Patent Publication Number: US-11654675-B2

Title: Inkjet recording device including controller controlling valve to close air communication opening formed in ink storage portion in case of occurrence of abnormality

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority from Japanese Patent Application No. 2020-062033 filed Mar. 31, 2020. The entire content of the priority application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to an inkjet recording device for recording an image on a recording medium by ejecting ink thereto. 
     BACKGROUND 
     In an inkjet recording device provided with a head, a meniscus that has a concave shape as viewed from the outside is formed in each nozzle of the head in order to stabilize ink ejection. 
     In an inkjet recording device in which ink is supplied to a head from an ink storage portion provided in a carriage on which the head is mounted, a concave meniscus is formed in each nozzle by setting an interior of the ink storage portion to negative pressure. Here, excessive negative pressure may result in the meniscus being broken. Therefore, the negative pressure of the interior of the ink storage portion needs to be maintained within a proper pressure range. 
     Japanese Patent Application Publication No. 2017-94658 discloses a printer including a valve. The valve is opened when the level of the negative pressure in an ink storage portion becomes great, thereby introducing air into the interior of the ink storage portion. When this introduction of air returns the level of the negative pressure into a proper pressure range, the valve is closed. In this way, in the disclosed printer, the valve is automatically opened and closed based on the level of the negative pressure in the ink storage portion to maintain the internal negative pressure within the proper range. 
     SUMMARY 
     However, with the conventional inkjet recording device described above, ink leakage may occur by permeation of ink into a recording medium from the nozzles due to contact of the nozzles with the recording medium. This contact may occur when jamming of the recording medium occurs in the inkjet recording device during an image recordation to the recording medium. The ink leakage causes reduction in amount of ink in the ink storage portion, which leads to pressure decrease (elevation in the level of negative pressure) in the storage portion. Hence, the permeation of ink into the recording medium can be suppressed. 
     However, according to the printer disclosed in the &#39;658 Publication, the valve is temporarily opened in response to decrease in the internal pressure (rise in the level of negative pressure), so that the level of the pressure in the storage portion is returned into the proper pressure range. As a result, the permeation of ink in the nozzles into the recording medium is again accelerated. As such, according to the disclosed printer, ink may be endlessly leaked in case of occurrence of ink permeation into the recording medium. 
     In view of the foregoing, it is an object of the disclosure to provide an inkjet recording device capable of reducing ink leakage from nozzles. 
     In order to attain the above and other objects, according to one aspect, the disclosure provides an inkjet recording device configured to perform an image recordation on a recoding medium by ejecting ink thereto. The inkjet recording device includes: a head, a support member, a storage portion, a valve, an actuator, a state sensor, and a controller. The head includes a nozzle configured to eject ink to the recording medium. The support member supports the head. The storage portion is configured to store therein ink. The storage portion has a part positioned above the nozzle. The storage portion has an air communication opening allowing an interior of the storage portion to be communicated with an outside of the storage portion. The valve is movable between: an opening position in which the valve opens the air communication opening; and a closing position in which the valve closes the air communication opening. The actuator is configured to move the valve. The state sensor is configured to detect a state of the inkjet recording device and to output a detection signal based on the detected state. The controller is configured to perform: (a) determining, on the basis of the detection signal, whether the inkjet recording device has an abnormality; and (b) controlling, in a case where determination is made in (a) that the inkjet recording device has an abnormality, the actuator to move the valve to the closing position from the opening position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The particular features and advantages of the embodiment(s) as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: 
         FIG.  1    is a perspective view of a multifunction peripheral  10  according to one embodiment; 
         FIG.  2    is a schematic vertical cross-sectional view illustrating the internal structure of a printer portion  11 ; 
         FIG.  3    is a vertical cross-sectional view of a platen  42  and a recording unit  24  taken along a plane perpendicular to a front-rear direction  8 , and particularly illustrates a state where a carriage  40  is at a maintenance position and a cap  70  is at a capping position; 
         FIG.  4    is a vertical cross-sectional view of the platen  42  and the recording unit  24  taken along the plane perpendicular to the front-rear direction  8 , and particularly illustrates a state where the carriage  40  is at the maintenance position and the cap  70  is at a separation position; 
         FIG.  5    is a vertical cross-sectional view of the platen  42  and the recording unit  24  taken along the plane perpendicular to the front-rear direction  8 , and particularly illustrates a state where the carriage  40  is positioned above a medium passing region  36  and the cap  70  is at the separation position; 
         FIG.  6    is a functional block diagram of the multifunction peripheral  10 ; 
         FIG.  7    is a flowchart illustrating control of opening and closing of a valve  89 ; 
         FIG.  8    is a flowchart illustrating an error process performed in the multifunction peripheral  10 ; 
         FIG.  9    is part of a flowchart illustrating image recording control in the multifunction peripheral  10 ; 
         FIG.  10    is the remaining part of the flowchart illustrating the image recordation control in the multifunction peripheral  10 ; 
         FIG.  11    is a flowchart illustrating an error process performed in a modification of the embodiment; and 
         FIG.  12    is a vertical cross-sectional view of a recording unit  24  taken along a plane perpendicular to the front-rear direction  8  in another modification of the embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a multifunction peripheral  10  according to one embodiment of the present disclosure will be described with reference to the accompanying drawings. In the following description, the directions indicated by the arrows in the drawings will be referred to the frontward direction, the rearward direction, the upward direction, the downward direction, the leftward direction, and the rightward direction. Further, the bi-direction indicated by two of the arrows that are directed opposite to each other will be referred to as the front-rear direction, the up-down direction, and the left-right direction. The up-down direction  7  is defined based on a state where the multifunction peripheral  10  is installed so as to be usable (the state illustrated in  FIG.  1   ). The front-rear direction  8  is defined such that a front surface  23  formed with an opening  13  (described later) is at the front side of the multifunction peripheral  10 . The left-right direction  9  is defined based on the front view of the multifunction peripheral  10 . The up-down direction  7 , the front-rear direction  8 , and the left-right direction  9  are perpendicular to one another. 
     [Overall Structure of Multifunction Peripheral  10 ] 
     As illustrated in  FIG.  1   , the multifunction peripheral  10  includes a housing  14  having a generally rectangular parallelepiped shape. A printer portion  11  is provided in a lower portion of the housing  14 . The multifunction peripheral  10  has various function such as facsimile function and printing function. The multifunction peripheral  10  has, as the printing function, a function of performing image recordation on one side of a sheet  12  (see  FIG.  2   ) with an inkjet recording system. Incidentally, the multifunction peripheral  10  may be of the type configured to perform image recordation on both sides of the sheet  12 . The multifunction peripheral  10  is an example of the inkjet recording device. The sheet  12  is an example of the recording medium. 
     An operating portion  17  is provided at an upper portion of the housing  14 . The operating portion  17  includes buttons configured to be operated for instruction of image recordation and various settings, and a liquid crystal display configured to display various information. In this embodiment, the operating portion  17  is configured of a touch panel having both the functions of the buttons and liquid crystal display. The operating portion  17  is an example of the receiving portion. 
     As illustrated in  FIG.  2   , the printer portion  11  includes a sheet tray  20 , a sheet feeding unit  16 , an outer guide member  18 , an inner guide member  19 , a pair of conveyer rollers  59 , a pair of discharge rollers  44 , a platen  42 , a recording unit  24 , a cap  70  ( FIG.  3   ), an electromagnetic valve  92  ( FIG.  3   ), a sheet sensor  120 , a rotary encoder  75  ( FIG.  6   ), a controller  130  ( FIG.  6   ), and a memory  140  ( FIG.  6   ). These are positioned in an interior of the housing  14 . Further, in the inside of the housing  14 , there are provided various state sensors configured to detect the state of the multifunction peripheral  10  and to output signals based on the detection results. The state sensors in the present embodiment includes an installation sensor  30 , a tray sensor  110 , a cover sensor  150 , an encoder  35 , and the sheet sensor  120 . However, the state sensors are not limited to these, and sensors employed in well-known multifunction peripherals are also available as the state sensors. 
     As illustrated in  FIG.  1   , the installation sensor  30  is positioned at a lower surface  14 A of the housing  14 . The installation sensor  30  is configured to detect whether the multifunction peripheral  10  is installed. That is, the installation sensor  30  is configured to detect the installation state of the multifunction peripheral  10 . Various types of known sensors are available as the installation sensor  30 . 
     In a state where the multifunction peripheral  10  is installed (placed) on a desk and the like, the lower surface  14 A of the housing  14  and the installation sensor  30  positioned at the lower surface  14 A are in contact with an upper surface of the desk. At this time, the installation sensor  30  outputs one of a high-level signal and a low-level signal to the controller  130 . In the present embodiment, the installation sensor  30  outputs the high-level signal to the controller  130  in a state where the multifunction peripheral  10  is installed. The upper surface of the desk and the like is an example of the installation surface. The high-level signal from the installation sensor  30  is an example of the installation signal and is also an example of the detection signal. 
     On the other hand, in a state the multifunction peripheral  10  is separated from the upper surface of the desk by, for example, user&#39;s lifting of the multifunction peripheral  10 , the lower surface  14 A and the installation sensor  30  are out of contact with (i.e., are not in contact with) the upper surface of the disk. At this time the installation sensor  30  outputs the other of the high-level signal and low-level signal to the controller  130 . In the present embodiment, the installation sensor  30  outputs the low-level signal in a state where the multifunction peripheral  10  is not installed. The low-level signal from the installation sensor  30  is an example of the uninstallation signal and is also an example of the detection signal. 
     [Sheet Tray  20 ] 
     As illustrated in  FIG.  1   , the opening  13  is formed at the front surface  23  of the printer portion  11 . The sheet tray  20  is movable in the front-rear direction  8  through the opening  13  so that the sheet tray  20  is insertable into and removable from the housing  14 . More specifically, the sheet tray  20  is movable between a sheet supply position (illustrated in  FIGS.  1  and  2   ) in which the sheet tray  20  is attached to the housing  14  and a sheet non-supply position in which the sheet tray  20  is removed from the housing  14 . The sheet tray  20  is moved to the sheet supply position by being inserted rearward relative to the housing  14 . The sheet tray  20  is moved to the sheet non-supply position by being pulled frontward from the housing  14 . The sheet tray  20  is an example of the tray. 
     The sheet tray  20  has a box shape having upper open end, and is configured to accommodate therein the sheets  12 . As illustrated in  FIG.  2   , the sheets  12  are supported in a stacked state on a bottom plate  22  of the sheet tray  20 . A discharge tray  21  is positioned above a front portion of the sheet tray  20 . The sheet  12  on which an image has been recorded by the recording unit  24  is discharged therefrom and then is supported on an upper surface of the discharge tray  21 . 
     As illustrated in  FIG.  2   , the sheet  12  supported on the sheet tray  20  can be conveyed to a sheet conveying passage  65  in a state where the sheet tray  20  is at the sheet supply position. 
     The tray sensor  110  is positioned at a rear lower internal portion of the housing  14 . The tray sensor  110  is supported by a lower wall  141  of the housing  14 . The tray sensor  110  is configured to detect whether the sheet tray  20  is positioned at the sheet supply position. Various types of well-known tray sensors may be available as the tray sensor  110 . For example, as illustrated in  FIG.  2   , the tray sensor  110  according to the present embodiment includes a shaft  111 , a detection probe  112 , and an optical sensor  113 . The detection probe is pivotally movable about an axis of the shaft  111 . The optical sensor  113  includes a light emitting element and a light receiving element configured to receive light emitted from the light emitting element. 
     The detection probe  112  is in a posture indicated by the broken line in  FIG.  2    in a state where the sheet tray  20  is not at the sheet supply position. At this time, an upper portion of the detection probe  112  is positioned in a space where a rear end portion of the sheet tray  20  is positioned when the sheet tray  20  is at the sheet supply position. The detection probe  112  is offset from an optical path extending from the light emitting element to the light receiving element, and thus, the detection probe  112  allows the light to pass through the optical path. Hence, a high-level signal is outputted from the optical sensor  113  to the controller  130 . The detection probe  112  is urged to the posture indicated by the broken line in  FIG.  2    by a spring (not illustrated). The high-level signal from the optical sensor  113  of the tray sensor  110  is an example of the feeding impossibility signal and is also an example of the detection signal. 
     When the sheet tray  20  is inserted into the housing  14  and moved from the sheet non-supply position to the sheet supply position, the rear end portion of the sheet tray  20  pushes the detection probe  112  rearward. Hence, the detection probe  112  is pivotally moved from the posture indicated by the broken line to the posture indicated by the solid line in  FIG.  2   . As a result, the rear upper end portion of the detection probe  112  enters the optical path and blocks the light. Hence, a low-level signal is outputted from the optical sensor  113  to the controller  130 . The low-level signal from the optical sensor  113  of the tray sensor  110  is an example of the feeding possibility signal and is also an example of the detection signal. 
     [Sheet Feeding Unit  16 ] 
     As illustrated in  FIG.  2   , the sheet feeding unit  16  is positioned below the recording unit  24  and above the bottom plate  22  of the sheet tray  20 . The sheet feeding unit  16  includes a sheet feeding roller  25 , a sheet feeding arm  26 , a power transmission mechanism  27 , and a shaft  28 . The sheet feeding roller  25  is rotatably supported by a tip end portion of the sheet feeding arm  26 . The sheet feeding arm  26  has a base end portion at which the shaft  28  is positioned. The sheet feeding arm  26  is pivotally movable about the axis of the shaft  28  along the directions indicated by an arrow  29 . Hence, the sheet feeding roller  25  is contactable with and separable from the sheet tray  20  or the uppermost sheet  12  of the sheet stack supported on the sheet tray  20 . 
     The power transmission mechanism  27  includes a gear train (a plurality of gears) and is configured to transmit the driving force of a sheet supply motor  102  (see  FIG.  6   ) to the sheet feeding roller  25  to rotate the same. When the sheet supply roller  25  is rotated, the sheet  12  that is positioned uppermost in the sheet stack supported on the sheet tray  20  and is in contact with the sheet supply roller  25  is conveyed to a sheet conveying passage  65 . Incidentally, the power transmission mechanism  27  may include, instead of the gear train, a belt looped over the shaft  28  and the shaft of the sheet feeding roller  25 . 
     [Sheet Conveying Passage  65 ] 
     As illustrated in  FIG.  2   , the sheet conveying passage  65  extends from the rear end portion of the sheet tray  20 . The sheet conveying passage  65  includes a curved portion  33  and a linear portion  34 . The curved portion  33  is U-shaped extending diagonally upward and rearward and then extending frontward. The linear portion  34  extends approximately in the front-rear direction  8 . 
     The curved portion  33  is defined by the outer guide member  18  and the inner guide member  19 , which face each other and are spaced away from each other by a predetermined interval. The outer guide member  18  and inner guide member  19  extend in the left-right direction  9 . A part of the linear portion  34  is defined by the recording unit  24  and the platen  42 , which face each other with a predetermined interval therebetween. 
     The sheet  12  supported by the sheet tray  20  is conveyed along the curved portion  33  by the sheet feeding roller  25 , and reaches the pair of conveyer rollers  59 . Then, the sheet  12  is nipped and conveyed frontward toward the recording unit  24  along the linear portion  34  by the pair of conveyer rollers  59 . After the sheet  12  has reached the position immediately below the recording unit  24 , the sheet  12  is subjected to image recordation by the recording unit  24 . Thereafter, the sheet  12  having an image recorded thereon is conveyed frontward along the linear portion  34  and discharged onto the discharge tray  21 . In this way, the sheet  12  is conveyed in a conveying direction  15  indicated by the one-dotted chain line in  FIG.  2   . 
     [Movable Cover  145 ] 
     As illustrated in  FIG.  2   , a movable cover  145  is supported by a rear wall  142  of the housing  14  so as to be pivotally movable about the axis of a shaft  145 A extending in the left-right direction  9 . The shaft  145 A is positioned at a lower end portion of the movable cover  145 . However, the position of the shaft  145 A is not limited to this. The movable cover  145  is an example of the cover. 
     The movable cover  145  is pivotally movable between a closed position and an open position indicated by a solid line and a broken line in  FIG.  2   , respectively. The outer guide member  18  is attached to the movable cover  145 . That is, the outer guide member  18  is pivotally movable integrally with the movable cover  145 . The outer guide member  18  constitutes the curved portion  33  when the movable cover  145  is at the closed position. At this time, the curved portion  33  is blocked from an outside of the housing  14 . The curved portion  33  is exposed to the outside of the housing  14  when the movable cover  145  is at the open position. Hence, removal of the sheet jammed in the sheet conveying passage  65  can be facilitated for a user. 
     The cover sensor  150  is positioned at a rear upper internal portion of the housing  14 . The cover sensor  150  is supported by a frame (not illustrated) of the housing  14 . The cover sensor  150  is configured to detect the position of the movable cover  145 . Note that, well-known movable covers may be available as the cover sensor  150 . The cover sensor  150  in the present embodiment includes, for example, a shaft  151 , a detection probe  152  pivotally movable about the axis of the shaft  151 , and an optical sensor  153  including a light emitting element and a light receiving element configured to receive light emitted from the light emitting element. 
     In a state where the movable cover  145  is at the open position, the detection probe  152  is in the posture indicated by the broken line in  FIG.  2    because of its own weight. At this time, a tip end portion of the detection probe  152  is positioned in a space where an upper portion of the movable cover  145  is positioned when the movable cover  145  is at the closed position. The detection probe  152  is offset from an optical path extending from the light emitting element to the light receiving element, and thus, the detection probe  152  allows the light to pass through the optical path. Hence, a high-level signal is outputted from the optical sensor  153  to the controller  130 . The high-level signal from the optical sensor  153  of the cover sensor  150  is an example of the open signal and is also an example of the detection signal. 
     When the movable cover  145  is pivotally moved from the open position to the closed position, the upper end portion of the movable cover  145  pushes the detection probe  152  frontward. Hence, the detection probe  152  is pivotally moved from the posture indicated by the broken line to the posture indicated by the solid line in  FIG.  2   . As a result, the tip end portion of the detection probe  152  enters into the optical path and blocks the light. Hence, a low-level signal is outputted from the optical sensor  153  to the controller  130 . Note that, although the detection probe  152  is urged by its own weight toward the posture indicated by the broken line in  FIG.  2    in the present embodiment, alternative manners may be employed for urging the detection probe  152  toward the posture indicated by the broken line in  FIG.  2   . For example, the detection probe  152  may be urged by a spring toward the posture indicated by the broken line in  FIG.  2   . The low-level signal from the optical sensor  153  of the cover sensor  150  is an example of the close signal and is also an example of the detection signal. 
     Incidentally, movement of the movable cover  145  between the closed position and the open position may be performed by alternative motions other than pivotal movement. For example, the movable cover  145  may be slidingly moved upward from the closed position to the open position. Alternatively, there may be employed a configuration in which the movable cover  145  is attachable to and detachable from the housing  14 . In this case, the closed position is provided by attaching the movable cover  145  to the housing  14 , and the open position is provided by detaching the movable cover  145  from the housing  14 . 
     [Pair of Conveyer Rollers  59  and Pair of Discharge Rollers  44 ] 
     As illustrated in  FIG.  2   , the pair of conveyer rollers  59  is positioned at the linear portion  34 . The pair of discharge rollers  44  is positioned at the linear portion  34  and downstream of the pair of conveyer rollers  59  in the conveying direction  15 . 
     The pair of conveyer rollers  59  includes a conveyer roller  60  and a pinch roller  61  positioned below and facing the conveyer roller  60 . The pinch roller  61  is urged toward the conveyer roller  60  by an elastic member such as a coil spring (not illustrated). The pair of conveyer rollers  59  is configured to nip the sheet  12  between the conveyer roller  60  and the pinch roller  61 . 
     The pair of discharge rollers  44  includes a discharge roller  62  and a spur roller  63  positioned above and facing the discharge roller  62 . The spur roller  63  is urged toward the discharge roller  62  by an elastic member such as a coil spring (not illustrated). The pair of discharge rollers  44  is configured to nip the sheet  12  between the discharge roller  62  and the spur roller  63 . 
     The conveyer roller  60  and the discharge roller  62  receive the drive force from a conveyer motor  101  (see,  FIG.  6   ) to rotate. When the conveyer roller  60  rotates in a state where the sheet  12  is nipped by the pair of conveyer rollers  59 , the sheet  12  is conveyed in the conveying direction  15  onto the platen  42  by the pair of conveyer rollers  59 . Further, when the discharge roller  62  rotates in a state where the sheet  12  is nipped by the pair of discharge rollers  44 , the sheet  12  is conveyed in the conveying direction  15  and discharged onto the discharge tray  21  by the pair of discharge rollers  44 . Incidentally, there may be employed a single common motor serving as both the conveyer motor  101  and the sheet supply motor  102 . In this case, power transmission paths from the common motor to each of the conveyer roller  60  and the discharge roller  62  are switchable from each other. 
     Incidentally, instead of rollers such as the pair of conveyer rollers  59  and the pair of discharge rollers  44 , a conveyer belt may be available for conveying the sheet  12 . 
     [Platen  42 ] 
     As illustrated in  FIG.  2   , the platen  42  is positioned at the linear portion  34  of the sheet conveying passage  65 . The platen  42  faces the recording unit  24  in the up-down direction  7 . The platen  42  is configured to support the sheet  12  conveyed along the sheet conveying passage  65  from below. 
     As illustrated in  FIGS.  3  through  5   , a medium passing region  36  is provided between the right edge and left edge of the platen  42  in the left-right direction  9 . The sheet  12  conveyed along the sheet conveying passage  65  passes through the medium passing region  36 . 
     [Recording Unit  24 ] 
     As illustrated in  FIG.  2   , the recording unit  24  is positioned above the platen  42  and faces the same. The recording unit  24  includes a carriage  40 , a head  38 , and a storage portion  80 . The carriage  40  is an example of the support member. 
     The carriage  40  is supported by guide rails  56  and  57  so as to be movable in the left-right direction  9  perpendicular to the conveying direction  15 . The left-right direction  9  is an example of the scanning direction. The guide rails  56  and  57  are positioned spaced away from each other in the front-rear direction  8  and extend in the left-right direction  9 . The carriage  40  is movable between a position rightward of the medium passing region  36  and a position leftward of the medium passing region  36 . Incidentally, the moving direction of the carriage  40  is not limited to the left-right direction  9 , but may be a direction crossing the conveying direction  15 . 
     The guide rail  56  is positioned upstream of the head  38  in the conveying direction  15 , and the guide rail  57  is positioned downstream of the head  38  in the conveying direction  15 . The guide rails  56  and  57  are supported by a pair of side frames (not illustrated) positioned outward of the linear portion  34  of the sheet conveying passage  65  in the left-right direction  9 . The carriage  40  receives the drive force from a carriage drive motor  103  (see  FIG.  6   ) to move. 
     The encoder  35  (see  FIG.  6   ) includes an encoder strip and an optical sensor. The encoder strip is positioned at one of the guide rails  56  and  57 . The encoder strip extends in the left-right direction  9 , and has a pattern of light transmission portions and light blocking portions alternately arrayed in the left-right direction  9  with equal intervals. The optical sensor is provided at the carriage  40  at a position facing the encoder strip. The optical sensor is configured to detect the light transmission portions and the light blocking portions to generate a pulse signal. The generated pulse signal is a signal identifying the position of the carriage  40  in the left-right direction  9 . The generated pulse signal is outputted to the controller  130  ( FIG.  6   ). The pulse signal from the optical sensor of the encoder  35  is an example of the position signal and is also an example of the detection signal. 
     The head  38  is supported by the carriage  40 . The head  38  has a lower surface  68  exposed downward and facing the platen  42 . The head  38  includes a plurality of nozzles  39 , an ink passage  37 , and piezoelectric elements  45  (see  FIG.  6   ). 
     The plurality of nozzles  39  are open at the lower surface  68  of the head  38 . The head  38  connects the storage portion  80  to the plurality of nozzles  39 . Each piezoelectric element  45  is configured to deform a part of the ink passage  37  to eject ink droplet downward from the corresponding nozzle  39 . The piezoelectric element  45  is driven upon electric supply controlled by the controller  130 . 
     The storage portion  80  is attached to and supported by the carriage  40 . The storage portion  80  has an internal space  81  in which ink is storable. In the present embodiment, the recording unit  24  includes a single storage portion  80  in which black ink is stored. Color of ink stored in the storage portion  80  is not limiting. 
     The storage portion  80  is positioned above the head  38 . Incidentally, in the present embodiment, the entire storage portion  80  is positioned above the head  38 . However, as an alternative, a part of the storage portion  80  may be positioned above the head  38  and the remaining part of the storage portion  80  may be positioned lower than the head  38  or even with the head  38 . 
     The internal space  81  of the storage portion  80  is in communication with the plurality of nozzles  39  through the ink passage  37 . Hence, ink can be supplied from the internal space  81  to the nozzles  39 . 
     The storage portion  80  has an upper wall  82  formed with an ink inlet  83  for injection of ink into the internal space  81 . The ink inlet  83  penetrates the upper wall  82  in the thickness direction to allow the internal space  81  to be communicated with an outside of the storage portion  80 . 
     A protruding wall  84  surrounding the ink inlet  83  protrudes upward from an upper surface of the upper wall  82 . The ink inlet  83  is closed by fitting a lid  85  with the protruding wall  84 . The ink inlet  83  is exposed to the outside by detaching the lid  85  from the protruding wall  84 . In this state, an ink bottle (not illustrated) can be inserted into the ink inlet  83  and ink can be injected from the ink bottle into the internal space  81  through the ink inlet  83  for replenishing the storage portion  80  with ink. Incidentally, the position of the ink inlet  83  is not limiting as long as the ink inlet  83  is at a position enabling the ink inlet  83  to communicate the upper portion of the internal space  81  with the outside. 
     As illustrated in  FIGS.  3  through  5   , the storage portion  80  has a side wall  87  formed with an air communication opening  88 . The air communication opening  88  is configured to provide communication between the internal space  81  of the storage portion  80  and the outside thereof. The electromagnetic valve  92  is positioned adjacent to the air communication hole  88 . Well known electromagnetic valves are available as the electromagnetic valve  92 . For example, the electromagnetic valve  92  includes a valve  89 , and a solenoid  93  for moving the valve  89 . The solenoid  93  is an example of the actuator. 
     The solenoid  93  is supported by a support base  94  provided at the side wall  87 . The valve  89  is supported by the solenoid  93  so as to be movable in the left-right direction  9  relative to the solenoid  93 . The valve  89  is moved in the left-right direction  9  relative to the solenoid  93  upon flowing electrical current through a coil in the solenoid  93 . 
     As indicated by the solid line in  FIG.  3   , in a state where the valve  89  has protruded leftward relative to the solenoid  93 , the valve  89  is at a closing position in which the valve  89  is in abutment with the air communication opening  88  to close the same. Further, as indicated by the broken line in  FIG.  3   , in a state where the protruding length of the valve  89  from the solenoid  93  is shorter than that when the valve  89  is in the closing position, the valve  89  is at an opening position in which the valve  89  is separated away from the air communication opening  88  to open the same. 
     [Cap  70 ] 
     As illustrated in  FIGS.  3  through  5   , the cap  70  is positioned outward of the platen  42  in the left-right direction  9  (rightward of the platen  42  in the present embodiment). That is, the cap  70  is positioned outward of the medium passing region  36  in the left-right direction  9 . In a state where the carriage  40  is at a maintenance position (i.e., the position illustrated in  FIGS.  3  and  4   ) rightward of the medium passing region  36 , the cap  70  is positioned below the carriage  40  and faces the same (more specifically, the cap  70  faces the nozzles  39  of the head  38 ). 
     The cap  70  has a box-like shape having upper open end. The cap  70  is made of an elastic member such as rubber. The cap  70  is supported by a frame  46  through a known movable mechanism  71 , and is movable in the up-down direction by the movable mechanism  71  applied with a driving force from a cap drive motor  104  (see  FIG.  6   ). The frame  46  is positioned rightward of the platen  42 , and is a plate-shaped member extending both in the front-rear direction  8  and the left-right direction  9 . The movable mechanism  71  includes, for example, a ball screw or a cam. 
     The cap  70  is movable upward and downward between a capping position illustrated in  FIG.  3    and a separation position illustrated in  FIG.  4   . In a state where the cap  70  is at the capping position as illustrated in  FIG.  3   , the upper end of the cap  70  is in pressure contact with the lower surface  68  of the head  38  from below. Hence, in this state, the plurality of nozzles  39  which open at the lower surface  68  is covered by the cap  70  from below. The separation position is positioned below the capping position. The cap  70  at its separation position is separated from the lower surface  68  of the head  38 . 
     The cap  70  has a bottom wall formed with a through-hole  72 . The through-hole  72  has one end opening at a bottom surface  70 A of the cap  70 , and the other end connected to one end of a tube  73 . The other end of the tube  73  is connected to a waste ink tank (not illustrated) through a pump (not illustrated). The tube  73  is made of resin and has a flexibility. 
     In a state where the cap  70  is at the capping position and covers the nozzles  39 , ink and foreign substance in the nozzles  39  are sucked by the actuation of the pump and is ejected to the cap  70 . The ejected ink and foreign substance are received by the cap  70  and then sucked into the tube  73 , and are discharged to the waste ink tank through the tube  73 . 
     [Sheet Sensor  120 ] 
     As illustrated in  FIG.  2   , the sheet sensor  120  is positioned at the sheet conveying passage  65  and upstream of the pair of conveyer rollers  59  in the conveying direction  15 . The sheet sensor  120  is configured to detect whether the sheet  12  is present at the disposed position of the sheet sensor  120  (i.e., at the position at which the sheet sensor  120  is disposed). Incidentally, known sheet sensors are available as the sheet sensor  120 . In the present embodiment, the sheet sensor  120  includes, for example, a shaft  121 , a detection probe  122  pivotally movable about the axis of the shaft  121 , and an optical sensor  123  including a light emitting element and a light receiving element configured to receive light emitted from the light emitting element. The sheet sensor  120  is an example of the medium sensor. 
     The detection probe  122  has one end portion protruding to the sheet conveying passage  65 . The other end portion of the detection probe  122  is configured to advance into and retract from an optical path extending from the light emitting element to the light receiving element. 
     In a state where no external force is applied to the one end portion of the detection probe  122 , the other end portion of the detection probe  120  is positioned in the optical path and blocks light emitted from the light emitting element, as indicated by the solid line in  FIG.  2   . At this time, a low-level signal is outputted from the optical sensor  123  to the controller  130 . The low-level signal from the optical sensor  123  of the sheet sensor  120  is an example of the medium absence signal and is also an example of the detection signal. 
     When the one end portion of the detection probe  122  is pushed by the leading end of the sheet  12  during conveyance thereof, the detection probe  122  pivotally moves and the other end portion of the detection probe  122  retracts from the optical path (as indicated by the broken line in  FIG.  2   ), thereby allowing the light to reach the light receiving element. At this time, a high-level signal is outputted from the optical sensor  123  to the controller  130 . Incidentally, the detection probe  122  is urged to the position indicated by the solid line by a spring and the like. The high-level signal from the optical sensor  123  of the sheet sensor  120  is an example of the medium presence signal and is also an example of the detection signal. 
     The sheet sensor  120  may be positioned at the sheet conveying passage  65  and downstream of the pair of discharge rollers  44  in the conveying direction  15 . Alternatively, two sheet sensors  120  may be provided on the sheet conveying passage  65 : one positioned upstream of the pair of conveyer rollers  59  in the conveying direction  15 , and the other downstream of the pair of discharge rollers  44  in the conveying direction  15 . 
     [Rotary Encoder  75 ] 
     The rotary encoder  75  ( FIG.  6   ) includes an encoder disc provided at the shaft of the conveyer motor  101  ( FIG.  6   ) and rotatable together with the shaft, and an optical sensor. The encoder disc is formed with a pattern of light transmission portions and light blocking portions alternately arrayed in a circumferential direction of the encoder disc with equal intervals. When the encoder disc rotates, the optical sensor detects the light transmission portions and light blocking portions to generate a pulse signal. The generated pulse signal is outputted to the controller  130  from the optical sensor of the rotary encoder  75 . The controller  130  calculates rotation amount of the conveyer motor  101  on the basis of the outputted pulse signal. Incidentally, in addition to the rotary encoder  75  for the conveyer motor  101 , other rotary encoders may be provided for the sheet supply motor  102  and the conveyer roller  60 , for example. The pulse signal from the optical sensor of the rotary encoder  75  is an example of the detection signal. 
     [Controller  130  and Memory  140 ] 
     Details of the controller  130  and the memory  140  will next be described with reference to  FIG.  6   . Particular features in the present disclosure are attained by the controller  130  performing processes in accordance with flowcharts described later. The controller  130  is configured to control overall operation of the multifunction peripheral  10 . The controller  130  includes CPU  131  and ASIC  135 . The memory  140  includes a ROM  132 , a RAM  133 , and an EEPROM  134 . The CPU  131 , the ASIC  135 , the ROM  132 , the RAM  133  and the EEPROM  134  are connected to each other via an internal bus  137 . 
     The ROM  132  stores therein programs which the CPU  131  executes to control various operations. The RAM  133  is used as a memory region to temporarily store data and signals used when the CPU  131  is executing the programs, or a working region for data processing. The EEPROM  134  stores settings and flags, etc. to be held after power off. 
     The ASIC  135  is connected to the conveyer motor  101 , the sheet supply motor  102 , the carriage drive motor  103 , and the cap drive motor  104 . Driver circuits for controlling the corresponding motors are incorporated in the ASIC  135 . The CPU  131  is configured to output drive signals for rotating the motors to the corresponding driver circuit. Each driver circuit is configured to output driving current based on the drive signal acquired from the CPU  131  to the corresponding motor to thereby rotate the same. 
     That is, the controller  130  controls the sheet supply motor  102  to control the sheet feeding unit  16  to feed the sheet  12 . The controller  130  controls the conveyer motor  101  to control the pair of conveyer rollers  59  and the pair of discharge rollers  44  to convey the sheet  12 . The controller  130  controls the carriage drive motor  103  to move the carriage  40 . Further, the controller  130  controls the cap drive motor  104  to drive the movable mechanism  71  to move the cap  70 . 
     The ASIC  135  is connected also to the installation sensor  30 . In a case where the controller  130  acquires the high-level signal from the installation sensor  30 , the controller  130  determines (detects) that the multifunction peripheral  10  is installed on an installation surface such as the upper surface of a desk. On the other hand, in a case where the controller  130  acquires the low-level signal from the installation sensor  30 , the controller  130  determines (detects) that the multifunction peripheral  10  is not installed on the installation surface, such as a state where the multifunction peripheral  10  is lifted from the installation surface. 
     Further, the ASIC  135  is connected to the tray sensor  110 . In a case where the controller  130  acquires the low-level signal from the tray sensor  110 , the controller  130  determines (detects) that the sheet tray  20  is at the sheet supply position. On the other hand, in a case where the controller  130  acquires the high-level signal from the tray sensor  110 , the controller  130  determines (detects) that the sheet tray  20  is not at the sheet supply position. 
     Further, the ASIC  135  is connected to the cover sensor  150 . In a case where the controller  130  acquires the low-level signal from the cover sensor  150 , the controller  130  determines (detects) that the movable cover  145  is at the closed position. On the other hand, in a case where the controller  130  acquires the high-level signal from the cover sensor  150 , the controller  130  determines (detects) that the movable cover  145  is at the open position. 
     Further, the ASIC  135  is connected to the sheet sensor  120 . In a case where the controller  130  acquires the high-level signal from the sheet sensor  120 , the controller  130  determines (detects) that the sheet  12  is present at the disposed position of the sheet sensor  120 . On the other hand, in a case where the controller  130  acquires the low-level signal from the sheet sensor  120 , the controller  130  determines (detects) that the sheet  12  is not present at the disposed position of the sheet sensor  120 . 
     Further, the ASIC  135  is connected to the optical sensor of the rotary encoder  75 . The controller  130  calculates rotation amount of the conveyer motor  101  on the basis of the pulse signal (electric signal) received from the optical sensor of the rotary encoder  75 . 
     The controller  130  calculates (identifies) the position of the sheet  12  on the basis of the rotation amount of the conveyer motor  101  counted from a timing at which the pulse signal received from the sheet sensor  120  is changed from the low-level signal to the high-level signal (i.e., from a timing of detecting arrival of the leading end of the sheet  12  at the disposed position of the sheet sensor  120 ). 
     Further, the ASIC  135  is connected to the encoder  35 . On the basis of the pulse signal (an electric signal) received from the encoder  35 , the controller  130  identifies the position of the carriage  40  and determines whether or not the carriage  40  is moving. 
     Further, the ASIC  135  is connected to the piezoelectric elements  45 . The piezoelectric elements  45  are driven by being supplied with electric power through a driver circuit (not illustrated) under control by the controller  130 . The controller  130  controls supply of electric power to the piezoelectric elements  45  to cause the nozzles  39  to eject ink droplets. More specifically, the controller  130  supplies electric power to one or more of the piezoelectric elements  45  corresponding to selected one or more of the plurality of nozzles  39  to thereby cause the selected one or more nozzles to eject ink droplets. 
     Further, the ASIC  135  is connected to the solenoid  93 . The controller  130  controls supply of electrical current to the coil of the solenoid  93  to move the valve  89 . 
     The controller  130  alternately performs a conveying process and a printing process for recording an image on the sheet  12 . The conveying process is a process in which the pair of conveyer rollers  59  and the pair of discharge rollers  44  are controlled to convey the sheet  12  by a predetermined amount of line feed. The controller  130  controls, by controlling the conveyer motor  101 , the pair of conveyer rollers  59  and the pair of discharge rollers  44  to perform the conveying process. 
     The printing process is a process in which the controller  130  controls, while moving the carriage  40  in the left-right direction  9 , supply of electric power to the piezoelectric elements  45  to cause the head  38  to eject ink droplets from the nozzles  39 . During the printing process, the carriage  40  is positioned within the medium passing region  36  and faces the platen  42 , as illustrated in  FIG.  5   . 
     The controller  130  temporarily stops conveyance of the sheet  12  for a predetermined time period between a preceding conveying process and a subsequent conveying process. The printing process is performed during the time period for stopping the sheet  12 . That is, in the printing process, the controller  130  performs a single pass operation in which ink droplets are ejected from the nozzles  39  while moving the carriage  40  rightward or leftward. Hence, image recordation for one pass operation is performed on the sheet  12 . 
     The controller  130  repeatedly and alternately performs the conveying process and the printing process, so that image recordation is performed on the entire image recordable region of the sheet  12 . That is, the controller  130  performs the pass operation a plurality of times to record an image on the sheet  12 . 
     Incidentally, the controller  130  is not limited to the above-described configuration. For example, the controller  130  may have a configuration in which only the CPU  131  performs various processes, a configuration in which only the ASIC  135  performs the various processes, or a configuration in which the CPU  131  and the ASIC  135  perform the various processes in cooperation with each other. Further, the controller  130  may have a configuration in which a single CPU  131  solely performs processes, or a configuration in which a plurality of CPUs  131  shares the processes. Alternatively, the controller  130  may have a configuration in which a single ASIC  135  solely performs processes, or a configuration in which a plurality of ASICs  135  shares the processes. 
     [Control of Opening/Closing of Valve  89  by Controller  130 ] 
     In the printer portion  11  constructed as described above, the controller  130  performs opening/closing control to the valve  89 . Opening/closing control to the valve  89  will be described with reference to flowcharts illustrated in  FIGS.  7  and  8   . 
     The valve  89  is at the opening position indicated by the broken line in  FIG.  3    in a case where the multifunction peripheral  10  has no abnormality. In a state where the valve  89  is at the opening position, the internal space  81  is communicated with the atmosphere and thus the pressure in the internal space  81  is equal to the atmospheric pressure. 
     As illustrated in  FIG.  7   , the controller  130  repeatedly performs the process of steps S 10  to S 30  at predetermined time intervals (for example, several milliseconds). That is, the controller  130  references the signal acquired from the installation sensor  30  (S 10 ), references the signal acquired from the tray sensor  110  (S 20 ), and references the signal acquired from the cover sensor  150  (S 30 ). Incidentally, steps S 10  to S 30  may be performed in any order, or these steps may be performed in parallel. 
     In a case where the controller  130  acquires the high-level signal from the installation sensor  30  (S 10 : No), the controller  130  determines that the multifunction peripheral  10  is in a normal state since the multifunction peripheral  10  is installed on the installation surface such as the upper surface of a desk. On the other hand, in a case where the controller  130  acquires the low-level signal from the installation sensor  30  (S 10 : Yes), the controller  130  determines that the multifunction peripheral  10  is in an abnormal state. This is because, in this case, the multifunction peripheral  10  is not installed on the installation surface (for example, the multifunction peripheral  10  has been lifted up from the installation surface). When determining in S 10  that the multifunction peripheral  10  is in an abnormal state, in S 40  the controller  130  performs an error process, i.e., a process to be performed at the time of abnormality (described later). 
     In a case where the controller  130  acquires the low-level signal from the tray sensor  110  (S 20 : No), the controller  130  determines that the multifunction peripheral  10  is in a normal state because the sheet tray  20  is positioned at the sheet supply position in the housing  14 . On the other hand, in a case where the controller  130  acquires the high-level signal from the tray sensor  110  (S 20 : Yes), that is, in a case where the signal acquired from the tray sensor  110  is changed from the low-level signal to the high-level signal, the controller  130  determines that the multifunction peripheral  10  is in an abnormal state. This is because, in this case, the sheet tray  20  has been pulled out of the housing  14 . In the latter case, the error process is performed (S 40 ). 
     In a case where the controller  130  acquires the low-level signal from the cover sensor  150  (S 30 : No), the controller  130  determines that the multifunction peripheral  10  is in a normal state since the movable cover  145  is at the closed position. On the other hand, in a case where the controller  130  acquires the high-level signal from the cover sensor  150  (S 30 : Yes), the controller  130  determines that the multifunction peripheral  10  is in an abnormal state. This is because, in this case, the movable cover  145  is at the open position. In the latter case, the error process is performed (S 40 ). In this way, in the process of steps S 10  to S 30 , the controller  130  determines whether the multifunction peripheral  10  has an abnormality on the basis of the acquired signals. 
     The error process will be described with reference to  FIG.  8   . The controller  130  energizes (i.e., passes electrical current through) the coil in the solenoid  93  to move the valve  89  from the opening position to the closing position (S 110 ). That is, in a case where the controller  130  determines on the basis of the acquired signals that the multifunction peripheral  10  is in an abnormal state (i.e., that the multifunction has an abnormality), the controller  130  controls the solenoid  93  to move the valve  89  to the closing position. The internal space  81  of the storage portion  80  is shut off from the atmosphere (i.e., enters a sealed state) upon movement of the valve  89  to the closing position. 
     Then, the controller  130  determines whether the abnormality in the multifunction peripheral  10  is eliminated (S 120 ). For example, in a case where the multifunction peripheral  10  is determined to be in an abnormal state in step S 10 , the controller  130  determines that the abnormality is eliminated (S 120 : Yes) in response to acquiring the high-level signal from the installation sensor  30 . This is because, in this case, the high-level signal from the installation sensor  30  means that the multifunction peripheral  10  has been installed again on the installation surface. Further, for example, in a case where the multifunction peripheral  10  is determined to be in an abnormal state in step S 20 , the controller  130  determines that the abnormality is eliminated (S 120 : Yes) in response to acquiring the low-level signal from the tray sensor  110 . This is because, in this case, the low-level signal from the tray sensor  110  means that the sheet tray  20  has been inserted again to the housing  14  (i.e., means that the sheet tray  20  has returned back to the sheet supply position). Further, for example, in a case where the multifunction peripheral  10  is in an abnormal state in step S 30 , the controller  130  determines that the abnormality is eliminated (S 120 : Yes) in response to acquiring the low-level signal from the cover sensor  150 . This is because, in this case, the low-level signal from the cover sensor  150  means that the movable cover  145  has been closed again (i.e., means that the movable cover  145  has returned back to the closed position). 
     After the elimination of the abnormality, the controller  130  determines whether the carriage  40  is at the maintenance position (S 130 ). In a case where the carriage  40  is not at the maintenance position (S 130 : No), the controller  130  moves the carriage  40  to the maintenance position (S 140 ). Then, the controller  130  drives the cap drive motor  104  to move the cap  70  to the capping position (S 150 ). 
     On the other hand, in a case where the carriage  40  is at the maintenance position (S 130 : Yes), the controller  130  determines whether the cap  70  is at the capping position (S 160 ). This determination is made on the basis of a signal inputted from a cap sensor (not illustrated). In a case where the cap  70  is not at the capping position (S 160 : No), the controller  130  drives the cap drive motor  104  to move the cap  70  to the capping position (S 150 ). 
     In a state where the carriage  40  is at the maintenance position and the cap  70  is at the capping position, (S 150 , S 160 : Yes), the controller  130  moves the valve  89  from the closing position to the opening position (S 170 ), whereupon the error process is terminated. 
     As described above, in a case where the controller  130  determines that the abnormality in the multifunction peripheral  10  is eliminated (S 120 : Yes) on the basis of the signals acquired after determining that the multifunction peripheral  10  is in the abnormal state, the controller  130  controls the solenoid  93  to move the valve  89  to the opening position (S 170 ). Further, in a case where the controller  130  determines that the abnormality in the multifunction peripheral  10  is eliminated (S 120 : Yes), the controller  130  moves the cap  70  to the capping position to cover the nozzles  39  (S 150 ), and controls, after the cap  70  covers the nozzles  39 , the solenoid  93  to move the valve  89  to the opening position (S 170 ). 
     [Control of Image Recordation by Controller  130 ] 
     In the printer portion  11  constructed as described above, the controller  130  performs sequential image recordation control in which the sheet  12  is conveyed and image is recorded on the conveyed sheet  12 . Control of the image recordation by the controller  130  will next be described with reference to the flowcharts illustrated in  FIGS.  9  and  10   . Further, the controller  130  performs the above-described error process ( FIG.  8   ) in a case where an abnormality occurs in the multifunction peripheral  10  during control of the image recordation. The error process during the control to the image recordation will also be described. 
     The control illustrated in  FIG.  7    is repeatedly performed at prescribed time intervals during execution of the image recordation control illustrated in  FIGS.  9  and  10   . In this case, the image recordation control may be interrupted at the time of executing the error process (S 40 ) illustrated in  FIG.  7   . Alternatively, the image recordation control may be continued at the time of executing the error process (S 40 ) illustrated in  FIG.  7   . 
     In a case where the image recordation control is not performed, the recording unit  24  and the cap  70  are at the positions illustrated in  FIG.  3   . Specifically, the carriage  40  is at the maintenance position, and the cap  70  is at the capping position. Further, in a state where the multifunction peripheral  10  has no abnormality, the valve  89  is at the opening position indicated by the broken line in  FIG.  3   . 
     Print command is transmitted to the controller  130  from the operating portion  17  (see,  FIG.  1   ) of the multifunction peripheral  10  or from an external device connected to the multifunction peripheral  10 . The print command contains a command to start image recordation control, information on the size of the sheet  12 , and print data for an image to be recorded on the sheet  12 . 
     When acquiring print command (S 310 : Yes), the controller  130  starts feeding the sheet  12  (S 320 ) supported on the sheet tray  20 . 
     In step S 320 , the controller  130  starts driving the sheet supply motor  102 , whereby the sheet feeding roller  25  feeds the sheet  12  supported on the sheet tray  20  to the sheet conveying passage  65 . Further, the controller  130  drives the conveyer motor  101 , whereby the pair of conveyer rollers  59  conveys the sheet  12  in the conveying direction  15  when the leading end (the downstream end in the conveying direction  15 ) of the sheet  12  fed to the sheet conveying passage  65  by the sheet feeding roller  25  arrives at the pair of conveyer rollers  59 . 
     Further, in step S 320 , the controller  130  drives the cap drive motor  104 , whereby the movable mechanism  71  is actuated to move the cap  70  from the capping position to the separation position. That is, the cap  70  is moved away from the head  38 . Next, the controller  130  drives the carriage drive motor  103  to move the carriage  40  from the maintenance position to a print-start position. The print-start position is a position from which the carriage  40  starts to move at the time of execution of the printing process (S 360 ). The print-start position is determined on the basis of the print data. 
     In step S 320 , the feeding of the sheet  12 , and the moving of the cap  70 , and the moving of the carriage  40  are performed in parallel. 
     The controller  130  determines whether a feeding abnormality (a sheet supply abnormality) has occurred (i.e., whether the multifunction peripheral  10  has a feeding abnormality) (S 330 ). For example, the controller  130  counts an elapsed time period from a timing of staring driving the sheet supply motor  102  in S 320 . In a case where the high-level signal is not acquired by the controller  130  from the sheet sensor  120  within a preset prescribed time period from the start timing of driving the sheet supply motor  102 , the controller  130  determines that the multifunction peripheral  10  is in an abnormal state (the multifunction peripheral  10  has a feeding abnormality) (S 330 : Yes). This is because, in this case, one of the following feeding abnormalities is more likely to have occurred: feeding abnormality A (the sheet  12  has not been supplied from the sheet tray  20 ), feeding abnormality B (there is no sheet  12  on the sheet tray  20 ), and feeding abnormality C (the sheet  12  supplied from the sheet tray  20  is jammed at the curved portion  33 ). Then, the above-described error process is performed (S 340 ,  FIG.  8   ). 
     The error process in step S 340  is performed on the basis of the flowchart illustrated in  FIG.  8   . At this time, in step S 120 , when acquiring the high-level signal from the tray sensor  110  and then acquiring the low-level signal therefrom, the controller  130  determines that the feeding abnormality A or B is eliminated. This is because, in this case, change from the high-level signal to the low-level signal in the signal acquired from the tray sensor  110  is likely to denote that the sheet tray  20  is detached from the housing  14 , replenishment of sheets is performed, and then the sheet tray  20  is again inserted to the housing  14 . Further, in step S 120 , when acquiring the high-level signal from the cover sensor  150  and then acquiring the low-level signal therefrom, the controller  130  determines that feeding abnormality C is eliminated. This is because, in this case, change from the high-level signal to the low-level signal in the signal acquired from the tray cover sensor  150  is likely to mean that the movable cover  145  is opened, jammed sheet  12  is removed, and then the movable cover  145  is closed again. When determining that the abnormality is eliminated, the controller  130  resumes the feeding of the sheet (S 320 ). 
     Incidentally, in the step S 120 , the controller  130  may determine that the abnormality has been eliminated in a case where the controller  130  acquires an input signal from the operating portion  17  in addition to the above-described change in the acquired signal. Specifically, in this case, when a feeding abnormality has occurred, the controller  130  displays, on the touch panel of the operating portion  17 , both a notification that a feeding abnormality has occurred and a button to be pressed by the user after the user eliminates the feeding abnormality. When the user presses the button after the user replenishes new sheets  12  or removes a jammed sheet  12 , i.e., when the operating portion  17  receives from the outside an input signal indicative of completion of replenishment of the sheets  12  or completion of removal of the jammed sheet  12 , the operating portion  17  transmits the input signal to the controller  130 . When the controller  130  acquires the input signal in addition to detection of change in the signal acquired from the tray sensor  110  or the cover sensor  150 , the controller  130  determines that the abnormality has been eliminated. 
     Further, a sheet sensor used for detecting (determining) the feeding abnormality B (no sheet  12  is present on the sheet tray  20 ) may be provided on the sheet tray  20 . For example, the sheet sensor is positioned on the upper surface of the bottom plate  22  of the sheet tray  20  and is configured to output detection signals differing depending on presence or absence of the sheet  12  on the upper surface (i.e., output a detection signal indicating presence or absence of the sheet  12  on the upper surface). 
     In a case where no feeding abnormality occurs (S 330 : No), the controller  130  performs a cueing process (S 350 ). In the cueing, the controller  130  stops the sheet  12  that is being conveyed in the conveying direction  15  at an image recordation start position. The image recording start position is a position where the leading end (downstream end) of the image forming region of the sheet  12  in the conveying direction  15  faces the nozzle(s)  39  positioned at most downstream in the conveying direction  15  of the plurality of nozzles  39 . 
     Next, the controller  130  performs the printing process (S 360 ). The controller  130  performs a pass operation once. That is, the controller  130  controls the nozzles  39  to eject ink droplets while moving the carriage  40  from the print start position. Incidentally, in S 320 , the carriage  40  which starts moving from the maintenance position may continue moving for the printing process without stopping at the print start position. Alternatively, the carriage  40  may temporarily stop at the print start position. 
     During the printing process, the controller  130  maintains the valve  89  at the opening position as long as an abnormality does not occur. That is, as long as the head  39  is ejecting ink droplets from the nozzles  39  toward the sheet  12  and the controller  130  is determining that the multifunction peripheral  10  is in the normal state (i.e., the multifunction peripheral  10  has no abnormality) on the basis of the acquired signals, the controller  130  controls the solenoid  93  to maintain the valve  89  at the opening position. 
     Then, the controller  130  determines whether a printing abnormality has occurred (i.e., whether the multifunction peripheral  10  has a printing abnormality) (S 370 ). For example, the controller  130  determines, on the basis of the signals acquired from the sheet sensor  120 , the rotary encoder  75  and the encoder  35 , that an abnormality occurs such as sheet jamming at the linear portion  34  or an immovable state of the carriage  40  due to the sheet  12  catching the carriage  40  (S 370 : Yes). For example, in a case where the pulse signal is not acquired from the encoder  35 , the controller  130  determines that an abnormality occurs that the carriage  40  is incapable of moving. In this case, the above-described error process is performed (S 380 ,  FIG.  8   ). 
     The error process in the step S 380  is also performed on the basis of the flowchart illustrated in  FIG.  8   . In step S 120  of this error process, the controller  130  determines that the abnormality is eliminated in response to again acquiring the low-level signal from the cover sensor  150  after acquiring the high-level signal therefrom. This is because, in this case, it is likely that the movable cover  145  has been once opened, the sheet  12  jammed at the linear portion  34  has been removed and then the movable cover  145  has been closed again. The controller  130  resumes the printing process (S 360 ) when determining that the abnormality is eliminated. Incidentally, the controller  130  may determine that the abnormality is eliminated in a case where the input signal is acquired from the operating portion  17  as in the process in case of occurrence of the feeding abnormality. 
     In a case where no printing abnormality occurs (S 370 : No), the controller  130  determines whether image recordation to the present sheet  12  is completed on the basis of the information on the size of the sheet and print data those contained in the print command is terminated (S 390 ). 
     In a case where the image recordation on the present sheet  12  is not completed (S 390 : No), a sheet conveying process is performed (S 400 ). In the sheet conveying process, the controller  130  drives the conveyer motor  101  to cause the pair of conveyer rollers  59  and the pair of discharge rollers  44  to convey the sheet  12  by a predetermined line feed amount. 
     The controller  130  determines whether a conveying abnormality has occurred (i.e., whether the multifunction peripheral  10  has a conveying abnormality) (S 410 ). For example, on the basis of the signals transmitted from the sheet sensor  120  and the rotary encoder  75 , the controller  130  determines that an abnormality occurs such as jamming of the sheet  12  at the curved portion  33  or the linear portion  34  (S 410 : Yes). In this case, the above-described error process is performed (S 420 ,  FIG.  8   ). 
     The error process in step S 420  is also performed on the basis of the flowchart illustrated in  FIG.  8   . In step S 120  in this error process, the controller  130  determines that the abnormality is eliminated in response to again acquiring the low-level signal from the cover sensor  150  after acquiring the high-level signal therefrom. This is because, in this case, it is likely that the movable cover  145  has been opened once, the sheet  12  jammed at the curved portion  33  or the linear portion  34  has been removed and then the movable cover  145  has been closed again. The controller  130  resumes the conveying process (S 400 ) when determining that the abnormality is eliminated. Incidentally, the controller  130  may determine that the abnormality is eliminated in a case where that the input signal is acquired from the operating portion  17  as in the processes in case of occurrence of the feeding abnormality and the printing abnormality. 
     In a case where the image recordation on the present sheet  12  is completed (S 390 : Yes), the controller  130  controls the pair of conveyer rollers  59  and the pair of discharge rollers  44  to convey the sheet  12  in the conveying direction  15  and to discharge the sheet  12  onto the discharge tray  21  (S 430 ). In this case, as in steps S 410  and S 420 , the controller  130  determines whether the multifunction peripheral  10  has a conveying abnormality (S 440 ) and performs the error process in case of occurrence of a conveying abnormality (S 450 ,  FIG.  8   ). 
     Then, the controller  130  determines whether there is image data left to be recorded on the sheet  12  in the image data contained in the print command (i.e., whether image data that has not yet been recorded on the sheet  12  is left in the image data contained in the print command). That is, the controller  130  determines whether there is image recordation for the next page (S 460 ). 
     In a case where the image recordation for the next page is required (S 460 : Yes), the controller  130  feeds a subsequent sheet  12  from the sheet tray  20  to the sheet conveying passage  65  (S 320 ). Incidentally, the feeding of the subsequent sheet  12  (S 320 ) may be performed in parallel to the discharge of the preceding sheet  12  (S 430 ). 
     In a case where no there is no image recordation for the next page (S 460 : No), the controller  130  terminates the series of image recordation control. 
     Effect and Technical Advantages of the Embodiment 
     According to the embodiment, the valve  89  is moved to the closing position when an abnormality such as jamming of the sheet  12  occurs in the multifunction peripheral  10 . Hence, even in a case where the sheet  12  is brought into contact with the nozzles  39  and thus ink permeates the sheet  12  from the nozzles  39 , the inner pressure of the storage portion  80  is lowered (negative pressure level in the storage portion  80  rises) as the permeation of the ink advances. Thus, further permeation of the ink can be stopped. 
     Further, according to the present embodiment, the valve  89  is at the opening position during image recordation on the sheet  12  as long as the multifunction peripheral  10  is in the normal state. Therefore, during the image recordation, an operation to open the valve  89  for the purpose of preventing the inner pressure of the storage portion  80  from lowering is unnecessary. Hence, speed of image recordation on the sheet  12  can be suppressed from becoming slow. 
     Further, according to the present embodiment, the valve  89  is moved to the opening position after an abnormality is eliminated. Therefore, ink leakage caused by moving the valve  89  to the opening position during the abnormal state of the multifunction peripheral  10  can be prevented. 
     Further, according to the present embodiment, the valve  89  is moved to the opening position after the cap  70  covers the nozzles  39 . Therefore, even if ink is leaked from the nozzle  39  by shifting the valve  89  to the opening position, the cap  70  can receive the leaked ink. Hence, adhesion of ink to other components in the multifunction peripheral  10  can be prevented. 
     Further, according to the present embodiment, the controller  130  can determine whether an abnormality occurs in the sheet  12  on the basis of presence or absence of the high-level signal and the low-level signa from the sheet sensor  120  and the timing of output of the signals. 
     Further, according to the present embodiment, the controller  130  can determine whether the carriage  40  is normally moving on the basis of the presence or absence of the pulse signal outputted from the encoder  35 . 
     Further, in a case where the sheet  12  is jammed at the sheet conveying passage  65 , the jammed sheet  12  may contact the nozzles  39  and there is a risk that ink endlessly oozes out from the nozzles  39  into the sheet  12 . Typically, when the sheet  12  is jammed in the sheet conveying passage  65 , the movable cover  145  is opened for the purpose of removing the jammed sheet  12 . According to the present embodiment, the valve  89  is moved to the closing position when the movable cover  145  is opened, that is, when the sheet  12  is more likely to have been jammed in the sheet conveying passage  65 . Hence, the above-described endless permeation of ink can be prevented. 
     Further, in a case where the sheet  12  is jammed at the sheet conveying passage  65 , the jammed sheet  12  may contact the nozzles  39  and there is a risk that the ink in the nozzle  39  is endlessly oozed out into the sheet  12 . Further, there is a possibility that the sheet tray  20  is pulled out of the housing  14  in a state where the sheet  12  is jammed in the sheet conveying passage  65 . However, in such cases, the valve  89  is moved to the closing position in the present embodiment, thereby preventing the above-described endless ink permeation. 
     Further, when the housing  14  is separated from the installation surface (such as when the housing  14  is lifted up), meniscus of the nozzles  39  may be broken due to impact generated at the time of the separation, which leads to leakage of ink from the nozzles  39 . In such a case, the valve  89  is moved to the closing position in the present embodiment, whereby ink leakage can be reduced. 
     [Modifications] 
     In the above-described embodiment, the valve  89  is firstly moved from the opening position to the closing position in the error process (S 110  in  FIG.  8   ). However, the valve  89  may be moved from the opening position to the closing position provided that the nozzles  39  and the sheet  12  face each other at the time of execution of the error process. 
     That is, as illustrated in the flowchart of  FIG.  11   , in the error process, the controller  130  firstly determines whether the carriage  40  is at the maintenance position (S 510 ). 
     In a case where the carriage  40  is not at the maintenance position (S 510 : No), the controller  130  waits until an abnormality in the multifunction peripheral  10  is eliminated without moving the valve  89  to the closed position (S 520 : Yes). Then, the controller  130  terminates the error process. 
     On the other hand, in a case where the carriage  40  is at the maintenance position (S 510 : Yes), that is, in a case where there is a possibility that the nozzles  39  and the sheet  12  face each other, the controller  130  moves the valve  89  from the opening position to the closing position. (S 110 ). Then, step S 120  and subsequent steps are performed as in the error process performed in the above-described embodiment (see  FIG.  8   ). However, in step S 120  and subsequent steps, steps S 130  and S 140  in  FIG.  8    is not performed since the carriage  40  has already been positioned at the maintenance position. 
     Incidentally, in a case where the carriage  40  is not at the maintenance position (S 510 : No), the controller  130  may move the valve  89  to the closing position after the controller  130  moves the carriage  40  to the maintenance position. 
     In a case where the multifunction peripheral  10  enters an abnormal state in a state where the nozzles  39  and the sheet  12  face each other, the sheet  12  is more likely to contact the nozzles  39 . In a case where the valve  89  is at the opening position when the sheet  12  contacts the nozzles  39 , ink in the nozzles  39  is likely to endlessly permeate into the sheet  12 . However, in such a case, the valve  39  is moved to the closing position in the modification described above, thereby preventing the above-described endless ink permeation into the sheet  12 . 
     In the above-described embodiment, a serial head type in which an image is recorded on a sheet while the head  38  is being moved by the carriage  40  is employed as an image recording system. However, a line head type is also available in which the recording unit  24  does not include the carriage  40  and an image is recorded on a sheet without moving the head  38 . In a case where the line head type is employed, the head  38  extending over the length from the right edge to the left edge of the medium passing region  36  is provided. Further, the conveying process and the printing process are performed in parallel and continuously. That is, ink droplets are continuously ejected from the nozzles  39  while the sheet  12  is being conveyed. Further, the head  38  is fixed to a frame of the housing  14  in the line head type. This frame is an example of the support member. 
     In the above-described embodiment, the storage portion  80  is singular. However, a plurality of storage portions  80  may be provided. For example, as illustrated in  FIG.  12   , the recording unit  24  may include four storage portions  80 C,  80 M,  80 Y,  80 B. 
     The storage portion  80 C stores therein cyan ink. The storage portion  80 M stores therein magenta ink. The storage portion  80 Y stores therein yellow ink. The storage portion  80 B stores therein black ink. The storage portions  80 C,  80 M,  80 Y,  80 B are arrayed in the left-right direction  9  in this order. Incidentally, the storage portions  80 C,  80 M,  80 Y,  80 B may be arrayed in a direction other than the left-right direction  9  such as in the front-rear direction  8 . Further, the arrangement order of the storage portions  80 C,  80 M,  80 Y,  80 B is not limited to the order illustrated in  FIG.  12   . Further, the sizes of the storage portions  80 C,  80 M,  80 Y,  80 B may be equal to one another or may be different from one another. 
     The air communication opening  88  is formed in each of the storage portions  80 C,  80 M,  80 Y,  80 B. The valve  89  is provided for each of the four air communication openings  88 . The four valves  89  are supported by a common solenoid  93  so as to be movable in the up-down direction  7 . Incidentally,  FIG.  12    illustrates a state where the four valves  89  are at their closing position. Further, illustration of a member supporting the solenoid  93  is omitted in  FIG.  12   . The four valves  89  are simultaneously moved from the opening positions to the closing positions by the supply of electrical current from the controller  130  to the solenoid  93 . That is, all of the four air communication openings  88  are opened by the movement of the four valves  89  from the closing positions to the opening positions. Further, all of the four air communication openings  88  are closed by the movement of the four valves  89  from the opening positions to the closing positions. 
     According to the modification described above, an individual operation for providing communication between the inside and outside of the storage portion  80  and shutting off the communication is not required for each of the four storage portions  80 . Therefore, a time period required to open and close the valves  89  can be reduced. 
     According to the modification, the single solenoid  93  is configured to move the plurality of valves  89  as described above. However, a plurality of solenoids  93  may be provided in one-to-one correspondence with the plurality of valves  89 . In this case, the plurality of solenoids  93  moves the valves  89  at the same timing or at different timings. 
     The sheet  12  may be fed to the sheet conveying passage  65  from a tray other than the sheet tray  20 . For example, instead of the sheet tray  20  of the multifunction peripheral  10 , or in addition to the sheet tray  20 , a tray pivotally movably supported by the upper surface or a side surface of the housing  14  may be provided. This tray is pivotally movable between an upright position in which the tray extends along the upper surface or the side surface of the housing  14  and an inclined position in which the tray is inclined relative to the upper surface or the side surface. When the tray is at the inclined position, at least one sheet  12  can be supported on the upper surface of the tray. The sheet  12  supported on the tray that is at the inclined position is fed to the sheet conveying passage  65  through an opening formed in the upper surface or the side surface of the housing  14  at which the tray is provided. In this case, needless to say, the controller  130  determines whether a feeding abnormality occurs with respect to the sheet  12  supported on the tray. 
     In the present embodiment, the storage portion  80  is assembled to the carriage  40 , and replenishment of ink is performed by injecting ink through the ink inlet  83 . However, the storage portion  80  is not limited to such a configuration. For example, the storage portion  80  may be a cartridge attachable to and detachable from the carriage  40 . In the latter case, the cartridge is replaced with a new cartridge when ink in the cartridge has become low or run out. 
     In the present embodiment, the storage portion  80  is supported by the carriage  40 . However, the storage portion  80  need not necessarily be supported by the carriage  40 . For example, the storage portion  80  may be disposed at a portion of the multifunction peripheral  10  different from the disposed position of the carriage  40 . In the latter case, the storage portion  80  and the head  38  is connected to each other by a tube, and ink stored in the storage portion  80  is supplied to the head  38  through the tube and the like. Further, in this case, at least a part of the storage portion  80  is positioned above the head  38 . 
     While the description has been made in detail with reference to the specific embodiment and modifications, it would be apparent to those skilled in the art that various changes and modifications may be made thereto.