Patent Publication Number: US-10308027-B2

Title: Liquid ejecting apparatus and cleaning apparatus

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     The entire disclosure of Japanese Patent Application No. 2016-249948, filed Dec. 22, 2016 is expressly incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a liquid ejecting apparatus such as, for example, an ink-jet printer, and relates to a cleaning apparatus. 
     2. Related Art 
     As a kind of a liquid ejecting apparatus, an ink-jet printer that performs printing by ejecting liquid such as ink onto paper from nozzles arranged on a liquid ejecting head is known. Some of these printers are equipped with a liquid discharging head cleaner (cleaning apparatus) that wipes the discharging surface (nozzle surface in which nozzles are arranged) of a liquid discharging head (liquid ejecting head) with a wiping member (absorption member) to absorb liquid on the discharging surface (for example, see JP-A-2011-067985). 
     Specifically, a liquid discharging head cleaner according to related art includes a first pressing roller and a second pressing roller that function as a pressing means (pressing section) for pressing a wiping member against, for contact, the discharging surface of a liquid discharging head. After the non-finish wiping of the entire discharging surface by an entire-width roller that is the first pressing roller, the finish wiping of the discharging surface is performed by a nozzle-surface roller that is the second pressing roller. 
     However, there are the following problems in a liquid discharging head cleaner (cleaning apparatus) according to related art. In a case where the discharging surface (nozzle surface) has a convex portion and a concave portion (level difference therebetween), if the force of pressing the absorption member (wiping member) against the discharging surface by the roller member is increased in order to increase the performance of wiping liquid on the discharging surface in non-finish wiping, the increased pressing force makes the discharging surface more susceptible to damage and resultant deterioration. Moreover, since the width of the nozzle-surface roller is less than that of the entire-width roller, the pressing force applied to, of the discharging surface, the nozzle peripheral area including the nozzles in finish wiping by the nozzle-surface roller is high, which makes the area especially susceptible to damage and resultant deterioration. 
     These problems and the like are not unique to ink-jet printers that perform printing by ejecting liquid ink from nozzles. These problems and the like are common to various liquid ejecting apparatuses equipped with a cleaning apparatus that wipes, by holding an absorption member in contact with a nozzle surface in which nozzles are arranged, liquid that is on the nozzle surface by means of the absorption member. 
     SUMMARY 
     An advantage of some aspects of the invention is to provide a liquid ejecting apparatus and a cleaning apparatus for achieving a reduction in the deterioration of a nozzle surface. 
     Solving means according to some aspects, and operational effects thereof, are described below. 
     A liquid ejecting apparatus according to an aspect comprises: a liquid ejecting head that ejects liquid from a plurality of nozzles arranged in a nozzle surface; an absorption member that is brought into contact with the nozzle surface and is able to absorb liquid that is on the nozzle surface; and a contacting section that performs a first contact of the absorption member with the nozzle surface and performs, after the first contact, a second contact of the absorption member with the nozzle surface by pressing the absorption member against the nozzle surface from an opposite side that is opposite of a side of contact with the nozzle surface, wherein pressure applied to, of the nozzle surface, a nozzle peripheral area including the nozzles due to contact of the absorption member in the first contact is lower than pressure applied to the nozzle peripheral area due to contact of the absorption member in the second contact. 
     Before the second contact, in which pressure for finish wiping is to be applied to the nozzle peripheral area, the first contact is performed, wherein pressure that is lower than pressure applied to the nozzle peripheral area in the second contact is applied to the nozzle peripheral area in the first contact. Therefore, the structure of the above aspect makes it possible to catch a foreign object and/or an inorganic substance in ink, thereby reducing the deterioration of the nozzle surface. 
     In the above liquid ejecting apparatus, preferably, the contacting section should include a first contacting section that performs the first contact by holding the absorption member in contact with the nozzle surface and a second contacting section that performs the second contact by holding the absorption member in contact with the nozzle surface. 
     With the preferred structure, by using the first contacting section, which is different from the second contacting section, it is possible to perform the first contact of applying pressure that is lower than pressure applied in the second contact. 
     In the above liquid ejecting apparatus, preferably, the first contacting section should have a concave portion that is recessed away from the absorption member at a portion corresponding to the nozzle peripheral area in comparison with a portion corresponding to an area other than the nozzle peripheral area. 
     The first contacting section having the preferred structure is suitable because it easily achieves a reduction in pressure applied to the nozzle peripheral area in the first contact. 
     In the above liquid ejecting apparatus, preferably, the pressure applied to the nozzle peripheral area of the nozzle surface due to the contact of the absorption member in the first contact should be lower than pressure applied to an area other than the nozzle peripheral area of the nozzle surface due to the contact of the absorption member in the first contact. 
     With the preferred structure, when the absorption member is in contact with the nozzle surface to absorb liquid, it is possible to absorb the liquid on the nozzle surface while suppressing the damage to the nozzle peripheral area. 
     In the above liquid ejecting apparatus, preferably, a coefficient of compressibility of a portion of the absorption member pressed against the nozzle peripheral area in the first contact should be smaller than a coefficient of compressibility of a portion of the absorption member pressed against the area other than the nozzle peripheral area in the first contact. 
     Since the coefficient of compressibility of the portion of the absorption member pressed against the nozzle peripheral area is smaller than the coefficient of compressibility of the portion of the absorption member pressed against the area other than the nozzle peripheral area, with the preferred structure, pressure is adjusted properly depending on a difference between the portions of the absorption member pressed against the nozzle surface. Therefore, it is possible to absorb the liquid on the nozzle surface while suppressing the damage to the nozzle peripheral area during the contact of the absorption member. 
     In the above liquid ejecting apparatus, preferably, in the first contact, the absorption member should be in contact with the nozzle surface without any contact with the nozzle peripheral area. 
     With the preferred structure, in the first contact, the absorption member is able to absorb liquid on the nozzle peripheral area or a liquid meniscus protruding from the nozzle by coming into contact with the liquid, without any contact with the nozzle peripheral area. Therefore, it is possible to absorb the liquid while suppressing the damage to the nozzle peripheral area. 
     In the above liquid ejecting apparatus, preferably, an area other than the nozzle peripheral area should be a raised surface that is higher in level than the nozzle peripheral area and should have lower liquid repellency than liquid repellency of the nozzle peripheral area. 
     Because of the wet-spreading of liquid on the raised surface, the liquid repellency of which is relatively low, with the preferred structure, the absorption member is able to absorb the liquid on the raised surface efficiently. 
     In the above liquid ejecting apparatus, preferably, the absorption member should be a belt-shaped member; and the belt-shaped member should be supplied from a supplying section to a second contact area where the second contact is performed, next from the second contact area to a first contact area where the first contact is performed, and next from the first contact area to a collecting section. 
     In the preferred structure, the common absorption member is used for the first contact and the second contact, resulting in efficiency in use of the absorption member. 
     In the above liquid ejecting apparatus, preferably, the absorption member should be supplied in such a way as to bring a contact portion that was in contact with the nozzle surface in the second contact to a position for contact with the nozzle surface in the first contact. 
     Since the contact region of the absorption member that was used for contact with the nozzle surface in the second contact is reused in the next first contact, the preferred structure makes it possible to reduce the amount of use of the absorption member. 
     A cleaning apparatus according to an aspect comprises: an absorption member that is brought into contact with a nozzle surface of a liquid ejecting head that ejects liquid from a plurality of nozzles arranged in the nozzle surface, and is able to absorb liquid that is on the nozzle surface; and a contacting section that performs a first contact of the absorption member with the nozzle surface and performs, after the first contact, a second contact of the absorption member with the nozzle surface by pressing the absorption member against the nozzle surface from an opposite side that is opposite of a side of contact with the nozzle surface, wherein pressure applied to, of the nozzle surface, a nozzle peripheral area including the nozzles due to contact of the absorption member in the first contact is lower than pressure applied to the nozzle peripheral area due to contact of the absorption member in the second contact. 
     Before the second contact, in which pressure for finish wiping is to be applied to the nozzle peripheral area, the first contact is performed, wherein pressure that is lower than pressure applied to the nozzle peripheral area in the second contact is applied to the nozzle peripheral area in the first contact. Therefore, the structure of the above aspect makes it possible to catch a foreign object and/or an inorganic substance in ink, thereby reducing the deterioration of the nozzle surface. 
    
    
     
       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 schematic diagram that illustrates an exemplary overall structure of a printer according to an exemplary embodiment. 
         FIG. 2  is a schematic plan view of a positional relationship between a supporting table and a maintenance mechanism. 
         FIG. 3  is a perspective view of a head unit. 
         FIG. 4  is a schematic plan view of a nozzle surface. 
         FIG. 5  is a schematic cross-sectional view of the head unit. 
         FIG. 6  is a perspective view of a wiper unit. 
         FIG. 7  is a perspective view of the wiper unit, taken from an opposite side in relation to  FIG. 6 . 
         FIG. 8  is an exploded perspective diagram that illustrates an exemplary structure of the wiper unit. 
         FIG. 9  is an exploded perspective diagram that illustrates an exemplary structure of a wiper cassette. 
         FIG. 10  is a side view of the wiper unit, illustrating a state of starting an operation for wiping a nozzle surface. 
         FIG. 11  is a side view of the wiper unit, illustrating a state of wiping the nozzle surface in the first contact. 
         FIG. 12  is a side view of the wiper unit, illustrating a state of wiping the nozzle surface in the first contact and the second contact. 
         FIG. 13  is a side view of the wiper unit, illustrating a state of completion of the operation for wiping the nozzle surface. 
         FIG. 14  is a schematic side view of a state of wiping the nozzle surface with the cloth sheet of the wiper cassette. 
         FIG. 15  is a schematic plan view of the state illustrated in  FIG. 14 , taken from the nozzle-surface side. 
         FIG. 16  is a schematic diagram that illustrates a state of wiping the nozzle surface with the cloth sheet in the first contact. 
         FIG. 17  is a schematic diagram that illustrates a state of wiping the nozzle surface with the cloth sheet in the second contact. 
         FIG. 18  is a side view of the wiper cassette, illustrating an operation of reeling the cloth sheet after the wiping. 
         FIG. 19  is a side view of a variation example of the structure of the wiper cassette. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     With reference to the accompanying drawings, a liquid ejecting apparatus according to an exemplary embodiment will now be explained. As illustrated in  FIG. 1 , a printer  11 , which is an example of a liquid ejecting apparatus, is an ink-jet printer that includes a transportation unit  14  and a printing unit  15 . The transportation unit  14  transports a recording target medium  13  such as paper supported on a supporting table  12  in a transportation direction Y along the surface of the supporting table  12 . The printing unit  15  performs printing by ejecting ink, which is an example of a liquid, onto the recording target medium  13  that is transported. 
     The supporting table  12 , the transportation unit  14 , and the printing unit  15  are built in, and assembled to, a printer body  16  such as housing or a frame. The supporting table  12  of the printer  11  extends in the width direction of the recording target medium  13  (in the direction orthogonal to sheet face of  FIG. 1 ). A cover  17 , which can be opened and closed, is provided on the printer body  16 . 
     The transportation unit  14  includes a pair of transportation rollers  18  and  19 , which are provided respectively upstream and downstream of the supporting table  12  in the transportation direction Y, and a guide plate  20 , which is provided downstream of the pair of transportation rollers  18  and  19  in the transportation direction Y and guides the recording target medium  13  while supporting it. Driven by a transportation motor (not illustrated), the pair of transportation rollers  18  and  19  of the transportation unit  14  rotate while nipping the recording target medium  13  therebetween. As a result of roller rotation, the recording target medium  13  is transported in the transportation direction Y along the surface of the supporting table  12  and then along the surface of the guide plate  20 . 
     The printing unit  15  includes guide shafts  22  and  23  and a carriage  25 . The guide shafts  22  and  23  are elongated in a scan direction X, which is the same as the width direction of the recording target medium  13  orthogonal to (intersecting with) the transportation direction Y of the recording target medium  13 . The carriage  25  is able to travel in a reciprocating manner in the scan direction X while being guided by the guide shafts  22  and  23 . Driven by a carriage motor  24  (see  FIG. 2 ), the carriage  25  reciprocates in the scan direction X. 
     At least one liquid ejecting head  27  (two heads in the present embodiment), which has nozzles  26  for ink ejection, is mounted on the bottom of the carriage  25 . That is, the liquid ejecting head  27  is mounted on the carriage  25  in a face-down orientation toward the supporting table  12  with a predetermined clearance therebetween in a vertical direction Z, and reciprocates in the scan direction X together with the carriage  25  driven by the carriage motor (see  FIG. 2 ). The two liquid ejecting heads  27  of the present embodiment are located at a predetermined distance from each other in the scan direction X, with a predetermined positional shift from each other in the transportation direction Y. 
     A part of a supply mechanism  31  for supplying ink from an ink cartridge  30  to the liquid ejecting head  27  is fixed at the opposite side with respect to the direction of gravity, that is, partially over the carriage  25 . The supply mechanism  31  causes ink to flow in a supply direction A from the ink cartridge  30 , which is on the upstream side, to the liquid ejecting head  27 , which is on the downstream side. The ink cartridge  30  and the supply mechanism  31  are provided as at least one pair for each kind of ink. In the present embodiment, four pairs are provided respectively for four kinds of ink. 
     The four ink cartridges  30  are detachably attached to respective (four in the present embodiment) attachment units  32  and contain ink of respective colors (kinds) that are different from one another. For example, the ink cartridges  30  contain cyan ink (C), magenta ink (M), yellow ink (Y), and black ink (K) respectively. Color printing, etc. on the recording target medium  13  is performed by ejecting, from the liquid ejecting head  27 , ink supplied from each ink cartridge  30 . 
     Each supply mechanism  31  includes a supply passage  33 , through which ink is supplied from the ink cartridge  30  to the liquid ejecting head  27 . The following components are provided on the supply passage  33  in order mentioned herein as viewed from the upstream side in the supply direction A: a supply pump  34  for sending ink, a filter unit  35  for trapping air bubbles and foreign particles in the ink, if any, a static mixer  36  for stirring the ink by causing a change in the flow of the ink through the supply passage  33 , an ink reservoir  37 , and a pressure adjustment unit  38  for adjusting ink pressure. 
     The supply pump  34  includes a diaphragm pump  40 , which has a variable pump chamber capacity, an inlet valve  41 , which is provided upstream of the diaphragm pump  40 , and an outlet valve  42 , which is provided downstream of the diaphragm pump  40 . The inlet valve  41  and the outlet valve  42  constitute a one-way valve that allows ink to flow toward the downstream side and does not allow ink to flow toward the upstream side. 
     Therefore, the supply pump  34  takes in ink through the inlet valve  41  from the ink cartridge  30  when the capacity of the pump chamber of the diaphragm pump  40  increases, and discharges the ink through the outlet valve  42  toward the liquid ejecting head  27  when the capacity of the pump chamber of the diaphragm pump  40  decreases. The filter unit  35  is provided detachably on the supply passage  33  at a position corresponding to the position of the cover  17  of the printer body  16 . A user is able to replace the filter unit  35  with new one after opening the cover  17 . 
     The printer  11  includes a controller  39 , which, for example, controls the rotation of the transportation motor (not illustrated) for driving the pair of transportation rollers  18  and  19 , controls the driving of the carriage motor  24  (see  FIG. 2 ) and the supply pump  34 , etc., and controls the ejection of ink from each nozzle  26  of the liquid ejecting head  27 . The liquid ejecting head  27  ejects ink from each nozzle  26  toward the recording target medium  13  transported over the supporting table  12  while reciprocating in the scan direction X together with the carriage  25  driven by the carriage motor  24 , thereby performing printing. 
     As illustrated in  FIG. 2 , a maintenance mechanism  43  for the maintenance of the liquid ejecting head(s)  27  is provided at a position adjacent to one end of the supporting table  12  in the scan direction X. In the present embodiment, the area where the liquid ejecting head  27  ejects ink onto the recording target medium  13  for the purpose of printing and where the recording target medium  13  is transported is referred to as transportation area PA. In the present case, the maintenance mechanism  43  is provided inside the scan area of the carriage  25  in the scan direction X and outside (in  FIG. 2 , to the right of) the transportation area PA. 
     The maintenance mechanism  43  includes a flushing unit  45 , a wiper unit  46 , and a cap unit  48 . They are arranged in this order as viewed from the transportation area PA in the scan direction X, meaning that the flushing unit  45  is the closest to the transportation area PA. The flushing unit  45  includes an ink receiver  44 . The wiper unit  46  is an example of a cleaning apparatus. The cap unit  48  includes two caps  47 , each of which has a shape like an open-topped box. 
     The carriage  25  and the liquid ejecting head  27  are in a standby state at a home position HP when printing is not performed, when power is OFF, and the like. The home position HP is a location where the cap unit  48  is provided. That is, the liquid ejecting head  27  is able to move from the transportation area PA to the home position HP, and vice versa, in the scan direction X orthogonal to (intersecting with) the transportation direction Y. 
     When the two liquid ejecting heads  27  are located at the home position HP, the two liquid ejecting heads  27  and the two caps  47  face each other in the vertical direction. Driving by a capping motor  49 , each of the two caps  47  moves vertically to a position of being in contact with the corresponding one of the two liquid ejecting heads  27  from a position of being distanced from the corresponding one of the two liquid ejecting heads  27 , and vice versa. 
     Each cap  47  performs capping, which is an operation of coming into contact with the corresponding liquid ejecting head  27  in such a way as to enclose the plurality of nozzles  26  and form a closed space by working together with the corresponding liquid ejecting head  27 , thereby preventing ink in the nozzles  26  from drying. Each liquid ejecting head  27  is capped by the corresponding cap  47  at the home position HP when, for example, printing is not performed. 
     One end of each suction tube (not illustrated) is connected to the corresponding cap  47  so that a suction force can be applied to the inside of the cap  47  via the tube by a suction pump  50 . Each liquid ejecting head  27  is capped by the corresponding cap  47  at the home position HP, and the suction pump  50  is driven in this head-capped state. Therefore, a suction force is applied to the inside (closed space) of the cap  47 , and, as a result, thickened ink, air bubbles, and the like inside the liquid ejecting head  27  are sucked out into the cap  47 . This is called as head cleaning. The operation of the capping motor  49  and the suction pump  50  is controlled by the controller  39  (see  FIG. 1 ). 
     The wiper unit  46  includes a wiper cassette  70  and a cassette holder  52 , to which the wiper cassette  70  is attached. The wiper cassette  70  is provided with a cloth sheet  70 S and is configured to wipe, for cleaning, the liquid ejecting head  27  by using the cloth sheet  70 S. The cloth sheet  70 S is an example of an absorption member that is capable of absorbing liquid such as ink. In the present embodiment, the wiper unit  46  includes an ink receiver cassette  51  for receiving ink ejected from the liquid ejecting head  27  when the wiping of the liquid ejecting head  27  by the wiper cassette  70  is to be performed. The ink receiver cassette  51  is attached to the cassette holder  52  at an attachment position downstream of the wiper cassette  70  in the transportation direction Y. The wiper unit  46  further includes a guide frame  53  and a holder driver  80 . The guide frame  53  is configured to guide the two X-directional sides (scan-directional sides) of the movable cassette holder  52  to which the wiper cassette  70  and the ink receiver cassette  51  are attached. The holder driver  80  is provided on the guide frame  53  and causes the cassette holder  52  to reciprocate in the transportation direction Y. The guide frame  53  is fixed to the printer body  16 . 
     When so-called flushing is performed, the liquid receiver  44  of the flushing unit  45  receives ejected (discharged) ink. Flushing is an operation of ejecting an ink droplet from each nozzle  26  for the purpose of prevention or troubleshooting of the clogging of the nozzle  26 , not for the purpose of printing. Regarding the position of the flushing unit  45 , the liquid receiver  44  is designed to be located under the left one of the two liquid ejecting heads  27  illustrated in  FIG. 2  when the right one of the two liquid ejecting heads  27  illustrated in  FIG. 2  is positioned over the wiper unit  46  (ink receiver cassette  51 ). 
     As illustrated in  FIG. 3 , a head unit  55  is designed to be mounted on the gravitation-directional face, that is, the bottom, of the carriage  25 , and includes a bracket portion  56 , which is to be mounted onto the carriage  25 , and the liquid ejecting head  27 , which has a shape like a rectangular parallelepiped protruding downward from the bracket portion  56 . The liquid ejecting head  27  includes a flow passage forming portion  57 , which has a shape like a rectangular parallelepiped protruding downward from the bracket portion  56  as mentioned herein, and a head body  58 , which has a shape like a rectangular plate and is fixed to the bottom of the flow passage forming portion  57 . The bottom face of the head body  58  illustrated in  FIG. 3  has a plurality of nozzle lines  59  (for example, eight lines). 
     A cover member  60 , which is a plate-like member that has a plurality of windows  60   a  (for example, four windows) as its through holes, is fixed to the bottom face of the head body  58  in such a way as to cover a part of a nozzle-opening face  61  (in the present example, bottom face), which has orifices of the nozzles  26  constituting the nozzle lines  59  (see  FIG. 4 ). A predetermined number of lines among the plurality of nozzle lines  59  are exposed through each one through-hole window  60   a  (for example, two lines each). Needless to say, the through-hole window  60   a  may be provided for each one of the plurality of nozzle lines  59 . 
     In the present embodiment, of the nozzle-opening face  61 , the area exposed through each through-hole window  60   a  is defined as nozzle neighborhood area  62  (nozzle peripheral area  62 ), inclusive of the nozzles  26 . That is, the nozzle-opening face  61 , which has orifices of the nozzles  26  of the liquid ejecting head  27 , is partially covered by the cover member  60 , which has the through-hole windows  60   a  each exposing a part that is defined as the corresponding nozzle neighborhood area  62  and is in the neighborhood of the orifices of the nozzles  26 . The nozzle “neighborhood” area  62  (the nozzle “peripheral” area  62 ) is inclusive of the orifices of the nozzles  26  themselves (see  FIG. 4 ). 
     As illustrated in  FIGS. 4 and 5 , the cover member  60  is fixed to the liquid ejecting head  27  by means of a fixing structure such as fastening, etc. in such a state that the nozzle-opening face  61  is covered except for each nozzle neighborhood area  62  exposed through the corresponding through-hole window  60   a . The entire bottom of the liquid ejecting head  27  with respect to the direction of gravity is a nozzle surface  63  that is the target of wiping by the wiper unit  46 . That is, the nozzle surface  63  includes the nozzle neighborhood area(s)  62  (i.e., the area inside each through-hole window  60   a ) and a nozzle non-neighborhood area (a nozzle non-peripheral area) that is other than the nozzle neighborhood area  62 , wherein the nozzle non-neighborhood area is the area of a raised surface  64 , which is slightly higher in level (i.e., convex-structured) than the nozzle neighborhood area  62  by an amount substantially equal to the thickness of the cover member  60  (in the present example, 0.1 mm). 
     Therefore, there is a level difference  65  of 0.1 mm between the nozzle neighborhood area  62  and the raised surface  64  (nozzle non-neighborhood area). That is, the nozzle surface  63  has a partially-concave-and-partially-convex structure, meaning that the part corresponding to the nozzle neighborhood area  62  is its concave part and that the part corresponding to the raised surface  64  is its convex part. The cover member  60  is made of, for example, metal (e.g., stainless steel). 
     As illustrated in  FIG. 4 , the nozzle line  59  is made up of many nozzles  26  (for example, one hundred eighty nozzles or three hundred sixty nozzles) that are arranged at a constant pitch in the transportation direction Y. Each nozzle line  59  ejects ink of one color corresponding to the ink color of the ink cartridge  30  (see  FIG. 1 ). Needless to say, the colors of ink ejected are not limited to the CMYK four colors. Ink of different colors, for example, light magenta, light cyan, light yellow, gray, orange, white, and the like may be ejected. The number of colors used by the liquid ejecting head  27  is not limited to the CMYK four colors. For example, it may be CMY three colors, black only, or the like. The plurality of nozzle lines  59  may include a non-used nozzle line(s) from which no ink is ejected. 
     In the present embodiment, liquid-repellent treatment (ink-repellent treatment) for making it easier to repel ink is applied to the nozzle-opening face  61  to form a liquid-repellent film  66  (ink-repellent film) thereon. On the other hand, an example of ink used in the present embodiment is pigment ink. In pigment ink, many pigment particles are dispersed in a liquid that is used as its dispersion medium. An organic pigment having an average particle diameter of 100 nm is used for cyan, magenta, and yellow, whereas carbon black (inorganic pigment) having an average particle diameter of 120 nm is used for black. 
     Pigment ink in the present example is water-based ink. Accordingly, many pigment particles are dispersed in water that is used as its dispersion medium. Therefore, in the present example, the liquid-repellent film  66  is a water-repellent film that has a function of repelling water-based ink. For example, the liquid-repellent film  66  may include a thin-film ground layer whose main ingredient is polyorganosiloxane containing an alkyl group and a liquid-repellent film layer made of metalalkoxide having a long chain polymeric matrix containing fluorine. The liquid-repellent film  66  wears away gradually due to abrasion through the processes of repetitive wiping of the nozzle-opening face  61 . If the degree of wear of the liquid-repellent film  66  exceeds a predetermined level, its liquid repellency decreases. The liquid-repellent film  66  may be a liquid-repellent coating film or a liquid-repellent monomolecular film. A film thickness and a liquid-repellent treatment method may be selected arbitrarily. 
     If the liquid repellency of the liquid-repellent film  66  decreases, the wetting angle (contact angle) of a liquid such as ink mist on the nozzle neighborhood area  62  decreases. Therefore, ink mist particles on the nozzle neighborhood area  62  tend to wet-spread and grow into one ink droplet (adhesion ink) that is comparatively large. Therefore, adhesion ink formed in this way could exist near the nozzle  26 ; in some cases, the orifice of the nozzle  26  becomes closed by the ink, and/or the ink flows into the nozzle  26 . 
     For example, if an ink droplet is ejected from a nozzle  26  in a state in which adhesion ink exists near this nozzle  26 , the contact of the ejected ink droplet with the adhesion ink could happen. In such a case, the contact induces a non-straight traveling of the ejected ink droplet in the air. Such a non-straight traveling of the ejected ink droplet in the air causes a deviation in the landing position of the ink droplet onto the recording target medium  13  (i.e., print dot forming position) from the targeted landing position, resulting in poor print quality. For this reason, the wear of the liquid-repellent film  66  due to wiping damage needs to be minimized. 
     On the other hand, the cover member  60  is manufactured by machine-pressing a metal plate into a predetermined shape. The surface of the cover member  60  is not treated to be liquid repellent. For this reason, the liquid repellency of the raised surface  64  (nozzle non-neighborhood area) is lower than that of the nozzle neighborhood area  62 . That is, the wetting angle of ink on the raised surface  64  is smaller than the wetting angle of ink on the nozzle neighborhood area  62 . 
     As illustrated in  FIG. 5 , the liquid ejecting head  27  includes a plurality of recording heads  67  (unit heads) (four heads in the present embodiment) that are arranged in a line at a constant pitch in the scan direction X. The periphery of the nozzle-opening face  61  that is the bottom face of each recording head  67  is covered by the cover member  60 , and each nozzle neighborhood area  62  including two lines of nozzles  26  is exposed through the corresponding through-hole window  60   a  of the cover member  60 . 
     Each nozzle  26  is in communication with the corresponding ink flow passage  57   a  formed inside the flow passage forming portion  57 . There is a plurality of supply tubes  55   a  protruding upward from the top of the flow passage forming portion  57 . The ink flow passages  57   a  are in communication with the supply tube  55   a  via flow passages not illustrated. Each supply tube  55   a  is in communication with, via a flow passage not illustrated, the supply port of the corresponding pressure adjustment unit  38  mounted on the carriage  25  (see  FIG. 1 ). 
     Therefore, from each pressure adjustment unit  38  (see  FIG. 1 ), ink of the corresponding color is supplied to the nozzles  26  of the corresponding recording head  67  via the supply tube  55   a  and the ink flow passages  57   a , etc. The liquid ejecting head  27  may have a single-head structure with three or more nozzle lines. 
     Next, the structure of the wiper unit  46  will now be explained. 
     As illustrated in  FIGS. 6 and 7 , the holder driver  80 , which includes an electric motor  81  serving as a power source and a power transmission mechanism  82  for transmitting the power of the electric motor  81  to the cassette holder  52  via a belt  83 , is provided on the guide frame  53 , which is fixed to the printer body  16 . Due to rotation of the electric motor  81 , the cassette holder  52  is driven by the holder driver  80  to reciprocate in the transportation direction Y while being guided by the guide frame  53  at its two X-directional sides (scan-directional sides). 
     For example, the rotation of the electric motor  81  in the forward direction causes “going” movement from the state illustrated in  FIG. 6  toward the downstream side in the transportation direction Y (rightward movement in  FIG. 6 ) in the wiper unit  46 . The going movement stops at a predetermined position when the rotation of the electric motor  81  stops. After the stop, next, the electric motor  81  is driven in the reverse direction. The reverse rotation causes “coming-back” movement for returning the cassette holder  52  to the original position illustrated in  FIG. 6  toward the upstream side in the transportation direction Y (leftward movement in  FIG. 6 ). As indicated by the dot-dot-dash line and the solid line in  FIG. 7 , the state of return of the cassette holder  52  to the original position is detected on the basis of a change in the position of a pivot lever  52   a  provided on the cassette holder  52 . 
     On one side of the cassette holder  52  in the scan direction X, a power transmission mechanism  90 , which includes an electric motor  91  and a gear train  92 , is provided. The gear train  92  is made up of a plurality of spur gears for transmitting the rotation of the electric motor  91 . When the electric motor  91  rotates, the rotation is transmitted by these gears of the power transmission mechanism  90  to the wiper cassette  70  attached to the cassette holder  52 . 
     In the present embodiment, the wiper cassette  70  includes a cloth sheet  70 S, an unreeling roller  74  (see  FIG. 9 ), and a reeling roller  73  (see  FIG. 9 ). The cloth sheet  70 S is an example of a belt-shaped member that has a predetermined length and is provided in the form of a roll on the unreeling roller  74 . The reeling roller  73  is configured to take up the cloth sheet  70 S unreeled out of the roll. A gear  74 G, which is fixed to a roller shaft end  74 J of the unreeling roller  74 , and a gear  73 G, which is fixed to a roller shaft end  73 J of the reeling roller  73  (see  FIG. 9 ), rotate by receiving the transmitted power of rotation of the electric motor  91 . Due to rotation of these gears, the cloth sheet  70 S is reeled onto the reeling roller  73  by a predetermined length. 
     A rotatable gear  97  and a rotary encoder  98  configured to rotate due to rotation of the gear  97  are provided on the cassette holder  52 . The wiper cassette  70  includes a rotation roller  76  (see  FIG. 9 ), which rotates due to reeling of the cloth sheet  70 S. A gear  76 G is fixed to a roller shaft end  76 J of the rotation roller  76 . The gear  76 G is in meshing engagement with a gear  77 , which is also provided on the wiper cassette  70  and is in meshing engagement with a gear  97 . Therefore, in the power transmission mechanism  90  of the cassette holder  52 , the rotation of the electric motor  91  is controlled in such a way as to reel the cloth sheet  70 S by a predetermined length using an output signal of the rotary encoder  98 . 
     The wiper cassette  70  includes a first roller  71  and a second roller  72  for holding the cloth sheet  70 S in contact with the nozzle surface  63  (see  FIG. 4 ) of the liquid ejecting head  27  by pressing the cloth sheet  70 S against the nozzle surface  63  from an opposite side that is opposite of a side of contact with the nozzle surface  63  when the nozzle surface  63  is wiped. The wiper cassette  70  includes a cassette frame  78 . Roller shaft ends  71 J of the first roller  71  and roller shaft ends  72 J of the second roller  72  are rotatably supported by the cassette frame  78 . 
     As illustrated in  FIG. 8 , in the wiper unit  46  of the present embodiment, the wiper cassette  70  and the ink receiver cassette  51  are detachably attached to the cassette holder  52 . Specifically, each of the two sidewalls of the cassette holder  52  in the scan direction X has two oblique slits that are inclined with respect to the vertical direction Z. The wiper cassette  70  is detached from the cassette holder  52  by disengaging convex parts  78   b  provided on the cassette frame  78  obliquely upward from the slits, and is attached to the cassette holder  52  by engaging the convex parts  78   b  obliquely downward with the slits. The ink receiver cassette  51  is detached from the cassette holder  52  by being pulled out upward in the vertical direction Z, and is attached to the cassette holder  52  by being pushed in downward in the vertical direction Z. The ink receiver cassette  51  can be pulled out of the cassette holder  52  by raising a lever  85 , which is provided on the cassette holder  52  and is pivotable. 
     Next, the structure of the wiper cassette  70  will now be explained. 
     As illustrated in  FIG. 9 , the wiper cassette  70  includes a cassette frame  78 , a first roller  71 , a second roller  72 , a rotation roller  75 , and a rotation roller  76 . The cassette frame  78  has two sidewalls at the respective sides in the scan direction X. The roller shaft ends  71 J of the first roller  71 , the roller shaft ends  72 J of the second roller  72 , the roller shaft ends  75 J of the rotation roller  75 , and the roller shaft ends  76 J of the rotation roller  76  are rotatably supported by the two sidewalls of the cassette frame  78 . The roller shaft ends  73 J of the reeling roller  73  and the roller shaft ends  74 J of the unreeling roller  74  are inserted into slits  78   a  of the two sidewalls of the cassette frame  78 . The cloth sheet  70 S of the wiper cassette  70  is set to have a shape that is determined by contact with each of the rollers  76 ,  72 ,  71 , and  75  as illustrated in the upper part of  FIG. 9 . 
     The unreeling roller  74  and the reeling roller  73 , the shaft ends of which are in the slits  78   a  of the two sidewalls of the cassette frame  78 , are rotatably supported at a predetermined distance from each other in the transportation direction Y in the internal space of the wiper cassette  70 . A yet-to-be-used cloth sheet  70 S is supported in the form of a roll on the unreeling roller  74 . As indicated by an arrow in  FIG. 9 , the unreeling roller  74  rotates to unreel the cloth sheet  70 S. As indicated by an arrow in  FIG. 9 , the reeling roller  73  rotates to reel the cloth sheet  70 S used after having been unreeled from the unreeling roller  74 , and supports the roll. Therefore, the unreeling roller  74  functions as an example of a supplying section that supplies the cloth sheet  70 S as an example of a belt-shaped member, and the reeling roller  73  functions as an example of a collecting section that collects the cloth sheet  70 S. 
     The rotation roller  76 , the second roller  72 , the first roller  71 , and the rotation roller  75  are rotatably supported at respective top positions by the two sidewalls of the cassette frame  78 . The unreeled part of the cloth sheet  70 S going from the unreeling roller  74  toward the reeling roller  73  is wrapped on the circumferential surface of each of the rollers  76 ,  72 ,  71 , and  75  in this order from the outside. Of the cloth sheet  70 S, the part that is in contact with the first roller  71  is defined as a first wrapped-on region S 1 , and the part that is in contact with the second roller  72  is defined as a second wrapped-on region S 2 . Similarly, the part that is in contact with the rotation roller  75  is defined as another wrapped-on region S 5 , and the part that is in contact with the rotation roller  76  is defined as another wrapped-on region S 6 . The cloth sheet  70 S supported on the roller surface as described above is tensioned between the unreeling roller  74  and the reeling roller  73  of the wiper cassette  70 . 
     Among the rollers on which the cloth sheet  70 S is wrapped, the first roller  71  is in a state of pressing the first wrapped-on region S 1  of the cloth sheet  70 S upward because the roller shaft ends  71 J of the first roller  71  are urged upward by compression springs B 1 . The second roller  72  is in a state of pressing the second wrapped-on region S 2  of the cloth sheet  70 S upward because the roller shaft ends  72 J of the second roller  72  are urged upward by compression springs B 2 . In the present embodiment, the urging force (compression force) of each of the compression springs B 1  is substantially equal to the urging force (compression force) of each of the compression springs B 2 . 
     Accordingly, the first roller  71  is configured to be able to hold at least a part of the first wrapped-on region S 1  of the cloth sheet  70 S in contact with the nozzle surface  63  by pressing the cloth sheet  70 S against the nozzle surface  63  from, of the cloth sheet  70 S, an opposite side that is opposite of a side of contact with the nozzle surface  63 . The first roller  71  functions as an example of a contacting section for contact of the cloth sheet  70 S with the nozzle surface  63 . The second roller  72  is configured to be able to hold at least a part of the second wrapped-on region S 2  of the cloth sheet  70 S in contact with the nozzle surface  63  by pressing the cloth sheet  70 S against the nozzle surface  63  from, of the cloth sheet  70 S, an opposite side that is opposite of a side of contact with the nozzle surface  63 . The second roller  72  also functions as an example of a contacting section for contact of the cloth sheet  70 S with the nozzle surface  63 . 
     The width of the cloth sheet  70 S of the present embodiment in the scan direction X is slightly greater than the width of the nozzle surface  63  of the liquid ejecting head  27  in the scan direction X. Therefore, it is possible to wipe the entire area of the nozzle surface  63  with the cloth sheet  70 S. The cloth sheet  70 S of the present embodiment has a thickness of 0.34 to 0.41 mm. The cloth sheet  70 S of the present embodiment is capable of absorbing and retaining 350% of a liquid in terms of weight ratio (ink and cleaning liquid). 
     In the present embodiment, the outer circumferential surface of the first roller  71  is a partially-concave-and-partially-convex surface, which has a level difference. Specifically, the first roller  71  includes a plurality of annular smaller-diameter sections  71   b , which are arranged at equal spaces in an axial direction and constitute an example of a concave portion that is recessed away from the cloth sheet  70 S, and a plurality of annular larger-diameter sections  71   a , some of which are arranged between the smaller-diameter sections  71   b  and the others of which are arranged near the two ends of the shaft. Each of the larger-diameter sections  71   a  has a larger outside diameter than that of each of the smaller-diameter sections  71   b . In the present embodiment, the first roller  71  includes five larger-diameter sections  71   a  and four smaller-diameter sections  71   b , and the level difference between the outer circumferential surface of each of the larger-diameter sections  71   a  and the outer circumferential surface of each of the smaller-diameter sections  71   b  (the height of steps existing along the roller axis direction in the outer circumferential surface of the first roller  71 ) is 0.6±0.1 mm. 
     The first roller  71  is made of a hard material, for example, metal or hard synthetic resin. The larger-diameter sections  71   a  and the smaller-diameter sections  71   b  are arranged alternately and integrally without any clearance therebetween from the roller shaft end  71 J to the roller shaft end  71 J in the axial direction. Each of the larger-diameter sections  71   a  may be made of an elastic material, for example, rubber. 
     Unlike the first roller  71 , the second roller  72  has a cylindrical outer circumferential surface without any level difference in the roller axis direction. That is, the second roller  72  has a shape like a round bar with a predetermined outside diameter between the roller shaft ends  72 J. In the present embodiment, the outside diameter of each of the larger-diameter sections  71   a  of the first roller  71  is the same as the outside diameter of the second roller  72 . The second roller  72  is made of a hard material, for example, metal or hard synthetic resin. 
     Next, the printer&#39;s operation of wiping the nozzle surface  63  will now be explained. 
     As illustrated in  FIG. 10 , in the printer  11 , during printing on the recording target medium  13 , the cassette holder  52  of the wiper unit  46  is in a standby state at its retracted position (which is the same as the position illustrated in  FIG. 6 ). In the present embodiment, when the cassette holder  52  waits at the retracted position, the ink receiver cassette  51  for receiving ink ejected from the liquid ejecting head  27  (nozzles  26 ) is positioned at the scan area of the liquid ejecting head  27  (carriage  25 ). In the wiper cassette  70 , the first wrapped-on region S 1  and the second wrapped-on region S 2  (see  FIG. 9 ), which are pressed upward by the first roller  71  and the second roller  72  respectively to serve as the wiping part of the cloth sheet  70 S, are located upstream of the scan area of the liquid ejecting head  27  in the transportation direction Y. The first wrapped-on region S 1  and the second wrapped-on region S 2  are arranged in this order as viewed toward the upstream side. 
     The printer  11  performs printing on the recording target medium  13  by alternately repeating recording operation and transportation operation, wherein, in the recording operation, an ink droplet is ejected from each nozzle  26  of the liquid ejecting head  27  onto the recording target medium  13  during the traveling of the carriage  25  in the scan direction X, and wherein, in the transportation operation, the recording target medium  13  is fed to the next recording position after the one-scan recording. 
     In the printer  11 , head cleaning of forcibly sucking ink out of each liquid ejecting head  27  through the nozzles  26  is performed at the home position HP at predetermined timing (for example, at the timing of replacement of the ink cartridge  30 , in the event of occurrence of faulty ink ejection from the nozzles  26 , before printing, etc.). Of the nozzle surface  63  of the liquid ejecting head  27 , the area corresponding to the inside of the cap  47  is wet with ink due to head cleaning. Therefore, wiping operation (cleaning operation) of wiping the nozzle surface  63  by means of the wiper cassette  70  (wiping it with the cloth sheet  70 S) of the wiper unit  46  is performed in order to remove the ink. Since the nozzle-opening face  61 , more particularly, the nozzle neighborhood area  62  (see  FIG. 5 ), is coated with the liquid-repellent film  66 , fine ink droplets on the nozzle neighborhood area (fine ink droplets smaller than the level difference  65  of 0.1 mm) flow when the cap  47  is released from the liquid ejecting head  27 . Therefore, comparatively large ink droplets (ink droplets larger than the level difference  65  of 0.1 mm) remain on the nozzle neighborhood area  62 . 
     To cause the nozzle surface  63  that is in such a state to be wiped by the wiper cassette  70  (with the cloth sheet  70 S), first, the carriage motor  24  is operated to move the carriage  25  to the position where the nozzle surface  63  of the liquid ejecting head  27  is to be wiped by the wiper cassette  70 . 
     Next, as illustrated in  FIGS. 11, 12, and 13 , the holder driver  80  of the wiper unit  46  is operated to move the cassette holder  52  from the retracted position in the transportation direction Y. Due to the movement, the nozzle surface  63  of the liquid ejecting head  27  is wiped with the cloth sheet  70 S. The operation of wiping it with the cloth sheet  70 S will now be explained in order. 
     Because of the movement of the cassette holder  52  of the wiper unit  46  from the retracted position, as illustrated in  FIG. 11 , first, the first roller  71 , the roller shaft ends  71 J of which are pushed upward by the compression springs B 1 , presses the cloth sheet  70 S of the wiper cassette  70  against the nozzle surface  63  from an opposite side that is opposite of a side of contact with the nozzle surface  63 . Pressed by the first roller  71 , the first wrapped-on region S 1  of the cloth sheet  70 S of the wiper cassette  70  is held in contact with the nozzle surface  63 . This contact is hereinafter referred to as “first contact”. Therefore, the first roller  71  functions as an example of a first contacting section configured to perform the first contact. 
     As illustrated in  FIGS. 14 and 15 , in the first contact, the cloth sheet  70 S (first wrapped-on region S 1 ) is pressed against the raised surface  64  by the larger-diameter sections  71   a  of the first roller  71  to produce the region of contact of the cloth sheet  70 S with the raised surface  64  as indicated by each hatched area in  FIG. 15 . In addition, the cloth sheet  70 S is pressed by the smaller-diameter sections  71   b  of the first roller  71  at the nozzle neighborhood areas  62  to produce the region of the cloth sheet  70 S at the nozzle neighborhood area  62  as indicated by each dotted shade area in  FIG. 15 . Therefore, in the first contact, the coefficient of compressibility P 2  of the region of the cloth sheet  70 S at the nozzle neighborhood area  62  is smaller than the coefficient of compressibility P 1  of the contact region of the cloth sheet  70 S pressed against the raised surface  64  (nozzle non-neighborhood area). In a state in which the cloth sheet  70 S is pressed with the coefficient of compressibility P 1  at the contact region and the coefficient of compressibility P 2  at the region each as enclosed by the dot-dot-dash line in  FIG. 15 , the cloth sheet  70 S moves in the transportation direction Y, which is the wiping direction, as indicated by the solid line and the dot-dot-dash line in  FIG. 14 . As a result, ink on the nozzle surface  63  is wiped with the cloth sheet  70 S. 
     In the present embodiment, the region of contact of the cloth sheet  70 S with the nozzle surface  63  in the first contact, that is, an example of a first contact area, includes at least a part of the first wrapped-on region S 1  and has a predetermined width in the transportation direction Y across the circumferential top of the first roller  71  in the vertical direction Z. In  FIG. 15 , the cloth sheet  70 S is not illustrated. 
     As illustrated in  FIG. 16 , in the first contact, since the smaller-diameter sections  71   b  of the first roller  71  correspond to the through-hole windows  60   a , in this state, almost no pressing (compression) by the first roller  71  acts on each part of the cloth sheet  70 S corresponding to the nozzle neighborhood area  62 . Therefore, the coefficient of compressibility P 2  of the region of the cloth sheet  70 S at the nozzle neighborhood area  62  is zero or almost zero, meaning that the cloth sheet  70 S is in contact with the nozzle surface  63  in a state of non-contact with the nozzle neighborhood area  62 . Even though the cloth sheet  70 S is not in contact with the nozzle neighborhood area  62 , since an ink droplet on the nozzle neighborhood area  62  will probably be greater in size than the level difference  65  (0.1 mm), the cloth sheet  70 S comes into contact with the ink droplet on the nozzle neighborhood area  62 . Therefore, in the first contact, the cloth sheet  70 S is able to absorb, and thus remove, the ink droplet on the nozzle neighborhood area  62  without any contact with the nozzle neighborhood area  62 . 
     Ink absorbed by the cloth sheet  70 S with which the nozzle surface  63  is wiped contains pigment particles as an inorganic substance. Therefore, if the cloth sheet  70 S moves in the wiping process while being in contact under a strong pressing force at the nozzle neighborhood area  62 , the pigment particles might function as abrasive grains to cause a damage at the nozzle neighborhood area  62 . If liquid repellency at the nozzle neighborhood area  62  decreases as a result of accumulation of repetitive damages, it might induce a non-straight traveling of an ejected ink droplet in the air, resulting in poor print image quality. 
     In this respect, in the present embodiment, the nozzle surface  63  is wiped with the cloth sheet  70 S with lower pressure at the nozzle neighborhood area  62  in comparison with pressure applied to the raised surface  64  in the first contact as illustrated in  FIG. 16 . Therefore, even if the wiping of the nozzle surface  63  with the cloth sheet  70 S in the first contact is repeated, the structure of the present embodiment prevents the cloth sheet  70 S from being pressed to the inside of the through-hole window  60   a  with a strong pressing force, making it less likely that liquid repellency at the nozzle neighborhood area  62  decreases. This reduces the possibility of the occurrence of a phenomenon of non-straight traveling of an ink droplet ejected from each nozzle  26  during printing. As a result, it is possible to offer excellent print image quality for a comparatively long period of time. 
     As illustrated in  FIG. 16 , the width M of the larger-diameter section  71   a  as viewed in the direction along the nozzle surface  63  intersecting with the direction of relative movement of the cloth sheet  70 S in relation to the liquid ejecting head  27  while being in held in contact with the nozzle surface  63  is less than the width L of the nozzle neighborhood area  62  in said intersecting direction along the nozzle surface  63 . In other words, the width M of the larger-diameter section  71   a  in the scan direction X orthogonal to the transportation direction Y, in which the cloth sheet  70 S moves in the process of wiping the nozzle surface  63 , is less than the width L of the nozzle neighborhood area  62  in the scan direction X. 
     Moreover, in the present embodiment, the width of the through-hole window  60   a  in the scan direction X, that is, the width L of the nozzle neighborhood area  62  in the scan direction X, is substantially equal to the width of the smaller-diameter section  71   b  of the first roller  71  in the scan direction X. For example, in the present embodiment, the width L of the nozzle neighborhood area  62  in the scan direction X is 6.58 mm. 
     Moreover, of the cover member  60 , the width of each part of the raised surface  64  between two adjacent nozzle neighborhood areas  62  in the scan direction X, that is, the interval between two adjacent nozzle neighborhood areas  62 , is substantially equal to the width M of the larger-diameter section  71   a  in the scan direction X. Therefore, the five larger-diameter sections  71   a  of the first roller  71  are arranged in the scan direction X at intervals substantially equal to the width L of the nozzle neighborhood area  62  in the scan direction X, and the four nozzle neighborhood areas  62  are arranged in the scan direction X at intervals substantially equal to the width M of the larger-diameter section  71   a  in the scan direction X. 
     Next, as illustrated in  FIG. 12 , because of the further movement of the cassette holder  52  of the wiper unit  46 , the second roller  72 , the roller shaft ends  72 J of which are pushed upward by the compression springs B 2 , presses the cloth sheet  70 S of the wiper cassette  70  against the nozzle surface  63  from an opposite side that is opposite of a side of contact with the nozzle surface  63  after the first contact by the first roller  71 . Pressed by the second roller  72 , the second wrapped-on region S 2  of the cloth sheet  70 S of the wiper cassette  70  is held in contact with the nozzle surface  63 . This contact is hereinafter referred to as “second contact”. Therefore, the second roller  72  functions as an example of a second contacting section configured to perform the second contact. 
     As illustrated in  FIG. 17 , in the second contact, the cloth sheet  70 S (second wrapped-on region S 2 ) is pressed by the outer circumferential surface of the second roller  72  against the raised surface  64  of the nozzle surface  63  and against the nozzle neighborhood areas  62  of the nozzle surface  63 . In the second contact, because of the existence of the level difference  65 , the coefficient of compressibility P 2  of the contact region of the cloth sheet  70 S pressed against the nozzle neighborhood area  62  is smaller than the coefficient of compressibility P 1  of the contact region of the cloth sheet  70 S pressed against the raised surface  64  (nozzle non-neighborhood area). In a state in which the cloth sheet  70 S is pressed with the coefficient of compressibility P 1  and the coefficient of compressibility P 2  each in the second contact, the cloth sheet  70 S moves in the transportation direction Y, which is the wiping direction, as indicated by the solid line and the dot-dot-dash line in  FIG. 14 . As a result, ink on the nozzle surface  63  is wiped with the cloth sheet  70 S. 
     Though its illustration is omitted, the region of contact of the cloth sheet  70 S with the nozzle surface  63  in the second contact, that is, an example of a second contact area, includes at least a part of the second wrapped-on region S 2  and has a predetermined width in the transportation direction Y across the circumferential top of the second roller  72  in the vertical direction Z. 
     In the present embodiment, the coefficient of compressibility P 2  of the contact region of the cloth sheet  70 S pressed against the nozzle neighborhood area  62  in the second contact is larger than the coefficient of compressibility P 2  in the first contact. That is, the second roller  72  is a non-recessed cylindrical roller that has “larger-diameter section  71   a ” only, meaning that there is no concave portion (smaller-diameter section  71   b ) at the position corresponding to each nozzle neighborhood area  62 , unlike the first roller  71 . Therefore, the pressure applied to the nozzle neighborhood area  62  by the second roller  72  due to the second contact of the cloth sheet  70 S is higher than the pressure applied to the nozzle neighborhood area  62  by the first roller  71  due to the first contact of the cloth sheet  70 S. Accordingly, in the second contact, the nozzle neighborhood area  62  is wiped with the cloth sheet  70 S at pressure higher than that in the first contact. For this reason, fine ink droplets remaining on the nozzle neighborhood area  62  without having been absorbed during the first contact are wiped away with the cloth sheet  70 S during the second contact. That is, the finish wiping of the nozzle surface  63  is performed as a result of the second contact. 
     The coefficient of compressibility P 1  of the contact region of the cloth sheet  70 S pressed against the raised surface  64  (nozzle non-neighborhood area) in the second contact is large, similarly to a large coefficient of compressibility in the first contact. Ink on the raised surface  64 , which has lower repellency to liquid ink as compared with each nozzle neighborhood area  62 , is more likely to wet-spread. Since ink having spread on the raised surface  64  is wiped with the cloth sheet  70 S with a large coefficient of compressibility twice successively, effective absorption by the cloth sheet  70 S is ensured. In the present embodiment, the amount of compression of the cloth sheet  70 S having a thickness of 0.34 to 0.41 mm is 0.07 to 0.08 mm when the cloth sheet  70 S is pressed against the raised surface  64  by the first roller  71  and the second roller  72  each. Accordingly, in the present embodiment, the thickness of the cloth sheet  70 S during the wiping of the raised surface  64  with it is 0.26 to 0.34 mm. 
     Next, as illustrated in  FIG. 13 , the cassette holder  52  of the wiper unit  46  arrives at its going movement end position. This ends the wiping of the nozzle surface  63  with the cloth sheet  70 S by the first roller  71  of the wiper cassette  70  due to the first contact and the wiping of the nozzle surface  63  with the cloth sheet  70 S by the second roller  72  of the wiper cassette  70  due to the second contact after the first contact. Through the going movement described above, the ink on the nozzle surface  63  is wiped away with the cloth sheet  70 S. 
     As illustrated in  FIG. 18 , in the present embodiment, in a state in which the cassette holder  52  is located at the going movement end position, the operation of reeling the cloth sheet  70 S of the wiper cassette  70  is performed. The rotation of the electric motor  91  (see  FIG. 6 ) is controlled to reel the cloth sheet  70 S by a predetermined length. Specifically, as indicated by arrows in  FIG. 18 , the roller shaft ends  74 J of the unreeling roller  74  and the roller shaft ends  73 J of the reeling roller  73  rotate to unreel the cloth sheet  70 S, which is an example of a belt-shaped member, from the unreeling roller  74 , which is an example of a supplying section. First, the cloth sheet  70 S is supplied to the second contact area where the second contact is performed. After that, the cloth sheet  70 S is supplied to the first contact area where the first contact is performed. Finally, the cloth sheet  70 S is reeled onto the reeling roller  73 , which is an example of a collecting section. The reeling onto the reeling roller  73  is referred to as collection herein. 
     In the present embodiment, in the operation of reeling the cloth sheet  70 S, the cloth sheet  70 S is unreeled and supplied from the unreeling roller  74  in such a way as to bring the second contact area part, which is the sheet&#39;s region that was in contact with the nozzle surface  63  in the second contact, to a position for contact with the nozzle surface  63  in the first contact. In the present embodiment, the cloth sheet  70 S is reeled by a length Ls that brings the area part in the second wrapped-on region S 2  corresponding to the circumferential top part of the second roller  72  in the vertical direction Z to a position of the area part in the first wrapped-on region S 1  corresponding to the circumferential top part of the first roller  71  in the vertical direction Z. Therefore, the second contact area (region), which includes at least a part of the second wrapped-on region S 2 , and the first contact area (region), which includes at least a part of the first wrapped-on region S 1 , share a common region of contact. 
     In the present embodiment, during the operation of reeling the cloth sheet  70 S, the carriage  25  (see  FIG. 2 ) is moved in the scan direction X away from the position where the nozzle surface  63  of the liquid ejecting head  27  is to be wiped by the wiper cassette  70 . Then, in the wiper unit  46 , after the completion of wiping by the wiper cassette  70 , the electric motor  81  is driven in the reverse direction. The reverse rotation causes coming-back movement for returning the cassette holder  52  from the going movement end position toward the retracted position illustrated in  FIG. 6  in the wiper unit  46 . 
     The exemplary embodiment described above in detail produces, for example, the following effects. 
     (1) Before the second contact, in which pressure for finish wiping is to be applied to the nozzle neighborhood area  62 , the first contact is performed, wherein pressure that is lower than pressure applied to the nozzle neighborhood area  62  in the second contact is applied to the nozzle neighborhood area  62  in the first contact. Therefore, it is possible to catch a foreign object and/or an inorganic substance in ink, thereby reducing the deterioration of the nozzle surface  63 . 
     (2) By using the first roller  71 , which is an example of a first contacting section and is different from a second contacting section such as the second roller  72 , it is possible to perform the first contact of applying pressure that is lower than pressure applied in the second contact. 
     (3) The first roller  71  is suitable as an example of a first contacting section because the smaller-diameter section  71   b  functioning as an example of a concave portion easily achieves a reduction in pressure applied to the nozzle neighborhood area  62  in the first contact. 
     (4) Since the pressure applied to the nozzle neighborhood area  62  is low, when the cloth sheet  70 S functioning as an example of an absorption member is in contact with the nozzle surface  63  to absorb ink, it is possible to absorb the ink on the nozzle surface  63  while suppressing the damage to the nozzle neighborhood area  62 . 
     (5) Since the coefficient of compressibility P 2  of the regional part of the cloth sheet  70 S pressed against the nozzle neighborhood area  62  is smaller than the coefficient of compressibility P 1  of the regional part of the cloth sheet  70 S pressed against the area other than the nozzle neighborhood area  62 , pressure is adjusted properly depending on a difference between the regions of the cloth sheet  70 S pressed against the nozzle surface  63 . Therefore, it is possible to absorb the ink on the nozzle surface  63  while suppressing the damage to the nozzle neighborhood area  62  during the contact of the cloth sheet  70 S. 
     (6) Even if the cloth sheet  70 S is not in contact with the nozzle neighborhood area  62  during the first contact, the cloth sheet  70 S is able to absorb ink (containing pigment as an inorganic substance) on the nozzle neighborhood area  62  or an ink meniscus protruding from the nozzle  26  by coming into contact with the ink. Therefore, it is possible to absorb the ink while suppressing the damage to the nozzle neighborhood area  62 . 
     (7) Because of the wet-spreading of ink on the raised surface  64 , the liquid repellency of which is relatively low, the cloth sheet  70 S is able to absorb the ink on the raised surface  64  efficiently. 
     (8) The common cloth sheet  70 S is used for the first contact and the second contact, resulting in efficiency in use of the cloth sheet  70 S. 
     (9) Since the contact region of the cloth sheet  70 S that was used for contact with the nozzle surface  63  in the second contact is reused in the next first contact, it is possible to reduce the amount of use of the cloth sheet  70 S. 
     The exemplary embodiment described above may be modified as follows. 
     In the exemplary embodiment described above, the wiper cassette  70  may include a tension roller that applies tension to the cloth sheet  70 S by pressing the part of the cloth sheet  70 S between the first roller  71  and the second roller  72  away from the nozzle surface  63  from the side where the nozzle surface  63  is located. 
     As illustrated in  FIG. 19 , in this variation example, a tension roller  79  for applying a force to the cloth sheet  70 S in a direction of tightening the wrap of the cloth sheet  70 S onto the first roller  71  and the second roller  72  each is provided between the first roller  71  and the second roller  72 . The tension roller  79  is pulled downward, which is the direction of going away from the nozzle surface  63 , by tension springs B 3 , one end of each of which is connected to the corresponding one of the roller shaft ends  79 J of the tension roller  79  and the other end of each of which is fixed. 
     The wiper cassette  70  including the tension roller  79  according to this variation example makes it possible to, by adjusting the tensile force of the tension springs B 3  pulling the tension roller  79 , adjust the pressure of the cloth sheet  70 S against the nozzle surface  63  (nozzle neighborhood area  62 ) by the first roller  71  in the first contact and adjust the coefficient of compressibility of the cloth sheet  70 S. In addition, it is possible to adjust the pressure of the cloth sheet  70 S against the nozzle surface  63  (nozzle neighborhood area  62 ) by the second roller  72  in the second contact and adjust the coefficient of compressibility of the cloth sheet  70 S. 
     In the exemplary embodiment described above, it is not always necessary to provide the first roller  71 , which is configured to perform the first contact, and the second roller  72 , which is configured to perform the second contact. For example, a single contact member may be provided instead, wherein the single contact member has a cylindrical shape section that forms the first wrapped-on region S 1  by being in contact with the cloth sheet  70 S and a cylindrical shape section that forms the second wrapped-on region S 2  by being in contact with the cloth sheet  70 S, and wherein the cloth sheet  70 S is pressed against the nozzle surface  63  from an opposite side that is opposite of a side of contact with the nozzle surface  63 . In this case, the contact member is urged by an urging member (e.g., compression spring) adjusted in such a manner that the force of pressing the cloth sheet  70 S by the cylindrical shape section that forms the first wrapped-on region S 1  is weaker than the force of pressing the cloth sheet  70 S by the cylindrical shape section that forms the second wrapped-on region S 2 . 
     In the exemplary embodiment described above, it is not always necessary that the first roller  71  have a concave portion that is recessed away from the cloth sheet  70 S at each section corresponding to the nozzle neighborhood area  62  in comparison with each section corresponding to the area other than the nozzle neighborhood area  62 . That is, the first roller  71  may be a non-recessed cylindrical roller that has the same shape as the shape of the second roller  72 . In this case, the compression force of the compression spring B 1  may be designed to be weaker than the compression force of the compression spring B 2 , thereby ensuring that the pressure applied to the nozzle neighborhood area  62  due to the contact of the cloth sheet  70 S in the first contact is lower than the pressure applied to the nozzle neighborhood area  62  due to the contact of the cloth sheet  70 S in the second contact. 
     Alternatively, the first roller  71  may be a non-recessed cylindrical roller that has a smaller diameter to ensure non-contact of the wrapped-on part of the cloth sheet  70 S on the first roller  71  with the nozzle surface  63 , and the tension of the cloth sheet  70 S between the first roller  71  and the second roller  72  may be decreased so that the cloth sheet  70 S will slightly bulge toward the nozzle surface  63 , and the cloth sheet  70 S that is in such a bulged state may be brought into contact with the nozzle surface  63  to perform the first contact. Similarly to the foregoing embodiment, this variation example makes it possible to make the pressure applied to the nozzle neighborhood area  62  due to the contact of the cloth sheet  70 S in the first contact lower than the pressure applied to the nozzle neighborhood area  62  due to the contact of the cloth sheet  70 S in the second contact by the second roller  72 . 
     In the exemplary embodiment described above, it is not always necessary that, in the first contact, the pressure applied to the nozzle neighborhood area  62  of the nozzle surface  63  due to the contact of the cloth sheet  70 S be lower than the pressure applied to the area other than the nozzle neighborhood area  62  of the nozzle surface  63  due to the contact of the cloth sheet  70 S. For example, the former pressure may be equal to the latter pressure. In such a case, the first contact may be performed with a decreased (weakened) force of pressing the cloth sheet  70 S by the first roller  71  by, for example, setting the compression force of the compression spring B 1  to be weaker than the compression force of the compression spring B 2 . 
     In the exemplary embodiment described above, it is not always necessary that, in the first contact, the coefficient of compressibility P 2  of the regional part of the cloth sheet  70 S pressed against the nozzle neighborhood area  62  be smaller than the coefficient of compressibility P 1  of the regional part of the cloth sheet  70 S pressed against the area other than the nozzle neighborhood area  62 . For example, the value of the coefficient of compressibility P 2  may be the same as the value of the coefficient of compressibility P 1 . In such a case, the first contact may be performed with a decreased (weakened) force of pressing the cloth sheet  70 S by the first roller  71  by, for example, setting the compression force of the compression spring B 1  to be weaker than the compression force of the compression spring B 2 . 
     In the exemplary embodiment described above, in the first contact, the cloth sheet  70 S may be in contact with the nozzle surface  63  in a state of contact with the nozzle neighborhood area  62 . In such a case, in order to prevent a strong force from being applied to the nozzle neighborhood area  62  due to the contact of the cloth sheet  70 S with the nozzle neighborhood area  62 , that is, in order to avoid a large force of pressing the cloth sheet  70 S, for example, preferably, the compression force of the compression spring B 1  should be small to suppress the force of pressing the cloth sheet  70 S. 
     In the exemplary embodiment described above, instead of providing the raised surface  64 , a treatment for liquid repellency may be applied to the area that is located in the neighborhood of the orifices of the nozzles  26  of the nozzle-opening face  61  (area corresponding to the nozzle neighborhood area  62  in the exemplary embodiment described above) without applying a treatment for liquid repellency to the area (area corresponding to the nozzle non-neighborhood area in the exemplary embodiment described above) located outside the liquid-repellent treated area. In this case, the nozzle-opening face  61  corresponds to the nozzle surface  63  that is the target of wiping with the cloth sheet  70 S of the wiper cassette  70  in the exemplary embodiment described above. 
     In the exemplary embodiment described above, it is not always necessary that the liquid repellency of the raised surface  64  be lower than that of the nozzle neighborhood area  62 . For example, the liquid repellency of the raised surface  64  may be equal to that of the nozzle neighborhood area  62 . 
     In the exemplary embodiment described above, it is not always necessary that, in the wiper cassette  70 , the cloth sheet  70 S supplied from the unreeling roller  74  (supplying section) be collected onto the reeling roller  73  (collecting section). For example, the cloth sheet  70 S may have a shape of an endless belt wrapped on at least the second roller  72  and the first roller  71  and may be configured to turn for repetition of the second contact and the first contact. 
     In the exemplary embodiment described above, it is not always necessary that the cloth sheet  70 S be supplied in such a way as to bring the contact part that was in contact with the nozzle surface  63  in the second contact to a position for contact with the nozzle surface  63  in the first contact. For example, the cloth sheet  70 S may be supplied in such a way as to bring the part of the cloth sheet  70 S between the first-execution contact part of the cloth sheet  70 S that was, in wiping operation, in contact with the nozzle surface  63  in the first-execution second contact and the second-execution contact part of the cloth sheet  70 S that was in contact with the nozzle surface  63  in the second-execution second contact to a position for contact with the nozzle surface  63  in the first contact. In this case, preferably, the part of the cloth sheet  70 S for contact with the nozzle surface  63  in the first contact should be a middle part between the first-execution contact part of the cloth sheet  70 S and the second-execution contact part of the cloth sheet  70 S. 
     In the exemplary embodiment described above, a yet-to-be-used cloth sheet  70 S, with which the nozzle surface  63  has not been wiped yet, may have been impregnated in advance with a cleaning liquid (for example, water) for improving the performance of wiping the nozzle surface  63 . Alternatively, a cleaning liquid may be applied before wiping the nozzle surface  63  with a yet-to-be-used cloth sheet  70 S, instead of advance impregnation of the cloth sheet  70 S with the cleaning liquid. In a case of cleaning liquid application before wiping, a cleaning liquid may be applied to the cloth sheet  70 S in such a way that the first contact is to be performed in a state of containing the cleaning liquid and that the second contact is to be performed in a state of not containing the cleaning liquid. 
     In the exemplary embodiment described above, pressurized cleaning operation may be performed. In pressurized cleaning operation, the nozzle surface  63  is wiped by means of the wiper cassette  70  in a state in which ink bulges from the nozzle surface  63 . That is, the nozzle surface  63  may be wiped due to the first contact while activating the supply pump  34  to pressurize the supply passage  33 , through which ink is supplied from the ink cartridge  30  to the liquid ejecting head  27 , thereby causing ink to bulge from the nozzle surface  63 . 
     When such pressurized cleaning operation is performed, ink may be discharged through the nozzles  26  into the ink receiver cassette  51  in a state in which the cassette holder  52  is located at the retracted position. After that, the cassette holder  52  may be moved toward the downstream side in the transportation direction Y to perform the first contact by the first roller  71  and the second contact by the second roller  72 , thereby wiping the nozzle surface  63  with the cloth sheet  70 S. 
     In the exemplary embodiment described above, in the wiper unit  46 , the ink receiver cassette  51  may be provided upstream of the wiper cassette  70  in the transportation direction Y. In this case, at the retracted position (which is the same as the position illustrated in  FIG. 10 ) where the ink receiver cassette  51  is positioned at the scan area of the liquid ejecting head  27  (carriage  25 ), the first wrapped-on region S 1  and the second wrapped-on region S 2 , which are pressed upward by the first roller  71  and the second roller  72  respectively to serve as the wiping part of the cloth sheet  70 S, are located downstream of the scan area of the liquid ejecting head  27  in the transportation direction Y, and the first wrapped-on region S 1  and the second wrapped-on region S 2  are arranged in this order as viewed toward the downstream side. The holder driver  80  of the wiper unit  46  is operated to move the cassette holder  52  from the retracted position in the direction that is the opposite of the transportation direction Y (i.e., from the downstream side to the upstream side of the transportation direction), thereby wiping the nozzle surface  63  of the liquid ejecting head  27  with the cloth sheet  70 S. 
     In the exemplary embodiment described above, after wiping the nozzle surface  63  with the cloth sheet  70 S by moving the cassette holder  52  of the wiper unit  46  from the upstream side toward the downstream side in the transportation direction Y (going movement), the cassette holder  52  may be moved from the downstream side toward the upstream side in the transportation direction Y (coming-back movement) to wipe the nozzle surface  63  with the cloth sheet  70 S. In this case, it follows that the nozzle surface  63  is wiped with the cloth sheet  70 S in the first contact by the first roller  71  after having been wiped with the cloth sheet  70 S in the second contact by the second roller  72 . 
     In the exemplary embodiment described above, flushing of ejecting an ink droplet from each nozzle  26  may be performed into the ink receiver cassette  51 . Alternatively, flushing may be performed onto the cloth sheet  70 S. In a case where flushing is performed onto the cloth sheet  70 S, the already-used region (the region with which nozzle surface  63  has been wiped) of the cloth sheet  70 S may be used for the flushing. 
     In the exemplary embodiment described above, it is not always necessary that the width M of the larger-diameter section  71   a  in the scan direction X be less than the width L of the nozzle neighborhood area  62  in the scan direction X. 
     In the exemplary embodiment described above, the raised surface  64  may be formed integrally as a part of the liquid ejecting head  27  without providing the cover member  60 . In such a case, the nozzle-opening face  61  is a partially-concave-and-partially-convex surface. 
     In the exemplary embodiment described above, the cleaning of the liquid ejecting head  27  may be performed while capping the nozzle line  59  on a line-by-line basis. This makes it possible to reduce cap size as compared with a case where head cleaning is performed while capping all of the plurality of nozzle lines  59  with the cap  47 , thereby reducing the amount of ink consumption during head cleaning. 
     In the exemplary embodiment described above, instead of impregnating a yet-to-be-used cloth sheet  70 S with a cleaning liquid in advance, a cleaning liquid applying mechanism such as an ejection nozzle may be provided, and the nozzle surface  63  may be wiped with the cloth sheet  70 S after applying a cleaning liquid to the nozzle surface  63 . 
     In the exemplary embodiment described above, the nozzle surface  63  may be wiped by means of the wiper cassette  70  by moving the nozzle surface  63  in relation to the wiper cassette  70  (cassette holder  52 ) that is stationary. Alternatively, the wiping may be performed by moving both the wiper cassette  70  and the nozzle surface  63 . 
     In the exemplary embodiment described above, the ink-jet printer  11  may be a line-head-type printer that does not include the carriage  25  supporting the liquid ejecting head  27  and includes a line head whose print range encompasses the entire width of the recording target medium  13 . In this case, since the line head is fixed and immovable, the nozzle surface  63  is wiped by moving the wiper cassette  70 . 
     The printer  11  according to the exemplary embodiment described above has four nozzle neighborhood areas  62  corresponding to four recording heads  67  of the liquid ejecting head  27 . However, the number of nozzle neighborhood areas  62 , and the corresponding number of recording heads  67 , is not limited to four. The printer  11  may have, for example, five or more nozzle neighborhood areas  62 , the number of which corresponds to the number of recording heads  67 . 
     The liquid ejecting apparatus according to the exemplary embodiment described above may eject and/or discharge other liquid that is not ink instead of ink. Examples of the state of a droplet outputted as an ultra-small amount of the liquid from the liquid ejecting apparatus are: a particulate droplet, a tear-shaped droplet, and a viscous droplet that forms a thread tail. The “liquid” mentioned herein may be made of any material as long as it can be ejected from the liquid ejecting apparatus. Any material whose substance is in the liquid phase can be used, for example: liquid that has high viscosity or low viscosity, sol or gel water, or other fluid such as inorganic solvent, organic solvent, solution, liquid resin, or liquid metal (metal melt), though not limited thereto. The liquid is not limited to liquid as a state of substance. It encompasses a liquid matter that is made as a result of dissolution, dispersion, or mixture of particles of a functional material made of a solid such as pigment, metal particles, or the like into/with a solvent, though not limited thereto. Typical examples of the liquid are: liquid crystal, various liquid compositions such as water-based ink, non-water-based ink, oil-based ink, gel ink, and hot melt ink, etc. A specific example of the liquid ejecting apparatus is: an apparatus that ejects liquid in which, for example, a material such as an electrode material, a color material, or the like that is used in the production of a liquid crystal display, an EL (electroluminescence) display, a surface emission display, a color filter, or the like is dispersed or dissolved. The liquid ejecting apparatus may be an apparatus that ejects a living organic material used for production of biochips, or is used as a high precision pipette and ejects a liquid sample, a textile printing apparatus, or a micro dispenser, etc. The liquid ejecting apparatus may be an apparatus that ejects, with high precision, lubricating oil onto precision equipment, for example, a watch or a camera. The liquid ejecting apparatus may be an apparatus that ejects liquid of a transparent resin such as an ultraviolet ray curing resin, etc. onto a substrate so as to form a micro hemispherical lens (optical lens) that is used in an optical communication element, etc. The liquid ejecting apparatus may be an apparatus that ejects an etchant such as acid or alkali that is used for the etching of a substrate, etc.