JP2016193499A - Inkjet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relieve the clogging of a flow path due to solidification of ink.SOLUTION: A control unit of a printer executes: a determination process of determining which one of connection flow paths 81-83 is clogged, on the basis of an inputted signal; a preparation process including a pressure reduction process of driving a suction pump with a clogged one of the connection flow paths 81-83 communicating with the suction pump, and reducing pressure in the clogged connection flow path, and an ink filling process of causing a cap connected to one, not being clogged, of the connection flow paths 81, 82 to be in a first state, driving the suction pump with the connection flow path not being clogged communicating with the suction pump, discharging ink from an outlet toward the cap, and filling the connection flow path not being clogged with the ink; and a changeover process of changing a changeover mechanism so that the clogged connection flow path communicates with the connection flow path not being clogged, after the preparation process.SELECTED DRAWING: Figure 14

Description

  The present invention relates to an ink jet recording apparatus.

  In Patent Document 1, an ink jet head in which a plurality of nozzles (openings) for discharging black ink and a plurality of nozzles (openings) for discharging color ink are formed, and a plurality of ink jet surfaces of the ink jet head are in close contact with each other. An ink jet printer including a cap member capable of taking a capping state covering a nozzle, a suction pump, and a switching device is described. The cap member of the ink jet printer includes a first cap portion that can cover a plurality of nozzles that discharge black ink, and a second cap portion that can cover a plurality of nozzles that discharge color ink. Each of the first and second cap portions is connected to the switching device by two tubes (first and second connection flow paths). The switching device is connected to the suction pump by a single tube (third connection flow path). The switching device can switch the connection destination of the suction pump between the first cap portion and the second cap portion. In this configuration, the cap member is in the capping state, and the suction pump is operated in a state where the first cap portion and the suction pump communicate with each other, whereby black ink is discharged from the plurality of nozzles that discharge black ink to the first cap portion. It can be forcibly purged. In addition, when the cap member is in the capping state and the second cap portion and the suction pump communicate with each other, the color pump is forced from the plurality of nozzles that discharge the color ink to the second cap portion. Can be purged.

Japanese Patent Application Laid-Open No. 2014-162086

  In the ink jet printer described in Patent Document 1, pigment-based ink is used for black ink, and dye-based ink is used for color ink. For this reason, black ink is easier to solidify by drying than color ink. Therefore, when the ink jet printer is not used for a long period of time, the ink remaining in the flow path (the connection hole portion connected to the tube or the tube of the first cap portion) that connects the first cap portion and the switching device is solidified. The flow path may become clogged. Further, when the flow path is clogged, ejection failure may occur due to thickened ink in all nozzles that eject black ink. In this case, ink cannot be supplied from the nozzle to the first cap portion. Therefore, even if the ink that can be re-dispersed and brought into a solidified state by contacting with the non-solidified ink even if it is in a solidified state, clogging of the flow path cannot be solved. The problem arises.

  Accordingly, an object of the present invention is to provide an ink jet recording apparatus capable of eliminating clogging of a flow path due to solidification of ink.

  The liquid ejection device of the present invention includes an inkjet head having an internal flow path, a plurality of openings connected to the internal flow path and capable of discharging ink, and the openings different from each other by contacting the inkjet head. Two caps capable of covering each of the two, and the two caps so as to selectively take a first state in which the two caps abut against the inkjet head and cover the opening, and a second state in which the two caps are separated from the inkjet head. A cap moving mechanism for moving one cap toward and away from the inkjet head, a pump, a switching mechanism, a first connection flow path connecting one of the two caps and the switching mechanism, and the two caps A second connection channel that connects the other of the switching mechanism and the switching mechanism, a third connection channel that connects the switching mechanism and the pump, and the carrier. Flop moving mechanism, and a control unit for controlling said pump and said switching mechanism. The switching mechanism includes a first communication state in which the first connection channel and the third connection channel are communicated, and a second communication in which the second connection channel and the third connection channel are communicated. And the control unit is capable of selectively switching between the first connection channel and the third connection channel that communicates the first connection channel and the second connection channel. In the determination process for determining whether each of the first and second connection flow paths is clogged based on the signal when a signal related to the clogging of the passage is input, and in the determination process, When it is determined that one of the second connection channels is clogged, (a) the pump is driven in a state where the one connection channel and the third connection channel are in communication with each other, A decompression process for decompressing the path; The pump is driven in a state in which the first connection state and the other connection flow path and the third connection flow path are communicated, and ink is discharged from the opening toward the cap so that the other connection flow path is in communication with the other connection flow path. A preparatory process for performing an ink filling process for filling the connection flow path with ink and a switching process for switching the switching mechanism to the third communication state after the preparatory process are executed.

  According to the ink jet recording apparatus of the present invention, even if clogging occurs due to ink solidified by drying in a connection channel (first connection channel or second connection channel) connected to one of two caps, Ink filled in the connection flow path (second connection flow path or first connection flow path) connected to the cap can be made to flow through one of the connection flow paths. For this reason, the ink that has flowed through one of the connection channels comes into contact with the solidified ink, and the solidified ink can be redispersed. Therefore, one channel blockage can be eliminated.

1 is a perspective view of a multifunction machine. It is a schematic side view which shows the internal structure of the printer part shown in FIG. FIG. 2 is a schematic plan view of a printer unit illustrated in FIG. 1. FIG. 3 is a schematic cross-sectional view regarding a vertical plane orthogonal to the left-right direction of the recording head. It is a top view of a head body. (A) is the B section enlarged view of FIG. 5, (b) is CC sectional view taken on the line of FIG. 6 (a). FIG. 4 is a schematic cross-sectional view regarding a vertical plane perpendicular to the left-right direction of the exhaust unit, the exhaust cap of the maintenance unit, the opening / closing member, and the moving mechanism when the recording head is in the maintenance position. It is a schematic side view of a maintenance part. (A) is a situation figure when a suction cap exists in a separation position, (b) is a situation figure when a suction cap exists in a contact position. It is a top view of a switching mechanism. It is a situation figure when the switching member is arrange | positioned in the position which takes the 1st-6th communication state. It is a block diagram of a control part. It is a flowchart which shows the procedure of the maintenance operation | movement which concerns on clogging recovery processing. It is a flowchart which shows the procedure of the maintenance operation | movement which concerns on clogging recovery processing. It is a situation figure which shows the operation | movement which eliminates the clogging which arose in the connection flow path connected to an exhaust cap. It is a situation figure which shows the operation | movement which eliminates the clogging which arose in the connection flow path connected to the cap for black. It is a schematic block diagram of the maintenance part in the modification of one Embodiment of this invention. It is a flowchart which shows the procedure of the maintenance operation | movement which concerns on the clogging recovery process in the modification of one Embodiment of this invention.

  Hereinafter, a multi-function apparatus 1 that employs a printer unit according to an embodiment of the present invention will be described. The multi-function device 1 is installed and used in the state shown in FIG. In the present embodiment, three directions indicated by arrows in FIG. 1 are a vertical direction A1, a front-rear direction A2, and a left-right direction A3. The three directions shown in FIG. 1 are the same in other drawings.

<Overview of MFP 1>
As shown in FIG. 1, the multifunction machine 1 is formed in a generally thin rectangular parallelepiped, and has a display unit, operation buttons 91 to 95, and the like on its upper surface. A printer unit 10, which is an example of a liquid ejection device of the present invention, is provided at the lower part of the multifunction device 1. The multifunction device 1 has various functions such as a scanner function and a print function.

  The printer unit 10 has a housing 11. An opening 12 is formed in the approximate center of the front wall 11 a of the housing 11. A paper feed tray 15 and a paper discharge tray 16 are provided in two upper and lower stages. The paper feed tray 15 is configured to be insertable / removable from the opening 12 in the front-rear direction A2, that is, to be detachable from the housing 11. A paper P having a desired size is placed on the paper feed tray 15. The multifunction device 1 can be connected to an external device such as a personal computer (hereinafter referred to as a PC), and performs a recording operation based on a recording command from the PC. In addition, the operation buttons 91 to 95 are pressed by an operator to output first to fifth signals described later to the control unit 5 (described later).

<Internal structure of printer unit 10>
Next, the internal structure of the printer unit 10 will be described. 2 and 3, the printer unit (inkjet recording apparatus) 10 includes a feeding unit 20, a conveyance roller pair 35, a recording unit 40, a holder 17, a paper discharge roller pair 36, an ASF ( An Auto Sheet Feed) motor 20M (see FIG. 12), an LF (Line Feed) motor 35M (see FIG. 12), a maintenance unit 60, and a control unit 5 (see FIG. 12) are included. The feeding unit 20 feeds the paper P placed on the paper feed tray 15 to the transport path 25. The conveyance roller pair 35 conveys the paper P fed by the feeding unit 20 to the recording unit 40. The recording unit 40 has, for example, an inkjet recording system configuration, and records an image on the paper P conveyed by the conveyance roller pair 35. The paper discharge roller pair 36 discharges the paper P recorded by the recording unit 40 to the paper discharge tray 16.

  As shown in FIG. 3, the holder 17 is provided on the front right side in the housing 11. Four ink cartridges 18 a to 18 d are detachably mounted on the holder 17. Four ink cartridges 18a to 18d store inks of four colors, yellow, cyan, magenta, and black, respectively. In the present embodiment, pigment-based ink is employed as the black ink, and dye-based ink is employed as the color ink.

<Feeding unit 20>
As shown in FIG. 2, the feeding unit 20 is provided on the upper side of the paper feed tray 15. The feeding unit 20 includes a sheet feeding roller 21 and an arm 22. The paper feed roller 21 is pivotally supported at the tip of the arm 22. The arm 22 is rotatably supported by the support shaft 22 a and is biased by a spring or the like so as to be rotated downward so that the paper feed roller 21 contacts the paper feed tray 15. The arm 22 is configured to be retractable upward when the paper feed tray 15 is inserted and removed. The paper feed roller 21 is rotated by the power of the ASF motor 20M transmitted through a transmission mechanism (not shown), and the paper P stacked in the paper feed tray 15 is fed to the transport path 25.

<Paper Tray 15>
As shown in FIG. 2, the paper feed tray 15 has a slanted wall portion 15a. The inclined wall portion 15 a guides the paper P to the transport path 25 when the paper P placed on the paper feed tray 15 is fed by the paper feed roller 31.

<Conveyance path 25>
As shown in FIG. 2, the conveyance path 25 is formed by an outer guide member 25a and an inner guide member 25b that face each other at a predetermined interval. The conveyance path 25 is configured to bend upward from the rear end portion of the paper feed tray 15 and to the front side of the printer unit 10. The paper P fed from the paper feed tray 15 is guided to make a U-turn from the lower side to the upper side by the transport path 25 and reaches the recording unit 40.

<Conveying roller pair 35 and paper discharge roller pair 36>
The conveyance roller pair 35 includes a conveyance roller 35a disposed on the lower side and a pinch roller 35b disposed on the upper side. The conveyance roller 35a rotates by receiving the power of the LF motor 35M via a transmission mechanism (not shown). The pinch roller 35b is rotated along with the rotation of the conveying roller 35a. The transport roller 35a and the pinch roller 35b cooperate to sandwich the paper P from the vertical direction A1, and transport the paper P to the recording unit 40.

  The paper discharge roller pair 36 includes a paper discharge roller 36a disposed on the lower side and a spur roller 36b disposed on the upper side. The paper discharge roller 36a rotates when the power of the LF motor 35M is transmitted through a transmission mechanism (not shown). The spur roller 36b rotates with the rotation of the paper discharge roller 36a. The paper discharge roller 36a and the spur roller 36b cooperate to sandwich the paper P from the vertical direction A1 and convey the paper P to the paper discharge tray 16.

<Recording unit 40>
As shown in FIGS. 2 and 3, the recording unit 40 includes an inkjet head 41, a head moving mechanism 50, and a platen 6. The head moving mechanism 50 includes a carriage 51. The carriage 51 reciprocates in the scanning direction (the left-right direction A3 and the direction orthogonal to the conveyance direction of the paper P). The inkjet head 41 is supported by the carriage 51.

  The ink jet head 41 includes a head main body 42, four buffer tanks 43a to 43d, and four exhaust units 45a to 45d. The lower surface of the head main body 42 is an ejection surface 41 b in which a plurality of ejection ports 41 a that eject ink to the paper P conveyed below the inkjet head 41 are formed.

  The four buffer tanks 43a to 43d are arranged side by side along the scanning direction. Further, a tube joint 44 is integrally provided in the four buffer tanks 43a to 43d. The four buffer tanks 43a to 43d and the four ink cartridges 18a to 18d are connected to each other through four flexible tubes (not shown) connected to the tube joint 44. The four buffer tanks 43 a to 43 d supply ink of each color to the head main body 42. The four exhaust units 45a to 45d are arranged side by side in the front-rear direction A2 on the right side of the buffer tank 43d. These exhaust units 45a to 45d are in communication with the four buffer tanks 43a to 43d, respectively, and are for discharging bubbles that remain in the buffer tanks 43a to 43d.

  Below the inkjet head 41, a platen 6 that supports the paper P conveyed by the conveyance roller pair 35 is disposed. The platen 6 is disposed in a portion where the paper P passes in the reciprocating range of the carriage 51. Since the width of the platen 6 is sufficiently larger than the maximum width of the transportable paper P, the paper P transported through the transport path 25 always passes over the platen 6. The area on the platen 6 is an image recording area G1.

  As shown in FIG. 3, the head moving mechanism 50 includes a pair of guide rails 52 and a belt transmission mechanism 53. The pair of guide rails 52 are spaced apart in the front-rear direction A2 and extend parallel to each other in the left-right direction A3. The carriage 51 is disposed so as to straddle the pair of guide rails 52, and is reciprocated along the left-right direction A3 on the pair of guide rails 52.

  The belt transmission mechanism 53 includes two pulleys 54 and 55, an endless timing belt 56, and a CR motor 50M. The two pulleys 54 and 55 are spaced apart from each other in the left-right direction A <b> 3, and a timing belt 56 is stretched over the pulleys 54 and 55. The pulley 54 is connected to the drive shaft of the CR motor 50M. When the CR motor 50M is driven, the timing belt 56 travels, and the inkjet head 41 moves in the scanning direction together with the carriage 51.

  The inkjet head 41 ejects ink of each color from the ejection port 41a under the control of the control unit 5 based on the recording command. That is, the carriage 51 reciprocates in the left-right direction A3, whereby the inkjet head 41 is scanned with respect to the paper P, and the ink of each color is ejected from the ejection port 41a, thereby being conveyed on the platen 6. An image is recorded on the paper P. In the printer unit 10, a linear encoder (not shown) having a large number of light transmitting parts (slits) arranged at intervals in the scanning direction is provided. On the other hand, the carriage 51 is provided with a transmission type position detection sensor (not shown) having a light emitting element and a light receiving element. The printer unit 10 can recognize the current position in the scanning direction of the carriage 51 from the count value of the light transmitting portion of the linear encoder detected by the position detection sensor while the carriage 51 is moving, and the CR motor 50M. Rotational drive of is controlled.

<Maintenance unit 60>
The maintenance unit 60 forcibly discharges ink from the discharge port 41a of the head main body 42 to recover its discharge performance, and mainly discharges bubbles from the buffer tanks 43a to 43d via the exhaust port 152a of the exhaust unit 45. In the movement range of the carriage 51 in the scanning direction, it is disposed at a maintenance position in the maintenance area G2 on the right side of the image recording area G1. Details of the maintenance unit 60 will be described later.

  Next, the buffer tanks 43a to 43d will be described. Since the structure of the four buffer tanks 43a to 43d that respectively store the four color inks is basically the same, one of the buffer tanks 43 (hereinafter sometimes referred to as reference numeral 43) will be described below. To do.

  As shown in FIG. 4, the buffer tank 43 has a flow path 46 having one end connected to the tube joint 44. As shown in FIG. 4, the flow path 46 (supply flow path: a part of the internal flow path) includes a damper chamber 46a and a bubble storage chamber 46b. The damper chamber 46a is connected to the tube joint 44 and extends in the front-rear direction A2. The upper portion of the damper chamber 46a is covered with a flexible film 47. Thereby, the pressure fluctuation generated in the ink in the flow path 46 is absorbed by the damper chamber 46a. As a result, pressure fluctuations are not easily transmitted to the ink in the head flow path 123 (a part of the internal flow path) in the head main body 42, and ink ejection can be stabilized.

  The bubble storage chamber (bubble storage portion) 46b extends in the vertical direction A1, has an upper end connected to the damper chamber 46a and a lower end connected to the supply port 125 of the head main body 42. The ink in the buffer tank 43 flows from the damper chamber 46a to the supply port 125 through the bubble storage chamber 46b. Due to such an ink flow, the air bubbles that have entered the flow path 46 from the outside are gathered and stored in the upper part of the air bubble storage chamber 46b.

  Next, the head body 42 will be described. As shown in FIGS. 5 and 6, the head body 42 includes a flow path unit 121 and an actuator unit 122. As shown in FIG. 6B, the flow path unit 121 has a structure in which five plates 131 to 135 are stacked. Of the five plates 131 to 135, the lowermost plate 135 is a nozzle plate 135 in which a plurality of nozzles 135a constituting the discharge ports (openings) 41a are formed. On the other hand, holes such as a manifold 136 and a pressure chamber 137 communicating with the plurality of nozzles 135a are formed in the remaining four plates 131 to 134 on the upper side.

  As shown in FIG. 5, the plurality of discharge ports (openings) 41a are arranged such that four rows of discharge port arrays 124 arranged in the front-rear direction A2 are formed in the left-right direction A3. In the present embodiment, black ink is ejected from the ejection ports 41a belonging to the rightmost ejection port array 124d in FIG. 5, and from the ejection ports 41a belonging to the other three ejection port arrays 124a, 124b, and 124c, Color ink (yellow, cyan, magenta) is ejected. More specifically, yellow, cyan, and magenta inks are ejected in order from the leftmost ejection port array 124 in FIG.

  Next, a flow path structure that is formed on the upper four plates 131 to 134 of the flow path unit 121 and communicates with the plurality of nozzles 135a will be described. First, as shown in FIG. 5, four supply ports 125 arranged in the scanning direction are formed at the rear end portion (upstream end portion in the transport direction) of the upper surface of the flow path unit 121. Four color inks are supplied to these supply ports 125 from the buffer tanks 43a to 43d. The four supply ports 125 are a yellow supply port 125a, a cyan supply port 125b, a magenta supply port 125c, and a black supply port 125d.

  In addition, four manifolds 136 that extend in the front-rear direction A <b> 2 are formed inside the flow path unit 121. The four manifolds 136 are respectively connected to the four supply ports 125 at their rear end portions. In each manifold 136, ink flows from the rear to the front. That is, ink flows in the transport direction.

  Further, the flow path unit 121 has a plurality of pressure chambers 137 respectively corresponding to the plurality of nozzles 135a. The plurality of pressure chambers 137 are formed in the plate 131 positioned in the uppermost layer of the flow path unit 121, and are arranged in a plane corresponding to the plurality of nozzles 135a. As shown in FIG. 5, the pressure chambers 137 are arranged so that four pressure chamber rows arranged along the front-rear direction A2 are formed in the left-right direction A3, corresponding to the four discharge port rows 124, respectively. ing. As described above, as indicated by arrows in FIG. 6B, a plurality of individual flow paths 126 branched from the respective manifolds 136 and reaching the nozzles 135 a through the pressure chambers 137 are formed in the flow path unit 121. . These four manifolds 136 and a plurality of individual flow paths 126 constitute a head flow path 123 formed in the flow path unit 121.

  As shown in FIGS. 5 and 6, the actuator unit (energy applying means) 122 includes a vibration plate 141, piezoelectric layers 142 and 143, a plurality of individual electrodes 144, and a common electrode 145. The vibration plate 141 is joined to the upper surface of the flow path unit 121 in a state of covering the plurality of pressure chambers 137. The two piezoelectric layers 142 and 143 are stacked on the upper surface of the vibration plate 141. The plurality of individual electrodes 144 are arranged on the upper surface of the upper piezoelectric layer 143 so as to face the plurality of pressure chambers 137, respectively. The common electrode 145 is disposed across the plurality of pressure chambers 137 between the two piezoelectric layers 142 and 143.

  When a drive signal is supplied from the driver IC 138 to the individual electrode 144 in response to a signal from the control unit 5, a piezoelectric strain is generated in a portion facing the pressure chamber 137 of the upper piezoelectric layer 143, so that the diaphragm It deform | transforms so that 141 may bend. At this time, as the volume of the pressure chamber 137 changes, pressure is applied to the ink in the individual flow path 126 and ink is ejected from the nozzle 135a (ejection port 41a).

  Next, the exhaust units 45a to 45d will be described. As shown in FIG. 3, the exhaust units 45a to 45d are provided on the right side of the buffer tank 43d. As shown in FIG. 7, exhaust units 45a to 45d are respectively provided for the four buffer tanks 43a to 43d that store four colors of ink (yellow, cyan, magenta, and black).

  Since the structures of the four exhaust units 45a to 45d corresponding to the four buffer tanks 43a to 43d are basically the same, one of the exhaust units 45 (hereinafter sometimes referred to as 45) will be described below. explain. The exhaust unit 45 includes a case 151 fixed to the side surface of the buffer tank 43d, an exhaust passage 152 extending in the vertical direction A1 in the case 151, and an on-off valve 153 that opens and closes the exhaust passage 152. The exhaust channel 152 is connected via a connection channel 48 (see FIG. 4) whose upper end communicates with the upper end of the bubble storage chamber 46b. The exhaust passage 152 extends to an exhaust port (opening) 152 a formed at the lower end of the case 151. The exhaust passage 152 and the connection passage 48 constitute a communication passage 161.

  The on-off valve 153 includes a valve member 154 that is disposed in the exhaust passage 152 so as to be movable in the vertical direction A1 and can close the exhaust passage 152, and a coil spring 155 that biases the valve member 154 downward. Have.

  The valve member 154 has a bottomed cylindrical valve body 156 that can move in the vertical direction A <b> 1 in the exhaust flow path 152, and a valve rod 157 that extends downward from the bottom of the valve body 156. The outer diameter of the valve body 156 is smaller than the inner diameter of the exhaust flow path 152, and ink can flow between the valve body 156 and the inner wall surface of the exhaust flow path 152. An annular sealing material 158 is attached to the lower surface of the valve body 156, and the valve body 156 contacts the valve seat surface 159 provided at a step portion in the middle of the exhaust passage 152 via the sealing material 158. The exhaust channel 152 is configured to be closed by contact.

  The coil spring 155 is disposed in a compressed state between the upper end portion of the case 151 and the valve body 156 of the valve member 154, and the valve member 154 is urged downward by the coil spring 155. When the valve body 156 is driven upward against the biasing force of the coil spring 155 by the opening / closing members 78a to 78d described later, the valve body 156 is separated from the valve seat surface 159 and the exhaust passage 152 is opened. The

  Next, the maintenance unit 60 will be described. As shown in FIGS. 3 and 7 to 11, the maintenance unit 60 includes a cap mechanism 61, a maintenance frame 65, a suction pump 66, a switching mechanism 67, a waste liquid tank 68, and a pump motor 66M (see FIG. 12). ).

  The maintenance frame 65 is formed of a flat plate as shown in FIG. The maintenance frame 65 supports the cap mechanism 61 from below.

  7 to 9, the cap mechanism 61 includes a suction cap 71, an exhaust cap 72, a cap holder 73 that supports the suction cap 71 and the exhaust cap 72, and a cap lifting mechanism 74 that moves the cap holder 73 up and down. And four open / close members 78a to 78d for opening / closing the open / close valves 153 in the exhaust units 45a to 45d, and a moving mechanism 79 for moving the open / close members 78a to 78d.

  The suction cap 71 has a cap 71a in which a recess 71a1 that opens upward is formed, and a cap 71b in which a recess 71b1 that opens upward is formed. These two caps 71a and 71b are integrally formed as shown in FIG. 8, and are formed of a flexible material such as rubber or synthetic resin. A communication hole 71a2 is formed at the bottom of the cap 71a. The communication hole 71a2 is connected to the tube 71a3. A communication hole 71b2 is also formed at the bottom of the cap 71b. The communication hole 71b2 is connected to the tube 71b3. As shown by a two-dot chain line in FIG. 8, when the ink jet head 41 (carriage 51) has moved to the maintenance position, the suction cap 71 faces the ejection surface 41b. In this state, when the cap holder 73 is moved upward by the cap lifting mechanism 74, the suction cap 71 is disposed at a contact position (described later) where the suction cap 71 contacts the discharge surface 41b, and a plurality of discharge ports 41a (openings). (First state). At this time, the region of the discharge surface 41b where the discharge ports 41a for discharging the three color inks are formed is covered with the cap 71a, and a sealed space K1 is formed in the recess 71a1 (see FIG. 15A). Further, the region of the discharge surface 41b where the discharge port 41a for discharging black ink is formed is covered with the cap 71b, and a sealed space K2 is formed in the recess 71b1 (see FIG. 15A).

  The exhaust cap 72 has a recess 72a that opens upward, and is formed of a flexible material such as rubber or synthetic resin. A communication hole 72 b is formed at the bottom of the exhaust cap 72. As shown in FIG. 7A, the communication hole 72 b is formed at the front end of the exhaust cap 72. The communication hole 72b is connected to the tube 72c. Then, as indicated by a two-dot chain line in FIG. 8, when the inkjet head 41 (carriage 51) has moved to the maintenance position, the exhaust cap 72 faces the lower surfaces of the four exhaust units 45. In this state, when the cap holder 73 is moved upward by the cap lifting mechanism 74, the exhaust cap 72 is disposed at a contact position (described later) where the exhaust cap 72 contacts the lower surface of the exhaust unit 45, and four exhaust ports 152a ( (Opening) is covered (first state). At this time, a sealed space K3 is formed in the recess 72a (see FIG. 7B).

  The cap holder 73 supports the suction cap 71 and the exhaust cap 72 from below. On the lower surface of the cap holder 73, a plate-like protruding portion 73a protruding downward is formed. A pair of protrusions 73b protruding in the left-right direction A3 are formed at the tip of the protrusion 73a. The pair of protrusions 73b has a cylindrical shape.

  As shown in FIGS. 8 and 9, the cap lifting mechanism (cap moving mechanism) 74 drives a pair of slide cams 74a, a gear 74b, a link 74c connecting the gear 74b and the slide cam 74a, and the gear 74b. And a cap lifting motor 74M (see FIG. 12). A pair of slide cam 74a is comprised from the plate-shaped member, and is arrange | positioned on both sides of the protrusion part 73a in the left-right direction A3. In addition, the pair of slide cams 74a is supported so as to be slidable in the front-rear direction A2 in a state of being erected on the maintenance frame 65. Each slide cam 74a is formed with a guide hole 74a1 penetrating in the left-right direction A3 and capable of disposing a projection 73b. The guide hole 74a1 has a front part 74a2, a rear part 74a3, and a connection part 74a4 that connects the front part 74a2 and the rear part 74a3. Both the front part 74a2 and the rear part 74a3 extend horizontally in the front-rear direction A2. The front part 74a2 is disposed below the rear part 74a3. Thus, the connecting portion 74a4 extends obliquely.

  In the configuration of the cap lifting mechanism 74, as shown in FIG. 9A, when the slide cam 74a is in the rearward position, the protrusion 73b is disposed on the front portion 74a2, and the cap holder 73 is attached to the maintenance frame 65. It is arranged at the nearest position. At this time, the suction cap 71 and the exhaust cap 72 are disposed at separate positions that are separated from the discharge surface 41 b of the inkjet head 41 and the lower surface of the exhaust unit 45 disposed at the maintenance position. That is, the suction cap 71 and the exhaust cap 72 are in a second state in which they are separated from the ejection surface 41b of the inkjet head 41 and the lower surface of the exhaust unit 45 disposed at the maintenance position. When the suction cap 71 and the exhaust cap 72 are disposed at the separated positions, the suction cap 71 does not cover the discharge port 41a, and the exhaust cap 72 does not cover the exhaust port 152a. Then, the cap lifting motor 74M is driven, and the gear 74b rotates 180 ° clockwise from the position shown in FIG. 9A to the position shown in FIG. 9B, whereby a pair connected to the link 74c. Slide cam 74a moves forward. At this time, the protrusion 73b is guided upward by the connecting portion 74a4 and is disposed on the rear portion 74a3. When the slide cam 74a moves to a position closer to the front in this way, the protrusion 73b is disposed at the rear portion 74a3, and the cap holder 73 is disposed at the position farthest from the maintenance frame 65. At this time, the suction cap 71 and the exhaust cap 72 are disposed at contact positions that can contact the discharge surface 41b of the inkjet head 41 and the lower surface of the exhaust unit 45 disposed at the maintenance position. As a result, the suction cap 71 and the exhaust cap 72 are in the first state covering the discharge port 41a and the exhaust port 152a, respectively.

  In this way, the cap lifting mechanism 74 is driven by the cap lifting motor 74M so that the suction cap 71 and the exhaust cap 72 selectively take the first state and the second state by driving the gear 74b. In addition, the exhaust cap 72 can be moved between the contact position and the separation position. Further, the position of the slide cam 74a in the front-rear direction A2 can be detected based on the output value (number of rotations) of a rotary encoder (not shown) connected to the cap lifting / lowering motor 74M. By controlling the position in the direction A2, the arrangement position (separation position or contact position) of the suction cap 71 and the exhaust cap 72 can be controlled.

  The four open / close members 78a to 78d (reference numeral 78 may be used below for matters common to all open / close members) are respectively rod-like members extending in the vertical direction, as shown in FIG. These are arranged side by side at intervals in the front-rear direction A2. Further, the four opening / closing members 78 are disposed so as to be airtight between the bottom wall of the exhaust cap 72 and are configured to be movable relative to the exhaust cap 72 in the vertical direction. The exhaust cap 72 is arranged in such a manner that the four open / close members 78a to 78d pass therethrough, so that the suction cap 71 and the exhaust cap 72 are in contact with the discharge surface 41b and the lower surface of the exhaust unit 45. Compared with the suction cap 71, the gas barrier property against the outside is lowered. In other words, the suction cap 71 has a higher gas barrier property than the exhaust cap 72. When the inkjet head 41 has moved to the maintenance position, the four opening / closing members 78 are positioned directly below the exhaust ports 152a on the lower surface of the corresponding exhaust unit 45, as shown in FIG.

  As shown in FIG. 7, the four opening / closing members 78 a to 78 d are connected to each other at their lower ends, and can be moved up and down integrally by a moving mechanism 79. The moving mechanism 79 has a valve drive motor 79M (see FIG. 12). When the valve drive motor 79M is driven, the opening / closing members 78a to 78d are moved between the valve open position and the valve close position. As shown in FIG. 7A, the valve closing position is a position where the opening / closing members 78 a to 78 d are separated from the opening / closing valve 153 and the opening / closing valve 153 is closed. As shown in FIG. 7B, the valve opening position is a position where the opening / closing members 78 a to 78 d abut against the opening / closing valve 153 to open the opening / closing valve 153.

  7B, the valve drive motor 79M is driven to open / close members 78a to 78d in a state where the exhaust cap 72 covers the exhaust port 152a on the lower surface of the exhaust unit 45 (first state). Is moved upward with respect to the exhaust cap 72. Then, the upper ends of the opening / closing members 78a to 78d are inserted into the exhaust passage 152 from the exhaust port 152a, and press the valve rod 157 in the exhaust passage 152 upward. As a result, the valve body 156 moves upward integrally with the valve stem 157 and is separated from the valve seat surface 159, and the exhaust passage 152 is opened (valve opening). When the opening / closing members 78a to 78d move downward, the upper ends of the opening / closing members 78a to 78d are separated from the valve rod 157. As a result, the valve body 156 (seal member 158) is pressed against the valve seat surface 159 by the biasing force of the coil spring 155, and the exhaust passage 152 is closed.

  The switching mechanism 67 is for switching the connection state among the suction pump 66, the color cap 71 a, the black cap 71 b, and the exhaust cap 72. Although not particularly illustrated, a tube 71a3 connected to the cap 71a and a Co port 67b3 described later are connected. Further, a tube 71b3 connected to the cap 71b and a Bk port 67b2 described later are connected. Further, a tube 72c connected to the exhaust cap 72 and an exhaust port 67b4 described later are connected. A connection channel 81 (first or second connection channel: see FIG. 8) that connects the cap 71a and the suction pump 66 is configured by the communication hole 71a2, the tube 71a3, and the Co port 67b3 of the cap 71a. A connection channel 82 (first or second connection channel: see FIG. 8) that connects the cap 71b and the suction pump 66 is configured by the communication hole 71b2, the tube 71b3, and the Bk port 67b2 of the cap 71b. The communication hole 72b of the exhaust cap 72, the tube 72c, and the exhaust port 67b4 constitute a connection flow path 83 (first or second connection flow path: see FIG. 8) that connects the exhaust cap 72 and the suction pump 66. The three tubes 71a3, 71b3, and 72c all have the same inner diameter and the same length. As shown in FIGS. 10 and 11, the switching mechanism 67 has a switching member 67a, a cover 67b that accommodates the switching member 67a, and a switching motor 67M (see FIG. 12).

  The switching member 67a is formed of an elastic member such as rubber and has a columnar shape extending along the up-down direction A1. The switching member 67a rotates in the rotation direction A5 shown in FIG. 11 when the switching motor 67M is driven. A switching channel 67c is formed in the switching member 67a. The switching channel 67c includes a circular central groove 67d formed in the center of the upper surface of the switching member 67a, five vertical grooves 67e1 to 67e5 formed on the outer peripheral side surface of the switching member 67a, a central groove 67d, and five vertical grooves. There are five horizontal grooves 67f1 to 67f5 that connect the grooves 67e1 to 67e5, respectively. The five vertical grooves 67e1 to 67e5 extend along the vertical direction A1 and are spaced apart from each other along the rotational direction A5. The five horizontal grooves 67f1 to 67f5 extend horizontally from the central groove 67d along the radial direction of the switching member 67a.

  The cover 67b is composed of a cylindrical member whose upper and lower ends are closed, and a switching member 67a is disposed therein. The cover 67b is supported by the maintenance frame 65, and is configured to be rotatable relative to the switching member 67a. As shown in FIG. 10, an intake port 67b1 is formed in the upper end wall of the cover 67b. The intake port 67b1 is connected to the suction pump 66 via a tube 66a (third connection flow path: see FIG. 3). The intake port 67b1 is disposed at a position facing the central groove 67d and communicates with the central groove 67d. Three ports 67b2 to 67b4 are formed on the circular peripheral wall of the cover 67b so as to be separated from each other along the rotation direction A5.

  The first port is a Bk port 67b2 that communicates with the cap 71b and communicates with the space in which black ink is discharged. The second port is a Co port 67b3 that communicates with the cap 71a and communicates with the space in which the color ink is discharged. The third port is an exhaust port 67b4 which communicates with the exhaust cap 72 and mainly communicates with the space where the bubbles in the buffer tanks 43a to 43d are discharged.

  The switching member 67a rotates when the power of the switching motor 67M is transmitted by a transmission mechanism (not shown), and selectively takes six communication states. In the first communication state, as shown in FIG. 11A, the suction pump 66 communicates with the Co port 67b3 via the switching channel 67c. That is, the suction pump 66 and the tube 71a3 (that is, the cap 71a) communicate with each other. In the second communication state, as shown in FIG. 11B, the suction pump 66 communicates with the Bk port 67b2 via the switching channel 67c. That is, the suction pump 66 and the tube 71b3 (that is, the cap 71b) communicate with each other. In the third communication state, as shown in FIG. 11C, the suction pump 66 communicates with the exhaust port 67b4 via the switching channel 67c. That is, the suction pump 66 and the tube 72c (that is, the exhaust cap 72) communicate with each other. In the fourth communication state, as shown in FIG. 11D, the Bk port 67b2 communicates with the exhaust port 67b4 via the switching flow path 67c. That is, the tube 71b3 (cap 71b) and the tube 72c (exhaust cap 72) communicate with each other. In the fifth communication state, as shown in FIG. 11E, the Co port 67b3 communicates with the exhaust port 67b4 via the switching flow path 67c. That is, the tube 71a3 (cap 71a) and the tube 72c (exhaust cap 72) communicate with each other. In the sixth communication state, as shown in FIG. 11 (f), the Co port 67b3 communicates with the Bk port 67b2 via the switching channel 67c. That is, the tube 71a3 (cap 71a) and the tube 71b3 (cap 71b) communicate with each other.

  The position of the switching member 67a in the rotation direction A5 with respect to the cover 67b is controlled based on the output value of a rotary encoder (not shown) connected to the switching motor 67M, so that the switching mechanism 67 is in a first communication state to Control for selectively taking the sixth communication state can be performed.

  As the suction pump 66, a known tube pump is adopted, and when the switching member 67a is in any one of the first communication state to the third communication state, the suction pump 66 is rotated to rotate the suction pump 66. Ink and bubbles can be discharged to either the cap 71 or the exhaust cap 72. The suction pump 66 rotates when a pump motor 66M (see FIG. 12) connected to the rotor is driven. The waste liquid tank 68 is connected to the suction pump 66 by a tube 68a and stores the waste ink sucked by the suction pump 66.

  When the suction cap 71 is in the first state and the switching mechanism 67 is in the first communication state, when the suction pump 66 performs the suction operation, the air in the sealed space K1 is sucked and the pressure is increased. The color ink is lowered and discharged from the discharge port 41a for discharging the color ink into the recess 71a1 (first liquid purge). When the suction cap 71 is in the first state and the switching mechanism 67 is in the second communication state, when the suction pump 66 performs the suction operation, the air in the sealed space K2 is sucked and the pressure is increased. The black ink is discharged into the recess 71b1 from the discharge port 41a for discharging the black ink (first liquid purge). Accordingly, it is possible to discharge the thickened ink in the ejection port 41a and the bubbles in the inkjet head 41 (mainly bubbles in the head main body 42) from the ejection port 41a together with the ink.

  Further, in the present embodiment, the suction pump 66 can perform a suction operation with a higher suction speed than when the first liquid purge is performed (hereinafter referred to as high speed suction). In the second liquid purge by this high-speed suction, the pressure in the sealed space K1 or the sealed space K2 is rapidly reduced so that the flow velocity of the ink flowing through the flow path 46 and the head flow path 123 is faster than the first liquid purge. The purpose is to discharge the air bubbles staying in the upper part of the air bubble storage chamber 46b through the head flow path 123 together with the ink from the discharge port 41a.

  On the other hand, when the exhaust cap 72 is in the first state, the switching mechanism 67 is in the third communication state, and the exhaust passage 152 is opened by the opening / closing members 78a to 78d, the suction of the suction pump 66 is performed. When the operation is performed, the air in the sealed space K3 formed by the exhaust cap 72 and the lower surfaces of the exhaust units 45a to 45d is sucked and the pressure is reduced. At this time, bubbles staying in the upper part of the bubble storage chamber 46b of the buffer tanks 43a to 43d are discharged through the connection channel 48 and the exhaust channel 152 (exhaust operation). In this exhaust operation, although the air bubbles staying in the air bubble storage chamber 46b are mainly discharged, the ink in the buffer tanks 43a to 43d is also discharged. However, the amount of ink discharged by the exhaust operation is significantly smaller than the amount of ink discharged by the second liquid purge that is discharged in order to discharge bubbles by the same amount as the amount of bubble discharged by the exhaust operation.

  As shown in FIG. 12, the control unit 5 measures a CPU (Central Processing Unit) 5a, a ROM (Read Only Memory) 5b, a RAM (Random Access Memory) 5c, an ASIC (Application Specific Integrated Circuit) 5d, and time. The time measuring unit 5e and the like that cooperate with each other include an ASF motor 20M, an LF motor 35M, a CR motor 50M, an inkjet head 41, a pump motor 66M, a cap lifting motor 74M, a switching motor 67M, a valve drive motor 79M, and the like. Control the behavior. For example, the control unit 5 controls the inkjet head 41, the ASF motor 20M, the LF motor 35M, the CR motor 50M, and the like based on a recording command transmitted from the PC, and records an image or the like on the paper P. Further, the control unit 5 controls the cap lifting / lowering motor 74M, the switching motor 67M, the pump motor 66M, the valve drive motor 79M, and the like to perform liquid purging for discharging ink from the discharge port 41a and buffering from the exhaust port 152a of the exhaust unit 45. A maintenance operation such as an exhausting operation for discharging air bubbles in the tank 43 together with the ink and a clogging recovery process for recovering the clogging when any of the connection channels 81 to 83 is clogged due to drying of the ink is performed. A storage battery 85 is connected to the control unit 5. The timer unit 5e is driven by the electricity charged in the storage battery 85 when the connection with the external power source of the multifunction device 1 is cut off (for example, the power cable is disconnected from the outlet).

  Note that the control unit 5 of the present embodiment has one CPU 5a and one ASIC 5d, but the control unit 5 includes only one CPU 5a, and the one CPU 5a collectively performs necessary processing. Alternatively, a plurality of CPUs 5a may be included, and the plurality of CPUs 5a may share and perform necessary processing. Further, the control unit 5 may include only one ASIC 5d and perform processing necessary for the one ASIC 5d in a lump, or may include a plurality of ASICs 5d and share the processing necessary for the plurality of ASICs 5d. May be performed.

  Next, the maintenance operation of the printer unit 10 will be described below with reference to FIGS. When the time measured by the time measuring unit 5e reaches a predetermined time, the control unit 5 performs a periodic maintenance operation for performing a first liquid purge or an exhaust operation. However, when the operator cuts off the connection with the external power supply of the multifunction device 1, the electricity of the rechargeable battery 85 is not a few days, for example. When the rechargeable battery 85 is depleted, the time measuring unit 5e cannot measure time. In this way, when a clock loss occurs in which the time measuring unit 5e cannot measure time, there is a high possibility that the connection with the external power source of the multifunction device 1 is interrupted for a long time. In this case, the ink remaining in the connection channels 81 to 83 may be dried and solidified. Even in such a case, in the present embodiment, the clogging of the connection flow paths 81 to 83 can be recovered by the clogging recovery process. Hereinafter, the maintenance operation related to the clogging recovery process will be described. In the following description, it is assumed that the connection with the external power source of the multifunction device 1 is cut off in a state where the suction cap 71 and the exhaust cap 72 are in the first state.

  When the connection with the external power source of the multifunction device 1 is turned ON, the control unit 5 first determines whether or not a clock has been lost (S1). At this time, when the output voltage of the rechargeable battery 85 is equal to or higher than the predetermined value, the control unit 5 determines that the clock has not been lost (S1: NO), and ends the control flow. On the other hand, when the output voltage of the rechargeable battery 85 is smaller than the predetermined value, the control unit 5 determines that the clock is lost (S1: NO), and executes the exhaust process (S2). The exhaust process is a process of performing the first liquid purge after performing the exhaust operation.

  In S2, the control unit 5 controls the switching motor 67M, the valve drive motor 79M, and the pump motor 66M to place the switching mechanism 67 in the third communication state, and the exhaust passages of the exhaust units 45a to 45d by the opening and closing members 78a to 78d. The suction pump 66 is driven for a predetermined time with the 152 being opened. Thereby, the sealed space K3 is depressurized, and the bubbles in the bubble storage chamber 46b of the buffer tanks 43a to 43d are discharged together with the ink from the exhaust port 152a to the exhaust cap 72 (exhaust operation). Then, the control unit 5 controls the valve drive motor 79M, the cap raising / lowering motor 74M, and the pump motor 66M, closes the exhaust passage 152 of the exhaust units 45a to 45d, and sets the suction cap 71 and the exhaust cap 72 to the second state. In this state, the suction pump 66 is driven for a predetermined time. Thus, the ink discharged to the exhaust cap 72 is discharged to the waste liquid tank 68 (exhaust air suction operation).

  The control unit 5 controls the cap lifting motor 74M, the switching motor 67M, and the pump motor 66M, the suction cap 71 and the exhaust cap 72 are set to the first state, and the switching mechanism 67 is set to the first communication state. 66 is driven for a predetermined time. As a result, the sealed space K1 is depressurized, and the color ink is discharged from the discharge port 41a (first liquid purge). Then, the control unit 5 controls the cap lifting motor 74M and the pump motor 66M to drive the suction pump 66 for a predetermined time with the suction cap 71 and the exhaust cap 72 in the second state. As a result, the color ink discharged to the cap 71a is discharged to the waste liquid tank 68 (color empty suction operation).

  The controller 5 controls the cap lifting / lowering motor 74M, the switching motor 67M, and the pump motor 66M so that the suction cap 71 and the exhaust cap 72 are in the first state and the switching mechanism 67 is in the second communication state. 66 is driven for a predetermined time. As a result, the sealed space K2 is depressurized, and the black ink is discharged from the discharge port 41a (first liquid purge). Then, the control unit 5 controls the cap lifting motor 74M and the pump motor 66M to drive the suction pump 66 for a predetermined time with the suction cap 71 and the exhaust cap 72 in the second state. As a result, the black ink discharged to the cap 71b is discharged to the waste liquid tank 68 (black empty suction operation).

  Next, the control unit 5 executes a test pattern recording process (S3). That is, the control unit 5 controls the inkjet head 41, the ASF motor 20M, the LF motor 35M, and the CR motor 50M to determine whether or not ink is being ejected from all the ejection ports 41a. Is recorded on the paper P. A first ejection failure state in which no ink is ejected from any of the ejection ports 41a that eject color ink and black ink from the test pattern recorded on the paper P by the operator, and at least the color ink is ejected. A second ejection failure state where ink is ejected from some of the ejection ports 41a, but no ink is ejected from any of the ejection ports 41a that eject black ink, and at least some of the ejections ejecting black ink. Ink is ejected from the outlet 41a, but the third ejection failure state in which ink is not ejected from any of the ejection ports 41a that eject color ink, and all the ejection ports 41a that eject color ink and black ink. Unlike the normal state in which ink is being ejected, the second and third ejection failure states, and the normal state, In any or true from some of the discharge port 41a for discharging a part of the discharge port 41a and the black ink ejected from the fourth ejection failure state where the ink each is discharged to Rainku is determined. When it is determined that the first ejection failure state, the operation button 91 is pressed by the operator. At this time, a first signal indicating the first ejection failure state is output from the operation button 91 to the control unit 5. When it is determined that the second ejection failure state, the operation button 92 is pressed by the operator. At this time, a second signal indicating the second ejection failure state is output from the operation button 92 to the control unit 5. When it is determined that the third ejection failure state, the operation button 93 is pressed by the operator. At this time, a third signal indicating the third ejection failure state is output from the operation button 93 to the control unit 5. When it is determined that the fourth ejection failure state is present, the operation button 94 is pressed by the operator. At this time, a fourth signal indicating the fourth ejection failure state is output from the operation button 94 to the control unit 5. When the normal state is determined, the operation button 95 is pressed by the operator. At this time, a fifth signal indicating a normal state is output from the operation button 95 to the control unit 5.

  Next, the control unit 5 determines whether any of the operation buttons 91 to 95 is pressed (S4). When the operation buttons 91 to 95 are not pressed (S4: NO), the control unit 5 repeats S4. When the operation buttons 91 to 95 are pressed (S4: YES), the control unit 5 determines whether the fourth signal or the fifth signal is received (S5).

  In S5, when the fourth signal or the fifth signal is received (S5: YES), the control unit 5 determines whether or not the fifth signal is received (S6). When the fifth signal is received (S6: YES), the control unit 5 determines that the state is normal and ends the flow. When the fifth signal is not received (that is, the fourth signal is received) (S6: NO), the control unit 5 executes the first liquid purge process (S7).

  The first liquid purge process in S7 includes the first liquid purge and color empty suction operation for discharging color ink and the first liquid purge and black empty suction operation for discharging black ink, which are executed in S2 described above. Run in order. In addition, since it is the same process, the detailed description is abbreviate | omitted. Thereafter, the process returns to S3 described above.

  In S5, when neither the fourth signal nor the fifth signal is received (that is, the first to third signals are received) (S5: NO), the control unit 5 executes the exhaust process similar to S2. (S8). When the first to third signals are received, the amount of bubbles in the buffer tank 43 is large, the amount of ink supplied from the buffer tank 43 to the supply port 125 is insufficient due to the bubbles, and ink is discharged from the discharge ports 41a. It is considered that the ink cannot be discharged. For this reason, exhaust processing is executed again in S8.

  Next, the control part 5 performs S9-S11 similar to S3, S4, and S5. In S11, when the fourth signal or the fifth signal is received (S11: YES), the control unit 5 determines that the bubble discharge amount in S2 is only small, and proceeds to S6. On the other hand, when neither the fourth signal nor the fifth signal is received (that is, the first to third signals are received) (S11: NO), the control unit 5 is one of the connection channels 81 to 83. Is determined to be clogged, and clogging recovery processing is executed (S12).

  In the clogging recovery process, the control unit 5 first determines whether or not a first signal (a signal related to the flow path clogging) has been received (determination process: SA1). When the first signal is received (SA1: YES), the control unit 5 executes the second liquid purge process (SA2). The ink remaining in the exhaust cap 72 tends to gather at the communication hole 72b portion of the connection channel 83 as time passes. For this reason, the ink remaining in the communication hole 72b portion is dried and solidified, so that the connection channel 83 is likely to be clogged. In the present embodiment, the communication hole 72b is described as a portion where clogging occurs in the connection flow path 83, but it may be in the tube 72c. When the connection channel 83 is clogged in this way, the inside of the exhaust cap 72 cannot be decompressed even if the exhaust operation is executed, and bubbles cannot be discharged from the buffer tanks 43a to 43d. In this way, if bubbles are not discharged from the buffer tanks 43a to 43d, the amount of ink supplied from the buffer tanks 43a to 43d to the supply port 125 is insufficient due to the bubbles, and ink discharge failure cannot discharge ink from any of the discharge ports 41a. (First ejection failure state) occurs. Thus, when receiving the first signal, it is determined that the solidified ink is clogged in the connection flow path 83 and the exhaust operation is not normally executed, and the bubbles in the buffer tanks 43a to 43d are discharged. A second liquid purge process is performed.

  The control unit 5 performs substantially the same process as S7 in SA2. At this time, the second liquid purge is executed instead of the first liquid purge executed in the first liquid purge process of S7. In the second liquid purge, as described above, the pressure in the sealed spaces K1 and K2 is drastically decreased as compared with the first liquid purge, and bubbles remaining in the bubble storage chamber 46b through the head flow path 123 are discharged from the discharge port 41a. It is the operation of discharging with ink. In short, the second liquid purge is performed by making the rotational speed of the suction pump faster than the first liquid purge. For this reason, detailed description is abbreviate | omitted. In this way, the second liquid purge is executed in both the discharge port 41 a that discharges the color ink and the discharge port 41 a that discharges the black ink, so that bubbles in the buffer tanks 43 a to 43 d pass through the head channel 123. Discharged. In this way, ink ejection defects at all the ejection ports 41a are recovered. Note that a color empty suction operation is executed after the second liquid purge corresponding to the color ink, and a black empty suction operation is executed after the second liquid purge corresponding to the black ink.

  Next, the control unit 5 executes a first preparation process that sequentially executes a first ink filling process and a first decompression process (SA3). That is, the control unit 5 controls the cap lifting motor 74M, the switching motor 67M, and the pump motor 66M, the suction cap 71 and the exhaust cap 72 are in the first state, and the switching mechanism 67 is in the first communication state. The suction pump 66 is driven for a predetermined time. Thereafter, the control unit 5 controls the switching motor 67M to place the switching mechanism 67 in the third communication state. As a result, as shown in FIG. 15A, the color ink is discharged from the discharge port 41a into the decompressed sealed space K1 and the connection channel 81. That is, the cap 71a and the connection flow path 81 are filled with ink (first ink filling process).

  In the present embodiment, the three tubes 71a3, 71b3, and 72c all have the same inner diameter and the same length. For this reason, the volume of the connection flow path 81 and the volume of the connection flow path 83 are substantially the same. Therefore, the total volume of the volume of the connection channel 81 and the internal volume of the cap 71a is increased by the content integral of the cap 71a. In the first ink filling process, the suction pump 66 is controlled so that not only the connection channel 81 but also the cap 71a is filled with ink. Therefore, the amount of ink filled in the first ink filling process is an amount that satisfies the volume of the connection channel 83. For this reason, in the first switching process described later, the ink filled in the first ink filling process can be reliably brought into contact with the solidified ink.

  The control unit 5 controls the pump motor 66M to drive the suction pump 66 for a predetermined time. Thereby, the inside of the connection channel 83 is depressurized. In the present embodiment, the pump motor 66M is controlled by the suction pump 66 so that a negative pressure of, for example, about −80 Kpa to −90 Kpa is generated in the connection channel 83. The negative pressure in the connection flow path 83 is such that the ink filled in the cap 71a and the connection flow path 81 is in an amount of ink that comes into contact with the solidified ink in the connection flow path 83 in the first switching process described later. Any size that allows inflow is acceptable. As described above, in the first preparation process, the first pressure reduction process is performed after the first ink filling process is performed. For this reason, compared with the time when the first ink filling process is executed after the first pressure reducing process, the time from the first pressure reducing process until the first switching process is performed is shortened. For this reason, it can suppress that the pressure of the connection flow path 83 pressure-reduced by the 1st pressure reduction process rises.

  Next, the control part 5 performs a 1st switching process (SA4). First, the controller 5 controls the cap lifting / lowering motor 74M and the switching motor 67M to place the suction cap 71 and the exhaust cap 72 in the second state and the switching mechanism 67 in the fifth communication state. Accordingly, as shown in FIG. 15B, the ink filled in the cap 71 a and the connection flow path 81 due to the negative pressure of the connection flow path 83 flows into the connection flow path 83 via the switching mechanism 67. Thus, the ink that has flowed into the connection flow path 83 comes into contact with the solidified ink in the communication hole 72b. The solidified ink begins to re-disperse when it comes into contact with non-solidified ink. In the first switching process, the switching mechanism 67 is switched to the fifth communication state after the suction cap 71 connected to the connection channel 81 is set to the second state. For this reason, when the connection channel 83 and the connection channel 81 communicate with each other, it is possible to prevent the ink from being discharged from the ejection port 41a that ejects the color ink.

  Next, the control unit 5 executes a first standby process and a first remaining ink discharge process (SA5). The controller 5 waits for a first waiting time from when the switching mechanism 67 is brought into the fifth communication state at SA4 until sufficient fluidity returns to the solidified ink (first waiting process). The first waiting time is that when the negative pressure of about −90 Kpa is applied to the connection channel 83 by the suction pump 66, the solidified ink has fluidity, and the rotor of the suction pump 66 rotates at a constant speed. It is time when the state which flows in the connection flow path 83 continuously can be ensured. Note that the first waiting time is obtained in advance by experiments and stored in the ROM 5b. Further, the control unit 5 controls the switching motor 67M and the pump motor 66M while the first standby process is being performed, and sets the suction pump 66 in a state where the switching mechanism 67 is in the first communication state. Drive time. Accordingly, the ink remaining in the cap 71a and the connection channel 81 can be discharged to the waste liquid tank 68 as shown in FIG. 15C by effectively using the waiting time during which the first waiting process is executed. It becomes possible (first residual ink discharge process).

  Next, the controller 5 executes a first ink discharge process (SA6). That is, when the first standby time has elapsed, the control unit 5 controls the switching motor 67M and the pump motor 66M to drive the suction pump 66 for a predetermined time in a state where the switching mechanism 67 is in the third communication state. As a result, as shown in FIG. 15 (d), the ink (such as the re-dispersed solidified ink) in the connection channel 83 is discharged to the waste liquid tank 68. Thus, the clogging of the connection channel 83 is recovered.

  In SA1, when the first signal is not received (SA1: NO), the control unit 5 determines whether or not the second signal (signal related to the flow path clogging) is received (determination process: SA7). When the second signal is received (SA7: YES), the control unit 5 executes a second preparation process for sequentially executing the second ink filling process and the second decompression process (SA8). The ink remaining in the cap 71b is likely to gather in the communication hole 71b2 portion of the connection channel 82 as time passes. For this reason, the ink remaining in the communicating hole 71b2 portion is dried and solidified, so that the connection channel 82 is likely to be clogged. In the present embodiment, the communication hole 71b2 portion is described as a portion where clogging occurs in the connection flow path 82, but it may be in the tube 71b3. When the connection channel 82 is clogged in this way, the exhaust operation is normally executed, but the liquid purge for discharging the thickened ink from the discharge port 41a for discharging the black ink cannot be performed. For this reason, ink ejection failure occurs from all ejection ports 41a that eject black ink (second ejection failure state). When the second signal is received in this way, it is determined that the connection channel 82 is clogged, and it is determined that the liquid purge for discharging the thickened ink from the discharge port 41a for discharging the black ink cannot be performed. 2 Preparation processing is executed.

  In SA8, the controller 5 controls the cap lifting / lowering motor 74M, the switching motor 67M, and the pump motor 66M, the suction cap 71 and the exhaust cap 72 are in the first state, and the switching mechanism 67 is in the first communication state. The suction pump 66 is driven for a predetermined time. Thereafter, the control unit 5 controls the switching motor 67M to place the switching mechanism 67 in the second communication state. Accordingly, as shown in FIG. 16A, the color ink is discharged from the discharge port 41a into the decompressed sealed space K1 and the connection flow path 81. That is, the cap 71a and the connection flow path 81 are filled with ink (second ink filling process). Also in this second ink filling process, the suction pump 66 is controlled so that not only the connection flow path 81 but also the cap 71a is filled with ink. For this reason, the amount of ink filled in the second ink filling process is an amount that satisfies the volume of the connection channel 82. For this reason, in the 2nd switching process mentioned later, the ink filled by the 2nd ink filling process can be made to contact solidified ink reliably.

  The controller 5 controls the pump motor 66M to drive the suction pump 66 for a predetermined time, as in SA3. Thereby, the inside of the connection channel 82 is decompressed similarly to the connection channel 83 in SA3. Note that the negative pressure in the connection channel 82 is such that the ink filled in the cap 71a and the connection channel 81 is in contact with the solidified ink in the connection channel 82 in the second switching process described later. Any size that allows inflow is acceptable. As described above, in the second preparation process, as in the first preparation process, the second pressure reduction process is performed after the second ink filling process is performed. For this reason, it can suppress that the pressure of the connection flow path 82 decompressed | decompressed by the 2nd pressure reduction process raises similarly to a 1st preparation process.

  Next, the control part 5 performs a 2nd switching process (SA9). First, the controller 5 controls the cap lifting / lowering motor 74M and the switching motor 67M to place the suction cap 71 and the exhaust cap 72 in the second state and the switching mechanism 67 in the sixth communication state. Thereby, as shown in FIG. 16B, the ink filled in the cap 71 a and the connection flow path 81 due to the negative pressure of the connection flow path 82 flows into the connection flow path 82 via the switching mechanism 67. In this way, the ink that has flowed into the connection channel 82 comes into contact with the solidified ink in the communication hole 71b2. In the second switching process, the switching mechanism 67 is switched to the sixth communication state after the cap 71a connected to the connection flow path 81 is set to the second state. For this reason, when the connection channel 82 and the connection channel 81 communicate with each other, it is possible to prevent the ink from being discharged from the ejection port 41a that ejects the color ink.

  Next, the control unit 5 executes a second standby process and a second remaining ink discharge process (SA10). The controller 5 waits for the second waiting time until the fluidity sufficient for the solidified ink returns from the time when the switching mechanism 67 is brought into the sixth communication state in SA9 (second waiting process). The second standby time is the same time as the first standby time described above, and is a time during which it is possible to ensure a state in which ink continuously flows in the connection flow path 82. The second waiting time is also obtained in advance by experiments and stored in the ROM 5b. Further, the control unit 5 controls the switching motor 67M and the pump motor 66M while the second standby process is being performed, and sets the suction pump 66 in a state where the switching mechanism 67 is in the first communication state. Drive time. Thus, the ink remaining in the cap 71a and the connection channel 81 can be discharged to the waste liquid tank 68 as shown in FIG. 16C by effectively using the waiting time during which the second waiting process is executed. It becomes possible (second residual ink discharge process).

  Next, the controller 5 executes a second ink discharge process (SA11). That is, when the second standby time has elapsed, the control unit 5 controls the switching motor 67M and the pump motor 66M to drive the suction pump 66 for a predetermined time in a state where the switching mechanism 67 is in the second communication state. As a result, as shown in FIG. 16 (d), the ink (such as the re-dispersed solidified ink) in the connection channel 82 is discharged to the waste liquid tank 68. Thus, the clogging of the connection channel 82 is recovered.

  Thereafter, the control unit 5 executes a black ink purge process (SA12). That is, the control unit 5 executes the first liquid purge for discharging black ink and the black suction operation performed in S2. In addition, since it is the same process, the detailed description is abbreviate | omitted.

  In SA7, when the second signal is not received (that is, when the third signal (the signal related to the flow path clogging) is received) (SA7: NO), the control unit 5 performs the third ink filling process and the third decompression. A third preparation process for sequentially executing the processes is executed (SA13). The ink remaining in the cap 71a tends to gather in the communication hole 71a2 portion of the connection channel 81 as time passes. For this reason, the ink remaining in the communicating hole 71a2 portion is dried and solidified, so that the connection channel 81 is likely to be clogged. In the present embodiment, the communication hole 71a2 portion is described as a portion where clogging occurs in the connection flow path 81, but it may be in the tube 71a3. When the connection flow path 81 is clogged in this way, although the exhaust operation is normally performed, the liquid purge for discharging the thickened ink from the discharge port 41a for discharging the color ink cannot be performed. For this reason, ink ejection failure occurs from all ejection ports 41a that eject color ink (third ejection failure state). Thus, when receiving the third signal, it is determined that the connection channel 81 is clogged, and it is determined that the liquid purge for discharging the thickened ink from the discharge port 41a for discharging the color ink cannot be performed. 3 Preparation processing is executed.

  In SA13, the control unit 5 controls the cap lifting motor 74M, the switching motor 67M, and the pump motor 66M, the suction cap 71 and the exhaust cap 72 are in the first state, and the switching mechanism 67 is in the second communication state. The suction pump 66 is driven for a predetermined time. Thereafter, the control unit 5 controls the switching motor 67M to place the switching mechanism 67 in the first communication state. As a result, the black ink is discharged from the discharge port 41a into the sealed space K2 and the connection flow path 82 that have been decompressed. That is, ink is filled into the cap 71b and the connection channel 82 (third ink filling process). Also in the third ink filling process, the suction pump 66 is controlled so that not only the connection channel 82 but also the cap 71b is filled with ink. For this reason, the amount of ink filled in the third ink filling process is an amount that satisfies the volume of the connection channel 81. For this reason, in the 3rd switching process mentioned later, the ink filled by the 3rd ink filling process can be reliably made to contact solidified ink.

  Further, similarly to SA3, the control unit 5 controls the pump motor 66M to drive the suction pump 66 for a predetermined time. Thereby, the inside of the connection flow path 81 is decompressed similarly to the connection flow path 83 in SA3. Note that the negative pressure in the connection flow path 81 is such that the ink filled in the cap 71b and the connection flow path 82 comes into contact with the solidified ink in the connection flow path 81 in the third switching process described later. Any size that allows inflow is acceptable. As described above, in the third preparation process, as in the second preparation process, the third pressure reduction process is performed after the third ink filling process is performed. For this reason, similarly to the second preparation process, it is possible to suppress an increase in the pressure of the connection channel 81 decompressed by the third decompression process.

  Next, the control part 5 performs a 3rd switching process (SA14). First, the controller 5 controls the cap lifting / lowering motor 74M and the switching motor 67M to place the suction cap 71 and the exhaust cap 72 in the second state and the switching mechanism 67 in the sixth communication state. As a result, the ink filled in the cap 71 b and the connection channel 82 due to the negative pressure in the connection channel 81 flows into the connection channel 81 via the switching mechanism 67. Thus, the ink that has flowed into the connection flow path 81 comes into contact with the solidified ink in the communication hole 71a2. In the third switching process, after the cap 71b connected to the connection channel 82 is set to the second state, the switching mechanism 67 is switched to the sixth communication state. For this reason, when the connection flow path 81 and the connection flow path 82 communicate with each other, it is possible to prevent the ink from being discharged from the discharge port 41a that discharges the black ink.

  Next, the controller 5 executes a third standby process and a third remaining ink discharge process (SA15). The controller 5 waits for a third waiting time from when the switching mechanism 67 is brought into the sixth communication state at SA14 until sufficient fluidity returns to the solidified ink (third waiting process). The third standby time is also the same time as the above-described second standby time, and is a time during which it is possible to ensure a state in which ink flows continuously in the connection flow path 81. Note that the third standby time is obtained in advance by experiments and stored in the ROM 5b. Further, the control unit 5 controls the switching motor 67M and the pump motor 66M while the third standby process is being performed, and sets the suction pump 66 in a state where the switching mechanism 67 is in the second communication state. Drive time. Accordingly, it is possible to discharge the ink remaining in the cap 71b and the connection channel 82 to the waste liquid tank 68 by effectively using the waiting time during which the third standby process is executed (third residual ink discharge process). ).

  Next, the controller 5 executes a third ink discharge process (SA16). That is, when the third waiting time has elapsed, the control unit 5 controls the switching motor 67M and the pump motor 66M to drive the suction pump 66 for a predetermined time in a state where the switching mechanism 67 is in the first communication state. As a result, ink (such as re-dispersed solidified ink) in the connection channel 81 is discharged to the waste liquid tank 68. Thus, the clogging of the connection channel 81 is recovered.

  Thereafter, the controller 5 executes a color ink purge process (SA17). That is, the control unit 5 executes the first liquid purge and the color idle suction operation for discharging the color ink, which is executed in S2. In addition, since it is the same process, the detailed description is abbreviate | omitted. Thus, even when the solidified ink is clogged in the connection channels 81 to 83, the clogged connection channels 81 to 83 are recovered, and the ink discharge failure of the discharge port 41a is also recovered. The operation flow ends.

  As described above, according to the printer unit 10 according to the present embodiment, any one of the three connection channels 81 to 83 connected to the suction cap 71 and the exhaust cap 72 is clogged with ink solidified by drying. Even if it occurs, the ink filled in the connection flow path where clogging has not occurred can be allowed to flow through the connection flow path where clogging has occurred. For this reason, it is possible to re-disperse the solidified ink in the connection flow path where the clogging has occurred. Therefore, the clogging of the connection channel where the clogging has occurred can be eliminated.

  In the first state, the exhaust cap 72 is configured to have a lower gas barrier property than the suction cap 71. For this reason, among the three connection channels 81 to 83, the connection channel 83 connected to the exhaust cap 72 has a configuration in which ink is more easily solidified and clogged than the connection channels 81 and 82 connected to the suction cap 71.

  Since pigment-based ink is used for the black ink and dye-based ink is used for the color ink, the black ink containing the pigment is discharged to the cap 71b, and the color ink containing the dye is discharged to the cap 71a. Pigment-based inks are easier to solidify by drying than dye inks. As a result, the connection flow path 82 connected to the cap 71b has a configuration in which ink is more easily solidified and clogged than the connection flow path 81 connected to the cap 71a.

  In the above-described embodiment, the connection flow paths 81 to 83 are determined by the first to third signals input by the operator from the test pattern recorded in the test pattern recording process of S9 executed after the exhaust process of S8. Although it has been determined which is clogged, photosensors 211 to 213 that detect whether or not ink flows in the connection channels 81 to 83 are provided, and the connection flow is based on signals from the photosensors 211 to 213. It may be determined which of the paths 81 to 83 is clogged.

  As such a modified example, as shown in FIG. 17, transparent cylinders 201 to 203 are provided in the middle of the tubes 71a3, 71b3, and 72c, and it is detected whether ink passes through the cylinders 201 to 203. Photosensors 211 to 213 may be provided. Each of the optical sensors 211 to 213 includes a light emitting unit and a light receiving unit arranged with the cylinders 201 to 203 interposed therebetween. The optical sensors 211 to 213 are supplied with electric power when the exhaust operation and the liquid purge operation are performed. In the connection channels 81 to 83, the light receiving unit receives the light from the light emitting unit until the ink passes. At this time, a non-passing signal through which ink does not pass continues to be output from the optical sensors 211 to 213 to the control unit 5. On the other hand, when the ink passes through the cylinders 201 to 203, the light from the light emitting unit is blocked by the ink, and a passage signal indicating that the ink has passed is output from the optical sensors 211 to 213 to the control unit 5. Thereby, the control part 5 can determine whether the ink is flowing in the connection flow paths 81-83. In other words, the control unit 5 can determine which of the connection flow paths 81 to 83 is clogged by inputting a signal (information regarding flow path clogging) from the optical sensors 211 to 213. Hereinafter, the maintenance operation related to the clogging recovery process will be described with reference to FIG.

  First, the control unit 5 executes F1 and F2 similar to S1 and S2 described above. Next, the control unit 5 receives only non-passing signals from the optical sensors 211 to 213 in any of the exhaust operation, the first liquid purge of color ink, and the first liquid purge of black ink executed in F2. It is determined whether or not (F3). In any of the exhaust operation, the first liquid purge of color ink, and the first liquid purge of black ink, if the passage signal is received (F3: NO), the control unit 5 determines that the exhaust process has been executed normally. To end the flow.

  When only the non-pass signal is received in any of the exhaust operation, the first liquid purge of color ink and the first liquid purge of black ink (F3: YES), the control unit 5 is clogged in the connection flow path 83. Is determined (determination process: F4). The determination at this time is determined by whether or not the control unit 5 has received a passage signal from the optical sensor 213 in the exhaust operation. In F4, when the passage signal is not received and the connection channel 83 is clogged (F4: YES), the control unit 5 executes F5 to F9 similar to SA2 to SA6 described above.

  In F4, when the passage signal is received and the connection channel 83 is not clogged (F4: NO), the control unit 5 determines whether or not the connection channels 81 and 82 are clogged ( Determination process: F10). The determination at this time is determined by whether or not the control unit 5 has received a passage signal from the optical sensor 213 in the first liquid purge of color ink and the first liquid purge of black ink.

  In F10, when the passage signal is received in any one of the first liquid purges and any of the connection flow paths 81 and 82 is not clogged (F10: NO), the control unit 5 is clogged in the connection flow path 82. Is determined (determination process: F11). This determination is made based on whether or not the control unit 5 has received a passage signal from the optical sensor 213 in the first liquid purge of black ink. In F11, when the passage signal is not received and the connection channel 82 is clogged (F11: YES), the control unit 5 executes F12 to F16 similar to the above-described SA8 to SA12.

  In F11, when the passage signal is received and the connection flow path 82 is not clogged (F11: NO), the control unit 5 determines that the connection flow path 81 is clogged, and the above-described SA13- F17 to F21 similar to SA17 are executed.

  In F10, when the passage signal is not received in any of the first liquid purges and the connection flow paths 81 and 82 are clogged (F10: YES), the control unit 5 executes the ink ejection process ( F22). That is, the control unit 5 controls the driver IC 138 of the inkjet head 41 to discharge ink from all the discharge ports 41 a toward the suction cap 71. As a result, the ink ejected into the caps 71a and 71b comes into contact with the solidified ink in the connection channels 81 and 82.

  Next, the control unit 5 executes a fourth standby process (F23). The control unit 5 waits for a fourth waiting time from when the ink is ejected to F22 until sufficient fluidity returns to the solidified ink (fourth waiting process). Note that the fourth waiting time is also obtained in advance by experiments and stored in the ROM 5b. The fourth waiting time is the same time as the longer one of the second waiting time and the third time described above.

  Next, the control unit 5 executes a fourth ink discharge process (F24). That is, when the fourth waiting time has elapsed, the control unit 5 sequentially performs the color blank suction operation and the black blank suction operation performed in F2. As a result, the redispersed ink in the connection channels 81 and 82 and the ink in the suction cap 71 are discharged to the waste liquid tank 68. Thus, the clogging of the connection channels 81 and 82 is recovered.

  Next, the control part 5 performs F25 similar to above-mentioned S7. Thus, even if the solidified ink is clogged in the connection channels 81 to 83, the clogged connection channels 81 to 83 are recovered and the recovery operation of the discharge port 41a (first liquid purge or second liquid purge). And the maintenance operation flow related to the clogging recovery process is completed.

  As described above, according to the printer unit 10 according to the present embodiment, even if one of the three connection channels 81 to 83 is clogged with ink solidified by drying, no clogging occurs. It becomes possible to flow the ink filled in the connection channel to the connection channel where clogging has occurred. For this reason, it is possible to re-disperse the solidified ink in the connection flow path where the clogging has occurred. Therefore, similarly to the above-described embodiment, the clogging of the connection channel where clogging has occurred can be eliminated.

  When the connection channels 81 and 82 are clogged, ink is discharged from the discharge port 41a to the suction cap 71 connected to the connection channels 81 and 82, thereby eliminating the blockage of the connection channels 81 and 82. can do. When the connection flow path 83 is clogged, the clogging of the connection flow path 83 can be eliminated by causing the ink filled in the connection flow path 81 or 82 to flow through the connection flow path 83.

  In the above-described modification, when only the connection flow path 81 (or connection flow path 82) is clogged, the connection flow clogged with ink filled in the connection flow path 82 (or connection flow path 81) that is not clogged. When the connection channels 81 and 82 are clogged, the ink is ejected from the ejection port 41a to the caps 71a and 71b of the clogged connection channels 81 and 82. The clogging may be eliminated.

  In the opening and closing members 78a to 78d of the above-described embodiments and modifications, the ink remaining in the exhaust cap 72 may solidify in the vicinity of the opening and closing members 78a to 78d and become inoperable. As a configuration for recovering such a malfunction of the opening / closing members 78a to 78d, a motor that outputs a current value (a value indicating a moving load of the opening / closing member 78) to the control unit 5 when the valve drive motor 79M is driven. A load detection circuit is provided. And the control part 5 determines whether the electric current value output from a motor load detection circuit is larger than predetermined value. When the current value is larger than the predetermined value, the motor load is large and an overcurrent is generated, and the open / close members 78a to 78d are malfunctioning. In this way, when it is determined that an operation failure has occurred in the opening / closing members 78a to 78d, the control unit 5 performs the same processing as SA3 described above. And the switching mechanism 67 is made into a 5th communication state with a 2nd state. Thereby, the ink filled in the cap 71a and the connection flow path 81 flows into the exhaust cap 72 and comes into contact with the ink solidified in the vicinity of the open / close members 78a to 78d. In this way, the solidified ink can be redispersed, and malfunctions of the open / close members 78a to 78d can be eliminated.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, in the above-described embodiment, the suction cap 71 has the two recesses 71a1 and 71b1, but it may have only one recess. In this case, only one connection channel 81, 82 may be provided. Even in this case, when the connection channel 83 is clogged, the connection channel connected to the suction cap is filled with ink, the pressure of the connection channel 83 is reduced, and then the connection channel connected to the suction cap and the connection channel 83 are communicated. Thus, the ink may be brought into contact with the solidified ink in the connection channel 83. Even in this case, the same effect as described above can be obtained. At this time, when the connection flow path connected to the suction cap is clogged, the clogging of the connection flow path can be eliminated by discharging ink from the discharge port 41a. At this time, when both the connection flow path connected to the suction cap and the connection flow path 83 are clogged, first, the clogging of the connection flow path connected to the suction cap is eliminated by discharging ink from the discharge port 41a. Thereafter, the connection channel connected to the suction cap is filled with ink, the pressure of the connection channel 83 is reduced, and the connection channel and the connection channel 83 connected to the suction cap are communicated to solidify the ink. What is necessary is just to contact ink. By carrying out like this, clogging of both connection flow paths can be eliminated.

  In each of the preparation processes described above, the ink filling process may be executed after the decompression process. Each advanced residual ink discharge process may be performed after the standby process. Further, each switching process described above may be performed while the suction cap 71 and the exhaust cap 72 remain in the second state.

  In the above-described embodiments and modifications, all of the employed inks may be pigment-based inks or dye-based inks. Further, a dye-based ink may be employed as the black ink, and a pigment-based ink may be employed as the color ink. Further, the exhaust cap 72 may be configured to have a higher gas barrier property than the suction cap 71 in the first state.

  In the above-described embodiment, the control unit 5 determines whether or not to perform the exhaust processing only by determining whether the clock is lost, but is not limited thereto. For example, the control unit 5 issues an exhaust process execution command from the operator until the determination result of the clock loss and the connection to the external power supply is turned ON for the first time after the clock is lost and the recording command is executed a predetermined number of times. Whether or not the exhaust processing is to be executed may be determined based on both the determination result and the determination result. For example, when the clock is lost for about two days, there is a case where there is no discharge failure and there is no need to perform exhaust processing. Therefore, after the connection to the external power source is turned on for the first time after the clock is lost, the operator looks at the result of the image recorded on the paper and determines that the exhaust process is necessary, and the control unit 5 performs the exhaust process. When the execution command is issued, the control unit 5 executes the exhaust process. Accordingly, the exhaust process is not performed unnecessarily, and wasteful consumption of ink can be suppressed.

  In the above-described embodiment, the three tubes 71a3, 71b3, and 72c have the same volume, but may be different from each other. Further, the total volume of the volume of the connection flow path and the internal volume of the cap connected to the connection flow path may not be configured to be larger than the volume of any connection flow path.

  In the above-described embodiment, the first to fifth signals are input to the control unit 5 by pressing the operation buttons 91 to 95. However, the first to fourth ejection failure states and normality from an external device such as a PC. A signal corresponding to the state may be input to the control unit 5. In S8 of the above-described embodiment, the exhaust process is performed. For example, the operator selects an OFF period in which the power of the multifunction machine is turned off from a plurality of periods. Or the liquid purge may be powerful.

  Further, the present invention can be applied to both a line type and a serial type.

5 Control unit 10 Printer unit (inkjet recording device)
41 Inkjet head 41a Discharge port (opening)
42 Head body 43a to 43d Buffer tank 46 Flow path (Supply flow path: Part of internal flow path)
46b Bubble storage chamber (bubble storage part)
66 Suction pump (pump)
66a Tube (third connection flow path)
67 Switching mechanism 71 Suction cap 71a Cap 71b Cap 72 Exhaust cap 74 Cap lifting mechanism (cap moving mechanism)
81-83 connection flow path (first or second connection flow path)
122 Actuator unit (energy application means)
123 Head channel (part of internal channel)
152a Exhaust port (opening)

Claims (9)

An ink jet head having an internal flow path and a plurality of openings connected to the internal flow path and capable of discharging ink;
Two caps each capable of covering the different openings by contacting the inkjet head;
The two caps are brought into contact with and separated from the inkjet head so as to selectively take a first state in which the two caps abut against the inkjet head and cover the opening and a second state in which the two caps are separated from the inkjet head. A cap moving mechanism for
A pump,
A switching mechanism;
A first connection flow path connecting one of the two caps and the switching mechanism;
A second connection flow path connecting the other of the two caps and the switching mechanism;
A third connection flow path connecting the switching mechanism and the pump;
A controller that controls the cap moving mechanism, the pump, and the switching mechanism;
The switching mechanism includes a first communication state in which the first connection channel and the third connection channel are communicated, and a second communication state in which the second connection channel and the third connection channel are communicated. , Can be selectively switched to any one of a third communication state for communicating the first connection channel and the second connection channel,
The controller is
A determination process for determining whether each of the first and second connection flow paths is clogged based on the signal when a signal related to the blockage of the first and second connection flow paths is input;
In the determination process, when it is determined that one of the first and second connection channels is clogged, (a) the pump is connected in a state where the one connection channel and the third connection channel are in communication with each other. A pressure reducing process for driving to depressurize the one connection flow path; and (b) setting the cap connected to the other connection flow path to the first state and the other connection flow path and the third connection flow path. A preparatory process for performing an ink filling process in which the pump is driven in a state in which the pump is connected, the ink is discharged from the opening toward the cap, and the other connection flow path is filled with ink;
An inkjet recording apparatus, wherein after the preparation process, a switching process for switching the switching mechanism to the third communication state is executed. The controller is
The inkjet recording apparatus according to claim 1, wherein, in the preparation process, the decompression process is executed after the ink filling process. The controller is
A waiting process for waiting for a time during which the solidified ink can be re-dispersed after the switching process;
After the standby process, the pump is driven in a state where the one connection flow path and the pump are in communication with each other, and an ink discharge process for discharging the ink in the one connection flow path is further executed. The ink jet recording apparatus according to claim 1 or 2. The inkjet head includes a head body having a head flow path that forms part of the internal flow path, and a supply flow path that forms part of the internal flow path and supplies ink to the head flow path. A buffer tank,
The head body is formed with a portion of the plurality of openings communicating with the head flow path,
The remaining opening is formed in the buffer tank,
The buffer tank has a bubble storage section that stores bubbles in the supply flow path, and a communication path that forms part of the internal flow path and communicates the bubble storage section and the opening.
The cap connected to the first connection flow path can cover the opening formed in the buffer tank,
The cap connected to the second connection flow path can cover the opening formed in the head main body, and in the first state, has a gas barrier property than the cap connected to the first connection flow path. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is high. The head body has energy applying means for applying energy for ejecting ink from the opening formed in the head body to the ink in the head flow path.
When the control unit determines that the second connection flow path is clogged in the determination process, the control unit controls the energy applying unit to discharge ink toward the cap connected to the second connection flow path. Further execute the ink ejection process,
5. The inkjet recording apparatus according to claim 4, wherein, in the determination process, when it is determined that the first connection flow path is clogged, the switching process is executed after the preparation process is executed. The total volume of the volume of the second connection flow path and the internal volume of the cap connected to the second connection flow path is equal to or greater than the volume of the first connection flow path;
The said control part fills the said cap connected with the said 2nd connection flow path and the said 2nd connection flow path with the ink more than the volume of the said 1st connection flow path in the said ink filling process. The inkjet recording apparatus of any one of 1-3.   In the cap connected to the first connection flow path, ink containing pigment is discharged from the opening, and in the cap connected to the second connection flow path, ink containing dye is discharged from the opening. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus is characterized in that   The said control part switches the said switching mechanism to the said 3rd communication state after setting the said cap connected with said other connection flow path to the said 2nd state in the said switching process. 2. An ink jet recording apparatus according to item 1. The controller is
When the standby process is being performed, the cap connected to the other connection flow path is in the second state and the pump is driven in a state where the other connection flow path and the pump are in communication with each other; 4. The ink jet recording apparatus according to claim 3, further comprising a remaining ink discharging process for discharging the ink remaining in the other connection channel.

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