Patent Publication Number: US-10766263-B2

Title: Maintenance unit and ink-jet recording apparatus therewith

Description:
INCORPORATION BY REFERENCE 
     This application is based upon and claims the benefit of priority from the corresponding Japanese Patent Application No. 2018-214526 filed on Nov. 15, 2018, the contents of which are hereby incorporated by reference. 
     BACKGROUND 
     The present disclosure relates to a maintenance unit for cleaning a recording head which ejects ink on a recording medium such as a sheet. The present disclosure relates to an ink-jet recording apparatus provided with a maintenance unit. 
     Recording apparatuses include, for example, facsimile machines, copiers, and printers. Ink-jet recording apparatuses, which form images by ejecting ink, can form high-definition images. Ink-jet recording apparatuses are widely used. 
     In conventional ink-jet recording apparatuses, recovery operation is usually performed. Recovery operation is an operation in which thickened ink in an ink ejection opening of a recording head is forcibly pushed out and the pushed-out ink is wiped off by a wiper. In some known ink-jet recording apparatuses, recovery operation of the recording head is performed using a maintenance unit. 
     The maintenance unit, for example, includes a wiper, a wiper carriage, and a collection tray. The wiper wipes off ink pushed out forcibly. The wiper carriage, while holding the wiper, moves along the wiping direction. The collection tray is arranged under the wiper and collects ink wiped off by the wiper. Some wiper carriages are provided with a holding plate for holding the wiper. 
     In a conventional maintenance unit, ink fallen from an ink ejection face can attach to the holding plate. When a large amount of ink is pushed out of the ink ejection face, ink tends to attach to the holding plate. The ink attached to the holding plate can coagulate on the holding plate. The ink attached to the holding plate can flow to an end part of the wiper carriage to affect the reciprocating movement of the wiper carriage. However, if an opening portion (an opening for guiding ink to the collection tray) in the holding plate is made larger for preventing ink from attaching to the holding plate, the strength of the holding plate is degraded. 
     SUMMARY 
     A maintenance unit according to one aspect of the present disclosure is a maintenance unit that cleans a recording head having an ink ejection face in which ink ejection openings for ejecting ink onto a recording medium are open. The maintenance unit includes a wiper for wiping off ink pushed out forcibly from the ink ejection face, a wiper carriage which, while holding the wiper, moves along the wiping direction, and a collection tray which is arranged under the wiper and has a tray face for collecting ink wiped off by the wiper. The wiper carriage has a holding plate for holding the wiper. In a part of the holding plate facing the ink ejection face, a communication portion which connects together an upper space and a lower space is formed. The communication portion is provided with an ink guide member having an upper opening which receives ink fallen from the ink ejection face when ink is pushed out forcibly from the ink ejection face, and a lower opening which is connected to the upper opening and makes ink fall on the collection tray. The length of the upper opening in the orthogonal direction perpendicular to the wiping direction is larger than the length of the ink ejection face in the orthogonal direction, and the length of the communication portion in the orthogonal direction is smaller than the length of the ink ejection face in the orthogonal direction, and the length of the lower opening in the orthogonal direction is smaller than the length of the communication portion in the orthogonal direction. 
     This and other objects of the present disclosure, and the specific benefits obtained according to the present disclosure, will become apparent from the description of embodiments which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram showing one example of a printer provided with a maintenance unit according to one embodiment of the present disclosure; 
         FIG. 2  is a diagram showing a first conveying unit and a recording portion in the printer according to the one embodiment of the present disclosure, as seen from above; 
         FIG. 3  is a diagram showing one example of a structure of the recording portion in the printer according to the one embodiment of the present disclosure; 
         FIG. 4  is a diagram showing one example of a structure of a recording head constituting a line head according to the one embodiment of the present disclosure; 
         FIG. 5  is a diagram showing one example of the recording head according to the one embodiment of the present disclosure, as seen from the ink ejection face-side; 
         FIG. 6  is a diagram showing one example of a structure of a cap unit, the first conveying unit, and the like in the printer according to the one embodiment of the present disclosure in a state where the first conveying unit is arranged in a raised position; 
         FIG. 7  is a diagram showing one example of the structure of the cap unit, the first conveying unit, and the like in the printer according to the one embodiment of the present disclosure in a state where the first conveying unit is arranged in a lowered position; 
         FIG. 8  is a diagram showing one example of the structure of the cap unit and the like in the printer according to the one embodiment of the present disclosure in a state where the cap unit and the maintenance unit are arranged in a first position; 
         FIG. 9  is a diagram showing a state where the cap unit and the maintenance unit are raised from the state in  FIG. 8 ; 
         FIG. 10  is a diagram showing one example of the structure of the cap unit in the printer according to the one embodiment of the present disclosure; 
         FIG. 11  is a diagram showing one example of the structure of the cap unit, the maintenance unit, and the like in the printer according to the one embodiment of the present disclosure in a state where the cap unit is arranged in a second position and the maintenance unit is arranged in the first position; 
         FIG. 12  is a diagram showing a state where the maintenance unit is raised from the state in  FIG. 11 ; 
         FIG. 13  is a diagram showing a state where a wiper carriage is moved from the state in  FIG. 12  in the arrow B direction; 
         FIG. 14  is a diagram showing one example of a structure of and around a unit lift mechanism in the printer according to the one embodiment of the present disclosure; 
         FIG. 15  is a diagram showing one example of a structure of and around a coupling pin and a push-up piece in the printer according to the one embodiment of the present disclosure in a state where the maintenance unit and the cap unit are not coupled together; 
         FIG. 16  is a diagram showing one example of the structure of and around the coupling pin and the push-up piece in the printer according to the one embodiment of the present disclosure in a state where the maintenance unit and the cap unit are coupled together; 
         FIG. 17  is a diagram showing one example of a structure of and around the wiper carriage and the wiper unit of the maintenance unit according to the one embodiment of the present disclosure; 
         FIG. 18  is a diagram showing one example of the structure of the wiper carriage of the maintenance unit according to the one embodiment of the present disclosure; 
         FIG. 19  is a diagram showing one example of the structure of the wiper unit of the maintenance unit according to the one embodiment of the present disclosure; 
         FIG. 20  is a diagram showing one example of a structure of a holding metal plate of the maintenance unit according to the one embodiment of the present disclosure; 
         FIG. 21  is a diagram showing one example of a structure of an ink guide member of the maintenance unit according to the one embodiment of the present disclosure: 
         FIG. 22  is a diagram showing one example of a cross section of the ink guide member of the maintenance unit according to the one embodiment of the present disclosure cut along the arrow AA′ direction; 
         FIG. 23  is a diagram showing one example of a structure of and around the wiper carriage, the ink guide members, and the tray face of the maintenance unit according to the one embodiment of the present disclosure; and 
         FIG. 24  is a diagram showing one example of a structure of and around a collection tray of the maintenance unit according to the one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is aimed at preventing, in a maintenance unit, adhesion of ink to a holding plate while suppressing degradation of strength of the holding plate. Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. 
     With reference to  FIGS. 1 to 24 , an ink-jet printer  100  (ink-jet recording apparatus) according to one embodiment of the present disclosure will be described. The printer  100  includes a maintenance unit  19 . As shown in  FIG. 1 , a sheet feeding cassette  2  (a sheet storage portion) is arranged in a lower part inside a printer main body  1 . Sheets P (one example of a recording medium) are stored inside the sheet feeding cassette  2 . A sheet feeding device  3  is arranged on the downstream side of the sheet feeding cassette  2  in the sheet conveying direction (on the upper right side of the sheet feeding cassette  2  in  FIG. 1 ). The sheet feeding device  3  feeds out sheets P one after another separately to the upper right of the sheet feeding cassette  2  in  FIG. 1 . 
     The printer  100  has a first sheet conveying passage  4   a  inside. The first sheet conveying passage  4   a  is located in the sheet feeding direction (to the upper right) of the sheet feeding cassette  2 . The first sheet conveying passage  4   a  conveys a sheet P fed out from the sheet feeding cassette  2  vertically upward along a side face of the printer main body  1 . 
     A registration roller pair  13  is provided at the downstream end of the first sheet conveying passage  4   a  in the sheet conveying direction. A first conveying unit  5  and a recording portion  9  are arranged close to a downstream-side part of the registration roller pair  13  in the sheet conveying direction. A sheet P fed out of the sheet feeding cassette  2  reaches the registration roller pair  13  via the first sheet conveying passage  4   a . The registration roller pair  13  corrects skewed feeding of the sheet P. After correction, the registration roller pair  13  feeds out the sheet P toward the first conveying unit  5  in coordination with the timing of ink ejecting operation by the recording portion  9 . 
     A second conveying unit  12  is arranged on the downstream side (the left side in  FIG. 1 ) of the first conveying unit  5  in the sheet conveying direction. A sheet P having an ink image recorded on it at the recording portion  9  is conveyed to the second conveying unit  12 . The second conveying unit  12 , while conveying the sheet, dries the ink on the surface of the sheet P. 
     A decurler portion  14  is provided on the downstream side of the second conveying unit  12  in the sheet conveying direction. The decurler portion  14  is provided near the left side face of the printer main body  1  shown in  FIG. 1 . The sheet P with the ink dried at the second conveying unit  12  is conveyed to the decurler portion  14 . The decurler portion  14  straightens the curl of the sheet P. 
     A second sheet conveying passage  4   b  is arranged on the downstream side of (above in  FIG. 1 ) the decurler portion  14  in the sheet conveying direction. When no double-sided recording is performed, the second sheet conveying passage  4   b  discharges the sheet P that has passed through the decurler portion  14  onto a sheet discharge tray  15 . The sheet discharge tray  15  is arranged outside, at the left side of, the printer  100  shown in  FIG. 1 . 
     A reversing conveying passage  16  for double-sided recording is provided above the recording portion  9  and the second conveying unit  12 . When double-sided recording is performed, the sheet P having been recorded on its first side and having passed through the second conveying unit  12  and the decurler portion  14  is conveyed via the second sheet conveying passage  4   b  to the reversing conveying passage  16 . The sheet P conveyed to the reversing conveying passage  16  has its conveying direction switched for recording on the second side. The sheet P is conveyed rightward in  FIG. 1  in the reversing conveying passage  16 . The sheet P passes back into the first sheet conveying passage  4   a . The sheet P is conveyed via the registration roller pair  13  to the first conveying unit  5  again with the second side up. 
     The maintenance unit  19  and a cap unit  50  are arranged below the second conveying unit  12 . During purging (details will be given later), the maintenance unit  19  moves horizontally to under the recording portion  9 . The maintenance unit  19  wipes off ink pushed out of ink ejection openings in recording heads. The maintenance unit  19  collects ink wiped off. When capping the ink ejection faces of the recording heads, the cap unit  50  horizontally moves to under the recording portion  9 . Then, the cap unit  50  moves upward to be attached to the bottom faces of the recording heads. 
     As shown in  FIGS. 2 and 3 , the recording portion  9  includes a head housing  10  and line heads  11 C,  11 M,  11 Y and  11 K, These line heads  11 C to  11 K are held by the head housing  10 . The first conveying unit  5  includes a driving roller, a plurality of driven rollers, and a first conveying belt. The first conveying belt is stretched around these rollers. The line heads  11 C to  11 K are supported at such a height as to leave a predetermined clearance (for example, 1 mm) between the ink ejection openings and the conveying face of the first conveying belt. For each line head  11 , a plurality of (here, three) recording heads  17   a  to  17   c  are arranged in a staggered manner along the sheet orthogonal direction (the direction perpendicular to the sheet conveying direction). In  FIG. 2  and the following relevant diagrams, the direction A indicates the sheet conveying direction. In  FIG. 2  and the following relevant diagrams, the sheet orthogonal direction (the direction perpendicular to the sheet conveying direction) is indicated by arrows BB′. 
     As shown in  FIGS. 4 and 5 , the recording heads  17   a  to  17   c  include ink ejection faces F. The bottom faces of the recording heads  17   a  to  17   c  are the ink ejection faces F. The ink ejection face F has an ink ejection region R. A large number of ink ejection openings  18  (see  FIG. 2 ) are arrayed in the ink ejection region R. The recording heads  17   a  to  17   c  have the same shape and structure. The recording head shown in  FIGS. 4 and 5  can be any of the recording heads  17   a ,  17   b , and  17   c.    
     The recording heads  17   a  to  17   c  constituting the line heads  11 C to  11 K are fed with ink. The line heads  11 C to  11 K are fed with ink of different colors (cyan, magenta, yellow, and black) corresponding to them. An ink tank (unillustrated) that stores and feeds ink is provided for each color. 
     A control portion  110  (see  FIG. 1 ) which controls the whole printer  100  is provided. The control portion  110  transmits a control signal corresponding to image data received from an external computer or the like. A sheet P is conveyed while being held by suction on the conveying face of the first conveying belt. The recording heads  17   a  to  17   c , based on a control signal from the control portion  110 , eject ink from the ink ejection openings  18  onto a sheet. A color image having ink of four colors, namely cyan, magenta, yellow and black, overlaid together is formed on the sheet P. 
     To prepare for the subsequent printing, the printer  100  cleans the ink ejection faces F of the recording heads  17   a  to  17   c  at the start of printing after a long out-of-operation period and at intermissions during printing. In cleaning, ink is forcibly discharged from the ink ejection openings  18  of all the recording heads  17   a  to  17   c  and the ink ejection faces F are wiped using wipers  35   a  to  35   c  (see  FIG. 12 , details will be given later). 
     Next, the cap unit  50 , the maintenance unit  19 , and the structure around them will be described in detail. 
     As shown in  FIGS. 6 and 7 , the first conveying unit  5  is housed in a housing frame  70 . The first conveying unit  5  is configured to be ascendable/descendable in the up-down direction by the action of a conveying lift mechanism (unillustrated). The conveying lift mechanism includes a lifting drive source and a gear train. During printing, the first conveying unit  5  is arranged in a raised position (the position in  FIG. 6 ). In the lifted position, the first conveying unit  5  moves close to the ink ejection faces F of the recording heads  17   a  to  17   c . During recovery operation (details will be given later) and capping operation of the recording heads  17   a  to  17   c , the first conveying unit  5  is arranged in a lowered position (the position in  FIG. 7 ). 
     As shown in  FIGS. 7 and 8 , the cap unit  50  is configured to be reciprocatable between a first position (the position in  FIG. 8 ) and a second position (the position in  FIG. 7 ). The first position is right under the recording portion  9 . The second position is a position retracted from the first position in the horizontal direction (arrow A direction). When the cap unit  50  is arranged in the first position, the first conveying unit  5  is arranged in the lowered position. As shown in  FIGS. 8 and 9 , the cap unit  50  is configured to be ascendable/descendable in the up-down direction in the first position. 
     During printing and recovery operation, the cap unit  50  is arranged in the second position (the position in  FIG. 6 ). The cap unit  50  is so configured that, during capping operation, it moves to the first position (the position in  FIGS. 8 and 9 ) and then up to cover the ink ejection faces F of the recording heads  17   a  to  17   c  with the cap portions  53 . The cap unit  50  is so configured that, in the second position, it is coupleable/decouplable to and from the maintenance unit  19  (details will be given later). The cap unit  50  moves in the horizontal and up-down directions with the maintenance unit  19  coupled with the cap unit  50 . 
     As shown in  FIG. 10 , the cap unit  50  includes a cap tray  51 , a pair of tray side plates  52 , cap portions  53 , and height-direction positioning projections  54 . The cap tray  51  is made of sheet metal. The pair of tray side plates  52  is formed at opposite ends of the cap tray  51  in the arrow BB′ direction (wiping direction). The cap portions  53  comprise 12 of them; these are arranged on the top face of the cap tray  51 , and have depressed sections as seen from the orthogonal direction. The height-direction positioning projections  54  comprise four of them. 
     The cap portions  53  are arranged at the positions corresponding to the recording heads  17   a  to  17   c . As shown in  FIG. 9 , when the cap unit  50  in the first direction moves upward, the ink ejection faces F of the recording heads  17   a  to  17   c  fit in the cap portions  53 . When the cap unit  50  is raised toward the recording portion  9 , the height-direction positioning projections  54  make contact with the housing  10  of the recording portion  9 . This determines the position of the cap tray  51  in the height direction. Between bottom parts of both ends of the cap portions  53  in their longitudinal direction (arrow BB′ direction, wiping direction) and the cap tray  51 , a cap spring  55  is arranged. The cap spring  55  comprises a compression spring. The cap spring  55  serves to keep constant the pressure of contact between the cap portions  53  and the ink ejection face F. 
     As shown in  FIGS. 7 and 11 , the maintenance unit  19  is configured to be reciprocatable between the first position (the position in  FIG. 11 ) and the second position (the position in  FIG. 7 ). The first position is right under the recording portion  9 . The second position is a position retracted from the first position in the horizontal direction (arrow A direction). When the maintenance unit  19  is arranged in the first position, the first conveying unit  5  is arranged in the lowered position. As shown in  FIGS. 11 and 12 , the maintenance unit  19  is configured to be ascendable/descendable in the up-down direction in the first position. 
     During printing, the maintenance unit  19  is arranged in the second position. The maintenance unit  19  is so configured that, during recovery and capping operation, it moves up in the first position (position in  FIG. 11 ). 
     As shown in  FIGS. 12 and 13 , the maintenance unit  19  includes a wiper carriage  31  and a supporting frame  40 . The wiper carriage  31  is substantially in a rectangular shape. A plurality of wipers  35   a  to  35   c  are fixed to the wiper carriage  31 . The supporting frame  40  supports the wiper carriage  31 . 
     Rail portions  41   a  and  41   b  are formed on the opposite edges of the top face of the supporting frame  40  in the arrow AA′ direction (orthogonal direction). Rollers  36  provided at the four corners of the wiper carriage  31  make contact with rail portions  41   a  and  41   b . The wiper carriage  31  is supported so as to be movable inside the supporting frame  40  in the arrow BB′ direction (wiping direction). 
     To the outside of the supporting frame  40 , a wiper carriage moving motor  45  and a gear train (unillustrated) are fitted. The wiper carriage moving motor  45  is a motor for moving the wiper carriage  31  horizontally (in the arrow BB′ direction). One gear in the gear trains meshes with rack teeth (unillustrated) on the wiper carriage  31 . As the wiper carriage moving motor  45  rotates forward and backward, the gear train rotates forward and backward. In accordance with the rotation, the wiper carriage  31  reciprocates horizontally (in the arrow BB′ direction). 
     The wipers  35   a  to  35   c  scrape the ink ejection openings  18  of each of the recording heads  17   a  to  17   c . The wipers  35   a  to  35   c  wipe ink pushed out of the ink ejection openings  18 . The wipers  35   a  to  35   c  are elastic members (blades). The wipers  35   a  to  35   c  are, for example, members made of rubber such as EPDM. The wipers  35   a  to  35   c  are pressed into contact with the ink ejection faces F at wiping start positions outside the ink ejection regions R (see  FIG. 5 ). As the wiper carriage  31  moves, the wipers  35   a  to  35   c , while wiping the ink ejection face F, move in a predetermined direction (the arrow B direction in  FIG. 12 , the opposite direction of the wiping direction). The wipers  35   a  wipe the ink ejection face F of the recording head  17   a , The wipers  35   b  wipe the ink ejection face F of the recording head  17   b . The wipers  35   c  wipe the ink ejection face F of the recording head  17   c.    
     Four wipers  35   a  are arranged at substantially equal intervals in the sheet conveying direction. Likewise, also four wipers  35   b  and four wipers  35   c  are arranged at substantially equal intervals in the sheet conveying direction. The line heads  11 C to  11 K each include the recording heads  17   a ,  17   b  and  17   c . For each of the recording heads  17   a  (see  FIG. 3 ), one wiper  35   a  is arranged at a position corresponding to the recording head  17   a , For each of the recording heads  17   b  (see  FIG. 3 ), one wiper  35   b  is arranged at a position corresponding to the recording head  17   b . Each of the wipers  35   b  is fixed deviated by a predetermined distance with respect to the wipers  35   a  and  35   c  in the direction (arrow AA′ direction) perpendicular to the moving direction (wiping direction) of the wiper carriage  31 . For each of the recording heads  17   c  (see  FIG. 3 ), one wiper  35   c  is arranged at a position corresponding to the recording head  17   c.    
     A collection tray  44  is arranged on the top face of the supporting frame  40 . The collection tray  44  is arranged under the wiper carriage  31 . The ink collection tray  44  collects waste ink wiped off the ink ejection faces F by the wipers  35   a  to  35   c . The waste ink collected in the collection tray  44  is stored in a waste ink tank (unillustrated). The structure around the collection tray  44  will be described in detail later. 
     As shown in  FIG. 7 , the maintenance unit  19  is housed in a carriage  80 . In the second position, the maintenance unit  19  is arranged below the cap unit  50 . As shown in  FIGS. 7 and 11 , when moving horizontally (in the arrow AA′ direction), the maintenance unit  19  moves together with the carriage  80 . As shown in  FIGS. 11 and 12 , when moving in the up-down direction, the maintenance unit  19  moves in the up-down direction with respect to the carriage  80 . 
     The carriage  80  includes a carriage bottom plate  81  (see  FIG. 14 ) made of sheet metal and a pair of carriage side plates  82 . The maintenance unit  19  is placed on the carriage bottom plate  81  (see  FIG. 14 ). A pair of carriage side plates  82  is erect from both ends, in the arrow BB′ direction (the wiping direction), of the carriage bottom plate  81 . The carriage side plates  82  are configured so as to be slidable relative to carriage support rails (unillustrated) in the printer main body  1 . As shown in  FIG. 14 , on the top face of the carriage side plate  82 , a rack portion  82   a  is formed. The rack portion  82   a  has rack teeth. The rack portion  82   a  meshes with a gear  85   a . A gear train including the gear  85   a  couples to a carriage drive source (unillustrated motor). As the carriage drive source rotates forward and backward, the gear train rotates forward and backward. The carriage  80  can thus reciprocate between the first and second positions. The gear train including the gear  85   a  and the carriage drive source constitutes a unit horizontal-movement mechanism  85 . The unit horizontal-movement mechanism  85  makes the cap unit  50  and the maintenance unit  19  move horizontally. 
     As shown in  FIG. 14 , a unit lift mechanism  60  is provided inside the carriage  80 . The unit lift mechanism  60  raises and lowers the maintenance unit  19  in the up-down direction. The unit lift mechanism  60  includes wires  61   a  and  61   b , a wind-up pulley  62 , pulleys  63   a  and  63   b , and a wind-up drive motor (wind-up drive source)  64 . The wind-up pulley  62  winds up the wires  61   a  and  61   b . The pulleys  63   a  and  63   b  change the direction of the wires  61   a  and  61   b.    
     The wire  61   a  is stretched from the wind-up pulley  62  via the pulley  63   a  to be attached to a lower part of the maintenance unit  19  in the arrow A′ direction. The wire  61   b  is stretched from the wind-up pulley  62  via the pulleys  63   a  and  63   b  to be attached to a lower part of the maintenance unit  19  in the arrow A direction. The wires  61   a  and  61   b , the wind-up pulley  62 , and the pulleys  63   a  and  63   b  are provided one each on either side (on each of the front and back sides of the plane of  FIG. 14 ) in the arrow BB′ direction (wiping direction). A pair of wind-up pulleys  62  is fixed at opposite ends of a rotary shaft  65 . A rotary shaft gear (unillustrated) is fixed to the rotary shaft  65 . The rotary shaft gear meshes with the gear in the gear train (unillustrated) which couples to the wind-up drive motor  64 . As the wind-up drive motor  64  rotates forward and backward, the wind-up pulley  62  rotates forward and backward. 
     As shown in  FIGS. 14 and 15 , the maintenance unit  19  includes a plurality of coupling pins  42 . The coupling pins  42  all point up. On the bottom face of the tray side plate  52  in the cap unit  50 , there are formed coupling holes  52   a  (see  FIG. 15 ). The positions of the coupling holes  52   a  correspond to the coupling pins  42 . The coupling pins  42  and the coupling holes  52   a  constitute a coupling mechanism. The coupling mechanism couples and decouples the cap unit  50  and the maintenance unit  19  to and from each other. 
     When the maintenance unit  19  is lowered in the second position (the state in  FIG. 14 , the state arranged in a first height position), as shown in  FIG. 15 , the coupling pins  42  are not inserted in the coupling holes  52   a . Thus, the maintenance unit  19  and the cap unit  50  are not coupled with each other (decoupled from each other). On the other hand, when the maintenance unit  19  in the second position is raised (arranged in a second height position higher than the first height position), as shown in  FIG. 16 , the coupling pins  42  are inserted in the coupling holes  52   a . The maintenance unit  19  and the cap unit  50  are coupled with each other. As a result of the coupling, the cap unit  50  and the maintenance unit  19  are united. The cap unit  50  is now movable in the horizontal and up-down directions. 
     A cap supporting portion (unillustrated) is provided. The cap supporting portion supports the cap unit  50  in a decoupled state and in the second position. A lid member (unillustrated) is provided. The lid member, in a decoupled slate and except during capping operation, makes close contact with the cap portion  53  of the cap unit  50  in the second position. The lid member makes close contact with the cap portion  53  from above and protects the cap portion  53 . The lid member prevents foreign matter (dust, paper powder, or the like) from sticking to the top face (face which makes close contact with the ink ejection face F) of the cap portion  53 , and suppresses evaporation of moisture inside the cap portion  53 . 
     Next, the structure around the wiper carriage  31  will be described in detail. As shown in  FIGS. 17 and 18 , the wiper carriage  31  includes a carriage main body  120  made of sheet metal and a pair of rail portions  125 . Each rail portion  125  has a roller  36 . As shown in  FIG. 18 , the carriage main body  120  has a bottom face portion  120   a  and side face portions  120   b . The side face portions  120   b  are erect from end parts, in the arrow AA′ direction (orthogonal direction perpendicular to the wiping direction), of the bottom face portion  120   a . A pair of rail portions  125  is fixed to the side face portions  120   b.    
     On the bottom face portion  120   a , a wiper unit  130  shown in  FIG. 19  is fixed. As shown in  FIG. 19 , the wiper unit  130  includes wipers  35   a  to  35   c , a holding metal plate (holding plate)  131 , and an ink guide member  135 . The holding metal plate holds wipers  35   a  to  35   c.    
     The holding metal plate  131  is arranged parallel to the bottom face portion  120   a  (see  FIG. 18 ) of the carriage main body  120 . The holding metal plate  131  is placed on the bottom face portion  120   a . The holding metal plate  131  is, compared to the bottom face portion  120   a , formed slightly shorter in the arrow AA′ direction (orthogonal direction) and longer in the arrow BB′ direction (wiping direction). 
     As shown in  FIG. 20 , in the holding metal plate  131  in this embodiment, communication portions  132  and  133  are formed. The communication portions  132  and  133  connect together the upper space and the lower space. When purging, which will be described later, is started (that is, when the wiper carriage  31  is in the position in  FIG. 12 ), the communication portions  132  and  133  are formed at parts facing (right under) the ink ejection face F of the recording heads  17   a  to  17   c  (see  FIG. 3 ). 
     At the start of purging (when the wiper carriage  31  is in the position in  FIG. 12 , when the wiper carriage  31  is at the end in the arrow B′ direction, when the wiper carriage  31  is at the end on one side in the wiping direction), the holding metal plate  131  is arranged right under the recording head  17   c . The holding metal plate  131  is located right under the recording head  17   b  so as to overlap approximately one half of the recording head  17   b  on the arrow B′-direction side. The communication portion  132  of the holding metal plate  131  faces the ink ejection face F of the recording head  17   c . A plurality of communication portions  132  are provided for one recording head  17   c .  FIG. 20  shows an example where three communication portions  132  are provided for each recording head  17   c  The communication portion  133  faces approximately one half of the recording head  17   b  on the arrow a′-direction side. A plurality of communication portions  133  are provided for one recording head  17   b .  FIG. 20  shows an example where two communication portions  133  are provided for each recording head  17   b.    
     The wipers  35   c  are fitted farther to the arrow B′-direction side than the communication portion  132  farthest to the arrow B′-direction side (farthest to one side in the wiping direction) (see  FIG. 19 ). The wipers  35   b  are fitted farther to the arrow B′-direction side than the communication portion  133  farthest to the arrow B′-direction side (farthest to one side in the orthogonal direction) (see  FIG. 19 ). In the holding metal plate  131 , ink passage holes  134   a  and  134   b  are formed. Through the ink passage holes  134   a , ink wiped off by the wipers  35   c  passes downward. Through the ink passage holes  134   b , ink wiped off by the wipers  35   b  passes downward. 
     On the bottom face portion  120   a  of the carriage main body  120 , ink passage holes  124  corresponding to the ink passage holes  134   b  are formed. On the other hand, the ink passage holes  134   a  in the holding metal plate  131  are arranged farther to the arrow B′ direction (farther to the one side in the wiping direction) than the bottom face portion  120   a  of the carriage main body  120 . The bottom face portion  120   a  of the carriage main body  120  has no ink passage holes corresponding to the ink passage holes  134   a.    
     As shown in  FIGS. 19 and 20 , the ink guide members  135  are fixed to the holding metal plate  131  so as to cover the communication portions  132  and  133 . The ink guide members  135  are fitted in the communication portions  132  and  133 . As shown in  FIG. 21 , the ink guide member  135  includes guide portions  135   a  and  135   b . The guide portions  135   a  correspond to the communication portions  132 , The guide portions  135   b  correspond to the communication portions  133 .  FIGS. 19 and 21  show an example where the ink guide member  135  includes three guide portions  135   a  and two guide portions  135   b  The ink guide member  135  is integrally formed of resin. 
     As shown in  FIG. 22 , each of the guide portions  135   a  and  135   b  includes an ink receiving portion  136  and an ink guide portion  137 . The ink receiving portion  136  includes an upper opening  136   a  (opens upward). The upper opening  136   a  receives ink which falls from the ink ejection face F when ink is forcibly pushed out of the ink ejection opening  18 . In other words, ink falls from the ink ejection opening  18  into the upper opening  136   a . The ink guide portion  137  extends from the lower end of the ink receiving portion  136  downward. The ink guide member  137  is inserted in one of the communication portion  132  or  133 . In a lower end of the ink guide portion  137 , a lower opening  137   a  is formed. Ink falls from the lower opening  137   a  onto the collection tray  44 . 
     The ink receiving portion  136  has a pair of inclined faces  136   b  and a pair of inclined faces  136   c  (see  FIG. 21 ). The pair of inclined faces  136   b  is arranged on opposite sides in the arrow AA′ direction (orthogonal direction). The pair of inclined faces  136   b  is perpendicular to the arrow AA′ direction. The pair of inclined faces  136   b  is increasingly close together downward. The length or the ink receiving portion  136  in the orthogonal direction is increasingly small downward. The pair of inclined faces  136   c  is arranged on opposite sides in the arrow BB′ direction (wiping direction). The pair of inclined faces  136   c  is parallel to the arrow AA′ direction. The pair of inclined faces  136   c  is increasingly close together. The length of the ink receiving portion  136  in the wiping direction is increasingly small downward. That is, the ink receiving portion  136  has a tapered shape. On the other hand, the ink guide portion  137  is formed such that its inner face extends in the vertical direction. The opening&#39;s inner area (ink passage area) is constant in the up-down direction. 
     As shown in  FIGS. 22 and 23 , the length L 136   a  of the upper opening  136   a  in the arrow AA′ direction (orthogonal direction) is larger than the length Lf of the ink ejection face F in the arrow AA′ direction. On the other hand, the length L 137   a  of the lower opening  137   a  in the arrow AA′ direction is smaller than the length Lf of the ink ejection face F in the arrow AA′ direction. The length L 132  (=L 133 ) of the communication portions  132  and  133  in the arrow AA′ direction is smaller than the length Lf of the ink ejection face F in the arrow AA′ direction. 
     The length of the lower opening  137   a  in the arrow BB′ direction (wiping direction) is smaller than the length of the upper opening  136   a  in the arrow BB′ direction. Thus, as shown in  FIG. 20 , it is possible to provide bridging portions  138  between the communication portions  132  and between the communication portions  133  in the holding metal plate  131 . The bridging portions  138  are unpunched-out parts of the holding metal plate  131  (unpenetrated parts in the up-down direction). Compared to in a case where large communication portions  132  and  133  with respect to the ink ejection face F are provided, it is possible to suppress degradation in strength of the holding metal plate  131 . 
     As shown in  FIGS. 18 and 20 , in the bottom face portion  120   a  of the carriage main body  120  (see  FIG. 18 ), the communication portions  122  and  123 , the ink passage holes  124 , and the bridging portions  128  are formed. The communication portions  122  and  123 , the ink passage holes  124 , and the bridging portions  128  are formed in the same sizes and at the same positions as (right under) the communication portions  132  and  133 , the ink passage holes  134   b , and the bridging portions  138  (see  FIG. 20 ) of the holding metal plate  131 . 
     Next, the structure of the collection tray  44  will be described. As shown in  FIG. 17 , the collection tray  44  is arranged under the wipers  35   a  to  35   c  (carriage main body  120 ). The collection tray  44  collects ink wiped off by the wipers  35   a  to  35   c . As shown in  FIG. 24 , the top face of the collection tray  44  has a center groove  21  and a pair of tray faces  22 . The center groove  21  is located in a central part in the arrow BB′ direction (wiping direction) and extends in the arrow AA′ direction (orthogonal direction). On both sides of the center groove  21  in the arrow BB′ direction, the pair of tray faces  22  is arranged. The tray faces  22  are inclined downward toward the center groove  21 . Ink fallen onto the tray faces  22  flows toward the center groove  21 . The waste ink is thus collected. 
     The center groove  21  is formed so as to be inclined downward toward a central part in the arrow AA′ direction (orthogonal direction). A discharge port  23  is arranged in the center groove  21 . The discharge port  23  is arranged in the central part of the center groove  21  in the arrow AA′ direction. The discharge port  23  discharges collected ink downward. To the discharge port  23 , a discharge tube connected to a waste ink tank (none of these are illustrated) is connected. The ink fallen from the ink ejection face F onto the tray faces  22  flows on the tray faces  22  toward the center groove  21 . Then, the ink on the center groove  21  flows toward the discharge port  23 . Finally, the ink is discharged in the waste ink tank through the discharge port  23 . 
     A plurality of grooves  25  are arranged in the tray faces  22 , Each groove  25  extends in the arrow BB′ direction (wiping direction). Each groove  25  is formed in a shape with a V-shaped cross section as seen from the arrow BB′ direction. Ink fallen onto the tray faces  22  flows in the groove  25  toward the center groove  21 . 
     As shown in  FIG. 23 , the grooves  25  are provided so as to correspond to the ink guide members  135 . Each groove  25  is formed by a pair of inclined faces. The deepest portion  25   a  of the groove  25  faces the lower opening  137   a  of the ink guide member  135 . The pitch of the grooves  25  as seen from the wiping direction (the arrow BB′ direction) is equal to that of the lower openings  137   a.    
     Next, recovery operation for the recording heads  17   a  to  17   c  in the printer  100  according to this embodiment will be described. The control portion  110  (see  FIG. 1 ) controls recovery operation and capping operation which will be described below. The control portion  110  transmits a control signal. Based on the control signal, the control portion  110  controls operations of the recording heads  17   a  to  17   c , the maintenance unit  19 , the unit lift mechanism  60 , the unit horizontal-movement mechanism  85 , the conveying lift mechanism, different drive sources, and the like. 
     When recovery operation for the recording heads  17   a  to  17   c  is performed, the first conveying unit  5  facing the bottom face of the recording head  9  (see  FIG. 1 ) is lowered from the state in  FIG. 6  (see  FIG. 7 ). Here, the maintenance unit  19  is arranged in the first height position. The maintenance unit  19  and the cap unit  50  are not coupled with each other. 
     Next, the carriage  80  is moved horizontally from the second position to the first position. As shown in  FIG. 11 , the cap unit  50  is left in the second position. The maintenance unit  19  in the first height position is moved horizontally from the second position to the first position. 
     As shown in  FIG. 12 , the unit lift mechanism  60  raises the maintenance unit  19 . As a result, the wipers  35   a  to  35   c  in the maintenance unit  19  make contact with the wiping start positions of the ink ejection faces F of the corresponding recording heads  17   a  to  17   c.    
     Prior to wiping operation, the recording heads  17   a  to  17   c  are supplied with ink. The supplied ink is pushed (purged) forcibly out of the ink ejection openings  18  (see  FIG. 2 ). By this purging operation, thickened ink, foreign matter, and air bubbles inside the ejection openings  18  are discharged. The purged ink is pushed out to the ink ejection face F along the shape of the ink ejection region R (see  FIG. 5 ). 
     The amount of ink forcibly pushed out of the ink ejection openings  18  changes according to the purpose. When a large amount of ink is forcibly pushed out, ink falls (spills) from the ink ejection face F. The ink fallen from the ink ejection face F fails onto the collection tray  44  via the ink guide member  135  or directly. The ink fallen on the ink guide member  135  is collected by the ink receiving portion  136  in the arrow AA′ direction (orthogonal direction) and in the arrow BB′ direction (wiping direction) and then falls on the collection tray  44 . 
     After the ink is forcibly discharged, wiping operation in which ink (purged ink) on the ink ejection face F is wiped off is performed. Specifically, the wiper carriage moving motor  45  rotates forward from the state shown in  FIG. 12 . As shown in  FIG. 13 , the wiper carriage  31  moves horizontally in the arrow B direction (toward the other side of the wiping direction). The wipers  35   a  wipe off the ink on the ink ejection face F of the recording head  17   a . The wipers  35   b  wipe off the ink on the ink ejection face F of the recording head  17   b . The wipers  35   c  wipe off the ink on the ink ejection face F of the recording head  17   c . The waste ink wiped off by the wipers  35   a  to  35   c  is collected in the ink collection tray  44 . 
     Then, as shown in  FIG. 11 , the unit lift mechanism  60  (see  FIG. 14 ) lowers the maintenance unit  19  down to the first height position. The wipers  35   a  to  35   c  move downward away from the ink ejection faces F of the recording heads  17   a  to  17   c . Then, the control portion  110  makes the wiper carriage  31  move in the direction opposite to the wiping direction (the arrow B′ direction, the one side of the wiping direction). The maintenance unit  19  returns to its original state. 
     Then, the control portion  110  makes the carriage  80  and the maintenance unit  19  move horizontally from the first position to the second position. The maintenance unit  19  is thereby positioned under the cap unit  50 . Recovery operation for the recording heads  17   a  to  17   c  is finished. 
     Next, operation (capping operation) for attaching the cap unit  50  to the recording heads  17   a  to  17   c  in the printer  100  according to this embodiment will be described. 
     When the recording heads  17   a  to  17   c  are capped with the cap unit  50 , the control portion  110  makes the first conveying unit  5  facing the bottom face of the recording portion  9  (see  FIG. 1 ) descend (from the state in  FIG. 6  to the state in  FIG. 7 ). Here, the maintenance unit  19  is arranged in the first height position. The maintenance unit  19  and the cap unit  50  are not coupled with each other. 
     Then, the unit lift mechanism  60  (see  FIG. 14 ) raises the maintenance unit  19  from the first height position to the second height position. As shown in  FIG. 16 , the maintenance unit  19  and the cap unit  50  are thereby coupled with each other. 
     Then, the control portion  110  makes the carriage  80  move horizontally from the second position to the first position (see  FIG. 8 ). The cap unit  50 , while remaining coupled with the maintenance unit  19 , moves horizontally from the second position to the first position. 
     Then, the unit lift mechanism  60  makes the maintenance unit  19  and the cap unit  50  ascend (see  FIG. 9 ). When the cap portion  53  makes close contact with the ink ejection faces F of the recording heads  17   a  to  17   c , the control portion  110  makes the wind-up drive motor  64  (see  FIG. 14 ) stop rotation. Capping is thus completed. 
     The maintenance unit  19  according to the embodiment is a maintenance unit  19  that cleans the recording heads  17   a  to  17   c  having an ink ejection face F in which ink ejection openings  18  for ejecting ink onto a recording medium (sheet P) are open. The maintenance unit  19  includes wipers  35   a  to  35   c , a wiper carriage  31 , and a collection tray  44 . The wipers  35   a  to  35   c  wipe off ink on the ink ejection faces F. The wiper carriage  31 , while holding the wipers  35   a  to  35   c , moves along the wiping direction. The collection tray  44  has tray faces  22  arranged under the wipers  35   a  to  35   c . The collection tray  44  collects ink wiped off by the wipers  35   a  to  35   c . The wiper carriage  31  has a holding metal plate  131  (holding plate) for holding the wipers  35   a  to  35   c  and an ink guide members  135 . In a part of the holding metal plate  131  (holding plate) facing the ink ejection face F, communication portions  132  and  133  which connect together the upper space and the lower space are formed. The ink guide member  135  has an upper opening  136   a  and a lower opening  137   a  connected to the upper opening  136   a . The upper opening  136   a  receives ink fallen from the ink ejection face F and is arranged above the holding metal plate  131  (holding plate). The lower opening  137   a  is arranged in or under the communication portions  132  and  133  and above the tray faces  22 . The length of the upper opening  136   a  in the orthogonal direction (AA′ direction) which is perpendicular to the wiping direction is larger than the length Lf of the ink ejection face F in the orthogonal direction (AA′ direction). The length L 132  and L 133  of the communication portions  132  and  133  in the orthogonal direction (arrow AA′ direction) is smaller than the length Lf of the ink ejection face F in the orthogonal direction (arrow AA′ direction). The length L 137   a  of the lower opening  137   a  in the orthogonal direction (arrow AA′ direction) is smaller than the length L 132  and L 133  of the communication portions  132  and  133  in the orthogonal direction (AA′ direction). 
     Thus, even when the amount of ink pushed out of the ink ejection openings  18  is large, ink fallen from the ink ejection face F can be received with the ink guide members  135  without fail. It is possible to prevent ink from attaching to the holding metal plate  131 . Thus, ink does not coagulate on the holding metal plate  131 . Ink also does not flow to an end part of the wiper carriage  31  to affect the reciprocating movement of the wiper carriage  31 . 
     The length L 132  and L 133  of the communication portions  132  and  133  in the arrow AA′ direction (orthogonal direction) is smaller than the length Lf of the ink ejection face F in the arrow AA′ direction. This prevents the communication portions  132  and  133  from having a large width in the arrow AA′ direction. Degradation in strength of the holding metal plate  131  can thus be suppressed. 
     The length  137   a  of the lower opening  137   a  in the arrow AA′ direction (orthogonal direction) is smaller than the length L 136   a  of the upper opening  136   a  in the arrow AA′ direction. It is possible to make ink fall onto the tray faces  22  while collecting it. This allows the ink fallen on the tray faces  22  to easily flow. This prevents ink from coagulating on the tray faces  22 , Ink falls onto the tray faces  22  without spreading in the arrow AA′ direction, and thus it is possible to prevent small amount of ink from being scattered on the tray faces  22 . Ink flowability due to dispersion is not degraded and thus it is possible to prevent ink from coagulating. 
     The tray face  22  is inclined along the wiping direction. The tray face  22  has grooves extending along the wiping direction. The groove has a V-shaped cross section as seen from the wiping direction. The deepest portion of the groove faces the lower opening  137   a . This allows ink fallen from the lower opening  137   a  to fall onto the deepest portion  25   a  of the groove  25 . This makes ink flow smoothly in the groove  25 . 
     The length of the lower opening  137   a  in the wiping direction (arrow BB′ direction) is smaller than the length of the upper opening  136   a  in the wiping direction. This prevents the communication portions  132  and  133  from having a large width in the arrow BB′ direction. Degradation in strength of the holding metal plate  131  can thus be suppressed. Ink collected also in the arrow BB′ direction falls on the tray faces  22 . This allows the ink fallen on the tray faces  22  to easily flow. 
     A plurality of upper openings  136   a  and a plurality of communication portions  132  and  133  are provided for one ink ejection face F. On the holding metal plate  131  (holding plate), the bridging portions  138  are provided between a plurality of communication portions  132  and  133  for one ink ejection face F. The bridging portions  138  are the unpenetrated parts. The bridging portion  138  can be provided between the communication portions  132  corresponding to one ink ejection face F and between the communication portions  133  corresponding to one ink ejection face F. In this way, it is possible to make the size of each communication portion  132  and  133  small. Degradation in strength of the holding metal plate  131  can thus be suppressed. 
     The ink guide members  135  includes an ink receiving portion  136  and an ink guide portion  137 . The ink receiving portion  136  has an upper opening  136   a  and its length in the orthogonal direction (AA′ direction) is increasingly small downward. The ink guide portion  137  has a lower opening  137   a , extends from the lower end of the ink receiving portion  136  downward, and is inserted in the communication portions  132  and  133 . It is possible to prevent ink fallen from the ink ejection face F from attaching to the holding metal plate  131 . It is also possible to make ink fail on the collection tray  44 . 
     The length of the ink receiving portion  136  is increasingly small downward in the wiping direction. 
     It should be understood that the embodiments disclosed herein are in every aspect illustrative and not restrictive. The scope of the present disclosure is not limited by the description of the embodiments given above but by the appended claims, and encompasses any modifications made within a sense and scope equivalent to those of the claims. 
     For example, the above embodiments deal with an example where a plurality of communication portions  132  and  133  are provided in each ink ejection face F. Instead, one each of the communication portions  132  and  133  may be provided for each ink ejection face F. 
     The above embodiments also deal with an example where the holding metal plate (holding plate)  131  is provided on the bottom face portion  120   a  of the carriage main body  120  and the ink guide members  135  are provided on the holding metal plate  131 . However, this is not meant to limit the present disclosure. For example, with no holding metal plate  131  provided, the wipers  35   a  to  35   c  may be fixed to the bottom face portion  120   a  of the carriage main body  120 . The ink guide members  135  may be provided on the bottom face portion  120   a , in this case, the bottom face portion  120   a  of the carriage main body  120  corresponds to the “holding plate” according to the present disclosure. 
     The above embodiments deal with an example where the grooves  25  with the V shape cross section are formed on the tray faces  22 . This is in no way meant to limit the present disclosure. The tray faces  22  do not necessarily need to have grooves  25  formed in it.