the wiping method according to the seventh aspect, the same actions and effects as those of the wiping mechanism according to the first aspect are exhibited. 
     According to an eighth aspect of the present invention, in the wiping method, the wiping member, in which the weft yarns have a diameter smaller than that of the warp yarn and/or are weaved more loosely than the warp yarns, is used. 
     In the wiping method according to the eighth aspect, the same actions and effects as those of the wiping mechanism according to the second aspect are exhibited. 
     According to a ninth aspect of the present invention, in the wiping method, the wiping member, in which the diameter of the weft yarn is smaller than an opening diameter of the nozzle, is used. 
     In the wiping method according to the ninth aspect, the same actions and effects as those of the wiping mechanism according to the third aspect are exhibited. 
     According to a tenth aspect of the present invention, in the wiping method, the wiping member, in which a plurality of weft yarn bundles are formed by binding a plurality of the weft yarns, a gap is formed between the weft yarn bundles, and a width of the gap is greater than the opening diameter of the nozzle in at least a portion of the gap, is used. 
     In the wiping method according to the tenth aspect, the same actions and effects as those of the wiping mechanism according to the fourth aspect are exhibited. 
     According to the present invention, when the nozzle surface is wiped by the wiping member, infiltration of bubbles into the nozzle can be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating a liquid droplet jetting apparatus according to an embodiment. 
         FIG. 2  is a perspective view illustrating a wiping mechanism according to the embodiment. 
         FIG. 3  is a view illustrating a wiping unit according to the embodiment. 
         FIG. 4  is a view illustrating a wiping member according to the embodiment. 
         FIG. 5  is a view illustrating a weft yarn bundle according to the embodiment. 
         FIG. 6  is a view illustrating a portion of the wiping member according to the embodiment. 
         FIGS. 7A to 7C  are views for explaining the definition of the nozzle according to the embodiment. 
         FIG. 8  is a table showing evaluation results. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an example of an embodiment according to the present invention will be described with reference to the drawings. 
     (Configuration of Liquid Droplet Jetting Apparatus  10 ) 
     First, the configuration of the liquid droplet jetting apparatus  10  will be described.  FIG. 1  is a schematic view illustrating the configuration of the liquid droplet jetting apparatus  10  according to this embodiment. 
     As illustrated in  FIG. 1 , the liquid droplet jetting apparatus  10  according to this embodiment is configured to record (form) an image on a recording medium (for example, sheet) P as a jetting object using a photocurable ink (for example, ultraviolet curable ink using an aqueous medium) as an example of a liquid in an ink jet manner. The liquid droplet jetting apparatus  10  includes, as main parts, a feeding part  12  which feeds the recording medium P, a processing liquid adding part  14 , a processing liquid drying part  16 , an image recording part  18 , an ink fixing part  20  as ink fixing means including a drying part  21  and a light irradiation part  22 , control means (not illustrated) responsible for control of the entire system, and a discharge part  24  which discharges the recording medium P. 
     (Feeding Part  12 ) 
     The feeding part  12  is configured to feed the recording media P stacked on a feeding table  30  to the processing liquid adding part  14  one by one. The feeding part  12  is mainly constituted by the feeding table  30 , a sucker device  32 , a feeding roll pair  34 , a feeder board  36 , a front guard  38 , and a feeding drum  40 . 
     A large number of the recording media P are loaded on the feeding table  30  in a state of being stacked as a bundle. The feeding table  30  is provided so as to be elevated by a feeding table elevating device (not illustrated). The feeding table elevating device is controlled to be driven in conjunction with variation in the recording media P stacked on the feeding table  30 , and is configured so that the feeding table  30  is elevated to cause the recording medium P at the uppermost position of the bundle to be always at a constant height. 
     In the sucker device  32 , the recording media P stacked on the feeding table  30  are picked up one by one in order from above and are fed to the feeding roll pair  34 . The sucker device  32  includes a suction foot  32 A provided to be elevated and oscillated. The upper surface of the recording medium P is adsorbed and held by the suction foot  32 A and the recording medium P is transported to the feeding roll pair  34  from the feeding table  30 . At this time, the suction foot  32 A is configured to adsorb and hold the upper surface of the leading end side of the recording medium P positioned at the uppermost position of the bundle so as to cause the recording medium P to be pulled upward, and to cause the leading end of the recording medium pulled upward to be inserted between a pair of rolls  34 A and  34 B constituting the feeding roll pair  34 . 
     One of the rolls  34 A and  34 B is a driving roll (for example, the roll  34 A), and the other thereof is a driven roll (for example, the roll  34 B). The driving roll is connected to a motor (not illustrated) and is driven to rotate by the rotation of the motor. The motor is driven in conjunction with the feeding of the recording medium P, and when the recording medium P is fed from the sucker device  32 , the motor rotates the driving roll according to the timing. The recording medium P inserted between the pair of rolls  34 A and  34 B is nipped between the rolls  34 A and  34 B and is sent out in an installation direction of the feeder board  36 . 
     The feeder board  36  is formed to correspond to the recording medium width and is configured to guide the recording medium P sent out from the feeding roll pair  34  to the front guard  38 . The feeder board  36  is provided to be inclined downward, and the recording medium P placed on a transport surface of a transport path of the feeder board  36  slides along the transport surface and is guided to the front guard  38 . 
     In the feeder board  36 , a plurality of tape feeders  36 A which transport the recording medium P and have the transport direction as the longitudinal direction are provided with intervals therebetween in the width direction. The tape feeder  36 A is formed in an endless shape and is configured to rotate by a motor (not illustrated) as a driving source. The recording medium P placed on the transport surface of the feeder board  36  is transported on the feeder board  36  by the tape feeders  36 A. 
     In addition, on the feeder board  36 , retainers  36 B and a roller  36 C are provided. A plurality of (in this embodiment, two) the retainers  36 B are arranged in tandem in the front and rear along the transport surface of the recording medium P. The retainer  36 B is configured as a plate spring having a width corresponding to the recording medium width and comes into pressing contact with the transport surface. As the recording medium P transported on the feeder board  36  by the tape feeders  36 A passes through the retainers  36 B, unevenness of the recording medium P is corrected. The roller  36 C is disposed between the retainer  36 B disposed on the upstream side in the transport direction and the retainer  36 B on the downstream side. The roller  36 C comes in pressing contact with the transport surface of the recording medium P. The recording medium P transported between the retainers  36 B is transported while the upper surface thereof is pressed by the roller  36 C. 
     The front guard  38  is configured to correct the posture of the recording medium P. The front guard  38  is formed in a plate shape, and the plate-like surface thereof is disposed to be perpendicular to the transport direction of the recording medium P. In addition, the front guard  38  is connected to a motor (not illustrated), and is driven by the motor so as to be oscillated. At a time point at which the leading end of the recording medium P transported on the feeder board  36  abuts the front guard  38 , the transporting posture of the recording medium P is corrected (so-called skew prevention is performed). The front guard  38  is oscillated in conjunction with feeding of the recording medium P to the feeding drum  40 , and the recording medium P of which the transporting posture is corrected is delivered to the feeding drum  40 . 
     The feeding drum  40  receives the recording medium P fed from the feeder board  36  via the front guard  38  and transports the recording medium P to the processing liquid adding part  14 . The feeding drum  40  is formed in a cylindrical shape, and is configured to be connected to a motor (not illustrated) and be rotated by driving of the motor. A gripper  40 A is provided on the outer circumferential surface of the feeding drum  40 , and the leading end of the recording medium P is gripped by the gripper  40 A. As the gripper  40 A grips and rotates the leading end of the recording medium P, the feeding drum  40  transports the recording medium P to the processing liquid adding part  14  while winding the recording medium P around the circumferential surface. 
     (Processing Liquid Adding Part  14 ) 
     The processing liquid adding part  14  adds a processing liquid to the surface (image recording surface) of the recording medium P. The processing liquid adding part  14  is mainly constituted by a processing liquid adding drum  42  which transports the recording medium P, and a processing liquid adding unit  44  which adds the processing liquid to the image recording surface of the recording medium P transported by the processing liquid adding drum  42 . The processing liquid added to the surface of the recording medium P is an aggregating agent having a function of causing a coloring material (pigment) in the photocurable ink jetted onto the recording medium P in the image recording part  18  disposed on the downstream side in the transport direction, to collect. 
     The processing liquid adding drum  42  transports the recording medium P transported from the feeding drum  40  of the feeding part  12  to the processing liquid drying part  16 . The processing liquid adding drum  42  is formed in a cylindrical shape, and is configured to be connected to a motor (not illustrated) and be driven by the rotation of the motor. Gripper  42 A are provided on the outer circumferential surface of the processing liquid adding drum  42 , and the gripper  42 A is configured to grip the leading end of the recording medium P. As the gripper  42 A grips and rotates the leading end of the recording medium P, the processing liquid adding drum  42  transports the recording medium P to the processing liquid drying part  16  while winding the recording medium P around the circumferential surface. When the processing liquid adding drum  42  rotates once, a single recording medium P is transported. Rotation of the processing liquid adding drum  42  and the feeding drum  40  is controlled so as to cause reception and delivery timings of the recording medium P of the two to be coincident with each other. That is, the processing liquid adding drum  42  and the feeding drum  40  are driven while causing the circumferential speeds of the two to be coincident with each other and are driven while causing the positions of the grippers  40 A and  42 A of the two to be coincident with each other. 
     In the processing liquid adding unit  44 , the processing liquid is applied by rolls to the surface of the recording medium P transported by the processing liquid adding drum  42 . The processing liquid adding unit  44  is mainly constituted by an application roll  44 A which applies the processing liquid to the recording medium P, a processing liquid tank  44 B which stores the processing liquid, and a drawing roll  44 C which draws the processing liquid stored in the processing liquid tank  44 B and supplies the processing liquid to the application roll  44 A. 
     (Processing Liquid Drying Part  16 ) 
     In the processing liquid drying part  16 , the recording medium P having the processing liquid added to the surface thereof is dried. The processing liquid drying part  16  is mainly constituted by a processing liquid drying drum  46  which transports the recording medium P, a sheet transport guide  48 , and a processing liquid drying unit  50  which blows dry wind toward the image recording surface of the recording medium P transported by the processing liquid drying drum  46  so as to be dried. 
     The processing liquid drying drum  46  is configured to receive the recording medium P from the processing liquid adding drum  42  of the processing liquid adding part  14  and transport the recording medium P to the image recording part  18 . The processing liquid drying drum  46  is configured as a frame body assembled in a cylindrical shape, is connected to a motor (not illustrated), and is driven by rotation of the motor. A grippers  46 A is provided on the outer circumferential surface of the processing liquid drying drum  46 , and the leading end of the recording medium P is gripped by the gripper  46 A. As the gripper  46 A grips and rotates the leading end of the recording medium P, the processing liquid drying drum  46  transports the recording medium P to the image recording part  18 . In addition, in the processing liquid drying drum  46  in this embodiment, the grippers  46 A are disposed at two points on the outer circumferential surface and are configured to transport two recording media P by one rotation. Rotation of the processing liquid drying drum  46  and the processing liquid adding drum  42  is controlled so as to cause reception and delivery timings of the recording medium P of the two to be coincident with each other. That is, the processing liquid drying drum  46  and the processing liquid adding drum  42  are driven while causing the circumferential speeds of the two to be coincident with each other and are driven while causing the positions of the grippers  42 A and  46 A thereof to be coincident with each other. 
     The sheet transport guide  48  is disposed around the outer periphery of the processing liquid drying drum  46  along the transport path of the recording medium P. The sheet transport guide  48  guides the recording medium P so as not to deviate from the processing liquid drying drum  46  (transport path). 
     The processing liquid drying unit  50  is installed on the inside of the processing liquid drying drum  46 , and is configured to blow dry wind toward the surface of the recording medium P transported by the processing liquid drying drum  46  so as to be dried. Accordingly, solvent components in the processing liquid are removed, and an ink aggregating layer is formed on the surface of the recording medium P. In this embodiment, two processing liquid drying units  50  are disposed in the processing liquid drying drum  46  and are configured to blow dry wind toward the surface of the recording medium P transported by the processing liquid drying drum  46 . 
     (Image Recording Part  18 ) 
     The image recording part  18  is configured to record a color image on an image formation surface of the recording medium P by jetting ink droplets (an example of liquid droplets) of the photocurable ink with M, K, C, and Y colors onto the image recording surface of the recording medium P. The image recording part  18  is mainly constituted by an image recording drum  52  which transports the recording medium P, a recording medium pressing roll  54  which causes the recording medium P to come into close contact with the circumferential surface of the image recording drum  52  by pressing the recording medium P transported by the image recording drum  52 , ink jet heads  56 M,  56 K,  56 C, and  56 Y which jet ink droplets with M, K, C, and Y colors onto the recording medium P, an inline sensor  58  which reads the image recorded on the recording medium P, a mist filter  60  which captures ink mist, and a drum cooling unit  62 . In addition, as described above, as the ink jetted from the ink jet heads  56 M,  56 K,  56 C, and  56 Y, the photocurable ink is used. The photocurable ink is cured by being irradiated with light (ultraviolet rays) by the ink fixing means, which will be described later and is thus dried. In the following description, in a case where there is no need to distinguish magenta (M), black (K), cyan (C), and yellow (Y) from each other, M, K, C, and Y attached to reference numerals are omitted. 
     The ink jet head  56  (an example of a liquid droplet jetting head) has a nozzle surface  78  in which a plurality of nozzles  78 A through which ink droplets are jetted (see  FIG. 3 ). 
     The image recording drum  52  is configured to receive the recording medium P from the processing liquid drying drum  46  of the processing liquid drying part  16  and transport the recording medium P to an ink fixing part  20 . The image recording drum  52  is formed in a cylindrical shape, is connected to a motor (not illustrated), and is driven by rotation of the motor. Grippers  52 A are provided on the outer circumferential surface of the image recording drum  52 , and the leading end of the recording medium P is gripped by the gripper  52 A. As the gripper  52 A grips and rotates the leading end of the recording medium P, the image recording drum  52  transports the recording medium P to the ink fixing part  20  while winding the recording medium P around the circumferential surface. In addition, a large number of adsorption holes (suction holes) (not illustrated) are provided in the circumferential surface of the image recording drum  52  in a predetermined pattern. The recording medium P wound around the circumferential surface of the image recording drum  52  is suctioned through the adsorption holes and thus can be transported while being adsorbed and held onto the circumferential surface of the image recording drum  52 . Accordingly, the recording medium P can be transported with high smoothness. 
     In addition, in the image recording drum  52  in this embodiment, the grippers  52 A are disposed at two points on the outer circumferential surface and can transport two recording media P by one rotation. Rotation of the image recording drum  52  and the processing liquid drying drum  46  is controlled so as to cause reception and delivery timings of the recording medium P of the two to be coincident with each other. That is, the image recording drum  52  and the processing liquid drying drum  46  are driven while causing the circumferential speeds thereof to be coincident with each other and are driven while causing the positions of the grippers  46 A and  52 A thereof to be coincident with each other. 
     The recording medium pressing roll  54  is disposed in the vicinity of a reception position (a position at which the recording medium P is received from the processing liquid drying drum  46 ) of the recording medium P of the image recording drum  52 . The recording medium pressing roll  54  is configured as, for example, a rubber roll and is installed to come into pressing contact with the circumferential surface of the image recording drum  52 . The recording medium P delivered from the processing liquid drying drum  46  to the image recording drum  52  is nipped by passing through the recording medium pressing roll  54  and thus comes into close contact with the circumferential surface of the image recording drum  52 . 
     The four ink jet heads  56 M,  56 K,  56 C, and  56 Y are disposed at predetermined intervals on the outer circumferential surface of the image recording drum  52  along the transport path of the recording medium P. The ink jet head  56  of each color is configured as a line head corresponding to the recording medium width and is configured so that the nozzle surface  78  (see  FIG. 3 ) is disposed to face the circumferential surface of the image recording drum  52 . The ink jet head  56  of each color records an image on the recording medium P transported by the image recording drum  52  by jetting liquid droplets of the photocurable ink toward the image recording drum  52  from the plurality of nozzles  78 A (see  FIG. 3 ) formed in the nozzle surface  78 . 
     The inline sensor  58  is installed closer to the downstream side than the rearmost ink jet head  56 K in the transport direction of the recording medium P transported by the image recording drum  52  and is configured to read the image recorded by the ink jet head  56  of each color. The inline sensor  58  is configured as, for example, a line scanner. 
     In addition, on the downstream side of the inline sensor  58 , a contact prevention plate  59  installed close to the inline sensor  58  is provided. The contact prevention plate  59  can prevent contact between the inline sensor  58  and the recording medium P in a case where lifting, folding, or the like of the recording medium P occurs due to transport problems or the like. 
     The mist filter  60  is disposed between the rearmost ink jet head  56 Y and the inline sensor  58  and captures ink mist by suctioning air in the vicinity of the image recording drum  52 . By capturing the ink mist, infiltration of the ink mist into the inline sensor  58  is prevented, and occurrence of image reading failure or the like is effectively prevented. 
     The drum cooling unit  62  is configured to cool the image recording drum  52  by blowing cold air toward the image recording drum  52 . The drum cooling unit  62  is mainly constituted by an air conditioner (not illustrated) and a duct  62 A through which the cold air supplied from the air conditioner is blown toward the circumferential surface of the image recording drum  52 . The duct  62 A is configured to cool the image recording drum  52  by blowing cold air toward the image recording drum  52  in a region other than a transport region of the recording medium P. In this embodiment, since the recording medium P is transported along the arc-shaped outer circumferential surface of substantially the upper half of the image recording drum  52 , the duct  62 A cools the image recording drum  52  by blowing cold air toward a region of substantially the lower half of the image recording drum  52 . Specifically, outlets (not illustrated) of the duct  62 A are arranged in an arc shape so as to cover substantially the lower half of the image recording drum  52 . 
     Furthermore, the image recording part  18  has a wiping mechanism  80  which wipes the nozzle surface  78  of the ink jet head  56  of each color as illustrated in  FIG. 2 . In addition, a specific configuration of the wiping mechanism  80  will be described later. 
     (Ink Fixing Part  20 ) 
     The ink fixing part  20  is configured to perform post-processing on the recording medium P after the image recording by removing liquid components remaining on the image recording surface of the recording medium P. As illustrated in  FIG. 1 , the ink fixing part  20  is provided with a chain gripper  64  which transport the recording medium P on which an image is recorded, a back tension applying mechanism  66  which applies back tension to the recording medium P transported by the chain gripper  64 , and the drying part  21  and the light irradiation part  22  as the ink fixing means for fixing the recording medium P transported by the chain gripper  64 . 
     The chain gripper  64  is used in the drying part  21 , the light irradiation part  22 , and the discharge part  24  in common, and is configured to receive the recording medium P delivered from the image recording part  18  and transport the recording medium P to the discharge part  24 . 
     The chain gripper  64  is configured to mainly include a first sprocket  64 A installed close to the image recording drum  52  side, a second sprocket  64 B installed on the discharge part  24  side, chains  64 C as endless transport paths wound around the first sprocket  64 A and the second sprocket  64 B, a plurality of chain guides (not illustrated) which guide the travelling of the chain  64 C, and a plurality of grippers  64 D attached to the chains  64 C with predetermined intervals therebetween. The first sprocket  64 A, the second sprocket  64 B, the chains  64 C, and the chain guides form a pair on both sides in the transport width direction of the recording medium P. The gripper  64 D is provided for each of the chains  64 C forming a pair. The first sprocket  64 A is connected to a motor (not illustrated) and is driven by rotation of the motor. The second sprocket  64 B is allowed to rotate in a subordinate manner. 
     The back tension applying mechanism  66  is configured to apply back tension to the recording medium P transported while the leading end thereof is gripped by the chain gripper  64 . Although detailed illustration of the back tension applying mechanism  66  is omitted, the back tension applying mechanism  66  mainly includes a guide plate  72 , and a plurality of adsorption fans  72 A as adsorption means for suctioning air from a large number of adsorption holes formed in the guide plate  72 . In addition, on the lower surface of the guide plate  72 , a large number of holes through which the suctioned air is discharged are provided. As the recording medium P transported by the chain gripper  64  is suctioned by the adsorption fans  72 A through the adsorption holes of the guide plate  72 , back tension is applied. 
     (Drying Part  21 ) 
     The drying part  21  is provided inside the chain gripper  64  on the upstream side in the transport direction of the chain gripper  64  and includes a plurality of drying units  68  arranged along the transport direction. The drying unit  68  is configured to blow dry wind (for example, hot wind) toward the image recording surface of the recording medium P. When dry wind is blown by the drying unit  68 , the amount of moisture in the photocurable ink is reduced before irradiation of light (ultraviolet rays) by the light irradiation part  22 . Accordingly, curing properties of the photocurable ink are secured by subsequent light irradiation. 
     (Light Irradiation Part  22 ) 
     The light irradiation part  22  is configured to irradiate the image recorded by using the photocurable ink with ultraviolet rays (UV) as light in this embodiment, thereby fixing the image. The light irradiation part  22  is configured to mainly include the chain gripper  64  which transports the recording medium P, the back tension applying mechanism  66  which applies back tension to the recording medium P and also functions as adsorption means, and irradiation units  74  which irradiate the recording medium P with light. 
     The irradiation units  74  are provided closer to the downstream side than the drying part  21  in the transport direction of the chain gripper  64  inside the chain gripper  64 , and a plurality of the irradiation units  74  are arranged along the transport direction. The irradiation unit  74  includes an ultraviolet lamp as a light source (not illustrated). The back tension applying mechanism  66  mainly includes the guide plate  72 , and the plurality of adsorption fans  72 B as adsorption means for suctioning air from a large number of the adsorption holes formed in the guide plate  72 . In addition, on the lower surface of the guide plate  72 , a large number of holes through which the suctioned air is discharged are provided. As the recording medium P transported by the chain gripper  64  is suctioned by the adsorption fans  72 B through the adsorption holes of the guide plate  72 , back tension is applied. 
     (Discharge Part  24 ) 
     The discharge part  24  is configured to collect the recording medium P subjected to a series of image recording processes. The discharge part  24  is configured to mainly include the chain gripper  64  which transports the recording medium P on which the photocurable ink is fixed by light irradiation, and a discharge table  76  on which the recording media P are stacked and collected. Although not illustrated, the discharge table  76  is provided with sheet guards (a front sheet guide, a rear sheet guard, a transverse sheet guide, and the like) for orderly stacking the recording media P. In addition, in the discharge table  76 , a discharge table elevating device (not illustrated) is provided to elevate the recording media P. The discharge table elevating device is controlled to be elevated in conjunction with variation in the recording media P collected on the discharge table  76 , and is adjusted so that the recording medium P at the uppermost is always at a constant height. 
     (Photocurable Ink) 
     As the photocurable ink, for example, an aqueous ultraviolet ink which is cured by irradiation of ultraviolet rays as the light is used. The aqueous ultraviolet ink preferably includes a pigment, polymer particles, an aqueous polymerizable compound which is polymerized by active energy rays, and a photopolymerization initiator. When the aqueous ultraviolet ink is irradiated with ultraviolet rays and cured, the image obtains excellent rub resistance and the film hardness of the image increases. In addition, as the coloring material, a dye may be included. 
     (Wiping Mechanism  80 ) 
     As illustrated in  FIG. 2 , the wiping mechanism  80  includes a moving unit  82  as an example of a moving mechanism which moves the ink jet head  56 , and wiping units  86  which wipe ink and the like adhered to the nozzle surface  78  (see  FIG. 3 ) of the ink jet head  56 . The wiping units  86  and the image recording drum  52  are arranged in this order in an apparatus depth direction (X direction). 
     (Moving Unit  82 ) 
     The moving unit  82  (an example of the moving mechanism) includes a box-shaped support member  90  which collectively supports the ink jet heads  56  of the respective colors, a vertical mechanism  92  which moves the support member  90  in a device upward direction (Y direction), and a horizontal mechanism  94  which moves the support member  90  in the apparatus depth direction (X direction). 
     The vertical mechanism  92  has a rail portion  92 B which supports the support member  90  so as to be moved in the device upward and downward directions. In the vertical mechanism  92 , the support member  90  is moved along the rail portion  92 B by a driving part (not illustrated). 
     The horizontal mechanism  94  has a rail portion  94 B which supports the rail portion  92 B of the vertical mechanism  92  to be moved in the apparatus depth direction and the opposite direction thereof. In the horizontal mechanism  94 , the support member  90  is moved along the rail portion  94 B via the rail portion  92 B by a driving part (not illustrated). 
     (Wiping Unit  86 ) 
     As illustrated in  FIG. 2 , the four wiping units  86  are provided to correspond to the ink jet heads  56  of the respective colors. As illustrated in  FIG. 3 , each of the wiping units  86  has a band-like wiping member  200  which comes into contact with the nozzle surface  78  of the ink jet head  56 , a winding roll  114 A around which the wiping member  200  is wound, a sending-out roll  114 B, a counter roll  114 C, and a plurality of driven rolls  116 . 
     Furthermore, each of the wiping units  86  has a housing  112  which accommodates the wiping member  200  and the rolls  114 A,  114 B,  114 C, and  116  described above, and an application device  110  which applies a cleaning liquid to the wiping member  200 . In addition, a detailed configuration of the wiping member  200  will be described later. 
     The winding roll  114 A, the sending-out roll  114 B, the counter roll  114 C are disposed in this order in an upward direction from below at the center in the apparatus depth direction (X direction) in the housing  112  and are rotatably supported in the housing  112 . 
     One end side of the band-like wiping member  200  in the longitudinal direction thereof is wound around the sending-out roll  114 B, and the other end portion thereof in the longitudinal direction is fixed to the winding roll  114 A. Furthermore, as the band-like wiping member  200  is wound around the counter roll  114 C and the plurality of driven rolls  116 , the band-like wiping member  200  passes through a predetermined path from the sending-out roll  114 B and reaches the winding roll  114 A. 
     The winding roll  114 A winds the band-like wiping member  200  by being rotated by driving force of a motor  140 . The sending-out roll  114 B sends out the wiping member  200  as the wiping member  200  is wound by the winding roll  114 A. 
     The counter roll  114 C is exposed to the outside from the upper side of the housing  112 . In addition, the counter roll  114 C supports the wiping member  200  at a position in contact with the nozzle surface  78  of the ink jet head  56  between the sending-out roll  114 B and the winding roll  114 A on a movement path of the wiping member  200 . That is, the wiping member  200  comes into contact with the nozzle surface  78  of the ink jet head  56  moved by the moving unit  82  at a portion wound around the counter roll  114 C. 
     In addition, the counter roll  114 C and the driven rolls  116  are rotated in a subordinate manner as the wiping member  200  is moved. 
     The application device  110  includes a head  128  which allows the cleaning liquid (for example, a liquid containing a surfactant) to fall dropwise, a storage tank  130  which is disposed on the lower side with respect to the head  128  and stores the cleaning liquid, and a pump  134  which pumps up the cleaning liquid from the storage tank  130  to the head  128  through a hose  132 . 
     In the application device  110 , the pump  134  pumps up the cleaning liquid from the storage tank  130  and causes the cleaning liquid to fall dropwise from the head  128  to be applied to a portion of the wiping member  200  moved between the sending-out roll  114 B and the counter roll  114 C. 
     In addition, the wiping unit  86  is detachable from the liquid droplet jetting apparatus  10  (the wiping mechanism  80 ) such that the wiping member  200  can be replaced. 
     (Wiping Member  200 ) 
     As illustrated in  FIG. 4 , the wiping member  200  is configured as a fabric (web) formed by weaving warp yarns  210  and weft yarns  220  (see  FIG. 5 ) having different diameters. Specifically, a plurality (for example, tends to hundreds) of the weft yarns  220  are bound together to constitute a weft yarn bundle  222 , and a plurality of the weft yarn bundles  222  constitute a weft yarn bundle bunch  224 . The wiping member  200  is configured by weaving the weft yarn bundle bunches  224  and a plurality of the warp yarns  210  to cross each other. In  FIG. 4 , illustration of each of the weft yarns  220  constituting the weft yarn bundle  222  is omitted. In  FIG. 5 , a single weft yarn bundle  222  (a portion within two-dot chain line  5  in  FIG. 4 ) constituted by the plurality of weft yarns  220  is illustrated. 
     As illustrated in  FIG. 6 , the weft yarns  220  (the weft yarn bundle  222 ) are further exposed to the nozzle surface  78  than the warp yarns  210 . That is, in the wiping member  200  of this embodiment, among the warp yarns  210  and the weft yarns  220 , the weft yarns  220  come into contact with the nozzle surface  78 . 
     In addition, the warp yarns  210  are arranged along the direction of relative movement between the wiping member  200  and the nozzle surface  78  (inward direction in  FIG. 6 ). That is, the weft yarns  220  intersect the relative movement direction (wiping direction). In addition, the weft yarns  220  may intersect the relative movement direction in a range of 60 degrees to 120 degrees. 
     Furthermore, the diameter of the weft yarn  220  is set to be smaller than that of the warp yarn  210 . As an example, the diameter of the weft yarn  220  is set to 2 μm, and as an example, the diameter of the warp yarn  210  is set to 20 μm. In addition, as an example, the width of the weft yarn bundle  222  is set to 100 μm, and as an example, the width of the weft yarn bundle bunch  224  is set to 1 mm. 
     In addition, the weft yarns  220  are more loosely weaved than the warp yarns  210 . That is, in a weaved state, tension applied to the weft yarns  220  is weaker than tension applied to the warp yarns  210 . Accordingly, while the warp yarns  210  are constrained, the weft yarns  220  are movable in a predetermined range in the relative movement direction (wiping direction) and the opposite direction in a region R (see  FIG. 4 ) between the warp yarn  210  and the warp yarn  210 . Therefore, the individual weft yarns  220  constituting the weft yarn bundle  222  are likely to scatter one by one. 
     Furthermore, in the wiping member  200 , the diameter φ of the weft yarn  220  is smaller than an opening diameter D of the nozzle  78 A. In addition, in a case where the nozzle  78 A is a circle, the diameter of the circle is determined as the opening diameter D (see  FIG. 7A ), in a case where the nozzle  78 A is an ellipse, the minor axis of the ellipse is determined as the opening diameter D (see  FIG. 7B ), and in a case where the nozzle  78 A has a polygonal shape, the inscribed circle thereof is determined as the opening diameter D (see  FIG. 7C ). As an example, the opening diameter of the nozzle  78 A is set to 16 μm and is greater than the diameter of the weft yarn  220  set to 2 μm as an example. 
     In addition, as illustrated in  FIG. 4 , in the wiping member  200 , gaps are formed between the weft yarn bundles  222 , and a width L of the gap is greater than the opening diameter D of the nozzle  78 A in at least a portion of the gap. As an example, the width L of the gap is set to 100 μm, and is greater than the opening diameter of the nozzle  78 A set to 16 μm as an example. 
     In addition, for the weft yarns  220  and the warp yarns  210 , as an example, polyethylene terephthalate is used. 
     (Other Configurations in Wiping Mechanism  80 ) 
     The wiping mechanism  80  has a configuration for notifying a user of the apparatus of a possibility of infiltration of bubbles into the nozzle  78 A. Specifically, as illustrated in  FIG. 3 , the wiping mechanism  80  includes a measuring part  88  which measures the amount of ink adhered to the wiping member  200  that has wiped the nozzle surface  78 , and a determination part  89  which determines whether or not the amount of ink measured by the measuring part  88  is equal to or more than a predetermined specified amount. 
     Furthermore, the wiping mechanism  80  includes a display part  87  as an example of a notification part which notifies the user of the apparatus of predetermined notification in a case where the determination part  89  determines that the amount of ink measured by the measuring part  88  is equal to or more than the predetermined specified amount. 
     Specifically, the measuring part  88  is configured as a sensor which irradiates the wiping member  200  after wiping the nozzle surface  78  with light and detects the amount of light passing through the wiping member  200 . The measuring part  88  is disposed on the downstream side of the counter roll  114 C in the movement path of the wiping member  200 , and has a light-emitting section  88 A and a light-receiving section  88 B. The light-emitting section  88 A irradiates the wiping member  200  passing through the counter roll  114 C with light. The light-receiving section  88 B receives the light which is emitted from the light-emitting section  88 A and passes through the wiping member  200 . The measuring part  88  measures the amount of ink adhered to the wiping member  200  by measuring the amount of light incident on the light-receiving section  88 B. That is, the measuring part  88  measures the amount of ink by using the fact that when the amount of ink adhered to the wiping member  200  increases, the light from the light-emitting section  88 A is blocked by the ink and the amount of light received by the light-receiving section  88 B decreases. 
     Here, the amount of ink adhered to the wiping member  200  is measured to indirectly measure the amount of ink drawn from the nozzle  78 A because the amount of ink adhered to the wiping member  200  increases as the amount of ink drawn from the nozzle  78 A by the wiping member  200  absorbing the ink increases. In addition, when the ink is drawn from the nozzle  78 A by the wiping member  200 , bubbles infiltrate into the space. Accordingly, as the amount of ink drawn from the nozzle  78 A increases, bubbles infiltrate into the nozzle  78 A. Therefore, as the amount of ink adhered to the wiping member  200  increases, there is a higher possibility of infiltration of bubbles into the nozzle  78 A. 
     In addition, information regarding the amount of light detected by the measuring part  88  is sent to the determination part  89 , and the determination part  89  determines whether or not the amount of light detected by the measuring part  88  is equal to or less than the predetermined specified amount. In a case where the determination part  89  determines that the amount of light detected by the measuring part  88  is equal to or less than the predetermined specified value, the determination part  89  sends a display command to the display part  87 . 
     The display part  87  performs predetermined displaying in order to notify the user of the apparatus based on the display command. The display part  87  displays, as a predetermined display, for example, an instruction to replace the wiping unit  86  (wiping member  200 ), an instruction to check whether or not streaks are present in the recording medium P on which an image is formed, or the like. In addition, streaks in the recording medium P are caused by jetting failure of ink caused by infiltration of bubbles into the nozzle  78 A. 
     Action of this Embodiment 
     Next, as an action of this embodiment, a method of wiping the nozzle surface  78  of the ink jet head  56  using the wiping mechanism  80  will be described. For example, a wiping operation according to the wiping method is performed after the end of an image forming operation of jetting ink droplets from the ink jet head  56  of each color onto the recording medium P transported by the image recording drum  52  so as to form an image until a subsequent image forming operation is performed. In addition, for example, the wiping operation is also performed after a purging operation of discharging ink from all the nozzles  78 A while the inside of the nozzles is in a pressurized state, in order to remove bubbles in the ink, thickened ink, and the like. 
     In this wiping method, first, as illustrated in  FIG. 3 , the pump  134  of the application device  110  of each of the wiping units  86  is driven to pump up the cleaning liquid from the storage tank  130  and causes the cleaning liquid to fall dropwise from the head  128  onto the wiping member  200  so as to be applied thereto. 
     Next, as the wiping member  200  is wound by the winding roll  114 A by driving the motor  140  of each of the wiping units  86 , a portion of the wiping member  200  to which the cleaning liquid is applied is moved toward the counter roll  114 C. Accordingly, the portion of the wiping member  200  to which the cleaning liquid is applied is moved to a position where the portion is wound around the counter roll  114 C, that is, a position here the portion can come into contact with the nozzle surface  78 . 
     Next, the ink jet head  56  is moved in the apparatus depth direction (in the X direction) by the moving unit  82 . Due to the movement of the ink jet head  56  in the apparatus depth direction, the portion of the wiping member  200  wound around the counter roll  114 C starts to come into contact with the nozzle surface  78  of the ink jet head  56 . As the ink jet head  56  is moved in the apparatus depth direction, the position where the nozzle surface  78  of the ink jet head  56  comes into contact with the wiping member  200  can be changed, and the nozzle surface  78  is wiped by the wiping member  200 . Accordingly, ink adhered to the nozzle surface  78  is removed. Here, while the wiping member  200  comes into contact with the nozzle surface  78  of the ink jet head  56 , the wiping member  200  may be moved by driving the motor  140  of the wiping unit  86  simultaneously with the movement of the ink jet head  56  in the apparatus depth direction. Accordingly, it becomes possible to wipe the nozzle surface  78  with a fresh surface which does not perform wiping. 
     Here, according to the configuration of this embodiment, as illustrated in  FIG. 6 , the weft yarns  220  of the wiping member  200  are further exposed to the nozzle surface  78  than the warp yarns  210 , and when the nozzle surface  78  is wiped, the weft yarns  220  among the warp yarns  210  and the weft yarns  220  come into contact with the nozzle surface  78 . Furthermore, the wiping member  200  moves relative to the nozzle surface  78  along the warp yarns  210  of the wiping member  200 . 
     Therefore, the weft yarns  220  that come into contact with the nozzle surface  78  move relative to the nozzle  78 A in a direction substantially perpendicular to its own axis. Therefore, compared to a case where the weft yarns  220  move relative to the nozzle  78 A along its own axial direction, a contact time for which each individual weft yarn  220  comes into contact with the ink in the nozzle  78 A is shortened. Accordingly, the ink in the nozzle  78 A is not drawn more than necessary, and infiltration of bubbles into the nozzle  78 A can be prevented. 
     As described above, in the configuration of this embodiment, since infiltration of bubbles into the nozzle  78 A can be prevented, image failure such as streaks occurring on the recording medium P due to ink jetting failure (non-jetting, bending in the jetting direction, and the like) caused by infiltration of bubbles into the nozzle  78 A can be prevented. 
     In addition, according to the configuration of this embodiment, since the diameter of the weft yarn  220  that comes into contact with the nozzle surface  78  is smaller than the diameter of the warp yarn  210 , compared to a case where the diameter of the weft yarn  220  is equal to or greater than the diameter of the warp yarn  210 , small foreign matter such as ink semi-solidified by drying or powder of the recording medium P (paper powder) can be scraped off and removed. In addition, since the weft yarns  220  are more loosely weaved than the warp yarns  210 , the weft yarns  220  behave during movement and increases the effect of scraping off the foreign matter. 
     On the other hand, since the diameter of the warp yarn  210  is greater than the diameter of the weft yarn  220 , compared to a case where the diameter of the warp yarn  210  is equal to or smaller than the diameter of the weft yarn  220 , the strength of the wiping member  200  can be secured by the warp yarns  210 . 
     As described above, in this embodiment, the weft yarns  220  have a function of removing foreign matter including ink, and the warp yarns  210  have a function of securing the strength of the wiping member  200 . That is, the weft yarns  220  and the warp yarns  210  are functionally separated (roles are divided). 
     Furthermore, in this embodiment, since the diameter of the weft yarn  220  is smaller than the opening diameter D of the nozzle  78 A, when the nozzle surface  78  is wiped, the weft yarn  220  can enter the nozzle  78 A and can scrape off ink semi-solidified by drying in the vicinity of the opening of the nozzle  78 A. 
     In addition, in this embodiment, the width L of the gap formed between the weft yarn bundles  222  is greater than the opening diameter D of the nozzle  78 A in at least a portion of the gap. 
     Therefore, when the nozzle surface  78  is wiped by the wiping member  200 , in a case where a portion of the wiping member  200  in which the width L of the gap is greater than the opening diameter D of the nozzle  78 A passes through the nozzle  78 A, weft yarns  220  that belong to different weft yarn bundles  222  do not simultaneously come into contact with a single nozzle  78 A. That is, in a case where the portion of the wiping member  200  in which the width L of the gap is greater than the opening diameter D of the nozzle  78 A passes through the nozzle  78 A, weft yarns  220  that belong to a certain weft yarn bundle  222  come into contact with the nozzle  78 A and absorb ink, and absorption of the ink is stopped once. Weft yarns  220  that belong to a weft yarn bundle  222  which subsequently passes through the nozzle  78 A come into contact with the nozzle  78 A and absorb ink again. As described above, absorption of the ink is stopped once. Therefore, not a large amount of ink is absorbed from the nozzle  78 A. Accordingly, infiltration of bubbles into the nozzle  78 A can be prevented. 
     Furthermore, in this embodiment, in a case where the amount of ink adhered to the wiping member  200  after wiping is equal to or more than the specified amount, predetermined notification is notified to the user of the apparatus. Accordingly, a possibility of infiltration of bubbles into the nozzle  78 A can be notified to the user of the apparatus. Specifically, for example, displaying for prompting the user to check the presence or absence of streaks formed on the recording medium P due to ink jetting failure caused by infiltration of bubbles into the nozzle  78 A can be performed. 
     (Evaluations) 
     In these evaluations, wiping performance, scraping performance, and bubble infiltration prevention performance of Examples 1, 2, 3 and a comparative example described below were evaluated. 
     Wiping performance was evaluated as A and B as follow by wiping the nozzle surface  78  with the wiping member  200  and thereafter observing the state of the nozzle surface  78  with a microscope depending on whether or not a liquid residue is present on the nozzle surface  78 . 
     A: there is no liquid residue. 
     B: a liquid residue is present. 
     Scraping performance was evaluated as A, B, and C as follows by wiping the nozzle surface  78  with the wiping member  200  and thereafter observing the inside of the nozzle with the microscope depending on whether or not ink solidified matter remains. 
     A: no ink solidified matter remains. 
     B: ink solidified matter remains to an extent that does not affect jetting of the ink. 
     C: ink solidified matter remains and affects jetting of the ink. 
     Bubble infiltration prevention performance: was evaluated by wiping the nozzle surface  78  with the wiping member  200  and thereafter forming a solid image depending on whether or not streaks were formed on the image. In addition, as the streaks on the image, those caused by ink jetting failure due to infiltration of bubbles into the nozzle  78 A are the target. 
     A: no streaks are formed on the image. 
     B: streaks are slightly formed on the image to an extent that does not affect the image quality. 
     C: streaks are formed on the image and affect the image quality. 
     Example 1 
     In the liquid droplet jetting apparatus  10  described above, the ink jet head  56  in which the opening diameter D of the nozzle  78 A is set to 16 μm was used, and the wiping member  200  in which the diameter of the weft yarn  220  was set to 2 μm and the width L of the gap between the weft yarn bundles  222  was set to 100 μm was used. 
     Example 2 
     In the liquid droplet jetting apparatus  10  described above, the ink jet head  56  in which the opening diameter D of the nozzle  78 A is set to 16 μm was used, and the wiping member  200  in which the diameter of the weft yarn  220  was set to 20 μm and the width L of the gap between the weft yarn bundles  222  was set to 100 μm was used. 
     Example 3 
     In the liquid droplet jetting apparatus  10  described above, the ink jet head  56  in which the opening diameter D of the nozzle  78 A is set to 16 μm was used, and the wiping member  200  in which the diameter of the weft yarn  220  was set to 2 μm and the width L of the gap between the weft yarn bundles  222  was set to 10 μm was used. 
     Comparative Example 
     In the configuration of Example 1, the weft yarns  220  were arranged along the direction of relative movement (wiping direction) between the wiping member  200  and the nozzle surface  78 . That is, in the comparative example, a configuration in which the wiping member  200  moves relative to the nozzle surface  78  along the weft yarns  220  is employed. 
     As shown in  FIG. 8 , as a result of the evaluations, in Example 1, the wiping performance, the scraping performance, and the bubble infiltration prevention function were all evaluated as A. In Example 2, the wiping performance and the bubble infiltration prevention function were evaluated as A, and the scraping performance was evaluated as B. In Example 3, the wiping performance and the scraping performance were evaluated as A, and the bubble infiltration prevention function was evaluated as B. In the comparative example, although the wiping performance was evaluated as A, the scraping performance and the bubble infiltration prevention function were evaluated as C. 
     (Modification Example of Measuring Part  88 ) 
     In the embodiment described above, the measuring part  88  is configured as a sensor that irradiates the wiping member  200  with light after the nozzle surface  78  is wiped and detects the amount of light passing through the wiping member  200 , but is not limited thereto. For example, as the measuring part  88 , an imaging device (for example, a camera or microscope) which images the surface of the wiping member  200  may be used. In this configuration, for example, light which is reflected on the wiping member  200  and is incident on the measuring part  88  is converted into an electrical signal by an imaging element, and the amount of ink can be measured by the signal value. Specifically, for example, in a case where the wiping member  200  is white and the ink is magenta, the green component of the light is absorbed by the ink, and the green component of the light incident on the measuring part  88  decreases. Therefore, when the amount of ink adhered to the wiping member  200  increases, a signal value corresponding to the green component decreases. In addition, information regarding the signal value generated by the measuring part  88  is transmitted to the determination part  89 , and the determination part  89  determines whether or not the signal value generated by the measuring part  88  is equal to or lower than a predetermined specified value. In a case where the determination part  89  determines that the signal value generated by the measuring part  88  is equal to or lower than the predetermined specified value, the determination part  89  transmits a display command to the display part  87 . 
     Furthermore, as the measuring part  88 , an analysis device which analyzes the components of the ink adhered to the wiping member  200 . In this configuration, the wiping member  200  is advanced into the analysis device, and the amount of the ink components (for example, pigment) are measured. That is, in this configuration, the amount of ink is measured by using the fact that as the amount of ink adhered to the wiping member  200  increases, the amount of the ink components increases. In addition, information regarding the amount of the components measured by the measuring part  88  is transmitted to the determination part  89 , and the determination part  89  determines whether or not the amount of the components measured by the measuring part  88  is equal to or more than a predetermined specified amount. In a case where the determination part  89  determines that the amount of the components measured by the measuring part  88  is equal to or more than the predetermined specified amount, the determination part  89  transmits a display command to the display part  87 . 
     Other Modification Examples 
     In the embodiment described above, the weft yarns  220  are further exposed to the nozzle surface  78  side than the warp yarns  210 , and as a result, the configuration in which the weft yarns  220  among the warp yarns  210  and the weft yarns  220  come into contact with the nozzle surface  78  is employed. However, the embodiment is not limited thereto. For example, contact between the warp yarns  210  and the nozzle surface  78  in an area smaller than the area in which the weft yarns  220  come into contact with the nozzle surface  78  is allowed. 
     In addition, in the embodiment described above, the wiping member  200  is formed by weaving the weft yarn bundle bunches  224  and the plurality of warp yarns  210  to cross each other. However, the wiping member  200  is not limited thereto. For example, the wiping member  200  may also be formed by weaving the plurality of weft yarns  220  and the plurality of warp yarns  210  to cross one another. 
     In addition, in the embodiment described above, the display part  87  which performs predetermined displaying is used as an example of the notification part which notifies predetermined notification to the user of the apparatus. However, the notification part is not limited thereto. As the notification part, for example, the user of the apparatus may be notified by a method other than displaying (for example, sound). 
     In addition, in the embodiment described above, as the liquid droplet jetting apparatus for jetting liquid droplets, an ink jet apparatus which records an image by jetting ink droplets has been described. However, the liquid droplet jetting apparatus is not limited thereto. For example, the present invention can be applied to any liquid droplet jetting apparatus used industrially, such as an apparatus which produces a display color filter by jetting ink onto a polymer film or glass, or an apparatus which forms bumps for mounting components by jetting solder in a welded state onto a substrate. 
     In addition, in the embodiment described above, the wiping member  200  and the ink jet head  56  are moved relative to each other by moving the ink jet head  56  using the moving unit  82 . However, the embodiment is not limited thereto. For example, the wiping member  200  and the ink jet head  56  may be moved relative to each other by moving the wiping units  86  using the moving mechanism. Furthermore, the wiping member  200  and the ink jet head  56  may be moved relative to each other by individually moving the wiping units  86  and the ink jet head  56  using the moving mechanism. 
     In addition, in the embodiment described above, the wiping member  200  and the ink jet head  56  are moved relative to each other by moving the ink jet head  56  with the driving force of the moving unit  82 . However, the embodiment is not limited thereto. For example, the wiping member  200  and the ink jet head  56  may be moved relative to each other by manually moving the wiping member  200 . 
     The present invention is not limited to the above-described embodiments, and various modifications, changes, and improvements can be made in a scope without departing from the gist thereof. For example, a plurality of the above-described modification examples may be appropriately combined. 
     EXPLANATION OF REFERENCES 
     
         
         
           
               10 : liquid droplet jetting apparatus 
               56 : ink jet head (example of liquid droplet jetting head) 
               78 A: nozzle 
               78 : nozzle surface 
               80 : wiping mechanism 
               82 : moving unit (example of moving mechanism) 
               87 : display part (example of notification part) 
               88 : measuring part 
               200 : wiping member 
               210 : warp yarn 
               220 : weft yarn 
               222 : weft yarn bundle